text: /*	$NetBSD: if_spppsubr.c,v 1.125 2011/12/17 20:05:39 tls Exp $	 */
  
  /*
   * Synchronous PPP/Cisco link level subroutines.
   * Keepalive protocol implemented in both Cisco and PPP modes.
   *
   * Copyright (C) 1994-1996 Cronyx Engineering Ltd.
   * Author: Serge Vakulenko, <vak@cronyx.ru>
   *
   * Heavily revamped to conform to RFC 1661.
   * Copyright (C) 1997, Joerg Wunsch.
   *
   * RFC2472 IPv6CP support.
   * Copyright (C) 2000, Jun-ichiro itojun Hagino <itojun@iijlab.net>.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   * 1. Redistributions of source code must retain the above copyright notice,
   *    this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE FREEBSD PROJECT ``AS IS'' AND ANY
   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE FREEBSD PROJECT OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   * From: Version 2.4, Thu Apr 30 17:17:21 MSD 1997
   *
   * From: if_spppsubr.c,v 1.39 1998/04/04 13:26:03 phk Exp
   *
   * From: Id: if_spppsubr.c,v 1.23 1999/02/23 14:47:50 hm Exp
   */
  
  #include <special_includes/sys/cdefs.h>
  __KERNEL_RCSID(0, "$NetBSD: if_spppsubr.c,v 1.125 2011/12/17 20:05:39 tls Exp $");
  
  #if defined(_KERNEL_OPT)
  #include "opt_inet.h"
  #include "opt_ipx.h"
  #include "opt_iso.h"
  #include "opt_pfil_hooks.h"
  #include "opt_modular.h"
  #include "opt_compat_netbsd.h"
  #endif
  
  
  #include <special_includes/sys/param.h>
  #include <special_includes/sys/proc.h>
  #include <special_includes/sys/systm.h>
  #include <special_includes/sys/kernel.h>
  #include <special_includes/sys/sockio.h>
  #include <special_includes/sys/socket.h>
  #include <special_includes/sys/syslog.h>
  #include <special_includes/sys/malloc.h>
  #include <special_includes/sys/mbuf.h>
  #include <special_includes/sys/callout.h>
  #include <special_includes/sys/md5.h>
  #include <special_includes/sys/inttypes.h>
  #include <special_includes/sys/kauth.h>
  #include <special_includes/sys/cprng.h>
  
  #include <net/if.h>
  #include <net/netisr.h>
  #include <net/if_types.h>
  #include <net/route.h>
  #include <net/ppp_defs.h>
  
  #include <netinet/in.h>
  #include <netinet/in_systm.h>
  #include <netinet/in_var.h>
  #ifdef INET
  #include <netinet/ip.h>
  #include <netinet/tcp.h>
  #endif
  #include <net/ethertypes.h>
  
  #ifdef INET6
  #include <netinet6/scope6_var.h>
  #endif
  
  #ifdef IPX
  #include <netipx/ipx.h>
  #include <netipx/ipx_if.h>
  #endif
  
  
  #ifdef ISO
  #include <netiso/argo_debug.h>
  #include <netiso/iso.h>
  #include <netiso/iso_var.h>
  #include <netiso/iso_snpac.h>
  #endif
  
  #include <net/if_sppp.h>
  #include <net/if_spppvar.h>
  
  #define	LCP_KEEPALIVE_INTERVAL		10	/* seconds between checks */
  #define LOOPALIVECNT     		3	/* loopback detection tries */
  #define DEFAULT_MAXALIVECNT    		3	/* max. missed alive packets */
  #define	DEFAULT_NORECV_TIME		15	/* before we get worried */
  #define DEFAULT_MAX_AUTH_FAILURES	5	/* max. auth. failures */
  
  /*
   * Interface flags that can be set in an ifconfig command.
   *
   * Setting link0 will make the link passive, i.e. it will be marked
   * as being administrative openable, but won't be opened to begin
   * with.  Incoming calls will be answered, or subsequent calls with
   * -link1 will cause the administrative open of the LCP layer.
   *
   * Setting link1 will cause the link to auto-dial only as packets
   * arrive to be sent.
   *
   * Setting IFF_DEBUG will syslog the option negotiation and state
   * transitions at level kern.debug.  Note: all logs consistently look
   * like
   *
   *   <if-name><unit>: <proto-name> <additional info...>
   *
   * with <if-name><unit> being something like "bppp0", and <proto-name>
   * being one of "lcp", "ipcp", "cisco", "chap", "pap", etc.
   */
  
  #define IFF_PASSIVE	IFF_LINK0	/* wait passively for connection */
  #define IFF_AUTO	IFF_LINK1	/* auto-dial on output */
  
  #define CONF_REQ	1		/* PPP configure request */
  #define CONF_ACK	2		/* PPP configure acknowledge */
  #define CONF_NAK	3		/* PPP configure negative ack */
  #define CONF_REJ	4		/* PPP configure reject */
  #define TERM_REQ	5		/* PPP terminate request */
  #define TERM_ACK	6		/* PPP terminate acknowledge */
  #define CODE_REJ	7		/* PPP code reject */
  #define PROTO_REJ	8		/* PPP protocol reject */
  #define ECHO_REQ	9		/* PPP echo request */
  #define ECHO_REPLY	10		/* PPP echo reply */
  #define DISC_REQ	11		/* PPP discard request */
  
  #define LCP_OPT_MRU		1	/* maximum receive unit */
  #define LCP_OPT_ASYNC_MAP	2	/* async control character map */
  #define LCP_OPT_AUTH_PROTO	3	/* authentication protocol */
  #define LCP_OPT_QUAL_PROTO	4	/* quality protocol */
  #define LCP_OPT_MAGIC		5	/* magic number */
  #define LCP_OPT_RESERVED	6	/* reserved */
  #define LCP_OPT_PROTO_COMP	7	/* protocol field compression */
  #define LCP_OPT_ADDR_COMP	8	/* address/control field compression */
  
  #define IPCP_OPT_ADDRESSES	1	/* both IP addresses; deprecated */
  #define IPCP_OPT_COMPRESSION	2	/* IP compression protocol */
  #define IPCP_OPT_ADDRESS	3	/* local IP address */
  #define	IPCP_OPT_PRIMDNS	129	/* primary remote dns address */
  #define	IPCP_OPT_SECDNS		131	/* secondary remote dns address */
  
  #define IPV6CP_OPT_IFID		1	/* interface identifier */
  #define IPV6CP_OPT_COMPRESSION	2	/* IPv6 compression protocol */
  
  #define PAP_REQ			1	/* PAP name/password request */
  #define PAP_ACK			2	/* PAP acknowledge */
  #define PAP_NAK			3	/* PAP fail */
  
  #define CHAP_CHALLENGE		1	/* CHAP challenge request */
  #define CHAP_RESPONSE		2	/* CHAP challenge response */
  #define CHAP_SUCCESS		3	/* CHAP response ok */
  #define CHAP_FAILURE		4	/* CHAP response failed */
  
  #define CHAP_MD5		5	/* hash algorithm - MD5 */
  
  #define CISCO_MULTICAST		0x8f	/* Cisco multicast address */
  #define CISCO_UNICAST		0x0f	/* Cisco unicast address */
  #define CISCO_KEEPALIVE		0x8035	/* Cisco keepalive protocol */
  #define CISCO_ADDR_REQ		0	/* Cisco address request */
  #define CISCO_ADDR_REPLY	1	/* Cisco address reply */
  #define CISCO_KEEPALIVE_REQ	2	/* Cisco keepalive request */
  
  /* states are named and numbered according to RFC 1661 */
  #define STATE_INITIAL	0
  #define STATE_STARTING	1
  #define STATE_CLOSED	2
  #define STATE_STOPPED	3
  #define STATE_CLOSING	4
  #define STATE_STOPPING	5
  #define STATE_REQ_SENT	6
  #define STATE_ACK_RCVD	7
  #define STATE_ACK_SENT	8
  #define STATE_OPENED	9
  
  struct ppp_header {
  	uint8_t address;
  	uint8_t control;
  	uint16_t protocol;
  } __packed;
  #define PPP_HEADER_LEN          sizeof (struct ppp_header)
  
  struct lcp_header {
  	uint8_t type;
  	uint8_t ident;
  	uint16_t len;
  } __packed;
  #define LCP_HEADER_LEN          sizeof (struct lcp_header)
  
  struct cisco_packet {
  	uint32_t type;
  	uint32_t par1;
  	uint32_t par2;
  	uint16_t rel;
  	uint16_t time0;
  	uint16_t time1;
  } __packed;
  #define CISCO_PACKET_LEN 18
  
  /*
   * We follow the spelling and capitalization of RFC 1661 here, to make
   * it easier comparing with the standard.  Please refer to this RFC in
   * case you can't make sense out of these abbreviation; it will also
   * explain the semantics related to the various events and actions.
   */
  struct cp {
  	u_short	proto;		/* PPP control protocol number */
  	u_char protoidx;	/* index into state table in struct sppp */
  	u_char flags;
  #define CP_LCP		0x01	/* this is the LCP */
  #define CP_AUTH		0x02	/* this is an authentication protocol */
  #define CP_NCP		0x04	/* this is a NCP */
  #define CP_QUAL		0x08	/* this is a quality reporting protocol */
  	const char *name;	/* name of this control protocol */
  	/* event handlers */
  	void	(*Up)(struct sppp *sp);
  	void	(*Down)(struct sppp *sp);
  	void	(*Open)(struct sppp *sp);
  	void	(*Close)(struct sppp *sp);
  	void	(*TO)(void *sp);
  	int	(*RCR)(struct sppp *sp, struct lcp_header *h, int len);
  	void	(*RCN_rej)(struct sppp *sp, struct lcp_header *h, int len);
  	void	(*RCN_nak)(struct sppp *sp, struct lcp_header *h, int len);
  	/* actions */
  	void	(*tlu)(struct sppp *sp);
  	void	(*tld)(struct sppp *sp);
  	void	(*tls)(struct sppp *sp);
  	void	(*tlf)(struct sppp *sp);
  	void	(*scr)(struct sppp *sp);
  };
  
  static struct sppp *spppq;
  static callout_t keepalive_ch;
  
  #ifdef INET
  /*
   * The following disgusting hack gets around the problem that IP TOS
   * can't be set yet.  We want to put "interactive" traffic on a high
   * priority queue.  To decide if traffic is interactive, we check that
   * a) it is TCP and b) one of its ports is telnet, rlogin or ftp control.
   *
   * XXX is this really still necessary?  - joerg -
   */
  static u_short interactive_ports[8] = {
  	0,	513,	0,	0,
  	0,	21,	0,	23,
  };
  #define INTERACTIVE(p)	(interactive_ports[(p) & 7] == (p))
  #endif
  
  /* almost every function needs these */
  #define STDDCL							\
  	struct ifnet *ifp = &sp->pp_if;				\
  	int debug = ifp->if_flags & IFF_DEBUG
  
  static int sppp_output(struct ifnet *ifp, struct mbuf *m,
  		       const struct sockaddr *dst, struct rtentry *rt);
  
  static void sppp_cisco_send(struct sppp *sp, int type, int32_t par1, int32_t par2);
  static void sppp_cisco_input(struct sppp *sp, struct mbuf *m);
  
  static void sppp_cp_input(const struct cp *cp, struct sppp *sp,
  			  struct mbuf *m);
  static void sppp_cp_send(struct sppp *sp, u_short proto, u_char type,
  			 u_char ident, u_short len, void *data);
  /* static void sppp_cp_timeout(void *arg); */
  static void sppp_cp_change_state(const struct cp *cp, struct sppp *sp,
  				 int newstate);
  static void sppp_auth_send(const struct cp *cp,
  			   struct sppp *sp, unsigned int type, unsigned int id,
  			   ...);
  
  static void sppp_up_event(const struct cp *cp, struct sppp *sp);
  static void sppp_down_event(const struct cp *cp, struct sppp *sp);
  static void sppp_open_event(const struct cp *cp, struct sppp *sp);
  static void sppp_close_event(const struct cp *cp, struct sppp *sp);
  static void sppp_to_event(const struct cp *cp, struct sppp *sp);
  
  static void sppp_null(struct sppp *sp);
  
  static void sppp_lcp_init(struct sppp *sp);
  static void sppp_lcp_up(struct sppp *sp);
  static void sppp_lcp_down(struct sppp *sp);
  static void sppp_lcp_open(struct sppp *sp);
  static void sppp_lcp_close(struct sppp *sp);
  static void sppp_lcp_TO(void *sp);
  static int sppp_lcp_RCR(struct sppp *sp, struct lcp_header *h, int len);
  static void sppp_lcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len);
  static void sppp_lcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len);
  static void sppp_lcp_tlu(struct sppp *sp);
  static void sppp_lcp_tld(struct sppp *sp);
  static void sppp_lcp_tls(struct sppp *sp);
  static void sppp_lcp_tlf(struct sppp *sp);
  static void sppp_lcp_scr(struct sppp *sp);
  static void sppp_lcp_check_and_close(struct sppp *sp);
  static int sppp_ncp_check(struct sppp *sp);
  
  static void sppp_ipcp_init(struct sppp *sp);
  static void sppp_ipcp_up(struct sppp *sp);
  static void sppp_ipcp_down(struct sppp *sp);
  static void sppp_ipcp_open(struct sppp *sp);
  static void sppp_ipcp_close(struct sppp *sp);
  static void sppp_ipcp_TO(void *sp);
  static int sppp_ipcp_RCR(struct sppp *sp, struct lcp_header *h, int len);
  static void sppp_ipcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len);
  static void sppp_ipcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len);
  static void sppp_ipcp_tlu(struct sppp *sp);
  static void sppp_ipcp_tld(struct sppp *sp);
  static void sppp_ipcp_tls(struct sppp *sp);
  static void sppp_ipcp_tlf(struct sppp *sp);
  static void sppp_ipcp_scr(struct sppp *sp);
  
  static void sppp_ipv6cp_init(struct sppp *sp);
  static void sppp_ipv6cp_up(struct sppp *sp);
  static void sppp_ipv6cp_down(struct sppp *sp);
  static void sppp_ipv6cp_open(struct sppp *sp);
  static void sppp_ipv6cp_close(struct sppp *sp);
  static void sppp_ipv6cp_TO(void *sp);
  static int sppp_ipv6cp_RCR(struct sppp *sp, struct lcp_header *h, int len);
  static void sppp_ipv6cp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len);
  static void sppp_ipv6cp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len);
  static void sppp_ipv6cp_tlu(struct sppp *sp);
  static void sppp_ipv6cp_tld(struct sppp *sp);
  static void sppp_ipv6cp_tls(struct sppp *sp);
  static void sppp_ipv6cp_tlf(struct sppp *sp);
  static void sppp_ipv6cp_scr(struct sppp *sp);
  
  static void sppp_pap_input(struct sppp *sp, struct mbuf *m);
  static void sppp_pap_init(struct sppp *sp);
  static void sppp_pap_open(struct sppp *sp);
  static void sppp_pap_close(struct sppp *sp);
  static void sppp_pap_TO(void *sp);
  static void sppp_pap_my_TO(void *sp);
  static void sppp_pap_tlu(struct sppp *sp);
  static void sppp_pap_tld(struct sppp *sp);
  static void sppp_pap_scr(struct sppp *sp);
  
  static void sppp_chap_input(struct sppp *sp, struct mbuf *m);
  static void sppp_chap_init(struct sppp *sp);
  static void sppp_chap_open(struct sppp *sp);
  static void sppp_chap_close(struct sppp *sp);
  static void sppp_chap_TO(void *sp);
  static void sppp_chap_tlu(struct sppp *sp);
  static void sppp_chap_tld(struct sppp *sp);
  static void sppp_chap_scr(struct sppp *sp);
  
  static const char *sppp_auth_type_name(u_short proto, u_char type);
  static const char *sppp_cp_type_name(u_char type);
  static const char *sppp_dotted_quad(uint32_t addr);
  static const char *sppp_ipcp_opt_name(u_char opt);
  #ifdef INET6
  static const char *sppp_ipv6cp_opt_name(u_char opt);
  #endif
  static const char *sppp_lcp_opt_name(u_char opt);
  static const char *sppp_phase_name(int phase);
  static const char *sppp_proto_name(u_short proto);
  static const char *sppp_state_name(int state);
  static int sppp_params(struct sppp *sp, u_long cmd, void *data);
  #ifdef INET
  static void sppp_get_ip_addrs(struct sppp *sp, uint32_t *src, uint32_t *dst,
  			      uint32_t *srcmask);
  static void sppp_set_ip_addrs(struct sppp *sp, uint32_t myaddr, uint32_t hisaddr);
  static void sppp_clear_ip_addrs(struct sppp *sp);
  #endif
  static void sppp_keepalive(void *dummy);
  static void sppp_phase_network(struct sppp *sp);
  static void sppp_print_bytes(const u_char *p, u_short len);
  static void sppp_print_string(const char *p, u_short len);
  #ifdef INET6
  static void sppp_get_ip6_addrs(struct sppp *sp, struct in6_addr *src,
  				struct in6_addr *dst, struct in6_addr *srcmask);
  #ifdef IPV6CP_MYIFID_DYN
  static void sppp_set_ip6_addr(struct sppp *sp, const struct in6_addr *src);
  static void sppp_gen_ip6_addr(struct sppp *sp, const struct in6_addr *src);
  #endif
  static void sppp_suggest_ip6_addr(struct sppp *sp, struct in6_addr *src);
  #endif
  
  /* our control protocol descriptors */
  static const struct cp lcp = {
  	PPP_LCP, IDX_LCP, CP_LCP, "lcp",
  	sppp_lcp_up, sppp_lcp_down, sppp_lcp_open, sppp_lcp_close,
  	sppp_lcp_TO, sppp_lcp_RCR, sppp_lcp_RCN_rej, sppp_lcp_RCN_nak,
  	sppp_lcp_tlu, sppp_lcp_tld, sppp_lcp_tls, sppp_lcp_tlf,
  	sppp_lcp_scr
  };
  
  static const struct cp ipcp = {
  	PPP_IPCP, IDX_IPCP,
  #ifdef INET
  	CP_NCP,	/*don't run IPCP if there's no IPv4 support*/
  #else
  	0,
  #endif
  	"ipcp",
  	sppp_ipcp_up, sppp_ipcp_down, sppp_ipcp_open, sppp_ipcp_close,
  	sppp_ipcp_TO, sppp_ipcp_RCR, sppp_ipcp_RCN_rej, sppp_ipcp_RCN_nak,
  	sppp_ipcp_tlu, sppp_ipcp_tld, sppp_ipcp_tls, sppp_ipcp_tlf,
  	sppp_ipcp_scr
  };
  
  static const struct cp ipv6cp = {
  	PPP_IPV6CP, IDX_IPV6CP,
  #ifdef INET6	/*don't run IPv6CP if there's no IPv6 support*/
  	CP_NCP,
  #else
  	0,
  #endif
  	"ipv6cp",
  	sppp_ipv6cp_up, sppp_ipv6cp_down, sppp_ipv6cp_open, sppp_ipv6cp_close,
  	sppp_ipv6cp_TO, sppp_ipv6cp_RCR, sppp_ipv6cp_RCN_rej, sppp_ipv6cp_RCN_nak,
  	sppp_ipv6cp_tlu, sppp_ipv6cp_tld, sppp_ipv6cp_tls, sppp_ipv6cp_tlf,
  	sppp_ipv6cp_scr
  };
  
  static const struct cp pap = {
  	PPP_PAP, IDX_PAP, CP_AUTH, "pap",
  	sppp_null, sppp_null, sppp_pap_open, sppp_pap_close,
  	sppp_pap_TO, 0, 0, 0,
  	sppp_pap_tlu, sppp_pap_tld, sppp_null, sppp_null,
  	sppp_pap_scr
  };
  
  static const struct cp chap = {
  	PPP_CHAP, IDX_CHAP, CP_AUTH, "chap",
  	sppp_null, sppp_null, sppp_chap_open, sppp_chap_close,
  	sppp_chap_TO, 0, 0, 0,
  	sppp_chap_tlu, sppp_chap_tld, sppp_null, sppp_null,
  	sppp_chap_scr
  };
  
  static const struct cp *cps[IDX_COUNT] = {
  	&lcp,			/* IDX_LCP */
  	&ipcp,			/* IDX_IPCP */
  	&ipv6cp,		/* IDX_IPV6CP */
  	&pap,			/* IDX_PAP */
  	&chap,			/* IDX_CHAP */
  };
  
  
  void spppattach(int);
  void
  /*ARGSUSED*/
  spppattach(int count)
  {
  }
  
  /*
   * Exported functions, comprising our interface to the lower layer.
   */
  
  /*
   * Process the received packet.
   */
  void
  sppp_input(struct ifnet *ifp, struct mbuf *m)
  {
  	struct ppp_header *h = NULL;
  	struct ifqueue *inq = 0;
  	uint16_t protocol;
  	int s;
  	struct sppp *sp = (struct sppp *)ifp;
  	int debug = ifp->if_flags & IFF_DEBUG;
  
  	if (ifp->if_flags & IFF_UP) {
  		/* Count received bytes, add hardware framing */
  		ifp->if_ibytes += m->m_pkthdr.len + sp->pp_framebytes;
  		/* Note time of last receive */
  		sp->pp_last_receive = time_uptime;
  	}
  
  	if (m->m_pkthdr.len <= PPP_HEADER_LEN) {
  		/* Too small packet, drop it. */
  		if (debug)
  			log(LOG_DEBUG,
  			    "%s: input packet is too small, %d bytes\n",
  			    ifp->if_xname, m->m_pkthdr.len);
  	  drop:
  		++ifp->if_ierrors;
  		++ifp->if_iqdrops;
  		m_freem(m);
  		return;
  	}
  
  	if (sp->pp_flags & PP_NOFRAMING) {
  		memcpy(&protocol, mtod(m, void *), 2);
  		protocol = ntohs(protocol);
  		m_adj(m, 2);
  	} else {
  
  		/* Get PPP header. */
  		h = mtod(m, struct ppp_header *);
  		m_adj(m, PPP_HEADER_LEN);
  
  		switch (h->address) {
  		case PPP_ALLSTATIONS:
  			if (h->control != PPP_UI)
  				goto invalid;
  			if (sp->pp_flags & PP_CISCO) {
  				if (debug)
  					log(LOG_DEBUG,
  					    "%s: PPP packet in Cisco mode "
  					    "<addr=0x%x ctrl=0x%x proto=0x%x>\n",
  					    ifp->if_xname,
  					    h->address, h->control, ntohs(h->protocol));
  				goto drop;
  			}
  			break;
  		case CISCO_MULTICAST:
  		case CISCO_UNICAST:
  			/* Don't check the control field here (RFC 1547). */
  			if (! (sp->pp_flags & PP_CISCO)) {
  				if (debug)
  					log(LOG_DEBUG,
  					    "%s: Cisco packet in PPP mode "
  					    "<addr=0x%x ctrl=0x%x proto=0x%x>\n",
  					    ifp->if_xname,
  					    h->address, h->control, ntohs(h->protocol));
  				goto drop;
  			}
  			switch (ntohs(h->protocol)) {
  			default:
  				++ifp->if_noproto;
  				goto invalid;
  			case CISCO_KEEPALIVE:
  				sppp_cisco_input((struct sppp *) ifp, m);
  				m_freem(m);
  				return;
  #ifdef INET
  			case ETHERTYPE_IP:
  				schednetisr(NETISR_IP);
  				inq = &ipintrq;
  				break;
  #endif
  #ifdef INET6
  			case ETHERTYPE_IPV6:
  				schednetisr(NETISR_IPV6);
  				inq = &ip6intrq;
  				break;
  #endif
  #ifdef IPX
  			case ETHERTYPE_IPX:
  				schednetisr(NETISR_IPX);
  				inq = &ipxintrq;
  				break;
  #endif
  			}
  			goto queue_pkt;
  		default:        /* Invalid PPP packet. */
  		  invalid:
  			if (debug)
  				log(LOG_DEBUG,
  				    "%s: invalid input packet "
  				    "<addr=0x%x ctrl=0x%x proto=0x%x>\n",
  				    ifp->if_xname,
  				    h->address, h->control, ntohs(h->protocol));
  			goto drop;
  		}
  		protocol = ntohs(h->protocol);
  	}
  
  	switch (protocol) {
  	default:
  		if (sp->state[IDX_LCP] == STATE_OPENED) {
  			uint16_t prot = htons(protocol);
  			sppp_cp_send(sp, PPP_LCP, PROTO_REJ,
  			    ++sp->pp_seq[IDX_LCP], m->m_pkthdr.len + 2,
  			    &prot);
  		}
  		if (debug)
  			log(LOG_DEBUG,
  			    "%s: invalid input protocol "
  			    "<proto=0x%x>\n", ifp->if_xname, ntohs(protocol));
  		++ifp->if_noproto;
  		goto drop;
  	case PPP_LCP:
  		sppp_cp_input(&lcp, sp, m);
  		m_freem(m);
  		return;
  	case PPP_PAP:
  		if (sp->pp_phase >= SPPP_PHASE_AUTHENTICATE)
  			sppp_pap_input(sp, m);
  		m_freem(m);
  		return;
  	case PPP_CHAP:
  		if (sp->pp_phase >= SPPP_PHASE_AUTHENTICATE)
  			sppp_chap_input(sp, m);
  		m_freem(m);
  		return;
  #ifdef INET
  	case PPP_IPCP:
  		if (sp->pp_phase == SPPP_PHASE_NETWORK)
  			sppp_cp_input(&ipcp, sp, m);
  		m_freem(m);
  		return;
  	case PPP_IP:
  		if (sp->state[IDX_IPCP] == STATE_OPENED) {
  			schednetisr(NETISR_IP);
  			inq = &ipintrq;
  			sp->pp_last_activity = time_uptime;
  		}
  		break;
  #endif
  #ifdef INET6
  	case PPP_IPV6CP:
  		if (sp->pp_phase == SPPP_PHASE_NETWORK)
  			sppp_cp_input(&ipv6cp, sp, m);
  		m_freem(m);
  		return;
  
  	case PPP_IPV6:
  		if (sp->state[IDX_IPV6CP] == STATE_OPENED) {
  			schednetisr(NETISR_IPV6);
  			inq = &ip6intrq;
  			sp->pp_last_activity = time_uptime;
  		}
  		break;
  #endif
  #ifdef IPX
  	case PPP_IPX:
  		/* IPX IPXCP not implemented yet */
  		if (sp->pp_phase == SPPP_PHASE_NETWORK) {
  			schednetisr(NETISR_IPX);
  			inq = &ipxintrq;
  		}
  		break;
  #endif
  #ifdef ISO
  	case PPP_ISO:
  		/* OSI NLCP not implemented yet */
  		if (sp->pp_phase == SPPP_PHASE_NETWORK) {
  			schednetisr(NETISR_ISO);
  			inq = &clnlintrq;
  		}
  		break;
  #endif
  	}
  
  queue_pkt:
  	if (! (ifp->if_flags & IFF_UP) || ! inq)
  		goto drop;
  
  	/* Check queue. */
  	s = splnet();
  	if (IF_QFULL(inq)) {
  		/* Queue overflow. */
  		IF_DROP(inq);
  		splx(s);
  		if (debug)
  			log(LOG_DEBUG, "%s: protocol queue overflow\n",
  				ifp->if_xname);
  		goto drop;
  	}
  	IF_ENQUEUE(inq, m);
  	splx(s);
  }
  
  /*
   * Enqueue transmit packet.
   */
  static int
  sppp_output(struct ifnet *ifp, struct mbuf *m,
      const struct sockaddr *dst, struct rtentry *rt)
  {
  	struct sppp *sp = (struct sppp *) ifp;
  	struct ppp_header *h = NULL;
  	struct ifqueue *ifq = NULL;		/* XXX */
  	int s, error = 0;
  	uint16_t protocol;
  	ALTQ_DECL(struct altq_pktattr pktattr;)
  
  	s = splnet();
  
  	sp->pp_last_activity = time_uptime;
  
  	if ((ifp->if_flags & IFF_UP) == 0 ||
  	    (ifp->if_flags & (IFF_RUNNING | IFF_AUTO)) == 0) {
  		m_freem(m);
  		splx(s);
  		return (ENETDOWN);
  	}
  
  	if ((ifp->if_flags & (IFF_RUNNING | IFF_AUTO)) == IFF_AUTO) {
  		/*
  		 * Interface is not yet running, but auto-dial.  Need
  		 * to start LCP for it.
  		 */
  		ifp->if_flags |= IFF_RUNNING;
  		splx(s);
  		lcp.Open(sp);
  		s = splnet();
  	}
  
  	/*
  	 * If the queueing discipline needs packet classification,
  	 * do it before prepending link headers.
  	 */
  	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
  
  #ifdef INET
  	if (dst->sa_family == AF_INET) {
  		struct ip *ip = NULL;
  		struct tcphdr *th = NULL;
  
  		if (m->m_len >= sizeof(struct ip)) {
  			ip = mtod(m, struct ip *);
  			if (ip->ip_p == IPPROTO_TCP &&
  			    m->m_len >= sizeof(struct ip) + (ip->ip_hl << 2) +
  			    sizeof(struct tcphdr)) {
  				th = (struct tcphdr *)
  				    ((char *)ip + (ip->ip_hl << 2));
  			}
  		} else
  			ip = NULL;
  
  		/*
  		 * When using dynamic local IP address assignment by using
  		 * 0.0.0.0 as a local address, the first TCP session will
  		 * not connect because the local TCP checksum is computed
  		 * using 0.0.0.0 which will later become our real IP address
  		 * so the TCP checksum computed at the remote end will
  		 * become invalid. So we
  		 * - don't let packets with src ip addr 0 thru
  		 * - we flag TCP packets with src ip 0 as an error
  		 */
  		if (ip && ip->ip_src.s_addr == INADDR_ANY) {
  			uint8_t proto = ip->ip_p;
  
  			m_freem(m);
  			splx(s);
  			if (proto == IPPROTO_TCP)
  				return (EADDRNOTAVAIL);
  			else
  				return (0);
  		}
  
  		/*
  		 * Put low delay, telnet, rlogin and ftp control packets
  		 * in front of the queue.
  		 */
  
  		if (!IF_QFULL(&sp->pp_fastq) &&
  		    ((ip && (ip->ip_tos & IPTOS_LOWDELAY)) ||
  		     (th && (INTERACTIVE(ntohs(th->th_sport)) ||
  		      INTERACTIVE(ntohs(th->th_dport))))))
  			ifq = &sp->pp_fastq;
  	}
  #endif
  
  #ifdef INET6
  	if (dst->sa_family == AF_INET6) {
  		/* XXX do something tricky here? */
  	}
  #endif
  
  	if ((sp->pp_flags & PP_NOFRAMING) == 0) {
  		/*
  		 * Prepend general data packet PPP header. For now, IP only.
  		 */
  		M_PREPEND(m, PPP_HEADER_LEN, M_DONTWAIT);
  		if (! m) {
  			if (ifp->if_flags & IFF_DEBUG)
  				log(LOG_DEBUG, "%s: no memory for transmit header\n",
  					ifp->if_xname);
  			++ifp->if_oerrors;
  			splx(s);
  			return (ENOBUFS);
  		}
  		/*
  		 * May want to check size of packet
  		 * (albeit due to the implementation it's always enough)
  		 */
  		h = mtod(m, struct ppp_header *);
  		if (sp->pp_flags & PP_CISCO) {
  			h->address = CISCO_UNICAST;        /* unicast address */
  			h->control = 0;
  		} else {
  			h->address = PPP_ALLSTATIONS;        /* broadcast address */
  			h->control = PPP_UI;                 /* Unnumbered Info */
  		}
  	}
  
  	switch (dst->sa_family) {
  #ifdef INET
  	case AF_INET:   /* Internet Protocol */
  		if (sp->pp_flags & PP_CISCO)
  			protocol = htons(ETHERTYPE_IP);
  		else {
  			/*
  			 * Don't choke with an ENETDOWN early.  It's
  			 * possible that we just started dialing out,
  			 * so don't drop the packet immediately.  If
  			 * we notice that we run out of buffer space
  			 * below, we will however remember that we are
  			 * not ready to carry IP packets, and return
  			 * ENETDOWN, as opposed to ENOBUFS.
  			 */
  			protocol = htons(PPP_IP);
  			if (sp->state[IDX_IPCP] != STATE_OPENED)
  				error = ENETDOWN;
  		}
  		break;
  #endif
  #ifdef INET6
  	case AF_INET6:   /* Internet Protocol version 6 */
  		if (sp->pp_flags & PP_CISCO)
  			protocol = htons(ETHERTYPE_IPV6);
  		else {
  			/*
  			 * Don't choke with an ENETDOWN early.  It's
  			 * possible that we just started dialing out,
  			 * so don't drop the packet immediately.  If
  			 * we notice that we run out of buffer space
  			 * below, we will however remember that we are
  			 * not ready to carry IP packets, and return
  			 * ENETDOWN, as opposed to ENOBUFS.
  			 */
  			protocol = htons(PPP_IPV6);
  			if (sp->state[IDX_IPV6CP] != STATE_OPENED)
  				error = ENETDOWN;
  		}
  		break;
  #endif
  #ifdef IPX
  	case AF_IPX:     /* Novell IPX Protocol */
  		protocol = htons((sp->pp_flags & PP_CISCO) ?
  			ETHERTYPE_IPX : PPP_IPX);
  		break;
  #endif
  #ifdef ISO
  	case AF_ISO:    /* ISO OSI Protocol */
  		if (sp->pp_flags & PP_CISCO)
  			goto nosupport;
  		protocol = htons(PPP_ISO);
  		break;
  nosupport:
  #endif
  	default:
  		m_freem(m);
  		++ifp->if_oerrors;
  		splx(s);
  		return (EAFNOSUPPORT);
  	}
  
  	if (sp->pp_flags & PP_NOFRAMING) {
  		M_PREPEND(m, 2, M_DONTWAIT);
  		if (m == NULL) {
  			if (ifp->if_flags & IFF_DEBUG)
  				log(LOG_DEBUG, "%s: no memory for transmit header\n",
  					ifp->if_xname);
  			++ifp->if_oerrors;
  			splx(s);
  			return (ENOBUFS);
  		}
  		*mtod(m, uint16_t *) = protocol;
  	} else {
  		h->protocol = protocol;
  	}
  
  
  	error = ifq_enqueue2(ifp, ifq, m ALTQ_COMMA ALTQ_DECL(&pktattr));
  
  	if (error == 0) {
  		/*
  		 * Count output packets and bytes.
  		 * The packet length includes header + additional hardware
  		 * framing according to RFC 1333.
  		 */
  		if (!(ifp->if_flags & IFF_OACTIVE))
  			(*ifp->if_start)(ifp);
  		ifp->if_obytes += m->m_pkthdr.len + sp->pp_framebytes;
  	}
  	splx(s);
  	return error;
  }
  
  void
  sppp_attach(struct ifnet *ifp)
  {
  	struct sppp *sp = (struct sppp *) ifp;
  
  	/* Initialize keepalive handler. */
  	if (! spppq) {
  		callout_init(&keepalive_ch, 0);
  		callout_reset(&keepalive_ch, hz * LCP_KEEPALIVE_INTERVAL, sppp_keepalive, NULL);
  	}
  
  	/* Insert new entry into the keepalive list. */
  	sp->pp_next = spppq;
  	spppq = sp;
  
  	sp->pp_if.if_type = IFT_PPP;
  	sp->pp_if.if_output = sppp_output;
  	sp->pp_fastq.ifq_maxlen = 32;
  	sp->pp_cpq.ifq_maxlen = 20;
  	sp->pp_loopcnt = 0;
  	sp->pp_alivecnt = 0;
  	sp->pp_last_activity = 0;
  	sp->pp_last_receive = 0;
  	sp->pp_maxalive = DEFAULT_MAXALIVECNT;
  	sp->pp_max_noreceive = DEFAULT_NORECV_TIME;
  	sp->pp_idle_timeout = 0;
  	memset(&sp->pp_seq[0], 0, sizeof(sp->pp_seq));
  	memset(&sp->pp_rseq[0], 0, sizeof(sp->pp_rseq));
  	sp->pp_auth_failures = 0;
  	sp->pp_max_auth_fail = DEFAULT_MAX_AUTH_FAILURES;
  	sp->pp_phase = SPPP_PHASE_DEAD;
  	sp->pp_up = lcp.Up;
  	sp->pp_down = lcp.Down;
  
  	if_alloc_sadl(ifp);
  
  	memset(&sp->myauth, 0, sizeof sp->myauth);
  	memset(&sp->hisauth, 0, sizeof sp->hisauth);
  	sppp_lcp_init(sp);
  	sppp_ipcp_init(sp);
  	sppp_ipv6cp_init(sp);
  	sppp_pap_init(sp);
  	sppp_chap_init(sp);
  }
  
  void
  sppp_detach(struct ifnet *ifp)
  {
  	struct sppp **q, *p, *sp = (struct sppp *) ifp;
  
  	/* Remove the entry from the keepalive list. */
  	for (q = &spppq; (p = *q); q = &p->pp_next)
  		if (p == sp) {
  			*q = p->pp_next;
  			break;
  		}
  
  	/* Stop keepalive handler. */
  	if (! spppq) {
  		callout_stop(&keepalive_ch);
  	}
  
  	callout_stop(&sp->ch[IDX_LCP]);
  	callout_stop(&sp->ch[IDX_IPCP]);
  	callout_stop(&sp->ch[IDX_PAP]);
  	callout_stop(&sp->ch[IDX_CHAP]);
  #ifdef INET6
  	callout_stop(&sp->ch[IDX_IPV6CP]);
  #endif
  	callout_stop(&sp->pap_my_to_ch);
  
  	/* free authentication info */
  	if (sp->myauth.name) free(sp->myauth.name, M_DEVBUF);
  	if (sp->myauth.secret) free(sp->myauth.secret, M_DEVBUF);
  	if (sp->hisauth.name) free(sp->hisauth.name, M_DEVBUF);
  	if (sp->hisauth.secret) free(sp->hisauth.secret, M_DEVBUF);
  
  #if 0	/* done in if_detach() */
  	if_free_sadl(ifp);
  #endif
  }
  
  /*
   * Flush the interface output queue.
   */
  void
  sppp_flush(struct ifnet *ifp)
  {
  	struct sppp *sp = (struct sppp *) ifp;
  
  	IFQ_PURGE(&sp->pp_if.if_snd);
  	IF_PURGE(&sp->pp_fastq);
  	IF_PURGE(&sp->pp_cpq);
  }
  
  /*
   * Check if the output queue is empty.
   */
  int
  sppp_isempty(struct ifnet *ifp)
  {
  	struct sppp *sp = (struct sppp *) ifp;
  	int empty, s;
  
  	s = splnet();
  	empty = IF_IS_EMPTY(&sp->pp_fastq) && IF_IS_EMPTY(&sp->pp_cpq) &&
  		IFQ_IS_EMPTY(&sp->pp_if.if_snd);
  	splx(s);
  	return (empty);
  }
  
  /*
   * Get next packet to send.
   */
  struct mbuf *
  sppp_dequeue(struct ifnet *ifp)
  {
  	struct sppp *sp = (struct sppp *) ifp;
  	struct mbuf *m;
  	int s;
  
  	s = splnet();
  	/*
  	 * Process only the control protocol queue until we have at
  	 * least one NCP open.
  	 *
  	 * Do always serve all three queues in Cisco mode.
  	 */
  	IF_DEQUEUE(&sp->pp_cpq, m);
  	if (m == NULL &&
  	    (sppp_ncp_check(sp) || (sp->pp_flags & PP_CISCO) != 0)) {
  		IF_DEQUEUE(&sp->pp_fastq, m);
  		if (m == NULL)
  			IFQ_DEQUEUE(&sp->pp_if.if_snd, m);
  	}
  	splx(s);
  	return m;
  }
  
  /*
   * Process an ioctl request.  Called on low priority level.
   */
  int
  sppp_ioctl(struct ifnet *ifp, u_long cmd, void *data)
  {
  	struct lwp *l = curlwp;	/* XXX */
  	struct ifreq *ifr = (struct ifreq *) data;
  	struct sppp *sp = (struct sppp *) ifp;
  	int s, error=0, going_up, going_down, newmode;
  
  	s = splnet();
  	switch (cmd) {
  	case SIOCINITIFADDR:
  		break;
  
  	case SIOCSIFFLAGS:
  		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
  			break;
  		going_up = ifp->if_flags & IFF_UP &&
  			(ifp->if_flags & IFF_RUNNING) == 0;
  		going_down = (ifp->if_flags & IFF_UP) == 0 &&
  			ifp->if_flags & IFF_RUNNING;
  		newmode = ifp->if_flags & (IFF_AUTO | IFF_PASSIVE);
  		if (newmode == (IFF_AUTO | IFF_PASSIVE)) {
  			/* sanity */
  			newmode = IFF_PASSIVE;
  			ifp->if_flags &= ~IFF_AUTO;
  		}
  
  		if (going_up || going_down)
  			lcp.Close(sp);
  		if (going_up && newmode == 0) {
  			/* neither auto-dial nor passive */
  			ifp->if_flags |= IFF_RUNNING;
  			if (!(sp->pp_flags & PP_CISCO))
  				lcp.Open(sp);
  		} else if (going_down) {
  			sppp_flush(ifp);
  			ifp->if_flags &= ~IFF_RUNNING;
  		}
  
  		break;
  
  	case SIOCSIFMTU:
  		if (ifr->ifr_mtu < PPP_MINMRU ||
  		    ifr->ifr_mtu > sp->lcp.their_mru) {
  			error = EINVAL;
  			break;
  		}
  		/*FALLTHROUGH*/
  	case SIOCGIFMTU:
  		if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
  			error = 0;
  		break;
  	case SIOCADDMULTI:
  	case SIOCDELMULTI:
  		break;
  
  	case SPPPSETAUTHCFG:
  	case SPPPSETLCPCFG:
  	case SPPPSETIDLETO:
  	case SPPPSETAUTHFAILURE:
  	case SPPPSETDNSOPTS:
  	case SPPPSETKEEPALIVE:
  #if defined(COMPAT_50) || defined(MODULAR)
  	case __SPPPSETIDLETO50:
  	case __SPPPSETKEEPALIVE50:
  #endif /* COMPAT_50 || MODULAR */
  		error = kauth_authorize_network(l->l_cred,
  		    KAUTH_NETWORK_INTERFACE,
  		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
  		    NULL);
  		if (error)
  			break;
  		error = sppp_params(sp, cmd, data);
  		break;
  
  	case SPPPGETAUTHCFG:
  	case SPPPGETLCPCFG:
  	case SPPPGETAUTHFAILURES:
  		error = kauth_authorize_network(l->l_cred,
  		    KAUTH_NETWORK_INTERFACE,
  		    KAUTH_REQ_NETWORK_INTERFACE_GETPRIV, ifp, (void *)cmd,
  		    NULL);
  		if (error)
  			break;
  		error = sppp_params(sp, cmd, data);
  		break;
  
  	case SPPPGETSTATUS:
  	case SPPPGETSTATUSNCP:
  	case SPPPGETIDLETO:
  	case SPPPGETDNSOPTS:
  	case SPPPGETDNSADDRS:
  	case SPPPGETKEEPALIVE:
  #if defined(COMPAT_50) || defined(MODULAR)
  	case __SPPPGETIDLETO50:
  	case __SPPPGETKEEPALIVE50:
  #endif /* COMPAT_50 || MODULAR */
  		error = sppp_params(sp, cmd, data);
  		break;
  
  	default:
  		error = ifioctl_common(ifp, cmd, data);
  		break;
  	}
  	splx(s);
  	return (error);
  }
  
  
  /*
   * Cisco framing implementation.
   */
  
  /*
   * Handle incoming Cisco keepalive protocol packets.
   */
  static void
  sppp_cisco_input(struct sppp *sp, struct mbuf *m)
  {
  	STDDCL;
  	struct cisco_packet *h;
  #ifdef INET
  	uint32_t me, mymask = 0;	/* XXX: GCC */
  #endif
  
  	if (m->m_pkthdr.len < CISCO_PACKET_LEN) {
  		if (debug)
  			log(LOG_DEBUG,
  			    "%s: cisco invalid packet length: %d bytes\n",
  			    ifp->if_xname, m->m_pkthdr.len);
  		return;
  	}
  	h = mtod(m, struct cisco_packet *);
  	if (debug)
  		log(LOG_DEBUG,
  		    "%s: cisco input: %d bytes "
  		    "<0x%x 0x%x 0x%x 0x%x 0x%x-0x%x>\n",
  		    ifp->if_xname, m->m_pkthdr.len,
  		    ntohl(h->type), h->par1, h->par2, (u_int)h->rel,
  		    (u_int)h->time0, (u_int)h->time1);
  	switch (ntohl(h->type)) {
  	default:
  		if (debug)
  			addlog("%s: cisco unknown packet type: 0x%x\n",
  			       ifp->if_xname, ntohl(h->type));
  		break;
  	case CISCO_ADDR_REPLY:
  		/* Reply on address request, ignore */
  		break;
  	case CISCO_KEEPALIVE_REQ:
  		sp->pp_alivecnt = 0;
  		sp->pp_rseq[IDX_LCP] = ntohl(h->par1);
  		if (sp->pp_seq[IDX_LCP] == sp->pp_rseq[IDX_LCP]) {
  			/* Local and remote sequence numbers are equal.
  			 * Probably, the line is in loopback mode. */
  			if (sp->pp_loopcnt >= LOOPALIVECNT) {
  				printf ("%s: loopback\n",
  					ifp->if_xname);
  				sp->pp_loopcnt = 0;
  				if (ifp->if_flags & IFF_UP) {
  					if_down(ifp);
  					IF_PURGE(&sp->pp_cpq);
  				}
  			}
  			++sp->pp_loopcnt;
  
  			/* Generate new local sequence number */
  			sp->pp_seq[IDX_LCP] = cprng_fast32();
  			break;
  		}
  		sp->pp_loopcnt = 0;
  		if (! (ifp->if_flags & IFF_UP) &&
  		    (ifp->if_flags & IFF_RUNNING)) {
  			if_up(ifp);
  		}
  		break;
  	case CISCO_ADDR_REQ:
  #ifdef INET
  		sppp_get_ip_addrs(sp, &me, 0, &mymask);
  		if (me != 0L)
  			sppp_cisco_send(sp, CISCO_ADDR_REPLY, me, mymask);
  #endif
  		break;
  	}
  }
  
  /*
   * Send Cisco keepalive packet.
   */
  static void
  sppp_cisco_send(struct sppp *sp, int type, int32_t par1, int32_t par2)
  {
  	STDDCL;
  	struct ppp_header *h;
  	struct cisco_packet *ch;
  	struct mbuf *m;
  	uint32_t t;
  
  	t = time_uptime * 1000;
  	MGETHDR(m, M_DONTWAIT, MT_DATA);
  	if (! m)
  		return;
  	m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + CISCO_PACKET_LEN;
  	m->m_pkthdr.rcvif = 0;
  
  	h = mtod(m, struct ppp_header *);
  	h->address = CISCO_MULTICAST;
  	h->control = 0;
  	h->protocol = htons(CISCO_KEEPALIVE);
  
  	ch = (struct cisco_packet *)(h + 1);
  	ch->type = htonl(type);
  	ch->par1 = htonl(par1);
  	ch->par2 = htonl(par2);
  	ch->rel = -1;
  
  	ch->time0 = htons((u_short)(t >> 16));
  	ch->time1 = htons((u_short) t);
  
  	if (debug)
  		log(LOG_DEBUG,
  		    "%s: cisco output: <0x%x 0x%x 0x%x 0x%x 0x%x-0x%x>\n",
  			ifp->if_xname, ntohl(ch->type), ch->par1,
  			ch->par2, (u_int)ch->rel, (u_int)ch->time0,
  			(u_int)ch->time1);
  
  	if (IF_QFULL(&sp->pp_cpq)) {
  		IF_DROP(&sp->pp_fastq);
  		IF_DROP(&ifp->if_snd);
  		m_freem(m);
  		++ifp->if_oerrors;
  		return;
  	} else
  		IF_ENQUEUE(&sp->pp_cpq, m);
  	if (! (ifp->if_flags & IFF_OACTIVE))
  		(*ifp->if_start)(ifp);
  	ifp->if_obytes += m->m_pkthdr.len + sp->pp_framebytes;
  }
  
  /*
   * PPP protocol implementation.
   */
  
  /*
   * Send PPP control protocol packet.
   */
  static void
  sppp_cp_send(struct sppp *sp, u_short proto, u_char type,
  	     u_char ident, u_short len, void *data)
  {
  	STDDCL;
  	struct lcp_header *lh;
  	struct mbuf *m;
  	size_t pkthdrlen;
  
  	pkthdrlen = (sp->pp_flags & PP_NOFRAMING) ? 2 : PPP_HEADER_LEN;
  
  	if (len > MHLEN - pkthdrlen - LCP_HEADER_LEN)
  		len = MHLEN - pkthdrlen - LCP_HEADER_LEN;
  	MGETHDR(m, M_DONTWAIT, MT_DATA);
  	if (! m)
  		return;
  	m->m_pkthdr.len = m->m_len = pkthdrlen + LCP_HEADER_LEN + len;
  	m->m_pkthdr.rcvif = 0;
  
  	if (sp->pp_flags & PP_NOFRAMING) {
  		*mtod(m, uint16_t *) = htons(proto);
  		lh = (struct lcp_header *)(mtod(m, uint8_t *) + 2);
  	} else {
  		struct ppp_header *h;
  		h = mtod(m, struct ppp_header *);
  		h->address = PPP_ALLSTATIONS;        /* broadcast address */
  		h->control = PPP_UI;                 /* Unnumbered Info */
  		h->protocol = htons(proto);         /* Link Control Protocol */
  		lh = (struct lcp_header *)(h + 1);
  	}
  	lh->type = type;
  	lh->ident = ident;
  	lh->len = htons(LCP_HEADER_LEN + len);
  	if (len)
  		bcopy (data, lh + 1, len);
  
  	if (debug) {
  		log(LOG_DEBUG, "%s: %s output <%s id=0x%x len=%d",
  		    ifp->if_xname,
  		    sppp_proto_name(proto),
  		    sppp_cp_type_name(lh->type), lh->ident, ntohs(lh->len));
  		if (len)
  			sppp_print_bytes((u_char *)(lh + 1), len);
  		addlog(">\n");
  	}
  	if (IF_QFULL(&sp->pp_cpq)) {
  		IF_DROP(&sp->pp_fastq);
  		IF_DROP(&ifp->if_snd);
  		m_freem(m);
  		++ifp->if_oerrors;
  		return;
  	} else
  		IF_ENQUEUE(&sp->pp_cpq, m);
  	if (! (ifp->if_flags & IFF_OACTIVE))
  		(*ifp->if_start)(ifp);
  	ifp->if_obytes += m->m_pkthdr.len + sp->pp_framebytes;
  }
  
  /*
   * Handle incoming PPP control protocol packets.
   */
  static void
  sppp_cp_input(const struct cp *cp, struct sppp *sp, struct mbuf *m)
  {
  	STDDCL;
  	struct lcp_header *h;
  	int printlen, len = m->m_pkthdr.len;
  	int rv;
  	u_char *p;
  	uint32_t u32;
  
  	if (len < 4) {
  		if (debug)
  			log(LOG_DEBUG,
  			    "%s: %s invalid packet length: %d bytes\n",
  			    ifp->if_xname, cp->name, len);
  		return;
  	}
  	h = mtod(m, struct lcp_header *);
  	if (debug) {
  		printlen = ntohs(h->len);
  		log(LOG_DEBUG,
  		    "%s: %s input(%s): <%s id=0x%x len=%d",
  		    ifp->if_xname, cp->name,
  		    sppp_state_name(sp->state[cp->protoidx]),
  		    sppp_cp_type_name(h->type), h->ident, printlen);
  		if (len < printlen)
  			printlen = len;
  		if (printlen > 4)
  			sppp_print_bytes((u_char *)(h + 1), printlen - 4);
  		addlog(">\n");
  	}
  	if (len > ntohs(h->len))
  		len = ntohs(h->len);
  	p = (u_char *)(h + 1);
  	switch (h->type) {
  	case CONF_REQ:
  		if (len < 4) {
  			if (debug)
  				addlog("%s: %s invalid conf-req length %d\n",
  				       ifp->if_xname, cp->name,
  				       len);
  			++ifp->if_ierrors;
  			break;
  		}
  		/* handle states where RCR doesn't get a SCA/SCN */
  		switch (sp->state[cp->protoidx]) {
  		case STATE_CLOSING:
  		case STATE_STOPPING:
  			return;
  		case STATE_CLOSED:
  			sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident,
  				     0, 0);
  			return;
  		}
  		rv = (cp->RCR)(sp, h, len);
  		if (rv < 0) {
  			/* fatal error, shut down */
  			(cp->tld)(sp);
  			sppp_lcp_tlf(sp);
  			return;
  		}
  		switch (sp->state[cp->protoidx]) {
  		case STATE_OPENED:
  			(cp->tld)(sp);
  			(cp->scr)(sp);
  			/* fall through... */
  		case STATE_ACK_SENT:
  		case STATE_REQ_SENT:
  			sppp_cp_change_state(cp, sp, rv?
  					     STATE_ACK_SENT: STATE_REQ_SENT);
  			break;
  		case STATE_STOPPED:
  			sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
  			(cp->scr)(sp);
  			sppp_cp_change_state(cp, sp, rv?
  					     STATE_ACK_SENT: STATE_REQ_SENT);
  			break;
  		case STATE_ACK_RCVD:
  			if (rv) {
  				sppp_cp_change_state(cp, sp, STATE_OPENED);
  				if (debug)
  					log(LOG_DEBUG, "%s: %s tlu\n",
  					    ifp->if_xname,
  					    cp->name);
  				(cp->tlu)(sp);
  			} else
  				sppp_cp_change_state(cp, sp, STATE_ACK_RCVD);
  			break;
  		default:
  			printf("%s: %s illegal %s in state %s\n",
  			       ifp->if_xname, cp->name,
  			       sppp_cp_type_name(h->type),
  			       sppp_state_name(sp->state[cp->protoidx]));
  			++ifp->if_ierrors;
  		}
  		break;
  	case CONF_ACK:
  		if (h->ident != sp->confid[cp->protoidx]) {
  			if (debug)
  				addlog("%s: %s id mismatch 0x%x != 0x%x\n",
  				       ifp->if_xname, cp->name,
  				       h->ident, sp->confid[cp->protoidx]);
  			++ifp->if_ierrors;
  			break;
  		}
  		switch (sp->state[cp->protoidx]) {
  		case STATE_CLOSED:
  		case STATE_STOPPED:
  			sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident, 0, 0);
  			break;
  		case STATE_CLOSING:
  		case STATE_STOPPING:
  			break;
  		case STATE_REQ_SENT:
  			sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
  			sppp_cp_change_state(cp, sp, STATE_ACK_RCVD);
  			break;
  		case STATE_OPENED:
  			(cp->tld)(sp);
  			/* fall through */
  		case STATE_ACK_RCVD:
  			(cp->scr)(sp);
  			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
  			break;
  		case STATE_ACK_SENT:
  			sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
  			sppp_cp_change_state(cp, sp, STATE_OPENED);
  			if (debug)
  				log(LOG_DEBUG, "%s: %s tlu\n",
  				       ifp->if_xname, cp->name);
  			(cp->tlu)(sp);
  			break;
  		default:
  			printf("%s: %s illegal %s in state %s\n",
  			       ifp->if_xname, cp->name,
  			       sppp_cp_type_name(h->type),
  			       sppp_state_name(sp->state[cp->protoidx]));
  			++ifp->if_ierrors;
  		}
  		break;
  	case CONF_NAK:
  	case CONF_REJ:
  		if (h->ident != sp->confid[cp->protoidx]) {
  			if (debug)
  				addlog("%s: %s id mismatch 0x%x != 0x%x\n",
  				       ifp->if_xname, cp->name,
  				       h->ident, sp->confid[cp->protoidx]);
  			++ifp->if_ierrors;
  			break;
  		}
  		if (h->type == CONF_NAK)
  			(cp->RCN_nak)(sp, h, len);
  		else /* CONF_REJ */
  			(cp->RCN_rej)(sp, h, len);
  
  		switch (sp->state[cp->protoidx]) {
  		case STATE_CLOSED:
  		case STATE_STOPPED:
  			sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident, 0, 0);
  			break;
  		case STATE_REQ_SENT:
  		case STATE_ACK_SENT:
  			sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
  			(cp->scr)(sp);
  			break;
  		case STATE_OPENED:
  			(cp->tld)(sp);
  			/* fall through */
  		case STATE_ACK_RCVD:
  			sppp_cp_change_state(cp, sp, STATE_ACK_SENT);
  			(cp->scr)(sp);
  			break;
  		case STATE_CLOSING:
  		case STATE_STOPPING:
  			break;
  		default:
  			printf("%s: %s illegal %s in state %s\n",
  			       ifp->if_xname, cp->name,
  			       sppp_cp_type_name(h->type),
  			       sppp_state_name(sp->state[cp->protoidx]));
  			++ifp->if_ierrors;
  		}
  		break;
  
  	case TERM_REQ:
  		switch (sp->state[cp->protoidx]) {
  		case STATE_ACK_RCVD:
  		case STATE_ACK_SENT:
  			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
  			/* fall through */
  		case STATE_CLOSED:
  		case STATE_STOPPED:
  		case STATE_CLOSING:
  		case STATE_STOPPING:
  		case STATE_REQ_SENT:
  		  sta:
  			/* Send Terminate-Ack packet. */
  			if (debug)
  				log(LOG_DEBUG, "%s: %s send terminate-ack\n",
  				    ifp->if_xname, cp->name);
  			sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident, 0, 0);
  			break;
  		case STATE_OPENED:
  			(cp->tld)(sp);
  			sp->rst_counter[cp->protoidx] = 0;
  			sppp_cp_change_state(cp, sp, STATE_STOPPING);
  			goto sta;
  		default:
  			printf("%s: %s illegal %s in state %s\n",
  			       ifp->if_xname, cp->name,
  			       sppp_cp_type_name(h->type),
  			       sppp_state_name(sp->state[cp->protoidx]));
  			++ifp->if_ierrors;
  		}
  		break;
  	case TERM_ACK:
  		switch (sp->state[cp->protoidx]) {
  		case STATE_CLOSED:
  		case STATE_STOPPED:
  		case STATE_REQ_SENT:
  		case STATE_ACK_SENT:
  			break;
  		case STATE_CLOSING:
  			(cp->tlf)(sp);
  			sppp_cp_change_state(cp, sp, STATE_CLOSED);
  			sppp_lcp_check_and_close(sp);
  			break;
  		case STATE_STOPPING:
  			(cp->tlf)(sp);
  			sppp_cp_change_state(cp, sp, STATE_STOPPED);
  			sppp_lcp_check_and_close(sp);
  			break;
  		case STATE_ACK_RCVD:
  			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
  			break;
  		case STATE_OPENED:
  			(cp->tld)(sp);
  			(cp->scr)(sp);
  			sppp_cp_change_state(cp, sp, STATE_ACK_RCVD);
  			break;
  		default:
  			printf("%s: %s illegal %s in state %s\n",
  			       ifp->if_xname, cp->name,
  			       sppp_cp_type_name(h->type),
  			       sppp_state_name(sp->state[cp->protoidx]));
  			++ifp->if_ierrors;
  		}
  		break;
  	case CODE_REJ:
  		/* XXX catastrophic rejects (RXJ-) aren't handled yet. */
  		log(LOG_INFO,
  		    "%s: %s: ignoring RXJ (%s) for code ?, "
  		    "danger will robinson\n",
  		    ifp->if_xname, cp->name,
  		    sppp_cp_type_name(h->type));
  		switch (sp->state[cp->protoidx]) {
  		case STATE_CLOSED:
  		case STATE_STOPPED:
  		case STATE_REQ_SENT:
  		case STATE_ACK_SENT:
  		case STATE_CLOSING:
  		case STATE_STOPPING:
  		case STATE_OPENED:
  			break;
  		case STATE_ACK_RCVD:
  			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
  			break;
  		default:
  			printf("%s: %s illegal %s in state %s\n",
  			       ifp->if_xname, cp->name,
  			       sppp_cp_type_name(h->type),
  			       sppp_state_name(sp->state[cp->protoidx]));
  			++ifp->if_ierrors;
  		}
  		break;
  	case PROTO_REJ:
  	    {
  		int catastrophic;
  		const struct cp *upper;
  		int i;
  		uint16_t proto;
  
  		catastrophic = 0;
  		upper = NULL;
  		proto = p[0] << 8 | p[1];
  		for (i = 0; i < IDX_COUNT; i++) {
  			if (cps[i]->proto == proto) {
  				upper = cps[i];
  				break;
  			}
  		}
  		if (upper == NULL)
  			catastrophic++;
  
  		if (debug)
  			log(LOG_INFO,
  			    "%s: %s: RXJ%c (%s) for proto 0x%x (%s/%s)\n",
  			    ifp->if_xname, cp->name, catastrophic ? '-' : '+',
  			    sppp_cp_type_name(h->type), proto,
  			    upper ? upper->name : "unknown",
  			    upper ? sppp_state_name(sp->state[upper->protoidx]) : "?");
  
  		/*
  		 * if we got RXJ+ against conf-req, the peer does not implement
  		 * this particular protocol type.  terminate the protocol.
  		 */
  		if (upper && !catastrophic) {
  			if (sp->state[upper->protoidx] == STATE_REQ_SENT) {
  				upper->Close(sp);
  				break;
  			}
  		}
  
  		/* XXX catastrophic rejects (RXJ-) aren't handled yet. */
  		switch (sp->state[cp->protoidx]) {
  		case STATE_CLOSED:
  		case STATE_STOPPED:
  		case STATE_REQ_SENT:
  		case STATE_ACK_SENT:
  		case STATE_CLOSING:
  		case STATE_STOPPING:
  		case STATE_OPENED:
  			break;
  		case STATE_ACK_RCVD:
  			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
  			break;
  		default:
  			printf("%s: %s illegal %s in state %s\n",
  			       ifp->if_xname, cp->name,
  			       sppp_cp_type_name(h->type),
  			       sppp_state_name(sp->state[cp->protoidx]));
  			++ifp->if_ierrors;
  		}
  		break;
  	    }
  	case DISC_REQ:
  		if (cp->proto != PPP_LCP)
  			goto illegal;
  		/* Discard the packet. */
  		break;
  	case ECHO_REQ:
  		if (cp->proto != PPP_LCP)
  			goto illegal;
  		if (sp->state[cp->protoidx] != STATE_OPENED) {
  			if (debug)
  				addlog("%s: lcp echo req but lcp closed\n",
  				       ifp->if_xname);
  			++ifp->if_ierrors;
  			break;
  		}
  		if (len < 8) {
  			if (debug)
  				addlog("%s: invalid lcp echo request "
  				       "packet length: %d bytes\n",
  				       ifp->if_xname, len);
  			break;
  		}
  		memcpy(&u32, h + 1, sizeof u32);
  		if (ntohl(u32) == sp->lcp.magic) {
  			/* Line loopback mode detected. */
  			printf("%s: loopback\n", ifp->if_xname);
  			if_down(ifp);
  			IF_PURGE(&sp->pp_cpq);
  
  			/* Shut down the PPP link. */
  			/* XXX */
  			lcp.Down(sp);
  			lcp.Up(sp);
  			break;
  		}
  		u32 = htonl(sp->lcp.magic);
  		memcpy(h + 1, &u32, sizeof u32);
  		if (debug)
  			addlog("%s: got lcp echo req, sending echo rep\n",
  			       ifp->if_xname);
  		sppp_cp_send(sp, PPP_LCP, ECHO_REPLY, h->ident, len - 4,
  		    h + 1);
  		break;
  	case ECHO_REPLY:
  		if (cp->proto != PPP_LCP)
  			goto illegal;
  		if (h->ident != sp->lcp.echoid) {
  			++ifp->if_ierrors;
  			break;
  		}
  		if (len < 8) {
  			if (debug)
  				addlog("%s: lcp invalid echo reply "
  				       "packet length: %d bytes\n",
  				       ifp->if_xname, len);
  			break;
  		}
  		if (debug)
  			addlog("%s: lcp got echo rep\n",
  			       ifp->if_xname);
  		memcpy(&u32, h + 1, sizeof u32);
  		if (ntohl(u32) != sp->lcp.magic)
  			sp->pp_alivecnt = 0;
  		break;
  	default:
  		/* Unknown packet type -- send Code-Reject packet. */
  	  illegal:
  		if (debug)
  			addlog("%s: %s send code-rej for 0x%x\n",
  			       ifp->if_xname, cp->name, h->type);
  		sppp_cp_send(sp, cp->proto, CODE_REJ,
  		    ++sp->pp_seq[cp->protoidx], m->m_pkthdr.len, h);
  		++ifp->if_ierrors;
  	}
  }
  
  
  /*
   * The generic part of all Up/Down/Open/Close/TO event handlers.
   * Basically, the state transition handling in the automaton.
   */
  static void
  sppp_up_event(const struct cp *cp, struct sppp *sp)
  {
  	STDDCL;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: %s up(%s)\n",
  		    ifp->if_xname, cp->name,
  		    sppp_state_name(sp->state[cp->protoidx]));
  
  	switch (sp->state[cp->protoidx]) {
  	case STATE_INITIAL:
  		sppp_cp_change_state(cp, sp, STATE_CLOSED);
  		break;
  	case STATE_STARTING:
  		sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
  		(cp->scr)(sp);
  		sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
  		break;
  	default:
  		printf("%s: %s illegal up in state %s\n",
  		       ifp->if_xname, cp->name,
  		       sppp_state_name(sp->state[cp->protoidx]));
  	}
  }
  
  static void
  sppp_down_event(const struct cp *cp, struct sppp *sp)
  {
  	STDDCL;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: %s down(%s)\n",
  		    ifp->if_xname, cp->name,
  		    sppp_state_name(sp->state[cp->protoidx]));
  
  	switch (sp->state[cp->protoidx]) {
  	case STATE_CLOSED:
  	case STATE_CLOSING:
  		sppp_cp_change_state(cp, sp, STATE_INITIAL);
  		break;
  	case STATE_STOPPED:
  		(cp->tls)(sp);
  		/* fall through */
  	case STATE_STOPPING:
  	case STATE_REQ_SENT:
  	case STATE_ACK_RCVD:
  	case STATE_ACK_SENT:
  		sppp_cp_change_state(cp, sp, STATE_STARTING);
  		break;
  	case STATE_OPENED:
  		(cp->tld)(sp);
  		sppp_cp_change_state(cp, sp, STATE_STARTING);
  		break;
  	default:
  		printf("%s: %s illegal down in state %s\n",
  		       ifp->if_xname, cp->name,
  		       sppp_state_name(sp->state[cp->protoidx]));
  	}
  }
  
  
  static void
  sppp_open_event(const struct cp *cp, struct sppp *sp)
  {
  	STDDCL;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: %s open(%s)\n",
  		    ifp->if_xname, cp->name,
  		    sppp_state_name(sp->state[cp->protoidx]));
  
  	switch (sp->state[cp->protoidx]) {
  	case STATE_INITIAL:
  		sppp_cp_change_state(cp, sp, STATE_STARTING);
  		(cp->tls)(sp);
  		break;
  	case STATE_STARTING:
  		break;
  	case STATE_CLOSED:
  		sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
  		(cp->scr)(sp);
  		sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
  		break;
  	case STATE_STOPPED:
  	case STATE_STOPPING:
  	case STATE_REQ_SENT:
  	case STATE_ACK_RCVD:
  	case STATE_ACK_SENT:
  	case STATE_OPENED:
  		break;
  	case STATE_CLOSING:
  		sppp_cp_change_state(cp, sp, STATE_STOPPING);
  		break;
  	}
  }
  
  
  static void
  sppp_close_event(const struct cp *cp, struct sppp *sp)
  {
  	STDDCL;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: %s close(%s)\n",
  		    ifp->if_xname, cp->name,
  		    sppp_state_name(sp->state[cp->protoidx]));
  
  	switch (sp->state[cp->protoidx]) {
  	case STATE_INITIAL:
  	case STATE_CLOSED:
  	case STATE_CLOSING:
  		break;
  	case STATE_STARTING:
  		sppp_cp_change_state(cp, sp, STATE_INITIAL);
  		(cp->tlf)(sp);
  		break;
  	case STATE_STOPPED:
  		sppp_cp_change_state(cp, sp, STATE_CLOSED);
  		break;
  	case STATE_STOPPING:
  		sppp_cp_change_state(cp, sp, STATE_CLOSING);
  		break;
  	case STATE_OPENED:
  		(cp->tld)(sp);
  		/* fall through */
  	case STATE_REQ_SENT:
  	case STATE_ACK_RCVD:
  	case STATE_ACK_SENT:
  		sp->rst_counter[cp->protoidx] = sp->lcp.max_terminate;
  		sppp_cp_send(sp, cp->proto, TERM_REQ,
  		    ++sp->pp_seq[cp->protoidx], 0, 0);
  		sppp_cp_change_state(cp, sp, STATE_CLOSING);
  		break;
  	}
  }
  
  static void
  sppp_to_event(const struct cp *cp, struct sppp *sp)
  {
  	STDDCL;
  	int s;
  
  	s = splnet();
  	if (debug)
  		log(LOG_DEBUG, "%s: %s TO(%s) rst_counter = %d\n",
  		    ifp->if_xname, cp->name,
  		    sppp_state_name(sp->state[cp->protoidx]),
  		    sp->rst_counter[cp->protoidx]);
  
  	if (--sp->rst_counter[cp->protoidx] < 0)
  		/* TO- event */
  		switch (sp->state[cp->protoidx]) {
  		case STATE_CLOSING:
  			(cp->tlf)(sp);
  			sppp_cp_change_state(cp, sp, STATE_CLOSED);
  			sppp_lcp_check_and_close(sp);
  			break;
  		case STATE_STOPPING:
  			(cp->tlf)(sp);
  			sppp_cp_change_state(cp, sp, STATE_STOPPED);
  			sppp_lcp_check_and_close(sp);
  			break;
  		case STATE_REQ_SENT:
  		case STATE_ACK_RCVD:
  		case STATE_ACK_SENT:
  			(cp->tlf)(sp);
  			sppp_cp_change_state(cp, sp, STATE_STOPPED);
  			sppp_lcp_check_and_close(sp);
  			break;
  		}
  	else
  		/* TO+ event */
  		switch (sp->state[cp->protoidx]) {
  		case STATE_CLOSING:
  		case STATE_STOPPING:
  			sppp_cp_send(sp, cp->proto, TERM_REQ,
  			    ++sp->pp_seq[cp->protoidx], 0, 0);
  			callout_reset(&sp->ch[cp->protoidx], sp->lcp.timeout,
  			    cp->TO, sp);
  			break;
  		case STATE_REQ_SENT:
  		case STATE_ACK_RCVD:
  			(cp->scr)(sp);
  			/* sppp_cp_change_state() will restart the timer */
  			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
  			break;
  		case STATE_ACK_SENT:
  			(cp->scr)(sp);
  			callout_reset(&sp->ch[cp->protoidx], sp->lcp.timeout,
  			    cp->TO, sp);
  			break;
  		}
  
  	splx(s);
  }
  
  /*
   * Change the state of a control protocol in the state automaton.
   * Takes care of starting/stopping the restart timer.
   */
  void
  sppp_cp_change_state(const struct cp *cp, struct sppp *sp, int newstate)
  {
  	sp->state[cp->protoidx] = newstate;
  	callout_stop(&sp->ch[cp->protoidx]);
  	switch (newstate) {
  	case STATE_INITIAL:
  	case STATE_STARTING:
  	case STATE_CLOSED:
  	case STATE_STOPPED:
  	case STATE_OPENED:
  		break;
  	case STATE_CLOSING:
  	case STATE_STOPPING:
  	case STATE_REQ_SENT:
  	case STATE_ACK_RCVD:
  	case STATE_ACK_SENT:
  		callout_reset(&sp->ch[cp->protoidx], sp->lcp.timeout,
  		    cp->TO, sp);
  		break;
  	}
  }
  
  /*
   *--------------------------------------------------------------------------*
   *                                                                          *
   *                         The LCP implementation.                          *
   *                                                                          *
   *--------------------------------------------------------------------------*
   */
  static void
  sppp_lcp_init(struct sppp *sp)
  {
  	sp->lcp.opts = (1 << LCP_OPT_MAGIC);
  	sp->lcp.magic = 0;
  	sp->state[IDX_LCP] = STATE_INITIAL;
  	sp->fail_counter[IDX_LCP] = 0;
  	sp->pp_seq[IDX_LCP] = 0;
  	sp->pp_rseq[IDX_LCP] = 0;
  	sp->lcp.protos = 0;
  
  	/*
  	 * Initialize counters and timeout values.  Note that we don't
  	 * use the 3 seconds suggested in RFC 1661 since we are likely
  	 * running on a fast link.  XXX We should probably implement
  	 * the exponential backoff option.  Note that these values are
  	 * relevant for all control protocols, not just LCP only.
  	 */
  	sp->lcp.timeout = 1 * hz;
  	sp->lcp.max_terminate = 2;
  	sp->lcp.max_configure = 10;
  	sp->lcp.max_failure = 10;
  	callout_init(&sp->ch[IDX_LCP], 0);
  }
  
  static void
  sppp_lcp_up(struct sppp *sp)
  {
  	STDDCL;
  
  	/* Initialize activity timestamp: opening a connection is an activity */
  	sp->pp_last_receive = sp->pp_last_activity = time_uptime;
  
  	/*
  	 * If this interface is passive or dial-on-demand, and we are
  	 * still in Initial state, it means we've got an incoming
  	 * call.  Activate the interface.
  	 */
  	if ((ifp->if_flags & (IFF_AUTO | IFF_PASSIVE)) != 0) {
  		if (debug)
  			log(LOG_DEBUG,
  			    "%s: Up event", ifp->if_xname);
  		ifp->if_flags |= IFF_RUNNING;
  		if (sp->state[IDX_LCP] == STATE_INITIAL) {
  			if (debug)
  				addlog("(incoming call)\n");
  			sp->pp_flags |= PP_CALLIN;
  			lcp.Open(sp);
  		} else if (debug)
  			addlog("\n");
  	} else if ((ifp->if_flags & (IFF_AUTO | IFF_PASSIVE)) == 0 &&
  		   (sp->state[IDX_LCP] == STATE_INITIAL)) {
  			ifp->if_flags |= IFF_RUNNING;
  			lcp.Open(sp);
  	}
  
  	sppp_up_event(&lcp, sp);
  }
  
  static void
  sppp_lcp_down(struct sppp *sp)
  {
  	STDDCL;
  
  	sppp_down_event(&lcp, sp);
  
  	/*
  	 * If this is neither a dial-on-demand nor a passive
  	 * interface, simulate an ``ifconfig down'' action, so the
  	 * administrator can force a redial by another ``ifconfig
  	 * up''.  XXX For leased line operation, should we immediately
  	 * try to reopen the connection here?
  	 */
  	if ((ifp->if_flags & (IFF_AUTO | IFF_PASSIVE)) == 0) {
  		if (debug)
  			log(LOG_INFO,
  			    "%s: Down event (carrier loss), taking interface down.\n",
  			    ifp->if_xname);
  		if_down(ifp);
  	} else {
  		if (debug)
  			log(LOG_DEBUG,
  			    "%s: Down event (carrier loss)\n",
  			    ifp->if_xname);
  	}
  	sp->pp_flags &= ~PP_CALLIN;
  	if (sp->state[IDX_LCP] != STATE_INITIAL)
  		lcp.Close(sp);
  	ifp->if_flags &= ~IFF_RUNNING;
  }
  
  static void
  sppp_lcp_open(struct sppp *sp)
  {
  	if (sp->pp_if.if_mtu < PP_MTU) {
  		sp->lcp.mru = sp->pp_if.if_mtu;
  		sp->lcp.opts |= (1 << LCP_OPT_MRU);
  	} else
  		sp->lcp.mru = PP_MTU;
  	sp->lcp.their_mru = PP_MTU;
  
  	/*
  	 * If we are authenticator, negotiate LCP_AUTH
  	 */
  	if (sp->hisauth.proto != 0)
  		sp->lcp.opts |= (1 << LCP_OPT_AUTH_PROTO);
  	else
  		sp->lcp.opts &= ~(1 << LCP_OPT_AUTH_PROTO);
  	sp->pp_flags &= ~PP_NEEDAUTH;
  	sppp_open_event(&lcp, sp);
  }
  
  static void
  sppp_lcp_close(struct sppp *sp)
  {
  	sppp_close_event(&lcp, sp);
  }
  
  static void
  sppp_lcp_TO(void *cookie)
  {
  	sppp_to_event(&lcp, (struct sppp *)cookie);
  }
  
  /*
   * Analyze a configure request.  Return true if it was agreeable, and
   * caused action sca, false if it has been rejected or nak'ed, and
   * caused action scn.  (The return value is used to make the state
   * transition decision in the state automaton.)
   */
  static int
  sppp_lcp_RCR(struct sppp *sp, struct lcp_header *h, int len)
  {
  	STDDCL;
  	u_char *buf, *r, *p;
  	int origlen, rlen;
  	uint32_t nmagic;
  	u_short authproto;
  
  	len -= 4;
  	origlen = len;
  	buf = r = malloc (len, M_TEMP, M_NOWAIT);
  	if (! buf)
  		return (0);
  
  	if (debug)
  		log(LOG_DEBUG, "%s: lcp parse opts:",
  		    ifp->if_xname);
  
  	/* pass 1: check for things that need to be rejected */
  	p = (void *)(h + 1);
  	for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
  		/* Sanity check option length */
  		if (p[1] > len) {
  			/*
  			 * Malicious option - drop immediately.
  			 * XXX Maybe we should just RXJ it?
  			 */
  			addlog("%s: received malicious LCP option 0x%02x, "
  			    "length 0x%02x, (len: 0x%02x) dropping.\n", ifp->if_xname,
  			    p[0], p[1], len);
  			goto drop;
  		}
  		if (debug)
  			addlog(" %s", sppp_lcp_opt_name(*p));
  		switch (*p) {
  		case LCP_OPT_MAGIC:
  			/* Magic number. */
  			/* fall through, both are same length */
  		case LCP_OPT_ASYNC_MAP:
  			/* Async control character map. */
  			if (len >= 6 || p[1] == 6)
  				continue;
  			if (debug)
  				addlog(" [invalid]");
  			break;
  		case LCP_OPT_MRU:
  			/* Maximum receive unit. */
  			if (len >= 4 && p[1] == 4)
  				continue;
  			if (debug)
  				addlog(" [invalid]");
  			break;
  		case LCP_OPT_AUTH_PROTO:
  			if (len < 4) {
  				if (debug)
  					addlog(" [invalid]");
  				break;
  			}
  			authproto = (p[2] << 8) + p[3];
  			if (authproto == PPP_CHAP && p[1] != 5) {
  				if (debug)
  					addlog(" [invalid chap len]");
  				break;
  			}
  			if (sp->myauth.proto == 0) {
  				/* we are not configured to do auth */
  				if (debug)
  					addlog(" [not configured]");
  				break;
  			}
  			/*
  			 * Remote want us to authenticate, remember this,
  			 * so we stay in SPPP_PHASE_AUTHENTICATE after LCP got
  			 * up.
  			 */
  			sp->pp_flags |= PP_NEEDAUTH;
  			continue;
  		default:
  			/* Others not supported. */
  			if (debug)
  				addlog(" [rej]");
  			break;
  		}
  		/* Add the option to rejected list. */
  		bcopy (p, r, p[1]);
  		r += p[1];
  		rlen += p[1];
  	}
  	if (rlen) {
  		if (debug)
  			addlog(" send conf-rej\n");
  		sppp_cp_send(sp, PPP_LCP, CONF_REJ, h->ident, rlen, buf);
  		goto end;
  	} else if (debug)
  		addlog("\n");
  
  	/*
  	 * pass 2: check for option values that are unacceptable and
  	 * thus require to be nak'ed.
  	 */
  	if (debug)
  		log(LOG_DEBUG, "%s: lcp parse opt values: ",
  		    ifp->if_xname);
  
  	p = (void *)(h + 1);
  	len = origlen;
  	for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
  		if (debug)
  			addlog(" %s", sppp_lcp_opt_name(*p));
  		switch (*p) {
  		case LCP_OPT_MAGIC:
  			/* Magic number -- extract. */
  			nmagic = (uint32_t)p[2] << 24 |
  				(uint32_t)p[3] << 16 | p[4] << 8 | p[5];
  			if (nmagic != sp->lcp.magic) {
  				if (debug)
  					addlog(" 0x%x", nmagic);
  				continue;
  			}
  			/*
  			 * Local and remote magics equal -- loopback?
  			 */
  			if (sp->pp_loopcnt >= LOOPALIVECNT*5) {
  				printf ("%s: loopback\n",
  					ifp->if_xname);
  				sp->pp_loopcnt = 0;
  				if (ifp->if_flags & IFF_UP) {
  					if_down(ifp);
  					IF_PURGE(&sp->pp_cpq);
  					/* XXX ? */
  					lcp.Down(sp);
  					lcp.Up(sp);
  				}
  			} else if (debug)
  				addlog(" [glitch]");
  			++sp->pp_loopcnt;
  			/*
  			 * We negate our magic here, and NAK it.  If
  			 * we see it later in an NAK packet, we
  			 * suggest a new one.
  			 */
  			nmagic = ~sp->lcp.magic;
  			/* Gonna NAK it. */
  			p[2] = nmagic >> 24;
  			p[3] = nmagic >> 16;
  			p[4] = nmagic >> 8;
  			p[5] = nmagic;
  			break;
  
  		case LCP_OPT_ASYNC_MAP:
  			/*
  			 * Async control character map -- just ignore it.
  			 *
  			 * Quote from RFC 1662, chapter 6:
  			 * To enable this functionality, synchronous PPP
  			 * implementations MUST always respond to the
  			 * Async-Control-Character-Map Configuration
  			 * Option with the LCP Configure-Ack.  However,
  			 * acceptance of the Configuration Option does
  			 * not imply that the synchronous implementation
  			 * will do any ACCM mapping.  Instead, all such
  			 * octet mapping will be performed by the
  			 * asynchronous-to-synchronous converter.
  			 */
  			continue;
  
  		case LCP_OPT_MRU:
  			/*
  			 * Maximum receive unit.  Always agreeable,
  			 * but ignored by now.
  			 */
  			sp->lcp.their_mru = p[2] * 256 + p[3];
  			if (debug)
  				addlog(" %ld", sp->lcp.their_mru);
  			continue;
  
  		case LCP_OPT_AUTH_PROTO:
  			authproto = (p[2] << 8) + p[3];
  			if (sp->myauth.proto != authproto) {
  				/* not agreed, nak */
  				if (debug)
  					addlog(" [mine %s != his %s]",
  					       sppp_proto_name(sp->myauth.proto),
  					       sppp_proto_name(authproto));
  				p[2] = sp->myauth.proto >> 8;
  				p[3] = sp->myauth.proto;
  				break;
  			}
  			if (authproto == PPP_CHAP && p[4] != CHAP_MD5) {
  				if (debug)
  					addlog(" [chap not MD5]");
  				p[4] = CHAP_MD5;
  				break;
  			}
  			continue;
  		}
  		/* Add the option to nak'ed list. */
  		bcopy (p, r, p[1]);
  		r += p[1];
  		rlen += p[1];
  	}
  	if (rlen) {
  		if (++sp->fail_counter[IDX_LCP] >= sp->lcp.max_failure) {
  			if (debug)
  				addlog(" max_failure (%d) exceeded, "
  				       "send conf-rej\n",
  				       sp->lcp.max_failure);
  			sppp_cp_send(sp, PPP_LCP, CONF_REJ, h->ident, rlen, buf);
  		} else {
  			if (debug)
  				addlog(" send conf-nak\n");
  			sppp_cp_send(sp, PPP_LCP, CONF_NAK, h->ident, rlen, buf);
  		}
  		goto end;
  	} else {
  		if (debug)
  			addlog(" send conf-ack\n");
  		sp->fail_counter[IDX_LCP] = 0;
  		sp->pp_loopcnt = 0;
  		sppp_cp_send(sp, PPP_LCP, CONF_ACK, h->ident, origlen, h + 1);
  	}
  
   end:
  	free(buf, M_TEMP);
  	return (rlen == 0);
  
   drop:
  	free(buf, M_TEMP);
  	return -1;
  }
  
  /*
   * Analyze the LCP Configure-Reject option list, and adjust our
   * negotiation.
   */
  static void
  sppp_lcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
  {
  	STDDCL;
  	u_char *buf, *p;
  
  	len -= 4;
  	buf = malloc (len, M_TEMP, M_NOWAIT);
  	if (!buf)
  		return;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: lcp rej opts:",
  		    ifp->if_xname);
  
  	p = (void *)(h + 1);
  	for (; len > 1 && p[1]; len -= p[1], p += p[1]) {
  		/* Sanity check option length */
  		if (p[1] > len) {
  			/*
  			 * Malicious option - drop immediately.
  			 * XXX Maybe we should just RXJ it?
  			 */
  			addlog("%s: received malicious LCP option, "
  			    "dropping.\n", ifp->if_xname);
  			goto drop;
  		}
  		if (debug)
  			addlog(" %s", sppp_lcp_opt_name(*p));
  		switch (*p) {
  		case LCP_OPT_MAGIC:
  			/* Magic number -- can't use it, use 0 */
  			sp->lcp.opts &= ~(1 << LCP_OPT_MAGIC);
  			sp->lcp.magic = 0;
  			break;
  		case LCP_OPT_MRU:
  			/*
  			 * We try to negotiate a lower MRU if the underlying
  			 * link's MTU is less than PP_MTU (e.g. PPPoE). If the
  			 * peer rejects this lower rate, fallback to the
  			 * default.
  			 */
  			if (debug) {
  				addlog("%s: warning: peer rejected our MRU of "
  				    "%ld bytes. Defaulting to %d bytes\n",
  				    ifp->if_xname, sp->lcp.mru, PP_MTU);
  			}
  			sp->lcp.opts &= ~(1 << LCP_OPT_MRU);
  			sp->lcp.mru = PP_MTU;
  			break;
  		case LCP_OPT_AUTH_PROTO:
  			/*
  			 * Peer doesn't want to authenticate himself,
  			 * deny unless this is a dialout call, and
  			 * SPPP_AUTHFLAG_NOCALLOUT is set.
  			 */
  			if ((sp->pp_flags & PP_CALLIN) == 0 &&
  			    (sp->hisauth.flags & SPPP_AUTHFLAG_NOCALLOUT) != 0) {
  				if (debug)
  					addlog(" [don't insist on auth "
  					       "for callout]");
  				sp->lcp.opts &= ~(1 << LCP_OPT_AUTH_PROTO);
  				break;
  			}
  			if (debug)
  				addlog("[access denied]\n");
  			lcp.Close(sp);
  			break;
  		}
  	}
  	if (debug)
  		addlog("\n");
  drop:
  	free(buf, M_TEMP);
  	return;
  }
  
  /*
   * Analyze the LCP Configure-NAK option list, and adjust our
   * negotiation.
   */
  static void
  sppp_lcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
  {
  	STDDCL;
  	u_char *buf, *p;
  	uint32_t magic;
  
  	len -= 4;
  	buf = malloc (len, M_TEMP, M_NOWAIT);
  	if (!buf)
  		return;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: lcp nak opts:",
  		    ifp->if_xname);
  
  	p = (void *)(h + 1);
  	for (; len > 1 && p[1]; len -= p[1], p += p[1]) {
  		/* Sanity check option length */
  		if (p[1] > len) {
  			/*
  			 * Malicious option - drop immediately.
  			 * XXX Maybe we should just RXJ it?
  			 */
  			addlog("%s: received malicious LCP option, "
  			    "dropping.\n", ifp->if_xname);
  			goto drop;
  		}
  		if (debug)
  			addlog(" %s", sppp_lcp_opt_name(*p));
  		switch (*p) {
  		case LCP_OPT_MAGIC:
  			/* Magic number -- renegotiate */
  			if ((sp->lcp.opts & (1 << LCP_OPT_MAGIC)) &&
  			    len >= 6 && p[1] == 6) {
  				magic = (uint32_t)p[2] << 24 |
  					(uint32_t)p[3] << 16 | p[4] << 8 | p[5];
  				/*
  				 * If the remote magic is our negated one,
  				 * this looks like a loopback problem.
  				 * Suggest a new magic to make sure.
  				 */
  				if (magic == ~sp->lcp.magic) {
  					if (debug)
  						addlog(" magic glitch");
  					sp->lcp.magic = cprng_fast32();
  				} else {
  					sp->lcp.magic = magic;
  					if (debug)
  						addlog(" %d", magic);
  				}
  			}
  			break;
  		case LCP_OPT_MRU:
  			/*
  			 * Peer wants to advise us to negotiate an MRU.
  			 * Agree on it if it's reasonable, or use
  			 * default otherwise.
  			 */
  			if (len >= 4 && p[1] == 4) {
  				u_int mru = p[2] * 256 + p[3];
  				if (debug)
  					addlog(" %d", mru);
  				if (mru < PPP_MINMRU || mru > sp->pp_if.if_mtu)
  					mru = sp->pp_if.if_mtu;
  				sp->lcp.mru = mru;
  				sp->lcp.opts |= (1 << LCP_OPT_MRU);
  			}
  			break;
  		case LCP_OPT_AUTH_PROTO:
  			/*
  			 * Peer doesn't like our authentication method,
  			 * deny.
  			 */
  			if (debug)
  				addlog("[access denied]\n");
  			lcp.Close(sp);
  			break;
  		}
  	}
  	if (debug)
  		addlog("\n");
  drop:
  	free(buf, M_TEMP);
  	return;
  }
  
  static void
  sppp_lcp_tlu(struct sppp *sp)
  {
  	STDDCL;
  	int i;
  	uint32_t mask;
  
  	/* XXX ? */
  	if (! (ifp->if_flags & IFF_UP) &&
  	    (ifp->if_flags & IFF_RUNNING)) {
  		/* Coming out of loopback mode. */
  		if_up(ifp);
  	}
  
  	for (i = 0; i < IDX_COUNT; i++)
  		if ((cps[i])->flags & CP_QUAL)
  			(cps[i])->Open(sp);
  
  	if ((sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) != 0 ||
  	    (sp->pp_flags & PP_NEEDAUTH) != 0)
  		sp->pp_phase = SPPP_PHASE_AUTHENTICATE;
  	else
  		sp->pp_phase = SPPP_PHASE_NETWORK;
  
  	if (debug)
  	{
  		log(LOG_INFO, "%s: phase %s\n", ifp->if_xname,
  		    sppp_phase_name(sp->pp_phase));
  	}
  
  	/*
  	 * Open all authentication protocols.  This is even required
  	 * if we already proceeded to network phase, since it might be
  	 * that remote wants us to authenticate, so we might have to
  	 * send a PAP request.  Undesired authentication protocols
  	 * don't do anything when they get an Open event.
  	 */
  	for (i = 0; i < IDX_COUNT; i++)
  		if ((cps[i])->flags & CP_AUTH)
  			(cps[i])->Open(sp);
  
  	if (sp->pp_phase == SPPP_PHASE_NETWORK) {
  		/* Notify all NCPs. */
  		for (i = 0; i < IDX_COUNT; i++)
  			if ((cps[i])->flags & CP_NCP)
  				(cps[i])->Open(sp);
  	}
  
  	/* Send Up events to all started protos. */
  	for (i = 0, mask = 1; i < IDX_COUNT; i++, mask <<= 1)
  		if ((sp->lcp.protos & mask) && ((cps[i])->flags & CP_LCP) == 0)
  			(cps[i])->Up(sp);
  
  	/* notify low-level driver of state change */
  	if (sp->pp_chg)
  		sp->pp_chg(sp, (int)sp->pp_phase);
  
  	if (sp->pp_phase == SPPP_PHASE_NETWORK)
  		/* if no NCP is starting, close down */
  		sppp_lcp_check_and_close(sp);
  }
  
  static void
  sppp_lcp_tld(struct sppp *sp)
  {
  	STDDCL;
  	int i;
  	uint32_t mask;
  
  	sp->pp_phase = SPPP_PHASE_TERMINATE;
  
  	if (debug)
  	{
  		log(LOG_INFO, "%s: phase %s\n", ifp->if_xname,
  			sppp_phase_name(sp->pp_phase));
  	}
  
  	/*
  	 * Take upper layers down.  We send the Down event first and
  	 * the Close second to prevent the upper layers from sending
  	 * ``a flurry of terminate-request packets'', as the RFC
  	 * describes it.
  	 */
  	for (i = 0, mask = 1; i < IDX_COUNT; i++, mask <<= 1)
  		if ((sp->lcp.protos & mask) && ((cps[i])->flags & CP_LCP) == 0) {
  			(cps[i])->Down(sp);
  			(cps[i])->Close(sp);
  		}
  }
  
  static void
  sppp_lcp_tls(struct sppp *sp)
  {
  	STDDCL;
  
  	if (sp->pp_max_auth_fail != 0 && sp->pp_auth_failures >= sp->pp_max_auth_fail) {
  	    printf("%s: authentication failed %d times, not retrying again\n",
  		sp->pp_if.if_xname, sp->pp_auth_failures);
  	    if_down(&sp->pp_if);
  	    return;
  	}
  
  	sp->pp_phase = SPPP_PHASE_ESTABLISH;
  
  	if (debug)
  	{
  		log(LOG_INFO, "%s: phase %s\n", ifp->if_xname,
  			sppp_phase_name(sp->pp_phase));
  	}
  
  	/* Notify lower layer if desired. */
  	if (sp->pp_tls)
  		(sp->pp_tls)(sp);
  }
  
  static void
  sppp_lcp_tlf(struct sppp *sp)
  {
  	STDDCL;
  
  	sp->pp_phase = SPPP_PHASE_DEAD;
  
  	if (debug)
  	{
  		log(LOG_INFO, "%s: phase %s\n", ifp->if_xname,
  			sppp_phase_name(sp->pp_phase));
  	}
  
  	/* Notify lower layer if desired. */
  	if (sp->pp_tlf)
  		(sp->pp_tlf)(sp);
  }
  
  static void
  sppp_lcp_scr(struct sppp *sp)
  {
  	char opt[6 /* magicnum */ + 4 /* mru */ + 5 /* chap */];
  	int i = 0;
  	u_short authproto;
  
  	if (sp->lcp.opts & (1 << LCP_OPT_MAGIC)) {
  		if (! sp->lcp.magic)
  			sp->lcp.magic = cprng_fast32();
  		opt[i++] = LCP_OPT_MAGIC;
  		opt[i++] = 6;
  		opt[i++] = sp->lcp.magic >> 24;
  		opt[i++] = sp->lcp.magic >> 16;
  		opt[i++] = sp->lcp.magic >> 8;
  		opt[i++] = sp->lcp.magic;
  	}
  
  	if (sp->lcp.opts & (1 << LCP_OPT_MRU)) {
  		opt[i++] = LCP_OPT_MRU;
  		opt[i++] = 4;
  		opt[i++] = sp->lcp.mru >> 8;
  		opt[i++] = sp->lcp.mru;
  	}
  
  	if (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) {
  		authproto = sp->hisauth.proto;
  		opt[i++] = LCP_OPT_AUTH_PROTO;
  		opt[i++] = authproto == PPP_CHAP? 5: 4;
  		opt[i++] = authproto >> 8;
  		opt[i++] = authproto;
  		if (authproto == PPP_CHAP)
  			opt[i++] = CHAP_MD5;
  	}
  
  	sp->confid[IDX_LCP] = ++sp->pp_seq[IDX_LCP];
  	sppp_cp_send(sp, PPP_LCP, CONF_REQ, sp->confid[IDX_LCP], i, &opt);
  }
  
  /*
   * Check the open NCPs, return true if at least one NCP is open.
   */
  static int
  sppp_ncp_check(struct sppp *sp)
  {
  	int i, mask;
  
  	for (i = 0, mask = 1; i < IDX_COUNT; i++, mask <<= 1)
  		if ((sp->lcp.protos & mask) && (cps[i])->flags & CP_NCP)
  			return 1;
  	return 0;
  }
  
  /*
   * Re-check the open NCPs and see if we should terminate the link.
   * Called by the NCPs during their tlf action handling.
   */
  static void
  sppp_lcp_check_and_close(struct sppp *sp)
  {
  
  	if (sp->pp_phase < SPPP_PHASE_NETWORK)
  		/* don't bother, we are already going down */
  		return;
  
  	if (sppp_ncp_check(sp))
  		return;
  
  	lcp.Close(sp);
  }
  
  
  /*
   *--------------------------------------------------------------------------*
   *                                                                          *
   *                        The IPCP implementation.                          *
   *                                                                          *
   *--------------------------------------------------------------------------*
   */
  
  static void
  sppp_ipcp_init(struct sppp *sp)
  {
  	sp->ipcp.opts = 0;
  	sp->ipcp.flags = 0;
  	sp->state[IDX_IPCP] = STATE_INITIAL;
  	sp->fail_counter[IDX_IPCP] = 0;
  	sp->pp_seq[IDX_IPCP] = 0;
  	sp->pp_rseq[IDX_IPCP] = 0;
  	callout_init(&sp->ch[IDX_IPCP], 0);
  }
  
  static void
  sppp_ipcp_up(struct sppp *sp)
  {
  	sppp_up_event(&ipcp, sp);
  }
  
  static void
  sppp_ipcp_down(struct sppp *sp)
  {
  	sppp_down_event(&ipcp, sp);
  }
  
  static void
  sppp_ipcp_open(struct sppp *sp)
  {
  	STDDCL;
  	uint32_t myaddr, hisaddr;
  
  	sp->ipcp.flags &= ~(IPCP_HISADDR_SEEN|IPCP_MYADDR_SEEN|IPCP_MYADDR_DYN|IPCP_HISADDR_DYN);
  	sp->ipcp.req_myaddr = 0;
  	sp->ipcp.req_hisaddr = 0;
  	memset(&sp->dns_addrs, 0, sizeof sp->dns_addrs);
  
  #ifdef INET
  	sppp_get_ip_addrs(sp, &myaddr, &hisaddr, 0);
  #else
  	myaddr = hisaddr = 0;
  #endif
  	/*
  	 * If we don't have his address, this probably means our
  	 * interface doesn't want to talk IP at all.  (This could
  	 * be the case if somebody wants to speak only IPX, for
  	 * example.)  Don't open IPCP in this case.
  	 */
  	if (hisaddr == 0) {
  		/* XXX this message should go away */
  		if (debug)
  			log(LOG_DEBUG, "%s: ipcp_open(): no IP interface\n",
  			    ifp->if_xname);
  		return;
  	}
  
  	if (myaddr == 0) {
  		/*
  		 * I don't have an assigned address, so i need to
  		 * negotiate my address.
  		 */
  		sp->ipcp.flags |= IPCP_MYADDR_DYN;
  		sp->ipcp.opts |= (1 << IPCP_OPT_ADDRESS);
  	}
  	if (hisaddr == 1) {
  		/*
  		 * XXX - remove this hack!
  		 * remote has no valid address, we need to get one assigned.
  		 */
  		sp->ipcp.flags |= IPCP_HISADDR_DYN;
  	}
  	sppp_open_event(&ipcp, sp);
  }
  
  static void
  sppp_ipcp_close(struct sppp *sp)
  {
  	STDDCL;
  
  	sppp_close_event(&ipcp, sp);
  #ifdef INET
  	if (sp->ipcp.flags & (IPCP_MYADDR_DYN|IPCP_HISADDR_DYN))
  		/*
  		 * Some address was dynamic, clear it again.
  		 */
  		sppp_clear_ip_addrs(sp);
  #endif
  
  	if (sp->pp_saved_mtu > 0) {
  		ifp->if_mtu = sp->pp_saved_mtu;
  		sp->pp_saved_mtu = 0;
  		if (debug)
  			log(LOG_DEBUG,
  			    "%s: resetting MTU to %" PRIu64 " bytes\n",
  			    ifp->if_xname, ifp->if_mtu);
  	}
  }
  
  static void
  sppp_ipcp_TO(void *cookie)
  {
  	sppp_to_event(&ipcp, (struct sppp *)cookie);
  }
  
  /*
   * Analyze a configure request.  Return true if it was agreeable, and
   * caused action sca, false if it has been rejected or nak'ed, and
   * caused action scn.  (The return value is used to make the state
   * transition decision in the state automaton.)
   */
  static int
  sppp_ipcp_RCR(struct sppp *sp, struct lcp_header *h, int len)
  {
  	u_char *buf, *r, *p;
  	struct ifnet *ifp = &sp->pp_if;
  	int rlen, origlen, debug = ifp->if_flags & IFF_DEBUG;
  	uint32_t hisaddr, desiredaddr;
  
  	len -= 4;
  	origlen = len;
  	/*
  	 * Make sure to allocate a buf that can at least hold a
  	 * conf-nak with an `address' option.  We might need it below.
  	 */
  	buf = r = malloc ((len < 6? 6: len), M_TEMP, M_NOWAIT);
  	if (! buf)
  		return (0);
  
  	/* pass 1: see if we can recognize them */
  	if (debug)
  		log(LOG_DEBUG, "%s: ipcp parse opts:",
  		    ifp->if_xname);
  	p = (void *)(h + 1);
  	for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
  		/* Sanity check option length */
  		if (p[1] > len) {
  			/* XXX should we just RXJ? */
  			addlog("%s: malicious IPCP option received, dropping\n",
  			    ifp->if_xname);
  			goto drop;
  		}
  		if (debug)
  			addlog(" %s", sppp_ipcp_opt_name(*p));
  		switch (*p) {
  #ifdef notyet
  		case IPCP_OPT_COMPRESSION:
  			if (len >= 6 && p[1] >= 6) {
  				/* correctly formed compress option */
  				continue;
  			}
  			if (debug)
  				addlog(" [invalid]");
  			break;
  #endif
  		case IPCP_OPT_ADDRESS:
  			if (len >= 6 && p[1] == 6) {
  				/* correctly formed address option */
  				continue;
  			}
  			if (debug)
  				addlog(" [invalid]");
  			break;
  		default:
  			/* Others not supported. */
  			if (debug)
  				addlog(" [rej]");
  			break;
  		}
  		/* Add the option to rejected list. */
  		bcopy (p, r, p[1]);
  		r += p[1];
  		rlen += p[1];
  	}
  	if (rlen) {
  		if (debug)
  			addlog(" send conf-rej\n");
  		sppp_cp_send(sp, PPP_IPCP, CONF_REJ, h->ident, rlen, buf);
  		goto end;
  	} else if (debug)
  		addlog("\n");
  
  	/* pass 2: parse option values */
  	if (sp->ipcp.flags & IPCP_HISADDR_SEEN)
  		hisaddr = sp->ipcp.req_hisaddr;	/* we already aggreed on that */
  	else
  #ifdef INET
  		sppp_get_ip_addrs(sp, 0, &hisaddr, 0);	/* user configuration */
  #else
  		hisaddr = 0;
  #endif
  	if (debug)
  		log(LOG_DEBUG, "%s: ipcp parse opt values: ",
  		       ifp->if_xname);
  	p = (void *)(h + 1);
  	len = origlen;
  	for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
  		if (debug)
  			addlog(" %s", sppp_ipcp_opt_name(*p));
  		switch (*p) {
  #ifdef notyet
  		case IPCP_OPT_COMPRESSION:
  			continue;
  #endif
  		case IPCP_OPT_ADDRESS:
  			desiredaddr = p[2] << 24 | p[3] << 16 |
  				p[4] << 8 | p[5];
  			if (desiredaddr == hisaddr ||
  		    	   ((sp->ipcp.flags & IPCP_HISADDR_DYN) && desiredaddr != 0)) {
  				/*
  			 	* Peer's address is same as our value,
  			 	* this is agreeable.  Gonna conf-ack
  			 	* it.
  			 	*/
  				if (debug)
  					addlog(" %s [ack]",
  				       		sppp_dotted_quad(hisaddr));
  				/* record that we've seen it already */
  				sp->ipcp.flags |= IPCP_HISADDR_SEEN;
  				sp->ipcp.req_hisaddr = desiredaddr;
  				hisaddr = desiredaddr;
  				continue;
  			}
  			/*
  		 	* The address wasn't agreeable.  This is either
  		 	* he sent us 0.0.0.0, asking to assign him an
  		 	* address, or he send us another address not
  		 	* matching our value.  Either case, we gonna
  		 	* conf-nak it with our value.
  		 	*/
  			if (debug) {
  				if (desiredaddr == 0)
  					addlog(" [addr requested]");
  				else
  					addlog(" %s [not agreed]",
  				       		sppp_dotted_quad(desiredaddr));
  			}
  
  			p[2] = hisaddr >> 24;
  			p[3] = hisaddr >> 16;
  			p[4] = hisaddr >> 8;
  			p[5] = hisaddr;
  			break;
  		}
  		/* Add the option to nak'ed list. */
  		bcopy (p, r, p[1]);
  		r += p[1];
  		rlen += p[1];
  	}
  
  	/*
  	 * If we are about to conf-ack the request, but haven't seen
  	 * his address so far, gonna conf-nak it instead, with the
  	 * `address' option present and our idea of his address being
  	 * filled in there, to request negotiation of both addresses.
  	 *
  	 * XXX This can result in an endless req - nak loop if peer
  	 * doesn't want to send us his address.  Q: What should we do
  	 * about it?  XXX  A: implement the max-failure counter.
  	 */
  	if (rlen == 0 && !(sp->ipcp.flags & IPCP_HISADDR_SEEN)) {
  		buf[0] = IPCP_OPT_ADDRESS;
  		buf[1] = 6;
  		buf[2] = hisaddr >> 24;
  		buf[3] = hisaddr >> 16;
  		buf[4] = hisaddr >> 8;
  		buf[5] = hisaddr;
  		rlen = 6;
  		if (debug)
  			addlog(" still need hisaddr");
  	}
  
  	if (rlen) {
  		if (debug)
  			addlog(" send conf-nak\n");
  		sppp_cp_send(sp, PPP_IPCP, CONF_NAK, h->ident, rlen, buf);
  	} else {
  		if (debug)
  			addlog(" send conf-ack\n");
  		sppp_cp_send(sp, PPP_IPCP, CONF_ACK, h->ident, origlen, h + 1);
  	}
  
   end:
  	free(buf, M_TEMP);
  	return (rlen == 0);
  
   drop:
  	free(buf, M_TEMP);
  	return -1;
  }
  
  /*
   * Analyze the IPCP Configure-Reject option list, and adjust our
   * negotiation.
   */
  static void
  sppp_ipcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
  {
  	u_char *buf, *p;
  	struct ifnet *ifp = &sp->pp_if;
  	int debug = ifp->if_flags & IFF_DEBUG;
  
  	len -= 4;
  	buf = malloc (len, M_TEMP, M_NOWAIT);
  	if (!buf)
  		return;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: ipcp rej opts:",
  		    ifp->if_xname);
  
  	p = (void *)(h + 1);
  	for (; len > 1 && p[1]; len -= p[1], p += p[1]) {
  		/* Sanity check option length */
  		if (p[1] > len) {
  			/* XXX should we just RXJ? */
  			addlog("%s: malicious IPCP option received, dropping\n",
  			    ifp->if_xname);
  			goto drop;
  		}
  		if (debug)
  			addlog(" %s", sppp_ipcp_opt_name(*p));
  		switch (*p) {
  		case IPCP_OPT_ADDRESS:
  			/*
  			 * Peer doesn't grok address option.  This is
  			 * bad.  XXX  Should we better give up here?
  			 */
  			sp->ipcp.opts &= ~(1 << IPCP_OPT_ADDRESS);
  			break;
  #ifdef notyet
  		case IPCP_OPT_COMPRESS:
  			sp->ipcp.opts &= ~(1 << IPCP_OPT_COMPRESS);
  			break;
  #endif
  		}
  	}
  	if (debug)
  		addlog("\n");
  drop:
  	free(buf, M_TEMP);
  	return;
  }
  
  /*
   * Analyze the IPCP Configure-NAK option list, and adjust our
   * negotiation.
   */
  static void
  sppp_ipcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
  {
  	u_char *p;
  	struct ifnet *ifp = &sp->pp_if;
  	int debug = ifp->if_flags & IFF_DEBUG;
  	uint32_t wantaddr;
  
  	len -= 4;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: ipcp nak opts:",
  		    ifp->if_xname);
  
  	p = (void *)(h + 1);
  	for (; len > 1 && p[1]; len -= p[1], p += p[1]) {
  		/* Sanity check option length */
  		if (p[1] > len) {
  			/* XXX should we just RXJ? */
  			addlog("%s: malicious IPCP option received, dropping\n",
  			    ifp->if_xname);
  			return;
  		}
  		if (debug)
  			addlog(" %s", sppp_ipcp_opt_name(*p));
  		switch (*p) {
  		case IPCP_OPT_ADDRESS:
  			/*
  			 * Peer doesn't like our local IP address.  See
  			 * if we can do something for him.  We'll drop
  			 * him our address then.
  			 */
  			if (len >= 6 && p[1] == 6) {
  				wantaddr = p[2] << 24 | p[3] << 16 |
  					p[4] << 8 | p[5];
  				sp->ipcp.opts |= (1 << IPCP_OPT_ADDRESS);
  				if (debug)
  					addlog(" [wantaddr %s]",
  					       sppp_dotted_quad(wantaddr));
  				/*
  				 * When doing dynamic address assignment,
  				 * we accept his offer.  Otherwise, we
  				 * ignore it and thus continue to negotiate
  				 * our already existing value.
  				 */
  				if (sp->ipcp.flags & IPCP_MYADDR_DYN) {
  					if (debug)
  						addlog(" [agree]");
  					sp->ipcp.flags |= IPCP_MYADDR_SEEN;
  					sp->ipcp.req_myaddr = wantaddr;
  				}
  			}
  			break;
  
  		case IPCP_OPT_PRIMDNS:
  			if (len >= 6 && p[1] == 6) {
  				sp->dns_addrs[0] = p[2] << 24 | p[3] << 16 |
  					p[4] << 8 | p[5];
  			}
  			break;
  
  		case IPCP_OPT_SECDNS:
  			if (len >= 6 && p[1] == 6) {
  				sp->dns_addrs[1] = p[2] << 24 | p[3] << 16 |
  					p[4] << 8 | p[5];
  			}
  			break;
  #ifdef notyet
  		case IPCP_OPT_COMPRESS:
  			/*
  			 * Peer wants different compression parameters.
  			 */
  			break;
  #endif
  		}
  	}
  	if (debug)
  		addlog("\n");
  }
  
  static void
  sppp_ipcp_tlu(struct sppp *sp)
  {
  #ifdef INET
  	/* we are up. Set addresses and notify anyone interested */
  	STDDCL;
  	uint32_t myaddr, hisaddr;
  
  	sppp_get_ip_addrs(sp, &myaddr, &hisaddr, 0);
  	if ((sp->ipcp.flags & IPCP_MYADDR_DYN) && (sp->ipcp.flags & IPCP_MYADDR_SEEN))
  		myaddr = sp->ipcp.req_myaddr;
  	if ((sp->ipcp.flags & IPCP_HISADDR_DYN) && (sp->ipcp.flags & IPCP_HISADDR_SEEN))
  		hisaddr = sp->ipcp.req_hisaddr;
  	sppp_set_ip_addrs(sp, myaddr, hisaddr);
  
  	if (ifp->if_mtu > sp->lcp.their_mru) {
  		sp->pp_saved_mtu = ifp->if_mtu;
  		ifp->if_mtu = sp->lcp.their_mru;
  		if (debug)
  			log(LOG_DEBUG,
  			    "%s: setting MTU to %" PRIu64 " bytes\n",
  			    ifp->if_xname, ifp->if_mtu);
  	}
  
  	if (sp->pp_con)
  		sp->pp_con(sp);
  #endif
  }
  
  static void
  sppp_ipcp_tld(struct sppp *sp)
  {
  }
  
  static void
  sppp_ipcp_tls(struct sppp *sp)
  {
  	/* indicate to LCP that it must stay alive */
  	sp->lcp.protos |= (1 << IDX_IPCP);
  }
  
  static void
  sppp_ipcp_tlf(struct sppp *sp)
  {
  	/* we no longer need LCP */
  	sp->lcp.protos &= ~(1 << IDX_IPCP);
  }
  
  static void
  sppp_ipcp_scr(struct sppp *sp)
  {
  	char opt[6 /* compression */ + 6 /* address */ + 12 /* dns addresses */];
  #ifdef INET
  	uint32_t ouraddr;
  #endif
  	int i = 0;
  
  #ifdef notyet
  	if (sp->ipcp.opts & (1 << IPCP_OPT_COMPRESSION)) {
  		opt[i++] = IPCP_OPT_COMPRESSION;
  		opt[i++] = 6;
  		opt[i++] = 0;	/* VJ header compression */
  		opt[i++] = 0x2d; /* VJ header compression */
  		opt[i++] = max_slot_id;
  		opt[i++] = comp_slot_id;
  	}
  #endif
  
  #ifdef INET
  	if (sp->ipcp.opts & (1 << IPCP_OPT_ADDRESS)) {
  		if (sp->ipcp.flags & IPCP_MYADDR_SEEN)
  			ouraddr = sp->ipcp.req_myaddr;	/* not sure if this can ever happen */
  		else
  			sppp_get_ip_addrs(sp, &ouraddr, 0, 0);
  		opt[i++] = IPCP_OPT_ADDRESS;
  		opt[i++] = 6;
  		opt[i++] = ouraddr >> 24;
  		opt[i++] = ouraddr >> 16;
  		opt[i++] = ouraddr >> 8;
  		opt[i++] = ouraddr;
  	}
  #endif
  
  	if (sp->query_dns & 1) {
  		opt[i++] = IPCP_OPT_PRIMDNS;
  		opt[i++] = 6;
  		opt[i++] = sp->dns_addrs[0] >> 24;
  		opt[i++] = sp->dns_addrs[0] >> 16;
  		opt[i++] = sp->dns_addrs[0] >> 8;
  		opt[i++] = sp->dns_addrs[0];
  	}
  	if (sp->query_dns & 2) {
  		opt[i++] = IPCP_OPT_SECDNS;
  		opt[i++] = 6;
  		opt[i++] = sp->dns_addrs[1] >> 24;
  		opt[i++] = sp->dns_addrs[1] >> 16;
  		opt[i++] = sp->dns_addrs[1] >> 8;
  		opt[i++] = sp->dns_addrs[1];
  	}
  
  	sp->confid[IDX_IPCP] = ++sp->pp_seq[IDX_IPCP];
  	sppp_cp_send(sp, PPP_IPCP, CONF_REQ, sp->confid[IDX_IPCP], i, &opt);
  }
  
  
  /*
   *--------------------------------------------------------------------------*
   *                                                                          *
   *                      The IPv6CP implementation.                          *
   *                                                                          *
   *--------------------------------------------------------------------------*
   */
  
  #ifdef INET6
  static void
  sppp_ipv6cp_init(struct sppp *sp)
  {
  	sp->ipv6cp.opts = 0;
  	sp->ipv6cp.flags = 0;
  	sp->state[IDX_IPV6CP] = STATE_INITIAL;
  	sp->fail_counter[IDX_IPV6CP] = 0;
  	sp->pp_seq[IDX_IPV6CP] = 0;
  	sp->pp_rseq[IDX_IPV6CP] = 0;
  	callout_init(&sp->ch[IDX_IPV6CP], 0);
  }
  
  static void
  sppp_ipv6cp_up(struct sppp *sp)
  {
  	sppp_up_event(&ipv6cp, sp);
  }
  
  static void
  sppp_ipv6cp_down(struct sppp *sp)
  {
  	sppp_down_event(&ipv6cp, sp);
  }
  
  static void
  sppp_ipv6cp_open(struct sppp *sp)
  {
  	STDDCL;
  	struct in6_addr myaddr, hisaddr;
  
  #ifdef IPV6CP_MYIFID_DYN
  	sp->ipv6cp.flags &= ~(IPV6CP_MYIFID_SEEN|IPV6CP_MYIFID_DYN);
  #else
  	sp->ipv6cp.flags &= ~IPV6CP_MYIFID_SEEN;
  #endif
  
  	sppp_get_ip6_addrs(sp, &myaddr, &hisaddr, 0);
  	/*
  	 * If we don't have our address, this probably means our
  	 * interface doesn't want to talk IPv6 at all.  (This could
  	 * be the case if somebody wants to speak only IPX, for
  	 * example.)  Don't open IPv6CP in this case.
  	 */
  	if (IN6_IS_ADDR_UNSPECIFIED(&myaddr)) {
  		/* XXX this message should go away */
  		if (debug)
  			log(LOG_DEBUG, "%s: ipv6cp_open(): no IPv6 interface\n",
  			    ifp->if_xname);
  		return;
  	}
  
  	sp->ipv6cp.flags |= IPV6CP_MYIFID_SEEN;
  	sp->ipv6cp.opts |= (1 << IPV6CP_OPT_IFID);
  	sppp_open_event(&ipv6cp, sp);
  }
  
  static void
  sppp_ipv6cp_close(struct sppp *sp)
  {
  	sppp_close_event(&ipv6cp, sp);
  }
  
  static void
  sppp_ipv6cp_TO(void *cookie)
  {
  	sppp_to_event(&ipv6cp, (struct sppp *)cookie);
  }
  
  /*
   * Analyze a configure request.  Return true if it was agreeable, and
   * caused action sca, false if it has been rejected or nak'ed, and
   * caused action scn.  (The return value is used to make the state
   * transition decision in the state automaton.)
   */
  static int
  sppp_ipv6cp_RCR(struct sppp *sp, struct lcp_header *h, int len)
  {
  	u_char *buf, *r, *p;
  	struct ifnet *ifp = &sp->pp_if;
  	int rlen, origlen, debug = ifp->if_flags & IFF_DEBUG;
  	struct in6_addr myaddr, desiredaddr, suggestaddr;
  	int ifidcount;
  	int type;
  	int collision, nohisaddr;
  
  	len -= 4;
  	origlen = len;
  	/*
  	 * Make sure to allocate a buf that can at least hold a
  	 * conf-nak with an `address' option.  We might need it below.
  	 */
  	buf = r = malloc ((len < 6? 6: len), M_TEMP, M_NOWAIT);
  	if (! buf)
  		return (0);
  
  	/* pass 1: see if we can recognize them */
  	if (debug)
  		log(LOG_DEBUG, "%s: ipv6cp parse opts:",
  		    ifp->if_xname);
  	p = (void *)(h + 1);
  	ifidcount = 0;
  	for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
  		/* Sanity check option length */
  		if (p[1] > len) {
  			/* XXX just RXJ? */
  			addlog("%s: received malicious IPCPv6 option, "
  			    "dropping\n", ifp->if_xname);
  			goto drop;
  		}
  		if (debug)
  			addlog(" %s", sppp_ipv6cp_opt_name(*p));
  		switch (*p) {
  		case IPV6CP_OPT_IFID:
  			if (len >= 10 && p[1] == 10 && ifidcount == 0) {
  				/* correctly formed address option */
  				ifidcount++;
  				continue;
  			}
  			if (debug)
  				addlog(" [invalid]");
  			break;
  #ifdef notyet
  		case IPV6CP_OPT_COMPRESSION:
  			if (len >= 4 && p[1] >= 4) {
  				/* correctly formed compress option */
  				continue;
  			}
  			if (debug)
  				addlog(" [invalid]");
  			break;
  #endif
  		default:
  			/* Others not supported. */
  			if (debug)
  				addlog(" [rej]");
  			break;
  		}
  		/* Add the option to rejected list. */
  		bcopy (p, r, p[1]);
  		r += p[1];
  		rlen += p[1];
  	}
  	if (rlen) {
  		if (debug)
  			addlog(" send conf-rej\n");
  		sppp_cp_send(sp, PPP_IPV6CP, CONF_REJ, h->ident, rlen, buf);
  		goto end;
  	} else if (debug)
  		addlog("\n");
  
  	/* pass 2: parse option values */
  	sppp_get_ip6_addrs(sp, &myaddr, 0, 0);
  	if (debug)
  		log(LOG_DEBUG, "%s: ipv6cp parse opt values: ",
  		       ifp->if_xname);
  	p = (void *)(h + 1);
  	len = origlen;
  	type = CONF_ACK;
  	for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
  		if (debug)
  			addlog(" %s", sppp_ipv6cp_opt_name(*p));
  		switch (*p) {
  #ifdef notyet
  		case IPV6CP_OPT_COMPRESSION:
  			continue;
  #endif
  		case IPV6CP_OPT_IFID:
  			memset(&desiredaddr, 0, sizeof(desiredaddr));
  			memcpy(&desiredaddr.s6_addr[8], &p[2], 8);
  			collision = (memcmp(&desiredaddr.s6_addr[8],
  					&myaddr.s6_addr[8], 8) == 0);
  			nohisaddr = IN6_IS_ADDR_UNSPECIFIED(&desiredaddr);
  
  			desiredaddr.s6_addr16[0] = htons(0xfe80);
  			(void)in6_setscope(&desiredaddr, &sp->pp_if, NULL);
  
  			if (!collision && !nohisaddr) {
  				/* no collision, hisaddr known - Conf-Ack */
  				type = CONF_ACK;
  
  				if (debug) {
  					addlog(" %s [%s]",
  					    ip6_sprintf(&desiredaddr),
  					    sppp_cp_type_name(type));
  				}
  				continue;
  			}
  
  			memset(&suggestaddr, 0, sizeof(suggestaddr));
  			if (collision && nohisaddr) {
  				/* collision, hisaddr unknown - Conf-Rej */
  				type = CONF_REJ;
  				memset(&p[2], 0, 8);
  			} else {
  				/*
  				 * - no collision, hisaddr unknown, or
  				 * - collision, hisaddr known
  				 * Conf-Nak, suggest hisaddr
  				 */
  				type = CONF_NAK;
  				sppp_suggest_ip6_addr(sp, &suggestaddr);
  				memcpy(&p[2], &suggestaddr.s6_addr[8], 8);
  			}
  			if (debug)
  				addlog(" %s [%s]", ip6_sprintf(&desiredaddr),
  				    sppp_cp_type_name(type));
  			break;
  		}
  		/* Add the option to nak'ed list. */
  		bcopy (p, r, p[1]);
  		r += p[1];
  		rlen += p[1];
  	}
  
  	if (rlen == 0 && type == CONF_ACK) {
  		if (debug)
  			addlog(" send %s\n", sppp_cp_type_name(type));
  		sppp_cp_send(sp, PPP_IPV6CP, type, h->ident, origlen, h + 1);
  	} else {
  #ifdef notdef
  		if (type == CONF_ACK)
  			panic("IPv6CP RCR: CONF_ACK with non-zero rlen");
  #endif
  
  		if (debug) {
  			addlog(" send %s suggest %s\n",
  			    sppp_cp_type_name(type), ip6_sprintf(&suggestaddr));
  		}
  		sppp_cp_send(sp, PPP_IPV6CP, type, h->ident, rlen, buf);
  	}
  
   end:
  	free(buf, M_TEMP);
  	return (rlen == 0);
  
   drop:
  	free(buf, M_TEMP);
  	return -1;
  }
  
  /*
   * Analyze the IPv6CP Configure-Reject option list, and adjust our
   * negotiation.
   */
  static void
  sppp_ipv6cp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
  {
  	u_char *buf, *p;
  	struct ifnet *ifp = &sp->pp_if;
  	int debug = ifp->if_flags & IFF_DEBUG;
  
  	len -= 4;
  	buf = malloc (len, M_TEMP, M_NOWAIT);
  	if (!buf)
  		return;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: ipv6cp rej opts:",
  		    ifp->if_xname);
  
  	p = (void *)(h + 1);
  	for (; len > 1 && p[1]; len -= p[1], p += p[1]) {
  		if (p[1] > len) {
  			/* XXX just RXJ? */
  			addlog("%s: received malicious IPCPv6 option, "
  			    "dropping\n", ifp->if_xname);
  			goto drop;
  		}
  		if (debug)
  			addlog(" %s", sppp_ipv6cp_opt_name(*p));
  		switch (*p) {
  		case IPV6CP_OPT_IFID:
  			/*
  			 * Peer doesn't grok address option.  This is
  			 * bad.  XXX  Should we better give up here?
  			 */
  			sp->ipv6cp.opts &= ~(1 << IPV6CP_OPT_IFID);
  			break;
  #ifdef notyet
  		case IPV6CP_OPT_COMPRESS:
  			sp->ipv6cp.opts &= ~(1 << IPV6CP_OPT_COMPRESS);
  			break;
  #endif
  		}
  	}
  	if (debug)
  		addlog("\n");
  drop:
  	free(buf, M_TEMP);
  	return;
  }
  
  /*
   * Analyze the IPv6CP Configure-NAK option list, and adjust our
   * negotiation.
   */
  static void
  sppp_ipv6cp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
  {
  	u_char *buf, *p;
  	struct ifnet *ifp = &sp->pp_if;
  	int debug = ifp->if_flags & IFF_DEBUG;
  	struct in6_addr suggestaddr;
  
  	len -= 4;
  	buf = malloc (len, M_TEMP, M_NOWAIT);
  	if (!buf)
  		return;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: ipv6cp nak opts:",
  		    ifp->if_xname);
  
  	p = (void *)(h + 1);
  	for (; len > 1 && p[1]; len -= p[1], p += p[1]) {
  		if (p[1] > len) {
  			/* XXX just RXJ? */
  			addlog("%s: received malicious IPCPv6 option, "
  			    "dropping\n", ifp->if_xname);
  			goto drop;
  		}
  		if (debug)
  			addlog(" %s", sppp_ipv6cp_opt_name(*p));
  		switch (*p) {
  		case IPV6CP_OPT_IFID:
  			/*
  			 * Peer doesn't like our local ifid.  See
  			 * if we can do something for him.  We'll drop
  			 * him our address then.
  			 */
  			if (len < 10 || p[1] != 10)
  				break;
  			memset(&suggestaddr, 0, sizeof(suggestaddr));
  			suggestaddr.s6_addr16[0] = htons(0xfe80);
  			(void)in6_setscope(&suggestaddr, &sp->pp_if, NULL);
  			memcpy(&suggestaddr.s6_addr[8], &p[2], 8);
  
  			sp->ipv6cp.opts |= (1 << IPV6CP_OPT_IFID);
  			if (debug)
  				addlog(" [suggestaddr %s]",
  				       ip6_sprintf(&suggestaddr));
  #ifdef IPV6CP_MYIFID_DYN
  			/*
  			 * When doing dynamic address assignment,
  			 * we accept his offer.
  			 */
  			if (sp->ipv6cp.flags & IPV6CP_MYIFID_DYN) {
  				struct in6_addr lastsuggest;
  				/*
  				 * If <suggested myaddr from peer> equals to
  				 * <hisaddr we have suggested last time>,
  				 * we have a collision.  generate new random
  				 * ifid.
  				 */
  				sppp_suggest_ip6_addr(&lastsuggest);
  				if (IN6_ARE_ADDR_EQUAL(&suggestaddr,
  						 lastsuggest)) {
  					if (debug)
  						addlog(" [random]");
  					sppp_gen_ip6_addr(sp, &suggestaddr);
  				}
  				sppp_set_ip6_addr(sp, &suggestaddr, 0);
  				if (debug)
  					addlog(" [agree]");
  				sp->ipv6cp.flags |= IPV6CP_MYIFID_SEEN;
  			}
  #else
  			/*
  			 * Since we do not do dynamic address assignment,
  			 * we ignore it and thus continue to negotiate
  			 * our already existing value.  This can possibly
  			 * go into infinite request-reject loop.
  			 *
  			 * This is not likely because we normally use
  			 * ifid based on MAC-address.
  			 * If you have no ethernet card on the node, too bad.
  			 * XXX should we use fail_counter?
  			 */
  #endif
  			break;
  #ifdef notyet
  		case IPV6CP_OPT_COMPRESS:
  			/*
  			 * Peer wants different compression parameters.
  			 */
  			break;
  #endif
  		}
  	}
  	if (debug)
  		addlog("\n");
  drop:
  	free(buf, M_TEMP);
  	return;
  }
  
  static void
  sppp_ipv6cp_tlu(struct sppp *sp)
  {
  	/* we are up - notify isdn daemon */
  	if (sp->pp_con)
  		sp->pp_con(sp);
  }
  
  static void
  sppp_ipv6cp_tld(struct sppp *sp)
  {
  }
  
  static void
  sppp_ipv6cp_tls(struct sppp *sp)
  {
  	/* indicate to LCP that it must stay alive */
  	sp->lcp.protos |= (1 << IDX_IPV6CP);
  }
  
  static void
  sppp_ipv6cp_tlf(struct sppp *sp)
  {
  	/* we no longer need LCP */
  	sp->lcp.protos &= ~(1 << IDX_IPV6CP);
  }
  
  static void
  sppp_ipv6cp_scr(struct sppp *sp)
  {
  	char opt[10 /* ifid */ + 4 /* compression, minimum */];
  	struct in6_addr ouraddr;
  	int i = 0;
  
  	if (sp->ipv6cp.opts & (1 << IPV6CP_OPT_IFID)) {
  		sppp_get_ip6_addrs(sp, &ouraddr, 0, 0);
  		opt[i++] = IPV6CP_OPT_IFID;
  		opt[i++] = 10;
  		memcpy(&opt[i], &ouraddr.s6_addr[8], 8);
  		i += 8;
  	}
  
  #ifdef notyet
  	if (sp->ipv6cp.opts & (1 << IPV6CP_OPT_COMPRESSION)) {
  		opt[i++] = IPV6CP_OPT_COMPRESSION;
  		opt[i++] = 4;
  		opt[i++] = 0;	/* TBD */
  		opt[i++] = 0;	/* TBD */
  		/* variable length data may follow */
  	}
  #endif
  
  	sp->confid[IDX_IPV6CP] = ++sp->pp_seq[IDX_IPV6CP];
  	sppp_cp_send(sp, PPP_IPV6CP, CONF_REQ, sp->confid[IDX_IPV6CP], i, &opt);
  }
  #else /*INET6*/
  static void
  sppp_ipv6cp_init(struct sppp *sp)
  {
  }
  
  static void
  sppp_ipv6cp_up(struct sppp *sp)
  {
  }
  
  static void
  sppp_ipv6cp_down(struct sppp *sp)
  {
  }
  
  static void
  sppp_ipv6cp_open(struct sppp *sp)
  {
  }
  
  static void
  sppp_ipv6cp_close(struct sppp *sp)
  {
  }
  
  static void
  sppp_ipv6cp_TO(void *sp)
  {
  }
  
  static int
  sppp_ipv6cp_RCR(struct sppp *sp, struct lcp_header *h,
  		int len)
  {
  	return 0;
  }
  
  static void
  sppp_ipv6cp_RCN_rej(struct sppp *sp, struct lcp_header *h,
  		    int len)
  {
  }
  
  static void
  sppp_ipv6cp_RCN_nak(struct sppp *sp, struct lcp_header *h,
  		    int len)
  {
  }
  
  static void
  sppp_ipv6cp_tlu(struct sppp *sp)
  {
  }
  
  static void
  sppp_ipv6cp_tld(struct sppp *sp)
  {
  }
  
  static void
  sppp_ipv6cp_tls(struct sppp *sp)
  {
  }
  
  static void
  sppp_ipv6cp_tlf(struct sppp *sp)
  {
  }
  
  static void
  sppp_ipv6cp_scr(struct sppp *sp)
  {
  }
  #endif /*INET6*/
  
  
  /*
   *--------------------------------------------------------------------------*
   *                                                                          *
   *                        The CHAP implementation.                          *
   *                                                                          *
   *--------------------------------------------------------------------------*
   */
  
  /*
   * The authentication protocols don't employ a full-fledged state machine as
   * the control protocols do, since they do have Open and Close events, but
   * not Up and Down, nor are they explicitly terminated.  Also, use of the
   * authentication protocols may be different in both directions (this makes
   * sense, think of a machine that never accepts incoming calls but only
   * calls out, it doesn't require the called party to authenticate itself).
   *
   * Our state machine for the local authentication protocol (we are requesting
   * the peer to authenticate) looks like:
   *
   *						    RCA-
   *	      +--------------------------------------------+
   *	      V					    scn,tld|
   *	  +--------+			       Close   +---------+ RCA+
   *	  |	   |<----------------------------------|	 |------+
   *   +--->| Closed |				TO*    | Opened	 | sca	|
   *   |	  |	   |-----+		       +-------|	 |<-----+
   *   |	  +--------+ irc |		       |       +---------+
   *   |	    ^		 |		       |	   ^
   *   |	    |		 |		       |	   |
   *   |	    |		 |		       |	   |
   *   |	 TO-|		 |		       |	   |
   *   |	    |tld  TO+	 V		       |	   |
   *   |	    |	+------->+		       |	   |
   *   |	    |	|	 |		       |	   |
   *   |	  +--------+	 V		       |	   |
   *   |	  |	   |<----+<--------------------+	   |
   *   |	  | Req-   | scr				   |
   *   |	  | Sent   |					   |
   *   |	  |	   |					   |
   *   |	  +--------+					   |
   *   | RCA- |	| RCA+					   |
   *   +------+	+------------------------------------------+
   *   scn,tld	  sca,irc,ict,tlu
   *
   *
   *   with:
   *
   *	Open:	LCP reached authentication phase
   *	Close:	LCP reached terminate phase
   *
   *	RCA+:	received reply (pap-req, chap-response), acceptable
   *	RCN:	received reply (pap-req, chap-response), not acceptable
   *	TO+:	timeout with restart counter >= 0
   *	TO-:	timeout with restart counter < 0
   *	TO*:	reschedule timeout for CHAP
   *
   *	scr:	send request packet (none for PAP, chap-challenge)
   *	sca:	send ack packet (pap-ack, chap-success)
   *	scn:	send nak packet (pap-nak, chap-failure)
   *	ict:	initialize re-challenge timer (CHAP only)
   *
   *	tlu:	this-layer-up, LCP reaches network phase
   *	tld:	this-layer-down, LCP enters terminate phase
   *
   * Note that in CHAP mode, after sending a new challenge, while the state
   * automaton falls back into Req-Sent state, it doesn't signal a tld
   * event to LCP, so LCP remains in network phase.  Only after not getting
   * any response (or after getting an unacceptable response), CHAP closes,
   * causing LCP to enter terminate phase.
   *
   * With PAP, there is no initial request that can be sent.  The peer is
   * expected to send one based on the successful negotiation of PAP as
   * the authentication protocol during the LCP option negotiation.
   *
   * Incoming authentication protocol requests (remote requests
   * authentication, we are peer) don't employ a state machine at all,
   * they are simply answered.  Some peers [Ascend P50 firmware rev
   * 4.50] react allergically when sending IPCP/IPv6CP requests while they are
   * still in authentication phase (thereby violating the standard that
   * demands that these NCP packets are to be discarded), so we keep
   * track of the peer demanding us to authenticate, and only proceed to
   * phase network once we've seen a positive acknowledge for the
   * authentication.
   */
  
  /*
   * Handle incoming CHAP packets.
   */
  void
  sppp_chap_input(struct sppp *sp, struct mbuf *m)
  {
  	STDDCL;
  	struct lcp_header *h;
  	int len, x;
  	u_char *value, *name, digest[sizeof(sp->myauth.challenge)], dsize;
  	int value_len, name_len;
  	MD5_CTX ctx;
  
  	len = m->m_pkthdr.len;
  	if (len < 4) {
  		if (debug)
  			log(LOG_DEBUG,
  			    "%s: chap invalid packet length: %d bytes\n",
  			    ifp->if_xname, len);
  		return;
  	}
  	h = mtod(m, struct lcp_header *);
  	if (len > ntohs(h->len))
  		len = ntohs(h->len);
  
  	switch (h->type) {
  	/* challenge, failure and success are his authproto */
  	case CHAP_CHALLENGE:
  		if (sp->myauth.secret == NULL || sp->myauth.name == NULL) {
  		    /* can't do anything useful */
  		    sp->pp_auth_failures++;
  		    printf("%s: chap input without my name and my secret being set\n",
  		    	ifp->if_xname);
  		    break;
  		}
  		value = 1 + (u_char *)(h + 1);
  		value_len = value[-1];
  		name = value + value_len;
  		name_len = len - value_len - 5;
  		if (name_len < 0) {
  			if (debug) {
  				log(LOG_DEBUG,
  				    "%s: chap corrupted challenge "
  				    "<%s id=0x%x len=%d",
  				    ifp->if_xname,
  				    sppp_auth_type_name(PPP_CHAP, h->type),
  				    h->ident, ntohs(h->len));
  				if (len > 4)
  					sppp_print_bytes((u_char *)(h + 1),
  					    len - 4);
  				addlog(">\n");
  			}
  			break;
  		}
  
  		if (debug) {
  			log(LOG_DEBUG,
  			    "%s: chap input <%s id=0x%x len=%d name=",
  			    ifp->if_xname,
  			    sppp_auth_type_name(PPP_CHAP, h->type), h->ident,
  			    ntohs(h->len));
  			sppp_print_string((char *) name, name_len);
  			addlog(" value-size=%d value=", value_len);
  			sppp_print_bytes(value, value_len);
  			addlog(">\n");
  		}
  
  		/* Compute reply value. */
  		MD5Init(&ctx);
  		MD5Update(&ctx, &h->ident, 1);
  		MD5Update(&ctx, sp->myauth.secret, sp->myauth.secret_len);
  		MD5Update(&ctx, value, value_len);
  		MD5Final(digest, &ctx);
  		dsize = sizeof digest;
  
  		sppp_auth_send(&chap, sp, CHAP_RESPONSE, h->ident,
  			       sizeof dsize, (const char *)&dsize,
  			       sizeof digest, digest,
  			       sp->myauth.name_len,
  			       sp->myauth.name,
  			       0);
  		break;
  
  	case CHAP_SUCCESS:
  		if (debug) {
  			log(LOG_DEBUG, "%s: chap success",
  			    ifp->if_xname);
  			if (len > 4) {
  				addlog(": ");
  				sppp_print_string((char *)(h + 1), len - 4);
  			}
  			addlog("\n");
  		}
  		x = splnet();
  		sp->pp_auth_failures = 0;
  		sp->pp_flags &= ~PP_NEEDAUTH;
  		if (sp->myauth.proto == PPP_CHAP &&
  		    (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) &&
  		    (sp->lcp.protos & (1 << IDX_CHAP)) == 0) {
  			/*
  			 * We are authenticator for CHAP but didn't
  			 * complete yet.  Leave it to tlu to proceed
  			 * to network phase.
  			 */
  			splx(x);
  			break;
  		}
  		splx(x);
  		sppp_phase_network(sp);
  		break;
  
  	case CHAP_FAILURE:
  		x = splnet();
  		sp->pp_auth_failures++;
  		splx(x);
  		if (debug) {
  			log(LOG_INFO, "%s: chap failure",
  			    ifp->if_xname);
  			if (len > 4) {
  				addlog(": ");
  				sppp_print_string((char *)(h + 1), len - 4);
  			}
  			addlog("\n");
  		} else
  			log(LOG_INFO, "%s: chap failure\n",
  			    ifp->if_xname);
  		/* await LCP shutdown by authenticator */
  		break;
  
  	/* response is my authproto */
  	case CHAP_RESPONSE:
  		if (sp->hisauth.secret == NULL) {
  		    /* can't do anything useful */
  		    printf("%s: chap input without his secret being set\n",
  		    	ifp->if_xname);
  		    break;
  		}
  		value = 1 + (u_char *)(h + 1);
  		value_len = value[-1];
  		name = value + value_len;
  		name_len = len - value_len - 5;
  		if (name_len < 0) {
  			if (debug) {
  				log(LOG_DEBUG,
  				    "%s: chap corrupted response "
  				    "<%s id=0x%x len=%d",
  				    ifp->if_xname,
  				    sppp_auth_type_name(PPP_CHAP, h->type),
  				    h->ident, ntohs(h->len));
  				if (len > 4)
  					sppp_print_bytes((u_char *)(h + 1),
  					    len - 4);
  				addlog(">\n");
  			}
  			break;
  		}
  		if (h->ident != sp->confid[IDX_CHAP]) {
  			if (debug)
  				log(LOG_DEBUG,
  				    "%s: chap dropping response for old ID "
  				    "(got %d, expected %d)\n",
  				    ifp->if_xname,
  				    h->ident, sp->confid[IDX_CHAP]);
  			break;
  		}
  		if (sp->hisauth.name != NULL &&
  		    (name_len != sp->hisauth.name_len
  		    || memcmp(name, sp->hisauth.name, name_len) != 0)) {
  			log(LOG_INFO, "%s: chap response, his name ",
  			    ifp->if_xname);
  			sppp_print_string(name, name_len);
  			addlog(" != expected ");
  			sppp_print_string(sp->hisauth.name,
  					  sp->hisauth.name_len);
  			addlog("\n");
  		    goto chap_failure;
  		}
  		if (debug) {
  			log(LOG_DEBUG, "%s: chap input(%s) "
  			    "<%s id=0x%x len=%d name=",
  			    ifp->if_xname,
  			    sppp_state_name(sp->state[IDX_CHAP]),
  			    sppp_auth_type_name(PPP_CHAP, h->type),
  			    h->ident, ntohs(h->len));
  			sppp_print_string((char *)name, name_len);
  			addlog(" value-size=%d value=", value_len);
  			sppp_print_bytes(value, value_len);
  			addlog(">\n");
  		}
  		if (value_len != sizeof(sp->myauth.challenge)) {
  			if (debug)
  				log(LOG_DEBUG,
  				    "%s: chap bad hash value length: "
  				    "%d bytes, should be %ld\n",
  				    ifp->if_xname, value_len,
  				    (long) sizeof(sp->myauth.challenge));
  			goto chap_failure;
  		}
  
  		MD5Init(&ctx);
  		MD5Update(&ctx, &h->ident, 1);
  		MD5Update(&ctx, sp->hisauth.secret, sp->hisauth.secret_len);
  		MD5Update(&ctx, sp->myauth.challenge, sizeof(sp->myauth.challenge));
  		MD5Final(digest, &ctx);
  
  #define FAILMSG "Failed..."
  #define SUCCMSG "Welcome!"
  
  		if (value_len != sizeof digest ||
  		    memcmp(digest, value, value_len) != 0) {
  chap_failure:
  			/* action scn, tld */
  			x = splnet();
  			sp->pp_auth_failures++;
  			splx(x);
  			sppp_auth_send(&chap, sp, CHAP_FAILURE, h->ident,
  				       sizeof(FAILMSG) - 1, (const u_char *)FAILMSG,
  				       0);
  			chap.tld(sp);
  			break;
  		}
  		sp->pp_auth_failures = 0;
  		/* action sca, perhaps tlu */
  		if (sp->state[IDX_CHAP] == STATE_REQ_SENT ||
  		    sp->state[IDX_CHAP] == STATE_OPENED)
  			sppp_auth_send(&chap, sp, CHAP_SUCCESS, h->ident,
  				       sizeof(SUCCMSG) - 1, (const u_char *)SUCCMSG,
  				       0);
  		if (sp->state[IDX_CHAP] == STATE_REQ_SENT) {
  			sppp_cp_change_state(&chap, sp, STATE_OPENED);
  			chap.tlu(sp);
  		}
  		break;
  
  	default:
  		/* Unknown CHAP packet type -- ignore. */
  		if (debug) {
  			log(LOG_DEBUG, "%s: chap unknown input(%s) "
  			    "<0x%x id=0x%xh len=%d",
  			    ifp->if_xname,
  			    sppp_state_name(sp->state[IDX_CHAP]),
  			    h->type, h->ident, ntohs(h->len));
  			if (len > 4)
  				sppp_print_bytes((u_char *)(h + 1), len - 4);
  			addlog(">\n");
  		}
  		break;
  
  	}
  }
  
  static void
  sppp_chap_init(struct sppp *sp)
  {
  	/* Chap doesn't have STATE_INITIAL at all. */
  	sp->state[IDX_CHAP] = STATE_CLOSED;
  	sp->fail_counter[IDX_CHAP] = 0;
  	sp->pp_seq[IDX_CHAP] = 0;
  	sp->pp_rseq[IDX_CHAP] = 0;
  	callout_init(&sp->ch[IDX_CHAP], 0);
  }
  
  static void
  sppp_chap_open(struct sppp *sp)
  {
  	if (sp->myauth.proto == PPP_CHAP &&
  	    (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) != 0) {
  		/* we are authenticator for CHAP, start it */
  		chap.scr(sp);
  		sp->rst_counter[IDX_CHAP] = sp->lcp.max_configure;
  		sppp_cp_change_state(&chap, sp, STATE_REQ_SENT);
  	}
  	/* nothing to be done if we are peer, await a challenge */
  }
  
  static void
  sppp_chap_close(struct sppp *sp)
  {
  	if (sp->state[IDX_CHAP] != STATE_CLOSED)
  		sppp_cp_change_state(&chap, sp, STATE_CLOSED);
  }
  
  static void
  sppp_chap_TO(void *cookie)
  {
  	struct sppp *sp = (struct sppp *)cookie;
  	STDDCL;
  	int s;
  
  	s = splnet();
  	if (debug)
  		log(LOG_DEBUG, "%s: chap TO(%s) rst_counter = %d\n",
  		    ifp->if_xname,
  		    sppp_state_name(sp->state[IDX_CHAP]),
  		    sp->rst_counter[IDX_CHAP]);
  
  	if (--sp->rst_counter[IDX_CHAP] < 0)
  		/* TO- event */
  		switch (sp->state[IDX_CHAP]) {
  		case STATE_REQ_SENT:
  			chap.tld(sp);
  			sppp_cp_change_state(&chap, sp, STATE_CLOSED);
  			break;
  		}
  	else
  		/* TO+ (or TO*) event */
  		switch (sp->state[IDX_CHAP]) {
  		case STATE_OPENED:
  			/* TO* event */
  			sp->rst_counter[IDX_CHAP] = sp->lcp.max_configure;
  			/* fall through */
  		case STATE_REQ_SENT:
  			chap.scr(sp);
  			/* sppp_cp_change_state() will restart the timer */
  			sppp_cp_change_state(&chap, sp, STATE_REQ_SENT);
  			break;
  		}
  
  	splx(s);
  }
  
  static void
  sppp_chap_tlu(struct sppp *sp)
  {
  	STDDCL;
  	int i, x;
  
  	i = 0;
  	sp->rst_counter[IDX_CHAP] = sp->lcp.max_configure;
  
  	/*
  	 * Some broken CHAP implementations (Conware CoNet, firmware
  	 * 4.0.?) don't want to re-authenticate their CHAP once the
  	 * initial challenge-response exchange has taken place.
  	 * Provide for an option to avoid rechallenges.
  	 */
  	if ((sp->hisauth.flags & SPPP_AUTHFLAG_NORECHALLENGE) == 0) {
  		/*
  		 * Compute the re-challenge timeout.  This will yield
  		 * a number between 300 and 810 seconds.
  		 */
  		i = 300 + ((unsigned)(cprng_fast32() & 0xff00) >> 7);
  
  		callout_reset(&sp->ch[IDX_CHAP], i * hz, chap.TO, sp);
  	}
  
  	if (debug) {
  		log(LOG_DEBUG,
  		    "%s: chap %s, ",
  		    ifp->if_xname,
  		    sp->pp_phase == SPPP_PHASE_NETWORK? "reconfirmed": "tlu");
  		if ((sp->hisauth.flags & SPPP_AUTHFLAG_NORECHALLENGE) == 0)
  			addlog("next re-challenge in %d seconds\n", i);
  		else
  			addlog("re-challenging supressed\n");
  	}
  
  	x = splnet();
  	sp->pp_auth_failures = 0;
  	/* indicate to LCP that we need to be closed down */
  	sp->lcp.protos |= (1 << IDX_CHAP);
  
  	if (sp->pp_flags & PP_NEEDAUTH) {
  		/*
  		 * Remote is authenticator, but his auth proto didn't
  		 * complete yet.  Defer the transition to network
  		 * phase.
  		 */
  		splx(x);
  		return;
  	}
  	splx(x);
  
  	/*
  	 * If we are already in phase network, we are done here.  This
  	 * is the case if this is a dummy tlu event after a re-challenge.
  	 */
  	if (sp->pp_phase != SPPP_PHASE_NETWORK)
  		sppp_phase_network(sp);
  }
  
  static void
  sppp_chap_tld(struct sppp *sp)
  {
  	STDDCL;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: chap tld\n", ifp->if_xname);
  	callout_stop(&sp->ch[IDX_CHAP]);
  	sp->lcp.protos &= ~(1 << IDX_CHAP);
  
  	lcp.Close(sp);
  }
  
  static void
  sppp_chap_scr(struct sppp *sp)
  {
  	uint32_t *ch;
  	u_char clen = 4 * sizeof(uint32_t);
  
  	if (sp->myauth.name == NULL) {
  	    /* can't do anything useful */
  	    printf("%s: chap starting without my name being set\n",
  	    	sp->pp_if.if_xname);
  	    return;
  	}
  
  	/* Compute random challenge. */
  	ch = (uint32_t *)sp->myauth.challenge;
  	cprng_strong(kern_cprng, ch, clen, 0);
  
  	sp->confid[IDX_CHAP] = ++sp->pp_seq[IDX_CHAP];
  
  	sppp_auth_send(&chap, sp, CHAP_CHALLENGE, sp->confid[IDX_CHAP],
  		       sizeof clen, (const char *)&clen,
  		       sizeof(sp->myauth.challenge), sp->myauth.challenge,
  		       sp->myauth.name_len,
  		       sp->myauth.name,
  		       0);
  }
  
  /*
   *--------------------------------------------------------------------------*
   *                                                                          *
   *                        The PAP implementation.                           *
   *                                                                          *
   *--------------------------------------------------------------------------*
   */
  /*
   * For PAP, we need to keep a little state also if we are the peer, not the
   * authenticator.  This is since we don't get a request to authenticate, but
   * have to repeatedly authenticate ourself until we got a response (or the
   * retry counter is expired).
   */
  
  /*
   * Handle incoming PAP packets.  */
  static void
  sppp_pap_input(struct sppp *sp, struct mbuf *m)
  {
  	STDDCL;
  	struct lcp_header *h;
  	int len, x;
  	u_char mlen;
  	char *name, *secret;
  	int name_len, secret_len;
  
  	/*
  	 * Malicious input might leave this uninitialized, so
  	 * init to an impossible value.
  	 */
  	secret_len = -1;
  
  	len = m->m_pkthdr.len;
  	if (len < 5) {
  		if (debug)
  			log(LOG_DEBUG,
  			    "%s: pap invalid packet length: %d bytes\n",
  			    ifp->if_xname, len);
  		return;
  	}
  	h = mtod(m, struct lcp_header *);
  	if (len > ntohs(h->len))
  		len = ntohs(h->len);
  	switch (h->type) {
  	/* PAP request is my authproto */
  	case PAP_REQ:
  		if (sp->hisauth.name == NULL || sp->hisauth.secret == NULL) {
  		    /* can't do anything useful */
  		    printf("%s: pap request without his name and his secret being set\n",
  		    	ifp->if_xname);
  		    break;
  		}
  		name = 1 + (u_char *)(h + 1);
  		name_len = name[-1];
  		secret = name + name_len + 1;
  		if (name_len > len - 6 ||
  		    (secret_len = secret[-1]) > len - 6 - name_len) {
  			if (debug) {
  				log(LOG_DEBUG, "%s: pap corrupted input "
  				    "<%s id=0x%x len=%d",
  				    ifp->if_xname,
  				    sppp_auth_type_name(PPP_PAP, h->type),
  				    h->ident, ntohs(h->len));
  				if (len > 4)
  					sppp_print_bytes((u_char *)(h + 1),
  					    len - 4);
  				addlog(">\n");
  			}
  			break;
  		}
  		if (debug) {
  			log(LOG_DEBUG, "%s: pap input(%s) "
  			    "<%s id=0x%x len=%d name=",
  			    ifp->if_xname,
  			    sppp_state_name(sp->state[IDX_PAP]),
  			    sppp_auth_type_name(PPP_PAP, h->type),
  			    h->ident, ntohs(h->len));
  			sppp_print_string((char *)name, name_len);
  			addlog(" secret=");
  			sppp_print_string((char *)secret, secret_len);
  			addlog(">\n");
  		}
  		if (name_len != sp->hisauth.name_len ||
  		    secret_len != sp->hisauth.secret_len ||
  		    memcmp(name, sp->hisauth.name, name_len) != 0 ||
  		    memcmp(secret, sp->hisauth.secret, secret_len) != 0) {
  			/* action scn, tld */
  			sp->pp_auth_failures++;
  			mlen = sizeof(FAILMSG) - 1;
  			sppp_auth_send(&pap, sp, PAP_NAK, h->ident,
  				       sizeof mlen, (const char *)&mlen,
  				       sizeof(FAILMSG) - 1, (const u_char *)FAILMSG,
  				       0);
  			pap.tld(sp);
  			break;
  		}
  		/* action sca, perhaps tlu */
  		if (sp->state[IDX_PAP] == STATE_REQ_SENT ||
  		    sp->state[IDX_PAP] == STATE_OPENED) {
  			mlen = sizeof(SUCCMSG) - 1;
  			sppp_auth_send(&pap, sp, PAP_ACK, h->ident,
  				       sizeof mlen, (const char *)&mlen,
  				       sizeof(SUCCMSG) - 1, (const u_char *)SUCCMSG,
  				       0);
  		}
  		if (sp->state[IDX_PAP] == STATE_REQ_SENT) {
  			sppp_cp_change_state(&pap, sp, STATE_OPENED);
  			pap.tlu(sp);
  		}
  		break;
  
  	/* ack and nak are his authproto */
  	case PAP_ACK:
  		callout_stop(&sp->pap_my_to_ch);
  		if (debug) {
  			log(LOG_DEBUG, "%s: pap success",
  			    ifp->if_xname);
  			name = 1 + (u_char *)(h + 1);
  			name_len = name[-1];
  			if (len > 5 && name_len < len+4) {
  				addlog(": ");
  				sppp_print_string(name, name_len);
  			}
  			addlog("\n");
  		}
  		x = splnet();
  		sp->pp_auth_failures = 0;
  		sp->pp_flags &= ~PP_NEEDAUTH;
  		if (sp->myauth.proto == PPP_PAP &&
  		    (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) &&
  		    (sp->lcp.protos & (1 << IDX_PAP)) == 0) {
  			/*
  			 * We are authenticator for PAP but didn't
  			 * complete yet.  Leave it to tlu to proceed
  			 * to network phase.
  			 */
  			splx(x);
  			break;
  		}
  		splx(x);
  		sppp_phase_network(sp);
  		break;
  
  	case PAP_NAK:
  		callout_stop(&sp->pap_my_to_ch);
  		sp->pp_auth_failures++;
  		if (debug) {
  			log(LOG_INFO, "%s: pap failure",
  			    ifp->if_xname);
  			name = 1 + (u_char *)(h + 1);
  			name_len = name[-1];
  			if (len > 5 && name_len < len+4) {
  				addlog(": ");
  				sppp_print_string(name, name_len);
  			}
  			addlog("\n");
  		} else
  			log(LOG_INFO, "%s: pap failure\n",
  			    ifp->if_xname);
  		/* await LCP shutdown by authenticator */
  		break;
  
  	default:
  		/* Unknown PAP packet type -- ignore. */
  		if (debug) {
  			log(LOG_DEBUG, "%s: pap corrupted input "
  			    "<0x%x id=0x%x len=%d",
  			    ifp->if_xname,
  			    h->type, h->ident, ntohs(h->len));
  			if (len > 4)
  				sppp_print_bytes((u_char *)(h + 1), len - 4);
  			addlog(">\n");
  		}
  		break;
  
  	}
  }
  
  static void
  sppp_pap_init(struct sppp *sp)
  {
  	/* PAP doesn't have STATE_INITIAL at all. */
  	sp->state[IDX_PAP] = STATE_CLOSED;
  	sp->fail_counter[IDX_PAP] = 0;
  	sp->pp_seq[IDX_PAP] = 0;
  	sp->pp_rseq[IDX_PAP] = 0;
  	callout_init(&sp->ch[IDX_PAP], 0);
  	callout_init(&sp->pap_my_to_ch, 0);
  }
  
  static void
  sppp_pap_open(struct sppp *sp)
  {
  	if (sp->hisauth.proto == PPP_PAP &&
  	    (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) != 0) {
  		/* we are authenticator for PAP, start our timer */
  		sp->rst_counter[IDX_PAP] = sp->lcp.max_configure;
  		sppp_cp_change_state(&pap, sp, STATE_REQ_SENT);
  	}
  	if (sp->myauth.proto == PPP_PAP) {
  		/* we are peer, send a request, and start a timer */
  		pap.scr(sp);
  		callout_reset(&sp->pap_my_to_ch, sp->lcp.timeout,
  		    sppp_pap_my_TO, sp);
  	}
  }
  
  static void
  sppp_pap_close(struct sppp *sp)
  {
  	if (sp->state[IDX_PAP] != STATE_CLOSED)
  		sppp_cp_change_state(&pap, sp, STATE_CLOSED);
  }
  
  /*
   * That's the timeout routine if we are authenticator.  Since the
   * authenticator is basically passive in PAP, we can't do much here.
   */
  static void
  sppp_pap_TO(void *cookie)
  {
  	struct sppp *sp = (struct sppp *)cookie;
  	STDDCL;
  	int s;
  
  	s = splnet();
  	if (debug)
  		log(LOG_DEBUG, "%s: pap TO(%s) rst_counter = %d\n",
  		    ifp->if_xname,
  		    sppp_state_name(sp->state[IDX_PAP]),
  		    sp->rst_counter[IDX_PAP]);
  
  	if (--sp->rst_counter[IDX_PAP] < 0)
  		/* TO- event */
  		switch (sp->state[IDX_PAP]) {
  		case STATE_REQ_SENT:
  			pap.tld(sp);
  			sppp_cp_change_state(&pap, sp, STATE_CLOSED);
  			break;
  		}
  	else
  		/* TO+ event, not very much we could do */
  		switch (sp->state[IDX_PAP]) {
  		case STATE_REQ_SENT:
  			/* sppp_cp_change_state() will restart the timer */
  			sppp_cp_change_state(&pap, sp, STATE_REQ_SENT);
  			break;
  		}
  
  	splx(s);
  }
  
  /*
   * That's the timeout handler if we are peer.  Since the peer is active,
   * we need to retransmit our PAP request since it is apparently lost.
   * XXX We should impose a max counter.
   */
  static void
  sppp_pap_my_TO(void *cookie)
  {
  	struct sppp *sp = (struct sppp *)cookie;
  	STDDCL;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: pap peer TO\n",
  		    ifp->if_xname);
  
  	pap.scr(sp);
  }
  
  static void
  sppp_pap_tlu(struct sppp *sp)
  {
  	STDDCL;
  	int x;
  
  	sp->rst_counter[IDX_PAP] = sp->lcp.max_configure;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: %s tlu\n",
  		    ifp->if_xname, pap.name);
  
  	x = splnet();
  	sp->pp_auth_failures = 0;
  	/* indicate to LCP that we need to be closed down */
  	sp->lcp.protos |= (1 << IDX_PAP);
  
  	if (sp->pp_flags & PP_NEEDAUTH) {
  		/*
  		 * Remote is authenticator, but his auth proto didn't
  		 * complete yet.  Defer the transition to network
  		 * phase.
  		 */
  		splx(x);
  		return;
  	}
  	splx(x);
  	sppp_phase_network(sp);
  }
  
  static void
  sppp_pap_tld(struct sppp *sp)
  {
  	STDDCL;
  
  	if (debug)
  		log(LOG_DEBUG, "%s: pap tld\n", ifp->if_xname);
  	callout_stop(&sp->ch[IDX_PAP]);
  	callout_stop(&sp->pap_my_to_ch);
  	sp->lcp.protos &= ~(1 << IDX_PAP);
  
  	lcp.Close(sp);
  }
  
  static void
  sppp_pap_scr(struct sppp *sp)
  {
  	u_char idlen, pwdlen;
  
  	if (sp->myauth.secret == NULL || sp->myauth.name == NULL) {
  	    /* can't do anything useful */
  	    printf("%s: pap starting without my name and secret being set\n",
  	    	sp->pp_if.if_xname);
  	    return;
  	}
  
  	sp->confid[IDX_PAP] = ++sp->pp_seq[IDX_PAP];
  	pwdlen = sp->myauth.secret_len;
  	idlen = sp->myauth.name_len;
  
  	sppp_auth_send(&pap, sp, PAP_REQ, sp->confid[IDX_PAP],
  		       sizeof idlen, (const char *)&idlen,
  		       idlen, sp->myauth.name,
  		       sizeof pwdlen, (const char *)&pwdlen,
  		       pwdlen, sp->myauth.secret,
  		       0);
  }
  
  /*
   * Random miscellaneous functions.
   */
  
  /*
   * Send a PAP or CHAP proto packet.
   *
   * Varadic function, each of the elements for the ellipsis is of type
   * ``size_t mlen, const u_char *msg''.  Processing will stop iff
   * mlen == 0.
   * NOTE: never declare variadic functions with types subject to type
   * promotion (i.e. u_char). This is asking for big trouble depending
   * on the architecture you are on...
   */
  
  static void
  sppp_auth_send(const struct cp *cp, struct sppp *sp,
                 unsigned int type, unsigned int id,
  	       ...)
  {
  	STDDCL;
  	struct lcp_header *lh;
  	struct mbuf *m;
  	u_char *p;
  	int len;
  	size_t pkthdrlen;
  	unsigned int mlen;
  	const char *msg;
  	va_list ap;
  
  	MGETHDR(m, M_DONTWAIT, MT_DATA);
  	if (! m)
  		return;
  	m->m_pkthdr.rcvif = 0;
  
  	if (sp->pp_flags & PP_NOFRAMING) {
  		*mtod(m, uint16_t *) = htons(cp->proto);
  		pkthdrlen = 2;
  		lh = (struct lcp_header *)(mtod(m, uint8_t *)+2);
  	} else {
  		struct ppp_header *h;
  		h = mtod(m, struct ppp_header *);
  		h->address = PPP_ALLSTATIONS;		/* broadcast address */
  		h->control = PPP_UI;			/* Unnumbered Info */
  		h->protocol = htons(cp->proto);
  		pkthdrlen = PPP_HEADER_LEN;
  
  		lh = (struct lcp_header *)(h + 1);
  	}
  
  	lh->type = type;
  	lh->ident = id;
  	p = (u_char *)(lh + 1);
  
  	va_start(ap, id);
  	len = 0;
  
  	while ((mlen = (unsigned int)va_arg(ap, size_t)) != 0) {
  		msg = va_arg(ap, const char *);
  		len += mlen;
  		if (len > MHLEN - pkthdrlen - LCP_HEADER_LEN) {
  			va_end(ap);
  			m_freem(m);
  			return;
  		}
  
  		memcpy(p, msg, mlen);
  		p += mlen;
  	}
  	va_end(ap);
  
  	m->m_pkthdr.len = m->m_len = pkthdrlen + LCP_HEADER_LEN + len;
  	lh->len = htons(LCP_HEADER_LEN + len);
  
  	if (debug) {
  		log(LOG_DEBUG, "%s: %s output <%s id=0x%x len=%d",
  		    ifp->if_xname, cp->name,
  		    sppp_auth_type_name(cp->proto, lh->type),
  		    lh->ident, ntohs(lh->len));
  		if (len)
  			sppp_print_bytes((u_char *)(lh + 1), len);
  		addlog(">\n");
  	}
  	if (IF_QFULL(&sp->pp_cpq)) {
  		IF_DROP(&sp->pp_fastq);
  		IF_DROP(&ifp->if_snd);
  		m_freem(m);
  		++ifp->if_oerrors;
  		return;
  	} else
  		IF_ENQUEUE(&sp->pp_cpq, m);
  	if (! (ifp->if_flags & IFF_OACTIVE))
  		(*ifp->if_start)(ifp);
  	ifp->if_obytes += m->m_pkthdr.len + 3;
  }
  
  /*
   * Send keepalive packets, every 10 seconds.
   */
  static void
  sppp_keepalive(void *dummy)
  {
  	struct sppp *sp;
  	int s;
  	time_t now;
  
  	s = splnet();
  	now = time_uptime;
  	for (sp=spppq; sp; sp=sp->pp_next) {
  		struct ifnet *ifp = &sp->pp_if;
  
  		/* check idle timeout */
  		if ((sp->pp_idle_timeout != 0) && (ifp->if_flags & IFF_RUNNING)
  		    && (sp->pp_phase == SPPP_PHASE_NETWORK)) {
  		    /* idle timeout is enabled for this interface */
  		    if ((now-sp->pp_last_activity) >= sp->pp_idle_timeout) {
  		    	if (ifp->if_flags & IFF_DEBUG)
  			    printf("%s: no activity for %lu seconds\n",
  				sp->pp_if.if_xname,
  				(unsigned long)(now-sp->pp_last_activity));
  			lcp.Close(sp);
  			continue;
  		    }
  		}
  
  		/* Keepalive mode disabled or channel down? */
  		if (! (sp->pp_flags & PP_KEEPALIVE) ||
  		    ! (ifp->if_flags & IFF_RUNNING))
  			continue;
  
  		/* No keepalive in PPP mode if LCP not opened yet. */
  		if (! (sp->pp_flags & PP_CISCO) &&
  		    sp->pp_phase < SPPP_PHASE_AUTHENTICATE)
  			continue;
  
  		/* No echo reply, but maybe user data passed through? */
  		if ((now - sp->pp_last_receive) < sp->pp_max_noreceive) {
  			sp->pp_alivecnt = 0;
  			continue;
  		}
  
  		if (sp->pp_alivecnt >= sp->pp_maxalive) {
  			/* No keepalive packets got.  Stop the interface. */
  			if_down (ifp);
  			IF_PURGE(&sp->pp_cpq);
  			if (! (sp->pp_flags & PP_CISCO)) {
  				printf("%s: LCP keepalive timed out, going to restart the connection\n",
  					ifp->if_xname);
  				sp->pp_alivecnt = 0;
  
  				/* we are down, close all open protocols */
  				lcp.Close(sp);
  
  				/* And now prepare LCP to reestablish the link, if configured to do so. */
  				sppp_cp_change_state(&lcp, sp, STATE_STOPPED);
  
  				/* Close connection immediately, completition of this
  				 * will summon the magic needed to reestablish it. */
  				if (sp->pp_tlf)
  					sp->pp_tlf(sp);
  				continue;
  			}
  		}
  		if (sp->pp_alivecnt < sp->pp_maxalive)
  			++sp->pp_alivecnt;
  		if (sp->pp_flags & PP_CISCO)
  			sppp_cisco_send(sp, CISCO_KEEPALIVE_REQ,
  			    ++sp->pp_seq[IDX_LCP], sp->pp_rseq[IDX_LCP]);
  		else if (sp->pp_phase >= SPPP_PHASE_AUTHENTICATE) {
  			int32_t nmagic = htonl(sp->lcp.magic);
  			sp->lcp.echoid = ++sp->pp_seq[IDX_LCP];
  			sppp_cp_send(sp, PPP_LCP, ECHO_REQ,
  				sp->lcp.echoid, 4, &nmagic);
  		}
  	}
  	splx(s);
  	callout_reset(&keepalive_ch, hz * LCP_KEEPALIVE_INTERVAL, sppp_keepalive, NULL);
  }
  
  #ifdef INET
  /*
   * Get both IP addresses.
   */
  static void
  sppp_get_ip_addrs(struct sppp *sp, uint32_t *src, uint32_t *dst, uint32_t *srcmask)
  {
  	struct ifnet *ifp = &sp->pp_if;
  	struct ifaddr *ifa;
  	struct sockaddr_in *si, *sm;
  	uint32_t ssrc, ddst;
  
  	sm = NULL;
  	ssrc = ddst = 0;
  	/*
  	 * Pick the first AF_INET address from the list,
  	 * aliases don't make any sense on a p2p link anyway.
  	 */
  	si = 0;
  	IFADDR_FOREACH(ifa, ifp) {
  		if (ifa->ifa_addr->sa_family == AF_INET) {
  			si = (struct sockaddr_in *)ifa->ifa_addr;
  			sm = (struct sockaddr_in *)ifa->ifa_netmask;
  			if (si)
  				break;
  		}
  	}
  	if (ifa) {
  		if (si && si->sin_addr.s_addr) {
  			ssrc = si->sin_addr.s_addr;
  			if (srcmask)
  				*srcmask = ntohl(sm->sin_addr.s_addr);
  		}
  
  		si = (struct sockaddr_in *)ifa->ifa_dstaddr;
  		if (si && si->sin_addr.s_addr)
  			ddst = si->sin_addr.s_addr;
  	}
  
  	if (dst) *dst = ntohl(ddst);
  	if (src) *src = ntohl(ssrc);
  }
  
  /*
   * Set IP addresses.  Must be called at splnet.
   * If an address is 0, leave it the way it is.
   */
  static void
  sppp_set_ip_addrs(struct sppp *sp, uint32_t myaddr, uint32_t hisaddr)
  {
  	STDDCL;
  	struct ifaddr *ifa;
  	struct sockaddr_in *si, *dest;
  
  	/*
  	 * Pick the first AF_INET address from the list,
  	 * aliases don't make any sense on a p2p link anyway.
  	 */
  
  	IFADDR_FOREACH(ifa, ifp) {
  		if (ifa->ifa_addr->sa_family == AF_INET) {
  			si = (struct sockaddr_in *)ifa->ifa_addr;
  			dest = (struct sockaddr_in *)ifa->ifa_dstaddr;
  			goto found;
  		}
  	}
  	return;
  
  found:
  	{
  		int error;
  		struct sockaddr_in new_sin = *si;
  		struct sockaddr_in new_dst = *dest;
  
  		/*
  		 * Scrub old routes now instead of calling in_ifinit with
  		 * scrub=1, because we may change the dstaddr
  		 * before the call to in_ifinit.
  		 */
  		in_ifscrub(ifp, ifatoia(ifa));
  
  		if (myaddr != 0)
  			new_sin.sin_addr.s_addr = htonl(myaddr);
  		if (hisaddr != 0) {
  			new_dst.sin_addr.s_addr = htonl(hisaddr);
  			if (new_dst.sin_addr.s_addr != dest->sin_addr.s_addr) {
  				sp->ipcp.saved_hisaddr = dest->sin_addr.s_addr;
  				*dest = new_dst; /* fix dstaddr in place */
  			}
  		}
  		error = in_ifinit(ifp, ifatoia(ifa), &new_sin, 0);
  		if (debug && error)
  		{
  			log(LOG_DEBUG, "%s: sppp_set_ip_addrs: in_ifinit "
  			" failed, error=%d\n", ifp->if_xname, error);
  		}
  #ifdef PFIL_HOOKS
  		if (!error)
  			(void)pfil_run_hooks(&if_pfil,
  			    (struct mbuf **)SIOCAIFADDR, ifp, PFIL_IFADDR);
  #endif
  	}
  }
  
  /*
   * Clear IP addresses.  Must be called at splnet.
   */
  static void
  sppp_clear_ip_addrs(struct sppp *sp)
  {
  	struct ifnet *ifp = &sp->pp_if;
  	struct ifaddr *ifa;
  	struct sockaddr_in *si, *dest;
  
  	uint32_t remote;
  	if (sp->ipcp.flags & IPCP_HISADDR_DYN)
  		remote = sp->ipcp.saved_hisaddr;
  	else
  		sppp_get_ip_addrs(sp, 0, &remote, 0);
  
  	/*
  	 * Pick the first AF_INET address from the list,
  	 * aliases don't make any sense on a p2p link anyway.
  	 */
  
  	IFADDR_FOREACH(ifa, ifp) {
  		if (ifa->ifa_addr->sa_family == AF_INET) {
  			si = (struct sockaddr_in *)ifa->ifa_addr;
  			dest = (struct sockaddr_in *)ifa->ifa_dstaddr;
  			goto found;
  		}
  	}
  	return;
  
  found:
  	{
  		struct sockaddr_in new_sin = *si;
  
  		in_ifscrub(ifp, ifatoia(ifa));
  		if (sp->ipcp.flags & IPCP_MYADDR_DYN)
  			new_sin.sin_addr.s_addr = 0;
  		if (sp->ipcp.flags & IPCP_HISADDR_DYN)
  			/* replace peer addr in place */
  			dest->sin_addr.s_addr = sp->ipcp.saved_hisaddr;
  		in_ifinit(ifp, ifatoia(ifa), &new_sin, 0);
  #ifdef PFIL_HOOKS
  		(void)pfil_run_hooks(&if_pfil,
  		    (struct mbuf **)SIOCDIFADDR, ifp, PFIL_IFADDR);
  #endif
  	}
  }
  #endif
  
  #ifdef INET6
  /*
   * Get both IPv6 addresses.
   */
  static void
  sppp_get_ip6_addrs(struct sppp *sp, struct in6_addr *src, struct in6_addr *dst,
  		   struct in6_addr *srcmask)
  {
  	struct ifnet *ifp = &sp->pp_if;
  	struct ifaddr *ifa;
  	struct sockaddr_in6 *si, *sm;
  	struct in6_addr ssrc, ddst;
  
  	sm = NULL;
  	memset(&ssrc, 0, sizeof(ssrc));
  	memset(&ddst, 0, sizeof(ddst));
  	/*
  	 * Pick the first link-local AF_INET6 address from the list,
  	 * aliases don't make any sense on a p2p link anyway.
  	 */
  	si = 0;
  	IFADDR_FOREACH(ifa, ifp)
  		if (ifa->ifa_addr->sa_family == AF_INET6) {
  			si = (struct sockaddr_in6 *)ifa->ifa_addr;
  			sm = (struct sockaddr_in6 *)ifa->ifa_netmask;
  			if (si && IN6_IS_ADDR_LINKLOCAL(&si->sin6_addr))
  				break;
  		}
  	if (ifa) {
  		if (si && !IN6_IS_ADDR_UNSPECIFIED(&si->sin6_addr)) {
  			memcpy(&ssrc, &si->sin6_addr, sizeof(ssrc));
  			if (srcmask) {
  				memcpy(srcmask, &sm->sin6_addr,
  				    sizeof(*srcmask));
  			}
  		}
  
  		si = (struct sockaddr_in6 *)ifa->ifa_dstaddr;
  		if (si && !IN6_IS_ADDR_UNSPECIFIED(&si->sin6_addr))
  			memcpy(&ddst, &si->sin6_addr, sizeof(ddst));
  	}
  
  	if (dst)
  		memcpy(dst, &ddst, sizeof(*dst));
  	if (src)
  		memcpy(src, &ssrc, sizeof(*src));
  }
  
  #ifdef IPV6CP_MYIFID_DYN
  /*
   * Generate random ifid.
   */
  static void
  sppp_gen_ip6_addr(struct sppp *sp, struct in6_addr *addr)
  {
  	/* TBD */
  }
  
  /*
   * Set my IPv6 address.  Must be called at splnet.
   */
  static void
  sppp_set_ip6_addr(struct sppp *sp, const struct in6_addr *src)
  {
  	STDDCL;
  	struct ifaddr *ifa;
  	struct sockaddr_in6 *sin6;
  
  	/*
  	 * Pick the first link-local AF_INET6 address from the list,
  	 * aliases don't make any sense on a p2p link anyway.
  	 */
  
  	sin6 = NULL;
  	IFADDR_FOREACH(ifa, ifp)
  	{
  		if (ifa->ifa_addr->sa_family == AF_INET6)
  		{
  			sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
  			if (sin6 && IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
  				break;
  		}
  	}
  
  	if (ifa && sin6)
  	{
  		int error;
  		struct sockaddr_in6 new_sin6 = *sin6;
  
  		memcpy(&new_sin6.sin6_addr, src, sizeof(new_sin6.sin6_addr));
  		error = in6_ifinit(ifp, ifatoia6(ifa), &new_sin6, 1);
  		if (debug && error)
  		{
  			log(LOG_DEBUG, "%s: sppp_set_ip6_addr: in6_ifinit "
  			" failed, error=%d\n", ifp->if_xname, error);
  		}
  #ifdef PFIL_HOOKS
  		if (!error)
  			(void)pfil_run_hooks(&if_pfil,
  			    (struct mbuf **)SIOCAIFADDR_IN6, ifp, PFIL_IFADDR);
  #endif
  	}
  }
  #endif
  
  /*
   * Suggest a candidate address to be used by peer.
   */
  static void
  sppp_suggest_ip6_addr(struct sppp *sp, struct in6_addr *suggest)
  {
  	struct in6_addr myaddr;
  	struct timeval tv;
  
  	sppp_get_ip6_addrs(sp, &myaddr, 0, 0);
  
  	myaddr.s6_addr[8] &= ~0x02;	/* u bit to "local" */
  	microtime(&tv);
  	if ((tv.tv_usec & 0xff) == 0 && (tv.tv_sec & 0xff) == 0) {
  		myaddr.s6_addr[14] ^= 0xff;
  		myaddr.s6_addr[15] ^= 0xff;
  	} else {
  		myaddr.s6_addr[14] ^= (tv.tv_usec & 0xff);
  		myaddr.s6_addr[15] ^= (tv.tv_sec & 0xff);
  	}
  	if (suggest)
  		memcpy(suggest, &myaddr, sizeof(myaddr));
  }
  #endif /*INET6*/
  
  /*
   * Process ioctl requests specific to the PPP interface.
   * Permissions have already been checked.
   */
  static int
  sppp_params(struct sppp *sp, u_long cmd, void *data)
  {
  	switch (cmd) {
  	case SPPPGETAUTHCFG:
  	    {
  		struct spppauthcfg *cfg = (struct spppauthcfg *)data;
  		int error;
  		size_t len;
  
  		cfg->myauthflags = sp->myauth.flags;
  		cfg->hisauthflags = sp->hisauth.flags;
  		strncpy(cfg->ifname, sp->pp_if.if_xname, IFNAMSIZ);
  		cfg->hisauth = 0;
  		if (sp->hisauth.proto)
  		    cfg->hisauth = (sp->hisauth.proto == PPP_PAP) ? SPPP_AUTHPROTO_PAP : SPPP_AUTHPROTO_CHAP;
  		cfg->myauth = 0;
  		if (sp->myauth.proto)
  		    cfg->myauth = (sp->myauth.proto == PPP_PAP) ? SPPP_AUTHPROTO_PAP : SPPP_AUTHPROTO_CHAP;
  		if (cfg->myname_length == 0) {
  		    if (sp->myauth.name != NULL)
  			cfg->myname_length = sp->myauth.name_len + 1;
  		} else {
  		    if (sp->myauth.name == NULL) {
  			cfg->myname_length = 0;
  		    } else {
  			len = sp->myauth.name_len + 1;
  			if (cfg->myname_length < len)
  			    return (ENAMETOOLONG);
  			error = copyout(sp->myauth.name, cfg->myname, len);
  			if (error) return error;
  		    }
  		}
  		if (cfg->hisname_length == 0) {
  		    if (sp->hisauth.name != NULL)
  			cfg->hisname_length = sp->hisauth.name_len + 1;
  		} else {
  		    if (sp->hisauth.name == NULL) {
  		    	cfg->hisname_length = 0;
  		    } else {
  			len = sp->hisauth.name_len + 1;
  			if (cfg->hisname_length < len)
  			    return (ENAMETOOLONG);
  			error = copyout(sp->hisauth.name, cfg->hisname, len);
  			if (error) return error;
  		    }
  		}
  	    }
  	    break;
  	case SPPPSETAUTHCFG:
  	    {
  		struct spppauthcfg *cfg = (struct spppauthcfg *)data;
  		int error;
  
  		if (sp->myauth.name) {
  			free(sp->myauth.name, M_DEVBUF);
  			sp->myauth.name = NULL;
  		}
  		if (sp->myauth.secret) {
  			free(sp->myauth.secret, M_DEVBUF);
  			sp->myauth.secret = NULL;
  		}
  		if (sp->hisauth.name) {
  			free(sp->hisauth.name, M_DEVBUF);
  			sp->hisauth.name = NULL;
  		}
  		if (sp->hisauth.secret) {
  			free(sp->hisauth.secret, M_DEVBUF);
  			sp->hisauth.secret = NULL;
  		}
  
  		if (cfg->hisname != NULL && cfg->hisname_length > 0) {
  		    if (cfg->hisname_length >= MCLBYTES)
  			return (ENAMETOOLONG);
  		    sp->hisauth.name = malloc(cfg->hisname_length, M_DEVBUF, M_WAITOK);
  		    error = copyin(cfg->hisname, sp->hisauth.name, cfg->hisname_length);
  		    if (error) {
  			free(sp->hisauth.name, M_DEVBUF);
  			sp->hisauth.name = NULL;
  			return error;
  		    }
  		    sp->hisauth.name_len = cfg->hisname_length - 1;
  		    sp->hisauth.name[sp->hisauth.name_len] = 0;
  		}
  		if (cfg->hissecret != NULL && cfg->hissecret_length > 0) {
  		    if (cfg->hissecret_length >= MCLBYTES)
  			return (ENAMETOOLONG);
  		    sp->hisauth.secret = malloc(cfg->hissecret_length, M_DEVBUF, M_WAITOK);
  		    error = copyin(cfg->hissecret, sp->hisauth.secret, cfg->hissecret_length);
  		    if (error) {
  		    	free(sp->hisauth.secret, M_DEVBUF);
  		    	sp->hisauth.secret = NULL;
  			return error;
  		    }
  		    sp->hisauth.secret_len = cfg->hissecret_length - 1;
  		    sp->hisauth.secret[sp->hisauth.secret_len] = 0;
  		}
  		if (cfg->myname != NULL && cfg->myname_length > 0) {
  		    if (cfg->myname_length >= MCLBYTES)
  			return (ENAMETOOLONG);
  		    sp->myauth.name = malloc(cfg->myname_length, M_DEVBUF, M_WAITOK);
  		    error = copyin(cfg->myname, sp->myauth.name, cfg->myname_length);
  		    if (error) {
  			free(sp->myauth.name, M_DEVBUF);
  			sp->myauth.name = NULL;
  			return error;
  		    }
  		    sp->myauth.name_len = cfg->myname_length - 1;
  		    sp->myauth.name[sp->myauth.name_len] = 0;
  		}
  		if (cfg->mysecret != NULL && cfg->mysecret_length > 0) {
  		    if (cfg->mysecret_length >= MCLBYTES)
  			return (ENAMETOOLONG);
  		    sp->myauth.secret = malloc(cfg->mysecret_length, M_DEVBUF, M_WAITOK);
  		    error = copyin(cfg->mysecret, sp->myauth.secret, cfg->mysecret_length);
  		    if (error) {
  		    	free(sp->myauth.secret, M_DEVBUF);
  		    	sp->myauth.secret = NULL;
  			return error;
  		    }
  		    sp->myauth.secret_len = cfg->mysecret_length - 1;
  		    sp->myauth.secret[sp->myauth.secret_len] = 0;
  		}
  		sp->myauth.flags = cfg->myauthflags;
  		if (cfg->myauth)
  		    sp->myauth.proto = (cfg->myauth == SPPP_AUTHPROTO_PAP) ? PPP_PAP : PPP_CHAP;
  		sp->hisauth.flags = cfg->hisauthflags;
  		if (cfg->hisauth)
  		    sp->hisauth.proto = (cfg->hisauth == SPPP_AUTHPROTO_PAP) ? PPP_PAP : PPP_CHAP;
  		sp->pp_auth_failures = 0;
  		if (sp->hisauth.proto != 0)
  		    sp->lcp.opts |= (1 << LCP_OPT_AUTH_PROTO);
  		else
  		    sp->lcp.opts &= ~(1 << LCP_OPT_AUTH_PROTO);
  	    }
  	    break;
  	case SPPPGETLCPCFG:
  	    {
  	    	struct sppplcpcfg *lcpp = (struct sppplcpcfg *)data;
  	    	lcpp->lcp_timeout = sp->lcp.timeout;
  	    }
  	    break;
  	case SPPPSETLCPCFG:
  	    {
  	    	struct sppplcpcfg *lcpp = (struct sppplcpcfg *)data;
  	    	sp->lcp.timeout = lcpp->lcp_timeout;
  	    }
  	    break;
  	case SPPPGETSTATUS:
  	    {
  		struct spppstatus *status = (struct spppstatus *)data;
  		status->phase = sp->pp_phase;
  	    }
  	    break;
  	case SPPPGETSTATUSNCP:
  	    {
  		struct spppstatusncp *status = (struct spppstatusncp *)data;
  		status->phase = sp->pp_phase;
  		status->ncpup = sppp_ncp_check(sp);
  	    }
  	    break;
  	case SPPPGETIDLETO:
  	    {
  	    	struct spppidletimeout *to = (struct spppidletimeout *)data;
  		to->idle_seconds = sp->pp_idle_timeout;
  	    }
  	    break;
  	case SPPPSETIDLETO:
  	    {
  	    	struct spppidletimeout *to = (struct spppidletimeout *)data;
  	    	sp->pp_idle_timeout = to->idle_seconds;
  	    }
  	    break;
  	case SPPPSETAUTHFAILURE:
  	    {
  	    	struct spppauthfailuresettings *afsettings = (struct spppauthfailuresettings *)data;
  	    	sp->pp_max_auth_fail = afsettings->max_failures;
  	    	sp->pp_auth_failures = 0;
  	    }
  	    break;
  	case SPPPGETAUTHFAILURES:
  	    {
  	    	struct spppauthfailurestats *stats = (struct spppauthfailurestats *)data;
  	    	stats->auth_failures = sp->pp_auth_failures;
  	    	stats->max_failures = sp->pp_max_auth_fail;
  	    }
  	    break;
  	case SPPPSETDNSOPTS:
  	    {
  		struct spppdnssettings *req = (struct spppdnssettings *)data;
  		sp->query_dns = req->query_dns & 3;
  	    }
  	    break;
  	case SPPPGETDNSOPTS:
  	    {
  		struct spppdnssettings *req = (struct spppdnssettings *)data;
  		req->query_dns = sp->query_dns;
  	    }
  	    break;
  	case SPPPGETDNSADDRS:
  	    {
  	    	struct spppdnsaddrs *addrs = (struct spppdnsaddrs *)data;
  	    	memcpy(&addrs->dns, &sp->dns_addrs, sizeof addrs->dns);
  	    }
  	    break;
  	case SPPPGETKEEPALIVE:
  	    {
  	    	struct spppkeepalivesettings *settings =
  		     (struct spppkeepalivesettings*)data;
  		settings->maxalive = sp->pp_maxalive;
  		settings->max_noreceive = sp->pp_max_noreceive;
  	    }
  	    break;
  	case SPPPSETKEEPALIVE:
  	    {
  	    	struct spppkeepalivesettings *settings =
  		     (struct spppkeepalivesettings*)data;
  		sp->pp_maxalive = settings->maxalive;
  		sp->pp_max_noreceive = settings->max_noreceive;
  	    }
  	    break;
  #if defined(COMPAT_50) || defined(MODULAR)
  	case __SPPPGETIDLETO50:
  	    {
  	    	struct spppidletimeout50 *to = (struct spppidletimeout50 *)data;
  		to->idle_seconds = (uint32_t)sp->pp_idle_timeout;
  	    }
  	    break;
  	case __SPPPSETIDLETO50:
  	    {
  	    	struct spppidletimeout50 *to = (struct spppidletimeout50 *)data;
  	    	sp->pp_idle_timeout = (time_t)to->idle_seconds;
  	    }
  	    break;
  	case __SPPPGETKEEPALIVE50:
  	    {
  	    	struct spppkeepalivesettings50 *settings =
  		     (struct spppkeepalivesettings50*)data;
  		settings->maxalive = sp->pp_maxalive;
  		settings->max_noreceive = (uint32_t)sp->pp_max_noreceive;
  	    }
  	    break;
  	case __SPPPSETKEEPALIVE50:
  	    {
  	    	struct spppkeepalivesettings50 *settings =
  		     (struct spppkeepalivesettings50*)data;
  		sp->pp_maxalive = settings->maxalive;
  		sp->pp_max_noreceive = (time_t)settings->max_noreceive;
  	    }
  	    break;
  #endif /* COMPAT_50 || MODULAR */
  	default:
  		return (EINVAL);
  	}
  
  	return (0);
  }
  
  static void
  sppp_phase_network(struct sppp *sp)
  {
  	STDDCL;
  	int i;
  	uint32_t mask;
  
  	sp->pp_phase = SPPP_PHASE_NETWORK;
  
  	if (debug)
  	{
  		log(LOG_INFO, "%s: phase %s\n", ifp->if_xname,
  			sppp_phase_name(sp->pp_phase));
  	}
  
  	/* Notify NCPs now. */
  	for (i = 0; i < IDX_COUNT; i++)
  		if ((cps[i])->flags & CP_NCP)
  			(cps[i])->Open(sp);
  
  	/* Send Up events to all NCPs. */
  	for (i = 0, mask = 1; i < IDX_COUNT; i++, mask <<= 1)
  		if ((sp->lcp.protos & mask) && ((cps[i])->flags & CP_NCP))
  			(cps[i])->Up(sp);
  
  	/* if no NCP is starting, all this was in vain, close down */
  	sppp_lcp_check_and_close(sp);
  }
  
  
  static const char *
  sppp_cp_type_name(u_char type)
  {
  	static char buf[12];
  	switch (type) {
  	case CONF_REQ:   return "conf-req";
  	case CONF_ACK:   return "conf-ack";
  	case CONF_NAK:   return "conf-nak";
  	case CONF_REJ:   return "conf-rej";
  	case TERM_REQ:   return "term-req";
  	case TERM_ACK:   return "term-ack";
  	case CODE_REJ:   return "code-rej";
  	case PROTO_REJ:  return "proto-rej";
  	case ECHO_REQ:   return "echo-req";
  	case ECHO_REPLY: return "echo-reply";
  	case DISC_REQ:   return "discard-req";
  	}
  	snprintf(buf, sizeof(buf), "0x%x", type);
  	return buf;
  }
  
  static const char *
  sppp_auth_type_name(u_short proto, u_char type)
  {
  	static char buf[12];
  	switch (proto) {
  	case PPP_CHAP:
  		switch (type) {
  		case CHAP_CHALLENGE:	return "challenge";
  		case CHAP_RESPONSE:	return "response";
  		case CHAP_SUCCESS:	return "success";
  		case CHAP_FAILURE:	return "failure";
  		}
  	case PPP_PAP:
  		switch (type) {
  		case PAP_REQ:		return "req";
  		case PAP_ACK:		return "ack";
  		case PAP_NAK:		return "nak";
  		}
  	}
  	snprintf(buf, sizeof(buf), "0x%x", type);
  	return buf;
  }
  
  static const char *
  sppp_lcp_opt_name(u_char opt)
  {
  	static char buf[12];
  	switch (opt) {
  	case LCP_OPT_MRU:		return "mru";
  	case LCP_OPT_ASYNC_MAP:		return "async-map";
  	case LCP_OPT_AUTH_PROTO:	return "auth-proto";
  	case LCP_OPT_QUAL_PROTO:	return "qual-proto";
  	case LCP_OPT_MAGIC:		return "magic";
  	case LCP_OPT_PROTO_COMP:	return "proto-comp";
  	case LCP_OPT_ADDR_COMP:		return "addr-comp";
  	}
  	snprintf(buf, sizeof(buf), "0x%x", opt);
  	return buf;
  }
  
  static const char *
  sppp_ipcp_opt_name(u_char opt)
  {
  	static char buf[12];
  	switch (opt) {
  	case IPCP_OPT_ADDRESSES:	return "addresses";
  	case IPCP_OPT_COMPRESSION:	return "compression";
  	case IPCP_OPT_ADDRESS:		return "address";
  	}
  	snprintf(buf, sizeof(buf), "0x%x", opt);
  	return buf;
  }
  
  #ifdef INET6
  static const char *
  sppp_ipv6cp_opt_name(u_char opt)
  {
  	static char buf[12];
  	switch (opt) {
  	case IPV6CP_OPT_IFID:		return "ifid";
  	case IPV6CP_OPT_COMPRESSION:	return "compression";
  	}
  	snprintf(buf, sizeof(buf), "0x%x", opt);
  	return buf;
  }
  #endif
  
  static const char *
  sppp_state_name(int state)
  {
  	switch (state) {
  	case STATE_INITIAL:	return "initial";
  	case STATE_STARTING:	return "starting";
  	case STATE_CLOSED:	return "closed";
  	case STATE_STOPPED:	return "stopped";
  	case STATE_CLOSING:	return "closing";
  	case STATE_STOPPING:	return "stopping";
  	case STATE_REQ_SENT:	return "req-sent";
  	case STATE_ACK_RCVD:	return "ack-rcvd";
  	case STATE_ACK_SENT:	return "ack-sent";
  	case STATE_OPENED:	return "opened";
  	}
  	return "illegal";
  }
  
  static const char *
  sppp_phase_name(int phase)
  {
  	switch (phase) {
  	case SPPP_PHASE_DEAD:		return "dead";
  	case SPPP_PHASE_ESTABLISH:	return "establish";
  	case SPPP_PHASE_TERMINATE:	return "terminate";
  	case SPPP_PHASE_AUTHENTICATE: 	return "authenticate";
  	case SPPP_PHASE_NETWORK:	return "network";
  	}
  	return "illegal";
  }
  
  static const char *
  sppp_proto_name(u_short proto)
  {
  	static char buf[12];
  	switch (proto) {
  	case PPP_LCP:	return "lcp";
  	case PPP_IPCP:	return "ipcp";
  	case PPP_PAP:	return "pap";
  	case PPP_CHAP:	return "chap";
  	case PPP_IPV6CP: return "ipv6cp";
  	}
  	snprintf(buf, sizeof(buf), "0x%x", (unsigned)proto);
  	return buf;
  }
  
  static void
  sppp_print_bytes(const u_char *p, u_short len)
  {
  	addlog(" %02x", *p++);
  	while (--len > 0)
  		addlog("-%02x", *p++);
  }
  
  static void
  sppp_print_string(const char *p, u_short len)
  {
  	u_char c;
  
  	while (len-- > 0) {
  		c = *p++;
  		/*
  		 * Print only ASCII chars directly.  RFC 1994 recommends
  		 * using only them, but we don't rely on it.  */
  		if (c < ' ' || c > '~')
  			addlog("\\x%x", c);
  		else
  			addlog("%c", c);
  	}
  }
  
  static const char *
  sppp_dotted_quad(uint32_t addr)
  {
  	static char s[16];
  	snprintf(s, sizeof(s), "%d.%d.%d.%d",
  		(int)((addr >> 24) & 0xff),
  		(int)((addr >> 16) & 0xff),
  		(int)((addr >> 8) & 0xff),
  		(int)(addr & 0xff));
  	return s;
  }
  
  /* a dummy, used to drop uninteresting events */
  static void
  sppp_null(struct sppp *unused)
  {
  	/* do just nothing */
  }
  /*
   * This file is large.  Tell emacs to highlight it nevertheless.
   *
   * Local Variables:
   * hilit-auto-highlight-maxout: 120000
   * End:
   */
  