text: /*	$NetBSD: ip_var.h,v 1.22 1997/10/18 21:18:32 kml Exp $	*/
  
  /*
   * Copyright (c) 1982, 1986, 1993
   *	The Regents of the University of California.  All rights reserved.
   *
   * 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.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the University of
   *	California, Berkeley and its contributors.
   * 4. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS 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.
   *
   *	@(#)ip_var.h	8.1 (Berkeley) 6/10/93
   */
  
  #include <sys/queue.h>
  
  /*
   * Overlay for ip header used by other protocols (tcp, udp).
   */
  struct ipovly {
  	u_int8_t  ih_x1[9];		/* (unused) */
  	u_int8_t  ih_pr;		/* protocol */
  	u_int16_t ih_len;		/* protocol length */
  	struct	  in_addr ih_src;	/* source internet address */
  	struct	  in_addr ih_dst;	/* destination internet address */
  };
  
  /*
   * Ip (reassembly or sequence) queue structures.
   *
   * XXX -- The following explains why the ipqe_m field is here, for TCP's use:
   * We want to avoid doing m_pullup on incoming packets but that
   * means avoiding dtom on the tcp reassembly code.  That in turn means
   * keeping an mbuf pointer in the reassembly queue (since we might
   * have a cluster).  As a quick hack, the source & destination
   * port numbers (which are no longer needed once we've located the
   * tcpcb) are overlayed with an mbuf pointer.
   */
  LIST_HEAD(ipqehead, ipqent);
  struct ipqent {
  	LIST_ENTRY(ipqent) ipqe_q;
  	union {
  		struct ip	*_ip;
  		struct tcpiphdr *_tcp;
  	} _ipqe_u1;
  	struct mbuf	*ipqe_m;	/* mbuf contains packet */
  	u_int8_t	ipqe_mff;	/* for IP fragmentation */
  };
  #define	ipqe_ip		_ipqe_u1._ip
  #define	ipqe_tcp	_ipqe_u1._tcp
  
  /*
   * Ip reassembly queue structure.  Each fragment
   * being reassembled is attached to one of these structures.
   * They are timed out after ipq_ttl drops to 0, and may also
   * be reclaimed if memory becomes tight.
   */
  struct ipq {
  	LIST_ENTRY(ipq) ipq_q;		/* to other reass headers */
  	u_int8_t  ipq_ttl;		/* time for reass q to live */
  	u_int8_t  ipq_p;		/* protocol of this fragment */
  	u_int16_t ipq_id;		/* sequence id for reassembly */
  	struct	  ipqehead ipq_fragq;	/* to ip fragment queue */
  	struct	  in_addr ipq_src, ipq_dst;
  };
  
  /*
   * Structure stored in mbuf in inpcb.ip_options
   * and passed to ip_output when ip options are in use.
   * The actual length of the options (including ipopt_dst)
   * is in m_len.
   */
  #define	MAX_IPOPTLEN	40
  
  struct ipoption {
  	struct	in_addr ipopt_dst;	/* first-hop dst if source routed */
  	int8_t	ipopt_list[MAX_IPOPTLEN];	/* options proper */
  };
  
  /*
   * Structure attached to inpcb.ip_moptions and
   * passed to ip_output when IP multicast options are in use.
   */
  struct ip_moptions {
  	struct	  ifnet *imo_multicast_ifp; /* ifp for outgoing multicasts */
  	u_int8_t  imo_multicast_ttl;	/* TTL for outgoing multicasts */
  	u_int8_t  imo_multicast_loop;	/* 1 => hear sends if a member */
  	u_int16_t imo_num_memberships;	/* no. memberships this socket */
  	struct	  in_multi *imo_membership[IP_MAX_MEMBERSHIPS];
  };
  
  struct	ipstat {
  	u_long	ips_total;		/* total packets received */
  	u_long	ips_badsum;		/* checksum bad */
  	u_long	ips_tooshort;		/* packet too short */
  	u_long	ips_toosmall;		/* not enough data */
  	u_long	ips_badhlen;		/* ip header length < data size */
  	u_long	ips_badlen;		/* ip length < ip header length */
  	u_long	ips_fragments;		/* fragments received */
  	u_long	ips_fragdropped;	/* frags dropped (dups, out of space) */
  	u_long	ips_fragtimeout;	/* fragments timed out */
  	u_long	ips_forward;		/* packets forwarded */
  	u_long	ips_cantforward;	/* packets rcvd for unreachable dest */
  	u_long	ips_redirectsent;	/* packets forwarded on same net */
  	u_long	ips_noproto;		/* unknown or unsupported protocol */
  	u_long	ips_delivered;		/* datagrams delivered to upper level*/
  	u_long	ips_localout;		/* total ip packets generated here */
  	u_long	ips_odropped;		/* lost packets due to nobufs, etc. */
  	u_long	ips_reassembled;	/* total packets reassembled ok */
  	u_long	ips_fragmented;		/* datagrams sucessfully fragmented */
  	u_long	ips_ofragments;		/* output fragments created */
  	u_long	ips_cantfrag;		/* don't fragment flag was set, etc. */
  	u_long	ips_badoptions;		/* error in option processing */
  	u_long	ips_noroute;		/* packets discarded due to no route */
  	u_long	ips_badvers;		/* ip version != 4 */
  	u_long	ips_rawout;		/* total raw ip packets generated */
  	u_long	ips_badfrags;		/* malformed fragments (bad length) */
  	u_long	ips_rcvmemdrop;		/* frags dropped for lack of memory */
  	u_long	ips_toolong;		/* ip length > max ip packet size */
  };
  
  #ifdef _KERNEL
  /* flags passed to ip_output as last parameter */
  #define	IP_FORWARDING		0x1		/* most of ip header exists */
  #define	IP_RAWOUTPUT		0x2		/* raw ip header exists */
  #define	IP_RETURNMTU		0x4		/* pass back mtu on EMSGSIZE */
  #define	IP_ROUTETOIF		SO_DONTROUTE	/* bypass routing tables */
  #define	IP_ALLOWBROADCAST	SO_BROADCAST	/* can send broadcast packets */
  
  struct	  ipstat ipstat;
  LIST_HEAD(ipqhead, ipq)	ipq;		/* ip reass. queue */
  u_int16_t  ip_id;			/* ip packet ctr, for ids */
  int        ip_defttl;			/* default IP ttl */
  extern int ip_mtudisc;			/* mtu discovery */
  
  struct	 inpcb;
  
  int	 ip_ctloutput __P((int, struct socket *, int, int, struct mbuf **));
  int	 ip_dooptions __P((struct mbuf *));
  void	 ip_drain __P((void));
  void	 ip_forward __P((struct mbuf *, int));
  void	 ip_freef __P((struct ipq *));
  void	 ip_freemoptions __P((struct ip_moptions *));
  int	 ip_getmoptions __P((int, struct ip_moptions *, struct mbuf **));
  void	 ip_init __P((void));
  int	 ip_mforward __P((struct mbuf *, struct ifnet *));
  int	 ip_optcopy __P((struct ip *, struct ip *));
  int	 ip_output __P((struct mbuf *, ...));
  int	 ip_pcbopts __P((struct mbuf **, struct mbuf *));
  struct mbuf *
  	 ip_reass __P((struct ipqent *, struct ipq *));
  struct in_ifaddr *
  	 ip_rtaddr __P((struct in_addr));
  void	 ip_savecontrol __P((struct inpcb *, struct mbuf **, struct ip *,
  	   struct mbuf *));
  int	 ip_setmoptions __P((int, struct ip_moptions **, struct mbuf *));
  void	 ip_slowtimo __P((void));
  struct mbuf *
  	 ip_srcroute __P((void));
  void	 ip_stripoptions __P((struct mbuf *, struct mbuf *));
  int	 ip_sysctl __P((int *, u_int, void *, size_t *, void *, size_t));
  void	 ipintr __P((void));
  int	 rip_ctloutput __P((int, struct socket *, int, int, struct mbuf **));
  void	 rip_init __P((void));
  void	 rip_input __P((struct mbuf *, ...));
  int	 rip_output __P((struct mbuf *, ...));
  int	 rip_usrreq __P((struct socket *,
  	    int, struct mbuf *, struct mbuf *, struct mbuf *, struct proc *));
  #endif
  