text: /*
   * dhcpcd - DHCP client daemon
   * Copyright (c) 2006-2018 Roy Marples <roy@marples.name>
   * 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.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
   */
  
  #ifndef DHCP_H
  #define DHCP_H
  
  #include <arpa/inet.h>
  #include <netinet/in.h>
  
  #include <netinet/ip.h>
  #define __FAVOR_BSD /* Nasty glibc hack so we can use BSD semantics for UDP */
  #include <netinet/udp.h>
  #undef __FAVOR_BSD
  
  #include <limits.h>
  #include <stdint.h>
  
  #include "arp.h"
  #include "auth.h"
  #include "dhcp-common.h"
  
  /* UDP port numbers for BOOTP */
  #define BOOTPS			67
  #define BOOTPC			68
  
  #define MAGIC_COOKIE		0x63825363
  #define BROADCAST_FLAG		0x8000
  
  /* BOOTP message OP code */
  #define BOOTREQUEST		1
  #define BOOTREPLY		2
  
  /* DHCP message type */
  #define DHCP_DISCOVER		1
  #define DHCP_OFFER		2
  #define DHCP_REQUEST		3
  #define DHCP_DECLINE		4
  #define DHCP_ACK		5
  #define DHCP_NAK		6
  #define DHCP_RELEASE		7
  #define DHCP_INFORM		8
  #define DHCP_FORCERENEW		9
  
  /* Constants taken from RFC 2131. */
  #define T1			0.5
  #define T2			0.875
  #define DHCP_BASE		4
  #define DHCP_MAX		64
  #define DHCP_RAND_MIN		-1
  #define DHCP_RAND_MAX		1
  
  #ifdef RFC2131_STRICT
  /* Be strictly conformant for section 4.1.1 */
  #  define DHCP_MIN_DELAY	1
  #  define DHCP_MAX_DELAY	10
  #else
  /* or mirror the more modern IPv6RS and DHCPv6 delays */
  #  define DHCP_MIN_DELAY	0
  #  define DHCP_MAX_DELAY	1
  #endif
  
  /* DHCP options */
  enum DHO {
  	DHO_PAD                    = 0,
  	DHO_SUBNETMASK             = 1,
  	DHO_ROUTER                 = 3,
  	DHO_DNSSERVER              = 6,
  	DHO_HOSTNAME               = 12,
  	DHO_DNSDOMAIN              = 15,
  	DHO_MTU                    = 26,
  	DHO_BROADCAST              = 28,
  	DHO_STATICROUTE            = 33,
  	DHO_NISDOMAIN              = 40,
  	DHO_NISSERVER              = 41,
  	DHO_NTPSERVER              = 42,
  	DHO_VENDOR                 = 43,
  	DHO_IPADDRESS              = 50,
  	DHO_LEASETIME              = 51,
  	DHO_OPTSOVERLOADED         = 52,
  	DHO_MESSAGETYPE            = 53,
  	DHO_SERVERID               = 54,
  	DHO_PARAMETERREQUESTLIST   = 55,
  	DHO_MESSAGE                = 56,
  	DHO_MAXMESSAGESIZE         = 57,
  	DHO_RENEWALTIME            = 58,
  	DHO_REBINDTIME             = 59,
  	DHO_VENDORCLASSID          = 60,
  	DHO_CLIENTID               = 61,
  	DHO_USERCLASS              = 77,  /* RFC 3004 */
  	DHO_RAPIDCOMMIT            = 80,  /* RFC 4039 */
  	DHO_FQDN                   = 81,
  	DHO_AUTHENTICATION         = 90,  /* RFC 3118 */
  	DHO_AUTOCONFIGURE          = 116, /* RFC 2563 */
  	DHO_DNSSEARCH              = 119, /* RFC 3397 */
  	DHO_CSR                    = 121, /* RFC 3442 */
  	DHO_VIVCO                  = 124, /* RFC 3925 */
  	DHO_VIVSO                  = 125, /* RFC 3925 */
  	DHO_FORCERENEW_NONCE       = 145, /* RFC 6704 */
  	DHO_MUDURL                 = 161, /* draft-ietf-opsawg-mud */
  	DHO_SIXRD                  = 212, /* RFC 5969 */
  	DHO_MSCSR                  = 249, /* MS code for RFC 3442 */
  	DHO_END                    = 255
  };
  
  /* FQDN values - lsnybble used in flags
   * hsnybble to create order
   * and to allow 0x00 to mean disable
   */
  enum FQDN {
  	FQDN_DISABLE    = 0x00,
  	FQDN_NONE       = 0x18,
  	FQDN_PTR        = 0x20,
  	FQDN_BOTH       = 0x31
  };
  
  /* Sizes for BOOTP options */
  #define	BOOTP_CHADDR_LEN	 16
  #define	BOOTP_SNAME_LEN		 64
  #define	BOOTP_FILE_LEN		128
  #define	BOOTP_VEND_LEN		 64
  
  /* DHCP is basically an extension to BOOTP */
  struct bootp {
  	uint8_t op;		/* message type */
  	uint8_t htype;		/* hardware address type */
  	uint8_t hlen;		/* hardware address length */
  	uint8_t hops;		/* should be zero in client message */
  	uint32_t xid;		/* transaction id */
  	uint16_t secs;		/* elapsed time in sec. from boot */
  	uint16_t flags;		/* such as broadcast flag */
  	uint32_t ciaddr;	/* (previously allocated) client IP */
  	uint32_t yiaddr;	/* 'your' client IP address */
  	uint32_t siaddr;	/* should be zero in client's messages */
  	uint32_t giaddr;	/* should be zero in client's messages */
  	uint8_t chaddr[BOOTP_CHADDR_LEN];	/* client's hardware address */
  	uint8_t sname[BOOTP_SNAME_LEN];		/* server host name */
  	uint8_t file[BOOTP_FILE_LEN];		/* boot file name */
  	uint8_t vend[BOOTP_VEND_LEN];		/* vendor specific area */
  	/* DHCP allows a variable length vendor area */
  };
  
  struct bootp_pkt
  {
  	struct ip ip;
  	struct udphdr udp;
  	struct bootp bootp;
  };
  
  struct dhcp_lease {
  	struct in_addr addr;
  	struct in_addr mask;
  	struct in_addr brd;
  	uint32_t leasetime;
  	uint32_t renewaltime;
  	uint32_t rebindtime;
  	struct in_addr server;
  	uint8_t frominfo;
  	uint32_t cookie;
  };
  
  enum DHS {
  	DHS_NONE,
  	DHS_INIT,
  	DHS_DISCOVER,
  	DHS_REQUEST,
  	DHS_PROBE,
  	DHS_BOUND,
  	DHS_RENEW,
  	DHS_REBIND,
  	DHS_REBOOT,
  	DHS_INFORM,
  	DHS_RENEW_REQUESTED,
  	DHS_RELEASE
  };
  
  struct dhcp_state {
  	enum DHS state;
  	struct bootp *sent;
  	size_t sent_len;
  	struct bootp *offer;
  	size_t offer_len;
  	struct bootp *new;
  	size_t new_len;
  	struct bootp *old;
  	size_t old_len;
  	struct dhcp_lease lease;
  	const char *reason;
  	time_t interval;
  	time_t nakoff;
  	uint32_t xid;
  	int socket;
  
  	int bpf_fd;
  	unsigned int bpf_flags;
  	struct ipv4_addr *addr;
  	uint8_t added;
  
  	char leasefile[sizeof(LEASEFILE) + IF_NAMESIZE + (IF_SSIDLEN * 4)];
  	struct timespec started;
  	unsigned char *clientid;
  	struct authstate auth;
  #ifdef ARPING
  	ssize_t arping_index;
  #endif
  };
  
  #define D_STATE(ifp)							       \
  	((struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP])
  #define D_CSTATE(ifp)							       \
  	((const struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP])
  #define D_STATE_RUNNING(ifp)						       \
  	(D_CSTATE((ifp)) && D_CSTATE((ifp))->new && D_CSTATE((ifp))->reason)
  
  #define IS_DHCP(b)	((b)->vend[0] == 0x63 &&	\
  			 (b)->vend[1] == 0x82 &&	\
  			 (b)->vend[2] == 0x53 &&	\
  			 (b)->vend[3] == 0x63)
  
  #include "dhcpcd.h"
  #include "if-options.h"
  
  #ifdef INET
  char *decode_rfc3361(const uint8_t *, size_t);
  ssize_t decode_rfc3442(char *, size_t, const uint8_t *p, size_t);
  
  void dhcp_printoptions(const struct dhcpcd_ctx *,
      const struct dhcp_opt *, size_t);
  uint16_t dhcp_get_mtu(const struct interface *);
  int dhcp_get_routes(struct rt_head *, struct interface *);
  ssize_t dhcp_env(char **, const char *, const struct bootp *, size_t,
      const struct interface *);
  
  void dhcp_handleifa(int, struct ipv4_addr *);
  void dhcp_drop(struct interface *, const char *);
  void dhcp_start(struct interface *);
  void dhcp_abort(struct interface *);
  void dhcp_discover(void *);
  void dhcp_inform(struct interface *);
  void dhcp_renew(struct interface *);
  void dhcp_bind(struct interface *);
  void dhcp_reboot_newopts(struct interface *, unsigned long long);
  void dhcp_close(struct interface *);
  void dhcp_free(struct interface *);
  int dhcp_dump(struct interface *);
  #else
  #define dhcp_drop(a, b) {}
  #define dhcp_start(a) {}
  #define dhcp_abort(a) {}
  #define dhcp_renew(a) {}
  #define dhcp_reboot(a, b) (b = b)
  #define dhcp_reboot_newopts(a, b) (b = b)
  #define dhcp_close(a) {}
  #define dhcp_free(a) {}
  #define dhcp_dump(a) (-1)
  #endif
  
  #endif
  