slirp/src/ip.h

   1 /* SPDX-License-Identifier: BSD-3-Clause */
   2 /*
   3  * Copyright (c) 1982, 1986, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. Neither the name of the University nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  *
  30  *      @(#)ip.h        8.1 (Berkeley) 6/10/93
  31  * ip.h,v 1.3 1994/08/21 05:27:30 paul Exp
  32  */
  33
  34 #ifndef IP_H
  35 #define IP_H
  36
  37 #include <glib.h>
  38
  39 #if G_BYTE_ORDER == G_BIG_ENDIAN
  40 # undef NTOHL
  41 # undef NTOHS
  42 # undef HTONL
  43 # undef HTONS
  44 # define NTOHL(d)
  45 # define NTOHS(d)
  46 # define HTONL(d)
  47 # define HTONS(d)
  48 #else
  49 # ifndef NTOHL
  50 #  define NTOHL(d) ((d) = ntohl((d)))
  51 # endif
  52 # ifndef NTOHS
  53 #  define NTOHS(d) ((d) = ntohs((uint16_t)(d)))
  54 # endif
  55 # ifndef HTONL
  56 #  define HTONL(d) ((d) = htonl((d)))
  57 # endif
  58 # ifndef HTONS
  59 #  define HTONS(d) ((d) = htons((uint16_t)(d)))
  60 # endif
  61 #endif
  62
  63 typedef uint32_t n_long;                 /* long as received from the net */
  64
  65 /*
  66  * Definitions for internet protocol version 4.
  67  * Per RFC 791, September 1981.
  68  */
  69 #define IPVERSION       4
  70
  71 /*
  72  * Structure of an internet header, naked of options.
  73  */
  74 struct ip {
  75 #if G_BYTE_ORDER == G_BIG_ENDIAN
  76         uint8_t ip_v:4,                 /* version */
  77                 ip_hl:4;                /* header length */
  78 #else
  79         uint8_t ip_hl:4,                /* header length */
  80                 ip_v:4;                 /* version */
  81 #endif
  82         uint8_t         ip_tos;                 /* type of service */
  83         uint16_t        ip_len;                 /* total length */
  84         uint16_t        ip_id;                  /* identification */
  85         uint16_t        ip_off;                 /* fragment offset field */
  86 #define IP_DF 0x4000                    /* don't fragment flag */
  87 #define IP_MF 0x2000                    /* more fragments flag */
  88 #define IP_OFFMASK 0x1fff               /* mask for fragmenting bits */
  89         uint8_t ip_ttl;                 /* time to live */
  90         uint8_t ip_p;                   /* protocol */
  91         uint16_t        ip_sum;                 /* checksum */
  92         struct  in_addr ip_src,ip_dst;  /* source and dest address */
  93 } SLIRP_PACKED;
  94
  95 #define IP_MAXPACKET    65535           /* maximum packet size */
  96
  97 /*
  98  * Definitions for IP type of service (ip_tos)
  99  */
 100 #define IPTOS_LOWDELAY          0x10
 101 #define IPTOS_THROUGHPUT        0x08
 102 #define IPTOS_RELIABILITY       0x04
 103
 104 /*
 105  * Definitions for options.
 106  */
 107 #define IPOPT_COPIED(o)         ((o)&0x80)
 108 #define IPOPT_CLASS(o)          ((o)&0x60)
 109 #define IPOPT_NUMBER(o)         ((o)&0x1f)
 110
 111 #define IPOPT_CONTROL           0x00
 112 #define IPOPT_RESERVED1         0x20
 113 #define IPOPT_DEBMEAS           0x40
 114 #define IPOPT_RESERVED2         0x60
 115
 116 #define IPOPT_EOL               0               /* end of option list */
 117 #define IPOPT_NOP               1               /* no operation */
 118
 119 #define IPOPT_RR                7               /* record packet route */
 120 #define IPOPT_TS                68              /* timestamp */
 121 #define IPOPT_SECURITY          130             /* provide s,c,h,tcc */
 122 #define IPOPT_LSRR              131             /* loose source route */
 123 #define IPOPT_SATID             136             /* satnet id */
 124 #define IPOPT_SSRR              137             /* strict source route */
 125
 126 /*
 127  * Offsets to fields in options other than EOL and NOP.
 128  */
 129 #define IPOPT_OPTVAL            0               /* option ID */
 130 #define IPOPT_OLEN              1               /* option length */
 131 #define IPOPT_OFFSET            2               /* offset within option */
 132 #define IPOPT_MINOFF            4               /* min value of above */
 133
 134 /*
 135  * Time stamp option structure.
 136  */
 137 struct  ip_timestamp {
 138         uint8_t ipt_code;               /* IPOPT_TS */
 139         uint8_t ipt_len;                /* size of structure (variable) */
 140         uint8_t ipt_ptr;                /* index of current entry */
 141 #if G_BYTE_ORDER == G_BIG_ENDIAN
 142         uint8_t ipt_oflw:4,             /* overflow counter */
 143                 ipt_flg:4;              /* flags, see below */
 144 #else
 145         uint8_t ipt_flg:4,              /* flags, see below */
 146                 ipt_oflw:4;             /* overflow counter */
 147 #endif
 148         union ipt_timestamp {
 149                 n_long  ipt_time[1];
 150                 struct  ipt_ta {
 151                         struct in_addr ipt_addr;
 152                         n_long ipt_time;
 153                 } ipt_ta[1];
 154         } ipt_timestamp;
 155 } SLIRP_PACKED;
 156
 157 /* flag bits for ipt_flg */
 158 #define IPOPT_TS_TSONLY         0               /* timestamps only */
 159 #define IPOPT_TS_TSANDADDR      1               /* timestamps and addresses */
 160 #define IPOPT_TS_PRESPEC        3               /* specified modules only */
 161
 162 /* bits for security (not byte swapped) */
 163 #define IPOPT_SECUR_UNCLASS     0x0000
 164 #define IPOPT_SECUR_CONFID      0xf135
 165 #define IPOPT_SECUR_EFTO        0x789a
 166 #define IPOPT_SECUR_MMMM        0xbc4d
 167 #define IPOPT_SECUR_RESTR       0xaf13
 168 #define IPOPT_SECUR_SECRET      0xd788
 169 #define IPOPT_SECUR_TOPSECRET   0x6bc5
 170
 171 /*
 172  * Internet implementation parameters.
 173  */
 174 #define MAXTTL          255             /* maximum time to live (seconds) */
 175 #define IPDEFTTL        64              /* default ttl, from RFC 1340 */
 176 #define IPFRAGTTL       60              /* time to live for frags, slowhz */
 177 #define IPTTLDEC        1               /* subtracted when forwarding */
 178
 179 #define IP_MSS          576             /* default maximum segment size */
 180
 181 #if GLIB_SIZEOF_VOID_P == 4
 182 struct mbuf_ptr {
 183         struct mbuf *mptr;
 184         uint32_t dummy;
 185 } SLIRP_PACKED;
 186 #else
 187 struct mbuf_ptr {
 188         struct mbuf *mptr;
 189 } SLIRP_PACKED;
 190 #endif
 191 struct qlink {
 192         void *next, *prev;
 193 };
 194
 195 /*
 196  * Overlay for ip header used by other protocols (tcp, udp).
 197  */
 198 struct ipovly {
 199         struct mbuf_ptr ih_mbuf;        /* backpointer to mbuf */
 200         uint8_t ih_x1;                  /* (unused) */
 201         uint8_t ih_pr;                  /* protocol */
 202         uint16_t        ih_len;                 /* protocol length */
 203         struct  in_addr ih_src;         /* source internet address */
 204         struct  in_addr ih_dst;         /* destination internet address */
 205 } SLIRP_PACKED;
 206
 207 /*
 208  * Ip reassembly queue structure.  Each fragment
 209  * being reassembled is attached to one of these structures.
 210  * They are timed out after ipq_ttl drops to 0, and may also
 211  * be reclaimed if memory becomes tight.
 212  * size 28 bytes
 213  */
 214 struct ipq {
 215         struct qlink frag_link;                 /* to ip headers of fragments */
 216         struct qlink ip_link;                           /* to other reass headers */
 217         uint8_t ipq_ttl;                /* time for reass q to live */
 218         uint8_t ipq_p;                  /* protocol of this fragment */
 219         uint16_t        ipq_id;                 /* sequence id for reassembly */
 220         struct  in_addr ipq_src,ipq_dst;
 221 };
 222
 223 /*
 224  * Ip header, when holding a fragment.
 225  *
 226  * Note: ipf_link must be at same offset as frag_link above
 227  */
 228 struct  ipasfrag {
 229         struct qlink ipf_link;
 230         struct ip ipf_ip;
 231 };
 232
 233 G_STATIC_ASSERT(offsetof(struct ipq, frag_link) ==
 234                 offsetof(struct ipasfrag, ipf_link));
 235
 236 #define ipf_off      ipf_ip.ip_off
 237 #define ipf_tos      ipf_ip.ip_tos
 238 #define ipf_len      ipf_ip.ip_len
 239 #define ipf_next     ipf_link.next
 240 #define ipf_prev     ipf_link.prev
 241
 242 #endif