slirp/ip6.h

   1 /*
   2  * Copyright (c) 2013
   3  * Guillaume Subiron, Yann Bordenave, Serigne Modou Wagne.
   4  */
   5
   6 #ifndef SLIRP_IP6_H
   7 #define SLIRP_IP6_H
   8
   9 #include <glib.h>
  10 #include <string.h>
  11
  12 #define ALLNODES_MULTICAST  { .s6_addr = \
  13                             { 0xff, 0x02, 0x00, 0x00,\
  14                             0x00, 0x00, 0x00, 0x00,\
  15                             0x00, 0x00, 0x00, 0x00,\
  16                             0x00, 0x00, 0x00, 0x01 } }
  17
  18 #define SOLICITED_NODE_PREFIX { .s6_addr = \
  19                             { 0xff, 0x02, 0x00, 0x00,\
  20                             0x00, 0x00, 0x00, 0x00,\
  21                             0x00, 0x00, 0x00, 0x01,\
  22                             0xff, 0x00, 0x00, 0x00 } }
  23
  24 #define LINKLOCAL_ADDR  { .s6_addr = \
  25                         { 0xfe, 0x80, 0x00, 0x00,\
  26                         0x00, 0x00, 0x00, 0x00,\
  27                         0x00, 0x00, 0x00, 0x00,\
  28                         0x00, 0x00, 0x00, 0x02 } }
  29
  30 #define ZERO_ADDR  { .s6_addr = \
  31                         { 0x00, 0x00, 0x00, 0x00,\
  32                         0x00, 0x00, 0x00, 0x00,\
  33                         0x00, 0x00, 0x00, 0x00,\
  34                         0x00, 0x00, 0x00, 0x00 } }
  35
  36 static inline bool in6_equal(const struct in6_addr *a, const struct in6_addr *b)
  37 {
  38     return memcmp(a, b, sizeof(*a)) == 0;
  39 }
  40
  41 static inline bool in6_equal_net(const struct in6_addr *a,
  42                                  const struct in6_addr *b,
  43                                  int prefix_len)
  44 {
  45     if (memcmp(a, b, prefix_len / 8) != 0) {
  46         return 0;
  47     }
  48
  49     if (prefix_len % 8 == 0) {
  50         return 1;
  51     }
  52
  53     return a->s6_addr[prefix_len / 8] >> (8 - (prefix_len % 8))
  54         == b->s6_addr[prefix_len / 8] >> (8 - (prefix_len % 8));
  55 }
  56
  57 static inline bool in6_equal_mach(const struct in6_addr *a,
  58                                   const struct in6_addr *b,
  59                                   int prefix_len)
  60 {
  61     if (memcmp(&(a->s6_addr[DIV_ROUND_UP(prefix_len, 8)]),
  62                &(b->s6_addr[DIV_ROUND_UP(prefix_len, 8)]),
  63                16 - DIV_ROUND_UP(prefix_len, 8)) != 0) {
  64         return 0;
  65     }
  66
  67     if (prefix_len % 8 == 0) {
  68         return 1;
  69     }
  70
  71     return (a->s6_addr[prefix_len / 8] & ((1U << (8 - (prefix_len % 8))) - 1))
  72         == (b->s6_addr[prefix_len / 8] & ((1U << (8 - (prefix_len % 8))) - 1));
  73 }
  74
  75
  76 #define in6_equal_router(a)\
  77     ((in6_equal_net(a, &slirp->vprefix_addr6, slirp->vprefix_len)\
  78       && in6_equal_mach(a, &slirp->vhost_addr6, slirp->vprefix_len))\
  79   || (in6_equal_net(a, &(struct in6_addr)LINKLOCAL_ADDR, 64)\
  80       && in6_equal_mach(a, &slirp->vhost_addr6, 64)))
  81
  82 #define in6_equal_dns(a)\
  83     ((in6_equal_net(a, &slirp->vprefix_addr6, slirp->vprefix_len)\
  84       && in6_equal_mach(a, &slirp->vnameserver_addr6, slirp->vprefix_len))\
  85   || (in6_equal_net(a, &(struct in6_addr)LINKLOCAL_ADDR, 64)\
  86       && in6_equal_mach(a, &slirp->vnameserver_addr6, 64)))
  87
  88 #define in6_equal_host(a)\
  89     (in6_equal_router(a) || in6_equal_dns(a))
  90
  91 #define in6_solicitednode_multicast(a)\
  92     (in6_equal_net(a, &(struct in6_addr)SOLICITED_NODE_PREFIX, 104))
  93
  94 #define in6_zero(a)\
  95     (in6_equal(a, &(struct in6_addr)ZERO_ADDR))
  96
  97 /* Compute emulated host MAC address from its ipv6 address */
  98 static inline void in6_compute_ethaddr(struct in6_addr ip,
  99                                        uint8_t eth[ETH_ALEN])
 100 {
 101     eth[0] = 0x52;
 102     eth[1] = 0x56;
 103     memcpy(&eth[2], &ip.s6_addr[16 - (ETH_ALEN - 2)], ETH_ALEN - 2);
 104 }
 105
 106 /*
 107  * Definitions for internet protocol version 6.
 108  * Per RFC 2460, December 1998.
 109  */
 110 #define IP6VERSION      6
 111 #define IP6_HOP_LIMIT 255
 112
 113 /*
 114  * Structure of an internet header, naked of options.
 115  */
 116 struct ip6 {
 117 #if G_BYTE_ORDER == G_BIG_ENDIAN
 118     uint32_t
 119         ip_v:4,         /* version */
 120         ip_tc_hi:4,     /* traffic class */
 121         ip_tc_lo:4,
 122         ip_fl_hi:4,     /* flow label */
 123         ip_fl_lo:16;
 124 #else
 125     uint32_t
 126         ip_tc_hi:4,
 127         ip_v:4,
 128         ip_fl_hi:4,
 129         ip_tc_lo:4,
 130         ip_fl_lo:16;
 131 #endif
 132     uint16_t    ip_pl;               /* payload length */
 133     uint8_t     ip_nh;               /* next header */
 134     uint8_t     ip_hl;               /* hop limit */
 135     struct in6_addr ip_src, ip_dst;  /* source and dest address */
 136 };
 137
 138 /*
 139  * IPv6 pseudo-header used by upper-layer protocols
 140  */
 141 struct ip6_pseudohdr {
 142     struct      in6_addr ih_src;  /* source internet address */
 143     struct      in6_addr ih_dst;  /* destination internet address */
 144     uint32_t    ih_pl;            /* upper-layer packet length */
 145     uint16_t    ih_zero_hi;       /* zero */
 146     uint8_t     ih_zero_lo;       /* zero */
 147     uint8_t     ih_nh;            /* next header */
 148 };
 149
 150 /*
 151  * We don't want to mark these ip6 structs as packed as they are naturally
 152  * correctly aligned; instead assert that there is no stray padding.
 153  * If we marked the struct as packed then we would be unable to take
 154  * the address of any of the fields in it.
 155  */
 156 G_STATIC_ASSERT(sizeof(struct ip6) == 40);
 157 G_STATIC_ASSERT(sizeof(struct ip6_pseudohdr) == 40);
 158
 159 #endif