sysdep/linux/sysio.h

   1 /*
   2  *      BIRD Internet Routing Daemon -- Linux Multicasting and Network Includes
   3  *
   4  *      (c) 1998--2000 Martin Mares <mj@ucw.cz>
   5  *
   6  *      Can be freely distributed and used under the terms of the GNU GPL.
   7  */
   8
   9 #ifndef IPV6_MINHOPCOUNT
  10 #define IPV6_MINHOPCOUNT 73
  11 #endif
  12
  13 #ifndef TCP_MD5SIG_EXT
  14 #define TCP_MD5SIG_EXT 32
  15 #endif
  16
  17 #ifndef TCP_MD5SIG_FLAG_PREFIX
  18 #define TCP_MD5SIG_FLAG_PREFIX 1
  19 #endif
  20
  21 /* We redefine the tcp_md5sig structure with different name to avoid collision with older headers */
  22 struct tcp_md5sig_ext {
  23   struct  sockaddr_storage tcpm_addr;           /* Address associated */
  24   u8    tcpm_flags;                             /* Extension flags */
  25   u8    tcpm_prefixlen;                         /* Address prefix */
  26   u16   tcpm_keylen;                            /* Key length */
  27   u32   __tcpm_pad2;                            /* Zero */
  28   u8    tcpm_key[TCP_MD5SIG_MAXKEYLEN];         /* Key (binary) */
  29 };
  30
  31
  32 /* Linux does not care if sa_len is larger than needed */
  33 #define SA_LEN(x) sizeof(sockaddr)
  34
  35
  36 /*
  37  *      Linux IPv4 multicast syscalls
  38  */
  39
  40 #define INIT_MREQ4(maddr,ifa) \
  41   { .imr_multiaddr = ipa_to_in4(maddr), .imr_ifindex = ifa->index }
  42
  43 static inline int
  44 sk_setup_multicast4(sock *s)
  45 {
  46   struct ip_mreqn mr = { .imr_ifindex = s->iface->index };
  47   int ttl = s->ttl;
  48   int n = 0;
  49
  50   /* This defines where should we send _outgoing_ multicasts */
  51   if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_IF, &mr, sizeof(mr)) < 0)
  52     ERR("IP_MULTICAST_IF");
  53
  54   if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
  55     ERR("IP_MULTICAST_TTL");
  56
  57   if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_LOOP, &n, sizeof(n)) < 0)
  58     ERR("IP_MULTICAST_LOOP");
  59
  60   return 0;
  61 }
  62
  63 static inline int
  64 sk_join_group4(sock *s, ip_addr maddr)
  65 {
  66   struct ip_mreqn mr = INIT_MREQ4(maddr, s->iface);
  67
  68   if (setsockopt(s->fd, SOL_IP, IP_ADD_MEMBERSHIP, &mr, sizeof(mr)) < 0)
  69     ERR("IP_ADD_MEMBERSHIP");
  70
  71   return 0;
  72 }
  73
  74 static inline int
  75 sk_leave_group4(sock *s, ip_addr maddr)
  76 {
  77   struct ip_mreqn mr = INIT_MREQ4(maddr, s->iface);
  78
  79   if (setsockopt(s->fd, SOL_IP, IP_DROP_MEMBERSHIP, &mr, sizeof(mr)) < 0)
  80     ERR("IP_DROP_MEMBERSHIP");
  81
  82   return 0;
  83 }
  84
  85
  86 /*
  87  *      Linux IPv4 packet control messages
  88  */
  89
  90 /* Mostly similar to standardized IPv6 code */
  91
  92 #define CMSG4_SPACE_PKTINFO CMSG_SPACE(sizeof(struct in_pktinfo))
  93 #define CMSG4_SPACE_TTL CMSG_SPACE(sizeof(int))
  94
  95 static inline int
  96 sk_request_cmsg4_pktinfo(sock *s)
  97 {
  98   int y = 1;
  99
 100   if (setsockopt(s->fd, SOL_IP, IP_PKTINFO, &y, sizeof(y)) < 0)
 101     ERR("IP_PKTINFO");
 102
 103   return 0;
 104 }
 105
 106 static inline int
 107 sk_request_cmsg4_ttl(sock *s)
 108 {
 109   int y = 1;
 110
 111   if (setsockopt(s->fd, SOL_IP, IP_RECVTTL, &y, sizeof(y)) < 0)
 112     ERR("IP_RECVTTL");
 113
 114   return 0;
 115 }
 116
 117 static inline void
 118 sk_process_cmsg4_pktinfo(sock *s, struct cmsghdr *cm)
 119 {
 120   if (cm->cmsg_type == IP_PKTINFO)
 121   {
 122     struct in_pktinfo *pi = (struct in_pktinfo *) CMSG_DATA(cm);
 123     s->laddr = ipa_from_in4(pi->ipi_addr);
 124     s->lifindex = pi->ipi_ifindex;
 125   }
 126 }
 127
 128 static inline void
 129 sk_process_cmsg4_ttl(sock *s, struct cmsghdr *cm)
 130 {
 131   if (cm->cmsg_type == IP_TTL)
 132     s->rcv_ttl = * (int *) CMSG_DATA(cm);
 133 }
 134
 135 static inline void
 136 sk_prepare_cmsgs4(sock *s, struct msghdr *msg, void *cbuf, size_t cbuflen)
 137 {
 138   struct cmsghdr *cm;
 139   struct in_pktinfo *pi;
 140   int controllen = 0;
 141
 142   msg->msg_control = cbuf;
 143   msg->msg_controllen = cbuflen;
 144
 145   cm = CMSG_FIRSTHDR(msg);
 146   cm->cmsg_level = SOL_IP;
 147   cm->cmsg_type = IP_PKTINFO;
 148   cm->cmsg_len = CMSG_LEN(sizeof(*pi));
 149   controllen += CMSG_SPACE(sizeof(*pi));
 150
 151   pi = (struct in_pktinfo *) CMSG_DATA(cm);
 152   pi->ipi_ifindex = s->iface ? s->iface->index : 0;
 153   pi->ipi_spec_dst = ipa_to_in4(s->saddr);
 154   pi->ipi_addr = ipa_to_in4(IPA_NONE);
 155
 156   msg->msg_controllen = controllen;
 157 }
 158
 159
 160 /*
 161  *      Miscellaneous Linux socket syscalls
 162  */
 163
 164 int
 165 sk_set_md5_auth(sock *s, ip_addr local UNUSED, ip_addr remote, int pxlen, struct iface *ifa, char *passwd, int setkey UNUSED)
 166 {
 167   struct tcp_md5sig_ext md5;
 168
 169   memset(&md5, 0, sizeof(md5));
 170   sockaddr_fill((sockaddr *) &md5.tcpm_addr, s->af, remote, ifa, 0);
 171
 172   if (passwd)
 173   {
 174     int len = strlen(passwd);
 175
 176     if (len > TCP_MD5SIG_MAXKEYLEN)
 177       ERR_MSG("The password for TCP MD5 Signature is too long");
 178
 179     md5.tcpm_keylen = len;
 180     memcpy(&md5.tcpm_key, passwd, len);
 181   }
 182
 183   if (pxlen < 0)
 184   {
 185     if (setsockopt(s->fd, SOL_TCP, TCP_MD5SIG, &md5, sizeof(md5)) < 0)
 186       if (errno == ENOPROTOOPT)
 187         ERR_MSG("Kernel does not support TCP MD5 signatures");
 188       else
 189         ERR("TCP_MD5SIG");
 190   }
 191   else
 192   {
 193     md5.tcpm_flags = TCP_MD5SIG_FLAG_PREFIX;
 194     md5.tcpm_prefixlen = pxlen;
 195
 196     if (setsockopt(s->fd, SOL_TCP, TCP_MD5SIG_EXT, &md5, sizeof(md5)) < 0)
 197     {
 198       if (errno == ENOPROTOOPT)
 199         ERR_MSG("Kernel does not support extended TCP MD5 signatures");
 200       else
 201         ERR("TCP_MD5SIG_EXT");
 202     }
 203   }
 204
 205   return 0;
 206 }
 207
 208 static inline int
 209 sk_set_min_ttl4(sock *s, int ttl)
 210 {
 211   if (setsockopt(s->fd, SOL_IP, IP_MINTTL, &ttl, sizeof(ttl)) < 0)
 212   {
 213     if (errno == ENOPROTOOPT)
 214       ERR_MSG("Kernel does not support IPv4 TTL security");
 215     else
 216       ERR("IP_MINTTL");
 217   }
 218
 219   return 0;
 220 }
 221
 222 static inline int
 223 sk_set_min_ttl6(sock *s, int ttl)
 224 {
 225   if (setsockopt(s->fd, SOL_IPV6, IPV6_MINHOPCOUNT, &ttl, sizeof(ttl)) < 0)
 226   {
 227     if (errno == ENOPROTOOPT)
 228       ERR_MSG("Kernel does not support IPv6 TTL security");
 229     else
 230       ERR("IPV6_MINHOPCOUNT");
 231   }
 232
 233   return 0;
 234 }
 235
 236 static inline int
 237 sk_disable_mtu_disc4(sock *s)
 238 {
 239   int dont = IP_PMTUDISC_DONT;
 240
 241   if (setsockopt(s->fd, SOL_IP, IP_MTU_DISCOVER, &dont, sizeof(dont)) < 0)
 242     ERR("IP_MTU_DISCOVER");
 243
 244   return 0;
 245 }
 246
 247 static inline int
 248 sk_disable_mtu_disc6(sock *s)
 249 {
 250   int dont = IPV6_PMTUDISC_DONT;
 251
 252   if (setsockopt(s->fd, SOL_IPV6, IPV6_MTU_DISCOVER, &dont, sizeof(dont)) < 0)
 253     ERR("IPV6_MTU_DISCOVER");
 254
 255   return 0;
 256 }
 257
 258 int sk_priority_control = 7;
 259
 260 static inline int
 261 sk_set_priority(sock *s, int prio)
 262 {
 263   if (setsockopt(s->fd, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio)) < 0)
 264     ERR("SO_PRIORITY");
 265
 266   return 0;
 267 }
 268