lib/sockopt.c

   1 /* setsockopt functions
   2  * Copyright (C) 1999 Kunihiro Ishiguro
   3  *
   4  * This file is part of GNU Zebra.
   5  *
   6  * GNU Zebra is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2, or (at your option) any
   9  * later version.
  10  *
  11  * GNU Zebra is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  18  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  19  * 02111-1307, USA.
  20  */
  21
  22 #include <zebra.h>
  23 #include "log.h"
  24 #include "sockopt.h"
  25
  26 int
  27 setsockopt_so_recvbuf (int sock, int size)
  28 {
  29   int ret;
  30
  31   if ( (ret = setsockopt (sock, SOL_SOCKET, SO_RCVBUF, (char *)
  32                           &size, sizeof (int))) < 0)
  33     zlog_err ("fd %d: can't setsockopt SO_RCVBUF to %d: %s",
  34               sock,size,safe_strerror(errno));
  35
  36   return ret;
  37 }
  38
  39 static void *
  40 getsockopt_cmsg_data (struct msghdr *msgh, int level, int type)
  41 {
  42   struct cmsghdr *cmsg;
  43   void *ptr = NULL;
  44
  45   for (cmsg = CMSG_FIRSTHDR(msgh);
  46        cmsg != NULL;
  47        cmsg = CMSG_NXTHDR(msgh, cmsg))
  48     if (cmsg->cmsg_level == level && cmsg->cmsg_type)
  49       return (ptr = CMSG_DATA(cmsg));
  50
  51   return NULL;
  52 }
  53
  54 #ifdef HAVE_IPV6
  55 /* Set IPv6 packet info to the socket. */
  56 int
  57 setsockopt_ipv6_pktinfo (int sock, int val)
  58 {
  59   int ret;
  60
  61 #ifdef IPV6_RECVPKTINFO         /*2292bis-01*/
  62   ret = setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
  63   if (ret < 0)
  64     zlog_warn ("can't setsockopt IPV6_RECVPKTINFO : %s", safe_strerror (errno));
  65 #else   /*RFC2292*/
  66   ret = setsockopt(sock, IPPROTO_IPV6, IPV6_PKTINFO, &val, sizeof(val));
  67   if (ret < 0)
  68     zlog_warn ("can't setsockopt IPV6_PKTINFO : %s", safe_strerror (errno));
  69 #endif /* INIA_IPV6 */
  70   return ret;
  71 }
  72
  73 /* Set multicast hops val to the socket. */
  74 int
  75 setsockopt_ipv6_checksum (int sock, int val)
  76 {
  77   int ret;
  78
  79 #ifdef GNU_LINUX
  80   ret = setsockopt(sock, IPPROTO_RAW, IPV6_CHECKSUM, &val, sizeof(val));
  81 #else
  82   ret = setsockopt(sock, IPPROTO_IPV6, IPV6_CHECKSUM, &val, sizeof(val));
  83 #endif /* GNU_LINUX */
  84   if (ret < 0)
  85     zlog_warn ("can't setsockopt IPV6_CHECKSUM");
  86   return ret;
  87 }
  88
  89 /* Set multicast hops val to the socket. */
  90 int
  91 setsockopt_ipv6_multicast_hops (int sock, int val)
  92 {
  93   int ret;
  94
  95   ret = setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &val, sizeof(val));
  96   if (ret < 0)
  97     zlog_warn ("can't setsockopt IPV6_MULTICAST_HOPS");
  98   return ret;
  99 }
 100
 101 /* Set multicast hops val to the socket. */
 102 int
 103 setsockopt_ipv6_unicast_hops (int sock, int val)
 104 {
 105   int ret;
 106
 107   ret = setsockopt(sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &val, sizeof(val));
 108   if (ret < 0)
 109     zlog_warn ("can't setsockopt IPV6_UNICAST_HOPS");
 110   return ret;
 111 }
 112
 113 int
 114 setsockopt_ipv6_hoplimit (int sock, int val)
 115 {
 116   int ret;
 117
 118 #ifdef IPV6_RECVHOPLIMIT        /*2292bis-01*/
 119   ret = setsockopt (sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &val, sizeof(val));
 120   if (ret < 0)
 121     zlog_warn ("can't setsockopt IPV6_RECVHOPLIMIT");
 122 #else   /*RFC2292*/
 123   ret = setsockopt (sock, IPPROTO_IPV6, IPV6_HOPLIMIT, &val, sizeof(val));
 124   if (ret < 0)
 125     zlog_warn ("can't setsockopt IPV6_HOPLIMIT");
 126 #endif
 127   return ret;
 128 }
 129
 130 /* Set multicast loop zero to the socket. */
 131 int
 132 setsockopt_ipv6_multicast_loop (int sock, int val)
 133 {
 134   int ret;
 135
 136   ret = setsockopt (sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val,
 137                     sizeof (val));
 138   if (ret < 0)
 139     zlog_warn ("can't setsockopt IPV6_MULTICAST_LOOP");
 140   return ret;
 141 }
 142
 143 static int
 144 getsockopt_ipv6_ifindex (struct msghdr *msgh)
 145 {
 146   struct in6_pktinfo *pktinfo;
 147
 148   pktinfo = getsockopt_cmsg_data (msgh, IPPROTO_IPV6, IPV6_PKTINFO);
 149
 150   return pktinfo->ipi6_ifindex;
 151 }
 152 #endif /* HAVE_IPV6 */
 153
 154
 155 /* Set up a multicast socket options for IPv4
 156    This is here so that people only have to do their OS multicast mess
 157    in one place rather than all through zebra, ospfd, and ripd
 158    NB: This is a hookpoint for specific OS functionality */
 159 int
 160 setsockopt_multicast_ipv4(int sock,
 161                         int optname,
 162                         struct in_addr if_addr,
 163                         unsigned int mcast_addr,
 164                         unsigned int ifindex)
 165 {
 166
 167   /* Linux 2.2.0 and up */
 168 #if defined(GNU_LINUX) && LINUX_VERSION_CODE > 131584
 169   /* This is better because it uses ifindex directly */
 170   struct ip_mreqn mreqn;
 171
 172   switch (optname)
 173     {
 174     case IP_MULTICAST_IF:
 175     case IP_ADD_MEMBERSHIP:
 176     case IP_DROP_MEMBERSHIP:
 177       memset (&mreqn, 0, sizeof(mreqn));
 178
 179       if (mcast_addr)
 180         mreqn.imr_multiaddr.s_addr = mcast_addr;
 181
 182       if (ifindex)
 183         mreqn.imr_ifindex = ifindex;
 184       else
 185         mreqn.imr_address = if_addr;
 186
 187       return setsockopt(sock, IPPROTO_IP, optname, (void *)&mreqn, sizeof(mreqn));
 188       break;
 189
 190     default:
 191       /* Can out and give an understandable error */
 192       errno = EINVAL;
 193       return -1;
 194       break;
 195     }
 196
 197   /* Example defines for another OS, boilerplate off other code in this
 198      function, AND handle optname as per other sections for consistency !! */
 199   /* #elif  defined(BOGON_NIX) && EXAMPLE_VERSION_CODE > -100000 */
 200   /* Add your favourite OS here! */
 201
 202 #else /* #if OS_TYPE */
 203   /* default OS support */
 204
 205   struct in_addr m;
 206   struct ip_mreq mreq;
 207
 208   switch (optname)
 209     {
 210     case IP_MULTICAST_IF:
 211       m = if_addr;
 212
 213       return setsockopt (sock, IPPROTO_IP, optname, (void *)&m, sizeof(m));
 214       break;
 215
 216     case IP_ADD_MEMBERSHIP:
 217     case IP_DROP_MEMBERSHIP:
 218       memset (&mreq, 0, sizeof(mreq));
 219       mreq.imr_multiaddr.s_addr = mcast_addr;
 220       mreq.imr_interface = if_addr;
 221
 222       return setsockopt (sock,
 223                          IPPROTO_IP,
 224                          optname,
 225                          (void *)&mreq,
 226                          sizeof(mreq));
 227       break;
 228
 229     default:
 230       /* Can out and give an understandable error */
 231       errno = EINVAL;
 232       return -1;
 233       break;
 234     }
 235 #endif /* #if OS_TYPE */
 236
 237 }
 238
 239 static int
 240 setsockopt_ipv4_ifindex (int sock, int val)
 241 {
 242   int ret;
 243
 244 #if defined (IP_PKTINFO)
 245   ret = setsockopt (sock, IPPROTO_IP, IP_PKTINFO, &val, sizeof (val));
 246 #elif defined (IP_RECVIF)
 247   ret = setsockopt (sock, IPPROTO_IP, IP_RECVIF, &val, sizeof (val));
 248 #else
 249 #warning "Neither IP_PKTINFO nor IP_RECVIF is available."
 250 #warning "Will not be able to receive link info."
 251 #warning "Things might be seriously broken.."
 252 #endif
 253
 254   if (ret < 0)
 255     zlog_warn ("Can't set IP_PKTINFO option");
 256   return ret;
 257 }
 258
 259 int
 260 setsockopt_ifindex (int af, int sock, int val)
 261 {
 262   int ret = -1;
 263
 264   switch (af)
 265     {
 266       case AF_INET:
 267         ret = setsockopt_ipv4_ifindex (sock, val);
 268         break;
 269 #ifdef HAVE_IPV6
 270       case AF_INET6:
 271         ret = setsockopt_ipv6_pktinfo (sock, val);
 272         break;
 273 #endif
 274       default:
 275         zlog_warn ("setsockopt_ifindex: unknown address family %d", af);
 276     }
 277   return ret;
 278 }
 279
 280 static int
 281 getsockopt_ipv4_ifindex (struct msghdr *msgh)
 282 {
 283   int ifindex = -1;
 284 #if defined(IP_PKTINFO)
 285 /* Linux pktinfo based ifindex retrieval */
 286   struct in_pktinfo *pktinfo;
 287
 288   pktinfo =
 289     (struct in_pktinfo *)getsockopt_cmsg_data (msgh, IPPROTO_IP, IP_PKTINFO);
 290   ifindex = pktinfo->ipi_ifindex;
 291
 292 #elif defined(IP_RECVIF)
 293 /* BSD/other IP_RECVIF based ifindex retrieval */
 294 #ifndef SUNOS_5
 295   /* RECVIF, but not SUNOS, so BSD */
 296   struct sockaddr_dl *sdl;
 297 #endif /* SUNOS_5 */
 298   /* SUNOS_5 doesn't need a structure to extract ifindex */
 299
 300 #ifndef SUNOS_5
 301   sdl =
 302     (struct sockaddr_dl *)getsockopt_cmsg_data (msgh, IPPROTO_IP, IP_RECVIF);
 303   ifindex = sdl->sdl_index;
 304 #else /* !SUNOS_5 */
 305   ifindex = *(uint_t *)getsockopt_cmsg_data (msgh, IPPROTO_IP, IP_RECVIF);
 306 #endif /* SUNOS_5 */
 307
 308 #else /* neither IP_PKTINFO nor IP_RECVIF, broken */
 309
 310 #warning "getsockopt_ipv4_pktinfo_ifindex: dont have PKTINFO or RECVIF"
 311 #warning "things probably will be broken on this platform!"
 312   /* XXX why not -1 - this is a failure condition. */
 313   ifindex = 0;
 314 #endif /* IP_PKTINFO */
 315   return ifindex;
 316 }
 317
 318 /* return ifindex, 0 if none found */
 319 int
 320 getsockopt_ifindex (int af, struct msghdr *msgh)
 321 {
 322   int ifindex = 0;
 323
 324   switch (af)
 325     {
 326       case AF_INET:
 327         return (getsockopt_ipv4_ifindex (msgh));
 328         break;
 329 #ifdef HAVE_IPV6
 330       case AF_INET6:
 331         return (getsockopt_ipv6_ifindex (msgh));
 332         break;
 333 #endif
 334       default:
 335         zlog_warn ("getsockopt_ifindex: unknown address family %d", af);
 336         return (ifindex = 0);
 337     }
 338 }
 339
 340 /* swab iph between order system uses for IP_HDRINCL and host order */
 341 void
 342 sockopt_iphdrincl_swab_htosys (struct ip *iph)
 343 {
 344   /* BSD and derived take iph in network order, except for
 345    * ip_len and ip_off
 346    */
 347 #ifndef HAVE_IP_HDRINCL_BSD_ORDER
 348   iph->ip_len = htons(iph->ip_len);
 349   iph->ip_off = htons(iph->ip_off);
 350 #endif /* HAVE_IP_HDRINCL_BSD_ORDER */
 351
 352   iph->ip_id = htons(iph->ip_id);
 353 }
 354
 355 void
 356 sockopt_iphdrincl_swab_systoh (struct ip *iph)
 357 {
 358 #ifndef HAVE_IP_HDRINCL_BSD_ORDER
 359   iph->ip_len = ntohs(iph->ip_len);
 360   iph->ip_off = ntohs(iph->ip_off);
 361 #endif /* HAVE_IP_HDRINCL_BSD_ORDER */
 362
 363   iph->ip_id = ntohs(iph->ip_id);
 364 }