pimd/pim_sock.c

   1 /*
   2   PIM for Quagga
   3   Copyright (C) 2008  Everton da Silva Marques
   4
   5   This program is free software; you can redistribute it and/or modify
   6   it under the terms of the GNU General Public License as published by
   7   the Free Software Foundation; either version 2 of the License, or
   8   (at your option) any later version.
   9
  10   This program is distributed in the hope that it will be useful, but
  11   WITHOUT ANY WARRANTY; without even the implied warranty of
  12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13   General Public License for more details.
  14
  15   You should have received a copy of the GNU General Public License
  16   along with this program; see the file COPYING; if not, write to the
  17   Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  18   MA 02110-1301 USA
  19 */
  20
  21 #include <zebra.h>
  22
  23 #include <sys/types.h>
  24 #include <sys/socket.h>
  25 #include <netinet/in.h>
  26 #include <netinet/igmp.h>
  27 #include <arpa/inet.h>
  28 #include <unistd.h>
  29 #include <netdb.h>
  30 #include <errno.h>
  31
  32 #include "log.h"
  33 #include "privs.h"
  34 #include "if.h"
  35 #include "vrf.h"
  36 #include "sockopt.h"
  37
  38 #include "pimd.h"
  39 #include "pim_mroute.h"
  40 #include "pim_sock.h"
  41 #include "pim_str.h"
  42 #include "pim_igmp_join.h"
  43
  44 /* GLOBAL VARS */
  45 extern struct zebra_privs_t pimd_privs;
  46
  47 int
  48 pim_socket_raw (int protocol)
  49 {
  50   int fd;
  51
  52   if ( pimd_privs.change (ZPRIVS_RAISE) )
  53        zlog_err ("pim_sockek_raw: could not raise privs, %s",
  54                  safe_strerror (errno) );
  55
  56   fd = socket(AF_INET, SOCK_RAW, protocol);
  57
  58   if ( pimd_privs.change (ZPRIVS_LOWER) )
  59        zlog_err ("pim_socket_raw: could not lower privs, %s",
  60                  safe_strerror (errno) );
  61
  62   if (fd < 0) {
  63     zlog_warn("Could not create raw socket: errno=%d: %s",
  64               errno, safe_strerror(errno));
  65     return PIM_SOCK_ERR_SOCKET;
  66   }
  67
  68   return fd;
  69 }
  70
  71 int
  72 pim_socket_ip_hdr (int fd)
  73 {
  74   const int on = 1;
  75   int ret;
  76
  77   if (pimd_privs.change (ZPRIVS_RAISE))
  78     zlog_err ("%s: could not raise privs, %s",
  79               __PRETTY_FUNCTION__, safe_strerror (errno));
  80
  81   ret = setsockopt (fd, IPPROTO_IP, IP_HDRINCL, &on, sizeof (on));
  82
  83   if (pimd_privs.change (ZPRIVS_LOWER))
  84     zlog_err ("%s: could not lower privs, %s",
  85               __PRETTY_FUNCTION__, safe_strerror (errno));
  86
  87   return ret;
  88 }
  89
  90 /*
  91  * Given a socket and a interface,
  92  * Bind that socket to that interface
  93  */
  94 int
  95 pim_socket_bind (int fd, struct interface *ifp)
  96 {
  97   int ret = 0;
  98 #ifdef SO_BINDTODEVICE
  99
 100   if (pimd_privs.change (ZPRIVS_RAISE))
 101     zlog_err ("%s: could not raise privs, %s",
 102               __PRETTY_FUNCTION__, safe_strerror (errno));
 103
 104   ret = setsockopt (fd, SOL_SOCKET,
 105                     SO_BINDTODEVICE, ifp->name, strlen (ifp->name));
 106
 107   if (pimd_privs.change (ZPRIVS_LOWER))
 108     zlog_err ("%s: could not lower privs, %s",
 109               __PRETTY_FUNCTION__, safe_strerror (errno));
 110
 111 #endif
 112   return ret;
 113 }
 114
 115 int pim_socket_mcast(int protocol, struct in_addr ifaddr, int ifindex, u_char loop)
 116 {
 117   int rcvbuf = 1024 * 1024 * 8;
 118   struct ip_mreqn mreq;
 119   int fd;
 120
 121   fd = pim_socket_raw(protocol);
 122   if (fd < 0) {
 123     zlog_warn("Could not create multicast socket: errno=%d: %s",
 124               errno, safe_strerror(errno));
 125     return PIM_SOCK_ERR_SOCKET;
 126   }
 127
 128 #ifdef SO_BINDTODEVICE
 129   if (protocol == IPPROTO_PIM)
 130     {
 131       int ret;
 132       struct interface *ifp = NULL;
 133
 134       ifp = if_lookup_by_index_vrf (ifindex, VRF_DEFAULT);
 135
 136       ret = pim_socket_bind (fd, ifp);
 137       if (ret)
 138         {
 139           zlog_warn("Could not set fd: %d for interface: %s to device",
 140                     fd, ifp->name);
 141           return PIM_SOCK_ERR_BIND;
 142         }
 143     }
 144 #else
 145   /* XXX: use IP_PKTINFO / IP_RECVIF to emulate behaviour?  Or change to
 146    * only use 1 socket for all interfaces? */
 147 #endif
 148
 149   /* Needed to obtain destination address from recvmsg() */
 150   {
 151 #if defined(HAVE_IP_PKTINFO)
 152     /* Linux and Solaris IP_PKTINFO */
 153     int opt = 1;
 154     if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &opt, sizeof(opt))) {
 155       zlog_warn("Could not set IP_PKTINFO on socket fd=%d: errno=%d: %s",
 156                 fd, errno, safe_strerror(errno));
 157     }
 158 #elif defined(HAVE_IP_RECVDSTADDR)
 159     /* BSD IP_RECVDSTADDR */
 160     int opt = 1;
 161     if (setsockopt(fd, IPPROTO_IP, IP_RECVDSTADDR, &opt, sizeof(opt))) {
 162       zlog_warn("Could not set IP_RECVDSTADDR on socket fd=%d: errno=%d: %s",
 163                 fd, errno, safe_strerror(errno));
 164     }
 165 #else
 166     zlog_err("%s %s: Missing IP_PKTINFO and IP_RECVDSTADDR: unable to get dst addr from recvmsg()",
 167              __FILE__, __PRETTY_FUNCTION__);
 168     close(fd);
 169     return PIM_SOCK_ERR_DSTADDR;
 170 #endif
 171   }
 172
 173
 174   /* Set router alert (RFC 2113) for all IGMP messages (RFC 3376 4. Message Formats)*/
 175   if (protocol == IPPROTO_IGMP) {
 176     char ra[4];
 177     ra[0] = 148;
 178     ra[1] = 4;
 179     ra[2] = 0;
 180     ra[3] = 0;
 181     if (setsockopt(fd, IPPROTO_IP, IP_OPTIONS, ra, 4)) {
 182       zlog_warn("Could not set Router Alert Option on socket fd=%d: errno=%d: %s",
 183                 fd, errno, safe_strerror(errno));
 184       close(fd);
 185       return PIM_SOCK_ERR_RA;
 186     }
 187   }
 188
 189   {
 190     int reuse = 1;
 191     if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
 192                    (void *) &reuse, sizeof(reuse))) {
 193       zlog_warn("Could not set Reuse Address Option on socket fd=%d: errno=%d: %s",
 194                 fd, errno, safe_strerror(errno));
 195       close(fd);
 196       return PIM_SOCK_ERR_REUSE;
 197     }
 198   }
 199
 200   {
 201     const int MTTL = 1;
 202     int ttl = MTTL;
 203     if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL,
 204                    (void *) &ttl, sizeof(ttl))) {
 205       zlog_warn("Could not set multicast TTL=%d on socket fd=%d: errno=%d: %s",
 206                 MTTL, fd, errno, safe_strerror(errno));
 207       close(fd);
 208       return PIM_SOCK_ERR_TTL;
 209     }
 210   }
 211
 212   if (setsockopt_ipv4_multicast_loop (fd, loop)) {
 213     zlog_warn("Could not %s Multicast Loopback Option on socket fd=%d: errno=%d: %s",
 214               loop ? "enable" : "disable",
 215               fd, errno, safe_strerror(errno));
 216     close(fd);
 217     return PIM_SOCK_ERR_LOOP;
 218   }
 219
 220   memset (&mreq, 0, sizeof (mreq));
 221   mreq.imr_ifindex = ifindex;
 222   if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
 223                  (void *) &mreq, sizeof(mreq))) {
 224     zlog_warn("Could not set Outgoing Interface Option on socket fd=%d: errno=%d: %s",
 225               fd, errno, safe_strerror(errno));
 226     close(fd);
 227     return PIM_SOCK_ERR_IFACE;
 228   }
 229
 230   if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &rcvbuf, sizeof(rcvbuf)))
 231       zlog_warn("%s: Failure to set buffer size to %d",
 232                 __PRETTY_FUNCTION__, rcvbuf);
 233
 234   {
 235     long flags;
 236
 237     flags = fcntl(fd, F_GETFL, 0);
 238     if (flags < 0) {
 239       zlog_warn("Could not get fcntl(F_GETFL,O_NONBLOCK) on socket fd=%d: errno=%d: %s",
 240                 fd, errno, safe_strerror(errno));
 241       close(fd);
 242       return PIM_SOCK_ERR_NONBLOCK_GETFL;
 243     }
 244
 245     if (fcntl(fd, F_SETFL, flags | O_NONBLOCK)) {
 246       zlog_warn("Could not set fcntl(F_SETFL,O_NONBLOCK) on socket fd=%d: errno=%d: %s",
 247                 fd, errno, safe_strerror(errno));
 248       close(fd);
 249       return PIM_SOCK_ERR_NONBLOCK_SETFL;
 250     }
 251   }
 252
 253   return fd;
 254 }
 255
 256 int pim_socket_join(int fd, struct in_addr group,
 257                     struct in_addr ifaddr, ifindex_t ifindex)
 258 {
 259   int ret;
 260
 261 #ifdef HAVE_STRUCT_IP_MREQN_IMR_IFINDEX
 262   struct ip_mreqn opt;
 263 #else
 264   struct ip_mreq opt;
 265 #endif
 266
 267   opt.imr_multiaddr = group;
 268
 269 #ifdef HAVE_STRUCT_IP_MREQN_IMR_IFINDEX
 270   opt.imr_address   = ifaddr;
 271   opt.imr_ifindex   = ifindex;
 272 #else
 273   opt.imr_interface = ifaddr;
 274 #endif
 275
 276   ret = setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &opt, sizeof(opt));
 277   if (ret) {
 278     char group_str[INET_ADDRSTRLEN];
 279     char ifaddr_str[INET_ADDRSTRLEN];
 280     if (!inet_ntop(AF_INET, &group, group_str , sizeof(group_str)))
 281       sprintf(group_str, "<group?>");
 282     if (!inet_ntop(AF_INET, &ifaddr, ifaddr_str , sizeof(ifaddr_str)))
 283       sprintf(ifaddr_str, "<ifaddr?>");
 284
 285     zlog_err("Failure socket joining fd=%d group %s on interface address %s: errno=%d: %s",
 286              fd, group_str, ifaddr_str, errno, safe_strerror(errno));
 287     return ret;
 288   }
 289
 290   if (PIM_DEBUG_TRACE) {
 291     char group_str[INET_ADDRSTRLEN];
 292     char ifaddr_str[INET_ADDRSTRLEN];
 293     if (!inet_ntop(AF_INET, &group, group_str , sizeof(group_str)))
 294       sprintf(group_str, "<group?>");
 295     if (!inet_ntop(AF_INET, &ifaddr, ifaddr_str , sizeof(ifaddr_str)))
 296       sprintf(ifaddr_str, "<ifaddr?>");
 297
 298     zlog_debug("Socket fd=%d joined group %s on interface address %s",
 299                fd, group_str, ifaddr_str);
 300   }
 301
 302   return ret;
 303 }
 304
 305 int pim_socket_join_source(int fd, ifindex_t ifindex,
 306                            struct in_addr group_addr,
 307                            struct in_addr source_addr,
 308                            const char *ifname)
 309 {
 310   if (pim_igmp_join_source(fd, ifindex, group_addr, source_addr)) {
 311     char group_str[INET_ADDRSTRLEN];
 312     char source_str[INET_ADDRSTRLEN];
 313     pim_inet4_dump("<grp?>", group_addr, group_str, sizeof(group_str));
 314     pim_inet4_dump("<src?>", source_addr, source_str, sizeof(source_str));
 315     zlog_warn("%s: setsockopt(fd=%d) failure for IGMP group %s source %s ifindex %d on interface %s: errno=%d: %s",
 316               __PRETTY_FUNCTION__,
 317               fd, group_str, source_str, ifindex, ifname,
 318               errno, safe_strerror(errno));
 319     return -1;
 320   }
 321
 322   return 0;
 323 }
 324
 325 int pim_socket_recvfromto(int fd, uint8_t *buf, size_t len,
 326                           struct sockaddr_in *from, socklen_t *fromlen,
 327                           struct sockaddr_in *to, socklen_t *tolen,
 328                           ifindex_t *ifindex)
 329 {
 330   struct msghdr msgh;
 331   struct cmsghdr *cmsg;
 332   struct iovec iov;
 333   char cbuf[1000];
 334   int err;
 335
 336   /*
 337    * IP_PKTINFO / IP_RECVDSTADDR don't yield sin_port.
 338    * Use getsockname() to get sin_port.
 339    */
 340   if (to) {
 341     struct sockaddr_in si;
 342     socklen_t si_len = sizeof(si);
 343
 344     memset (&si, 0, sizeof (si));
 345     to->sin_family = AF_INET;
 346
 347     pim_socket_getsockname(fd, (struct sockaddr *) &si, &si_len);
 348
 349     to->sin_port = si.sin_port;
 350     to->sin_addr = si.sin_addr;
 351
 352     if (tolen)
 353       *tolen = sizeof(si);
 354   }
 355
 356   memset(&msgh, 0, sizeof(struct msghdr));
 357   iov.iov_base = buf;
 358   iov.iov_len  = len;
 359   msgh.msg_control = cbuf;
 360   msgh.msg_controllen = sizeof(cbuf);
 361   msgh.msg_name = from;
 362   msgh.msg_namelen = fromlen ? *fromlen : 0;
 363   msgh.msg_iov  = &iov;
 364   msgh.msg_iovlen = 1;
 365   msgh.msg_flags = 0;
 366
 367   err = recvmsg(fd, &msgh, 0);
 368   if (err < 0)
 369     return err;
 370
 371   if (fromlen)
 372     *fromlen = msgh.msg_namelen;
 373
 374   for (cmsg = CMSG_FIRSTHDR(&msgh);
 375        cmsg != NULL;
 376        cmsg = CMSG_NXTHDR(&msgh,cmsg)) {
 377
 378 #ifdef HAVE_IP_PKTINFO
 379     if ((cmsg->cmsg_level == IPPROTO_IP) && (cmsg->cmsg_type == IP_PKTINFO)) {
 380       struct in_pktinfo *i = (struct in_pktinfo *) CMSG_DATA(cmsg);
 381       if (to)
 382         ((struct sockaddr_in *) to)->sin_addr = i->ipi_addr;
 383       if (tolen)
 384         *tolen = sizeof(struct sockaddr_in);
 385       if (ifindex)
 386         *ifindex = i->ipi_ifindex;
 387
 388       break;
 389     }
 390 #endif
 391
 392 #ifdef HAVE_IP_RECVDSTADDR
 393     if ((cmsg->cmsg_level == IPPROTO_IP) && (cmsg->cmsg_type == IP_RECVDSTADDR)) {
 394       struct in_addr *i = (struct in_addr *) CMSG_DATA(cmsg);
 395       if (to)
 396         ((struct sockaddr_in *) to)->sin_addr = *i;
 397       if (tolen)
 398         *tolen = sizeof(struct sockaddr_in);
 399
 400       break;
 401     }
 402 #endif
 403
 404 #if defined(HAVE_IP_RECVIF) && defined(CMSG_IFINDEX)
 405       if (cmsg->cmsg_type == IP_RECVIF)
 406         if (ifindex)
 407           *ifindex = CMSG_IFINDEX(cmsg);
 408 #endif
 409
 410   } /* for (cmsg) */
 411
 412   return err; /* len */
 413 }
 414
 415 int pim_socket_mcastloop_get(int fd)
 416 {
 417   int loop;
 418   socklen_t loop_len = sizeof(loop);
 419
 420   if (getsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
 421                  &loop, &loop_len)) {
 422     int e = errno;
 423     zlog_warn("Could not get Multicast Loopback Option on socket fd=%d: errno=%d: %s",
 424               fd, errno, safe_strerror(errno));
 425     errno = e;
 426     return PIM_SOCK_ERR_LOOP;
 427   }
 428
 429   return loop;
 430 }
 431
 432 int pim_socket_getsockname(int fd, struct sockaddr *name, socklen_t *namelen)
 433 {
 434   if (getsockname(fd, name, namelen)) {
 435     int e = errno;
 436     zlog_warn("Could not get Socket Name for socket fd=%d: errno=%d: %s",
 437               fd, errno, safe_strerror(errno));
 438     errno = e;
 439     return PIM_SOCK_ERR_NAME;
 440   }
 441
 442   return PIM_SOCK_ERR_NONE;
 443 }