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