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