pimd/pim_ssmpingd.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 "if.h"
  23 #include "log.h"
  24 #include "memory.h"
  25 #include "sockopt.h"
  26 #include "vrf.h"
  27 #include "lib_errors.h"
  28
  29 #include "pimd.h"
  30 #include "pim_ssmpingd.h"
  31 #include "pim_time.h"
  32 #include "pim_sock.h"
  33
  34 static const char *const PIM_SSMPINGD_REPLY_GROUP = "232.43.211.234";
  35
  36 enum { PIM_SSMPINGD_REQUEST = 'Q', PIM_SSMPINGD_REPLY = 'A' };
  37
  38 static void ssmpingd_read_on(struct ssmpingd_sock *ss);
  39
  40 void pim_ssmpingd_init(struct pim_instance *pim)
  41 {
  42         int result;
  43
  44         zassert(!pim->ssmpingd_list);
  45
  46         result = inet_pton(AF_INET, PIM_SSMPINGD_REPLY_GROUP,
  47                            &pim->ssmpingd_group_addr);
  48
  49         zassert(result > 0);
  50 }
  51
  52 void pim_ssmpingd_destroy(struct pim_instance *pim)
  53 {
  54         if (pim->ssmpingd_list)
  55                 list_delete(&pim->ssmpingd_list);
  56 }
  57
  58 static struct ssmpingd_sock *ssmpingd_find(struct pim_instance *pim,
  59                                            struct in_addr source_addr)
  60 {
  61         struct listnode *node;
  62         struct ssmpingd_sock *ss;
  63
  64         if (!pim->ssmpingd_list)
  65                 return 0;
  66
  67         for (ALL_LIST_ELEMENTS_RO(pim->ssmpingd_list, node, ss))
  68                 if (source_addr.s_addr == ss->source_addr.s_addr)
  69                         return ss;
  70
  71         return 0;
  72 }
  73
  74 static void ssmpingd_free(struct ssmpingd_sock *ss)
  75 {
  76         XFREE(MTYPE_PIM_SSMPINGD, ss);
  77 }
  78
  79 static int ssmpingd_socket(struct in_addr addr, int port, int mttl)
  80 {
  81         struct sockaddr_in sockaddr;
  82         int fd;
  83
  84         fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
  85         if (fd < 0) {
  86                 flog_err_sys(EC_LIB_SOCKET,
  87                              "%s: could not create socket: errno=%d: %s",
  88                              __PRETTY_FUNCTION__, errno, safe_strerror(errno));
  89                 return -1;
  90         }
  91
  92         sockaddr.sin_family = AF_INET;
  93         sockaddr.sin_addr = addr;
  94         sockaddr.sin_port = htons(port);
  95
  96         if (bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr))) {
  97                 char addr_str[INET_ADDRSTRLEN];
  98                 pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
  99                 zlog_warn(
 100                         "%s: bind(fd=%d,addr=%s,port=%d,len=%zu) failure: errno=%d: %s",
 101                         __PRETTY_FUNCTION__, fd, addr_str, port,
 102                         sizeof(sockaddr), errno, safe_strerror(errno));
 103                 close(fd);
 104                 return -1;
 105         }
 106
 107         /* Needed to obtain destination address from recvmsg() */
 108         {
 109 #if defined(HAVE_IP_PKTINFO)
 110                 /* Linux and Solaris IP_PKTINFO */
 111                 int opt = 1;
 112                 if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &opt, sizeof(opt))) {
 113                         zlog_warn(
 114                                 "%s: could not set IP_PKTINFO on socket fd=%d: errno=%d: %s",
 115                                 __PRETTY_FUNCTION__, fd, errno,
 116                                 safe_strerror(errno));
 117                 }
 118 #elif defined(HAVE_IP_RECVDSTADDR)
 119                 /* BSD IP_RECVDSTADDR */
 120                 int opt = 1;
 121                 if (setsockopt(fd, IPPROTO_IP, IP_RECVDSTADDR, &opt,
 122                                sizeof(opt))) {
 123                         zlog_warn(
 124                                 "%s: could not set IP_RECVDSTADDR on socket fd=%d: errno=%d: %s",
 125                                 __PRETTY_FUNCTION__, fd, errno,
 126                                 safe_strerror(errno));
 127                 }
 128 #else
 129                 flog_err(
 130                         EC_LIB_DEVELOPMENT,
 131                         "%s %s: missing IP_PKTINFO and IP_RECVDSTADDR: unable to get dst addr from recvmsg()",
 132                         __FILE__, __PRETTY_FUNCTION__);
 133                 close(fd);
 134                 return -1;
 135 #endif
 136         }
 137
 138         {
 139                 int reuse = 1;
 140                 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (void *)&reuse,
 141                                sizeof(reuse))) {
 142                         zlog_warn(
 143                                 "%s: could not set Reuse Address Option on socket fd=%d: errno=%d: %s",
 144                                 __PRETTY_FUNCTION__, fd, errno,
 145                                 safe_strerror(errno));
 146                         close(fd);
 147                         return -1;
 148                 }
 149         }
 150
 151         if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, (void *)&mttl,
 152                        sizeof(mttl))) {
 153                 zlog_warn(
 154                         "%s: could not set multicast TTL=%d on socket fd=%d: errno=%d: %s",
 155                         __PRETTY_FUNCTION__, mttl, fd, errno,
 156                         safe_strerror(errno));
 157                 close(fd);
 158                 return -1;
 159         }
 160
 161         if (setsockopt_ipv4_multicast_loop(fd, 0)) {
 162                 zlog_warn(
 163                         "%s: could not disable Multicast Loopback Option on socket fd=%d: errno=%d: %s",
 164                         __PRETTY_FUNCTION__, fd, errno, safe_strerror(errno));
 165                 close(fd);
 166                 return PIM_SOCK_ERR_LOOP;
 167         }
 168
 169         if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF, (void *)&addr,
 170                        sizeof(addr))) {
 171                 zlog_warn(
 172                         "%s: could not set Outgoing Interface Option on socket fd=%d: errno=%d: %s",
 173                         __PRETTY_FUNCTION__, fd, errno, safe_strerror(errno));
 174                 close(fd);
 175                 return -1;
 176         }
 177
 178         {
 179                 long flags;
 180
 181                 flags = fcntl(fd, F_GETFL, 0);
 182                 if (flags < 0) {
 183                         zlog_warn(
 184                                 "%s: could not get fcntl(F_GETFL,O_NONBLOCK) on socket fd=%d: errno=%d: %s",
 185                                 __PRETTY_FUNCTION__, fd, errno,
 186                                 safe_strerror(errno));
 187                         close(fd);
 188                         return -1;
 189                 }
 190
 191                 if (fcntl(fd, F_SETFL, flags | O_NONBLOCK)) {
 192                         zlog_warn(
 193                                 "%s: could not set fcntl(F_SETFL,O_NONBLOCK) on socket fd=%d: errno=%d: %s",
 194                                 __PRETTY_FUNCTION__, fd, errno,
 195                                 safe_strerror(errno));
 196                         close(fd);
 197                         return -1;
 198                 }
 199         }
 200
 201         return fd;
 202 }
 203
 204 static void ssmpingd_delete(struct ssmpingd_sock *ss)
 205 {
 206         zassert(ss);
 207
 208         THREAD_OFF(ss->t_sock_read);
 209
 210         if (close(ss->sock_fd)) {
 211                 char source_str[INET_ADDRSTRLEN];
 212                 pim_inet4_dump("<src?>", ss->source_addr, source_str,
 213                                sizeof(source_str));
 214                 zlog_warn(
 215                         "%s: failure closing ssmpingd sock_fd=%d for source %s: errno=%d: %s",
 216                         __PRETTY_FUNCTION__, ss->sock_fd, source_str, errno,
 217                         safe_strerror(errno));
 218                 /* warning only */
 219         }
 220
 221         listnode_delete(ss->pim->ssmpingd_list, ss);
 222         ssmpingd_free(ss);
 223 }
 224
 225 static void ssmpingd_sendto(struct ssmpingd_sock *ss, const uint8_t *buf,
 226                             int len, struct sockaddr_in to)
 227 {
 228         socklen_t tolen = sizeof(to);
 229         int sent;
 230
 231         sent = sendto(ss->sock_fd, buf, len, MSG_DONTWAIT,
 232                       (struct sockaddr *)&to, tolen);
 233         if (sent != len) {
 234                 char to_str[INET_ADDRSTRLEN];
 235                 pim_inet4_dump("<to?>", to.sin_addr, to_str, sizeof(to_str));
 236                 if (sent < 0) {
 237                         zlog_warn(
 238                                 "%s: sendto() failure to %s,%d: fd=%d len=%d: errno=%d: %s",
 239                                 __PRETTY_FUNCTION__, to_str, ntohs(to.sin_port),
 240                                 ss->sock_fd, len, errno, safe_strerror(errno));
 241                 } else {
 242                         zlog_warn(
 243                                 "%s: sendto() partial to %s,%d: fd=%d len=%d: sent=%d",
 244                                 __PRETTY_FUNCTION__, to_str, ntohs(to.sin_port),
 245                                 ss->sock_fd, len, sent);
 246                 }
 247         }
 248 }
 249
 250 static int ssmpingd_read_msg(struct ssmpingd_sock *ss)
 251 {
 252         struct interface *ifp;
 253         struct sockaddr_in from;
 254         struct sockaddr_in to;
 255         socklen_t fromlen = sizeof(from);
 256         socklen_t tolen = sizeof(to);
 257         ifindex_t ifindex = -1;
 258         uint8_t buf[1000];
 259         int len;
 260
 261         ++ss->requests;
 262
 263         len = pim_socket_recvfromto(ss->sock_fd, buf, sizeof(buf), &from,
 264                                     &fromlen, &to, &tolen, &ifindex);
 265         if (len < 0) {
 266                 char source_str[INET_ADDRSTRLEN];
 267                 pim_inet4_dump("<src?>", ss->source_addr, source_str,
 268                                sizeof(source_str));
 269                 zlog_warn(
 270                         "%s: failure receiving ssmping for source %s on fd=%d: errno=%d: %s",
 271                         __PRETTY_FUNCTION__, source_str, ss->sock_fd, errno,
 272                         safe_strerror(errno));
 273                 return -1;
 274         }
 275
 276         ifp = if_lookup_by_index(ifindex, ss->pim->vrf_id);
 277
 278         if (buf[0] != PIM_SSMPINGD_REQUEST) {
 279                 char source_str[INET_ADDRSTRLEN];
 280                 char from_str[INET_ADDRSTRLEN];
 281                 char to_str[INET_ADDRSTRLEN];
 282                 pim_inet4_dump("<src?>", ss->source_addr, source_str,
 283                                sizeof(source_str));
 284                 pim_inet4_dump("<from?>", from.sin_addr, from_str,
 285                                sizeof(from_str));
 286                 pim_inet4_dump("<to?>", to.sin_addr, to_str, sizeof(to_str));
 287                 zlog_warn(
 288                         "%s: bad ssmping type=%d from %s,%d to %s,%d on interface %s ifindex=%d fd=%d src=%s",
 289                         __PRETTY_FUNCTION__, buf[0], from_str,
 290                         ntohs(from.sin_port), to_str, ntohs(to.sin_port),
 291                         ifp ? ifp->name : "<iface?>", ifindex, ss->sock_fd,
 292                         source_str);
 293                 return 0;
 294         }
 295
 296         if (PIM_DEBUG_SSMPINGD) {
 297                 char source_str[INET_ADDRSTRLEN];
 298                 char from_str[INET_ADDRSTRLEN];
 299                 char to_str[INET_ADDRSTRLEN];
 300                 pim_inet4_dump("<src?>", ss->source_addr, source_str,
 301                                sizeof(source_str));
 302                 pim_inet4_dump("<from?>", from.sin_addr, from_str,
 303                                sizeof(from_str));
 304                 pim_inet4_dump("<to?>", to.sin_addr, to_str, sizeof(to_str));
 305                 zlog_debug(
 306                         "%s: recv ssmping from %s,%d to %s,%d on interface %s ifindex=%d fd=%d src=%s",
 307                         __PRETTY_FUNCTION__, from_str, ntohs(from.sin_port),
 308                         to_str, ntohs(to.sin_port),
 309                         ifp ? ifp->name : "<iface?>", ifindex, ss->sock_fd,
 310                         source_str);
 311         }
 312
 313         buf[0] = PIM_SSMPINGD_REPLY;
 314
 315         /* unicast reply */
 316         ssmpingd_sendto(ss, buf, len, from);
 317
 318         /* multicast reply */
 319         from.sin_addr = ss->pim->ssmpingd_group_addr;
 320         ssmpingd_sendto(ss, buf, len, from);
 321
 322         return 0;
 323 }
 324
 325 static int ssmpingd_sock_read(struct thread *t)
 326 {
 327         struct ssmpingd_sock *ss;
 328         int result;
 329
 330         ss = THREAD_ARG(t);
 331
 332         result = ssmpingd_read_msg(ss);
 333
 334         /* Keep reading */
 335         ssmpingd_read_on(ss);
 336
 337         return result;
 338 }
 339
 340 static void ssmpingd_read_on(struct ssmpingd_sock *ss)
 341 {
 342         thread_add_read(master, ssmpingd_sock_read, ss, ss->sock_fd,
 343                         &ss->t_sock_read);
 344 }
 345
 346 static struct ssmpingd_sock *ssmpingd_new(struct pim_instance *pim,
 347                                           struct in_addr source_addr)
 348 {
 349         struct ssmpingd_sock *ss;
 350         int sock_fd;
 351
 352         if (!pim->ssmpingd_list) {
 353                 pim->ssmpingd_list = list_new();
 354                 pim->ssmpingd_list->del = (void (*)(void *))ssmpingd_free;
 355         }
 356
 357         sock_fd =
 358                 ssmpingd_socket(source_addr, /* port: */ 4321, /* mTTL: */ 64);
 359         if (sock_fd < 0) {
 360                 char source_str[INET_ADDRSTRLEN];
 361                 pim_inet4_dump("<src?>", source_addr, source_str,
 362                                sizeof(source_str));
 363                 zlog_warn("%s: ssmpingd_socket() failure for source %s",
 364                           __PRETTY_FUNCTION__, source_str);
 365                 return 0;
 366         }
 367
 368         ss = XCALLOC(MTYPE_PIM_SSMPINGD, sizeof(*ss));
 369
 370         ss->pim = pim;
 371         ss->sock_fd = sock_fd;
 372         ss->t_sock_read = NULL;
 373         ss->source_addr = source_addr;
 374         ss->creation = pim_time_monotonic_sec();
 375         ss->requests = 0;
 376
 377         listnode_add(pim->ssmpingd_list, ss);
 378
 379         ssmpingd_read_on(ss);
 380
 381         return ss;
 382 }
 383
 384 int pim_ssmpingd_start(struct pim_instance *pim, struct in_addr source_addr)
 385 {
 386         struct ssmpingd_sock *ss;
 387
 388         ss = ssmpingd_find(pim, source_addr);
 389         if (ss) {
 390                 /* silently ignore request to recreate entry */
 391                 return 0;
 392         }
 393
 394         {
 395                 char source_str[INET_ADDRSTRLEN];
 396                 pim_inet4_dump("<src?>", source_addr, source_str,
 397                                sizeof(source_str));
 398                 zlog_info("%s: starting ssmpingd for source %s",
 399                           __PRETTY_FUNCTION__, source_str);
 400         }
 401
 402         ss = ssmpingd_new(pim, source_addr);
 403         if (!ss) {
 404                 char source_str[INET_ADDRSTRLEN];
 405                 pim_inet4_dump("<src?>", source_addr, source_str,
 406                                sizeof(source_str));
 407                 zlog_warn("%s: ssmpingd_new() failure for source %s",
 408                           __PRETTY_FUNCTION__, source_str);
 409                 return -1;
 410         }
 411
 412         return 0;
 413 }
 414
 415 int pim_ssmpingd_stop(struct pim_instance *pim, struct in_addr source_addr)
 416 {
 417         struct ssmpingd_sock *ss;
 418
 419         ss = ssmpingd_find(pim, source_addr);
 420         if (!ss) {
 421                 char source_str[INET_ADDRSTRLEN];
 422                 pim_inet4_dump("<src?>", source_addr, source_str,
 423                                sizeof(source_str));
 424                 zlog_warn("%s: could not find ssmpingd for source %s",
 425                           __PRETTY_FUNCTION__, source_str);
 426                 return -1;
 427         }
 428
 429         {
 430                 char source_str[INET_ADDRSTRLEN];
 431                 pim_inet4_dump("<src?>", source_addr, source_str,
 432                                sizeof(source_str));
 433                 zlog_info("%s: stopping ssmpingd for source %s",
 434                           __PRETTY_FUNCTION__, source_str);
 435         }
 436
 437         ssmpingd_delete(ss);
 438
 439         return 0;
 440 }