pimd/pim_msdp_socket.c

   1 /*
   2  * IP MSDP socket management
   3  * Copyright (C) 2016 Cumulus Networks, Inc.
   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 <lib/log.h>
  23 #include <lib/network.h>
  24 #include <lib/sockunion.h>
  25 #include <lib/thread.h>
  26 #include <lib/vty.h>
  27 #include <lib/if.h>
  28 #include <lib/vrf.h>
  29 #include <lib/lib_errors.h>
  30
  31 #include "pimd.h"
  32 #include "pim_sock.h"
  33 #include "pim_errors.h"
  34
  35 #include "pim_msdp.h"
  36 #include "pim_msdp_socket.h"
  37
  38 /* increase socket send buffer size */
  39 static void pim_msdp_update_sock_send_buffer_size(int fd)
  40 {
  41         int size = PIM_MSDP_SOCKET_SNDBUF_SIZE;
  42         int optval;
  43         socklen_t optlen = sizeof(optval);
  44
  45         if (getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &optval, &optlen) < 0) {
  46                 flog_err_sys(EC_LIB_SOCKET,
  47                              "getsockopt of SO_SNDBUF failed %s\n",
  48                              safe_strerror(errno));
  49                 return;
  50         }
  51
  52         if (optval < size) {
  53                 if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &size, sizeof(size))
  54                     < 0) {
  55                         flog_err_sys(EC_LIB_SOCKET,
  56                                      "Couldn't increase send buffer: %s\n",
  57                                      safe_strerror(errno));
  58                 }
  59         }
  60 }
  61
  62 /* passive peer socket accept */
  63 static int pim_msdp_sock_accept(struct thread *thread)
  64 {
  65         union sockunion su;
  66         struct pim_instance *pim = THREAD_ARG(thread);
  67         int accept_sock;
  68         int msdp_sock;
  69         struct pim_msdp_peer *mp;
  70         char buf[SU_ADDRSTRLEN];
  71
  72         sockunion_init(&su);
  73
  74         /* re-register accept thread */
  75         accept_sock = THREAD_FD(thread);
  76         if (accept_sock < 0) {
  77                 flog_err(EC_LIB_DEVELOPMENT, "accept_sock is negative value %d",
  78                          accept_sock);
  79                 return -1;
  80         }
  81         pim->msdp.listener.thread = NULL;
  82         thread_add_read(master, pim_msdp_sock_accept, pim, accept_sock,
  83                         &pim->msdp.listener.thread);
  84
  85         /* accept client connection. */
  86         msdp_sock = sockunion_accept(accept_sock, &su);
  87         if (msdp_sock < 0) {
  88                 flog_err_sys(EC_LIB_SOCKET, "pim_msdp_sock_accept failed (%s)",
  89                              safe_strerror(errno));
  90                 return -1;
  91         }
  92
  93         /* see if have peer config for this */
  94         mp = pim_msdp_peer_find(pim, su.sin.sin_addr);
  95         if (!mp || !PIM_MSDP_PEER_IS_LISTENER(mp)) {
  96                 ++pim->msdp.rejected_accepts;
  97                 if (PIM_DEBUG_MSDP_EVENTS) {
  98                         flog_err(EC_PIM_MSDP_PACKET,
  99                                  "msdp peer connection refused from %s",
 100                                  sockunion2str(&su, buf, SU_ADDRSTRLEN));
 101                 }
 102                 close(msdp_sock);
 103                 return -1;
 104         }
 105
 106         if (PIM_DEBUG_MSDP_INTERNAL) {
 107                 zlog_debug("MSDP peer %s accept success%s", mp->key_str,
 108                            mp->fd >= 0 ? "(dup)" : "");
 109         }
 110
 111         /* if we have an existing connection we need to kill that one
 112          * with this one */
 113         if (mp->fd >= 0) {
 114                 if (PIM_DEBUG_MSDP_EVENTS) {
 115                         zlog_notice(
 116                                 "msdp peer new connection from %s stop old connection",
 117                                 sockunion2str(&su, buf, SU_ADDRSTRLEN));
 118                 }
 119                 pim_msdp_peer_stop_tcp_conn(mp, true /* chg_state */);
 120         }
 121         mp->fd = msdp_sock;
 122         set_nonblocking(mp->fd);
 123         pim_msdp_update_sock_send_buffer_size(mp->fd);
 124         pim_msdp_peer_established(mp);
 125         return 0;
 126 }
 127
 128 /* global listener for the MSDP well know TCP port */
 129 int pim_msdp_sock_listen(struct pim_instance *pim)
 130 {
 131         int sock;
 132         int socklen;
 133         struct sockaddr_in sin;
 134         int rc;
 135         struct pim_msdp_listener *listener = &pim->msdp.listener;
 136
 137         if (pim->msdp.flags & PIM_MSDPF_LISTENER) {
 138                 /* listener already setup */
 139                 return 0;
 140         }
 141
 142         sock = socket(AF_INET, SOCK_STREAM, 0);
 143         if (sock < 0) {
 144                 flog_err_sys(EC_LIB_SOCKET, "socket: %s", safe_strerror(errno));
 145                 return sock;
 146         }
 147
 148         memset(&sin, 0, sizeof(struct sockaddr_in));
 149         sin.sin_family = AF_INET;
 150         sin.sin_port = htons(PIM_MSDP_TCP_PORT);
 151         socklen = sizeof(struct sockaddr_in);
 152 #ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
 153         sin.sin_len = socklen;
 154 #endif /* HAVE_STRUCT_SOCKADDR_IN_SIN_LEN */
 155
 156         sockopt_reuseaddr(sock);
 157         sockopt_reuseport(sock);
 158
 159         if (pim->vrf_id != VRF_DEFAULT) {
 160                 struct interface *ifp =
 161                         if_lookup_by_name(pim->vrf->name, pim->vrf_id);
 162                 if (!ifp) {
 163                         flog_err(EC_LIB_INTERFACE,
 164                                  "%s: Unable to lookup vrf interface: %s",
 165                                  __PRETTY_FUNCTION__, pim->vrf->name);
 166                         close(sock);
 167                         return -1;
 168                 }
 169                 if (pim_socket_bind(sock, ifp)) {
 170                         flog_err_sys(EC_LIB_SOCKET,
 171                                      "%s: Unable to bind to socket: %s",
 172                                      __PRETTY_FUNCTION__, safe_strerror(errno));
 173                         close(sock);
 174                         return -1;
 175                 }
 176         }
 177
 178         frr_elevate_privs(&pimd_privs) {
 179                 /* bind to well known TCP port */
 180                 rc = bind(sock, (struct sockaddr *)&sin, socklen);
 181         }
 182
 183         if (rc < 0) {
 184                 flog_err_sys(EC_LIB_SOCKET,
 185                              "pim_msdp_socket bind to port %d: %s",
 186                              ntohs(sin.sin_port), safe_strerror(errno));
 187                 close(sock);
 188                 return rc;
 189         }
 190
 191         rc = listen(sock, 3 /* backlog */);
 192         if (rc < 0) {
 193                 flog_err_sys(EC_LIB_SOCKET, "pim_msdp_socket listen: %s",
 194                              safe_strerror(errno));
 195                 close(sock);
 196                 return rc;
 197         }
 198
 199         /* add accept thread */
 200         listener->fd = sock;
 201         memcpy(&listener->su, &sin, socklen);
 202         listener->thread = NULL;
 203         thread_add_read(pim->msdp.master, pim_msdp_sock_accept, pim, sock,
 204                         &listener->thread);
 205
 206         pim->msdp.flags |= PIM_MSDPF_LISTENER;
 207         return 0;
 208 }
 209
 210 /* active peer socket setup */
 211 int pim_msdp_sock_connect(struct pim_msdp_peer *mp)
 212 {
 213         int rc;
 214
 215         if (PIM_DEBUG_MSDP_INTERNAL) {
 216                 zlog_debug("MSDP peer %s attempt connect%s", mp->key_str,
 217                            mp->fd < 0 ? "" : "(dup)");
 218         }
 219
 220         /* if we have an existing connection we need to kill that one
 221          * with this one */
 222         if (mp->fd >= 0) {
 223                 if (PIM_DEBUG_MSDP_EVENTS) {
 224                         zlog_notice(
 225                                 "msdp duplicate connect to %s nuke old connection",
 226                                 mp->key_str);
 227                 }
 228                 pim_msdp_peer_stop_tcp_conn(mp, false /* chg_state */);
 229         }
 230
 231         /* Make socket for the peer. */
 232         mp->fd = sockunion_socket(&mp->su_peer);
 233         if (mp->fd < 0) {
 234                 flog_err_sys(EC_LIB_SOCKET,
 235                              "pim_msdp_socket socket failure: %s",
 236                              safe_strerror(errno));
 237                 return -1;
 238         }
 239
 240         if (mp->pim->vrf_id != VRF_DEFAULT) {
 241                 struct interface *ifp =
 242                         if_lookup_by_name(mp->pim->vrf->name, mp->pim->vrf_id);
 243                 if (!ifp) {
 244                         flog_err(EC_LIB_INTERFACE,
 245                                  "%s: Unable to lookup vrf interface: %s",
 246                                  __PRETTY_FUNCTION__, mp->pim->vrf->name);
 247                         return -1;
 248                 }
 249                 if (pim_socket_bind(mp->fd, ifp)) {
 250                         flog_err_sys(EC_LIB_SOCKET,
 251                                      "%s: Unable to bind to socket: %s",
 252                                      __PRETTY_FUNCTION__, safe_strerror(errno));
 253                         close(mp->fd);
 254                         mp->fd = -1;
 255                         return -1;
 256                 }
 257         }
 258
 259         set_nonblocking(mp->fd);
 260
 261         /* Set socket send buffer size */
 262         pim_msdp_update_sock_send_buffer_size(mp->fd);
 263         sockopt_reuseaddr(mp->fd);
 264         sockopt_reuseport(mp->fd);
 265
 266         /* source bind */
 267         rc = sockunion_bind(mp->fd, &mp->su_local, 0, &mp->su_local);
 268         if (rc < 0) {
 269                 flog_err_sys(EC_LIB_SOCKET,
 270                              "pim_msdp_socket connect bind failure: %s",
 271                              safe_strerror(errno));
 272                 close(mp->fd);
 273                 mp->fd = -1;
 274                 return rc;
 275         }
 276
 277         /* Connect to the remote mp. */
 278         return (sockunion_connect(mp->fd, &mp->su_peer,
 279                                   htons(PIM_MSDP_TCP_PORT), 0));
 280 }