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(LIB_ERR_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(LIB_ERR_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(LIB_ERR_DEVELOPMENT,
  78                           "accept_sock is negative value %d", 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(LIB_ERR_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(PIM_ERR_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(LIB_ERR_SOCKET, "socket: %s",
 145                              safe_strerror(errno));
 146                 return sock;
 147         }
 148
 149         memset(&sin, 0, sizeof(struct sockaddr_in));
 150         sin.sin_family = AF_INET;
 151         sin.sin_port = htons(PIM_MSDP_TCP_PORT);
 152         socklen = sizeof(struct sockaddr_in);
 153 #ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
 154         sin.sin_len = socklen;
 155 #endif /* HAVE_STRUCT_SOCKADDR_IN_SIN_LEN */
 156
 157         sockopt_reuseaddr(sock);
 158         sockopt_reuseport(sock);
 159
 160         if (pim->vrf_id != VRF_DEFAULT) {
 161                 struct interface *ifp =
 162                         if_lookup_by_name(pim->vrf->name, pim->vrf_id);
 163                 if (!ifp) {
 164                         flog_err(LIB_ERR_INTERFACE,
 165                                   "%s: Unable to lookup vrf interface: %s",
 166                                   __PRETTY_FUNCTION__, pim->vrf->name);
 167                         close(sock);
 168                         return -1;
 169                 }
 170                 if (pim_socket_bind(sock, ifp)) {
 171                         flog_err_sys(LIB_ERR_SOCKET,
 172                                      "%s: Unable to bind to socket: %s",
 173                                      __PRETTY_FUNCTION__, safe_strerror(errno));
 174                         close(sock);
 175                         return -1;
 176                 }
 177         }
 178
 179         frr_elevate_privs(&pimd_privs) {
 180                 /* bind to well known TCP port */
 181                 rc = bind(sock, (struct sockaddr *)&sin, socklen);
 182         }
 183
 184         if (rc < 0) {
 185                 flog_err_sys(LIB_ERR_SOCKET,
 186                              "pim_msdp_socket bind to port %d: %s",
 187                              ntohs(sin.sin_port), safe_strerror(errno));
 188                 close(sock);
 189                 return rc;
 190         }
 191
 192         rc = listen(sock, 3 /* backlog */);
 193         if (rc < 0) {
 194                 flog_err_sys(LIB_ERR_SOCKET, "pim_msdp_socket listen: %s",
 195                              safe_strerror(errno));
 196                 close(sock);
 197                 return rc;
 198         }
 199
 200         /* add accept thread */
 201         listener->fd = sock;
 202         memcpy(&listener->su, &sin, socklen);
 203         listener->thread = NULL;
 204         thread_add_read(pim->msdp.master, pim_msdp_sock_accept, pim, sock,
 205                         &listener->thread);
 206
 207         pim->msdp.flags |= PIM_MSDPF_LISTENER;
 208         return 0;
 209 }
 210
 211 /* active peer socket setup */
 212 int pim_msdp_sock_connect(struct pim_msdp_peer *mp)
 213 {
 214         int rc;
 215
 216         if (PIM_DEBUG_MSDP_INTERNAL) {
 217                 zlog_debug("MSDP peer %s attempt connect%s", mp->key_str,
 218                            mp->fd < 0 ? "" : "(dup)");
 219         }
 220
 221         /* if we have an existing connection we need to kill that one
 222          * with this one */
 223         if (mp->fd >= 0) {
 224                 if (PIM_DEBUG_MSDP_EVENTS) {
 225                         zlog_notice(
 226                                 "msdp duplicate connect to %s nuke old connection",
 227                                 mp->key_str);
 228                 }
 229                 pim_msdp_peer_stop_tcp_conn(mp, false /* chg_state */);
 230         }
 231
 232         /* Make socket for the peer. */
 233         mp->fd = sockunion_socket(&mp->su_peer);
 234         if (mp->fd < 0) {
 235                 flog_err_sys(LIB_ERR_SOCKET,
 236                              "pim_msdp_socket socket failure: %s",
 237                              safe_strerror(errno));
 238                 return -1;
 239         }
 240
 241         if (mp->pim->vrf_id != VRF_DEFAULT) {
 242                 struct interface *ifp =
 243                         if_lookup_by_name(mp->pim->vrf->name, mp->pim->vrf_id);
 244                 if (!ifp) {
 245                         flog_err(LIB_ERR_INTERFACE,
 246                                   "%s: Unable to lookup vrf interface: %s",
 247                                   __PRETTY_FUNCTION__, mp->pim->vrf->name);
 248                         return -1;
 249                 }
 250                 if (pim_socket_bind(mp->fd, ifp)) {
 251                         flog_err_sys(LIB_ERR_SOCKET,
 252                                      "%s: Unable to bind to socket: %s",
 253                                      __PRETTY_FUNCTION__, safe_strerror(errno));
 254                         close(mp->fd);
 255                         mp->fd = -1;
 256                         return -1;
 257                 }
 258         }
 259
 260         set_nonblocking(mp->fd);
 261
 262         /* Set socket send buffer size */
 263         pim_msdp_update_sock_send_buffer_size(mp->fd);
 264         sockopt_reuseaddr(mp->fd);
 265         sockopt_reuseport(mp->fd);
 266
 267         /* source bind */
 268         rc = sockunion_bind(mp->fd, &mp->su_local, 0, &mp->su_local);
 269         if (rc < 0) {
 270                 flog_err_sys(LIB_ERR_SOCKET,
 271                              "pim_msdp_socket connect bind failure: %s",
 272                              safe_strerror(errno));
 273                 close(mp->fd);
 274                 mp->fd = -1;
 275                 return rc;
 276         }
 277
 278         /* Connect to the remote mp. */
 279         return (sockunion_connect(mp->fd, &mp->su_peer,
 280                                   htons(PIM_MSDP_TCP_PORT), 0));
 281 }