diff options
Diffstat (limited to 'bgpd/bgp_network.c')
| -rw-r--r-- | bgpd/bgp_network.c | 1059 |
1 files changed, 1059 insertions, 0 deletions
diff --git a/bgpd/bgp_network.c b/bgpd/bgp_network.c new file mode 100644 index 0000000..d831c6a --- /dev/null +++ b/bgpd/bgp_network.c @@ -0,0 +1,1059 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* BGP network related fucntions + * Copyright (C) 1999 Kunihiro Ishiguro + */ + +#include <zebra.h> + +#include "frrevent.h" +#include "sockunion.h" +#include "sockopt.h" +#include "memory.h" +#include "log.h" +#include "if.h" +#include "prefix.h" +#include "command.h" +#include "privs.h" +#include "linklist.h" +#include "network.h" +#include "queue.h" +#include "hash.h" +#include "filter.h" +#include "ns.h" +#include "lib_errors.h" +#include "nexthop.h" + +#include "bgpd/bgpd.h" +#include "bgpd/bgp_open.h" +#include "bgpd/bgp_fsm.h" +#include "bgpd/bgp_attr.h" +#include "bgpd/bgp_debug.h" +#include "bgpd/bgp_errors.h" +#include "bgpd/bgp_network.h" +#include "bgpd/bgp_zebra.h" +#include "bgpd/bgp_nht.h" + +extern struct zebra_privs_t bgpd_privs; + +static char *bgp_get_bound_name(struct peer_connection *connection); + +void bgp_dump_listener_info(struct vty *vty) +{ + struct listnode *node; + struct bgp_listener *listener; + + vty_out(vty, "Name fd Address\n"); + vty_out(vty, "---------------------------\n"); + for (ALL_LIST_ELEMENTS_RO(bm->listen_sockets, node, listener)) + vty_out(vty, "%-16s %d %pSU\n", + listener->name ? listener->name : VRF_DEFAULT_NAME, + listener->fd, &listener->su); +} + +/* + * Set MD5 key for the socket, for the given IPv4 peer address. + * If the password is NULL or zero-length, the option will be disabled. + */ +static int bgp_md5_set_socket(int socket, union sockunion *su, + uint16_t prefixlen, const char *password) +{ + int ret = -1; + int en = ENOSYS; +#if HAVE_DECL_TCP_MD5SIG + union sockunion su2; +#endif /* HAVE_TCP_MD5SIG */ + + assert(socket >= 0); + +#if HAVE_DECL_TCP_MD5SIG + /* Ensure there is no extraneous port information. */ + memcpy(&su2, su, sizeof(union sockunion)); + if (su2.sa.sa_family == AF_INET) + su2.sin.sin_port = 0; + else + su2.sin6.sin6_port = 0; + + /* For addresses, use the non-extended signature functionality */ + if ((su2.sa.sa_family == AF_INET && prefixlen == IPV4_MAX_BITLEN) + || (su2.sa.sa_family == AF_INET6 && prefixlen == IPV6_MAX_BITLEN)) + ret = sockopt_tcp_signature(socket, &su2, password); + else + ret = sockopt_tcp_signature_ext(socket, &su2, prefixlen, + password); + en = errno; +#endif /* HAVE_TCP_MD5SIG */ + + if (ret < 0) { + switch (ret) { + case -2: + flog_warn( + EC_BGP_NO_TCP_MD5, + "Unable to set TCP MD5 option on socket for peer %pSU (sock=%d): This platform does not support MD5 auth for prefixes", + su, socket); + break; + default: + flog_warn( + EC_BGP_NO_TCP_MD5, + "Unable to set TCP MD5 option on socket for peer %pSU (sock=%d): %s", + su, socket, safe_strerror(en)); + } + } + + return ret; +} + +/* Helper for bgp_connect */ +static int bgp_md5_set_connect(int socket, union sockunion *su, + uint16_t prefixlen, const char *password) +{ + int ret = -1; + +#if HAVE_DECL_TCP_MD5SIG + frr_with_privs(&bgpd_privs) { + ret = bgp_md5_set_socket(socket, su, prefixlen, password); + } +#endif /* HAVE_TCP_MD5SIG */ + + return ret; +} + +static int bgp_md5_set_password(struct peer_connection *connection, + const char *password) +{ + struct listnode *node; + int ret = 0; + struct bgp_listener *listener; + struct peer *peer = connection->peer; + + /* + * Set or unset the password on the listen socket(s). Outbound + * connections are taken care of in bgp_connect() below. + */ + frr_with_privs(&bgpd_privs) { + for (ALL_LIST_ELEMENTS_RO(bm->listen_sockets, node, listener)) + if (listener->su.sa.sa_family == + connection->su.sa.sa_family) { + uint16_t prefixlen = + connection->su.sa.sa_family == AF_INET + ? IPV4_MAX_BITLEN + : IPV6_MAX_BITLEN; + + /* + * if we have stored a BGP vrf instance in the + * listener it must match the bgp instance in + * the peer otherwise the peer bgp instance + * must be the default vrf or a view instance + */ + if (!listener->bgp) { + if (peer->bgp->vrf_id != VRF_DEFAULT) + continue; + } else if (listener->bgp != peer->bgp) + continue; + + ret = bgp_md5_set_socket(listener->fd, + &connection->su, + prefixlen, password); + break; + } + } + return ret; +} + +int bgp_md5_set_prefix(struct bgp *bgp, struct prefix *p, const char *password) +{ + int ret = 0; + union sockunion su; + struct listnode *node; + struct bgp_listener *listener; + + /* Set or unset the password on the listen socket(s). */ + frr_with_privs(&bgpd_privs) { + for (ALL_LIST_ELEMENTS_RO(bm->listen_sockets, node, listener)) + if (listener->su.sa.sa_family == p->family + && ((bgp->vrf_id == VRF_DEFAULT) + || (listener->bgp == bgp))) { + prefix2sockunion(p, &su); + ret = bgp_md5_set_socket(listener->fd, &su, + p->prefixlen, + password); + break; + } + } + + return ret; +} + +int bgp_md5_unset_prefix(struct bgp *bgp, struct prefix *p) +{ + return bgp_md5_set_prefix(bgp, p, NULL); +} + +int bgp_md5_set(struct peer_connection *connection) +{ + /* Set the password from listen socket. */ + return bgp_md5_set_password(connection, connection->peer->password); +} + +static void bgp_update_setsockopt_tcp_keepalive(struct bgp *bgp, int fd) +{ + if (!bgp) + return; + if (bgp->tcp_keepalive_idle != 0) { + int ret; + + ret = setsockopt_tcp_keepalive(fd, bgp->tcp_keepalive_idle, + bgp->tcp_keepalive_intvl, + bgp->tcp_keepalive_probes); + if (ret < 0) + zlog_err( + "Can't set TCP keepalive on socket %d, idle %u intvl %u probes %u", + fd, bgp->tcp_keepalive_idle, + bgp->tcp_keepalive_intvl, + bgp->tcp_keepalive_probes); + } +} + +int bgp_md5_unset(struct peer_connection *connection) +{ + /* Unset the password from listen socket. */ + return bgp_md5_set_password(connection, NULL); +} + +int bgp_set_socket_ttl(struct peer_connection *connection) +{ + int ret = 0; + struct peer *peer = connection->peer; + + if (!peer->gtsm_hops) { + ret = sockopt_ttl(connection->su.sa.sa_family, connection->fd, + peer->ttl); + if (ret) { + flog_err( + EC_LIB_SOCKET, + "%s: Can't set TxTTL on peer (rtrid %pI4) socket, err = %d", + __func__, &peer->remote_id, errno); + return ret; + } + } else { + /* On Linux, setting minttl without setting ttl seems to mess + with the + outgoing ttl. Therefore setting both. + */ + ret = sockopt_ttl(connection->su.sa.sa_family, connection->fd, + MAXTTL); + if (ret) { + flog_err( + EC_LIB_SOCKET, + "%s: Can't set TxTTL on peer (rtrid %pI4) socket, err = %d", + __func__, &peer->remote_id, errno); + return ret; + } + ret = sockopt_minttl(connection->su.sa.sa_family, connection->fd, + MAXTTL + 1 - peer->gtsm_hops); + if (ret) { + flog_err( + EC_LIB_SOCKET, + "%s: Can't set MinTTL on peer (rtrid %pI4) socket, err = %d", + __func__, &peer->remote_id, errno); + return ret; + } + } + + return ret; +} + +/* + * Obtain the BGP instance that the incoming connection should be processed + * against. This is important because more than one VRF could be using the + * same IP address space. The instance is got by obtaining the device to + * which the incoming connection is bound to. This could either be a VRF + * or it could be an interface, which in turn determines the VRF. + */ +static int bgp_get_instance_for_inc_conn(int sock, struct bgp **bgp_inst) +{ +#ifndef SO_BINDTODEVICE + /* only Linux has SO_BINDTODEVICE, but we're in Linux-specific code here + * anyway since the assumption is that the interface name returned by + * getsockopt() is useful in identifying the VRF, particularly with + * Linux's + * VRF l3master device. The whole mechanism is specific to Linux, so... + * when other platforms add VRF support, this will need handling here as + * well. (or, some restructuring) */ + *bgp_inst = bgp_get_default(); + return !*bgp_inst; + +#else + char name[VRF_NAMSIZ + 1]; + socklen_t name_len = VRF_NAMSIZ; + struct bgp *bgp; + int rc; + struct listnode *node, *nnode; + + *bgp_inst = NULL; + name[0] = '\0'; + rc = getsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, name, &name_len); + if (rc != 0) { +#if defined(HAVE_CUMULUS) + flog_err(EC_LIB_SOCKET, + "[Error] BGP SO_BINDTODEVICE get failed (%s), sock %d", + safe_strerror(errno), sock); + return -1; +#endif + } + + if (!strlen(name)) { + *bgp_inst = bgp_get_default(); + return 0; /* default instance. */ + } + + /* First try match to instance; if that fails, check for interfaces. */ + bgp = bgp_lookup_by_name(name); + if (bgp) { + if (!bgp->vrf_id) // unexpected + return -1; + *bgp_inst = bgp; + return 0; + } + + /* TODO - This will be optimized once interfaces move into the NS */ + for (ALL_LIST_ELEMENTS(bm->bgp, node, nnode, bgp)) { + struct interface *ifp; + + if (bgp->inst_type == BGP_INSTANCE_TYPE_VIEW) + continue; + + ifp = if_lookup_by_name(name, bgp->vrf_id); + if (ifp) { + *bgp_inst = bgp; + return 0; + } + } + + /* We didn't match to either an instance or an interface. */ + return -1; +#endif +} + +int bgp_tcp_mss_set(struct peer *peer) +{ + struct listnode *node; + int ret = 0; + struct bgp_listener *listener; + uint32_t min_mss = 0; + struct peer *p; + + for (ALL_LIST_ELEMENTS_RO(peer->bgp->peer, node, p)) { + if (!CHECK_FLAG(p->flags, PEER_FLAG_TCP_MSS)) + continue; + + if (!p->tcp_mss) + continue; + + if (!min_mss) + min_mss = p->tcp_mss; + + min_mss = MIN(min_mss, p->tcp_mss); + } + + frr_with_privs(&bgpd_privs) { + for (ALL_LIST_ELEMENTS_RO(bm->listen_sockets, node, listener)) { + if (listener->su.sa.sa_family != + peer->connection->su.sa.sa_family) + continue; + + if (!listener->bgp) { + if (peer->bgp->vrf_id != VRF_DEFAULT) + continue; + } else if (listener->bgp != peer->bgp) + continue; + + /* Set TCP MSS per listener only if there is at least + * one peer that is in passive mode. Otherwise, TCP MSS + * is set per socket via bgp_connect(). + */ + if (CHECK_FLAG(peer->flags, PEER_FLAG_PASSIVE)) + sockopt_tcp_mss_set(listener->fd, min_mss); + + break; + } + } + + return ret; +} + +static void bgp_socket_set_buffer_size(const int fd) +{ + if (getsockopt_so_sendbuf(fd) < (int)bm->socket_buffer) + setsockopt_so_sendbuf(fd, bm->socket_buffer); + if (getsockopt_so_recvbuf(fd) < (int)bm->socket_buffer) + setsockopt_so_recvbuf(fd, bm->socket_buffer); +} + +/* Accept bgp connection. */ +static void bgp_accept(struct event *thread) +{ + int bgp_sock; + int accept_sock; + union sockunion su; + struct bgp_listener *listener = EVENT_ARG(thread); + struct peer *peer, *peer1; + struct peer_connection *connection, *connection1; + char buf[SU_ADDRSTRLEN]; + struct bgp *bgp = NULL; + + sockunion_init(&su); + + bgp = bgp_lookup_by_name(listener->name); + + /* Register accept thread. */ + accept_sock = EVENT_FD(thread); + if (accept_sock < 0) { + flog_err_sys(EC_LIB_SOCKET, + "[Error] BGP accept socket fd is negative: %d", + accept_sock); + return; + } + + event_add_read(bm->master, bgp_accept, listener, accept_sock, + &listener->thread); + + /* Accept client connection. */ + bgp_sock = sockunion_accept(accept_sock, &su); + int save_errno = errno; + if (bgp_sock < 0) { + if (save_errno == EINVAL) { + struct vrf *vrf = + bgp ? vrf_lookup_by_id(bgp->vrf_id) : NULL; + + /* + * It appears that sometimes, when VRFs are deleted on + * the system, it takes a little while for us to get + * notified about that. In the meantime we endlessly + * loop on accept(), because the socket, having been + * bound to a now-deleted VRF device, is in some weird + * state which causes accept() to fail. + * + * To avoid this, if we see accept() fail with EINVAL, + * we cancel ourselves and trust that when the VRF + * deletion notification comes in the event handler for + * that will take care of cleaning us up. + */ + flog_err_sys( + EC_LIB_SOCKET, + "[Error] accept() failed with error \"%s\" on BGP listener socket %d for BGP instance in VRF \"%s\"; refreshing socket", + safe_strerror(save_errno), accept_sock, + VRF_LOGNAME(vrf)); + EVENT_OFF(listener->thread); + } else { + flog_err_sys( + EC_LIB_SOCKET, + "[Error] BGP socket accept failed (%s); retrying", + safe_strerror(save_errno)); + } + return; + } + set_nonblocking(bgp_sock); + + /* Obtain BGP instance this connection is meant for. + * - if it is a VRF netns sock, then BGP is in listener structure + * - otherwise, the bgp instance need to be demultiplexed + */ + if (listener->bgp) + bgp = listener->bgp; + else if (bgp_get_instance_for_inc_conn(bgp_sock, &bgp)) { + if (bgp_debug_neighbor_events(NULL)) + zlog_debug( + "[Event] Could not get instance for incoming conn from %s", + inet_sutop(&su, buf)); + close(bgp_sock); + return; + } + + bgp_socket_set_buffer_size(bgp_sock); + + /* Set TCP keepalive when TCP keepalive is enabled */ + bgp_update_setsockopt_tcp_keepalive(bgp, bgp_sock); + + /* Check remote IP address */ + peer1 = peer_lookup(bgp, &su); + + if (!peer1) { + peer1 = peer_lookup_dynamic_neighbor(bgp, &su); + if (peer1) { + connection1 = peer1->connection; + /* Dynamic neighbor has been created, let it proceed */ + connection1->fd = bgp_sock; + + /* Set the user configured MSS to TCP socket */ + if (CHECK_FLAG(peer1->flags, PEER_FLAG_TCP_MSS)) + sockopt_tcp_mss_set(bgp_sock, peer1->tcp_mss); + + bgp_fsm_change_status(connection1, Active); + EVENT_OFF(connection1->t_start); + + if (peer_active(peer1)) { + if (CHECK_FLAG(peer1->flags, + PEER_FLAG_TIMER_DELAYOPEN)) + BGP_EVENT_ADD(connection1, + TCP_connection_open_w_delay); + else + BGP_EVENT_ADD(connection1, + TCP_connection_open); + } + + return; + } + } + + if (!peer1) { + if (bgp_debug_neighbor_events(NULL)) { + zlog_debug( + "[Event] %s connection rejected(%s:%u:%s) - not configured and not valid for dynamic", + inet_sutop(&su, buf), bgp->name_pretty, bgp->as, + VRF_LOGNAME(vrf_lookup_by_id(bgp->vrf_id))); + } + close(bgp_sock); + return; + } + + connection1 = peer1->connection; + if (CHECK_FLAG(peer1->flags, PEER_FLAG_SHUTDOWN) + || CHECK_FLAG(peer1->bgp->flags, BGP_FLAG_SHUTDOWN)) { + if (bgp_debug_neighbor_events(peer1)) + zlog_debug( + "[Event] connection from %s rejected(%s:%u:%s) due to admin shutdown", + inet_sutop(&su, buf), bgp->name_pretty, bgp->as, + VRF_LOGNAME(vrf_lookup_by_id(bgp->vrf_id))); + close(bgp_sock); + return; + } + + /* + * Do not accept incoming connections in Clearing state. This can result + * in incorect state transitions - e.g., the connection goes back to + * Established and then the Clearing_Completed event is generated. Also, + * block incoming connection in Deleted state. + */ + if (connection1->status == Clearing || connection1->status == Deleted) { + if (bgp_debug_neighbor_events(peer1)) + zlog_debug("[Event] Closing incoming conn for %s (%p) state %d", + peer1->host, peer1, + peer1->connection->status); + close(bgp_sock); + return; + } + + /* Check that at least one AF is activated for the peer. */ + if (!peer_active(peer1)) { + if (bgp_debug_neighbor_events(peer1)) + zlog_debug( + "%s - incoming conn rejected - no AF activated for peer", + peer1->host); + close(bgp_sock); + return; + } + + /* Do not try to reconnect if the peer reached maximum + * prefixes, restart timer is still running or the peer + * is shutdown. + */ + if (BGP_PEER_START_SUPPRESSED(peer1)) { + if (bgp_debug_neighbor_events(peer1)) { + if (peer1->shut_during_cfg) + zlog_debug( + "[Event] Incoming BGP connection rejected from %s due to configuration being currently read in", + peer1->host); + else + zlog_debug( + "[Event] Incoming BGP connection rejected from %s due to maximum-prefix or shutdown", + peer1->host); + } + close(bgp_sock); + return; + } + + if (bgp_debug_neighbor_events(peer1)) + zlog_debug("[Event] connection from %s fd %d, active peer status %d fd %d", + inet_sutop(&su, buf), bgp_sock, connection1->status, + connection1->fd); + + if (peer1->doppelganger) { + /* We have an existing connection. Kill the existing one and run + with this one. + */ + if (bgp_debug_neighbor_events(peer1)) + zlog_debug( + "[Event] New active connection from peer %s, Killing previous active connection", + peer1->host); + peer_delete(peer1->doppelganger); + } + + peer = peer_create(&su, peer1->conf_if, peer1->bgp, peer1->local_as, + peer1->as, peer1->as_type, NULL, false, NULL); + + connection = peer->connection; + + peer_xfer_config(peer, peer1); + bgp_peer_gr_flags_update(peer); + + BGP_GR_ROUTER_DETECT_AND_SEND_CAPABILITY_TO_ZEBRA(peer->bgp, + peer->bgp->peer); + + if (bgp_peer_gr_mode_get(peer) == PEER_DISABLE) { + + UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_MODE); + + if (CHECK_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT)) { + peer_nsf_stop(peer); + } + } + + peer->doppelganger = peer1; + peer1->doppelganger = peer; + connection->fd = bgp_sock; + + if (bgp_set_socket_ttl(connection) < 0) + if (bgp_debug_neighbor_events(peer)) + zlog_debug("[Event] Unable to set min/max TTL on peer %s, Continuing", + peer->host); + + frr_with_privs(&bgpd_privs) { + vrf_bind(peer->bgp->vrf_id, bgp_sock, + bgp_get_bound_name(peer->connection)); + } + bgp_peer_reg_with_nht(peer); + bgp_fsm_change_status(connection, Active); + EVENT_OFF(connection->t_start); /* created in peer_create() */ + + SET_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER); + /* Make dummy peer until read Open packet. */ + if (peer_established(connection1) && + CHECK_FLAG(peer1->sflags, PEER_STATUS_NSF_MODE)) { + /* If we have an existing established connection with graceful + * restart + * capability announced with one or more address families, then + * drop + * existing established connection and move state to connect. + */ + peer1->last_reset = PEER_DOWN_NSF_CLOSE_SESSION; + + if (CHECK_FLAG(peer1->flags, PEER_FLAG_GRACEFUL_RESTART) + || CHECK_FLAG(peer1->flags, + PEER_FLAG_GRACEFUL_RESTART_HELPER)) + SET_FLAG(peer1->sflags, PEER_STATUS_NSF_WAIT); + + bgp_event_update(connection1, TCP_connection_closed); + } + + if (peer_active(peer)) { + if (CHECK_FLAG(peer->flags, PEER_FLAG_TIMER_DELAYOPEN)) + BGP_EVENT_ADD(connection, TCP_connection_open_w_delay); + else + BGP_EVENT_ADD(connection, TCP_connection_open); + } + + /* + * If we are doing nht for a peer that is v6 LL based + * massage the event system to make things happy + */ + bgp_nht_interface_events(peer); +} + +/* BGP socket bind. */ +static char *bgp_get_bound_name(struct peer_connection *connection) +{ + struct peer *peer = connection->peer; + + if ((peer->bgp->vrf_id == VRF_DEFAULT) && !peer->ifname + && !peer->conf_if) + return NULL; + + if (connection->su.sa.sa_family != AF_INET && + connection->su.sa.sa_family != AF_INET6) + return NULL; // unexpected + + /* For IPv6 peering, interface (unnumbered or link-local with interface) + * takes precedence over VRF. For IPv4 peering, explicit interface or + * VRF are the situations to bind. + */ + if (connection->su.sa.sa_family == AF_INET6 && peer->conf_if) + return peer->conf_if; + + if (peer->ifname) + return peer->ifname; + + if (peer->bgp->inst_type == BGP_INSTANCE_TYPE_VIEW) + return NULL; + + return peer->bgp->name; +} + +int bgp_update_address(struct interface *ifp, const union sockunion *dst, + union sockunion *addr) +{ + struct prefix *p, *sel, d; + struct connected *connected; + struct listnode *node; + int common; + + if (!sockunion2hostprefix(dst, &d)) + return 1; + + sel = NULL; + common = -1; + + for (ALL_LIST_ELEMENTS_RO(ifp->connected, node, connected)) { + p = connected->address; + if (p->family != d.family) + continue; + if (prefix_common_bits(p, &d) > common) { + sel = p; + common = prefix_common_bits(sel, &d); + } + } + + if (!sel) + return 1; + + prefix2sockunion(sel, addr); + return 0; +} + +/* Update source selection. */ +static int bgp_update_source(struct peer_connection *connection) +{ + struct interface *ifp; + union sockunion addr; + int ret = 0; + struct peer *peer = connection->peer; + + sockunion_init(&addr); + + /* Source is specified with interface name. */ + if (peer->update_if) { + ifp = if_lookup_by_name(peer->update_if, peer->bgp->vrf_id); + if (!ifp) + return -1; + + if (bgp_update_address(ifp, &connection->su, &addr)) + return -1; + + ret = sockunion_bind(connection->fd, &addr, 0, &addr); + } + + /* Source is specified with IP address. */ + if (peer->update_source) + ret = sockunion_bind(connection->fd, peer->update_source, 0, + peer->update_source); + + return ret; +} + +/* BGP try to connect to the peer. */ +int bgp_connect(struct peer_connection *connection) +{ + struct peer *peer = connection->peer; + + assert(!CHECK_FLAG(connection->thread_flags, PEER_THREAD_WRITES_ON)); + assert(!CHECK_FLAG(connection->thread_flags, PEER_THREAD_READS_ON)); + ifindex_t ifindex = 0; + + if (peer->conf_if && BGP_CONNECTION_SU_UNSPEC(connection)) { + if (bgp_debug_neighbor_events(peer)) + zlog_debug("Peer address not learnt: Returning from connect"); + return 0; + } + frr_with_privs(&bgpd_privs) { + /* Make socket for the peer. */ + connection->fd = + vrf_sockunion_socket(&connection->su, peer->bgp->vrf_id, + bgp_get_bound_name(connection)); + } + if (connection->fd < 0) { + peer->last_reset = PEER_DOWN_SOCKET_ERROR; + if (bgp_debug_neighbor_events(peer)) + zlog_debug("%s: Failure to create socket for connection to %s, error received: %s(%d)", + __func__, peer->host, safe_strerror(errno), + errno); + return -1; + } + + set_nonblocking(connection->fd); + + /* Set the user configured MSS to TCP socket */ + if (CHECK_FLAG(peer->flags, PEER_FLAG_TCP_MSS)) + sockopt_tcp_mss_set(connection->fd, peer->tcp_mss); + + bgp_socket_set_buffer_size(connection->fd); + + /* Set TCP keepalive when TCP keepalive is enabled */ + bgp_update_setsockopt_tcp_keepalive(peer->bgp, connection->fd); + + if (bgp_set_socket_ttl(peer->connection) < 0) { + peer->last_reset = PEER_DOWN_SOCKET_ERROR; + if (bgp_debug_neighbor_events(peer)) + zlog_debug("%s: Failure to set socket ttl for connection to %s, error received: %s(%d)", + __func__, peer->host, safe_strerror(errno), + errno); + + return -1; + } + + sockopt_reuseaddr(connection->fd); + sockopt_reuseport(connection->fd); + +#ifdef IPTOS_PREC_INTERNETCONTROL + frr_with_privs(&bgpd_privs) { + if (sockunion_family(&connection->su) == AF_INET) + setsockopt_ipv4_tos(connection->fd, bm->tcp_dscp); + else if (sockunion_family(&connection->su) == AF_INET6) + setsockopt_ipv6_tclass(connection->fd, bm->tcp_dscp); + } +#endif + + if (peer->password) { + uint16_t prefixlen = peer->connection->su.sa.sa_family == AF_INET + ? IPV4_MAX_BITLEN + : IPV6_MAX_BITLEN; + + if (!BGP_CONNECTION_SU_UNSPEC(connection)) + bgp_md5_set(connection); + + bgp_md5_set_connect(connection->fd, &connection->su, prefixlen, + peer->password); + } + + /* Update source bind. */ + if (bgp_update_source(connection) < 0) { + peer->last_reset = PEER_DOWN_SOCKET_ERROR; + return connect_error; + } + + /* If the peer is passive mode, force to move to Active mode. */ + if (CHECK_FLAG(peer->flags, PEER_FLAG_PASSIVE)) { + BGP_EVENT_ADD(connection, TCP_connection_open_failed); + return BGP_FSM_SUCCESS; + } + + if (peer->conf_if || peer->ifname) + ifindex = ifname2ifindex(peer->conf_if ? peer->conf_if + : peer->ifname, + peer->bgp->vrf_id); + + if (bgp_debug_neighbor_events(peer)) + zlog_debug("%s [Event] Connect start to %s fd %d", peer->host, + peer->host, connection->fd); + + /* Connect to the remote peer. */ + return sockunion_connect(connection->fd, &connection->su, + htons(peer->port), ifindex); +} + +/* After TCP connection is established. Get local address and port. */ +int bgp_getsockname(struct peer *peer) +{ + if (peer->su_local) { + sockunion_free(peer->su_local); + peer->su_local = NULL; + } + + if (peer->su_remote) { + sockunion_free(peer->su_remote); + peer->su_remote = NULL; + } + + peer->su_local = sockunion_getsockname(peer->connection->fd); + if (!peer->su_local) + return -1; + peer->su_remote = sockunion_getpeername(peer->connection->fd); + if (!peer->su_remote) + return -1; + + if (!bgp_zebra_nexthop_set(peer->su_local, peer->su_remote, + &peer->nexthop, peer)) { + flog_err( + EC_BGP_NH_UPD, + "%s: nexthop_set failed, local: %pSUp remote: %pSUp update_if: %s resetting connection - intf %s", + peer->host, peer->su_local, peer->su_remote, + peer->update_if ? peer->update_if : "(None)", + peer->nexthop.ifp ? peer->nexthop.ifp->name + : "(Unknown)"); + return -1; + } + return 0; +} + + +static int bgp_listener(int sock, struct sockaddr *sa, socklen_t salen, + struct bgp *bgp) +{ + struct bgp_listener *listener; + int ret, en; + + sockopt_reuseaddr(sock); + sockopt_reuseport(sock); + + frr_with_privs(&bgpd_privs) { + +#ifdef IPTOS_PREC_INTERNETCONTROL + if (sa->sa_family == AF_INET) + setsockopt_ipv4_tos(sock, bm->tcp_dscp); + else if (sa->sa_family == AF_INET6) + setsockopt_ipv6_tclass(sock, bm->tcp_dscp); +#endif + + sockopt_v6only(sa->sa_family, sock); + + ret = bind(sock, sa, salen); + en = errno; + } + + if (ret < 0) { + flog_err_sys(EC_LIB_SOCKET, "bind: %s", safe_strerror(en)); + return ret; + } + + ret = listen(sock, SOMAXCONN); + if (ret < 0) { + flog_err_sys(EC_LIB_SOCKET, "listen: %s", safe_strerror(errno)); + return ret; + } + + listener = XCALLOC(MTYPE_BGP_LISTENER, sizeof(*listener)); + listener->fd = sock; + listener->name = XSTRDUP(MTYPE_BGP_LISTENER, bgp->name); + + /* this socket is in a vrf record bgp back pointer */ + if (bgp->vrf_id != VRF_DEFAULT) + listener->bgp = bgp; + + memcpy(&listener->su, sa, salen); + event_add_read(bm->master, bgp_accept, listener, sock, + &listener->thread); + listnode_add(bm->listen_sockets, listener); + + return 0; +} + +/* IPv6 supported version of BGP server socket setup. */ +int bgp_socket(struct bgp *bgp, unsigned short port, const char *address) +{ + struct addrinfo *ainfo; + struct addrinfo *ainfo_save; + static const struct addrinfo req = { + .ai_family = AF_UNSPEC, + .ai_flags = AI_PASSIVE, + .ai_socktype = SOCK_STREAM, + }; + int ret, count; + char port_str[BUFSIZ]; + + snprintf(port_str, sizeof(port_str), "%d", port); + port_str[sizeof(port_str) - 1] = '\0'; + + frr_with_privs(&bgpd_privs) { + ret = vrf_getaddrinfo(address, port_str, &req, &ainfo_save, + bgp->vrf_id); + } + if (ret != 0) { + flog_err_sys(EC_LIB_SOCKET, "getaddrinfo: %s", + gai_strerror(ret)); + return -1; + } + if (bgp_option_check(BGP_OPT_NO_ZEBRA) && + bgp->vrf_id != VRF_DEFAULT) { + freeaddrinfo(ainfo_save); + return -1; + } + count = 0; + for (ainfo = ainfo_save; ainfo; ainfo = ainfo->ai_next) { + int sock; + + if (ainfo->ai_family != AF_INET && ainfo->ai_family != AF_INET6) + continue; + + frr_with_privs(&bgpd_privs) { + sock = vrf_socket(ainfo->ai_family, + ainfo->ai_socktype, + ainfo->ai_protocol, + bgp->vrf_id, + (bgp->inst_type + == BGP_INSTANCE_TYPE_VRF + ? bgp->name : NULL)); + } + if (sock < 0) { + flog_err_sys(EC_LIB_SOCKET, "socket: %s", + safe_strerror(errno)); + continue; + } + + /* if we intend to implement ttl-security, this socket needs + * ttl=255 */ + sockopt_ttl(ainfo->ai_family, sock, MAXTTL); + + ret = bgp_listener(sock, ainfo->ai_addr, ainfo->ai_addrlen, + bgp); + if (ret == 0) + ++count; + else + close(sock); + } + freeaddrinfo(ainfo_save); + if (count == 0 && bgp->inst_type != BGP_INSTANCE_TYPE_VRF) { + flog_err( + EC_LIB_SOCKET, + "%s: no usable addresses please check other programs usage of specified port %d", + __func__, port); + flog_err_sys(EC_LIB_SOCKET, "%s: Program cannot continue", + __func__); + exit(-1); + } + + return 0; +} + +/* this function closes vrf socket + * this should be called only for vrf socket with netns backend + */ +void bgp_close_vrf_socket(struct bgp *bgp) +{ + struct listnode *node, *next; + struct bgp_listener *listener; + + if (!bgp) + return; + + if (bm->listen_sockets == NULL) + return; + + for (ALL_LIST_ELEMENTS(bm->listen_sockets, node, next, listener)) { + if (listener->bgp == bgp) { + EVENT_OFF(listener->thread); + close(listener->fd); + listnode_delete(bm->listen_sockets, listener); + XFREE(MTYPE_BGP_LISTENER, listener->name); + XFREE(MTYPE_BGP_LISTENER, listener); + } + } +} + +/* this function closes main socket + */ +void bgp_close(void) +{ + struct listnode *node, *next; + struct bgp_listener *listener; + + if (bm->listen_sockets == NULL) + return; + + for (ALL_LIST_ELEMENTS(bm->listen_sockets, node, next, listener)) { + if (listener->bgp) + continue; + EVENT_OFF(listener->thread); + close(listener->fd); + listnode_delete(bm->listen_sockets, listener); + XFREE(MTYPE_BGP_LISTENER, listener->name); + XFREE(MTYPE_BGP_LISTENER, listener); + } +} |