/* * Copyright (c) 2011-2016 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /** * @file * @brief BFD nodes implementation */ #if WITH_LIBSSL > 0 #include #endif #if __SSE4_2__ #include #endif #include #include #include #include #include #include #include #include #include static u64 bfd_calc_echo_checksum (u32 discriminator, u64 expire_time, u32 secret) { u64 checksum = 0; #if __SSE4_2__ && !defined (__i386__) checksum = _mm_crc32_u64 (0, discriminator); checksum = _mm_crc32_u64 (checksum, expire_time); checksum = _mm_crc32_u64 (checksum, secret); #else checksum = clib_xxhash (discriminator ^ expire_time ^ secret); #endif return checksum; } static u64 bfd_usec_to_clocks (const bfd_main_t * bm, u64 us) { return bm->cpu_cps * ((f64) us / USEC_PER_SECOND); } u32 bfd_clocks_to_usec (const bfd_main_t * bm, u64 clocks) { return (clocks / bm->cpu_cps) * USEC_PER_SECOND; } static vlib_node_registration_t bfd_process_node; u8 * format_bfd_auth_key (u8 * s, va_list * args) { const bfd_auth_key_t *key = va_arg (*args, bfd_auth_key_t *); if (key) { s = format (s, "{auth-type=%u:%s, conf-key-id=%u, use-count=%u}, ", key->auth_type, bfd_auth_type_str (key->auth_type), key->conf_key_id, key->use_count); } else { s = format (s, "{none}"); } return s; } /* * We actually send all bfd pkts to the "error" node after scanning * them, so the graph node has only one next-index. The "error-drop" * node automatically bumps our per-node packet counters for us. */ typedef enum { BFD_INPUT_NEXT_NORMAL, BFD_INPUT_N_NEXT, } bfd_input_next_t; static void bfd_on_state_change (bfd_main_t * bm, bfd_session_t * bs, u64 now, int handling_wakeup); static void bfd_set_defaults (bfd_main_t * bm, bfd_session_t * bs) { bs->local_state = BFD_STATE_down; bs->local_diag = BFD_DIAG_CODE_no_diag; bs->remote_state = BFD_STATE_down; bs->remote_discr = 0; bs->hop_type = BFD_HOP_TYPE_SINGLE; bs->config_desired_min_tx_usec = BFD_DEFAULT_DESIRED_MIN_TX_USEC; bs->config_desired_min_tx_clocks = bm->default_desired_min_tx_clocks; bs->effective_desired_min_tx_clocks = bm->default_desired_min_tx_clocks; bs->remote_min_rx_usec = 1; bs->remote_min_rx_clocks = bfd_usec_to_clocks (bm, bs->remote_min_rx_usec); bs->remote_min_echo_rx_usec = 0; bs->remote_min_echo_rx_clocks = 0; bs->remote_demand = 0; bs->auth.remote_seq_number = 0; bs->auth.remote_seq_number_known = 0; bs->auth.local_seq_number = random_u32 (&bm->random_seed); bs->echo_secret = random_u32 (&bm->random_seed); } static void bfd_set_diag (bfd_session_t * bs, bfd_diag_code_e code) { if (bs->local_diag != code) { BFD_DBG ("set local_diag, bs_idx=%d: '%d:%s'", bs->bs_idx, code, bfd_diag_code_string (code)); bs->local_diag = code; } } static void bfd_set_state (bfd_main_t * bm, bfd_session_t * bs, bfd_state_e new_state, int handling_wakeup) { if (bs->local_state != new_state) { BFD_DBG ("Change state, bs_idx=%d: %s->%s", bs->bs_idx, bfd_state_string (bs->local_state), bfd_state_string (new_state)); bs->local_state = new_state; bfd_on_state_change (bm, bs, clib_cpu_time_now (), handling_wakeup); } } const char * bfd_poll_state_string (bfd_poll_state_e state) { switch (state) { #define F(x) \ case BFD_POLL_##x: \ return "BFD_POLL_" #x; foreach_bfd_poll_state (F) #undef F } return "UNKNOWN"; } static void bfd_set_poll_state (bfd_session_t * bs, bfd_poll_state_e state) { if (bs->poll_state != state) { BFD_DBG ("Setting poll state=%s, bs_idx=%u", bfd_poll_state_string (state), bs->bs_idx); bs->poll_state = state; } } static void bfd_recalc_tx_interval (bfd_main_t * bm, bfd_session_t * bs) { bs->transmit_interval_clocks = clib_max (bs->effective_desired_min_tx_clocks, bs->remote_min_rx_clocks); BFD_DBG ("Recalculated transmit interval " BFD_CLK_FMT, BFD_CLK_PRN (bs->transmit_interval_clocks)); } static void bfd_recalc_echo_tx_interval (bfd_main_t * bm, bfd_session_t * bs) { bs->echo_transmit_interval_clocks = clib_max (bs->effective_desired_min_tx_clocks, bs->remote_min_echo_rx_clocks); BFD_DBG ("Recalculated echo transmit interval " BFD_CLK_FMT, BFD_CLK_PRN (bs->echo_transmit_interval_clocks)); } static void bfd_calc_next_tx (bfd_main_t * bm, bfd_session_t * bs, u64 now) { if (bs->local_detect_mult > 1) { /* common case - 75-100% of transmit interval */ bs->tx_timeout_clocks = bs->last_tx_clocks + (1 - .25 * (random_f64 (&bm->random_seed))) * bs->transmit_interval_clocks; if (bs->tx_timeout_clocks < now) { /* * the timeout is in the past, which means that either remote * demand mode was set or performance/clock issues ... */ BFD_DBG ("Missed %lu transmit events (now is %lu, calc " "tx_timeout is %lu)", (now - bs->tx_timeout_clocks) / bs->transmit_interval_clocks, now, bs->tx_timeout_clocks); bs->tx_timeout_clocks = now; } } else { /* special case - 75-90% of transmit interval */ bs->tx_timeout_clocks = bs->last_tx_clocks + (.9 - .15 * (random_f64 (&bm->random_seed))) * bs->transmit_interval_clocks; if (bs->tx_timeout_clocks < now) { /* * the timeout is in the past, which means that either remote * demand mode was set or performance/clock issues ... */ BFD_DBG ("Missed %lu transmit events (now is %lu, calc " "tx_timeout is %lu)", (now - bs->tx_timeout_clocks) / bs->transmit_interval_clocks, now, bs->tx_timeout_clocks); bs->tx_timeout_clocks = now; } } if (bs->tx_timeout_clocks) { BFD_DBG ("Next transmit in %lu clocks/%.02fs@%lu", bs->tx_timeout_clocks - now, (bs->tx_timeout_clocks - now) / bm->cpu_cps, bs->tx_timeout_clocks); } } static void bfd_calc_next_echo_tx (bfd_main_t * bm, bfd_session_t * bs, u64 now) { bs->echo_tx_timeout_clocks = bs->echo_last_tx_clocks + bs->echo_transmit_interval_clocks; if (bs->echo_tx_timeout_clocks < now) { /* huh, we've missed it already, transmit now */ BFD_DBG ("Missed %lu echo transmit events (now is %lu, calc tx_timeout " "is %lu)", (now - bs->echo_tx_timeout_clocks) / bs->echo_transmit_interval_clocks, now, bs->echo_tx_timeout_clocks); bs->echo_tx_timeout_clocks = now; } BFD_DBG ("Next echo transmit in %lu clocks/%.02fs@%lu", bs->echo_tx_timeout_clocks - now, (bs->echo_tx_timeout_clocks - now) / bm->cpu_cps, bs->echo_tx_timeout_clocks); } static void bfd_recalc_detection_time (bfd_main_t * bm, bfd_session_t * bs) { if (bs->local_state == BFD_STATE_init || bs->local_state == BFD_STATE_up) { bs->detection_time_clocks = bs->remote_detect_mult * clib_max (bs->effective_required_min_rx_clocks, bs->remote_desired_min_tx_clocks); BFD_DBG ("Recalculated detection time %lu clocks/%.2fs", bs->detection_time_clocks, bs->detection_time_clocks / bm->cpu_cps); } } static void bfd_set_timer (bfd_main_t * bm, bfd_session_t * bs, u64 now, int handling_wakeup) { u64 next = 0; u64 rx_timeout = 0; u64 tx_timeout = 0; if (BFD_STATE_up == bs->local_state) { rx_timeout = bs->last_rx_clocks + bs->detection_time_clocks; } if (BFD_STATE_up != bs->local_state || (!bs->remote_demand && bs->remote_min_rx_usec) || BFD_POLL_NOT_NEEDED != bs->poll_state) { tx_timeout = bs->tx_timeout_clocks; } if (tx_timeout && rx_timeout) { next = clib_min (tx_timeout, rx_timeout); } else if (tx_timeout) { next = tx_timeout; } else if (rx_timeout) { next = rx_timeout; } if (bs->echo && next > bs->echo_tx_timeout_clocks) { next = bs->echo_tx_timeout_clocks; } BFD_DBG ("bs_idx=%u, tx_timeout=%lu, echo_tx_timeout=%lu, rx_timeout=%lu, " "next=%s", bs->bs_idx, tx_timeout, bs->echo_tx_timeout_clocks, rx_timeout, next == tx_timeout ? "tx" : (next == bs->echo_tx_timeout_clocks ? "echo tx" : "rx")); /* sometimes the wheel expires an event a bit sooner than requested, account for that here */ if (next && (now + bm->wheel_inaccuracy > bs->wheel_time_clocks || next < bs->wheel_time_clocks || !bs->wheel_time_clocks)) { bs->wheel_time_clocks = next; BFD_DBG ("timing_wheel_insert(%p, %lu (%ld clocks/%.2fs in the " "future), %u);", &bm->wheel, bs->wheel_time_clocks, (i64) bs->wheel_time_clocks - clib_cpu_time_now (), (i64) (bs->wheel_time_clocks - clib_cpu_time_now ()) / bm->cpu_cps, bs->bs_idx); timing_wheel_insert (&bm->wheel, bs->wheel_time_clocks, bs->bs_idx); if (!handling_wakeup) { vlib_process_signal_event (bm->vlib_main, bm->bfd_process_node_index, BFD_EVENT_RESCHEDULE, bs->bs_idx); } } } static void bfd_set_effective_desired_min_tx (bfd_main_t * bm, bfd_session_t * bs, u64 now, u64 desired_min_tx_clocks) { bs->effective_desired_min_tx_clocks = desired_min_tx_clocks; BFD_DBG ("Set effective desired min tx to " BFD_CLK_FMT, BFD_CLK_PRN (bs->effective_desired_min_tx_clocks)); bfd_recalc_detection_time (bm, bs); bfd_recalc_tx_interval (bm, bs); bfd_recalc_echo_tx_interval (bm, bs); bfd_calc_next_tx (bm, bs, now); } static void bfd_set_effective_required_min_rx (bfd_main_t * bm, bfd_session_t * bs, u64 required_min_rx_clocks) { bs->effective_required_min_rx_clocks = required_min_rx_clocks; BFD_DBG ("Set effective required min rx to " BFD_CLK_FMT, BFD_CLK_PRN (bs->effective_required_min_rx_clocks)); bfd_recalc_detection_time (bm, bs); } static void bfd_set_remote_required_min_rx (bfd_main_t * bm, bfd_session_t * bs, u64 now, u32 remote_required_min_rx_usec) { if (bs->remote_min_rx_usec != remote_required_min_rx_usec) { bs->remote_min_rx_usec = remote_required_min_rx_usec; bs->remote_min_rx_clocks = bfd_usec_to_clocks (bm, remote_required_min_rx_usec); BFD_DBG ("Set remote min rx to " BFD_CLK_FMT, BFD_CLK_PRN (bs->remote_min_rx_clocks)); bfd_recalc_detection_time (bm, bs); bfd_recalc_tx_interval (bm, bs); } } static void bfd_set_remote_required_min_echo_rx (bfd_main_t * bm, bfd_session_t * bs, u64 now, u32 remote_required_min_echo_rx_usec) { if (bs->remote_min_echo_rx_usec != remote_required_min_echo_rx_usec) { bs->remote_min_echo_rx_usec = remote_required_min_echo_rx_usec; bs->remote_min_echo_rx_clocks = bfd_usec_to_clocks (bm, bs->remote_min_echo_rx_usec); BFD_DBG ("Set remote min echo rx to " BFD_CLK_FMT, BFD_CLK_PRN (bs->remote_min_echo_rx_clocks)); bfd_recalc_echo_tx_interval (bm, bs); } } static void bfd_notify_listeners (bfd_main_t * bm, bfd_listen_event_e event, const bfd_session_t * bs) { bfd_notify_fn_t *fn; vec_foreach (fn, bm->listeners) { (*fn) (event, bs); } } void bfd_session_start (bfd_main_t * bm, bfd_session_t * bs) { BFD_DBG ("\nStarting session: %U", format_bfd_session, bs); bfd_set_effective_required_min_rx (bm, bs, bs->config_required_min_rx_clocks); bfd_recalc_tx_interval (bm, bs); vlib_process_signal_event (bm->vlib_main, bm->bfd_process_node_index, BFD_EVENT_NEW_SESSION, bs->bs_idx); bfd_notify_listeners (bm, BFD_LISTEN_EVENT_CREATE, bs); } void bfd_session_set_flags (bfd_session_t * bs, u8 admin_up_down) { bfd_main_t *bm = &bfd_main; u64 now = clib_cpu_time_now (); if (admin_up_down) { BFD_DBG ("Session set admin-up, bs-idx=%u", bs->bs_idx); bfd_set_state (bm, bs, BFD_STATE_down, 0); bfd_set_diag (bs, BFD_DIAG_CODE_no_diag); bfd_calc_next_tx (bm, bs, now); bfd_set_timer (bm, bs, now, 0); } else { BFD_DBG ("Session set admin-down, bs-idx=%u", bs->bs_idx); bfd_set_diag (bs, BFD_DIAG_CODE_admin_down); bfd_set_state (bm, bs, BFD_STATE_admin_down, 0); bfd_calc_next_tx (bm, bs, now); bfd_set_timer (bm, bs, now, 0); } } u8 * bfd_input_format_trace (u8 * s, va_list * args) { CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); const bfd_input_trace_t *t = va_arg (*args, bfd_input_trace_t *); const bfd_pkt_t *pkt = (bfd_pkt_t *) t->data; if (t->len > STRUCT_SIZE_OF (bfd_pkt_t, head)) { s = format (s, "BFD v%u, diag=%u(%s), state=%u(%s),\n" " flags=(P:%u, F:%u, C:%u, A:%u, D:%u, M:%u), " "detect_mult=%u, length=%u\n", bfd_pkt_get_version (pkt), bfd_pkt_get_diag_code (pkt), bfd_diag_code_string (bfd_pkt_get_diag_code (pkt)), bfd_pkt_get_state (pkt), bfd_state_string (bfd_pkt_get_state (pkt)), bfd_pkt_get_poll (pkt), bfd_pkt_get_final (pkt), bfd_pkt_get_control_plane_independent (pkt), bfd_pkt_get_auth_present (pkt), bfd_pkt_get_demand (pkt), bfd_pkt_get_multipoint (pkt), pkt->head.detect_mult, pkt->head.length); if (t->len >= sizeof (bfd_pkt_t) && pkt->head.length >= sizeof (bfd_pkt_t)) { s = format (s, " my discriminator: %u\n", clib_net_to_host_u32 (pkt->my_disc)); s = format (s, " your discriminator: %u\n", clib_net_to_host_u32 (pkt->your_disc)); s = format (s, " desired min tx interval: %u\n", clib_net_to_host_u32 (pkt->des_min_tx)); s = format (s, " required min rx interval: %u\n", clib_net_to_host_u32 (pkt->req_min_rx)); s = format (s, " required min echo rx interval: %u", clib_net_to_host_u32 (pkt->req_min_echo_rx)); } if (t->len >= sizeof (bfd_pkt_with_common_auth_t) && pkt->head.length >= sizeof (bfd_pkt_with_common_auth_t) && bfd_pkt_get_auth_present (pkt)) { const bfd_pkt_with_common_auth_t *with_auth = (void *) pkt; const bfd_auth_common_t *common = &with_auth->common_auth; s = format (s, "\n auth len: %u\n", common->len); s = format (s, " auth type: %u:%s\n", common->type, bfd_auth_type_str (common->type)); if (t->len >= sizeof (bfd_pkt_with_sha1_auth_t) && pkt->head.length >= sizeof (bfd_pkt_with_sha1_auth_t) && (BFD_AUTH_TYPE_keyed_sha1 == common->type || BFD_AUTH_TYPE_meticulous_keyed_sha1 == common->type)) { const bfd_pkt_with_sha1_auth_t *with_sha1 = (void *) pkt; const bfd_auth_sha1_t *sha1 = &with_sha1->sha1_auth; s = format (s, " seq num: %u\n", clib_net_to_host_u32 (sha1->seq_num)); s = format (s, " key id: %u\n", sha1->key_id); s = format (s, " hash: %U", format_hex_bytes, sha1->hash, sizeof (sha1->hash)); } } else { s = format (s, "\n"); } } return s; } static void bfd_on_state_change (bfd_main_t * bm, bfd_session_t * bs, u64 now, int handling_wakeup) { BFD_DBG ("\nState changed: %U", format_bfd_session, bs); bfd_event (bm, bs); switch (bs->local_state) { case BFD_STATE_admin_down: bs->echo = 0; bfd_set_effective_desired_min_tx (bm, bs, now, clib_max (bs->config_desired_min_tx_clocks, bm->default_desired_min_tx_clocks)); bfd_set_effective_required_min_rx (bm, bs, bs->config_required_min_rx_clocks); bfd_set_timer (bm, bs, now, handling_wakeup); break; case BFD_STATE_down: bs->echo = 0; bfd_set_effective_desired_min_tx (bm, bs, now, clib_max (bs->config_desired_min_tx_clocks, bm->default_desired_min_tx_clocks)); bfd_set_effective_required_min_rx (bm, bs, bs->config_required_min_rx_clocks); bfd_set_timer (bm, bs, now, handling_wakeup); break; case BFD_STATE_init: bs->echo = 0; bfd_set_effective_desired_min_tx (bm, bs, now, bs->config_desired_min_tx_clocks); bfd_set_timer (bm, bs, now, handling_wakeup); break; case BFD_STATE_up: bfd_set_effective_desired_min_tx (bm, bs, now, bs->config_desired_min_tx_clocks); if (BFD_POLL_NOT_NEEDED == bs->poll_state) { bfd_set_effective_required_min_rx (bm, bs, bs->config_required_min_rx_clocks); } bfd_set_timer (bm, bs, now, handling_wakeup); break; } bfd_notify_listeners (bm, BFD_LISTEN_EVENT_UPDATE, bs); } static void bfd_on_config_change (vlib_main_t * vm, vlib_node_runtime_t * rt, bfd_main_t * bm, bfd_session_t * bs, u64 now) { /* * if remote demand mode is set and we need to do a poll, set the next * timeout so that the session wakes up immediately */ if (bs->remote_demand && BFD_POLL_NEEDED == bs->poll_state && bs->poll_state_start_or_timeout_clocks < now) { bs->tx_timeout_clocks = now; } bfd_recalc_detection_time (bm, bs); bfd_set_timer (bm, bs, now, 0); } static void bfd_add_transport_layer (vlib_main_t * vm, u32 bi, bfd_session_t * bs) { switch (bs->transport) { case BFD_TRANSPORT_UDP4: BFD_DBG ("Transport bfd via udp4, bs_idx=%u", bs->bs_idx); bfd_add_udp4_transport (vm, bi, bs, 0 /* is_echo */ ); break; case BFD_TRANSPORT_UDP6: BFD_DBG ("Transport bfd via udp6, bs_idx=%u", bs->bs_idx); bfd_add_udp6_transport (vm, bi, bs, 0 /* is_echo */ ); break; } } static int bfd_transport_control_frame (vlib_main_t * vm, u32 bi, bfd_session_t * bs) { switch (bs->transport) { case BFD_TRANSPORT_UDP4: BFD_DBG ("Transport bfd via udp4, bs_idx=%u", bs->bs_idx); return bfd_transport_udp4 (vm, bi, bs); break; case BFD_TRANSPORT_UDP6: BFD_DBG ("Transport bfd via udp6, bs_idx=%u", bs->bs_idx); return bfd_transport_udp6 (vm, bi, bs); break; } return 0; } static int bfd_echo_add_transport_layer (vlib_main_t * vm, u32 bi, bfd_session_t * bs) { switch (bs->transport) { case BFD_TRANSPORT_UDP4: BFD_DBG ("Transport bfd echo via udp4, bs_idx=%u", bs->bs_idx); return bfd_add_udp4_transport (vm, bi, bs, 1 /* is_echo */ ); break; case BFD_TRANSPORT_UDP6: BFD_DBG ("Transport bfd echo via udp6, bs_idx=%u", bs->bs_idx); return bfd_add_udp6_transport (vm, bi, bs, 1 /* is_echo */ ); break; } return 0; } static int bfd_transport_echo (vlib_main_t * vm, u32 bi, bfd_session_t * bs) { switch (bs->transport) { case BFD_TRANSPORT_UDP4: BFD_DBG ("Transport bfd echo via udp4, bs_idx=%u", bs->bs_idx); return bfd_transport_udp4 (vm, bi, bs); break; case BFD_TRANSPORT_UDP6: BFD_DBG ("Transport bfd echo via udp6, bs_idx=%u", bs->bs_idx); return bfd_transport_udp6 (vm, bi, bs); break; } return 0; } #if WITH_LIBSSL > 0 static void bfd_add_sha1_auth_section (vlib_buffer_t * b, bfd_session_t * bs) { bfd_pkt_with_sha1_auth_t *pkt = vlib_buffer_get_current (b); bfd_auth_sha1_t *auth = &pkt->sha1_auth; b->current_length += sizeof (*auth); pkt->pkt.head.length += sizeof (*auth); bfd_pkt_set_auth_present (&pkt->pkt); memset (auth, 0, sizeof (*auth)); auth->type_len.type = bs->auth.curr_key->auth_type; /* * only meticulous authentication types require incrementing seq number * for every message, but doing so doesn't violate the RFC */ ++bs->auth.local_seq_number; auth->type_len.len = sizeof (bfd_auth_sha1_t); auth->key_id = bs->auth.curr_bfd_key_id; auth->seq_num = clib_host_to_net_u32 (bs->auth.local_seq_number); /* * first copy the password into the packet, then calculate the hash * and finally replace the password with the calculated hash */ clib_memcpy (auth->hash, bs->auth.curr_key->key, sizeof (bs->auth.curr_key->key)); unsigned char hash[sizeof (auth->hash)]; SHA1 ((unsigned char *) pkt, sizeof (*pkt), hash); BFD_DBG ("hashing: %U", format_hex_bytes, pkt, sizeof (*pkt)); clib_memcpy (auth->hash, hash, sizeof (hash)); } #endif static void bfd_add_auth_section (vlib_buffer_t * b, bfd_session_t * bs) { if (bs->auth.curr_key) { const bfd_auth_type_e auth_type = bs->auth.curr_key->auth_type; switch (auth_type) { case BFD_AUTH_TYPE_reserved: /* fallthrough */ case BFD_AUTH_TYPE_simple_password: /* fallthrough */ case BFD_AUTH_TYPE_keyed_md5: /* fallthrough */ case BFD_AUTH_TYPE_meticulous_keyed_md5: clib_warning ("Internal error, unexpected BFD auth type '%d'", auth_type); break; #if WITH_LIBSSL > 0 case BFD_AUTH_TYPE_keyed_sha1: /* fallthrough */ case BFD_AUTH_TYPE_meticulous_keyed_sha1: bfd_add_sha1_auth_section (b, bs); break; #else case BFD_AUTH_TYPE_keyed_sha1: /* fallthrough */ case BFD_AUTH_TYPE_meticulous_keyed_sha1: clib_warning ("Internal error, unexpected BFD auth type '%d'", auth_type); break; #endif } } } static int bfd_is_echo_possible (bfd_session_t * bs) { if (BFD_STATE_up == bs->local_state && BFD_STATE_up == bs->remote_state && bs->remote_min_echo_rx_usec > 0) { switch (bs->transport) { case BFD_TRANSPORT_UDP4: return bfd_udp_is_echo_available (BFD_TRANSPORT_UDP4); case BFD_TRANSPORT_UDP6: return bfd_udp_is_echo_available (BFD_TRANSPORT_UDP6); } } return 0; } static void bfd_init_control_frame (bfd_main_t * bm, bfd_session_t * bs, vlib_buffer_t * b) { bfd_pkt_t *pkt = vlib_buffer_get_current (b); u32 bfd_length = 0; bfd_length = sizeof (bfd_pkt_t); memset (pkt, 0, sizeof (*pkt)); bfd_pkt_set_version (pkt, 1); bfd_pkt_set_diag_code (pkt, bs->local_diag); bfd_pkt_set_state (pkt, bs->local_state); pkt->head.detect_mult = bs->local_detect_mult; pkt->head.length = bfd_length; pkt->my_disc = bs->local_discr; pkt->your_disc = bs->remote_discr; pkt->des_min_tx = clib_host_to_net_u32 (bs->config_desired_min_tx_usec); if (bs->echo) { pkt->req_min_rx = clib_host_to_net_u32 (bfd_clocks_to_usec (bm, bs->effective_required_min_rx_clocks)); } else { pkt->req_min_rx = clib_host_to_net_u32 (bs->config_required_min_rx_usec); } pkt->req_min_echo_rx = clib_host_to_net_u32 (1); b->current_length = bfd_length; } static void bfd_send_echo (vlib_main_t * vm, vlib_node_runtime_t * rt, bfd_main_t * bm, bfd_session_t * bs, u64 now) { if (!bfd_is_echo_possible (bs)) { BFD_DBG ("\nSwitching off echo function: %U", format_bfd_session, bs); bs->echo = 0; return; } /* sometimes the wheel expires an event a bit sooner than requested, account for that here */ if (now + bm->wheel_inaccuracy >= bs->echo_tx_timeout_clocks) { BFD_DBG ("\nSending echo packet: %U", format_bfd_session, bs); u32 bi; if (vlib_buffer_alloc (vm, &bi, 1) != 1) { clib_warning ("buffer allocation failure"); return; } vlib_buffer_t *b = vlib_get_buffer (vm, bi); ASSERT (b->current_data == 0); memset (vnet_buffer (b), 0, sizeof (*vnet_buffer (b))); VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b); bfd_echo_pkt_t *pkt = vlib_buffer_get_current (b); memset (pkt, 0, sizeof (*pkt)); pkt->discriminator = bs->local_discr; pkt->expire_time_clocks = now + bs->echo_transmit_interval_clocks * bs->local_detect_mult; pkt->checksum = bfd_calc_echo_checksum (bs->local_discr, pkt->expire_time_clocks, bs->echo_secret); b->current_length = sizeof (*pkt); if (!bfd_echo_add_transport_layer (vm, bi, bs)) { BFD_ERR ("cannot send echo packet out, turning echo off"); bs->echo = 0; vlib_buffer_free_one (vm, bi); return; } if (!bfd_transport_echo (vm, bi, bs)) { BFD_ERR ("cannot send echo packet out, turning echo off"); bs->echo = 0; vlib_buffer_free_one (vm, bi); return; } bs->echo_last_tx_clocks = now; bfd_calc_next_echo_tx (bm, bs, now); } else { BFD_DBG ("No need to send echo packet now, now is %lu, tx_timeout is %lu", now, bs->echo_tx_timeout_clocks); } } static void bfd_send_periodic (vlib_main_t * vm, vlib_node_runtime_t * rt, bfd_main_t * bm, bfd_session_t * bs, u64 now) { if (!bs->remote_min_rx_usec && BFD_POLL_NOT_NEEDED == bs->poll_state) { BFD_DBG ("Remote min rx interval is zero, not sending periodic control " "frame"); return; } if (BFD_POLL_NOT_NEEDED == bs->poll_state && bs->remote_demand && BFD_STATE_up == bs->local_state && BFD_STATE_up == bs->remote_state) { /* * A system MUST NOT periodically transmit BFD Control packets if Demand * mode is active on the remote system (bfd.RemoteDemandMode is 1, * bfd.SessionState is Up, and bfd.RemoteSessionState is Up) and a Poll * Sequence is not being transmitted. */ BFD_DBG ("Remote demand is set, not sending periodic control frame"); return; } /* * sometimes the wheel expires an event a bit sooner than requested, account * for that here */ if (now + bm->wheel_inaccuracy >= bs->tx_timeout_clocks) { BFD_DBG ("\nSending periodic control frame: %U", format_bfd_session, bs); u32 bi; if (vlib_buffer_alloc (vm, &bi, 1) != 1) { clib_warning ("buffer allocation failure"); return; } vlib_buffer_t *b = vlib_get_buffer (vm, bi); ASSERT (b->current_data == 0); memset (vnet_buffer (b), 0, sizeof (*vnet_buffer (b))); VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b); bfd_init_control_frame (bm, bs, b); switch (bs->poll_state) { case BFD_POLL_NEEDED: if (now < bs->poll_state_start_or_timeout_clocks) { BFD_DBG ("Cannot start a poll sequence yet, need to wait " "for " BFD_CLK_FMT, BFD_CLK_PRN (bs->poll_state_start_or_timeout_clocks - now)); break; } bs->poll_state_start_or_timeout_clocks = now; bfd_set_poll_state (bs, BFD_POLL_IN_PROGRESS); /* fallthrough */ case BFD_POLL_IN_PROGRESS: case BFD_POLL_IN_PROGRESS_AND_QUEUED: bfd_pkt_set_poll (vlib_buffer_get_current (b)); BFD_DBG ("Setting poll bit in packet, bs_idx=%u", bs->bs_idx); break; case BFD_POLL_NOT_NEEDED: /* fallthrough */ break; } bfd_add_auth_section (b, bs); bfd_add_transport_layer (vm, bi, bs); if (!bfd_transport_control_frame (vm, bi, bs)) { vlib_buffer_free_one (vm, bi); } bs->last_tx_clocks = now; bfd_calc_next_tx (bm, bs, now); } else { BFD_DBG ("No need to send control frame now, now is %lu, tx_timeout is %lu", now, bs->tx_timeout_clocks); } } void bfd_init_final_control_frame (vlib_main_t * vm, vlib_buffer_t * b, bfd_main_t * bm, bfd_session_t * bs, int is_local) { BFD_DBG ("Send final control frame for bs_idx=%lu", bs->bs_idx); bfd_init_control_frame (bm, bs, b); bfd_pkt_set_final (vlib_buffer_get_current (b)); bfd_add_auth_section (b, bs); u32 bi = vlib_get_buffer_index (vm, b); bfd_add_transport_layer (vm, bi, bs); bs->last_tx_clocks = clib_cpu_time_now (); /* * RFC allows to include changes in final frame, so if there were any * pending, we already did that, thus we can clear any pending poll needs */ bfd_set_poll_state (bs, BFD_POLL_NOT_NEEDED); } static void bfd_check_rx_timeout (bfd_main_t * bm, bfd_session_t * bs, u64 now, int handling_wakeup) { /* * sometimes the wheel expires an event a bit sooner than requested, account * for that here */ if (bs->last_rx_clocks + bs->detection_time_clocks <= now + bm->wheel_inaccuracy) { BFD_DBG ("Rx timeout, session goes down"); bfd_set_diag (bs, BFD_DIAG_CODE_det_time_exp); bfd_set_state (bm, bs, BFD_STATE_down, handling_wakeup); /* * If the remote system does not receive any * BFD Control packets for a Detection Time, it SHOULD reset * bfd.RemoteMinRxInterval to its initial value of 1 (per section 6.8.1, * since it is no longer required to maintain previous session state) * and then can transmit at its own rate. */ bfd_set_remote_required_min_rx (bm, bs, now, 1); } else if (bs->echo && bs->echo_last_rx_clocks + bs->echo_transmit_interval_clocks * bs->local_detect_mult <= now + bm->wheel_inaccuracy) { BFD_DBG ("Echo rx timeout, session goes down"); bfd_set_diag (bs, BFD_DIAG_CODE_echo_failed); bfd_set_state (bm, bs, BFD_STATE_down, handling_wakeup); } } void bfd_on_timeout (vlib_main_t * vm, vlib_node_runtime_t * rt, bfd_main_t * bm, bfd_session_t * bs, u64 now) { BFD_DBG ("Timeout for bs_idx=%lu", bs->bs_idx); switch (bs->local_state) { case BFD_STATE_admin_down: bfd_send_periodic (vm, rt, bm, bs, now); break; case BFD_STATE_down: bfd_send_periodic (vm, rt, bm, bs, now); break; case BFD_STATE_init: bfd_check_rx_timeout (bm, bs, now, 1); bfd_send_periodic (vm, rt, bm, bs, now); break; case BFD_STATE_up: bfd_check_rx_timeout (bm, bs, now, 1); if (BFD_POLL_NOT_NEEDED == bs->poll_state && !bs->echo && bfd_is_echo_possible (bs)) { /* switch on echo function as main detection method now */ BFD_DBG ("Switching on echo function, bs_idx=%u", bs->bs_idx); bs->echo = 1; bs->echo_last_rx_clocks = now; bs->echo_tx_timeout_clocks = now; bfd_set_effective_required_min_rx (bm, bs, clib_max (bm->min_required_min_rx_while_echo_clocks, bs->config_required_min_rx_clocks)); bfd_set_poll_state (bs, BFD_POLL_NEEDED); } bfd_send_periodic (vm, rt, bm, bs, now); if (bs->echo) { bfd_send_echo (vm, rt, bm, bs, now); } break; } } /* * bfd process node function */ static uword bfd_process (vlib_main_t * vm, vlib_node_runtime_t * rt, vlib_frame_t * f) { bfd_main_t *bm = &bfd_main; u32 *expired = 0; uword event_type, *event_data = 0; /* So we can send events to the bfd process */ bm->bfd_process_node_index = bfd_process_node.index; while (1) { u64 now = clib_cpu_time_now (); u64 next_expire = timing_wheel_next_expiring_elt_time (&bm->wheel); BFD_DBG ("timing_wheel_next_expiring_elt_time(%p) returns %lu", &bm->wheel, next_expire); if ((i64) next_expire < 0) { BFD_DBG ("wait for event without timeout"); (void) vlib_process_wait_for_event (vm); event_type = vlib_process_get_events (vm, &event_data); } else { f64 timeout = ((i64) next_expire - (i64) now) / bm->cpu_cps; BFD_DBG ("wait for event with timeout %.02f", timeout); if (timeout < 0) { BFD_DBG ("negative timeout, already expired, skipping wait"); event_type = ~0; } else { (void) vlib_process_wait_for_event_or_clock (vm, timeout); event_type = vlib_process_get_events (vm, &event_data); } } now = clib_cpu_time_now (); switch (event_type) { case ~0: /* no events => timeout */ /* nothing to do here */ break; case BFD_EVENT_RESCHEDULE: /* nothing to do here - reschedule is done automatically after * each event or timeout */ break; case BFD_EVENT_NEW_SESSION: if (!pool_is_free_index (bm->sessions, *event_data)) { bfd_session_t *bs = pool_elt_at_index (bm->sessions, *event_data); bfd_send_periodic (vm, rt, bm, bs, now); bfd_set_timer (bm, bs, now, 1); } else { BFD_DBG ("Ignoring event for non-existent session index %u", (u32) * event_data); } break; case BFD_EVENT_CONFIG_CHANGED: if (!pool_is_free_index (bm->sessions, *event_data)) { bfd_session_t *bs = pool_elt_at_index (bm->sessions, *event_data); bfd_on_config_change (vm, rt, bm, bs, now); } else { BFD_DBG ("Ignoring event for non-existent session index %u", (u32) * event_data); } break; default: clib_warning ("BUG: event type 0x%wx", event_type); break; } BFD_DBG ("advancing wheel, now is %lu", now); BFD_DBG ("timing_wheel_advance (%p, %lu, %p, 0);", &bm->wheel, now, expired); expired = timing_wheel_advance (&bm->wheel, now, expired, 0); BFD_DBG ("Expired %d elements", vec_len (expired)); u32 *p = NULL; vec_foreach (p, expired) { const u32 bs_idx = *p; if (!pool_is_free_index (bm->sessions, bs_idx)) { bfd_session_t *bs = pool_elt_at_index (bm->sessions, bs_idx); bfd_on_timeout (vm, rt, bm, bs, now); bfd_set_timer (bm, bs, now, 1); } } if (expired) { _vec_len (expired) = 0; } if (event_data) { _vec_len (event_data) = 0; } } return 0; } /* * bfd process node declaration */ /* *INDENT-OFF* */ VLIB_REGISTER_NODE (bfd_process_node, static) = { .function = bfd_process, .type = VLIB_NODE_TYPE_PROCESS, .name = "bfd-process", .n_next_nodes = 0, .next_nodes = {}, }; /* *INDENT-ON* */ static clib_error_t * bfd_sw_interface_up_down (vnet_main_t * vnm, u32 sw_if_index, u32 flags) { // bfd_main_t *bm = &bfd_main; // vnet_hw_interface_t *hi = vnet_get_sup_hw_interface (vnm, sw_if_index); if (!(flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)) { /* TODO */ } return 0; } VNET_SW_INTERFACE_ADMIN_UP_DOWN_FUNCTION (bfd_sw_interface_up_down); static clib_error_t * bfd_hw_interface_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags) { // bfd_main_t *bm = &bfd_main; if (flags & VNET_HW_INTERFACE_FLAG_LINK_UP) { /* TODO */ } return 0; } VNET_HW_INTERFACE_LINK_UP_DOWN_FUNCTION (bfd_hw_interface_up_down); void bfd_register_listener (bfd_notify_fn_t fn) { bfd_main_t *bm = &bfd_main; vec_add1 (bm->listeners, fn); } /* * setup function */ static clib_error_t * bfd_main_init (vlib_main_t * vm) { #if BFD_DEBUG setbuf (stdout, NULL); #endif bfd_main_t *bm = &bfd_main; bm->random_seed = random_default_seed (); bm->vlib_main = vm; bm->vnet_main = vnet_get_main (); memset (&bm->wheel, 0, sizeof (bm->wheel)); bm->cpu_cps = vm->clib_time.clocks_per_second; BFD_DBG ("cps is %.2f", bm->cpu_cps); bm->default_desired_min_tx_clocks = bfd_usec_to_clocks (bm, BFD_DEFAULT_DESIRED_MIN_TX_USEC); bm->min_required_min_rx_while_echo_clocks = bfd_usec_to_clocks (bm, BFD_REQUIRED_MIN_RX_USEC_WHILE_ECHO); const u64 now = clib_cpu_time_now (); timing_wheel_init (&bm->wheel, now, bm->cpu_cps); bm->wheel_inaccuracy = 2 << bm->wheel.log2_clocks_per_bin; return 0; } VLIB_INIT_FUNCTION (bfd_main_init); bfd_session_t * bfd_get_session (bfd_main_t * bm, bfd_transport_e t) { bfd_session_t *result; pool_get (bm->sessions, result); memset (result, 0, sizeof (*result)); result->bs_idx = result - bm->sessions; result->transport = t; const unsigned limit = 1000; unsigned counter = 0; do { result->local_discr = random_u32 (&bm->random_seed); if (counter > limit) { clib_warning ("Couldn't allocate unused session discriminator even " "after %u tries!", limit); pool_put (bm->sessions, result); return NULL; } ++counter; } while (hash_get (bm->session_by_disc, result->local_discr)); bfd_set_defaults (bm, result); hash_set (bm->session_by_disc, result->local_discr, result->bs_idx); return result; } void bfd_put_session (bfd_main_t * bm, bfd_session_t * bs) { bfd_notify_listeners (bm, BFD_LISTEN_EVENT_DELETE, bs); if (bs->auth.curr_key) { --bs->auth.curr_key->use_count; } if (bs->auth.next_key) { --bs->auth.next_key->use_count; } hash_unset (bm->session_by_disc, bs->local_discr); pool_put (bm->sessions, bs); } bfd_session_t * bfd_find_session_by_idx (bfd_main_t * bm, uword bs_idx) { if (!pool_is_free_index (bm->sessions, bs_idx)) { return pool_elt_at_index (bm->sessions, bs_idx); } return NULL; } bfd_session_t * bfd_find_session_by_disc (bfd_main_t * bm, u32 disc) { uword *p = hash_get (bfd_main.session_by_disc, disc); if (p) { return pool_elt_at_index (bfd_main.sessions, *p); } return NULL; } /** * @brief verify bfd packet - common checks * * @param pkt * * @return 1 if bfd packet is valid */ int bfd_verify_pkt_common (const bfd_pkt_t * pkt) { if (1 != bfd_pkt_get_version (pkt)) { BFD_ERR ("BFD verification failed - unexpected version: '%d'", bfd_pkt_get_version (pkt)); return 0; } if (pkt->head.length < sizeof (bfd_pkt_t) || (bfd_pkt_get_auth_present (pkt) && pkt->head.length < sizeof (bfd_pkt_with_common_auth_t))) { BFD_ERR ("BFD verification failed - unexpected length: '%d' (auth " "present: %d)", pkt->head.length, bfd_pkt_get_auth_present (pkt)); return 0; } if (!pkt->head.detect_mult) { BFD_ERR ("BFD verification failed - unexpected detect-mult: '%d'", pkt->head.detect_mult); return 0; } if (bfd_pkt_get_multipoint (pkt)) { BFD_ERR ("BFD verification failed - unexpected multipoint: '%d'", bfd_pkt_get_multipoint (pkt)); return 0; } if (!pkt->my_disc) { BFD_ERR ("BFD verification failed - unexpected my-disc: '%d'", pkt->my_disc); return 0; } if (!pkt->your_disc) { const u8 pkt_state = bfd_pkt_get_state (pkt); if (pkt_state != BFD_STATE_down && pkt_state != BFD_STATE_admin_down) { BFD_ERR ("BFD verification failed - unexpected state: '%s' " "(your-disc is zero)", bfd_state_string (pkt_state)); return 0; } } return 1; } static void bfd_session_switch_auth_to_next (bfd_session_t * bs) { BFD_DBG ("Switching authentication key from %U to %U for bs_idx=%u", format_bfd_auth_key, bs->auth.curr_key, format_bfd_auth_key, bs->auth.next_key, bs->bs_idx); bs->auth.is_delayed = 0; if (bs->auth.curr_key) { --bs->auth.curr_key->use_count; } bs->auth.curr_key = bs->auth.next_key; bs->auth.next_key = NULL; bs->auth.curr_bfd_key_id = bs->auth.next_bfd_key_id; } static int bfd_auth_type_is_meticulous (bfd_auth_type_e auth_type) { if (BFD_AUTH_TYPE_meticulous_keyed_md5 == auth_type || BFD_AUTH_TYPE_meticulous_keyed_sha1 == auth_type) { return 1; } return 0; } static int bfd_verify_pkt_auth_seq_num (bfd_session_t * bs, u32 received_seq_num, int is_meticulous) { /* * RFC 5880 6.8.1: * * This variable MUST be set to zero after no packets have been * received on this session for at least twice the Detection Time. */ u64 now = clib_cpu_time_now (); if (now - bs->last_rx_clocks > bs->detection_time_clocks * 2) { BFD_DBG ("BFD peer unresponsive for %lu clocks, which is > 2 * " "detection_time=%u clocks, resetting remote_seq_number_known " "flag", now - bs->last_rx_clocks, bs->detection_time_clocks * 2); bs->auth.remote_seq_number_known = 0; } if (bs->auth.remote_seq_number_known) { /* remote sequence number is known, verify its validity */ const u32 max_u32 = 0xffffffff; /* the calculation might wrap, account for the special case... */ if (bs->auth.remote_seq_number > max_u32 - 3 * bs->local_detect_mult) { /* * special case * * x y z * |----------+----------------------------+-----------| * 0 ^ ^ 0xffffffff * | remote_seq_num------+ * | * +-----(remote_seq_num + 3*detect_mult) % * 0xffffffff * * x + y + z = 0xffffffff * x + z = 3 * detect_mult */ const u32 z = max_u32 - bs->auth.remote_seq_number; const u32 x = 3 * bs->local_detect_mult - z; if (received_seq_num > x && received_seq_num < bs->auth.remote_seq_number + is_meticulous) { BFD_ERR ("Recvd sequence number=%u out of ranges <0, %u>, <%u, %u>", received_seq_num, x, bs->auth.remote_seq_number + is_meticulous, max_u32); return 0; } } else { /* regular case */ const u32 min = bs->auth.remote_seq_number + is_meticulous; const u32 max = bs->auth.remote_seq_number + 3 * bs->local_detect_mult; if (received_seq_num < min || received_seq_num > max) { BFD_ERR ("Recvd sequence number=%u out of range <%u, %u>", received_seq_num, min, max); return 0; } } } return 1; } static int bfd_verify_pkt_auth_key_sha1 (const bfd_pkt_t * pkt, u32 pkt_size, bfd_session_t * bs, u8 bfd_key_id, bfd_auth_key_t * auth_key) { ASSERT (auth_key->auth_type == BFD_AUTH_TYPE_keyed_sha1 || auth_key->auth_type == BFD_AUTH_TYPE_meticulous_keyed_sha1); u8 result[SHA_DIGEST_LENGTH]; bfd_pkt_with_common_auth_t *with_common = (void *) pkt; if (pkt_size < sizeof (*with_common)) { BFD_ERR ("Packet size too small to hold authentication common header"); return 0; } if (with_common->common_auth.type != auth_key->auth_type) { BFD_ERR ("BFD auth type mismatch, packet auth=%d:%s doesn't match " "in-use auth=%d:%s", with_common->common_auth.type, bfd_auth_type_str (with_common->common_auth.type), auth_key->auth_type, bfd_auth_type_str (auth_key->auth_type)); return 0; } bfd_pkt_with_sha1_auth_t *with_sha1 = (void *) pkt; if (pkt_size < sizeof (*with_sha1) || with_sha1->sha1_auth.type_len.len < sizeof (with_sha1->sha1_auth)) { BFD_ERR ("BFD size mismatch, payload size=%u, expected=%u, auth_len=%u, " "expected=%u", pkt_size, sizeof (*with_sha1), with_sha1->sha1_auth.type_len.len, sizeof (with_sha1->sha1_auth)); return 0; } if (with_sha1->sha1_auth.key_id != bfd_key_id) { BFD_ERR ("BFD key ID mismatch, packet key ID=%u doesn't match key ID=%u%s", with_sha1->sha1_auth.key_id, bfd_key_id, bs-> auth.is_delayed ? " (but a delayed auth change is scheduled)" : ""); return 0; } SHA_CTX ctx; if (!SHA1_Init (&ctx)) { BFD_ERR ("SHA1_Init failed"); return 0; } /* ignore last 20 bytes - use the actual key data instead pkt data */ if (!SHA1_Update (&ctx, with_sha1, sizeof (*with_sha1) - sizeof (with_sha1->sha1_auth.hash))) { BFD_ERR ("SHA1_Update failed"); return 0; } if (!SHA1_Update (&ctx, auth_key->key, sizeof (auth_key->key))) { BFD_ERR ("SHA1_Update failed"); return 0; } if (!SHA1_Final (result, &ctx)) { BFD_ERR ("SHA1_Final failed"); return 0; } if (0 == memcmp (result, with_sha1->sha1_auth.hash, SHA_DIGEST_LENGTH)) { return 1; } BFD_ERR ("SHA1 hash: %U doesn't match the expected value: %U", format_hex_bytes, with_sha1->sha1_auth.hash, SHA_DIGEST_LENGTH, format_hex_bytes, result, SHA_DIGEST_LENGTH); return 0; } static int bfd_verify_pkt_auth_key (const bfd_pkt_t * pkt, u32 pkt_size, bfd_session_t * bs, u8 bfd_key_id, bfd_auth_key_t * auth_key) { switch (auth_key->auth_type) { case BFD_AUTH_TYPE_reserved: clib_warning ("Internal error, unexpected auth_type=%d:%s", auth_key->auth_type, bfd_auth_type_str (auth_key->auth_type)); return 0; case BFD_AUTH_TYPE_simple_password: clib_warning ("Internal error, not implemented, unexpected auth_type=%d:%s", auth_key->auth_type, bfd_auth_type_str (auth_key->auth_type)); return 0; case BFD_AUTH_TYPE_keyed_md5: /* fallthrough */ case BFD_AUTH_TYPE_meticulous_keyed_md5: clib_warning ("Internal error, not implemented, unexpected auth_type=%d:%s", auth_key->auth_type, bfd_auth_type_str (auth_key->auth_type)); return 0; case BFD_AUTH_TYPE_keyed_sha1: /* fallthrough */ case BFD_AUTH_TYPE_meticulous_keyed_sha1: #if WITH_LIBSSL > 0 do { const u32 seq_num = clib_net_to_host_u32 (((bfd_pkt_with_sha1_auth_t *) pkt)-> sha1_auth.seq_num); return bfd_verify_pkt_auth_seq_num (bs, seq_num, bfd_auth_type_is_meticulous (auth_key->auth_type)) && bfd_verify_pkt_auth_key_sha1 (pkt, pkt_size, bs, bfd_key_id, auth_key); } while (0); #else clib_warning ("Internal error, attempt to use SHA1 without SSL support"); return 0; #endif } return 0; } /** * @brief verify bfd packet - authentication * * @param pkt * * @return 1 if bfd packet is valid */ int bfd_verify_pkt_auth (const bfd_pkt_t * pkt, u16 pkt_size, bfd_session_t * bs) { if (bfd_pkt_get_auth_present (pkt)) { /* authentication present in packet */ if (!bs->auth.curr_key) { /* currently not using authentication - can we turn it on? */ if (bs->auth.is_delayed && bs->auth.next_key) { /* yes, switch is scheduled - make sure the auth is valid */ if (bfd_verify_pkt_auth_key (pkt, pkt_size, bs, bs->auth.next_bfd_key_id, bs->auth.next_key)) { /* auth matches next key, do the switch, packet is valid */ bfd_session_switch_auth_to_next (bs); return 1; } } } else { /* yes, using authentication, verify the key */ if (bfd_verify_pkt_auth_key (pkt, pkt_size, bs, bs->auth.curr_bfd_key_id, bs->auth.curr_key)) { /* verification passed, packet is valid */ return 1; } else { /* verification failed - but maybe we need to switch key */ if (bs->auth.is_delayed && bs->auth.next_key) { /* delayed switch present, verify if that key works */ if (bfd_verify_pkt_auth_key (pkt, pkt_size, bs, bs->auth.next_bfd_key_id, bs->auth.next_key)) { /* auth matches next key, switch key, packet is valid */ bfd_session_switch_auth_to_next (bs); return 1; } } } } } else { /* authentication in packet not present */ if (pkt_size > sizeof (*pkt)) { BFD_ERR ("BFD verification failed - unexpected packet size '%d' " "(auth not present)", pkt_size); return 0; } if (bs->auth.curr_key) { /* currently authenticating - could we turn it off? */ if (bs->auth.is_delayed && !bs->auth.next_key) { /* yes, delayed switch to NULL key is scheduled */ bfd_session_switch_auth_to_next (bs); return 1; } } else { /* no auth in packet, no auth in use - packet is valid */ return 1; } } return 0; } void bfd_consume_pkt (bfd_main_t * bm, const bfd_pkt_t * pkt, u32 bs_idx) { bfd_session_t *bs = bfd_find_session_by_idx (bm, bs_idx); if (!bs || (pkt->your_disc && pkt->your_disc != bs->local_discr)) { return; } BFD_DBG ("Scanning bfd packet, bs_idx=%d", bs->bs_idx); bs->remote_discr = pkt->my_disc; bs->remote_state = bfd_pkt_get_state (pkt); bs->remote_demand = bfd_pkt_get_demand (pkt); bs->remote_diag = bfd_pkt_get_diag_code (pkt); u64 now = clib_cpu_time_now (); bs->last_rx_clocks = now; if (bfd_pkt_get_auth_present (pkt)) { bfd_auth_type_e auth_type = ((bfd_pkt_with_common_auth_t *) (pkt))->common_auth.type; switch (auth_type) { case BFD_AUTH_TYPE_reserved: /* fallthrough */ case BFD_AUTH_TYPE_simple_password: /* fallthrough */ case BFD_AUTH_TYPE_keyed_md5: /* fallthrough */ case BFD_AUTH_TYPE_meticulous_keyed_md5: clib_warning ("Internal error, unexpected auth_type=%d:%s", auth_type, bfd_auth_type_str (auth_type)); break; case BFD_AUTH_TYPE_keyed_sha1: /* fallthrough */ case BFD_AUTH_TYPE_meticulous_keyed_sha1: do { bfd_pkt_with_sha1_auth_t *with_sha1 = (bfd_pkt_with_sha1_auth_t *) pkt; bs->auth.remote_seq_number = clib_net_to_host_u32 (with_sha1->sha1_auth.seq_num); bs->auth.remote_seq_number_known = 1; BFD_DBG ("Received sequence number %u", bs->auth.remote_seq_number); } while (0); } } bs->remote_desired_min_tx_clocks = bfd_usec_to_clocks (bm, clib_net_to_host_u32 (pkt->des_min_tx)); bs->remote_detect_mult = pkt->head.detect_mult; bfd_set_remote_required_min_rx (bm, bs, now, clib_net_to_host_u32 (pkt->req_min_rx)); bfd_set_remote_required_min_echo_rx (bm, bs, now, clib_net_to_host_u32 (pkt->req_min_echo_rx)); if (bfd_pkt_get_final (pkt)) { if (BFD_POLL_IN_PROGRESS == bs->poll_state) { BFD_DBG ("Poll sequence terminated, bs_idx=%u", bs->bs_idx); bfd_set_poll_state (bs, BFD_POLL_NOT_NEEDED); if (BFD_STATE_up == bs->local_state) { bfd_set_effective_required_min_rx (bm, bs, clib_max (bs->echo * bm->min_required_min_rx_while_echo_clocks, bs->config_required_min_rx_clocks)); } } else if (BFD_POLL_IN_PROGRESS_AND_QUEUED == bs->poll_state) { /* * next poll sequence must be delayed by at least the round trip * time, so calculate that here */ BFD_DBG ("Next poll sequence can commence in " BFD_CLK_FMT, BFD_CLK_PRN (now - bs->poll_state_start_or_timeout_clocks)); bs->poll_state_start_or_timeout_clocks = now + (now - bs->poll_state_start_or_timeout_clocks); BFD_DBG ("Poll sequence terminated, but another is needed, bs_idx=%u", bs->bs_idx); bfd_set_poll_state (bs, BFD_POLL_NEEDED); } } bfd_calc_next_tx (bm, bs, now); bfd_set_timer (bm, bs, now, 0); if (BFD_STATE_admin_down == bs->local_state) { BFD_DBG ("Session is admin-down, ignoring packet, bs_idx=%u", bs->bs_idx); return; } if (BFD_STATE_admin_down == bs->remote_state) { bfd_set_diag (bs, BFD_DIAG_CODE_neighbor_sig_down); bfd_set_state (bm, bs, BFD_STATE_down, 0); } else if (BFD_STATE_down == bs->local_state) { if (BFD_STATE_down == bs->remote_state) { bfd_set_diag (bs, BFD_DIAG_CODE_no_diag); bfd_set_state (bm, bs, BFD_STATE_init, 0); } else if (BFD_STATE_init == bs->remote_state) { bfd_set_diag (bs, BFD_DIAG_CODE_no_diag); bfd_set_state (bm, bs, BFD_STATE_up, 0); } } else if (BFD_STATE_init == bs->local_state) { if (BFD_STATE_up == bs->remote_state || BFD_STATE_init == bs->remote_state) { bfd_set_diag (bs, BFD_DIAG_CODE_no_diag); bfd_set_state (bm, bs, BFD_STATE_up, 0); } } else /* BFD_STATE_up == bs->local_state */ { if (BFD_STATE_down == bs->remote_state) { bfd_set_diag (bs, BFD_DIAG_CODE_neighbor_sig_down); bfd_set_state (bm, bs, BFD_STATE_down, 0); } } } int bfd_consume_echo_pkt (bfd_main_t * bm, vlib_buffer_t * b) { bfd_echo_pkt_t *pkt = NULL; if (b->current_length != sizeof (*pkt)) { return 0; } pkt = vlib_buffer_get_current (b); bfd_session_t *bs = bfd_find_session_by_disc (bm, pkt->discriminator); if (!bs) { return 0; } BFD_DBG ("Scanning bfd echo packet, bs_idx=%d", bs->bs_idx); u64 checksum = bfd_calc_echo_checksum (bs->local_discr, pkt->expire_time_clocks, bs->echo_secret); if (checksum != pkt->checksum) { BFD_DBG ("Invalid echo packet, checksum mismatch"); return 1; } u64 now = clib_cpu_time_now (); if (pkt->expire_time_clocks < now) { BFD_DBG ("Stale packet received, expire time %lu < now %lu", pkt->expire_time_clocks, now); } else { bs->echo_last_rx_clocks = now; } return 1; } u8 * format_bfd_session (u8 * s, va_list * args) { const bfd_session_t *bs = va_arg (*args, bfd_session_t *); uword indent = format_get_indent (s); s = format (s, "bs_idx=%u local-state=%s remote-state=%s\n" "%Ulocal-discriminator=%u remote-discriminator=%u\n" "%Ulocal-diag=%s echo-active=%s\n" "%Udesired-min-tx=%u required-min-rx=%u\n" "%Urequired-min-echo-rx=%u detect-mult=%u\n" "%Uremote-min-rx=%u remote-min-echo-rx=%u\n" "%Uremote-demand=%s poll-state=%s\n" "%Uauth: local-seq-num=%u remote-seq-num=%u\n" "%U is-delayed=%s\n" "%U curr-key=%U\n" "%U next-key=%U", bs->bs_idx, bfd_state_string (bs->local_state), bfd_state_string (bs->remote_state), format_white_space, indent, bs->local_discr, bs->remote_discr, format_white_space, indent, bfd_diag_code_string (bs->local_diag), (bs->echo ? "yes" : "no"), format_white_space, indent, bs->config_desired_min_tx_usec, bs->config_required_min_rx_usec, format_white_space, indent, 1, bs->local_detect_mult, format_white_space, indent, bs->remote_min_rx_usec, bs->remote_min_echo_rx_usec, format_white_space, indent, (bs->remote_demand ? "yes" : "no"), bfd_poll_state_string (bs->poll_state), format_white_space, indent, bs->auth.local_seq_number, bs->auth.remote_seq_number, format_white_space, indent, (bs->auth.is_delayed ? "yes" : "no"), format_white_space, indent, format_bfd_auth_key, bs->auth.curr_key, format_white_space, indent, format_bfd_auth_key, bs->auth.next_key); return s; } unsigned bfd_auth_type_supported (bfd_auth_type_e auth_type) { if (auth_type == BFD_AUTH_TYPE_keyed_sha1 || auth_type == BFD_AUTH_TYPE_meticulous_keyed_sha1) { return 1; } return 0; } vnet_api_error_t bfd_auth_activate (bfd_session_t * bs, u32 conf_key_id, u8 bfd_key_id, u8 is_delayed) { bfd_main_t *bm = &bfd_main; const uword *key_idx_p = hash_get (bm->auth_key_by_conf_key_id, conf_key_id); if (!key_idx_p) { clib_warning ("Authentication key with config ID %u doesn't exist)", conf_key_id); return VNET_API_ERROR_BFD_ENOENT; } const uword key_idx = *key_idx_p; bfd_auth_key_t *key = pool_elt_at_index (bm->auth_keys, key_idx); if (is_delayed) { if (bs->auth.next_key == key) { /* already using this key, no changes required */ return 0; } bs->auth.next_key = key; bs->auth.next_bfd_key_id = bfd_key_id; bs->auth.is_delayed = 1; } else { if (bs->auth.curr_key == key) { /* already using this key, no changes required */ return 0; } if (bs->auth.curr_key) { --bs->auth.curr_key->use_count; } bs->auth.curr_key = key; bs->auth.curr_bfd_key_id = bfd_key_id; bs->auth.is_delayed = 0; } ++key->use_count; BFD_DBG ("\nSession auth modified: %U", format_bfd_session, bs); return 0; } vnet_api_error_t bfd_auth_deactivate (bfd_session_t * bs, u8 is_delayed) { #if WITH_LIBSSL > 0 if (!is_delayed) { /* not delayed - deactivate the current key right now */ if (bs->auth.curr_key) { --bs->auth.curr_key->use_count; bs->auth.curr_key = NULL; } bs->auth.is_delayed = 0; } else { /* delayed - mark as so */ bs->auth.is_delayed = 1; } /* * clear the next key unconditionally - either the auth change is not delayed * in which case the caller expects the session to not use authentication * from this point forward, or it is delayed, in which case the next_key * needs to be set to NULL to make it so in the future */ if (bs->auth.next_key) { --bs->auth.next_key->use_count; bs->auth.next_key = NULL; } BFD_DBG ("\nSession auth modified: %U", format_bfd_session, bs); return 0; #else clib_warning ("SSL missing, cannot deactivate BFD authentication"); return VNET_API_ERROR_BFD_NOTSUPP; #endif } vnet_api_error_t bfd_session_set_params (bfd_main_t * bm, bfd_session_t * bs, u32 desired_min_tx_usec, u32 required_min_rx_usec, u8 detect_mult) { if (bs->local_detect_mult != detect_mult || bs->config_desired_min_tx_usec != desired_min_tx_usec || bs->config_required_min_rx_usec != required_min_rx_usec) { BFD_DBG ("\nChanging session params: %U", format_bfd_session, bs); switch (bs->poll_state) { case BFD_POLL_NOT_NEEDED: if (BFD_STATE_up == bs->local_state || BFD_STATE_init == bs->local_state) { /* poll sequence is not needed for detect multiplier change */ if (bs->config_desired_min_tx_usec != desired_min_tx_usec || bs->config_required_min_rx_usec != required_min_rx_usec) { bfd_set_poll_state (bs, BFD_POLL_NEEDED); } } break; case BFD_POLL_NEEDED: case BFD_POLL_IN_PROGRESS_AND_QUEUED: /* * nothing to do - will be handled in the future poll which is * already scheduled for execution */ break; case BFD_POLL_IN_PROGRESS: /* poll sequence is not needed for detect multiplier change */ if (bs->config_desired_min_tx_usec != desired_min_tx_usec || bs->config_required_min_rx_usec != required_min_rx_usec) { BFD_DBG ("Poll in progress, queueing extra poll, bs_idx=%u", bs->bs_idx); bfd_set_poll_state (bs, BFD_POLL_IN_PROGRESS_AND_QUEUED); } } bs->local_detect_mult = detect_mult; bs->config_desired_min_tx_usec = desired_min_tx_usec; bs->config_desired_min_tx_clocks = bfd_usec_to_clocks (bm, desired_min_tx_usec); bs->config_required_min_rx_usec = required_min_rx_usec; bs->config_required_min_rx_clocks = bfd_usec_to_clocks (bm, required_min_rx_usec); BFD_DBG ("\nChanged session params: %U", format_bfd_session, bs); vlib_process_signal_event (bm->vlib_main, bm->bfd_process_node_index, BFD_EVENT_CONFIG_CHANGED, bs->bs_idx); } else { BFD_DBG ("Ignore parameter change - no change, bs_idx=%u", bs->bs_idx); } return 0; } vnet_api_error_t bfd_auth_set_key (u32 conf_key_id, u8 auth_type, u8 key_len, const u8 * key_data) { #if WITH_LIBSSL > 0 bfd_auth_key_t *auth_key = NULL; if (!key_len || key_len > bfd_max_key_len_for_auth_type (auth_type)) { clib_warning ("Invalid authentication key length for auth_type=%d:%s " "(key_len=%u, must be " "non-zero, expected max=%u)", auth_type, bfd_auth_type_str (auth_type), key_len, (u32) bfd_max_key_len_for_auth_type (auth_type)); return VNET_API_ERROR_INVALID_VALUE; } if (!bfd_auth_type_supported (auth_type)) { clib_warning ("Unsupported auth type=%d:%s", auth_type, bfd_auth_type_str (auth_type)); return VNET_API_ERROR_BFD_NOTSUPP; } bfd_main_t *bm = &bfd_main; uword *key_idx_p = hash_get (bm->auth_key_by_conf_key_id, conf_key_id); if (key_idx_p) { /* modifying existing key - must not be used */ const uword key_idx = *key_idx_p; auth_key = pool_elt_at_index (bm->auth_keys, key_idx); if (auth_key->use_count > 0) { clib_warning ("Authentication key with conf ID %u in use by %u BFD " "session(s) - cannot modify", conf_key_id, auth_key->use_count); return VNET_API_ERROR_BFD_EINUSE; } } else { /* adding new key */ pool_get (bm->auth_keys, auth_key); auth_key->conf_key_id = conf_key_id; hash_set (bm->auth_key_by_conf_key_id, conf_key_id, auth_key - bm->auth_keys); } auth_key->auth_type = auth_type; memset (auth_key->key, 0, sizeof (auth_key->key)); clib_memcpy (auth_key->key, key_data, key_len); return 0; #else clib_warning ("SSL missing, cannot manipulate authentication keys"); return VNET_API_ERROR_BFD_NOTSUPP; #endif } vnet_api_error_t bfd_auth_del_key (u32 conf_key_id) { #if WITH_LIBSSL > 0 bfd_auth_key_t *auth_key = NULL; bfd_main_t *bm = &bfd_main; uword *key_idx_p = hash_get (bm->auth_key_by_conf_key_id, conf_key_id); if (key_idx_p) { /* deleting existing key - must not be used */ const uword key_idx = *key_idx_p; auth_key = pool_elt_at_index (bm->auth_keys, key_idx); if (auth_key->use_count > 0) { clib_warning ("Authentication key with conf ID %u in use by %u BFD " "session(s) - cannot delete", conf_key_id, auth_key->use_count); return VNET_API_ERROR_BFD_EINUSE; } hash_unset (bm->auth_key_by_conf_key_id, conf_key_id); memset (auth_key, 0, sizeof (*auth_key)); pool_put (bm->auth_keys, auth_key); } else { /* no such key */ clib_warning ("Authentication key with conf ID %u does not exist", conf_key_id); return VNET_API_ERROR_BFD_ENOENT; } return 0; #else clib_warning ("SSL missing, cannot manipulate authentication keys"); return VNET_API_ERROR_BFD_NOTSUPP; #endif } bfd_main_t bfd_main; /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */