diff options
Diffstat (limited to 'src/vnet/bfd/bfd_main.c')
| -rw-r--r-- | src/vnet/bfd/bfd_main.c | 2058 |
1 files changed, 2058 insertions, 0 deletions
diff --git a/src/vnet/bfd/bfd_main.c b/src/vnet/bfd/bfd_main.c new file mode 100644 index 00000000..b58a5132 --- /dev/null +++ b/src/vnet/bfd/bfd_main.c @@ -0,0 +1,2058 @@ +/* + * 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 <openssl/sha.h> +#endif + +#if __SSE4_2__ +#include <x86intrin.h> +#endif + +#include <vppinfra/random.h> +#include <vppinfra/error.h> +#include <vppinfra/hash.h> +#include <vppinfra/xxhash.h> +#include <vnet/ethernet/ethernet.h> +#include <vnet/ethernet/packet.h> +#include <vnet/bfd/bfd_debug.h> +#include <vnet/bfd/bfd_protocol.h> +#include <vnet/bfd/bfd_main.h> + +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: + */ |