diff options
Diffstat (limited to 'bfdd/dplane.c')
| -rw-r--r-- | bfdd/dplane.c | 1176 |
1 files changed, 1176 insertions, 0 deletions
diff --git a/bfdd/dplane.c b/bfdd/dplane.c new file mode 100644 index 0000000..d853981 --- /dev/null +++ b/bfdd/dplane.c @@ -0,0 +1,1176 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * BFD data plane implementation (distributed BFD). + * + * Copyright (C) 2020 Network Device Education Foundation, Inc. ("NetDEF") + * Rafael Zalamena + */ + +#include <zebra.h> + +#include <netinet/in.h> +#include <netinet/tcp.h> +#include <sys/socket.h> +#include <sys/un.h> + +#ifdef __FreeBSD__ +#include <sys/endian.h> +#else +#include <endian.h> +#endif /* __FreeBSD__ */ + +#include <errno.h> +#include <time.h> + +#include "lib/hook.h" +#include "lib/network.h" +#include "lib/printfrr.h" +#include "lib/stream.h" +#include "lib/frrevent.h" + +#include "bfd.h" +#include "bfddp_packet.h" + +#include "lib/openbsd-queue.h" + +DEFINE_MTYPE_STATIC(BFDD, BFDD_DPLANE_CTX, + "Data plane client allocated memory"); + +/** Data plane client socket buffer size. */ +#define BFD_DPLANE_CLIENT_BUF_SIZE 8192 + +struct bfd_dplane_ctx { + /** Client file descriptor. */ + int sock; + /** Is this a connected or accepted? */ + bool client; + /** Is the socket still connecting? */ + bool connecting; + /** Client/server address. */ + union { + struct sockaddr sa; + struct sockaddr_in sin; + struct sockaddr_in6 sin6; + struct sockaddr_un sun; + } addr; + /** Address length. */ + socklen_t addrlen; + /** Data plane current last used ID. */ + uint16_t last_id; + + /** Input buffer data. */ + struct stream *inbuf; + /** Output buffer data. */ + struct stream *outbuf; + /** Input event data. */ + struct event *inbufev; + /** Output event data. */ + struct event *outbufev; + /** Connection event. */ + struct event *connectev; + + /** Amount of bytes read. */ + uint64_t in_bytes; + /** Amount of bytes read peak. */ + uint64_t in_bytes_peak; + /** Amount of bytes written. */ + uint64_t out_bytes; + /** Amount of bytes written peak. */ + uint64_t out_bytes_peak; + /** Amount of output buffer full events (`bfd_dplane_enqueue` failed). + */ + uint64_t out_fullev; + + /** Amount of messages read (full messages). */ + uint64_t in_msgs; + /** Amount of messages enqueued (maybe written). */ + uint64_t out_msgs; + + TAILQ_ENTRY(bfd_dplane_ctx) entry; +}; + +/** + * Callback type for `bfd_dplane_expect`. \see bfd_dplane_expect. + */ +typedef void (*bfd_dplane_expect_cb)(struct bfddp_message *msg, void *arg); + +static void bfd_dplane_client_connect(struct event *t); +static bool bfd_dplane_client_connecting(struct bfd_dplane_ctx *bdc); +static void bfd_dplane_ctx_free(struct bfd_dplane_ctx *bdc); +static int _bfd_dplane_add_session(struct bfd_dplane_ctx *bdc, + struct bfd_session *bs); + +/* + * BFD data plane helper functions. + */ +static const char *bfd_dplane_messagetype2str(enum bfddp_message_type bmt) +{ + switch (bmt) { + case ECHO_REQUEST: + return "ECHO_REQUEST"; + case ECHO_REPLY: + return "ECHO_REPLY"; + case DP_ADD_SESSION: + return "DP_ADD_SESSION"; + case DP_DELETE_SESSION: + return "DP_DELETE_SESSION"; + case BFD_STATE_CHANGE: + return "BFD_STATE_CHANGE"; + case DP_REQUEST_SESSION_COUNTERS: + return "DP_REQUEST_SESSION_COUNTERS"; + case BFD_SESSION_COUNTERS: + return "BFD_SESSION_COUNTERS"; + default: + return "UNKNOWN"; + } +} + +static void bfd_dplane_debug_message(const struct bfddp_message *msg) +{ + enum bfddp_message_type bmt; + char buf[256], addrs[256]; + uint32_t flags; + int rv; + + if (!bglobal.debug_dplane) + return; + + bmt = ntohs(msg->header.type); + zlog_debug("dplane-packet: [version=%d length=%d type=%s (%d)]", + msg->header.version, ntohs(msg->header.length), + bfd_dplane_messagetype2str(bmt), bmt); + + switch (bmt) { + case ECHO_REPLY: + case ECHO_REQUEST: + zlog_debug(" [dp_time=%" PRIu64 " bfdd_time=%" PRIu64 "]", + be64toh(msg->data.echo.dp_time), + be64toh(msg->data.echo.bfdd_time)); + break; + + case DP_ADD_SESSION: + case DP_DELETE_SESSION: + flags = ntohl(msg->data.session.flags); + if (flags & SESSION_IPV6) + snprintfrr(addrs, sizeof(addrs), "src=%pI6 dst=%pI6", + &msg->data.session.src, + &msg->data.session.dst); + else + snprintfrr(addrs, sizeof(addrs), "src=%pI4 dst=%pI4", + (struct in_addr *)&msg->data.session.src, + (struct in_addr *)&msg->data.session.dst); + + buf[0] = 0; + if (flags & SESSION_CBIT) + strlcat(buf, "cpi ", sizeof(buf)); + if (flags & SESSION_ECHO) + strlcat(buf, "echo ", sizeof(buf)); + if (flags & SESSION_IPV6) + strlcat(buf, "ipv6 ", sizeof(buf)); + if (flags & SESSION_DEMAND) + strlcat(buf, "demand ", sizeof(buf)); + if (flags & SESSION_PASSIVE) + strlcat(buf, "passive ", sizeof(buf)); + if (flags & SESSION_MULTIHOP) + strlcat(buf, "multihop ", sizeof(buf)); + if (flags & SESSION_SHUTDOWN) + strlcat(buf, "shutdown ", sizeof(buf)); + + /* Remove the last space to make things prettier. */ + rv = (int)strlen(buf); + if (rv > 0) + buf[rv - 1] = 0; + + zlog_debug( + " [flags=0x%08x{%s} %s ttl=%d detect_mult=%d " + "ifindex=%d ifname=%s]", + flags, buf, addrs, msg->data.session.ttl, + msg->data.session.detect_mult, + ntohl(msg->data.session.ifindex), + msg->data.session.ifname); + break; + + case BFD_STATE_CHANGE: + buf[0] = 0; + flags = ntohl(msg->data.state.remote_flags); + if (flags & RBIT_CPI) + strlcat(buf, "cbit ", sizeof(buf)); + if (flags & RBIT_DEMAND) + strlcat(buf, "demand ", sizeof(buf)); + if (flags & RBIT_MP) + strlcat(buf, "mp ", sizeof(buf)); + + /* Remove the last space to make things prettier. */ + rv = (int)strlen(buf); + if (rv > 0) + buf[rv - 1] = 0; + + zlog_debug( + " [lid=%u rid=%u flags=0x%02x{%s} state=%s " + "diagnostics=%s mult=%d tx=%u rx=%u erx=%u]", + ntohl(msg->data.state.lid), ntohl(msg->data.state.rid), + flags, buf, state_list[msg->data.state.state].str, + diag2str(msg->data.state.diagnostics), + msg->data.state.detection_multiplier, + ntohl(msg->data.state.desired_tx), + ntohl(msg->data.state.required_rx), + ntohl(msg->data.state.required_echo_rx)); + break; + + case DP_REQUEST_SESSION_COUNTERS: + zlog_debug(" [lid=%u]", ntohl(msg->data.counters_req.lid)); + break; + + case BFD_SESSION_COUNTERS: + zlog_debug( + " [lid=%u " + "control{in %" PRIu64 " bytes (%" PRIu64 + " packets), " + "out %" PRIu64 " bytes (%" PRIu64 + " packets)} " + "echo{in %" PRIu64 " bytes (%" PRIu64 + " packets), " + "out %" PRIu64 " bytes (%" PRIu64 " packets)}]", + ntohl(msg->data.session_counters.lid), + be64toh(msg->data.session_counters.control_input_bytes), + be64toh(msg->data.session_counters + .control_input_packets), + be64toh(msg->data.session_counters + .control_output_bytes), + be64toh(msg->data.session_counters + .control_output_packets), + be64toh(msg->data.session_counters.echo_input_bytes), + be64toh(msg->data.session_counters.echo_input_packets), + be64toh(msg->data.session_counters.echo_output_bytes), + be64toh(msg->data.session_counters + .echo_output_packets)); + break; + } +} + +/** + * Gets the next unused non zero identification. + * + * \param bdc the data plane context. + * + * \returns next usable id. + */ +static uint16_t bfd_dplane_next_id(struct bfd_dplane_ctx *bdc) +{ + bdc->last_id++; + + /* Don't use reserved id `0`. */ + if (bdc->last_id == 0) + bdc->last_id = 1; + + return bdc->last_id; +} + +static ssize_t bfd_dplane_flush(struct bfd_dplane_ctx *bdc) +{ + ssize_t total = 0; + int rv; + + while (STREAM_READABLE(bdc->outbuf)) { + /* Flush buffer contents to socket. */ + rv = stream_flush(bdc->outbuf, bdc->sock); + if (rv == -1) { + /* Interruption: try again. */ + if (errno == EAGAIN || errno == EWOULDBLOCK + || errno == EINTR) + continue; + + zlog_warn("%s: socket failed: %s", __func__, + strerror(errno)); + bfd_dplane_ctx_free(bdc); + return 0; + } + if (rv == 0) { + if (bglobal.debug_dplane) + zlog_info("%s: connection closed", __func__); + + bfd_dplane_ctx_free(bdc); + return 0; + } + + /* Account total written. */ + total += rv; + + /* Account output bytes. */ + bdc->out_bytes += (uint64_t)rv; + + /* Forward pointer. */ + stream_forward_getp(bdc->outbuf, (size_t)rv); + } + + /* Make more space for new data. */ + stream_pulldown(bdc->outbuf); + + /* Disable write ready events. */ + EVENT_OFF(bdc->outbufev); + + return total; +} + +static void bfd_dplane_write(struct event *t) +{ + struct bfd_dplane_ctx *bdc = EVENT_ARG(t); + + /* Handle connection stage. */ + if (bdc->connecting && bfd_dplane_client_connecting(bdc)) + return; + + bfd_dplane_flush(bdc); +} + +static void +bfd_dplane_session_state_change(struct bfd_dplane_ctx *bdc, + const struct bfddp_state_change *state) +{ + struct bfd_session *bs; + uint32_t flags; + int old_state; + + /* Look up session. */ + bs = bfd_id_lookup(ntohl(state->lid)); + if (bs == NULL) { + if (bglobal.debug_dplane) + zlog_debug("%s: failed to find session to update", + __func__); + return; + } + + flags = ntohl(state->remote_flags); + old_state = bs->ses_state; + + /* Update session state. */ + bs->ses_state = state->state; + bs->remote_diag = state->diagnostics; + bs->discrs.remote_discr = ntohl(state->rid); + bs->remote_cbit = !!(flags & RBIT_CPI); + bs->remote_detect_mult = state->detection_multiplier; + bs->remote_timers.desired_min_tx = ntohl(state->desired_tx); + bs->remote_timers.required_min_rx = ntohl(state->required_rx); + bs->remote_timers.required_min_echo = ntohl(state->required_echo_rx); + + /* Notify and update counters. */ + control_notify(bs, bs->ses_state); + + /* No state change. */ + if (old_state == bs->ses_state) + return; + + switch (bs->ses_state) { + case PTM_BFD_ADM_DOWN: + case PTM_BFD_DOWN: + /* Both states mean down. */ + if (old_state == PTM_BFD_ADM_DOWN || old_state == PTM_BFD_DOWN) + break; + + monotime(&bs->downtime); + bs->stats.session_down++; + break; + case PTM_BFD_UP: + monotime(&bs->uptime); + bs->stats.session_up++; + break; + case PTM_BFD_INIT: + /* NOTHING */ + break; + + default: + zlog_warn("%s: unhandled new state %d", __func__, + bs->ses_state); + break; + } + + if (bglobal.debug_peer_event) + zlog_debug("state-change: [data plane: %s] %s -> %s", + bs_to_string(bs), state_list[old_state].str, + state_list[bs->ses_state].str); +} + +/** + * Enqueue message in output buffer. + * + * \param[in,out] bdc data plane client context. + * \param[in] buf the message to buffer. + * \param[in] buflen the amount of bytes to buffer. + * + * \returns `-1` on failure (buffer full) or `0` on success. + */ +static int bfd_dplane_enqueue(struct bfd_dplane_ctx *bdc, const void *buf, + size_t buflen) +{ + size_t rlen; + + /* Handle not connected yet client. */ + if (bdc->client && bdc->sock == -1) + return -1; + + /* Not enough space. */ + if (buflen > STREAM_WRITEABLE(bdc->outbuf)) { + bdc->out_fullev++; + return -1; + } + + /* Show debug message if active. */ + bfd_dplane_debug_message((struct bfddp_message *)buf); + + /* Buffer the message. */ + stream_write(bdc->outbuf, buf, buflen); + + /* Account message as sent. */ + bdc->out_msgs++; + /* Register peak buffered bytes. */ + rlen = STREAM_READABLE(bdc->outbuf); + if (bdc->out_bytes_peak < rlen) + bdc->out_bytes_peak = rlen; + + /* Schedule if it is not yet. */ + if (bdc->outbufev == NULL) + event_add_write(master, bfd_dplane_write, bdc, bdc->sock, + &bdc->outbufev); + + return 0; +} + +static void bfd_dplane_echo_request_handle(struct bfd_dplane_ctx *bdc, + const struct bfddp_message *bm) +{ + struct bfddp_message msg = {}; + uint16_t msglen = sizeof(msg.header) + sizeof(msg.data.echo); + struct timeval tv; + + gettimeofday(&tv, NULL); + + /* Prepare header. */ + msg.header.version = BFD_DP_VERSION; + msg.header.type = htons(ECHO_REPLY); + msg.header.length = htons(msglen); + + /* Prepare payload. */ + msg.data.echo.dp_time = bm->data.echo.dp_time; + msg.data.echo.bfdd_time = + htobe64((uint64_t)((tv.tv_sec * 1000000) + tv.tv_usec)); + + /* Enqueue for output. */ + bfd_dplane_enqueue(bdc, &msg, msglen); +} + +static void bfd_dplane_handle_message(struct bfddp_message *msg, void *arg) +{ + enum bfddp_message_type bmt; + struct bfd_dplane_ctx *bdc = arg; + + /* Call the appropriated handler. */ + bmt = ntohs(msg->header.type); + switch (bmt) { + case ECHO_REQUEST: + bfd_dplane_echo_request_handle(bdc, msg); + break; + case BFD_STATE_CHANGE: + bfd_dplane_session_state_change(bdc, &msg->data.state); + break; + case ECHO_REPLY: + /* NOTHING: we don't do anything with this information. */ + break; + case DP_ADD_SESSION: + case DP_DELETE_SESSION: + case DP_REQUEST_SESSION_COUNTERS: + /* NOTHING: we are not supposed to receive this. */ + break; + case BFD_SESSION_COUNTERS: + /* + * NOTHING: caller of DP_REQUEST_SESSION_COUNTERS should + * handle this with `bfd_dplane_expect`. + */ + break; + + default: + zlog_debug("%s: unhandled message type %d", __func__, bmt); + break; + } +} + +/** + * Reads the socket immediately to receive data plane answer to query. + * + * \param bdc the data plane context. + * \param id the message ID waiting response. + * \param cb the callback to call when ready. + * \param arg the callback argument. + * + * \return + * `-2` on unavailability (try again), `-1` on failure or `0` on success. + */ +static int bfd_dplane_expect(struct bfd_dplane_ctx *bdc, uint16_t id, + bfd_dplane_expect_cb cb, void *arg) +{ + struct bfddp_message_header *bh; + size_t rlen = 0, reads = 0; + ssize_t rv; + + /* + * Don't attempt to read if buffer is full, otherwise we'll get a + * bogus 'connection closed' signal (rv == 0). + */ + if (bdc->inbuf->endp == bdc->inbuf->size) + goto skip_read; + +read_again: + /* Attempt to read message from client. */ + rv = stream_read_try(bdc->inbuf, bdc->sock, + STREAM_WRITEABLE(bdc->inbuf)); + if (rv == 0) { + if (bglobal.debug_dplane) + zlog_info("%s: socket closed", __func__); + + bfd_dplane_ctx_free(bdc); + return -1; + } + if (rv == -1) { + zlog_warn("%s: socket failed: %s", __func__, strerror(errno)); + bfd_dplane_ctx_free(bdc); + return -1; + } + + /* We got interrupted, reschedule read. */ + if (rv == -2) + return -2; + + /* Account read bytes. */ + bdc->in_bytes += (uint64_t)rv; + /* Register peak buffered bytes. */ + rlen = STREAM_READABLE(bdc->inbuf); + if (bdc->in_bytes_peak < rlen) + bdc->in_bytes_peak = rlen; + +skip_read: + while (rlen > 0) { + bh = (struct bfddp_message_header *)stream_pnt(bdc->inbuf); + /* Not enough data read. */ + if (ntohs(bh->length) > rlen) + goto read_again; + + /* Account full message read. */ + bdc->in_msgs++; + + /* Account this message as whole read for buffer reorganize. */ + reads++; + + /* Check for bad version. */ + if (bh->version != BFD_DP_VERSION) { + zlog_err("%s: bad data plane client version: %d", + __func__, bh->version); + return -1; + } + + /* Show debug message if active. */ + bfd_dplane_debug_message((struct bfddp_message *)bh); + + /* + * Handle incoming message with callback if the ID matches, + * otherwise fallback to default handler. + */ + if (id && ntohs(bh->id) == id) + cb((struct bfddp_message *)bh, arg); + else + bfd_dplane_handle_message((struct bfddp_message *)bh, + bdc); + + /* Advance current read pointer. */ + stream_forward_getp(bdc->inbuf, ntohs(bh->length)); + + /* Reduce the buffer available bytes. */ + rlen -= ntohs(bh->length); + + /* Reorganize buffer to handle more bytes read. */ + if (reads >= 3) { + stream_pulldown(bdc->inbuf); + reads = 0; + } + + /* We found the message, return to caller. */ + if (id && ntohs(bh->id) == id) + break; + } + + return 0; +} + +static void bfd_dplane_read(struct event *t) +{ + struct bfd_dplane_ctx *bdc = EVENT_ARG(t); + int rv; + + rv = bfd_dplane_expect(bdc, 0, bfd_dplane_handle_message, NULL); + if (rv == -1) + return; + + stream_pulldown(bdc->inbuf); + event_add_read(master, bfd_dplane_read, bdc, bdc->sock, &bdc->inbufev); +} + +static void _bfd_session_register_dplane(struct hash_bucket *hb, void *arg) +{ + struct bfd_session *bs = hb->data; + struct bfd_dplane_ctx *bdc = arg; + + if (bs->bdc != NULL) + return; + + /* Disable software session. */ + bfd_session_disable(bs); + + /* Move session to data plane. */ + _bfd_dplane_add_session(bdc, bs); +} + +static struct bfd_dplane_ctx *bfd_dplane_ctx_new(int sock) +{ + struct bfd_dplane_ctx *bdc; + + bdc = XCALLOC(MTYPE_BFDD_DPLANE_CTX, sizeof(*bdc)); + + bdc->sock = sock; + bdc->inbuf = stream_new(BFD_DPLANE_CLIENT_BUF_SIZE); + bdc->outbuf = stream_new(BFD_DPLANE_CLIENT_BUF_SIZE); + + /* If not socket ready, skip read and session registration. */ + if (sock == -1) + return bdc; + + event_add_read(master, bfd_dplane_read, bdc, sock, &bdc->inbufev); + + /* Register all unattached sessions. */ + bfd_key_iterate(_bfd_session_register_dplane, bdc); + + return bdc; +} + +static void _bfd_session_unregister_dplane(struct hash_bucket *hb, void *arg) +{ + struct bfd_session *bs = hb->data; + struct bfd_dplane_ctx *bdc = arg; + + if (bs->bdc != bdc) + return; + + bs->bdc = NULL; + + /* Fallback to software. */ + bfd_session_enable(bs); +} + +static void bfd_dplane_ctx_free(struct bfd_dplane_ctx *bdc) +{ + if (bglobal.debug_dplane) + zlog_debug("%s: terminating data plane client %d", __func__, + bdc->sock); + + /* Client mode has special treatment. */ + if (bdc->client) { + /* Disable connection event if any. */ + EVENT_OFF(bdc->connectev); + + /* Normal treatment on shutdown. */ + if (bglobal.bg_shutdown) + goto free_resources; + + /* Attempt reconnection. */ + socket_close(&bdc->sock); + EVENT_OFF(bdc->inbufev); + EVENT_OFF(bdc->outbufev); + event_add_timer(master, bfd_dplane_client_connect, bdc, 3, + &bdc->connectev); + return; + } + +free_resources: + /* Remove from the list of attached data planes. */ + TAILQ_REMOVE(&bglobal.bg_dplaneq, bdc, entry); + + /* Detach all associated sessions. */ + if (bglobal.bg_shutdown == false) + bfd_key_iterate(_bfd_session_unregister_dplane, bdc); + + /* Free resources. */ + socket_close(&bdc->sock); + stream_free(bdc->inbuf); + stream_free(bdc->outbuf); + EVENT_OFF(bdc->inbufev); + EVENT_OFF(bdc->outbufev); + XFREE(MTYPE_BFDD_DPLANE_CTX, bdc); +} + +static void _bfd_dplane_session_fill(const struct bfd_session *bs, + struct bfddp_message *msg) +{ + uint16_t msglen = sizeof(msg->header) + sizeof(msg->data.session); + + /* Message header. */ + msg->header.version = BFD_DP_VERSION; + msg->header.length = ntohs(msglen); + msg->header.type = ntohs(DP_ADD_SESSION); + + /* Message payload. */ + msg->data.session.dst = bs->key.peer; + msg->data.session.src = bs->key.local; + msg->data.session.detect_mult = bs->detect_mult; + + if (bs->ifp) { + msg->data.session.ifindex = htonl(bs->ifp->ifindex); + strlcpy(msg->data.session.ifname, bs->ifp->name, + sizeof(msg->data.session.ifname)); + } + if (bs->flags & BFD_SESS_FLAG_MH) { + msg->data.session.flags |= SESSION_MULTIHOP; + msg->data.session.ttl = bs->mh_ttl; + } else + msg->data.session.ttl = BFD_TTL_VAL; + + if (bs->flags & BFD_SESS_FLAG_IPV6) + msg->data.session.flags |= SESSION_IPV6; + if (bs->flags & BFD_SESS_FLAG_ECHO) + msg->data.session.flags |= SESSION_ECHO; + if (bs->flags & BFD_SESS_FLAG_CBIT) + msg->data.session.flags |= SESSION_CBIT; + if (bs->flags & BFD_SESS_FLAG_PASSIVE) + msg->data.session.flags |= SESSION_PASSIVE; + if (bs->flags & BFD_SESS_FLAG_SHUTDOWN) + msg->data.session.flags |= SESSION_SHUTDOWN; + + msg->data.session.flags = htonl(msg->data.session.flags); + msg->data.session.lid = htonl(bs->discrs.my_discr); + msg->data.session.min_tx = htonl(bs->timers.desired_min_tx); + msg->data.session.min_rx = htonl(bs->timers.required_min_rx); + msg->data.session.min_echo_tx = htonl(bs->timers.desired_min_echo_tx); + msg->data.session.min_echo_rx = htonl(bs->timers.required_min_echo_rx); +} + +static int _bfd_dplane_add_session(struct bfd_dplane_ctx *bdc, + struct bfd_session *bs) +{ + int rv; + + /* Associate session. */ + bs->bdc = bdc; + + /* Reset previous state. */ + bs->remote_diag = 0; + bs->local_diag = 0; + bs->ses_state = PTM_BFD_DOWN; + + /* Enqueue message to data plane client. */ + rv = bfd_dplane_update_session(bs); + if (rv != 0) + bs->bdc = NULL; + + return rv; +} + +static void _bfd_dplane_update_session_counters(struct bfddp_message *msg, + void *arg) +{ + struct bfd_session *bs = arg; + + bs->stats.rx_ctrl_pkt = + be64toh(msg->data.session_counters.control_input_packets); + bs->stats.tx_ctrl_pkt = + be64toh(msg->data.session_counters.control_output_packets); + bs->stats.rx_echo_pkt = + be64toh(msg->data.session_counters.echo_input_packets); + bs->stats.tx_echo_pkt = + be64toh(msg->data.session_counters.echo_output_bytes); +} + +/** + * Send message to data plane requesting the session counters. + * + * \param bs the BFD session. + * + * \returns `0` on failure or the request id. + */ +static uint16_t bfd_dplane_request_counters(const struct bfd_session *bs) +{ + struct bfddp_message msg = {}; + size_t msglen = sizeof(msg.header) + sizeof(msg.data.counters_req); + + /* Fill header information. */ + msg.header.version = BFD_DP_VERSION; + msg.header.length = htons(msglen); + msg.header.type = htons(DP_REQUEST_SESSION_COUNTERS); + msg.header.id = htons(bfd_dplane_next_id(bs->bdc)); + + /* Session to get counters. */ + msg.data.counters_req.lid = htonl(bs->discrs.my_discr); + + /* If enqueue failed, let caller know. */ + if (bfd_dplane_enqueue(bs->bdc, &msg, msglen) == -1) + return 0; + + /* Flush socket. */ + bfd_dplane_flush(bs->bdc); + + return ntohs(msg.header.id); +} + +/* + * Data plane listening socket. + */ +static void bfd_dplane_accept(struct event *t) +{ + struct bfd_global *bg = EVENT_ARG(t); + struct bfd_dplane_ctx *bdc; + int sock; + + /* Accept new connection. */ + sock = accept(bg->bg_dplane_sock, NULL, 0); + if (sock == -1) { + zlog_warn("%s: accept failed: %s", __func__, strerror(errno)); + goto reschedule_and_return; + } + + /* Create and handle new connection. */ + bdc = bfd_dplane_ctx_new(sock); + TAILQ_INSERT_TAIL(&bglobal.bg_dplaneq, bdc, entry); + + if (bglobal.debug_dplane) + zlog_debug("%s: new data plane client connected", __func__); + +reschedule_and_return: + event_add_read(master, bfd_dplane_accept, bg, bg->bg_dplane_sock, + &bglobal.bg_dplane_sockev); +} + +/* + * Data plane connecting socket. + */ +static void _bfd_dplane_client_bootstrap(struct bfd_dplane_ctx *bdc) +{ + bdc->connecting = false; + + /* Clean up buffers. */ + stream_reset(bdc->inbuf); + stream_reset(bdc->outbuf); + + /* Ask for read notifications. */ + event_add_read(master, bfd_dplane_read, bdc, bdc->sock, &bdc->inbufev); + + /* Remove all sessions then register again to send them all. */ + bfd_key_iterate(_bfd_session_unregister_dplane, bdc); + bfd_key_iterate(_bfd_session_register_dplane, bdc); +} + +static bool bfd_dplane_client_connecting(struct bfd_dplane_ctx *bdc) +{ + int rv; + socklen_t rvlen = sizeof(rv); + + /* Make sure `errno` is reset, then test `getsockopt` success. */ + errno = 0; + if (getsockopt(bdc->sock, SOL_SOCKET, SO_ERROR, &rv, &rvlen) == -1) + rv = -1; + + /* Connection successful. */ + if (rv == 0) { + if (bglobal.debug_dplane) + zlog_debug("%s: connected to server: %d", __func__, + bdc->sock); + + _bfd_dplane_client_bootstrap(bdc); + return false; + } + + switch (rv) { + case EINTR: + case EAGAIN: + case EALREADY: + case EINPROGRESS: + /* non error, wait more. */ + return true; + + default: + zlog_warn("%s: connection failed: %s", __func__, + strerror(errno)); + bfd_dplane_ctx_free(bdc); + return true; + } +} + +static void bfd_dplane_client_connect(struct event *t) +{ + struct bfd_dplane_ctx *bdc = EVENT_ARG(t); + int rv, sock; + socklen_t rvlen = sizeof(rv); + + /* Allocate new socket. */ + sock = socket(bdc->addr.sa.sa_family, SOCK_STREAM, 0); + if (sock == -1) { + zlog_warn("%s: failed to initialize socket: %s", __func__, + strerror(errno)); + goto reschedule_connect; + } + + /* Set non blocking socket. */ + set_nonblocking(sock); + + /* Set 'no delay' (disables nagle algorithm) for IPv4/IPv6. */ + rv = 1; + if (bdc->addr.sa.sa_family != AF_UNIX + && setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, &rv, rvlen) == -1) + zlog_warn("%s: TCP_NODELAY: %s", __func__, strerror(errno)); + + /* Attempt to connect. */ + rv = connect(sock, &bdc->addr.sa, bdc->addrlen); + if (rv == -1 && (errno != EINPROGRESS && errno != EAGAIN)) { + zlog_warn("%s: data plane connection failed: %s", __func__, + strerror(errno)); + goto reschedule_connect; + } + + bdc->sock = sock; + if (rv == -1) { + if (bglobal.debug_dplane) + zlog_debug("%s: server connection in progress: %d", + __func__, sock); + + /* If we are not connected yet, ask for write notifications. */ + bdc->connecting = true; + event_add_write(master, bfd_dplane_write, bdc, bdc->sock, + &bdc->outbufev); + } else { + if (bglobal.debug_dplane) + zlog_debug("%s: server connection: %d", __func__, sock); + + /* Otherwise just start accepting data. */ + _bfd_dplane_client_bootstrap(bdc); + } + +reschedule_connect: + EVENT_OFF(bdc->inbufev); + EVENT_OFF(bdc->outbufev); + socket_close(&sock); + event_add_timer(master, bfd_dplane_client_connect, bdc, 3, + &bdc->connectev); +} + +static void bfd_dplane_client_init(const struct sockaddr *sa, socklen_t salen) +{ + struct bfd_dplane_ctx *bdc; + + /* Allocate context and copy address for reconnection. */ + bdc = bfd_dplane_ctx_new(-1); + if (salen <= sizeof(bdc->addr)) { + memcpy(&bdc->addr, sa, salen); + bdc->addrlen = sizeof(bdc->addr); + } else { + memcpy(&bdc->addr, sa, sizeof(bdc->addr)); + bdc->addrlen = sizeof(bdc->addr); + zlog_warn("%s: server address truncated (from %d to %d)", + __func__, salen, bdc->addrlen); + } + + bdc->client = true; + + event_add_timer(master, bfd_dplane_client_connect, bdc, 0, + &bdc->connectev); + + /* Insert into data plane lists. */ + TAILQ_INSERT_TAIL(&bglobal.bg_dplaneq, bdc, entry); +} + +/** + * Termination phase of the distributed BFD infrastructure: free all allocated + * resources. + */ +static int bfd_dplane_finish_late(void) +{ + struct bfd_dplane_ctx *bdc; + + if (bglobal.debug_dplane) + zlog_debug("%s: terminating distributed BFD", __func__); + + /* Free all data plane client contexts. */ + while ((bdc = TAILQ_FIRST(&bglobal.bg_dplaneq)) != NULL) + bfd_dplane_ctx_free(bdc); + + /* Cancel accept thread and close socket. */ + EVENT_OFF(bglobal.bg_dplane_sockev); + close(bglobal.bg_dplane_sock); + + return 0; +} + +/* + * Data plane exported functions. + */ +void bfd_dplane_init(const struct sockaddr *sa, socklen_t salen, bool client) +{ + int sock; + + zlog_info("initializing distributed BFD"); + + /* Initialize queue header. */ + TAILQ_INIT(&bglobal.bg_dplaneq); + + /* Initialize listening socket. */ + bglobal.bg_dplane_sock = -1; + + /* Observe shutdown events. */ + hook_register(frr_fini, bfd_dplane_finish_late); + + /* Handle client mode. */ + if (client) { + bfd_dplane_client_init(sa, salen); + return; + } + + /* + * Data plane socket creation: + * - Set REUSEADDR option for taking over previously open socket. + * - Bind to address requested (maybe IPv4, IPv6, UNIX etc...). + * - Listen on that address for new connections. + * - Ask to be waken up when a new connection comes. + */ + sock = socket(sa->sa_family, SOCK_STREAM, 0); + if (sock == -1) { + zlog_warn("%s: failed to initialize socket: %s", __func__, + strerror(errno)); + return; + } + + if (sockopt_reuseaddr(sock) == -1) { + zlog_warn("%s: failed to set reuseaddr: %s", __func__, + strerror(errno)); + close(sock); + return; + } + + /* Handle UNIX socket: delete previous socket if any. */ + if (sa->sa_family == AF_UNIX) + unlink(((struct sockaddr_un *)sa)->sun_path); + + if (bind(sock, sa, salen) == -1) { + zlog_warn("%s: failed to bind socket: %s", __func__, + strerror(errno)); + close(sock); + return; + } + + if (listen(sock, SOMAXCONN) == -1) { + zlog_warn("%s: failed to put socket on listen: %s", __func__, + strerror(errno)); + close(sock); + return; + } + + bglobal.bg_dplane_sock = sock; + event_add_read(master, bfd_dplane_accept, &bglobal, sock, + &bglobal.bg_dplane_sockev); +} + +int bfd_dplane_add_session(struct bfd_session *bs) +{ + struct bfd_dplane_ctx *bdc; + + /* Select a data plane client to install session. */ + TAILQ_FOREACH (bdc, &bglobal.bg_dplaneq, entry) { + if (_bfd_dplane_add_session(bdc, bs) == 0) + return 0; + } + + return -1; +} + +int bfd_dplane_update_session(const struct bfd_session *bs) +{ + struct bfddp_message msg = {}; + + if (bs->bdc == NULL) + return 0; + + _bfd_dplane_session_fill(bs, &msg); + + /* Enqueue message to data plane client. */ + return bfd_dplane_enqueue(bs->bdc, &msg, ntohs(msg.header.length)); +} + +int bfd_dplane_delete_session(struct bfd_session *bs) +{ + struct bfddp_message msg = {}; + int rv; + + /* Not using data plane, just return success. */ + if (bs->bdc == NULL) + return 0; + + /* Fill most of the common fields. */ + _bfd_dplane_session_fill(bs, &msg); + + /* Change the message type. */ + msg.header.type = ntohs(DP_DELETE_SESSION); + + /* Enqueue message to data plane client. */ + rv = bfd_dplane_enqueue(bs->bdc, &msg, ntohs(msg.header.length)); + + /* Remove association. */ + bs->bdc = NULL; + + return rv; +} + +/* + * Data plane CLI. + */ +void bfd_dplane_show_counters(struct vty *vty) +{ + struct bfd_dplane_ctx *bdc; + +#define SHOW_COUNTER(label, counter, formatter) \ + vty_out(vty, "%28s: %" formatter "\n", (label), (counter)) + + vty_out(vty, "%28s\n%28s\n", "Data plane", "=========="); + TAILQ_FOREACH (bdc, &bglobal.bg_dplaneq, entry) { + SHOW_COUNTER("File descriptor", bdc->sock, "d"); + SHOW_COUNTER("Input bytes", bdc->in_bytes, PRIu64); + SHOW_COUNTER("Input bytes peak", bdc->in_bytes_peak, PRIu64); + SHOW_COUNTER("Input messages", bdc->in_msgs, PRIu64); + SHOW_COUNTER("Input current usage", STREAM_READABLE(bdc->inbuf), + "zu"); + SHOW_COUNTER("Output bytes", bdc->out_bytes, PRIu64); + SHOW_COUNTER("Output bytes peak", bdc->out_bytes_peak, PRIu64); + SHOW_COUNTER("Output messages", bdc->out_msgs, PRIu64); + SHOW_COUNTER("Output full events", bdc->out_fullev, PRIu64); + SHOW_COUNTER("Output current usage", + STREAM_READABLE(bdc->inbuf), "zu"); + vty_out(vty, "\n"); + } +#undef SHOW_COUNTER +} + +int bfd_dplane_update_session_counters(struct bfd_session *bs) +{ + uint16_t id; + int rv; + + /* If session is not using data plane, then just return success. */ + if (bs->bdc == NULL) + return 0; + + /* Make the request. */ + id = bfd_dplane_request_counters(bs); + if (id == 0) { + zlog_debug("%s: counters request failed", __func__); + return -1; + } + + /* Handle interruptions. */ + do { + rv = bfd_dplane_expect(bs->bdc, id, + _bfd_dplane_update_session_counters, bs); + } while (rv == -2); + + return rv; +} |