/* BGP packet management routine.
+ * Contains utility functions for constructing and consuming BGP messages.
+ * Copyright (C) 2017 Cumulus Networks
* Copyright (C) 1999 Kunihiro Ishiguro
*
* This file is part of GNU Zebra.
*/
#include <zebra.h>
+#include <sys/time.h>
#include "thread.h"
#include "stream.h"
#include "bgpd/bgp_vty.h"
#include "bgpd/bgp_updgrp.h"
#include "bgpd/bgp_label.h"
+#include "bgpd/bgp_io.h"
+#include "bgpd/bgp_keepalives.h"
-/* Set up BGP packet marker and packet type. */
+/**
+ * Sets marker and type fields for a BGP message.
+ *
+ * @param s the stream containing the packet
+ * @param type the packet type
+ * @return the size of the stream
+ */
int bgp_packet_set_marker(struct stream *s, u_char type)
{
int i;
return stream_get_endp(s);
}
-/* Set BGP packet header size entry. If size is zero then use current
- stream size. */
+/**
+ * Sets size field for a BGP message.
+ *
+ * Size field is set to the size of the stream passed.
+ *
+ * @param s the stream containing the packet
+ * @return the size of the stream
+ */
int bgp_packet_set_size(struct stream *s)
{
int cp;
return cp;
}
-/* Add new packet to the peer. */
-void bgp_packet_add(struct peer *peer, struct stream *s)
+/*
+ * Push a packet onto the beginning of the peer's output queue.
+ * This function acquires the peer's write mutex before proceeding.
+ */
+static void bgp_packet_add(struct peer *peer, struct stream *s)
{
- /* Add packet to the end of list. */
+ pthread_mutex_lock(&peer->io_mtx);
stream_fifo_push(peer->obuf, s);
-}
-
-/* Free first packet. */
-static void bgp_packet_delete(struct peer *peer)
-{
- stream_free(stream_fifo_pop(peer->obuf));
-}
-
-/* Check file descriptor whether connect is established. */
-int bgp_connect_check(struct peer *peer, int change_state)
-{
- int status;
- socklen_t slen;
- int ret;
-
- /* Anyway I have to reset read and write thread. */
- BGP_READ_OFF(peer->t_read);
- BGP_WRITE_OFF(peer->t_write);
-
- /* Check file descriptor. */
- slen = sizeof(status);
- ret = getsockopt(peer->fd, SOL_SOCKET, SO_ERROR, (void *)&status,
- &slen);
-
- /* If getsockopt is fail, this is fatal error. */
- if (ret < 0) {
- zlog_info("can't get sockopt for nonblocking connect");
- BGP_EVENT_ADD(peer, TCP_fatal_error);
- return -1;
- }
-
- /* When status is 0 then TCP connection is established. */
- if (status == 0) {
- BGP_EVENT_ADD(peer, TCP_connection_open);
- return 1;
- } else {
- if (bgp_debug_neighbor_events(peer))
- zlog_debug("%s [Event] Connect failed (%s)", peer->host,
- safe_strerror(errno));
- if (change_state)
- BGP_EVENT_ADD(peer, TCP_connection_open_failed);
- return 0;
- }
+ pthread_mutex_unlock(&peer->io_mtx);
}
static struct stream *bgp_update_packet_eor(struct peer *peer, afi_t afi,
}
bgp_packet_set_size(s);
- bgp_packet_add(peer, s);
return s;
}
-/* Get next packet to be written. */
-static struct stream *bgp_write_packet(struct peer *peer)
+/* Called when there is a change in the EOR(implicit or explicit) status of a
+ * peer. Ends the update-delay if all expected peers are done with EORs. */
+void bgp_check_update_delay(struct bgp *bgp)
+{
+ struct listnode *node, *nnode;
+ struct peer *peer = NULL;
+
+ if (bgp_debug_neighbor_events(peer))
+ zlog_debug("Checking update delay, T: %d R: %d I:%d E: %d",
+ bgp->established, bgp->restarted_peers,
+ bgp->implicit_eors, bgp->explicit_eors);
+
+ if (bgp->established
+ <= bgp->restarted_peers + bgp->implicit_eors + bgp->explicit_eors) {
+ /*
+ * This is an extra sanity check to make sure we wait for all
+ * the eligible configured peers. This check is performed if
+ * establish wait timer is on, or establish wait option is not
+ * given with the update-delay command
+ */
+ if (bgp->t_establish_wait
+ || (bgp->v_establish_wait == bgp->v_update_delay))
+ for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
+ if (CHECK_FLAG(peer->flags,
+ PEER_FLAG_CONFIG_NODE)
+ && !CHECK_FLAG(peer->flags,
+ PEER_FLAG_SHUTDOWN)
+ && !peer->update_delay_over) {
+ if (bgp_debug_neighbor_events(peer))
+ zlog_debug(
+ " Peer %s pending, continuing read-only mode",
+ peer->host);
+ return;
+ }
+ }
+
+ zlog_info(
+ "Update delay ended, restarted: %d, EORs implicit: %d, explicit: %d",
+ bgp->restarted_peers, bgp->implicit_eors,
+ bgp->explicit_eors);
+ bgp_update_delay_end(bgp);
+ }
+}
+
+/*
+ * Called if peer is known to have restarted. The restart-state bit in
+ * Graceful-Restart capability is used for that
+ */
+void bgp_update_restarted_peers(struct peer *peer)
+{
+ if (!bgp_update_delay_active(peer->bgp))
+ return; /* BGP update delay has ended */
+ if (peer->update_delay_over)
+ return; /* This peer has already been considered */
+
+ if (bgp_debug_neighbor_events(peer))
+ zlog_debug("Peer %s: Checking restarted", peer->host);
+
+ if (peer->status == Established) {
+ peer->update_delay_over = 1;
+ peer->bgp->restarted_peers++;
+ bgp_check_update_delay(peer->bgp);
+ }
+}
+
+/*
+ * Called as peer receives a keep-alive. Determines if this occurence can be
+ * taken as an implicit EOR for this peer.
+ * NOTE: The very first keep-alive after the Established state of a peer is
+ * considered implicit EOR for the update-delay purposes
+ */
+void bgp_update_implicit_eors(struct peer *peer)
+{
+ if (!bgp_update_delay_active(peer->bgp))
+ return; /* BGP update delay has ended */
+ if (peer->update_delay_over)
+ return; /* This peer has already been considered */
+
+ if (bgp_debug_neighbor_events(peer))
+ zlog_debug("Peer %s: Checking implicit EORs", peer->host);
+
+ if (peer->status == Established) {
+ peer->update_delay_over = 1;
+ peer->bgp->implicit_eors++;
+ bgp_check_update_delay(peer->bgp);
+ }
+}
+
+/*
+ * Should be called only when there is a change in the EOR_RECEIVED status
+ * for any afi/safi on a peer.
+ */
+static void bgp_update_explicit_eors(struct peer *peer)
+{
+ afi_t afi;
+ safi_t safi;
+
+ if (!bgp_update_delay_active(peer->bgp))
+ return; /* BGP update delay has ended */
+ if (peer->update_delay_over)
+ return; /* This peer has already been considered */
+
+ if (bgp_debug_neighbor_events(peer))
+ zlog_debug("Peer %s: Checking explicit EORs", peer->host);
+
+ for (afi = AFI_IP; afi < AFI_MAX; afi++)
+ for (safi = SAFI_UNICAST; safi < SAFI_MAX; safi++) {
+ if (peer->afc_nego[afi][safi]
+ && !CHECK_FLAG(peer->af_sflags[afi][safi],
+ PEER_STATUS_EOR_RECEIVED)) {
+ if (bgp_debug_neighbor_events(peer))
+ zlog_debug(
+ " afi %d safi %d didnt receive EOR",
+ afi, safi);
+ return;
+ }
+ }
+
+ peer->update_delay_over = 1;
+ peer->bgp->explicit_eors++;
+ bgp_check_update_delay(peer->bgp);
+}
+
+/**
+ * Frontend for NLRI parsing, to fan-out to AFI/SAFI specific parsers.
+ *
+ * mp_withdraw, if set, is used to nullify attr structure on most of the
+ * calling safi function and for evpn, passed as parameter
+ */
+int bgp_nlri_parse(struct peer *peer, struct attr *attr,
+ struct bgp_nlri *packet, int mp_withdraw)
{
- struct stream *s = NULL;
+ switch (packet->safi) {
+ case SAFI_UNICAST:
+ case SAFI_MULTICAST:
+ return bgp_nlri_parse_ip(peer, mp_withdraw ? NULL : attr,
+ packet);
+ case SAFI_LABELED_UNICAST:
+ return bgp_nlri_parse_label(peer, mp_withdraw ? NULL : attr,
+ packet);
+ case SAFI_MPLS_VPN:
+ return bgp_nlri_parse_vpn(peer, mp_withdraw ? NULL : attr,
+ packet);
+ case SAFI_EVPN:
+ return bgp_nlri_parse_evpn(peer, attr, packet, mp_withdraw);
+ }
+ return -1;
+}
+
+/*
+ * Checks a variety of conditions to determine whether the peer needs to be
+ * rescheduled for packet generation again, and does so if necessary.
+ *
+ * @param peer to check for rescheduling
+ */
+static void bgp_write_proceed_actions(struct peer *peer)
+{
+ afi_t afi;
+ safi_t safi;
struct peer_af *paf;
struct bpacket *next_pkt;
+ struct update_subgroup *subgrp;
+
+ FOREACH_AFI_SAFI (afi, safi) {
+ paf = peer_af_find(peer, afi, safi);
+ if (!paf)
+ continue;
+ subgrp = paf->subgroup;
+ if (!subgrp)
+ continue;
+
+ next_pkt = paf->next_pkt_to_send;
+ if (next_pkt && next_pkt->buffer) {
+ BGP_TIMER_ON(peer->t_generate_updgrp_packets,
+ bgp_generate_updgrp_packets, 0);
+ return;
+ }
+
+ /* No packets readily available for AFI/SAFI, are there
+ * subgroup packets
+ * that need to be generated? */
+ if (bpacket_queue_is_full(SUBGRP_INST(subgrp),
+ SUBGRP_PKTQ(subgrp))
+ || subgroup_packets_to_build(subgrp)) {
+ BGP_TIMER_ON(peer->t_generate_updgrp_packets,
+ bgp_generate_updgrp_packets, 0);
+ return;
+ }
+
+ /* No packets to send, see if EOR is pending */
+ if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV)) {
+ if (!subgrp->t_coalesce && peer->afc_nego[afi][safi]
+ && peer->synctime
+ && !CHECK_FLAG(peer->af_sflags[afi][safi],
+ PEER_STATUS_EOR_SEND)
+ && safi != SAFI_MPLS_VPN) {
+ BGP_TIMER_ON(peer->t_generate_updgrp_packets,
+ bgp_generate_updgrp_packets, 0);
+ return;
+ }
+ }
+ }
+}
+
+/*
+ * Generate advertisement information (withdraws, updates, EOR) from each
+ * update group a peer belongs to, encode this information into packets, and
+ * enqueue the packets onto the peer's output buffer.
+ */
+int bgp_generate_updgrp_packets(struct thread *thread)
+{
+ struct peer *peer = THREAD_ARG(thread);
+
+ struct stream *s;
+ struct peer_af *paf;
+ struct bpacket *next_pkt;
+ uint32_t wpq;
+ uint32_t generated = 0;
afi_t afi;
safi_t safi;
- s = stream_fifo_head(peer->obuf);
- if (s)
- return s;
+ wpq = atomic_load_explicit(&peer->bgp->wpkt_quanta,
+ memory_order_relaxed);
/*
* The code beyond this part deals with update packets, proceed only
* update-delay post processing).
*/
if (peer->status != Established)
- return NULL;
+ return 0;
if (peer->bgp && peer->bgp->main_peers_update_hold)
- return NULL;
+ return 0;
- for (afi = AFI_IP; afi < AFI_MAX; afi++)
- for (safi = SAFI_UNICAST; safi < SAFI_MAX; safi++) {
+ do {
+ s = NULL;
+ FOREACH_AFI_SAFI (afi, safi) {
paf = peer_af_find(peer, afi, safi);
if (!paf || !PAF_SUBGRP(paf))
continue;
next_pkt = paf->next_pkt_to_send;
- /* Try to generate a packet for the peer if we are at
- * the end of
- * the list. Always try to push out WITHDRAWs first. */
+ /*
+ * Try to generate a packet for the peer if we are at
+ * the end of the list. Always try to push out
+ * WITHDRAWs first.
+ */
if (!next_pkt || !next_pkt->buffer) {
next_pkt = subgroup_withdraw_packet(
PAF_SUBGRP(paf));
next_pkt = paf->next_pkt_to_send;
}
- /* If we still don't have a packet to send to the peer,
- * then
- * try to find out out if we have to send eor or if not,
- * skip to
- * the next AFI, SAFI.
- * Don't send the EOR prematurely... if the subgroup's
- * coalesce
- * timer is running, the adjacency-out structure is not
- * created
+ /*
+ * If we still don't have a packet to send to the peer,
+ * then try to find out out if we have to send eor or
+ * if not, skip to the next AFI, SAFI. Don't send the
+ * EOR prematurely; if the subgroup's coalesce timer is
+ * running, the adjacency-out structure is not created
* yet.
*/
if (!next_pkt || !next_pkt->buffer) {
SET_FLAG(peer->af_sflags[afi]
[safi],
PEER_STATUS_EOR_SEND);
- return bgp_update_packet_eor(
- peer, afi, safi);
+
+ if ((s = bgp_update_packet_eor(
+ peer, afi,
+ safi))) {
+ bgp_packet_add(peer, s);
+ }
}
}
continue;
}
- /*
- * Found a packet template to send, overwrite packet
- * with appropriate
- * attributes from peer and advance peer
- */
+ /* Found a packet template to send, overwrite
+ * packet with appropriate attributes from peer
+ * and advance peer */
s = bpacket_reformat_for_peer(next_pkt, paf);
+ bgp_packet_add(peer, s);
bpacket_queue_advance_peer(paf);
- return s;
- }
-
- return NULL;
-}
-
-/* The next action for the peer from a write perspective */
-static void bgp_write_proceed_actions(struct peer *peer)
-{
- afi_t afi;
- safi_t safi;
- struct peer_af *paf;
- struct bpacket *next_pkt;
- int fullq_found = 0;
- struct update_subgroup *subgrp;
-
- if (stream_fifo_head(peer->obuf)) {
- BGP_WRITE_ON(peer->t_write, bgp_write, peer->fd);
- return;
- }
-
- for (afi = AFI_IP; afi < AFI_MAX; afi++)
- for (safi = SAFI_UNICAST; safi < SAFI_MAX; safi++) {
- paf = peer_af_find(peer, afi, safi);
- if (!paf)
- continue;
- subgrp = paf->subgroup;
- if (!subgrp)
- continue;
-
- next_pkt = paf->next_pkt_to_send;
- if (next_pkt && next_pkt->buffer) {
- BGP_WRITE_ON(peer->t_write, bgp_write,
- peer->fd);
- return;
- }
-
- /* No packets readily available for AFI/SAFI, are there
- * subgroup packets
- * that need to be generated? */
- if (bpacket_queue_is_full(SUBGRP_INST(subgrp),
- SUBGRP_PKTQ(subgrp)))
- fullq_found = 1;
- else if (subgroup_packets_to_build(subgrp)) {
- BGP_WRITE_ON(peer->t_write, bgp_write,
- peer->fd);
- return;
- }
-
- /* No packets to send, see if EOR is pending */
- if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV)) {
- if (!subgrp->t_coalesce
- && peer->afc_nego[afi][safi]
- && peer->synctime
- && !CHECK_FLAG(peer->af_sflags[afi][safi],
- PEER_STATUS_EOR_SEND)
- && safi != SAFI_MPLS_VPN) {
- BGP_WRITE_ON(peer->t_write, bgp_write,
- peer->fd);
- return;
- }
- }
}
- if (fullq_found) {
- BGP_WRITE_ON(peer->t_write, bgp_write, peer->fd);
- return;
- }
-}
-
-/* Write packet to the peer. */
-int bgp_write(struct thread *thread)
-{
- struct peer *peer;
- u_char type;
- struct stream *s;
- int num;
- int update_last_write = 0;
- unsigned int count = 0;
- unsigned int oc = 0;
+ } while (s && (++generated < wpq));
- /* Yes first of all get peer pointer. */
- peer = THREAD_ARG(thread);
- peer->t_write = NULL;
-
- /* For non-blocking IO check. */
- if (peer->status == Connect) {
- bgp_connect_check(peer, 1);
- return 0;
- }
-
- s = bgp_write_packet(peer);
- if (!s) {
- bgp_write_proceed_actions(peer);
- return 0;
- }
-
- sockopt_cork(peer->fd, 1);
-
- oc = peer->update_out;
-
- /* Nonblocking write until TCP output buffer is full. */
- do {
- int writenum;
-
- /* Number of bytes to be sent. */
- writenum = stream_get_endp(s) - stream_get_getp(s);
-
- /* Call write() system call. */
- num = write(peer->fd, STREAM_PNT(s), writenum);
- if (num < 0) {
- /* write failed either retry needed or error */
- if (ERRNO_IO_RETRY(errno))
- break;
-
- BGP_EVENT_ADD(peer, TCP_fatal_error);
- return 0;
- }
-
- if (num != writenum) {
- /* Partial write */
- stream_forward_getp(s, num);
- break;
- }
-
- /* Retrieve BGP packet type. */
- stream_set_getp(s, BGP_MARKER_SIZE + 2);
- type = stream_getc(s);
-
- switch (type) {
- case BGP_MSG_OPEN:
- peer->open_out++;
- break;
- case BGP_MSG_UPDATE:
- peer->update_out++;
- break;
- case BGP_MSG_NOTIFY:
- peer->notify_out++;
- /* Double start timer. */
- peer->v_start *= 2;
-
- /* Overflow check. */
- if (peer->v_start >= (60 * 2))
- peer->v_start = (60 * 2);
-
- /* Flush any existing events */
- BGP_EVENT_ADD(peer, BGP_Stop);
- goto done;
-
- case BGP_MSG_KEEPALIVE:
- peer->keepalive_out++;
- break;
- case BGP_MSG_ROUTE_REFRESH_NEW:
- case BGP_MSG_ROUTE_REFRESH_OLD:
- peer->refresh_out++;
- break;
- case BGP_MSG_CAPABILITY:
- peer->dynamic_cap_out++;
- break;
- }
-
- /* OK we send packet so delete it. */
- bgp_packet_delete(peer);
- update_last_write = 1;
- } while (++count < peer->bgp->wpkt_quanta
- && (s = bgp_write_packet(peer)) != NULL);
+ if (generated)
+ bgp_writes_on(peer);
bgp_write_proceed_actions(peer);
-done:
- /* Update last_update if UPDATEs were written. */
- if (peer->update_out > oc)
- peer->last_update = bgp_clock();
-
- /* If we TXed any flavor of packet update last_write */
- if (update_last_write)
- peer->last_write = bgp_clock();
-
- sockopt_cork(peer->fd, 0);
- return 0;
-}
-
-/* This is only for sending NOTIFICATION message to neighbor. */
-static int bgp_write_notify(struct peer *peer)
-{
- int ret, val;
- u_char type;
- struct stream *s;
-
- /* There should be at least one packet. */
- s = stream_fifo_head(peer->obuf);
- if (!s)
- return 0;
- assert(stream_get_endp(s) >= BGP_HEADER_SIZE);
-
- /* Stop collecting data within the socket */
- sockopt_cork(peer->fd, 0);
-
- /* socket is in nonblocking mode, if we can't deliver the NOTIFY, well,
- * we only care about getting a clean shutdown at this point. */
- ret = write(peer->fd, STREAM_DATA(s), stream_get_endp(s));
-
- /* only connection reset/close gets counted as TCP_fatal_error, failure
- * to write the entire NOTIFY doesn't get different FSM treatment */
- if (ret <= 0) {
- BGP_EVENT_ADD(peer, TCP_fatal_error);
- return 0;
- }
-
- /* Disable Nagle, make NOTIFY packet go out right away */
- val = 1;
- (void)setsockopt(peer->fd, IPPROTO_TCP, TCP_NODELAY, (char *)&val,
- sizeof(val));
-
- /* Retrieve BGP packet type. */
- stream_set_getp(s, BGP_MARKER_SIZE + 2);
- type = stream_getc(s);
-
- assert(type == BGP_MSG_NOTIFY);
-
- /* Type should be notify. */
- peer->notify_out++;
-
- /* Double start timer. */
- peer->v_start *= 2;
-
- /* Overflow check. */
- if (peer->v_start >= (60 * 2))
- peer->v_start = (60 * 2);
-
- /* Handle Graceful Restart case where the state changes to
- Connect instead of Idle */
- BGP_EVENT_ADD(peer, BGP_Stop);
-
return 0;
}
-/* Make keepalive packet and send it to the peer. */
+/*
+ * Creates a BGP Keepalive packet and appends it to the peer's output queue.
+ */
void bgp_keepalive_send(struct peer *peer)
{
struct stream *s;
/* Add packet to the peer. */
bgp_packet_add(peer, s);
- BGP_WRITE_ON(peer->t_write, bgp_write, peer->fd);
+ bgp_writes_on(peer);
}
-/* Make open packet and send it to the peer. */
+/*
+ * Creates a BGP Open packet and appends it to the peer's output queue.
+ * Sets capabilities as necessary.
+ */
void bgp_open_send(struct peer *peer)
{
struct stream *s;
/* Dump packet if debug option is set. */
/* bgp_packet_dump (s); */
- /* Add packet to the peer. */
- bgp_packet_add(peer, s);
+ /* Add packet to the peer. */
+ bgp_packet_add(peer, s);
+
+ bgp_writes_on(peer);
+}
+
+/*
+ * Writes NOTIFICATION message directly to a peer socket without waiting for
+ * the I/O thread.
+ *
+ * There must be exactly one stream on the peer->obuf FIFO, and the data within
+ * this stream must match the format of a BGP NOTIFICATION message.
+ * Transmission is best-effort.
+ *
+ * @requires peer->io_mtx
+ * @param peer
+ * @return 0
+ */
+static int bgp_write_notify(struct peer *peer)
+{
+ int ret, val;
+ u_char type;
+ struct stream *s;
+
+ /* There should be at least one packet. */
+ s = stream_fifo_pop(peer->obuf);
+
+ if (!s)
+ return 0;
+
+ assert(stream_get_endp(s) >= BGP_HEADER_SIZE);
+
+ /* Stop collecting data within the socket */
+ sockopt_cork(peer->fd, 0);
+
+ /*
+ * socket is in nonblocking mode, if we can't deliver the NOTIFY, well,
+ * we only care about getting a clean shutdown at this point.
+ */
+ ret = write(peer->fd, STREAM_DATA(s), stream_get_endp(s));
+
+ /*
+ * only connection reset/close gets counted as TCP_fatal_error, failure
+ * to write the entire NOTIFY doesn't get different FSM treatment
+ */
+ if (ret <= 0) {
+ stream_free(s);
+ BGP_EVENT_ADD(peer, TCP_fatal_error);
+ return 0;
+ }
+
+ /* Disable Nagle, make NOTIFY packet go out right away */
+ val = 1;
+ (void)setsockopt(peer->fd, IPPROTO_TCP, TCP_NODELAY, (char *)&val,
+ sizeof(val));
+
+ /* Retrieve BGP packet type. */
+ stream_set_getp(s, BGP_MARKER_SIZE + 2);
+ type = stream_getc(s);
+
+ assert(type == BGP_MSG_NOTIFY);
+
+ /* Type should be notify. */
+ atomic_fetch_add_explicit(&peer->notify_out, 1, memory_order_relaxed);
+ peer->notify_out++;
+
+ /* Double start timer. */
+ peer->v_start *= 2;
+
+ /* Overflow check. */
+ if (peer->v_start >= (60 * 2))
+ peer->v_start = (60 * 2);
+
+ /*
+ * Handle Graceful Restart case where the state changes to
+ * Connect instead of Idle
+ */
+ BGP_EVENT_ADD(peer, BGP_Stop);
+
+ stream_free(s);
- BGP_WRITE_ON(peer->t_write, bgp_write, peer->fd);
+ return 0;
}
-/* Send BGP notify packet with data potion. */
+/*
+ * Creates a BGP Notify and appends it to the peer's output queue.
+ *
+ * This function attempts to write the packet from the thread it is called
+ * from, to ensure the packet gets out ASAP.
+ *
+ * This function may be called from multiple threads. Since the function
+ * modifies I/O buffer(s) in the peer, these are locked for the duration of the
+ * call to prevent tampering from other threads.
+ *
+ * Delivery of the NOTIFICATION is attempted once and is best-effort. After
+ * return, the peer structure *must* be reset; no assumptions about session
+ * state are valid.
+ *
+ * @param peer
+ * @param code BGP error code
+ * @param sub_code BGP error subcode
+ * @param data Data portion
+ * @param datalen length of data portion
+ */
void bgp_notify_send_with_data(struct peer *peer, u_char code, u_char sub_code,
u_char *data, size_t datalen)
{
struct stream *s;
int length;
+ /* Lock I/O mutex to prevent other threads from pushing packets */
+ pthread_mutex_lock(&peer->io_mtx);
+ /* ============================================== */
+
/* Allocate new stream. */
s = stream_new(BGP_MAX_PACKET_SIZE);
- /* Make nitify packet. */
+ /* Make notify packet. */
bgp_packet_set_marker(s, BGP_MSG_NOTIFY);
/* Set notify packet values. */
/* Set BGP packet length. */
length = bgp_packet_set_size(s);
- /* Add packet to the peer. */
+ /* wipe output buffer */
stream_fifo_clean(peer->obuf);
- bgp_packet_add(peer, s);
+
+ /*
+ * If possible, store last packet for debugging purposes. This check is
+ * in place because we are sometimes called with a doppelganger peer,
+ * who tends to have a plethora of fields nulled out.
+ */
+ if (peer->curr && peer->last_reset_cause_size) {
+ size_t packetsize = stream_get_endp(peer->curr);
+ assert(packetsize <= peer->last_reset_cause_size);
+ memcpy(peer->last_reset_cause, peer->curr->data, packetsize);
+ peer->last_reset_cause_size = packetsize;
+ }
/* For debug */
{
} else
peer->last_reset = PEER_DOWN_NOTIFY_SEND;
- /* Call immediately. */
- BGP_WRITE_OFF(peer->t_write);
+ /* Add packet to peer's output queue */
+ stream_fifo_push(peer->obuf, s);
bgp_write_notify(peer);
+
+ /* ============================================== */
+ pthread_mutex_unlock(&peer->io_mtx);
}
-/* Send BGP notify packet. */
+/*
+ * Creates a BGP Notify and appends it to the peer's output queue.
+ *
+ * This function attempts to write the packet from the thread it is called
+ * from, to ensure the packet gets out ASAP.
+ *
+ * @param peer
+ * @param code BGP error code
+ * @param sub_code BGP error subcode
+ */
void bgp_notify_send(struct peer *peer, u_char code, u_char sub_code)
{
bgp_notify_send_with_data(peer, code, sub_code, NULL, 0);
}
-/* Send route refresh message to the peer. */
+/*
+ * Creates BGP Route Refresh packet and appends it to the peer's output queue.
+ *
+ * @param peer
+ * @param afi Address Family Identifier
+ * @param safi Subsequent Address Family Identifier
+ * @param orf_type Outbound Route Filtering type
+ * @param when_to_refresh Whether to refresh immediately or defer
+ * @param remove Whether to remove ORF for specified AFI/SAFI
+ */
void bgp_route_refresh_send(struct peer *peer, afi_t afi, safi_t safi,
u_char orf_type, u_char when_to_refresh, int remove)
{
/* Add packet to the peer. */
bgp_packet_add(peer, s);
- BGP_WRITE_ON(peer->t_write, bgp_write, peer->fd);
+ bgp_writes_on(peer);
}
-/* Send capability message to the peer. */
+/*
+ * Create a BGP Capability packet and append it to the peer's output queue.
+ *
+ * @param peer
+ * @param afi Address Family Identifier
+ * @param safi Subsequent Address Family Identifier
+ * @param capability_code BGP Capability Code
+ * @param action Set or Remove capability
+ */
void bgp_capability_send(struct peer *peer, afi_t afi, safi_t safi,
int capability_code, int action)
{
/* Add packet to the peer. */
bgp_packet_add(peer, s);
- BGP_WRITE_ON(peer->t_write, bgp_write, peer->fd);
+ bgp_writes_on(peer);
}
/* RFC1771 6.8 Connection collision detection. */
return 0;
}
+/* Packet processing routines ---------------------------------------------- */
+/*
+ * This is a family of functions designed to be called from
+ * bgp_process_packet(). These functions all share similar behavior and should
+ * adhere to the following invariants and restrictions:
+ *
+ * Return codes
+ * ------------
+ * The return code of any one of those functions should be one of the FSM event
+ * codes specified in bgpd.h. If a NOTIFY was sent, this event code MUST be
+ * BGP_Stop. Otherwise, the code SHOULD correspond to the function's expected
+ * packet type. For example, bgp_open_receive() should return BGP_Stop upon
+ * error and Receive_OPEN_message otherwise.
+ *
+ * If no action is necessary, the correct return code is BGP_PACKET_NOOP as
+ * defined below.
+ *
+ * Side effects
+ * ------------
+ * - May send NOTIFY messages
+ * - May not modify peer->status
+ * - May not call bgp_event_update()
+ */
+
+#define BGP_PACKET_NOOP 0
+
+/**
+ * Process BGP OPEN message for peer.
+ *
+ * If any errors are encountered in the OPEN message, immediately sends NOTIFY
+ * and returns BGP_Stop.
+ *
+ * @param peer
+ * @param size size of the packet
+ * @return as in summary
+ */
static int bgp_open_receive(struct peer *peer, bgp_size_t size)
{
int ret;
u_int16_t *holdtime_ptr;
/* Parse open packet. */
- version = stream_getc(peer->ibuf);
- memcpy(notify_data_remote_as, stream_pnt(peer->ibuf), 2);
- remote_as = stream_getw(peer->ibuf);
- holdtime_ptr = (u_int16_t *)stream_pnt(peer->ibuf);
- holdtime = stream_getw(peer->ibuf);
- memcpy(notify_data_remote_id, stream_pnt(peer->ibuf), 4);
- remote_id.s_addr = stream_get_ipv4(peer->ibuf);
+ version = stream_getc(peer->curr);
+ memcpy(notify_data_remote_as, stream_pnt(peer->curr), 2);
+ remote_as = stream_getw(peer->curr);
+ holdtime_ptr = (u_int16_t *)stream_pnt(peer->curr);
+ holdtime = stream_getw(peer->curr);
+ memcpy(notify_data_remote_id, stream_pnt(peer->curr), 4);
+ remote_id.s_addr = stream_get_ipv4(peer->curr);
/* Receive OPEN message log */
if (bgp_debug_neighbor_events(peer))
/* BEGIN to read the capability here, but dont do it yet */
mp_capability = 0;
- optlen = stream_getc(peer->ibuf);
+ optlen = stream_getc(peer->curr);
if (optlen != 0) {
/* If not enough bytes, it is an error. */
- if (STREAM_READABLE(peer->ibuf) < optlen) {
+ if (STREAM_READABLE(peer->curr) < optlen) {
bgp_notify_send(peer, BGP_NOTIFY_OPEN_ERR,
BGP_NOTIFY_OPEN_MALFORMED_ATTR);
- return -1;
+ return BGP_Stop;
}
/* We need the as4 capability value *right now* because
bgp_notify_send_with_data(peer, BGP_NOTIFY_OPEN_ERR,
BGP_NOTIFY_OPEN_BAD_PEER_AS,
notify_data_remote_as4, 4);
- return -1;
+ return BGP_Stop;
}
if (remote_as == BGP_AS_TRANS) {
bgp_notify_send_with_data(peer, BGP_NOTIFY_OPEN_ERR,
BGP_NOTIFY_OPEN_BAD_PEER_AS,
notify_data_remote_as4, 4);
- return -1;
+ return BGP_Stop;
}
if (!as4 && BGP_DEBUG(as4, AS4))
bgp_notify_send_with_data(peer, BGP_NOTIFY_OPEN_ERR,
BGP_NOTIFY_OPEN_BAD_PEER_AS,
notify_data_remote_as4, 4);
- return -1;
+ return BGP_Stop;
}
}
bgp_notify_send_with_data(peer, BGP_NOTIFY_OPEN_ERR,
BGP_NOTIFY_OPEN_BAD_BGP_IDENT,
notify_data_remote_id, 4);
- return -1;
+ return BGP_Stop;
}
/* Set remote router-id */
bgp_notify_send_with_data(peer, BGP_NOTIFY_OPEN_ERR,
BGP_NOTIFY_OPEN_UNSUP_VERSION,
(u_int8_t *)&maxver, 2);
- return -1;
+ return BGP_Stop;
}
/* Check neighbor as number. */
bgp_notify_send_with_data(peer, BGP_NOTIFY_OPEN_ERR,
BGP_NOTIFY_OPEN_BAD_PEER_AS,
notify_data_remote_as, 2);
- return -1;
+ return BGP_Stop;
} else if (peer->as_type == AS_INTERNAL) {
if (remote_as != peer->bgp->as) {
if (bgp_debug_neighbor_events(peer))
bgp_notify_send_with_data(peer, BGP_NOTIFY_OPEN_ERR,
BGP_NOTIFY_OPEN_BAD_PEER_AS,
notify_data_remote_as, 2);
- return -1;
+ return BGP_Stop;
}
peer->as = peer->local_as;
} else if (peer->as_type == AS_EXTERNAL) {
bgp_notify_send_with_data(peer, BGP_NOTIFY_OPEN_ERR,
BGP_NOTIFY_OPEN_BAD_PEER_AS,
notify_data_remote_as, 2);
- return -1;
+ return BGP_Stop;
}
peer->as = remote_as;
} else if ((peer->as_type == AS_SPECIFIED) && (remote_as != peer->as)) {
bgp_notify_send_with_data(peer, BGP_NOTIFY_OPEN_ERR,
BGP_NOTIFY_OPEN_BAD_PEER_AS,
notify_data_remote_as, 2);
- return -1;
+ return BGP_Stop;
}
/* From the rfc: Upon receipt of an OPEN message, a BGP speaker MUST
bgp_notify_send_with_data(peer, BGP_NOTIFY_OPEN_ERR,
BGP_NOTIFY_OPEN_UNACEP_HOLDTIME,
(u_char *)holdtime_ptr, 2);
- return -1;
+ return BGP_Stop;
}
/* From the rfc: A reasonable maximum time between KEEPALIVE messages
if (optlen != 0) {
if ((ret = bgp_open_option_parse(peer, optlen, &mp_capability))
< 0)
- return ret;
+ return BGP_Stop;
} else {
if (bgp_debug_neighbor_events(peer))
zlog_debug("%s rcvd OPEN w/ OPTION parameter len: 0",
immidiately. */
ret = bgp_collision_detect(peer, remote_id);
if (ret < 0)
- return ret;
+ return BGP_Stop;
/* Get sockname. */
if ((ret = bgp_getsockname(peer)) < 0) {
zlog_err("%s: bgp_getsockname() failed for peer: %s",
__FUNCTION__, peer->host);
- return (ret);
+ return BGP_Stop;
}
/* Verify valid local address present based on negotiated
peer->host, peer->fd);
bgp_notify_send(peer, BGP_NOTIFY_CEASE,
BGP_NOTIFY_SUBCODE_UNSPECIFIC);
- return -1;
+ return BGP_Stop;
#endif
}
}
peer->host, peer->fd);
bgp_notify_send(peer, BGP_NOTIFY_CEASE,
BGP_NOTIFY_SUBCODE_UNSPECIFIC);
- return -1;
+ return BGP_Stop;
#endif
}
}
peer->rtt = sockopt_tcp_rtt(peer->fd);
- if ((ret = bgp_event_update(peer, Receive_OPEN_message)) < 0) {
- zlog_err("%s: BGP event update failed for peer: %s",
- __FUNCTION__, peer->host);
- /* DD: bgp send notify and reset state */
- return (ret);
- }
-
- peer->packet_size = 0;
- if (peer->ibuf)
- stream_reset(peer->ibuf);
-
- return 0;
-}
-
-/* Called when there is a change in the EOR(implicit or explicit) status of a
- peer.
- Ends the update-delay if all expected peers are done with EORs. */
-void bgp_check_update_delay(struct bgp *bgp)
-{
- struct listnode *node, *nnode;
- struct peer *peer = NULL;
-
- if (bgp_debug_neighbor_events(peer))
- zlog_debug("Checking update delay, T: %d R: %d I:%d E: %d",
- bgp->established, bgp->restarted_peers,
- bgp->implicit_eors, bgp->explicit_eors);
-
- if (bgp->established
- <= bgp->restarted_peers + bgp->implicit_eors + bgp->explicit_eors) {
- /* This is an extra sanity check to make sure we wait for all
- the
- eligible configured peers. This check is performed if
- establish wait
- timer is on, or establish wait option is not given with the
- update-delay command */
- if (bgp->t_establish_wait
- || (bgp->v_establish_wait == bgp->v_update_delay))
- for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
- if (CHECK_FLAG(peer->flags,
- PEER_FLAG_CONFIG_NODE)
- && !CHECK_FLAG(peer->flags,
- PEER_FLAG_SHUTDOWN)
- && !peer->update_delay_over) {
- if (bgp_debug_neighbor_events(peer))
- zlog_debug(
- " Peer %s pending, continuing read-only mode",
- peer->host);
- return;
- }
- }
-
- zlog_info(
- "Update delay ended, restarted: %d, EORs implicit: %d, explicit: %d",
- bgp->restarted_peers, bgp->implicit_eors,
- bgp->explicit_eors);
- bgp_update_delay_end(bgp);
- }
-}
-
-/* Called if peer is known to have restarted. The restart-state bit in
- Graceful-Restart capability is used for that */
-void bgp_update_restarted_peers(struct peer *peer)
-{
- if (!bgp_update_delay_active(peer->bgp))
- return; /* BGP update delay has ended */
- if (peer->update_delay_over)
- return; /* This peer has already been considered */
-
- if (bgp_debug_neighbor_events(peer))
- zlog_debug("Peer %s: Checking restarted", peer->host);
-
- if (peer->status == Established) {
- peer->update_delay_over = 1;
- peer->bgp->restarted_peers++;
- bgp_check_update_delay(peer->bgp);
- }
+ return Receive_OPEN_message;
}
-/* Called as peer receives a keep-alive. Determines if this occurence can be
- taken as an implicit EOR for this peer.
- NOTE: The very first keep-alive after the Established state of a peer is
- considered implicit EOR for the update-delay purposes */
-void bgp_update_implicit_eors(struct peer *peer)
+/**
+ * Process BGP KEEPALIVE message for peer.
+ *
+ * @param peer
+ * @param size size of the packet
+ * @return as in summary
+ */
+static int bgp_keepalive_receive(struct peer *peer, bgp_size_t size)
{
- if (!bgp_update_delay_active(peer->bgp))
- return; /* BGP update delay has ended */
- if (peer->update_delay_over)
- return; /* This peer has already been considered */
+ if (bgp_debug_keepalive(peer))
+ zlog_debug("%s KEEPALIVE rcvd", peer->host);
- if (bgp_debug_neighbor_events(peer))
- zlog_debug("Peer %s: Checking implicit EORs", peer->host);
+ bgp_update_implicit_eors(peer);
- if (peer->status == Established) {
- peer->update_delay_over = 1;
- peer->bgp->implicit_eors++;
- bgp_check_update_delay(peer->bgp);
- }
+ return Receive_KEEPALIVE_message;
}
-/* Should be called only when there is a change in the EOR_RECEIVED status
- for any afi/safi on a peer */
-static void bgp_update_explicit_eors(struct peer *peer)
-{
- afi_t afi;
- safi_t safi;
-
- if (!bgp_update_delay_active(peer->bgp))
- return; /* BGP update delay has ended */
- if (peer->update_delay_over)
- return; /* This peer has already been considered */
-
- if (bgp_debug_neighbor_events(peer))
- zlog_debug("Peer %s: Checking explicit EORs", peer->host);
-
- for (afi = AFI_IP; afi < AFI_MAX; afi++)
- for (safi = SAFI_UNICAST; safi < SAFI_MAX; safi++) {
- if (peer->afc_nego[afi][safi]
- && !CHECK_FLAG(peer->af_sflags[afi][safi],
- PEER_STATUS_EOR_RECEIVED)) {
- if (bgp_debug_neighbor_events(peer))
- zlog_debug(
- " afi %d safi %d didnt receive EOR",
- afi, safi);
- return;
- }
- }
-
- peer->update_delay_over = 1;
- peer->bgp->explicit_eors++;
- bgp_check_update_delay(peer->bgp);
-}
-/* Frontend for NLRI parsing, to fan-out to AFI/SAFI specific parsers
- * mp_withdraw, if set, is used to nullify attr structure on most of the calling
- * safi function
- * and for evpn, passed as parameter
+/**
+ * Process BGP UPDATE message for peer.
+ *
+ * Parses UPDATE and creates attribute object.
+ *
+ * @param peer
+ * @param size size of the packet
+ * @return as in summary
*/
-int bgp_nlri_parse(struct peer *peer, struct attr *attr,
- struct bgp_nlri *packet, int mp_withdraw)
-{
- switch (packet->safi) {
- case SAFI_UNICAST:
- case SAFI_MULTICAST:
- return bgp_nlri_parse_ip(peer, mp_withdraw ? NULL : attr,
- packet);
- case SAFI_LABELED_UNICAST:
- return bgp_nlri_parse_label(peer, mp_withdraw ? NULL : attr,
- packet);
- case SAFI_MPLS_VPN:
- return bgp_nlri_parse_vpn(peer, mp_withdraw ? NULL : attr,
- packet);
- case SAFI_EVPN:
- return bgp_nlri_parse_evpn(peer, attr, packet, mp_withdraw);
- default:
- return -1;
- }
-}
-
-/* Parse BGP Update packet and make attribute object. */
static int bgp_update_receive(struct peer *peer, bgp_size_t size)
{
int ret, nlri_ret;
peer->host,
lookup_msg(bgp_status_msg, peer->status, NULL));
bgp_notify_send(peer, BGP_NOTIFY_FSM_ERR, 0);
- return -1;
+ return BGP_Stop;
}
/* Set initial values. */
memset(peer->rcvd_attr_str, 0, BUFSIZ);
peer->rcvd_attr_printed = 0;
- s = peer->ibuf;
+ s = peer->curr;
end = stream_pnt(s) + size;
/* RFC1771 6.3 If the Unfeasible Routes Length or Total Attribute
peer->host);
bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
BGP_NOTIFY_UPDATE_MAL_ATTR);
- return -1;
+ return BGP_Stop;
}
/* Unfeasible Route Length. */
peer->host, withdraw_len);
bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
BGP_NOTIFY_UPDATE_MAL_ATTR);
- return -1;
+ return BGP_Stop;
}
/* Unfeasible Route packet format check. */
peer->host);
bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
BGP_NOTIFY_UPDATE_MAL_ATTR);
- return -1;
+ return BGP_Stop;
}
/* Fetch attribute total length. */
peer->host, attribute_len);
bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
BGP_NOTIFY_UPDATE_MAL_ATTR);
- return -1;
+ return BGP_Stop;
}
/* Certain attribute parsing errors should not be considered bad enough
&nlris[NLRI_MP_WITHDRAW]);
if (attr_parse_ret == BGP_ATTR_PARSE_ERROR) {
bgp_attr_unintern_sub(&attr);
- return -1;
+ return BGP_Stop;
}
}
? BGP_NOTIFY_UPDATE_INVAL_NETWORK
: BGP_NOTIFY_UPDATE_OPT_ATTR_ERR);
bgp_attr_unintern_sub(&attr);
- return -1;
+ return BGP_Stop;
}
}
* Non-MP IPv4/Unicast EoR is a completely empty UPDATE
* and MP EoR should have only an empty MP_UNREACH
*/
- if ((!update_len && !withdraw_len &&
- nlris[NLRI_MP_UPDATE].length == 0) ||
- (attr_parse_ret == BGP_ATTR_PARSE_EOR)) {
+ if ((!update_len && !withdraw_len && nlris[NLRI_MP_UPDATE].length == 0)
+ || (attr_parse_ret == BGP_ATTR_PARSE_EOR)) {
afi_t afi = 0;
safi_t safi;
interned in bgp_attr_parse(). */
bgp_attr_unintern_sub(&attr);
- /* If peering is stopped due to some reason, do not generate BGP
- event. */
- if (peer->status != Established)
- return 0;
-
- /* Increment packet counter. */
- peer->update_in++;
peer->update_time = bgp_clock();
/* Rearm holdtime timer */
BGP_TIMER_OFF(peer->t_holdtime);
bgp_timer_set(peer);
- return 0;
+ return Receive_UPDATE_message;
}
-/* Notify message treatment function. */
-static void bgp_notify_receive(struct peer *peer, bgp_size_t size)
+/**
+ * Process BGP NOTIFY message for peer.
+ *
+ * @param peer
+ * @param size size of the packet
+ * @return as in summary
+ */
+static int bgp_notify_receive(struct peer *peer, bgp_size_t size)
{
struct bgp_notify bgp_notify;
peer->notify.length = 0;
}
- bgp_notify.code = stream_getc(peer->ibuf);
- bgp_notify.subcode = stream_getc(peer->ibuf);
+ bgp_notify.code = stream_getc(peer->curr);
+ bgp_notify.subcode = stream_getc(peer->curr);
bgp_notify.length = size - 2;
bgp_notify.data = NULL;
if (bgp_notify.length) {
peer->notify.length = size - 2;
peer->notify.data = XMALLOC(MTYPE_TMP, size - 2);
- memcpy(peer->notify.data, stream_pnt(peer->ibuf), size - 2);
+ memcpy(peer->notify.data, stream_pnt(peer->curr), size - 2);
}
/* For debug */
for (i = 0; i < bgp_notify.length; i++)
if (first) {
sprintf(c, " %02x",
- stream_getc(peer->ibuf));
+ stream_getc(peer->curr));
strcat(bgp_notify.data, c);
} else {
first = 1;
sprintf(c, "%02x",
- stream_getc(peer->ibuf));
+ stream_getc(peer->curr));
strcpy(bgp_notify.data, c);
}
bgp_notify.raw_data = (u_char *)peer->notify.data;
}
/* peer count update */
- peer->notify_in++;
+ atomic_fetch_add_explicit(&peer->notify_in, 1, memory_order_relaxed);
peer->last_reset = PEER_DOWN_NOTIFY_RECEIVED;
&& bgp_notify.subcode == BGP_NOTIFY_OPEN_UNSUP_PARAM)
UNSET_FLAG(peer->sflags, PEER_STATUS_CAPABILITY_OPEN);
- BGP_EVENT_ADD(peer, Receive_NOTIFICATION_message);
-}
-
-/* Keepalive treatment function -- get keepalive send keepalive */
-static void bgp_keepalive_receive(struct peer *peer, bgp_size_t size)
-{
- if (bgp_debug_keepalive(peer))
- zlog_debug("%s KEEPALIVE rcvd", peer->host);
-
- BGP_EVENT_ADD(peer, Receive_KEEPALIVE_message);
+ return Receive_NOTIFICATION_message;
}
-/* Route refresh message is received. */
-static void bgp_route_refresh_receive(struct peer *peer, bgp_size_t size)
+/**
+ * Process BGP ROUTEREFRESH message for peer.
+ *
+ * @param peer
+ * @param size size of the packet
+ * @return as in summary
+ */
+static int bgp_route_refresh_receive(struct peer *peer, bgp_size_t size)
{
iana_afi_t pkt_afi;
afi_t afi;
peer->host);
bgp_notify_send(peer, BGP_NOTIFY_HEADER_ERR,
BGP_NOTIFY_HEADER_BAD_MESTYPE);
- return;
+ return BGP_Stop;
}
/* Status must be Established. */
peer->host,
lookup_msg(bgp_status_msg, peer->status, NULL));
bgp_notify_send(peer, BGP_NOTIFY_FSM_ERR, 0);
- return;
+ return BGP_Stop;
}
- s = peer->ibuf;
+ s = peer->curr;
/* Parse packet. */
pkt_afi = stream_getw(s);
zlog_info(
"%s REFRESH_REQ for unrecognized afi/safi: %d/%d - ignored",
peer->host, pkt_afi, pkt_safi);
- return;
+ return BGP_PACKET_NOOP;
}
if (size != BGP_MSG_ROUTE_REFRESH_MIN_SIZE - BGP_HEADER_SIZE) {
zlog_info("%s ORF route refresh length error",
peer->host);
bgp_notify_send(peer, BGP_NOTIFY_CEASE, 0);
- return;
+ return BGP_Stop;
}
when_to_refresh = stream_getc(s);
? "Defer"
: "Immediate");
if (when_to_refresh == REFRESH_DEFER)
- return;
+ return BGP_PACKET_NOOP;
}
/* First update is deferred until ORF or ROUTE-REFRESH is received */
/* Perform route refreshment to the peer */
bgp_announce_route(peer, afi, safi);
+
+ /* No FSM action necessary */
+ return BGP_PACKET_NOOP;
}
+/**
+ * Parse BGP CAPABILITY message for peer.
+ *
+ * @param peer
+ * @param size size of the packet
+ * @return as in summary
+ */
static int bgp_capability_msg_parse(struct peer *peer, u_char *pnt,
bgp_size_t length)
{
if (pnt + 3 > end) {
zlog_info("%s Capability length error", peer->host);
bgp_notify_send(peer, BGP_NOTIFY_CEASE, 0);
- return -1;
+ return BGP_Stop;
}
action = *pnt;
hdr = (struct capability_header *)(pnt + 1);
zlog_info("%s Capability Action Value error %d",
peer->host, action);
bgp_notify_send(peer, BGP_NOTIFY_CEASE, 0);
- return -1;
+ return BGP_Stop;
}
if (bgp_debug_neighbor_events(peer))
if ((pnt + hdr->length + 3) > end) {
zlog_info("%s Capability length error", peer->host);
bgp_notify_send(peer, BGP_NOTIFY_CEASE, 0);
- return -1;
+ return BGP_Stop;
}
/* Fetch structure to the byte stream. */
memcpy(&mpc, pnt + 3, sizeof(struct capability_mp_data));
+ pnt += hdr->length + 3;
/* We know MP Capability Code. */
if (hdr->code == CAPABILITY_CODE_MP) {
if (peer_active_nego(peer))
bgp_clear_route(peer, afi, safi);
else
- BGP_EVENT_ADD(peer, BGP_Stop);
+ return BGP_Stop;
}
} else {
zlog_warn(
"%s unrecognized capability code: %d - ignored",
peer->host, hdr->code);
}
- pnt += hdr->length + 3;
}
- return 0;
+
+ /* No FSM action necessary */
+ return BGP_PACKET_NOOP;
}
-/* Dynamic Capability is received.
+/**
+ * Parse BGP CAPABILITY message for peer.
+ *
+ * Exported for unit testing.
*
- * This is exported for unit-test purposes
+ * @param peer
+ * @param size size of the packet
+ * @return as in summary
*/
int bgp_capability_receive(struct peer *peer, bgp_size_t size)
{
u_char *pnt;
/* Fetch pointer. */
- pnt = stream_pnt(peer->ibuf);
+ pnt = stream_pnt(peer->curr);
if (bgp_debug_neighbor_events(peer))
zlog_debug("%s rcv CAPABILITY", peer->host);
peer->host);
bgp_notify_send(peer, BGP_NOTIFY_HEADER_ERR,
BGP_NOTIFY_HEADER_BAD_MESTYPE);
- return -1;
+ return BGP_Stop;
}
/* Status must be Established. */
peer->host,
lookup_msg(bgp_status_msg, peer->status, NULL));
bgp_notify_send(peer, BGP_NOTIFY_FSM_ERR, 0);
- return -1;
+ return BGP_Stop;
}
/* Parse packet. */
return bgp_capability_msg_parse(peer, pnt, size);
}
-/* BGP read utility function. */
-static int bgp_read_packet(struct peer *peer)
+/**
+ * Processes a peer's input buffer.
+ *
+ * This function sidesteps the event loop and directly calls bgp_event_update()
+ * after processing each BGP message. This is necessary to ensure proper
+ * ordering of FSM events and unifies the behavior that was present previously,
+ * whereby some of the packet handling functions would update the FSM and some
+ * would not, making event flow difficult to understand. Please think twice
+ * before hacking this.
+ *
+ * Thread type: THREAD_EVENT
+ * @param thread
+ * @return 0
+ */
+int bgp_process_packet(struct thread *thread)
{
- int nbytes;
- int readsize;
+ /* Yes first of all get peer pointer. */
+ struct peer *peer; // peer
+ uint32_t rpkt_quanta_old; // how many packets to read
+ int fsm_update_result; // return code of bgp_event_update()
+ int mprc; // message processing return code
- readsize = peer->packet_size - stream_get_endp(peer->ibuf);
+ peer = THREAD_ARG(thread);
+ rpkt_quanta_old = atomic_load_explicit(&peer->bgp->rpkt_quanta,
+ memory_order_relaxed);
+ fsm_update_result = 0;
- /* If size is zero then return. */
- if (!readsize)
+ /* Guard against scheduled events that occur after peer deletion. */
+ if (peer->status == Deleted || peer->status == Clearing)
return 0;
- /* Read packet from fd. */
- nbytes = stream_read_try(peer->ibuf, peer->fd, readsize);
-
- /* If read byte is smaller than zero then error occured. */
- if (nbytes < 0) {
- /* Transient error should retry */
- if (nbytes == -2)
- return -1;
+ unsigned int processed = 0;
- zlog_err("%s [Error] bgp_read_packet error: %s", peer->host,
- safe_strerror(errno));
-
- if (peer->status == Established) {
- if (CHECK_FLAG(peer->sflags, PEER_STATUS_NSF_MODE)) {
- peer->last_reset = PEER_DOWN_NSF_CLOSE_SESSION;
- SET_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT);
- } else
- peer->last_reset = PEER_DOWN_CLOSE_SESSION;
- }
-
- BGP_EVENT_ADD(peer, TCP_fatal_error);
- return -1;
- }
+ while (processed < rpkt_quanta_old) {
+ u_char type = 0;
+ bgp_size_t size;
+ char notify_data_length[2];
- /* When read byte is zero : clear bgp peer and return */
- if (nbytes == 0) {
- if (bgp_debug_neighbor_events(peer))
- zlog_debug("%s [Event] BGP connection closed fd %d",
- peer->host, peer->fd);
-
- if (peer->status == Established) {
- if (CHECK_FLAG(peer->sflags, PEER_STATUS_NSF_MODE)) {
- peer->last_reset = PEER_DOWN_NSF_CLOSE_SESSION;
- SET_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT);
- } else
- peer->last_reset = PEER_DOWN_CLOSE_SESSION;
+ pthread_mutex_lock(&peer->io_mtx);
+ {
+ peer->curr = stream_fifo_pop(peer->ibuf);
}
+ pthread_mutex_unlock(&peer->io_mtx);
- BGP_EVENT_ADD(peer, TCP_connection_closed);
- return -1;
- }
-
- /* We read partial packet. */
- if (stream_get_endp(peer->ibuf) != peer->packet_size)
- return -1;
-
- return 0;
-}
-
-/* Marker check. */
-static int bgp_marker_all_one(struct stream *s, int length)
-{
- int i;
-
- for (i = 0; i < length; i++)
- if (s->data[i] != 0xff)
+ if (peer->curr == NULL) // no packets to process, hmm...
return 0;
- return 1;
-}
-
-/* Starting point of packet process function. */
-int bgp_read(struct thread *thread)
-{
- int ret;
- u_char type = 0;
- struct peer *peer;
- bgp_size_t size;
- char notify_data_length[2];
- u_int32_t notify_out;
-
- /* Yes first of all get peer pointer. */
- peer = THREAD_ARG(thread);
- peer->t_read = NULL;
+ /* skip the marker and copy the packet length */
+ stream_forward_getp(peer->curr, BGP_MARKER_SIZE);
+ memcpy(notify_data_length, stream_pnt(peer->curr), 2);
- /* Note notify_out so we can check later to see if we sent another one
- */
- notify_out = peer->notify_out;
+ /* read in the packet length and type */
+ size = stream_getw(peer->curr);
+ type = stream_getc(peer->curr);
- /* For non-blocking IO check. */
- if (peer->status == Connect) {
- bgp_connect_check(peer, 1);
- goto done;
- } else {
- if (peer->fd < 0) {
- zlog_err("bgp_read peer's fd is negative value %d",
- peer->fd);
- return -1;
- }
- BGP_READ_ON(peer->t_read, bgp_read, peer->fd);
- }
+ /* BGP packet dump function. */
+ bgp_dump_packet(peer, type, peer->curr);
- /* Read packet header to determine type of the packet */
- if (peer->packet_size == 0)
- peer->packet_size = BGP_HEADER_SIZE;
-
- if (stream_get_endp(peer->ibuf) < BGP_HEADER_SIZE) {
- ret = bgp_read_packet(peer);
-
- /* Header read error or partial read packet. */
- if (ret < 0)
- goto done;
-
- /* Get size and type. */
- stream_forward_getp(peer->ibuf, BGP_MARKER_SIZE);
- memcpy(notify_data_length, stream_pnt(peer->ibuf), 2);
- size = stream_getw(peer->ibuf);
- type = stream_getc(peer->ibuf);
-
- /* Marker check */
- if (((type == BGP_MSG_OPEN) || (type == BGP_MSG_KEEPALIVE))
- && !bgp_marker_all_one(peer->ibuf, BGP_MARKER_SIZE)) {
- bgp_notify_send(peer, BGP_NOTIFY_HEADER_ERR,
- BGP_NOTIFY_HEADER_NOT_SYNC);
- goto done;
- }
+ /* adjust size to exclude the marker + length + type */
+ size -= BGP_HEADER_SIZE;
- /* BGP type check. */
- if (type != BGP_MSG_OPEN && type != BGP_MSG_UPDATE
- && type != BGP_MSG_NOTIFY && type != BGP_MSG_KEEPALIVE
- && type != BGP_MSG_ROUTE_REFRESH_NEW
- && type != BGP_MSG_ROUTE_REFRESH_OLD
- && type != BGP_MSG_CAPABILITY) {
- if (bgp_debug_neighbor_events(peer))
- zlog_debug("%s unknown message type 0x%02x",
- peer->host, type);
- bgp_notify_send_with_data(peer, BGP_NOTIFY_HEADER_ERR,
- BGP_NOTIFY_HEADER_BAD_MESTYPE,
- &type, 1);
- goto done;
- }
- /* Mimimum packet length check. */
- if ((size < BGP_HEADER_SIZE) || (size > BGP_MAX_PACKET_SIZE)
- || (type == BGP_MSG_OPEN && size < BGP_MSG_OPEN_MIN_SIZE)
- || (type == BGP_MSG_UPDATE
- && size < BGP_MSG_UPDATE_MIN_SIZE)
- || (type == BGP_MSG_NOTIFY
- && size < BGP_MSG_NOTIFY_MIN_SIZE)
- || (type == BGP_MSG_KEEPALIVE
- && size != BGP_MSG_KEEPALIVE_MIN_SIZE)
- || (type == BGP_MSG_ROUTE_REFRESH_NEW
- && size < BGP_MSG_ROUTE_REFRESH_MIN_SIZE)
- || (type == BGP_MSG_ROUTE_REFRESH_OLD
- && size < BGP_MSG_ROUTE_REFRESH_MIN_SIZE)
- || (type == BGP_MSG_CAPABILITY
- && size < BGP_MSG_CAPABILITY_MIN_SIZE)) {
- if (bgp_debug_neighbor_events(peer))
- zlog_debug("%s bad message length - %d for %s",
- peer->host, size,
- type == 128
- ? "ROUTE-REFRESH"
- : bgp_type_str[(int)type]);
- bgp_notify_send_with_data(peer, BGP_NOTIFY_HEADER_ERR,
- BGP_NOTIFY_HEADER_BAD_MESLEN,
- (u_char *)notify_data_length,
- 2);
- goto done;
+ /* Read rest of the packet and call each sort of packet routine
+ */
+ switch (type) {
+ case BGP_MSG_OPEN:
+ atomic_fetch_add_explicit(&peer->open_in, 1,
+ memory_order_relaxed);
+ mprc = bgp_open_receive(peer, size);
+ if (mprc == BGP_Stop)
+ zlog_err(
+ "%s: BGP OPEN receipt failed for peer: %s",
+ __FUNCTION__, peer->host);
+ break;
+ case BGP_MSG_UPDATE:
+ atomic_fetch_add_explicit(&peer->update_in, 1,
+ memory_order_relaxed);
+ peer->readtime = monotime(NULL);
+ mprc = bgp_update_receive(peer, size);
+ if (mprc == BGP_Stop)
+ zlog_err(
+ "%s: BGP UPDATE receipt failed for peer: %s",
+ __FUNCTION__, peer->host);
+ break;
+ case BGP_MSG_NOTIFY:
+ atomic_fetch_add_explicit(&peer->notify_in, 1,
+ memory_order_relaxed);
+ mprc = bgp_notify_receive(peer, size);
+ if (mprc == BGP_Stop)
+ zlog_err(
+ "%s: BGP NOTIFY receipt failed for peer: %s",
+ __FUNCTION__, peer->host);
+ break;
+ case BGP_MSG_KEEPALIVE:
+ peer->readtime = monotime(NULL);
+ atomic_fetch_add_explicit(&peer->keepalive_in, 1,
+ memory_order_relaxed);
+ mprc = bgp_keepalive_receive(peer, size);
+ if (mprc == BGP_Stop)
+ zlog_err(
+ "%s: BGP KEEPALIVE receipt failed for peer: %s",
+ __FUNCTION__, peer->host);
+ break;
+ case BGP_MSG_ROUTE_REFRESH_NEW:
+ case BGP_MSG_ROUTE_REFRESH_OLD:
+ atomic_fetch_add_explicit(&peer->refresh_in, 1,
+ memory_order_relaxed);
+ mprc = bgp_route_refresh_receive(peer, size);
+ if (mprc == BGP_Stop)
+ zlog_err(
+ "%s: BGP ROUTEREFRESH receipt failed for peer: %s",
+ __FUNCTION__, peer->host);
+ break;
+ case BGP_MSG_CAPABILITY:
+ atomic_fetch_add_explicit(&peer->dynamic_cap_in, 1,
+ memory_order_relaxed);
+ mprc = bgp_capability_receive(peer, size);
+ if (mprc == BGP_Stop)
+ zlog_err(
+ "%s: BGP CAPABILITY receipt failed for peer: %s",
+ __FUNCTION__, peer->host);
+ break;
+ default:
+ /*
+ * The message type should have been sanitized before
+ * we ever got here. Receipt of a message with an
+ * invalid header at this point is indicative of a
+ * security issue.
+ */
+ assert (!"Message of invalid type received during input processing");
}
- /* Adjust size to message length. */
- peer->packet_size = size;
- }
+ /* delete processed packet */
+ stream_free(peer->curr);
+ peer->curr = NULL;
+ processed++;
- ret = bgp_read_packet(peer);
- if (ret < 0)
- goto done;
-
- /* Get size and type again. */
- (void)stream_getw_from(peer->ibuf, BGP_MARKER_SIZE);
- type = stream_getc_from(peer->ibuf, BGP_MARKER_SIZE + 2);
-
- /* BGP packet dump function. */
- bgp_dump_packet(peer, type, peer->ibuf);
-
- size = (peer->packet_size - BGP_HEADER_SIZE);
-
- /* Read rest of the packet and call each sort of packet routine */
- switch (type) {
- case BGP_MSG_OPEN:
- peer->open_in++;
- bgp_open_receive(peer, size); /* XXX return value ignored! */
- break;
- case BGP_MSG_UPDATE:
- peer->readtime = monotime(NULL);
- bgp_update_receive(peer, size);
- break;
- case BGP_MSG_NOTIFY:
- bgp_notify_receive(peer, size);
- break;
- case BGP_MSG_KEEPALIVE:
- peer->readtime = monotime(NULL);
- bgp_keepalive_receive(peer, size);
- break;
- case BGP_MSG_ROUTE_REFRESH_NEW:
- case BGP_MSG_ROUTE_REFRESH_OLD:
- peer->refresh_in++;
- bgp_route_refresh_receive(peer, size);
- break;
- case BGP_MSG_CAPABILITY:
- peer->dynamic_cap_in++;
- bgp_capability_receive(peer, size);
- break;
- }
+ /* Update FSM */
+ if (mprc != BGP_PACKET_NOOP)
+ fsm_update_result = bgp_event_update(peer, mprc);
+ else
+ continue;
- /* If reading this packet caused us to send a NOTIFICATION then store a
- * copy
- * of the packet for troubleshooting purposes
- */
- if (notify_out < peer->notify_out) {
- memcpy(peer->last_reset_cause, peer->ibuf->data,
- peer->packet_size);
- peer->last_reset_cause_size = peer->packet_size;
- notify_out = peer->notify_out;
+ /*
+ * If peer was deleted, do not process any more packets. This
+ * is usually due to executing BGP_Stop or a stub deletion.
+ */
+ if (fsm_update_result == FSM_PEER_TRANSFERRED
+ || fsm_update_result == FSM_PEER_STOPPED)
+ break;
}
- /* Clear input buffer. */
- peer->packet_size = 0;
- if (peer->ibuf)
- stream_reset(peer->ibuf);
-
-done:
- /* If reading this packet caused us to send a NOTIFICATION then store a
- * copy
- * of the packet for troubleshooting purposes
- */
- if (notify_out < peer->notify_out) {
- memcpy(peer->last_reset_cause, peer->ibuf->data,
- peer->packet_size);
- peer->last_reset_cause_size = peer->packet_size;
+ if (fsm_update_result != FSM_PEER_TRANSFERRED
+ && fsm_update_result != FSM_PEER_STOPPED) {
+ pthread_mutex_lock(&peer->io_mtx);
+ {
+ // more work to do, come back later
+ if (peer->ibuf->count > 0)
+ thread_add_timer_msec(
+ bm->master, bgp_process_packet, peer, 0,
+ &peer->t_process_packet);
+ }
+ pthread_mutex_unlock(&peer->io_mtx);
}
return 0;
projects / mirror_frr.git / blobdiff