/* BGP I/O.
- * Implements packet I/O in a consumer pthread.
+ * Implements packet I/O in a pthread.
* Copyright (C) 2017 Cumulus Networks
+ * Quentin Young
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* MA 02110-1301 USA
*/
+/* clang-format off */
#include <zebra.h>
-#include <pthread.h> // for pthread_mutex_unlock, pthread_mutex_lock
-
-#include "frr_pthread.h" // for frr_pthread_get, frr_pthread
-#include "linklist.h" // for list_delete, list_delete_all_node, lis...
-#include "log.h" // for zlog_debug, safe_strerror, zlog_err
-#include "memory.h" // for MTYPE_TMP, XCALLOC, XFREE
-#include "network.h" // for ERRNO_IO_RETRY
-#include "stream.h" // for stream_get_endp, stream_getw_from, str...
-#include "thread.h" // for THREAD_OFF, THREAD_ARG, thread, thread...
-#include "zassert.h" // for assert
+#include <pthread.h> // for pthread_mutex_unlock, pthread_mutex_lock
+
+#include "frr_pthread.h" // for frr_pthread_get, frr_pthread
+#include "linklist.h" // for list_delete, list_delete_all_node, lis...
+#include "log.h" // for zlog_debug, safe_strerror, zlog_err
+#include "memory.h" // for MTYPE_TMP, XCALLOC, XFREE
+#include "network.h" // for ERRNO_IO_RETRY
+#include "stream.h" // for stream_get_endp, stream_getw_from, str...
+#include "ringbuf.h" // for ringbuf_remain, ringbuf_peek, ringbuf_...
+#include "thread.h" // for THREAD_OFF, THREAD_ARG, thread, thread...
+#include "zassert.h" // for assert
#include "bgpd/bgp_io.h"
-#include "bgpd/bgp_debug.h" // for bgp_debug_neighbor_events, bgp_type_str
-#include "bgpd/bgp_fsm.h" // for BGP_EVENT_ADD, bgp_event
-#include "bgpd/bgp_packet.h" // for bgp_notify_send_with_data, bgp_notify...
-#include "bgpd/bgpd.h" // for peer, BGP_MARKER_SIZE, bgp_master, bm
+#include "bgpd/bgp_debug.h" // for bgp_debug_neighbor_events, bgp_type_str
+#include "bgpd/bgp_fsm.h" // for BGP_EVENT_ADD, bgp_event
+#include "bgpd/bgp_packet.h" // for bgp_notify_send_with_data, bgp_notify...
+#include "bgpd/bgpd.h" // for peer, BGP_MARKER_SIZE, bgp_master, bm
+/* clang-format on */
/* forward declarations */
static uint16_t bgp_write(struct peer *);
static bool validate_header(struct peer *);
/* generic i/o status codes */
-#define BGP_IO_TRANS_ERR (1 << 0) // EAGAIN or similar occurred
-#define BGP_IO_FATAL_ERR (1 << 1) // some kind of fatal TCP error
+#define BGP_IO_TRANS_ERR (1 << 0) // EAGAIN or similar occurred
+#define BGP_IO_FATAL_ERR (1 << 1) // some kind of fatal TCP error
-/* Start and stop routines for I/O pthread + control variables
+/* Plumbing & control variables for thread lifecycle
* ------------------------------------------------------------------------ */
-_Atomic bool bgp_io_thread_run;
-_Atomic bool bgp_io_thread_started;
+bool bgp_io_thread_run;
+pthread_mutex_t *running_cond_mtx;
+pthread_cond_t *running_cond;
+
+/* Unused callback for thread_add_read() */
+static int bgp_io_dummy(struct thread *thread) { return 0; }
+
+/* Poison pill task */
+static int bgp_io_finish(struct thread *thread)
+{
+ bgp_io_thread_run = false;
+ return 0;
+}
+/* Extern lifecycle control functions. init -> start -> stop
+ * ------------------------------------------------------------------------ */
void bgp_io_init()
{
bgp_io_thread_run = false;
- bgp_io_thread_started = false;
+
+ running_cond_mtx = XCALLOC(MTYPE_PTHREAD_PRIM, sizeof(pthread_mutex_t));
+ running_cond = XCALLOC(MTYPE_PTHREAD_PRIM, sizeof(pthread_cond_t));
+
+ pthread_mutex_init(running_cond_mtx, NULL);
+ pthread_cond_init(running_cond, NULL);
+
+ /* unlocked in bgp_io_wait_running() */
+ pthread_mutex_lock(running_cond_mtx);
}
void *bgp_io_start(void *arg)
struct frr_pthread *fpt = frr_pthread_get(PTHREAD_IO);
fpt->master->owner = pthread_self();
+ // fd so we can sleep in poll()
+ int sleeper[2];
+ pipe(sleeper);
+ thread_add_read(fpt->master, &bgp_io_dummy, NULL, sleeper[0], NULL);
+
// we definitely don't want to handle signals
fpt->master->handle_signals = false;
struct thread task;
- atomic_store_explicit(&bgp_io_thread_run, true, memory_order_relaxed);
- atomic_store_explicit(&bgp_io_thread_started, true,
- memory_order_relaxed);
+ pthread_mutex_lock(running_cond_mtx);
+ {
+ bgp_io_thread_run = true;
+ pthread_cond_signal(running_cond);
+ }
+ pthread_mutex_unlock(running_cond_mtx);
while (bgp_io_thread_run) {
if (thread_fetch(fpt->master, &task)) {
}
}
+ close(sleeper[1]);
+ close(sleeper[0]);
+
return NULL;
}
-int bgp_io_stop(void **result, struct frr_pthread *fpt)
+void bgp_io_wait_running()
{
+ while (!bgp_io_thread_run)
+ pthread_cond_wait(running_cond, running_cond_mtx);
- bgp_io_thread_run = false;
- /* let the loop break */
- fpt->master->spin = false;
- /* break poll */
- pthread_kill(fpt->thread, SIGINT);
+ /* locked in bgp_io_init() */
+ pthread_mutex_unlock(running_cond_mtx);
+}
+
+int bgp_io_stop(void **result, struct frr_pthread *fpt)
+{
+ thread_add_event(fpt->master, &bgp_io_finish, NULL, 0, NULL);
pthread_join(fpt->thread, result);
+ pthread_mutex_destroy(running_cond_mtx);
+ pthread_cond_destroy(running_cond);
+
+ XFREE(MTYPE_PTHREAD_PRIM, running_cond_mtx);
+ XFREE(MTYPE_PTHREAD_PRIM, running_cond);
+
return 0;
}
-/* ------------------------------------------------------------------------ */
+
+/* Extern API -------------------------------------------------------------- */
void bgp_writes_on(struct peer *peer)
{
- while (!atomic_load_explicit(&bgp_io_thread_started,
- memory_order_relaxed))
- ;
+ assert(bgp_io_thread_run);
assert(peer->status != Deleted);
assert(peer->obuf);
assert(peer->ibuf);
assert(peer->ibuf_work);
- assert(!peer->t_connect_check);
+ assert(!peer->t_connect_check_r);
+ assert(!peer->t_connect_check_w);
assert(peer->fd);
struct frr_pthread *fpt = frr_pthread_get(PTHREAD_IO);
void bgp_writes_off(struct peer *peer)
{
- while (!atomic_load_explicit(&bgp_io_thread_started,
- memory_order_relaxed))
- ;
+ assert(bgp_io_thread_run);
struct frr_pthread *fpt = frr_pthread_get(PTHREAD_IO);
void bgp_reads_on(struct peer *peer)
{
- while (!atomic_load_explicit(&bgp_io_thread_started,
- memory_order_relaxed))
- ;
+ assert(bgp_io_thread_run);
assert(peer->status != Deleted);
assert(peer->ibuf);
assert(peer->fd);
assert(peer->ibuf_work);
- assert(stream_get_endp(peer->ibuf_work) == 0);
assert(peer->obuf);
- assert(!peer->t_connect_check);
+ assert(!peer->t_connect_check_r);
+ assert(!peer->t_connect_check_w);
assert(peer->fd);
struct frr_pthread *fpt = frr_pthread_get(PTHREAD_IO);
void bgp_reads_off(struct peer *peer)
{
- while (!atomic_load_explicit(&bgp_io_thread_started,
- memory_order_relaxed))
- ;
+ assert(bgp_io_thread_run);
struct frr_pthread *fpt = frr_pthread_get(PTHREAD_IO);
UNSET_FLAG(peer->thread_flags, PEER_THREAD_READS_ON);
}
+/* Internal functions ------------------------------------------------------- */
+
/**
- * Called from PTHREAD_IO when select() or poll() determines that the file
- * descriptor is ready to be written to.
+ * Called from I/O pthread when a file descriptor has become ready for writing.
*/
static int bgp_process_writes(struct thread *thread)
{
peer = THREAD_ARG(thread);
uint16_t status;
bool reschedule;
+ bool fatal = false;
if (peer->fd < 0)
return -1;
if (CHECK_FLAG(status, BGP_IO_TRANS_ERR)) { /* no problem */
}
- if (CHECK_FLAG(status, BGP_IO_FATAL_ERR))
+ if (CHECK_FLAG(status, BGP_IO_FATAL_ERR)) {
reschedule = false; /* problem */
+ fatal = true;
+ }
if (reschedule) {
thread_add_write(fpt->master, bgp_process_writes, peer,
peer->fd, &peer->t_write);
- thread_add_timer_msec(bm->master, bgp_generate_updgrp_packets,
- peer, 0,
- &peer->t_generate_updgrp_packets);
+ } else if (!fatal) {
+ BGP_TIMER_ON(peer->t_generate_updgrp_packets,
+ bgp_generate_updgrp_packets, 0);
}
return 0;
}
/**
- * Called from PTHREAD_IO when select() or poll() determines that the file
- * descriptor is ready to be read from.
+ * Called from I/O pthread when a file descriptor has become ready for reading,
+ * or has hung up.
*
* We read as much data as possible, process as many packets as we can and
* place them on peer->ibuf for secondary processing by the main thread.
*/
static int bgp_process_reads(struct thread *thread)
{
- static struct peer *peer; // peer to read from
- uint16_t status; // bgp_read status code
- bool more = true; // whether we got more data
- bool fatal = false; // whether fatal error occurred
- bool added_pkt = false; // whether we pushed onto ->ibuf
- bool header_valid = true; // whether header is valid
+ /* clang-format off */
+ static struct peer *peer; // peer to read from
+ uint16_t status; // bgp_read status code
+ bool more = true; // whether we got more data
+ bool fatal = false; // whether fatal error occurred
+ bool added_pkt = false; // whether we pushed onto ->ibuf
+ bool header_valid = true; // whether header is valid
+ /* clang-format on */
peer = THREAD_ARG(thread);
/* static buffer for transferring packets */
static unsigned char pktbuf[BGP_MAX_PACKET_SIZE];
/* shorter alias to peer's input buffer */
- struct stream *ibw = peer->ibuf_work;
- /* offset of start of current packet */
- size_t offset = stream_get_getp(ibw);
+ struct ringbuf *ibw = peer->ibuf_work;
/* packet size as given by header */
- u_int16_t pktsize = 0;
+ uint16_t pktsize = 0;
/* check that we have enough data for a header */
- if (STREAM_READABLE(ibw) < BGP_HEADER_SIZE)
+ if (ringbuf_remain(ibw) < BGP_HEADER_SIZE)
break;
/* validate header */
}
/* header is valid; retrieve packet size */
- pktsize = stream_getw_from(ibw, offset + BGP_MARKER_SIZE);
+ ringbuf_peek(ibw, BGP_MARKER_SIZE, &pktsize, sizeof(pktsize));
+
+ pktsize = ntohs(pktsize);
/* if this fails we are seriously screwed */
assert(pktsize <= BGP_MAX_PACKET_SIZE);
/* If we have that much data, chuck it into its own
* stream and append to input queue for processing. */
- if (STREAM_READABLE(ibw) >= pktsize) {
+ if (ringbuf_remain(ibw) >= pktsize) {
struct stream *pkt = stream_new(pktsize);
- stream_get(pktbuf, ibw, pktsize);
+ assert(ringbuf_get(ibw, pktbuf, pktsize) == pktsize);
stream_put(pkt, pktbuf, pktsize);
pthread_mutex_lock(&peer->io_mtx);
break;
}
- /* After reading:
- * 1. Move unread data to stream start to make room for more.
- * 2. Reschedule and return when we have additional data.
- *
- * XXX: Heavy abuse of stream API. This needs a ring buffer.
- */
- if (more && STREAM_WRITEABLE(peer->ibuf_work) < BGP_MAX_PACKET_SIZE) {
- void *from = stream_pnt(peer->ibuf_work);
- void *to = peer->ibuf_work->data;
- size_t siz = STREAM_READABLE(peer->ibuf_work);
- memmove(to, from, siz);
- stream_set_getp(peer->ibuf_work, 0);
- stream_set_endp(peer->ibuf_work, siz);
- }
-
- assert(STREAM_WRITEABLE(peer->ibuf_work) >= BGP_MAX_PACKET_SIZE);
+ assert(ringbuf_space(peer->ibuf_work) >= BGP_MAX_PACKET_SIZE);
/* handle invalid header */
if (fatal) {
- if (!header_valid) {
- bgp_size_t pktsize = BGP_HEADER_SIZE;
- stream_get(peer->last_reset_cause, peer->ibuf_work,
- pktsize);
- peer->last_reset_cause_size = pktsize;
- }
-
/* wipe buffer just in case someone screwed up */
- stream_reset(peer->ibuf_work);
+ ringbuf_wipe(peer->ibuf_work);
} else {
thread_add_read(fpt->master, bgp_process_reads, peer, peer->fd,
&peer->t_read);
if (added_pkt)
- thread_add_event(bm->master, bgp_process_packet, peer,
- 0, NULL);
+ thread_add_timer_msec(bm->master, bgp_process_packet,
+ peer, 0, &peer->t_process_packet);
}
return 0;
int num;
int update_last_write = 0;
unsigned int count = 0;
- unsigned int oc = 0;
+ uint32_t uo = 0;
uint16_t status = 0;
uint32_t wpkt_quanta_old;
// cache current write quanta
- wpkt_quanta_old = atomic_load_explicit(&peer->bgp->wpkt_quanta,
- memory_order_relaxed);
+ wpkt_quanta_old =
+ atomic_load_explicit(&peer->bgp->wpkt_quanta, memory_order_relaxed);
while (count < wpkt_quanta_old && (s = stream_fifo_head(peer->obuf))) {
int writenum;
switch (type) {
case BGP_MSG_OPEN:
- peer->open_out++;
+ atomic_fetch_add_explicit(&peer->open_out, 1,
+ memory_order_relaxed);
break;
case BGP_MSG_UPDATE:
- peer->update_out++;
+ atomic_fetch_add_explicit(&peer->update_out, 1,
+ memory_order_relaxed);
+ uo++;
break;
case BGP_MSG_NOTIFY:
- peer->notify_out++;
+ atomic_fetch_add_explicit(&peer->notify_out, 1,
+ memory_order_relaxed);
/* Double start timer. */
peer->v_start *= 2;
peer->v_start = (60 * 2);
/* Handle Graceful Restart case where the state changes
- to
- Connect instead of Idle */
- /* Flush any existing events */
+ * to Connect instead of Idle */
BGP_EVENT_ADD(peer, BGP_Stop);
goto done;
case BGP_MSG_KEEPALIVE:
- peer->keepalive_out++;
+ atomic_fetch_add_explicit(&peer->keepalive_out, 1,
+ memory_order_relaxed);
break;
case BGP_MSG_ROUTE_REFRESH_NEW:
case BGP_MSG_ROUTE_REFRESH_OLD:
- peer->refresh_out++;
+ atomic_fetch_add_explicit(&peer->refresh_out, 1,
+ memory_order_relaxed);
break;
case BGP_MSG_CAPABILITY:
- peer->dynamic_cap_out++;
+ atomic_fetch_add_explicit(&peer->dynamic_cap_out, 1,
+ memory_order_relaxed);
break;
}
}
done : {
- /* Update last_update if UPDATEs were written. */
- if (peer->update_out > oc)
- peer->last_update = bgp_clock();
+ /*
+ * Update last_update if UPDATEs were written.
+ * Note: that these are only updated at end,
+ * not per message (i.e., per loop)
+ */
+ if (uo)
+ atomic_store_explicit(&peer->last_update, bgp_clock(),
+ memory_order_relaxed);
- /* If we TXed any flavor of packet update last_write */
+ /* If we TXed any flavor of packet */
if (update_last_write)
- peer->last_write = bgp_clock();
+ atomic_store_explicit(&peer->last_write, bgp_clock(),
+ memory_order_relaxed);
}
return status;
}
/**
- * Reads <= 1 packet worth of data from peer->fd into peer->ibuf_work.
+ * Reads a chunk of data from peer->fd into peer->ibuf_work.
*
- * @return whether a full packet was read
+ * @return status flag (see top-of-file)
*/
static uint16_t bgp_read(struct peer *peer)
{
size_t readsize; // how many bytes we want to read
ssize_t nbytes; // how many bytes we actually read
uint16_t status = 0;
+ static uint8_t ibw[BGP_MAX_PACKET_SIZE * BGP_READ_PACKET_MAX];
+
+ readsize = MIN(ringbuf_space(peer->ibuf_work), sizeof(ibw));
+ nbytes = read(peer->fd, ibw, readsize);
+
+ /* EAGAIN or EWOULDBLOCK; come back later */
+ if (nbytes < 0 && ERRNO_IO_RETRY(errno)) {
+ SET_FLAG(status, BGP_IO_TRANS_ERR);
+ /* Fatal error; tear down session */
+ } else if (nbytes < 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;
+ }
- readsize = STREAM_WRITEABLE(peer->ibuf_work);
-
- nbytes = stream_read_try(peer->ibuf_work, peer->fd, readsize);
-
- if (nbytes <= 0) // handle errors
- {
- switch (nbytes) {
- case -1: // fatal error; tear down the session
- 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);
- SET_FLAG(status, BGP_IO_FATAL_ERR);
- break;
-
- case 0: // TCP session closed
- 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;
- }
-
- BGP_EVENT_ADD(peer, TCP_connection_closed);
- SET_FLAG(status, BGP_IO_FATAL_ERR);
- break;
-
- case -2: // temporary error; come back later
- SET_FLAG(status, BGP_IO_TRANS_ERR);
- break;
- default:
- break;
+ BGP_EVENT_ADD(peer, TCP_fatal_error);
+ SET_FLAG(status, BGP_IO_FATAL_ERR);
+ /* Received EOF / TCP session closed */
+ } else 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;
}
- return status;
+ BGP_EVENT_ADD(peer, TCP_connection_closed);
+ SET_FLAG(status, BGP_IO_FATAL_ERR);
+ } else {
+ assert(ringbuf_put(peer->ibuf_work, ibw, nbytes)
+ == (size_t)nbytes);
}
return status;
/*
* Called after we have read a BGP packet header. Validates marker, message
* type and packet length. If any of these aren't correct, sends a notify.
+ *
+ * Assumes that there are at least BGP_HEADER_SIZE readable bytes in the input
+ * buffer.
*/
static bool validate_header(struct peer *peer)
{
- u_int16_t size, type;
- struct stream *pkt = peer->ibuf_work;
- size_t getp = stream_get_getp(pkt);
+ uint16_t size;
+ uint8_t type;
+ struct ringbuf *pkt = peer->ibuf_work;
- static uint8_t marker[BGP_MARKER_SIZE] = {
+ static uint8_t m_correct[BGP_MARKER_SIZE] = {
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+ uint8_t m_rx[BGP_MARKER_SIZE] = {0x00};
+
+ if (ringbuf_peek(pkt, 0, m_rx, BGP_MARKER_SIZE) != BGP_MARKER_SIZE)
+ return false;
- if (memcmp(marker, stream_pnt(pkt), BGP_MARKER_SIZE) != 0) {
+ if (memcmp(m_correct, m_rx, BGP_MARKER_SIZE) != 0) {
bgp_notify_send(peer, BGP_NOTIFY_HEADER_ERR,
BGP_NOTIFY_HEADER_NOT_SYNC);
return false;
}
- /* Get size and type. */
- size = stream_getw_from(pkt, getp + BGP_MARKER_SIZE);
- type = stream_getc_from(pkt, getp + BGP_MARKER_SIZE + 2);
+ /* Get size and type in network byte order. */
+ ringbuf_peek(pkt, BGP_MARKER_SIZE, &size, sizeof(size));
+ ringbuf_peek(pkt, BGP_MARKER_SIZE + 2, &type, sizeof(type));
+
+ size = ntohs(size);
/* BGP type check. */
if (type != BGP_MSG_OPEN && type != BGP_MSG_UPDATE
bgp_notify_send_with_data(peer, BGP_NOTIFY_HEADER_ERR,
BGP_NOTIFY_HEADER_BAD_MESTYPE,
- (u_char *)&type, 1);
+ &type, 1);
return false;
}
- /* Mimimum packet length check. */
+ /* Minimum 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)
&& size < BGP_MSG_ROUTE_REFRESH_MIN_SIZE)
|| (type == BGP_MSG_CAPABILITY
&& size < BGP_MSG_CAPABILITY_MIN_SIZE)) {
- if (bgp_debug_neighbor_events(peer))
+ 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_type_str[(int) type]);
+ }
+
+ uint16_t nsize = htons(size);
bgp_notify_send_with_data(peer, BGP_NOTIFY_HEADER_ERR,
BGP_NOTIFY_HEADER_BAD_MESLEN,
- (u_char *)&size, 2);
+ (unsigned char *) &nsize, 2);
return false;
}
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