1 /* Copyright (c) 2013 Nicira, Inc.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License. */
18 #include <sys/types.h>
19 #include <arpa/inet.h>
20 #include <netinet/in_systm.h>
21 #include <netinet/ip.h>
23 #include "byte-order.h"
24 #include "connectivity.h"
27 #include "dynamic-string.h"
36 #include "ovs-thread.h"
37 #include "openvswitch/types.h"
39 #include "poll-loop.h"
44 #include "unaligned.h"
49 VLOG_DEFINE_THIS_MODULE(bfd
);
53 * The goal of this module is to replace CFM with something both more flexible
54 * and standards compliant. In service of this goal, the following needs to be
58 * * Implement Demand mode.
59 * * Go through the RFC line by line and verify we comply.
60 * * Test against a hardware implementation. Preferably a popular one.
61 * * Delete BFD packets with nw_ttl != 255 in the datapath to prevent DOS
66 * - Set TOS/PCP on the outer tunnel header when encapped.
68 * - Sending BFD messages should be in its own thread/process.
70 * - Scale testing. How does it operate when there are large number of bfd
71 * sessions? Do we ever have random flaps? What's the CPU utilization?
73 * - Rely on data traffic for liveness by using BFD demand mode.
74 * If we're receiving traffic on a port, we can safely assume it's up (modulo
75 * unidrectional failures). BFD has a demand mode in which it can stay quiet
76 * unless it feels the need to check the status of the port. Using this, we
77 * can implement a strategy in which BFD only sends control messages on dark
80 * - Depending on how one interprets the spec, it appears that a BFD session
81 * can never change bfd.LocalDiag to "No Diagnostic". We should verify that
82 * this is what hardware implementations actually do. Seems like "No
83 * Diagnostic" should be set once a BFD session state goes UP. */
88 FLAG_MULTIPOINT
= 1 << 0,
97 STATE_ADMIN_DOWN
= 0 << 6,
104 DIAG_NONE
= 0, /* No Diagnostic. */
105 DIAG_EXPIRED
= 1, /* Control Detection Time Expired. */
106 DIAG_ECHO_FAILED
= 2, /* Echo Function Failed. */
107 DIAG_RMT_DOWN
= 3, /* Neighbor Signaled Session Down. */
108 DIAG_FWD_RESET
= 4, /* Forwarding Plane Reset. */
109 DIAG_PATH_DOWN
= 5, /* Path Down. */
110 DIAG_CPATH_DOWN
= 6, /* Concatenated Path Down. */
111 DIAG_ADMIN_DOWN
= 7, /* Administratively Down. */
112 DIAG_RCPATH_DOWN
= 8 /* Reverse Concatenated Path Down. */
115 /* RFC 5880 Section 4.1
117 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
118 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
119 * |Vers | Diag |Sta|P|F|C|A|D|M| Detect Mult | Length |
120 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
121 * | My Discriminator |
122 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
123 * | Your Discriminator |
124 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
125 * | Desired Min TX Interval |
126 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
127 * | Required Min RX Interval |
128 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
129 * | Required Min Echo RX Interval |
130 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */
132 uint8_t vers_diag
; /* Version and diagnostic. */
133 uint8_t flags
; /* 2bit State field followed by flags. */
134 uint8_t mult
; /* Fault detection multiplier. */
135 uint8_t length
; /* Length of this BFD message. */
136 ovs_be32 my_disc
; /* My discriminator. */
137 ovs_be32 your_disc
; /* Your discriminator. */
138 ovs_be32 min_tx
; /* Desired minimum tx interval. */
139 ovs_be32 min_rx
; /* Required minimum rx interval. */
140 ovs_be32 min_rx_echo
; /* Required minimum echo rx interval. */
142 BUILD_ASSERT_DECL(BFD_PACKET_LEN
== sizeof(struct msg
));
144 #define DIAG_MASK 0x1f
146 #define STATE_MASK 0xC0
147 #define FLAGS_MASK 0x3f
150 struct hmap_node node
; /* In 'all_bfds'. */
151 uint32_t disc
; /* bfd.LocalDiscr. Key in 'all_bfds' hmap. */
153 char *name
; /* Name used for logging. */
155 bool cpath_down
; /* Concatenated Path Down. */
156 uint8_t mult
; /* bfd.DetectMult. */
158 struct netdev
*netdev
;
159 uint64_t rx_packets
; /* Packets received by 'netdev'. */
161 enum state state
; /* bfd.SessionState. */
162 enum state rmt_state
; /* bfd.RemoteSessionState. */
164 enum diag diag
; /* bfd.LocalDiag. */
165 enum diag rmt_diag
; /* Remote diagnostic. */
167 enum flags flags
; /* Flags sent on messages. */
168 enum flags rmt_flags
; /* Flags last received. */
170 uint32_t rmt_disc
; /* bfd.RemoteDiscr. */
172 uint8_t eth_dst
[ETH_ADDR_LEN
];/* Ethernet destination address. */
173 bool eth_dst_set
; /* 'eth_dst' set through database. */
175 uint16_t udp_src
; /* UDP source port. */
177 /* All timers in milliseconds. */
178 long long int rmt_min_rx
; /* bfd.RemoteMinRxInterval. */
179 long long int rmt_min_tx
; /* Remote minimum TX interval. */
181 long long int cfg_min_tx
; /* Configured minimum TX rate. */
182 long long int cfg_min_rx
; /* Configured required minimum RX rate. */
183 long long int poll_min_tx
; /* Min TX negotating in a poll sequence. */
184 long long int poll_min_rx
; /* Min RX negotating in a poll sequence. */
185 long long int min_tx
; /* bfd.DesiredMinTxInterval. */
186 long long int min_rx
; /* bfd.RequiredMinRxInterval. */
188 long long int last_tx
; /* Last TX time. */
189 long long int next_tx
; /* Next TX time. */
190 long long int detect_time
; /* RFC 5880 6.8.4 Detection time. */
192 bool last_forwarding
; /* Last calculation of forwarding flag. */
193 int forwarding_override
; /* Manual override of 'forwarding' status. */
195 atomic_bool check_tnl_key
; /* Verify tunnel key of inbound packets? */
198 /* When forward_if_rx is true, bfd_forwarding() will return
199 * true as long as there are incoming packets received.
200 * Note, forwarding_override still has higher priority. */
201 bool forwarding_if_rx
;
202 long long int forwarding_if_rx_detect_time
;
204 /* BFD decay related variables. */
205 bool in_decay
; /* True when bfd is in decay. */
206 int decay_min_rx
; /* min_rx is set to decay_min_rx when */
208 int decay_rx_ctl
; /* Count bfd packets received within decay */
209 /* detect interval. */
210 uint64_t decay_rx_packets
; /* Packets received by 'netdev'. */
211 long long int decay_detect_time
; /* Decay detection time. */
213 uint64_t flap_count
; /* Counts bfd forwarding flaps. */
216 static struct ovs_mutex mutex
= OVS_MUTEX_INITIALIZER
;
217 static struct hmap all_bfds__
= HMAP_INITIALIZER(&all_bfds__
);
218 static struct hmap
*const all_bfds
OVS_GUARDED_BY(mutex
) = &all_bfds__
;
220 static bool bfd_forwarding__(struct bfd
*) OVS_REQUIRES(mutex
);
221 static bool bfd_in_poll(const struct bfd
*) OVS_REQUIRES(mutex
);
222 static void bfd_poll(struct bfd
*bfd
) OVS_REQUIRES(mutex
);
223 static const char *bfd_diag_str(enum diag
) OVS_REQUIRES(mutex
);
224 static const char *bfd_state_str(enum state
) OVS_REQUIRES(mutex
);
225 static long long int bfd_min_tx(const struct bfd
*) OVS_REQUIRES(mutex
);
226 static long long int bfd_tx_interval(const struct bfd
*)
228 static long long int bfd_rx_interval(const struct bfd
*)
230 static void bfd_set_next_tx(struct bfd
*) OVS_REQUIRES(mutex
);
231 static void bfd_set_state(struct bfd
*, enum state
, enum diag
)
233 static uint32_t generate_discriminator(void) OVS_REQUIRES(mutex
);
234 static void bfd_put_details(struct ds
*, const struct bfd
*)
236 static uint64_t bfd_rx_packets(const struct bfd
*) OVS_REQUIRES(mutex
);
237 static void bfd_try_decay(struct bfd
*) OVS_REQUIRES(mutex
);
238 static void bfd_decay_update(struct bfd
*) OVS_REQUIRES(mutex
);
240 static void bfd_forwarding_if_rx_update(struct bfd
*) OVS_REQUIRES(mutex
);
241 static void bfd_unixctl_show(struct unixctl_conn
*, int argc
,
242 const char *argv
[], void *aux OVS_UNUSED
);
243 static void bfd_unixctl_set_forwarding_override(struct unixctl_conn
*,
244 int argc
, const char *argv
[],
245 void *aux OVS_UNUSED
);
246 static void log_msg(enum vlog_level
, const struct msg
*, const char *message
,
247 const struct bfd
*) OVS_REQUIRES(mutex
);
249 static struct vlog_rate_limit rl
= VLOG_RATE_LIMIT_INIT(20, 20);
251 /* Returns true if the interface on which 'bfd' is running may be used to
252 * forward traffic according to the BFD session state. */
254 bfd_forwarding(struct bfd
*bfd
) OVS_EXCLUDED(mutex
)
258 ovs_mutex_lock(&mutex
);
259 ret
= bfd_forwarding__(bfd
);
260 ovs_mutex_unlock(&mutex
);
264 /* When forwarding_if_rx is enabled, if there are packets received,
265 * updates forwarding_if_rx_detect_time. */
267 bfd_account_rx(struct bfd
*bfd
, const struct dpif_flow_stats
*stats
)
269 if (stats
->n_packets
&& bfd
->forwarding_if_rx
) {
270 ovs_mutex_lock(&mutex
);
271 bfd_forwarding__(bfd
);
272 bfd_forwarding_if_rx_update(bfd
);
273 bfd_forwarding__(bfd
);
274 ovs_mutex_unlock(&mutex
);
278 /* Returns a 'smap' of key value pairs representing the status of 'bfd'
279 * intended for the OVS database. */
281 bfd_get_status(const struct bfd
*bfd
, struct smap
*smap
)
284 ovs_mutex_lock(&mutex
);
285 smap_add(smap
, "forwarding",
286 bfd_forwarding__(CONST_CAST(struct bfd
*, bfd
))
288 smap_add(smap
, "state", bfd_state_str(bfd
->state
));
289 smap_add(smap
, "diagnostic", bfd_diag_str(bfd
->diag
));
290 smap_add_format(smap
, "flap_count", "%"PRIu64
, bfd
->flap_count
);
292 if (bfd
->state
!= STATE_DOWN
) {
293 smap_add(smap
, "remote_state", bfd_state_str(bfd
->rmt_state
));
294 smap_add(smap
, "remote_diagnostic", bfd_diag_str(bfd
->rmt_diag
));
296 ovs_mutex_unlock(&mutex
);
299 /* Initializes, destroys, or reconfigures the BFD session 'bfd' (named 'name'),
300 * according to the database configuration contained in 'cfg'. Takes ownership
301 * of 'bfd', which may be NULL. Returns a BFD object which may be used as a
302 * handle for the session, or NULL if BFD is not enabled according to 'cfg'.
303 * Also returns NULL if cfg is NULL. */
305 bfd_configure(struct bfd
*bfd
, const char *name
, const struct smap
*cfg
,
306 struct netdev
*netdev
) OVS_EXCLUDED(mutex
)
308 static struct ovsthread_once once
= OVSTHREAD_ONCE_INITIALIZER
;
309 static atomic_uint16_t udp_src
= ATOMIC_VAR_INIT(0);
312 long long int min_tx
, min_rx
;
313 bool need_poll
= false;
314 bool cfg_min_rx_changed
= false;
315 bool cpath_down
, forwarding_if_rx
;
317 uint8_t ea
[ETH_ADDR_LEN
];
319 if (ovsthread_once_start(&once
)) {
320 unixctl_command_register("bfd/show", "[interface]", 0, 1,
321 bfd_unixctl_show
, NULL
);
322 unixctl_command_register("bfd/set-forwarding",
323 "[interface] normal|false|true", 1, 2,
324 bfd_unixctl_set_forwarding_override
, NULL
);
325 ovsthread_once_done(&once
);
328 if (!cfg
|| !smap_get_bool(cfg
, "enable", false)) {
333 ovs_mutex_lock(&mutex
);
335 bfd
= xzalloc(sizeof *bfd
);
336 bfd
->name
= xstrdup(name
);
337 bfd
->forwarding_override
= -1;
338 bfd
->disc
= generate_discriminator();
339 hmap_insert(all_bfds
, &bfd
->node
, bfd
->disc
);
341 bfd
->diag
= DIAG_NONE
;
344 atomic_init(&bfd
->ref_cnt
, 1);
345 bfd
->netdev
= netdev_ref(netdev
);
346 bfd
->rx_packets
= bfd_rx_packets(bfd
);
347 bfd
->in_decay
= false;
350 /* RFC 5881 section 4
351 * The source port MUST be in the range 49152 through 65535. The same
352 * UDP source port number MUST be used for all BFD Control packets
353 * associated with a particular session. The source port number SHOULD
354 * be unique among all BFD sessions on the system. */
355 atomic_add(&udp_src
, 1, &bfd
->udp_src
);
356 bfd
->udp_src
= (bfd
->udp_src
% 16384) + 49152;
358 bfd_set_state(bfd
, STATE_DOWN
, DIAG_NONE
);
360 memcpy(bfd
->eth_dst
, eth_addr_bfd
, ETH_ADDR_LEN
);
363 atomic_store(&bfd
->check_tnl_key
,
364 smap_get_bool(cfg
, "check_tnl_key", false));
365 min_tx
= smap_get_int(cfg
, "min_tx", 100);
366 min_tx
= MAX(min_tx
, 100);
367 if (bfd
->cfg_min_tx
!= min_tx
) {
368 bfd
->cfg_min_tx
= min_tx
;
369 if (bfd
->state
!= STATE_UP
370 || (!bfd_in_poll(bfd
) && bfd
->cfg_min_tx
< bfd
->min_tx
)) {
371 bfd
->min_tx
= bfd
->cfg_min_tx
;
376 min_rx
= smap_get_int(cfg
, "min_rx", 1000);
377 min_rx
= MAX(min_rx
, 100);
378 if (bfd
->cfg_min_rx
!= min_rx
) {
379 bfd
->cfg_min_rx
= min_rx
;
380 if (bfd
->state
!= STATE_UP
381 || (!bfd_in_poll(bfd
) && bfd
->cfg_min_rx
> bfd
->min_rx
)) {
382 bfd
->min_rx
= bfd
->cfg_min_rx
;
384 cfg_min_rx_changed
= true;
388 decay_min_rx
= smap_get_int(cfg
, "decay_min_rx", 0);
389 if (bfd
->decay_min_rx
!= decay_min_rx
|| cfg_min_rx_changed
) {
390 if (decay_min_rx
> 0 && decay_min_rx
< bfd
->cfg_min_rx
) {
391 VLOG_WARN("%s: decay_min_rx cannot be less than %lld ms",
392 bfd
->name
, bfd
->cfg_min_rx
);
393 bfd
->decay_min_rx
= 0;
395 bfd
->decay_min_rx
= decay_min_rx
;
398 bfd
->in_decay
= false;
399 bfd_decay_update(bfd
);
403 cpath_down
= smap_get_bool(cfg
, "cpath_down", false);
404 if (bfd
->cpath_down
!= cpath_down
) {
405 bfd
->cpath_down
= cpath_down
;
406 if (bfd
->diag
== DIAG_NONE
|| bfd
->diag
== DIAG_CPATH_DOWN
) {
407 bfd_set_state(bfd
, bfd
->state
, DIAG_NONE
);
412 hwaddr
= smap_get(cfg
, "bfd_dst_mac");
413 if (hwaddr
&& eth_addr_from_string(hwaddr
, ea
) && !eth_addr_is_zero(ea
)) {
414 memcpy(bfd
->eth_dst
, ea
, ETH_ADDR_LEN
);
415 bfd
->eth_dst_set
= true;
416 } else if (bfd
->eth_dst_set
) {
417 memcpy(bfd
->eth_dst
, eth_addr_bfd
, ETH_ADDR_LEN
);
418 bfd
->eth_dst_set
= false;
421 forwarding_if_rx
= smap_get_bool(cfg
, "forwarding_if_rx", false);
422 if (bfd
->forwarding_if_rx
!= forwarding_if_rx
) {
423 bfd
->forwarding_if_rx
= forwarding_if_rx
;
424 if (bfd
->state
== STATE_UP
&& bfd
->forwarding_if_rx
) {
425 bfd_forwarding_if_rx_update(bfd
);
427 bfd
->forwarding_if_rx_detect_time
= 0;
434 ovs_mutex_unlock(&mutex
);
439 bfd_ref(const struct bfd
*bfd_
)
441 struct bfd
*bfd
= CONST_CAST(struct bfd
*, bfd_
);
444 atomic_add(&bfd
->ref_cnt
, 1, &orig
);
445 ovs_assert(orig
> 0);
451 bfd_unref(struct bfd
*bfd
) OVS_EXCLUDED(mutex
)
456 atomic_sub(&bfd
->ref_cnt
, 1, &orig
);
457 ovs_assert(orig
> 0);
459 ovs_mutex_lock(&mutex
);
460 hmap_remove(all_bfds
, &bfd
->node
);
461 netdev_close(bfd
->netdev
);
464 ovs_mutex_unlock(&mutex
);
470 bfd_wait(const struct bfd
*bfd
) OVS_EXCLUDED(mutex
)
472 poll_timer_wait_until(bfd_wake_time(bfd
));
475 /* Returns the next wake up time. */
477 bfd_wake_time(const struct bfd
*bfd
) OVS_EXCLUDED(mutex
)
479 long long int retval
;
485 ovs_mutex_lock(&mutex
);
486 if (bfd
->flags
& FLAG_FINAL
) {
489 retval
= bfd
->next_tx
;
490 if (bfd
->state
> STATE_DOWN
) {
491 retval
= MIN(bfd
->detect_time
, retval
);
494 ovs_mutex_unlock(&mutex
);
499 bfd_run(struct bfd
*bfd
) OVS_EXCLUDED(mutex
)
504 ovs_mutex_lock(&mutex
);
506 old_in_decay
= bfd
->in_decay
;
508 if (bfd
->state
> STATE_DOWN
&& now
>= bfd
->detect_time
) {
509 bfd_set_state(bfd
, STATE_DOWN
, DIAG_EXPIRED
);
511 bfd_forwarding__(bfd
);
513 /* Decay may only happen when state is STATE_UP, bfd->decay_min_rx is
514 * configured, and decay_detect_time is reached. */
515 if (bfd
->state
== STATE_UP
&& bfd
->decay_min_rx
> 0
516 && now
>= bfd
->decay_detect_time
) {
520 if (bfd
->min_tx
!= bfd
->cfg_min_tx
521 || (bfd
->min_rx
!= bfd
->cfg_min_rx
&& bfd
->min_rx
!= bfd
->decay_min_rx
)
522 || bfd
->in_decay
!= old_in_decay
) {
525 ovs_mutex_unlock(&mutex
);
529 bfd_should_send_packet(const struct bfd
*bfd
) OVS_EXCLUDED(mutex
)
532 ovs_mutex_lock(&mutex
);
533 ret
= bfd
->flags
& FLAG_FINAL
|| time_msec() >= bfd
->next_tx
;
534 ovs_mutex_unlock(&mutex
);
539 bfd_put_packet(struct bfd
*bfd
, struct ofpbuf
*p
,
540 uint8_t eth_src
[ETH_ADDR_LEN
]) OVS_EXCLUDED(mutex
)
542 long long int min_tx
, min_rx
;
543 struct udp_header
*udp
;
544 struct eth_header
*eth
;
545 struct ip_header
*ip
;
548 ovs_mutex_lock(&mutex
);
550 long long int delay
= time_msec() - bfd
->next_tx
;
551 long long int interval
= bfd_tx_interval(bfd
);
552 if (delay
> interval
* 3 / 2) {
553 VLOG_INFO("%s: long delay of %lldms (expected %lldms) sending BFD"
554 " control message", bfd
->name
, delay
, interval
);
558 /* RFC 5880 Section 6.5
559 * A BFD Control packet MUST NOT have both the Poll (P) and Final (F) bits
561 ovs_assert(!(bfd
->flags
& FLAG_POLL
) || !(bfd
->flags
& FLAG_FINAL
));
563 ofpbuf_reserve(p
, 2); /* Properly align after the ethernet header. */
564 eth
= ofpbuf_put_uninit(p
, sizeof *eth
);
565 memcpy(eth
->eth_src
, eth_src
, ETH_ADDR_LEN
);
566 memcpy(eth
->eth_dst
, bfd
->eth_dst
, ETH_ADDR_LEN
);
567 eth
->eth_type
= htons(ETH_TYPE_IP
);
569 ip
= ofpbuf_put_zeros(p
, sizeof *ip
);
570 ip
->ip_ihl_ver
= IP_IHL_VER(5, 4);
571 ip
->ip_tot_len
= htons(sizeof *ip
+ sizeof *udp
+ sizeof *msg
);
573 ip
->ip_tos
= IPTOS_LOWDELAY
| IPTOS_THROUGHPUT
;
574 ip
->ip_proto
= IPPROTO_UDP
;
575 /* Use link local addresses: */
576 put_16aligned_be32(&ip
->ip_src
, htonl(0xA9FE0100)); /* 169.254.1.0. */
577 put_16aligned_be32(&ip
->ip_dst
, htonl(0xA9FE0101)); /* 169.254.1.1. */
578 ip
->ip_csum
= csum(ip
, sizeof *ip
);
580 udp
= ofpbuf_put_zeros(p
, sizeof *udp
);
581 udp
->udp_src
= htons(bfd
->udp_src
);
582 udp
->udp_dst
= htons(BFD_DEST_PORT
);
583 udp
->udp_len
= htons(sizeof *udp
+ sizeof *msg
);
585 msg
= ofpbuf_put_uninit(p
, sizeof *msg
);
586 msg
->vers_diag
= (BFD_VERSION
<< 5) | bfd
->diag
;
587 msg
->flags
= (bfd
->state
& STATE_MASK
) | bfd
->flags
;
589 msg
->mult
= bfd
->mult
;
590 msg
->length
= BFD_PACKET_LEN
;
591 msg
->my_disc
= htonl(bfd
->disc
);
592 msg
->your_disc
= htonl(bfd
->rmt_disc
);
593 msg
->min_rx_echo
= htonl(0);
595 if (bfd_in_poll(bfd
)) {
596 min_tx
= bfd
->poll_min_tx
;
597 min_rx
= bfd
->poll_min_rx
;
599 min_tx
= bfd_min_tx(bfd
);
600 min_rx
= bfd
->min_rx
;
603 msg
->min_tx
= htonl(min_tx
* 1000);
604 msg
->min_rx
= htonl(min_rx
* 1000);
606 bfd
->flags
&= ~FLAG_FINAL
;
608 log_msg(VLL_DBG
, msg
, "Sending BFD Message", bfd
);
610 bfd
->last_tx
= time_msec();
611 bfd_set_next_tx(bfd
);
612 ovs_mutex_unlock(&mutex
);
616 bfd_should_process_flow(const struct bfd
*bfd_
, const struct flow
*flow
,
617 struct flow_wildcards
*wc
)
619 struct bfd
*bfd
= CONST_CAST(struct bfd
*, bfd_
);
622 memset(&wc
->masks
.dl_dst
, 0xff, sizeof wc
->masks
.dl_dst
);
623 if (bfd
->eth_dst_set
&& memcmp(bfd
->eth_dst
, flow
->dl_dst
, ETH_ADDR_LEN
)) {
627 memset(&wc
->masks
.nw_proto
, 0xff, sizeof wc
->masks
.nw_proto
);
628 memset(&wc
->masks
.tp_dst
, 0xff, sizeof wc
->masks
.tp_dst
);
630 atomic_read(&bfd
->check_tnl_key
, &check_tnl_key
);
632 memset(&wc
->masks
.tunnel
.tun_id
, 0xff, sizeof wc
->masks
.tunnel
.tun_id
);
634 return (flow
->dl_type
== htons(ETH_TYPE_IP
)
635 && flow
->nw_proto
== IPPROTO_UDP
636 && flow
->tp_dst
== htons(BFD_DEST_PORT
)
637 && (!check_tnl_key
|| flow
->tunnel
.tun_id
== htonll(0)));
641 bfd_process_packet(struct bfd
*bfd
, const struct flow
*flow
,
642 const struct ofpbuf
*p
) OVS_EXCLUDED(mutex
)
644 uint32_t rmt_min_rx
, pkt_your_disc
;
645 enum state rmt_state
;
650 /* This function is designed to follow section RFC 5880 6.8.6 closely. */
652 ovs_mutex_lock(&mutex
);
653 /* Increments the decay rx counter. */
656 bfd_forwarding__(bfd
);
658 if (flow
->nw_ttl
!= 255) {
659 /* XXX Should drop in the kernel to prevent DOS. */
663 msg
= ofpbuf_at(p
, (uint8_t *)p
->l7
- (uint8_t *)p
->data
, BFD_PACKET_LEN
);
665 VLOG_INFO_RL(&rl
, "%s: Received too-short BFD control message (only "
666 "%"PRIdPTR
" bytes long, at least %d required).",
667 bfd
->name
, (uint8_t *) ofpbuf_tail(p
) - (uint8_t *) p
->l7
,
672 /* RFC 5880 Section 6.8.6
673 * If the Length field is greater than the payload of the encapsulating
674 * protocol, the packet MUST be discarded.
676 * Note that we make this check implicity. Above we use ofpbuf_at() to
677 * ensure that there are at least BFD_PACKET_LEN bytes in the payload of
678 * the encapsulating protocol. Below we require msg->length to be exactly
679 * BFD_PACKET_LEN bytes. */
681 flags
= msg
->flags
& FLAGS_MASK
;
682 rmt_state
= msg
->flags
& STATE_MASK
;
683 version
= msg
->vers_diag
>> VERS_SHIFT
;
685 log_msg(VLL_DBG
, msg
, "Received BFD control message", bfd
);
687 if (version
!= BFD_VERSION
) {
688 log_msg(VLL_WARN
, msg
, "Incorrect version", bfd
);
692 /* Technically this should happen after the length check. We don't support
693 * authentication however, so it's simpler to do the check first. */
694 if (flags
& FLAG_AUTH
) {
695 log_msg(VLL_WARN
, msg
, "Authenticated control message with"
696 " authentication disabled", bfd
);
700 if (msg
->length
!= BFD_PACKET_LEN
) {
701 log_msg(VLL_WARN
, msg
, "Unexpected length", bfd
);
702 if (msg
->length
< BFD_PACKET_LEN
) {
708 log_msg(VLL_WARN
, msg
, "Zero multiplier", bfd
);
712 if (flags
& FLAG_MULTIPOINT
) {
713 log_msg(VLL_WARN
, msg
, "Unsupported multipoint flag", bfd
);
718 log_msg(VLL_WARN
, msg
, "NULL my_disc", bfd
);
722 pkt_your_disc
= ntohl(msg
->your_disc
);
724 /* Technically, we should use the your discriminator field to figure
725 * out which 'struct bfd' this packet is destined towards. That way a
726 * bfd session could migrate from one interface to another
727 * transparently. This doesn't fit in with the OVS structure very
728 * well, so in this respect, we are not compliant. */
729 if (pkt_your_disc
!= bfd
->disc
) {
730 log_msg(VLL_WARN
, msg
, "Incorrect your_disc", bfd
);
733 } else if (rmt_state
> STATE_DOWN
) {
734 log_msg(VLL_WARN
, msg
, "Null your_disc", bfd
);
738 bfd
->rmt_disc
= ntohl(msg
->my_disc
);
739 bfd
->rmt_state
= rmt_state
;
740 bfd
->rmt_flags
= flags
;
741 bfd
->rmt_diag
= msg
->vers_diag
& DIAG_MASK
;
743 if (flags
& FLAG_FINAL
&& bfd_in_poll(bfd
)) {
744 bfd
->min_tx
= bfd
->poll_min_tx
;
745 bfd
->min_rx
= bfd
->poll_min_rx
;
746 bfd
->flags
&= ~FLAG_POLL
;
747 log_msg(VLL_INFO
, msg
, "Poll sequence terminated", bfd
);
750 if (flags
& FLAG_POLL
) {
751 /* RFC 5880 Section 6.5
752 * When the other system receives a Poll, it immediately transmits a
753 * BFD Control packet with the Final (F) bit set, independent of any
754 * periodic BFD Control packets it may be sending
755 * (see section 6.8.7). */
756 bfd
->flags
&= ~FLAG_POLL
;
757 bfd
->flags
|= FLAG_FINAL
;
760 rmt_min_rx
= MAX(ntohl(msg
->min_rx
) / 1000, 1);
761 if (bfd
->rmt_min_rx
!= rmt_min_rx
) {
762 bfd
->rmt_min_rx
= rmt_min_rx
;
764 bfd_set_next_tx(bfd
);
766 log_msg(VLL_INFO
, msg
, "New remote min_rx", bfd
);
769 bfd
->rmt_min_tx
= MAX(ntohl(msg
->min_tx
) / 1000, 1);
770 bfd
->detect_time
= bfd_rx_interval(bfd
) * bfd
->mult
+ time_msec();
772 if (bfd
->state
== STATE_ADMIN_DOWN
) {
773 VLOG_DBG_RL(&rl
, "Administratively down, dropping control message.");
777 if (rmt_state
== STATE_ADMIN_DOWN
) {
778 if (bfd
->state
!= STATE_DOWN
) {
779 bfd_set_state(bfd
, STATE_DOWN
, DIAG_RMT_DOWN
);
782 switch (bfd
->state
) {
784 if (rmt_state
== STATE_DOWN
) {
785 bfd_set_state(bfd
, STATE_INIT
, bfd
->diag
);
786 } else if (rmt_state
== STATE_INIT
) {
787 bfd_set_state(bfd
, STATE_UP
, bfd
->diag
);
791 if (rmt_state
> STATE_DOWN
) {
792 bfd_set_state(bfd
, STATE_UP
, bfd
->diag
);
796 if (rmt_state
<= STATE_DOWN
) {
797 bfd_set_state(bfd
, STATE_DOWN
, DIAG_RMT_DOWN
);
798 log_msg(VLL_INFO
, msg
, "Remote signaled STATE_DOWN", bfd
);
801 case STATE_ADMIN_DOWN
:
806 /* XXX: RFC 5880 Section 6.8.6 Demand mode related calculations here. */
809 bfd_forwarding__(bfd
);
810 ovs_mutex_unlock(&mutex
);
813 /* Must be called when the netdev owned by 'bfd' should change. */
815 bfd_set_netdev(struct bfd
*bfd
, const struct netdev
*netdev
)
818 ovs_mutex_lock(&mutex
);
819 if (bfd
->netdev
!= netdev
) {
820 netdev_close(bfd
->netdev
);
821 bfd
->netdev
= netdev_ref(netdev
);
822 if (bfd
->decay_min_rx
&& bfd
->state
== STATE_UP
) {
823 bfd_decay_update(bfd
);
825 if (bfd
->forwarding_if_rx
&& bfd
->state
== STATE_UP
) {
826 bfd_forwarding_if_rx_update(bfd
);
828 bfd
->rx_packets
= bfd_rx_packets(bfd
);
830 ovs_mutex_unlock(&mutex
);
834 /* Updates the forwarding flag. If override is not configured and
835 * the forwarding flag value changes, increments the flap count.
837 * Note this function may be called multiple times in a function
838 * (e.g. bfd_account_rx) before and after the bfd state or status
839 * change. This is to capture any forwarding flag flap. */
841 bfd_forwarding__(struct bfd
*bfd
) OVS_REQUIRES(mutex
)
844 bool last_forwarding
= bfd
->last_forwarding
;
846 if (bfd
->forwarding_override
!= -1) {
847 return bfd
->forwarding_override
== 1;
850 time
= bfd
->forwarding_if_rx_detect_time
;
851 bfd
->last_forwarding
= (bfd
->state
== STATE_UP
852 || (bfd
->forwarding_if_rx
&& time
> time_msec()))
853 && bfd
->rmt_diag
!= DIAG_PATH_DOWN
854 && bfd
->rmt_diag
!= DIAG_CPATH_DOWN
855 && bfd
->rmt_diag
!= DIAG_RCPATH_DOWN
;
856 if (bfd
->last_forwarding
!= last_forwarding
) {
858 seq_change(connectivity_seq_get());
860 return bfd
->last_forwarding
;
865 bfd_in_poll(const struct bfd
*bfd
) OVS_REQUIRES(mutex
)
867 return (bfd
->flags
& FLAG_POLL
) != 0;
871 bfd_poll(struct bfd
*bfd
) OVS_REQUIRES(mutex
)
873 if (bfd
->state
> STATE_DOWN
&& !bfd_in_poll(bfd
)
874 && !(bfd
->flags
& FLAG_FINAL
)) {
875 bfd
->poll_min_tx
= bfd
->cfg_min_tx
;
876 bfd
->poll_min_rx
= bfd
->in_decay
? bfd
->decay_min_rx
: bfd
->cfg_min_rx
;
877 bfd
->flags
|= FLAG_POLL
;
879 VLOG_INFO_RL(&rl
, "%s: Initiating poll sequence", bfd
->name
);
884 bfd_min_tx(const struct bfd
*bfd
) OVS_REQUIRES(mutex
)
886 /* RFC 5880 Section 6.8.3
887 * When bfd.SessionState is not Up, the system MUST set
888 * bfd.DesiredMinTxInterval to a value of not less than one second
889 * (1,000,000 microseconds). This is intended to ensure that the
890 * bandwidth consumed by BFD sessions that are not Up is negligible,
891 * particularly in the case where a neighbor may not be running BFD. */
892 return (bfd
->state
== STATE_UP
? bfd
->min_tx
: MAX(bfd
->min_tx
, 1000));
896 bfd_tx_interval(const struct bfd
*bfd
) OVS_REQUIRES(mutex
)
898 long long int interval
= bfd_min_tx(bfd
);
899 return MAX(interval
, bfd
->rmt_min_rx
);
903 bfd_rx_interval(const struct bfd
*bfd
) OVS_REQUIRES(mutex
)
905 return MAX(bfd
->min_rx
, bfd
->rmt_min_tx
);
909 bfd_set_next_tx(struct bfd
*bfd
) OVS_REQUIRES(mutex
)
911 long long int interval
= bfd_tx_interval(bfd
);
912 interval
-= interval
* random_range(26) / 100;
913 bfd
->next_tx
= bfd
->last_tx
+ interval
;
917 bfd_flag_str(enum flags flags
)
919 struct ds ds
= DS_EMPTY_INITIALIZER
;
920 static char flag_str
[128];
926 if (flags
& FLAG_MULTIPOINT
) {
927 ds_put_cstr(&ds
, "multipoint ");
930 if (flags
& FLAG_DEMAND
) {
931 ds_put_cstr(&ds
, "demand ");
934 if (flags
& FLAG_AUTH
) {
935 ds_put_cstr(&ds
, "auth ");
938 if (flags
& FLAG_CTL
) {
939 ds_put_cstr(&ds
, "ctl ");
942 if (flags
& FLAG_FINAL
) {
943 ds_put_cstr(&ds
, "final ");
946 if (flags
& FLAG_POLL
) {
947 ds_put_cstr(&ds
, "poll ");
950 /* Do not copy the trailing whitespace. */
952 ovs_strlcpy(flag_str
, ds_cstr(&ds
), sizeof flag_str
);
958 bfd_state_str(enum state state
)
961 case STATE_ADMIN_DOWN
: return "admin_down";
962 case STATE_DOWN
: return "down";
963 case STATE_INIT
: return "init";
964 case STATE_UP
: return "up";
965 default: return "invalid";
970 bfd_diag_str(enum diag diag
) {
972 case DIAG_NONE
: return "No Diagnostic";
973 case DIAG_EXPIRED
: return "Control Detection Time Expired";
974 case DIAG_ECHO_FAILED
: return "Echo Function Failed";
975 case DIAG_RMT_DOWN
: return "Neighbor Signaled Session Down";
976 case DIAG_FWD_RESET
: return "Forwarding Plane Reset";
977 case DIAG_PATH_DOWN
: return "Path Down";
978 case DIAG_CPATH_DOWN
: return "Concatenated Path Down";
979 case DIAG_ADMIN_DOWN
: return "Administratively Down";
980 case DIAG_RCPATH_DOWN
: return "Reverse Concatenated Path Down";
981 default: return "Invalid Diagnostic";
986 log_msg(enum vlog_level level
, const struct msg
*p
, const char *message
,
987 const struct bfd
*bfd
) OVS_REQUIRES(mutex
)
989 struct ds ds
= DS_EMPTY_INITIALIZER
;
991 if (vlog_should_drop(THIS_MODULE
, level
, &rl
)) {
997 "\n\tvers:%"PRIu8
" diag:\"%s\" state:%s mult:%"PRIu8
1000 "\n\tmy_disc:0x%"PRIx32
" your_disc:0x%"PRIx32
1001 "\n\tmin_tx:%"PRIu32
"us (%"PRIu32
"ms)"
1002 "\n\tmin_rx:%"PRIu32
"us (%"PRIu32
"ms)"
1003 "\n\tmin_rx_echo:%"PRIu32
"us (%"PRIu32
"ms)",
1004 bfd
->name
, message
, p
->vers_diag
>> VERS_SHIFT
,
1005 bfd_diag_str(p
->vers_diag
& DIAG_MASK
),
1006 bfd_state_str(p
->flags
& STATE_MASK
),
1007 p
->mult
, p
->length
, bfd_flag_str(p
->flags
& FLAGS_MASK
),
1008 ntohl(p
->my_disc
), ntohl(p
->your_disc
),
1009 ntohl(p
->min_tx
), ntohl(p
->min_tx
) / 1000,
1010 ntohl(p
->min_rx
), ntohl(p
->min_rx
) / 1000,
1011 ntohl(p
->min_rx_echo
), ntohl(p
->min_rx_echo
) / 1000);
1012 bfd_put_details(&ds
, bfd
);
1013 VLOG(level
, "%s", ds_cstr(&ds
));
1018 bfd_set_state(struct bfd
*bfd
, enum state state
, enum diag diag
)
1021 if (diag
== DIAG_NONE
&& bfd
->cpath_down
) {
1022 diag
= DIAG_CPATH_DOWN
;
1025 if (bfd
->state
!= state
|| bfd
->diag
!= diag
) {
1026 if (!VLOG_DROP_INFO(&rl
)) {
1027 struct ds ds
= DS_EMPTY_INITIALIZER
;
1029 ds_put_format(&ds
, "%s: BFD state change: %s->%s"
1030 " \"%s\"->\"%s\".\n",
1031 bfd
->name
, bfd_state_str(bfd
->state
),
1032 bfd_state_str(state
), bfd_diag_str(bfd
->diag
),
1033 bfd_diag_str(diag
));
1034 bfd_put_details(&ds
, bfd
);
1035 VLOG_INFO("%s", ds_cstr(&ds
));
1042 if (bfd
->state
<= STATE_DOWN
) {
1043 bfd
->rmt_state
= STATE_DOWN
;
1044 bfd
->rmt_diag
= DIAG_NONE
;
1045 bfd
->rmt_min_rx
= 1;
1048 bfd
->rmt_min_tx
= 0;
1049 /* Resets the min_rx if in_decay. */
1050 if (bfd
->in_decay
) {
1051 bfd
->min_rx
= bfd
->cfg_min_rx
;
1052 bfd
->in_decay
= false;
1055 /* Resets the decay when state changes to STATE_UP
1056 * and decay_min_rx is configured. */
1057 if (bfd
->state
== STATE_UP
&& bfd
->decay_min_rx
) {
1058 bfd_decay_update(bfd
);
1061 seq_change(connectivity_seq_get());
1066 bfd_rx_packets(const struct bfd
*bfd
) OVS_REQUIRES(mutex
)
1068 struct netdev_stats stats
;
1070 if (!netdev_get_stats(bfd
->netdev
, &stats
)) {
1071 return stats
.rx_packets
;
1077 /* Decays the bfd->min_rx to bfd->decay_min_rx when 'diff' is less than
1078 * the 'expect' value. */
1080 bfd_try_decay(struct bfd
*bfd
) OVS_REQUIRES(mutex
)
1082 int64_t diff
, expect
;
1084 /* The 'diff' is the difference between current interface rx_packets
1085 * stats and last-time check. The 'expect' is the recorded number of
1086 * bfd control packets received within an approximately decay_min_rx
1087 * (2000 ms if decay_min_rx is less than 2000 ms) interval.
1089 * Since the update of rx_packets stats at interface happens
1090 * asynchronously to the bfd_rx_packets() function, the 'diff' value
1091 * can be jittered. Thusly, we double the decay_rx_ctl to provide
1092 * more wiggle room. */
1093 diff
= bfd_rx_packets(bfd
) - bfd
->decay_rx_packets
;
1094 expect
= 2 * MAX(bfd
->decay_rx_ctl
, 1);
1095 bfd
->in_decay
= diff
<= expect
? true : false;
1096 bfd_decay_update(bfd
);
1099 /* Updates the rx_packets, decay_rx_ctl and decay_detect_time. */
1101 bfd_decay_update(struct bfd
* bfd
) OVS_REQUIRES(mutex
)
1103 bfd
->decay_rx_packets
= bfd_rx_packets(bfd
);
1104 bfd
->decay_rx_ctl
= 0;
1105 bfd
->decay_detect_time
= MAX(bfd
->decay_min_rx
, 2000) + time_msec();
1109 bfd_forwarding_if_rx_update(struct bfd
*bfd
) OVS_REQUIRES(mutex
)
1111 int64_t incr
= bfd_rx_interval(bfd
) * bfd
->mult
;
1112 bfd
->forwarding_if_rx_detect_time
= MAX(incr
, 2000) + time_msec();
1116 generate_discriminator(void)
1120 /* RFC 5880 Section 6.8.1
1121 * It SHOULD be set to a random (but still unique) value to improve
1122 * security. The value is otherwise outside the scope of this
1128 /* 'disc' is by definition random, so there's no reason to waste time
1130 disc
= random_uint32();
1131 HMAP_FOR_EACH_IN_BUCKET (bfd
, node
, disc
, all_bfds
) {
1132 if (bfd
->disc
== disc
) {
1143 bfd_find_by_name(const char *name
) OVS_REQUIRES(mutex
)
1147 HMAP_FOR_EACH (bfd
, node
, all_bfds
) {
1148 if (!strcmp(bfd
->name
, name
)) {
1156 bfd_put_details(struct ds
*ds
, const struct bfd
*bfd
) OVS_REQUIRES(mutex
)
1158 ds_put_format(ds
, "\tForwarding: %s\n",
1159 bfd_forwarding__(CONST_CAST(struct bfd
*, bfd
))
1160 ? "true" : "false");
1161 ds_put_format(ds
, "\tDetect Multiplier: %d\n", bfd
->mult
);
1162 ds_put_format(ds
, "\tConcatenated Path Down: %s\n",
1163 bfd
->cpath_down
? "true" : "false");
1164 ds_put_format(ds
, "\tTX Interval: Approx %lldms\n", bfd_tx_interval(bfd
));
1165 ds_put_format(ds
, "\tRX Interval: Approx %lldms\n", bfd_rx_interval(bfd
));
1166 ds_put_format(ds
, "\tDetect Time: now %+lldms\n",
1167 time_msec() - bfd
->detect_time
);
1168 ds_put_format(ds
, "\tNext TX Time: now %+lldms\n",
1169 time_msec() - bfd
->next_tx
);
1170 ds_put_format(ds
, "\tLast TX Time: now %+lldms\n",
1171 time_msec() - bfd
->last_tx
);
1173 ds_put_cstr(ds
, "\n");
1175 ds_put_format(ds
, "\tLocal Flags: %s\n", bfd_flag_str(bfd
->flags
));
1176 ds_put_format(ds
, "\tLocal Session State: %s\n",
1177 bfd_state_str(bfd
->state
));
1178 ds_put_format(ds
, "\tLocal Diagnostic: %s\n", bfd_diag_str(bfd
->diag
));
1179 ds_put_format(ds
, "\tLocal Discriminator: 0x%"PRIx32
"\n", bfd
->disc
);
1180 ds_put_format(ds
, "\tLocal Minimum TX Interval: %lldms\n",
1182 ds_put_format(ds
, "\tLocal Minimum RX Interval: %lldms\n", bfd
->min_rx
);
1184 ds_put_cstr(ds
, "\n");
1186 ds_put_format(ds
, "\tRemote Flags: %s\n", bfd_flag_str(bfd
->rmt_flags
));
1187 ds_put_format(ds
, "\tRemote Session State: %s\n",
1188 bfd_state_str(bfd
->rmt_state
));
1189 ds_put_format(ds
, "\tRemote Diagnostic: %s\n",
1190 bfd_diag_str(bfd
->rmt_diag
));
1191 ds_put_format(ds
, "\tRemote Discriminator: 0x%"PRIx32
"\n", bfd
->rmt_disc
);
1192 ds_put_format(ds
, "\tRemote Minimum TX Interval: %lldms\n",
1194 ds_put_format(ds
, "\tRemote Minimum RX Interval: %lldms\n",
1199 bfd_unixctl_show(struct unixctl_conn
*conn
, int argc
, const char *argv
[],
1200 void *aux OVS_UNUSED
) OVS_EXCLUDED(mutex
)
1202 struct ds ds
= DS_EMPTY_INITIALIZER
;
1205 ovs_mutex_lock(&mutex
);
1207 bfd
= bfd_find_by_name(argv
[1]);
1209 unixctl_command_reply_error(conn
, "no such bfd object");
1212 bfd_put_details(&ds
, bfd
);
1214 HMAP_FOR_EACH (bfd
, node
, all_bfds
) {
1215 ds_put_format(&ds
, "---- %s ----\n", bfd
->name
);
1216 bfd_put_details(&ds
, bfd
);
1219 unixctl_command_reply(conn
, ds_cstr(&ds
));
1223 ovs_mutex_unlock(&mutex
);
1228 bfd_unixctl_set_forwarding_override(struct unixctl_conn
*conn
, int argc
,
1229 const char *argv
[], void *aux OVS_UNUSED
)
1232 const char *forward_str
= argv
[argc
- 1];
1233 int forwarding_override
;
1236 ovs_mutex_lock(&mutex
);
1237 if (!strcasecmp("true", forward_str
)) {
1238 forwarding_override
= 1;
1239 } else if (!strcasecmp("false", forward_str
)) {
1240 forwarding_override
= 0;
1241 } else if (!strcasecmp("normal", forward_str
)) {
1242 forwarding_override
= -1;
1244 unixctl_command_reply_error(conn
, "unknown fault string");
1249 bfd
= bfd_find_by_name(argv
[1]);
1251 unixctl_command_reply_error(conn
, "no such BFD object");
1254 bfd
->forwarding_override
= forwarding_override
;
1256 HMAP_FOR_EACH (bfd
, node
, all_bfds
) {
1257 bfd
->forwarding_override
= forwarding_override
;
1261 unixctl_command_reply(conn
, "OK");
1264 ovs_mutex_unlock(&mutex
);