ofproto/ofproto-dpif-monitor.c

   1 /*
   2  * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <config.h>
  18 #include "ofproto-dpif-monitor.h"
  19
  20 #include <string.h>
  21
  22 #include "bfd.h"
  23 #include "cfm.h"
  24 #include "dp-packet.h"
  25 #include "guarded-list.h"
  26 #include "hash.h"
  27 #include "heap.h"
  28 #include "openvswitch/hmap.h"
  29 #include "latch.h"
  30 #include "openvswitch/ofpbuf.h"
  31 #include "ofproto-dpif.h"
  32 #include "ovs-lldp.h"
  33 #include "ovs-thread.h"
  34 #include "openvswitch/poll-loop.h"
  35 #include "seq.h"
  36 #include "timeval.h"
  37 #include "util.h"
  38 #include "openvswitch/vlog.h"
  39
  40 VLOG_DEFINE_THIS_MODULE(ofproto_dpif_monitor);
  41
  42 /* Converts the time in millisecond to heap priority. */
  43 #define MSEC_TO_PRIO(TIME) (LLONG_MAX - (TIME))
  44 /* Converts the heap priority to time in millisecond. */
  45 #define PRIO_TO_MSEC(PRIO) (LLONG_MAX - (PRIO))
  46
  47 /* Monitored port.  It owns references to ofport, bfd, cfm, and lldp structs. */
  48 struct mport {
  49     struct hmap_node hmap_node;       /* In monitor_hmap. */
  50     struct heap_node heap_node;       /* In monitor_heap. */
  51     const struct ofport_dpif *ofport; /* The corresponding ofport. */
  52
  53     struct cfm *cfm;                  /* Reference to cfm. */
  54     struct bfd *bfd;                  /* Reference to bfd. */
  55     struct lldp *lldp;                /* Reference to lldp. */
  56     struct eth_addr hw_addr;          /* Hardware address. */
  57 };
  58
  59 /* Entry of the 'send_soon' list.  Contains the pointer to the
  60  * 'ofport_dpif'.  Note, the pointed object is not protected, so
  61  * users should always use the mport_find() to convert it to 'mport'. */
  62 struct send_soon_entry {
  63     struct ovs_list list_node;        /* In send_soon. */
  64     const struct ofport_dpif *ofport;
  65 };
  66
  67 /* hmap that contains "struct mport"s. */
  68 static struct hmap monitor_hmap = HMAP_INITIALIZER(&monitor_hmap);
  69
  70 /* heap for ordering mport based on bfd/cfm wakeup time. */
  71 static struct heap monitor_heap;
  72
  73 /* guarded-list for storing the mports that need to send bfd/cfm control
  74  * packet soon. */
  75 static struct guarded_list send_soon = GUARDED_OVS_LIST_INITIALIZER(&send_soon);
  76
  77 /* The monitor thread id. */
  78 static pthread_t monitor_tid;
  79 /* True if the monitor thread is running. */
  80 static bool monitor_running;
  81
  82 static struct latch monitor_exit_latch;
  83 static struct ovs_mutex monitor_mutex = OVS_MUTEX_INITIALIZER;
  84
  85 static void *monitor_main(void *);
  86 static void monitor_check_send_soon(struct dp_packet *);
  87 static void monitor_run(void);
  88 static void monitor_mport_run(struct mport *, struct dp_packet *);
  89
  90 static void mport_register(const struct ofport_dpif *, struct bfd *,
  91                            struct cfm *, struct lldp *,
  92                            const struct eth_addr *)
  93     OVS_REQUIRES(monitor_mutex);
  94 static void mport_unregister(const struct ofport_dpif *)
  95     OVS_REQUIRES(monitor_mutex);
  96 static void mport_update(struct mport *, struct bfd *, struct cfm *,
  97                          struct lldp *, const struct eth_addr *)
  98     OVS_REQUIRES(monitor_mutex);
  99 static struct mport *mport_find(const struct ofport_dpif *)
 100     OVS_REQUIRES(monitor_mutex);
 101
 102 /* Tries finding and returning the 'mport' from the monitor_hmap.
 103  * If there is no such 'mport', returns NULL. */
 104 static struct mport *
 105 mport_find(const struct ofport_dpif *ofport) OVS_REQUIRES(monitor_mutex)
 106 {
 107     struct mport *node;
 108
 109     HMAP_FOR_EACH_WITH_HASH (node, hmap_node, hash_pointer(ofport, 0),
 110                              &monitor_hmap) {
 111         if (node->ofport == ofport) {
 112             return node;
 113         }
 114     }
 115     return NULL;
 116 }
 117
 118 /* Creates a new mport and inserts it into monitor_hmap and monitor_heap,
 119  * if it doesn't exist.  Otherwise, just updates its fields. */
 120 static void
 121 mport_register(const struct ofport_dpif *ofport, struct bfd *bfd,
 122                struct cfm *cfm, struct lldp *lldp,
 123                const struct eth_addr *hw_addr)
 124     OVS_REQUIRES(monitor_mutex)
 125 {
 126     struct mport *mport = mport_find(ofport);
 127
 128     if (!mport) {
 129         mport = xzalloc(sizeof *mport);
 130         mport->ofport = ofport;
 131         hmap_insert(&monitor_hmap, &mport->hmap_node, hash_pointer(ofport, 0));
 132         heap_insert(&monitor_heap, &mport->heap_node, 0);
 133     }
 134     mport_update(mport, bfd, cfm, lldp, hw_addr);
 135 }
 136
 137 /* Removes mport from monitor_hmap and monitor_heap and frees it. */
 138 static void
 139 mport_unregister(const struct ofport_dpif *ofport)
 140     OVS_REQUIRES(monitor_mutex)
 141 {
 142     struct mport *mport = mport_find(ofport);
 143
 144     if (mport) {
 145         mport_update(mport, NULL, NULL, NULL, NULL);
 146         hmap_remove(&monitor_hmap, &mport->hmap_node);
 147         heap_remove(&monitor_heap, &mport->heap_node);
 148         free(mport);
 149     }
 150 }
 151
 152 /* Updates the fields of an existing mport struct. */
 153 static void
 154 mport_update(struct mport *mport, struct bfd *bfd, struct cfm *cfm,
 155              struct lldp *lldp, const struct eth_addr *hw_addr)
 156     OVS_REQUIRES(monitor_mutex)
 157 {
 158     ovs_assert(mport);
 159
 160     if (mport->cfm != cfm) {
 161         cfm_unref(mport->cfm);
 162         mport->cfm = cfm_ref(cfm);
 163     }
 164     if (mport->bfd != bfd) {
 165         bfd_unref(mport->bfd);
 166         mport->bfd = bfd_ref(bfd);
 167     }
 168     if (mport->lldp != lldp) {
 169         lldp_unref(mport->lldp);
 170         mport->lldp = lldp_ref(lldp);
 171     }
 172     if (hw_addr && !eth_addr_equals(mport->hw_addr, *hw_addr)) {
 173         mport->hw_addr = *hw_addr;
 174     }
 175     /* If bfd/cfm/lldp is added or reconfigured, move the mport on top of the heap
 176      * so that the monitor thread can run the mport next time it wakes up. */
 177     if (mport->bfd || mport->cfm || mport->lldp) {
 178         heap_change(&monitor_heap, &mport->heap_node, LLONG_MAX);
 179     }
 180 }
 181 \f
 182
 183 /* The 'main' function for the monitor thread. */
 184 static void *
 185 monitor_main(void * args OVS_UNUSED)
 186 {
 187     VLOG_INFO("monitor thread created");
 188     while (!latch_is_set(&monitor_exit_latch)) {
 189         monitor_run();
 190         latch_wait(&monitor_exit_latch);
 191         poll_block();
 192     }
 193     VLOG_INFO("monitor thread terminated");
 194     return NULL;
 195 }
 196
 197 /* The monitor thread should wake up this often to ensure that newly added or
 198  * reconfigured monitoring ports are run in a timely manner. */
 199 #define MONITOR_INTERVAL_MSEC 100
 200
 201 /* Checks the 'send_soon' list and the heap for mports that have timed
 202  * out bfd/cfm sessions. */
 203 static void
 204 monitor_run(void)
 205 {
 206     uint32_t stub[512 / 4];
 207     long long int prio_now;
 208     struct dp_packet packet;
 209
 210     dp_packet_use_stub(&packet, stub, sizeof stub);
 211     ovs_mutex_lock(&monitor_mutex);
 212
 213     /* The monitor_check_send_soon() needs to be run twice.  The first
 214      * time is for preventing the same 'mport' from being processed twice
 215      * (i.e. once from heap, the other from the 'send_soon' array).
 216      * The second run is to cover the case when the control packet is sent
 217      * via patch port and the other end needs to send back immediately. */
 218     monitor_check_send_soon(&packet);
 219
 220     prio_now = MSEC_TO_PRIO(time_msec());
 221     /* Peeks the top of heap and checks if we should run this mport. */
 222     while (!heap_is_empty(&monitor_heap)
 223            && heap_max(&monitor_heap)->priority >= prio_now) {
 224         struct mport *mport;
 225
 226         mport = CONTAINER_OF(heap_max(&monitor_heap), struct mport, heap_node);
 227         monitor_mport_run(mport, &packet);
 228     }
 229
 230     monitor_check_send_soon(&packet);
 231
 232     /* Waits on the earliest next wakeup time. */
 233     if (!heap_is_empty(&monitor_heap)) {
 234         long long int next_timeout, next_mport_wakeup;
 235
 236         next_timeout = time_msec() + MONITOR_INTERVAL_MSEC;
 237         next_mport_wakeup = PRIO_TO_MSEC(heap_max(&monitor_heap)->priority);
 238         poll_timer_wait_until(MIN(next_timeout, next_mport_wakeup));
 239     }
 240     ovs_mutex_unlock(&monitor_mutex);
 241     dp_packet_uninit(&packet);
 242 }
 243
 244 /* Checks the 'send_soon' list for any mport that needs to send cfm/bfd
 245  * control packet immediately, and calls monitor_mport_run(). */
 246 static void
 247 monitor_check_send_soon(struct dp_packet *packet)
 248     OVS_REQUIRES(monitor_mutex)
 249 {
 250     while (!guarded_list_is_empty(&send_soon)) {
 251         struct send_soon_entry *entry;
 252         struct mport *mport;
 253
 254         entry = CONTAINER_OF(guarded_list_pop_front(&send_soon),
 255                              struct send_soon_entry, list_node);
 256         mport = mport_find(entry->ofport);
 257         if (mport) {
 258             monitor_mport_run(mport, packet);
 259         }
 260         free(entry);
 261     }
 262 }
 263
 264 /* Checks the sending of control packet on 'mport'.  Sends the control
 265  * packet if needed.  Executes bfd and cfm periodic functions (run, wait)
 266  * on 'mport'.  And changes the location of 'mport' in heap based on next
 267  * timeout. */
 268 static void
 269 monitor_mport_run(struct mport *mport, struct dp_packet *packet)
 270     OVS_REQUIRES(monitor_mutex)
 271 {
 272     long long int next_wake_time;
 273     long long int bfd_wake_time = LLONG_MAX;
 274     long long int cfm_wake_time = LLONG_MAX;
 275     long long int lldp_wake_time = LLONG_MAX;
 276
 277     if (mport->cfm && cfm_should_send_ccm(mport->cfm)) {
 278         dp_packet_clear(packet);
 279         cfm_compose_ccm(mport->cfm, packet, mport->hw_addr);
 280         ofproto_dpif_send_packet(mport->ofport, false, packet);
 281     }
 282     if (mport->bfd && bfd_should_send_packet(mport->bfd)) {
 283         bool oam;
 284
 285         dp_packet_clear(packet);
 286         bfd_put_packet(mport->bfd, packet, mport->hw_addr, &oam);
 287         ofproto_dpif_send_packet(mport->ofport, oam, packet);
 288     }
 289     if (mport->lldp && lldp_should_send_packet(mport->lldp)) {
 290         dp_packet_clear(packet);
 291         lldp_put_packet(mport->lldp, packet, mport->hw_addr);
 292         ofproto_dpif_send_packet(mport->ofport, false, packet);
 293     }
 294
 295     if (mport->cfm) {
 296         cfm_run(mport->cfm);
 297         cfm_wake_time = cfm_wait(mport->cfm);
 298     }
 299     if (mport->bfd) {
 300         bfd_run(mport->bfd);
 301         bfd_wake_time = bfd_wait(mport->bfd);
 302     }
 303     if (mport->lldp) {
 304         lldp_wake_time = lldp_wait(mport->lldp);
 305     }
 306     /* Computes the next wakeup time for this mport. */
 307     next_wake_time = MIN(bfd_wake_time,
 308                          cfm_wake_time);
 309     next_wake_time = MIN(next_wake_time, lldp_wake_time);
 310     heap_change(&monitor_heap, &mport->heap_node,
 311                 MSEC_TO_PRIO(next_wake_time));
 312 }
 313 \f
 314
 315 /* Creates the mport in monitor module if either bfd or cfm
 316  * is configured.  Otherwise, deletes the mport.
 317  * Also checks whether the monitor thread should be started
 318  * or terminated. */
 319 void
 320 ofproto_dpif_monitor_port_update(const struct ofport_dpif *ofport,
 321                                  struct bfd *bfd, struct cfm *cfm,
 322                                  struct lldp *lldp,
 323                                  const struct eth_addr *hw_addr)
 324 {
 325     ovs_mutex_lock(&monitor_mutex);
 326     if (!cfm && !bfd && !lldp) {
 327         mport_unregister(ofport);
 328     } else {
 329         mport_register(ofport, bfd, cfm, lldp, hw_addr);
 330     }
 331     ovs_mutex_unlock(&monitor_mutex);
 332
 333     /* If the monitor thread is not running and the hmap
 334      * is not empty, starts it.  If it is and the hmap is empty,
 335      * terminates it. */
 336     if (!monitor_running && !hmap_is_empty(&monitor_hmap))  {
 337         latch_init(&monitor_exit_latch);
 338         monitor_tid = ovs_thread_create("monitor", monitor_main, NULL);
 339         monitor_running = true;
 340     } else if (monitor_running && hmap_is_empty(&monitor_hmap))  {
 341         latch_set(&monitor_exit_latch);
 342         xpthread_join(monitor_tid, NULL);
 343         latch_destroy(&monitor_exit_latch);
 344         monitor_running = false;
 345     }
 346 }
 347
 348 /* Registers the 'ofport' in the 'send_soon' list.  We cannot directly
 349  * insert the corresponding mport to the 'send_soon' list, since the
 350  * 'send_soon' list is not updated when the mport is removed.
 351  *
 352  * Reader of the 'send_soon' list is responsible for freeing the entry. */
 353 void
 354 ofproto_dpif_monitor_port_send_soon(const struct ofport_dpif *ofport)
 355 {
 356     struct send_soon_entry *entry = xzalloc(sizeof *entry);
 357     entry->ofport = ofport;
 358
 359     guarded_list_push_back(&send_soon, &entry->list_node, SIZE_MAX);
 360 }