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 "guarded-list.h"
  25 #include "hash.h"
  26 #include "heap.h"
  27 #include "hmap.h"
  28 #include "latch.h"
  29 #include "ofpbuf.h"
  30 #include "ofproto-dpif.h"
  31 #include "ovs-thread.h"
  32 #include "poll-loop.h"
  33 #include "seq.h"
  34 #include "timeval.h"
  35 #include "util.h"
  36 #include "vlog.h"
  37
  38 VLOG_DEFINE_THIS_MODULE(ofproto_dpif_monitor);
  39
  40 /* Converts the time in millisecond to heap priority. */
  41 #define MSEC_TO_PRIO(TIME) (LLONG_MAX - (TIME))
  42 /* Converts the heap priority to time in millisecond. */
  43 #define PRIO_TO_MSEC(PRIO) (LLONG_MAX - (PRIO))
  44
  45 /* Monitored port.  It owns references to ofport, bfd, cfm structs. */
  46 struct mport {
  47     struct hmap_node hmap_node;       /* In monitor_hmap. */
  48     struct heap_node heap_node;       /* In monitor_heap. */
  49     const struct ofport_dpif *ofport; /* The corresponding ofport. */
  50
  51     struct cfm *cfm;                  /* Reference to cfm. */
  52     struct bfd *bfd;                  /* Reference to bfd. */
  53     uint8_t hw_addr[OFP_ETH_ALEN];    /* Hardware address. */
  54 };
  55
  56 /* Entry of the 'send_soon' list.  Contains the pointer to the
  57  * 'ofport_dpif'.  Note, the pointed object is not protected, so
  58  * users should always use the mport_find() to convert it to 'mport'. */
  59 struct send_soon_entry {
  60     struct list list_node;            /* In send_soon. */
  61     const struct ofport_dpif *ofport;
  62 };
  63
  64 /* hmap that contains "struct mport"s. */
  65 static struct hmap monitor_hmap = HMAP_INITIALIZER(&monitor_hmap);
  66
  67 /* heap for ordering mport based on bfd/cfm wakeup time. */
  68 static struct heap monitor_heap;
  69
  70 /* guarded-list for storing the mports that need to send bfd/cfm control
  71  * packet soon. */
  72 static struct guarded_list send_soon = GUARDED_LIST_INITIALIZER(&send_soon);
  73
  74 /* The monitor thread id. */
  75 static pthread_t monitor_tid;
  76 /* True if the monitor thread is running. */
  77 static bool monitor_running;
  78
  79 static struct latch monitor_exit_latch;
  80 static struct ovs_mutex monitor_mutex = OVS_MUTEX_INITIALIZER;
  81
  82 static void *monitor_main(void *);
  83 static void monitor_check_send_soon(struct ofpbuf *);
  84 static void monitor_run(void);
  85 static void monitor_mport_run(struct mport *, struct ofpbuf *);
  86
  87 static void mport_register(const struct ofport_dpif *, struct bfd *,
  88                            struct cfm *, uint8_t[ETH_ADDR_LEN])
  89     OVS_REQUIRES(monitor_mutex);
  90 static void mport_unregister(const struct ofport_dpif *)
  91     OVS_REQUIRES(monitor_mutex);
  92 static void mport_update(struct mport *, struct bfd *, struct cfm *,
  93                          uint8_t[ETH_ADDR_LEN]) OVS_REQUIRES(monitor_mutex);
  94 static struct mport *mport_find(const struct ofport_dpif *)
  95     OVS_REQUIRES(monitor_mutex);
  96
  97 /* Tries finding and returning the 'mport' from the monitor_hmap.
  98  * If there is no such 'mport', returns NULL. */
  99 static struct mport *
 100 mport_find(const struct ofport_dpif *ofport) OVS_REQUIRES(monitor_mutex)
 101 {
 102     struct mport *node;
 103
 104     HMAP_FOR_EACH_WITH_HASH (node, hmap_node, hash_pointer(ofport, 0),
 105                              &monitor_hmap) {
 106         if (node->ofport == ofport) {
 107             return node;
 108         }
 109     }
 110     return NULL;
 111 }
 112
 113 /* Creates a new mport and inserts it into monitor_hmap and monitor_heap,
 114  * if it doesn't exist.  Otherwise, just updates its fields. */
 115 static void
 116 mport_register(const struct ofport_dpif *ofport, struct bfd *bfd,
 117                struct cfm *cfm, uint8_t *hw_addr)
 118     OVS_REQUIRES(monitor_mutex)
 119 {
 120     struct mport *mport = mport_find(ofport);
 121
 122     if (!mport) {
 123         mport = xzalloc(sizeof *mport);
 124         mport->ofport = ofport;
 125         hmap_insert(&monitor_hmap, &mport->hmap_node, hash_pointer(ofport, 0));
 126         heap_insert(&monitor_heap, &mport->heap_node, 0);
 127     }
 128     mport_update(mport, bfd, cfm, hw_addr);
 129 }
 130
 131 /* Removes mport from monitor_hmap and monitor_heap and frees it. */
 132 static void
 133 mport_unregister(const struct ofport_dpif *ofport)
 134     OVS_REQUIRES(monitor_mutex)
 135 {
 136     struct mport *mport = mport_find(ofport);
 137
 138     if (mport) {
 139         mport_update(mport, NULL, NULL, NULL);
 140         hmap_remove(&monitor_hmap, &mport->hmap_node);
 141         heap_remove(&monitor_heap, &mport->heap_node);
 142         free(mport);
 143     }
 144 }
 145
 146 /* Updates the fields of an existing mport struct. */
 147 static void
 148 mport_update(struct mport *mport, struct bfd *bfd, struct cfm *cfm,
 149              uint8_t hw_addr[ETH_ADDR_LEN]) OVS_REQUIRES(monitor_mutex)
 150 {
 151     ovs_assert(mport);
 152
 153     if (mport->cfm != cfm) {
 154         cfm_unref(mport->cfm);
 155         mport->cfm = cfm_ref(cfm);
 156     }
 157     if (mport->bfd != bfd) {
 158         bfd_unref(mport->bfd);
 159         mport->bfd = bfd_ref(bfd);
 160     }
 161     if (hw_addr && memcmp(mport->hw_addr, hw_addr, ETH_ADDR_LEN)) {
 162         memcpy(mport->hw_addr, hw_addr, ETH_ADDR_LEN);
 163     }
 164     /* If bfd/cfm is added or reconfigured, move the mport on top of the heap
 165      * so that the monitor thread can run the mport next time it wakes up. */
 166     if (mport->bfd || mport->cfm) {
 167         heap_change(&monitor_heap, &mport->heap_node, LLONG_MAX);
 168     }
 169 }
 170 \f
 171
 172 /* The 'main' function for the monitor thread. */
 173 static void *
 174 monitor_main(void * args OVS_UNUSED)
 175 {
 176     VLOG_INFO("monitor thread created");
 177     while (!latch_is_set(&monitor_exit_latch)) {
 178         monitor_run();
 179         latch_wait(&monitor_exit_latch);
 180         poll_block();
 181     }
 182     VLOG_INFO("monitor thread terminated");
 183     return NULL;
 184 }
 185
 186 /* The monitor thread should wake up this often to ensure that newly added or
 187  * reconfigured monitoring ports are run in a timely manner. */
 188 #define MONITOR_INTERVAL_MSEC 100
 189
 190 /* Checks the 'send_soon' list and the heap for mports that have timed
 191  * out bfd/cfm sessions. */
 192 static void
 193 monitor_run(void)
 194 {
 195     uint32_t stub[512 / 4];
 196     long long int prio_now;
 197     struct ofpbuf packet;
 198
 199     ofpbuf_use_stub(&packet, stub, sizeof stub);
 200     ovs_mutex_lock(&monitor_mutex);
 201
 202     /* The monitor_check_send_soon() needs to be run twice.  The first
 203      * time is for preventing the same 'mport' from being processed twice
 204      * (i.e. once from heap, the other from the 'send_soon' array).
 205      * The second run is to cover the case when the control packet is sent
 206      * via patch port and the other end needs to send back immediately. */
 207     monitor_check_send_soon(&packet);
 208
 209     prio_now = MSEC_TO_PRIO(time_msec());
 210     /* Peeks the top of heap and checks if we should run this mport. */
 211     while (!heap_is_empty(&monitor_heap)
 212            && heap_max(&monitor_heap)->priority >= prio_now) {
 213         struct mport *mport;
 214
 215         mport = CONTAINER_OF(heap_max(&monitor_heap), struct mport, heap_node);
 216         monitor_mport_run(mport, &packet);
 217     }
 218
 219     monitor_check_send_soon(&packet);
 220
 221     /* Waits on the earliest next wakeup time. */
 222     if (!heap_is_empty(&monitor_heap)) {
 223         long long int next_timeout, next_mport_wakeup;
 224
 225         next_timeout = time_msec() + MONITOR_INTERVAL_MSEC;
 226         next_mport_wakeup = PRIO_TO_MSEC(heap_max(&monitor_heap)->priority);
 227         poll_timer_wait_until(MIN(next_timeout, next_mport_wakeup));
 228     }
 229     ovs_mutex_unlock(&monitor_mutex);
 230     ofpbuf_uninit(&packet);
 231 }
 232
 233 /* Checks the 'send_soon' list for any mport that needs to send cfm/bfd
 234  * control packet immediately, and calls monitor_mport_run(). */
 235 static void
 236 monitor_check_send_soon(struct ofpbuf *packet)
 237     OVS_REQUIRES(monitor_mutex)
 238 {
 239     while (!guarded_list_is_empty(&send_soon)) {
 240         struct send_soon_entry *entry;
 241         struct mport *mport;
 242
 243         entry = CONTAINER_OF(guarded_list_pop_front(&send_soon),
 244                              struct send_soon_entry, list_node);
 245         mport = mport_find(entry->ofport);
 246         if (mport) {
 247             monitor_mport_run(mport, packet);
 248         }
 249         free(entry);
 250     }
 251 }
 252
 253 /* Checks the sending of control packet on 'mport'.  Sends the control
 254  * packet if needed.  Executes bfd and cfm periodic functions (run, wait)
 255  * on 'mport'.  And changes the location of 'mport' in heap based on next
 256  * timeout. */
 257 static void
 258 monitor_mport_run(struct mport *mport, struct ofpbuf *packet)
 259     OVS_REQUIRES(monitor_mutex)
 260 {
 261     long long int next_wake_time;
 262
 263     if (mport->cfm && cfm_should_send_ccm(mport->cfm)) {
 264         ofpbuf_clear(packet);
 265         cfm_compose_ccm(mport->cfm, packet, mport->hw_addr);
 266         ofproto_dpif_send_packet(mport->ofport, packet);
 267     }
 268     if (mport->bfd && bfd_should_send_packet(mport->bfd)) {
 269         ofpbuf_clear(packet);
 270         bfd_put_packet(mport->bfd, packet, mport->hw_addr);
 271         ofproto_dpif_send_packet(mport->ofport, packet);
 272     }
 273     if (mport->cfm) {
 274         cfm_run(mport->cfm);
 275         cfm_wait(mport->cfm);
 276     }
 277     if (mport->bfd) {
 278         bfd_run(mport->bfd);
 279         bfd_wait(mport->bfd);
 280     }
 281     /* Computes the next wakeup time for this mport. */
 282     next_wake_time = MIN(bfd_wake_time(mport->bfd),
 283                          cfm_wake_time(mport->cfm));
 284     heap_change(&monitor_heap, &mport->heap_node,
 285                 MSEC_TO_PRIO(next_wake_time));
 286 }
 287 \f
 288
 289 /* Creates the mport in monitor module if either bfd or cfm
 290  * is configured.  Otherwise, deletes the mport.
 291  * Also checks whether the monitor thread should be started
 292  * or terminated. */
 293 void
 294 ofproto_dpif_monitor_port_update(const struct ofport_dpif *ofport,
 295                                  struct bfd *bfd, struct cfm *cfm,
 296                                  uint8_t hw_addr[ETH_ADDR_LEN])
 297 {
 298     ovs_mutex_lock(&monitor_mutex);
 299     if (!cfm && !bfd) {
 300         mport_unregister(ofport);
 301     } else {
 302         mport_register(ofport, bfd, cfm, hw_addr);
 303     }
 304     ovs_mutex_unlock(&monitor_mutex);
 305
 306     /* If the monitor thread is not running and the hmap
 307      * is not empty, starts it.  If it is and the hmap is empty,
 308      * terminates it. */
 309     if (!monitor_running && !hmap_is_empty(&monitor_hmap))  {
 310         latch_init(&monitor_exit_latch);
 311         monitor_tid = ovs_thread_create("monitor", monitor_main, NULL);
 312         monitor_running = true;
 313     } else if (monitor_running && hmap_is_empty(&monitor_hmap))  {
 314         latch_set(&monitor_exit_latch);
 315         xpthread_join(monitor_tid, NULL);
 316         latch_destroy(&monitor_exit_latch);
 317         monitor_running = false;
 318     }
 319 }
 320
 321 /* Registers the 'ofport' in the 'send_soon' list.  We cannot directly
 322  * insert the corresponding mport to the 'send_soon' list, since the
 323  * 'send_soon' list is not updated when the mport is removed.
 324  *
 325  * Reader of the 'send_soon' list is responsible for freeing the entry. */
 326 void
 327 ofproto_dpif_monitor_port_send_soon(const struct ofport_dpif *ofport)
 328 {
 329     struct send_soon_entry *entry = xzalloc(sizeof *entry);
 330     entry->ofport = ofport;
 331
 332     guarded_list_push_back(&send_soon, &entry->list_node, SIZE_MAX);
 333 }