examples/l2fwd-keepalive/shm.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2016 Intel Corporation
   3  */
   4
   5 #include <time.h>
   6
   7 #include <rte_common.h>
   8 #include <rte_log.h>
   9 #include <rte_keepalive.h>
  10
  11 #include "shm.h"
  12
  13 struct rte_keepalive_shm *rte_keepalive_shm_create(void)
  14 {
  15         int fd;
  16         int idx_core;
  17         struct rte_keepalive_shm *ka_shm;
  18
  19         /* If any existing object is not unlinked, it makes it all too easy
  20          * for clients to end up with stale shared memory blocks when
  21          * restarted. Unlinking makes sure subsequent shm_open by clients
  22          * will get the new block mapped below.
  23          */
  24         if (shm_unlink(RTE_KEEPALIVE_SHM_NAME) == -1 && errno != ENOENT)
  25                 printf("Warning: Error unlinking stale %s (%s)\n",
  26                         RTE_KEEPALIVE_SHM_NAME, strerror(errno));
  27
  28         fd = shm_open(RTE_KEEPALIVE_SHM_NAME,
  29                 O_CREAT | O_TRUNC | O_RDWR, 0666);
  30         if (fd < 0)
  31                 RTE_LOG(INFO, EAL,
  32                         "Failed to open %s as SHM (%s)\n",
  33                         RTE_KEEPALIVE_SHM_NAME,
  34                         strerror(errno));
  35         else if (ftruncate(fd, sizeof(struct rte_keepalive_shm)) != 0)
  36                 RTE_LOG(INFO, EAL,
  37                         "Failed to resize SHM (%s)\n", strerror(errno));
  38         else {
  39                 ka_shm = (struct rte_keepalive_shm *) mmap(
  40                         0, sizeof(struct rte_keepalive_shm),
  41                         PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
  42                 close(fd);
  43                 if (ka_shm == MAP_FAILED)
  44                         RTE_LOG(INFO, EAL,
  45                                 "Failed to mmap SHM (%s)\n", strerror(errno));
  46                 else {
  47                         memset(ka_shm, 0, sizeof(struct rte_keepalive_shm));
  48
  49                         /* Initialize the semaphores for IPC/SHM use */
  50                         if (sem_init(&ka_shm->core_died, 1, 0) != 0) {
  51                                 RTE_LOG(INFO, EAL,
  52                                         "Failed to setup SHM semaphore (%s)\n",
  53                                         strerror(errno));
  54                                 munmap(ka_shm,
  55                                         sizeof(struct rte_keepalive_shm));
  56                                 return NULL;
  57                         }
  58
  59                         /* Set all cores to 'not present' */
  60                         for (idx_core = 0;
  61                                         idx_core < RTE_KEEPALIVE_MAXCORES;
  62                                         idx_core++) {
  63                                 ka_shm->core_state[idx_core] =
  64                                         RTE_KA_STATE_UNUSED;
  65                                 ka_shm->core_last_seen_times[idx_core] = 0;
  66                         }
  67
  68                         return ka_shm;
  69                 }
  70         }
  71 return NULL;
  72 }
  73
  74 void rte_keepalive_relayed_state(struct rte_keepalive_shm *shm,
  75         const int id_core, const enum rte_keepalive_state core_state,
  76         __rte_unused uint64_t last_alive)
  77 {
  78         int count;
  79
  80         shm->core_state[id_core] = core_state;
  81         shm->core_last_seen_times[id_core] = last_alive;
  82
  83         if (core_state == RTE_KEEPALIVE_SHM_DEAD) {
  84                 /* Since core has died, also signal ka_agent.
  85                  *
  86                  * Limit number of times semaphore can be incremented, in case
  87                  * ka_agent is not active.
  88                  */
  89                 if (sem_getvalue(&shm->core_died, &count) == -1) {
  90                         RTE_LOG(INFO, EAL, "Semaphore check failed(%s)\n",
  91                                 strerror(errno));
  92                         return;
  93                 }
  94                 if (count > 1)
  95                         return;
  96
  97                 if (sem_post(&shm->core_died) != 0)
  98                         RTE_LOG(INFO, EAL,
  99                                 "Failed to increment semaphore (%s)\n",
 100                                 strerror(errno));
 101         }
 102 }
 103
 104 void rte_keepalive_shm_cleanup(struct rte_keepalive_shm *ka_shm)
 105 {
 106         if (shm_unlink(RTE_KEEPALIVE_SHM_NAME) == -1 && errno != ENOENT)
 107                 printf("Warning: Error unlinking  %s (%s)\n",
 108                         RTE_KEEPALIVE_SHM_NAME, strerror(errno));
 109
 110         if (ka_shm && munmap(ka_shm, sizeof(struct rte_keepalive_shm)) != 0)
 111                 printf("Warning: munmap() failed\n");
 112 }