drivers/common/mlx5/mlx5_common.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright 2019 Mellanox Technologies, Ltd
   3  */
   4
   5 #include <dlfcn.h>
   6 #include <unistd.h>
   7 #include <string.h>
   8
   9 #include <rte_errno.h>
  10
  11 #include "mlx5_common.h"
  12 #include "mlx5_common_utils.h"
  13 #include "mlx5_glue.h"
  14
  15
  16 int mlx5_common_logtype;
  17
  18
  19 #ifdef RTE_IBVERBS_LINK_DLOPEN
  20
  21 /**
  22  * Suffix RTE_EAL_PMD_PATH with "-glue".
  23  *
  24  * This function performs a sanity check on RTE_EAL_PMD_PATH before
  25  * suffixing its last component.
  26  *
  27  * @param buf[out]
  28  *   Output buffer, should be large enough otherwise NULL is returned.
  29  * @param size
  30  *   Size of @p out.
  31  *
  32  * @return
  33  *   Pointer to @p buf or @p NULL in case suffix cannot be appended.
  34  */
  35 static char *
  36 mlx5_glue_path(char *buf, size_t size)
  37 {
  38         static const char *const bad[] = { "/", ".", "..", NULL };
  39         const char *path = RTE_EAL_PMD_PATH;
  40         size_t len = strlen(path);
  41         size_t off;
  42         int i;
  43
  44         while (len && path[len - 1] == '/')
  45                 --len;
  46         for (off = len; off && path[off - 1] != '/'; --off)
  47                 ;
  48         for (i = 0; bad[i]; ++i)
  49                 if (!strncmp(path + off, bad[i], (int)(len - off)))
  50                         goto error;
  51         i = snprintf(buf, size, "%.*s-glue", (int)len, path);
  52         if (i == -1 || (size_t)i >= size)
  53                 goto error;
  54         return buf;
  55 error:
  56         RTE_LOG(ERR, PMD, "unable to append \"-glue\" to last component of"
  57                 " RTE_EAL_PMD_PATH (\"" RTE_EAL_PMD_PATH "\"), please"
  58                 " re-configure DPDK");
  59         return NULL;
  60 }
  61 #endif
  62
  63 /**
  64  * Initialization routine for run-time dependency on rdma-core.
  65  */
  66 RTE_INIT_PRIO(mlx5_glue_init, CLASS)
  67 {
  68         void *handle = NULL;
  69
  70         /* Initialize common log type. */
  71         mlx5_common_logtype = rte_log_register("pmd.common.mlx5");
  72         if (mlx5_common_logtype >= 0)
  73                 rte_log_set_level(mlx5_common_logtype, RTE_LOG_NOTICE);
  74         /*
  75          * RDMAV_HUGEPAGES_SAFE tells ibv_fork_init() we intend to use
  76          * huge pages. Calling ibv_fork_init() during init allows
  77          * applications to use fork() safely for purposes other than
  78          * using this PMD, which is not supported in forked processes.
  79          */
  80         setenv("RDMAV_HUGEPAGES_SAFE", "1", 1);
  81         /* Match the size of Rx completion entry to the size of a cacheline. */
  82         if (RTE_CACHE_LINE_SIZE == 128)
  83                 setenv("MLX5_CQE_SIZE", "128", 0);
  84         /*
  85          * MLX5_DEVICE_FATAL_CLEANUP tells ibv_destroy functions to
  86          * cleanup all the Verbs resources even when the device was removed.
  87          */
  88         setenv("MLX5_DEVICE_FATAL_CLEANUP", "1", 1);
  89         /* The glue initialization was done earlier by mlx5 common library. */
  90 #ifdef RTE_IBVERBS_LINK_DLOPEN
  91         char glue_path[sizeof(RTE_EAL_PMD_PATH) - 1 + sizeof("-glue")];
  92         const char *path[] = {
  93                 /*
  94                  * A basic security check is necessary before trusting
  95                  * MLX5_GLUE_PATH, which may override RTE_EAL_PMD_PATH.
  96                  */
  97                 (geteuid() == getuid() && getegid() == getgid() ?
  98                  getenv("MLX5_GLUE_PATH") : NULL),
  99                 /*
 100                  * When RTE_EAL_PMD_PATH is set, use its glue-suffixed
 101                  * variant, otherwise let dlopen() look up libraries on its
 102                  * own.
 103                  */
 104                 (*RTE_EAL_PMD_PATH ?
 105                  mlx5_glue_path(glue_path, sizeof(glue_path)) : ""),
 106         };
 107         unsigned int i = 0;
 108         void **sym;
 109         const char *dlmsg;
 110
 111         while (!handle && i != RTE_DIM(path)) {
 112                 const char *end;
 113                 size_t len;
 114                 int ret;
 115
 116                 if (!path[i]) {
 117                         ++i;
 118                         continue;
 119                 }
 120                 end = strpbrk(path[i], ":;");
 121                 if (!end)
 122                         end = path[i] + strlen(path[i]);
 123                 len = end - path[i];
 124                 ret = 0;
 125                 do {
 126                         char name[ret + 1];
 127
 128                         ret = snprintf(name, sizeof(name), "%.*s%s" MLX5_GLUE,
 129                                        (int)len, path[i],
 130                                        (!len || *(end - 1) == '/') ? "" : "/");
 131                         if (ret == -1)
 132                                 break;
 133                         if (sizeof(name) != (size_t)ret + 1)
 134                                 continue;
 135                         DRV_LOG(DEBUG, "Looking for rdma-core glue as "
 136                                 "\"%s\"", name);
 137                         handle = dlopen(name, RTLD_LAZY);
 138                         break;
 139                 } while (1);
 140                 path[i] = end + 1;
 141                 if (!*end)
 142                         ++i;
 143         }
 144         if (!handle) {
 145                 rte_errno = EINVAL;
 146                 dlmsg = dlerror();
 147                 if (dlmsg)
 148                         DRV_LOG(WARNING, "Cannot load glue library: %s", dlmsg);
 149                 goto glue_error;
 150         }
 151         sym = dlsym(handle, "mlx5_glue");
 152         if (!sym || !*sym) {
 153                 rte_errno = EINVAL;
 154                 dlmsg = dlerror();
 155                 if (dlmsg)
 156                         DRV_LOG(ERR, "Cannot resolve glue symbol: %s", dlmsg);
 157                 goto glue_error;
 158         }
 159         mlx5_glue = *sym;
 160 #endif /* RTE_IBVERBS_LINK_DLOPEN */
 161 #ifndef NDEBUG
 162         /* Glue structure must not contain any NULL pointers. */
 163         {
 164                 unsigned int i;
 165
 166                 for (i = 0; i != sizeof(*mlx5_glue) / sizeof(void *); ++i)
 167                         assert(((const void *const *)mlx5_glue)[i]);
 168         }
 169 #endif
 170         if (strcmp(mlx5_glue->version, MLX5_GLUE_VERSION)) {
 171                 rte_errno = EINVAL;
 172                 DRV_LOG(ERR, "rdma-core glue \"%s\" mismatch: \"%s\" is "
 173                         "required", mlx5_glue->version, MLX5_GLUE_VERSION);
 174                 goto glue_error;
 175         }
 176         mlx5_glue->fork_init();
 177         return;
 178 glue_error:
 179         if (handle)
 180                 dlclose(handle);
 181         DRV_LOG(WARNING, "Cannot initialize MLX5 common due to missing"
 182                 " run-time dependency on rdma-core libraries (libibverbs,"
 183                 " libmlx5)");
 184         mlx5_glue = NULL;
 185         return;
 186 }