+#ifdef RTE_IBVERBS_LINK_DLOPEN
+
+/**
+ * Suffix RTE_EAL_PMD_PATH with "-glue".
+ *
+ * This function performs a sanity check on RTE_EAL_PMD_PATH before
+ * suffixing its last component.
+ *
+ * @param buf[out]
+ * Output buffer, should be large enough otherwise NULL is returned.
+ * @param size
+ * Size of @p out.
+ *
+ * @return
+ * Pointer to @p buf or @p NULL in case suffix cannot be appended.
+ */
+static char *
+mlx4_glue_path(char *buf, size_t size)
+{
+ static const char *const bad[] = { "/", ".", "..", NULL };
+ const char *path = RTE_EAL_PMD_PATH;
+ size_t len = strlen(path);
+ size_t off;
+ int i;
+
+ while (len && path[len - 1] == '/')
+ --len;
+ for (off = len; off && path[off - 1] != '/'; --off)
+ ;
+ for (i = 0; bad[i]; ++i)
+ if (!strncmp(path + off, bad[i], (int)(len - off)))
+ goto error;
+ i = snprintf(buf, size, "%.*s-glue", (int)len, path);
+ if (i == -1 || (size_t)i >= size)
+ goto error;
+ return buf;
+error:
+ ERROR("unable to append \"-glue\" to last component of"
+ " RTE_EAL_PMD_PATH (\"" RTE_EAL_PMD_PATH "\"),"
+ " please re-configure DPDK");
+ return NULL;
+}
+
+/**
+ * Initialization routine for run-time dependency on rdma-core.
+ */
+static int
+mlx4_glue_init(void)
+{
+ char glue_path[sizeof(RTE_EAL_PMD_PATH) - 1 + sizeof("-glue")];
+ const char *path[] = {
+ /*
+ * A basic security check is necessary before trusting
+ * MLX4_GLUE_PATH, which may override RTE_EAL_PMD_PATH.
+ */
+ (geteuid() == getuid() && getegid() == getgid() ?
+ getenv("MLX4_GLUE_PATH") : NULL),
+ /*
+ * When RTE_EAL_PMD_PATH is set, use its glue-suffixed
+ * variant, otherwise let dlopen() look up libraries on its
+ * own.
+ */
+ (*RTE_EAL_PMD_PATH ?
+ mlx4_glue_path(glue_path, sizeof(glue_path)) : ""),
+ };
+ unsigned int i = 0;
+ void *handle = NULL;
+ void **sym;
+ const char *dlmsg;
+
+ while (!handle && i != RTE_DIM(path)) {
+ const char *end;
+ size_t len;
+ int ret;
+
+ if (!path[i]) {
+ ++i;
+ continue;
+ }
+ end = strpbrk(path[i], ":;");
+ if (!end)
+ end = path[i] + strlen(path[i]);
+ len = end - path[i];
+ ret = 0;
+ do {
+ char name[ret + 1];
+
+ ret = snprintf(name, sizeof(name), "%.*s%s" MLX4_GLUE,
+ (int)len, path[i],
+ (!len || *(end - 1) == '/') ? "" : "/");
+ if (ret == -1)
+ break;
+ if (sizeof(name) != (size_t)ret + 1)
+ continue;
+ DEBUG("looking for rdma-core glue as \"%s\"", name);
+ handle = dlopen(name, RTLD_LAZY);
+ break;
+ } while (1);
+ path[i] = end + 1;
+ if (!*end)
+ ++i;
+ }
+ if (!handle) {
+ rte_errno = EINVAL;
+ dlmsg = dlerror();
+ if (dlmsg)
+ WARN("cannot load glue library: %s", dlmsg);
+ goto glue_error;
+ }
+ sym = dlsym(handle, "mlx4_glue");
+ if (!sym || !*sym) {
+ rte_errno = EINVAL;
+ dlmsg = dlerror();
+ if (dlmsg)
+ ERROR("cannot resolve glue symbol: %s", dlmsg);
+ goto glue_error;
+ }
+ mlx4_glue = *sym;
+ return 0;
+glue_error:
+ if (handle)
+ dlclose(handle);
+ WARN("cannot initialize PMD due to missing run-time"
+ " dependency on rdma-core libraries (libibverbs,"
+ " libmlx4)");
+ return -rte_errno;
+}
+
+#endif
+