return found;
}
+#ifdef HAVE_NFS_PLUGIN_H
+#include <dlfcn.h>
+#include <nfs-plugin.h>
+
+/*
+ * Walk through a set of FS locations and build a set of export options.
+ * Returns true if all went to plan; otherwise, false.
+ */
+static _Bool
+locations_to_options(struct jp_ops *ops, nfs_fsloc_set_t locations,
+ char *options, size_t remaining, int *ttl)
+{
+ char *server, *last_path, *rootpath, *ptr;
+ _Bool seen = false;
+
+ last_path = NULL;
+ rootpath = NULL;
+ server = NULL;
+ ptr = options;
+ *ttl = 0;
+
+ for (;;) {
+ enum jp_status status;
+ int len;
+
+ status = ops->jp_get_next_location(locations, &server,
+ &rootpath, ttl);
+ if (status == JP_EMPTY)
+ break;
+ if (status != JP_OK) {
+ xlog(D_GENERAL, "%s: failed to parse location: %s",
+ __func__, ops->jp_error(status));
+ goto out_false;
+ }
+ xlog(D_GENERAL, "%s: Location: %s:%s",
+ __func__, server, rootpath);
+
+ if (last_path && strcmp(rootpath, last_path) == 0) {
+ len = snprintf(ptr, remaining, "+%s", server);
+ if (len < 0) {
+ xlog(D_GENERAL, "%s: snprintf: %m", __func__);
+ goto out_false;
+ }
+ if ((size_t)len >= remaining) {
+ xlog(D_GENERAL, "%s: options buffer overflow", __func__);
+ goto out_false;
+ }
+ remaining -= (size_t)len;
+ ptr += len;
+ } else {
+ if (last_path == NULL)
+ len = snprintf(ptr, remaining, "refer=%s@%s",
+ rootpath, server);
+ else
+ len = snprintf(ptr, remaining, ":%s@%s",
+ rootpath, server);
+ if (len < 0) {
+ xlog(D_GENERAL, "%s: snprintf: %m", __func__);
+ goto out_false;
+ }
+ if ((size_t)len >= remaining) {
+ xlog(D_GENERAL, "%s: options buffer overflow",
+ __func__);
+ goto out_false;
+ }
+ remaining -= (size_t)len;
+ ptr += len;
+ last_path = rootpath;
+ }
+
+ seen = true;
+ free(rootpath);
+ free(server);
+ }
+
+ xlog(D_CALL, "%s: options='%s', ttl=%d",
+ __func__, options, *ttl);
+ return seen;
+
+out_false:
+ free(rootpath);
+ free(server);
+ return false;
+}
+
+/*
+ * Walk through the set of FS locations and build an exportent.
+ * Returns pointer to an exportent if "junction" refers to a junction.
+ *
+ * Returned exportent points to static memory.
+ */
+static struct exportent *do_locations_to_export(struct jp_ops *ops,
+ nfs_fsloc_set_t locations, const char *junction,
+ char *options, size_t options_len)
+{
+ struct exportent *exp;
+ int ttl;
+
+ if (!locations_to_options(ops, locations, options, options_len, &ttl))
+ return NULL;
+
+ exp = mkexportent("*", (char *)junction, options);
+ if (exp == NULL) {
+ xlog(L_ERROR, "%s: Failed to construct exportent", __func__);
+ return NULL;
+ }
+
+ exp->e_uuid = NULL;
+ exp->e_ttl = ttl;
+ return exp;
+}
+
+/*
+ * Convert set of FS locations to an exportent. Returns pointer to
+ * an exportent if "junction" refers to a junction.
+ *
+ * Returned exportent points to static memory.
+ */
+static struct exportent *locations_to_export(struct jp_ops *ops,
+ nfs_fsloc_set_t locations, const char *junction)
+{
+ struct exportent *exp;
+ char *options;
+
+ options = malloc(BUFSIZ);
+ if (options == NULL) {
+ xlog(D_GENERAL, "%s: failed to allocate options buffer",
+ __func__);
+ return NULL;
+ }
+ options[0] = '\0';
+
+ exp = do_locations_to_export(ops, locations, junction,
+ options, BUFSIZ);
+
+ free(options);
+ return exp;
+}
+
+/*
+ * Retrieve locations information in "junction" and dump it to the
+ * kernel. Returns pointer to an exportent if "junction" refers
+ * to a junction.
+ *
+ * Returned exportent points to static memory.
+ */
+static struct exportent *invoke_junction_ops(void *handle,
+ const char *junction)
+{
+ nfs_fsloc_set_t locations;
+ struct exportent *exp;
+ enum jp_status status;
+ struct jp_ops *ops;
+ char *error;
+
+ ops = (struct jp_ops *)dlsym(handle, "nfs_junction_ops");
+ error = dlerror();
+ if (error != NULL) {
+ xlog(D_GENERAL, "%s: dlsym(jp_junction_ops): %s",
+ __func__, error);
+ return NULL;
+ }
+ if (ops->jp_api_version != JP_API_VERSION) {
+ xlog(D_GENERAL, "%s: unrecognized junction API version: %u",
+ __func__, ops->jp_api_version);
+ return NULL;
+ }
+
+ status = ops->jp_init(false);
+ if (status != JP_OK) {
+ xlog(D_GENERAL, "%s: failed to resolve %s: %s",
+ __func__, junction, ops->jp_error(status));
+ return NULL;
+ }
+
+ status = ops->jp_get_locations(junction, &locations);
+ if (status != JP_OK) {
+ xlog(D_GENERAL, "%s: failed to resolve %s: %s",
+ __func__, junction, ops->jp_error(status));
+ return NULL;
+ }
+
+ exp = locations_to_export(ops, locations, junction);
+
+ ops->jp_put_locations(locations);
+ ops->jp_done();
+ return exp;
+}
+
+/*
+ * Load the junction plug-in, then try to resolve "pathname".
+ * Returns pointer to an initialized exportent if "junction"
+ * refers to a junction, or NULL if not.
+ *
+ * Returned exportent points to static memory.
+ */
+static struct exportent *lookup_junction(const char *pathname)
+{
+ struct exportent *exp;
+ void *handle;
+
+ handle = dlopen("libnfsjunct.so", RTLD_NOW);
+ if (handle == NULL) {
+ xlog(D_GENERAL, "%s: dlopen: %s", __func__, dlerror());
+ return NULL;
+ }
+ (void)dlerror(); /* Clear any error */
+
+ exp = invoke_junction_ops(handle, pathname);
+
+ /* We could leave it loaded to make junction resolution
+ * faster next time. However, if we want to replace the
+ * library, that would require restarting mountd. */
+ (void)dlclose(handle);
+ return exp;
+}
+#else /* !HAVE_NFS_PLUGIN_H */
+static inline struct exportent *lookup_junction(const char *UNUSED(pathname))
+{
+ return NULL;
+}
+#endif /* !HAVE_NFS_PLUGIN_H */
+
static void nfsd_export(FILE *f)
{
/* requests are:
dump_to_cache(f, dom, path, NULL);
}
} else {
- dump_to_cache(f, dom, path, NULL);
+ dump_to_cache(f, dom, path, lookup_junction(path));
}
out:
xlog(D_CALL, "nfsd_export: found %p path %s", found, path ? path : NULL);
projects / nfs-utils.git / commitdiff