+struct callback_query {
+ /** The function to be called. */
+ callback_function *handler;
+ /** The number of bytes of the query */
+ size_t query_size;
+};
+
+/**
+ * Structure embedded in the result of a callback.
+ *
+ * If the callback produced a result, an instance of that structure is embeeded
+ * into the shared memory area holding the result, mainly to let the command
+ * handler know the size of the result.
+ *
+ * \sa struct callback_query.
+ */
+struct callback_result {
+ /** The number of bytes of the result. */
+ size_t result_size;
+};
+
+/**
+ * Ask the afs process to call a given function.
+ *
+ * \param f The function to be called.
+ * \param query Pointer to arbitrary data for the callback.
+ * \param result Callback result will be stored here.
+ *
+ * This function creates a shared memory area, copies the buffer pointed to by
+ * query to that area and notifies the afs process that \a f should be
+ * called ASAP.
+ *
+ * \return Negative, on errors, the return value of the callback function
+ * otherwise.
+ *
+ * \sa send_option_arg_callback_request(), send_standard_callback_request().
+ */
+int send_callback_request(callback_function *f, struct osl_object *query,
+ struct osl_object *result)
+{
+ struct callback_query *cq;
+ struct callback_result *cr;
+ int ret, fd = -1, query_shmid, result_shmid;
+ void *query_shm, *result_shm;
+ char buf[sizeof(afs_socket_cookie) + sizeof(int)];
+ struct sockaddr_un unix_addr;
+ size_t query_shm_size = sizeof(*cq);
+
+ if (query)
+ query_shm_size += query->size;
+ ret = shm_new(query_shm_size);
+ if (ret < 0)
+ return ret;
+ query_shmid = ret;
+ ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
+ if (ret < 0)
+ goto out;
+ cq = query_shm;
+ cq->handler = f;
+ cq->query_size = query_shm_size - sizeof(*cq);
+
+ if (query)
+ memcpy(query_shm + sizeof(*cq), query->data, query->size);
+ ret = shm_detach(query_shm);
+ if (ret < 0)
+ goto out;
+
+ *(uint32_t *) buf = afs_socket_cookie;
+ *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
+
+ ret = get_stream_socket(PF_UNIX);
+ if (ret < 0)
+ goto out;
+ fd = ret;
+ ret = init_unix_addr(&unix_addr, conf.afs_socket_arg);
+ if (ret < 0)
+ goto out;
+ ret = PARA_CONNECT(fd, &unix_addr);
+ if (ret < 0)
+ goto out;
+ ret = send_bin_buffer(fd, buf, sizeof(buf));
+ if (ret < 0)
+ goto out;
+ ret = recv_bin_buffer(fd, buf, sizeof(buf));
+ if (ret < 0)
+ goto out;
+ if (ret != sizeof(int)) {
+ ret = -E_RECV;
+ goto out;
+ }
+ ret = *(int *) buf;
+ if (ret <= 0)
+ goto out;
+ result_shmid = ret;
+ ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
+ if (ret >= 0) {
+ assert(result);
+ cr = result_shm;
+ result->size = cr->result_size;
+ result->data = para_malloc(result->size);
+ memcpy(result->data, result_shm + sizeof(*cr), result->size);
+ ret = shm_detach(result_shm);
+ if (ret < 0)
+ PARA_ERROR_LOG("can not detach result\n");
+ } else
+ PARA_ERROR_LOG("attach result failed: %d\n", ret);
+ if (shm_destroy(result_shmid) < 0)
+ PARA_ERROR_LOG("destroy result failed\n");
+ ret = 1;
+out:
+ if (shm_destroy(query_shmid) < 0)
+ PARA_ERROR_LOG("%s\n", "shm destroy error");
+ if (fd >= 0)
+ close(fd);
+// PARA_DEBUG_LOG("callback_ret: %d\n", ret);
+ return ret;
+}
+
+/**
+ * Send a callback request passing an options structure and an argument vector.
+ *
+ * \param options pointer to an arbitrary data structure.
+ * \param argc Argument count.
+ * \param argv Standard argument vector.
+ * \param f The callback function.
+ * \param result The result of the query is stored here.
+ *
+ * Some commands have a couple of options that are parsed in child context for
+ * syntactic correctness and are stored in a special options structure for that
+ * command. This function allows to pass such a structure together with a list
+ * of further arguments (often a list of audio files) to the parent process.
+ *
+ * \sa send_standard_callback_request(), send_callback_request().
+ */
+int send_option_arg_callback_request(struct osl_object *options,
+ int argc, char * const * const argv, callback_function *f,
+ struct osl_object *result)
+{
+ char *p;
+ int i, ret;
+ struct osl_object query = {.size = options? options->size : 0};
+
+ for (i = 0; i < argc; i++)
+ query.size += strlen(argv[i]) + 1;
+ query.data = para_malloc(query.size);
+ p = query.data;
+ if (options) {
+ memcpy(query.data, options->data, options->size);
+ p += options->size;
+ }
+ for (i = 0; i < argc; i++) {
+ strcpy(p, argv[i]); /* OK */
+ p += strlen(argv[i]) + 1;
+ }
+ ret = send_callback_request(f, &query, result);
+ free(query.data);
+ return ret;
+}
+
+/**
+ * Send a callback request with an argument vector only.
+ *
+ * \param argc The same meaning as in send_option_arg_callback_request().
+ * \param argv The same meaning as in send_option_arg_callback_request().
+ * \param f The same meaning as in send_option_arg_callback_request().
+ * \param result The same meaning as in send_option_arg_callback_request().
+ *
+ * This is similar to send_option_arg_callback_request(), but no options buffer
+ * is passed to the parent process.
+ *
+ * \return The return value of the underlying call to
+ * send_option_arg_callback_request().
+ */
+int send_standard_callback_request(int argc, char * const * const argv,
+ callback_function *f, struct osl_object *result)
+{
+ return send_option_arg_callback_request(NULL, argc, argv, f, result);
+}
+
+static int action_if_pattern_matches(struct osl_row *row, void *data)
+{
+ struct pattern_match_data *pmd = data;
+ struct osl_object name_obj;
+ const char *p, *name;
+ int ret = osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj);
+ const char *pattern_txt = (const char *)pmd->patterns.data;
+
+ if (ret < 0)
+ return ret;
+ name = (char *)name_obj.data;
+ if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
+ return 1;
+ if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
+ return pmd->action(pmd->table, row, name, pmd->data);
+ for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
+ p += strlen(p) + 1) {
+ ret = fnmatch(p, name, pmd->fnmatch_flags);
+ if (ret == FNM_NOMATCH)
+ continue;
+ if (ret)
+ return -E_FNMATCH;
+ return pmd->action(pmd->table, row, name, pmd->data);
+ }
+ return 1;
+}
+
+/**
+ * Execute the given function for each matching row.
+ *
+ * \param pmd Describes what to match and how.
+ *
+ * \return The return value of the underlying call to osl_rbtree_loop()
+ * or osl_rbtree_loop_reverse().
+ */
+int for_each_matching_row(struct pattern_match_data *pmd)
+{
+ if (pmd->pm_flags & PM_REVERSE_LOOP)
+ return osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
+ action_if_pattern_matches);
+ return osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
+ action_if_pattern_matches);
+}
+
+/**
+ * Compare two osl objects of string type.
+ *
+ * \param obj1 Pointer to the first object.
+ * \param obj2 Pointer to the second object.
+ *
+ * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
+ * are taken into account.
+ *
+ * \return It returns an integer less than, equal to, or greater than zero if
+ * \a obj1 is found, respectively, to be less than, to match, or be greater than
+ * obj2.
+ *
+ * \sa strcmp(3), strncmp(3), osl_compare_func.
+ */
+int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
+{
+ const char *str1 = (const char *)obj1->data;
+ const char *str2 = (const char *)obj2->data;
+ return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
+}
+
+/*
+ * write input from fd to dynamically allocated buffer,
+ * but maximal max_size byte.
+ */
+static int fd2buf(int fd, unsigned max_size, struct osl_object *obj)
+{
+ const size_t chunk_size = 1024;
+ size_t size = 2048, received = 0;
+ int ret;
+ char *buf = para_malloc(size);
+
+ for (;;) {
+ ret = recv_bin_buffer(fd, buf + received, chunk_size);
+ if (ret <= 0)
+ break;
+ received += ret;
+ if (received + chunk_size >= size) {
+ size *= 2;
+ ret = -E_INPUT_TOO_LARGE;
+ if (size > max_size)
+ break;
+ buf = para_realloc(buf, size);
+ }
+ }
+ obj->data = buf;
+ obj->size = received;
+ if (ret < 0)
+ free(buf);
+ return ret;
+}
+
+/**
+ * Read data from a file descriptor, and send it to the afs process.
+ *
+ * \param fd File descriptor to read data from.
+ * \param arg_obj Pointer to the arguments to \a f.
+ * \param f The callback function.
+ * \param max_len Don't read more than that many bytes from stdin.
+ * \param result The result of the query is stored here.
+ *
+ * This function is used by commands that wish to let para_server store
+ * arbitrary data specified by the user (for instance the add_blob family of
+ * commands). First, at most \a max_len bytes are read from \a fd, the result
+ * is concatenated with the buffer given by \a arg_obj, and the combined buffer
+ * is made available to the parent process via shared memory.
+ *
+ * \return Negative on errors, the return value of the underlying call to
+ * send_callback_request() otherwise.
+ */
+int stdin_command(int fd, struct osl_object *arg_obj, callback_function *f,
+ unsigned max_len, struct osl_object *result)
+{
+ struct osl_object query, stdin_obj;
+ int ret;
+
+ ret = send_buffer(fd, AWAITING_DATA_MSG);
+ if (ret < 0)
+ return ret;
+ ret = fd2buf(fd, max_len, &stdin_obj);
+ if (ret < 0)
+ return ret;
+ query.size = arg_obj->size + stdin_obj.size;
+ query.data = para_malloc(query.size);
+ memcpy(query.data, arg_obj->data, arg_obj->size);
+ memcpy((char *)query.data + arg_obj->size, stdin_obj.data, stdin_obj.size);
+ free(stdin_obj.data);
+ ret = send_callback_request(f, &query, result);
+ free(query.data);
+ return ret;
+}
+
+static int pass_afd(int fd, char *buf, size_t size)
+{
+ struct msghdr msg = {.msg_iov = NULL};
+ struct cmsghdr *cmsg;
+ char control[255];