2 * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file send_common.c Functions used by more than one paraslash sender. */
21 #include "close_on_fork.h"
22 #include "chunk_queue.h"
25 /** Clients will be kicked if there are more than that many bytes pending. */
26 #define MAX_CQ_BYTES 40000
29 * Open a passive socket of given layer4 type.
31 * Set the resulting file descriptor to nonblocking mode and add it to the list
32 * of fds that are being closed in the child process when the server calls
35 * \param l4type The transport-layer protocol.
36 * \param port The port number.
38 * \return The listening fd on success, negative on errors.
40 static int open_sender(unsigned l4type, int port)
42 int fd, ret = para_listen(AF_UNSPEC, l4type, port);
47 ret = mark_fd_nonblocking(fd);
52 add_close_on_fork_list(fd);
57 * Shut down a client connected to a paraslash sender.
59 * \param sc The client to shut down.
60 * \param ss The sender whose clients are to be shut down.
62 * Close the file descriptor given by \a sc, remove it from the close-on-fork
63 * list, destroy the chunk queue of this client, delete the client from the
64 * list of connected clients and free the sender_client struct.
66 void shutdown_client(struct sender_client *sc, struct sender_status *ss)
68 PARA_INFO_LOG("shutting down %s on fd %d\n", sc->name, sc->fd);
71 del_close_on_fork_list(sc->fd);
74 free(sc->private_data);
79 void shutdown_clients(struct sender_status *ss)
81 struct sender_client *sc, *tmp;
82 list_for_each_entry_safe(sc, tmp, &ss->client_list, node)
83 shutdown_client(sc, ss);
87 * Write a buffer to a non-blocking file descriptor.
89 * \param fd The file descriptor.
90 * \param buf the buffer to write.
91 * \param len the number of bytes of \a buf.
92 * \param max_bytes_per_write Do not write more than that many bytes at once.
94 * If \a max_bytes_per_write is non-zero, do not send more than that many bytes
97 * EAGAIN is not considered an error condition. For example CCID3 has a
98 * sending wait queue which fills up and is emptied asynchronously. The EAGAIN
99 * case means that there is currently no space in the wait queue, but this can
100 * change at any moment.
102 * \return Negative on errors, number of bytes written else.
104 static int write_nonblock(int fd, const char *buf, size_t len,
105 size_t max_bytes_per_write)
110 while (written < len) {
111 size_t num = len - written;
113 if (max_bytes_per_write && max_bytes_per_write < num)
114 num = max_bytes_per_write;
115 ret = write(fd, buf + written, num);
116 if (ret < 0 && errno == EAGAIN)
119 return -ERRNO_TO_PARA_ERROR(errno);
125 static int queue_chunk_or_shutdown(struct sender_client *sc,
126 struct sender_status *ss, const char *buf, size_t num_bytes)
128 int ret = cq_enqueue(sc->cq, buf, num_bytes);
130 shutdown_client(sc, ss);
134 /* return: negative on errors, zero if not everything was sent, one otherwise */
135 static int send_queued_chunks(struct sender_client *sc,
136 size_t max_bytes_per_write)
138 struct queued_chunk *qc;
139 while ((qc = cq_peek(sc->cq))) {
143 cq_get(qc, &buf, &len);
144 ret = write_nonblock(sc->fd, buf, len, max_bytes_per_write);
147 cq_update(sc->cq, ret);
156 * Send one chunk of audio data to a connected client.
158 * \param sc The client.
159 * \param ss The sender.
160 * \param max_bytes_per_write Split writes to chunks of at most that many bytes.
161 * \param current_chunk The number of the chunk to write.
162 * \param buf The data to write.
163 * \param len The number of bytes of \a buf.
164 * \param header_buf The audio file header.
165 * \param header_len The number of bytes of \a header_buf.
167 * On errors, the client is shut down. If only a part of the buffer could be
168 * written, the remainder is put into the chunk queue for that client.
170 void send_chunk(struct sender_client *sc, struct sender_status *ss,
171 size_t max_bytes_per_write, long unsigned current_chunk,
172 const char *buf, size_t len, const char *header_buf,
177 if (!sc->header_sent && current_chunk) {
178 if (header_buf && header_len > 0) {
179 ret = queue_chunk_or_shutdown(sc, ss, header_buf, header_len);
185 ret = send_queued_chunks(sc, max_bytes_per_write);
187 shutdown_client(sc, ss);
192 if (!ret) { /* still data left in the queue */
193 ret = queue_chunk_or_shutdown(sc, ss, buf, len);
196 ret = write_nonblock(sc->fd, buf, len, max_bytes_per_write);
198 shutdown_client(sc, ss);
202 ret = queue_chunk_or_shutdown(sc, ss, buf + ret, len - ret);
205 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
209 * Initialize a struct sender status.
211 * \param ss The struct to initialize.
212 * \param access_arg The array of access arguments given at the command line.
213 * \param num_access_args The number of elements in \a access_arg.
214 * \param port The tcp or dccp port to listen on.
215 * \param max_clients The maximal number of simultaneous connections.
216 * \param default_deny Whether a blacklist should be used for access control.
218 void init_sender_status(struct sender_status *ss, char **access_arg,
219 int num_access_args, int port, int max_clients, int default_deny)
222 INIT_LIST_HEAD(&ss->client_list);
224 acl_init(&ss->acl, access_arg, num_access_args);
226 ss->max_clients = max_clients;
227 ss->default_deny = default_deny;
231 * Return a string containing the current status of a sender.
233 * \param ss The sender.
234 * \param name Used for printing the header line.
236 * \return The string printed in the "si" command.
238 char *get_sender_info(struct sender_status *ss, char *name)
240 char *clnts = NULL, *ret;
241 struct sender_client *sc, *tmp_sc;
243 char *acl_contents = acl_get_contents(&ss->acl);
244 list_for_each_entry_safe(sc, tmp_sc, &ss->client_list, node) {
245 char *tmp = make_message("%s%s ", clnts? clnts : "", sc->name);
253 "\tnumber of connected clients: %d\n"
254 "\tmaximal number of clients: %d%s\n"
255 "\tconnected clients: %s\n"
256 "\taccess %s list: %s\n",
258 (ss->listen_fd >= 0)? "on" : "off",
262 ss->max_clients > 0? "" : " (unlimited)",
263 clnts? clnts : "(none)",
264 ss->default_deny? "allow" : "deny",
265 acl_contents? acl_contents : "(empty)"
273 * Allow connections from the given range of IP addresses.
275 * \param scd Contains the IP and the netmask.
276 * \param ss The sender.
278 * \sa generic_com_deny().
280 void generic_com_allow(struct sender_command_data *scd,
281 struct sender_status *ss)
283 acl_allow(scd->addr, scd->netmask, &ss->acl, ss->default_deny);
287 * Deny connections from the given range of IP addresses.
289 * \param scd see \ref generic_com_allow().
290 * \param ss see \ref generic_com_allow().
292 * \sa generic_com_allow().
294 void generic_com_deny(struct sender_command_data *scd,
295 struct sender_status *ss)
297 acl_deny(scd->addr, scd->netmask, &ss->acl, ss->default_deny);
301 * Activate a paraslash sender.
303 * \param ss The sender to activate.
304 * \param protocol The symbolic name of the transport-layer protocol.
308 int generic_com_on(struct sender_status *ss, unsigned protocol)
312 if (ss->listen_fd >= 0)
314 ret = open_sender(protocol, ss->port);
322 * Deactivate a paraslash sender.
324 * Shutdown all connected clients and stop listening on the TCP/DCCP socket.
326 * \param ss The sender to deactivate.
328 * \sa \ref del_close_on_fork_list(), shutdown_clients().
330 void generic_com_off(struct sender_status *ss)
332 if (ss->listen_fd < 0)
334 PARA_NOTICE_LOG("closing port %d\n", ss->port);
335 close(ss->listen_fd);
336 del_close_on_fork_list(ss->listen_fd);
337 shutdown_clients(ss);
342 * Accept a connection on the socket this server is listening on.
344 * \param ss The sender whose listening fd is ready for reading.
346 * This must be called only if the socket fd of \a ss is ready for reading. It
347 * calls para_accept() to accept the connection and performs the following
348 * actions on the resulting file descriptor \a fd:
350 * - Checks whether the maximal number of connections are exceeded.
351 * - Sets \a fd to nonblocking mode.
352 * - Checks the acl of the sender to find out whether connections
353 * are allowed from the IP of the connecting peer.
354 * - Increases the number of connections for this sender.
355 * - Creates and initializes a new chunk queue for queuing network
356 * packets that can not be sent immediately.
357 * - Allocates a new struct sender_client and fills in its \a fd, \a cq
358 * and \a name members.
359 * - Adds \a fd to the list of connected clients for this sender.
360 * - Adds \a fd to the list of file descriptors that should be closed
361 * in the child process when the server calls fork().
363 * \return A pointer to the allocated sender_client structure on success, \p
366 * \sa \ref para_accept(), \ref mark_fd_nonblocking(), \ref acl_check_access(),
367 * \ref cq_new(), \ref add_close_on_fork_list().
369 struct sender_client *accept_sender_client(struct sender_status *ss)
371 struct sender_client *sc;
372 int fd, ret = para_accept(ss->listen_fd, NULL, 0);
374 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
378 ret = -E_MAX_CLIENTS;
379 if (ss->max_clients > 0 && ss->num_clients >= ss->max_clients)
381 ret = mark_fd_nonblocking(fd);
384 ret = acl_check_access(fd, &ss->acl, ss->default_deny);
388 sc = para_calloc(sizeof(*sc));
390 sc->name = make_message("%s", remote_name(fd));
391 sc->cq = cq_new(MAX_CQ_BYTES);
392 para_list_add(&sc->node, &ss->client_list);
393 add_close_on_fork_list(fd);
394 PARA_INFO_LOG("accepted client #%d: %s (fd %d)\n", ss->num_clients,
398 PARA_WARNING_LOG("%s\n", para_strerror(-ret));
404 * Get the generic help text.
406 * \return A dynamically allocated string containing the help text for
407 * a paraslash sender.
409 char *generic_sender_help(void)
413 "usage: {allow|deny} IP mask\n"
414 "example: allow 127.0.0.1 32\n"