2 * Copyright (C) 2005-2009 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 * \sa shutdown_clients().
68 void shutdown_client(struct sender_client *sc, struct sender_status *ss)
70 PARA_INFO_LOG("shutting down %s on fd %d\n", sc->name, sc->fd);
73 del_close_on_fork_list(sc->fd);
76 free(sc->private_data);
82 * Shut down all clients connected to a paraslash sender.
84 * \param ss The sender whose clients are to be shut down.
86 * This just loops over all connected clients and calls shutdown_client()
89 void shutdown_clients(struct sender_status *ss)
91 struct sender_client *sc, *tmp;
92 list_for_each_entry_safe(sc, tmp, &ss->client_list, node)
93 shutdown_client(sc, ss);
96 static int queue_chunk_or_shutdown(struct sender_client *sc,
97 struct sender_status *ss, const char *buf, size_t num_bytes)
99 int ret = cq_enqueue(sc->cq, buf, num_bytes);
101 shutdown_client(sc, ss);
106 * Try to empty the chunk queue for this fd.
108 * \param fd The file descriptor.
109 * \param cq The list of queued chunks.
110 * \param max_bytes_per_write Do not send more than this in one go.
112 * \return Negative on errors, zero if not everything was sent, one otherwise.
114 int send_queued_chunks(int fd, struct chunk_queue *cq,
115 size_t max_bytes_per_write)
117 struct queued_chunk *qc;
118 while ((qc = cq_peek(cq))) {
122 cq_get(qc, &buf, &len);
123 ret = write_nonblock(fd, buf, len, max_bytes_per_write);
135 * Send one chunk of audio data to a connected client.
137 * \param sc The client.
138 * \param ss The sender.
139 * \param max_bytes_per_write Split writes to chunks of at most that many bytes.
140 * \param current_chunk The number of the chunk to write.
141 * \param buf The data to write.
142 * \param len The number of bytes of \a buf.
143 * \param header_buf The audio file header.
144 * \param header_len The number of bytes of \a header_buf.
146 * On errors, the client is shut down. If only a part of the buffer could be
147 * written, the remainder is put into the chunk queue for that client.
149 void send_chunk(struct sender_client *sc, struct sender_status *ss,
150 size_t max_bytes_per_write, long unsigned current_chunk,
151 const char *buf, size_t len, const char *header_buf,
156 if (!sc->header_sent && current_chunk) {
157 if (header_buf && header_len > 0) {
158 ret = queue_chunk_or_shutdown(sc, ss, header_buf, header_len);
164 ret = send_queued_chunks(sc->fd, sc->cq, max_bytes_per_write);
166 shutdown_client(sc, ss);
171 if (!ret) { /* still data left in the queue */
172 ret = queue_chunk_or_shutdown(sc, ss, buf, len);
175 ret = write_nonblock(sc->fd, buf, len, max_bytes_per_write);
177 shutdown_client(sc, ss);
181 ret = queue_chunk_or_shutdown(sc, ss, buf + ret, len - ret);
184 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
188 * Initialize a struct sender status.
190 * \param ss The struct to initialize.
191 * \param access_arg The array of access arguments given at the command line.
192 * \param num_access_args The number of elements in \a access_arg.
193 * \param port The tcp or dccp port to listen on.
194 * \param max_clients The maximal number of simultaneous connections.
195 * \param default_deny Whether a blacklist should be used for access control.
197 void init_sender_status(struct sender_status *ss, char **access_arg,
198 int num_access_args, int port, int max_clients, int default_deny)
201 INIT_LIST_HEAD(&ss->client_list);
203 acl_init(&ss->acl, access_arg, num_access_args);
205 ss->max_clients = max_clients;
206 ss->default_deny = default_deny;
210 * Return a string containing the current status of a sender.
212 * \param ss The sender.
213 * \param name Used for printing the header line.
215 * \return The string printed in the "si" command.
217 char *get_sender_info(struct sender_status *ss, char *name)
219 char *clnts = NULL, *ret;
220 struct sender_client *sc, *tmp_sc;
222 char *acl_contents = acl_get_contents(&ss->acl);
223 list_for_each_entry_safe(sc, tmp_sc, &ss->client_list, node) {
224 char *tmp = make_message("%s%s ", clnts? clnts : "", sc->name);
232 "\tnumber of connected clients: %d\n"
233 "\tmaximal number of clients: %d%s\n"
234 "\tconnected clients: %s\n"
235 "\taccess %s list: %s\n",
237 (ss->listen_fd >= 0)? "on" : "off",
241 ss->max_clients > 0? "" : " (unlimited)",
242 clnts? clnts : "(none)",
243 ss->default_deny? "allow" : "deny",
244 acl_contents? acl_contents : "(empty)"
252 * Allow connections from the given range of IP addresses.
254 * \param scd Contains the IP and the netmask.
255 * \param ss The sender.
257 * \sa generic_com_deny().
259 void generic_com_allow(struct sender_command_data *scd,
260 struct sender_status *ss)
262 acl_allow(scd->addr, scd->netmask, &ss->acl, ss->default_deny);
266 * Deny connections from the given range of IP addresses.
268 * \param scd see \ref generic_com_allow().
269 * \param ss see \ref generic_com_allow().
271 * \sa generic_com_allow().
273 void generic_com_deny(struct sender_command_data *scd,
274 struct sender_status *ss)
276 acl_deny(scd->addr, scd->netmask, &ss->acl, ss->default_deny);
280 * Activate a paraslash sender.
282 * \param ss The sender to activate.
283 * \param protocol The symbolic name of the transport-layer protocol.
287 int generic_com_on(struct sender_status *ss, unsigned protocol)
291 if (ss->listen_fd >= 0)
293 ret = open_sender(protocol, ss->port);
301 * Deactivate a paraslash sender.
303 * Shutdown all connected clients and stop listening on the TCP/DCCP socket.
305 * \param ss The sender to deactivate.
307 * \sa \ref del_close_on_fork_list(), shutdown_clients().
309 void generic_com_off(struct sender_status *ss)
311 if (ss->listen_fd < 0)
313 PARA_NOTICE_LOG("closing port %d\n", ss->port);
314 close(ss->listen_fd);
315 del_close_on_fork_list(ss->listen_fd);
316 shutdown_clients(ss);
321 * Accept a connection on the socket this server is listening on.
323 * \param ss The sender whose listening fd is ready for reading.
325 * This must be called only if the socket fd of \a ss is ready for reading. It
326 * calls para_accept() to accept the connection and performs the following
327 * actions on the resulting file descriptor \a fd:
329 * - Checks whether the maximal number of connections are exceeded.
330 * - Sets \a fd to nonblocking mode.
331 * - Checks the acl of the sender to find out whether connections
332 * are allowed from the IP of the connecting peer.
333 * - Increases the number of connections for this sender.
334 * - Creates and initializes a new chunk queue for queuing network
335 * packets that can not be sent immediately.
336 * - Allocates a new struct sender_client and fills in its \a fd, \a cq
337 * and \a name members.
338 * - Adds \a fd to the list of connected clients for this sender.
339 * - Adds \a fd to the list of file descriptors that should be closed
340 * in the child process when the server calls fork().
342 * \return A pointer to the allocated sender_client structure on success, \p
345 * \sa \ref para_accept(), \ref mark_fd_nonblocking(), \ref acl_check_access(),
346 * \ref cq_new(), \ref add_close_on_fork_list().
348 struct sender_client *accept_sender_client(struct sender_status *ss)
350 struct sender_client *sc;
351 int fd, ret = para_accept(ss->listen_fd, NULL, 0);
353 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
357 ret = -E_MAX_CLIENTS;
358 if (ss->max_clients > 0 && ss->num_clients >= ss->max_clients)
360 ret = mark_fd_nonblocking(fd);
363 ret = acl_check_access(fd, &ss->acl, ss->default_deny);
367 sc = para_calloc(sizeof(*sc));
369 sc->name = make_message("%s", remote_name(fd));
370 sc->cq = cq_new(MAX_CQ_BYTES);
371 para_list_add(&sc->node, &ss->client_list);
372 add_close_on_fork_list(fd);
373 PARA_INFO_LOG("accepted client #%d: %s (fd %d)\n", ss->num_clients,
377 PARA_WARNING_LOG("%s\n", para_strerror(-ret));
383 * Get the generic help text.
385 * \return A dynamically allocated string containing the help text for
386 * a paraslash sender.
388 char *generic_sender_help(void)
392 "usage: {allow|deny} IP mask\n"
393 "example: allow 127.0.0.1 32\n"