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);
105 /* return: negative on errors, zero if not everything was sent, one otherwise */
106 static int send_queued_chunks(struct sender_client *sc,
107 size_t max_bytes_per_write)
109 struct queued_chunk *qc;
110 while ((qc = cq_peek(sc->cq))) {
114 cq_get(qc, &buf, &len);
115 ret = write_nonblock(sc->fd, buf, len, max_bytes_per_write);
118 cq_update(sc->cq, ret);
127 * Send one chunk of audio data to a connected client.
129 * \param sc The client.
130 * \param ss The sender.
131 * \param max_bytes_per_write Split writes to chunks of at most that many bytes.
132 * \param current_chunk The number of the chunk to write.
133 * \param buf The data to write.
134 * \param len The number of bytes of \a buf.
135 * \param header_buf The audio file header.
136 * \param header_len The number of bytes of \a header_buf.
138 * On errors, the client is shut down. If only a part of the buffer could be
139 * written, the remainder is put into the chunk queue for that client.
141 void send_chunk(struct sender_client *sc, struct sender_status *ss,
142 size_t max_bytes_per_write, long unsigned current_chunk,
143 const char *buf, size_t len, const char *header_buf,
148 if (!sc->header_sent && current_chunk) {
149 if (header_buf && header_len > 0) {
150 ret = queue_chunk_or_shutdown(sc, ss, header_buf, header_len);
156 ret = send_queued_chunks(sc, max_bytes_per_write);
158 shutdown_client(sc, ss);
163 if (!ret) { /* still data left in the queue */
164 ret = queue_chunk_or_shutdown(sc, ss, buf, len);
167 ret = write_nonblock(sc->fd, buf, len, max_bytes_per_write);
169 shutdown_client(sc, ss);
173 ret = queue_chunk_or_shutdown(sc, ss, buf + ret, len - ret);
176 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
180 * Initialize a struct sender status.
182 * \param ss The struct to initialize.
183 * \param access_arg The array of access arguments given at the command line.
184 * \param num_access_args The number of elements in \a access_arg.
185 * \param port The tcp or dccp port to listen on.
186 * \param max_clients The maximal number of simultaneous connections.
187 * \param default_deny Whether a blacklist should be used for access control.
189 void init_sender_status(struct sender_status *ss, char **access_arg,
190 int num_access_args, int port, int max_clients, int default_deny)
193 INIT_LIST_HEAD(&ss->client_list);
195 acl_init(&ss->acl, access_arg, num_access_args);
197 ss->max_clients = max_clients;
198 ss->default_deny = default_deny;
202 * Return a string containing the current status of a sender.
204 * \param ss The sender.
205 * \param name Used for printing the header line.
207 * \return The string printed in the "si" command.
209 char *get_sender_info(struct sender_status *ss, char *name)
211 char *clnts = NULL, *ret;
212 struct sender_client *sc, *tmp_sc;
214 char *acl_contents = acl_get_contents(&ss->acl);
215 list_for_each_entry_safe(sc, tmp_sc, &ss->client_list, node) {
216 char *tmp = make_message("%s%s ", clnts? clnts : "", sc->name);
224 "\tnumber of connected clients: %d\n"
225 "\tmaximal number of clients: %d%s\n"
226 "\tconnected clients: %s\n"
227 "\taccess %s list: %s\n",
229 (ss->listen_fd >= 0)? "on" : "off",
233 ss->max_clients > 0? "" : " (unlimited)",
234 clnts? clnts : "(none)",
235 ss->default_deny? "allow" : "deny",
236 acl_contents? acl_contents : "(empty)"
244 * Allow connections from the given range of IP addresses.
246 * \param scd Contains the IP and the netmask.
247 * \param ss The sender.
249 * \sa generic_com_deny().
251 void generic_com_allow(struct sender_command_data *scd,
252 struct sender_status *ss)
254 acl_allow(scd->addr, scd->netmask, &ss->acl, ss->default_deny);
258 * Deny connections from the given range of IP addresses.
260 * \param scd see \ref generic_com_allow().
261 * \param ss see \ref generic_com_allow().
263 * \sa generic_com_allow().
265 void generic_com_deny(struct sender_command_data *scd,
266 struct sender_status *ss)
268 acl_deny(scd->addr, scd->netmask, &ss->acl, ss->default_deny);
272 * Activate a paraslash sender.
274 * \param ss The sender to activate.
275 * \param protocol The symbolic name of the transport-layer protocol.
279 int generic_com_on(struct sender_status *ss, unsigned protocol)
283 if (ss->listen_fd >= 0)
285 ret = open_sender(protocol, ss->port);
293 * Deactivate a paraslash sender.
295 * Shutdown all connected clients and stop listening on the TCP/DCCP socket.
297 * \param ss The sender to deactivate.
299 * \sa \ref del_close_on_fork_list(), shutdown_clients().
301 void generic_com_off(struct sender_status *ss)
303 if (ss->listen_fd < 0)
305 PARA_NOTICE_LOG("closing port %d\n", ss->port);
306 close(ss->listen_fd);
307 del_close_on_fork_list(ss->listen_fd);
308 shutdown_clients(ss);
313 * Accept a connection on the socket this server is listening on.
315 * \param ss The sender whose listening fd is ready for reading.
317 * This must be called only if the socket fd of \a ss is ready for reading. It
318 * calls para_accept() to accept the connection and performs the following
319 * actions on the resulting file descriptor \a fd:
321 * - Checks whether the maximal number of connections are exceeded.
322 * - Sets \a fd to nonblocking mode.
323 * - Checks the acl of the sender to find out whether connections
324 * are allowed from the IP of the connecting peer.
325 * - Increases the number of connections for this sender.
326 * - Creates and initializes a new chunk queue for queuing network
327 * packets that can not be sent immediately.
328 * - Allocates a new struct sender_client and fills in its \a fd, \a cq
329 * and \a name members.
330 * - Adds \a fd to the list of connected clients for this sender.
331 * - Adds \a fd to the list of file descriptors that should be closed
332 * in the child process when the server calls fork().
334 * \return A pointer to the allocated sender_client structure on success, \p
337 * \sa \ref para_accept(), \ref mark_fd_nonblocking(), \ref acl_check_access(),
338 * \ref cq_new(), \ref add_close_on_fork_list().
340 struct sender_client *accept_sender_client(struct sender_status *ss)
342 struct sender_client *sc;
343 int fd, ret = para_accept(ss->listen_fd, NULL, 0);
345 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
349 ret = -E_MAX_CLIENTS;
350 if (ss->max_clients > 0 && ss->num_clients >= ss->max_clients)
352 ret = mark_fd_nonblocking(fd);
355 ret = acl_check_access(fd, &ss->acl, ss->default_deny);
359 sc = para_calloc(sizeof(*sc));
361 sc->name = make_message("%s", remote_name(fd));
362 sc->cq = cq_new(MAX_CQ_BYTES);
363 para_list_add(&sc->node, &ss->client_list);
364 add_close_on_fork_list(fd);
365 PARA_INFO_LOG("accepted client #%d: %s (fd %d)\n", ss->num_clients,
369 PARA_WARNING_LOG("%s\n", para_strerror(-ret));
375 * Get the generic help text.
377 * \return A dynamically allocated string containing the help text for
378 * a paraslash sender.
380 char *generic_sender_help(void)
384 "usage: {allow|deny} IP mask\n"
385 "example: allow 127.0.0.1 32\n"