c542e7e62fa52864b9ad8f44520b5dd495900e6a
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.
165 * On errors, the client is shut down. If only a part of the buffer could be
166 * written, the remainder is put into the chunk queue for that client.
168 void send_chunk(struct sender_client
*sc
, struct sender_status
*ss
,
169 size_t max_bytes_per_write
, long unsigned current_chunk
,
170 const char *buf
, size_t len
)
174 if (!sc
->header_sent
&& current_chunk
) {
178 vss_get_header(&header_buf
, &header_len
);
179 if (header_buf
&& header_len
> 0) {
180 ret
= queue_chunk_or_shutdown(sc
, ss
, header_buf
, header_len
);
186 ret
= send_queued_chunks(sc
, max_bytes_per_write
);
188 shutdown_client(sc
, ss
);
193 if (!ret
) { /* still data left in the queue */
194 ret
= queue_chunk_or_shutdown(sc
, ss
, buf
, len
);
197 ret
= write_nonblock(sc
->fd
, buf
, len
, max_bytes_per_write
);
199 shutdown_client(sc
, ss
);
203 ret
= queue_chunk_or_shutdown(sc
, ss
, buf
+ ret
, len
- ret
);
206 PARA_NOTICE_LOG("%s\n", para_strerror(-ret
));
210 * Initialize a struct sender status.
212 * \param ss The struct to initialize.
213 * \param access_arg The array of access arguments given at the command line.
214 * \param num_access_args The number of elements in \a access_arg.
215 * \param port The tcp or dccp port to listen on.
216 * \param max_clients The maximal number of simultaneous connections.
217 * \param default_deny Whether a blacklist should be used for access control.
219 void init_sender_status(struct sender_status
*ss
, char **access_arg
,
220 int num_access_args
, int port
, int max_clients
, int default_deny
)
223 INIT_LIST_HEAD(&ss
->client_list
);
225 acl_init(&ss
->acl
, access_arg
, num_access_args
);
227 ss
->max_clients
= max_clients
;
228 ss
->default_deny
= default_deny
;
232 * Return a string containing the current status of a sender.
234 * \param ss The sender.
235 * \param name Used for printing the header line.
237 * \return The string printed in the "si" command.
239 char *get_sender_info(struct sender_status
*ss
, char *name
)
241 char *clnts
= NULL
, *ret
;
242 struct sender_client
*sc
, *tmp_sc
;
244 char *acl_contents
= acl_get_contents(&ss
->acl
);
245 list_for_each_entry_safe(sc
, tmp_sc
, &ss
->client_list
, node
) {
246 char *tmp
= make_message("%s%s ", clnts
? clnts
: "", sc
->name
);
254 "\tnumber of connected clients: %d\n"
255 "\tmaximal number of clients: %d%s\n"
256 "\tconnected clients: %s\n"
257 "\taccess %s list: %s\n",
259 (ss
->listen_fd
>= 0)? "on" : "off",
263 ss
->max_clients
> 0? "" : " (unlimited)",
264 clnts
? clnts
: "(none)",
265 ss
->default_deny
? "allow" : "deny",
266 acl_contents
? acl_contents
: "(empty)"
274 * Allow connections from the given range of IP addresses.
276 * \param scd Contains the IP and the netmask.
277 * \param ss The sender.
279 * \sa generic_com_deny().
281 void generic_com_allow(struct sender_command_data
*scd
,
282 struct sender_status
*ss
)
284 acl_allow(scd
->addr
, scd
->netmask
, &ss
->acl
, ss
->default_deny
);
288 * Deny connections from the given range of IP addresses.
290 * \param scd see \ref generic_com_allow().
291 * \param ss see \ref generic_com_allow().
293 * \sa generic_com_allow().
295 void generic_com_deny(struct sender_command_data
*scd
,
296 struct sender_status
*ss
)
298 acl_deny(scd
->addr
, scd
->netmask
, &ss
->acl
, ss
->default_deny
);
302 * Activate a paraslash sender.
304 * \param ss The sender to activate.
305 * \param protocol The symbolic name of the transport-layer protocol.
309 int generic_com_on(struct sender_status
*ss
, unsigned protocol
)
313 if (ss
->listen_fd
>= 0)
315 ret
= open_sender(protocol
, ss
->port
);
323 * Deactivate a paraslash sender.
325 * Shutdown all connected clients and stop listening on the TCP/DCCP socket.
327 * \param ss The sender to deactivate.
329 * \sa \ref del_close_on_fork_list(), shutdown_clients().
331 void generic_com_off(struct sender_status
*ss
)
333 if (ss
->listen_fd
< 0)
335 PARA_NOTICE_LOG("closing port %d\n", ss
->port
);
336 close(ss
->listen_fd
);
337 del_close_on_fork_list(ss
->listen_fd
);
338 shutdown_clients(ss
);
343 * Accept a connection on the socket this server is listening on.
345 * \param ss The sender whose listening fd is ready for reading.
347 * This must be called only if the socket fd of \a ss is ready for reading. It
348 * calls para_accept() to accept the connection and performs the following
349 * actions on the resulting file descriptor \a fd:
351 * - Checks whether the maximal number of connections are exceeded.
352 * - Sets \a fd to nonblocking mode.
353 * - Checks the acl of the sender to find out whether connections
354 * are allowed from the IP of the connecting peer.
355 * - Increases the number of connections for this sender.
356 * - Creates and initializes a new chunk queue for queuing network
357 * packets that can not be sent immediately.
358 * - Allocates a new struct sender_client and fills in its \a fd, \a cq
359 * and \a name members.
360 * - Adds \a fd to the list of connected clients for this sender.
361 * - Adds \a fd to the list of file descriptors that should be closed
362 * in the child process when the server calls fork().
364 * \return A pointer to the allocated sender_client structure on success, \p
367 * \sa \ref para_accept(), \ref mark_fd_nonblocking(), \ref acl_check_access(),
368 * \ref cq_new(), \ref add_close_on_fork_list().
370 struct sender_client
*accept_sender_client(struct sender_status
*ss
)
372 struct sender_client
*sc
;
373 int fd
, ret
= para_accept(ss
->listen_fd
, NULL
, 0);
375 PARA_ERROR_LOG("%s\n", para_strerror(-ret
));
379 ret
= -E_MAX_CLIENTS
;
380 if (ss
->max_clients
> 0 && ss
->num_clients
>= ss
->max_clients
)
382 ret
= mark_fd_nonblocking(fd
);
385 ret
= acl_check_access(fd
, &ss
->acl
, ss
->default_deny
);
389 sc
= para_calloc(sizeof(*sc
));
391 sc
->name
= make_message("%s", remote_name(fd
));
392 sc
->cq
= cq_new(MAX_CQ_BYTES
);
393 para_list_add(&sc
->node
, &ss
->client_list
);
394 add_close_on_fork_list(fd
);
395 PARA_INFO_LOG("accepted client #%d: %s (fd %d)\n", ss
->num_clients
,
399 PARA_WARNING_LOG("%s\n", para_strerror(-ret
));
405 * Get the generic help text.
407 * \return A dynamically allocated string containing the help text for
408 * a paraslash sender.
410 char *generic_sender_help(void)
414 "usage: {allow|deny} IP mask\n"
415 "example: allow 127.0.0.1 32\n"