43aeb2b3b7597d4d5e46dfc51b036c5868d0cda1
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
, long unsigned chunk_num
,
129 int ret
= cq_enqueue(sc
->cq
, chunk_num
, sent
);
131 shutdown_client(sc
, ss
);
135 /* return: negative on errors, zero if not everything was sent, one otherwise */
136 static int send_queued_chunks(struct sender_client
*sc
,
137 size_t max_bytes_per_write
)
139 struct queued_chunk
*qc
;
140 while ((qc
= cq_peek(sc
->cq
))) {
144 cq_get(qc
, &buf
, &len
);
145 ret
= write_nonblock(sc
->fd
, buf
, len
, max_bytes_per_write
);
148 cq_update(sc
->cq
, ret
);
157 * Send one chunk of audio data to a connected client.
159 * \param sc The client.
160 * \param ss The sender.
161 * \param max_bytes_per_write Split writes to chunks of at most that many bytes.
162 * \param current_chunk The number of the chunk to write.
163 * \param buf The data to write.
164 * \param len The number of bytes of \a buf.
166 * On errors, the client is shut down. If only a part of the buffer could be
167 * written, the remainder is put into the chunk queue for that client.
169 void send_chunk(struct sender_client
*sc
, struct sender_status
*ss
,
170 size_t max_bytes_per_write
, long unsigned current_chunk
,
171 const char *buf
, size_t len
)
175 if (!sc
->header_sent
&& current_chunk
) {
179 vss_get_header(&header_buf
, &header_len
);
180 if (header_buf
&& header_len
> 0) {
181 ret
= queue_chunk_or_shutdown(sc
, ss
, -1U, 0);
187 ret
= send_queued_chunks(sc
, max_bytes_per_write
);
189 shutdown_client(sc
, ss
);
194 if (!ret
) { /* still data left in the queue */
195 ret
= queue_chunk_or_shutdown(sc
, ss
, current_chunk
, 0);
198 ret
= write_nonblock(sc
->fd
, buf
, len
, max_bytes_per_write
);
200 shutdown_client(sc
, ss
);
204 ret
= queue_chunk_or_shutdown(sc
, ss
, current_chunk
, ret
);
207 PARA_NOTICE_LOG("%s\n", para_strerror(-ret
));
211 * Initialize a struct sender status.
213 * \param ss The struct to initialize.
214 * \param access_arg The array of access arguments given at the command line.
215 * \param num_access_args The number of elements in \a access_arg.
216 * \param port The tcp or dccp port to listen on.
217 * \param max_clients The maximal number of simultaneous connections.
218 * \param default_deny Whether a blacklist should be used for access control.
220 void init_sender_status(struct sender_status
*ss
, char **access_arg
,
221 int num_access_args
, int port
, int max_clients
, int default_deny
)
224 INIT_LIST_HEAD(&ss
->client_list
);
226 acl_init(&ss
->acl
, access_arg
, num_access_args
);
228 ss
->max_clients
= max_clients
;
229 ss
->default_deny
= default_deny
;
233 * Return a string containing the current status of a sender.
235 * \param ss The sender.
236 * \param name Used for printing the header line.
238 * \return The string printed in the "si" command.
240 char *get_sender_info(struct sender_status
*ss
, char *name
)
242 char *clnts
= NULL
, *ret
;
243 struct sender_client
*sc
, *tmp_sc
;
245 char *acl_contents
= acl_get_contents(&ss
->acl
);
246 list_for_each_entry_safe(sc
, tmp_sc
, &ss
->client_list
, node
) {
247 char *tmp
= make_message("%s%s ", clnts
? clnts
: "", sc
->name
);
255 "\tnumber of connected clients: %d\n"
256 "\tmaximal number of clients: %d%s\n"
257 "\tconnected clients: %s\n"
258 "\taccess %s list: %s\n",
260 (ss
->listen_fd
>= 0)? "on" : "off",
264 ss
->max_clients
> 0? "" : " (unlimited)",
265 clnts
? clnts
: "(none)",
266 ss
->default_deny
? "allow" : "deny",
267 acl_contents
? acl_contents
: "(empty)"
275 * Allow connections from the given range of IP addresses.
277 * \param scd Contains the IP and the netmask.
278 * \param ss The sender.
280 * \sa generic_com_deny().
282 void generic_com_allow(struct sender_command_data
*scd
,
283 struct sender_status
*ss
)
285 acl_allow(scd
->addr
, scd
->netmask
, &ss
->acl
, ss
->default_deny
);
289 * Deny connections from the given range of IP addresses.
291 * \param scd see \ref generic_com_allow().
292 * \param ss see \ref generic_com_allow().
294 * \sa generic_com_allow().
296 void generic_com_deny(struct sender_command_data
*scd
,
297 struct sender_status
*ss
)
299 acl_deny(scd
->addr
, scd
->netmask
, &ss
->acl
, ss
->default_deny
);
303 * Activate a paraslash sender.
305 * \param ss The sender to activate.
306 * \param protocol The symbolic name of the transport-layer protocol.
310 int generic_com_on(struct sender_status
*ss
, unsigned protocol
)
314 if (ss
->listen_fd
>= 0)
316 ret
= open_sender(protocol
, ss
->port
);
324 * Deactivate a paraslash sender.
326 * Shutdown all connected clients and stop listening on the TCP/DCCP socket.
328 * \param ss The sender to deactivate.
330 * \sa \ref del_close_on_fork_list(), shutdown_clients().
332 void generic_com_off(struct sender_status
*ss
)
334 if (ss
->listen_fd
< 0)
336 PARA_NOTICE_LOG("closing port %d\n", ss
->port
);
337 close(ss
->listen_fd
);
338 del_close_on_fork_list(ss
->listen_fd
);
339 shutdown_clients(ss
);
344 * Accept a connection on the socket this server is listening on.
346 * \param ss The sender whose listening fd is ready for reading.
348 * This must be called only if the socket fd of \a ss is ready for reading. It
349 * calls para_accept() to accept the connection and performs the following
350 * actions on the resulting file descriptor \a fd:
352 * - Checks whether the maximal number of connections are exceeded.
353 * - Sets \a fd to nonblocking mode.
354 * - Checks the acl of the sender to find out whether connections
355 * are allowed from the IP of the connecting peer.
356 * - Increases the number of connections for this sender.
357 * - Creates and initializes a new chunk queue for queuing network
358 * packets that can not be sent immediately.
359 * - Allocates a new struct sender_client and fills in its \a fd, \a cq
360 * and \a name members.
361 * - Adds \a fd to the list of connected clients for this sender.
362 * - Adds \a fd to the list of file descriptors that should be closed
363 * in the child process when the server calls fork().
365 * \return A pointer to the allocated sender_client structure on success, \p
368 * \sa \ref para_accept(), \ref mark_fd_nonblocking(), \ref acl_check_access(),
369 * \ref cq_new(), \ref add_close_on_fork_list().
371 struct sender_client
*accept_sender_client(struct sender_status
*ss
)
373 struct sender_client
*sc
;
374 int fd
, ret
= para_accept(ss
->listen_fd
, NULL
, 0);
376 PARA_ERROR_LOG("%s\n", para_strerror(-ret
));
380 ret
= -E_MAX_CLIENTS
;
381 if (ss
->max_clients
> 0 && ss
->num_clients
>= ss
->max_clients
)
383 ret
= mark_fd_nonblocking(fd
);
386 ret
= acl_check_access(fd
, &ss
->acl
, ss
->default_deny
);
390 sc
= para_calloc(sizeof(*sc
));
392 sc
->name
= make_message("%s", remote_name(fd
));
393 sc
->cq
= cq_new(MAX_CQ_BYTES
);
394 para_list_add(&sc
->node
, &ss
->client_list
);
395 add_close_on_fork_list(fd
);
396 PARA_INFO_LOG("accepted client #%d: %s (fd %d)\n", ss
->num_clients
,
400 PARA_WARNING_LOG("%s\n", para_strerror(-ret
));
406 * Get the generic help text.
408 * \return A dynamically allocated string containing the help text for
409 * a paraslash sender.
411 char *generic_sender_help(void)
415 "usage: {allow|deny} IP mask\n"
416 "example: allow 127.0.0.1 32\n"