cleanup: remove redundant 'max length' argument
[paraslash.git] / send_common.c
1 /*
2 * Copyright (C) 2005-2010 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file send_common.c Functions used by more than one paraslash sender. */
8
9 #include <regex.h>
10 #include <dirent.h>
11 #include <osl.h>
12
13 #include "para.h"
14 #include "error.h"
15 #include "string.h"
16 #include "fd.h"
17 #include "net.h"
18 #include "list.h"
19 #include "afh.h"
20 #include "afs.h"
21 #include "server.h"
22 #include "acl.h"
23 #include "send.h"
24 #include "close_on_fork.h"
25 #include "chunk_queue.h"
26 #include "vss.h"
27
28 /** Clients will be kicked if there are more than that many bytes pending. */
29 #define MAX_CQ_BYTES 40000
30
31 /**
32 * Open a passive socket of given layer4 type.
33 *
34 * Set the resulting file descriptor to nonblocking mode and add it to the list
35 * of fds that are being closed in the child process when the server calls
36 * fork().
37 *
38 * \param l4type The transport-layer protocol.
39 * \param port The port number.
40 *
41 * \return The listening fd on success, negative on errors.
42 */
43 static int open_sender(unsigned l4type, int port)
44 {
45 int fd, ret = para_listen_simple(l4type, port);
46
47 if (ret < 0)
48 return ret;
49 fd = ret;
50 ret = mark_fd_nonblocking(fd);
51 if (ret < 0) {
52 close(fd);
53 return ret;
54 }
55 add_close_on_fork_list(fd);
56 return fd;
57 }
58
59 /**
60 * Shut down a client connected to a paraslash sender.
61 *
62 * \param sc The client to shut down.
63 * \param ss The sender whose clients are to be shut down.
64 *
65 * Close the file descriptor given by \a sc, remove it from the close-on-fork
66 * list, destroy the chunk queue of this client, delete the client from the
67 * list of connected clients and free the sender_client struct.
68 *
69 * \sa shutdown_clients().
70 */
71 void shutdown_client(struct sender_client *sc, struct sender_status *ss)
72 {
73 PARA_INFO_LOG("shutting down %s on fd %d\n", sc->name, sc->fd);
74 free(sc->name);
75 close(sc->fd);
76 del_close_on_fork_list(sc->fd);
77 cq_destroy(sc->cq);
78 list_del(&sc->node);
79 free(sc->private_data);
80 free(sc);
81 ss->num_clients--;
82 }
83
84 /**
85 * Shut down all clients connected to a paraslash sender.
86 *
87 * \param ss The sender whose clients are to be shut down.
88 *
89 * This just loops over all connected clients and calls shutdown_client()
90 * for each client.
91 */
92 void shutdown_clients(struct sender_status *ss)
93 {
94 struct sender_client *sc, *tmp;
95 list_for_each_entry_safe(sc, tmp, &ss->client_list, node)
96 shutdown_client(sc, ss);
97 }
98
99 static int queue_chunk_or_shutdown(struct sender_client *sc,
100 struct sender_status *ss, const char *buf, size_t num_bytes)
101 {
102 int ret = cq_enqueue(sc->cq, buf, num_bytes);
103 if (ret < 0)
104 shutdown_client(sc, ss);
105 return ret;
106 }
107
108 /**
109 * Try to empty the chunk queue for this fd.
110 *
111 * \param fd The file descriptor.
112 * \param cq The list of queued chunks.
113 *
114 * \return Negative on errors, zero if not everything was sent, one otherwise.
115 */
116 int send_queued_chunks(int fd, struct chunk_queue *cq)
117 {
118 struct queued_chunk *qc;
119 while ((qc = cq_peek(cq))) {
120 const char *buf;
121 size_t len;
122 int ret;
123
124 cq_get(qc, &buf, &len);
125 ret = write_nonblock(fd, buf, len);
126 if (ret < 0)
127 return ret;
128 cq_update(cq, ret);
129 if (ret != len)
130 return 0;
131 cq_dequeue(cq);
132 }
133 return 1;
134 }
135
136 /**
137 * Send one chunk of audio data to a connected client.
138 *
139 * \param sc The client.
140 * \param ss The sender.
141 * \param current_chunk The number of the chunk to write.
142 * \param buf The data to write.
143 * \param len The number of bytes of \a buf.
144 * \param header_buf The audio file header.
145 * \param header_len The number of bytes of \a header_buf.
146 *
147 * On errors, the client is shut down. If only a part of the buffer could be
148 * written, the remainder is put into the chunk queue for that client.
149 */
150 void send_chunk(struct sender_client *sc, struct sender_status *ss,
151 long unsigned current_chunk, const char *buf, size_t len,
152 const char *header_buf, size_t header_len)
153 {
154 int ret;
155
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);
159 if (ret < 0)
160 goto out;
161 }
162 }
163 sc->header_sent = 1;
164 ret = send_queued_chunks(sc->fd, sc->cq);
165 if (ret < 0) {
166 shutdown_client(sc, ss);
167 goto out;
168 }
169 if (!len)
170 goto out;
171 if (!ret) { /* still data left in the queue */
172 ret = queue_chunk_or_shutdown(sc, ss, buf, len);
173 goto out;
174 }
175 ret = write_nonblock(sc->fd, buf, len);
176 if (ret < 0) {
177 shutdown_client(sc, ss);
178 goto out;
179 }
180 if (ret != len)
181 ret = queue_chunk_or_shutdown(sc, ss, buf + ret, len - ret);
182 out:
183 if (ret < 0)
184 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
185 }
186
187 /**
188 * Initialize a struct sender status.
189 *
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.
196 */
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)
199 {
200 ss->listen_fd = -1;
201 INIT_LIST_HEAD(&ss->client_list);
202 ss->port = port;
203 acl_init(&ss->acl, access_arg, num_access_args);
204 ss->num_clients = 0;
205 ss->max_clients = max_clients;
206 ss->default_deny = default_deny;
207 }
208
209 /**
210 * Return a string containing the current status of a sender.
211 *
212 * \param ss The sender.
213 * \param name Used for printing the header line.
214 *
215 * \return The string printed in the "si" command.
216 */
217 char *get_sender_info(struct sender_status *ss, const char *name)
218 {
219 char *clnts = NULL, *ret;
220 struct sender_client *sc, *tmp_sc;
221
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);
225 free(clnts);
226 clnts = tmp;
227 }
228 ret = make_message(
229 "%s sender:\n"
230 "\tstatus: %s\n"
231 "\tport: %s\n"
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",
236 name,
237 (ss->listen_fd >= 0)? "on" : "off",
238 stringify_port(ss->port, strcmp(name, "http") ? "dccp" : "tcp"),
239 ss->num_clients,
240 ss->max_clients,
241 ss->max_clients > 0? "" : " (unlimited)",
242 clnts? clnts : "(none)",
243 ss->default_deny? "allow" : "deny",
244 acl_contents? acl_contents : "(empty)"
245 );
246 free(acl_contents);
247 free(clnts);
248 return ret;
249 }
250
251 /**
252 * Allow connections from the given range of IP addresses.
253 *
254 * \param scd Contains the IP and the netmask.
255 * \param ss The sender.
256 *
257 * \sa generic_com_deny().
258 */
259 void generic_com_allow(struct sender_command_data *scd,
260 struct sender_status *ss)
261 {
262 acl_allow(scd->host, scd->netmask, &ss->acl, ss->default_deny);
263 }
264
265 /**
266 * Deny connections from the given range of IP addresses.
267 *
268 * \param scd see \ref generic_com_allow().
269 * \param ss see \ref generic_com_allow().
270 *
271 * \sa generic_com_allow().
272 */
273 void generic_com_deny(struct sender_command_data *scd,
274 struct sender_status *ss)
275 {
276 acl_deny(scd->host, scd->netmask, &ss->acl, ss->default_deny);
277 }
278
279 /**
280 * Activate a paraslash sender.
281 *
282 * \param ss The sender to activate.
283 * \param protocol The symbolic name of the transport-layer protocol.
284 *
285 * \return Standard.
286 */
287 int generic_com_on(struct sender_status *ss, unsigned protocol)
288 {
289 int ret;
290
291 if (ss->listen_fd >= 0)
292 return 1;
293 ret = open_sender(protocol, ss->port);
294 if (ret < 0)
295 return ret;
296 ss->listen_fd = ret;
297 return 1;
298 }
299
300 /**
301 * Deactivate a paraslash sender.
302 *
303 * Shutdown all connected clients and stop listening on the TCP/DCCP socket.
304 *
305 * \param ss The sender to deactivate.
306 *
307 * \sa \ref del_close_on_fork_list(), shutdown_clients().
308 */
309 void generic_com_off(struct sender_status *ss)
310 {
311 if (ss->listen_fd < 0)
312 return;
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);
317 ss->listen_fd = -1;
318 }
319
320 /**
321 * Accept a connection on the socket this server is listening on.
322 *
323 * \param ss The sender whose listening fd is ready for reading.
324 *
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:
328 *
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().
341 *
342 * \return A pointer to the allocated sender_client structure on success, \p
343 * NULL on errors.
344 *
345 * \sa \ref para_accept(), \ref mark_fd_nonblocking(), \ref acl_check_access(),
346 * \ref cq_new(), \ref add_close_on_fork_list().
347 */
348 struct sender_client *accept_sender_client(struct sender_status *ss, fd_set *rfds)
349 {
350 struct sender_client *sc;
351 int fd, ret;
352
353 if (ss->listen_fd < 0)
354 return NULL;
355 ret = para_accept(ss->listen_fd, rfds, NULL, 0, &fd);
356 if (ret < 0)
357 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
358 if (ret <= 0)
359 return NULL;
360 ret = -E_MAX_CLIENTS;
361 if (ss->max_clients > 0 && ss->num_clients >= ss->max_clients)
362 goto err_out;
363 ret = mark_fd_nonblocking(fd);
364 if (ret < 0)
365 goto err_out;
366 ret = acl_check_access(fd, &ss->acl, ss->default_deny);
367 if (ret < 0)
368 goto err_out;
369 ss->num_clients++;
370 sc = para_calloc(sizeof(*sc));
371 sc->fd = fd;
372 sc->name = make_message("%s", remote_name(fd));
373 sc->cq = cq_new(MAX_CQ_BYTES);
374 para_list_add(&sc->node, &ss->client_list);
375 add_close_on_fork_list(fd);
376 PARA_INFO_LOG("accepted client #%d: %s (fd %d)\n", ss->num_clients,
377 sc->name, fd);
378 return sc;
379 err_out:
380 PARA_WARNING_LOG("%s\n", para_strerror(-ret));
381 close(fd);
382 return NULL;
383 }
384
385 /**
386 * Get the generic help text.
387 *
388 * \return A dynamically allocated string containing the help text for
389 * a paraslash sender.
390 */
391 char *generic_sender_help(void)
392 {
393 return make_message(
394 "usage: {on|off}\n"
395 "usage: {allow|deny} IP[/netmask]\n"
396 " where mask defaults to 32\n"
397 "example: allow 192.168.0.1/24\n"
398 );
399 }
400
401 static int parse_fec_parms(const char *arg, struct sender_command_data *scd)
402 {
403 int32_t val;
404 char *a = para_strdup(arg), *b = a, *e = strchr(b, ':');
405 int ret = -E_COMMAND_SYNTAX;
406
407 /* parse max slice bytes */
408 if (!e)
409 goto out;
410 *e = '\0';
411 ret = para_atoi32(b, &val);
412 if (ret < 0)
413 goto out;
414 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
415 if (val < 0 || val > 65535)
416 goto out;
417 scd->max_slice_bytes = val;
418 /* parse data_slices_per_group */
419 b = e + 1;
420 e = strchr(b, ':');
421 ret = -E_COMMAND_SYNTAX;
422 if (!e)
423 goto out;
424 *e = '\0';
425 ret = para_atoi32(b, &val);
426 if (ret < 0)
427 goto out;
428 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
429 if (val < 0 || val > 255)
430 goto out;
431 scd->data_slices_per_group = val;
432 /* parse slices_per_group */
433 b = e + 1;
434 ret = para_atoi32(b, &val);
435 if (ret < 0)
436 goto out;
437 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
438 if (val < 0 || val < scd->data_slices_per_group)
439 goto out;
440 scd->slices_per_group = val;
441 ret = 0;
442 out:
443 free(a);
444 return ret;
445 }
446
447 /**
448 * Parse a FEC URL string.
449 *
450 * \param arg the URL string to parse.
451 * \param scd The structure containing host, port and the FEC parameters.
452 *
453 * \return Standard.
454 *
455 * A FEC URL consists of an ordinary URL string according to RFC 3986,
456 * optionally followed by a slash and the three FEC parameters slice_size,
457 * data_slices_per_group and slices_per_group. The three FEC parameters are
458 * separated by colons.
459 *
460 * \sa \ref parse_url().
461 */
462 int parse_fec_url(const char *arg, struct sender_command_data *scd)
463 {
464 int ret;
465 ssize_t len = sizeof(scd->host);
466 char *a = para_strdup(arg), *p = strchr(a, '/');
467
468 if (p) {
469 *p = '\0';
470 len = strlen(a);
471 }
472 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
473 if (!parse_url(a, scd->host, len, &scd->port))
474 goto out;
475 if (p) {
476 ret = parse_fec_parms(p + 1, scd);
477 goto out;
478 }
479 /* use default fec parameters. */
480 scd->max_slice_bytes = 0;
481 scd->slices_per_group = 16;
482 scd->data_slices_per_group = 14;
483 ret = 0;
484 out:
485 free(a);
486 return ret;
487 }