Suppress gcc warning when compiling cmdline files.
[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 /**
100 * Try to empty the chunk queue for this fd.
101 *
102 * \param fd The file descriptor.
103 * \param cq The list of queued chunks.
104 *
105 * \return Negative on errors, zero if not everything was sent, one otherwise.
106 */
107 int send_queued_chunks(int fd, struct chunk_queue *cq)
108 {
109 struct queued_chunk *qc;
110 while ((qc = cq_peek(cq))) {
111 const char *buf;
112 size_t len;
113 int ret;
114
115 cq_get(qc, &buf, &len);
116 ret = write_nonblock(fd, buf, len);
117 if (ret < 0)
118 return ret;
119 cq_update(cq, ret);
120 if (ret != len)
121 return 0;
122 cq_dequeue(cq);
123 }
124 return 1;
125 }
126
127 /**
128 * Initialize a struct sender status.
129 *
130 * \param ss The struct to initialize.
131 * \param access_arg The array of access arguments given at the command line.
132 * \param num_access_args The number of elements in \a access_arg.
133 * \param port The tcp or dccp port to listen on.
134 * \param max_clients The maximal number of simultaneous connections.
135 * \param default_deny Whether a blacklist should be used for access control.
136 */
137 void init_sender_status(struct sender_status *ss, char **access_arg,
138 int num_access_args, int port, int max_clients, int default_deny)
139 {
140 ss->listen_fd = -1;
141 INIT_LIST_HEAD(&ss->client_list);
142 ss->port = port;
143 acl_init(&ss->acl, access_arg, num_access_args);
144 ss->num_clients = 0;
145 ss->max_clients = max_clients;
146 ss->default_deny = default_deny;
147 }
148
149 /**
150 * Return a string containing the current status of a sender.
151 *
152 * \param ss The sender.
153 * \param name Used for printing the header line.
154 *
155 * \return The string printed in the "si" command.
156 */
157 char *get_sender_info(struct sender_status *ss, const char *name)
158 {
159 char *clnts = NULL, *ret;
160 struct sender_client *sc, *tmp_sc;
161
162 char *acl_contents = acl_get_contents(&ss->acl);
163 list_for_each_entry_safe(sc, tmp_sc, &ss->client_list, node) {
164 char *tmp = make_message("%s%s ", clnts? clnts : "", sc->name);
165 free(clnts);
166 clnts = tmp;
167 }
168 ret = make_message(
169 "%s sender:\n"
170 "\tstatus: %s\n"
171 "\tport: %s\n"
172 "\tnumber of connected clients: %d\n"
173 "\tmaximal number of clients: %d%s\n"
174 "\tconnected clients: %s\n"
175 "\taccess %s list: %s\n",
176 name,
177 (ss->listen_fd >= 0)? "on" : "off",
178 stringify_port(ss->port, strcmp(name, "http") ? "dccp" : "tcp"),
179 ss->num_clients,
180 ss->max_clients,
181 ss->max_clients > 0? "" : " (unlimited)",
182 clnts? clnts : "(none)",
183 ss->default_deny? "allow" : "deny",
184 acl_contents? acl_contents : "(empty)"
185 );
186 free(acl_contents);
187 free(clnts);
188 return ret;
189 }
190
191 /**
192 * Allow connections from the given range of IP addresses.
193 *
194 * \param scd Contains the IP and the netmask.
195 * \param ss The sender.
196 *
197 * \sa generic_com_deny().
198 */
199 void generic_com_allow(struct sender_command_data *scd,
200 struct sender_status *ss)
201 {
202 acl_allow(scd->host, scd->netmask, &ss->acl, ss->default_deny);
203 }
204
205 /**
206 * Deny connections from the given range of IP addresses.
207 *
208 * \param scd see \ref generic_com_allow().
209 * \param ss see \ref generic_com_allow().
210 *
211 * \sa generic_com_allow().
212 */
213 void generic_com_deny(struct sender_command_data *scd,
214 struct sender_status *ss)
215 {
216 acl_deny(scd->host, scd->netmask, &ss->acl, ss->default_deny);
217 }
218
219 /**
220 * Activate a paraslash sender.
221 *
222 * \param ss The sender to activate.
223 * \param protocol The symbolic name of the transport-layer protocol.
224 *
225 * \return Standard.
226 */
227 int generic_com_on(struct sender_status *ss, unsigned protocol)
228 {
229 int ret;
230
231 if (ss->listen_fd >= 0)
232 return 1;
233 ret = open_sender(protocol, ss->port);
234 if (ret < 0)
235 return ret;
236 ss->listen_fd = ret;
237 return 1;
238 }
239
240 /**
241 * Deactivate a paraslash sender.
242 *
243 * Shutdown all connected clients and stop listening on the TCP/DCCP socket.
244 *
245 * \param ss The sender to deactivate.
246 *
247 * \sa \ref del_close_on_fork_list(), shutdown_clients().
248 */
249 void generic_com_off(struct sender_status *ss)
250 {
251 if (ss->listen_fd < 0)
252 return;
253 PARA_NOTICE_LOG("closing port %d\n", ss->port);
254 close(ss->listen_fd);
255 del_close_on_fork_list(ss->listen_fd);
256 shutdown_clients(ss);
257 ss->listen_fd = -1;
258 }
259
260 /**
261 * Accept a connection on the socket this server is listening on.
262 *
263 * \param ss The sender whose listening fd is ready for reading.
264 *
265 * This must be called only if the socket fd of \a ss is ready for reading. It
266 * calls para_accept() to accept the connection and performs the following
267 * actions on the resulting file descriptor \a fd:
268 *
269 * - Checks whether the maximal number of connections are exceeded.
270 * - Sets \a fd to nonblocking mode.
271 * - Checks the acl of the sender to find out whether connections
272 * are allowed from the IP of the connecting peer.
273 * - Increases the number of connections for this sender.
274 * - Creates and initializes a new chunk queue for queuing network
275 * packets that can not be sent immediately.
276 * - Allocates a new struct sender_client and fills in its \a fd, \a cq
277 * and \a name members.
278 * - Adds \a fd to the list of connected clients for this sender.
279 * - Adds \a fd to the list of file descriptors that should be closed
280 * in the child process when the server calls fork().
281 *
282 * \return A pointer to the allocated sender_client structure on success, \p
283 * NULL on errors.
284 *
285 * \sa \ref para_accept(), \ref mark_fd_nonblocking(), \ref acl_check_access(),
286 * \ref cq_new(), \ref add_close_on_fork_list().
287 */
288 struct sender_client *accept_sender_client(struct sender_status *ss, fd_set *rfds)
289 {
290 struct sender_client *sc;
291 int fd, ret;
292
293 if (ss->listen_fd < 0)
294 return NULL;
295 ret = para_accept(ss->listen_fd, rfds, NULL, 0, &fd);
296 if (ret < 0)
297 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
298 if (ret <= 0)
299 return NULL;
300 ret = -E_MAX_CLIENTS;
301 if (ss->max_clients > 0 && ss->num_clients >= ss->max_clients)
302 goto err_out;
303 ret = mark_fd_nonblocking(fd);
304 if (ret < 0)
305 goto err_out;
306 ret = acl_check_access(fd, &ss->acl, ss->default_deny);
307 if (ret < 0)
308 goto err_out;
309 ss->num_clients++;
310 sc = para_calloc(sizeof(*sc));
311 sc->fd = fd;
312 sc->name = para_strdup(remote_name(fd));
313 sc->cq = cq_new(MAX_CQ_BYTES);
314 para_list_add(&sc->node, &ss->client_list);
315 add_close_on_fork_list(fd);
316 PARA_INFO_LOG("accepted client #%d: %s (fd %d)\n", ss->num_clients,
317 sc->name, fd);
318 return sc;
319 err_out:
320 PARA_WARNING_LOG("%s\n", para_strerror(-ret));
321 close(fd);
322 return NULL;
323 }
324
325 /**
326 * Get the generic help text.
327 *
328 * \return A dynamically allocated string containing the help text for
329 * a paraslash sender.
330 */
331 char *generic_sender_help(void)
332 {
333 return make_message(
334 "usage: {on|off}\n"
335 "usage: {allow|deny} IP[/netmask]\n"
336 " where mask defaults to 32\n"
337 "example: allow 192.168.0.1/24\n"
338 );
339 }
340
341 static int parse_fec_parms(const char *arg, struct sender_command_data *scd)
342 {
343 int32_t val;
344 char *a = para_strdup(arg),
345 *b = strchr(a, ':'),
346 *c = strrchr(a, ':');
347 int ret = -E_COMMAND_SYNTAX;
348
349 if (!b || !c)
350 goto out;
351 *b = *c = '\0';
352
353 ret = para_atoi32(a, &val);
354 if (ret < 0)
355 goto out;
356
357 /* optional max_slice_bytes (0 means "use MTU") */
358 if (b == c) {
359 scd->max_slice_bytes = 0;
360 } else {
361 if (val < 0 || val > 65535)
362 goto fec_einval;
363 scd->max_slice_bytes = val;
364
365 ret = para_atoi32(b + 1, &val);
366 if (ret < 0)
367 goto out;
368 }
369
370 /* k = data_slices_per_group */
371 if (val < 0 || val > 255)
372 goto fec_einval;
373 scd->data_slices_per_group = val;
374
375 /* n = slices_per_group */
376 ret = para_atoi32(c + 1, &val);
377 if (ret < 0)
378 goto out;
379 if (val < 0 || val < scd->data_slices_per_group)
380 goto fec_einval;
381 scd->slices_per_group = val;
382 ret = 0;
383 out:
384 free(a);
385 return ret;
386 fec_einval:
387 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
388 goto out;
389 }
390
391 /**
392 * Parse a FEC URL string.
393 *
394 * \param arg the URL string to parse.
395 * \param scd The structure containing host, port and the FEC parameters.
396 *
397 * \return Standard.
398 *
399 * A FEC URL consists of an ordinary URL string according to RFC 3986,
400 * optionally followed by a slash and the three FEC parameters slice_size,
401 * data_slices_per_group and slices_per_group. The three FEC parameters are
402 * separated by colons.
403 *
404 * \sa \ref parse_url().
405 */
406 int parse_fec_url(const char *arg, struct sender_command_data *scd)
407 {
408 char *a = para_strdup(arg), *p = strchr(a, '/');
409 int ret = 0;
410
411 /* default fec parameters */
412 scd->max_slice_bytes = 0;
413 scd->data_slices_per_group = 14;
414 scd->slices_per_group = 16;
415
416 if (p) {
417 *p = '\0';
418 ret = parse_fec_parms(p + 1, scd);
419 if (ret < 0)
420 goto out;
421 }
422 if (!parse_url(a, scd->host, sizeof(scd->host), &scd->port))
423 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
424 out:
425 free(a);
426 return ret;
427 }