testsuite: Introduce a new test for para_server.
[paraslash.git] / send_common.c
1 /*
2 * Copyright (C) 2005-2011 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 <osl.h>
11
12 #include "para.h"
13 #include "error.h"
14 #include "string.h"
15 #include "fd.h"
16 #include "net.h"
17 #include "list.h"
18 #include "afh.h"
19 #include "afs.h"
20 #include "server.h"
21 #include "acl.h"
22 #include "send.h"
23 #include "close_on_fork.h"
24 #include "chunk_queue.h"
25 #include "vss.h"
26
27 /** Clients will be kicked if there are more than that many bytes pending. */
28 #define MAX_CQ_BYTES 40000
29
30 /**
31 * Open a passive socket of given layer4 type.
32 *
33 * Set the resulting file descriptor to nonblocking mode and add it to the list
34 * of fds that are being closed in the child process when the server calls
35 * fork().
36 *
37 * \param l4type The transport-layer protocol.
38 * \param port The port number.
39 *
40 * \return The listening fd on success, negative on errors.
41 */
42 static int open_sender(unsigned l4type, int port)
43 {
44 int fd, ret = para_listen_simple(l4type, port);
45
46 if (ret < 0)
47 return ret;
48 fd = ret;
49 ret = mark_fd_nonblocking(fd);
50 if (ret < 0) {
51 close(fd);
52 return ret;
53 }
54 add_close_on_fork_list(fd);
55 return fd;
56 }
57
58 /**
59 * Shut down a client connected to a paraslash sender.
60 *
61 * \param sc The client to shut down.
62 * \param ss The sender whose clients are to be shut down.
63 *
64 * Close the file descriptor given by \a sc, remove it from the close-on-fork
65 * list, destroy the chunk queue of this client, delete the client from the
66 * list of connected clients and free the sender_client struct.
67 *
68 * \sa shutdown_clients().
69 */
70 void shutdown_client(struct sender_client *sc, struct sender_status *ss)
71 {
72 PARA_INFO_LOG("shutting down %s on fd %d\n", sc->name, sc->fd);
73 free(sc->name);
74 close(sc->fd);
75 del_close_on_fork_list(sc->fd);
76 cq_destroy(sc->cq);
77 list_del(&sc->node);
78 free(sc->private_data);
79 free(sc);
80 ss->num_clients--;
81 }
82
83 /**
84 * Shut down all clients connected to a paraslash sender.
85 *
86 * \param ss The sender whose clients are to be shut down.
87 *
88 * This just loops over all connected clients and calls shutdown_client()
89 * for each client.
90 */
91 void shutdown_clients(struct sender_status *ss)
92 {
93 struct sender_client *sc, *tmp;
94 list_for_each_entry_safe(sc, tmp, &ss->client_list, node)
95 shutdown_client(sc, ss);
96 }
97
98 /**
99 * Try to empty the chunk queue for this fd.
100 *
101 * \param fd The file descriptor.
102 * \param cq The list of queued chunks.
103 *
104 * \return Negative on errors, zero if not everything was sent, one otherwise.
105 */
106 int send_queued_chunks(int fd, struct chunk_queue *cq)
107 {
108 struct queued_chunk *qc;
109 while ((qc = cq_peek(cq))) {
110 const char *buf;
111 size_t len;
112 int ret;
113
114 cq_get(qc, &buf, &len);
115 ret = write_nonblock(fd, buf, len);
116 if (ret < 0)
117 return ret;
118 cq_update(cq, ret);
119 if (ret != len)
120 return 0;
121 cq_dequeue(cq);
122 }
123 return 1;
124 }
125
126 /**
127 * Initialize a struct sender status.
128 *
129 * \param ss The struct to initialize.
130 * \param access_arg The array of access arguments given at the command line.
131 * \param num_access_args The number of elements in \a access_arg.
132 * \param port The tcp or dccp port to listen on.
133 * \param max_clients The maximal number of simultaneous connections.
134 * \param default_deny Whether a blacklist should be used for access control.
135 */
136 void init_sender_status(struct sender_status *ss, char **access_arg,
137 int num_access_args, int port, int max_clients, int default_deny)
138 {
139 ss->listen_fd = -1;
140 INIT_LIST_HEAD(&ss->client_list);
141 ss->port = port;
142 acl_init(&ss->acl, access_arg, num_access_args);
143 ss->num_clients = 0;
144 ss->max_clients = max_clients;
145 ss->default_deny = default_deny;
146 }
147
148 /**
149 * Return a string containing the current status of a sender.
150 *
151 * \param ss The sender.
152 * \param name Used for printing the header line.
153 *
154 * \return The string printed in the "si" command.
155 */
156 char *get_sender_info(struct sender_status *ss, const char *name)
157 {
158 char *clnts = NULL, *ret;
159 struct sender_client *sc, *tmp_sc;
160
161 char *acl_contents = acl_get_contents(&ss->acl);
162 list_for_each_entry_safe(sc, tmp_sc, &ss->client_list, node) {
163 char *tmp = make_message("%s%s ", clnts? clnts : "", sc->name);
164 free(clnts);
165 clnts = tmp;
166 }
167 ret = make_message(
168 "%s sender:\n"
169 "\tstatus: %s\n"
170 "\tport: %s\n"
171 "\tnumber of connected clients: %d\n"
172 "\tmaximal number of clients: %d%s\n"
173 "\tconnected clients: %s\n"
174 "\taccess %s list: %s\n",
175 name,
176 (ss->listen_fd >= 0)? "on" : "off",
177 stringify_port(ss->port, strcmp(name, "http") ? "dccp" : "tcp"),
178 ss->num_clients,
179 ss->max_clients,
180 ss->max_clients > 0? "" : " (unlimited)",
181 clnts? clnts : "(none)",
182 ss->default_deny? "allow" : "deny",
183 acl_contents? acl_contents : "(empty)"
184 );
185 free(acl_contents);
186 free(clnts);
187 return ret;
188 }
189
190 /**
191 * Allow connections from the given range of IP addresses.
192 *
193 * \param scd Contains the IP and the netmask.
194 * \param ss The sender.
195 *
196 * \sa generic_com_deny().
197 */
198 void generic_com_allow(struct sender_command_data *scd,
199 struct sender_status *ss)
200 {
201 acl_allow(scd->host, scd->netmask, &ss->acl, ss->default_deny);
202 }
203
204 /**
205 * Deny connections from the given range of IP addresses.
206 *
207 * \param scd see \ref generic_com_allow().
208 * \param ss see \ref generic_com_allow().
209 *
210 * \sa generic_com_allow().
211 */
212 void generic_com_deny(struct sender_command_data *scd,
213 struct sender_status *ss)
214 {
215 acl_deny(scd->host, scd->netmask, &ss->acl, ss->default_deny);
216 }
217
218 /**
219 * Activate a paraslash sender.
220 *
221 * \param ss The sender to activate.
222 * \param protocol The symbolic name of the transport-layer protocol.
223 *
224 * \return Standard.
225 */
226 int generic_com_on(struct sender_status *ss, unsigned protocol)
227 {
228 int ret;
229
230 if (ss->listen_fd >= 0)
231 return 1;
232 ret = open_sender(protocol, ss->port);
233 if (ret < 0)
234 return ret;
235 ss->listen_fd = ret;
236 return 1;
237 }
238
239 /**
240 * Deactivate a paraslash sender.
241 *
242 * Shutdown all connected clients and stop listening on the TCP/DCCP socket.
243 *
244 * \param ss The sender to deactivate.
245 *
246 * \sa \ref del_close_on_fork_list(), shutdown_clients().
247 */
248 void generic_com_off(struct sender_status *ss)
249 {
250 if (ss->listen_fd < 0)
251 return;
252 PARA_NOTICE_LOG("closing port %d\n", ss->port);
253 close(ss->listen_fd);
254 del_close_on_fork_list(ss->listen_fd);
255 shutdown_clients(ss);
256 ss->listen_fd = -1;
257 }
258
259 /**
260 * Accept a connection on the socket this server is listening on.
261 *
262 * \param ss The sender whose listening fd is ready for reading.
263 * \param rfds Passed to para_accept(),
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 }