afh: Unify name of init functions.
[paraslash.git] / send_common.c
1 /*
2 * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
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 <netinet/in.h>
10 #include <sys/socket.h>
11 #include <regex.h>
12 #include <osl.h>
13 #include <arpa/inet.h>
14 #include <sys/un.h>
15 #include <netdb.h>
16 #include <lopsub.h>
17
18 #include "para.h"
19 #include "error.h"
20 #include "string.h"
21 #include "fd.h"
22 #include "net.h"
23 #include "list.h"
24 #include "afh.h"
25 #include "afs.h"
26 #include "server.h"
27 #include "acl.h"
28 #include "send.h"
29 #include "close_on_fork.h"
30 #include "chunk_queue.h"
31 #include "sched.h"
32 #include "vss.h"
33
34 /** Clients will be kicked if there are more than that many bytes pending. */
35 #define MAX_CQ_BYTES 40000
36
37 /**
38 * Open a passive socket of given layer4 type.
39 *
40 * Set the resulting file descriptor to nonblocking mode and add it to the list
41 * of fds that are being closed in the child process when the server calls
42 * fork().
43 *
44 * \param l4type The transport-layer protocol.
45 * \param port The port number.
46 *
47 * \return The listening fd on success, negative on errors.
48 */
49 static int open_sender(unsigned l4type, int port)
50 {
51 int fd, ret = para_listen_simple(l4type, port);
52
53 if (ret < 0)
54 return ret;
55 fd = ret;
56 ret = mark_fd_nonblocking(fd);
57 if (ret < 0) {
58 close(fd);
59 return ret;
60 }
61 add_close_on_fork_list(fd);
62 return fd;
63 }
64
65 /**
66 * Shut down a client connected to a paraslash sender.
67 *
68 * \param sc The client to shut down.
69 * \param ss The sender whose clients are to be shut down.
70 *
71 * Close the file descriptor given by \a sc, remove it from the close-on-fork
72 * list, destroy the chunk queue of this client, delete the client from the
73 * list of connected clients and free the sender_client struct.
74 *
75 * \sa shutdown_clients().
76 */
77 void shutdown_client(struct sender_client *sc, struct sender_status *ss)
78 {
79 PARA_INFO_LOG("shutting down %s on fd %d\n", sc->name, sc->fd);
80 free(sc->name);
81 close(sc->fd);
82 del_close_on_fork_list(sc->fd);
83 cq_destroy(sc->cq);
84 list_del(&sc->node);
85 free(sc->private_data);
86 free(sc);
87 ss->num_clients--;
88 }
89
90 /**
91 * Shut down all clients connected to a paraslash sender.
92 *
93 * \param ss The sender whose clients are to be shut down.
94 *
95 * This just loops over all connected clients and calls shutdown_client()
96 * for each client.
97 */
98 void shutdown_clients(struct sender_status *ss)
99 {
100 struct sender_client *sc, *tmp;
101 list_for_each_entry_safe(sc, tmp, &ss->client_list, node)
102 shutdown_client(sc, ss);
103 }
104
105 /**
106 * Try to empty the chunk queue for this fd.
107 *
108 * \param fd The file descriptor.
109 * \param cq The list of queued chunks.
110 *
111 * \return Negative on errors, zero if not everything was sent, one otherwise.
112 */
113 int send_queued_chunks(int fd, struct chunk_queue *cq)
114 {
115 struct queued_chunk *qc;
116 while ((qc = cq_peek(cq))) {
117 const char *buf;
118 size_t len;
119 int ret;
120
121 cq_get(qc, &buf, &len);
122 ret = xwrite(fd, buf, len);
123 if (ret < 0)
124 return ret;
125 cq_update(cq, ret);
126 if (ret != len)
127 return 0;
128 cq_dequeue(cq);
129 }
130 return 1;
131 }
132
133 /**
134 * Initialize a struct sender status.
135 *
136 * \param ss The struct to initialize.
137 * \param acl_opt_result Contains array of --{http|dccp}-access arguments.
138 * \param port The tcp or dccp port to listen on.
139 * \param max_clients The maximal number of simultaneous connections.
140 * \param default_deny Whether a blacklist should be used for access control.
141 */
142 void init_sender_status(struct sender_status *ss,
143 const struct lls_opt_result *acl_opt_result, int port,
144 int max_clients, int default_deny)
145 {
146 int i;
147
148 ss->listen_fd = -1;
149 INIT_LIST_HEAD(&ss->client_list);
150 ss->port = port;
151
152 /* Initialize an access control list */
153 INIT_LIST_HEAD(&ss->acl);
154 for (i = 0; i < lls_opt_given(acl_opt_result); i++) {
155 const char *arg = lls_string_val(i, acl_opt_result);
156 char addr[16];
157 int mask;
158 if (!parse_cidr(arg, addr, sizeof(addr), &mask))
159 PARA_WARNING_LOG("ACL syntax error: %s, ignoring\n",
160 arg);
161 else
162 acl_add_entry(&ss->acl, addr, mask);
163 }
164 ss->num_clients = 0;
165 ss->max_clients = max_clients;
166 ss->default_deny = default_deny;
167 }
168
169 /**
170 * Return a string containing the current status of a sender.
171 *
172 * \param ss The sender.
173 * \param name Used for printing the header line.
174 *
175 * \return The string printed in the "si" command.
176 */
177 char *generic_sender_status(struct sender_status *ss, const char *name)
178 {
179 char *clnts = NULL, *ret;
180 struct sender_client *sc, *tmp_sc;
181
182 char *acl_contents = acl_get_contents(&ss->acl);
183 list_for_each_entry_safe(sc, tmp_sc, &ss->client_list, node) {
184 char *tmp = make_message("%s%s ", clnts? clnts : "", sc->name);
185 free(clnts);
186 clnts = tmp;
187 }
188 ret = make_message(
189 "status: %s\n"
190 "port: %s\n"
191 "number of connected clients: %d\n"
192 "maximal number of clients: %d%s\n"
193 "connected clients: %s\n"
194 "access %s list: %s\n",
195 (ss->listen_fd >= 0)? "on" : "off",
196 stringify_port(ss->port, strcmp(name, "http") ? "dccp" : "tcp"),
197 ss->num_clients,
198 ss->max_clients,
199 ss->max_clients > 0? "" : " (unlimited)",
200 clnts? clnts : "(none)",
201 ss->default_deny? "allow" : "deny",
202 acl_contents? acl_contents : "(empty)"
203 );
204 free(acl_contents);
205 free(clnts);
206 return ret;
207 }
208
209 /**
210 * Allow connections from the given range of IP addresses.
211 *
212 * \param scd Contains the IP and the netmask.
213 * \param ss The sender.
214 *
215 * \sa generic_com_deny().
216 */
217 void generic_com_allow(struct sender_command_data *scd,
218 struct sender_status *ss)
219 {
220 acl_allow(scd->host, scd->netmask, &ss->acl, ss->default_deny);
221 }
222
223 /**
224 * Deny connections from the given range of IP addresses.
225 *
226 * \param scd see \ref generic_com_allow().
227 * \param ss see \ref generic_com_allow().
228 *
229 * \sa generic_com_allow().
230 */
231 void generic_com_deny(struct sender_command_data *scd,
232 struct sender_status *ss)
233 {
234 acl_deny(scd->host, scd->netmask, &ss->acl, ss->default_deny);
235 }
236
237 /**
238 * Activate a paraslash sender.
239 *
240 * \param ss The sender to activate.
241 * \param protocol The symbolic name of the transport-layer protocol.
242 *
243 * \return Standard.
244 */
245 int generic_com_on(struct sender_status *ss, unsigned protocol)
246 {
247 int ret;
248
249 if (ss->listen_fd >= 0)
250 return 1;
251 ret = open_sender(protocol, ss->port);
252 if (ret < 0)
253 return ret;
254 ss->listen_fd = ret;
255 return 1;
256 }
257
258 /**
259 * Deactivate a paraslash sender.
260 *
261 * Shutdown all connected clients and stop listening on the TCP/DCCP socket.
262 *
263 * \param ss The sender to deactivate.
264 *
265 * \sa \ref del_close_on_fork_list(), shutdown_clients().
266 */
267 void generic_com_off(struct sender_status *ss)
268 {
269 if (ss->listen_fd < 0)
270 return;
271 PARA_NOTICE_LOG("closing port %d\n", ss->port);
272 close(ss->listen_fd);
273 del_close_on_fork_list(ss->listen_fd);
274 shutdown_clients(ss);
275 ss->listen_fd = -1;
276 }
277
278 /**
279 * Accept a connection on the socket this server is listening on.
280 *
281 * \param ss The sender whose listening fd is ready for reading.
282 * \param rfds Passed to para_accept(),
283 *
284 * This must be called only if the socket fd of \a ss is ready for reading. It
285 * calls para_accept() to accept the connection and performs the following
286 * actions on the resulting file descriptor \a fd:
287 *
288 * - Checks whether the maximal number of connections are exceeded.
289 * - Sets \a fd to nonblocking mode.
290 * - Checks the acl of the sender to find out whether connections
291 * are allowed from the IP of the connecting peer.
292 * - Increases the number of connections for this sender.
293 * - Creates and initializes a new chunk queue for queuing network
294 * packets that can not be sent immediately.
295 * - Allocates a new struct sender_client and fills in its \a fd, \a cq
296 * and \a name members.
297 * - Adds \a fd to the list of connected clients for this sender.
298 * - Adds \a fd to the list of file descriptors that should be closed
299 * in the child process when the server calls fork().
300 *
301 * \return A pointer to the allocated sender_client structure on success, \p
302 * NULL on errors.
303 *
304 * \sa \ref para_accept(), \ref mark_fd_nonblocking(), \ref acl_check_access(),
305 * \ref cq_new(), \ref add_close_on_fork_list().
306 */
307 struct sender_client *accept_sender_client(struct sender_status *ss, fd_set *rfds)
308 {
309 struct sender_client *sc;
310 int fd, ret;
311
312 if (ss->listen_fd < 0)
313 return NULL;
314 ret = para_accept(ss->listen_fd, rfds, NULL, 0, &fd);
315 if (ret < 0)
316 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
317 if (ret <= 0)
318 return NULL;
319 ret = -E_MAX_CLIENTS;
320 if (ss->max_clients > 0 && ss->num_clients >= ss->max_clients)
321 goto err_out;
322 ret = mark_fd_nonblocking(fd);
323 if (ret < 0)
324 goto err_out;
325 ret = acl_check_access(fd, &ss->acl, ss->default_deny);
326 if (ret < 0)
327 goto err_out;
328 ss->num_clients++;
329 sc = para_calloc(sizeof(*sc));
330 sc->fd = fd;
331 sc->name = para_strdup(remote_name(fd));
332 sc->cq = cq_new(MAX_CQ_BYTES);
333 para_list_add(&sc->node, &ss->client_list);
334 add_close_on_fork_list(fd);
335 PARA_INFO_LOG("accepted client #%d: %s (fd %d)\n", ss->num_clients,
336 sc->name, fd);
337 return sc;
338 err_out:
339 PARA_WARNING_LOG("%s\n", para_strerror(-ret));
340 close(fd);
341 return NULL;
342 }
343
344 /**
345 * Get the generic help text.
346 *
347 * \return A dynamically allocated string containing the help text for
348 * a paraslash sender.
349 */
350 char *generic_sender_help(void)
351 {
352 return make_message(
353 "usage: {on|off}\n"
354 "usage: {allow|deny} IP[/netmask]\n"
355 " where mask defaults to 32\n"
356 "example: allow 192.168.0.1/24\n"
357 );
358 }
359
360 static int parse_fec_parms(const char *arg, struct sender_command_data *scd)
361 {
362 int32_t val;
363 char *a = para_strdup(arg),
364 *b = strchr(a, ':'),
365 *c = strrchr(a, ':');
366 int ret = -E_COMMAND_SYNTAX;
367
368 if (!b || !c)
369 goto out;
370 *b = *c = '\0';
371
372 ret = para_atoi32(a, &val);
373 if (ret < 0)
374 goto out;
375
376 /* optional max_slice_bytes (0 means "use MTU") */
377 if (b == c) {
378 scd->max_slice_bytes = 0;
379 } else {
380 if (val < 0 || val > 65535)
381 goto fec_einval;
382 scd->max_slice_bytes = val;
383
384 ret = para_atoi32(b + 1, &val);
385 if (ret < 0)
386 goto out;
387 }
388
389 /* k = data_slices_per_group */
390 if (val < 0 || val > 255)
391 goto fec_einval;
392 scd->data_slices_per_group = val;
393
394 /* n = slices_per_group */
395 ret = para_atoi32(c + 1, &val);
396 if (ret < 0)
397 goto out;
398 if (val < 0 || val < scd->data_slices_per_group)
399 goto fec_einval;
400 scd->slices_per_group = val;
401 ret = 0;
402 out:
403 free(a);
404 return ret;
405 fec_einval:
406 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
407 goto out;
408 }
409
410 /**
411 * Parse a FEC URL string.
412 *
413 * \param arg the URL string to parse.
414 * \param scd The structure containing host, port and the FEC parameters.
415 *
416 * \return Standard.
417 *
418 * A FEC URL consists of an ordinary URL string according to RFC 3986,
419 * optionally followed by a slash and the three FEC parameters slice_size,
420 * data_slices_per_group and slices_per_group. The three FEC parameters are
421 * separated by colons.
422 *
423 * \sa \ref parse_url().
424 */
425 int parse_fec_url(const char *arg, struct sender_command_data *scd)
426 {
427 char *a = para_strdup(arg), *p = strchr(a, '/');
428 int ret = 0;
429
430 /* default fec parameters */
431 scd->max_slice_bytes = 0;
432 scd->data_slices_per_group = 14;
433 scd->slices_per_group = 16;
434
435 if (p) {
436 *p = '\0';
437 ret = parse_fec_parms(p + 1, scd);
438 if (ret < 0)
439 goto out;
440 }
441 if (!parse_url(a, scd->host, sizeof(scd->host), &scd->port))
442 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
443 out:
444 free(a);
445 return ret;
446 }