alsa: Remove pointless initialization.
[paraslash.git] / udp_send.c
1 /*
2 * Copyright (C) 2005-2013 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file udp_send.c Para_server's udp sender. */
8
9 #include <netinet/in.h>
10 #include <sys/socket.h>
11 #include <regex.h>
12 #include <sys/types.h>
13 #include <sys/socket.h>
14 #include <netinet/udp.h>
15 #include <net/if.h>
16 #include <arpa/inet.h>
17 #include <sys/un.h>
18 #include <osl.h>
19 #include <netdb.h>
20
21 #include "server.cmdline.h"
22 #include "para.h"
23 #include "error.h"
24 #include "string.h"
25 #include "afh.h"
26 #include "afs.h"
27 #include "server.h"
28 #include "list.h"
29 #include "send.h"
30 #include "sched.h"
31 #include "vss.h"
32 #include "portable_io.h"
33 #include "net.h"
34 #include "fd.h"
35 #include "close_on_fork.h"
36
37 /**
38 * Time window during which ICMP Destination/Port Unreachable messages are
39 * ignored, covering transient receiver problems such as restarting the
40 * client, rebooting, reconfiguration, or handover.
41 */
42 #define UDP_MAX_UNREACHABLE_TIME 30
43
44 /** Describes one entry in the list of targets for the udp sender. */
45 struct udp_target {
46 /** Track time (seconds) of last ICMP Port Unreachable error */
47 time_t last_unreachable;
48 /** The opaque structure returned by vss_add_fec_client(). */
49 struct fec_client *fc;
50 /** The FEC parameters for this target. */
51 struct fec_client_parms fcp;
52 };
53
54 static struct list_head targets;
55 static int sender_status;
56
57 static void udp_close_target(struct sender_client *sc)
58 {
59 const char *buf;
60 size_t len = vss_get_fec_eof_packet(&buf);
61
62 /*
63 * Ignore the return value of wirte() since we are closing the target
64 * anyway. The sole purpose of the "do_nothing" statement is to silence
65 * gcc.
66 */
67 if (write(sc->fd, buf, len))
68 do_nothing;
69 }
70
71 static void udp_delete_target(struct sender_client *sc, const char *msg)
72 {
73 struct udp_target *ut = sc->private_data;
74
75 PARA_NOTICE_LOG("deleting %s (%s) from list\n", sc->name, msg);
76 udp_close_target(sc);
77 close(sc->fd);
78 del_close_on_fork_list(sc->fd);
79 vss_del_fec_client(ut->fc);
80 list_del(&sc->node);
81 free(sc->name);
82 free(sc);
83 free(ut);
84 }
85
86 /**
87 * Perform AF-independent multicast sender setup.
88 *
89 * \param sc The connected sender client.
90 *
91 * \return Zero if okay, negative on error.
92 */
93 static int mcast_sender_setup(struct sender_client *sc)
94 {
95 struct sockaddr_storage ss;
96 socklen_t sslen = sizeof(ss);
97 int ttl = conf.udp_ttl_arg, id = 0;
98 const int on = 1;
99
100 if (conf.udp_mcast_iface_given) {
101 char *iface = conf.udp_mcast_iface_arg;
102
103 id = if_nametoindex(iface);
104 if (id == 0)
105 PARA_WARNING_LOG("could not resolve interface '%s', "
106 "using default", iface);
107 }
108
109 if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
110 goto err;
111 assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
112
113 /* RFC 3493, 5.2: -1 means 'use kernel default' */
114 if (ttl < 0 || ttl > 255)
115 ttl = -1;
116
117 switch (ss.ss_family) {
118 case AF_INET:
119 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
120 return 0;
121 if (id != 0) {
122 #ifdef HAVE_IP_MREQN
123 struct ip_mreqn mn;
124
125 memset(&mn, 0, sizeof(mn));
126 mn.imr_ifindex = id;
127 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
128 goto err;
129 #else
130 PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
131 #endif
132 }
133 /*
134 * Enable receiving multicast messages generated on the local host
135 * At least on Linux, this is enabled by default.
136 */
137 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
138 break;
139
140 /* Default: use local subnet (do not flood out into the WAN) */
141 if (ttl == -1)
142 ttl = 1;
143 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
144 break;
145 return 0;
146 case AF_INET6:
147 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
148 return 0;
149 if (id != 0 &&
150 setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
151 break;
152 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
153 break;
154 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
155 break;
156 return 0;
157 }
158 err:
159 return -ERRNO_TO_PARA_ERROR(errno);
160 }
161
162 static void udp_init_session(struct sender_client *sc)
163 {
164 PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
165 }
166
167 static void udp_shutdown_targets(void)
168 {
169 struct sender_client *sc, *tmp;
170 list_for_each_entry_safe(sc, tmp, &targets, node)
171 udp_close_target(sc);
172 }
173
174 static int udp_resolve_target(const char *url, struct sender_command_data *scd)
175 {
176 const char *result;
177 int ret, port;
178
179 ret = parse_fec_url(url, scd);
180 if (ret)
181 return ret;
182 port = scd->port > 0 ? scd->port : conf.udp_default_port_arg;
183
184 ret = para_connect_simple(IPPROTO_UDP, scd->host, port);
185 if (ret < 0)
186 return ret;
187
188 result = remote_name(ret);
189 close(ret);
190
191 if (!parse_url(result, scd->host, sizeof(scd->host), &scd->port))
192 return -E_ADDRESS_LOOKUP;
193 return 1;
194 }
195
196 static int udp_com_on(__a_unused struct sender_command_data *scd)
197 {
198 sender_status = SENDER_ON;
199 return 1;
200 }
201
202 static int udp_com_off(__a_unused struct sender_command_data *scd)
203 {
204 udp_shutdown_targets();
205 sender_status = SENDER_OFF;
206 return 1;
207 }
208
209 static struct sender_client *udp_lookup_target(struct sender_command_data *scd)
210 {
211 struct sender_client *sc, *tmp;
212 char host[MAX_HOSTLEN];
213 int32_t port;
214
215 list_for_each_entry_safe(sc, tmp, &targets, node) {
216 parse_url(sc->name, host, sizeof(host), &port);
217
218 /* Unspecified port means wildcard port match */
219 if (scd->port > 0 && scd->port != port)
220 continue;
221 if (strcmp(host, scd->host))
222 continue;
223 return sc;
224 }
225 return NULL;
226 }
227
228 static int udp_com_delete(struct sender_command_data *scd)
229 {
230 struct sender_client *sc = udp_lookup_target(scd);
231
232 if (sc) {
233 udp_delete_target(sc, "com_delete");
234 return 1;
235 }
236 PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd->host);
237 return -E_TARGET_NOT_FOUND;
238 }
239
240 /** Initialize UDP session and set maximum payload size. */
241 static int udp_init_fec(struct sender_client *sc)
242 {
243 int mps;
244
245 udp_init_session(sc);
246 mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
247 PARA_INFO_LOG("current MPS = %d bytes\n", mps);
248 return mps;
249 }
250
251 /** Check and clear socket error if any. */
252 static int udp_check_socket_state(struct sender_client *sc)
253 {
254 struct udp_target *ut = sc->private_data;
255 int ret;
256 socklen_t errlen = sizeof(ret);
257
258 if (getsockopt(sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
259 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
260 return 0;
261 } else if (ret == 0) {
262 return 0;
263 } else if (ret == ECONNREFUSED) {
264 time_t dist = now->tv_sec - ut->last_unreachable;
265
266 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
267 return 0;
268 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
269 ut->last_unreachable = now->tv_sec;
270 return 0;
271 } else {
272 /*
273 * unreachable_time < dist <= 2 * unreachable_time
274 * No errors are allowed during this time window.
275 */
276 PARA_NOTICE_LOG("Evicting %s after %d seconds "
277 "of connection errors.\n",
278 sc->name, (int)dist);
279 }
280 }
281 return -ERRNO_TO_PARA_ERROR(ret);
282 }
283
284 static void udp_send_fec(struct sender_client *sc, char *buf, size_t len)
285 {
286 int ret;
287
288 if (sender_status == SENDER_OFF)
289 return;
290 if (len == 0)
291 return;
292 ret = udp_check_socket_state(sc);
293 if (ret < 0)
294 goto fail;
295 ret = xwrite(sc->fd, buf, len);
296 if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
297 /*
298 * Happens if meanwhile an ICMP Destination / Port Unreachable
299 * has arrived. Ignore, persistent errors will be caught above.
300 */
301 ret = 0;
302 }
303 if (ret < 0)
304 goto fail;
305 return;
306 fail:
307 udp_delete_target(sc, para_strerror(-ret));
308 }
309
310 static int udp_com_add(struct sender_command_data *scd)
311 {
312 int ret;
313 struct udp_target *ut;
314 struct sender_client *sc = udp_lookup_target(scd);
315
316 if (sc) {
317 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
318 sc->name);
319 return -E_TARGET_EXISTS;
320 }
321 ut = para_calloc(sizeof(*ut));
322 sc = para_calloc(sizeof(*sc));
323 ut->fcp.slices_per_group = scd->slices_per_group;
324 ut->fcp.data_slices_per_group = scd->data_slices_per_group;
325 ut->fcp.init_fec = udp_init_fec;
326 ut->fcp.send_fec = udp_send_fec;
327 ut->fcp.need_periodic_header = true;
328
329 sc->private_data = ut;
330 sc->fd = -1;
331 ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
332 if (ret < 0)
333 goto err;
334 sc->fd = ret;
335
336 ret = mcast_sender_setup(sc);
337 if (ret < 0)
338 goto err;
339 ret = mark_fd_nonblocking(sc->fd);
340 if (ret < 0)
341 goto err;
342 sc->name = para_strdup(remote_name(sc->fd));
343 PARA_INFO_LOG("adding to target list (%s)\n", sc->name);
344 ut->fc = vss_add_fec_client(sc, &ut->fcp);
345 para_list_add(&sc->node, &targets);
346 add_close_on_fork_list(sc->fd);
347 return 1;
348 err:
349 if (sc->fd >= 0)
350 close(sc->fd);
351 PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
352 scd->host, scd->port, para_strerror(-ret));
353 free(sc);
354 free(ut);
355 return ret;
356 }
357
358 static char *udp_info(void)
359 {
360 struct sender_client *sc;
361 char *ret, *tgts = NULL;
362
363 list_for_each_entry(sc, &targets, node) {
364 struct udp_target *ut = sc->private_data;
365 char *tmp = make_message("%s%s/%u:%u ",
366 tgts ? : "", sc->name,
367 ut->fcp.data_slices_per_group,
368 ut->fcp.slices_per_group
369 );
370 free(tgts);
371 tgts = tmp;
372 }
373 ret = make_message(
374 "udp sender:\n"
375 "\tstatus: %s\n"
376 "\tport: %s\n"
377 "\ttargets: %s\n",
378 (sender_status == SENDER_ON)? "on" : "off",
379 stringify_port(conf.udp_default_port_arg, "udp"),
380 tgts? tgts : "(none)"
381 );
382 free(tgts);
383 return ret;
384 }
385
386 static void udp_init_target_list(void)
387 {
388 struct sender_command_data scd;
389 int i;
390
391 INIT_LIST_HEAD(&targets);
392 for (i = 0; i < conf.udp_target_given; i++) {
393 if (udp_resolve_target(conf.udp_target_arg[i], &scd) < 0)
394 PARA_CRIT_LOG("not adding requested target '%s'\n",
395 conf.udp_target_arg[i]);
396 else
397 udp_com_add(&scd);
398 }
399 }
400
401 static char *udp_help(void)
402 {
403 return make_message(
404 "usage: {on|off}\n"
405 "usage: {add|delete} ip_address[:port][/[packet_size:]k:n]\n"
406 " - k is the number of data slices per FEC group\n"
407 " - n is the total number of slices in a FEC group\n"
408 " - packet_size reduces the slice size below path MTU\n\n"
409 "examples: add 224.0.1.38:1500 (IPv4 multicast)\n"
410 " add 224.0.1.38:8080/14:16 (explicit FEC)\n"
411 " add 10.10.1.42 (using default port)\n"
412 " add [FF05::42]:1500 (IPv6 multicast)\n"
413 " add [::1] (IPv6 localhost/default port)\n"
414 " delete myhost.net (host with port wildcard)\n"
415 " delete 10.1.2.3:456 (IPv4 with explicit port)\n"
416 " delete [badc0de::1] (IPv6 with port wildcard)\n"
417 );
418 }
419
420 /**
421 * The init function of para_server's udp sender.
422 *
423 * \param s Pointer to the udp sender struct.
424 *
425 * It initializes all function pointers of \a s and the list of udp targets.
426 */
427 void udp_send_init(struct sender *s)
428 {
429 INIT_LIST_HEAD(&targets);
430 s->info = udp_info;
431 s->help = udp_help;
432 s->send = NULL;
433 s->pre_select = NULL;
434 s->post_select = NULL;
435 s->shutdown_clients = udp_shutdown_targets;
436 s->resolve_target = udp_resolve_target;
437 s->client_cmds[SENDER_ON] = udp_com_on;
438 s->client_cmds[SENDER_OFF] = udp_com_off;
439 s->client_cmds[SENDER_DENY] = NULL;
440 s->client_cmds[SENDER_ALLOW] = NULL;
441 s->client_cmds[SENDER_ADD] = udp_com_add;
442 s->client_cmds[SENDER_DELETE] = udp_com_delete;
443 sender_status = SENDER_OFF;
444 udp_init_target_list();
445 if (!conf.udp_no_autostart_given)
446 sender_status = SENDER_ON;
447 PARA_DEBUG_LOG("udp sender init complete\n");
448 }