Merge branch 'refs/heads/t/wma'
[paraslash.git] / udp_send.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 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 <netinet/udp.h>
14 #include <net/if.h>
15 #include <arpa/inet.h>
16 #include <sys/un.h>
17 #include <netdb.h>
18 #include <lopsub.h>
19
20 #include "server.lsg.h"
21 #include "para.h"
22 #include "error.h"
23 #include "string.h"
24 #include "afh.h"
25 #include "server.h"
26 #include "list.h"
27 #include "send.h"
28 #include "sched.h"
29 #include "vss.h"
30 #include "portable_io.h"
31 #include "net.h"
32 #include "fd.h"
33 #include "close_on_fork.h"
34
35 /**
36 * Time window during which ICMP Destination/Port Unreachable messages are
37 * ignored, covering transient receiver problems such as restarting the
38 * client, rebooting, reconfiguration, or handover.
39 */
40 #define UDP_MAX_UNREACHABLE_TIME 30
41
42 /** Describes one entry in the list of targets for the udp sender. */
43 struct udp_target {
44 /** Track time (seconds) of last ICMP Port Unreachable error */
45 time_t last_unreachable;
46 /** The opaque structure returned by vss_add_fec_client(). */
47 struct fec_client *fc;
48 /** The FEC parameters for this target. */
49 struct fec_client_parms fcp;
50 /** Whether we already sent the FEC eof packet to this target. */
51 bool sent_fec_eof;
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;
61 struct udp_target *ut = sc->private_data;
62
63 if (ut->sent_fec_eof)
64 return;
65 PARA_NOTICE_LOG("sending FEC EOF\n");
66 len = vss_get_fec_eof_packet(&buf);
67 /* Ignore write() errors since we are closing the target anyway. */
68 if (write(sc->fd, buf, len))
69 do_nothing; /* avoid "ignoring return value" warning */
70 ut->sent_fec_eof = true;
71 }
72
73 static void udp_delete_target(struct sender_client *sc, const char *msg)
74 {
75 struct udp_target *ut = sc->private_data;
76
77 PARA_NOTICE_LOG("deleting %s (%s) from list\n", sc->name, msg);
78 udp_close_target(sc);
79 close(sc->fd);
80 del_close_on_fork_list(sc->fd);
81 vss_del_fec_client(ut->fc);
82 list_del(&sc->node);
83 free(sc->name);
84 free(sc);
85 free(ut);
86 }
87
88 /**
89 * Perform AF-independent multicast sender setup.
90 *
91 * \param sc The connected sender client.
92 *
93 * \return Zero if okay, negative on error.
94 */
95 static int mcast_sender_setup(struct sender_client *sc)
96 {
97 struct sockaddr_storage ss;
98 socklen_t sslen = sizeof(ss);
99 int ttl = OPT_INT32_VAL(UDP_TTL), id = 0;
100 const int on = 1;
101
102 if (OPT_GIVEN(UDP_MCAST_IFACE)) {
103 const char *iface = OPT_STRING_VAL(UDP_MCAST_IFACE);
104
105 id = if_nametoindex(iface);
106 if (id == 0)
107 PARA_WARNING_LOG("could not resolve interface '%s', "
108 "using default", iface);
109 }
110
111 if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
112 goto err;
113 assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
114
115 /* RFC 3493, 5.2: -1 means 'use kernel default' */
116 if (ttl < 0 || ttl > 255)
117 ttl = -1;
118
119 switch (ss.ss_family) {
120 case AF_INET:
121 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
122 return 0;
123 if (id != 0) {
124 #ifdef HAVE_IP_MREQN
125 struct ip_mreqn mn;
126
127 memset(&mn, 0, sizeof(mn));
128 mn.imr_ifindex = id;
129 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
130 goto err;
131 #else
132 PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
133 #endif
134 }
135 /*
136 * Enable receiving multicast messages generated on the local host
137 * At least on Linux, this is enabled by default.
138 */
139 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
140 break;
141
142 /* Default: use local subnet (do not flood out into the WAN) */
143 if (ttl == -1)
144 ttl = 1;
145 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
146 break;
147 return 0;
148 case AF_INET6:
149 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
150 return 0;
151 if (id != 0 &&
152 setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
153 break;
154 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
155 break;
156 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
157 break;
158 return 0;
159 }
160 err:
161 return -ERRNO_TO_PARA_ERROR(errno);
162 }
163
164 static void udp_shutdown_targets(void)
165 {
166 struct sender_client *sc, *tmp;
167 list_for_each_entry_safe(sc, tmp, &targets, node)
168 udp_close_target(sc);
169 }
170
171 static int udp_resolve_target(const char *url, struct sender_command_data *scd)
172 {
173 const char *result;
174 int ret, port;
175
176 ret = parse_fec_url(url, scd);
177 if (ret)
178 return ret;
179 port = scd->port > 0 ? scd->port : OPT_UINT32_VAL(UDP_DEFAULT_PORT);
180
181 ret = para_connect_simple(IPPROTO_UDP, scd->host, port);
182 if (ret < 0)
183 return ret;
184
185 result = remote_name(ret);
186 close(ret);
187
188 if (!parse_url(result, scd->host, sizeof(scd->host), &scd->port))
189 return -E_ADDRESS_LOOKUP;
190 return 1;
191 }
192
193 static int udp_com_on(__a_unused struct sender_command_data *scd)
194 {
195 sender_status = SENDER_on;
196 return 1;
197 }
198
199 static int udp_com_off(__a_unused struct sender_command_data *scd)
200 {
201 udp_shutdown_targets();
202 sender_status = SENDER_off;
203 return 1;
204 }
205
206 static struct sender_client *udp_lookup_target(struct sender_command_data *scd)
207 {
208 struct sender_client *sc, *tmp;
209 char host[MAX_HOSTLEN];
210 int32_t port;
211
212 list_for_each_entry_safe(sc, tmp, &targets, node) {
213 parse_url(sc->name, host, sizeof(host), &port);
214
215 /* Unspecified port means wildcard port match */
216 if (scd->port > 0 && scd->port != port)
217 continue;
218 if (strcmp(host, scd->host))
219 continue;
220 return sc;
221 }
222 return NULL;
223 }
224
225 static int udp_com_delete(struct sender_command_data *scd)
226 {
227 struct sender_client *sc = udp_lookup_target(scd);
228
229 if (sc) {
230 udp_delete_target(sc, "com_delete");
231 return 1;
232 }
233 PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd->host);
234 return -E_TARGET_NOT_FOUND;
235 }
236
237 /** Initialize UDP session and set maximum payload size. */
238 static int udp_init_fec(struct sender_client *sc)
239 {
240 struct udp_target *ut = sc->private_data;
241 int mps;
242
243 PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
244 ut->sent_fec_eof = false;
245 mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
246 PARA_INFO_LOG("current MPS = %d bytes\n", mps);
247 return mps;
248 }
249
250 /** Check and clear socket error if any. */
251 static int udp_check_socket_state(struct sender_client *sc)
252 {
253 struct udp_target *ut = sc->private_data;
254 int ret;
255 socklen_t errlen = sizeof(ret);
256
257 if (getsockopt(sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
258 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
259 return 0;
260 } else if (ret == 0) {
261 return 0;
262 } else if (ret == ECONNREFUSED) {
263 time_t dist = now->tv_sec - ut->last_unreachable;
264
265 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
266 return 0;
267 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
268 ut->last_unreachable = now->tv_sec;
269 return 0;
270 } else {
271 /*
272 * unreachable_time < dist <= 2 * unreachable_time
273 * No errors are allowed during this time window.
274 */
275 PARA_NOTICE_LOG("Evicting %s after %d seconds "
276 "of connection errors.\n",
277 sc->name, (int)dist);
278 }
279 }
280 return -ERRNO_TO_PARA_ERROR(ret);
281 }
282
283 static void udp_send_fec(struct sender_client *sc, char *buf, size_t len)
284 {
285 int ret;
286
287 if (sender_status == SENDER_off)
288 return;
289 if (len == 0)
290 return;
291 ret = udp_check_socket_state(sc);
292 if (ret < 0)
293 goto fail;
294 ret = xwrite(sc->fd, buf, len);
295 if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
296 /*
297 * Happens if meanwhile an ICMP Destination / Port Unreachable
298 * has arrived. Ignore, persistent errors will be caught above.
299 */
300 ret = 0;
301 }
302 if (ret < 0)
303 goto fail;
304 return;
305 fail:
306 udp_delete_target(sc, para_strerror(-ret));
307 }
308
309 static int udp_com_add(struct sender_command_data *scd)
310 {
311 int ret;
312 struct udp_target *ut;
313 struct sender_client *sc = udp_lookup_target(scd);
314
315 if (sc) {
316 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
317 sc->name);
318 return -E_TARGET_EXISTS;
319 }
320 ut = para_calloc(sizeof(*ut));
321 sc = para_calloc(sizeof(*sc));
322 ut->fcp.slices_per_group = scd->slices_per_group;
323 ut->fcp.data_slices_per_group = scd->data_slices_per_group;
324 ut->fcp.init_fec = udp_init_fec;
325 ut->fcp.send_fec = udp_send_fec;
326 ut->fcp.need_periodic_header = true;
327
328 sc->private_data = ut;
329 sc->fd = -1;
330 ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
331 if (ret < 0)
332 goto err;
333 sc->fd = ret;
334
335 ret = mcast_sender_setup(sc);
336 if (ret < 0)
337 goto err;
338 ret = mark_fd_nonblocking(sc->fd);
339 if (ret < 0)
340 goto err;
341 sc->name = para_strdup(remote_name(sc->fd));
342 PARA_INFO_LOG("adding to target list (%s)\n", sc->name);
343 ut->fc = vss_add_fec_client(sc, &ut->fcp);
344 para_list_add(&sc->node, &targets);
345 add_close_on_fork_list(sc->fd);
346 return 1;
347 err:
348 if (sc->fd >= 0)
349 close(sc->fd);
350 PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
351 scd->host, scd->port, para_strerror(-ret));
352 free(sc);
353 free(ut);
354 return ret;
355 }
356
357 static char *udp_status(void)
358 {
359 struct sender_client *sc;
360 char *ret, *tgts = NULL;
361
362 list_for_each_entry(sc, &targets, node) {
363 struct udp_target *ut = sc->private_data;
364 char *tmp = make_message("%s%s/%u:%u ",
365 tgts ? : "", sc->name,
366 ut->fcp.data_slices_per_group,
367 ut->fcp.slices_per_group
368 );
369 free(tgts);
370 tgts = tmp;
371 }
372 ret = make_message(
373 "status: %s\n"
374 "port: %s\n"
375 "targets: %s\n",
376 (sender_status == SENDER_on)? "on" : "off",
377 stringify_port(OPT_UINT32_VAL(UDP_DEFAULT_PORT), "udp"),
378 tgts? tgts : "(none)"
379 );
380 free(tgts);
381 return ret;
382 }
383
384 static void udp_init_target_list(void)
385 {
386 struct sender_command_data scd;
387 int i;
388
389 INIT_LIST_HEAD(&targets);
390 for (i = 0; i < OPT_GIVEN(UDP_TARGET); i++) {
391 const char *arg = lls_string_val(i, OPT_RESULT(UDP_TARGET));
392 if (udp_resolve_target(arg, &scd) < 0)
393 PARA_CRIT_LOG("not adding requested target '%s'\n",
394 arg);
395 else
396 udp_com_add(&scd);
397 }
398 }
399
400 static char *udp_help(void)
401 {
402 return make_message(
403 "usage: {on|off}\n"
404 "usage: {add|delete} ip_address[:port][/[packet_size:]k:n]\n"
405 " - k is the number of data slices per FEC group\n"
406 " - n is the total number of slices in a FEC group\n"
407 " - packet_size reduces the slice size below path MTU\n\n"
408 "examples: add 224.0.1.38:1500 (IPv4 multicast)\n"
409 " add 224.0.1.38:8080/14:16 (explicit FEC)\n"
410 " add 10.10.1.42 (using default port)\n"
411 " add [FF05::42]:1500 (IPv6 multicast)\n"
412 " add [::1] (IPv6 localhost/default port)\n"
413 " delete myhost.net (host with port wildcard)\n"
414 " delete 10.1.2.3:456 (IPv4 with explicit port)\n"
415 " delete [badc0de::1] (IPv6 with port wildcard)\n"
416 );
417 }
418
419 /**
420 * The init function of para_server's udp sender.
421 *
422 * \param s Pointer to the udp sender struct.
423 *
424 * It initializes all function pointers of \a s and the list of udp targets.
425 */
426 void udp_send_init(struct sender *s)
427 {
428 INIT_LIST_HEAD(&targets);
429 s->status = udp_status;
430 s->help = udp_help;
431 s->send = NULL;
432 s->pre_select = NULL;
433 s->post_select = NULL;
434 s->shutdown_clients = udp_shutdown_targets;
435 s->resolve_target = udp_resolve_target;
436 s->client_cmds[SENDER_on] = udp_com_on;
437 s->client_cmds[SENDER_off] = udp_com_off;
438 s->client_cmds[SENDER_deny] = NULL;
439 s->client_cmds[SENDER_allow] = NULL;
440 s->client_cmds[SENDER_add] = udp_com_add;
441 s->client_cmds[SENDER_delete] = udp_com_delete;
442 sender_status = SENDER_off;
443 udp_init_target_list();
444 if (!OPT_GIVEN(UDP_NO_AUTOSTART))
445 sender_status = SENDER_on;
446 PARA_DEBUG_LOG("udp sender init complete\n");
447 }