Remove unused field "sc" of struct udp_target.
[paraslash.git] / udp_send.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 udp_send.c Para_server's udp sender. */
8
9
10 #include <regex.h>
11 #include <sys/time.h>
12 #include <dirent.h>
13 #include <sys/socket.h>
14 #include <netinet/udp.h>
15 #include <net/if.h>
16 #include <osl.h>
17
18 #include "server.cmdline.h"
19 #include "para.h"
20 #include "error.h"
21 #include "string.h"
22 #include "afh.h"
23 #include "afs.h"
24 #include "server.h"
25 #include "list.h"
26 #include "send.h"
27 #include "vss.h"
28 #include "portable_io.h"
29 #include "net.h"
30 #include "fd.h"
31 #include "sched.h"
32 #include "close_on_fork.h"
33 #include "chunk_queue.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 };
51
52 static struct list_head targets;
53 static int sender_status;
54
55 static void udp_close_target(struct sender_client *sc)
56 {
57 if (sc->cq != NULL) {
58 cq_destroy(sc->cq);
59 sc->cq = NULL;
60 }
61 }
62
63 static void udp_delete_target(struct sender_client *sc, const char *msg)
64 {
65 struct udp_target *ut = sc->private_data;
66
67 PARA_NOTICE_LOG("deleting %s (%s) from list\n", sc->name, msg);
68 udp_close_target(sc);
69 close(sc->fd);
70 del_close_on_fork_list(sc->fd);
71 vss_del_fec_client(ut->fc);
72 list_del(&sc->node);
73 free(sc->name);
74 free(sc);
75 free(ut);
76 }
77
78 /**
79 * Perform AF-independent multicast sender setup.
80 *
81 * \param sc The connected sender client.
82 *
83 * \return Zero if okay, negative on error.
84 */
85 static int mcast_sender_setup(struct sender_client *sc)
86 {
87 struct sockaddr_storage ss;
88 socklen_t sslen = sizeof(ss);
89 int ttl = conf.udp_ttl_arg, id = 0;
90 const int on = 1;
91
92 if (conf.udp_mcast_iface_given) {
93 char *iface = conf.udp_mcast_iface_arg;
94
95 id = if_nametoindex(iface);
96 if (id == 0)
97 PARA_WARNING_LOG("could not resolve interface '%s', "
98 "using default", iface);
99 }
100
101 if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
102 goto err;
103 assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
104
105 /* RFC 3493, 5.2: -1 means 'use kernel default' */
106 if (ttl < 0 || ttl > 255)
107 ttl = -1;
108
109 switch (ss.ss_family) {
110 case AF_INET:
111 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
112 return 0;
113 if (id != 0) {
114 #ifdef HAVE_IP_MREQN
115 struct ip_mreqn mn;
116
117 memset(&mn, 0, sizeof(mn));
118 mn.imr_ifindex = id;
119 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
120 goto err;
121 #else
122 PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
123 #endif
124 }
125 /*
126 * Enable receiving multicast messages generated on the local host
127 * At least on Linux, this is enabled by default.
128 */
129 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
130 break;
131
132 /* Default: use local subnet (do not flood out into the WAN) */
133 if (ttl == -1)
134 ttl = 1;
135 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
136 break;
137 return 0;
138 case AF_INET6:
139 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
140 return 0;
141 if (id != 0 &&
142 setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
143 break;
144 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
145 break;
146 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
147 break;
148 return 0;
149 }
150 err:
151 return -ERRNO_TO_PARA_ERROR(errno);
152 }
153
154 /** The maximal size of the per-target chunk queue. */
155 #define UDP_CQ_BYTES 40000
156
157 static void udp_init_session(struct sender_client *sc)
158 {
159 if (sc->cq == NULL) {
160 sc->cq = cq_new(UDP_CQ_BYTES);
161 PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
162 }
163 }
164
165 static void udp_shutdown_targets(void)
166 {
167 struct sender_client *sc, *tmp;
168 const char *buf;
169 size_t len = vss_get_fec_eof_packet(&buf);
170
171 list_for_each_entry_safe(sc, tmp, &targets, node)
172 if (sc->cq != NULL) {
173 /* ignore return value, closing the target anyway. */
174 (void)write(sc->fd, buf, len);
175 udp_close_target(sc);
176 }
177 }
178
179 static int udp_resolve_target(const char *url, struct sender_command_data *scd)
180 {
181 const char *result;
182 int ret, port;
183
184 ret = parse_fec_url(url, scd);
185 if (ret)
186 return ret;
187 port = scd->port > 0 ? scd->port : conf.udp_default_port_arg;
188
189 ret = para_connect_simple(IPPROTO_UDP, scd->host, port);
190 if (ret < 0)
191 return ret;
192
193 result = remote_name(ret);
194 close(ret);
195
196 if (!parse_url(result, scd->host, sizeof(scd->host), &scd->port))
197 return -E_ADDRESS_LOOKUP;
198 return 1;
199 }
200
201 static int udp_com_on(__a_unused struct sender_command_data *scd)
202 {
203 sender_status = SENDER_ON;
204 return 1;
205 }
206
207 static int udp_com_off(__a_unused struct sender_command_data *scd)
208 {
209 udp_shutdown_targets();
210 sender_status = SENDER_OFF;
211 return 1;
212 }
213
214 static struct sender_client *udp_lookup_target(struct sender_command_data *scd)
215 {
216 struct sender_client *sc, *tmp;
217 char host[MAX_HOSTLEN];
218 int32_t port;
219
220 list_for_each_entry_safe(sc, tmp, &targets, node) {
221 parse_url(sc->name, host, sizeof(host), &port);
222
223 /* Unspecified port means wildcard port match */
224 if (scd->port > 0 && scd->port != port)
225 continue;
226 if (strcmp(host, scd->host))
227 continue;
228 return sc;
229 }
230 return NULL;
231 }
232
233 static int udp_com_delete(struct sender_command_data *scd)
234 {
235 struct sender_client *sc = udp_lookup_target(scd);
236
237 if (sc) {
238 udp_delete_target(sc, "com_delete");
239 return 1;
240 }
241 PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd->host);
242 return -E_TARGET_NOT_FOUND;
243 }
244
245 /** Initialize UDP session and set maximum payload size. */
246 static int udp_init_fec(struct sender_client *sc)
247 {
248 int mps;
249
250 udp_init_session(sc);
251 mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
252 PARA_INFO_LOG("current MPS = %d bytes\n", mps);
253 return mps;
254 }
255
256 /** Check and clear socket error if any. */
257 static int udp_check_socket_state(struct sender_client *sc)
258 {
259 struct udp_target *ut = sc->private_data;
260 int ret;
261 socklen_t errlen = sizeof(ret);
262
263 if (getsockopt(sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
264 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
265 return 0;
266 } else if (ret == 0) {
267 return 0;
268 } else if (ret == ECONNREFUSED) {
269 time_t dist = now->tv_sec - ut->last_unreachable;
270
271 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
272 return 0;
273 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
274 ut->last_unreachable = now->tv_sec;
275 return 0;
276 } else {
277 /*
278 * unreachable_time < dist <= 2 * unreachable_time
279 * No errors are allowed during this time window.
280 */
281 PARA_NOTICE_LOG("Evicting %s after %d seconds "
282 "of connection errors.\n",
283 sc->name, (int)dist);
284 }
285 }
286 return -ERRNO_TO_PARA_ERROR(ret);
287 }
288
289 static int udp_send_fec(struct sender_client *sc, char *buf, size_t len)
290 {
291 int ret;
292
293 if (sender_status == SENDER_OFF)
294 return 0;
295 if (len == 0 && !cq_peek(sc->cq))
296 return 0;
297 ret = udp_check_socket_state(sc);
298 if (ret < 0)
299 goto fail;
300 ret = send_queued_chunks(sc->fd, sc->cq);
301 if (ret < 0)
302 goto fail;
303 if (!ret) { /* still data left in the queue */
304 ret = cq_force_enqueue(sc->cq, buf, len);
305 assert(ret >= 0);
306 return 0;
307 }
308 ret = write_nonblock(sc->fd, buf, len);
309 if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
310 /*
311 * Happens if meanwhile an ICMP Destination / Port Unreachable
312 * has arrived. Ignore, persistent errors will be caught above.
313 */
314 ret = 0;
315 }
316 if (ret < 0)
317 goto fail;
318 if (ret != len) {
319 ret = cq_force_enqueue(sc->cq, buf + ret, len - ret);
320 assert(ret >= 0);
321 }
322 return 1;
323 fail:
324 udp_delete_target(sc, para_strerror(-ret));
325 return ret;
326 }
327
328 static int udp_com_add(struct sender_command_data *scd)
329 {
330 int ret;
331 struct udp_target *ut;
332 struct sender_client *sc = udp_lookup_target(scd);
333
334 if (sc) {
335 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
336 sc->name);
337 return -E_TARGET_EXISTS;
338 }
339 ut = para_calloc(sizeof(*ut));
340 sc = para_calloc(sizeof(*sc));
341 ut->fcp.slices_per_group = scd->slices_per_group;
342 ut->fcp.data_slices_per_group = scd->data_slices_per_group;
343 ut->fcp.init_fec = udp_init_fec;
344 ut->fcp.send_fec = udp_send_fec;
345
346 sc->private_data = ut;
347 sc->fd = -1;
348 ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
349 if (ret < 0)
350 goto err;
351 sc->fd = ret;
352
353 ret = mcast_sender_setup(sc);
354 if (ret < 0)
355 goto err;
356 ret = mark_fd_nonblocking(sc->fd);
357 if (ret < 0)
358 goto err;
359 sc->name = para_strdup(remote_name(sc->fd));
360 PARA_INFO_LOG("adding to target list (%s)\n", sc->name);
361 ut->fc = vss_add_fec_client(sc, &ut->fcp);
362 para_list_add(&sc->node, &targets);
363 add_close_on_fork_list(sc->fd);
364 return 1;
365 err:
366 if (sc->fd >= 0)
367 close(sc->fd);
368 PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
369 scd->host, scd->port, para_strerror(-ret));
370 free(sc);
371 free(ut);
372 return ret;
373 }
374
375 static char *udp_info(void)
376 {
377 struct sender_client *sc;
378 char *ret, *tgts = NULL;
379
380 list_for_each_entry(sc, &targets, node) {
381 struct udp_target *ut = sc->private_data;
382 char *tmp = make_message("%s%s/%u:%u ",
383 tgts ? : "", sc->name,
384 ut->fcp.data_slices_per_group,
385 ut->fcp.slices_per_group
386 );
387 free(tgts);
388 tgts = tmp;
389 }
390 ret = make_message(
391 "udp sender:\n"
392 "\tstatus: %s\n"
393 "\tport: %s\n"
394 "\ttargets: %s\n",
395 (sender_status == SENDER_ON)? "on" : "off",
396 stringify_port(conf.udp_default_port_arg, "udp"),
397 tgts? tgts : "(none)"
398 );
399 free(tgts);
400 return ret;
401 }
402
403 static void udp_init_target_list(void)
404 {
405 struct sender_command_data scd;
406 int i;
407
408 INIT_LIST_HEAD(&targets);
409 for (i = 0; i < conf.udp_target_given; i++) {
410 if (udp_resolve_target(conf.udp_target_arg[i], &scd) < 0)
411 PARA_CRIT_LOG("not adding requested target '%s'\n",
412 conf.udp_target_arg[i]);
413 else
414 udp_com_add(&scd);
415 }
416 }
417
418 static char *udp_help(void)
419 {
420 return make_message(
421 "usage: {on|off}\n"
422 "usage: {add|delete} ip_address[:port][/[packet_size:]k:n]\n"
423 " - k is the number of data slices per FEC group\n"
424 " - n is the total number of slices in a FEC group\n"
425 " - packet_size reduces the slice size below path MTU\n\n"
426 "examples: add 224.0.1.38:1500 (IPv4 multicast)\n"
427 " add 224.0.1.38:8080/14:16 (explicit FEC)\n"
428 " add 10.10.1.42 (using default port)\n"
429 " add [FF05::42]:1500 (IPv6 multicast)\n"
430 " add [::1] (IPv6 localhost/default port)\n"
431 " delete myhost.net (host with port wildcard)\n"
432 " delete 10.1.2.3:456 (IPv4 with explicit port)\n"
433 " delete [badc0de::1] (IPv6 with port wildcard)\n"
434 );
435 }
436
437 /**
438 * The init function of para_server's udp sender.
439 *
440 * \param s Pointer to the udp sender struct.
441 *
442 * It initializes all function pointers of \a s and the list of udp targets.
443 */
444 void udp_send_init(struct sender *s)
445 {
446 INIT_LIST_HEAD(&targets);
447 s->info = udp_info;
448 s->help = udp_help;
449 s->send = NULL;
450 s->pre_select = NULL;
451 s->post_select = NULL;
452 s->shutdown_clients = udp_shutdown_targets;
453 s->resolve_target = udp_resolve_target;
454 s->client_cmds[SENDER_ON] = udp_com_on;
455 s->client_cmds[SENDER_OFF] = udp_com_off;
456 s->client_cmds[SENDER_DENY] = NULL;
457 s->client_cmds[SENDER_ALLOW] = NULL;
458 s->client_cmds[SENDER_ADD] = udp_com_add;
459 s->client_cmds[SENDER_DELETE] = udp_com_delete;
460 sender_status = SENDER_OFF;
461 udp_init_target_list();
462 if (!conf.udp_no_autostart_given)
463 sender_status = SENDER_ON;
464 PARA_DEBUG_LOG("udp sender init complete\n");
465 }