para.h: Fix typo in comment.
[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 /** Common sender client data */
47 struct sender_client *sc;
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 if (sc->cq != NULL) {
60 del_close_on_fork_list(sc->fd);
61 cq_destroy(sc->cq);
62 sc->cq = NULL;
63 }
64 }
65
66 static void udp_delete_target(struct sender_client *sc, const char *msg)
67 {
68 struct udp_target *ut = sc->private_data;
69
70 PARA_NOTICE_LOG("deleting %s (%s) from list\n", sc->name, msg);
71 udp_close_target(sc);
72 vss_del_fec_client(ut->fc);
73 list_del(&sc->node);
74 free(sc->name);
75 free(sc);
76 free(ut);
77 }
78
79 /**
80 * Perform AF-independent multicast sender setup.
81 *
82 * \param sc The connected sender client.
83 *
84 * \return Zero if okay, negative on error.
85 */
86 static int mcast_sender_setup(struct sender_client *sc)
87 {
88 struct sockaddr_storage ss;
89 socklen_t sslen = sizeof(ss);
90 int ttl = conf.udp_ttl_arg, id = 0;
91 const int on = 1;
92
93 if (conf.udp_mcast_iface_given) {
94 char *iface = conf.udp_mcast_iface_arg;
95
96 id = if_nametoindex(iface);
97 if (id == 0)
98 PARA_WARNING_LOG("could not resolve interface '%s', "
99 "using default", iface);
100 }
101
102 if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
103 goto err;
104 assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
105
106 /* RFC 3493, 5.2: -1 means 'use kernel default' */
107 if (ttl < 0 || ttl > 255)
108 ttl = -1;
109
110 switch (ss.ss_family) {
111 case AF_INET:
112 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
113 return 0;
114 if (id != 0) {
115 #ifdef HAVE_IP_MREQN
116 struct ip_mreqn mn;
117
118 memset(&mn, 0, sizeof(mn));
119 mn.imr_ifindex = id;
120 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
121 goto err;
122 #else
123 PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
124 #endif
125 }
126 /*
127 * Enable receiving multicast messages generated on the local host
128 * At least on Linux, this is enabled by default.
129 */
130 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
131 break;
132
133 /* Default: use local subnet (do not flood out into the WAN) */
134 if (ttl == -1)
135 ttl = 1;
136 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
137 break;
138 return 0;
139 case AF_INET6:
140 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
141 return 0;
142 if (id != 0 &&
143 setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
144 break;
145 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
146 break;
147 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
148 break;
149 return 0;
150 }
151 err:
152 return -ERRNO_TO_PARA_ERROR(errno);
153 }
154
155 /** The maximal size of the per-target chunk queue. */
156 #define UDP_CQ_BYTES 40000
157
158 static void udp_init_session(struct sender_client *sc)
159 {
160 if (sc->cq == NULL) {
161 sc->cq = cq_new(UDP_CQ_BYTES);
162 add_close_on_fork_list(sc->fd);
163 PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
164 }
165 }
166
167 static void udp_shutdown_targets(void)
168 {
169 struct sender_client *sc, *tmp;
170 const char *buf;
171 size_t len = vss_get_fec_eof_packet(&buf);
172
173 list_for_each_entry_safe(sc, tmp, &targets, node)
174 if (sc->cq != NULL) {
175 /* ignore return value, closing the target anyway. */
176 (void)write(sc->fd, buf, len);
177 udp_close_target(sc);
178 }
179 }
180
181 static int udp_resolve_target(const char *url, struct sender_command_data *scd)
182 {
183 const char *result;
184 int ret, port;
185
186 ret = parse_fec_url(url, scd);
187 if (ret)
188 return ret;
189 port = scd->port > 0 ? scd->port : conf.udp_default_port_arg;
190
191 ret = para_connect_simple(IPPROTO_UDP, scd->host, port);
192 if (ret < 0)
193 return ret;
194
195 result = remote_name(ret);
196 close(ret);
197
198 if (!parse_url(result, scd->host, sizeof(scd->host), &scd->port))
199 return -E_ADDRESS_LOOKUP;
200 return 1;
201 }
202
203 static int udp_com_on(__a_unused struct sender_command_data *scd)
204 {
205 sender_status = SENDER_ON;
206 return 1;
207 }
208
209 static int udp_com_off(__a_unused struct sender_command_data *scd)
210 {
211 udp_shutdown_targets();
212 sender_status = SENDER_OFF;
213 return 1;
214 }
215
216 static struct sender_client *udp_lookup_target(struct sender_command_data *scd)
217 {
218 struct sender_client *sc, *tmp;
219 char host[MAX_HOSTLEN];
220 int32_t port;
221
222 list_for_each_entry_safe(sc, tmp, &targets, node) {
223 parse_url(sc->name, host, sizeof(host), &port);
224
225 /* Unspecified port means wildcard port match */
226 if (scd->port > 0 && scd->port != port)
227 continue;
228 if (strcmp(host, scd->host))
229 continue;
230 return sc;
231 }
232 return NULL;
233 }
234
235 static int udp_com_delete(struct sender_command_data *scd)
236 {
237 struct sender_client *sc = udp_lookup_target(scd);
238
239 if (sc) {
240 udp_delete_target(sc, "com_delete");
241 return 1;
242 }
243 PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd->host);
244 return -E_TARGET_NOT_FOUND;
245 }
246
247 /** Initialize UDP session and set maximum payload size. */
248 static int udp_init_fec(struct sender_client *sc)
249 {
250 int mps;
251
252 udp_init_session(sc);
253 mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
254 PARA_INFO_LOG("current MPS = %d bytes\n", mps);
255 return mps;
256 }
257
258 /** Check and clear socket error if any. */
259 static int udp_check_socket_state(struct sender_client *sc)
260 {
261 struct udp_target *ut = sc->private_data;
262 int ret;
263 socklen_t errlen = sizeof(ret);
264
265 if (getsockopt(sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
266 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
267 return 0;
268 } else if (ret == 0) {
269 return 0;
270 } else if (ret == ECONNREFUSED) {
271 time_t dist = now->tv_sec - ut->last_unreachable;
272
273 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
274 return 0;
275 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
276 ut->last_unreachable = now->tv_sec;
277 return 0;
278 } else {
279 /*
280 * unreachable_time < dist <= 2 * unreachable_time
281 * No errors are allowed during this time window.
282 */
283 PARA_NOTICE_LOG("Evicting %s after %d seconds "
284 "of connection errors.\n",
285 sc->name, (int)dist);
286 }
287 }
288 return -ERRNO_TO_PARA_ERROR(ret);
289 }
290
291 static int udp_send_fec(struct sender_client *sc, char *buf, size_t len)
292 {
293 int ret;
294
295 if (sender_status == SENDER_OFF)
296 return 0;
297 if (len == 0 && !cq_peek(sc->cq))
298 return 0;
299 ret = udp_check_socket_state(sc);
300 if (ret < 0)
301 goto fail;
302 ret = send_queued_chunks(sc->fd, sc->cq);
303 if (ret < 0)
304 goto fail;
305 if (!ret) { /* still data left in the queue */
306 ret = cq_force_enqueue(sc->cq, buf, len);
307 assert(ret >= 0);
308 return 0;
309 }
310 ret = write_nonblock(sc->fd, buf, len);
311 if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
312 /*
313 * Happens if meanwhile an ICMP Destination / Port Unreachable
314 * has arrived. Ignore, persistent errors will be caught above.
315 */
316 ret = 0;
317 }
318 if (ret < 0)
319 goto fail;
320 if (ret != len) {
321 ret = cq_force_enqueue(sc->cq, buf + ret, len - ret);
322 assert(ret >= 0);
323 }
324 return 1;
325 fail:
326 udp_delete_target(sc, para_strerror(-ret));
327 return ret;
328 }
329
330 static int udp_com_add(struct sender_command_data *scd)
331 {
332 int ret;
333 struct udp_target *ut;
334 struct sender_client *sc = udp_lookup_target(scd);
335
336 if (sc) {
337 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
338 sc->name);
339 return -E_TARGET_EXISTS;
340 }
341 ut = para_calloc(sizeof(*ut));
342 sc = ut->sc = para_calloc(sizeof(*sc));
343 ut->fcp.slices_per_group = scd->slices_per_group;
344 ut->fcp.data_slices_per_group = scd->data_slices_per_group;
345 ut->fcp.max_slice_bytes = scd->max_slice_bytes;
346 ut->fcp.init_fec = udp_init_fec;
347 ut->fcp.send_fec = udp_send_fec;
348
349 sc->private_data = ut;
350 sc->fd = -1;
351 ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
352 if (ret < 0)
353 goto err;
354 sc->fd = ret;
355
356 ret = mcast_sender_setup(sc);
357 if (ret < 0)
358 goto err;
359 ret = mark_fd_nonblocking(sc->fd);
360 if (ret < 0)
361 goto err;
362 sc->name = para_strdup(remote_name(sc->fd));
363 PARA_INFO_LOG("adding to target list (%s)\n", sc->name);
364 ut->fc = vss_add_fec_client(sc, &ut->fcp);
365 para_list_add(&sc->node, &targets);
366 return 1;
367 err:
368 if (sc->fd >= 0)
369 close(sc->fd);
370 PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
371 scd->host, scd->port, para_strerror(-ret));
372 free(sc);
373 free(ut);
374 return ret;
375 }
376
377 static char *udp_info(void)
378 {
379 struct sender_client *sc;
380 char *ret, *tgts = NULL;
381
382 list_for_each_entry(sc, &targets, node) {
383 struct udp_target *ut = sc->private_data;
384 char *tmp = make_message("%s%s/%u:%u:%u ",
385 tgts ? : "", sc->name,
386 ut->fcp.max_slice_bytes,
387 ut->fcp.data_slices_per_group,
388 ut->fcp.slices_per_group
389 );
390 free(tgts);
391 tgts = tmp;
392 }
393 ret = make_message(
394 "udp sender:\n"
395 "\tstatus: %s\n"
396 "\tport: %s\n"
397 "\ttargets: %s\n",
398 (sender_status == SENDER_ON)? "on" : "off",
399 stringify_port(conf.udp_default_port_arg, "udp"),
400 tgts? tgts : "(none)"
401 );
402 free(tgts);
403 return ret;
404 }
405
406 static void udp_init_target_list(void)
407 {
408 struct sender_command_data scd;
409 int i;
410
411 INIT_LIST_HEAD(&targets);
412 for (i = 0; i < conf.udp_target_given; i++) {
413 if (udp_resolve_target(conf.udp_target_arg[i], &scd) < 0)
414 PARA_CRIT_LOG("not adding requested target '%s'\n",
415 conf.udp_target_arg[i]);
416 else
417 udp_com_add(&scd);
418 }
419 }
420
421 static char *udp_help(void)
422 {
423 return make_message(
424 "usage: {on|off}\n"
425 "usage: {add|delete} ip_address[:port][/[packet_size:]k:n]\n"
426 " - k is the number of data slices per FEC group\n"
427 " - n is the total number of slices in a FEC group\n"
428 " - packet_size reduces the slice size below path MTU\n\n"
429 "examples: add 224.0.1.38:1500 (IPv4 multicast)\n"
430 " add 224.0.1.38:8080/14:16 (explicit FEC)\n"
431 " add 10.10.1.42 (using default port)\n"
432 " add [FF05::42]:1500 (IPv6 multicast)\n"
433 " add [::1] (IPv6 localhost/default port)\n"
434 " delete myhost.net (host with port wildcard)\n"
435 " delete 10.1.2.3:456 (IPv4 with explicit port)\n"
436 " delete [badc0de::1] (IPv6 with port wildcard)\n"
437 );
438 }
439
440 /**
441 * The init function of para_server's udp sender.
442 *
443 * \param s Pointer to the udp sender struct.
444 *
445 * It initializes all function pointers of \a s and the list of udp targets.
446 */
447 void udp_send_init(struct sender *s)
448 {
449 INIT_LIST_HEAD(&targets);
450 s->info = udp_info;
451 s->help = udp_help;
452 s->send = NULL;
453 s->pre_select = NULL;
454 s->post_select = NULL;
455 s->shutdown_clients = udp_shutdown_targets;
456 s->resolve_target = udp_resolve_target;
457 s->client_cmds[SENDER_ON] = udp_com_on;
458 s->client_cmds[SENDER_OFF] = udp_com_off;
459 s->client_cmds[SENDER_DENY] = NULL;
460 s->client_cmds[SENDER_ALLOW] = NULL;
461 s->client_cmds[SENDER_ADD] = udp_com_add;
462 s->client_cmds[SENDER_DELETE] = udp_com_delete;
463 sender_status = SENDER_OFF;
464 udp_init_target_list();
465 if (!conf.udp_no_autostart_given)
466 sender_status = SENDER_ON;
467 PARA_DEBUG_LOG("udp sender init complete\n");
468 }