vss: Let the transport specify whether periodic headers are necessary.
[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 #include <stdbool.h>
18
19 #include "server.cmdline.h"
20 #include "para.h"
21 #include "error.h"
22 #include "string.h"
23 #include "afh.h"
24 #include "afs.h"
25 #include "server.h"
26 #include "list.h"
27 #include "send.h"
28 #include "vss.h"
29 #include "portable_io.h"
30 #include "net.h"
31 #include "fd.h"
32 #include "sched.h"
33 #include "close_on_fork.h"
34 #include "chunk_queue.h"
35
36 /**
37 * Time window during which ICMP Destination/Port Unreachable messages are
38 * ignored, covering transient receiver problems such as restarting the
39 * client, rebooting, reconfiguration, or handover.
40 */
41 #define UDP_MAX_UNREACHABLE_TIME 30
42
43 /** Describes one entry in the list of targets for the udp sender. */
44 struct udp_target {
45 /** Track time (seconds) of last ICMP Port Unreachable error */
46 time_t last_unreachable;
47 /** Common sender client data */
48 struct sender_client *sc;
49 /** The opaque structure returned by vss_add_fec_client(). */
50 struct fec_client *fc;
51 /** The FEC parameters for this target. */
52 struct fec_client_parms fcp;
53 };
54
55 static struct list_head targets;
56 static int sender_status;
57
58 static void udp_close_target(struct sender_client *sc)
59 {
60 if (sc->cq != NULL) {
61 del_close_on_fork_list(sc->fd);
62 cq_destroy(sc->cq);
63 sc->cq = NULL;
64 }
65 }
66
67 static void udp_delete_target(struct sender_client *sc, const char *msg)
68 {
69 struct udp_target *ut = sc->private_data;
70
71 PARA_NOTICE_LOG("deleting %s (%s) from list\n", sc->name, msg);
72 udp_close_target(sc);
73 vss_del_fec_client(ut->fc);
74 list_del(&sc->node);
75 free(sc->name);
76 free(sc);
77 free(ut);
78 }
79
80 /**
81 * Perform AF-independent multicast sender setup.
82 *
83 * \param sc The connected sender client.
84 *
85 * \return Zero if okay, negative on error.
86 */
87 static int mcast_sender_setup(struct sender_client *sc)
88 {
89 struct sockaddr_storage ss;
90 socklen_t sslen = sizeof(ss);
91 int ttl = conf.udp_ttl_arg, id = 0;
92 const int on = 1;
93
94 if (conf.udp_mcast_iface_given) {
95 char *iface = conf.udp_mcast_iface_arg;
96
97 id = if_nametoindex(iface);
98 if (id == 0)
99 PARA_WARNING_LOG("could not resolve interface '%s', "
100 "using default", iface);
101 }
102
103 if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
104 goto err;
105 assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
106
107 /* RFC 3493, 5.2: -1 means 'use kernel default' */
108 if (ttl < 0 || ttl > 255)
109 ttl = -1;
110
111 switch (ss.ss_family) {
112 case AF_INET:
113 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
114 return 0;
115 if (id != 0) {
116 #ifdef HAVE_IP_MREQN
117 struct ip_mreqn mn;
118
119 memset(&mn, 0, sizeof(mn));
120 mn.imr_ifindex = id;
121 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
122 goto err;
123 #else
124 PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
125 #endif
126 }
127 /*
128 * Enable receiving multicast messages generated on the local host
129 * At least on Linux, this is enabled by default.
130 */
131 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
132 break;
133
134 /* Default: use local subnet (do not flood out into the WAN) */
135 if (ttl == -1)
136 ttl = 1;
137 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
138 break;
139 return 0;
140 case AF_INET6:
141 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
142 return 0;
143 if (id != 0 &&
144 setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
145 break;
146 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
147 break;
148 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
149 break;
150 return 0;
151 }
152 err:
153 return -ERRNO_TO_PARA_ERROR(errno);
154 }
155
156 /** The maximal size of the per-target chunk queue. */
157 #define UDP_CQ_BYTES 40000
158
159 static void udp_init_session(struct sender_client *sc)
160 {
161 if (sc->cq == NULL) {
162 sc->cq = cq_new(UDP_CQ_BYTES);
163 add_close_on_fork_list(sc->fd);
164 PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
165 }
166 }
167
168 static void udp_shutdown_targets(void)
169 {
170 struct sender_client *sc, *tmp;
171 const char *buf;
172 size_t len = vss_get_fec_eof_packet(&buf);
173
174 list_for_each_entry_safe(sc, tmp, &targets, node)
175 if (sc->cq != NULL) {
176 /* ignore return value, closing the target anyway. */
177 (void)write(sc->fd, buf, len);
178 udp_close_target(sc);
179 }
180 }
181
182 static int udp_resolve_target(const char *url, struct sender_command_data *scd)
183 {
184 const char *result;
185 int ret, port;
186
187 ret = parse_fec_url(url, scd);
188 if (ret)
189 return ret;
190 port = scd->port > 0 ? scd->port : conf.udp_default_port_arg;
191
192 ret = para_connect_simple(IPPROTO_UDP, scd->host, port);
193 if (ret < 0)
194 return ret;
195
196 result = remote_name(ret);
197 close(ret);
198
199 if (!parse_url(result, scd->host, sizeof(scd->host), &scd->port))
200 return -E_ADDRESS_LOOKUP;
201 return 1;
202 }
203
204 static int udp_com_on(__a_unused struct sender_command_data *scd)
205 {
206 sender_status = SENDER_ON;
207 return 1;
208 }
209
210 static int udp_com_off(__a_unused struct sender_command_data *scd)
211 {
212 udp_shutdown_targets();
213 sender_status = SENDER_OFF;
214 return 1;
215 }
216
217 static struct sender_client *udp_lookup_target(struct sender_command_data *scd)
218 {
219 struct sender_client *sc, *tmp;
220 char host[MAX_HOSTLEN];
221 int32_t port;
222
223 list_for_each_entry_safe(sc, tmp, &targets, node) {
224 parse_url(sc->name, host, sizeof(host), &port);
225
226 /* Unspecified port means wildcard port match */
227 if (scd->port > 0 && scd->port != port)
228 continue;
229 if (strcmp(host, scd->host))
230 continue;
231 return sc;
232 }
233 return NULL;
234 }
235
236 static int udp_com_delete(struct sender_command_data *scd)
237 {
238 struct sender_client *sc = udp_lookup_target(scd);
239
240 if (sc) {
241 udp_delete_target(sc, "com_delete");
242 return 1;
243 }
244 PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd->host);
245 return -E_TARGET_NOT_FOUND;
246 }
247
248 /** Initialize UDP session and set maximum payload size. */
249 static int udp_init_fec(struct sender_client *sc)
250 {
251 int mps;
252
253 udp_init_session(sc);
254 mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
255 PARA_INFO_LOG("current MPS = %d bytes\n", mps);
256 return mps;
257 }
258
259 /** Check and clear socket error if any. */
260 static int udp_check_socket_state(struct sender_client *sc)
261 {
262 struct udp_target *ut = sc->private_data;
263 int ret;
264 socklen_t errlen = sizeof(ret);
265
266 if (getsockopt(sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
267 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
268 return 0;
269 } else if (ret == 0) {
270 return 0;
271 } else if (ret == ECONNREFUSED) {
272 time_t dist = now->tv_sec - ut->last_unreachable;
273
274 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
275 return 0;
276 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
277 ut->last_unreachable = now->tv_sec;
278 return 0;
279 } else {
280 /*
281 * unreachable_time < dist <= 2 * unreachable_time
282 * No errors are allowed during this time window.
283 */
284 PARA_NOTICE_LOG("Evicting %s after %d seconds "
285 "of connection errors.\n",
286 sc->name, (int)dist);
287 }
288 }
289 return -ERRNO_TO_PARA_ERROR(ret);
290 }
291
292 static int udp_send_fec(struct sender_client *sc, char *buf, size_t len)
293 {
294 int ret;
295
296 if (sender_status == SENDER_OFF)
297 return 0;
298 if (len == 0 && !cq_peek(sc->cq))
299 return 0;
300 ret = udp_check_socket_state(sc);
301 if (ret < 0)
302 goto fail;
303 ret = send_queued_chunks(sc->fd, sc->cq);
304 if (ret < 0)
305 goto fail;
306 if (!ret) { /* still data left in the queue */
307 ret = cq_force_enqueue(sc->cq, buf, len);
308 assert(ret >= 0);
309 return 0;
310 }
311 ret = write_nonblock(sc->fd, buf, len);
312 if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
313 /*
314 * Happens if meanwhile an ICMP Destination / Port Unreachable
315 * has arrived. Ignore, persistent errors will be caught above.
316 */
317 ret = 0;
318 }
319 if (ret < 0)
320 goto fail;
321 if (ret != len) {
322 ret = cq_force_enqueue(sc->cq, buf + ret, len - ret);
323 assert(ret >= 0);
324 }
325 return 1;
326 fail:
327 udp_delete_target(sc, para_strerror(-ret));
328 return ret;
329 }
330
331 static int udp_com_add(struct sender_command_data *scd)
332 {
333 int ret;
334 struct udp_target *ut;
335 struct sender_client *sc = udp_lookup_target(scd);
336
337 if (sc) {
338 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
339 sc->name);
340 return -E_TARGET_EXISTS;
341 }
342 ut = para_calloc(sizeof(*ut));
343 sc = ut->sc = para_calloc(sizeof(*sc));
344 ut->fcp.slices_per_group = scd->slices_per_group;
345 ut->fcp.data_slices_per_group = scd->data_slices_per_group;
346 ut->fcp.init_fec = udp_init_fec;
347 ut->fcp.send_fec = udp_send_fec;
348 ut->fcp.need_periodic_header = true;
349
350 sc->private_data = ut;
351 sc->fd = -1;
352 ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
353 if (ret < 0)
354 goto err;
355 sc->fd = ret;
356
357 ret = mcast_sender_setup(sc);
358 if (ret < 0)
359 goto err;
360 ret = mark_fd_nonblocking(sc->fd);
361 if (ret < 0)
362 goto err;
363 sc->name = para_strdup(remote_name(sc->fd));
364 PARA_INFO_LOG("adding to target list (%s)\n", sc->name);
365 ut->fc = vss_add_fec_client(sc, &ut->fcp);
366 para_list_add(&sc->node, &targets);
367 return 1;
368 err:
369 if (sc->fd >= 0)
370 close(sc->fd);
371 PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
372 scd->host, scd->port, para_strerror(-ret));
373 free(sc);
374 free(ut);
375 return ret;
376 }
377
378 static char *udp_info(void)
379 {
380 struct sender_client *sc;
381 char *ret, *tgts = NULL;
382
383 list_for_each_entry(sc, &targets, node) {
384 struct udp_target *ut = sc->private_data;
385 char *tmp = make_message("%s%s/%u:%u ",
386 tgts ? : "", sc->name,
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 }