udp: refuse to add the same target twice
[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 udp_target *ut, const char *msg)
67 {
68 PARA_NOTICE_LOG("deleting %s (%s) from list\n", ut->sc->name, msg);
69 udp_close_target(ut->sc);
70 vss_del_fec_client(ut->fc);
71 list_del(&ut->sc->node);
72 free(ut->sc->name);
73 free(ut->sc);
74 free(ut);
75 }
76
77 /**
78 * Perform AF-independent multicast sender setup.
79 *
80 * \param sc The connected sender client.
81 *
82 * \return Zero if okay, negative on error.
83 */
84 static int mcast_sender_setup(struct sender_client *sc)
85 {
86 struct sockaddr_storage ss;
87 socklen_t sslen = sizeof(ss);
88 int ttl = conf.udp_ttl_arg, id = 0;
89 const int on = 1;
90
91 if (conf.udp_mcast_iface_given) {
92 char *iface = conf.udp_mcast_iface_arg;
93
94 id = if_nametoindex(iface);
95 if (id == 0)
96 PARA_WARNING_LOG("could not resolve interface '%s', "
97 "using default", iface);
98 }
99
100 if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
101 goto err;
102
103 /* RFC 3493, 5.2: -1 means 'use kernel default' */
104 if (ttl < 0 || ttl > 255)
105 ttl = -1;
106
107 switch (ss.ss_family) {
108 case AF_INET:
109 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
110 return 0;
111 if (id != 0) {
112 #ifdef HAVE_IP_MREQN
113 struct ip_mreqn mn;
114
115 memset(&mn, 0, sizeof(mn));
116 mn.imr_ifindex = id;
117 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
118 goto err;
119 #else
120 PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
121 #endif
122 }
123 /*
124 * Enable receiving multicast messages generated on the local host
125 * At least on Linux, this is enabled by default.
126 */
127 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
128 break;
129
130 /* Default: use local subnet (do not flood out into the WAN) */
131 if (ttl == -1)
132 ttl = 1;
133 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
134 break;
135 return 0;
136 case AF_INET6:
137 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
138 return 0;
139 if (id != 0 &&
140 setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
141 break;
142 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
143 break;
144 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
145 break;
146 return 0;
147 default:
148 PARA_ERROR_LOG("address family %d not supported", ss.ss_family);
149 return -E_ADDRESS_LOOKUP;
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 udp_target *ut = sc->private_data;
238 struct sender_client *sc = udp_lookup_target(scd);
239
240 if (sc) {
241 udp_delete_target(ut, "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 udp_target *ut)
261 {
262 int ret;
263 socklen_t errlen = sizeof(ret);
264
265 if (getsockopt(ut->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 ut->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 struct udp_target *ut = sc->private_data;
294 int ret;
295
296 if (sender_status == SENDER_OFF)
297 return 0;
298 if (len == 0 && !cq_peek(ut->sc->cq))
299 return 0;
300 ret = udp_check_socket_state(ut);
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(ut, 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.max_slice_bytes = scd->max_slice_bytes;
347 ut->fcp.init_fec = udp_init_fec;
348 ut->fcp.send_fec = udp_send_fec;
349
350 ut->sc->private_data = ut;
351 ut->sc->fd = -1;
352 ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
353 if (ret < 0)
354 goto err;
355 ut->sc->fd = ret;
356
357 ret = mcast_sender_setup(ut->sc);
358 if (ret < 0)
359 goto err;
360 ret = mark_fd_nonblocking(ut->sc->fd);
361 if (ret < 0)
362 goto err;
363 ut->sc->name = para_strdup(remote_name(ut->sc->fd));
364 PARA_INFO_LOG("adding to target list (%s)\n", ut->sc->name);
365 ut->fc = vss_add_fec_client(ut->sc, &ut->fcp);
366 para_list_add(&ut->sc->node, &targets);
367 return 1;
368 err:
369 if (ut->sc->fd >= 0)
370 close(ut->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(ut->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:%u ", tgts ? : "",
386 ut->sc->name,
387 ut->fcp.max_slice_bytes,
388 ut->fcp.data_slices_per_group,
389 ut->fcp.slices_per_group
390 );
391 free(tgts);
392 tgts = tmp;
393 }
394 ret = make_message(
395 "udp sender:\n"
396 "\tstatus: %s\n"
397 "\tport: %s\n"
398 "\ttargets: %s\n",
399 (sender_status == SENDER_ON)? "on" : "off",
400 stringify_port(conf.udp_default_port_arg, "udp"),
401 tgts? tgts : "(none)"
402 );
403 free(tgts);
404 return ret;
405 }
406
407 static void udp_init_target_list(void)
408 {
409 struct sender_command_data scd;
410 int i;
411
412 INIT_LIST_HEAD(&targets);
413 for (i = 0; i < conf.udp_target_given; i++) {
414 if (udp_resolve_target(conf.udp_target_arg[i], &scd) < 0)
415 PARA_CRIT_LOG("not adding requested target '%s'\n",
416 conf.udp_target_arg[i]);
417 else
418 udp_com_add(&scd);
419 }
420 }
421
422 static char *udp_help(void)
423 {
424 return make_message(
425 "usage: {on|off}\n"
426 "usage: {add|delete} host[:port][/packet_size:k:n]\n"
427 "examples: add 224.0.1.38:1500 (IPv4 multicast)\n"
428 " add 224.0.1.38:1500/1400:14:16\n"
429 " (likewise, using 1400 byte packets, with 14\n"
430 " data slices per 16 slice FEC group)\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 [badc0de::1] (IPv6 with port wildcard)\n"
436 );
437 }
438
439 /**
440 * The init function of para_server's udp sender.
441 *
442 * \param s Pointer to the udp sender struct.
443 *
444 * It initializes all function pointers of \a s and the list of udp targets.
445 */
446 void udp_send_init(struct sender *s)
447 {
448 INIT_LIST_HEAD(&targets);
449 s->info = udp_info;
450 s->help = udp_help;
451 s->send = NULL;
452 s->pre_select = NULL;
453 s->post_select = NULL;
454 s->shutdown_clients = udp_shutdown_targets;
455 s->resolve_target = udp_resolve_target;
456 s->client_cmds[SENDER_ON] = udp_com_on;
457 s->client_cmds[SENDER_OFF] = udp_com_off;
458 s->client_cmds[SENDER_DENY] = NULL;
459 s->client_cmds[SENDER_ALLOW] = NULL;
460 s->client_cmds[SENDER_ADD] = udp_com_add;
461 s->client_cmds[SENDER_DELETE] = udp_com_delete;
462 sender_status = SENDER_OFF;
463 udp_init_target_list();
464 if (!conf.udp_no_autostart_given)
465 sender_status = SENDER_ON;
466 PARA_DEBUG_LOG("udp sender init complete\n");
467 }