b41c0ebf919ca902a6cafe55dd93471fe42aef46
[paraslash.git] / udp_send.c
1 /*
2 * Copyright (C) 2005-2013 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 <sys/socket.h>
13 #include <netinet/udp.h>
14 #include <net/if.h>
15 #include <osl.h>
16
17 #include "server.cmdline.h"
18 #include "para.h"
19 #include "error.h"
20 #include "string.h"
21 #include "afh.h"
22 #include "afs.h"
23 #include "server.h"
24 #include "list.h"
25 #include "send.h"
26 #include "sched.h"
27 #include "vss.h"
28 #include "portable_io.h"
29 #include "net.h"
30 #include "fd.h"
31 #include "close_on_fork.h"
32
33 /**
34 * Time window during which ICMP Destination/Port Unreachable messages are
35 * ignored, covering transient receiver problems such as restarting the
36 * client, rebooting, reconfiguration, or handover.
37 */
38 #define UDP_MAX_UNREACHABLE_TIME 30
39
40 /** Describes one entry in the list of targets for the udp sender. */
41 struct udp_target {
42 /** Track time (seconds) of last ICMP Port Unreachable error */
43 time_t last_unreachable;
44 /** The opaque structure returned by vss_add_fec_client(). */
45 struct fec_client *fc;
46 /** The FEC parameters for this target. */
47 struct fec_client_parms fcp;
48 };
49
50 static struct list_head targets;
51 static int sender_status;
52
53 static void udp_close_target(struct sender_client *sc)
54 {
55 const char *buf;
56 size_t len = vss_get_fec_eof_packet(&buf);
57
58 /*
59 * Ignore the return value of wirte() since we are closing the target
60 * anyway. The sole purpose of the "do_nothing" statement is to silence
61 * gcc.
62 */
63 if (write(sc->fd, buf, len))
64 do_nothing;
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 close(sc->fd);
74 del_close_on_fork_list(sc->fd);
75 vss_del_fec_client(ut->fc);
76 list_del(&sc->node);
77 free(sc->name);
78 free(sc);
79 free(ut);
80 }
81
82 /**
83 * Perform AF-independent multicast sender setup.
84 *
85 * \param sc The connected sender client.
86 *
87 * \return Zero if okay, negative on error.
88 */
89 static int mcast_sender_setup(struct sender_client *sc)
90 {
91 struct sockaddr_storage ss;
92 socklen_t sslen = sizeof(ss);
93 int ttl = conf.udp_ttl_arg, id = 0;
94 const int on = 1;
95
96 if (conf.udp_mcast_iface_given) {
97 char *iface = conf.udp_mcast_iface_arg;
98
99 id = if_nametoindex(iface);
100 if (id == 0)
101 PARA_WARNING_LOG("could not resolve interface '%s', "
102 "using default", iface);
103 }
104
105 if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
106 goto err;
107 assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
108
109 /* RFC 3493, 5.2: -1 means 'use kernel default' */
110 if (ttl < 0 || ttl > 255)
111 ttl = -1;
112
113 switch (ss.ss_family) {
114 case AF_INET:
115 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
116 return 0;
117 if (id != 0) {
118 #ifdef HAVE_IP_MREQN
119 struct ip_mreqn mn;
120
121 memset(&mn, 0, sizeof(mn));
122 mn.imr_ifindex = id;
123 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
124 goto err;
125 #else
126 PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
127 #endif
128 }
129 /*
130 * Enable receiving multicast messages generated on the local host
131 * At least on Linux, this is enabled by default.
132 */
133 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
134 break;
135
136 /* Default: use local subnet (do not flood out into the WAN) */
137 if (ttl == -1)
138 ttl = 1;
139 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
140 break;
141 return 0;
142 case AF_INET6:
143 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
144 return 0;
145 if (id != 0 &&
146 setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
147 break;
148 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
149 break;
150 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
151 break;
152 return 0;
153 }
154 err:
155 return -ERRNO_TO_PARA_ERROR(errno);
156 }
157
158 static void udp_init_session(struct sender_client *sc)
159 {
160 PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
161 }
162
163 static void udp_shutdown_targets(void)
164 {
165 struct sender_client *sc, *tmp;
166 list_for_each_entry_safe(sc, tmp, &targets, node)
167 udp_close_target(sc);
168 }
169
170 static int udp_resolve_target(const char *url, struct sender_command_data *scd)
171 {
172 const char *result;
173 int ret, port;
174
175 ret = parse_fec_url(url, scd);
176 if (ret)
177 return ret;
178 port = scd->port > 0 ? scd->port : conf.udp_default_port_arg;
179
180 ret = para_connect_simple(IPPROTO_UDP, scd->host, port);
181 if (ret < 0)
182 return ret;
183
184 result = remote_name(ret);
185 close(ret);
186
187 if (!parse_url(result, scd->host, sizeof(scd->host), &scd->port))
188 return -E_ADDRESS_LOOKUP;
189 return 1;
190 }
191
192 static int udp_com_on(__a_unused struct sender_command_data *scd)
193 {
194 sender_status = SENDER_ON;
195 return 1;
196 }
197
198 static int udp_com_off(__a_unused struct sender_command_data *scd)
199 {
200 udp_shutdown_targets();
201 sender_status = SENDER_OFF;
202 return 1;
203 }
204
205 static struct sender_client *udp_lookup_target(struct sender_command_data *scd)
206 {
207 struct sender_client *sc, *tmp;
208 char host[MAX_HOSTLEN];
209 int32_t port;
210
211 list_for_each_entry_safe(sc, tmp, &targets, node) {
212 parse_url(sc->name, host, sizeof(host), &port);
213
214 /* Unspecified port means wildcard port match */
215 if (scd->port > 0 && scd->port != port)
216 continue;
217 if (strcmp(host, scd->host))
218 continue;
219 return sc;
220 }
221 return NULL;
222 }
223
224 static int udp_com_delete(struct sender_command_data *scd)
225 {
226 struct sender_client *sc = udp_lookup_target(scd);
227
228 if (sc) {
229 udp_delete_target(sc, "com_delete");
230 return 1;
231 }
232 PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd->host);
233 return -E_TARGET_NOT_FOUND;
234 }
235
236 /** Initialize UDP session and set maximum payload size. */
237 static int udp_init_fec(struct sender_client *sc)
238 {
239 int mps;
240
241 udp_init_session(sc);
242 mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
243 PARA_INFO_LOG("current MPS = %d bytes\n", mps);
244 return mps;
245 }
246
247 /** Check and clear socket error if any. */
248 static int udp_check_socket_state(struct sender_client *sc)
249 {
250 struct udp_target *ut = sc->private_data;
251 int ret;
252 socklen_t errlen = sizeof(ret);
253
254 if (getsockopt(sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
255 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
256 return 0;
257 } else if (ret == 0) {
258 return 0;
259 } else if (ret == ECONNREFUSED) {
260 time_t dist = now->tv_sec - ut->last_unreachable;
261
262 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
263 return 0;
264 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
265 ut->last_unreachable = now->tv_sec;
266 return 0;
267 } else {
268 /*
269 * unreachable_time < dist <= 2 * unreachable_time
270 * No errors are allowed during this time window.
271 */
272 PARA_NOTICE_LOG("Evicting %s after %d seconds "
273 "of connection errors.\n",
274 sc->name, (int)dist);
275 }
276 }
277 return -ERRNO_TO_PARA_ERROR(ret);
278 }
279
280 static void udp_send_fec(struct sender_client *sc, char *buf, size_t len)
281 {
282 int ret;
283
284 if (sender_status == SENDER_OFF)
285 return;
286 if (len == 0)
287 return;
288 ret = udp_check_socket_state(sc);
289 if (ret < 0)
290 goto fail;
291 ret = xwrite(sc->fd, buf, len);
292 if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
293 /*
294 * Happens if meanwhile an ICMP Destination / Port Unreachable
295 * has arrived. Ignore, persistent errors will be caught above.
296 */
297 ret = 0;
298 }
299 if (ret < 0)
300 goto fail;
301 return;
302 fail:
303 udp_delete_target(sc, para_strerror(-ret));
304 }
305
306 static int udp_com_add(struct sender_command_data *scd)
307 {
308 int ret;
309 struct udp_target *ut;
310 struct sender_client *sc = udp_lookup_target(scd);
311
312 if (sc) {
313 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
314 sc->name);
315 return -E_TARGET_EXISTS;
316 }
317 ut = para_calloc(sizeof(*ut));
318 sc = para_calloc(sizeof(*sc));
319 ut->fcp.slices_per_group = scd->slices_per_group;
320 ut->fcp.data_slices_per_group = scd->data_slices_per_group;
321 ut->fcp.init_fec = udp_init_fec;
322 ut->fcp.send_fec = udp_send_fec;
323 ut->fcp.need_periodic_header = true;
324
325 sc->private_data = ut;
326 sc->fd = -1;
327 ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
328 if (ret < 0)
329 goto err;
330 sc->fd = ret;
331
332 ret = mcast_sender_setup(sc);
333 if (ret < 0)
334 goto err;
335 ret = mark_fd_nonblocking(sc->fd);
336 if (ret < 0)
337 goto err;
338 sc->name = para_strdup(remote_name(sc->fd));
339 PARA_INFO_LOG("adding to target list (%s)\n", sc->name);
340 ut->fc = vss_add_fec_client(sc, &ut->fcp);
341 para_list_add(&sc->node, &targets);
342 add_close_on_fork_list(sc->fd);
343 return 1;
344 err:
345 if (sc->fd >= 0)
346 close(sc->fd);
347 PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
348 scd->host, scd->port, para_strerror(-ret));
349 free(sc);
350 free(ut);
351 return ret;
352 }
353
354 static char *udp_info(void)
355 {
356 struct sender_client *sc;
357 char *ret, *tgts = NULL;
358
359 list_for_each_entry(sc, &targets, node) {
360 struct udp_target *ut = sc->private_data;
361 char *tmp = make_message("%s%s/%u:%u ",
362 tgts ? : "", sc->name,
363 ut->fcp.data_slices_per_group,
364 ut->fcp.slices_per_group
365 );
366 free(tgts);
367 tgts = tmp;
368 }
369 ret = make_message(
370 "udp sender:\n"
371 "\tstatus: %s\n"
372 "\tport: %s\n"
373 "\ttargets: %s\n",
374 (sender_status == SENDER_ON)? "on" : "off",
375 stringify_port(conf.udp_default_port_arg, "udp"),
376 tgts? tgts : "(none)"
377 );
378 free(tgts);
379 return ret;
380 }
381
382 static void udp_init_target_list(void)
383 {
384 struct sender_command_data scd;
385 int i;
386
387 INIT_LIST_HEAD(&targets);
388 for (i = 0; i < conf.udp_target_given; i++) {
389 if (udp_resolve_target(conf.udp_target_arg[i], &scd) < 0)
390 PARA_CRIT_LOG("not adding requested target '%s'\n",
391 conf.udp_target_arg[i]);
392 else
393 udp_com_add(&scd);
394 }
395 }
396
397 static char *udp_help(void)
398 {
399 return make_message(
400 "usage: {on|off}\n"
401 "usage: {add|delete} ip_address[:port][/[packet_size:]k:n]\n"
402 " - k is the number of data slices per FEC group\n"
403 " - n is the total number of slices in a FEC group\n"
404 " - packet_size reduces the slice size below path MTU\n\n"
405 "examples: add 224.0.1.38:1500 (IPv4 multicast)\n"
406 " add 224.0.1.38:8080/14:16 (explicit FEC)\n"
407 " add 10.10.1.42 (using default port)\n"
408 " add [FF05::42]:1500 (IPv6 multicast)\n"
409 " add [::1] (IPv6 localhost/default port)\n"
410 " delete myhost.net (host with port wildcard)\n"
411 " delete 10.1.2.3:456 (IPv4 with explicit port)\n"
412 " delete [badc0de::1] (IPv6 with port wildcard)\n"
413 );
414 }
415
416 /**
417 * The init function of para_server's udp sender.
418 *
419 * \param s Pointer to the udp sender struct.
420 *
421 * It initializes all function pointers of \a s and the list of udp targets.
422 */
423 void udp_send_init(struct sender *s)
424 {
425 INIT_LIST_HEAD(&targets);
426 s->info = udp_info;
427 s->help = udp_help;
428 s->send = NULL;
429 s->pre_select = NULL;
430 s->post_select = NULL;
431 s->shutdown_clients = udp_shutdown_targets;
432 s->resolve_target = udp_resolve_target;
433 s->client_cmds[SENDER_ON] = udp_com_on;
434 s->client_cmds[SENDER_OFF] = udp_com_off;
435 s->client_cmds[SENDER_DENY] = NULL;
436 s->client_cmds[SENDER_ALLOW] = NULL;
437 s->client_cmds[SENDER_ADD] = udp_com_add;
438 s->client_cmds[SENDER_DELETE] = udp_com_delete;
439 sender_status = SENDER_OFF;
440 udp_init_target_list();
441 if (!conf.udp_no_autostart_given)
442 sender_status = SENDER_ON;
443 PARA_DEBUG_LOG("udp sender init complete\n");
444 }