Convert para_server to lopsub.
[paraslash.git] / udp_send.c
1 /*
2 * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
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 #include <netinet/in.h>
10 #include <sys/socket.h>
11 #include <regex.h>
12 #include <sys/types.h>
13 #include <netinet/udp.h>
14 #include <net/if.h>
15 #include <arpa/inet.h>
16 #include <sys/un.h>
17 #include <netdb.h>
18 #include <lopsub.h>
19
20 #include "server.lsg.h"
21 #include "para.h"
22 #include "error.h"
23 #include "string.h"
24 #include "afh.h"
25 #include "server.h"
26 #include "list.h"
27 #include "send.h"
28 #include "sched.h"
29 #include "vss.h"
30 #include "portable_io.h"
31 #include "net.h"
32 #include "fd.h"
33 #include "close_on_fork.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 /** Whether we already sent the FEC eof packet to this target. */
51 bool sent_fec_eof;
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 const char *buf;
60 size_t len;
61 struct udp_target *ut = sc->private_data;
62
63 if (ut->sent_fec_eof)
64 return;
65 PARA_NOTICE_LOG("sending FEC EOF\n");
66 len = vss_get_fec_eof_packet(&buf);
67 /* Ignore write() errors since we are closing the target anyway. */
68 if (write(sc->fd, buf, len) == len)
69 ut->sent_fec_eof = true;
70 }
71
72 static void udp_delete_target(struct sender_client *sc, const char *msg)
73 {
74 struct udp_target *ut = sc->private_data;
75
76 PARA_NOTICE_LOG("deleting %s (%s) from list\n", sc->name, msg);
77 udp_close_target(sc);
78 close(sc->fd);
79 del_close_on_fork_list(sc->fd);
80 vss_del_fec_client(ut->fc);
81 list_del(&sc->node);
82 free(sc->name);
83 free(sc);
84 free(ut);
85 }
86
87 /**
88 * Perform AF-independent multicast sender setup.
89 *
90 * \param sc The connected sender client.
91 *
92 * \return Zero if okay, negative on error.
93 */
94 static int mcast_sender_setup(struct sender_client *sc)
95 {
96 struct sockaddr_storage ss;
97 socklen_t sslen = sizeof(ss);
98 int ttl = OPT_INT32_VAL(UDP_TTL), id = 0;
99 const int on = 1;
100
101 if (OPT_GIVEN(UDP_MCAST_IFACE)) {
102 const char *iface = OPT_STRING_VAL(UDP_MCAST_IFACE);
103
104 id = if_nametoindex(iface);
105 if (id == 0)
106 PARA_WARNING_LOG("could not resolve interface '%s', "
107 "using default", iface);
108 }
109
110 if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
111 goto err;
112 assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
113
114 /* RFC 3493, 5.2: -1 means 'use kernel default' */
115 if (ttl < 0 || ttl > 255)
116 ttl = -1;
117
118 switch (ss.ss_family) {
119 case AF_INET:
120 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
121 return 0;
122 if (id != 0) {
123 #ifdef HAVE_IP_MREQN
124 struct ip_mreqn mn;
125
126 memset(&mn, 0, sizeof(mn));
127 mn.imr_ifindex = id;
128 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
129 goto err;
130 #else
131 PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
132 #endif
133 }
134 /*
135 * Enable receiving multicast messages generated on the local host
136 * At least on Linux, this is enabled by default.
137 */
138 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
139 break;
140
141 /* Default: use local subnet (do not flood out into the WAN) */
142 if (ttl == -1)
143 ttl = 1;
144 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
145 break;
146 return 0;
147 case AF_INET6:
148 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
149 return 0;
150 if (id != 0 &&
151 setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
152 break;
153 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
154 break;
155 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
156 break;
157 return 0;
158 }
159 err:
160 return -ERRNO_TO_PARA_ERROR(errno);
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 : OPT_UINT32_VAL(UDP_DEFAULT_PORT);
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 struct udp_target *ut = sc->private_data;
240 int mps;
241
242 PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
243 ut->sent_fec_eof = false;
244 mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
245 PARA_INFO_LOG("current MPS = %d bytes\n", mps);
246 return mps;
247 }
248
249 /** Check and clear socket error if any. */
250 static int udp_check_socket_state(struct sender_client *sc)
251 {
252 struct udp_target *ut = sc->private_data;
253 int ret;
254 socklen_t errlen = sizeof(ret);
255
256 if (getsockopt(sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
257 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
258 return 0;
259 } else if (ret == 0) {
260 return 0;
261 } else if (ret == ECONNREFUSED) {
262 time_t dist = now->tv_sec - ut->last_unreachable;
263
264 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
265 return 0;
266 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
267 ut->last_unreachable = now->tv_sec;
268 return 0;
269 } else {
270 /*
271 * unreachable_time < dist <= 2 * unreachable_time
272 * No errors are allowed during this time window.
273 */
274 PARA_NOTICE_LOG("Evicting %s after %d seconds "
275 "of connection errors.\n",
276 sc->name, (int)dist);
277 }
278 }
279 return -ERRNO_TO_PARA_ERROR(ret);
280 }
281
282 static void udp_send_fec(struct sender_client *sc, char *buf, size_t len)
283 {
284 int ret;
285
286 if (sender_status == SENDER_off)
287 return;
288 if (len == 0)
289 return;
290 ret = udp_check_socket_state(sc);
291 if (ret < 0)
292 goto fail;
293 ret = xwrite(sc->fd, buf, len);
294 if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
295 /*
296 * Happens if meanwhile an ICMP Destination / Port Unreachable
297 * has arrived. Ignore, persistent errors will be caught above.
298 */
299 ret = 0;
300 }
301 if (ret < 0)
302 goto fail;
303 return;
304 fail:
305 udp_delete_target(sc, para_strerror(-ret));
306 }
307
308 static int udp_com_add(struct sender_command_data *scd)
309 {
310 int ret;
311 struct udp_target *ut;
312 struct sender_client *sc = udp_lookup_target(scd);
313
314 if (sc) {
315 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
316 sc->name);
317 return -E_TARGET_EXISTS;
318 }
319 ut = para_calloc(sizeof(*ut));
320 sc = para_calloc(sizeof(*sc));
321 ut->fcp.slices_per_group = scd->slices_per_group;
322 ut->fcp.data_slices_per_group = scd->data_slices_per_group;
323 ut->fcp.init_fec = udp_init_fec;
324 ut->fcp.send_fec = udp_send_fec;
325 ut->fcp.need_periodic_header = true;
326
327 sc->private_data = ut;
328 sc->fd = -1;
329 ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
330 if (ret < 0)
331 goto err;
332 sc->fd = ret;
333
334 ret = mcast_sender_setup(sc);
335 if (ret < 0)
336 goto err;
337 ret = mark_fd_nonblocking(sc->fd);
338 if (ret < 0)
339 goto err;
340 sc->name = para_strdup(remote_name(sc->fd));
341 PARA_INFO_LOG("adding to target list (%s)\n", sc->name);
342 ut->fc = vss_add_fec_client(sc, &ut->fcp);
343 para_list_add(&sc->node, &targets);
344 add_close_on_fork_list(sc->fd);
345 return 1;
346 err:
347 if (sc->fd >= 0)
348 close(sc->fd);
349 PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
350 scd->host, scd->port, para_strerror(-ret));
351 free(sc);
352 free(ut);
353 return ret;
354 }
355
356 static char *udp_status(void)
357 {
358 struct sender_client *sc;
359 char *ret, *tgts = NULL;
360
361 list_for_each_entry(sc, &targets, node) {
362 struct udp_target *ut = sc->private_data;
363 char *tmp = make_message("%s%s/%u:%u ",
364 tgts ? : "", sc->name,
365 ut->fcp.data_slices_per_group,
366 ut->fcp.slices_per_group
367 );
368 free(tgts);
369 tgts = tmp;
370 }
371 ret = make_message(
372 "status: %s\n"
373 "port: %s\n"
374 "targets: %s\n",
375 (sender_status == SENDER_on)? "on" : "off",
376 stringify_port(OPT_UINT32_VAL(UDP_DEFAULT_PORT), "udp"),
377 tgts? tgts : "(none)"
378 );
379 free(tgts);
380 return ret;
381 }
382
383 static void udp_init_target_list(void)
384 {
385 struct sender_command_data scd;
386 int i;
387
388 INIT_LIST_HEAD(&targets);
389 for (i = 0; i < OPT_GIVEN(UDP_TARGET); i++) {
390 const char *arg = lls_string_val(i, OPT_RESULT(UDP_TARGET));
391 if (udp_resolve_target(arg, &scd) < 0)
392 PARA_CRIT_LOG("not adding requested target '%s'\n",
393 arg);
394 else
395 udp_com_add(&scd);
396 }
397 }
398
399 static char *udp_help(void)
400 {
401 return make_message(
402 "usage: {on|off}\n"
403 "usage: {add|delete} ip_address[:port][/[packet_size:]k:n]\n"
404 " - k is the number of data slices per FEC group\n"
405 " - n is the total number of slices in a FEC group\n"
406 " - packet_size reduces the slice size below path MTU\n\n"
407 "examples: add 224.0.1.38:1500 (IPv4 multicast)\n"
408 " add 224.0.1.38:8080/14:16 (explicit FEC)\n"
409 " add 10.10.1.42 (using default port)\n"
410 " add [FF05::42]:1500 (IPv6 multicast)\n"
411 " add [::1] (IPv6 localhost/default port)\n"
412 " delete myhost.net (host with port wildcard)\n"
413 " delete 10.1.2.3:456 (IPv4 with explicit port)\n"
414 " delete [badc0de::1] (IPv6 with port wildcard)\n"
415 );
416 }
417
418 /**
419 * The init function of para_server's udp sender.
420 *
421 * \param s Pointer to the udp sender struct.
422 *
423 * It initializes all function pointers of \a s and the list of udp targets.
424 */
425 void udp_send_init(struct sender *s)
426 {
427 INIT_LIST_HEAD(&targets);
428 s->status = udp_status;
429 s->help = udp_help;
430 s->send = NULL;
431 s->pre_select = NULL;
432 s->post_select = NULL;
433 s->shutdown_clients = udp_shutdown_targets;
434 s->resolve_target = udp_resolve_target;
435 s->client_cmds[SENDER_on] = udp_com_on;
436 s->client_cmds[SENDER_off] = udp_com_off;
437 s->client_cmds[SENDER_deny] = NULL;
438 s->client_cmds[SENDER_allow] = NULL;
439 s->client_cmds[SENDER_add] = udp_com_add;
440 s->client_cmds[SENDER_delete] = udp_com_delete;
441 sender_status = SENDER_off;
442 udp_init_target_list();
443 if (!OPT_GIVEN(UDP_NO_AUTOSTART))
444 sender_status = SENDER_on;
445 PARA_DEBUG_LOG("udp sender init complete\n");
446 }