1 /* Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
3 /** \file udp_send.c Para_server's udp sender. */
5 #include <netinet/in.h>
6 #include <sys/socket.h>
9 #include <netinet/udp.h>
11 #include <arpa/inet.h>
16 #include "server.lsg.h"
27 #include "portable_io.h"
29 #include "close_on_fork.h"
32 * Time window during which ICMP Destination/Port Unreachable messages are
33 * ignored, covering transient receiver problems such as restarting the
34 * client, rebooting, reconfiguration, or handover.
36 #define UDP_MAX_UNREACHABLE_TIME 30
38 /** Describes one entry in the list of targets for the udp sender. */
40 /** Track time (seconds) of last ICMP Port Unreachable error */
41 time_t last_unreachable;
42 /** The opaque structure returned by vss_add_fec_client(). */
43 struct fec_client *fc;
44 /** The FEC parameters for this target. */
45 struct fec_client_parms fcp;
46 /** Whether we already sent the FEC eof packet to this target. */
50 static struct list_head targets;
51 static int sender_status;
53 static void udp_close_target(struct sender_client *sc)
57 struct udp_target *ut = sc->private_data;
61 PARA_NOTICE_LOG("sending FEC EOF\n");
62 len = vss_get_fec_eof_packet(&buf);
63 /* Ignore write() errors since we are closing the target anyway. */
64 if (write(sc->fd, buf, len))
65 do_nothing; /* avoid "ignoring return value" warning */
66 ut->sent_fec_eof = true;
69 static void udp_delete_target(struct sender_client *sc, const char *msg)
71 struct udp_target *ut = sc->private_data;
73 PARA_NOTICE_LOG("deleting %s (%s) from list\n", sc->name, msg);
75 /* command handlers already called close_listed_fds() */
76 if (!process_is_command_handler()) {
78 del_close_on_fork_list(sc->fd);
80 vss_del_fec_client(ut->fc);
88 * Perform AF-independent multicast sender setup.
90 * \param sc The connected sender client.
92 * \return Zero if okay, negative on error.
94 static int mcast_sender_setup(struct sender_client *sc)
96 struct sockaddr_storage ss;
97 socklen_t sslen = sizeof(ss);
98 int ttl = OPT_INT32_VAL(UDP_TTL), id = 0;
101 if (OPT_GIVEN(UDP_MCAST_IFACE)) {
102 const char *iface = OPT_STRING_VAL(UDP_MCAST_IFACE);
104 id = if_nametoindex(iface);
106 PARA_WARNING_LOG("could not resolve interface '%s', "
107 "using default", iface);
110 if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
112 assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
114 /* RFC 3493, 5.2: -1 means 'use kernel default' */
115 if (ttl < 0 || ttl > 255)
118 switch (ss.ss_family) {
120 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
126 memset(&mn, 0, sizeof(mn));
128 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
131 PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
135 * Enable receiving multicast messages generated on the local host
136 * At least on Linux, this is enabled by default.
138 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
141 /* Default: use local subnet (do not flood out into the WAN) */
144 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
148 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
151 setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
153 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
155 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
160 return -ERRNO_TO_PARA_ERROR(errno);
163 static void udp_shutdown_targets(void)
165 struct sender_client *sc, *tmp;
166 list_for_each_entry_safe(sc, tmp, &targets, node)
167 udp_close_target(sc);
170 static void udp_shutdown(void)
172 struct sender_client *sc, *tmp;
173 list_for_each_entry_safe(sc, tmp, &targets, node)
174 udp_delete_target(sc, "shutdown");
177 static int udp_resolve_target(const char *url, struct sender_command_data *scd)
182 ret = parse_fec_url(url, scd);
185 port = scd->port > 0 ? scd->port : OPT_UINT32_VAL(UDP_DEFAULT_PORT);
187 ret = para_connect_simple(IPPROTO_UDP, scd->host, port);
191 result = remote_name(ret);
194 if (!parse_url(result, scd->host, sizeof(scd->host), &scd->port))
195 return -E_ADDRESS_LOOKUP;
199 static int udp_com_on(__a_unused struct sender_command_data *scd)
201 sender_status = SENDER_on;
205 static int udp_com_off(__a_unused struct sender_command_data *scd)
207 udp_shutdown_targets();
208 sender_status = SENDER_off;
212 static struct sender_client *udp_lookup_target(struct sender_command_data *scd)
214 struct sender_client *sc, *tmp;
215 char host[MAX_HOSTLEN];
218 list_for_each_entry_safe(sc, tmp, &targets, node) {
219 parse_url(sc->name, host, sizeof(host), &port);
221 /* Unspecified port means wildcard port match */
222 if (scd->port > 0 && scd->port != port)
224 if (strcmp(host, scd->host))
231 static int udp_com_delete(struct sender_command_data *scd)
233 struct sender_client *sc = udp_lookup_target(scd);
236 udp_delete_target(sc, "com_delete");
239 PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd->host);
240 return -E_TARGET_NOT_FOUND;
243 /** Initialize UDP session and set maximum payload size. */
244 static int udp_init_fec(struct sender_client *sc)
246 struct udp_target *ut = sc->private_data;
249 PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
250 ut->sent_fec_eof = false;
251 mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
252 PARA_INFO_LOG("current MPS = %d bytes\n", mps);
256 /** Check and clear socket error if any. */
257 static int udp_check_socket_state(struct sender_client *sc)
259 struct udp_target *ut = sc->private_data;
261 socklen_t errlen = sizeof(ret);
263 if (getsockopt(sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
264 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
266 } else if (ret == 0) {
268 } else if (ret == ECONNREFUSED) {
269 time_t dist = now->tv_sec - ut->last_unreachable;
271 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
273 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
274 ut->last_unreachable = now->tv_sec;
278 * unreachable_time < dist <= 2 * unreachable_time
279 * No errors are allowed during this time window.
281 PARA_NOTICE_LOG("Evicting %s after %d seconds "
282 "of connection errors.\n",
283 sc->name, (int)dist);
286 return -ERRNO_TO_PARA_ERROR(ret);
289 static void udp_send_fec(struct sender_client *sc, char *buf, size_t len)
293 if (sender_status == SENDER_off)
297 ret = udp_check_socket_state(sc);
300 ret = xwrite(sc->fd, buf, len);
301 if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
303 * Happens if meanwhile an ICMP Destination / Port Unreachable
304 * has arrived. Ignore, persistent errors will be caught above.
312 udp_delete_target(sc, para_strerror(-ret));
315 static int udp_com_add(struct sender_command_data *scd)
318 struct udp_target *ut;
319 struct sender_client *sc = udp_lookup_target(scd);
322 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
324 return -E_TARGET_EXISTS;
326 ut = para_calloc(sizeof(*ut));
327 sc = para_calloc(sizeof(*sc));
328 ut->fcp.slices_per_group = scd->slices_per_group;
329 ut->fcp.data_slices_per_group = scd->data_slices_per_group;
330 ut->fcp.init_fec = udp_init_fec;
331 ut->fcp.send_fec = udp_send_fec;
332 ut->fcp.need_periodic_header = true;
334 sc->private_data = ut;
336 ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
341 ret = mcast_sender_setup(sc);
344 ret = mark_fd_nonblocking(sc->fd);
347 sc->name = para_strdup(remote_name(sc->fd));
348 PARA_INFO_LOG("adding to target list (%s)\n", sc->name);
349 ut->fc = vss_add_fec_client(sc, &ut->fcp);
350 para_list_add(&sc->node, &targets);
351 add_close_on_fork_list(sc->fd);
356 PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
357 scd->host, scd->port, para_strerror(-ret));
363 static char *udp_status(void)
365 struct sender_client *sc;
366 char *ret, *tgts = NULL;
368 list_for_each_entry(sc, &targets, node) {
369 struct udp_target *ut = sc->private_data;
370 char *tmp = make_message("%s%s/%u:%u ",
371 tgts ? : "", sc->name,
372 ut->fcp.data_slices_per_group,
373 ut->fcp.slices_per_group
382 (sender_status == SENDER_on)? "on" : "off",
383 stringify_port(OPT_UINT32_VAL(UDP_DEFAULT_PORT), "udp"),
384 tgts? tgts : "(none)"
390 static void udp_init_target_list(void)
392 struct sender_command_data scd;
395 INIT_LIST_HEAD(&targets);
396 for (i = 0; i < OPT_GIVEN(UDP_TARGET); i++) {
397 const char *arg = lls_string_val(i, OPT_RESULT(UDP_TARGET));
398 if (udp_resolve_target(arg, &scd) < 0)
399 PARA_CRIT_LOG("not adding requested target '%s'\n",
406 static char *udp_help(void)
410 "usage: {add|delete} ip_address[:port][/[packet_size:]k:n]\n"
411 " - k is the number of data slices per FEC group\n"
412 " - n is the total number of slices in a FEC group\n"
413 " - packet_size reduces the slice size below path MTU\n\n"
414 "examples: add 224.0.1.38:1500 (IPv4 multicast)\n"
415 " add 224.0.1.38:8080/14:16 (explicit FEC)\n"
416 " add 10.10.1.42 (using default port)\n"
417 " add [FF05::42]:1500 (IPv6 multicast)\n"
418 " add [::1] (IPv6 localhost/default port)\n"
419 " delete myhost.net (host with port wildcard)\n"
420 " delete 10.1.2.3:456 (IPv4 with explicit port)\n"
421 " delete [badc0de::1] (IPv6 with port wildcard)\n"
425 /* Initialize the list of udp targets. */
426 static void udp_send_init(void)
428 INIT_LIST_HEAD(&targets);
429 sender_status = SENDER_off;
430 udp_init_target_list();
431 if (!OPT_GIVEN(UDP_NO_AUTOSTART))
432 sender_status = SENDER_on;
433 PARA_DEBUG_LOG("udp sender init complete\n");
439 * In contrast to the other senders the UDP sender is active in the sense that
440 * it initiates the network connection according to its list of targets rather
441 * than passively waiting for clients to connect. Like DCCP streams, UDP
442 * streams are always sent FEC-encoded. The UDP sender is the only sender which
443 * supports IP multicasting.
445 const struct sender udp_sender = {
447 .init = udp_send_init,
448 .shutdown = udp_shutdown,
449 .shutdown_clients = udp_shutdown_targets,
450 .resolve_target = udp_resolve_target,
452 [SENDER_on] = udp_com_on,
453 [SENDER_off] = udp_com_off,
454 [SENDER_add] = udp_com_add,
455 [SENDER_delete] = udp_com_delete,
458 .status = udp_status,