2 * Copyright (C) 2005-2010 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file udp_send.c Para_server's udp sender. */
13 #include <sys/socket.h>
14 #include <netinet/udp.h>
18 #include "server.cmdline.h"
28 #include "portable_io.h"
32 #include "close_on_fork.h"
33 #include "chunk_queue.h"
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.
40 #define UDP_MAX_UNREACHABLE_TIME 30
42 /** Describes one entry in the list of targets for the udp sender. */
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;
52 static struct list_head targets;
53 static int sender_status;
55 static void udp_close_target(struct sender_client *sc)
63 static void udp_delete_target(struct sender_client *sc, const char *msg)
65 struct udp_target *ut = sc->private_data;
67 PARA_NOTICE_LOG("deleting %s (%s) from list\n", sc->name, msg);
70 del_close_on_fork_list(sc->fd);
71 vss_del_fec_client(ut->fc);
79 * Perform AF-independent multicast sender setup.
81 * \param sc The connected sender client.
83 * \return Zero if okay, negative on error.
85 static int mcast_sender_setup(struct sender_client *sc)
87 struct sockaddr_storage ss;
88 socklen_t sslen = sizeof(ss);
89 int ttl = conf.udp_ttl_arg, id = 0;
92 if (conf.udp_mcast_iface_given) {
93 char *iface = conf.udp_mcast_iface_arg;
95 id = if_nametoindex(iface);
97 PARA_WARNING_LOG("could not resolve interface '%s', "
98 "using default", iface);
101 if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
103 assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
105 /* RFC 3493, 5.2: -1 means 'use kernel default' */
106 if (ttl < 0 || ttl > 255)
109 switch (ss.ss_family) {
111 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
117 memset(&mn, 0, sizeof(mn));
119 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
122 PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
126 * Enable receiving multicast messages generated on the local host
127 * At least on Linux, this is enabled by default.
129 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
132 /* Default: use local subnet (do not flood out into the WAN) */
135 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
139 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
142 setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
144 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
146 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
151 return -ERRNO_TO_PARA_ERROR(errno);
154 /** The maximal size of the per-target chunk queue. */
155 #define UDP_CQ_BYTES 40000
157 static void udp_init_session(struct sender_client *sc)
159 if (sc->cq == NULL) {
160 sc->cq = cq_new(UDP_CQ_BYTES);
161 PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
165 static void udp_shutdown_targets(void)
167 struct sender_client *sc, *tmp;
169 size_t len = vss_get_fec_eof_packet(&buf);
171 list_for_each_entry_safe(sc, tmp, &targets, node)
172 if (sc->cq != NULL) {
173 /* ignore return value, closing the target anyway. */
174 (void)write(sc->fd, buf, len);
175 udp_close_target(sc);
179 static int udp_resolve_target(const char *url, struct sender_command_data *scd)
184 ret = parse_fec_url(url, scd);
187 port = scd->port > 0 ? scd->port : conf.udp_default_port_arg;
189 ret = para_connect_simple(IPPROTO_UDP, scd->host, port);
193 result = remote_name(ret);
196 if (!parse_url(result, scd->host, sizeof(scd->host), &scd->port))
197 return -E_ADDRESS_LOOKUP;
201 static int udp_com_on(__a_unused struct sender_command_data *scd)
203 sender_status = SENDER_ON;
207 static int udp_com_off(__a_unused struct sender_command_data *scd)
209 udp_shutdown_targets();
210 sender_status = SENDER_OFF;
214 static struct sender_client *udp_lookup_target(struct sender_command_data *scd)
216 struct sender_client *sc, *tmp;
217 char host[MAX_HOSTLEN];
220 list_for_each_entry_safe(sc, tmp, &targets, node) {
221 parse_url(sc->name, host, sizeof(host), &port);
223 /* Unspecified port means wildcard port match */
224 if (scd->port > 0 && scd->port != port)
226 if (strcmp(host, scd->host))
233 static int udp_com_delete(struct sender_command_data *scd)
235 struct sender_client *sc = udp_lookup_target(scd);
238 udp_delete_target(sc, "com_delete");
241 PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd->host);
242 return -E_TARGET_NOT_FOUND;
245 /** Initialize UDP session and set maximum payload size. */
246 static int udp_init_fec(struct sender_client *sc)
250 udp_init_session(sc);
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 int udp_send_fec(struct sender_client *sc, char *buf, size_t len)
293 if (sender_status == SENDER_OFF)
295 if (len == 0 && !cq_peek(sc->cq))
297 ret = udp_check_socket_state(sc);
300 ret = send_queued_chunks(sc->fd, sc->cq);
303 if (!ret) { /* still data left in the queue */
304 ret = cq_force_enqueue(sc->cq, buf, len);
308 ret = write_nonblock(sc->fd, buf, len);
309 if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
311 * Happens if meanwhile an ICMP Destination / Port Unreachable
312 * has arrived. Ignore, persistent errors will be caught above.
319 ret = cq_force_enqueue(sc->cq, buf + ret, len - ret);
324 udp_delete_target(sc, para_strerror(-ret));
328 static int udp_com_add(struct sender_command_data *scd)
331 struct udp_target *ut;
332 struct sender_client *sc = udp_lookup_target(scd);
335 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
337 return -E_TARGET_EXISTS;
339 ut = para_calloc(sizeof(*ut));
340 sc = para_calloc(sizeof(*sc));
341 ut->fcp.slices_per_group = scd->slices_per_group;
342 ut->fcp.data_slices_per_group = scd->data_slices_per_group;
343 ut->fcp.init_fec = udp_init_fec;
344 ut->fcp.send_fec = udp_send_fec;
346 sc->private_data = ut;
348 ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
353 ret = mcast_sender_setup(sc);
356 ret = mark_fd_nonblocking(sc->fd);
359 sc->name = para_strdup(remote_name(sc->fd));
360 PARA_INFO_LOG("adding to target list (%s)\n", sc->name);
361 ut->fc = vss_add_fec_client(sc, &ut->fcp);
362 para_list_add(&sc->node, &targets);
363 add_close_on_fork_list(sc->fd);
368 PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
369 scd->host, scd->port, para_strerror(-ret));
375 static char *udp_info(void)
377 struct sender_client *sc;
378 char *ret, *tgts = NULL;
380 list_for_each_entry(sc, &targets, node) {
381 struct udp_target *ut = sc->private_data;
382 char *tmp = make_message("%s%s/%u:%u ",
383 tgts ? : "", sc->name,
384 ut->fcp.data_slices_per_group,
385 ut->fcp.slices_per_group
395 (sender_status == SENDER_ON)? "on" : "off",
396 stringify_port(conf.udp_default_port_arg, "udp"),
397 tgts? tgts : "(none)"
403 static void udp_init_target_list(void)
405 struct sender_command_data scd;
408 INIT_LIST_HEAD(&targets);
409 for (i = 0; i < conf.udp_target_given; i++) {
410 if (udp_resolve_target(conf.udp_target_arg[i], &scd) < 0)
411 PARA_CRIT_LOG("not adding requested target '%s'\n",
412 conf.udp_target_arg[i]);
418 static char *udp_help(void)
422 "usage: {add|delete} ip_address[:port][/[packet_size:]k:n]\n"
423 " - k is the number of data slices per FEC group\n"
424 " - n is the total number of slices in a FEC group\n"
425 " - packet_size reduces the slice size below path MTU\n\n"
426 "examples: add 224.0.1.38:1500 (IPv4 multicast)\n"
427 " add 224.0.1.38:8080/14:16 (explicit FEC)\n"
428 " add 10.10.1.42 (using default port)\n"
429 " add [FF05::42]:1500 (IPv6 multicast)\n"
430 " add [::1] (IPv6 localhost/default port)\n"
431 " delete myhost.net (host with port wildcard)\n"
432 " delete 10.1.2.3:456 (IPv4 with explicit port)\n"
433 " delete [badc0de::1] (IPv6 with port wildcard)\n"
438 * The init function of para_server's udp sender.
440 * \param s Pointer to the udp sender struct.
442 * It initializes all function pointers of \a s and the list of udp targets.
444 void udp_send_init(struct sender *s)
446 INIT_LIST_HEAD(&targets);
450 s->pre_select = NULL;
451 s->post_select = NULL;
452 s->shutdown_clients = udp_shutdown_targets;
453 s->resolve_target = udp_resolve_target;
454 s->client_cmds[SENDER_ON] = udp_com_on;
455 s->client_cmds[SENDER_OFF] = udp_com_off;
456 s->client_cmds[SENDER_DENY] = NULL;
457 s->client_cmds[SENDER_ALLOW] = NULL;
458 s->client_cmds[SENDER_ADD] = udp_com_add;
459 s->client_cmds[SENDER_DELETE] = udp_com_delete;
460 sender_status = SENDER_OFF;
461 udp_init_target_list();
462 if (!conf.udp_no_autostart_given)
463 sender_status = SENDER_ON;
464 PARA_DEBUG_LOG("udp sender init complete\n");