2 * Copyright (C) 2005-2014 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. */
9 #include <netinet/in.h>
10 #include <sys/socket.h>
12 #include <sys/types.h>
13 #include <sys/socket.h>
14 #include <netinet/udp.h>
16 #include <arpa/inet.h>
21 #include "server.cmdline.h"
32 #include "portable_io.h"
35 #include "close_on_fork.h"
38 * Time window during which ICMP Destination/Port Unreachable messages are
39 * ignored, covering transient receiver problems such as restarting the
40 * client, rebooting, reconfiguration, or handover.
42 #define UDP_MAX_UNREACHABLE_TIME 30
44 /** Describes one entry in the list of targets for the udp sender. */
46 /** Track time (seconds) of last ICMP Port Unreachable error */
47 time_t last_unreachable;
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;
54 static struct list_head targets;
55 static int sender_status;
57 static void udp_close_target(struct sender_client *sc)
60 size_t len = vss_get_fec_eof_packet(&buf);
63 * Ignore the return value of wirte() since we are closing the target
64 * anyway. The sole purpose of the "do_nothing" statement is to silence
67 if (write(sc->fd, buf, len))
71 static void udp_delete_target(struct sender_client *sc, const char *msg)
73 struct udp_target *ut = sc->private_data;
75 PARA_NOTICE_LOG("deleting %s (%s) from list\n", sc->name, msg);
78 del_close_on_fork_list(sc->fd);
79 vss_del_fec_client(ut->fc);
87 * Perform AF-independent multicast sender setup.
89 * \param sc The connected sender client.
91 * \return Zero if okay, negative on error.
93 static int mcast_sender_setup(struct sender_client *sc)
95 struct sockaddr_storage ss;
96 socklen_t sslen = sizeof(ss);
97 int ttl = conf.udp_ttl_arg, id = 0;
100 if (conf.udp_mcast_iface_given) {
101 char *iface = conf.udp_mcast_iface_arg;
103 id = if_nametoindex(iface);
105 PARA_WARNING_LOG("could not resolve interface '%s', "
106 "using default", iface);
109 if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
111 assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
113 /* RFC 3493, 5.2: -1 means 'use kernel default' */
114 if (ttl < 0 || ttl > 255)
117 switch (ss.ss_family) {
119 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
125 memset(&mn, 0, sizeof(mn));
127 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
130 PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
134 * Enable receiving multicast messages generated on the local host
135 * At least on Linux, this is enabled by default.
137 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
140 /* Default: use local subnet (do not flood out into the WAN) */
143 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
147 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
150 setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
152 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
154 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
159 return -ERRNO_TO_PARA_ERROR(errno);
162 static void udp_init_session(struct sender_client *sc)
164 PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
167 static void udp_shutdown_targets(void)
169 struct sender_client *sc, *tmp;
170 list_for_each_entry_safe(sc, tmp, &targets, node)
171 udp_close_target(sc);
174 static int udp_resolve_target(const char *url, struct sender_command_data *scd)
179 ret = parse_fec_url(url, scd);
182 port = scd->port > 0 ? scd->port : conf.udp_default_port_arg;
184 ret = para_connect_simple(IPPROTO_UDP, scd->host, port);
188 result = remote_name(ret);
191 if (!parse_url(result, scd->host, sizeof(scd->host), &scd->port))
192 return -E_ADDRESS_LOOKUP;
196 static int udp_com_on(__a_unused struct sender_command_data *scd)
198 sender_status = SENDER_ON;
202 static int udp_com_off(__a_unused struct sender_command_data *scd)
204 udp_shutdown_targets();
205 sender_status = SENDER_OFF;
209 static struct sender_client *udp_lookup_target(struct sender_command_data *scd)
211 struct sender_client *sc, *tmp;
212 char host[MAX_HOSTLEN];
215 list_for_each_entry_safe(sc, tmp, &targets, node) {
216 parse_url(sc->name, host, sizeof(host), &port);
218 /* Unspecified port means wildcard port match */
219 if (scd->port > 0 && scd->port != port)
221 if (strcmp(host, scd->host))
228 static int udp_com_delete(struct sender_command_data *scd)
230 struct sender_client *sc = udp_lookup_target(scd);
233 udp_delete_target(sc, "com_delete");
236 PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd->host);
237 return -E_TARGET_NOT_FOUND;
240 /** Initialize UDP session and set maximum payload size. */
241 static int udp_init_fec(struct sender_client *sc)
245 udp_init_session(sc);
246 mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
247 PARA_INFO_LOG("current MPS = %d bytes\n", mps);
251 /** Check and clear socket error if any. */
252 static int udp_check_socket_state(struct sender_client *sc)
254 struct udp_target *ut = sc->private_data;
256 socklen_t errlen = sizeof(ret);
258 if (getsockopt(sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
259 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
261 } else if (ret == 0) {
263 } else if (ret == ECONNREFUSED) {
264 time_t dist = now->tv_sec - ut->last_unreachable;
266 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
268 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
269 ut->last_unreachable = now->tv_sec;
273 * unreachable_time < dist <= 2 * unreachable_time
274 * No errors are allowed during this time window.
276 PARA_NOTICE_LOG("Evicting %s after %d seconds "
277 "of connection errors.\n",
278 sc->name, (int)dist);
281 return -ERRNO_TO_PARA_ERROR(ret);
284 static void udp_send_fec(struct sender_client *sc, char *buf, size_t len)
288 if (sender_status == SENDER_OFF)
292 ret = udp_check_socket_state(sc);
295 ret = xwrite(sc->fd, buf, len);
296 if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
298 * Happens if meanwhile an ICMP Destination / Port Unreachable
299 * has arrived. Ignore, persistent errors will be caught above.
307 udp_delete_target(sc, para_strerror(-ret));
310 static int udp_com_add(struct sender_command_data *scd)
313 struct udp_target *ut;
314 struct sender_client *sc = udp_lookup_target(scd);
317 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
319 return -E_TARGET_EXISTS;
321 ut = para_calloc(sizeof(*ut));
322 sc = para_calloc(sizeof(*sc));
323 ut->fcp.slices_per_group = scd->slices_per_group;
324 ut->fcp.data_slices_per_group = scd->data_slices_per_group;
325 ut->fcp.init_fec = udp_init_fec;
326 ut->fcp.send_fec = udp_send_fec;
327 ut->fcp.need_periodic_header = true;
329 sc->private_data = ut;
331 ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
336 ret = mcast_sender_setup(sc);
339 ret = mark_fd_nonblocking(sc->fd);
342 sc->name = para_strdup(remote_name(sc->fd));
343 PARA_INFO_LOG("adding to target list (%s)\n", sc->name);
344 ut->fc = vss_add_fec_client(sc, &ut->fcp);
345 para_list_add(&sc->node, &targets);
346 add_close_on_fork_list(sc->fd);
351 PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
352 scd->host, scd->port, para_strerror(-ret));
358 static char *udp_info(void)
360 struct sender_client *sc;
361 char *ret, *tgts = NULL;
363 list_for_each_entry(sc, &targets, node) {
364 struct udp_target *ut = sc->private_data;
365 char *tmp = make_message("%s%s/%u:%u ",
366 tgts ? : "", sc->name,
367 ut->fcp.data_slices_per_group,
368 ut->fcp.slices_per_group
378 (sender_status == SENDER_ON)? "on" : "off",
379 stringify_port(conf.udp_default_port_arg, "udp"),
380 tgts? tgts : "(none)"
386 static void udp_init_target_list(void)
388 struct sender_command_data scd;
391 INIT_LIST_HEAD(&targets);
392 for (i = 0; i < conf.udp_target_given; i++) {
393 if (udp_resolve_target(conf.udp_target_arg[i], &scd) < 0)
394 PARA_CRIT_LOG("not adding requested target '%s'\n",
395 conf.udp_target_arg[i]);
401 static char *udp_help(void)
405 "usage: {add|delete} ip_address[:port][/[packet_size:]k:n]\n"
406 " - k is the number of data slices per FEC group\n"
407 " - n is the total number of slices in a FEC group\n"
408 " - packet_size reduces the slice size below path MTU\n\n"
409 "examples: add 224.0.1.38:1500 (IPv4 multicast)\n"
410 " add 224.0.1.38:8080/14:16 (explicit FEC)\n"
411 " add 10.10.1.42 (using default port)\n"
412 " add [FF05::42]:1500 (IPv6 multicast)\n"
413 " add [::1] (IPv6 localhost/default port)\n"
414 " delete myhost.net (host with port wildcard)\n"
415 " delete 10.1.2.3:456 (IPv4 with explicit port)\n"
416 " delete [badc0de::1] (IPv6 with port wildcard)\n"
421 * The init function of para_server's udp sender.
423 * \param s Pointer to the udp sender struct.
425 * It initializes all function pointers of \a s and the list of udp targets.
427 void udp_send_init(struct sender *s)
429 INIT_LIST_HEAD(&targets);
433 s->pre_select = NULL;
434 s->post_select = NULL;
435 s->shutdown_clients = udp_shutdown_targets;
436 s->resolve_target = udp_resolve_target;
437 s->client_cmds[SENDER_ON] = udp_com_on;
438 s->client_cmds[SENDER_OFF] = udp_com_off;
439 s->client_cmds[SENDER_DENY] = NULL;
440 s->client_cmds[SENDER_ALLOW] = NULL;
441 s->client_cmds[SENDER_ADD] = udp_com_add;
442 s->client_cmds[SENDER_DELETE] = udp_com_delete;
443 sender_status = SENDER_OFF;
444 udp_init_target_list();
445 if (!conf.udp_no_autostart_given)
446 sender_status = SENDER_ON;
447 PARA_DEBUG_LOG("udp sender init complete\n");