2 * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
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 <netinet/udp.h>
15 #include <arpa/inet.h>
20 #include "server.lsg.h"
30 #include "portable_io.h"
33 #include "close_on_fork.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;
50 /** Whether we already sent the FEC eof packet to this target. */
54 static struct list_head targets;
55 static int sender_status;
57 static void udp_close_target(struct sender_client *sc)
61 struct udp_target *ut = sc->private_data;
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))
69 do_nothing; /* avoid "ignoring return value" warning */
70 ut->sent_fec_eof = true;
73 static void udp_delete_target(struct sender_client *sc, const char *msg)
75 struct udp_target *ut = sc->private_data;
77 PARA_NOTICE_LOG("deleting %s (%s) from list\n", sc->name, msg);
80 del_close_on_fork_list(sc->fd);
81 vss_del_fec_client(ut->fc);
89 * Perform AF-independent multicast sender setup.
91 * \param sc The connected sender client.
93 * \return Zero if okay, negative on error.
95 static int mcast_sender_setup(struct sender_client *sc)
97 struct sockaddr_storage ss;
98 socklen_t sslen = sizeof(ss);
99 int ttl = OPT_INT32_VAL(UDP_TTL), id = 0;
102 if (OPT_GIVEN(UDP_MCAST_IFACE)) {
103 const char *iface = OPT_STRING_VAL(UDP_MCAST_IFACE);
105 id = if_nametoindex(iface);
107 PARA_WARNING_LOG("could not resolve interface '%s', "
108 "using default", iface);
111 if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
113 assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
115 /* RFC 3493, 5.2: -1 means 'use kernel default' */
116 if (ttl < 0 || ttl > 255)
119 switch (ss.ss_family) {
121 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
127 memset(&mn, 0, sizeof(mn));
129 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
132 PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
136 * Enable receiving multicast messages generated on the local host
137 * At least on Linux, this is enabled by default.
139 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
142 /* Default: use local subnet (do not flood out into the WAN) */
145 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
149 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
152 setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
154 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
156 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
161 return -ERRNO_TO_PARA_ERROR(errno);
164 static void udp_shutdown_targets(void)
166 struct sender_client *sc, *tmp;
167 list_for_each_entry_safe(sc, tmp, &targets, node)
168 udp_close_target(sc);
171 static int udp_resolve_target(const char *url, struct sender_command_data *scd)
176 ret = parse_fec_url(url, scd);
179 port = scd->port > 0 ? scd->port : OPT_UINT32_VAL(UDP_DEFAULT_PORT);
181 ret = para_connect_simple(IPPROTO_UDP, scd->host, port);
185 result = remote_name(ret);
188 if (!parse_url(result, scd->host, sizeof(scd->host), &scd->port))
189 return -E_ADDRESS_LOOKUP;
193 static int udp_com_on(__a_unused struct sender_command_data *scd)
195 sender_status = SENDER_on;
199 static int udp_com_off(__a_unused struct sender_command_data *scd)
201 udp_shutdown_targets();
202 sender_status = SENDER_off;
206 static struct sender_client *udp_lookup_target(struct sender_command_data *scd)
208 struct sender_client *sc, *tmp;
209 char host[MAX_HOSTLEN];
212 list_for_each_entry_safe(sc, tmp, &targets, node) {
213 parse_url(sc->name, host, sizeof(host), &port);
215 /* Unspecified port means wildcard port match */
216 if (scd->port > 0 && scd->port != port)
218 if (strcmp(host, scd->host))
225 static int udp_com_delete(struct sender_command_data *scd)
227 struct sender_client *sc = udp_lookup_target(scd);
230 udp_delete_target(sc, "com_delete");
233 PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd->host);
234 return -E_TARGET_NOT_FOUND;
237 /** Initialize UDP session and set maximum payload size. */
238 static int udp_init_fec(struct sender_client *sc)
240 struct udp_target *ut = sc->private_data;
243 PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
244 ut->sent_fec_eof = false;
245 mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
246 PARA_INFO_LOG("current MPS = %d bytes\n", mps);
250 /** Check and clear socket error if any. */
251 static int udp_check_socket_state(struct sender_client *sc)
253 struct udp_target *ut = sc->private_data;
255 socklen_t errlen = sizeof(ret);
257 if (getsockopt(sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
258 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
260 } else if (ret == 0) {
262 } else if (ret == ECONNREFUSED) {
263 time_t dist = now->tv_sec - ut->last_unreachable;
265 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
267 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
268 ut->last_unreachable = now->tv_sec;
272 * unreachable_time < dist <= 2 * unreachable_time
273 * No errors are allowed during this time window.
275 PARA_NOTICE_LOG("Evicting %s after %d seconds "
276 "of connection errors.\n",
277 sc->name, (int)dist);
280 return -ERRNO_TO_PARA_ERROR(ret);
283 static void udp_send_fec(struct sender_client *sc, char *buf, size_t len)
287 if (sender_status == SENDER_off)
291 ret = udp_check_socket_state(sc);
294 ret = xwrite(sc->fd, buf, len);
295 if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
297 * Happens if meanwhile an ICMP Destination / Port Unreachable
298 * has arrived. Ignore, persistent errors will be caught above.
306 udp_delete_target(sc, para_strerror(-ret));
309 static int udp_com_add(struct sender_command_data *scd)
312 struct udp_target *ut;
313 struct sender_client *sc = udp_lookup_target(scd);
316 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
318 return -E_TARGET_EXISTS;
320 ut = para_calloc(sizeof(*ut));
321 sc = para_calloc(sizeof(*sc));
322 ut->fcp.slices_per_group = scd->slices_per_group;
323 ut->fcp.data_slices_per_group = scd->data_slices_per_group;
324 ut->fcp.init_fec = udp_init_fec;
325 ut->fcp.send_fec = udp_send_fec;
326 ut->fcp.need_periodic_header = true;
328 sc->private_data = ut;
330 ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
335 ret = mcast_sender_setup(sc);
338 ret = mark_fd_nonblocking(sc->fd);
341 sc->name = para_strdup(remote_name(sc->fd));
342 PARA_INFO_LOG("adding to target list (%s)\n", sc->name);
343 ut->fc = vss_add_fec_client(sc, &ut->fcp);
344 para_list_add(&sc->node, &targets);
345 add_close_on_fork_list(sc->fd);
350 PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
351 scd->host, scd->port, para_strerror(-ret));
357 static char *udp_status(void)
359 struct sender_client *sc;
360 char *ret, *tgts = NULL;
362 list_for_each_entry(sc, &targets, node) {
363 struct udp_target *ut = sc->private_data;
364 char *tmp = make_message("%s%s/%u:%u ",
365 tgts ? : "", sc->name,
366 ut->fcp.data_slices_per_group,
367 ut->fcp.slices_per_group
376 (sender_status == SENDER_on)? "on" : "off",
377 stringify_port(OPT_UINT32_VAL(UDP_DEFAULT_PORT), "udp"),
378 tgts? tgts : "(none)"
384 static void udp_init_target_list(void)
386 struct sender_command_data scd;
389 INIT_LIST_HEAD(&targets);
390 for (i = 0; i < OPT_GIVEN(UDP_TARGET); i++) {
391 const char *arg = lls_string_val(i, OPT_RESULT(UDP_TARGET));
392 if (udp_resolve_target(arg, &scd) < 0)
393 PARA_CRIT_LOG("not adding requested target '%s'\n",
400 static char *udp_help(void)
404 "usage: {add|delete} ip_address[:port][/[packet_size:]k:n]\n"
405 " - k is the number of data slices per FEC group\n"
406 " - n is the total number of slices in a FEC group\n"
407 " - packet_size reduces the slice size below path MTU\n\n"
408 "examples: add 224.0.1.38:1500 (IPv4 multicast)\n"
409 " add 224.0.1.38:8080/14:16 (explicit FEC)\n"
410 " add 10.10.1.42 (using default port)\n"
411 " add [FF05::42]:1500 (IPv6 multicast)\n"
412 " add [::1] (IPv6 localhost/default port)\n"
413 " delete myhost.net (host with port wildcard)\n"
414 " delete 10.1.2.3:456 (IPv4 with explicit port)\n"
415 " delete [badc0de::1] (IPv6 with port wildcard)\n"
420 * The init function of para_server's udp sender.
422 * \param s Pointer to the udp sender struct.
424 * It initializes all function pointers of \a s and the list of udp targets.
426 void udp_send_init(struct sender *s)
428 INIT_LIST_HEAD(&targets);
429 s->status = udp_status;
432 s->pre_select = NULL;
433 s->post_select = NULL;
434 s->shutdown_clients = udp_shutdown_targets;
435 s->resolve_target = udp_resolve_target;
436 s->client_cmds[SENDER_on] = udp_com_on;
437 s->client_cmds[SENDER_off] = udp_com_off;
438 s->client_cmds[SENDER_deny] = NULL;
439 s->client_cmds[SENDER_allow] = NULL;
440 s->client_cmds[SENDER_add] = udp_com_add;
441 s->client_cmds[SENDER_delete] = udp_com_delete;
442 sender_status = SENDER_off;
443 udp_init_target_list();
444 if (!OPT_GIVEN(UDP_NO_AUTOSTART))
445 sender_status = SENDER_on;
446 PARA_DEBUG_LOG("udp sender init complete\n");