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
,