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
;
59 if (process_is_command_handler())
63 PARA_INFO_LOG("sending FEC EOF\n");
64 len
= vss_get_fec_eof_packet(&buf
);
65 /* Ignore write() errors since we are closing the target anyway. */
66 if (write(sc
->fd
, buf
, len
))
67 do_nothing
; /* avoid "ignoring return value" warning */
68 ut
->sent_fec_eof
= true;
71 static void udp_delete_target(struct sender_client
*sc
, const char *msg
)
73 struct udp_target
*ut
= sc
->private_data
;
75 if (!process_is_command_handler())
76 PARA_NOTICE_LOG("deleting %s (%s) from list\n", sc
->name
, msg
);
78 /* command handlers already called close_listed_fds() */
79 if (!process_is_command_handler()) {
81 del_close_on_fork_list(sc
->fd
);
83 vss_del_fec_client(ut
->fc
);
91 * Perform AF-independent multicast sender setup.
93 * \param sc The connected sender client.
95 * \return Zero if okay, negative on error.
97 static int mcast_sender_setup(struct sender_client
*sc
)
99 struct sockaddr_storage ss
;
100 socklen_t sslen
= sizeof(ss
);
101 int ttl
= OPT_INT32_VAL(UDP_TTL
), id
= 0;
104 if (OPT_GIVEN(UDP_MCAST_IFACE
)) {
105 const char *iface
= OPT_STRING_VAL(UDP_MCAST_IFACE
);
107 id
= if_nametoindex(iface
);
109 PARA_WARNING_LOG("could not resolve interface '%s', "
110 "using default", iface
);
113 if (getpeername(sc
->fd
, (struct sockaddr
*)&ss
, &sslen
) < 0)
115 assert(ss
.ss_family
== AF_INET
|| ss
.ss_family
== AF_INET6
);
117 /* RFC 3493, 5.2: -1 means 'use kernel default' */
118 if (ttl
< 0 || ttl
> 255)
121 switch (ss
.ss_family
) {
123 if (!IN_MULTICAST(htonl(((struct sockaddr_in
*)&ss
)->sin_addr
.s_addr
)))
129 memset(&mn
, 0, sizeof(mn
));
131 if (setsockopt(sc
->fd
, IPPROTO_IP
, IP_MULTICAST_IF
, &mn
, sizeof(mn
)) < 0)
134 PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
138 * Enable receiving multicast messages generated on the local host
139 * At least on Linux, this is enabled by default.
141 if (setsockopt(sc
->fd
, IPPROTO_IP
, IP_MULTICAST_LOOP
, &on
, sizeof(on
)) < 0)
144 /* Default: use local subnet (do not flood out into the WAN) */
147 if (setsockopt(sc
->fd
, IPPROTO_IP
, IP_MULTICAST_TTL
, &ttl
, sizeof(ttl
)) < 0)
151 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6
*)&ss
)->sin6_addr
))
154 setsockopt(sc
->fd
, IPPROTO_IPV6
, IPV6_MULTICAST_IF
, &id
, sizeof(id
)) < 0)
156 if (setsockopt(sc
->fd
, IPPROTO_IPV6
, IPV6_MULTICAST_LOOP
, &on
, sizeof(on
)) < 0)
158 if (setsockopt(sc
->fd
, IPPROTO_IPV6
, IPV6_MULTICAST_HOPS
, &ttl
, sizeof(ttl
)) < 0)
163 return -ERRNO_TO_PARA_ERROR(errno
);
166 static void udp_shutdown_targets(void)
168 struct sender_client
*sc
, *tmp
;
169 list_for_each_entry_safe(sc
, tmp
, &targets
, node
)
170 udp_close_target(sc
);
173 static void udp_shutdown(void)
175 struct sender_client
*sc
, *tmp
;
176 list_for_each_entry_safe(sc
, tmp
, &targets
, node
)
177 udp_delete_target(sc
, "shutdown");
180 static int udp_resolve_target(const char *url
, struct sender_command_data
*scd
)
185 ret
= parse_fec_url(url
, scd
);
188 port
= scd
->port
> 0 ? scd
->port
: OPT_UINT32_VAL(UDP_DEFAULT_PORT
);
190 ret
= para_connect(IPPROTO_UDP
, scd
->host
, port
);
194 result
= remote_name(ret
);
197 if (!parse_url(result
, scd
->host
, sizeof(scd
->host
), &scd
->port
))
198 return -E_ADDRESS_LOOKUP
;
202 static int udp_com_on(__a_unused
struct sender_command_data
*scd
)
204 sender_status
= SENDER_on
;
208 static int udp_com_off(__a_unused
struct sender_command_data
*scd
)
210 udp_shutdown_targets();
211 sender_status
= SENDER_off
;
215 static struct sender_client
*udp_lookup_target(struct sender_command_data
*scd
)
217 struct sender_client
*sc
, *tmp
;
218 char host
[MAX_HOSTLEN
];
221 list_for_each_entry_safe(sc
, tmp
, &targets
, node
) {
222 parse_url(sc
->name
, host
, sizeof(host
), &port
);
224 /* Unspecified port means wildcard port match */
225 if (scd
->port
> 0 && scd
->port
!= port
)
227 if (strcmp(host
, scd
->host
))
234 static int udp_com_delete(struct sender_command_data
*scd
)
236 struct sender_client
*sc
= udp_lookup_target(scd
);
239 udp_delete_target(sc
, "com_delete");
242 PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd
->host
);
243 return -E_TARGET_NOT_FOUND
;
246 /** Initialize UDP session and set maximum payload size. */
247 static int udp_init_fec(struct sender_client
*sc
)
249 struct udp_target
*ut
= sc
->private_data
;
252 PARA_INFO_LOG("sending to udp %s\n", sc
->name
);
253 ut
->sent_fec_eof
= false;
254 mps
= generic_max_transport_msg_size(sc
->fd
) - sizeof(struct udphdr
);
255 PARA_INFO_LOG("current MPS = %d bytes\n", mps
);
259 /** Check and clear socket error if any. */
260 static int udp_check_socket_state(struct sender_client
*sc
)
262 struct udp_target
*ut
= sc
->private_data
;
264 socklen_t errlen
= sizeof(ret
);
266 if (getsockopt(sc
->fd
, SOL_SOCKET
, SO_ERROR
, &ret
, &errlen
) < 0) {
267 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret
));
269 } else if (ret
== 0) {
271 } else if (ret
== ECONNREFUSED
) {
272 time_t dist
= now
->tv_sec
- ut
->last_unreachable
;
274 if (dist
<= UDP_MAX_UNREACHABLE_TIME
) {
276 } else if (dist
> 2 * UDP_MAX_UNREACHABLE_TIME
) {
277 ut
->last_unreachable
= now
->tv_sec
;
281 * unreachable_time < dist <= 2 * unreachable_time
282 * No errors are allowed during this time window.
284 PARA_NOTICE_LOG("Evicting %s after %d seconds "
285 "of connection errors.\n",
286 sc
->name
, (int)dist
);
289 return -ERRNO_TO_PARA_ERROR(ret
);
292 static void udp_send_fec(struct sender_client
*sc
, char *buf
, size_t len
)
296 if (sender_status
== SENDER_off
)
300 ret
= udp_check_socket_state(sc
);
303 ret
= xwrite(sc
->fd
, buf
, len
);
304 if (ret
== -ERRNO_TO_PARA_ERROR(ECONNREFUSED
)) {
306 * Happens if meanwhile an ICMP Destination / Port Unreachable
307 * has arrived. Ignore, persistent errors will be caught above.
315 udp_delete_target(sc
, para_strerror(-ret
));
318 static int udp_com_add(struct sender_command_data
*scd
)
321 struct udp_target
*ut
;
322 struct sender_client
*sc
= udp_lookup_target(scd
);
325 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
327 return -E_TARGET_EXISTS
;
329 ut
= zalloc(sizeof(*ut
));
330 sc
= zalloc(sizeof(*sc
));
331 ut
->fcp
.slices_per_group
= scd
->slices_per_group
;
332 ut
->fcp
.data_slices_per_group
= scd
->data_slices_per_group
;
333 ut
->fcp
.init_fec
= udp_init_fec
;
334 ut
->fcp
.send_fec
= udp_send_fec
;
335 ut
->fcp
.need_periodic_header
= true;
337 sc
->private_data
= ut
;
339 ret
= para_connect(IPPROTO_UDP
, scd
->host
, scd
->port
);
344 ret
= mcast_sender_setup(sc
);
347 ret
= mark_fd_nonblocking(sc
->fd
);
350 sc
->name
= para_strdup(remote_name(sc
->fd
));
351 PARA_INFO_LOG("adding to target list (%s)\n", sc
->name
);
352 ut
->fc
= vss_add_fec_client(sc
, &ut
->fcp
);
353 para_list_add(&sc
->node
, &targets
);
354 add_close_on_fork_list(sc
->fd
);
359 PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
360 scd
->host
, scd
->port
, para_strerror(-ret
));
366 static char *udp_status(void)
368 struct sender_client
*sc
;
369 char *ret
, *tgts
= NULL
;
371 list_for_each_entry(sc
, &targets
, node
) {
372 struct udp_target
*ut
= sc
->private_data
;
373 char *tmp
= make_message("%s%s/%u:%u ",
374 tgts
? : "", sc
->name
,
375 ut
->fcp
.data_slices_per_group
,
376 ut
->fcp
.slices_per_group
385 (sender_status
== SENDER_on
)? "on" : "off",
386 stringify_port(OPT_UINT32_VAL(UDP_DEFAULT_PORT
), "udp"),
387 tgts
? tgts
: "(none)"
393 static void udp_init_target_list(void)
395 struct sender_command_data scd
;
398 init_list_head(&targets
);
399 for (i
= 0; i
< OPT_GIVEN(UDP_TARGET
); i
++) {
400 const char *arg
= lls_string_val(i
, OPT_RESULT(UDP_TARGET
));
401 if (udp_resolve_target(arg
, &scd
) < 0)
402 PARA_CRIT_LOG("not adding requested target '%s'\n",
409 static char *udp_help(void)
413 "usage: {add|delete} ip_address[:port][/[packet_size:]k:n]\n"
414 " - k is the number of data slices per FEC group\n"
415 " - n is the total number of slices in a FEC group\n"
416 " - packet_size reduces the slice size below path MTU\n\n"
417 "examples: add 224.0.1.38:1500 (IPv4 multicast)\n"
418 " add 224.0.1.38:8080/14:16 (explicit FEC)\n"
419 " add 10.10.1.42 (using default port)\n"
420 " add [FF05::42]:1500 (IPv6 multicast)\n"
421 " add [::1] (IPv6 localhost/default port)\n"
422 " delete myhost.net (host with port wildcard)\n"
423 " delete 10.1.2.3:456 (IPv4 with explicit port)\n"
424 " delete [badc0de::1] (IPv6 with port wildcard)\n"
428 /* Initialize the list of udp targets. */
429 static void udp_send_init(void)
431 init_list_head(&targets
);
432 sender_status
= SENDER_off
;
433 udp_init_target_list();
434 if (!OPT_GIVEN(UDP_NO_AUTOSTART
))
435 sender_status
= SENDER_on
;
436 PARA_DEBUG_LOG("udp sender init complete\n");
442 * In contrast to the other senders the UDP sender is active in the sense that
443 * it initiates the network connection according to its list of targets rather
444 * than passively waiting for clients to connect. Like DCCP streams, UDP
445 * streams are always sent FEC-encoded. The UDP sender is the only sender which
446 * supports IP multicasting.
448 const struct sender udp_sender
= {
450 .init
= udp_send_init
,
451 .shutdown
= udp_shutdown
,
452 .shutdown_clients
= udp_shutdown_targets
,
453 .resolve_target
= udp_resolve_target
,
455 [SENDER_on
] = udp_com_on
,
456 [SENDER_off
] = udp_com_off
,
457 [SENDER_add
] = udp_com_add
,
458 [SENDER_delete
] = udp_com_delete
,
461 .status
= udp_status
,