2 This file is part of GNUnet
3 (C) 2010, 2011 Christian Grothoff (and other contributing authors)
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6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
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13 General Public License for more details.
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22 * @file transport/plugin_transport_udp_broadcasting.c
23 * @brief Neighbour discovery with UDP
24 * @author Christian Grothoff
25 * @author Matthias Wachs
28 #include "plugin_transport_udp.h"
29 #include "gnunet_hello_lib.h"
30 #include "gnunet_util_lib.h"
31 #include "gnunet_fragmentation_lib.h"
32 #include "gnunet_nat_lib.h"
33 #include "gnunet_protocols.h"
34 #include "gnunet_resolver_service.h"
35 #include "gnunet_signatures.h"
36 #include "gnunet_constants.h"
37 #include "gnunet_statistics_service.h"
38 #include "gnunet_transport_service.h"
39 #include "gnunet_transport_plugin.h"
40 #include "transport.h"
42 #define LOG(kind,...) GNUNET_log_from (kind, "transport-udp", __VA_ARGS__)
44 /* *********** Cryogenic ********** */
49 #include <sys/ioctl.h>
50 #include <sys/select.h>
54 #define PM_SET_DELAY_AND_TIMEOUT _IOW(PM_MAGIC, 1, struct pm_times)
57 unsigned long delay_msecs;
58 unsigned long timeout_msecs;
61 /************************************/
64 struct UDP_Beacon_Message
69 struct GNUNET_MessageHeader header;
72 * What is the identity of the sender
74 struct GNUNET_PeerIdentity sender;
78 struct BroadcastAddress
80 struct BroadcastAddress *next;
82 struct BroadcastAddress *prev;
85 * ID of select broadcast task
87 struct GNUNET_SCHEDULER_Task * broadcast_task;
89 struct Plugin *plugin;
91 struct sockaddr *addr;
99 struct GNUNET_DISK_FileHandle *cryogenic_fd;
102 * Time out for cryogenic.
104 struct pm_times cryogenic_times;
110 * Client-specific context for #broadcast_mst_cb().
114 struct Plugin *plugin;
116 const union UdpAddress *udp_addr;
123 enum GNUNET_ATS_Network_Type ats_address_network_type;
128 * Parse broadcast message received.
130 * @param cls the `struct Plugin`
131 * @param client the `struct MstContext` with sender address
132 * @param message the message we received
133 * @return #GNUNET_OK (always)
136 broadcast_mst_cb (void *cls,
138 const struct GNUNET_MessageHeader *message)
140 struct Plugin *plugin = cls;
141 struct MstContext *mc = client;
142 struct GNUNET_HELLO_Address *address;
143 const struct GNUNET_MessageHeader *hello;
144 const struct UDP_Beacon_Message *msg;
145 struct GNUNET_ATS_Information atsi;
147 msg = (const struct UDP_Beacon_Message *) message;
149 if (GNUNET_MESSAGE_TYPE_TRANSPORT_BROADCAST_BEACON !=
150 ntohs (msg->header.type))
152 LOG (GNUNET_ERROR_TYPE_DEBUG,
153 "Received beacon with %u bytes from peer `%s' via address `%s'\n",
154 ntohs (msg->header.size),
155 GNUNET_i2s (&msg->sender),
156 udp_address_to_string (NULL,
161 atsi.type = htonl (GNUNET_ATS_NETWORK_TYPE);
162 atsi.value = htonl (mc->ats_address_network_type);
163 GNUNET_break (ntohl(mc->ats_address_network_type) !=
164 GNUNET_ATS_NET_UNSPECIFIED);
166 hello = (struct GNUNET_MessageHeader *) &msg[1];
167 address = GNUNET_HELLO_address_allocate (&msg->sender,
171 GNUNET_HELLO_ADDRESS_INFO_NONE);
172 plugin->env->receive (plugin->env->cls,
176 plugin->env->update_address_metrics (plugin->env->cls,
181 GNUNET_HELLO_address_free (address);
182 GNUNET_STATISTICS_update (plugin->env->stats,
183 _("# Multicast HELLO beacons received via UDP"),
190 * We received a broadcast message. Process it and all subsequent
191 * messages in the same packet.
193 * @param plugin the UDP plugin
194 * @param buf the buffer with the message(s)
195 * @param size number of bytes in @a buf
196 * @param udp_addr address of the sender
197 * @param udp_addr_len number of bytes in @a udp_addr
198 * @param network_type network type of the sender's address
201 udp_broadcast_receive (struct Plugin *plugin,
204 const union UdpAddress *udp_addr,
206 enum GNUNET_ATS_Network_Type network_type)
208 struct MstContext mc;
210 mc.udp_addr = udp_addr;
211 mc.udp_addr_len = udp_addr_len;
212 mc.ats_address_network_type = network_type;
213 GNUNET_SERVER_mst_receive (plugin->broadcast_mst,
222 prepare_beacon (struct Plugin *plugin,
223 struct UDP_Beacon_Message *msg)
228 const struct GNUNET_MessageHeader *hello;
229 hello = plugin->env->get_our_hello ();
232 hello_size = GNUNET_HELLO_size ((struct GNUNET_HELLO_Message *) hello);
233 msg_size = hello_size + sizeof (struct UDP_Beacon_Message);
235 if (hello_size < (sizeof (struct GNUNET_MessageHeader)) ||
236 (msg_size > (UDP_MTU)))
239 msg->sender = *(plugin->env->my_identity);
240 msg->header.size = htons (msg_size);
241 msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_BROADCAST_BEACON);
242 memcpy (&msg[1], hello, hello_size);
248 udp_ipv4_broadcast_send (void *cls,
249 const struct GNUNET_SCHEDULER_TaskContext *tc)
251 struct BroadcastAddress *baddr = cls;
252 struct Plugin *plugin = baddr->plugin;
255 char buf[65536] GNUNET_ALIGN;
257 baddr->broadcast_task = NULL;
259 msg_size = prepare_beacon(plugin, (struct UDP_Beacon_Message *) &buf);
262 struct sockaddr_in *addr = (struct sockaddr_in *) baddr->addr;
264 addr->sin_port = htons (plugin->port);
265 sent = GNUNET_NETWORK_socket_sendto (plugin->sockv4, &buf, msg_size,
266 (const struct sockaddr *) addr,
268 if (sent == GNUNET_SYSERR)
270 if ((ENETUNREACH == errno) || (ENETDOWN == errno))
272 /* "Network unreachable" or "Network down"
274 * This indicates that we just do not have network connectivity
276 GNUNET_log (GNUNET_ERROR_TYPE_BULK | GNUNET_ERROR_TYPE_WARNING,
277 "Network connectivity is down, cannot send beacon!\n");
280 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "sendto");
284 LOG (GNUNET_ERROR_TYPE_DEBUG,
285 "Sent HELLO beacon broadcast with %i bytes to address %s\n", sent,
286 GNUNET_a2s (baddr->addr, baddr->addrlen));
294 if (NULL != baddr->cryogenic_fd)
296 baddr->cryogenic_times.delay_msecs = (plugin->broadcast_interval.rel_value_us/1000.0)*0.5;
297 baddr->cryogenic_times.timeout_msecs = (plugin->broadcast_interval.rel_value_us/1000.0)*1.5;
299 if (ioctl(baddr->cryogenic_fd->fd,
300 PM_SET_DELAY_AND_TIMEOUT,
301 &baddr->cryogenic_times) < 0)
303 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "ioctl");
304 baddr->broadcast_task =
305 GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
306 &udp_ipv4_broadcast_send, baddr);
309 GNUNET_SCHEDULER_add_write_file (GNUNET_TIME_UNIT_FOREVER_REL,
311 &udp_ipv4_broadcast_send,
317 baddr->broadcast_task =
318 GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
319 &udp_ipv4_broadcast_send, baddr);
324 udp_ipv6_broadcast_send (void *cls,
325 const struct GNUNET_SCHEDULER_TaskContext *tc)
327 struct BroadcastAddress *baddr = cls;
328 struct Plugin *plugin = baddr->plugin;
331 char buf[65536] GNUNET_ALIGN;
332 const struct sockaddr_in6 *s6 = (const struct sockaddr_in6 *) baddr->addr;
334 baddr->broadcast_task = NULL;
336 msg_size = prepare_beacon(plugin, (struct UDP_Beacon_Message *) &buf);
337 /* Note: unclear if this actually works to limit the multicast to
338 the specified interface as we're not (necessarily) using a
339 link-local multicast group and the kernel suggests that the
340 scope ID is only respected for link-local addresses; however,
341 if the scope ID is ignored, the kernel should just multicast
342 on ALL interfaces, which is merely slightly less efficient;
343 in that case, we might want to revert to only doing this
344 once, and not per interface (hard to test...) */
345 plugin->ipv6_multicast_address.sin6_scope_id = s6->sin6_scope_id;
346 sent = GNUNET_NETWORK_socket_sendto (plugin->sockv6, &buf, msg_size,
347 (const struct sockaddr *)
348 &plugin->ipv6_multicast_address,
349 sizeof (struct sockaddr_in6));
350 plugin->ipv6_multicast_address.sin6_scope_id = 0;
351 if (sent == GNUNET_SYSERR)
353 if ((ENETUNREACH == errno) || (ENETDOWN == errno))
355 /* "Network unreachable" or "Network down"
357 * This indicates that this system is IPv6 enabled, but does not
358 * have a valid global IPv6 address assigned
360 GNUNET_log (GNUNET_ERROR_TYPE_BULK | GNUNET_ERROR_TYPE_WARNING,
361 "Network connectivity is down, cannot send beacon!\n");
364 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "sendto");
368 LOG (GNUNET_ERROR_TYPE_DEBUG,
369 "Sending IPv6 HELLO beacon broadcast with %d bytes to address %s\n",
371 GNUNET_a2s ((const struct sockaddr *) &plugin->ipv6_multicast_address,
372 sizeof (struct sockaddr_in6)));
378 if (NULL != baddr->cryogenic_fd)
380 baddr->cryogenic_times.delay_msecs = (plugin->broadcast_interval.rel_value_us/1000.0)*0.5;
381 baddr->cryogenic_times.timeout_msecs = (plugin->broadcast_interval.rel_value_us/1000.0)*1.5;
383 if (ioctl(baddr->cryogenic_fd->fd,
384 PM_SET_DELAY_AND_TIMEOUT,
385 &baddr->cryogenic_times) < 0)
387 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "ioctl");
388 baddr->broadcast_task =
389 GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
390 &udp_ipv6_broadcast_send, baddr);
393 GNUNET_SCHEDULER_add_write_file (GNUNET_TIME_UNIT_FOREVER_REL,
395 &udp_ipv4_broadcast_send,
400 baddr->broadcast_task =
401 GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
402 &udp_ipv6_broadcast_send, baddr);
407 * Callback function invoked for each interface found.
409 * @param cls closure with the `struct Plugin`
410 * @param name name of the interface (can be NULL for unknown)
411 * @param isDefault is this presumably the default interface
412 * @param addr address of this interface (can be NULL for unknown or unassigned)
413 * @param broadcast_addr the broadcast address (can be NULL for unknown or unassigned)
414 * @param netmask the network mask (can be NULL for unknown or unassigned)
415 * @param addrlen length of the address
416 * @return #GNUNET_OK to continue iteration, #GNUNET_SYSERR to abort
419 iface_proc (void *cls,
422 const struct sockaddr *addr,
423 const struct sockaddr *broadcast_addr,
424 const struct sockaddr *netmask, socklen_t addrlen)
426 struct Plugin *plugin = cls;
427 struct BroadcastAddress *ba;
428 enum GNUNET_ATS_Network_Type network;
432 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
433 "address %s for interface %s %p\n ",
434 GNUNET_a2s (addr, addrlen), name, addr);
435 if (NULL == broadcast_addr)
437 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
438 "broadcast address %s for interface %s %p\n ",
439 GNUNET_a2s (broadcast_addr, addrlen), name, broadcast_addr);
440 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "netmask %s for interface %s %p\n ",
441 GNUNET_a2s (netmask, addrlen), name, netmask);
443 network = plugin->env->get_address_type (plugin->env->cls, broadcast_addr, addrlen);
444 if (GNUNET_ATS_NET_LOOPBACK == network)
446 /* Broadcasting on loopback does not make sense */
450 ba = GNUNET_new (struct BroadcastAddress);
452 ba->addr = GNUNET_malloc (addrlen);
453 memcpy (ba->addr, broadcast_addr, addrlen);
454 ba->addrlen = addrlen;
456 if ( (GNUNET_YES == plugin->enable_ipv4) &&
457 (NULL != plugin->sockv4) &&
458 (addrlen == sizeof (struct sockaddr_in)) )
462 * setup Cryogenic FD for ipv4 broadcasting
466 GNUNET_asprintf (&filename,
469 if (0 == ACCESS (name, R_OK))
472 GNUNET_DISK_file_open (filename,
473 GNUNET_DISK_OPEN_WRITE,
474 GNUNET_DISK_PERM_NONE);
476 GNUNET_free (filename);
479 GNUNET_SCHEDULER_add_now (&udp_ipv4_broadcast_send, ba);
481 if ((GNUNET_YES == plugin->enable_ipv6) &&
482 (NULL != plugin->sockv6) &&
483 (addrlen == sizeof (struct sockaddr_in6)))
485 /* Create IPv6 multicast request */
486 struct ipv6_mreq multicastRequest;
487 const struct sockaddr_in6 *s6 = (const struct sockaddr_in6 *) broadcast_addr;
489 multicastRequest.ipv6mr_multiaddr =
490 plugin->ipv6_multicast_address.sin6_addr;
491 /* http://tools.ietf.org/html/rfc2553#section-5.2:
495 * Join a multicast group on a specified local interface. If the
496 * interface index is specified as 0, the kernel chooses the local
497 * interface. For example, some kernels look up the multicast
498 * group in the normal IPv6 routing table and using the resulting
499 * interface; we do this for each interface, so no need to use
502 multicastRequest.ipv6mr_interface = s6->sin6_scope_id;
504 /* Join the multicast group */
506 GNUNET_NETWORK_socket_setsockopt
507 (plugin->sockv6, IPPROTO_IPV6, IPV6_JOIN_GROUP,
508 &multicastRequest, sizeof (multicastRequest)))
510 LOG (GNUNET_ERROR_TYPE_WARNING,
511 "Failed to join IPv6 multicast group: IPv6 broadcasting not running\n");
517 * setup Cryogenic FD for ipv6 broadcasting
521 GNUNET_asprintf (&filename,
524 if (0 == ACCESS (name, R_OK))
527 GNUNET_DISK_file_open (filename,
528 GNUNET_DISK_OPEN_WRITE,
529 GNUNET_DISK_PERM_NONE);
531 GNUNET_free (filename);
534 GNUNET_SCHEDULER_add_now (&udp_ipv6_broadcast_send, ba);
537 GNUNET_CONTAINER_DLL_insert (plugin->broadcast_head,
538 plugin->broadcast_tail, ba);
544 setup_broadcast (struct Plugin *plugin,
545 struct sockaddr_in6 *server_addrv6,
546 struct sockaddr_in *server_addrv4)
548 const struct GNUNET_MessageHeader *hello;
550 hello = plugin->env->get_our_hello ();
552 GNUNET_HELLO_is_friend_only ((const struct GNUNET_HELLO_Message *) hello))
554 LOG (GNUNET_ERROR_TYPE_WARNING,
555 _("Disabling HELLO broadcasting due to friend-to-friend only configuration!\n"));
559 /* always create tokenizers */
560 plugin->broadcast_mst =
561 GNUNET_SERVER_mst_create (&broadcast_mst_cb, plugin);
563 if (GNUNET_YES != plugin->enable_broadcasting)
564 return; /* We do not send, just receive */
566 /* create IPv4 broadcast socket */
567 if ((GNUNET_YES == plugin->enable_ipv4) && (NULL != plugin->sockv4))
571 if (GNUNET_NETWORK_socket_setsockopt
572 (plugin->sockv4, SOL_SOCKET, SO_BROADCAST, &yes,
573 sizeof (int)) != GNUNET_OK)
575 LOG (GNUNET_ERROR_TYPE_WARNING,
576 _("Failed to set IPv4 broadcast option for broadcast socket on port %d\n"),
577 ntohs (server_addrv4->sin_port));
580 /* create IPv6 multicast socket */
581 if ((GNUNET_YES == plugin->enable_ipv6) && (plugin->sockv6 != NULL))
583 memset (&plugin->ipv6_multicast_address, 0, sizeof (struct sockaddr_in6));
585 inet_pton (AF_INET6, "FF05::13B",
586 &plugin->ipv6_multicast_address.sin6_addr));
587 plugin->ipv6_multicast_address.sin6_family = AF_INET6;
588 plugin->ipv6_multicast_address.sin6_port = htons (plugin->port);
590 GNUNET_OS_network_interfaces_list (&iface_proc, plugin);
595 stop_broadcast (struct Plugin *plugin)
597 if (GNUNET_YES == plugin->enable_broadcasting)
599 /* Disable broadcasting */
600 while (plugin->broadcast_head != NULL)
602 struct BroadcastAddress *p = plugin->broadcast_head;
604 if (p->broadcast_task != NULL)
606 GNUNET_SCHEDULER_cancel (p->broadcast_task);
607 p->broadcast_task = NULL;
609 if ((GNUNET_YES == plugin->enable_ipv6) &&
610 (NULL != plugin->sockv6) &&
611 (p->addrlen == sizeof (struct sockaddr_in6)))
613 /* Create IPv6 multicast request */
614 struct ipv6_mreq multicastRequest;
615 const struct sockaddr_in6 *s6 = (const struct sockaddr_in6 *) p->addr;
617 multicastRequest.ipv6mr_multiaddr =
618 plugin->ipv6_multicast_address.sin6_addr;
619 multicastRequest.ipv6mr_interface = s6->sin6_scope_id;
621 /* Leave the multicast group */
623 GNUNET_NETWORK_socket_setsockopt
624 (plugin->sockv6, IPPROTO_IPV6, IPV6_LEAVE_GROUP,
625 &multicastRequest, sizeof (multicastRequest)))
627 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "setsockopt");
631 LOG (GNUNET_ERROR_TYPE_DEBUG, "IPv6 multicasting stopped\n");
636 GNUNET_DISK_file_close(p->cryogenic_fd);
638 GNUNET_CONTAINER_DLL_remove (plugin->broadcast_head,
639 plugin->broadcast_tail, p);
640 GNUNET_free (p->addr);
646 if (NULL != plugin->broadcast_mst)
648 GNUNET_SERVER_mst_destroy (plugin->broadcast_mst);
649 plugin->broadcast_mst = NULL;
653 /* end of plugin_transport_udp_broadcasting.c */