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3 Copyright (C) 2010, 2011 GNUnet e.V.
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
8 or (at your option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Affero General Public License for more details.
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
18 SPDX-License-Identifier: AGPL3.0-or-later
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_protocols.h"
33 #include "gnunet_resolver_service.h"
34 #include "gnunet_signatures.h"
35 #include "gnunet_constants.h"
36 #include "gnunet_statistics_service.h"
37 #include "gnunet_transport_service.h"
38 #include "gnunet_transport_plugin.h"
39 #include "transport.h"
41 #define LOG(kind, ...) GNUNET_log_from (kind, "transport-udp", __VA_ARGS__)
43 /* *********** Cryogenic ********** */
48 #include <sys/ioctl.h>
49 #include <sys/select.h>
53 #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_NetworkType 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,
137 const struct GNUNET_MessageHeader *message)
139 struct MstContext *mc = cls;
140 struct Plugin *plugin = mc->plugin;
141 struct GNUNET_HELLO_Address *address;
142 const struct GNUNET_MessageHeader *hello;
143 const struct UDP_Beacon_Message *msg;
145 msg = (const struct UDP_Beacon_Message *) message;
147 if (GNUNET_MESSAGE_TYPE_TRANSPORT_BROADCAST_BEACON !=
148 ntohs (msg->header.type))
150 LOG (GNUNET_ERROR_TYPE_DEBUG,
151 "Received beacon with %u bytes from peer `%s' via address `%s'\n",
152 ntohs (msg->header.size),
153 GNUNET_i2s (&msg->sender),
154 udp_address_to_string (NULL,
157 hello = (struct GNUNET_MessageHeader *) &msg[1];
158 address = GNUNET_HELLO_address_allocate (&msg->sender,
162 GNUNET_HELLO_ADDRESS_INFO_NONE);
163 plugin->env->receive (plugin->env->cls,
167 GNUNET_HELLO_address_free (address);
168 GNUNET_STATISTICS_update (plugin->env->stats,
169 _ ("# Multicast HELLO beacons received via UDP"),
176 * We received a broadcast message. Process it and all subsequent
177 * messages in the same packet.
179 * @param plugin the UDP plugin
180 * @param buf the buffer with the message(s)
181 * @param size number of bytes in @a buf
182 * @param udp_addr address of the sender
183 * @param udp_addr_len number of bytes in @a udp_addr
184 * @param network_type network type of the sender's address
187 udp_broadcast_receive (struct Plugin *plugin,
190 const union UdpAddress *udp_addr,
192 enum GNUNET_NetworkType network_type)
194 struct GNUNET_MessageStreamTokenizer *broadcast_mst;
195 struct MstContext mc;
197 broadcast_mst = GNUNET_MST_create (&broadcast_mst_cb,
200 mc.udp_addr = udp_addr;
201 mc.udp_addr_len = udp_addr_len;
202 mc.ats_address_network_type = network_type;
203 GNUNET_MST_from_buffer (broadcast_mst,
207 GNUNET_MST_destroy (broadcast_mst);
212 prepare_beacon (struct Plugin *plugin,
213 struct UDP_Beacon_Message *msg)
218 const struct GNUNET_MessageHeader *hello;
220 hello = plugin->env->get_our_hello ();
223 hello_size = GNUNET_HELLO_size ((struct GNUNET_HELLO_Message *) hello);
224 msg_size = hello_size + sizeof(struct UDP_Beacon_Message);
226 if ((hello_size < (sizeof(struct GNUNET_MessageHeader))) ||
227 (msg_size > (UDP_MTU)))
230 msg->sender = *(plugin->env->my_identity);
231 msg->header.size = htons (msg_size);
232 msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_BROADCAST_BEACON);
233 GNUNET_memcpy (&msg[1], hello, hello_size);
239 udp_ipv4_broadcast_send (void *cls)
241 struct BroadcastAddress *baddr = cls;
242 struct Plugin *plugin = baddr->plugin;
245 char buf[65536] GNUNET_ALIGN;
247 baddr->broadcast_task = NULL;
249 msg_size = prepare_beacon (plugin, (struct UDP_Beacon_Message *) &buf);
252 struct sockaddr_in *addr = (struct sockaddr_in *) baddr->addr;
254 addr->sin_port = htons (plugin->port);
255 sent = GNUNET_NETWORK_socket_sendto (plugin->sockv4, &buf, msg_size,
256 (const struct sockaddr *) addr,
258 if (sent == GNUNET_SYSERR)
260 if ((ENETUNREACH == errno) || (ENETDOWN == errno))
262 /* "Network unreachable" or "Network down"
264 * This indicates that we just do not have network connectivity
266 GNUNET_log (GNUNET_ERROR_TYPE_BULK | GNUNET_ERROR_TYPE_WARNING,
267 "Network connectivity is down, cannot send beacon!\n");
270 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "sendto");
274 LOG (GNUNET_ERROR_TYPE_DEBUG,
275 "Sent HELLO beacon broadcast with %i bytes to address %s\n", sent,
276 GNUNET_a2s (baddr->addr, baddr->addrlen));
284 if (NULL != baddr->cryogenic_fd)
286 baddr->cryogenic_times.delay_msecs =
287 (plugin->broadcast_interval.rel_value_us / 1000.0) * 0.5;
288 baddr->cryogenic_times.timeout_msecs =
289 (plugin->broadcast_interval.rel_value_us / 1000.0) * 1.5;
291 if (ioctl (baddr->cryogenic_fd->fd,
292 PM_SET_DELAY_AND_TIMEOUT,
293 &baddr->cryogenic_times) < 0)
295 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "ioctl");
296 baddr->broadcast_task =
297 GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
298 &udp_ipv4_broadcast_send, baddr);
301 GNUNET_SCHEDULER_add_write_file (GNUNET_TIME_UNIT_FOREVER_REL,
303 &udp_ipv4_broadcast_send,
308 baddr->broadcast_task =
309 GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
310 &udp_ipv4_broadcast_send, baddr);
315 udp_ipv6_broadcast_send (void *cls)
317 struct BroadcastAddress *baddr = cls;
318 struct Plugin *plugin = baddr->plugin;
321 char buf[65536] GNUNET_ALIGN;
322 const struct sockaddr_in6 *s6 = (const struct sockaddr_in6 *) baddr->addr;
324 baddr->broadcast_task = NULL;
326 msg_size = prepare_beacon (plugin, (struct UDP_Beacon_Message *) &buf);
327 /* Note: unclear if this actually works to limit the multicast to
328 the specified interface as we're not (necessarily) using a
329 link-local multicast group and the kernel suggests that the
330 scope ID is only respected for link-local addresses; however,
331 if the scope ID is ignored, the kernel should just multicast
332 on ALL interfaces, which is merely slightly less efficient;
333 in that case, we might want to revert to only doing this
334 once, and not per interface (hard to test...) */plugin->ipv6_multicast_address.sin6_scope_id = s6->sin6_scope_id;
335 sent = GNUNET_NETWORK_socket_sendto (plugin->sockv6, &buf, msg_size,
336 (const struct sockaddr *)
337 &plugin->ipv6_multicast_address,
338 sizeof(struct sockaddr_in6));
339 plugin->ipv6_multicast_address.sin6_scope_id = 0;
340 if (sent == GNUNET_SYSERR)
342 if ((ENETUNREACH == errno) || (ENETDOWN == errno))
344 /* "Network unreachable" or "Network down"
346 * This indicates that this system is IPv6 enabled, but does not
347 * have a valid global IPv6 address assigned
348 */GNUNET_log (GNUNET_ERROR_TYPE_BULK | GNUNET_ERROR_TYPE_WARNING,
349 "Network connectivity is down, cannot send beacon!\n");
352 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "sendto");
356 LOG (GNUNET_ERROR_TYPE_DEBUG,
357 "Sending IPv6 HELLO beacon broadcast with %d bytes to address %s\n",
359 GNUNET_a2s ((const struct sockaddr *) &plugin->ipv6_multicast_address,
360 sizeof(struct sockaddr_in6)));
366 if (NULL != baddr->cryogenic_fd)
368 baddr->cryogenic_times.delay_msecs =
369 (plugin->broadcast_interval.rel_value_us / 1000.0) * 0.5;
370 baddr->cryogenic_times.timeout_msecs =
371 (plugin->broadcast_interval.rel_value_us / 1000.0) * 1.5;
373 if (ioctl (baddr->cryogenic_fd->fd,
374 PM_SET_DELAY_AND_TIMEOUT,
375 &baddr->cryogenic_times) < 0)
377 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "ioctl");
378 baddr->broadcast_task =
379 GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
380 &udp_ipv6_broadcast_send, baddr);
383 GNUNET_SCHEDULER_add_write_file (GNUNET_TIME_UNIT_FOREVER_REL,
385 &udp_ipv6_broadcast_send,
390 baddr->broadcast_task =
391 GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
392 &udp_ipv6_broadcast_send, baddr);
397 * Callback function invoked for each interface found.
399 * @param cls closure with the `struct Plugin`
400 * @param name name of the interface (can be NULL for unknown)
401 * @param isDefault is this presumably the default interface
402 * @param addr address of this interface (can be NULL for unknown or unassigned)
403 * @param broadcast_addr the broadcast address (can be NULL for unknown or unassigned)
404 * @param netmask the network mask (can be NULL for unknown or unassigned)
405 * @param addrlen length of the address
406 * @return #GNUNET_OK to continue iteration, #GNUNET_SYSERR to abort
409 iface_proc (void *cls,
412 const struct sockaddr *addr,
413 const struct sockaddr *broadcast_addr,
414 const struct sockaddr *netmask, socklen_t addrlen)
416 struct Plugin *plugin = cls;
417 struct BroadcastAddress *ba;
418 enum GNUNET_NetworkType network;
422 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
423 "address %s for interface %s %p\n ",
424 GNUNET_a2s (addr, addrlen), name, addr);
425 if (NULL == broadcast_addr)
427 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
428 "broadcast address %s for interface %s %p\n ",
429 GNUNET_a2s (broadcast_addr, addrlen), name, broadcast_addr);
430 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "netmask %s for interface %s %p\n ",
431 GNUNET_a2s (netmask, addrlen), name, netmask);
433 network = plugin->env->get_address_type (plugin->env->cls, broadcast_addr,
435 if (GNUNET_NT_LOOPBACK == network)
437 /* Broadcasting on loopback does not make sense */
441 ba = GNUNET_new (struct BroadcastAddress);
443 ba->addr = GNUNET_malloc (addrlen);
444 GNUNET_memcpy (ba->addr, broadcast_addr, addrlen);
445 ba->addrlen = addrlen;
447 if ((GNUNET_YES == plugin->enable_ipv4) &&
448 (NULL != plugin->sockv4) &&
449 (addrlen == sizeof(struct sockaddr_in)))
453 * setup Cryogenic FD for ipv4 broadcasting
457 GNUNET_asprintf (&filename,
460 if (0 == access (name, R_OK))
463 GNUNET_DISK_file_open (filename,
464 GNUNET_DISK_OPEN_WRITE,
465 GNUNET_DISK_PERM_NONE);
467 GNUNET_free (filename);
470 GNUNET_SCHEDULER_add_now (&udp_ipv4_broadcast_send, ba);
472 if ((GNUNET_YES == plugin->enable_ipv6) &&
473 (NULL != plugin->sockv6) &&
474 (addrlen == sizeof(struct sockaddr_in6)))
476 /* Create IPv6 multicast request */
477 struct ipv6_mreq multicastRequest;
478 const struct sockaddr_in6 *s6 = (const struct
479 sockaddr_in6 *) broadcast_addr;
481 multicastRequest.ipv6mr_multiaddr =
482 plugin->ipv6_multicast_address.sin6_addr;
483 /* http://tools.ietf.org/html/rfc2553#section-5.2:
487 * Join a multicast group on a specified local interface. If the
488 * interface index is specified as 0, the kernel chooses the local
489 * interface. For example, some kernels look up the multicast
490 * group in the normal IPv6 routing table and using the resulting
491 * interface; we do this for each interface, so no need to use
493 */multicastRequest.ipv6mr_interface = s6->sin6_scope_id;
495 /* Join the multicast group */
497 GNUNET_NETWORK_socket_setsockopt
498 (plugin->sockv6, IPPROTO_IPV6, IPV6_JOIN_GROUP,
499 &multicastRequest, sizeof(multicastRequest)))
501 LOG (GNUNET_ERROR_TYPE_WARNING,
502 "Failed to join IPv6 multicast group: IPv6 broadcasting not running\n");
508 * setup Cryogenic FD for ipv6 broadcasting
512 GNUNET_asprintf (&filename,
515 if (0 == access (name, R_OK))
518 GNUNET_DISK_file_open (filename,
519 GNUNET_DISK_OPEN_WRITE,
520 GNUNET_DISK_PERM_NONE);
522 GNUNET_free (filename);
525 GNUNET_SCHEDULER_add_now (&udp_ipv6_broadcast_send, ba);
528 GNUNET_CONTAINER_DLL_insert (plugin->broadcast_head,
529 plugin->broadcast_tail, ba);
535 * Setup broadcasting subsystem.
538 * @param server_addrv6
539 * @param server_addrv4
542 setup_broadcast (struct Plugin *plugin,
543 struct sockaddr_in6 *server_addrv6,
544 struct sockaddr_in *server_addrv4)
547 GNUNET_CONFIGURATION_get_value_yesno (plugin->env->cfg,
551 LOG (GNUNET_ERROR_TYPE_WARNING,
553 "Disabling HELLO broadcasting due to friend-to-friend only configuration!\n"));
557 if (GNUNET_YES != plugin->enable_broadcasting)
558 return; /* We do not send, just receive */
560 /* create IPv4 broadcast socket */
561 if ((GNUNET_YES == plugin->enable_ipv4) && (NULL != plugin->sockv4))
565 if (GNUNET_NETWORK_socket_setsockopt
566 (plugin->sockv4, SOL_SOCKET, SO_BROADCAST, &yes,
567 sizeof(int)) != GNUNET_OK)
569 LOG (GNUNET_ERROR_TYPE_WARNING,
571 "Failed to set IPv4 broadcast option for broadcast socket on port %d\n"),
572 ntohs (server_addrv4->sin_port));
575 /* create IPv6 multicast socket */
576 if ((GNUNET_YES == plugin->enable_ipv6) && (plugin->sockv6 != NULL))
578 memset (&plugin->ipv6_multicast_address, 0, sizeof(struct sockaddr_in6));
580 inet_pton (AF_INET6, "FF05::13B",
581 &plugin->ipv6_multicast_address.sin6_addr));
582 plugin->ipv6_multicast_address.sin6_family = AF_INET6;
583 plugin->ipv6_multicast_address.sin6_port = htons (plugin->port);
585 GNUNET_OS_network_interfaces_list (&iface_proc, plugin);
590 * Stop broadcasting subsystem.
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);
647 /* end of plugin_transport_udp_broadcasting.c */