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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...) */
335 plugin->ipv6_multicast_address.sin6_scope_id = s6->sin6_scope_id;
336 sent = GNUNET_NETWORK_socket_sendto (plugin->sockv6, &buf, msg_size,
337 (const struct sockaddr *)
338 &plugin->ipv6_multicast_address,
339 sizeof(struct sockaddr_in6));
340 plugin->ipv6_multicast_address.sin6_scope_id = 0;
341 if (sent == GNUNET_SYSERR)
343 if ((ENETUNREACH == errno) || (ENETDOWN == errno))
345 /* "Network unreachable" or "Network down"
347 * This indicates that this system is IPv6 enabled, but does not
348 * have a valid global IPv6 address assigned
350 GNUNET_log (GNUNET_ERROR_TYPE_BULK | GNUNET_ERROR_TYPE_WARNING,
351 "Network connectivity is down, cannot send beacon!\n");
354 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "sendto");
358 LOG (GNUNET_ERROR_TYPE_DEBUG,
359 "Sending IPv6 HELLO beacon broadcast with %d bytes to address %s\n",
361 GNUNET_a2s ((const struct sockaddr *) &plugin->ipv6_multicast_address,
362 sizeof(struct sockaddr_in6)));
368 if (NULL != baddr->cryogenic_fd)
370 baddr->cryogenic_times.delay_msecs =
371 (plugin->broadcast_interval.rel_value_us / 1000.0) * 0.5;
372 baddr->cryogenic_times.timeout_msecs =
373 (plugin->broadcast_interval.rel_value_us / 1000.0) * 1.5;
375 if (ioctl (baddr->cryogenic_fd->fd,
376 PM_SET_DELAY_AND_TIMEOUT,
377 &baddr->cryogenic_times) < 0)
379 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "ioctl");
380 baddr->broadcast_task =
381 GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
382 &udp_ipv6_broadcast_send, baddr);
385 GNUNET_SCHEDULER_add_write_file (GNUNET_TIME_UNIT_FOREVER_REL,
387 &udp_ipv6_broadcast_send,
392 baddr->broadcast_task =
393 GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
394 &udp_ipv6_broadcast_send, baddr);
399 * Callback function invoked for each interface found.
401 * @param cls closure with the `struct Plugin`
402 * @param name name of the interface (can be NULL for unknown)
403 * @param isDefault is this presumably the default interface
404 * @param addr address of this interface (can be NULL for unknown or unassigned)
405 * @param broadcast_addr the broadcast address (can be NULL for unknown or unassigned)
406 * @param netmask the network mask (can be NULL for unknown or unassigned)
407 * @param addrlen length of the address
408 * @return #GNUNET_OK to continue iteration, #GNUNET_SYSERR to abort
411 iface_proc (void *cls,
414 const struct sockaddr *addr,
415 const struct sockaddr *broadcast_addr,
416 const struct sockaddr *netmask, socklen_t addrlen)
418 struct Plugin *plugin = cls;
419 struct BroadcastAddress *ba;
420 enum GNUNET_NetworkType network;
424 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
425 "address %s for interface %s %p\n ",
426 GNUNET_a2s (addr, addrlen), name, addr);
427 if (NULL == broadcast_addr)
429 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
430 "broadcast address %s for interface %s %p\n ",
431 GNUNET_a2s (broadcast_addr, addrlen), name, broadcast_addr);
432 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "netmask %s for interface %s %p\n ",
433 GNUNET_a2s (netmask, addrlen), name, netmask);
435 network = plugin->env->get_address_type (plugin->env->cls, broadcast_addr,
437 if (GNUNET_NT_LOOPBACK == network)
439 /* Broadcasting on loopback does not make sense */
443 ba = GNUNET_new (struct BroadcastAddress);
445 ba->addr = GNUNET_malloc (addrlen);
446 GNUNET_memcpy (ba->addr, broadcast_addr, addrlen);
447 ba->addrlen = addrlen;
449 if ((GNUNET_YES == plugin->enable_ipv4) &&
450 (NULL != plugin->sockv4) &&
451 (addrlen == sizeof(struct sockaddr_in)))
455 * setup Cryogenic FD for ipv4 broadcasting
459 GNUNET_asprintf (&filename,
462 if (0 == access (name, R_OK))
465 GNUNET_DISK_file_open (filename,
466 GNUNET_DISK_OPEN_WRITE,
467 GNUNET_DISK_PERM_NONE);
469 GNUNET_free (filename);
472 GNUNET_SCHEDULER_add_now (&udp_ipv4_broadcast_send, ba);
474 if ((GNUNET_YES == plugin->enable_ipv6) &&
475 (NULL != plugin->sockv6) &&
476 (addrlen == sizeof(struct sockaddr_in6)))
478 /* Create IPv6 multicast request */
479 struct ipv6_mreq multicastRequest;
480 const struct sockaddr_in6 *s6 = (const struct
481 sockaddr_in6 *) broadcast_addr;
483 multicastRequest.ipv6mr_multiaddr =
484 plugin->ipv6_multicast_address.sin6_addr;
485 /* http://tools.ietf.org/html/rfc2553#section-5.2:
489 * Join a multicast group on a specified local interface. If the
490 * interface index is specified as 0, the kernel chooses the local
491 * interface. For example, some kernels look up the multicast
492 * group in the normal IPv6 routing table and using the resulting
493 * interface; we do this for each interface, so no need to use
496 multicastRequest.ipv6mr_interface = s6->sin6_scope_id;
498 /* Join the multicast group */
500 GNUNET_NETWORK_socket_setsockopt
501 (plugin->sockv6, IPPROTO_IPV6, IPV6_JOIN_GROUP,
502 &multicastRequest, sizeof(multicastRequest)))
504 LOG (GNUNET_ERROR_TYPE_WARNING,
505 "Failed to join IPv6 multicast group: IPv6 broadcasting not running\n");
511 * setup Cryogenic FD for ipv6 broadcasting
515 GNUNET_asprintf (&filename,
518 if (0 == access (name, R_OK))
521 GNUNET_DISK_file_open (filename,
522 GNUNET_DISK_OPEN_WRITE,
523 GNUNET_DISK_PERM_NONE);
525 GNUNET_free (filename);
528 GNUNET_SCHEDULER_add_now (&udp_ipv6_broadcast_send, ba);
531 GNUNET_CONTAINER_DLL_insert (plugin->broadcast_head,
532 plugin->broadcast_tail, ba);
538 * Setup broadcasting subsystem.
541 * @param server_addrv6
542 * @param server_addrv4
545 setup_broadcast (struct Plugin *plugin,
546 struct sockaddr_in6 *server_addrv6,
547 struct sockaddr_in *server_addrv4)
550 GNUNET_CONFIGURATION_get_value_yesno (plugin->env->cfg,
554 LOG (GNUNET_ERROR_TYPE_WARNING,
556 "Disabling HELLO broadcasting due to friend-to-friend only configuration!\n"));
560 if (GNUNET_YES != plugin->enable_broadcasting)
561 return; /* We do not send, just receive */
563 /* create IPv4 broadcast socket */
564 if ((GNUNET_YES == plugin->enable_ipv4) && (NULL != plugin->sockv4))
568 if (GNUNET_NETWORK_socket_setsockopt
569 (plugin->sockv4, SOL_SOCKET, SO_BROADCAST, &yes,
570 sizeof(int)) != GNUNET_OK)
572 LOG (GNUNET_ERROR_TYPE_WARNING,
574 "Failed to set IPv4 broadcast option for broadcast socket on port %d\n"),
575 ntohs (server_addrv4->sin_port));
578 /* create IPv6 multicast socket */
579 if ((GNUNET_YES == plugin->enable_ipv6) && (plugin->sockv6 != NULL))
581 memset (&plugin->ipv6_multicast_address, 0, sizeof(struct sockaddr_in6));
583 inet_pton (AF_INET6, "FF05::13B",
584 &plugin->ipv6_multicast_address.sin6_addr));
585 plugin->ipv6_multicast_address.sin6_family = AF_INET6;
586 plugin->ipv6_multicast_address.sin6_port = htons (plugin->port);
588 GNUNET_OS_network_interfaces_list (&iface_proc, plugin);
593 * Stop broadcasting subsystem.
598 stop_broadcast (struct Plugin *plugin)
600 if (GNUNET_YES == plugin->enable_broadcasting)
602 /* Disable broadcasting */
603 while (plugin->broadcast_head != NULL)
605 struct BroadcastAddress *p = plugin->broadcast_head;
607 if (p->broadcast_task != NULL)
609 GNUNET_SCHEDULER_cancel (p->broadcast_task);
610 p->broadcast_task = NULL;
612 if ((GNUNET_YES == plugin->enable_ipv6) &&
613 (NULL != plugin->sockv6) &&
614 (p->addrlen == sizeof(struct sockaddr_in6)))
616 /* Create IPv6 multicast request */
617 struct ipv6_mreq multicastRequest;
618 const struct sockaddr_in6 *s6 = (const struct sockaddr_in6 *) p->addr;
620 multicastRequest.ipv6mr_multiaddr =
621 plugin->ipv6_multicast_address.sin6_addr;
622 multicastRequest.ipv6mr_interface = s6->sin6_scope_id;
624 /* Leave the multicast group */
626 GNUNET_NETWORK_socket_setsockopt
627 (plugin->sockv6, IPPROTO_IPV6, IPV6_LEAVE_GROUP,
628 &multicastRequest, sizeof(multicastRequest)))
630 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "setsockopt");
634 LOG (GNUNET_ERROR_TYPE_DEBUG, "IPv6 multicasting stopped\n");
639 GNUNET_DISK_file_close (p->cryogenic_fd);
641 GNUNET_CONTAINER_DLL_remove (plugin->broadcast_head,
642 plugin->broadcast_tail, p);
643 GNUNET_free (p->addr);
649 /* end of plugin_transport_udp_broadcasting.c */