2 This file is part of GNUnet.
3 Copyright (C) 2009-2013 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 util/connection.c
23 * @brief TCP connection management
24 * @author Christian Grothoff
26 * This code is rather complex. Only modify it if you
27 * 1) Have a NEW testcase showing that the new code
28 * is needed and correct
29 * 2) All EXISTING testcases pass with the new code
30 * These rules should apply in general, but for this
31 * module they are VERY, VERY important.
34 #include "gnunet_util_lib.h"
35 #include "gnunet_resolver_service.h"
39 * Timeout we use on TCP connect before trying another
40 * result from the DNS resolver. Actual value used
41 * is this value divided by the number of address families.
44 #define CONNECT_RETRY_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
48 #define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util-connection", syscall)
52 * Transmission handle. There can only be one for each connection.
54 struct GNUNET_CONNECTION_TransmitHandle
58 * Function to call if the send buffer has notify_size
61 GNUNET_CONNECTION_TransmitReadyNotify notify_ready;
64 * Closure for notify_ready.
66 void *notify_ready_cls;
69 * Our connection handle.
71 struct GNUNET_CONNECTION_Handle *connection;
74 * Timeout for receiving (in absolute time).
76 struct GNUNET_TIME_Absolute transmit_timeout;
79 * Task called on timeout.
81 struct GNUNET_SCHEDULER_Task * timeout_task;
84 * At what number of bytes available in the
85 * write buffer should the notify method be called?
93 * During connect, we try multiple possible IP addresses
94 * to find out which one might work.
100 * This is a linked list.
102 struct AddressProbe *next;
105 * This is a doubly-linked list.
107 struct AddressProbe *prev;
110 * The address; do not free (allocated at the end of this struct).
112 const struct sockaddr *addr;
115 * Underlying OS's socket.
117 struct GNUNET_NETWORK_Handle *sock;
120 * Connection for which we are probing.
122 struct GNUNET_CONNECTION_Handle *connection;
130 * Task waiting for the connection to finish connecting.
132 struct GNUNET_SCHEDULER_Task * task;
137 * @brief handle for a network connection
139 struct GNUNET_CONNECTION_Handle
143 * Configuration to use.
145 const struct GNUNET_CONFIGURATION_Handle *cfg;
148 * Linked list of sockets we are currently trying out
151 struct AddressProbe *ap_head;
154 * Linked list of sockets we are currently trying out
157 struct AddressProbe *ap_tail;
160 * Network address of the other end-point, may be NULL.
162 struct sockaddr *addr;
165 * Pointer to the hostname if connection was
166 * created using DNS lookup, otherwise NULL.
171 * Underlying OS's socket, set to NULL after fatal errors.
173 struct GNUNET_NETWORK_Handle *sock;
176 * Function to call on data received, NULL if no receive is pending.
178 GNUNET_CONNECTION_Receiver receiver;
181 * Closure for @e receiver.
186 * Pointer to our write buffer.
191 * Current size of our @e write_buffer.
193 size_t write_buffer_size;
196 * Current write-offset in @e write_buffer (where
197 * would we write next).
199 size_t write_buffer_off;
202 * Current read-offset in @e write_buffer (how many
203 * bytes have already been sent).
205 size_t write_buffer_pos;
213 * Read task that we may need to wait for.
215 struct GNUNET_SCHEDULER_Task *read_task;
218 * Write task that we may need to wait for.
220 struct GNUNET_SCHEDULER_Task *write_task;
223 * Handle to a pending DNS lookup request.
225 struct GNUNET_RESOLVER_RequestHandle *dns_active;
228 * The handle we return for #GNUNET_CONNECTION_notify_transmit_ready().
230 struct GNUNET_CONNECTION_TransmitHandle nth;
233 * Timeout for receiving (in absolute time).
235 struct GNUNET_TIME_Absolute receive_timeout;
238 * Maximum number of bytes to read (for receiving).
243 * Port to connect to.
248 * When shutdown, do not ever actually close the socket, but
249 * free resources. Only should ever be set if using program
250 * termination as a signal (because only then will the leaked
256 * Usually 0. Set to 1 if this handle is in use, and should
257 * #GNUNET_CONNECTION_destroy() be called right now, the action needs
258 * to be deferred by setting it to -1.
260 int8_t destroy_later;
263 * Handle to subsequent connection after proxy handshake completes,
265 struct GNUNET_CONNECTION_Handle *proxy_handshake;
271 * Set the persist option on this connection handle. Indicates
272 * that the underlying socket or fd should never really be closed.
273 * Used for indicating process death.
275 * @param connection the connection to set persistent
278 GNUNET_CONNECTION_persist_ (struct GNUNET_CONNECTION_Handle *connection)
280 connection->persist = GNUNET_YES;
285 * Disable the "CORK" feature for communication with the given connection,
286 * forcing the OS to immediately flush the buffer on transmission
287 * instead of potentially buffering multiple messages. Essentially
288 * reduces the OS send buffers to zero.
289 * Used to make sure that the last messages sent through the connection
290 * reach the other side before the process is terminated.
292 * @param connection the connection to make flushing and blocking
293 * @return #GNUNET_OK on success
296 GNUNET_CONNECTION_disable_corking (struct GNUNET_CONNECTION_Handle *connection)
298 return GNUNET_NETWORK_socket_disable_corking (connection->sock);
303 * Create a connection handle by boxing an existing OS socket. The OS
304 * socket should henceforth be no longer used directly.
305 * #GNUNET_connection_destroy() will close it.
307 * @param osSocket existing socket to box
308 * @return the boxed connection handle
310 struct GNUNET_CONNECTION_Handle *
311 GNUNET_CONNECTION_create_from_existing (struct GNUNET_NETWORK_Handle *osSocket)
313 struct GNUNET_CONNECTION_Handle *connection;
315 connection = GNUNET_new (struct GNUNET_CONNECTION_Handle);
316 connection->write_buffer_size = GNUNET_MIN_MESSAGE_SIZE;
317 connection->write_buffer = GNUNET_malloc (connection->write_buffer_size);
318 connection->sock = osSocket;
324 * Create a connection handle by accepting on a listen socket. This
325 * function may block if the listen socket has no connection ready.
327 * @param access_cb function to use to check if access is allowed
328 * @param access_cb_cls closure for @a access_cb
329 * @param lsock listen socket
330 * @return the connection handle, NULL on error
332 struct GNUNET_CONNECTION_Handle *
333 GNUNET_CONNECTION_create_from_accept (GNUNET_CONNECTION_AccessCheck access_cb,
335 struct GNUNET_NETWORK_Handle *lsock)
337 struct GNUNET_CONNECTION_Handle *connection;
340 struct GNUNET_NETWORK_Handle *sock;
342 struct sockaddr_in *v4;
343 struct sockaddr_in6 *v6;
350 struct GNUNET_CONNECTION_Credentials *gcp;
351 #if HAVE_GETPEEREID || defined(SO_PEERCRED) || HAVE_GETPEERUCRED
352 struct GNUNET_CONNECTION_Credentials gc;
358 addrlen = sizeof (addr);
360 GNUNET_NETWORK_socket_accept (lsock,
361 (struct sockaddr *) &addr,
366 LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING, "accept");
369 if ((addrlen > sizeof (addr)) || (addrlen < sizeof (sa_family_t)))
372 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock));
376 sa = (struct sockaddr *) addr;
377 v6 = (struct sockaddr_in6 *) addr;
378 if ( (AF_INET6 == sa->sa_family) &&
379 (IN6_IS_ADDR_V4MAPPED (&v6->sin6_addr)) )
381 /* convert to V4 address */
382 v4 = GNUNET_new (struct sockaddr_in);
383 memset (v4, 0, sizeof (struct sockaddr_in));
384 v4->sin_family = AF_INET;
385 #if HAVE_SOCKADDR_IN_SIN_LEN
386 v4->sin_len = (u_char) sizeof (struct sockaddr_in);
388 GNUNET_memcpy (&v4->sin_addr,
389 &((char *) &v6->sin6_addr)[sizeof (struct in6_addr) -
390 sizeof (struct in_addr)],
391 sizeof (struct in_addr));
392 v4->sin_port = v6->sin6_port;
394 addrlen = sizeof (struct sockaddr_in);
398 uaddr = GNUNET_malloc (addrlen);
399 GNUNET_memcpy (uaddr, addr, addrlen);
402 if (AF_UNIX == sa->sa_family)
406 if (0 == getpeereid (GNUNET_NETWORK_get_fd (sock),
412 /* largely traditional GNU/Linux */
415 getsockopt (GNUNET_NETWORK_get_fd (sock),
420 (olen == sizeof (uc)) )
427 #if HAVE_GETPEERUCRED
428 /* this is for Solaris 10 */
432 if (0 == getpeerucred (GNUNET_NETWORK_get_fd (sock), &uc))
434 gc.uid = ucred_geteuid (uc);
435 gc.gid = ucred_getegid (uc);
444 if ( (NULL != access_cb) &&
445 (GNUNET_YES != (aret = access_cb (access_cb_cls,
450 if (GNUNET_NO == aret)
451 LOG (GNUNET_ERROR_TYPE_INFO,
452 _("Access denied to `%s'\n"),
455 GNUNET_break (GNUNET_OK ==
456 GNUNET_NETWORK_socket_shutdown (sock,
458 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock));
462 connection = GNUNET_new (struct GNUNET_CONNECTION_Handle);
463 connection->write_buffer_size = GNUNET_MIN_MESSAGE_SIZE;
464 connection->write_buffer = GNUNET_malloc (connection->write_buffer_size);
465 connection->addr = uaddr;
466 connection->addrlen = addrlen;
467 connection->sock = sock;
468 LOG (GNUNET_ERROR_TYPE_INFO,
469 _("Accepting connection from `%s': %p\n"),
478 * Obtain the network address of the other party.
480 * @param connection the client to get the address for
481 * @param addr where to store the address
482 * @param addrlen where to store the length of the @a addr
483 * @return #GNUNET_OK on success
486 GNUNET_CONNECTION_get_address (struct GNUNET_CONNECTION_Handle *connection,
490 if ((NULL == connection->addr) || (0 == connection->addrlen))
492 *addr = GNUNET_malloc (connection->addrlen);
493 GNUNET_memcpy (*addr, connection->addr, connection->addrlen);
494 *addrlen = connection->addrlen;
500 * Tell the receiver callback that we had an IO error.
502 * @param connection connection to signal error
503 * @param errcode error code to send
506 signal_receive_error (struct GNUNET_CONNECTION_Handle *connection,
509 GNUNET_CONNECTION_Receiver receiver;
511 LOG (GNUNET_ERROR_TYPE_DEBUG,
512 "Receive encounters error (%s), connection closed (%p)\n",
515 GNUNET_assert (NULL != (receiver = connection->receiver));
516 connection->receiver = NULL;
517 receiver (connection->receiver_cls,
527 * Tell the receiver callback that a timeout was reached.
529 * @param connection connection to signal for
532 signal_receive_timeout (struct GNUNET_CONNECTION_Handle *connection)
534 GNUNET_CONNECTION_Receiver receiver;
536 LOG (GNUNET_ERROR_TYPE_DEBUG,
537 "Connection signals timeout to receiver (%p)!\n",
539 GNUNET_assert (NULL != (receiver = connection->receiver));
540 connection->receiver = NULL;
541 receiver (connection->receiver_cls, NULL, 0, NULL, 0, 0);
546 * We failed to transmit data to the service, signal the error.
548 * @param connection handle that had trouble
549 * @param ecode error code (errno)
552 signal_transmit_error (struct GNUNET_CONNECTION_Handle *connection,
555 GNUNET_CONNECTION_TransmitReadyNotify notify;
557 LOG (GNUNET_ERROR_TYPE_DEBUG,
558 "Transmission encounterd error (%s), connection closed (%p)\n",
561 if (NULL != connection->sock)
563 (void) GNUNET_NETWORK_socket_shutdown (connection->sock,
565 GNUNET_break (GNUNET_OK ==
566 GNUNET_NETWORK_socket_close (connection->sock));
567 connection->sock = NULL;
568 GNUNET_assert (NULL == connection->write_task);
570 if (NULL != connection->read_task)
572 /* send errors trigger read errors... */
573 GNUNET_SCHEDULER_cancel (connection->read_task);
574 connection->read_task = NULL;
575 signal_receive_timeout (connection);
578 if (NULL == connection->nth.notify_ready)
579 return; /* nobody to tell about it */
580 notify = connection->nth.notify_ready;
581 connection->nth.notify_ready = NULL;
582 notify (connection->nth.notify_ready_cls,
589 * We've failed for good to establish a connection (timeout or
590 * no more addresses to try).
592 * @param connection the connection we tried to establish
595 connect_fail_continuation (struct GNUNET_CONNECTION_Handle *connection)
597 LOG (GNUNET_ERROR_TYPE_INFO,
598 "Failed to establish TCP connection to `%s:%u', no further addresses to try.\n",
599 connection->hostname,
601 GNUNET_break (NULL == connection->ap_head);
602 GNUNET_break (NULL == connection->ap_tail);
603 GNUNET_break (GNUNET_NO == connection->dns_active);
604 GNUNET_break (NULL == connection->sock);
605 GNUNET_assert (NULL == connection->write_task);
606 GNUNET_assert (NULL == connection->proxy_handshake);
608 /* signal errors for jobs that used to wait on the connection */
609 connection->destroy_later = 1;
610 if (NULL != connection->receiver)
611 signal_receive_error (connection,
613 if (NULL != connection->nth.notify_ready)
615 GNUNET_assert (NULL != connection->nth.timeout_task);
616 GNUNET_SCHEDULER_cancel (connection->nth.timeout_task);
617 connection->nth.timeout_task = NULL;
618 signal_transmit_error (connection,
621 if (-1 == connection->destroy_later)
624 connection->destroy_later = 0;
625 GNUNET_CONNECTION_destroy (connection);
628 connection->destroy_later = 0;
633 * We are ready to transmit (or got a timeout).
635 * @param cls our connection handle
638 transmit_ready (void *cls);
642 * This function is called once we either timeout or have data ready
645 * @param cls connection to read from
648 receive_ready (void *cls);
652 * We've succeeded in establishing a connection.
654 * @param connection the connection we tried to establish
657 connect_success_continuation (struct GNUNET_CONNECTION_Handle *connection)
659 LOG (GNUNET_ERROR_TYPE_DEBUG,
660 "Connection to `%s' succeeded! (%p)\n",
661 GNUNET_a2s (connection->addr,
662 connection->addrlen),
664 /* trigger jobs that waited for the connection */
665 if (NULL != connection->receiver)
667 LOG (GNUNET_ERROR_TYPE_DEBUG,
668 "Connection succeeded, starting with receiving data (%p)\n",
670 GNUNET_assert (NULL == connection->read_task);
671 connection->read_task =
672 GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_absolute_get_remaining
673 (connection->receive_timeout),
675 &receive_ready, connection);
677 if (NULL != connection->nth.notify_ready)
679 LOG (GNUNET_ERROR_TYPE_DEBUG,
680 "Connection succeeded, starting with sending data (%p)\n",
682 GNUNET_assert (connection->nth.timeout_task != NULL);
683 GNUNET_SCHEDULER_cancel (connection->nth.timeout_task);
684 connection->nth.timeout_task = NULL;
685 GNUNET_assert (connection->write_task == NULL);
686 connection->write_task =
687 GNUNET_SCHEDULER_add_write_net (GNUNET_TIME_absolute_get_remaining
688 (connection->nth.transmit_timeout), connection->sock,
689 &transmit_ready, connection);
695 * Scheduler let us know that we're either ready to write on the
696 * socket OR connect timed out. Do the right thing.
698 * @param cls the `struct AddressProbe *` with the address that we are probing
701 connect_probe_continuation (void *cls)
703 struct AddressProbe *ap = cls;
704 struct GNUNET_CONNECTION_Handle *connection = ap->connection;
705 const struct GNUNET_SCHEDULER_TaskContext *tc;
706 struct AddressProbe *pos;
710 GNUNET_assert (NULL != ap->sock);
711 GNUNET_CONTAINER_DLL_remove (connection->ap_head,
714 len = sizeof (error);
717 tc = GNUNET_SCHEDULER_get_task_context ();
718 if ( (0 == (tc->reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) ||
720 GNUNET_NETWORK_socket_getsockopt (ap->sock,
727 GNUNET_break (GNUNET_OK ==
728 GNUNET_NETWORK_socket_close (ap->sock));
730 if ( (NULL == connection->ap_head) &&
731 (GNUNET_NO == connection->dns_active) &&
732 (NULL == connection->proxy_handshake) )
733 connect_fail_continuation (connection);
736 GNUNET_assert (NULL == connection->sock);
737 connection->sock = ap->sock;
738 GNUNET_assert (NULL == connection->addr);
739 connection->addr = GNUNET_malloc (ap->addrlen);
740 GNUNET_memcpy (connection->addr, ap->addr, ap->addrlen);
741 connection->addrlen = ap->addrlen;
743 /* cancel all other attempts */
744 while (NULL != (pos = connection->ap_head))
746 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (pos->sock));
747 GNUNET_SCHEDULER_cancel (pos->task);
748 GNUNET_CONTAINER_DLL_remove (connection->ap_head,
753 connect_success_continuation (connection);
758 * Try to establish a connection given the specified address.
759 * This function is called by the resolver once we have a DNS reply.
761 * @param cls our `struct GNUNET_CONNECTION_Handle *`
762 * @param addr address to try, NULL for "last call"
763 * @param addrlen length of @a addr
766 try_connect_using_address (void *cls,
767 const struct sockaddr *addr,
770 struct GNUNET_CONNECTION_Handle *connection = cls;
771 struct AddressProbe *ap;
772 struct GNUNET_TIME_Relative delay;
776 connection->dns_active = NULL;
777 if ((NULL == connection->ap_head) &&
778 (NULL == connection->sock) &&
779 (NULL == connection->proxy_handshake))
780 connect_fail_continuation (connection);
783 if (NULL != connection->sock)
784 return; /* already connected */
785 GNUNET_assert (NULL == connection->addr);
787 LOG (GNUNET_ERROR_TYPE_DEBUG,
788 "Trying to connect using address `%s:%u/%s:%u'\n",
789 connection->hostname,
791 GNUNET_a2s (addr, addrlen),
793 ap = GNUNET_malloc (sizeof (struct AddressProbe) + addrlen);
794 ap->addr = (const struct sockaddr *) &ap[1];
795 GNUNET_memcpy (&ap[1], addr, addrlen);
796 ap->addrlen = addrlen;
797 ap->connection = connection;
799 switch (ap->addr->sa_family)
802 ((struct sockaddr_in *) ap->addr)->sin_port = htons (connection->port);
805 ((struct sockaddr_in6 *) ap->addr)->sin6_port = htons (connection->port);
810 return; /* not supported by us */
812 ap->sock = GNUNET_NETWORK_socket_create (ap->addr->sa_family,
814 if (NULL == ap->sock)
817 return; /* not supported by OS */
819 LOG (GNUNET_ERROR_TYPE_INFO,
820 "Trying to connect to `%s' (%p)\n",
821 GNUNET_a2s (ap->addr, ap->addrlen),
824 GNUNET_NETWORK_socket_connect (ap->sock,
827 (EINPROGRESS != errno))
829 /* maybe refused / unsupported address, try next */
830 LOG_STRERROR (GNUNET_ERROR_TYPE_INFO, "connect");
831 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (ap->sock));
835 GNUNET_CONTAINER_DLL_insert (connection->ap_head, connection->ap_tail, ap);
836 delay = CONNECT_RETRY_TIMEOUT;
837 if (NULL != connection->nth.notify_ready)
838 delay = GNUNET_TIME_relative_min (delay,
839 GNUNET_TIME_absolute_get_remaining (connection->nth.transmit_timeout));
840 if (NULL != connection->receiver)
841 delay = GNUNET_TIME_relative_min (delay,
842 GNUNET_TIME_absolute_get_remaining (connection->receive_timeout));
843 ap->task = GNUNET_SCHEDULER_add_write_net (delay,
845 &connect_probe_continuation,
851 * Create a connection handle by (asynchronously) connecting to a host.
852 * This function returns immediately, even if the connection has not
853 * yet been established. This function only creates TCP connections.
855 * @param cfg configuration to use
856 * @param hostname name of the host to connect to
857 * @param port port to connect to
858 * @return the connection handle
860 struct GNUNET_CONNECTION_Handle *
861 GNUNET_CONNECTION_create_from_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
862 const char *hostname,
865 struct GNUNET_CONNECTION_Handle *connection;
867 GNUNET_assert (0 < strlen (hostname)); /* sanity check */
868 connection = GNUNET_new (struct GNUNET_CONNECTION_Handle);
869 connection->cfg = cfg;
870 connection->write_buffer_size = GNUNET_MIN_MESSAGE_SIZE;
871 connection->write_buffer = GNUNET_malloc (connection->write_buffer_size);
872 connection->port = port;
873 connection->hostname = GNUNET_strdup (hostname);
874 connection->dns_active =
875 GNUNET_RESOLVER_ip_get (connection->hostname,
877 CONNECT_RETRY_TIMEOUT,
878 &try_connect_using_address,
885 * Create a connection handle by connecting to a UNIX domain service.
886 * This function returns immediately, even if the connection has not
887 * yet been established. This function only creates UNIX connections.
889 * @param cfg configuration to use
890 * @param unixpath path to connect to
891 * @return the connection handle, NULL on systems without UNIX support
893 struct GNUNET_CONNECTION_Handle *
894 GNUNET_CONNECTION_create_from_connect_to_unixpath (const struct GNUNET_CONFIGURATION_Handle *cfg,
895 const char *unixpath)
898 struct GNUNET_CONNECTION_Handle *connection;
899 struct sockaddr_un *un;
901 GNUNET_assert (0 < strlen (unixpath)); /* sanity check */
902 un = GNUNET_new (struct sockaddr_un);
903 un->sun_family = AF_UNIX;
904 strncpy (un->sun_path, unixpath, sizeof (un->sun_path) - 1);
909 abstract = GNUNET_CONFIGURATION_get_value_yesno (cfg,
911 "USE_ABSTRACT_SOCKETS");
912 if (GNUNET_YES == abstract)
913 un->sun_path[0] = '\0';
916 #if HAVE_SOCKADDR_UN_SUN_LEN
917 un->sun_len = (u_char) sizeof (struct sockaddr_un);
919 connection = GNUNET_new (struct GNUNET_CONNECTION_Handle);
920 connection->cfg = cfg;
921 connection->write_buffer_size = GNUNET_MIN_MESSAGE_SIZE;
922 connection->write_buffer = GNUNET_malloc (connection->write_buffer_size);
923 connection->port = 0;
924 connection->hostname = NULL;
925 connection->addr = (struct sockaddr *) un;
926 connection->addrlen = sizeof (struct sockaddr_un);
927 connection->sock = GNUNET_NETWORK_socket_create (AF_UNIX,
930 if (NULL == connection->sock)
932 GNUNET_free (connection->addr);
933 GNUNET_free (connection->write_buffer);
934 GNUNET_free (connection);
938 GNUNET_NETWORK_socket_connect (connection->sock,
940 connection->addrlen)) &&
941 (EINPROGRESS != errno) )
943 /* Just return; we expect everything to work eventually so don't fail HARD */
944 GNUNET_break (GNUNET_OK ==
945 GNUNET_NETWORK_socket_close (connection->sock));
946 connection->sock = NULL;
949 connect_success_continuation (connection);
958 * Create a connection handle by (asynchronously) connecting to a host.
959 * This function returns immediately, even if the connection has not
960 * yet been established. This function only creates TCP connections.
962 * @param s socket to connect
963 * @param serv_addr server address
964 * @param addrlen length of @a serv_addr
965 * @return the connection handle
967 struct GNUNET_CONNECTION_Handle *
968 GNUNET_CONNECTION_connect_socket (struct GNUNET_NETWORK_Handle *s,
969 const struct sockaddr *serv_addr,
972 struct GNUNET_CONNECTION_Handle *connection;
975 GNUNET_NETWORK_socket_connect (s, serv_addr, addrlen)) &&
976 (EINPROGRESS != errno) )
978 /* maybe refused / unsupported address, try next */
979 LOG_STRERROR (GNUNET_ERROR_TYPE_DEBUG,
981 LOG (GNUNET_ERROR_TYPE_DEBUG,
982 "Attempt to connect to `%s' failed\n",
983 GNUNET_a2s (serv_addr,
985 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (s));
988 connection = GNUNET_CONNECTION_create_from_existing (s);
989 connection->addr = GNUNET_malloc (addrlen);
990 GNUNET_memcpy (connection->addr, serv_addr, addrlen);
991 connection->addrlen = addrlen;
992 LOG (GNUNET_ERROR_TYPE_INFO,
993 "Trying to connect to `%s' (%p)\n",
994 GNUNET_a2s (serv_addr, addrlen),
1001 * Create a connection handle by creating a socket and
1002 * (asynchronously) connecting to a host. This function returns
1003 * immediately, even if the connection has not yet been established.
1004 * This function only creates TCP connections.
1006 * @param af_family address family to use
1007 * @param serv_addr server address
1008 * @param addrlen length of @a serv_addr
1009 * @return the connection handle
1011 struct GNUNET_CONNECTION_Handle *
1012 GNUNET_CONNECTION_create_from_sockaddr (int af_family,
1013 const struct sockaddr *serv_addr,
1016 struct GNUNET_NETWORK_Handle *s;
1018 s = GNUNET_NETWORK_socket_create (af_family, SOCK_STREAM, 0);
1021 LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
1025 return GNUNET_CONNECTION_connect_socket (s,
1032 * Check if connection is valid (no fatal errors have happened so far).
1033 * Note that a connection that is still trying to connect is considered
1036 * @param connection connection to check
1037 * @return #GNUNET_YES if valid, #GNUNET_NO otherwise
1040 GNUNET_CONNECTION_check (struct GNUNET_CONNECTION_Handle *connection)
1042 if ((NULL != connection->ap_head) ||
1043 (NULL != connection->dns_active) ||
1044 (NULL != connection->proxy_handshake))
1045 return GNUNET_YES; /* still trying to connect */
1046 if ( (0 != connection->destroy_later) ||
1047 (NULL == connection->sock) )
1054 * Close the connection and free associated resources. There must
1055 * not be any pending requests for reading or writing to the
1056 * connection at this time.
1058 * @param connection connection to destroy
1061 GNUNET_CONNECTION_destroy (struct GNUNET_CONNECTION_Handle *connection)
1063 struct AddressProbe *pos;
1065 if (0 != connection->destroy_later)
1067 connection->destroy_later = -1;
1070 LOG (GNUNET_ERROR_TYPE_DEBUG,
1071 "Shutting down connection (%p)\n",
1073 GNUNET_assert (NULL == connection->nth.notify_ready);
1074 GNUNET_assert (NULL == connection->receiver);
1075 if (NULL != connection->write_task)
1077 GNUNET_SCHEDULER_cancel (connection->write_task);
1078 connection->write_task = NULL;
1079 connection->write_buffer_off = 0;
1081 if (NULL != connection->read_task)
1083 GNUNET_SCHEDULER_cancel (connection->read_task);
1084 connection->read_task = NULL;
1086 if (NULL != connection->nth.timeout_task)
1088 GNUNET_SCHEDULER_cancel (connection->nth.timeout_task);
1089 connection->nth.timeout_task = NULL;
1091 connection->nth.notify_ready = NULL;
1092 if (NULL != connection->dns_active)
1094 GNUNET_RESOLVER_request_cancel (connection->dns_active);
1095 connection->dns_active = NULL;
1097 if (NULL != connection->proxy_handshake)
1099 /* GNUNET_CONNECTION_destroy (connection->proxy_handshake); */
1100 connection->proxy_handshake->destroy_later = -1;
1101 connection->proxy_handshake = NULL; /* Not leaked ??? */
1103 while (NULL != (pos = connection->ap_head))
1105 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (pos->sock));
1106 GNUNET_SCHEDULER_cancel (pos->task);
1107 GNUNET_CONTAINER_DLL_remove (connection->ap_head,
1108 connection->ap_tail,
1112 if ( (NULL != connection->sock) &&
1113 (GNUNET_YES != connection->persist) )
1116 GNUNET_NETWORK_socket_shutdown (connection->sock,
1118 (ENOTCONN != errno) &&
1119 (ECONNRESET != errno) )
1120 LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING,
1123 if (NULL != connection->sock)
1125 if (GNUNET_YES != connection->persist)
1127 GNUNET_break (GNUNET_OK ==
1128 GNUNET_NETWORK_socket_close (connection->sock));
1132 GNUNET_NETWORK_socket_free_memory_only_ (connection->sock); /* at least no memory leak (we deliberately
1133 * leak the socket in this special case) ... */
1136 GNUNET_free_non_null (connection->addr);
1137 GNUNET_free_non_null (connection->hostname);
1138 GNUNET_free (connection->write_buffer);
1139 GNUNET_free (connection);
1144 * This function is called once we either timeout
1145 * or have data ready to read.
1147 * @param cls connection to read from
1150 receive_ready (void *cls)
1152 struct GNUNET_CONNECTION_Handle *connection = cls;
1153 const struct GNUNET_SCHEDULER_TaskContext *tc;
1154 char buffer[connection->max];
1156 GNUNET_CONNECTION_Receiver receiver;
1158 connection->read_task = NULL;
1159 tc = GNUNET_SCHEDULER_get_task_context ();
1160 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_TIMEOUT))
1162 LOG (GNUNET_ERROR_TYPE_DEBUG,
1163 "Receive from `%s' encounters error: timeout (%s, %p)\n",
1164 GNUNET_a2s (connection->addr,
1165 connection->addrlen),
1166 GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_duration (connection->receive_timeout),
1169 signal_receive_timeout (connection);
1172 if (NULL == connection->sock)
1174 /* connect failed for good */
1175 signal_receive_error (connection, ECONNREFUSED);
1178 GNUNET_assert (GNUNET_NETWORK_fdset_isset (tc->read_ready,
1181 ret = GNUNET_NETWORK_socket_recv (connection->sock,
1188 signal_receive_error (connection, errno);
1191 LOG (GNUNET_ERROR_TYPE_DEBUG,
1192 "receive_ready read %u/%u bytes from `%s' (%p)!\n",
1195 GNUNET_a2s (connection->addr,
1196 connection->addrlen),
1198 GNUNET_assert (NULL != (receiver = connection->receiver));
1199 connection->receiver = NULL;
1200 receiver (connection->receiver_cls,
1204 connection->addrlen,
1210 * Receive data from the given connection. Note that this function
1211 * will call @a receiver asynchronously using the scheduler. It will
1212 * "immediately" return. Note that there MUST only be one active
1213 * receive call per connection at any given point in time (so do not
1214 * call receive again until the receiver callback has been invoked).
1216 * @param connection connection handle
1217 * @param max maximum number of bytes to read
1218 * @param timeout maximum amount of time to wait
1219 * @param receiver function to call with received data
1220 * @param receiver_cls closure for @a receiver
1221 * @return #GNUNET_SYSERR if @a connection died (receiver was
1222 * called with error)
1225 GNUNET_CONNECTION_receive (struct GNUNET_CONNECTION_Handle *connection,
1227 struct GNUNET_TIME_Relative timeout,
1228 GNUNET_CONNECTION_Receiver receiver,
1231 GNUNET_assert ((NULL == connection->read_task) &&
1232 (NULL == connection->receiver));
1233 GNUNET_assert (NULL != receiver);
1234 connection->receiver = receiver;
1235 connection->receiver_cls = receiver_cls;
1236 connection->receive_timeout = GNUNET_TIME_relative_to_absolute (timeout);
1237 connection->max = max;
1238 if (NULL != connection->sock)
1240 connection->read_task =
1241 GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_absolute_get_remaining
1242 (connection->receive_timeout),
1248 if ((NULL == connection->dns_active) &&
1249 (NULL == connection->ap_head) &&
1250 (NULL == connection->proxy_handshake))
1252 connection->receiver = NULL;
1253 receiver (receiver_cls,
1257 return GNUNET_SYSERR;
1264 * Cancel receive job on the given connection. Note that the
1265 * receiver callback must not have been called yet in order
1266 * for the cancellation to be valid.
1268 * @param connection connection handle
1269 * @return closure of the original receiver callback closure
1272 GNUNET_CONNECTION_receive_cancel (struct GNUNET_CONNECTION_Handle *connection)
1274 if (NULL != connection->read_task)
1276 GNUNET_assert (connection ==
1277 GNUNET_SCHEDULER_cancel (connection->read_task));
1278 connection->read_task = NULL;
1280 connection->receiver = NULL;
1281 return connection->receiver_cls;
1286 * Try to call the transmit notify method (check if we do
1287 * have enough space available first)!
1289 * @param connection connection for which we should do this processing
1290 * @return #GNUNET_YES if we were able to call notify
1293 process_notify (struct GNUNET_CONNECTION_Handle *connection)
1298 GNUNET_CONNECTION_TransmitReadyNotify notify;
1300 LOG (GNUNET_ERROR_TYPE_DEBUG,
1301 "process_notify is running\n");
1302 GNUNET_assert (NULL == connection->write_task);
1303 if (NULL == (notify = connection->nth.notify_ready))
1305 LOG (GNUNET_ERROR_TYPE_DEBUG,
1306 "No one to notify\n");
1309 used = connection->write_buffer_off - connection->write_buffer_pos;
1310 avail = connection->write_buffer_size - used;
1311 size = connection->nth.notify_size;
1314 LOG (GNUNET_ERROR_TYPE_DEBUG,
1315 "Not enough buffer\n");
1318 connection->nth.notify_ready = NULL;
1319 if (connection->write_buffer_size - connection->write_buffer_off < size)
1321 /* need to compact */
1322 memmove (connection->write_buffer,
1323 &connection->write_buffer[connection->write_buffer_pos],
1325 connection->write_buffer_off -= connection->write_buffer_pos;
1326 connection->write_buffer_pos = 0;
1328 avail = connection->write_buffer_size - connection->write_buffer_off;
1329 GNUNET_assert (avail >= size);
1331 notify (connection->nth.notify_ready_cls, avail,
1332 &connection->write_buffer[connection->write_buffer_off]);
1333 GNUNET_assert (size <= avail);
1335 connection->write_buffer_off += size;
1341 * Task invoked by the scheduler when a call to transmit
1342 * is timing out (we never got enough buffer space to call
1343 * the callback function before the specified timeout
1346 * This task notifies the client about the timeout.
1348 * @param cls the `struct GNUNET_CONNECTION_Handle`
1351 transmit_timeout (void *cls)
1353 struct GNUNET_CONNECTION_Handle *connection = cls;
1354 GNUNET_CONNECTION_TransmitReadyNotify notify;
1356 connection->nth.timeout_task = NULL;
1357 LOG (GNUNET_ERROR_TYPE_DEBUG,
1358 "Transmit to `%s:%u/%s' fails, time out reached (%p).\n",
1359 connection->hostname,
1361 GNUNET_a2s (connection->addr,
1362 connection->addrlen),
1364 notify = connection->nth.notify_ready;
1365 GNUNET_assert (NULL != notify);
1366 connection->nth.notify_ready = NULL;
1367 notify (connection->nth.notify_ready_cls,
1374 * Task invoked by the scheduler when we failed to connect
1375 * at the time of being asked to transmit.
1377 * This task notifies the client about the error.
1379 * @param cls the `struct GNUNET_CONNECTION_Handle`
1382 connect_error (void *cls)
1384 struct GNUNET_CONNECTION_Handle *connection = cls;
1385 GNUNET_CONNECTION_TransmitReadyNotify notify;
1387 LOG (GNUNET_ERROR_TYPE_DEBUG,
1388 "Transmission request of size %u fails (%s/%u), connection failed (%p).\n",
1389 connection->nth.notify_size,
1390 connection->hostname,
1393 connection->write_task = NULL;
1394 notify = connection->nth.notify_ready;
1395 connection->nth.notify_ready = NULL;
1396 notify (connection->nth.notify_ready_cls,
1403 * We are ready to transmit (or got a timeout).
1405 * @param cls our connection handle
1408 transmit_ready (void *cls)
1410 struct GNUNET_CONNECTION_Handle *connection = cls;
1411 GNUNET_CONNECTION_TransmitReadyNotify notify;
1412 const struct GNUNET_SCHEDULER_TaskContext *tc;
1416 LOG (GNUNET_ERROR_TYPE_DEBUG,
1417 "transmit_ready running (%p).\n",
1419 GNUNET_assert (NULL != connection->write_task);
1420 connection->write_task = NULL;
1421 GNUNET_assert (NULL == connection->nth.timeout_task);
1422 tc = GNUNET_SCHEDULER_get_task_context ();
1423 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_TIMEOUT))
1425 LOG (GNUNET_ERROR_TYPE_DEBUG,
1426 "Transmit to `%s' fails, time out reached (%p).\n",
1427 GNUNET_a2s (connection->addr,
1428 connection->addrlen),
1430 notify = connection->nth.notify_ready;
1431 GNUNET_assert (NULL != notify);
1432 connection->nth.notify_ready = NULL;
1433 notify (connection->nth.notify_ready_cls, 0, NULL);
1436 GNUNET_assert (NULL != connection->sock);
1437 if (NULL == tc->write_ready)
1439 /* special circumstances (in particular, PREREQ_DONE after
1440 * connect): not yet ready to write, but no "fatal" error either.
1442 goto SCHEDULE_WRITE;
1444 if (! GNUNET_NETWORK_fdset_isset (tc->write_ready,
1447 GNUNET_assert (NULL == connection->write_task);
1448 /* special circumstances (in particular, shutdown): not yet ready
1449 * to write, but no "fatal" error either. Hence retry. */
1450 goto SCHEDULE_WRITE;
1452 GNUNET_assert (connection->write_buffer_off >= connection->write_buffer_pos);
1453 if ((NULL != connection->nth.notify_ready) &&
1454 (connection->write_buffer_size < connection->nth.notify_size))
1456 connection->write_buffer =
1457 GNUNET_realloc (connection->write_buffer, connection->nth.notify_size);
1458 connection->write_buffer_size = connection->nth.notify_size;
1460 process_notify (connection);
1461 have = connection->write_buffer_off - connection->write_buffer_pos;
1464 /* no data ready for writing, terminate write loop */
1467 GNUNET_assert (have <= connection->write_buffer_size);
1468 GNUNET_assert (have + connection->write_buffer_pos <= connection->write_buffer_size);
1469 GNUNET_assert (connection->write_buffer_pos <= connection->write_buffer_size);
1472 GNUNET_NETWORK_socket_send (connection->sock,
1473 &connection->write_buffer[connection->write_buffer_pos],
1479 if (NULL != connection->write_task)
1481 GNUNET_SCHEDULER_cancel (connection->write_task);
1482 connection->write_task = NULL;
1484 signal_transmit_error (connection, errno);
1487 LOG (GNUNET_ERROR_TYPE_DEBUG,
1488 "Connection transmitted %u/%u bytes to `%s' (%p)\n",
1491 GNUNET_a2s (connection->addr,
1492 connection->addrlen),
1494 connection->write_buffer_pos += ret;
1495 if (connection->write_buffer_pos == connection->write_buffer_off)
1497 /* transmitted all pending data */
1498 connection->write_buffer_pos = 0;
1499 connection->write_buffer_off = 0;
1501 if ( (0 == connection->write_buffer_off) &&
1502 (NULL == connection->nth.notify_ready) )
1503 return; /* all data sent! */
1504 /* not done writing, schedule more */
1506 LOG (GNUNET_ERROR_TYPE_DEBUG,
1507 "Re-scheduling transmit_ready (more to do) (%p).\n",
1509 have = connection->write_buffer_off - connection->write_buffer_pos;
1510 GNUNET_assert ( (NULL != connection->nth.notify_ready) ||
1512 if (NULL == connection->write_task)
1513 connection->write_task =
1514 GNUNET_SCHEDULER_add_write_net ((connection->nth.notify_ready ==
1515 NULL) ? GNUNET_TIME_UNIT_FOREVER_REL :
1516 GNUNET_TIME_absolute_get_remaining
1517 (connection->nth.transmit_timeout),
1519 &transmit_ready, connection);
1524 * Ask the connection to call us once the specified number of bytes
1525 * are free in the transmission buffer. Will never call the @a notify
1526 * callback in this task, but always first go into the scheduler.
1528 * @param connection connection
1529 * @param size number of bytes to send
1530 * @param timeout after how long should we give up (and call
1531 * @a notify with buf NULL and size 0)?
1532 * @param notify function to call
1533 * @param notify_cls closure for @a notify
1534 * @return non-NULL if the notify callback was queued,
1535 * NULL if we are already going to notify someone else (busy)
1537 struct GNUNET_CONNECTION_TransmitHandle *
1538 GNUNET_CONNECTION_notify_transmit_ready (struct GNUNET_CONNECTION_Handle *connection,
1540 struct GNUNET_TIME_Relative timeout,
1541 GNUNET_CONNECTION_TransmitReadyNotify notify,
1544 if (NULL != connection->nth.notify_ready)
1549 GNUNET_assert (NULL != notify);
1550 GNUNET_assert (size < GNUNET_MAX_MESSAGE_SIZE);
1551 GNUNET_assert (connection->write_buffer_off <= connection->write_buffer_size);
1552 GNUNET_assert (connection->write_buffer_pos <= connection->write_buffer_size);
1553 GNUNET_assert (connection->write_buffer_pos <= connection->write_buffer_off);
1554 connection->nth.notify_ready = notify;
1555 connection->nth.notify_ready_cls = notify_cls;
1556 connection->nth.connection = connection;
1557 connection->nth.notify_size = size;
1558 connection->nth.transmit_timeout = GNUNET_TIME_relative_to_absolute (timeout);
1559 GNUNET_assert (NULL == connection->nth.timeout_task);
1560 if ((NULL == connection->sock) &&
1561 (NULL == connection->ap_head) &&
1562 (NULL == connection->dns_active) &&
1563 (NULL == connection->proxy_handshake))
1565 if (NULL != connection->write_task)
1566 GNUNET_SCHEDULER_cancel (connection->write_task);
1567 connection->write_task = GNUNET_SCHEDULER_add_now (&connect_error,
1569 return &connection->nth;
1571 if (NULL != connection->write_task)
1572 return &connection->nth; /* previous transmission still in progress */
1573 if (NULL != connection->sock)
1575 /* connected, try to transmit now */
1576 LOG (GNUNET_ERROR_TYPE_DEBUG,
1577 "Scheduling transmission (%p).\n",
1579 connection->write_task =
1580 GNUNET_SCHEDULER_add_write_net (GNUNET_TIME_absolute_get_remaining
1581 (connection->nth.transmit_timeout),
1583 &transmit_ready, connection);
1584 return &connection->nth;
1586 /* not yet connected, wait for connection */
1587 LOG (GNUNET_ERROR_TYPE_DEBUG,
1588 "Need to wait to schedule transmission for connection, adding timeout task (%p).\n",
1590 connection->nth.timeout_task =
1591 GNUNET_SCHEDULER_add_delayed (timeout,
1594 return &connection->nth;
1599 * Cancel the specified transmission-ready notification.
1601 * @param th notification to cancel
1604 GNUNET_CONNECTION_notify_transmit_ready_cancel (struct GNUNET_CONNECTION_TransmitHandle *th)
1606 GNUNET_assert (NULL != th->notify_ready);
1607 th->notify_ready = NULL;
1608 if (NULL != th->timeout_task)
1610 GNUNET_SCHEDULER_cancel (th->timeout_task);
1611 th->timeout_task = NULL;
1613 if (NULL != th->connection->write_task)
1615 GNUNET_SCHEDULER_cancel (th->connection->write_task);
1616 th->connection->write_task = NULL;
1622 * Create a connection to be proxied using a given connection.
1624 * @param cph connection to proxy server
1625 * @return connection to be proxied
1627 struct GNUNET_CONNECTION_Handle *
1628 GNUNET_CONNECTION_create_proxied_from_handshake (struct GNUNET_CONNECTION_Handle *cph)
1630 struct GNUNET_CONNECTION_Handle *proxied = GNUNET_CONNECTION_create_from_existing (NULL);
1632 proxied->proxy_handshake = cph;
1638 * Activate proxied connection and destroy initial proxy handshake connection.
1639 * There must not be any pending requests for reading or writing to the
1640 * proxy hadshake connection at this time.
1642 * @param proxied connection connection to proxy server
1645 GNUNET_CONNECTION_acivate_proxied (struct GNUNET_CONNECTION_Handle *proxied)
1647 struct GNUNET_CONNECTION_Handle *cph = proxied->proxy_handshake;
1649 GNUNET_assert (NULL != cph);
1650 GNUNET_assert (NULL == proxied->sock);
1651 GNUNET_assert (NULL != cph->sock);
1652 proxied->sock = cph->sock;
1654 GNUNET_CONNECTION_destroy (cph);
1655 connect_success_continuation (proxied);
1659 /* end of connection.c */