2 This file is part of GNUnet.
3 (C) 2009-2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
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
8 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 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
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"
38 #define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
40 #define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util", syscall)
44 * Transmission handle. There can only be one for each connection.
46 struct GNUNET_CONNECTION_TransmitHandle
50 * Function to call if the send buffer has notify_size
53 GNUNET_CONNECTION_TransmitReadyNotify notify_ready;
56 * Closure for notify_ready.
58 void *notify_ready_cls;
61 * Our connection handle.
63 struct GNUNET_CONNECTION_Handle *connection;
66 * Timeout for receiving (in absolute time).
68 struct GNUNET_TIME_Absolute transmit_timeout;
71 * Task called on timeout.
73 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
76 * At what number of bytes available in the
77 * write buffer should the notify method be called?
85 * During connect, we try multiple possible IP addresses
86 * to find out which one might work.
92 * This is a linked list.
94 struct AddressProbe *next;
97 * This is a doubly-linked list.
99 struct AddressProbe *prev;
102 * The address; do not free (allocated at the end of this struct).
104 const struct sockaddr *addr;
107 * Underlying OS's socket.
109 struct GNUNET_NETWORK_Handle *sock;
112 * Connection for which we are probing.
114 struct GNUNET_CONNECTION_Handle *connection;
122 * Task waiting for the connection to finish connecting.
124 GNUNET_SCHEDULER_TaskIdentifier task;
129 * @brief handle for a network connection
131 struct GNUNET_CONNECTION_Handle
135 * Configuration to use.
137 const struct GNUNET_CONFIGURATION_Handle *cfg;
140 * Linked list of sockets we are currently trying out
143 struct AddressProbe *ap_head;
146 * Linked list of sockets we are currently trying out
149 struct AddressProbe *ap_tail;
152 * Network address of the other end-point, may be NULL.
154 struct sockaddr *addr;
157 * Pointer to the hostname if connection was
158 * created using DNS lookup, otherwise NULL.
163 * Underlying OS's socket, set to NULL after fatal errors.
165 struct GNUNET_NETWORK_Handle *sock;
168 * Function to call on data received, NULL if no receive is pending.
170 GNUNET_CONNECTION_Receiver receiver;
173 * Closure for receiver.
178 * Pointer to our write buffer.
183 * Current size of our write buffer.
185 size_t write_buffer_size;
188 * Current write-offset in write buffer (where
189 * would we write next).
191 size_t write_buffer_off;
194 * Current read-offset in write buffer (how many
195 * bytes have already been sent).
197 size_t write_buffer_pos;
205 * Read task that we may need to wait for.
207 GNUNET_SCHEDULER_TaskIdentifier read_task;
210 * Write task that we may need to wait for.
212 GNUNET_SCHEDULER_TaskIdentifier write_task;
215 * Handle to a pending DNS lookup request.
217 struct GNUNET_RESOLVER_RequestHandle *dns_active;
220 * The handle we return for GNUNET_CONNECTION_notify_transmit_ready.
222 struct GNUNET_CONNECTION_TransmitHandle nth;
225 * Timeout for receiving (in absolute time).
227 struct GNUNET_TIME_Absolute receive_timeout;
230 * Maximum number of bytes to read (for receiving).
235 * Port to connect to.
240 * When shutdown, do not ever actually close the socket, but
241 * free resources. Only should ever be set if using program
242 * termination as a signal (because only then will the leaked
248 * Usually 0. Set to 1 if this handle is in used and should
249 * 'GNUNET_CONNECTION_destroy' be called right now, the action needs
250 * to be deferred by setting it to -1.
252 int8_t destroy_later;
258 * Set the persist option on this connection handle. Indicates
259 * that the underlying socket or fd should never really be closed.
260 * Used for indicating process death.
262 * @param connection the connection to set persistent
265 GNUNET_CONNECTION_persist_ (struct GNUNET_CONNECTION_Handle *connection)
267 connection->persist = GNUNET_YES;
272 * Disable the "CORK" feature for communication with the given connection,
273 * forcing the OS to immediately flush the buffer on transmission
274 * instead of potentially buffering multiple messages. Essentially
275 * reduces the OS send buffers to zero.
276 * Used to make sure that the last messages sent through the connection
277 * reach the other side before the process is terminated.
279 * @param connection the connection to make flushing and blocking
280 * @return GNUNET_OK on success
283 GNUNET_CONNECTION_disable_corking (struct GNUNET_CONNECTION_Handle *connection)
285 return GNUNET_NETWORK_socket_disable_corking (connection->sock);
290 * Create a connection handle by boxing an existing OS socket. The OS
291 * socket should henceforth be no longer used directly.
292 * GNUNET_connection_destroy will close it.
294 * @param osSocket existing socket to box
295 * @return the boxed connection handle
297 struct GNUNET_CONNECTION_Handle *
298 GNUNET_CONNECTION_create_from_existing (struct GNUNET_NETWORK_Handle *osSocket)
300 struct GNUNET_CONNECTION_Handle *connection;
302 connection = GNUNET_new (struct GNUNET_CONNECTION_Handle);
303 connection->write_buffer_size = GNUNET_SERVER_MIN_BUFFER_SIZE;
304 connection->write_buffer = GNUNET_malloc (connection->write_buffer_size);
305 connection->sock = osSocket;
311 * Create a connection handle by accepting on a listen socket. This
312 * function may block if the listen socket has no connection ready.
314 * @param access function to use to check if access is allowed
315 * @param access_cls closure for access
316 * @param lsock listen socket
317 * @return the connection handle, NULL on error
319 struct GNUNET_CONNECTION_Handle *
320 GNUNET_CONNECTION_create_from_accept (GNUNET_CONNECTION_AccessCheck access,
322 struct GNUNET_NETWORK_Handle *lsock)
324 struct GNUNET_CONNECTION_Handle *connection;
327 struct GNUNET_NETWORK_Handle *sock;
329 struct sockaddr_in *v4;
330 struct sockaddr_in6 *v6;
333 struct GNUNET_CONNECTION_Credentials *gcp;
334 struct GNUNET_CONNECTION_Credentials gc;
340 addrlen = sizeof (addr);
342 GNUNET_NETWORK_socket_accept (lsock, (struct sockaddr *) &addr, &addrlen);
345 LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING, "accept");
348 if ((addrlen > sizeof (addr)) || (addrlen < sizeof (sa_family_t)))
351 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock));
355 sa = (struct sockaddr *) addr;
356 v6 = (struct sockaddr_in6 *) addr;
357 if ((AF_INET6 == sa->sa_family) && (IN6_IS_ADDR_V4MAPPED (&v6->sin6_addr)))
359 /* convert to V4 address */
360 v4 = GNUNET_new (struct sockaddr_in);
361 memset (v4, 0, sizeof (struct sockaddr_in));
362 v4->sin_family = AF_INET;
363 #if HAVE_SOCKADDR_IN_SIN_LEN
364 v4->sin_len = (u_char) sizeof (struct sockaddr_in);
366 memcpy (&v4->sin_addr,
367 &((char *) &v6->sin6_addr)[sizeof (struct in6_addr) -
368 sizeof (struct in_addr)],
369 sizeof (struct in_addr));
370 v4->sin_port = v6->sin6_port;
372 addrlen = sizeof (struct sockaddr_in);
376 uaddr = GNUNET_malloc (addrlen);
377 memcpy (uaddr, addr, addrlen);
382 if (AF_UNIX == sa->sa_family)
386 if (0 == getpeereid (GNUNET_NETWORK_get_fd (sock), &gc.uid, &gc.gid))
390 /* largely traditional GNU/Linux */
393 getsockopt (GNUNET_NETWORK_get_fd (sock), SOL_SOCKET, SO_PEERCRED, &uc,
394 &olen)) && (olen == sizeof (uc)))
401 #if HAVE_GETPEERUCRED
402 /* this is for Solaris 10 */
406 if (0 == getpeerucred (GNUNET_NETWORK_get_fd (sock), &uc))
408 gc.uid = ucred_geteuid (uc);
409 gc.gid = ucred_getegid (uc);
418 if ((NULL != access) &&
419 (GNUNET_YES != (aret = access (access_cls, gcp, uaddr, addrlen))))
421 if (GNUNET_NO == aret)
422 LOG (GNUNET_ERROR_TYPE_INFO, _("Access denied to `%s'\n"),
423 GNUNET_a2s (uaddr, addrlen));
424 GNUNET_break (GNUNET_OK ==
425 GNUNET_NETWORK_socket_shutdown (sock, SHUT_RDWR));
426 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock));
430 connection = GNUNET_new (struct GNUNET_CONNECTION_Handle);
431 connection->write_buffer_size = GNUNET_SERVER_MIN_BUFFER_SIZE;
432 connection->write_buffer = GNUNET_malloc (connection->write_buffer_size);
433 connection->addr = uaddr;
434 connection->addrlen = addrlen;
435 connection->sock = sock;
436 LOG (GNUNET_ERROR_TYPE_INFO,
437 _("Accepting connection from `%s': %p\n"),
438 GNUNET_a2s (uaddr, addrlen), connection);
444 * Obtain the network address of the other party.
446 * @param connection the client to get the address for
447 * @param addr where to store the address
448 * @param addrlen where to store the length of the address
449 * @return GNUNET_OK on success
452 GNUNET_CONNECTION_get_address (struct GNUNET_CONNECTION_Handle *connection,
453 void **addr, size_t * addrlen)
455 if ((NULL == connection->addr) || (0 == connection->addrlen))
457 *addr = GNUNET_malloc (connection->addrlen);
458 memcpy (*addr, connection->addr, connection->addrlen);
459 *addrlen = connection->addrlen;
465 * Tell the receiver callback that we had an IO error.
467 * @param connection connection to signal error
468 * @param errcode error code to send
471 signal_receive_error (struct GNUNET_CONNECTION_Handle *connection, int errcode)
473 GNUNET_CONNECTION_Receiver receiver;
475 LOG (GNUNET_ERROR_TYPE_DEBUG,
476 "Receive encounters error (%s), connection closed (%p)\n",
479 GNUNET_assert (NULL != (receiver = connection->receiver));
480 connection->receiver = NULL;
481 receiver (connection->receiver_cls, NULL, 0, connection->addr, connection->addrlen, errcode);
486 * Tell the receiver callback that a timeout was reached.
488 * @param connection connection to signal for
491 signal_receive_timeout (struct GNUNET_CONNECTION_Handle *connection)
493 GNUNET_CONNECTION_Receiver receiver;
495 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection signals timeout to receiver (%p)!\n",
497 GNUNET_assert (NULL != (receiver = connection->receiver));
498 connection->receiver = NULL;
499 receiver (connection->receiver_cls, NULL, 0, NULL, 0, 0);
504 * We failed to transmit data to the service, signal the error.
506 * @param connection handle that had trouble
507 * @param ecode error code (errno)
510 signal_transmit_error (struct GNUNET_CONNECTION_Handle *connection,
513 GNUNET_CONNECTION_TransmitReadyNotify notify;
515 LOG (GNUNET_ERROR_TYPE_DEBUG,
516 "Transmission encounterd error (%s), connection closed (%p)\n",
519 if (NULL != connection->sock)
521 GNUNET_NETWORK_socket_shutdown (connection->sock, SHUT_RDWR);
522 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (connection->sock));
523 connection->sock = NULL;
524 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == connection->write_task);
526 if (GNUNET_SCHEDULER_NO_TASK != connection->read_task)
528 /* send errors trigger read errors... */
529 GNUNET_SCHEDULER_cancel (connection->read_task);
530 connection->read_task = GNUNET_SCHEDULER_NO_TASK;
531 signal_receive_timeout (connection);
534 if (NULL == connection->nth.notify_ready)
535 return; /* nobody to tell about it */
536 notify = connection->nth.notify_ready;
537 connection->nth.notify_ready = NULL;
538 notify (connection->nth.notify_ready_cls, 0, NULL);
543 * We've failed for good to establish a connection (timeout or
544 * no more addresses to try).
546 * @param connection the connection we tried to establish
549 connect_fail_continuation (struct GNUNET_CONNECTION_Handle *connection)
551 LOG (GNUNET_ERROR_TYPE_INFO,
552 _("Failed to establish TCP connection to `%s:%u', no further addresses to try.\n"),
553 connection->hostname, connection->port);
554 GNUNET_break (NULL == connection->ap_head);
555 GNUNET_break (NULL == connection->ap_tail);
556 GNUNET_break (GNUNET_NO == connection->dns_active);
557 GNUNET_break (NULL == connection->sock);
558 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == connection->write_task);
560 /* signal errors for jobs that used to wait on the connection */
561 connection->destroy_later = 1;
562 if (NULL != connection->receiver)
563 signal_receive_error (connection, ECONNREFUSED);
564 if (NULL != connection->nth.notify_ready)
566 GNUNET_assert (connection->nth.timeout_task != GNUNET_SCHEDULER_NO_TASK);
567 GNUNET_SCHEDULER_cancel (connection->nth.timeout_task);
568 connection->nth.timeout_task = GNUNET_SCHEDULER_NO_TASK;
569 signal_transmit_error (connection, ECONNREFUSED);
571 if (-1 == connection->destroy_later)
574 connection->destroy_later = 0;
575 GNUNET_CONNECTION_destroy (connection);
578 connection->destroy_later = 0;
583 * We are ready to transmit (or got a timeout).
585 * @param cls our connection handle
586 * @param tc task context describing why we are here
589 transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
593 * This function is called once we either timeout or have data ready
596 * @param cls connection to read from
597 * @param tc scheduler context
600 receive_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
604 * We've succeeded in establishing a connection.
606 * @param connection the connection we tried to establish
609 connect_success_continuation (struct GNUNET_CONNECTION_Handle *connection)
611 LOG (GNUNET_ERROR_TYPE_DEBUG,
612 "Connection to `%s' succeeded! (%p)\n",
613 GNUNET_a2s (connection->addr, connection->addrlen), connection);
614 /* trigger jobs that waited for the connection */
615 if (NULL != connection->receiver)
617 LOG (GNUNET_ERROR_TYPE_DEBUG,
618 "Connection succeeded, starting with receiving data (%p)\n",
620 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == connection->read_task);
621 connection->read_task =
622 GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_absolute_get_remaining
623 (connection->receive_timeout), connection->sock,
624 &receive_ready, connection);
626 if (NULL != connection->nth.notify_ready)
628 LOG (GNUNET_ERROR_TYPE_DEBUG,
629 "Connection succeeded, starting with sending data (%p)\n",
631 GNUNET_assert (connection->nth.timeout_task != GNUNET_SCHEDULER_NO_TASK);
632 GNUNET_SCHEDULER_cancel (connection->nth.timeout_task);
633 connection->nth.timeout_task = GNUNET_SCHEDULER_NO_TASK;
634 GNUNET_assert (connection->write_task == GNUNET_SCHEDULER_NO_TASK);
635 connection->write_task =
636 GNUNET_SCHEDULER_add_write_net (GNUNET_TIME_absolute_get_remaining
637 (connection->nth.transmit_timeout), connection->sock,
638 &transmit_ready, connection);
644 * Scheduler let us know that we're either ready to write on the
645 * socket OR connect timed out. Do the right thing.
647 * @param cls the "struct AddressProbe*" with the address that we are probing
648 * @param tc success or failure info about the connect attempt.
651 connect_probe_continuation (void *cls,
652 const struct GNUNET_SCHEDULER_TaskContext *tc)
654 struct AddressProbe *ap = cls;
655 struct GNUNET_CONNECTION_Handle *connection = ap->connection;
656 struct AddressProbe *pos;
660 GNUNET_assert (NULL != ap->sock);
661 GNUNET_CONTAINER_DLL_remove (connection->ap_head, connection->ap_tail, ap);
662 len = sizeof (error);
665 if ((0 == (tc->reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) ||
667 GNUNET_NETWORK_socket_getsockopt (ap->sock, SOL_SOCKET, SO_ERROR, &error,
668 &len)) || (0 != error))
670 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (ap->sock));
672 if ((NULL == connection->ap_head) && (GNUNET_NO == connection->dns_active))
673 connect_fail_continuation (connection);
676 GNUNET_assert (NULL == connection->sock);
677 connection->sock = ap->sock;
678 GNUNET_assert (NULL == connection->addr);
679 connection->addr = GNUNET_malloc (ap->addrlen);
680 memcpy (connection->addr, ap->addr, ap->addrlen);
681 connection->addrlen = ap->addrlen;
683 /* cancel all other attempts */
684 while (NULL != (pos = connection->ap_head))
686 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (pos->sock));
687 GNUNET_SCHEDULER_cancel (pos->task);
688 GNUNET_CONTAINER_DLL_remove (connection->ap_head, connection->ap_tail, pos);
691 connect_success_continuation (connection);
696 * Try to establish a connection given the specified address.
697 * This function is called by the resolver once we have a DNS reply.
699 * @param cls our "struct GNUNET_CONNECTION_Handle *"
700 * @param addr address to try, NULL for "last call"
701 * @param addrlen length of addr
704 try_connect_using_address (void *cls, const struct sockaddr *addr,
707 struct GNUNET_CONNECTION_Handle *connection = cls;
708 struct AddressProbe *ap;
709 struct GNUNET_TIME_Relative delay;
713 connection->dns_active = NULL;
714 if ((NULL == connection->ap_head) && (NULL == connection->sock))
715 connect_fail_continuation (connection);
718 if (NULL != connection->sock)
719 return; /* already connected */
720 GNUNET_assert (NULL == connection->addr);
722 LOG (GNUNET_ERROR_TYPE_DEBUG,
723 "Trying to connect using address `%s:%u/%s:%u'\n", connection->hostname, connection->port,
724 GNUNET_a2s (addr, addrlen), connection->port);
725 ap = GNUNET_malloc (sizeof (struct AddressProbe) + addrlen);
726 ap->addr = (const struct sockaddr *) &ap[1];
727 memcpy (&ap[1], addr, addrlen);
728 ap->addrlen = addrlen;
729 ap->connection = connection;
731 switch (ap->addr->sa_family)
734 ((struct sockaddr_in *) ap->addr)->sin_port = htons (connection->port);
737 ((struct sockaddr_in6 *) ap->addr)->sin6_port = htons (connection->port);
742 return; /* not supported by us */
744 ap->sock = GNUNET_NETWORK_socket_create (ap->addr->sa_family, SOCK_STREAM, 0);
745 if (NULL == ap->sock)
748 return; /* not supported by OS */
750 LOG (GNUNET_ERROR_TYPE_INFO, _("Trying to connect to `%s' (%p)\n"),
751 GNUNET_a2s (ap->addr, ap->addrlen), connection);
753 GNUNET_NETWORK_socket_connect (ap->sock, ap->addr, ap->addrlen)) &&
754 (EINPROGRESS != errno))
756 /* maybe refused / unsupported address, try next */
757 LOG_STRERROR (GNUNET_ERROR_TYPE_INFO, "connect");
758 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (ap->sock));
762 GNUNET_CONTAINER_DLL_insert (connection->ap_head, connection->ap_tail, ap);
763 delay = GNUNET_CONNECTION_CONNECT_RETRY_TIMEOUT;
764 if (NULL != connection->nth.notify_ready)
766 GNUNET_TIME_relative_min (delay,
767 GNUNET_TIME_absolute_get_remaining (connection->
768 nth.transmit_timeout));
769 if (NULL != connection->receiver)
771 GNUNET_TIME_relative_min (delay,
772 GNUNET_TIME_absolute_get_remaining
773 (connection->receive_timeout));
775 GNUNET_SCHEDULER_add_write_net (delay, ap->sock,
776 &connect_probe_continuation, ap);
781 * Create a connection handle by (asynchronously) connecting to a host.
782 * This function returns immediately, even if the connection has not
783 * yet been established. This function only creates TCP connections.
785 * @param cfg configuration to use
786 * @param hostname name of the host to connect to
787 * @param port port to connect to
788 * @return the connection handle
790 struct GNUNET_CONNECTION_Handle *
791 GNUNET_CONNECTION_create_from_connect (const struct GNUNET_CONFIGURATION_Handle
792 *cfg, const char *hostname,
795 struct GNUNET_CONNECTION_Handle *connection;
797 GNUNET_assert (0 < strlen (hostname)); /* sanity check */
798 connection = GNUNET_new (struct GNUNET_CONNECTION_Handle);
799 connection->cfg = cfg;
800 connection->write_buffer_size = GNUNET_SERVER_MIN_BUFFER_SIZE;
801 connection->write_buffer = GNUNET_malloc (connection->write_buffer_size);
802 connection->port = port;
803 connection->hostname = GNUNET_strdup (hostname);
804 connection->dns_active =
805 GNUNET_RESOLVER_ip_get (connection->hostname, AF_UNSPEC,
806 GNUNET_CONNECTION_CONNECT_RETRY_TIMEOUT,
807 &try_connect_using_address, connection);
813 * Create a connection handle by connecting to a UNIX domain service.
814 * This function returns immediately, even if the connection has not
815 * yet been established. This function only creates UNIX connections.
817 * @param cfg configuration to use
818 * @param unixpath path to connect to
819 * @return the connection handle, NULL on systems without UNIX support
821 struct GNUNET_CONNECTION_Handle *
822 GNUNET_CONNECTION_create_from_connect_to_unixpath (const struct
823 GNUNET_CONFIGURATION_Handle
824 *cfg, const char *unixpath)
827 struct GNUNET_CONNECTION_Handle *connection;
828 struct sockaddr_un *un;
831 GNUNET_assert (0 < strlen (unixpath)); /* sanity check */
832 un = GNUNET_new (struct sockaddr_un);
833 un->sun_family = AF_UNIX;
834 slen = strlen (unixpath);
835 if (slen >= sizeof (un->sun_path))
836 slen = sizeof (un->sun_path) - 1;
837 memcpy (un->sun_path, unixpath, slen);
838 un->sun_path[slen] = '\0';
839 slen = sizeof (struct sockaddr_un);
840 #if HAVE_SOCKADDR_IN_SIN_LEN
841 un->sun_len = (u_char) slen;
844 un->sun_path[0] = '\0';
846 connection = GNUNET_new (struct GNUNET_CONNECTION_Handle);
847 connection->cfg = cfg;
848 connection->write_buffer_size = GNUNET_SERVER_MIN_BUFFER_SIZE;
849 connection->write_buffer = GNUNET_malloc (connection->write_buffer_size);
850 connection->port = 0;
851 connection->hostname = NULL;
852 connection->addr = (struct sockaddr *) un;
853 connection->addrlen = slen;
854 connection->sock = GNUNET_NETWORK_socket_create (AF_UNIX, SOCK_STREAM, 0);
855 if (NULL == connection->sock)
857 GNUNET_free (connection->addr);
858 GNUNET_free (connection->write_buffer);
859 GNUNET_free (connection);
863 GNUNET_NETWORK_socket_connect (connection->sock, connection->addr, connection->addrlen)) &&
864 (EINPROGRESS != errno) )
866 /* Just return; we expect everything to work eventually so don't fail HARD */
867 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (connection->sock));
868 connection->sock = NULL;
871 connect_success_continuation (connection);
880 * Create a connection handle by (asynchronously) connecting to a host.
881 * This function returns immediately, even if the connection has not
882 * yet been established. This function only creates TCP connections.
884 * @param af_family address family to use
885 * @param serv_addr server address
886 * @param addrlen length of server address
887 * @return the connection handle
889 struct GNUNET_CONNECTION_Handle *
890 GNUNET_CONNECTION_create_from_sockaddr (int af_family,
891 const struct sockaddr *serv_addr,
894 struct GNUNET_NETWORK_Handle *s;
895 struct GNUNET_CONNECTION_Handle *connection;
897 s = GNUNET_NETWORK_socket_create (af_family, SOCK_STREAM, 0);
900 LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK, "socket");
903 if ((GNUNET_OK != GNUNET_NETWORK_socket_connect (s, serv_addr, addrlen)) &&
904 (EINPROGRESS != errno))
906 /* maybe refused / unsupported address, try next */
907 LOG_STRERROR (GNUNET_ERROR_TYPE_INFO, "connect");
908 LOG (GNUNET_ERROR_TYPE_INFO, _("Attempt to connect to `%s' failed\n"),
909 GNUNET_a2s (serv_addr, addrlen));
910 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (s));
913 connection = GNUNET_CONNECTION_create_from_existing (s);
914 connection->addr = GNUNET_malloc (addrlen);
915 memcpy (connection->addr, serv_addr, addrlen);
916 connection->addrlen = addrlen;
917 LOG (GNUNET_ERROR_TYPE_INFO, _("Trying to connect to `%s' (%p)\n"),
918 GNUNET_a2s (serv_addr, addrlen), connection);
924 * Check if connection is valid (no fatal errors have happened so far).
925 * Note that a connection that is still trying to connect is considered
928 * @param connection connection to check
929 * @return GNUNET_YES if valid, GNUNET_NO otherwise
932 GNUNET_CONNECTION_check (struct GNUNET_CONNECTION_Handle *connection)
934 if ((NULL != connection->ap_head) || (NULL != connection->dns_active))
935 return GNUNET_YES; /* still trying to connect */
936 return (NULL == connection->sock) ? GNUNET_NO : GNUNET_YES;
941 * Close the connection and free associated resources. There must
942 * not be any pending requests for reading or writing to the
943 * connection at this time.
945 * @param connection connection to destroy
948 GNUNET_CONNECTION_destroy (struct GNUNET_CONNECTION_Handle *connection)
950 struct AddressProbe *pos;
952 if (0 != connection->destroy_later)
954 connection->destroy_later = -1;
957 LOG (GNUNET_ERROR_TYPE_DEBUG, "Shutting down connection (%p)\n", connection);
958 GNUNET_assert (NULL == connection->nth.notify_ready);
959 GNUNET_assert (NULL == connection->receiver);
960 if (GNUNET_SCHEDULER_NO_TASK != connection->write_task)
962 GNUNET_SCHEDULER_cancel (connection->write_task);
963 connection->write_task = GNUNET_SCHEDULER_NO_TASK;
964 connection->write_buffer_off = 0;
966 if (GNUNET_SCHEDULER_NO_TASK != connection->read_task)
968 GNUNET_SCHEDULER_cancel (connection->read_task);
969 connection->read_task = GNUNET_SCHEDULER_NO_TASK;
971 if (GNUNET_SCHEDULER_NO_TASK != connection->nth.timeout_task)
973 GNUNET_SCHEDULER_cancel (connection->nth.timeout_task);
974 connection->nth.timeout_task = GNUNET_SCHEDULER_NO_TASK;
976 connection->nth.notify_ready = NULL;
977 if (NULL != connection->dns_active)
979 GNUNET_RESOLVER_request_cancel (connection->dns_active);
980 connection->dns_active = NULL;
982 while (NULL != (pos = connection->ap_head))
984 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (pos->sock));
985 GNUNET_SCHEDULER_cancel (pos->task);
986 GNUNET_CONTAINER_DLL_remove (connection->ap_head, connection->ap_tail, pos);
989 if ( (NULL != connection->sock) &&
990 (GNUNET_YES != connection->persist) )
992 if ((GNUNET_YES != GNUNET_NETWORK_socket_shutdown (connection->sock, SHUT_RDWR)) &&
993 (ENOTCONN != errno) &&
994 (ECONNRESET != errno) )
995 LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING, "shutdown");
997 if (NULL != connection->sock)
999 if (GNUNET_YES != connection->persist)
1000 GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (connection->sock));
1003 GNUNET_NETWORK_socket_free_memory_only_ (connection->sock); /* at least no memory leak (we deliberately
1004 * leak the socket in this special case) ... */
1007 GNUNET_free_non_null (connection->addr);
1008 GNUNET_free_non_null (connection->hostname);
1009 GNUNET_free (connection->write_buffer);
1010 GNUNET_free (connection);
1015 * This function is called once we either timeout
1016 * or have data ready to read.
1018 * @param cls connection to read from
1019 * @param tc scheduler context
1022 receive_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1024 struct GNUNET_CONNECTION_Handle *connection = cls;
1025 char buffer[connection->max];
1027 GNUNET_CONNECTION_Receiver receiver;
1029 connection->read_task = GNUNET_SCHEDULER_NO_TASK;
1030 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1032 /* ignore shutdown request, go again immediately */
1033 connection->read_task =
1034 GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_absolute_get_remaining
1035 (connection->receive_timeout), connection->sock,
1036 &receive_ready, connection);
1039 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_TIMEOUT))
1041 LOG (GNUNET_ERROR_TYPE_DEBUG,
1042 "Receive from `%s' encounters error: timeout (%s, %p)\n",
1043 GNUNET_a2s (connection->addr, connection->addrlen),
1044 GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_duration (connection->receive_timeout), GNUNET_YES),
1046 signal_receive_timeout (connection);
1049 if (NULL == connection->sock)
1051 /* connect failed for good */
1052 signal_receive_error (connection, ECONNREFUSED);
1055 GNUNET_assert (GNUNET_NETWORK_fdset_isset (tc->read_ready, connection->sock));
1057 ret = GNUNET_NETWORK_socket_recv (connection->sock, buffer, connection->max);
1062 signal_receive_error (connection, errno);
1065 LOG (GNUNET_ERROR_TYPE_DEBUG,
1066 "receive_ready read %u/%u bytes from `%s' (%p)!\n", (unsigned int) ret,
1067 connection->max, GNUNET_a2s (connection->addr, connection->addrlen), connection);
1068 GNUNET_assert (NULL != (receiver = connection->receiver));
1069 connection->receiver = NULL;
1070 receiver (connection->receiver_cls, buffer, ret, connection->addr, connection->addrlen, 0);
1075 * Receive data from the given connection. Note that this function will
1076 * call "receiver" asynchronously using the scheduler. It will
1077 * "immediately" return. Note that there MUST only be one active
1078 * receive call per connection at any given point in time (so do not
1079 * call receive again until the receiver callback has been invoked).
1081 * @param connection connection handle
1082 * @param max maximum number of bytes to read
1083 * @param timeout maximum amount of time to wait
1084 * @param receiver function to call with received data
1085 * @param receiver_cls closure for receiver
1088 GNUNET_CONNECTION_receive (struct GNUNET_CONNECTION_Handle *connection, size_t max,
1089 struct GNUNET_TIME_Relative timeout,
1090 GNUNET_CONNECTION_Receiver receiver,
1093 GNUNET_assert ((GNUNET_SCHEDULER_NO_TASK == connection->read_task) &&
1094 (NULL == connection->receiver));
1095 GNUNET_assert (NULL != receiver);
1096 connection->receiver = receiver;
1097 connection->receiver_cls = receiver_cls;
1098 connection->receive_timeout = GNUNET_TIME_relative_to_absolute (timeout);
1099 connection->max = max;
1100 if (NULL != connection->sock)
1102 connection->read_task =
1103 GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_absolute_get_remaining
1104 (connection->receive_timeout), connection->sock,
1105 &receive_ready, connection);
1108 if ((NULL == connection->dns_active) && (NULL == connection->ap_head))
1110 connection->receiver = NULL;
1111 receiver (receiver_cls, NULL, 0, NULL, 0, ETIMEDOUT);
1118 * Cancel receive job on the given connection. Note that the
1119 * receiver callback must not have been called yet in order
1120 * for the cancellation to be valid.
1122 * @param connection connection handle
1123 * @return closure of the original receiver callback closure
1126 GNUNET_CONNECTION_receive_cancel (struct GNUNET_CONNECTION_Handle *connection)
1128 if (GNUNET_SCHEDULER_NO_TASK != connection->read_task)
1130 GNUNET_assert (connection == GNUNET_SCHEDULER_cancel (connection->read_task));
1131 connection->read_task = GNUNET_SCHEDULER_NO_TASK;
1133 connection->receiver = NULL;
1134 return connection->receiver_cls;
1139 * Try to call the transmit notify method (check if we do
1140 * have enough space available first)!
1142 * @param connection connection for which we should do this processing
1143 * @return GNUNET_YES if we were able to call notify
1146 process_notify (struct GNUNET_CONNECTION_Handle *connection)
1151 GNUNET_CONNECTION_TransmitReadyNotify notify;
1153 LOG (GNUNET_ERROR_TYPE_DEBUG, "process_notify is running\n");
1155 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == connection->write_task);
1156 if (NULL == (notify = connection->nth.notify_ready))
1158 LOG (GNUNET_ERROR_TYPE_DEBUG, "Noone to notify\n");
1161 used = connection->write_buffer_off - connection->write_buffer_pos;
1162 avail = connection->write_buffer_size - used;
1163 size = connection->nth.notify_size;
1166 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not enough buffer\n");
1169 connection->nth.notify_ready = NULL;
1170 if (connection->write_buffer_size - connection->write_buffer_off < size)
1172 /* need to compact */
1173 memmove (connection->write_buffer, &connection->write_buffer[connection->write_buffer_pos],
1175 connection->write_buffer_off -= connection->write_buffer_pos;
1176 connection->write_buffer_pos = 0;
1178 avail = connection->write_buffer_size - connection->write_buffer_off;
1179 GNUNET_assert (avail >= size);
1181 notify (connection->nth.notify_ready_cls, avail,
1182 &connection->write_buffer[connection->write_buffer_off]);
1183 GNUNET_assert (size <= avail);
1185 connection->write_buffer_off += size;
1191 * Task invoked by the scheduler when a call to transmit
1192 * is timing out (we never got enough buffer space to call
1193 * the callback function before the specified timeout
1196 * This task notifies the client about the timeout.
1198 * @param cls the 'struct GNUNET_CONNECTION_Handle'
1199 * @param tc scheduler context
1202 transmit_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1204 struct GNUNET_CONNECTION_Handle *connection = cls;
1205 GNUNET_CONNECTION_TransmitReadyNotify notify;
1207 connection->nth.timeout_task = GNUNET_SCHEDULER_NO_TASK;
1208 LOG (GNUNET_ERROR_TYPE_DEBUG,
1209 "Transmit to `%s:%u/%s' fails, time out reached (%p).\n",
1210 connection->hostname,
1211 connection->port, GNUNET_a2s (connection->addr, connection->addrlen), connection);
1212 notify = connection->nth.notify_ready;
1213 GNUNET_assert (NULL != notify);
1214 connection->nth.notify_ready = NULL;
1215 notify (connection->nth.notify_ready_cls, 0, NULL);
1220 * Task invoked by the scheduler when we failed to connect
1221 * at the time of being asked to transmit.
1223 * This task notifies the client about the error.
1225 * @param cls the 'struct GNUNET_CONNECTION_Handle'
1226 * @param tc scheduler context
1229 connect_error (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1231 struct GNUNET_CONNECTION_Handle *connection = cls;
1232 GNUNET_CONNECTION_TransmitReadyNotify notify;
1234 LOG (GNUNET_ERROR_TYPE_DEBUG,
1235 "Transmission request of size %u fails (%s/%u), connection failed (%p).\n",
1236 connection->nth.notify_size, connection->hostname, connection->port, connection);
1237 connection->write_task = GNUNET_SCHEDULER_NO_TASK;
1238 notify = connection->nth.notify_ready;
1239 connection->nth.notify_ready = NULL;
1240 notify (connection->nth.notify_ready_cls, 0, NULL);
1245 * We are ready to transmit (or got a timeout).
1247 * @param cls our connection handle
1248 * @param tc task context describing why we are here
1251 transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1253 struct GNUNET_CONNECTION_Handle *connection = cls;
1254 GNUNET_CONNECTION_TransmitReadyNotify notify;
1258 LOG (GNUNET_ERROR_TYPE_DEBUG, "transmit_ready running (%p).\n", connection);
1259 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK != connection->write_task);
1260 connection->write_task = GNUNET_SCHEDULER_NO_TASK;
1261 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == connection->nth.timeout_task);
1262 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1264 if (NULL != connection->sock)
1265 goto SCHEDULE_WRITE; /* ignore shutdown, go again immediately */
1266 LOG (GNUNET_ERROR_TYPE_DEBUG,
1267 "Transmit to `%s' fails, shutdown happened (%p).\n",
1268 GNUNET_a2s (connection->addr, connection->addrlen), connection);
1269 notify = connection->nth.notify_ready;
1272 connection->nth.notify_ready = NULL;
1273 notify (connection->nth.notify_ready_cls, 0, NULL);
1277 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_TIMEOUT))
1279 LOG (GNUNET_ERROR_TYPE_DEBUG,
1280 "Transmit to `%s' fails, time out reached (%p).\n",
1281 GNUNET_a2s (connection->addr, connection->addrlen), connection);
1282 notify = connection->nth.notify_ready;
1283 GNUNET_assert (NULL != notify);
1284 connection->nth.notify_ready = NULL;
1285 notify (connection->nth.notify_ready_cls, 0, NULL);
1288 GNUNET_assert (NULL != connection->sock);
1289 if (NULL == tc->write_ready)
1291 /* special circumstances (in particular, PREREQ_DONE after
1292 * connect): not yet ready to write, but no "fatal" error either.
1294 goto SCHEDULE_WRITE;
1296 if (!GNUNET_NETWORK_fdset_isset (tc->write_ready, connection->sock))
1298 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == connection->write_task);
1299 /* special circumstances (in particular, shutdown): not yet ready
1300 * to write, but no "fatal" error either. Hence retry. */
1301 goto SCHEDULE_WRITE;
1303 GNUNET_assert (connection->write_buffer_off >= connection->write_buffer_pos);
1304 if ((NULL != connection->nth.notify_ready) &&
1305 (connection->write_buffer_size < connection->nth.notify_size))
1307 connection->write_buffer =
1308 GNUNET_realloc (connection->write_buffer, connection->nth.notify_size);
1309 connection->write_buffer_size = connection->nth.notify_size;
1311 process_notify (connection);
1312 have = connection->write_buffer_off - connection->write_buffer_pos;
1315 /* no data ready for writing, terminate write loop */
1318 GNUNET_assert (have <= connection->write_buffer_size);
1319 GNUNET_assert (have + connection->write_buffer_pos <= connection->write_buffer_size);
1320 GNUNET_assert (connection->write_buffer_pos <= connection->write_buffer_size);
1323 GNUNET_NETWORK_socket_send (connection->sock,
1324 &connection->write_buffer[connection->write_buffer_pos],
1330 if (GNUNET_SCHEDULER_NO_TASK != connection->write_task)
1332 GNUNET_SCHEDULER_cancel (connection->write_task);
1333 connection->write_task = GNUNET_SCHEDULER_NO_TASK;
1335 signal_transmit_error (connection, errno);
1338 LOG (GNUNET_ERROR_TYPE_DEBUG,
1339 "Connection transmitted %u/%u bytes to `%s' (%p)\n",
1340 (unsigned int) ret, have, GNUNET_a2s (connection->addr, connection->addrlen), connection);
1341 connection->write_buffer_pos += ret;
1342 if (connection->write_buffer_pos == connection->write_buffer_off)
1344 /* transmitted all pending data */
1345 connection->write_buffer_pos = 0;
1346 connection->write_buffer_off = 0;
1348 if ((0 == connection->write_buffer_off) && (NULL == connection->nth.notify_ready))
1349 return; /* all data sent! */
1350 /* not done writing, schedule more */
1352 LOG (GNUNET_ERROR_TYPE_DEBUG,
1353 "Re-scheduling transmit_ready (more to do) (%p).\n", connection);
1354 have = connection->write_buffer_off - connection->write_buffer_pos;
1355 GNUNET_assert ((NULL != connection->nth.notify_ready) || (have > 0));
1356 if (GNUNET_SCHEDULER_NO_TASK == connection->write_task)
1357 connection->write_task =
1358 GNUNET_SCHEDULER_add_write_net ((connection->nth.notify_ready ==
1359 NULL) ? GNUNET_TIME_UNIT_FOREVER_REL :
1360 GNUNET_TIME_absolute_get_remaining
1361 (connection->nth.transmit_timeout),
1362 connection->sock, &transmit_ready, connection);
1367 * Ask the connection to call us once the specified number of bytes
1368 * are free in the transmission buffer. May call the notify
1369 * method immediately if enough space is available.
1371 * @param connection connection
1372 * @param size number of bytes to send
1373 * @param timeout after how long should we give up (and call
1374 * notify with buf NULL and size 0)?
1375 * @param notify function to call
1376 * @param notify_cls closure for notify
1377 * @return non-NULL if the notify callback was queued,
1378 * NULL if we are already going to notify someone else (busy)
1380 struct GNUNET_CONNECTION_TransmitHandle *
1381 GNUNET_CONNECTION_notify_transmit_ready (struct GNUNET_CONNECTION_Handle *connection,
1383 struct GNUNET_TIME_Relative timeout,
1384 GNUNET_CONNECTION_TransmitReadyNotify
1385 notify, void *notify_cls)
1387 if (NULL != connection->nth.notify_ready)
1392 GNUNET_assert (NULL != notify);
1393 GNUNET_assert (size < GNUNET_SERVER_MAX_MESSAGE_SIZE);
1394 GNUNET_assert (connection->write_buffer_off <= connection->write_buffer_size);
1395 GNUNET_assert (connection->write_buffer_pos <= connection->write_buffer_size);
1396 GNUNET_assert (connection->write_buffer_pos <= connection->write_buffer_off);
1397 connection->nth.notify_ready = notify;
1398 connection->nth.notify_ready_cls = notify_cls;
1399 connection->nth.connection = connection;
1400 connection->nth.notify_size = size;
1401 connection->nth.transmit_timeout = GNUNET_TIME_relative_to_absolute (timeout);
1402 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == connection->nth.timeout_task);
1403 if ((NULL == connection->sock) &&
1404 (NULL == connection->ap_head) &&
1405 (NULL == connection->dns_active))
1407 if (GNUNET_SCHEDULER_NO_TASK != connection->write_task)
1408 GNUNET_SCHEDULER_cancel (connection->write_task);
1409 connection->write_task = GNUNET_SCHEDULER_add_now (&connect_error, connection);
1410 return &connection->nth;
1412 if (GNUNET_SCHEDULER_NO_TASK != connection->write_task)
1413 return &connection->nth; /* previous transmission still in progress */
1414 if (NULL != connection->sock)
1416 /* connected, try to transmit now */
1417 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduling transmission (%p).\n", connection);
1418 connection->write_task =
1419 GNUNET_SCHEDULER_add_write_net (GNUNET_TIME_absolute_get_remaining
1420 (connection->nth.transmit_timeout),
1421 connection->sock, &transmit_ready, connection);
1422 return &connection->nth;
1424 /* not yet connected, wait for connection */
1425 LOG (GNUNET_ERROR_TYPE_DEBUG,
1426 "Need to wait to schedule transmission for connection, adding timeout task (%p).\n", connection);
1427 connection->nth.timeout_task =
1428 GNUNET_SCHEDULER_add_delayed (timeout, &transmit_timeout, connection);
1429 return &connection->nth;
1434 * Cancel the specified transmission-ready notification.
1436 * @param th notification to cancel
1439 GNUNET_CONNECTION_notify_transmit_ready_cancel (struct
1440 GNUNET_CONNECTION_TransmitHandle
1443 GNUNET_assert (NULL != th->notify_ready);
1444 th->notify_ready = NULL;
1445 if (GNUNET_SCHEDULER_NO_TASK != th->timeout_task)
1447 GNUNET_SCHEDULER_cancel (th->timeout_task);
1448 th->timeout_task = GNUNET_SCHEDULER_NO_TASK;
1450 if (GNUNET_SCHEDULER_NO_TASK != th->connection->write_task)
1452 GNUNET_SCHEDULER_cancel (th->connection->write_task);
1453 th->connection->write_task = GNUNET_SCHEDULER_NO_TASK;
1457 /* end of connection.c */