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1/*
2 This file is part of GNUnet.
3 (C) 2009 Christian Grothoff (and other contributing authors)
4
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 2, or (at your
8 option) any later version.
9
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.
14
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.
19*/
20
21/**
22 * @file util/network/network.c
23 * @brief basic, low-level TCP networking interface
24 * @author Christian Grothoff
25 *
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.
32 *
33 * TODO:
34 * - can we merge receive_ready and receive_again?
35 * - can we integrate the nth.timeout_task with the write_task's timeout?
36 */
37
38#include "platform.h"
39#include "gnunet_common.h"
40#include "gnunet_network_lib.h"
41#include "gnunet_scheduler_lib.h"
42
43#define DEBUG_NETWORK GNUNET_NO
44
45struct GNUNET_NETWORK_TransmitHandle
46{
47
48 /**
49 * Function to call if the send buffer has notify_size
50 * bytes available.
51 */
52 GNUNET_NETWORK_TransmitReadyNotify notify_ready;
53
54 /**
55 * Closure for notify_ready.
56 */
57 void *notify_ready_cls;
58
59 /**
60 * Our socket handle.
61 */
62 struct GNUNET_NETWORK_SocketHandle *sh;
63
64 /**
65 * Timeout for receiving (in absolute time).
66 */
67 struct GNUNET_TIME_Absolute transmit_timeout;
68
69 /**
70 * Task called on timeout.
71 */
72 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
73
74 /**
75 * At what number of bytes available in the
76 * write buffer should the notify method be called?
77 */
78 size_t notify_size;
79
80};
81
82/**
83 * @brief handle for a network socket
84 */
85struct GNUNET_NETWORK_SocketHandle
86{
87
88 /**
89 * Scheduler that was used for the connect task.
90 */
91 struct GNUNET_SCHEDULER_Handle *sched;
92
93 /**
94 * Address information for connect (may be NULL).
95 */
96 struct addrinfo *ai;
97
98 /**
99 * Index for the next struct addrinfo for connect attempts (may be NULL)
100 */
101 struct addrinfo *ai_pos;
102
103 /**
104 * Network address of the other end-point, may be NULL.
105 */
106 struct sockaddr *addr;
107
108 /**
109 * Pointer to our write buffer.
110 */
111 char *write_buffer;
112
113 /**
114 * Size of our write buffer.
115 */
116 size_t write_buffer_size;
117
118 /**
119 * Current write-offset in write buffer (where
120 * would we write next).
121 */
122 size_t write_buffer_off;
123
124 /**
125 * Current read-offset in write buffer (how many
126 * bytes have already been send).
127 */
128 size_t write_buffer_pos;
129
130 /**
131 * Length of addr.
132 */
133 socklen_t addrlen;
134
135 /**
136 * Connect task that we may need to wait for.
137 */
138 GNUNET_SCHEDULER_TaskIdentifier connect_task;
139
140 /**
141 * Read task that we may need to wait for.
142 */
143 GNUNET_SCHEDULER_TaskIdentifier read_task;
144
145 /**
146 * Write task that we may need to wait for.
147 */
148 GNUNET_SCHEDULER_TaskIdentifier write_task;
149
150 /**
151 * The handle we return for GNUNET_NETWORK_notify_transmit_ready.
152 */
153 struct GNUNET_NETWORK_TransmitHandle nth;
154
155 /**
156 * Underlying OS's socket, set to -1 after fatal errors.
157 */
158 int sock;
159
160 /**
161 * Port to connect to.
162 */
163 uint16_t port;
164
165 /**
166 * Function to call on data received, NULL
167 * if no receive is pending.
168 */
169 GNUNET_NETWORK_Receiver receiver;
170
171 /**
172 * Closure for receiver.
173 */
174 void *receiver_cls;
175
176 /**
177 * Timeout for receiving (in absolute time).
178 */
179 struct GNUNET_TIME_Absolute receive_timeout;
180
181 /**
182 * Maximum number of bytes to read
183 * (for receiving).
184 */
185 size_t max;
186
187};
188
189
190/**
191 * Create a socket handle by boxing an existing OS socket. The OS
192 * socket should henceforth be no longer used directly.
193 * GNUNET_socket_destroy will close it.
194 *
195 * @param sched scheduler to use
196 * @param osSocket existing socket to box
197 * @param maxbuf maximum write buffer size for the socket (use
198 * 0 for sockets that need no write buffers, such as listen sockets)
199 * @return the boxed socket handle
200 */
201struct GNUNET_NETWORK_SocketHandle *
202GNUNET_NETWORK_socket_create_from_existing (struct GNUNET_SCHEDULER_Handle
203 *sched, int osSocket,
204 size_t maxbuf)
205{
206 struct GNUNET_NETWORK_SocketHandle *ret;
207 ret = GNUNET_malloc (sizeof (struct GNUNET_NETWORK_SocketHandle) + maxbuf);
208 ret->write_buffer = (char *) &ret[1];
209 ret->write_buffer_size = maxbuf;
210 ret->sock = osSocket;
211 ret->sched = sched;
212 return ret;
213}
214
215
216/**
217 * Create a socket handle by accepting on a listen socket. This
218 * function may block if the listen socket has no connection ready.
219 *
220 * @param sched scheduler to use
221 * @param access function to use to check if access is allowed
222 * @param access_cls closure for access
223 * @param lsock listen socket
224 * @param maxbuf maximum write buffer size for the socket (use
225 * 0 for sockets that need no write buffers, such as listen sockets)
226 * @return the socket handle, NULL on error
227 */
228struct GNUNET_NETWORK_SocketHandle *
229GNUNET_NETWORK_socket_create_from_accept (struct GNUNET_SCHEDULER_Handle
230 *sched,
231 GNUNET_NETWORK_AccessCheck access,
232 void *access_cls, int lsock,
233 size_t maxbuf)
234{
235 struct GNUNET_NETWORK_SocketHandle *ret;
236 char addr[32];
237 char msg[INET6_ADDRSTRLEN];
238 socklen_t addrlen;
239 int fam;
240 int fd;
241 int aret;
242 struct sockaddr_in *v4;
243 struct sockaddr_in6 *v6;
244 struct sockaddr *sa;
245 void *uaddr;
246
247 addrlen = sizeof (addr);
248 fd = accept (lsock, (struct sockaddr *) &addr, &addrlen);
249 if (fd == -1)
250 {
251 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "accept");
252 return NULL;
253 }
254 if (0 != fcntl (fd, F_SETFD, fcntl (fd, F_GETFD) | FD_CLOEXEC))
255 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
256 "fcntl");
257 if (addrlen > sizeof (addr))
258 {
259 GNUNET_break (0);
260 GNUNET_break (0 == CLOSE (fd));
261 return NULL;
262 }
263
264 sa = (struct sockaddr *) addr;
265 v6 = (struct sockaddr_in6 *) addr;
266 if ((sa->sa_family == AF_INET6) && (IN6_IS_ADDR_V4MAPPED (&v6->sin6_addr)))
267 {
268 /* convert to V4 address */
269 v4 = GNUNET_malloc (sizeof (struct sockaddr_in));
270 memset (v4, 0, sizeof (struct sockaddr_in));
271 v4->sin_family = AF_INET;
272 memcpy (&v4->sin_addr,
273 &((char *) &v6->sin6_addr)[sizeof (struct in6_addr) -
274 sizeof (struct in_addr)],
275 sizeof (struct in_addr));
276 v4->sin_port = v6->sin6_port;
277 uaddr = v4;
278 addrlen = sizeof (struct sockaddr_in);
279 }
280 else
281 {
282 uaddr = GNUNET_malloc (addrlen);
283 memcpy (uaddr, addr, addrlen);
284 }
285
286 if ((access != NULL) &&
287 (GNUNET_YES != (aret = access (access_cls, uaddr, addrlen))))
288 {
289 if (aret == GNUNET_NO)
290 {
291 fam = ((struct sockaddr *) addr)->sa_family;
292 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
293 _("Access denied to `%s'\n"),
294 inet_ntop (fam,
295 (fam == AF_INET6)
296 ? (const void *) &((struct sockaddr_in6 *)
297 &addr)->
298 sin6_addr : (const void *)
299 &((struct sockaddr_in *) &addr)->sin_addr,
300 msg, sizeof (msg)));
301 }
302 GNUNET_break (0 == SHUTDOWN (fd, SHUT_RDWR));
303 GNUNET_break (0 == CLOSE (fd));
304 GNUNET_free (uaddr);
305 return NULL;
306 }
307 ret = GNUNET_malloc (sizeof (struct GNUNET_NETWORK_SocketHandle) + maxbuf);
308 ret->write_buffer = (char *) &ret[1];
309 ret->write_buffer_size = maxbuf;
310 ret->addr = uaddr;
311 ret->addrlen = addrlen;
312 ret->sock = fd;
313 ret->sched = sched;
314 return ret;
315}
316
317/**
318 * Obtain the network address of the other party.
319 *
320 * @param sock the client to get the address for
321 * @param addr where to store the address
322 * @param addrlen where to store the length of the address
323 * @return GNUNET_OK on success
324 */
325int
326GNUNET_NETWORK_socket_get_address (struct GNUNET_NETWORK_SocketHandle *sock,
327 void **addr, size_t * addrlen)
328{
329 if ((sock->addr == NULL) || (sock->addrlen == 0))
330 return GNUNET_NO;
331 *addr = GNUNET_malloc (sock->addrlen);
332 memcpy (*addr, sock->addr, sock->addrlen);
333 *addrlen = sock->addrlen;
334 return GNUNET_OK;
335}
336
337
338/**
339 * Set if a socket should use blocking or non-blocking IO.
340 *
341 * @return GNUNET_OK on success, GNUNET_SYSERR on error
342 */
343static int
344socket_set_blocking (int handle, int doBlock)
345{
346#if MINGW
347 u_long mode;
348 mode = !doBlock;
349#if HAVE_PLIBC_FD
350 if (ioctlsocket (plibc_fd_get_handle (handle), FIONBIO, &mode) ==
351 SOCKET_ERROR)
352 {
353 SetErrnoFromWinsockError (WSAGetLastError ());
354 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "ioctlsocket");
355 return GNUNET_SYSERR;
356 }
357#else
358 if (ioctlsocket (handle, FIONBIO, &mode) == SOCKET_ERROR)
359 {
360 SetErrnoFromWinsockError (WSAGetLastError ());
361 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "ioctlsocket");
362 return GNUNET_SYSERR;
363 }
364#endif
365 /* store the blocking mode */
366#if HAVE_PLIBC_FD
367 plibc_fd_set_blocking (handle, doBlock);
368#else
369 __win_SetHandleBlockingMode (handle, doBlock);
370#endif
371 return GNUNET_OK;
372
373#else
374 /* not MINGW */
375 int flags = fcntl (handle, F_GETFL);
376 if (flags == -1)
377 {
378 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "fcntl");
379 return GNUNET_SYSERR;
380 }
381 if (doBlock)
382 flags &= ~O_NONBLOCK;
383 else
384 flags |= O_NONBLOCK;
385 if (0 != fcntl (handle, F_SETFL, flags))
386 {
387 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "fcntl");
388 return GNUNET_SYSERR;
389 }
390 return GNUNET_OK;
391#endif
392}
393
394
395/**
396 * Initiate asynchronous TCP connect request.
397 *
398 * @param sock what socket to connect
399 * @return GNUNET_SYSERR error (no more addresses to try)
400 */
401static int
402try_connect (struct GNUNET_NETWORK_SocketHandle *sock)
403{
404 int s;
405
406 if (sock->addr != NULL)
407 {
408 GNUNET_free (sock->addr);
409 sock->addr = NULL;
410 sock->addrlen = 0;
411 }
412 while (1)
413 {
414 if (sock->ai_pos == NULL)
415 {
416 /* no more addresses to try, fatal! */
417 return GNUNET_SYSERR;
418 }
419 switch (sock->ai_pos->ai_family)
420 {
421 case AF_INET:
422 ((struct sockaddr_in *) sock->ai_pos->ai_addr)->sin_port =
423 htons (sock->port);
424 break;
425 case AF_INET6:
426 ((struct sockaddr_in6 *) sock->ai_pos->ai_addr)->sin6_port =
427 htons (sock->port);
428 break;
429 default:
430 sock->ai_pos = sock->ai_pos->ai_next;
431 continue;
432 }
433 s = SOCKET (sock->ai_pos->ai_family, SOCK_STREAM, 0);
434 if (s == -1)
435 {
436 /* maybe unsupported address family, try next */
437 GNUNET_log_strerror (GNUNET_ERROR_TYPE_INFO, "socket");
438 sock->ai_pos = sock->ai_pos->ai_next;
439 continue;
440 }
441 if (0 != fcntl (s, F_SETFD, fcntl (s, F_GETFD) | FD_CLOEXEC))
442 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
443 "fcntl");
444 if (GNUNET_SYSERR == socket_set_blocking (s, GNUNET_NO))
445 {
446 /* we'll treat this one as fatal */
447 GNUNET_break (0 == CLOSE (s));
448 return GNUNET_SYSERR;
449 }
450 if ((0 != CONNECT (s,
451 sock->ai_pos->ai_addr,
452 sock->ai_pos->ai_addrlen)) && (errno != EINPROGRESS))
453 {
454 /* maybe refused / unsupported address, try next */
455 GNUNET_log_strerror (GNUNET_ERROR_TYPE_INFO, "connect");
456 GNUNET_break (0 == CLOSE (s));
457 continue;
458 }
459 break;
460 }
461 /* got one! copy address information! */
462 sock->addrlen = sock->ai_pos->ai_addrlen;
463 sock->addr = GNUNET_malloc (sock->addrlen);
464 memcpy (sock->addr, sock->ai_pos->ai_addr, sock->addrlen);
465 sock->ai_pos = sock->ai_pos->ai_next;
466 sock->sock = s;
467 return GNUNET_OK;
468}
469
470
471/**
472 * Scheduler let us know that we're either ready to
473 * write on the socket OR connect timed out. Do the
474 * right thing.
475 */
476static void
477connect_continuation (void *cls,
478 const struct GNUNET_SCHEDULER_TaskContext *tc)
479{
480 struct GNUNET_NETWORK_SocketHandle *sock = cls;
481 unsigned int len;
482 int error;
483
484 /* nobody needs to wait for us anymore... */
485 sock->connect_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
486 /* Note: write-ready does NOT mean connect succeeded,
487 we need to use getsockopt to be sure */
488 len = sizeof (error);
489 errno = 0;
490 error = 0;
491 if ((0 == (tc->reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) ||
492 (0 != getsockopt (sock->sock, SOL_SOCKET, SO_ERROR, &error, &len)) ||
493 (error != 0) || (errno != 0))
494 {
495 /* connect failed / timed out */
496 GNUNET_break (0 == CLOSE (sock->sock));
497 sock->sock = -1;
498 if (GNUNET_SYSERR == try_connect (sock))
499 {
500 /* failed for good */
501 GNUNET_break (sock->ai_pos == NULL);
502 freeaddrinfo (sock->ai);
503 sock->ai = NULL;
504 return;
505 }
506 sock->connect_task = GNUNET_SCHEDULER_add_write (tc->sched, GNUNET_NO, /* abort on shutdown */
507 GNUNET_SCHEDULER_PRIORITY_KEEP,
508 GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
509 GNUNET_NETWORK_CONNECT_RETRY_TIMEOUT,
510 sock->sock,
511 &connect_continuation,
512 sock);
513 return;
514 }
515 /* connect succeeded! clean up "ai" */
516#if DEBUG_NETWORK
517 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connection succeeded!\n");
518#endif
519 freeaddrinfo (sock->ai);
520 sock->ai_pos = NULL;
521 sock->ai = NULL;
522}
523
524
525/**
526 * Create a socket handle by (asynchronously) connecting to a host.
527 * This function returns immediately, even if the connection has not
528 * yet been established. This function only creates TCP connections.
529 *
530 * @param sched scheduler to use
531 * @param hostname name of the host to connect to
532 * @param port port to connect to
533 * @param maxbuf maximum write buffer size for the socket (use
534 * 0 for sockets that need no write buffers, such as listen sockets)
535 * @return the socket handle
536 */
537struct GNUNET_NETWORK_SocketHandle *
538GNUNET_NETWORK_socket_create_from_connect (struct GNUNET_SCHEDULER_Handle
539 *sched, const char *hostname,
540 uint16_t port, size_t maxbuf)
541{
542 struct GNUNET_NETWORK_SocketHandle *ret;
543 struct addrinfo hints;
544 int ec;
545
546 ret = GNUNET_malloc (sizeof (struct GNUNET_NETWORK_SocketHandle) + maxbuf);
547 ret->sock = -1;
548 ret->sched = sched;
549 ret->write_buffer = (char *) &ret[1];
550 ret->write_buffer_size = maxbuf;
551 ret->port = port;
552 memset (&hints, 0, sizeof (hints));
553 hints.ai_family = AF_UNSPEC;
554 hints.ai_socktype = SOCK_STREAM;
555 if (0 != (ec = getaddrinfo (hostname, NULL, &hints, &ret->ai)))
556 {
557 GNUNET_log (GNUNET_ERROR_TYPE_INFO | GNUNET_ERROR_TYPE_BULK,
558 "`%s' failed for hostname `%s': %s\n",
559 "getaddrinfo", hostname, gai_strerror (ec));
560 GNUNET_free (ret);
561 return NULL;
562 }
563 ret->ai_pos = ret->ai;
564 if (GNUNET_SYSERR == try_connect (ret))
565 {
566 freeaddrinfo (ret->ai);
567 GNUNET_free (ret);
568 return NULL;
569 }
570 ret->connect_task = GNUNET_SCHEDULER_add_write (sched, GNUNET_NO, /* abort on shutdown */
571 GNUNET_SCHEDULER_PRIORITY_KEEP,
572 GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
573 GNUNET_NETWORK_CONNECT_RETRY_TIMEOUT,
574 ret->sock,
575 &connect_continuation, ret);
576 return ret;
577
578}
579
580
581/**
582 * Create a socket handle by (asynchronously) connecting to a host.
583 * This function returns immediately, even if the connection has not
584 * yet been established. This function only creates TCP connections.
585 *
586 * @param sched scheduler to use
587 * @param af_family address family to use
588 * @param serv_addr server address
589 * @param addrlen length of server address
590 * @param maxbuf maximum write buffer size for the socket (use
591 * 0 for sockets that need no write buffers, such as listen sockets)
592 * @return the socket handle
593 */
594struct GNUNET_NETWORK_SocketHandle *
595GNUNET_NETWORK_socket_create_from_sockaddr (struct GNUNET_SCHEDULER_Handle
596 *sched, int af_family,
597 const struct sockaddr *serv_addr,
598 socklen_t addrlen, size_t maxbuf)
599{
600 int s;
601
602 s = SOCKET (af_family, SOCK_STREAM, 0);
603 if (s == -1)
604 {
605 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING |
606 GNUNET_ERROR_TYPE_BULK, "socket");
607 return NULL;
608 }
609 if (0 != fcntl (s, F_SETFD, fcntl (s, F_GETFD) | FD_CLOEXEC))
610 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
611 "fcntl");
612 if (GNUNET_SYSERR == socket_set_blocking (s, GNUNET_NO))
613 {
614 /* we'll treat this one as fatal */
615 GNUNET_break (0 == CLOSE (s));
616 return NULL;
617 }
618 if ((0 != CONNECT (s, serv_addr, addrlen)) && (errno != EINPROGRESS))
619 {
620 /* maybe refused / unsupported address, try next */
621 GNUNET_log_strerror (GNUNET_ERROR_TYPE_INFO, "connect");
622 GNUNET_break (0 == CLOSE (s));
623 return NULL;
624 }
625 return GNUNET_NETWORK_socket_create_from_existing (sched, s, maxbuf);
626}
627
628
629/**
630 * Check if socket is valid (no fatal errors have happened so far).
631 * Note that a socket that is still trying to connect is considered
632 * valid.
633 *
634 * @param sock socket to check
635 * @return GNUNET_YES if valid, GNUNET_NO otherwise
636 */
637int
638GNUNET_NETWORK_socket_check (struct GNUNET_NETWORK_SocketHandle *sock)
639{
640 if (sock->ai != NULL)
641 return GNUNET_YES; /* still trying to connect */
642 return (sock->sock == -1) ? GNUNET_NO : GNUNET_YES;
643}
644
645
646/**
647 * Scheduler let us know that the connect task is finished (or was
648 * cancelled due to shutdown). Now really clean up.
649 */
650static void
651destroy_continuation (void *cls,
652 const struct GNUNET_SCHEDULER_TaskContext *tc)
653{
654 struct GNUNET_NETWORK_SocketHandle *sock = cls;
655 GNUNET_NETWORK_TransmitReadyNotify notify;
656
657 if (sock->write_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
658 {
659#if DEBUG_NETWORK
660 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
661 "Destroy code waiting for writes to complete.\n");
662#endif
663 GNUNET_SCHEDULER_add_after (sock->sched,
664 GNUNET_YES,
665 GNUNET_SCHEDULER_PRIORITY_KEEP,
666 sock->write_task,
667 &destroy_continuation, sock);
668 return;
669 }
670 if (sock->sock != -1)
671 {
672#if DEBUG_NETWORK
673 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Shutting down socket.\n");
674#endif
675 SHUTDOWN (sock->sock, SHUT_RDWR);
676 }
677 if (sock->read_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
678 {
679#if DEBUG_NETWORK
680 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
681 "Destroy code waiting for receive to complete.\n");
682#endif
683 GNUNET_SCHEDULER_add_after (sock->sched,
684 GNUNET_YES,
685 GNUNET_SCHEDULER_PRIORITY_KEEP,
686 sock->read_task,
687 &destroy_continuation, sock);
688 return;
689 }
690 if (NULL != (notify = sock->nth.notify_ready))
691 {
692 sock->nth.notify_ready = NULL;
693 notify (sock->nth.notify_ready_cls, 0, NULL);
694 if (sock->nth.timeout_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
695 {
696 GNUNET_SCHEDULER_cancel (sock->sched, sock->nth.timeout_task);
697 sock->nth.timeout_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
698 }
699 }
700 if (sock->sock != -1)
701 {
702#if DEBUG_NETWORK
703 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Closing socket.\n");
704#endif
705 GNUNET_break (0 == CLOSE (sock->sock));
706 }
707 GNUNET_free_non_null (sock->addr);
708 if (sock->ai != NULL)
709 freeaddrinfo (sock->ai);
710 GNUNET_free (sock);
711}
712
713
714/**
715 * Close the socket and free associated resources. Pending
716 * transmissions are simply dropped. A pending receive call will be
717 * called with an error code of "EPIPE".
718 *
719 * @param sock socket to destroy
720 */
721void
722GNUNET_NETWORK_socket_destroy (struct GNUNET_NETWORK_SocketHandle *sock)
723{
724#if DEBUG_NETWORK
725 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
726 "Network asked to destroy socket %p\n", sock);
727#endif
728 if (sock->write_buffer_off == 0)
729 sock->ai_pos = NULL; /* if we're still trying to connect and have
730 no message pending, stop trying! */
731 GNUNET_assert (sock->sched != NULL);
732 GNUNET_SCHEDULER_add_after (sock->sched,
733 GNUNET_YES,
734 GNUNET_SCHEDULER_PRIORITY_KEEP,
735 sock->connect_task,
736 &destroy_continuation, sock);
737}
738
739/**
740 * Tell the receiver callback that a timeout was reached.
741 */
742static void
743signal_timeout (struct GNUNET_NETWORK_SocketHandle *sh)
744{
745 GNUNET_NETWORK_Receiver receiver;
746
747#if DEBUG_NETWORK
748 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
749 "Network signals timeout to receiver!\n");
750#endif
751 GNUNET_assert (NULL != (receiver = sh->receiver));
752 sh->receiver = NULL;
753 receiver (sh->receiver_cls, NULL, 0, NULL, 0, 0);
754}
755
756
757/**
758 * Tell the receiver callback that we had an IO error.
759 */
760static void
761signal_error (struct GNUNET_NETWORK_SocketHandle *sh, int errcode)
762{
763 GNUNET_NETWORK_Receiver receiver;
764 GNUNET_assert (NULL != (receiver = sh->receiver));
765 sh->receiver = NULL;
766 receiver (sh->receiver_cls, NULL, 0, sh->addr, sh->addrlen, errcode);
767}
768
769
770/**
771 * This function is called once we either timeout
772 * or have data ready to read.
773 */
774static void
775receive_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
776{
777 struct GNUNET_NETWORK_SocketHandle *sh = cls;
778 struct GNUNET_TIME_Absolute now;
779 char buffer[sh->max];
780 ssize_t ret;
781 GNUNET_NETWORK_Receiver receiver;
782
783 sh->read_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
784 now = GNUNET_TIME_absolute_get ();
785 if ((now.value > sh->receive_timeout.value) ||
786 (0 != (tc->reason & GNUNET_SCHEDULER_REASON_TIMEOUT)) ||
787 (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)))
788 {
789#if DEBUG_NETWORK
790 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
791 "Receive encounters error: timeout...\n");
792#endif
793 signal_timeout (sh);
794 return;
795 }
796 if (sh->sock == -1)
797 {
798 /* connect failed for good */
799#if DEBUG_NETWORK
800 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
801 "Receive encounters error, socket closed...\n");
802#endif
803 signal_error (sh, ECONNREFUSED);
804 return;
805 }
806 GNUNET_assert (FD_ISSET (sh->sock, tc->read_ready));
807RETRY:
808 ret = RECV (sh->sock, buffer, sh->max, MSG_DONTWAIT);
809 if (ret == -1)
810 {
811 if (errno == EINTR)
812 goto RETRY;
813#if DEBUG_NETWORK
814 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
815 "Error receiving: %s\n", STRERROR (errno));
816#endif
817 signal_error (sh, errno);
818 return;
819 }
820#if DEBUG_NETWORK
821 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
822 "Receive got %d bytes from OS!\n", ret);
823#endif
824 GNUNET_assert (NULL != (receiver = sh->receiver));
825 sh->receiver = NULL;
826 receiver (sh->receiver_cls, buffer, ret, sh->addr, sh->addrlen, 0);
827}
828
829
830/**
831 * This function is called after establishing a connection either has
832 * succeeded or timed out. Note that it is possible that the attempt
833 * timed out and that we're immediately retrying. If we are retrying,
834 * we need to wait again (or timeout); if we succeeded, we need to
835 * wait for data (or timeout).
836 */
837static void
838receive_again (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
839{
840 struct GNUNET_NETWORK_SocketHandle *sh = cls;
841 struct GNUNET_TIME_Absolute now;
842
843 sh->read_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
844 if ((sh->sock == -1) &&
845 (sh->connect_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK))
846 {
847 /* not connected and no longer trying */
848#if DEBUG_NETWORK
849 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
850 "Receive encounters error, socket closed...\n");
851#endif
852 signal_error (sh, ECONNREFUSED);
853 return;
854 }
855 now = GNUNET_TIME_absolute_get ();
856 if ((now.value > sh->receive_timeout.value) ||
857 (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)))
858 {
859#if DEBUG_NETWORK
860 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
861 "Receive encounters error: timeout...\n");
862#endif
863 signal_timeout (sh);
864 return;
865 }
866 if (sh->connect_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
867 {
868 /* connect was retried */
869#if DEBUG_NETWORK
870 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
871 "Receive still waits on connect...\n");
872#endif
873 sh->read_task = GNUNET_SCHEDULER_add_after (tc->sched,
874 GNUNET_YES,
875 GNUNET_SCHEDULER_PRIORITY_KEEP,
876 sh->connect_task,
877 &receive_again, sh);
878 }
879 else
880 {
881 /* connect succeeded, wait for data! */
882#if DEBUG_NETWORK
883 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
884 "Receive now waits for socket...\n");
885#endif
886 sh->read_task = GNUNET_SCHEDULER_add_read (tc->sched,
887 GNUNET_YES,
888 GNUNET_SCHEDULER_PRIORITY_KEEP,
889 sh->connect_task,
890 GNUNET_TIME_absolute_get_remaining
891 (sh->receive_timeout),
892 sh->sock, &receive_ready,
893 sh);
894 }
895}
896
897
898/**
899 * Receive data from the given socket. Note that this function will
900 * call "receiver" asynchronously using the scheduler. It will
901 * "immediately" return. Note that there MUST only be one active
902 * receive call per socket at any given point in time (so do not
903 * call receive again until the receiver callback has been invoked).
904 *
905 * @param sched scheduler to use
906 * @param sock socket handle
907 * @param max maximum number of bytes to read
908 * @param timeout maximum amount of time to wait (use -1 for "forever")
909 * @param receiver function to call with received data
910 * @param receiver_cls closure for receiver
911 * @return scheduler task ID used for receiving, GNUNET_SCHEDULER_NO_PREREQUISITE_TASK on error
912 */
913GNUNET_SCHEDULER_TaskIdentifier
914GNUNET_NETWORK_receive (struct GNUNET_NETWORK_SocketHandle *sock,
915 size_t max,
916 struct GNUNET_TIME_Relative timeout,
917 GNUNET_NETWORK_Receiver receiver, void *receiver_cls)
918{
919 struct GNUNET_SCHEDULER_TaskContext tc;
920#if DEBUG_NETWORK
921 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
922 "Network asked to receive from socket...\n");
923#endif
924 GNUNET_assert ((sock->read_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK) &&
925 (sock->receiver == NULL));
926 sock->receiver = receiver;
927 sock->receiver_cls = receiver_cls;
928 sock->receive_timeout = GNUNET_TIME_relative_to_absolute (timeout);
929 sock->max = max;
930 memset (&tc, 0, sizeof (tc));
931 tc.sched = sock->sched;
932 tc.reason = GNUNET_SCHEDULER_REASON_PREREQ_DONE;
933 receive_again (sock, &tc);
934 return sock->read_task;
935}
936
937
938/**
939 * Cancel receive job on the given socket. Note that the
940 * receiver callback must not have been called yet in order
941 * for the cancellation to be valid.
942 *
943 * @param sock socket handle
944 * @param task task identifier returned from the receive call
945 * @return closure of the original receiver callback
946 */
947void *
948GNUNET_NETWORK_receive_cancel (struct GNUNET_NETWORK_SocketHandle *sock,
949 GNUNET_SCHEDULER_TaskIdentifier task)
950{
951 GNUNET_assert (sock->read_task == task);
952 GNUNET_assert (sock == GNUNET_SCHEDULER_cancel (sock->sched, task));
953 sock->read_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
954 sock->receiver = NULL;
955 return sock->receiver_cls;
956}
957
958
959/**
960 * Try to call the transmit notify method (check if we do
961 * have enough space available first)!
962 *
963 * @param sock socket for which we should do this processing
964 * @return GNUNET_YES if we were able to call notify
965 */
966static int
967process_notify (struct GNUNET_NETWORK_SocketHandle *sock)
968{
969 size_t used;
970 size_t avail;
971 size_t size;
972 GNUNET_NETWORK_TransmitReadyNotify notify;
973
974 GNUNET_assert (sock->write_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK);
975 if (NULL == (notify = sock->nth.notify_ready))
976 return GNUNET_NO;
977 used = sock->write_buffer_off - sock->write_buffer_pos;
978 avail = sock->write_buffer_size - used;
979 size = sock->nth.notify_size;
980 if (sock->nth.notify_size > avail)
981 return GNUNET_NO;
982 sock->nth.notify_ready = NULL;
983 if (sock->nth.timeout_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
984 {
985 GNUNET_SCHEDULER_cancel (sock->sched, sock->nth.timeout_task);
986 sock->nth.timeout_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
987 }
988 if (sock->write_buffer_size - sock->write_buffer_off < size)
989 {
990 /* need to compact */
991 memmove (sock->write_buffer,
992 &sock->write_buffer[sock->write_buffer_pos], used);
993 sock->write_buffer_off -= sock->write_buffer_pos;
994 sock->write_buffer_pos = 0;
995 }
996 GNUNET_assert (sock->write_buffer_size - sock->write_buffer_off >= size);
997 size = notify (sock->nth.notify_ready_cls,
998 sock->write_buffer_size - sock->write_buffer_off,
999 &sock->write_buffer[sock->write_buffer_off]);
1000 sock->write_buffer_off += size;
1001 return GNUNET_YES;
1002}
1003
1004
1005/**
1006 * Task invoked by the scheduler when a call to transmit
1007 * is timing out (we never got enough buffer space to call
1008 * the callback function before the specified timeout
1009 * expired).
1010 *
1011 * This task notifies the client about the timeout.
1012 */
1013static void
1014transmit_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1015{
1016 struct GNUNET_NETWORK_SocketHandle *sock = cls;
1017 GNUNET_NETWORK_TransmitReadyNotify notify;
1018
1019#if DEBUG_NETWORK
1020 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transmit fails, time out reached.\n");
1021#endif
1022 notify = sock->nth.notify_ready;
1023 sock->nth.notify_ready = NULL;
1024 notify (sock->nth.notify_ready_cls, 0, NULL);
1025}
1026
1027
1028static void
1029transmit_error (struct GNUNET_NETWORK_SocketHandle *sock)
1030{
1031 if (sock->nth.notify_ready == NULL)
1032 return; /* nobody to tell about it */
1033 if (sock->nth.timeout_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1034 {
1035 GNUNET_SCHEDULER_cancel (sock->sched, sock->nth.timeout_task);
1036 sock->nth.timeout_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1037 }
1038 transmit_timeout (sock, NULL);
1039}
1040
1041
1042/**
1043 * See if we are now connected. If not, wait longer for
1044 * connect to succeed. If connected, we should be able
1045 * to write now as well, unless we timed out.
1046 */
1047static void
1048transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1049{
1050 struct GNUNET_NETWORK_SocketHandle *sock = cls;
1051 ssize_t ret;
1052 size_t have;
1053
1054#if DEBUG_NETWORK
1055 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1056 "Transmit ready called --- will try to send\n");
1057#endif
1058 GNUNET_assert (sock->write_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK);
1059 sock->write_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1060 if (sock->connect_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1061 {
1062 /* still waiting for connect */
1063#if DEBUG_NETWORK
1064 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1065 "Transmission still waiting for connect...\n");
1066#endif
1067 GNUNET_assert (sock->write_task ==
1068 GNUNET_SCHEDULER_NO_PREREQUISITE_TASK);
1069 sock->write_task =
1070 GNUNET_SCHEDULER_add_delayed (tc->sched, GNUNET_NO,
1071 GNUNET_SCHEDULER_PRIORITY_KEEP,
1072 sock->connect_task,
1073 GNUNET_TIME_UNIT_ZERO, &transmit_ready,
1074 sock);
1075 return;
1076 }
1077 if (sock->sock == -1)
1078 {
1079 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1080 _
1081 ("Did not transmit request, socket closed or connect failed.\n"));
1082 transmit_error (sock);
1083 return; /* connect failed for good, we're finished */
1084 }
1085 if ((tc->write_ready == NULL) || (!FD_ISSET (sock->sock, tc->write_ready)))
1086 {
1087#if DEBUG_NETWORK
1088 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1089 "Socket not yet ready for writing, will wait for that.\n");
1090#endif
1091 goto SCHEDULE_WRITE;
1092 }
1093 GNUNET_assert (sock->write_buffer_off >= sock->write_buffer_pos);
1094 process_notify (sock);
1095 have = sock->write_buffer_off - sock->write_buffer_pos;
1096 if (have == 0)
1097 {
1098#if DEBUG_NETWORK
1099 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "No data ready for writing.\n");
1100#endif
1101 return;
1102 }
1103RETRY:
1104 ret = SEND (sock->sock,
1105 &sock->write_buffer[sock->write_buffer_pos],
1106 have, MSG_DONTWAIT | MSG_NOSIGNAL);
1107 if (ret == -1)
1108 {
1109 if (errno == EINTR)
1110 goto RETRY;
1111#if DEBUG_NETWORK
1112 GNUNET_log_strerror (GNUNET_ERROR_TYPE_DEBUG, "send");
1113#endif
1114 SHUTDOWN (sock->sock, SHUT_RDWR);
1115 GNUNET_break (0 == CLOSE (sock->sock));
1116 sock->sock = -1;
1117 transmit_error (sock);
1118 return;
1119 }
1120#if DEBUG_NETWORK
1121 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transmitted %d bytes to OS\n", ret);
1122#endif
1123 sock->write_buffer_pos += ret;
1124 if (sock->write_buffer_pos == sock->write_buffer_off)
1125 {
1126 /* transmitted all pending data */
1127 sock->write_buffer_pos = 0;
1128 sock->write_buffer_off = 0;
1129#if DEBUG_NETWORK
1130 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1131 "Transmission buffer now empty.\n", ret);
1132#endif
1133 }
1134 if ((sock->write_buffer_off == 0) && (NULL == sock->nth.notify_ready))
1135 return; /* all data sent! */
1136 /* not done writing, schedule more */
1137#if DEBUG_NETWORK
1138 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1139 "More data ready for transmission, scheduling task again!\n");
1140#endif
1141SCHEDULE_WRITE:
1142 if (sock->write_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1143 sock->write_task =
1144 GNUNET_SCHEDULER_add_write (tc->sched,
1145 GNUNET_NO,
1146 GNUNET_SCHEDULER_PRIORITY_KEEP,
1147 GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1148 GNUNET_TIME_UNIT_FOREVER_REL,
1149 sock->sock, &transmit_ready, sock);
1150}
1151
1152
1153/**
1154 * Ask the socket to call us once the specified number of bytes
1155 * are free in the transmission buffer. May call the notify
1156 * method immediately if enough space is available.
1157 *
1158 * @param sock socket
1159 * @param size number of bytes to send
1160 * @param timeout after how long should we give up (and call
1161 * notify with buf NULL and size 0)?
1162 * @param notify function to call
1163 * @param notify_cls closure for notify
1164 * @return non-NULL if the notify callback was queued,
1165 * NULL if we are already going to notify someone else (busy)
1166 */
1167struct GNUNET_NETWORK_TransmitHandle *
1168GNUNET_NETWORK_notify_transmit_ready (struct GNUNET_NETWORK_SocketHandle
1169 *sock, size_t size,
1170 struct GNUNET_TIME_Relative timeout,
1171 GNUNET_NETWORK_TransmitReadyNotify
1172 notify, void *notify_cls)
1173{
1174 if (sock->nth.notify_ready != NULL)
1175 return NULL;
1176 GNUNET_assert (notify != NULL);
1177 GNUNET_assert (sock->write_buffer_size >= size);
1178
1179 if ((sock->sock == -1) &&
1180 (sock->connect_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK))
1181 {
1182#if DEBUG_NETWORK
1183 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1184 "Transmit fails, connection failed.\n");
1185#endif
1186 notify (notify_cls, 0, NULL);
1187 return &sock->nth;
1188 }
1189 GNUNET_assert (sock->write_buffer_off <= sock->write_buffer_size);
1190 GNUNET_assert (sock->write_buffer_pos <= sock->write_buffer_size);
1191 GNUNET_assert (sock->write_buffer_pos <= sock->write_buffer_off);
1192 sock->nth.notify_ready = notify;
1193 sock->nth.notify_ready_cls = notify_cls;
1194 sock->nth.sh = sock;
1195 sock->nth.notify_size = size;
1196 sock->nth.transmit_timeout = GNUNET_TIME_relative_to_absolute (timeout);
1197 sock->nth.timeout_task = GNUNET_SCHEDULER_add_delayed (sock->sched,
1198 GNUNET_NO,
1199 GNUNET_SCHEDULER_PRIORITY_KEEP,
1200 GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1201 timeout,
1202 &transmit_timeout,
1203 sock);
1204#if DEBUG_NETWORK
1205 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1206 "Scheduling asynchronous transmission once connect is done...\n");
1207#endif
1208 if (sock->write_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1209 sock->write_task = GNUNET_SCHEDULER_add_delayed (sock->sched,
1210 GNUNET_NO,
1211 GNUNET_SCHEDULER_PRIORITY_KEEP,
1212 sock->connect_task,
1213 GNUNET_TIME_UNIT_ZERO,
1214 &transmit_ready, sock);
1215 return &sock->nth;
1216}
1217
1218
1219/**
1220 * Cancel the specified transmission-ready
1221 * notification.
1222 */
1223void
1224GNUNET_NETWORK_notify_transmit_ready_cancel (struct
1225 GNUNET_NETWORK_TransmitHandle *h)
1226{
1227 GNUNET_assert (h->notify_ready != NULL);
1228 GNUNET_SCHEDULER_cancel (h->sh->sched, h->timeout_task);
1229 h->timeout_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1230 h->notify_ready = NULL;
1231}
1232
1233
1234#if 0 /* keep Emacsens' auto-indent happy */
1235{
1236#endif
1237#ifdef __cplusplus
1238}
1239#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-25 05:40:39 +0000