1 /* Establishing and handling network connections.
2 Copyright (C) 1995, 1996, 1997, 2001, 2002 Free Software Foundation, Inc.
4 This file is part of GNU Wget.
6 GNU Wget is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 GNU Wget is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with Wget; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 In addition, as a special exception, the Free Software Foundation
21 gives permission to link the code of its release of Wget with the
22 OpenSSL project's "OpenSSL" library (or with modified versions of it
23 that use the same license as the "OpenSSL" library), and distribute
24 the linked executables. You must obey the GNU General Public License
25 in all respects for all of the code used other than "OpenSSL". If you
26 modify this file, you may extend this exception to your version of the
27 file, but you are not obligated to do so. If you do not wish to do
28 so, delete this exception statement from your version. */
34 #include <sys/types.h>
41 # include <sys/socket.h>
43 # include <netinet/in.h>
45 # include <arpa/inet.h>
47 #endif /* not WINDOWS */
54 #endif /* HAVE_STRING_H */
55 #ifdef HAVE_SYS_SELECT_H
56 # include <sys/select.h>
57 #endif /* HAVE_SYS_SELECT_H */
70 /* Fill SA as per the data in IP and PORT. SA shoult point to struct
71 sockaddr_storage if ENABLE_IPV6 is defined, to struct sockaddr_in
75 sockaddr_set_data (struct sockaddr *sa, const ip_address *ip, int port)
81 struct sockaddr_in *sin = (struct sockaddr_in *)sa;
82 sin->sin_family = AF_INET;
83 sin->sin_port = htons (port);
84 sin->sin_addr = ADDRESS_IPV4_IN_ADDR (ip);
90 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
91 sin6->sin6_family = AF_INET6;
92 sin6->sin6_port = htons (port);
93 sin6->sin6_addr = ADDRESS_IPV6_IN6_ADDR (ip);
94 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
95 sin6->sin6_scope_id = ADDRESS_IPV6_SCOPE (ip);
99 #endif /* ENABLE_IPV6 */
105 /* Get the data of SA, specifically the IP address and the port. If
106 you're not interested in one or the other information, pass NULL as
110 sockaddr_get_data (const struct sockaddr *sa, ip_address *ip, int *port)
112 switch (sa->sa_family)
116 struct sockaddr_in *sin = (struct sockaddr_in *)sa;
119 ip->type = IPV4_ADDRESS;
120 ADDRESS_IPV4_IN_ADDR (ip) = sin->sin_addr;
123 *port = ntohs (sin->sin_port);
129 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
132 ip->type = IPV6_ADDRESS;
133 ADDRESS_IPV6_IN6_ADDR (ip) = sin6->sin6_addr;
134 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
135 ADDRESS_IPV6_SCOPE (ip) = sin6->sin6_scope_id;
139 *port = ntohs (sin6->sin6_port);
148 /* Return the size of the sockaddr structure depending on its
152 sockaddr_size (const struct sockaddr *sa)
154 switch (sa->sa_family)
157 return sizeof (struct sockaddr_in);
160 return sizeof (struct sockaddr_in6);
164 return 0; /* so the compiler shuts up. */
169 resolve_bind_address (struct sockaddr *sa)
171 struct address_list *al;
173 /* Make sure this is called only once. opt.bind_address doesn't
174 change during a Wget run. */
175 static int called, should_bind;
176 static ip_address ip;
180 sockaddr_set_data (sa, &ip, 0);
185 al = lookup_host_passive (opt.bind_address);
188 /* #### We should be able to print the error message here. */
189 logprintf (LOG_NOTQUIET,
190 _("%s: unable to resolve bind address `%s'; disabling bind.\n"),
191 exec_name, opt.bind_address);
196 /* Pick the first address in the list and use it as bind address.
197 Perhaps we should try multiple addresses in succession, but I
198 don't think that's necessary in practice. */
199 ip = *address_list_address_at (al, 0);
200 address_list_release (al);
202 sockaddr_set_data (sa, &ip, 0);
209 const struct sockaddr *addr;
215 connect_with_timeout_callback (void *arg)
217 struct cwt_context *ctx = (struct cwt_context *)arg;
218 ctx->result = connect (ctx->fd, ctx->addr, ctx->addrlen);
221 /* Like connect, but specifies a timeout. If connecting takes longer
222 than TIMEOUT seconds, -1 is returned and errno is set to
226 connect_with_timeout (int fd, const struct sockaddr *addr, socklen_t addrlen,
229 struct cwt_context ctx;
232 ctx.addrlen = addrlen;
234 if (run_with_timeout (timeout, connect_with_timeout_callback, &ctx))
239 if (ctx.result == -1 && errno == EINTR)
244 /* Connect to a remote endpoint whose IP address is known. */
247 connect_to_ip (const ip_address *ip, int port, const char *print)
249 struct sockaddr_storage ss;
250 struct sockaddr *sa = (struct sockaddr *)&ss;
253 /* If PRINT is non-NULL, print the "Connecting to..." line, with
254 PRINT being the host name we're connecting to. */
257 const char *txt_addr = pretty_print_address (ip);
258 if (print && 0 != strcmp (print, txt_addr))
259 logprintf (LOG_VERBOSE,
260 _("Connecting to %s|%s|:%d... "), print, txt_addr, port);
262 logprintf (LOG_VERBOSE, _("Connecting to %s:%d... "), txt_addr, port);
265 /* Store the sockaddr info to SA. */
266 sockaddr_set_data (sa, ip, port);
268 /* Create the socket of the family appropriate for the address. */
269 sock = socket (sa->sa_family, SOCK_STREAM, 0);
273 /* For very small rate limits, set the buffer size (and hence,
274 hopefully, the kernel's TCP window size) to the per-second limit.
275 That way we should never have to sleep for more than 1s between
277 if (opt.limit_rate && opt.limit_rate < 8192)
279 int bufsize = opt.limit_rate;
281 bufsize = 512; /* avoid pathologically small values */
283 setsockopt (sock, SOL_SOCKET, SO_RCVBUF,
284 (void *)&bufsize, (socklen_t)sizeof (bufsize));
286 /* When we add limit_rate support for writing, which is useful
287 for POST, we should also set SO_SNDBUF here. */
290 if (opt.bind_address)
292 /* Bind the client side of the socket to the requested
294 struct sockaddr_storage bind_ss;
295 struct sockaddr *bind_sa = (struct sockaddr *)&bind_ss;
296 if (resolve_bind_address (bind_sa))
298 if (bind (sock, bind_sa, sockaddr_size (bind_sa)) < 0)
303 /* Connect the socket to the remote endpoint. */
304 if (connect_with_timeout (sock, sa, sockaddr_size (sa),
305 opt.connect_timeout) < 0)
311 logprintf (LOG_VERBOSE, _("connected.\n"));
312 DEBUGP (("Created socket %d.\n", sock));
317 /* Protect errno from possible modifications by close and
319 int save_errno = errno;
323 logprintf (LOG_VERBOSE, "failed: %s.\n", strerror (errno));
329 /* Connect to a remote endpoint specified by host name. */
332 connect_to_host (const char *host, int port)
335 struct address_list *al;
339 al = lookup_host (host, 0);
343 address_list_get_bounds (al, &start, &end);
344 for (i = start; i < end; i++)
346 const ip_address *ip = address_list_address_at (al, i);
347 sock = connect_to_ip (ip, port, host);
352 address_list_set_faulty (al, i);
354 /* The attempt to connect has failed. Continue with the loop
355 and try next address. */
357 address_list_release (al);
360 /* Mark a successful connection to one of the addresses. */
361 address_list_set_connected (al);
363 if (sock < 0 && address_list_connected_p (al))
365 /* We are unable to connect to any of HOST's addresses, although
366 we were previously able to connect to HOST. That might
367 indicate that HOST is under dynamic DNS and the addresses
368 we're connecting to have expired. Resolve it again. */
369 forget_host_lookup (host);
377 test_socket_open (int sock)
383 /* Check if we still have a valid (non-EOF) connection. From Andrew
384 * Maholski's code in the Unix Socket FAQ. */
386 FD_ZERO (&check_set);
387 FD_SET (sock, &check_set);
389 /* Wait one microsecond */
393 /* If we get a timeout, then that means still connected */
394 if (select (sock + 1, &check_set, NULL, NULL, &to) == 0)
396 /* Connection is valid (not EOF), so continue */
402 /* Without select, it's hard to know for sure. */
407 /* Create a socket, bind it to local interface BIND_ADDRESS on port
408 *PORT, set up a listen backlog, and return the resulting socket, or
411 BIND_ADDRESS is the address of the interface to bind to. If it is
412 NULL, the socket is bound to the default address. PORT should
413 point to the port number that will be used for the binding. If
414 that number is 0, the system will choose a suitable port, and the
415 chosen value will be written to *PORT.
417 Calling accept() on such a socket waits for and accepts incoming
421 bind_local (const ip_address *bind_address, int *port)
424 int family = AF_INET;
425 struct sockaddr_storage ss;
426 struct sockaddr *sa = (struct sockaddr *)&ss;
428 /* For setting options with setsockopt. */
430 void *setopt_ptr = (void *)&setopt_val;
431 socklen_t setopt_size = sizeof (setopt_val);
434 if (bind_address->type == IPV6_ADDRESS)
438 sock = socket (family, SOCK_STREAM, 0);
443 setsockopt (sock, SOL_SOCKET, SO_REUSEADDR, setopt_ptr, setopt_size);
447 # ifdef HAVE_IPV6_V6ONLY
448 if (family == AF_INET6)
449 setsockopt (sock, IPPROTO_IPV6, IPV6_V6ONLY, setopt_ptr, setopt_size);
454 sockaddr_set_data (sa, bind_address, *port);
455 if (bind (sock, sa, sockaddr_size (sa)) < 0)
460 DEBUGP (("Local socket fd %d bound.\n", sock));
462 /* If *PORT is 0, find out which port we've bound to. */
465 socklen_t sa_len = sockaddr_size (sa);
466 if (getsockname (sock, sa, &sa_len) < 0)
468 /* If we can't find out the socket's local address ("name"),
469 something is seriously wrong with the socket, and it's
470 unusable for us anyway because we must know the chosen
475 sockaddr_get_data (sa, NULL, port);
476 DEBUGP (("binding to address %s using port %i.\n",
477 pretty_print_address (bind_address), *port));
479 if (listen (sock, 1) < 0)
487 /* Like a call to accept(), but with the added check for timeout.
489 In other words, accept a client connection on LOCAL_SOCK, and
490 return the new socket used for communication with the client.
491 LOCAL_SOCK should have been bound, e.g. using bind_local().
493 The caller is blocked until a connection is established. If no
494 connection is established for opt.connect_timeout seconds, the
495 function exits with an error status. */
498 accept_connection (int local_sock)
502 /* We don't need the values provided by accept, but accept
503 apparently requires them to be present. */
504 struct sockaddr_storage ss;
505 struct sockaddr *sa = (struct sockaddr *)&ss;
506 socklen_t addrlen = sizeof (ss);
509 if (opt.connect_timeout)
511 int test = select_fd (local_sock, opt.connect_timeout, WAIT_FOR_READ);
518 sock = accept (local_sock, sa, &addrlen);
519 DEBUGP (("Accepted client at socket %d.\n", sock));
523 /* Get the IP address associated with the connection on FD and store
524 it to IP. Return 1 on success, 0 otherwise.
526 If ENDPOINT is ENDPOINT_LOCAL, it returns the address of the local
527 (client) side of the socket. Else if ENDPOINT is ENDPOINT_PEER, it
528 returns the address of the remote (peer's) side of the socket. */
531 socket_ip_address (int sock, ip_address *ip, int endpoint)
533 struct sockaddr_storage storage;
534 struct sockaddr *sockaddr = (struct sockaddr *)&storage;
535 socklen_t addrlen = sizeof (storage);
538 if (endpoint == ENDPOINT_LOCAL)
539 ret = getsockname (sock, sockaddr, &addrlen);
540 else if (endpoint == ENDPOINT_PEER)
541 ret = getpeername (sock, sockaddr, &addrlen);
547 switch (sockaddr->sa_family)
552 struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)&storage;
553 ip->type = IPV6_ADDRESS;
554 ADDRESS_IPV6_IN6_ADDR (ip) = sa6->sin6_addr;
555 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
556 ADDRESS_IPV6_SCOPE (ip) = sa6->sin6_scope_id;
558 DEBUGP (("conaddr is: %s\n", pretty_print_address (ip)));
564 struct sockaddr_in *sa = (struct sockaddr_in *)&storage;
565 ip->type = IPV4_ADDRESS;
566 ADDRESS_IPV4_IN_ADDR (ip) = sa->sin_addr;
567 DEBUGP (("conaddr is: %s\n", pretty_print_address (ip)));
577 /* Return non-zero if the error from the connect code can be
578 considered retryable. Wget normally retries after errors, but the
579 exception are the "unsupported protocol" type errors (possible on
580 IPv4/IPv6 dual family systems) and "connection refused". */
583 retryable_socket_connect_error (int err)
585 /* Have to guard against some of these values not being defined.
586 Cannot use a switch statement because some of the values might be
590 || err == EAFNOSUPPORT
593 || err == EPFNOSUPPORT
595 #ifdef ESOCKTNOSUPPORT /* no, "sockt" is not a typo! */
596 || err == ESOCKTNOSUPPORT
598 #ifdef EPROTONOSUPPORT
599 || err == EPROTONOSUPPORT
602 || err == ENOPROTOOPT
604 /* Apparently, older versions of Linux and BSD used EINVAL
605 instead of EAFNOSUPPORT and such. */
610 if (err == ECONNREFUSED && !opt.retry_connrefused)
618 /* Wait for file descriptor FD to be readable or writable or both,
619 timing out after MAXTIME seconds. Returns 1 if FD is available, 0
620 for timeout and -1 for error. The argument WAIT_FOR can be a
621 combination of WAIT_READ and WAIT_WRITE.
623 This is a mere convenience wrapper around the select call, and
624 should be taken as such. */
627 select_fd (int fd, double maxtime, int wait_for)
630 fd_set *rd = NULL, *wr = NULL;
631 struct timeval tmout;
636 if (wait_for & WAIT_FOR_READ)
638 if (wait_for & WAIT_FOR_WRITE)
641 tmout.tv_sec = (long) maxtime;
642 tmout.tv_usec = 1000000L * (maxtime - (long) maxtime);
645 result = select (fd + 1, rd, wr, NULL, &tmout);
646 while (result < 0 && errno == EINTR);
651 #endif /* HAVE_SELECT */
653 /* Basic socket operations, mostly EINTR wrappers. */
656 # define read(fd, buf, cnt) recv (fd, buf, cnt, 0)
657 # define write(fd, buf, cnt) send (fd, buf, cnt, 0)
658 # define close(fd) closesocket (fd)
662 # define read(fd, buf, cnt) recv (fd, buf, cnt, 0)
663 # define write(fd, buf, cnt) send (fd, buf, cnt, 0)
667 sock_read (int fd, char *buf, int bufsize)
671 res = read (fd, buf, bufsize);
672 while (res == -1 && errno == EINTR);
677 sock_write (int fd, char *buf, int bufsize)
681 res = write (fd, buf, bufsize);
682 while (res == -1 && errno == EINTR);
687 sock_poll (int fd, double timeout, int wait_for)
690 return select_fd (fd, timeout, wait_for);
700 DEBUGP (("Closed fd %d\n", fd));
706 /* Reading and writing from the network. We build around the socket
707 (file descriptor) API, but support "extended" operations for things
708 that are not mere file descriptors under the hood, such as SSL
711 That way the user code can call xread(fd, ...) and we'll run read
712 or SSL_read or whatever is necessary. */
714 static struct hash_table *transport_map;
715 static int transport_map_modified_tick;
717 struct transport_info {
725 /* Register the transport layer operations that will be used when
726 reading, writing, and polling FD.
728 This should be used for transport layers like SSL that piggyback on
729 sockets. FD should otherwise be a real socket, on which you can
730 call getpeername, etc. */
733 register_transport (int fd, xreader_t reader, xwriter_t writer,
734 xpoller_t poller, xcloser_t closer, void *ctx)
736 struct transport_info *info;
738 /* The file descriptor must be non-negative to be registered.
739 Negative values are ignored by xclose(), and -1 cannot be used as
743 info = xnew (struct transport_info);
744 info->reader = reader;
745 info->writer = writer;
746 info->poller = poller;
747 info->closer = closer;
750 transport_map = hash_table_new (0, NULL, NULL);
751 hash_table_put (transport_map, (void *) fd, info);
752 ++transport_map_modified_tick;
755 /* When xread/xwrite are called multiple times in a loop, they should
756 remember the INFO pointer instead of fetching it every time. It is
757 not enough to compare FD to LAST_FD because FD might have been
758 closed and reopened. modified_tick ensures that changes to
759 transport_map will not be unnoticed.
761 This is a macro because we want the static storage variables to be
764 #define LAZY_RETRIEVE_INFO(info) do { \
765 static struct transport_info *last_info; \
766 static int last_fd = -1, last_tick; \
767 if (!transport_map) \
769 else if (last_fd == fd && last_tick == transport_map_modified_tick) \
773 info = hash_table_get (transport_map, (void *) fd); \
776 last_tick = transport_map_modified_tick; \
780 /* Read no more than BUFSIZE bytes of data from FD, storing them to
781 BUF. If TIMEOUT is non-zero, the operation aborts if no data is
782 received after that many seconds. If TIMEOUT is -1, the value of
783 opt.timeout is used for TIMEOUT. */
786 xread (int fd, char *buf, int bufsize, double timeout)
788 struct transport_info *info;
789 LAZY_RETRIEVE_INFO (info);
791 timeout = opt.read_timeout;
795 if (info && info->poller)
796 test = info->poller (fd, timeout, WAIT_FOR_READ, info->ctx);
798 test = sock_poll (fd, timeout, WAIT_FOR_READ);
804 if (info && info->reader)
805 return info->reader (fd, buf, bufsize, info->ctx);
807 return sock_read (fd, buf, bufsize);
810 /* Write the entire contents of BUF to FD. If TIMEOUT is non-zero,
811 the operation aborts if no data is received after that many
812 seconds. If TIMEOUT is -1, the value of opt.timeout is used for
816 xwrite (int fd, char *buf, int bufsize, double timeout)
819 struct transport_info *info;
820 LAZY_RETRIEVE_INFO (info);
822 timeout = opt.read_timeout;
824 /* `write' may write less than LEN bytes, thus the loop keeps trying
825 it until all was written, or an error occurred. */
832 if (info && info->poller)
833 test = info->poller (fd, timeout, WAIT_FOR_WRITE, info->ctx);
835 test = sock_poll (fd, timeout, WAIT_FOR_WRITE);
841 if (info && info->writer)
842 res = info->writer (fd, buf, bufsize, info->ctx);
844 res = sock_write (fd, buf, bufsize);
853 /* Close the file descriptor FD. */
858 struct transport_info *info;
862 /* Don't use LAZY_RETRIEVE_INFO because xclose() is only called once
863 per socket, so that particular optimization wouldn't work. */
866 info = hash_table_get (transport_map, (void *) fd);
868 if (info && info->closer)
869 info->closer (fd, info->ctx);
875 hash_table_remove (transport_map, (void *) fd);
877 ++transport_map_modified_tick;