1 /* Establishing and handling network connections.
2 Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
3 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software
6 This file is part of GNU Wget.
8 GNU Wget is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 GNU Wget is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with Wget. If not, see <http://www.gnu.org/licenses/>.
21 Additional permission under GNU GPL version 3 section 7
23 If you modify this program, or any covered work, by linking or
24 combining it with the OpenSSL project's OpenSSL library (or a
25 modified version of that library), containing parts covered by the
26 terms of the OpenSSL or SSLeay licenses, the Free Software Foundation
27 grants you additional permission to convey the resulting work.
28 Corresponding Source for a non-source form of such a combination
29 shall include the source code for the parts of OpenSSL used as well
30 as that of the covered work. */
39 #ifdef HAVE_SYS_SOCKET_H
40 # include <sys/socket.h>
41 #endif /* def HAVE_SYS_SOCKET_H */
43 #ifdef HAVE_SYS_SELECT_H
44 # include <sys/select.h>
45 #endif /* def HAVE_SYS_SELECT_H */
50 # else /* def __VMS */
52 # endif /* def __VMS [else] */
53 # include <netinet/in.h>
55 # include <arpa/inet.h>
57 #endif /* not WINDOWS */
61 #ifdef HAVE_SYS_TIME_H
62 # include <sys/time.h>
69 /* Apparently needed for Interix: */
74 /* Define sockaddr_storage where unavailable (presumably on IPv4-only
78 # ifndef HAVE_STRUCT_SOCKADDR_STORAGE
79 # define sockaddr_storage sockaddr_in
81 #endif /* ENABLE_IPV6 */
83 /* Fill SA as per the data in IP and PORT. SA shoult point to struct
84 sockaddr_storage if ENABLE_IPV6 is defined, to struct sockaddr_in
88 sockaddr_set_data (struct sockaddr *sa, const ip_address *ip, int port)
94 struct sockaddr_in *sin = (struct sockaddr_in *)sa;
96 sin->sin_family = AF_INET;
97 sin->sin_port = htons (port);
98 sin->sin_addr = ip->data.d4;
104 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
106 sin6->sin6_family = AF_INET6;
107 sin6->sin6_port = htons (port);
108 sin6->sin6_addr = ip->data.d6;
109 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
110 sin6->sin6_scope_id = ip->ipv6_scope;
114 #endif /* ENABLE_IPV6 */
120 /* Get the data of SA, specifically the IP address and the port. If
121 you're not interested in one or the other information, pass NULL as
125 sockaddr_get_data (const struct sockaddr *sa, ip_address *ip, int *port)
127 switch (sa->sa_family)
131 struct sockaddr_in *sin = (struct sockaddr_in *)sa;
134 ip->family = AF_INET;
135 ip->data.d4 = sin->sin_addr;
138 *port = ntohs (sin->sin_port);
144 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
147 ip->family = AF_INET6;
148 ip->data.d6 = sin6->sin6_addr;
149 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
150 ip->ipv6_scope = sin6->sin6_scope_id;
154 *port = ntohs (sin6->sin6_port);
163 /* Return the size of the sockaddr structure depending on its
167 sockaddr_size (const struct sockaddr *sa)
169 switch (sa->sa_family)
172 return sizeof (struct sockaddr_in);
175 return sizeof (struct sockaddr_in6);
182 /* Resolve the bind address specified via --bind-address and store it
183 to SA. The resolved value is stored in a static variable and
184 reused after the first invocation of this function.
186 Returns true on success, false on failure. */
189 resolve_bind_address (struct sockaddr *sa)
191 struct address_list *al;
193 /* Make sure this is called only once. opt.bind_address doesn't
194 change during a Wget run. */
195 static bool called, should_bind;
196 static ip_address ip;
200 sockaddr_set_data (sa, &ip, 0);
205 al = lookup_host (opt.bind_address, LH_BIND | LH_SILENT);
208 /* #### We should be able to print the error message here. */
209 logprintf (LOG_NOTQUIET,
210 _("%s: unable to resolve bind address %s; disabling bind.\n"),
211 exec_name, quote (opt.bind_address));
216 /* Pick the first address in the list and use it as bind address.
217 Perhaps we should try multiple addresses in succession, but I
218 don't think that's necessary in practice. */
219 ip = *address_list_address_at (al, 0);
220 address_list_release (al);
222 sockaddr_set_data (sa, &ip, 0);
229 const struct sockaddr *addr;
235 connect_with_timeout_callback (void *arg)
237 struct cwt_context *ctx = (struct cwt_context *)arg;
238 ctx->result = connect (ctx->fd, ctx->addr, ctx->addrlen);
241 /* Like connect, but specifies a timeout. If connecting takes longer
242 than TIMEOUT seconds, -1 is returned and errno is set to
246 connect_with_timeout (int fd, const struct sockaddr *addr, socklen_t addrlen,
249 struct cwt_context ctx;
252 ctx.addrlen = addrlen;
254 if (run_with_timeout (timeout, connect_with_timeout_callback, &ctx))
259 if (ctx.result == -1 && errno == EINTR)
264 /* Connect via TCP to the specified address and port.
266 If PRINT is non-NULL, it is the host name to print that we're
270 connect_to_ip (const ip_address *ip, int port, const char *print)
272 struct sockaddr_storage ss;
273 struct sockaddr *sa = (struct sockaddr *)&ss;
276 /* If PRINT is non-NULL, print the "Connecting to..." line, with
277 PRINT being the host name we're connecting to. */
280 const char *txt_addr = print_address (ip);
281 if (0 != strcmp (print, txt_addr))
283 char *str = NULL, *name;
285 if (opt.enable_iri && (name = idn_decode ((char *) print)) != NULL)
287 int len = strlen (print) + strlen (name) + 4;
289 snprintf (str, len, "%s (%s)", name, print);
294 logprintf (LOG_VERBOSE, _("Connecting to %s|%s|:%d... "),
295 str ? str : escnonprint_uri (print), txt_addr, port);
302 if (ip->family == AF_INET)
303 logprintf (LOG_VERBOSE, _("Connecting to %s:%d... "), txt_addr, port);
304 else if (ip->family == AF_INET6)
305 logprintf (LOG_VERBOSE, _("Connecting to [%s]:%d... "), txt_addr, port);
309 /* Store the sockaddr info to SA. */
310 sockaddr_set_data (sa, ip, port);
312 /* Create the socket of the family appropriate for the address. */
313 sock = socket (sa->sa_family, SOCK_STREAM, 0);
317 #if defined(ENABLE_IPV6) && defined(IPV6_V6ONLY)
320 /* In case of error, we will go on anyway... */
321 int err = setsockopt (sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof (on));
324 DEBUGP (("Failed setting IPV6_V6ONLY: %s", strerror (errno)));
328 /* For very small rate limits, set the buffer size (and hence,
329 hopefully, the kernel's TCP window size) to the per-second limit.
330 That way we should never have to sleep for more than 1s between
332 if (opt.limit_rate && opt.limit_rate < 8192)
334 int bufsize = opt.limit_rate;
336 bufsize = 512; /* avoid pathologically small values */
338 setsockopt (sock, SOL_SOCKET, SO_RCVBUF,
339 (void *)&bufsize, (socklen_t)sizeof (bufsize));
341 /* When we add limit_rate support for writing, which is useful
342 for POST, we should also set SO_SNDBUF here. */
345 if (opt.bind_address)
347 /* Bind the client side of the socket to the requested
349 struct sockaddr_storage bind_ss;
350 struct sockaddr *bind_sa = (struct sockaddr *)&bind_ss;
351 if (resolve_bind_address (bind_sa))
353 if (bind (sock, bind_sa, sockaddr_size (bind_sa)) < 0)
358 /* Connect the socket to the remote endpoint. */
359 if (connect_with_timeout (sock, sa, sockaddr_size (sa),
360 opt.connect_timeout) < 0)
366 logprintf (LOG_VERBOSE, _("connected.\n"));
367 DEBUGP (("Created socket %d.\n", sock));
372 /* Protect errno from possible modifications by close and
374 int save_errno = errno;
378 logprintf (LOG_VERBOSE, _("failed: %s.\n"), strerror (errno));
384 /* Connect via TCP to a remote host on the specified port.
386 HOST is resolved as an Internet host name. If HOST resolves to
387 more than one IP address, they are tried in the order returned by
388 DNS until connecting to one of them succeeds. */
391 connect_to_host (const char *host, int port)
396 struct address_list *al = lookup_host (host, 0);
401 logprintf (LOG_NOTQUIET,
402 _("%s: unable to resolve host address %s\n"),
403 exec_name, quote (host));
407 address_list_get_bounds (al, &start, &end);
408 for (i = start; i < end; i++)
410 const ip_address *ip = address_list_address_at (al, i);
411 sock = connect_to_ip (ip, port, host);
415 address_list_set_connected (al);
416 address_list_release (al);
420 /* The attempt to connect has failed. Continue with the loop
421 and try next address. */
423 address_list_set_faulty (al, i);
426 /* Failed to connect to any of the addresses in AL. */
428 if (address_list_connected_p (al))
430 /* We connected to AL before, but cannot do so now. That might
431 indicate that our DNS cache entry for HOST has expired. */
432 address_list_release (al);
433 al = lookup_host (host, LH_REFRESH);
436 address_list_release (al);
441 /* Create a socket, bind it to local interface BIND_ADDRESS on port
442 *PORT, set up a listen backlog, and return the resulting socket, or
445 BIND_ADDRESS is the address of the interface to bind to. If it is
446 NULL, the socket is bound to the default address. PORT should
447 point to the port number that will be used for the binding. If
448 that number is 0, the system will choose a suitable port, and the
449 chosen value will be written to *PORT.
451 Calling accept() on such a socket waits for and accepts incoming
455 bind_local (const ip_address *bind_address, int *port)
458 struct sockaddr_storage ss;
459 struct sockaddr *sa = (struct sockaddr *)&ss;
461 /* For setting options with setsockopt. */
463 void *setopt_ptr = (void *)&setopt_val;
464 socklen_t setopt_size = sizeof (setopt_val);
466 sock = socket (bind_address->family, SOCK_STREAM, 0);
471 setsockopt (sock, SOL_SOCKET, SO_REUSEADDR, setopt_ptr, setopt_size);
475 sockaddr_set_data (sa, bind_address, *port);
476 if (bind (sock, sa, sockaddr_size (sa)) < 0)
481 DEBUGP (("Local socket fd %d bound.\n", sock));
483 /* If *PORT is 0, find out which port we've bound to. */
486 socklen_t addrlen = sockaddr_size (sa);
487 if (getsockname (sock, sa, &addrlen) < 0)
489 /* If we can't find out the socket's local address ("name"),
490 something is seriously wrong with the socket, and it's
491 unusable for us anyway because we must know the chosen
496 sockaddr_get_data (sa, NULL, port);
497 DEBUGP (("binding to address %s using port %i.\n",
498 print_address (bind_address), *port));
500 if (listen (sock, 1) < 0)
508 /* Like a call to accept(), but with the added check for timeout.
510 In other words, accept a client connection on LOCAL_SOCK, and
511 return the new socket used for communication with the client.
512 LOCAL_SOCK should have been bound, e.g. using bind_local().
514 The caller is blocked until a connection is established. If no
515 connection is established for opt.connect_timeout seconds, the
516 function exits with an error status. */
519 accept_connection (int local_sock)
523 /* We don't need the values provided by accept, but accept
524 apparently requires them to be present. */
525 struct sockaddr_storage ss;
526 struct sockaddr *sa = (struct sockaddr *)&ss;
527 socklen_t addrlen = sizeof (ss);
529 if (opt.connect_timeout)
531 int test = select_fd (local_sock, opt.connect_timeout, WAIT_FOR_READ);
537 sock = accept (local_sock, sa, &addrlen);
538 DEBUGP (("Accepted client at socket %d.\n", sock));
542 /* Get the IP address associated with the connection on FD and store
543 it to IP. Return true on success, false otherwise.
545 If ENDPOINT is ENDPOINT_LOCAL, it returns the address of the local
546 (client) side of the socket. Else if ENDPOINT is ENDPOINT_PEER, it
547 returns the address of the remote (peer's) side of the socket. */
550 socket_ip_address (int sock, ip_address *ip, int endpoint)
552 struct sockaddr_storage storage;
553 struct sockaddr *sockaddr = (struct sockaddr *) &storage;
554 socklen_t addrlen = sizeof (storage);
557 memset (sockaddr, 0, addrlen);
558 if (endpoint == ENDPOINT_LOCAL)
559 ret = getsockname (sock, sockaddr, &addrlen);
560 else if (endpoint == ENDPOINT_PEER)
561 ret = getpeername (sock, sockaddr, &addrlen);
567 ip->family = sockaddr->sa_family;
568 switch (sockaddr->sa_family)
573 struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)&storage;
574 ip->data.d6 = sa6->sin6_addr;
575 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
576 ip->ipv6_scope = sa6->sin6_scope_id;
578 DEBUGP (("conaddr is: %s\n", print_address (ip)));
584 struct sockaddr_in *sa = (struct sockaddr_in *)&storage;
585 ip->data.d4 = sa->sin_addr;
586 DEBUGP (("conaddr is: %s\n", print_address (ip)));
594 /* Get the socket family of connection on FD and store
595 Return family type on success, -1 otherwise.
597 If ENDPOINT is ENDPOINT_LOCAL, it returns the sock family of the local
598 (client) side of the socket. Else if ENDPOINT is ENDPOINT_PEER, it
599 returns the sock family of the remote (peer's) side of the socket. */
602 socket_family (int sock, int endpoint)
604 struct sockaddr_storage storage;
605 struct sockaddr *sockaddr = (struct sockaddr *) &storage;
606 socklen_t addrlen = sizeof (storage);
609 memset (sockaddr, 0, addrlen);
611 if (endpoint == ENDPOINT_LOCAL)
612 ret = getsockname (sock, sockaddr, &addrlen);
613 else if (endpoint == ENDPOINT_PEER)
614 ret = getpeername (sock, sockaddr, &addrlen);
621 return sockaddr->sa_family;
624 /* Return true if the error from the connect code can be considered
625 retryable. Wget normally retries after errors, but the exception
626 are the "unsupported protocol" type errors (possible on IPv4/IPv6
627 dual family systems) and "connection refused". */
630 retryable_socket_connect_error (int err)
632 /* Have to guard against some of these values not being defined.
633 Cannot use a switch statement because some of the values might be
637 || err == EAFNOSUPPORT
640 || err == EPFNOSUPPORT
642 #ifdef ESOCKTNOSUPPORT /* no, "sockt" is not a typo! */
643 || err == ESOCKTNOSUPPORT
645 #ifdef EPROTONOSUPPORT
646 || err == EPROTONOSUPPORT
649 || err == ENOPROTOOPT
651 /* Apparently, older versions of Linux and BSD used EINVAL
652 instead of EAFNOSUPPORT and such. */
657 if (!opt.retry_connrefused)
658 if (err == ECONNREFUSED
660 || err == ENETUNREACH /* network is unreachable */
663 || err == EHOSTUNREACH /* host is unreachable */
671 /* Wait for a single descriptor to become available, timing out after
672 MAXTIME seconds. Returns 1 if FD is available, 0 for timeout and
673 -1 for error. The argument WAIT_FOR can be a combination of
674 WAIT_FOR_READ and WAIT_FOR_WRITE.
676 This is a mere convenience wrapper around the select call, and
677 should be taken as such (for example, it doesn't implement Wget's
678 0-timeout-means-no-timeout semantics.) */
681 select_fd (int fd, double maxtime, int wait_for)
684 fd_set *rd = NULL, *wr = NULL;
685 struct timeval tmout;
690 if (wait_for & WAIT_FOR_READ)
692 if (wait_for & WAIT_FOR_WRITE)
695 tmout.tv_sec = (long) maxtime;
696 tmout.tv_usec = 1000000 * (maxtime - (long) maxtime);
700 result = select (fd + 1, rd, wr, NULL, &tmout);
702 /* gnulib select() converts blocking sockets to nonblocking in windows.
703 wget uses blocking sockets so we must convert them back to blocking. */
704 set_windows_fd_as_blocking_socket (fd);
707 while (result < 0 && errno == EINTR);
712 /* Return true iff the connection to the remote site established
713 through SOCK is still open.
715 Specifically, this function returns true if SOCK is not ready for
716 reading. This is because, when the connection closes, the socket
717 is ready for reading because EOF is about to be delivered. A side
718 effect of this method is that sockets that have pending data are
719 considered non-open. This is actually a good thing for callers of
720 this function, where such pending data can only be unwanted
721 leftover from a previous request. */
724 test_socket_open (int sock)
730 /* Check if we still have a valid (non-EOF) connection. From Andrew
731 * Maholski's code in the Unix Socket FAQ. */
733 FD_ZERO (&check_set);
734 FD_SET (sock, &check_set);
736 /* Wait one microsecond */
740 ret = select (sock + 1, &check_set, NULL, NULL, &to);
742 /* gnulib select() converts blocking sockets to nonblocking in windows.
743 wget uses blocking sockets so we must convert them back to blocking
745 set_windows_fd_as_blocking_socket ( sock );
749 /* We got a timeout, it means we're still connected. */
752 /* Read now would not wait, it means we have either pending data
757 /* Basic socket operations, mostly EINTR wrappers. */
760 sock_read (int fd, char *buf, int bufsize)
764 res = read (fd, buf, bufsize);
765 while (res == -1 && errno == EINTR);
770 sock_write (int fd, char *buf, int bufsize)
774 res = write (fd, buf, bufsize);
775 while (res == -1 && errno == EINTR);
780 sock_poll (int fd, double timeout, int wait_for)
782 return select_fd (fd, timeout, wait_for);
786 sock_peek (int fd, char *buf, int bufsize)
790 res = recv (fd, buf, bufsize, MSG_PEEK);
791 while (res == -1 && errno == EINTR);
799 DEBUGP (("Closed fd %d\n", fd));
805 /* Reading and writing from the network. We build around the socket
806 (file descriptor) API, but support "extended" operations for things
807 that are not mere file descriptors under the hood, such as SSL
810 That way the user code can call fd_read(fd, ...) and we'll run read
811 or SSL_read or whatever is necessary. */
813 static struct hash_table *transport_map;
814 static unsigned int transport_map_modified_tick;
816 struct transport_info {
817 struct transport_implementation *imp;
821 /* Register the transport layer operations that will be used when
822 reading, writing, and polling FD.
824 This should be used for transport layers like SSL that piggyback on
825 sockets. FD should otherwise be a real socket, on which you can
826 call getpeername, etc. */
829 fd_register_transport (int fd, struct transport_implementation *imp, void *ctx)
831 struct transport_info *info;
833 /* The file descriptor must be non-negative to be registered.
834 Negative values are ignored by fd_close(), and -1 cannot be used as
838 info = xnew (struct transport_info);
842 transport_map = hash_table_new (0, NULL, NULL);
843 hash_table_put (transport_map, (void *)(intptr_t) fd, info);
844 ++transport_map_modified_tick;
847 /* Return context of the transport registered with
848 fd_register_transport. This assumes fd_register_transport was
849 previously called on FD. */
852 fd_transport_context (int fd)
854 struct transport_info *info = hash_table_get (transport_map, (void *)(intptr_t) fd);
858 /* When fd_read/fd_write are called multiple times in a loop, they should
859 remember the INFO pointer instead of fetching it every time. It is
860 not enough to compare FD to LAST_FD because FD might have been
861 closed and reopened. modified_tick ensures that changes to
862 transport_map will not be unnoticed.
864 This is a macro because we want the static storage variables to be
867 #define LAZY_RETRIEVE_INFO(info) do { \
868 static struct transport_info *last_info; \
869 static int last_fd = -1; \
870 static unsigned int last_tick; \
871 if (!transport_map) \
873 else if (last_fd == fd && last_tick == transport_map_modified_tick) \
877 info = hash_table_get (transport_map, (void *)(intptr_t) fd); \
880 last_tick = transport_map_modified_tick; \
885 poll_internal (int fd, struct transport_info *info, int wf, double timeout)
888 timeout = opt.read_timeout;
892 if (info && info->imp->poller)
893 test = info->imp->poller (fd, timeout, wf, info->ctx);
895 test = sock_poll (fd, timeout, wf);
904 /* Read no more than BUFSIZE bytes of data from FD, storing them to
905 BUF. If TIMEOUT is non-zero, the operation aborts if no data is
906 received after that many seconds. If TIMEOUT is -1, the value of
907 opt.timeout is used for TIMEOUT. */
910 fd_read (int fd, char *buf, int bufsize, double timeout)
912 struct transport_info *info;
913 LAZY_RETRIEVE_INFO (info);
914 if (!poll_internal (fd, info, WAIT_FOR_READ, timeout))
916 if (info && info->imp->reader)
917 return info->imp->reader (fd, buf, bufsize, info->ctx);
919 return sock_read (fd, buf, bufsize);
922 /* Like fd_read, except it provides a "preview" of the data that will
923 be read by subsequent calls to fd_read. Specifically, it copies no
924 more than BUFSIZE bytes of the currently available data to BUF and
925 returns the number of bytes copied. Return values and timeout
926 semantics are the same as those of fd_read.
928 CAVEAT: Do not assume that the first subsequent call to fd_read
929 will retrieve the same amount of data. Reading can return more or
930 less data, depending on the TCP implementation and other
931 circumstances. However, barring an error, it can be expected that
932 all the peeked data will eventually be read by fd_read. */
935 fd_peek (int fd, char *buf, int bufsize, double timeout)
937 struct transport_info *info;
938 LAZY_RETRIEVE_INFO (info);
939 if (!poll_internal (fd, info, WAIT_FOR_READ, timeout))
941 if (info && info->imp->peeker)
942 return info->imp->peeker (fd, buf, bufsize, info->ctx);
944 return sock_peek (fd, buf, bufsize);
947 /* Write the entire contents of BUF to FD. If TIMEOUT is non-zero,
948 the operation aborts if no data is received after that many
949 seconds. If TIMEOUT is -1, the value of opt.timeout is used for
953 fd_write (int fd, char *buf, int bufsize, double timeout)
956 struct transport_info *info;
957 LAZY_RETRIEVE_INFO (info);
959 /* `write' may write less than LEN bytes, thus the loop keeps trying
960 it until all was written, or an error occurred. */
964 if (!poll_internal (fd, info, WAIT_FOR_WRITE, timeout))
966 if (info && info->imp->writer)
967 res = info->imp->writer (fd, buf, bufsize, info->ctx);
969 res = sock_write (fd, buf, bufsize);
978 /* Report the most recent error(s) on FD. This should only be called
979 after fd_* functions, such as fd_read and fd_write, and only if
980 they return a negative result. For errors coming from other calls
981 such as setsockopt or fopen, strerror should continue to be
984 If the transport doesn't support error messages or doesn't supply
985 one, strerror(errno) is returned. The returned error message
986 should not be used after fd_close has been called. */
991 /* Don't bother with LAZY_RETRIEVE_INFO, as this will only be called
992 in case of error, never in a tight loop. */
993 struct transport_info *info = NULL;
995 info = hash_table_get (transport_map, (void *)(intptr_t) fd);
997 if (info && info->imp->errstr)
999 const char *err = info->imp->errstr (fd, info->ctx);
1002 /* else, fall through and print the system error. */
1004 return strerror (errno);
1007 /* Close the file descriptor FD. */
1012 struct transport_info *info;
1016 /* Don't use LAZY_RETRIEVE_INFO because fd_close() is only called once
1017 per socket, so that particular optimization wouldn't work. */
1020 info = hash_table_get (transport_map, (void *)(intptr_t) fd);
1022 if (info && info->imp->closer)
1023 info->imp->closer (fd, info->ctx);
1029 hash_table_remove (transport_map, (void *)(intptr_t) fd);
1031 ++transport_map_modified_tick;