1 /***************************************************************************
3 * Project ___| | | | _ \| |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.haxx.se/docs/copyright.html.
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
21 ***************************************************************************/
22 #include "server_setup.h"
26 * 1. Accept a TCP connection on a custom port (IPv4 or IPv6), or connect
27 * to a given (localhost) port.
29 * 2. Get commands on STDIN. Pass data on to the TCP stream.
30 * Get data from TCP stream and pass on to STDOUT.
32 * This program is made to perform all the socket/stream/connection stuff for
33 * the test suite's (perl) FTP server. Previously the perl code did all of
34 * this by its own, but I decided to let this program do the socket layer
35 * because of several things:
37 * o We want the perl code to work with rather old perl installations, thus
38 * we cannot use recent perl modules or features.
40 * o We want IPv6 support for systems that provide it, and doing optional IPv6
41 * support in perl seems if not impossible so at least awkward.
43 * o We want FTP-SSL support, which means that a connection that starts with
44 * plain sockets needs to be able to "go SSL" in the midst. This would also
45 * require some nasty perl stuff I'd rather avoid.
47 * (Source originally based on sws.c)
51 * Signal handling notes for sockfilt
52 * ----------------------------------
54 * This program is a single-threaded process.
56 * This program is intended to be highly portable and as such it must be kept
57 * as simple as possible, due to this the only signal handling mechanisms used
58 * will be those of ANSI C, and used only in the most basic form which is good
59 * enough for the purpose of this program.
61 * For the above reason and the specific needs of this program signals SIGHUP,
62 * SIGPIPE and SIGALRM will be simply ignored on systems where this can be
63 * done. If possible, signals SIGINT and SIGTERM will be handled by this
64 * program as an indication to cleanup and finish execution as soon as
65 * possible. This will be achieved with a single signal handler
66 * 'exit_signal_handler' for both signals.
68 * The 'exit_signal_handler' upon the first SIGINT or SIGTERM received signal
69 * will just set to one the global var 'got_exit_signal' storing in global var
70 * 'exit_signal' the signal that triggered this change.
72 * Nothing fancy that could introduce problems is used, the program at certain
73 * points in its normal flow checks if var 'got_exit_signal' is set and in
74 * case this is true it just makes its way out of loops and functions in
75 * structured and well behaved manner to achieve proper program cleanup and
78 * Even with the above mechanism implemented it is worthwile to note that
79 * other signals might still be received, or that there might be systems on
80 * which it is not possible to trap and ignore some of the above signals.
81 * This implies that for increased portability and reliability the program
82 * must be coded as if no signal was being ignored or handled at all. Enjoy
89 #ifdef HAVE_NETINET_IN_H
90 #include <netinet/in.h>
92 #ifdef HAVE_ARPA_INET_H
93 #include <arpa/inet.h>
99 #define ENABLE_CURLX_PRINTF
100 /* make the curlx header define all printf() functions to use the curlx_*
102 #include "curlx.h" /* from the private lib dir */
104 #include "inet_pton.h"
106 #include "server_sockaddr.h"
107 #include "warnless.h"
109 /* include memdebug.h last */
110 #include "memdebug.h"
114 #define EINTR 4 /* errno.h value */
116 #define EAGAIN 11 /* errno.h value */
118 #define ENOMEM 12 /* errno.h value */
120 #define EINVAL 22 /* errno.h value */
123 #define DEFAULT_PORT 8999
125 #ifndef DEFAULT_LOGFILE
126 #define DEFAULT_LOGFILE "log/sockfilt.log"
129 const char *serverlogfile = DEFAULT_LOGFILE;
131 static bool verbose = FALSE;
132 static bool bind_only = FALSE;
134 static bool use_ipv6 = FALSE;
136 static const char *ipv_inuse = "IPv4";
137 static unsigned short port = DEFAULT_PORT;
138 static unsigned short connectport = 0; /* if non-zero, we activate this mode */
141 PASSIVE_LISTEN, /* as a server waiting for connections */
142 PASSIVE_CONNECT, /* as a server, connected to a client */
143 ACTIVE, /* as a client, connected to a server */
144 ACTIVE_DISCONNECT /* as a client, disconnected from server */
147 /* do-nothing macro replacement for systems which lack siginterrupt() */
149 #ifndef HAVE_SIGINTERRUPT
150 #define siginterrupt(x,y) do {} while(0)
153 /* vars used to keep around previous signal handlers */
155 typedef RETSIGTYPE (*SIGHANDLER_T)(int);
158 static SIGHANDLER_T old_sighup_handler = SIG_ERR;
162 static SIGHANDLER_T old_sigpipe_handler = SIG_ERR;
166 static SIGHANDLER_T old_sigalrm_handler = SIG_ERR;
170 static SIGHANDLER_T old_sigint_handler = SIG_ERR;
174 static SIGHANDLER_T old_sigterm_handler = SIG_ERR;
177 #if defined(SIGBREAK) && defined(WIN32)
178 static SIGHANDLER_T old_sigbreak_handler = SIG_ERR;
181 /* var which if set indicates that the program should finish execution */
183 SIG_ATOMIC_T got_exit_signal = 0;
185 /* if next is set indicates the first signal handled in exit_signal_handler */
187 static volatile int exit_signal = 0;
189 /* signal handler that will be triggered to indicate that the program
190 should finish its execution in a controlled manner as soon as possible.
191 The first time this is called it will set got_exit_signal to one and
192 store in exit_signal the signal that triggered its execution. */
194 static RETSIGTYPE exit_signal_handler(int signum)
196 int old_errno = errno;
197 if(got_exit_signal == 0) {
199 exit_signal = signum;
201 (void)signal(signum, exit_signal_handler);
205 static void install_signal_handlers(void)
208 /* ignore SIGHUP signal */
209 if((old_sighup_handler = signal(SIGHUP, SIG_IGN)) == SIG_ERR)
210 logmsg("cannot install SIGHUP handler: %s", strerror(errno));
213 /* ignore SIGPIPE signal */
214 if((old_sigpipe_handler = signal(SIGPIPE, SIG_IGN)) == SIG_ERR)
215 logmsg("cannot install SIGPIPE handler: %s", strerror(errno));
218 /* ignore SIGALRM signal */
219 if((old_sigalrm_handler = signal(SIGALRM, SIG_IGN)) == SIG_ERR)
220 logmsg("cannot install SIGALRM handler: %s", strerror(errno));
223 /* handle SIGINT signal with our exit_signal_handler */
224 if((old_sigint_handler = signal(SIGINT, exit_signal_handler)) == SIG_ERR)
225 logmsg("cannot install SIGINT handler: %s", strerror(errno));
227 siginterrupt(SIGINT, 1);
230 /* handle SIGTERM signal with our exit_signal_handler */
231 if((old_sigterm_handler = signal(SIGTERM, exit_signal_handler)) == SIG_ERR)
232 logmsg("cannot install SIGTERM handler: %s", strerror(errno));
234 siginterrupt(SIGTERM, 1);
236 #if defined(SIGBREAK) && defined(WIN32)
237 /* handle SIGBREAK signal with our exit_signal_handler */
238 if((old_sigbreak_handler = signal(SIGBREAK, exit_signal_handler)) == SIG_ERR)
239 logmsg("cannot install SIGBREAK handler: %s", strerror(errno));
241 siginterrupt(SIGBREAK, 1);
245 static void restore_signal_handlers(void)
248 if(SIG_ERR != old_sighup_handler)
249 (void)signal(SIGHUP, old_sighup_handler);
252 if(SIG_ERR != old_sigpipe_handler)
253 (void)signal(SIGPIPE, old_sigpipe_handler);
256 if(SIG_ERR != old_sigalrm_handler)
257 (void)signal(SIGALRM, old_sigalrm_handler);
260 if(SIG_ERR != old_sigint_handler)
261 (void)signal(SIGINT, old_sigint_handler);
264 if(SIG_ERR != old_sigterm_handler)
265 (void)signal(SIGTERM, old_sigterm_handler);
267 #if defined(SIGBREAK) && defined(WIN32)
268 if(SIG_ERR != old_sigbreak_handler)
269 (void)signal(SIGBREAK, old_sigbreak_handler);
275 * read-wrapper to support reading from stdin on Windows.
277 static ssize_t read_wincon(int fd, void *buf, size_t count)
279 HANDLE handle = NULL;
280 DWORD mode, rcount = 0;
283 if(fd == fileno(stdin)) {
284 handle = GetStdHandle(STD_INPUT_HANDLE);
287 return read(fd, buf, count);
290 if(GetConsoleMode(handle, &mode)) {
291 success = ReadConsole(handle, buf, curlx_uztoul(count), &rcount, NULL);
294 success = ReadFile(handle, buf, curlx_uztoul(count), &rcount, NULL);
300 errno = GetLastError();
304 #define read(a,b,c) read_wincon(a,b,c)
307 * write-wrapper to support writing to stdout and stderr on Windows.
309 static ssize_t write_wincon(int fd, const void *buf, size_t count)
311 HANDLE handle = NULL;
312 DWORD mode, wcount = 0;
315 if(fd == fileno(stdout)) {
316 handle = GetStdHandle(STD_OUTPUT_HANDLE);
318 else if(fd == fileno(stderr)) {
319 handle = GetStdHandle(STD_ERROR_HANDLE);
322 return write(fd, buf, count);
325 if(GetConsoleMode(handle, &mode)) {
326 success = WriteConsole(handle, buf, curlx_uztoul(count), &wcount, NULL);
329 success = WriteFile(handle, buf, curlx_uztoul(count), &wcount, NULL);
335 errno = GetLastError();
339 #define write(a,b,c) write_wincon(a,b,c)
343 * fullread is a wrapper around the read() function. This will repeat the call
344 * to read() until it actually has read the complete number of bytes indicated
345 * in nbytes or it fails with a condition that cannot be handled with a simple
346 * retry of the read call.
349 static ssize_t fullread(int filedes, void *buffer, size_t nbytes)
356 rc = read(filedes, (unsigned char *)buffer + nread, nbytes - nread);
358 if(got_exit_signal) {
359 logmsg("signalled to die");
365 if((error == EINTR) || (error == EAGAIN))
367 logmsg("reading from file descriptor: %d,", filedes);
368 logmsg("unrecoverable read() failure: (%d) %s",
369 error, strerror(error));
374 logmsg("got 0 reading from stdin");
380 } while((size_t)nread < nbytes);
383 logmsg("read %zd bytes", nread);
389 * fullwrite is a wrapper around the write() function. This will repeat the
390 * call to write() until it actually has written the complete number of bytes
391 * indicated in nbytes or it fails with a condition that cannot be handled
392 * with a simple retry of the write call.
395 static ssize_t fullwrite(int filedes, const void *buffer, size_t nbytes)
402 wc = write(filedes, (unsigned char *)buffer + nwrite, nbytes - nwrite);
404 if(got_exit_signal) {
405 logmsg("signalled to die");
411 if((error == EINTR) || (error == EAGAIN))
413 logmsg("writing to file descriptor: %d,", filedes);
414 logmsg("unrecoverable write() failure: (%d) %s",
415 error, strerror(error));
420 logmsg("put 0 writing to stdout");
426 } while((size_t)nwrite < nbytes);
429 logmsg("wrote %zd bytes", nwrite);
435 * read_stdin tries to read from stdin nbytes into the given buffer. This is a
436 * blocking function that will only return TRUE when nbytes have actually been
437 * read or FALSE when an unrecoverable error has been detected. Failure of this
438 * function is an indication that the sockfilt process should terminate.
441 static bool read_stdin(void *buffer, size_t nbytes)
443 ssize_t nread = fullread(fileno(stdin), buffer, nbytes);
444 if(nread != (ssize_t)nbytes) {
445 logmsg("exiting...");
452 * write_stdout tries to write to stdio nbytes from the given buffer. This is a
453 * blocking function that will only return TRUE when nbytes have actually been
454 * written or FALSE when an unrecoverable error has been detected. Failure of
455 * this function is an indication that the sockfilt process should terminate.
458 static bool write_stdout(const void *buffer, size_t nbytes)
460 ssize_t nwrite = fullwrite(fileno(stdout), buffer, nbytes);
461 if(nwrite != (ssize_t)nbytes) {
462 logmsg("exiting...");
468 static void lograw(unsigned char *buffer, ssize_t len)
472 unsigned char *ptr = buffer;
475 int left = sizeof(data);
477 for(i=0; i<len; i++) {
480 snprintf(optr, left, "\\n");
486 snprintf(optr, left, "\\r");
492 snprintf(optr, left, "%c", (ISGRAPH(ptr[i]) ||
493 ptr[i]==0x20) ?ptr[i]:'.');
501 logmsg("'%s'", data);
508 logmsg("'%s'", data);
513 * WinSock select() does not support standard file descriptors,
514 * it can only check SOCKETs. The following function is an attempt
515 * to re-create a select() function with support for other handle types.
517 * select() function with support for WINSOCK2 sockets and all
518 * other handle types supported by WaitForMultipleObjectsEx() as
519 * well as disk files, anonymous and names pipes, and character input.
521 * https://msdn.microsoft.com/en-us/library/windows/desktop/ms687028.aspx
522 * https://msdn.microsoft.com/en-us/library/windows/desktop/ms741572.aspx
524 struct select_ws_wait_data {
525 HANDLE handle; /* actual handle to wait for during select */
526 HANDLE event; /* internal event to abort waiting thread */
528 static DWORD WINAPI select_ws_wait_thread(LPVOID lpParameter)
530 struct select_ws_wait_data *data;
531 HANDLE handle, handles[2];
532 INPUT_RECORD inputrecord;
533 LARGE_INTEGER size, pos;
536 /* retrieve handles from internal structure */
537 data = (struct select_ws_wait_data *) lpParameter;
539 handle = data->handle;
540 handles[0] = data->event;
547 /* retrieve the type of file to wait on */
548 type = GetFileType(handle);
551 /* The handle represents a file on disk, this means:
552 * - WaitForMultipleObjectsEx will always be signalled for it.
553 * - comparison of current position in file and total size of
554 * the file can be used to check if we reached the end yet.
556 * Approach: Loop till either the internal event is signalled
557 * or if the end of the file has already been reached.
559 while(WaitForMultipleObjectsEx(1, handles, FALSE, 0, FALSE)
561 /* get total size of file */
564 size.LowPart = GetFileSize(handle, &length);
565 if((size.LowPart != INVALID_FILE_SIZE) ||
566 (GetLastError() == NO_ERROR)) {
567 size.HighPart = length;
568 /* get the current position within the file */
570 pos.LowPart = SetFilePointer(handle, 0, &pos.HighPart,
572 if((pos.LowPart != INVALID_SET_FILE_POINTER) ||
573 (GetLastError() == NO_ERROR)) {
574 /* compare position with size, abort if not equal */
575 if(size.QuadPart == pos.QuadPart) {
576 /* sleep and continue waiting */
582 /* there is some data available, stop waiting */
588 /* The handle represents a character input, this means:
589 * - WaitForMultipleObjectsEx will be signalled on any kind of input,
590 * including mouse and window size events we do not care about.
592 * Approach: Loop till either the internal event is signalled
593 * or we get signalled for an actual key-event.
595 while(WaitForMultipleObjectsEx(2, handles, FALSE, INFINITE, FALSE)
596 == WAIT_OBJECT_0 + 1) {
597 /* check if this is an actual console handle */
599 if(GetConsoleMode(handle, &length)) {
600 /* retrieve an event from the console buffer */
602 if(PeekConsoleInput(handle, &inputrecord, 1, &length)) {
603 /* check if the event is not an actual key-event */
604 if(length == 1 && inputrecord.EventType != KEY_EVENT) {
605 /* purge the non-key-event and continue waiting */
606 ReadConsoleInput(handle, &inputrecord, 1, &length);
611 /* there is some data available, stop waiting */
617 /* The handle represents an anonymous or named pipe, this means:
618 * - WaitForMultipleObjectsEx will always be signalled for it.
619 * - peek into the pipe and retrieve the amount of data available.
621 * Approach: Loop till either the internal event is signalled
622 * or there is data in the pipe available for reading.
624 while(WaitForMultipleObjectsEx(1, handles, FALSE, 0, FALSE)
626 /* peek into the pipe and retrieve the amount of data available */
628 if(PeekNamedPipe(handle, NULL, 0, NULL, &length, NULL)) {
629 /* if there is no data available, sleep and continue waiting */
636 /* if the pipe has been closed, sleep and continue waiting */
637 if(GetLastError() == ERROR_BROKEN_PIPE) {
642 /* there is some data available, stop waiting */
648 /* The handle has an unknown type, try to wait on it */
649 WaitForMultipleObjectsEx(2, handles, FALSE, INFINITE, FALSE);
655 static HANDLE select_ws_wait(HANDLE handle, HANDLE event)
657 struct select_ws_wait_data *data;
658 HANDLE thread = NULL;
660 /* allocate internal waiting data structure */
661 data = malloc(sizeof(struct select_ws_wait_data));
663 data->handle = handle;
666 /* launch waiting thread */
667 thread = CreateThread(NULL, 0,
668 &select_ws_wait_thread,
671 /* free data if thread failed to launch */
679 struct select_ws_data {
680 curl_socket_t fd; /* the original input handle (indexed by fds) */
681 curl_socket_t wsasock; /* the internal socket handle (indexed by wsa) */
682 WSAEVENT wsaevent; /* the internal WINSOCK2 event (indexed by wsa) */
683 HANDLE thread; /* the internal threads handle (indexed by thd) */
685 static int select_ws(int nfds, fd_set *readfds, fd_set *writefds,
686 fd_set *exceptfds, struct timeval *timeout)
688 DWORD milliseconds, wait, idx;
689 WSANETWORKEVENTS wsanetevents;
690 struct select_ws_data *data;
691 HANDLE handle, *handles;
696 HANDLE waitevent = NULL;
697 DWORD nfd = 0, thd = 0, wsa = 0;
700 /* check if the input value is valid */
706 /* check if we got descriptors, sleep in case we got none */
708 Sleep((timeout->tv_sec*1000)+(DWORD)(((double)timeout->tv_usec)/1000.0));
712 /* create internal event to signal waiting threads */
713 waitevent = CreateEvent(NULL, TRUE, FALSE, NULL);
719 /* allocate internal array for the internal data */
720 data = malloc(nfds * sizeof(struct select_ws_data));
726 /* allocate internal array for the internal event handles */
727 handles = malloc(nfds * sizeof(HANDLE));
728 if(handles == NULL) {
734 /* clear internal arrays */
735 memset(data, 0, nfds * sizeof(struct select_ws_data));
736 memset(handles, 0, nfds * sizeof(HANDLE));
738 /* loop over the handles in the input descriptor sets */
739 for(fds = 0; fds < nfds; fds++) {
743 if(FD_ISSET(fds, readfds))
744 networkevents |= FD_READ|FD_ACCEPT|FD_CLOSE;
746 if(FD_ISSET(fds, writefds))
747 networkevents |= FD_WRITE|FD_CONNECT;
749 if(FD_ISSET(fds, exceptfds))
750 networkevents |= FD_OOB|FD_CLOSE;
752 /* only wait for events for which we actually care */
754 data[nfd].fd = curlx_sitosk(fds);
755 if(fds == fileno(stdin)) {
756 handle = GetStdHandle(STD_INPUT_HANDLE);
757 handle = select_ws_wait(handle, waitevent);
758 handles[nfd] = handle;
759 data[thd].thread = handle;
762 else if(fds == fileno(stdout)) {
763 handles[nfd] = GetStdHandle(STD_OUTPUT_HANDLE);
765 else if(fds == fileno(stderr)) {
766 handles[nfd] = GetStdHandle(STD_ERROR_HANDLE);
769 wsaevent = WSACreateEvent();
770 if(wsaevent != WSA_INVALID_EVENT) {
771 error = WSAEventSelect(fds, wsaevent, networkevents);
772 if(error != SOCKET_ERROR) {
773 handle = (HANDLE) wsaevent;
774 handles[nfd] = handle;
775 data[wsa].wsasock = curlx_sitosk(fds);
776 data[wsa].wsaevent = wsaevent;
780 WSACloseEvent(wsaevent);
781 handle = (HANDLE) curlx_sitosk(fds);
782 handle = select_ws_wait(handle, waitevent);
783 handles[nfd] = handle;
784 data[thd].thread = handle;
793 /* convert struct timeval to milliseconds */
795 milliseconds = ((timeout->tv_sec * 1000) + (timeout->tv_usec / 1000));
798 milliseconds = INFINITE;
801 /* wait for one of the internal handles to trigger */
802 wait = WaitForMultipleObjectsEx(nfd, handles, FALSE, milliseconds, FALSE);
804 /* signal the event handle for the waiting threads */
807 /* loop over the internal handles returned in the descriptors */
808 for(idx = 0; idx < nfd; idx++) {
809 handle = handles[idx];
811 fds = curlx_sktosi(sock);
813 /* check if the current internal handle was triggered */
814 if(wait != WAIT_FAILED && (wait - WAIT_OBJECT_0) <= idx &&
815 WaitForSingleObjectEx(handle, 0, FALSE) == WAIT_OBJECT_0) {
816 /* first handle stdin, stdout and stderr */
817 if(fds == fileno(stdin)) {
818 /* stdin is never ready for write or exceptional */
819 FD_CLR(sock, writefds);
820 FD_CLR(sock, exceptfds);
822 else if(fds == fileno(stdout) || fds == fileno(stderr)) {
823 /* stdout and stderr are never ready for read or exceptional */
824 FD_CLR(sock, readfds);
825 FD_CLR(sock, exceptfds);
828 /* try to handle the event with the WINSOCK2 functions */
829 wsanetevents.lNetworkEvents = 0;
830 error = WSAEnumNetworkEvents(fds, handle, &wsanetevents);
831 if(error != SOCKET_ERROR) {
832 /* remove from descriptor set if not ready for read/accept/close */
833 if(!(wsanetevents.lNetworkEvents & (FD_READ|FD_ACCEPT|FD_CLOSE)))
834 FD_CLR(sock, readfds);
836 /* remove from descriptor set if not ready for write/connect */
837 if(!(wsanetevents.lNetworkEvents & (FD_WRITE|FD_CONNECT)))
838 FD_CLR(sock, writefds);
841 * use exceptfds together with readfds to signal
842 * that the connection was closed by the client.
844 * Reason: FD_CLOSE is only signaled once, sometimes
845 * at the same time as FD_READ with data being available.
846 * This means that recv/sread is not reliable to detect
847 * that the connection is closed.
849 /* remove from descriptor set if not exceptional */
850 if(!(wsanetevents.lNetworkEvents & (FD_OOB|FD_CLOSE)))
851 FD_CLR(sock, exceptfds);
855 /* check if the event has not been filtered using specific tests */
856 if(FD_ISSET(sock, readfds) || FD_ISSET(sock, writefds) ||
857 FD_ISSET(sock, exceptfds)) {
862 /* remove from all descriptor sets since this handle did not trigger */
863 FD_CLR(sock, readfds);
864 FD_CLR(sock, writefds);
865 FD_CLR(sock, exceptfds);
869 for(fds = 0; fds < nfds; fds++) {
870 if(FD_ISSET(fds, readfds))
871 logmsg("select_ws: %d is readable", fds);
873 if(FD_ISSET(fds, writefds))
874 logmsg("select_ws: %d is writable", fds);
876 if(FD_ISSET(fds, exceptfds))
877 logmsg("select_ws: %d is excepted", fds);
880 for(idx = 0; idx < wsa; idx++) {
881 WSAEventSelect(data[idx].wsasock, NULL, 0);
882 WSACloseEvent(data[idx].wsaevent);
885 for(idx = 0; idx < thd; idx++) {
886 WaitForSingleObject(data[idx].thread, INFINITE);
887 CloseHandle(data[idx].thread);
890 CloseHandle(waitevent);
897 #define select(a,b,c,d,e) select_ws(a,b,c,d,e)
898 #endif /* USE_WINSOCK */
901 sockfdp is a pointer to an established stream or CURL_SOCKET_BAD
903 if sockfd is CURL_SOCKET_BAD, listendfd is a listening socket we must
906 static bool juggle(curl_socket_t *sockfdp,
907 curl_socket_t listenfd,
910 struct timeval timeout;
914 curl_socket_t sockfd = CURL_SOCKET_BAD;
917 ssize_t nread_socket;
918 ssize_t bytes_written;
922 /* 'buffer' is this excessively large only to be able to support things like
923 test 1003 which tests exceedingly large server response lines */
924 unsigned char buffer[17010];
927 if(got_exit_signal) {
928 logmsg("signalled to die, exiting...");
933 /* As a last resort, quit if sockfilt process becomes orphan. Just in case
934 parent ftpserver process has died without killing its sockfilt children */
936 logmsg("process becomes orphan, exiting");
941 timeout.tv_sec = 120;
948 FD_SET((curl_socket_t)fileno(stdin), &fds_read);
956 /* there's always a socket to wait for */
957 FD_SET(sockfd, &fds_read);
961 case PASSIVE_CONNECT:
964 if(CURL_SOCKET_BAD == sockfd) {
965 /* eeek, we are supposedly connected and then this cannot be -1 ! */
966 logmsg("socket is -1! on %s:%d", __FILE__, __LINE__);
967 maxfd = 0; /* stdin */
970 /* there's always a socket to wait for */
971 FD_SET(sockfd, &fds_read);
973 FD_SET(sockfd, &fds_err);
982 /* sockfd turns CURL_SOCKET_BAD when our connection has been closed */
983 if(CURL_SOCKET_BAD != sockfd) {
984 FD_SET(sockfd, &fds_read);
986 FD_SET(sockfd, &fds_err);
991 logmsg("No socket to read on");
996 case ACTIVE_DISCONNECT:
998 logmsg("disconnected, no socket to read on");
1000 sockfd = CURL_SOCKET_BAD;
1003 } /* switch(*mode) */
1008 /* select() blocking behavior call on blocking descriptors please */
1010 rc = select(maxfd + 1, &fds_read, &fds_write, &fds_err, &timeout);
1012 if(got_exit_signal) {
1013 logmsg("signalled to die, exiting...");
1017 } while((rc == -1) && ((error = errno) == EINTR));
1020 logmsg("select() failed with error: (%d) %s",
1021 error, strerror(error));
1030 if(FD_ISSET(fileno(stdin), &fds_read)) {
1031 /* read from stdin, commands/data to be dealt with and possibly passed on
1036 4 letter command + LF [mandatory]
1038 4-digit hexadecimal data length + LF [if the command takes data]
1039 data [the data being as long as set above]
1043 DATA - plain pass-thru data
1046 if(!read_stdin(buffer, 5))
1049 logmsg("Received %c%c%c%c (on stdin)",
1050 buffer[0], buffer[1], buffer[2], buffer[3]);
1052 if(!memcmp("PING", buffer, 4)) {
1053 /* send reply on stdout, just proving we are alive */
1054 if(!write_stdout("PONG\n", 5))
1058 else if(!memcmp("PORT", buffer, 4)) {
1059 /* Question asking us what PORT number we are listening to.
1060 Replies to PORT with "IPv[num]/[port]" */
1061 snprintf((char *)buffer, sizeof(buffer), "%s/%hu\n", ipv_inuse, port);
1062 buffer_len = (ssize_t)strlen((char *)buffer);
1063 snprintf(data, sizeof(data), "PORT\n%04zx\n", buffer_len);
1064 if(!write_stdout(data, 10))
1066 if(!write_stdout(buffer, buffer_len))
1069 else if(!memcmp("QUIT", buffer, 4)) {
1074 else if(!memcmp("DATA", buffer, 4)) {
1075 /* data IN => data OUT */
1077 if(!read_stdin(buffer, 5))
1082 buffer_len = (ssize_t)strtol((char *)buffer, NULL, 16);
1083 if(buffer_len > (ssize_t)sizeof(buffer)) {
1084 logmsg("ERROR: Buffer size (%zu bytes) too small for data size "
1085 "(%zd bytes)", sizeof(buffer), buffer_len);
1088 logmsg("> %zd bytes data, server => client", buffer_len);
1090 if(!read_stdin(buffer, buffer_len))
1093 lograw(buffer, buffer_len);
1095 if(*mode == PASSIVE_LISTEN) {
1096 logmsg("*** We are disconnected!");
1097 if(!write_stdout("DISC\n", 5))
1101 /* send away on the socket */
1102 bytes_written = swrite(sockfd, buffer, buffer_len);
1103 if(bytes_written != buffer_len) {
1104 logmsg("Not all data was sent. Bytes to send: %zd sent: %zd",
1105 buffer_len, bytes_written);
1109 else if(!memcmp("DISC", buffer, 4)) {
1111 if(!write_stdout("DISC\n", 5))
1113 if(sockfd != CURL_SOCKET_BAD) {
1114 logmsg("====> Client forcibly disconnected");
1116 *sockfdp = CURL_SOCKET_BAD;
1117 if(*mode == PASSIVE_CONNECT)
1118 *mode = PASSIVE_LISTEN;
1120 *mode = ACTIVE_DISCONNECT;
1123 logmsg("attempt to close already dead connection");
1129 if((sockfd != CURL_SOCKET_BAD) && (FD_ISSET(sockfd, &fds_read)) ) {
1131 curl_socket_t newfd = CURL_SOCKET_BAD; /* newly accepted socket */
1133 if(*mode == PASSIVE_LISTEN) {
1134 /* there's no stream set up yet, this is an indication that there's a
1135 client connecting. */
1136 newfd = accept(sockfd, NULL, NULL);
1137 if(CURL_SOCKET_BAD == newfd) {
1139 logmsg("accept(%d, NULL, NULL) failed with error: (%d) %s",
1140 sockfd, error, strerror(error));
1143 logmsg("====> Client connect");
1144 if(!write_stdout("CNCT\n", 5))
1146 *sockfdp = newfd; /* store the new socket */
1147 *mode = PASSIVE_CONNECT; /* we have connected */
1152 /* read from socket, pass on data to stdout */
1153 nread_socket = sread(sockfd, buffer, sizeof(buffer));
1155 if(nread_socket > 0) {
1156 snprintf(data, sizeof(data), "DATA\n%04zx\n", nread_socket);
1157 if(!write_stdout(data, 10))
1159 if(!write_stdout(buffer, nread_socket))
1162 logmsg("< %zd bytes data, client => server", nread_socket);
1163 lograw(buffer, nread_socket);
1166 if(nread_socket <= 0
1168 || FD_ISSET(sockfd, &fds_err)
1171 logmsg("====> Client disconnect");
1172 if(!write_stdout("DISC\n", 5))
1175 *sockfdp = CURL_SOCKET_BAD;
1176 if(*mode == PASSIVE_CONNECT)
1177 *mode = PASSIVE_LISTEN;
1179 *mode = ACTIVE_DISCONNECT;
1187 static curl_socket_t sockdaemon(curl_socket_t sock,
1188 unsigned short *listenport)
1190 /* passive daemon style */
1191 srvr_sockaddr_union_t listener;
1203 rc = setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
1204 (void *)&flag, sizeof(flag));
1207 logmsg("setsockopt(SO_REUSEADDR) failed with error: (%d) %s",
1208 error, strerror(error));
1210 rc = wait_ms(delay);
1212 /* should not happen */
1214 logmsg("wait_ms() failed with error: (%d) %s",
1215 error, strerror(error));
1217 return CURL_SOCKET_BAD;
1219 if(got_exit_signal) {
1220 logmsg("signalled to die, exiting...");
1222 return CURL_SOCKET_BAD;
1225 delay *= 2; /* double the sleep for next attempt */
1228 } while(rc && maxretr--);
1231 logmsg("setsockopt(SO_REUSEADDR) failed %d times in %d ms. Error: (%d) %s",
1232 attempt, totdelay, error, strerror(error));
1233 logmsg("Continuing anyway...");
1236 /* When the specified listener port is zero, it is actually a
1237 request to let the system choose a non-zero available port. */
1242 memset(&listener.sa4, 0, sizeof(listener.sa4));
1243 listener.sa4.sin_family = AF_INET;
1244 listener.sa4.sin_addr.s_addr = INADDR_ANY;
1245 listener.sa4.sin_port = htons(*listenport);
1246 rc = bind(sock, &listener.sa, sizeof(listener.sa4));
1250 memset(&listener.sa6, 0, sizeof(listener.sa6));
1251 listener.sa6.sin6_family = AF_INET6;
1252 listener.sa6.sin6_addr = in6addr_any;
1253 listener.sa6.sin6_port = htons(*listenport);
1254 rc = bind(sock, &listener.sa, sizeof(listener.sa6));
1256 #endif /* ENABLE_IPV6 */
1259 logmsg("Error binding socket on port %hu: (%d) %s",
1260 *listenport, error, strerror(error));
1262 return CURL_SOCKET_BAD;
1266 /* The system was supposed to choose a port number, figure out which
1267 port we actually got and update the listener port value with it. */
1268 curl_socklen_t la_size;
1269 srvr_sockaddr_union_t localaddr;
1273 la_size = sizeof(localaddr.sa4);
1276 la_size = sizeof(localaddr.sa6);
1278 memset(&localaddr.sa, 0, (size_t)la_size);
1279 if(getsockname(sock, &localaddr.sa, &la_size) < 0) {
1281 logmsg("getsockname() failed with error: (%d) %s",
1282 error, strerror(error));
1284 return CURL_SOCKET_BAD;
1286 switch (localaddr.sa.sa_family) {
1288 *listenport = ntohs(localaddr.sa4.sin_port);
1292 *listenport = ntohs(localaddr.sa6.sin6_port);
1299 /* Real failure, listener port shall not be zero beyond this point. */
1300 logmsg("Apparently getsockname() succeeded, with listener port zero.");
1301 logmsg("A valid reason for this failure is a binary built without");
1302 logmsg("proper network library linkage. This might not be the only");
1303 logmsg("reason, but double check it before anything else.");
1305 return CURL_SOCKET_BAD;
1309 /* bindonly option forces no listening */
1311 logmsg("instructed to bind port without listening");
1315 /* start accepting connections */
1316 rc = listen(sock, 5);
1319 logmsg("listen(%d, 5) failed with error: (%d) %s",
1320 sock, error, strerror(error));
1322 return CURL_SOCKET_BAD;
1329 int main(int argc, char *argv[])
1331 srvr_sockaddr_union_t me;
1332 curl_socket_t sock = CURL_SOCKET_BAD;
1333 curl_socket_t msgsock = CURL_SOCKET_BAD;
1334 int wrotepidfile = 0;
1335 char *pidname= (char *)".sockfilt.pid";
1340 enum sockmode mode = PASSIVE_LISTEN; /* default */
1341 const char *addr = NULL;
1344 if(!strcmp("--version", argv[arg])) {
1345 printf("sockfilt IPv4%s\n",
1354 else if(!strcmp("--verbose", argv[arg])) {
1358 else if(!strcmp("--pidfile", argv[arg])) {
1361 pidname = argv[arg++];
1363 else if(!strcmp("--logfile", argv[arg])) {
1366 serverlogfile = argv[arg++];
1368 else if(!strcmp("--ipv6", argv[arg])) {
1375 else if(!strcmp("--ipv4", argv[arg])) {
1376 /* for completeness, we support this option as well */
1383 else if(!strcmp("--bindonly", argv[arg])) {
1387 else if(!strcmp("--port", argv[arg])) {
1391 unsigned long ulnum = strtoul(argv[arg], &endptr, 10);
1392 if((endptr != argv[arg] + strlen(argv[arg])) ||
1393 ((ulnum != 0UL) && ((ulnum < 1025UL) || (ulnum > 65535UL)))) {
1394 fprintf(stderr, "sockfilt: invalid --port argument (%s)\n",
1398 port = curlx_ultous(ulnum);
1402 else if(!strcmp("--connect", argv[arg])) {
1403 /* Asked to actively connect to the specified local port instead of
1404 doing a passive server-style listening. */
1408 unsigned long ulnum = strtoul(argv[arg], &endptr, 10);
1409 if((endptr != argv[arg] + strlen(argv[arg])) ||
1410 (ulnum < 1025UL) || (ulnum > 65535UL)) {
1411 fprintf(stderr, "sockfilt: invalid --connect argument (%s)\n",
1415 connectport = curlx_ultous(ulnum);
1419 else if(!strcmp("--addr", argv[arg])) {
1420 /* Set an IP address to use with --connect; otherwise use localhost */
1428 puts("Usage: sockfilt [option]\n"
1431 " --logfile [file]\n"
1432 " --pidfile [file]\n"
1437 " --connect [port]\n"
1438 " --addr [address]");
1445 atexit(win32_cleanup);
1447 setmode(fileno(stdin), O_BINARY);
1448 setmode(fileno(stdout), O_BINARY);
1449 setmode(fileno(stderr), O_BINARY);
1452 install_signal_handlers();
1457 sock = socket(AF_INET, SOCK_STREAM, 0);
1460 sock = socket(AF_INET6, SOCK_STREAM, 0);
1463 if(CURL_SOCKET_BAD == sock) {
1465 logmsg("Error creating socket: (%d) %s",
1466 error, strerror(error));
1467 write_stdout("FAIL\n", 5);
1468 goto sockfilt_cleanup;
1472 /* Active mode, we should connect to the given port number */
1477 memset(&me.sa4, 0, sizeof(me.sa4));
1478 me.sa4.sin_family = AF_INET;
1479 me.sa4.sin_port = htons(connectport);
1480 me.sa4.sin_addr.s_addr = INADDR_ANY;
1483 Curl_inet_pton(AF_INET, addr, &me.sa4.sin_addr);
1485 rc = connect(sock, &me.sa, sizeof(me.sa4));
1489 memset(&me.sa6, 0, sizeof(me.sa6));
1490 me.sa6.sin6_family = AF_INET6;
1491 me.sa6.sin6_port = htons(connectport);
1494 Curl_inet_pton(AF_INET6, addr, &me.sa6.sin6_addr);
1496 rc = connect(sock, &me.sa, sizeof(me.sa6));
1498 #endif /* ENABLE_IPV6 */
1501 logmsg("Error connecting to port %hu: (%d) %s",
1502 connectport, error, strerror(error));
1503 write_stdout("FAIL\n", 5);
1504 goto sockfilt_cleanup;
1506 logmsg("====> Client connect");
1507 msgsock = sock; /* use this as stream */
1510 /* passive daemon style */
1511 sock = sockdaemon(sock, &port);
1512 if(CURL_SOCKET_BAD == sock) {
1513 write_stdout("FAIL\n", 5);
1514 goto sockfilt_cleanup;
1516 msgsock = CURL_SOCKET_BAD; /* no stream socket yet */
1519 logmsg("Running %s version", ipv_inuse);
1522 logmsg("Connected to port %hu", connectport);
1524 logmsg("Bound without listening on port %hu", port);
1526 logmsg("Listening on port %hu", port);
1528 wrotepidfile = write_pidfile(pidname);
1530 write_stdout("FAIL\n", 5);
1531 goto sockfilt_cleanup;
1535 juggle_again = juggle(&msgsock, sock, &mode);
1536 } while(juggle_again);
1540 if((msgsock != sock) && (msgsock != CURL_SOCKET_BAD))
1543 if(sock != CURL_SOCKET_BAD)
1549 restore_signal_handlers();
1551 if(got_exit_signal) {
1552 logmsg("============> sockfilt exits with signal (%d)", exit_signal);
1554 * To properly set the return status of the process we
1555 * must raise the same signal SIGINT or SIGTERM that we
1556 * caught and let the old handler take care of it.
1561 logmsg("============> sockfilt quits");