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 old_sighup_handler = signal(SIGHUP, SIG_IGN);
210 if(old_sighup_handler == SIG_ERR)
211 logmsg("cannot install SIGHUP handler: %s", strerror(errno));
214 /* ignore SIGPIPE signal */
215 old_sigpipe_handler = signal(SIGPIPE, SIG_IGN);
216 if(old_sigpipe_handler == SIG_ERR)
217 logmsg("cannot install SIGPIPE handler: %s", strerror(errno));
220 /* ignore SIGALRM signal */
221 old_sigalrm_handler = signal(SIGALRM, SIG_IGN);
222 if(old_sigalrm_handler == SIG_ERR)
223 logmsg("cannot install SIGALRM handler: %s", strerror(errno));
226 /* handle SIGINT signal with our exit_signal_handler */
227 old_sigint_handler = signal(SIGINT, exit_signal_handler);
228 if(old_sigint_handler == SIG_ERR)
229 logmsg("cannot install SIGINT handler: %s", strerror(errno));
231 siginterrupt(SIGINT, 1);
234 /* handle SIGTERM signal with our exit_signal_handler */
235 old_sigterm_handler = signal(SIGTERM, exit_signal_handler);
236 if(old_sigterm_handler == SIG_ERR)
237 logmsg("cannot install SIGTERM handler: %s", strerror(errno));
239 siginterrupt(SIGTERM, 1);
241 #if defined(SIGBREAK) && defined(WIN32)
242 /* handle SIGBREAK signal with our exit_signal_handler */
243 old_sigbreak_handler = signal(SIGBREAK, exit_signal_handler);
244 if(old_sigbreak_handler == SIG_ERR)
245 logmsg("cannot install SIGBREAK handler: %s", strerror(errno));
247 siginterrupt(SIGBREAK, 1);
251 static void restore_signal_handlers(void)
254 if(SIG_ERR != old_sighup_handler)
255 (void)signal(SIGHUP, old_sighup_handler);
258 if(SIG_ERR != old_sigpipe_handler)
259 (void)signal(SIGPIPE, old_sigpipe_handler);
262 if(SIG_ERR != old_sigalrm_handler)
263 (void)signal(SIGALRM, old_sigalrm_handler);
266 if(SIG_ERR != old_sigint_handler)
267 (void)signal(SIGINT, old_sigint_handler);
270 if(SIG_ERR != old_sigterm_handler)
271 (void)signal(SIGTERM, old_sigterm_handler);
273 #if defined(SIGBREAK) && defined(WIN32)
274 if(SIG_ERR != old_sigbreak_handler)
275 (void)signal(SIGBREAK, old_sigbreak_handler);
281 * read-wrapper to support reading from stdin on Windows.
283 static ssize_t read_wincon(int fd, void *buf, size_t count)
285 HANDLE handle = NULL;
286 DWORD mode, rcount = 0;
289 if(fd == fileno(stdin)) {
290 handle = GetStdHandle(STD_INPUT_HANDLE);
293 return read(fd, buf, count);
296 if(GetConsoleMode(handle, &mode)) {
297 success = ReadConsole(handle, buf, curlx_uztoul(count), &rcount, NULL);
300 success = ReadFile(handle, buf, curlx_uztoul(count), &rcount, NULL);
306 errno = GetLastError();
310 #define read(a,b,c) read_wincon(a,b,c)
313 * write-wrapper to support writing to stdout and stderr on Windows.
315 static ssize_t write_wincon(int fd, const void *buf, size_t count)
317 HANDLE handle = NULL;
318 DWORD mode, wcount = 0;
321 if(fd == fileno(stdout)) {
322 handle = GetStdHandle(STD_OUTPUT_HANDLE);
324 else if(fd == fileno(stderr)) {
325 handle = GetStdHandle(STD_ERROR_HANDLE);
328 return write(fd, buf, count);
331 if(GetConsoleMode(handle, &mode)) {
332 success = WriteConsole(handle, buf, curlx_uztoul(count), &wcount, NULL);
335 success = WriteFile(handle, buf, curlx_uztoul(count), &wcount, NULL);
341 errno = GetLastError();
345 #define write(a,b,c) write_wincon(a,b,c)
349 * fullread is a wrapper around the read() function. This will repeat the call
350 * to read() until it actually has read the complete number of bytes indicated
351 * in nbytes or it fails with a condition that cannot be handled with a simple
352 * retry of the read call.
355 static ssize_t fullread(int filedes, void *buffer, size_t nbytes)
362 rc = read(filedes, (unsigned char *)buffer + nread, nbytes - nread);
364 if(got_exit_signal) {
365 logmsg("signalled to die");
371 if((error == EINTR) || (error == EAGAIN))
373 logmsg("reading from file descriptor: %d,", filedes);
374 logmsg("unrecoverable read() failure: (%d) %s",
375 error, strerror(error));
380 logmsg("got 0 reading from stdin");
386 } while((size_t)nread < nbytes);
389 logmsg("read %zd bytes", nread);
395 * fullwrite is a wrapper around the write() function. This will repeat the
396 * call to write() until it actually has written the complete number of bytes
397 * indicated in nbytes or it fails with a condition that cannot be handled
398 * with a simple retry of the write call.
401 static ssize_t fullwrite(int filedes, const void *buffer, size_t nbytes)
408 wc = write(filedes, (unsigned char *)buffer + nwrite, nbytes - nwrite);
410 if(got_exit_signal) {
411 logmsg("signalled to die");
417 if((error == EINTR) || (error == EAGAIN))
419 logmsg("writing to file descriptor: %d,", filedes);
420 logmsg("unrecoverable write() failure: (%d) %s",
421 error, strerror(error));
426 logmsg("put 0 writing to stdout");
432 } while((size_t)nwrite < nbytes);
435 logmsg("wrote %zd bytes", nwrite);
441 * read_stdin tries to read from stdin nbytes into the given buffer. This is a
442 * blocking function that will only return TRUE when nbytes have actually been
443 * read or FALSE when an unrecoverable error has been detected. Failure of this
444 * function is an indication that the sockfilt process should terminate.
447 static bool read_stdin(void *buffer, size_t nbytes)
449 ssize_t nread = fullread(fileno(stdin), buffer, nbytes);
450 if(nread != (ssize_t)nbytes) {
451 logmsg("exiting...");
458 * write_stdout tries to write to stdio nbytes from the given buffer. This is a
459 * blocking function that will only return TRUE when nbytes have actually been
460 * written or FALSE when an unrecoverable error has been detected. Failure of
461 * this function is an indication that the sockfilt process should terminate.
464 static bool write_stdout(const void *buffer, size_t nbytes)
466 ssize_t nwrite = fullwrite(fileno(stdout), buffer, nbytes);
467 if(nwrite != (ssize_t)nbytes) {
468 logmsg("exiting...");
474 static void lograw(unsigned char *buffer, ssize_t len)
478 unsigned char *ptr = buffer;
481 int left = sizeof(data);
483 for(i=0; i<len; i++) {
486 snprintf(optr, left, "\\n");
492 snprintf(optr, left, "\\r");
498 snprintf(optr, left, "%c", (ISGRAPH(ptr[i]) ||
499 ptr[i]==0x20) ?ptr[i]:'.');
507 logmsg("'%s'", data);
514 logmsg("'%s'", data);
519 * WinSock select() does not support standard file descriptors,
520 * it can only check SOCKETs. The following function is an attempt
521 * to re-create a select() function with support for other handle types.
523 * select() function with support for WINSOCK2 sockets and all
524 * other handle types supported by WaitForMultipleObjectsEx() as
525 * well as disk files, anonymous and names pipes, and character input.
527 * https://msdn.microsoft.com/en-us/library/windows/desktop/ms687028.aspx
528 * https://msdn.microsoft.com/en-us/library/windows/desktop/ms741572.aspx
530 struct select_ws_wait_data {
531 HANDLE handle; /* actual handle to wait for during select */
532 HANDLE event; /* internal event to abort waiting thread */
534 static DWORD WINAPI select_ws_wait_thread(LPVOID lpParameter)
536 struct select_ws_wait_data *data;
537 HANDLE handle, handles[2];
538 INPUT_RECORD inputrecord;
539 LARGE_INTEGER size, pos;
542 /* retrieve handles from internal structure */
543 data = (struct select_ws_wait_data *) lpParameter;
545 handle = data->handle;
546 handles[0] = data->event;
553 /* retrieve the type of file to wait on */
554 type = GetFileType(handle);
557 /* The handle represents a file on disk, this means:
558 * - WaitForMultipleObjectsEx will always be signalled for it.
559 * - comparison of current position in file and total size of
560 * the file can be used to check if we reached the end yet.
562 * Approach: Loop till either the internal event is signalled
563 * or if the end of the file has already been reached.
565 while(WaitForMultipleObjectsEx(1, handles, FALSE, 0, FALSE)
567 /* get total size of file */
570 size.LowPart = GetFileSize(handle, &length);
571 if((size.LowPart != INVALID_FILE_SIZE) ||
572 (GetLastError() == NO_ERROR)) {
573 size.HighPart = length;
574 /* get the current position within the file */
576 pos.LowPart = SetFilePointer(handle, 0, &pos.HighPart,
578 if((pos.LowPart != INVALID_SET_FILE_POINTER) ||
579 (GetLastError() == NO_ERROR)) {
580 /* compare position with size, abort if not equal */
581 if(size.QuadPart == pos.QuadPart) {
582 /* sleep and continue waiting */
588 /* there is some data available, stop waiting */
594 /* The handle represents a character input, this means:
595 * - WaitForMultipleObjectsEx will be signalled on any kind of input,
596 * including mouse and window size events we do not care about.
598 * Approach: Loop till either the internal event is signalled
599 * or we get signalled for an actual key-event.
601 while(WaitForMultipleObjectsEx(2, handles, FALSE, INFINITE, FALSE)
602 == WAIT_OBJECT_0 + 1) {
603 /* check if this is an actual console handle */
605 if(GetConsoleMode(handle, &length)) {
606 /* retrieve an event from the console buffer */
608 if(PeekConsoleInput(handle, &inputrecord, 1, &length)) {
609 /* check if the event is not an actual key-event */
610 if(length == 1 && inputrecord.EventType != KEY_EVENT) {
611 /* purge the non-key-event and continue waiting */
612 ReadConsoleInput(handle, &inputrecord, 1, &length);
617 /* there is some data available, stop waiting */
623 /* The handle represents an anonymous or named pipe, this means:
624 * - WaitForMultipleObjectsEx will always be signalled for it.
625 * - peek into the pipe and retrieve the amount of data available.
627 * Approach: Loop till either the internal event is signalled
628 * or there is data in the pipe available for reading.
630 while(WaitForMultipleObjectsEx(1, handles, FALSE, 0, FALSE)
632 /* peek into the pipe and retrieve the amount of data available */
634 if(PeekNamedPipe(handle, NULL, 0, NULL, &length, NULL)) {
635 /* if there is no data available, sleep and continue waiting */
642 /* if the pipe has been closed, sleep and continue waiting */
643 if(GetLastError() == ERROR_BROKEN_PIPE) {
648 /* there is some data available, stop waiting */
654 /* The handle has an unknown type, try to wait on it */
655 WaitForMultipleObjectsEx(2, handles, FALSE, INFINITE, FALSE);
661 static HANDLE select_ws_wait(HANDLE handle, HANDLE event)
663 struct select_ws_wait_data *data;
664 HANDLE thread = NULL;
666 /* allocate internal waiting data structure */
667 data = malloc(sizeof(struct select_ws_wait_data));
669 data->handle = handle;
672 /* launch waiting thread */
673 thread = CreateThread(NULL, 0,
674 &select_ws_wait_thread,
677 /* free data if thread failed to launch */
685 struct select_ws_data {
686 curl_socket_t fd; /* the original input handle (indexed by fds) */
687 curl_socket_t wsasock; /* the internal socket handle (indexed by wsa) */
688 WSAEVENT wsaevent; /* the internal WINSOCK2 event (indexed by wsa) */
689 HANDLE thread; /* the internal threads handle (indexed by thd) */
691 static int select_ws(int nfds, fd_set *readfds, fd_set *writefds,
692 fd_set *exceptfds, struct timeval *timeout)
694 DWORD milliseconds, wait, idx;
695 WSANETWORKEVENTS wsanetevents;
696 struct select_ws_data *data;
697 HANDLE handle, *handles;
702 HANDLE waitevent = NULL;
703 DWORD nfd = 0, thd = 0, wsa = 0;
706 /* check if the input value is valid */
712 /* check if we got descriptors, sleep in case we got none */
714 Sleep((timeout->tv_sec*1000)+(DWORD)(((double)timeout->tv_usec)/1000.0));
718 /* create internal event to signal waiting threads */
719 waitevent = CreateEvent(NULL, TRUE, FALSE, NULL);
725 /* allocate internal array for the internal data */
726 data = malloc(nfds * sizeof(struct select_ws_data));
732 /* allocate internal array for the internal event handles */
733 handles = malloc(nfds * sizeof(HANDLE));
734 if(handles == NULL) {
740 /* clear internal arrays */
741 memset(data, 0, nfds * sizeof(struct select_ws_data));
742 memset(handles, 0, nfds * sizeof(HANDLE));
744 /* loop over the handles in the input descriptor sets */
745 for(fds = 0; fds < nfds; fds++) {
749 if(FD_ISSET(fds, readfds))
750 networkevents |= FD_READ|FD_ACCEPT|FD_CLOSE;
752 if(FD_ISSET(fds, writefds))
753 networkevents |= FD_WRITE|FD_CONNECT;
755 if(FD_ISSET(fds, exceptfds))
756 networkevents |= FD_OOB|FD_CLOSE;
758 /* only wait for events for which we actually care */
760 data[nfd].fd = curlx_sitosk(fds);
761 if(fds == fileno(stdin)) {
762 handle = GetStdHandle(STD_INPUT_HANDLE);
763 handle = select_ws_wait(handle, waitevent);
764 handles[nfd] = handle;
765 data[thd].thread = handle;
768 else if(fds == fileno(stdout)) {
769 handles[nfd] = GetStdHandle(STD_OUTPUT_HANDLE);
771 else if(fds == fileno(stderr)) {
772 handles[nfd] = GetStdHandle(STD_ERROR_HANDLE);
775 wsaevent = WSACreateEvent();
776 if(wsaevent != WSA_INVALID_EVENT) {
777 error = WSAEventSelect(fds, wsaevent, networkevents);
778 if(error != SOCKET_ERROR) {
779 handle = (HANDLE) wsaevent;
780 handles[nfd] = handle;
781 data[wsa].wsasock = curlx_sitosk(fds);
782 data[wsa].wsaevent = wsaevent;
786 WSACloseEvent(wsaevent);
787 handle = (HANDLE) curlx_sitosk(fds);
788 handle = select_ws_wait(handle, waitevent);
789 handles[nfd] = handle;
790 data[thd].thread = handle;
799 /* convert struct timeval to milliseconds */
801 milliseconds = ((timeout->tv_sec * 1000) + (timeout->tv_usec / 1000));
804 milliseconds = INFINITE;
807 /* wait for one of the internal handles to trigger */
808 wait = WaitForMultipleObjectsEx(nfd, handles, FALSE, milliseconds, FALSE);
810 /* signal the event handle for the waiting threads */
813 /* loop over the internal handles returned in the descriptors */
814 for(idx = 0; idx < nfd; idx++) {
815 handle = handles[idx];
817 fds = curlx_sktosi(sock);
819 /* check if the current internal handle was triggered */
820 if(wait != WAIT_FAILED && (wait - WAIT_OBJECT_0) <= idx &&
821 WaitForSingleObjectEx(handle, 0, FALSE) == WAIT_OBJECT_0) {
822 /* first handle stdin, stdout and stderr */
823 if(fds == fileno(stdin)) {
824 /* stdin is never ready for write or exceptional */
825 FD_CLR(sock, writefds);
826 FD_CLR(sock, exceptfds);
828 else if(fds == fileno(stdout) || fds == fileno(stderr)) {
829 /* stdout and stderr are never ready for read or exceptional */
830 FD_CLR(sock, readfds);
831 FD_CLR(sock, exceptfds);
834 /* try to handle the event with the WINSOCK2 functions */
835 wsanetevents.lNetworkEvents = 0;
836 error = WSAEnumNetworkEvents(fds, handle, &wsanetevents);
837 if(error != SOCKET_ERROR) {
838 /* remove from descriptor set if not ready for read/accept/close */
839 if(!(wsanetevents.lNetworkEvents & (FD_READ|FD_ACCEPT|FD_CLOSE)))
840 FD_CLR(sock, readfds);
842 /* remove from descriptor set if not ready for write/connect */
843 if(!(wsanetevents.lNetworkEvents & (FD_WRITE|FD_CONNECT)))
844 FD_CLR(sock, writefds);
847 * use exceptfds together with readfds to signal
848 * that the connection was closed by the client.
850 * Reason: FD_CLOSE is only signaled once, sometimes
851 * at the same time as FD_READ with data being available.
852 * This means that recv/sread is not reliable to detect
853 * that the connection is closed.
855 /* remove from descriptor set if not exceptional */
856 if(!(wsanetevents.lNetworkEvents & (FD_OOB|FD_CLOSE)))
857 FD_CLR(sock, exceptfds);
861 /* check if the event has not been filtered using specific tests */
862 if(FD_ISSET(sock, readfds) || FD_ISSET(sock, writefds) ||
863 FD_ISSET(sock, exceptfds)) {
868 /* remove from all descriptor sets since this handle did not trigger */
869 FD_CLR(sock, readfds);
870 FD_CLR(sock, writefds);
871 FD_CLR(sock, exceptfds);
875 for(fds = 0; fds < nfds; fds++) {
876 if(FD_ISSET(fds, readfds))
877 logmsg("select_ws: %d is readable", fds);
879 if(FD_ISSET(fds, writefds))
880 logmsg("select_ws: %d is writable", fds);
882 if(FD_ISSET(fds, exceptfds))
883 logmsg("select_ws: %d is excepted", fds);
886 for(idx = 0; idx < wsa; idx++) {
887 WSAEventSelect(data[idx].wsasock, NULL, 0);
888 WSACloseEvent(data[idx].wsaevent);
891 for(idx = 0; idx < thd; idx++) {
892 WaitForSingleObject(data[idx].thread, INFINITE);
893 CloseHandle(data[idx].thread);
896 CloseHandle(waitevent);
903 #define select(a,b,c,d,e) select_ws(a,b,c,d,e)
904 #endif /* USE_WINSOCK */
907 sockfdp is a pointer to an established stream or CURL_SOCKET_BAD
909 if sockfd is CURL_SOCKET_BAD, listendfd is a listening socket we must
912 static bool juggle(curl_socket_t *sockfdp,
913 curl_socket_t listenfd,
916 struct timeval timeout;
920 curl_socket_t sockfd = CURL_SOCKET_BAD;
923 ssize_t nread_socket;
924 ssize_t bytes_written;
928 /* 'buffer' is this excessively large only to be able to support things like
929 test 1003 which tests exceedingly large server response lines */
930 unsigned char buffer[17010];
933 if(got_exit_signal) {
934 logmsg("signalled to die, exiting...");
939 /* As a last resort, quit if sockfilt process becomes orphan. Just in case
940 parent ftpserver process has died without killing its sockfilt children */
942 logmsg("process becomes orphan, exiting");
947 timeout.tv_sec = 120;
954 FD_SET((curl_socket_t)fileno(stdin), &fds_read);
962 /* there's always a socket to wait for */
963 FD_SET(sockfd, &fds_read);
967 case PASSIVE_CONNECT:
970 if(CURL_SOCKET_BAD == sockfd) {
971 /* eeek, we are supposedly connected and then this cannot be -1 ! */
972 logmsg("socket is -1! on %s:%d", __FILE__, __LINE__);
973 maxfd = 0; /* stdin */
976 /* there's always a socket to wait for */
977 FD_SET(sockfd, &fds_read);
979 FD_SET(sockfd, &fds_err);
988 /* sockfd turns CURL_SOCKET_BAD when our connection has been closed */
989 if(CURL_SOCKET_BAD != sockfd) {
990 FD_SET(sockfd, &fds_read);
992 FD_SET(sockfd, &fds_err);
997 logmsg("No socket to read on");
1002 case ACTIVE_DISCONNECT:
1004 logmsg("disconnected, no socket to read on");
1006 sockfd = CURL_SOCKET_BAD;
1009 } /* switch(*mode) */
1014 /* select() blocking behavior call on blocking descriptors please */
1016 rc = select(maxfd + 1, &fds_read, &fds_write, &fds_err, &timeout);
1018 if(got_exit_signal) {
1019 logmsg("signalled to die, exiting...");
1023 } while((rc == -1) && ((error = errno) == EINTR));
1026 logmsg("select() failed with error: (%d) %s",
1027 error, strerror(error));
1036 if(FD_ISSET(fileno(stdin), &fds_read)) {
1037 /* read from stdin, commands/data to be dealt with and possibly passed on
1042 4 letter command + LF [mandatory]
1044 4-digit hexadecimal data length + LF [if the command takes data]
1045 data [the data being as long as set above]
1049 DATA - plain pass-thru data
1052 if(!read_stdin(buffer, 5))
1055 logmsg("Received %c%c%c%c (on stdin)",
1056 buffer[0], buffer[1], buffer[2], buffer[3]);
1058 if(!memcmp("PING", buffer, 4)) {
1059 /* send reply on stdout, just proving we are alive */
1060 if(!write_stdout("PONG\n", 5))
1064 else if(!memcmp("PORT", buffer, 4)) {
1065 /* Question asking us what PORT number we are listening to.
1066 Replies to PORT with "IPv[num]/[port]" */
1067 snprintf((char *)buffer, sizeof(buffer), "%s/%hu\n", ipv_inuse, port);
1068 buffer_len = (ssize_t)strlen((char *)buffer);
1069 snprintf(data, sizeof(data), "PORT\n%04zx\n", buffer_len);
1070 if(!write_stdout(data, 10))
1072 if(!write_stdout(buffer, buffer_len))
1075 else if(!memcmp("QUIT", buffer, 4)) {
1080 else if(!memcmp("DATA", buffer, 4)) {
1081 /* data IN => data OUT */
1083 if(!read_stdin(buffer, 5))
1088 buffer_len = (ssize_t)strtol((char *)buffer, NULL, 16);
1089 if(buffer_len > (ssize_t)sizeof(buffer)) {
1090 logmsg("ERROR: Buffer size (%zu bytes) too small for data size "
1091 "(%zd bytes)", sizeof(buffer), buffer_len);
1094 logmsg("> %zd bytes data, server => client", buffer_len);
1096 if(!read_stdin(buffer, buffer_len))
1099 lograw(buffer, buffer_len);
1101 if(*mode == PASSIVE_LISTEN) {
1102 logmsg("*** We are disconnected!");
1103 if(!write_stdout("DISC\n", 5))
1107 /* send away on the socket */
1108 bytes_written = swrite(sockfd, buffer, buffer_len);
1109 if(bytes_written != buffer_len) {
1110 logmsg("Not all data was sent. Bytes to send: %zd sent: %zd",
1111 buffer_len, bytes_written);
1115 else if(!memcmp("DISC", buffer, 4)) {
1117 if(!write_stdout("DISC\n", 5))
1119 if(sockfd != CURL_SOCKET_BAD) {
1120 logmsg("====> Client forcibly disconnected");
1122 *sockfdp = CURL_SOCKET_BAD;
1123 if(*mode == PASSIVE_CONNECT)
1124 *mode = PASSIVE_LISTEN;
1126 *mode = ACTIVE_DISCONNECT;
1129 logmsg("attempt to close already dead connection");
1135 if((sockfd != CURL_SOCKET_BAD) && (FD_ISSET(sockfd, &fds_read)) ) {
1137 curl_socket_t newfd = CURL_SOCKET_BAD; /* newly accepted socket */
1139 if(*mode == PASSIVE_LISTEN) {
1140 /* there's no stream set up yet, this is an indication that there's a
1141 client connecting. */
1142 newfd = accept(sockfd, NULL, NULL);
1143 if(CURL_SOCKET_BAD == newfd) {
1145 logmsg("accept(%d, NULL, NULL) failed with error: (%d) %s",
1146 sockfd, error, strerror(error));
1149 logmsg("====> Client connect");
1150 if(!write_stdout("CNCT\n", 5))
1152 *sockfdp = newfd; /* store the new socket */
1153 *mode = PASSIVE_CONNECT; /* we have connected */
1158 /* read from socket, pass on data to stdout */
1159 nread_socket = sread(sockfd, buffer, sizeof(buffer));
1161 if(nread_socket > 0) {
1162 snprintf(data, sizeof(data), "DATA\n%04zx\n", nread_socket);
1163 if(!write_stdout(data, 10))
1165 if(!write_stdout(buffer, nread_socket))
1168 logmsg("< %zd bytes data, client => server", nread_socket);
1169 lograw(buffer, nread_socket);
1172 if(nread_socket <= 0
1174 || FD_ISSET(sockfd, &fds_err)
1177 logmsg("====> Client disconnect");
1178 if(!write_stdout("DISC\n", 5))
1181 *sockfdp = CURL_SOCKET_BAD;
1182 if(*mode == PASSIVE_CONNECT)
1183 *mode = PASSIVE_LISTEN;
1185 *mode = ACTIVE_DISCONNECT;
1193 static curl_socket_t sockdaemon(curl_socket_t sock,
1194 unsigned short *listenport)
1196 /* passive daemon style */
1197 srvr_sockaddr_union_t listener;
1209 rc = setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
1210 (void *)&flag, sizeof(flag));
1213 logmsg("setsockopt(SO_REUSEADDR) failed with error: (%d) %s",
1214 error, strerror(error));
1216 rc = wait_ms(delay);
1218 /* should not happen */
1220 logmsg("wait_ms() failed with error: (%d) %s",
1221 error, strerror(error));
1223 return CURL_SOCKET_BAD;
1225 if(got_exit_signal) {
1226 logmsg("signalled to die, exiting...");
1228 return CURL_SOCKET_BAD;
1231 delay *= 2; /* double the sleep for next attempt */
1234 } while(rc && maxretr--);
1237 logmsg("setsockopt(SO_REUSEADDR) failed %d times in %d ms. Error: (%d) %s",
1238 attempt, totdelay, error, strerror(error));
1239 logmsg("Continuing anyway...");
1242 /* When the specified listener port is zero, it is actually a
1243 request to let the system choose a non-zero available port. */
1248 memset(&listener.sa4, 0, sizeof(listener.sa4));
1249 listener.sa4.sin_family = AF_INET;
1250 listener.sa4.sin_addr.s_addr = INADDR_ANY;
1251 listener.sa4.sin_port = htons(*listenport);
1252 rc = bind(sock, &listener.sa, sizeof(listener.sa4));
1256 memset(&listener.sa6, 0, sizeof(listener.sa6));
1257 listener.sa6.sin6_family = AF_INET6;
1258 listener.sa6.sin6_addr = in6addr_any;
1259 listener.sa6.sin6_port = htons(*listenport);
1260 rc = bind(sock, &listener.sa, sizeof(listener.sa6));
1262 #endif /* ENABLE_IPV6 */
1265 logmsg("Error binding socket on port %hu: (%d) %s",
1266 *listenport, error, strerror(error));
1268 return CURL_SOCKET_BAD;
1272 /* The system was supposed to choose a port number, figure out which
1273 port we actually got and update the listener port value with it. */
1274 curl_socklen_t la_size;
1275 srvr_sockaddr_union_t localaddr;
1279 la_size = sizeof(localaddr.sa4);
1282 la_size = sizeof(localaddr.sa6);
1284 memset(&localaddr.sa, 0, (size_t)la_size);
1285 if(getsockname(sock, &localaddr.sa, &la_size) < 0) {
1287 logmsg("getsockname() failed with error: (%d) %s",
1288 error, strerror(error));
1290 return CURL_SOCKET_BAD;
1292 switch(localaddr.sa.sa_family) {
1294 *listenport = ntohs(localaddr.sa4.sin_port);
1298 *listenport = ntohs(localaddr.sa6.sin6_port);
1305 /* Real failure, listener port shall not be zero beyond this point. */
1306 logmsg("Apparently getsockname() succeeded, with listener port zero.");
1307 logmsg("A valid reason for this failure is a binary built without");
1308 logmsg("proper network library linkage. This might not be the only");
1309 logmsg("reason, but double check it before anything else.");
1311 return CURL_SOCKET_BAD;
1315 /* bindonly option forces no listening */
1317 logmsg("instructed to bind port without listening");
1321 /* start accepting connections */
1322 rc = listen(sock, 5);
1325 logmsg("listen(%d, 5) failed with error: (%d) %s",
1326 sock, error, strerror(error));
1328 return CURL_SOCKET_BAD;
1335 int main(int argc, char *argv[])
1337 srvr_sockaddr_union_t me;
1338 curl_socket_t sock = CURL_SOCKET_BAD;
1339 curl_socket_t msgsock = CURL_SOCKET_BAD;
1340 int wrotepidfile = 0;
1341 char *pidname= (char *)".sockfilt.pid";
1346 enum sockmode mode = PASSIVE_LISTEN; /* default */
1347 const char *addr = NULL;
1350 if(!strcmp("--version", argv[arg])) {
1351 printf("sockfilt IPv4%s\n",
1360 else if(!strcmp("--verbose", argv[arg])) {
1364 else if(!strcmp("--pidfile", argv[arg])) {
1367 pidname = argv[arg++];
1369 else if(!strcmp("--logfile", argv[arg])) {
1372 serverlogfile = argv[arg++];
1374 else if(!strcmp("--ipv6", argv[arg])) {
1381 else if(!strcmp("--ipv4", argv[arg])) {
1382 /* for completeness, we support this option as well */
1389 else if(!strcmp("--bindonly", argv[arg])) {
1393 else if(!strcmp("--port", argv[arg])) {
1397 unsigned long ulnum = strtoul(argv[arg], &endptr, 10);
1398 if((endptr != argv[arg] + strlen(argv[arg])) ||
1399 ((ulnum != 0UL) && ((ulnum < 1025UL) || (ulnum > 65535UL)))) {
1400 fprintf(stderr, "sockfilt: invalid --port argument (%s)\n",
1404 port = curlx_ultous(ulnum);
1408 else if(!strcmp("--connect", argv[arg])) {
1409 /* Asked to actively connect to the specified local port instead of
1410 doing a passive server-style listening. */
1414 unsigned long ulnum = strtoul(argv[arg], &endptr, 10);
1415 if((endptr != argv[arg] + strlen(argv[arg])) ||
1416 (ulnum < 1025UL) || (ulnum > 65535UL)) {
1417 fprintf(stderr, "sockfilt: invalid --connect argument (%s)\n",
1421 connectport = curlx_ultous(ulnum);
1425 else if(!strcmp("--addr", argv[arg])) {
1426 /* Set an IP address to use with --connect; otherwise use localhost */
1434 puts("Usage: sockfilt [option]\n"
1437 " --logfile [file]\n"
1438 " --pidfile [file]\n"
1443 " --connect [port]\n"
1444 " --addr [address]");
1451 atexit(win32_cleanup);
1453 setmode(fileno(stdin), O_BINARY);
1454 setmode(fileno(stdout), O_BINARY);
1455 setmode(fileno(stderr), O_BINARY);
1458 install_signal_handlers();
1463 sock = socket(AF_INET, SOCK_STREAM, 0);
1466 sock = socket(AF_INET6, SOCK_STREAM, 0);
1469 if(CURL_SOCKET_BAD == sock) {
1471 logmsg("Error creating socket: (%d) %s",
1472 error, strerror(error));
1473 write_stdout("FAIL\n", 5);
1474 goto sockfilt_cleanup;
1478 /* Active mode, we should connect to the given port number */
1483 memset(&me.sa4, 0, sizeof(me.sa4));
1484 me.sa4.sin_family = AF_INET;
1485 me.sa4.sin_port = htons(connectport);
1486 me.sa4.sin_addr.s_addr = INADDR_ANY;
1489 Curl_inet_pton(AF_INET, addr, &me.sa4.sin_addr);
1491 rc = connect(sock, &me.sa, sizeof(me.sa4));
1495 memset(&me.sa6, 0, sizeof(me.sa6));
1496 me.sa6.sin6_family = AF_INET6;
1497 me.sa6.sin6_port = htons(connectport);
1500 Curl_inet_pton(AF_INET6, addr, &me.sa6.sin6_addr);
1502 rc = connect(sock, &me.sa, sizeof(me.sa6));
1504 #endif /* ENABLE_IPV6 */
1507 logmsg("Error connecting to port %hu: (%d) %s",
1508 connectport, error, strerror(error));
1509 write_stdout("FAIL\n", 5);
1510 goto sockfilt_cleanup;
1512 logmsg("====> Client connect");
1513 msgsock = sock; /* use this as stream */
1516 /* passive daemon style */
1517 sock = sockdaemon(sock, &port);
1518 if(CURL_SOCKET_BAD == sock) {
1519 write_stdout("FAIL\n", 5);
1520 goto sockfilt_cleanup;
1522 msgsock = CURL_SOCKET_BAD; /* no stream socket yet */
1525 logmsg("Running %s version", ipv_inuse);
1528 logmsg("Connected to port %hu", connectport);
1530 logmsg("Bound without listening on port %hu", port);
1532 logmsg("Listening on port %hu", port);
1534 wrotepidfile = write_pidfile(pidname);
1536 write_stdout("FAIL\n", 5);
1537 goto sockfilt_cleanup;
1541 juggle_again = juggle(&msgsock, sock, &mode);
1542 } while(juggle_again);
1546 if((msgsock != sock) && (msgsock != CURL_SOCKET_BAD))
1549 if(sock != CURL_SOCKET_BAD)
1555 restore_signal_handlers();
1557 if(got_exit_signal) {
1558 logmsg("============> sockfilt exits with signal (%d)", exit_signal);
1560 * To properly set the return status of the process we
1561 * must raise the same signal SIGINT or SIGTERM that we
1562 * caught and let the old handler take care of it.
1567 logmsg("============> sockfilt quits");