1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
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.
13 *
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.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22#include "server_setup.h"
23
24/* Purpose
25 *
26 * 1. Accept a TCP connection on a custom port (IPv4 or IPv6), or connect
27 *    to a given (localhost) port.
28 *
29 * 2. Get commands on STDIN. Pass data on to the TCP stream.
30 *    Get data from TCP stream and pass on to STDOUT.
31 *
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:
36 *
37 * o We want the perl code to work with rather old perl installations, thus
38 *   we cannot use recent perl modules or features.
39 *
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.
42 *
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.
46 *
47 * (Source originally based on sws.c)
48 */
49
50/*
51 * Signal handling notes for sockfilt
52 * ----------------------------------
53 *
54 * This program is a single-threaded process.
55 *
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.
60 *
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.
67 *
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.
71 *
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
76 * termination.
77 *
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
83 * it!
84 */
85
86#ifdef HAVE_SIGNAL_H
87#include <signal.h>
88#endif
89#ifdef HAVE_NETINET_IN_H
90#include <netinet/in.h>
91#endif
92#ifdef HAVE_ARPA_INET_H
93#include <arpa/inet.h>
94#endif
95#ifdef HAVE_NETDB_H
96#include <netdb.h>
97#endif
98
99#define ENABLE_CURLX_PRINTF
100/* make the curlx header define all printf() functions to use the curlx_*
101   versions instead */
102#include "curlx.h" /* from the private lib dir */
103#include "getpart.h"
104#include "inet_pton.h"
105#include "util.h"
106#include "server_sockaddr.h"
107#include "warnless.h"
108
109/* include memdebug.h last */
110#include "memdebug.h"
111
112#ifdef USE_WINSOCK
113#undef  EINTR
114#define EINTR    4 /* errno.h value */
115#undef  EAGAIN
116#define EAGAIN  11 /* errno.h value */
117#undef  ENOMEM
118#define ENOMEM  12 /* errno.h value */
119#undef  EINVAL
120#define EINVAL  22 /* errno.h value */
121#endif
122
123#define DEFAULT_PORT 8999
124
125#ifndef DEFAULT_LOGFILE
126#define DEFAULT_LOGFILE "log/sockfilt.log"
127#endif
128
129const char *serverlogfile = DEFAULT_LOGFILE;
130
131static bool verbose = FALSE;
132static bool bind_only = FALSE;
133#ifdef ENABLE_IPV6
134static bool use_ipv6 = FALSE;
135#endif
136static const char *ipv_inuse = "IPv4";
137static unsigned short port = DEFAULT_PORT;
138static unsigned short connectport = 0; /* if non-zero, we activate this mode */
139
140enum sockmode {
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 */
145};
146
147/* do-nothing macro replacement for systems which lack siginterrupt() */
148
149#ifndef HAVE_SIGINTERRUPT
150#define siginterrupt(x,y) do {} while(0)
151#endif
152
153/* vars used to keep around previous signal handlers */
154
155typedef RETSIGTYPE (*SIGHANDLER_T)(int);
156
157#ifdef SIGHUP
158static SIGHANDLER_T old_sighup_handler  = SIG_ERR;
159#endif
160
161#ifdef SIGPIPE
162static SIGHANDLER_T old_sigpipe_handler = SIG_ERR;
163#endif
164
165#ifdef SIGALRM
166static SIGHANDLER_T old_sigalrm_handler = SIG_ERR;
167#endif
168
169#ifdef SIGINT
170static SIGHANDLER_T old_sigint_handler  = SIG_ERR;
171#endif
172
173#ifdef SIGTERM
174static SIGHANDLER_T old_sigterm_handler = SIG_ERR;
175#endif
176
177#if defined(SIGBREAK) && defined(WIN32)
178static SIGHANDLER_T old_sigbreak_handler = SIG_ERR;
179#endif
180
181/* var which if set indicates that the program should finish execution */
182
183SIG_ATOMIC_T got_exit_signal = 0;
184
185/* if next is set indicates the first signal handled in exit_signal_handler */
186
187static volatile int exit_signal = 0;
188
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. */
193
194static RETSIGTYPE exit_signal_handler(int signum)
195{
196  int old_errno = errno;
197  if(got_exit_signal == 0) {
198    got_exit_signal = 1;
199    exit_signal = signum;
200  }
201  (void)signal(signum, exit_signal_handler);
202  errno = old_errno;
203}
204
205static void install_signal_handlers(void)
206{
207#ifdef SIGHUP
208  /* ignore SIGHUP signal */
209  if((old_sighup_handler = signal(SIGHUP, SIG_IGN)) == SIG_ERR)
210    logmsg("cannot install SIGHUP handler: %s", strerror(errno));
211#endif
212#ifdef SIGPIPE
213  /* ignore SIGPIPE signal */
214  if((old_sigpipe_handler = signal(SIGPIPE, SIG_IGN)) == SIG_ERR)
215    logmsg("cannot install SIGPIPE handler: %s", strerror(errno));
216#endif
217#ifdef SIGALRM
218  /* ignore SIGALRM signal */
219  if((old_sigalrm_handler = signal(SIGALRM, SIG_IGN)) == SIG_ERR)
220    logmsg("cannot install SIGALRM handler: %s", strerror(errno));
221#endif
222#ifdef SIGINT
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));
226  else
227    siginterrupt(SIGINT, 1);
228#endif
229#ifdef SIGTERM
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));
233  else
234    siginterrupt(SIGTERM, 1);
235#endif
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));
240  else
241    siginterrupt(SIGBREAK, 1);
242#endif
243}
244
245static void restore_signal_handlers(void)
246{
247#ifdef SIGHUP
248  if(SIG_ERR != old_sighup_handler)
249    (void)signal(SIGHUP, old_sighup_handler);
250#endif
251#ifdef SIGPIPE
252  if(SIG_ERR != old_sigpipe_handler)
253    (void)signal(SIGPIPE, old_sigpipe_handler);
254#endif
255#ifdef SIGALRM
256  if(SIG_ERR != old_sigalrm_handler)
257    (void)signal(SIGALRM, old_sigalrm_handler);
258#endif
259#ifdef SIGINT
260  if(SIG_ERR != old_sigint_handler)
261    (void)signal(SIGINT, old_sigint_handler);
262#endif
263#ifdef SIGTERM
264  if(SIG_ERR != old_sigterm_handler)
265    (void)signal(SIGTERM, old_sigterm_handler);
266#endif
267#if defined(SIGBREAK) && defined(WIN32)
268  if(SIG_ERR != old_sigbreak_handler)
269    (void)signal(SIGBREAK, old_sigbreak_handler);
270#endif
271}
272
273#ifdef WIN32
274/*
275 * read-wrapper to support reading from stdin on Windows.
276 */
277static ssize_t read_wincon(int fd, void *buf, size_t count)
278{
279  HANDLE handle = NULL;
280  DWORD mode, rcount = 0;
281  BOOL success;
282
283  if(fd == fileno(stdin)) {
284    handle = GetStdHandle(STD_INPUT_HANDLE);
285  }
286  else {
287    return read(fd, buf, count);
288  }
289
290  if(GetConsoleMode(handle, &mode)) {
291    success = ReadConsole(handle, buf, curlx_uztoul(count), &rcount, NULL);
292  }
293  else {
294    success = ReadFile(handle, buf, curlx_uztoul(count), &rcount, NULL);
295  }
296  if(success) {
297    return rcount;
298  }
299
300  errno = GetLastError();
301  return -1;
302}
303#undef  read
304#define read(a,b,c) read_wincon(a,b,c)
305
306/*
307 * write-wrapper to support writing to stdout and stderr on Windows.
308 */
309static ssize_t write_wincon(int fd, const void *buf, size_t count)
310{
311  HANDLE handle = NULL;
312  DWORD mode, wcount = 0;
313  BOOL success;
314
315  if(fd == fileno(stdout)) {
316    handle = GetStdHandle(STD_OUTPUT_HANDLE);
317  }
318  else if(fd == fileno(stderr)) {
319    handle = GetStdHandle(STD_ERROR_HANDLE);
320  }
321  else {
322    return write(fd, buf, count);
323  }
324
325  if(GetConsoleMode(handle, &mode)) {
326    success = WriteConsole(handle, buf, curlx_uztoul(count), &wcount, NULL);
327  }
328  else {
329    success = WriteFile(handle, buf, curlx_uztoul(count), &wcount, NULL);
330  }
331  if(success) {
332    return wcount;
333  }
334
335  errno = GetLastError();
336  return -1;
337}
338#undef  write
339#define write(a,b,c) write_wincon(a,b,c)
340#endif
341
342/*
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.
347 */
348
349static ssize_t fullread(int filedes, void *buffer, size_t nbytes)
350{
351  int error;
352  ssize_t rc;
353  ssize_t nread = 0;
354
355  do {
356    rc = read(filedes, (unsigned char *)buffer + nread, nbytes - nread);
357
358    if(got_exit_signal) {
359      logmsg("signalled to die");
360      return -1;
361    }
362
363    if(rc < 0) {
364      error = errno;
365      if((error == EINTR) || (error == EAGAIN))
366        continue;
367      logmsg("reading from file descriptor: %d,", filedes);
368      logmsg("unrecoverable read() failure: (%d) %s",
369             error, strerror(error));
370      return -1;
371    }
372
373    if(rc == 0) {
374      logmsg("got 0 reading from stdin");
375      return 0;
376    }
377
378    nread += rc;
379
380  } while((size_t)nread < nbytes);
381
382  if(verbose)
383    logmsg("read %zd bytes", nread);
384
385  return nread;
386}
387
388/*
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.
393 */
394
395static ssize_t fullwrite(int filedes, const void *buffer, size_t nbytes)
396{
397  int error;
398  ssize_t wc;
399  ssize_t nwrite = 0;
400
401  do {
402    wc = write(filedes, (unsigned char *)buffer + nwrite, nbytes - nwrite);
403
404    if(got_exit_signal) {
405      logmsg("signalled to die");
406      return -1;
407    }
408
409    if(wc < 0) {
410      error = errno;
411      if((error == EINTR) || (error == EAGAIN))
412        continue;
413      logmsg("writing to file descriptor: %d,", filedes);
414      logmsg("unrecoverable write() failure: (%d) %s",
415             error, strerror(error));
416      return -1;
417    }
418
419    if(wc == 0) {
420      logmsg("put 0 writing to stdout");
421      return 0;
422    }
423
424    nwrite += wc;
425
426  } while((size_t)nwrite < nbytes);
427
428  if(verbose)
429    logmsg("wrote %zd bytes", nwrite);
430
431  return nwrite;
432}
433
434/*
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.
439 */
440
441static bool read_stdin(void *buffer, size_t nbytes)
442{
443  ssize_t nread = fullread(fileno(stdin), buffer, nbytes);
444  if(nread != (ssize_t)nbytes) {
445    logmsg("exiting...");
446    return FALSE;
447  }
448  return TRUE;
449}
450
451/*
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.
456 */
457
458static bool write_stdout(const void *buffer, size_t nbytes)
459{
460  ssize_t nwrite = fullwrite(fileno(stdout), buffer, nbytes);
461  if(nwrite != (ssize_t)nbytes) {
462    logmsg("exiting...");
463    return FALSE;
464  }
465  return TRUE;
466}
467
468static void lograw(unsigned char *buffer, ssize_t len)
469{
470  char data[120];
471  ssize_t i;
472  unsigned char *ptr = buffer;
473  char *optr = data;
474  ssize_t width=0;
475  int left = sizeof(data);
476
477  for(i=0; i<len; i++) {
478    switch(ptr[i]) {
479    case '\n':
480      snprintf(optr, left, "\\n");
481      width += 2;
482      optr += 2;
483      left-=2;
484      break;
485    case '\r':
486      snprintf(optr, left, "\\r");
487      width += 2;
488      optr += 2;
489      left-=2;
490      break;
491    default:
492      snprintf(optr, left, "%c", (ISGRAPH(ptr[i]) ||
493                                  ptr[i]==0x20) ?ptr[i]:'.');
494      width++;
495      optr++;
496      left--;
497      break;
498    }
499
500    if(width>60) {
501      logmsg("'%s'", data);
502      width = 0;
503      optr = data;
504      left = sizeof(data);
505    }
506  }
507  if(width)
508    logmsg("'%s'", data);
509}
510
511#ifdef USE_WINSOCK
512/*
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.
516 *
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.
520 *
521 * https://msdn.microsoft.com/en-us/library/windows/desktop/ms687028.aspx
522 * https://msdn.microsoft.com/en-us/library/windows/desktop/ms741572.aspx
523 */
524struct select_ws_wait_data {
525  HANDLE handle; /* actual handle to wait for during select */
526  HANDLE event;  /* internal event to abort waiting thread */
527};
528static DWORD WINAPI select_ws_wait_thread(LPVOID lpParameter)
529{
530  struct select_ws_wait_data *data;
531  HANDLE handle, handles[2];
532  INPUT_RECORD inputrecord;
533  LARGE_INTEGER size, pos;
534  DWORD type, length;
535
536  /* retrieve handles from internal structure */
537  data = (struct select_ws_wait_data *) lpParameter;
538  if(data) {
539    handle = data->handle;
540    handles[0] = data->event;
541    handles[1] = handle;
542    free(data);
543  }
544  else
545    return -1;
546
547  /* retrieve the type of file to wait on */
548  type = GetFileType(handle);
549  switch(type) {
550    case FILE_TYPE_DISK:
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.
555        *
556        * Approach: Loop till either the internal event is signalled
557        *           or if the end of the file has already been reached.
558        */
559      while(WaitForMultipleObjectsEx(1, handles, FALSE, 0, FALSE)
560            == WAIT_TIMEOUT) {
561        /* get total size of file */
562        length = 0;
563        size.QuadPart = 0;
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 */
569          pos.QuadPart = 0;
570          pos.LowPart = SetFilePointer(handle, 0, &pos.HighPart,
571                                       FILE_CURRENT);
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 */
577              SleepEx(0, FALSE);
578              continue;
579            }
580          }
581        }
582        /* there is some data available, stop waiting */
583        break;
584      }
585      break;
586
587    case FILE_TYPE_CHAR:
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.
591        *
592        * Approach: Loop till either the internal event is signalled
593        *           or we get signalled for an actual key-event.
594        */
595      while(WaitForMultipleObjectsEx(2, handles, FALSE, INFINITE, FALSE)
596            == WAIT_OBJECT_0 + 1) {
597        /* check if this is an actual console handle */
598        length = 0;
599        if(GetConsoleMode(handle, &length)) {
600          /* retrieve an event from the console buffer */
601          length = 0;
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);
607              continue;
608            }
609          }
610        }
611        /* there is some data available, stop waiting */
612        break;
613      }
614      break;
615
616    case FILE_TYPE_PIPE:
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.
620        *
621        * Approach: Loop till either the internal event is signalled
622        *           or there is data in the pipe available for reading.
623        */
624      while(WaitForMultipleObjectsEx(1, handles, FALSE, 0, FALSE)
625            == WAIT_TIMEOUT) {
626        /* peek into the pipe and retrieve the amount of data available */
627        length = 0;
628        if(PeekNamedPipe(handle, NULL, 0, NULL, &length, NULL)) {
629          /* if there is no data available, sleep and continue waiting */
630          if(length == 0) {
631            SleepEx(0, FALSE);
632            continue;
633          }
634        }
635        else {
636          /* if the pipe has been closed, sleep and continue waiting */
637          if(GetLastError() == ERROR_BROKEN_PIPE) {
638            SleepEx(0, FALSE);
639            continue;
640          }
641        }
642        /* there is some data available, stop waiting */
643        break;
644      }
645      break;
646
647    default:
648      /* The handle has an unknown type, try to wait on it */
649      WaitForMultipleObjectsEx(2, handles, FALSE, INFINITE, FALSE);
650      break;
651  }
652
653  return 0;
654}
655static HANDLE select_ws_wait(HANDLE handle, HANDLE event)
656{
657  struct select_ws_wait_data *data;
658  HANDLE thread = NULL;
659
660  /* allocate internal waiting data structure */
661  data = malloc(sizeof(struct select_ws_wait_data));
662  if(data) {
663    data->handle = handle;
664    data->event = event;
665
666    /* launch waiting thread */
667    thread = CreateThread(NULL, 0,
668                          &select_ws_wait_thread,
669                          data, 0, NULL);
670
671    /* free data if thread failed to launch */
672    if(!thread) {
673      free(data);
674    }
675  }
676
677  return thread;
678}
679struct 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) */
684};
685static int select_ws(int nfds, fd_set *readfds, fd_set *writefds,
686                     fd_set *exceptfds, struct timeval *timeout)
687{
688  DWORD milliseconds, wait, idx;
689  WSANETWORKEVENTS wsanetevents;
690  struct select_ws_data *data;
691  HANDLE handle, *handles;
692  curl_socket_t sock;
693  long networkevents;
694  WSAEVENT wsaevent;
695  int error, fds;
696  HANDLE waitevent = NULL;
697  DWORD nfd = 0, thd = 0, wsa = 0;
698  int ret = 0;
699
700  /* check if the input value is valid */
701  if(nfds < 0) {
702    errno = EINVAL;
703    return -1;
704  }
705
706  /* check if we got descriptors, sleep in case we got none */
707  if(!nfds) {
708    Sleep((timeout->tv_sec*1000)+(DWORD)(((double)timeout->tv_usec)/1000.0));
709    return 0;
710  }
711
712  /* create internal event to signal waiting threads */
713  waitevent = CreateEvent(NULL, TRUE, FALSE, NULL);
714  if(!waitevent) {
715    errno = ENOMEM;
716    return -1;
717  }
718
719  /* allocate internal array for the internal data */
720  data = malloc(nfds * sizeof(struct select_ws_data));
721  if(data == NULL) {
722    errno = ENOMEM;
723    return -1;
724  }
725
726  /* allocate internal array for the internal event handles */
727  handles = malloc(nfds * sizeof(HANDLE));
728  if(handles == NULL) {
729    free(data);
730    errno = ENOMEM;
731    return -1;
732  }
733
734  /* clear internal arrays */
735  memset(data, 0, nfds * sizeof(struct select_ws_data));
736  memset(handles, 0, nfds * sizeof(HANDLE));
737
738  /* loop over the handles in the input descriptor sets */
739  for(fds = 0; fds < nfds; fds++) {
740    networkevents = 0;
741    handles[nfd] = 0;
742
743    if(FD_ISSET(fds, readfds))
744      networkevents |= FD_READ|FD_ACCEPT|FD_CLOSE;
745
746    if(FD_ISSET(fds, writefds))
747      networkevents |= FD_WRITE|FD_CONNECT;
748
749    if(FD_ISSET(fds, exceptfds))
750      networkevents |= FD_OOB|FD_CLOSE;
751
752    /* only wait for events for which we actually care */
753    if(networkevents) {
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;
760        thd++;
761      }
762      else if(fds == fileno(stdout)) {
763        handles[nfd] = GetStdHandle(STD_OUTPUT_HANDLE);
764      }
765      else if(fds == fileno(stderr)) {
766        handles[nfd] = GetStdHandle(STD_ERROR_HANDLE);
767      }
768      else {
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;
777            wsa++;
778          }
779          else {
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;
785            thd++;
786          }
787        }
788      }
789      nfd++;
790    }
791  }
792
793  /* convert struct timeval to milliseconds */
794  if(timeout) {
795    milliseconds = ((timeout->tv_sec * 1000) + (timeout->tv_usec / 1000));
796  }
797  else {
798    milliseconds = INFINITE;
799  }
800
801  /* wait for one of the internal handles to trigger */
802  wait = WaitForMultipleObjectsEx(nfd, handles, FALSE, milliseconds, FALSE);
803
804  /* signal the event handle for the waiting threads */
805  SetEvent(waitevent);
806
807  /* loop over the internal handles returned in the descriptors */
808  for(idx = 0; idx < nfd; idx++) {
809    handle = handles[idx];
810    sock = data[idx].fd;
811    fds = curlx_sktosi(sock);
812
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);
821      }
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);
826      }
827      else {
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);
835
836          /* remove from descriptor set if not ready for write/connect */
837          if(!(wsanetevents.lNetworkEvents & (FD_WRITE|FD_CONNECT)))
838            FD_CLR(sock, writefds);
839
840          /* HACK:
841           * use exceptfds together with readfds to signal
842           * that the connection was closed by the client.
843           *
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.
848           */
849          /* remove from descriptor set if not exceptional */
850          if(!(wsanetevents.lNetworkEvents & (FD_OOB|FD_CLOSE)))
851            FD_CLR(sock, exceptfds);
852        }
853      }
854
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)) {
858        ret++;
859      }
860    }
861    else {
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);
866    }
867  }
868
869  for(fds = 0; fds < nfds; fds++) {
870    if(FD_ISSET(fds, readfds))
871      logmsg("select_ws: %d is readable", fds);
872
873    if(FD_ISSET(fds, writefds))
874      logmsg("select_ws: %d is writable", fds);
875
876    if(FD_ISSET(fds, exceptfds))
877      logmsg("select_ws: %d is excepted", fds);
878  }
879
880  for(idx = 0; idx < wsa; idx++) {
881    WSAEventSelect(data[idx].wsasock, NULL, 0);
882    WSACloseEvent(data[idx].wsaevent);
883  }
884
885  for(idx = 0; idx < thd; idx++) {
886    WaitForSingleObject(data[idx].thread, INFINITE);
887    CloseHandle(data[idx].thread);
888  }
889
890  CloseHandle(waitevent);
891
892  free(handles);
893  free(data);
894
895  return ret;
896}
897#define select(a,b,c,d,e) select_ws(a,b,c,d,e)
898#endif  /* USE_WINSOCK */
899
900/*
901  sockfdp is a pointer to an established stream or CURL_SOCKET_BAD
902
903  if sockfd is CURL_SOCKET_BAD, listendfd is a listening socket we must
904  accept()
905*/
906static bool juggle(curl_socket_t *sockfdp,
907                   curl_socket_t listenfd,
908                   enum sockmode *mode)
909{
910  struct timeval timeout;
911  fd_set fds_read;
912  fd_set fds_write;
913  fd_set fds_err;
914  curl_socket_t sockfd = CURL_SOCKET_BAD;
915  int maxfd = -99;
916  ssize_t rc;
917  ssize_t nread_socket;
918  ssize_t bytes_written;
919  ssize_t buffer_len;
920  int error = 0;
921
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];
925  char data[16];
926
927  if(got_exit_signal) {
928    logmsg("signalled to die, exiting...");
929    return FALSE;
930  }
931
932#ifdef HAVE_GETPPID
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 */
935  if(getppid() <= 1) {
936    logmsg("process becomes orphan, exiting");
937    return FALSE;
938  }
939#endif
940
941  timeout.tv_sec = 120;
942  timeout.tv_usec = 0;
943
944  FD_ZERO(&fds_read);
945  FD_ZERO(&fds_write);
946  FD_ZERO(&fds_err);
947
948  FD_SET((curl_socket_t)fileno(stdin), &fds_read);
949
950  switch(*mode) {
951
952  case PASSIVE_LISTEN:
953
954    /* server mode */
955    sockfd = listenfd;
956    /* there's always a socket to wait for */
957    FD_SET(sockfd, &fds_read);
958    maxfd = (int)sockfd;
959    break;
960
961  case PASSIVE_CONNECT:
962
963    sockfd = *sockfdp;
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 */
968    }
969    else {
970      /* there's always a socket to wait for */
971      FD_SET(sockfd, &fds_read);
972#ifdef USE_WINSOCK
973      FD_SET(sockfd, &fds_err);
974#endif
975      maxfd = (int)sockfd;
976    }
977    break;
978
979  case ACTIVE:
980
981    sockfd = *sockfdp;
982    /* sockfd turns CURL_SOCKET_BAD when our connection has been closed */
983    if(CURL_SOCKET_BAD != sockfd) {
984      FD_SET(sockfd, &fds_read);
985#ifdef USE_WINSOCK
986      FD_SET(sockfd, &fds_err);
987#endif
988      maxfd = (int)sockfd;
989    }
990    else {
991      logmsg("No socket to read on");
992      maxfd = 0;
993    }
994    break;
995
996  case ACTIVE_DISCONNECT:
997
998    logmsg("disconnected, no socket to read on");
999    maxfd = 0;
1000    sockfd = CURL_SOCKET_BAD;
1001    break;
1002
1003  } /* switch(*mode) */
1004
1005
1006  do {
1007
1008    /* select() blocking behavior call on blocking descriptors please */
1009
1010    rc = select(maxfd + 1, &fds_read, &fds_write, &fds_err, &timeout);
1011
1012    if(got_exit_signal) {
1013      logmsg("signalled to die, exiting...");
1014      return FALSE;
1015    }
1016
1017  } while((rc == -1) && ((error = errno) == EINTR));
1018
1019  if(rc < 0) {
1020    logmsg("select() failed with error: (%d) %s",
1021           error, strerror(error));
1022    return FALSE;
1023  }
1024
1025  if(rc == 0)
1026    /* timeout */
1027    return TRUE;
1028
1029
1030  if(FD_ISSET(fileno(stdin), &fds_read)) {
1031    /* read from stdin, commands/data to be dealt with and possibly passed on
1032       to the socket
1033
1034       protocol:
1035
1036       4 letter command + LF [mandatory]
1037
1038       4-digit hexadecimal data length + LF [if the command takes data]
1039       data                       [the data being as long as set above]
1040
1041       Commands:
1042
1043       DATA - plain pass-thru data
1044    */
1045
1046    if(!read_stdin(buffer, 5))
1047      return FALSE;
1048
1049    logmsg("Received %c%c%c%c (on stdin)",
1050           buffer[0], buffer[1], buffer[2], buffer[3]);
1051
1052    if(!memcmp("PING", buffer, 4)) {
1053      /* send reply on stdout, just proving we are alive */
1054      if(!write_stdout("PONG\n", 5))
1055        return FALSE;
1056    }
1057
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))
1065        return FALSE;
1066      if(!write_stdout(buffer, buffer_len))
1067        return FALSE;
1068    }
1069    else if(!memcmp("QUIT", buffer, 4)) {
1070      /* just die */
1071      logmsg("quits");
1072      return FALSE;
1073    }
1074    else if(!memcmp("DATA", buffer, 4)) {
1075      /* data IN => data OUT */
1076
1077      if(!read_stdin(buffer, 5))
1078        return FALSE;
1079
1080      buffer[5] = '\0';
1081
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);
1086        return FALSE;
1087      }
1088      logmsg("> %zd bytes data, server => client", buffer_len);
1089
1090      if(!read_stdin(buffer, buffer_len))
1091        return FALSE;
1092
1093      lograw(buffer, buffer_len);
1094
1095      if(*mode == PASSIVE_LISTEN) {
1096        logmsg("*** We are disconnected!");
1097        if(!write_stdout("DISC\n", 5))
1098          return FALSE;
1099      }
1100      else {
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);
1106        }
1107      }
1108    }
1109    else if(!memcmp("DISC", buffer, 4)) {
1110      /* disconnect! */
1111      if(!write_stdout("DISC\n", 5))
1112        return FALSE;
1113      if(sockfd != CURL_SOCKET_BAD) {
1114        logmsg("====> Client forcibly disconnected");
1115        sclose(sockfd);
1116        *sockfdp = CURL_SOCKET_BAD;
1117        if(*mode == PASSIVE_CONNECT)
1118          *mode = PASSIVE_LISTEN;
1119        else
1120          *mode = ACTIVE_DISCONNECT;
1121      }
1122      else
1123        logmsg("attempt to close already dead connection");
1124      return TRUE;
1125    }
1126  }
1127
1128
1129  if((sockfd != CURL_SOCKET_BAD) && (FD_ISSET(sockfd, &fds_read)) ) {
1130
1131    curl_socket_t newfd = CURL_SOCKET_BAD; /* newly accepted socket */
1132
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) {
1138        error = SOCKERRNO;
1139        logmsg("accept(%d, NULL, NULL) failed with error: (%d) %s",
1140               sockfd, error, strerror(error));
1141      }
1142      else {
1143        logmsg("====> Client connect");
1144        if(!write_stdout("CNCT\n", 5))
1145          return FALSE;
1146        *sockfdp = newfd; /* store the new socket */
1147        *mode = PASSIVE_CONNECT; /* we have connected */
1148      }
1149      return TRUE;
1150    }
1151
1152    /* read from socket, pass on data to stdout */
1153    nread_socket = sread(sockfd, buffer, sizeof(buffer));
1154
1155    if(nread_socket > 0) {
1156      snprintf(data, sizeof(data), "DATA\n%04zx\n", nread_socket);
1157      if(!write_stdout(data, 10))
1158        return FALSE;
1159      if(!write_stdout(buffer, nread_socket))
1160        return FALSE;
1161
1162      logmsg("< %zd bytes data, client => server", nread_socket);
1163      lograw(buffer, nread_socket);
1164    }
1165
1166    if(nread_socket <= 0
1167#ifdef USE_WINSOCK
1168       || FD_ISSET(sockfd, &fds_err)
1169#endif
1170       ) {
1171      logmsg("====> Client disconnect");
1172      if(!write_stdout("DISC\n", 5))
1173        return FALSE;
1174      sclose(sockfd);
1175      *sockfdp = CURL_SOCKET_BAD;
1176      if(*mode == PASSIVE_CONNECT)
1177        *mode = PASSIVE_LISTEN;
1178      else
1179        *mode = ACTIVE_DISCONNECT;
1180      return TRUE;
1181    }
1182  }
1183
1184  return TRUE;
1185}
1186
1187static curl_socket_t sockdaemon(curl_socket_t sock,
1188                                unsigned short *listenport)
1189{
1190  /* passive daemon style */
1191  srvr_sockaddr_union_t listener;
1192  int flag;
1193  int rc;
1194  int totdelay = 0;
1195  int maxretr = 10;
1196  int delay= 20;
1197  int attempt = 0;
1198  int error = 0;
1199
1200  do {
1201    attempt++;
1202    flag = 1;
1203    rc = setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
1204         (void *)&flag, sizeof(flag));
1205    if(rc) {
1206      error = SOCKERRNO;
1207      logmsg("setsockopt(SO_REUSEADDR) failed with error: (%d) %s",
1208             error, strerror(error));
1209      if(maxretr) {
1210        rc = wait_ms(delay);
1211        if(rc) {
1212          /* should not happen */
1213          error = errno;
1214          logmsg("wait_ms() failed with error: (%d) %s",
1215                 error, strerror(error));
1216          sclose(sock);
1217          return CURL_SOCKET_BAD;
1218        }
1219        if(got_exit_signal) {
1220          logmsg("signalled to die, exiting...");
1221          sclose(sock);
1222          return CURL_SOCKET_BAD;
1223        }
1224        totdelay += delay;
1225        delay *= 2; /* double the sleep for next attempt */
1226      }
1227    }
1228  } while(rc && maxretr--);
1229
1230  if(rc) {
1231    logmsg("setsockopt(SO_REUSEADDR) failed %d times in %d ms. Error: (%d) %s",
1232           attempt, totdelay, error, strerror(error));
1233    logmsg("Continuing anyway...");
1234  }
1235
1236  /* When the specified listener port is zero, it is actually a
1237     request to let the system choose a non-zero available port. */
1238
1239#ifdef ENABLE_IPV6
1240  if(!use_ipv6) {
1241#endif
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));
1247#ifdef ENABLE_IPV6
1248  }
1249  else {
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));
1255  }
1256#endif /* ENABLE_IPV6 */
1257  if(rc) {
1258    error = SOCKERRNO;
1259    logmsg("Error binding socket on port %hu: (%d) %s",
1260           *listenport, error, strerror(error));
1261    sclose(sock);
1262    return CURL_SOCKET_BAD;
1263  }
1264
1265  if(!*listenport) {
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;
1270#ifdef ENABLE_IPV6
1271    if(!use_ipv6)
1272#endif
1273      la_size = sizeof(localaddr.sa4);
1274#ifdef ENABLE_IPV6
1275    else
1276      la_size = sizeof(localaddr.sa6);
1277#endif
1278    memset(&localaddr.sa, 0, (size_t)la_size);
1279    if(getsockname(sock, &localaddr.sa, &la_size) < 0) {
1280      error = SOCKERRNO;
1281      logmsg("getsockname() failed with error: (%d) %s",
1282             error, strerror(error));
1283      sclose(sock);
1284      return CURL_SOCKET_BAD;
1285    }
1286    switch (localaddr.sa.sa_family) {
1287    case AF_INET:
1288      *listenport = ntohs(localaddr.sa4.sin_port);
1289      break;
1290#ifdef ENABLE_IPV6
1291    case AF_INET6:
1292      *listenport = ntohs(localaddr.sa6.sin6_port);
1293      break;
1294#endif
1295    default:
1296      break;
1297    }
1298    if(!*listenport) {
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.");
1304      sclose(sock);
1305      return CURL_SOCKET_BAD;
1306    }
1307  }
1308
1309  /* bindonly option forces no listening */
1310  if(bind_only) {
1311    logmsg("instructed to bind port without listening");
1312    return sock;
1313  }
1314
1315  /* start accepting connections */
1316  rc = listen(sock, 5);
1317  if(0 != rc) {
1318    error = SOCKERRNO;
1319    logmsg("listen(%d, 5) failed with error: (%d) %s",
1320           sock, error, strerror(error));
1321    sclose(sock);
1322    return CURL_SOCKET_BAD;
1323  }
1324
1325  return sock;
1326}
1327
1328
1329int main(int argc, char *argv[])
1330{
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";
1336  bool juggle_again;
1337  int rc;
1338  int error;
1339  int arg=1;
1340  enum sockmode mode = PASSIVE_LISTEN; /* default */
1341  const char *addr = NULL;
1342
1343  while(argc>arg) {
1344    if(!strcmp("--version", argv[arg])) {
1345      printf("sockfilt IPv4%s\n",
1346#ifdef ENABLE_IPV6
1347             "/IPv6"
1348#else
1349             ""
1350#endif
1351             );
1352      return 0;
1353    }
1354    else if(!strcmp("--verbose", argv[arg])) {
1355      verbose = TRUE;
1356      arg++;
1357    }
1358    else if(!strcmp("--pidfile", argv[arg])) {
1359      arg++;
1360      if(argc>arg)
1361        pidname = argv[arg++];
1362    }
1363    else if(!strcmp("--logfile", argv[arg])) {
1364      arg++;
1365      if(argc>arg)
1366        serverlogfile = argv[arg++];
1367    }
1368    else if(!strcmp("--ipv6", argv[arg])) {
1369#ifdef ENABLE_IPV6
1370      ipv_inuse = "IPv6";
1371      use_ipv6 = TRUE;
1372#endif
1373      arg++;
1374    }
1375    else if(!strcmp("--ipv4", argv[arg])) {
1376      /* for completeness, we support this option as well */
1377#ifdef ENABLE_IPV6
1378      ipv_inuse = "IPv4";
1379      use_ipv6 = FALSE;
1380#endif
1381      arg++;
1382    }
1383    else if(!strcmp("--bindonly", argv[arg])) {
1384      bind_only = TRUE;
1385      arg++;
1386    }
1387    else if(!strcmp("--port", argv[arg])) {
1388      arg++;
1389      if(argc>arg) {
1390        char *endptr;
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",
1395                  argv[arg]);
1396          return 0;
1397        }
1398        port = curlx_ultous(ulnum);
1399        arg++;
1400      }
1401    }
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. */
1405      arg++;
1406      if(argc>arg) {
1407        char *endptr;
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",
1412                  argv[arg]);
1413          return 0;
1414        }
1415        connectport = curlx_ultous(ulnum);
1416        arg++;
1417      }
1418    }
1419    else if(!strcmp("--addr", argv[arg])) {
1420      /* Set an IP address to use with --connect; otherwise use localhost */
1421      arg++;
1422      if(argc>arg) {
1423        addr = argv[arg];
1424        arg++;
1425      }
1426    }
1427    else {
1428      puts("Usage: sockfilt [option]\n"
1429           " --version\n"
1430           " --verbose\n"
1431           " --logfile [file]\n"
1432           " --pidfile [file]\n"
1433           " --ipv4\n"
1434           " --ipv6\n"
1435           " --bindonly\n"
1436           " --port [port]\n"
1437           " --connect [port]\n"
1438           " --addr [address]");
1439      return 0;
1440    }
1441  }
1442
1443#ifdef WIN32
1444  win32_init();
1445  atexit(win32_cleanup);
1446
1447  setmode(fileno(stdin), O_BINARY);
1448  setmode(fileno(stdout), O_BINARY);
1449  setmode(fileno(stderr), O_BINARY);
1450#endif
1451
1452  install_signal_handlers();
1453
1454#ifdef ENABLE_IPV6
1455  if(!use_ipv6)
1456#endif
1457    sock = socket(AF_INET, SOCK_STREAM, 0);
1458#ifdef ENABLE_IPV6
1459  else
1460    sock = socket(AF_INET6, SOCK_STREAM, 0);
1461#endif
1462
1463  if(CURL_SOCKET_BAD == sock) {
1464    error = SOCKERRNO;
1465    logmsg("Error creating socket: (%d) %s",
1466           error, strerror(error));
1467    write_stdout("FAIL\n", 5);
1468    goto sockfilt_cleanup;
1469  }
1470
1471  if(connectport) {
1472    /* Active mode, we should connect to the given port number */
1473    mode = ACTIVE;
1474#ifdef ENABLE_IPV6
1475    if(!use_ipv6) {
1476#endif
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;
1481      if(!addr)
1482        addr = "127.0.0.1";
1483      Curl_inet_pton(AF_INET, addr, &me.sa4.sin_addr);
1484
1485      rc = connect(sock, &me.sa, sizeof(me.sa4));
1486#ifdef ENABLE_IPV6
1487    }
1488    else {
1489      memset(&me.sa6, 0, sizeof(me.sa6));
1490      me.sa6.sin6_family = AF_INET6;
1491      me.sa6.sin6_port = htons(connectport);
1492      if(!addr)
1493        addr = "::1";
1494      Curl_inet_pton(AF_INET6, addr, &me.sa6.sin6_addr);
1495
1496      rc = connect(sock, &me.sa, sizeof(me.sa6));
1497    }
1498#endif /* ENABLE_IPV6 */
1499    if(rc) {
1500      error = SOCKERRNO;
1501      logmsg("Error connecting to port %hu: (%d) %s",
1502             connectport, error, strerror(error));
1503      write_stdout("FAIL\n", 5);
1504      goto sockfilt_cleanup;
1505    }
1506    logmsg("====> Client connect");
1507    msgsock = sock; /* use this as stream */
1508  }
1509  else {
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;
1515    }
1516    msgsock = CURL_SOCKET_BAD; /* no stream socket yet */
1517  }
1518
1519  logmsg("Running %s version", ipv_inuse);
1520
1521  if(connectport)
1522    logmsg("Connected to port %hu", connectport);
1523  else if(bind_only)
1524    logmsg("Bound without listening on port %hu", port);
1525  else
1526    logmsg("Listening on port %hu", port);
1527
1528  wrotepidfile = write_pidfile(pidname);
1529  if(!wrotepidfile) {
1530    write_stdout("FAIL\n", 5);
1531    goto sockfilt_cleanup;
1532  }
1533
1534  do {
1535    juggle_again = juggle(&msgsock, sock, &mode);
1536  } while(juggle_again);
1537
1538sockfilt_cleanup:
1539
1540  if((msgsock != sock) && (msgsock != CURL_SOCKET_BAD))
1541    sclose(msgsock);
1542
1543  if(sock != CURL_SOCKET_BAD)
1544    sclose(sock);
1545
1546  if(wrotepidfile)
1547    unlink(pidname);
1548
1549  restore_signal_handlers();
1550
1551  if(got_exit_signal) {
1552    logmsg("============> sockfilt exits with signal (%d)", exit_signal);
1553    /*
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.
1557     */
1558    raise(exit_signal);
1559  }
1560
1561  logmsg("============> sockfilt quits");
1562  return 0;
1563}
1564
1565