1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 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.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  * SPDX-License-Identifier: curl
22  *
23  ***************************************************************************/
24 #include "server_setup.h"
25 
26 #include <signal.h>
27 #ifdef HAVE_NETINET_IN_H
28 #include <netinet/in.h>
29 #endif
30 #ifdef _XOPEN_SOURCE_EXTENDED
31 /* This define is "almost" required to build on HPUX 11 */
32 #include <arpa/inet.h>
33 #endif
34 #ifdef HAVE_NETDB_H
35 #include <netdb.h>
36 #endif
37 #ifdef HAVE_POLL_H
38 #include <poll.h>
39 #elif defined(HAVE_SYS_POLL_H)
40 #include <sys/poll.h>
41 #endif
42 
43 #define ENABLE_CURLX_PRINTF
44 /* make the curlx header define all printf() functions to use the curlx_*
45    versions instead */
46 #include "curlx.h" /* from the private lib dir */
47 #include "getpart.h"
48 #include "util.h"
49 #include "timeval.h"
50 
51 #ifdef USE_WINSOCK
52 #undef  EINTR
53 #define EINTR    4 /* errno.h value */
54 #undef  EINVAL
55 #define EINVAL  22 /* errno.h value */
56 #endif
57 
58 static struct timeval tvnow(void);
59 
60 /* This function returns a pointer to STATIC memory. It converts the given
61  * binary lump to a hex formatted string usable for output in logs or
62  * whatever.
63  */
data_to_hex(char *data, size_t len)64 char *data_to_hex(char *data, size_t len)
65 {
66   static char buf[256*3];
67   size_t i;
68   char *optr = buf;
69   char *iptr = data;
70 
71   if(len > 255)
72     len = 255;
73 
74   for(i = 0; i < len; i++) {
75     if((data[i] >= 0x20) && (data[i] < 0x7f))
76       *optr++ = *iptr++;
77     else {
78       msnprintf(optr, 4, "%%%02x", *iptr++);
79       optr += 3;
80     }
81   }
82   *optr = 0; /* in case no sprintf was used */
83 
84   return buf;
85 }
86 
logmsg(const char *msg, ...)87 void logmsg(const char *msg, ...)
88 {
89   va_list ap;
90   char buffer[2048 + 1];
91   FILE *logfp;
92   struct timeval tv;
93   time_t sec;
94   struct tm *now;
95   char timebuf[20];
96   static time_t epoch_offset;
97   static int    known_offset;
98 
99   if(!serverlogfile) {
100     fprintf(stderr, "Error: serverlogfile not set\n");
101     return;
102   }
103 
104   tv = tvnow();
105   if(!known_offset) {
106     epoch_offset = time(NULL) - tv.tv_sec;
107     known_offset = 1;
108   }
109   sec = epoch_offset + tv.tv_sec;
110   /* !checksrc! disable BANNEDFUNC 1 */
111   now = localtime(&sec); /* not thread safe but we don't care */
112 
113   msnprintf(timebuf, sizeof(timebuf), "%02d:%02d:%02d.%06ld",
114             (int)now->tm_hour, (int)now->tm_min, (int)now->tm_sec,
115             (long)tv.tv_usec);
116 
117   va_start(ap, msg);
118   mvsnprintf(buffer, sizeof(buffer), msg, ap);
119   va_end(ap);
120 
121   logfp = fopen(serverlogfile, "ab");
122   if(logfp) {
123     fprintf(logfp, "%s %s\n", timebuf, buffer);
124     fclose(logfp);
125   }
126   else {
127     int error = errno;
128     fprintf(stderr, "fopen() failed with error: %d %s\n",
129             error, strerror(error));
130     fprintf(stderr, "Error opening file: %s\n", serverlogfile);
131     fprintf(stderr, "Msg not logged: %s %s\n", timebuf, buffer);
132   }
133 }
134 
135 #ifdef _WIN32
136 /* use instead of strerror() on generic Windows */
win32_strerror(int err, char *buf, size_t buflen)137 static const char *win32_strerror(int err, char *buf, size_t buflen)
138 {
139   if(!FormatMessageA((FORMAT_MESSAGE_FROM_SYSTEM |
140                       FORMAT_MESSAGE_IGNORE_INSERTS), NULL, (DWORD)err,
141                      LANG_NEUTRAL, buf, (DWORD)buflen, NULL))
142     msnprintf(buf, buflen, "Unknown error %d (%#x)", err, err);
143   return buf;
144 }
145 
146 /* use instead of perror() on generic windows */
win32_perror(const char *msg)147 void win32_perror(const char *msg)
148 {
149   char buf[512];
150   DWORD err = SOCKERRNO;
151   win32_strerror(err, buf, sizeof(buf));
152   if(msg)
153     fprintf(stderr, "%s: ", msg);
154   fprintf(stderr, "%s\n", buf);
155 }
156 
win32_init(void)157 void win32_init(void)
158 {
159 #ifdef USE_WINSOCK
160   WORD wVersionRequested;
161   WSADATA wsaData;
162   int err;
163 
164   wVersionRequested = MAKEWORD(2, 2);
165   err = WSAStartup(wVersionRequested, &wsaData);
166 
167   if(err) {
168     perror("Winsock init failed");
169     logmsg("Error initialising winsock -- aborting");
170     exit(1);
171   }
172 
173   if(LOBYTE(wsaData.wVersion) != LOBYTE(wVersionRequested) ||
174      HIBYTE(wsaData.wVersion) != HIBYTE(wVersionRequested) ) {
175     WSACleanup();
176     perror("Winsock init failed");
177     logmsg("No suitable winsock.dll found -- aborting");
178     exit(1);
179   }
180 #endif  /* USE_WINSOCK */
181 }
182 
win32_cleanup(void)183 void win32_cleanup(void)
184 {
185 #ifdef USE_WINSOCK
186   WSACleanup();
187 #endif  /* USE_WINSOCK */
188 
189   /* flush buffers of all streams regardless of their mode */
190   _flushall();
191 }
192 
193 /* socket-safe strerror (works on WinSock errors, too */
sstrerror(int err)194 const char *sstrerror(int err)
195 {
196   static char buf[512];
197   return win32_strerror(err, buf, sizeof(buf));
198 }
199 #endif  /* _WIN32 */
200 
201 /* set by the main code to point to where the test dir is */
202 const char *path = ".";
203 
test2fopen(long testno, const char *logdir)204 FILE *test2fopen(long testno, const char *logdir)
205 {
206   FILE *stream;
207   char filename[256];
208   /* first try the alternative, preprocessed, file */
209   msnprintf(filename, sizeof(filename), ALTTEST_DATA_PATH, logdir, testno);
210   stream = fopen(filename, "rb");
211   if(stream)
212     return stream;
213 
214   /* then try the source version */
215   msnprintf(filename, sizeof(filename), TEST_DATA_PATH, path, testno);
216   stream = fopen(filename, "rb");
217 
218   return stream;
219 }
220 
221 /*
222  * Portable function used for waiting a specific amount of ms.
223  * Waiting indefinitely with this function is not allowed, a
224  * zero or negative timeout value will return immediately.
225  *
226  * Return values:
227  *   -1 = system call error, or invalid timeout value
228  *    0 = specified timeout has elapsed
229  */
wait_ms(int timeout_ms)230 int wait_ms(int timeout_ms)
231 {
232 #if !defined(MSDOS) && !defined(USE_WINSOCK)
233 #ifndef HAVE_POLL_FINE
234   struct timeval pending_tv;
235 #endif
236   struct timeval initial_tv;
237   int pending_ms;
238 #endif
239   int r = 0;
240 
241   if(!timeout_ms)
242     return 0;
243   if(timeout_ms < 0) {
244     errno = EINVAL;
245     return -1;
246   }
247 #if defined(MSDOS)
248   delay(timeout_ms);
249 #elif defined(USE_WINSOCK)
250   Sleep((DWORD)timeout_ms);
251 #else
252   pending_ms = timeout_ms;
253   initial_tv = tvnow();
254   do {
255     int error;
256 #if defined(HAVE_POLL_FINE)
257     r = poll(NULL, 0, pending_ms);
258 #else
259     pending_tv.tv_sec = pending_ms / 1000;
260     pending_tv.tv_usec = (pending_ms % 1000) * 1000;
261     r = select(0, NULL, NULL, NULL, &pending_tv);
262 #endif /* HAVE_POLL_FINE */
263     if(r != -1)
264       break;
265     error = errno;
266     if(error && (error != EINTR))
267       break;
268     pending_ms = timeout_ms - (int)timediff(tvnow(), initial_tv);
269     if(pending_ms <= 0)
270       break;
271   } while(r == -1);
272 #endif /* USE_WINSOCK */
273   if(r)
274     r = -1;
275   return r;
276 }
277 
our_getpid(void)278 curl_off_t our_getpid(void)
279 {
280   curl_off_t pid;
281 
282   pid = (curl_off_t)getpid();
283 #if defined(_WIN32) || defined(_WIN32)
284   /* store pid + 65536 to avoid conflict with Cygwin/msys PIDs, see also:
285    * - https://cygwin.com/git/?p=newlib-cygwin.git;a=commit; ↵
286    *   h=b5e1003722cb14235c4f166be72c09acdffc62ea
287    * - https://cygwin.com/git/?p=newlib-cygwin.git;a=commit; ↵
288    *   h=448cf5aa4b429d5a9cebf92a0da4ab4b5b6d23fe
289    */
290   pid += 65536;
291 #endif
292   return pid;
293 }
294 
write_pidfile(const char *filename)295 int write_pidfile(const char *filename)
296 {
297   FILE *pidfile;
298   curl_off_t pid;
299 
300   pid = our_getpid();
301   pidfile = fopen(filename, "wb");
302   if(!pidfile) {
303     logmsg("Couldn't write pid file: %s %s", filename, strerror(errno));
304     return 0; /* fail */
305   }
306   fprintf(pidfile, "%" CURL_FORMAT_CURL_OFF_T "\n", pid);
307   fclose(pidfile);
308   logmsg("Wrote pid %" CURL_FORMAT_CURL_OFF_T " to %s", pid, filename);
309   return 1; /* success */
310 }
311 
312 /* store the used port number in a file */
write_portfile(const char *filename, int port)313 int write_portfile(const char *filename, int port)
314 {
315   FILE *portfile = fopen(filename, "wb");
316   if(!portfile) {
317     logmsg("Couldn't write port file: %s %s", filename, strerror(errno));
318     return 0; /* fail */
319   }
320   fprintf(portfile, "%d\n", port);
321   fclose(portfile);
322   logmsg("Wrote port %d to %s", port, filename);
323   return 1; /* success */
324 }
325 
set_advisor_read_lock(const char *filename)326 void set_advisor_read_lock(const char *filename)
327 {
328   FILE *lockfile;
329   int error = 0;
330   int res;
331 
332   do {
333     lockfile = fopen(filename, "wb");
334   } while(!lockfile && ((error = errno) == EINTR));
335   if(!lockfile) {
336     logmsg("Error creating lock file %s error: %d %s",
337            filename, error, strerror(error));
338     return;
339   }
340 
341   do {
342     res = fclose(lockfile);
343   } while(res && ((error = errno) == EINTR));
344   if(res)
345     logmsg("Error closing lock file %s error: %d %s",
346            filename, error, strerror(error));
347 }
348 
clear_advisor_read_lock(const char *filename)349 void clear_advisor_read_lock(const char *filename)
350 {
351   int error = 0;
352   int res;
353 
354   /*
355   ** Log all removal failures. Even those due to file not existing.
356   ** This allows to detect if unexpectedly the file has already been
357   ** removed by a process different than the one that should do this.
358   */
359 
360   do {
361     res = unlink(filename);
362   } while(res && ((error = errno) == EINTR));
363   if(res)
364     logmsg("Error removing lock file %s error: %d %s",
365            filename, error, strerror(error));
366 }
367 
368 
369 #if defined(_WIN32) && !defined(MSDOS)
370 
tvnow(void)371 static struct timeval tvnow(void)
372 {
373   /*
374   ** GetTickCount() is available on _all_ Windows versions from W95 up
375   ** to nowadays. Returns milliseconds elapsed since last system boot,
376   ** increases monotonically and wraps once 49.7 days have elapsed.
377   **
378   ** GetTickCount64() is available on Windows version from Windows Vista
379   ** and Windows Server 2008 up to nowadays. The resolution of the
380   ** function is limited to the resolution of the system timer, which
381   ** is typically in the range of 10 milliseconds to 16 milliseconds.
382   */
383   struct timeval now;
384 #if defined(_WIN32_WINNT) && (_WIN32_WINNT >= 0x0600)
385   ULONGLONG milliseconds = GetTickCount64();
386 #else
387   DWORD milliseconds = GetTickCount();
388 #endif
389   now.tv_sec = (long)(milliseconds / 1000);
390   now.tv_usec = (long)((milliseconds % 1000) * 1000);
391   return now;
392 }
393 
394 #elif defined(HAVE_CLOCK_GETTIME_MONOTONIC)
395 
tvnow(void)396 static struct timeval tvnow(void)
397 {
398   /*
399   ** clock_gettime() is granted to be increased monotonically when the
400   ** monotonic clock is queried. Time starting point is unspecified, it
401   ** could be the system start-up time, the Epoch, or something else,
402   ** in any case the time starting point does not change once that the
403   ** system has started up.
404   */
405   struct timeval now;
406   struct timespec tsnow;
407   if(0 == clock_gettime(CLOCK_MONOTONIC, &tsnow)) {
408     now.tv_sec = tsnow.tv_sec;
409     now.tv_usec = (int)(tsnow.tv_nsec / 1000);
410   }
411   /*
412   ** Even when the configure process has truly detected monotonic clock
413   ** availability, it might happen that it is not actually available at
414   ** run-time. When this occurs simply fallback to other time source.
415   */
416 #ifdef HAVE_GETTIMEOFDAY
417   else
418     (void)gettimeofday(&now, NULL);
419 #else
420   else {
421     now.tv_sec = time(NULL);
422     now.tv_usec = 0;
423   }
424 #endif
425   return now;
426 }
427 
428 #elif defined(HAVE_GETTIMEOFDAY)
429 
tvnow(void)430 static struct timeval tvnow(void)
431 {
432   /*
433   ** gettimeofday() is not granted to be increased monotonically, due to
434   ** clock drifting and external source time synchronization it can jump
435   ** forward or backward in time.
436   */
437   struct timeval now;
438   (void)gettimeofday(&now, NULL);
439   return now;
440 }
441 
442 #else
443 
tvnow(void)444 static struct timeval tvnow(void)
445 {
446   /*
447   ** time() returns the value of time in seconds since the Epoch.
448   */
449   struct timeval now;
450   now.tv_sec = time(NULL);
451   now.tv_usec = 0;
452   return now;
453 }
454 
455 #endif
456 
timediff(struct timeval newer, struct timeval older)457 long timediff(struct timeval newer, struct timeval older)
458 {
459   timediff_t diff = newer.tv_sec-older.tv_sec;
460   if(diff >= (LONG_MAX/1000))
461     return LONG_MAX;
462   else if(diff <= (LONG_MIN/1000))
463     return LONG_MIN;
464   return (long)(newer.tv_sec-older.tv_sec)*1000+
465     (long)(newer.tv_usec-older.tv_usec)/1000;
466 }
467 
468 /* vars used to keep around previous signal handlers */
469 
470 typedef void (*SIGHANDLER_T)(int);
471 
472 #ifdef SIGHUP
473 static SIGHANDLER_T old_sighup_handler  = SIG_ERR;
474 #endif
475 
476 #ifdef SIGPIPE
477 static SIGHANDLER_T old_sigpipe_handler = SIG_ERR;
478 #endif
479 
480 #ifdef SIGALRM
481 static SIGHANDLER_T old_sigalrm_handler = SIG_ERR;
482 #endif
483 
484 #ifdef SIGINT
485 static SIGHANDLER_T old_sigint_handler  = SIG_ERR;
486 #endif
487 
488 #ifdef SIGTERM
489 static SIGHANDLER_T old_sigterm_handler = SIG_ERR;
490 #endif
491 
492 #if defined(SIGBREAK) && defined(_WIN32)
493 static SIGHANDLER_T old_sigbreak_handler = SIG_ERR;
494 #endif
495 
496 #ifdef _WIN32
497 #ifdef _WIN32_WCE
498 static DWORD thread_main_id = 0;
499 #else
500 static unsigned int thread_main_id = 0;
501 #endif
502 static HANDLE thread_main_window = NULL;
503 static HWND hidden_main_window = NULL;
504 #endif
505 
506 /* var which if set indicates that the program should finish execution */
507 volatile int got_exit_signal = 0;
508 
509 /* if next is set indicates the first signal handled in exit_signal_handler */
510 volatile int exit_signal = 0;
511 
512 #ifdef _WIN32
513 /* event which if set indicates that the program should finish */
514 HANDLE exit_event = NULL;
515 #endif
516 
517 /* signal handler that will be triggered to indicate that the program
518  * should finish its execution in a controlled manner as soon as possible.
519  * The first time this is called it will set got_exit_signal to one and
520  * store in exit_signal the signal that triggered its execution.
521  */
exit_signal_handler(int signum)522 static void exit_signal_handler(int signum)
523 {
524   int old_errno = errno;
525   logmsg("exit_signal_handler: %d", signum);
526   if(got_exit_signal == 0) {
527     got_exit_signal = 1;
528     exit_signal = signum;
529 #ifdef _WIN32
530     if(exit_event)
531       (void)SetEvent(exit_event);
532 #endif
533   }
534   (void)signal(signum, exit_signal_handler);
535   errno = old_errno;
536 }
537 
538 #ifdef _WIN32
539 /* CTRL event handler for Windows Console applications to simulate
540  * SIGINT, SIGTERM and SIGBREAK on CTRL events and trigger signal handler.
541  *
542  * Background information from MSDN:
543  * SIGINT is not supported for any Win32 application. When a CTRL+C
544  * interrupt occurs, Win32 operating systems generate a new thread
545  * to specifically handle that interrupt. This can cause a single-thread
546  * application, such as one in UNIX, to become multithreaded and cause
547  * unexpected behavior.
548  * [...]
549  * The SIGILL and SIGTERM signals are not generated under Windows.
550  * They are included for ANSI compatibility. Therefore, you can set
551  * signal handlers for these signals by using signal, and you can also
552  * explicitly generate these signals by calling raise. Source:
553  * https://docs.microsoft.com/de-de/cpp/c-runtime-library/reference/signal
554  */
ctrl_event_handler(DWORD dwCtrlType)555 static BOOL WINAPI ctrl_event_handler(DWORD dwCtrlType)
556 {
557   int signum = 0;
558   logmsg("ctrl_event_handler: %lu", dwCtrlType);
559   switch(dwCtrlType) {
560 #ifdef SIGINT
561     case CTRL_C_EVENT: signum = SIGINT; break;
562 #endif
563 #ifdef SIGTERM
564     case CTRL_CLOSE_EVENT: signum = SIGTERM; break;
565 #endif
566 #ifdef SIGBREAK
567     case CTRL_BREAK_EVENT: signum = SIGBREAK; break;
568 #endif
569     default: return FALSE;
570   }
571   if(signum) {
572     logmsg("ctrl_event_handler: %lu -> %d", dwCtrlType, signum);
573     raise(signum);
574   }
575   return TRUE;
576 }
577 /* Window message handler for Windows applications to add support
578  * for graceful process termination via taskkill (without /f) which
579  * sends WM_CLOSE to all Windows of a process (even hidden ones).
580  *
581  * Therefore we create and run a hidden Window in a separate thread
582  * to receive and handle the WM_CLOSE message as SIGTERM signal.
583  */
main_window_proc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)584 static LRESULT CALLBACK main_window_proc(HWND hwnd, UINT uMsg,
585                                          WPARAM wParam, LPARAM lParam)
586 {
587   int signum = 0;
588   if(hwnd == hidden_main_window) {
589     switch(uMsg) {
590 #ifdef SIGTERM
591       case WM_CLOSE: signum = SIGTERM; break;
592 #endif
593       case WM_DESTROY: PostQuitMessage(0); break;
594     }
595     if(signum) {
596       logmsg("main_window_proc: %d -> %d", uMsg, signum);
597       raise(signum);
598     }
599   }
600   return DefWindowProc(hwnd, uMsg, wParam, lParam);
601 }
602 /* Window message queue loop for hidden main window, details see above.
603  */
604 #ifdef _WIN32_WCE
main_window_loop(LPVOID lpParameter)605 static DWORD WINAPI main_window_loop(LPVOID lpParameter)
606 #else
607 #include <process.h>
608 static unsigned int WINAPI main_window_loop(void *lpParameter)
609 #endif
610 {
611   WNDCLASS wc;
612   BOOL ret;
613   MSG msg;
614 
615   ZeroMemory(&wc, sizeof(wc));
616   wc.lpfnWndProc = (WNDPROC)main_window_proc;
617   wc.hInstance = (HINSTANCE)lpParameter;
618   wc.lpszClassName = TEXT("MainWClass");
619   if(!RegisterClass(&wc)) {
620     perror("RegisterClass failed");
621     return (DWORD)-1;
622   }
623 
624   hidden_main_window = CreateWindowEx(0, TEXT("MainWClass"),
625                                       TEXT("Recv WM_CLOSE msg"),
626                                       WS_OVERLAPPEDWINDOW,
627                                       CW_USEDEFAULT, CW_USEDEFAULT,
628                                       CW_USEDEFAULT, CW_USEDEFAULT,
629                                       (HWND)NULL, (HMENU)NULL,
630                                       wc.hInstance, (LPVOID)NULL);
631   if(!hidden_main_window) {
632     perror("CreateWindowEx failed");
633     return (DWORD)-1;
634   }
635 
636   do {
637     ret = GetMessage(&msg, NULL, 0, 0);
638     if(ret == -1) {
639       perror("GetMessage failed");
640       return (DWORD)-1;
641     }
642     else if(ret) {
643       if(msg.message == WM_APP) {
644         DestroyWindow(hidden_main_window);
645       }
646       else if(msg.hwnd && !TranslateMessage(&msg)) {
647         DispatchMessage(&msg);
648       }
649     }
650   } while(ret);
651 
652   hidden_main_window = NULL;
653   return (DWORD)msg.wParam;
654 }
655 #endif
656 
set_signal(int signum, SIGHANDLER_T handler, bool restartable)657 static SIGHANDLER_T set_signal(int signum, SIGHANDLER_T handler,
658                                bool restartable)
659 {
660 #if defined(HAVE_SIGACTION) && defined(SA_RESTART)
661   struct sigaction sa, oldsa;
662 
663   memset(&sa, 0, sizeof(sa));
664   sa.sa_handler = handler;
665   sigemptyset(&sa.sa_mask);
666   sigaddset(&sa.sa_mask, signum);
667   sa.sa_flags = restartable? SA_RESTART: 0;
668 
669   if(sigaction(signum, &sa, &oldsa))
670     return SIG_ERR;
671 
672   return oldsa.sa_handler;
673 #else
674   SIGHANDLER_T oldhdlr = signal(signum, handler);
675 
676 #ifdef HAVE_SIGINTERRUPT
677   if(oldhdlr != SIG_ERR)
678     siginterrupt(signum, (int) restartable);
679 #else
680   (void) restartable;
681 #endif
682 
683   return oldhdlr;
684 #endif
685 }
686 
install_signal_handlers(bool keep_sigalrm)687 void install_signal_handlers(bool keep_sigalrm)
688 {
689 #ifdef _WIN32
690 #ifdef _WIN32_WCE
691   typedef HANDLE curl_win_thread_handle_t;
692 #else
693   typedef uintptr_t curl_win_thread_handle_t;
694 #endif
695   curl_win_thread_handle_t thread;
696   /* setup windows exit event before any signal can trigger */
697   exit_event = CreateEvent(NULL, TRUE, FALSE, NULL);
698   if(!exit_event)
699     logmsg("cannot create exit event");
700 #endif
701 #ifdef SIGHUP
702   /* ignore SIGHUP signal */
703   old_sighup_handler = set_signal(SIGHUP, SIG_IGN, FALSE);
704   if(old_sighup_handler == SIG_ERR)
705     logmsg("cannot install SIGHUP handler: %s", strerror(errno));
706 #endif
707 #ifdef SIGPIPE
708   /* ignore SIGPIPE signal */
709   old_sigpipe_handler = set_signal(SIGPIPE, SIG_IGN, FALSE);
710   if(old_sigpipe_handler == SIG_ERR)
711     logmsg("cannot install SIGPIPE handler: %s", strerror(errno));
712 #endif
713 #ifdef SIGALRM
714   if(!keep_sigalrm) {
715     /* ignore SIGALRM signal */
716     old_sigalrm_handler = set_signal(SIGALRM, SIG_IGN, FALSE);
717     if(old_sigalrm_handler == SIG_ERR)
718       logmsg("cannot install SIGALRM handler: %s", strerror(errno));
719   }
720 #else
721   (void)keep_sigalrm;
722 #endif
723 #ifdef SIGINT
724   /* handle SIGINT signal with our exit_signal_handler */
725   old_sigint_handler = set_signal(SIGINT, exit_signal_handler, TRUE);
726   if(old_sigint_handler == SIG_ERR)
727     logmsg("cannot install SIGINT handler: %s", strerror(errno));
728 #endif
729 #ifdef SIGTERM
730   /* handle SIGTERM signal with our exit_signal_handler */
731   old_sigterm_handler = set_signal(SIGTERM, exit_signal_handler, TRUE);
732   if(old_sigterm_handler == SIG_ERR)
733     logmsg("cannot install SIGTERM handler: %s", strerror(errno));
734 #endif
735 #if defined(SIGBREAK) && defined(_WIN32)
736   /* handle SIGBREAK signal with our exit_signal_handler */
737   old_sigbreak_handler = set_signal(SIGBREAK, exit_signal_handler, TRUE);
738   if(old_sigbreak_handler == SIG_ERR)
739     logmsg("cannot install SIGBREAK handler: %s", strerror(errno));
740 #endif
741 #ifdef _WIN32
742   if(!SetConsoleCtrlHandler(ctrl_event_handler, TRUE))
743     logmsg("cannot install CTRL event handler");
744 #ifdef _WIN32_WCE
745   thread = CreateThread(NULL, 0, &main_window_loop,
746                         (LPVOID)GetModuleHandle(NULL), 0, &thread_main_id);
747 #else
748   thread = _beginthreadex(NULL, 0, &main_window_loop,
749                           (void *)GetModuleHandle(NULL), 0, &thread_main_id);
750 #endif
751   thread_main_window = (HANDLE)thread;
752   if(!thread_main_window || !thread_main_id)
753     logmsg("cannot start main window loop");
754 #endif
755 }
756 
restore_signal_handlers(bool keep_sigalrm)757 void restore_signal_handlers(bool keep_sigalrm)
758 {
759 #ifdef SIGHUP
760   if(SIG_ERR != old_sighup_handler)
761     (void) set_signal(SIGHUP, old_sighup_handler, FALSE);
762 #endif
763 #ifdef SIGPIPE
764   if(SIG_ERR != old_sigpipe_handler)
765     (void) set_signal(SIGPIPE, old_sigpipe_handler, FALSE);
766 #endif
767 #ifdef SIGALRM
768   if(!keep_sigalrm) {
769     if(SIG_ERR != old_sigalrm_handler)
770       (void) set_signal(SIGALRM, old_sigalrm_handler, FALSE);
771   }
772 #else
773   (void)keep_sigalrm;
774 #endif
775 #ifdef SIGINT
776   if(SIG_ERR != old_sigint_handler)
777     (void) set_signal(SIGINT, old_sigint_handler, FALSE);
778 #endif
779 #ifdef SIGTERM
780   if(SIG_ERR != old_sigterm_handler)
781     (void) set_signal(SIGTERM, old_sigterm_handler, FALSE);
782 #endif
783 #if defined(SIGBREAK) && defined(_WIN32)
784   if(SIG_ERR != old_sigbreak_handler)
785     (void) set_signal(SIGBREAK, old_sigbreak_handler, FALSE);
786 #endif
787 #ifdef _WIN32
788   (void)SetConsoleCtrlHandler(ctrl_event_handler, FALSE);
789   if(thread_main_window && thread_main_id) {
790     if(PostThreadMessage(thread_main_id, WM_APP, 0, 0)) {
791       if(WaitForSingleObjectEx(thread_main_window, INFINITE, TRUE)) {
792         if(CloseHandle(thread_main_window)) {
793           thread_main_window = NULL;
794           thread_main_id = 0;
795         }
796       }
797     }
798   }
799   if(exit_event) {
800     if(CloseHandle(exit_event)) {
801       exit_event = NULL;
802     }
803   }
804 #endif
805 }
806 
807 #ifdef USE_UNIX_SOCKETS
808 
bind_unix_socket(curl_socket_t sock, const char *unix_socket, struct sockaddr_un *sau)809 int bind_unix_socket(curl_socket_t sock, const char *unix_socket,
810         struct sockaddr_un *sau) {
811     int error;
812     int rc;
813 
814     memset(sau, 0, sizeof(struct sockaddr_un));
815     sau->sun_family = AF_UNIX;
816     strncpy(sau->sun_path, unix_socket, sizeof(sau->sun_path) - 1);
817     rc = bind(sock, (struct sockaddr*)sau, sizeof(struct sockaddr_un));
818     if(0 != rc && SOCKERRNO == EADDRINUSE) {
819       struct_stat statbuf;
820       /* socket already exists. Perhaps it is stale? */
821       curl_socket_t unixfd = socket(AF_UNIX, SOCK_STREAM, 0);
822       if(CURL_SOCKET_BAD == unixfd) {
823         logmsg("Failed to create socket at %s: (%d) %s",
824                unix_socket, SOCKERRNO, sstrerror(SOCKERRNO));
825         return -1;
826       }
827       /* check whether the server is alive */
828       rc = connect(unixfd, (struct sockaddr*)sau, sizeof(struct sockaddr_un));
829       error = SOCKERRNO;
830       sclose(unixfd);
831       if(0 != rc && ECONNREFUSED != error) {
832         logmsg("Failed to connect to %s: (%d) %s",
833                unix_socket, error, sstrerror(error));
834         return rc;
835       }
836       /* socket server is not alive, now check if it was actually a socket. */
837 #ifdef _WIN32
838       /* Windows does not have lstat function. */
839       rc = curlx_win32_stat(unix_socket, &statbuf);
840 #else
841       rc = lstat(unix_socket, &statbuf);
842 #endif
843       if(0 != rc) {
844         logmsg("Error binding socket, failed to stat %s: (%d) %s",
845                unix_socket, errno, strerror(errno));
846         return rc;
847       }
848 #ifdef S_IFSOCK
849       if((statbuf.st_mode & S_IFSOCK) != S_IFSOCK) {
850         logmsg("Error binding socket, failed to stat %s", unix_socket);
851         return -1;
852       }
853 #endif
854       /* dead socket, cleanup and retry bind */
855       rc = unlink(unix_socket);
856       if(0 != rc) {
857         logmsg("Error binding socket, failed to unlink %s: (%d) %s",
858                unix_socket, errno, strerror(errno));
859         return rc;
860       }
861       /* stale socket is gone, retry bind */
862       rc = bind(sock, (struct sockaddr*)sau, sizeof(struct sockaddr_un));
863     }
864     return rc;
865 }
866 #endif
867