Fixed webhttrack incompatibility with Chrome

  * closes:#53

Also fixed HTML-escaping issues inside webhttrack

Rationale: The webhttrack script made the wrong assumption that once the "browse" command returned, it meant the user killed the navigation window, and it had to kill the server itself. However, modern browsers tend to "attach" to an existing session (creating a new tab, for example, within an existing window), causing the browsing command to return immediately, thus causing the server to be killed immediately by the webhttrack script. I have rewritten the logic behind, and now the server is able to kill himself if the parent script dies, AND if the browsing client did not make any activity for two minutes. The "activity" can be any browser/refreshed page, or the internal "ping" iframe (which pings the server every 30 seconds). With this model, we *should* be compatible with old browsers, and modern ones.

1 files changed, 83 insertions, 4 deletions

diff --git a/src/htsweb.c b/src/htsweb.c
index c695f3a..c189c0a 100644
--- a/src/htsweb.c
+++ b/src/htsweb.c
@@ -77,6 +77,13 @@ Please visit our Website: http://www.httrack.com
 #else
 #endif
 
+#undef DEBUG
+#if 0
+#define DEBUG(A) do { A; } while(0)
+#else
+#define DEBUG(A) do {} while(0)
+#endif
+
 static htsmutex refreshMutex = HTSMUTEX_INIT;
 
 static int help_server(char *dest_path, int defaultPort);
@@ -91,10 +98,59 @@ static void htsweb_sig_brpipe(int code) {
   /* ignore */
 }
 
+/* Number of background threads */
+static int background_threads = 0;
+
+/* Server/client ping handling */
+static htsmutex pingMutex = HTSMUTEX_INIT;
+static unsigned int pingId = 0;
+static unsigned int getPingId(void) {
+  unsigned int id;
+  hts_mutexlock(&pingMutex);
+  id = pingId;
+  hts_mutexrelease(&pingMutex);
+  return id;
+}
+static void ping(void) {
+  hts_mutexlock(&pingMutex);
+  pingId++;
+  hts_mutexrelease(&pingMutex);
+}
+
+static void client_ping(void *pP) {
+#ifndef _WIN32
+  /* Timeout to 120s ; normally client pings every 30 second */
+  static int timeout = 120;
+  /* Wait for parent to die (legacy browser mode). */
+  const pid_t ppid = (pid_t) (uintptr_t) pP;
+  while (!kill(ppid, 0)) {
+    sleep(1);
+  }
+  /* Parent (webhttrack script) is dead: is client pinging ? */
+  for(;;) {
+    unsigned int id = getPingId();
+    sleep(timeout);
+    if (getPingId() == id) {
+      break;
+    }
+  }
+  /* Die! */
+  fprintf(stderr,
+          "Parent process %d died, and client did not ping for %ds: exiting!\n",
+          (int) ppid, timeout);
+  exit(EXIT_FAILURE);
+#endif
+}
+
+static void pingHandler(void*arg) {
+  ping();
+}
+
 int main(int argc, char *argv[]) {
   int i;
   int ret = 0;
   int defaultPort = 0;
+  int parentPid = 0;
 
   printf("Initialzing the server..\n");
 
@@ -120,7 +176,7 @@ int main(int argc, char *argv[]) {
   if (argc < 2 || (argc % 2) != 0) {
     fprintf(stderr, "** Warning: use the webhttrack frontend if available\n");
     fprintf(stderr,
-            "usage: %s [--port <port>] <path-to-html-root-dir> [key value [key value]..]\n",
+            "usage: %s [--port <port>] [--ppid parent-pid] <path-to-html-root-dir> [key value [key value]..]\n",
             argv[0]);
     fprintf(stderr, "example: %s /usr/share/httrack/\n", argv[0]);
     return 1;
@@ -200,14 +256,22 @@ int main(int argc, char *argv[]) {
 
   /* set commandline keys */
   for(i = 2; i < argc; i += 2) {
-    if (strcmp(argv[i], "--port") == 0) {
+    if (strcmp(argv[i], "--port") == 0 && i + 1 < argc) {
       if (sscanf(argv[i + 1], "%d", &defaultPort) != 1 || defaultPort < 0
           || defaultPort >= 65535) {
         fprintf(stderr, "couldn't set the port number to %s\n", argv[i + 1]);
         return -1;
       }
-    } else {
+    } else if (strcmp(argv[i], "--ppid") == 0 && i + 1 < argc) {
+      if (sscanf(argv[i + 1], "%u", &parentPid) != 1) {
+        fprintf(stderr, "couldn't set the parent PID to %s\n", argv[i + 1]);
+        return -1;
+      }
+    } else if (i + 1 < argc) {
       smallserver_setkey(argv[i], argv[i + 1]);
+    } else {
+      fprintf(stderr, "Error in commandline!\n");
+      return -1;
     }
   }
 
@@ -216,6 +280,13 @@ int main(int argc, char *argv[]) {
   signal(SIGPIPE, htsweb_sig_brpipe);   // broken pipe (write into non-opened socket)
 #endif
 
+  /* pinger */
+  if (parentPid > 0) {
+    hts_newthread(client_ping, (void *) (uintptr_t) parentPid);
+    background_threads++; /* Do not wait for this thread! */
+    smallserver_setpinghandler(pingHandler, NULL);
+  }
+
   /* launch */
   ret = help_server(argv[1], defaultPort);
 
@@ -292,6 +363,7 @@ static void back_launch_cmd(void *pP) {
 
   /* finished */
   commandEnd = 1;
+  DEBUG(fprintf(stderr, "commandEnd=1\n"));
 
   /* free */
   free(cmd);
@@ -301,7 +373,9 @@ static void back_launch_cmd(void *pP) {
 
 void webhttrack_main(char *cmd) {
   commandRunning = 1;
+  DEBUG(fprintf(stderr, "commandRunning=1\n"));
   hts_newthread(back_launch_cmd, (void *) strdup(cmd));
+  background_threads++; /* Do not wait for this thread! */
 }
 
 void webhttrack_lock(void) {
@@ -339,8 +413,11 @@ static int webhttrack_runmain(httrackp * opt, int argc, char **argv) {
   CHAIN_FUNCTION(opt, sendhead, htsshow_sendheader, NULL);
   CHAIN_FUNCTION(opt, receivehead, htsshow_receiveheader, NULL);
 
+  /* Rock'in! */
   ret = hts_main2(argc, argv, opt);
-  htsthread_wait_n(1);
+
+  /* Wait for pending threads to finish */
+  htsthread_wait_n(background_threads);
 
   return ret;
 }
@@ -404,12 +481,14 @@ void __cdecl htsshow_init(t_hts_callbackarg * carg) {
 void __cdecl htsshow_uninit(t_hts_callbackarg * carg) {
 }
 int __cdecl htsshow_start(t_hts_callbackarg * carg, httrackp * opt) {
+  DEBUG(fprintf(stderr, "htsshow_start()\n"));
   return 1;
 }
 int __cdecl htsshow_chopt(t_hts_callbackarg * carg, httrackp * opt) {
   return htsshow_start(carg, opt);
 }
 int __cdecl htsshow_end(t_hts_callbackarg * carg, httrackp * opt) {
+  DEBUG(fprintf(stderr, "htsshow_end()\n"));
   return 1;
 }
 int __cdecl htsshow_preprocesshtml(t_hts_callbackarg * carg, httrackp * opt,