Add a new global flag "capture_child", which is TRUE if we're a child

process for a sync mode or fork mode capture.

Have that flag control whether we do things that *only* the parent or
*only* the child should do, rather than basing it solely on the setting
of "sync_mode" or "fork_mode" (or, in the case of stuff done in the
child process either in sync mode or fork mode, rather than basing it on
the setting of those flags at all).

Split "do_capture()" into a "run_capture()" routine that starts a
capture (possibly by forking off and execing a child process, if we're
supposed to do sync mode or fork mode captures), and that assumes the
file to which the capture is to write has already been opened and that
"cf.save_file_fd" is the file descriptor for that file, and a
"do_capture()" routine that creates a temporary file, getting an FD for
it, and calls "run_capture()".

Use "run_capture()", rather than "capture()", for "-k" captures, so that
it'll do the capture in a child process if "-S" or "-F" was specified
("do_capture()" won't do because "-k" captures should write to the file
specified by the "-w" flag, not some random temporary file).

For child process captures, however, just use "capture()" - the child
process shouldn't itself fork off a child if we're in sync or fork mode,
and should just write to the file whose file descriptor was specified by
the "-W" flag on the command line.

All this allows you to do "ethereal -S -w <file> -i <interface> -k" to
start a sync mode capture from the command line.

svn path=/trunk/; revision=740

1 files changed, 44 insertions, 29 deletions

diff --git a/gtk/main.c b/gtk/main.c
index 70fc7e5d1f..15c86ebff4 100644
--- a/gtk/main.c
+++ b/gtk/main.c
@@ -1,6 +1,6 @@
 /* main.c
  *
- * $Id: main.c,v 1.10 1999/09/30 06:11:50 guy Exp $
+ * $Id: main.c,v 1.11 1999/09/30 06:50:01 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -103,7 +103,6 @@ GtkWidget   *file_sel, *packet_list, *tree_view, *byte_view, *prog_bar,
             *info_bar;
 GdkFont     *m_r_font, *m_b_font;
 guint        main_ctx, file_ctx;
-gint         start_capture = 0;
 gchar        comp_info_str[256];
 gchar       *ethereal_path = NULL;
 gchar       *medium_font = MONO_MEDIUM_FONT;
@@ -119,6 +118,7 @@ int sync_mode;	/* fork a child to do the capture, and sync between them */
 int sync_pipe[2]; /* used to sync father */
 int fork_mode;	/* fork a child to do the capture */
 int quit_after_cap; /* Makes a "capture only mode". Implies -k */
+gboolean capture_child;	/* if this is the child for "-F"/"-S" */
 #endif
 
 /* Specifies byte offsets for object selected in tree */
@@ -462,7 +462,7 @@ print_usage(void) {
 int
 main(int argc, char *argv[])
 {
-  char               *command_name, *s;
+  char                *command_name, *s;
   int                  i;
 #ifndef WIN32
   int                  opt;
@@ -471,6 +471,9 @@ main(int argc, char *argv[])
   char                *pf_path;
   int                 pf_open_errno = 0;
   int                 err;
+#ifdef HAVE_LIBPCAP
+  gboolean            start_capture = FALSE;
+#endif
   GtkWidget           *window, *main_vbox, *menubar, *u_pane, *l_pane,
                       *bv_table, *bv_hscroll, *bv_vscroll, *stat_hbox, 
                       *tv_scrollw, *filter_bt, *filter_te;
@@ -501,7 +504,11 @@ main(int argc, char *argv[])
     proto_registrar_dump();
     exit(0);
   }
-  
+
+  /* Set "capture_child" to indicate whether this is going to be a child
+     process for a "-S" or "-F" capture? */
+  capture_child = (strcmp(command_name, CHILD_NAME) == 0);
+
   /* Let GTK get its args */
   gtk_init (&argc, &argv);
   
@@ -589,7 +596,7 @@ main(int argc, char *argv[])
 	break;
 #ifdef HAVE_LIBPCAP
       case 'k':        /* Start capture immediately */
-        start_capture = 1;
+        start_capture = TRUE;
         break;
 #endif
       case 'P':        /* Packet list pane height */
@@ -598,7 +605,7 @@ main(int argc, char *argv[])
 #ifdef HAVE_LIBPCAP
       case 'Q':        /* Quit after capture (just capture to file) */
         quit_after_cap = 1;
-        start_capture = 1;  /*** -Q implies -k !! ***/
+        start_capture = TRUE;  /*** -Q implies -k !! ***/
         break;
 #endif
       case 'r':        /* Read capture file xxx */
@@ -659,7 +666,7 @@ main(int argc, char *argv[])
       exit(1);
     }
 #ifdef HAVE_LIBPCAP
-    if (sync_mode || fork_mode) {
+    if (capture_child && (sync_mode || fork_mode)) {
       if (cf.save_file_fd == -1) {
         fprintf(stderr, "ethereal: \"-k\" flag was specified with \"-%c\" flag but without \"-W\" flag\n",
             (sync_mode ? 'S' : 'F'));
@@ -859,7 +866,7 @@ main(int argc, char *argv[])
   /* Is this a "child" ethereal, which is only supposed to pop up a
      capture box to let us stop the capture, and run a capture
      to a file that our parent will read? */
-  if (strcmp(command_name, CHILD_NAME) != 0) {
+  if (!capture_child) {
     /* No.  Pop up the main window, and read in a capture file if
        we were told to. */
 
@@ -907,28 +914,36 @@ main(int argc, char *argv[])
   }
 
 #ifdef HAVE_LIBPCAP
-  if (start_capture) {
-    /* "-k" was specified; start a capture. */
-
-    /* Try to open/create the file specified on the command line with
-       the "-w" flag.  (We already checked in "main()" that "-w" was
-       specified. */
-    cf.save_file_fd = open(cf.save_file, O_RDWR|O_TRUNC|O_CREAT, 0600);
-    if (cf.save_file_fd == -1) {
-      /* XXX - display the error in a message box, or on the command line? */
-      simple_dialog(ESD_TYPE_WARN, NULL,
-	"The file to which the capture would be saved (\"%s\")"
-	"could not be opened: %s.", cf.save_file, strerror(errno));
-    } else {
-      /* XXX - "capture()" used to do this, but we now do it in
-         "do_capture()", before calling "capture()"; will we ever
-         have a capture file open here?
-	 Yes, if "-r" was specified - but that's arguably silly, so
-	 perhaps we should treate that as an error. */
-      close_cap_file(&cf, info_bar, file_ctx);
-      capture();
+  if (capture_child) {
+    /* This is the child process for a sync mode or fork mode capture,
+       so just do the low-level work of a capture - don't create
+       a temporary file (so don't call "do_capture()"), and don't
+       fork off *another* child process (so don't call "run_capture()"). */
+
+       capture();
+  } else {
+    if (start_capture) {
+      /* "-k" was specified; start a capture. */
+
+      /* Try to open/create the file specified on the command line with
+         the "-w" flag.  (We already checked in "main()" that "-w" was
+         specified. */
+      cf.save_file_fd = open(cf.save_file, O_RDWR|O_TRUNC|O_CREAT, 0600);
+      if (cf.save_file_fd == -1) {
+        /* XXX - display the error in a message box, or on the command line? */
+        simple_dialog(ESD_TYPE_WARN, NULL,
+		"The file to which the capture would be saved (\"%s\")"
+		"could not be opened: %s.", cf.save_file, strerror(errno));
+      } else {
+        /* XXX - "capture()" used to do this, but we now do it in
+           "do_capture()", before calling "capture()"; will we ever
+           have a capture file open here?
+           Yes, if "-r" was specified - but that's arguably silly, so
+           perhaps we should treate that as an error. */
+        close_cap_file(&cf, info_bar, file_ctx);
+        run_capture();
+      }
     }
-    start_capture = 0;
   }
 #endif