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

4 files changed, 93 insertions, 52 deletions

diff --git a/capture.c b/capture.c
index 2d22b54474..93c6785588 100644
--- a/capture.c
+++ b/capture.c
@@ -1,7 +1,7 @@
 /* capture.c
  * Routines for packet capture windows
  *
- * $Id: capture.c,v 1.73 1999/09/30 06:11:43 guy Exp $
+ * $Id: capture.c,v 1.74 1999/09/30 06:49:53 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -97,14 +97,11 @@ typedef struct _loop_data {
   wtap_dumper   *pdh;
 } loop_data;
 
+/* Create a temporary file and start a capture to it. */
 void
 do_capture(void)
 {
   char tmpname[128+1];
-  u_char c;
-  int i;
-  guint byte_count;
-  char *msg;
 
   /* Choose a random name for the capture buffer */
   cf.save_file_fd = create_tempfile(tmpname, sizeof tmpname, "ether");
@@ -123,7 +120,21 @@ do_capture(void)
   }
   cf.save_file = g_strdup(tmpname);
   cf.user_saved = 0;
-  
+
+  run_capture();
+}
+
+/* Start a capture to a file we've opened; "cf.save_file" is the
+   pathname of the file, and "cf.save_file_fd" is the file descriptor
+   we got when we opened it. */
+void
+run_capture(void)
+{ 
+  u_char c;
+  int i;
+  guint byte_count;
+  char *msg;
+
   if (sync_mode || fork_mode) {	/*  use fork() for capture */
     int  fork_child;
     char ssnap[24];
@@ -234,6 +245,7 @@ do_capture(void)
     capture();
 }
 
+/* Do the low-level work of a capture. */
 void
 capture(void)
 {
@@ -265,11 +277,12 @@ capture(void)
   pch = pcap_open_live(cf.iface, cf.snap, 1, 250, err_str);
 
   if (pch == NULL) {
-    /* Well, we couldn't start the capture. */
-    if (!sync_mode && !fork_mode) {
-      /* In fork mode, we shouldn't do any UI stuff until we pop up the
-         capture-progress window, and, since we couldn't start the
-	 capture, we haven't popped it up. */
+    /* Well, we couldn't start the capture.
+       If this is a child process that does the capturing in sync
+       mode or fork mode, it shouldn't do any UI stuff until we pop up the
+       capture-progress window, and, since we couldn't start the
+       capture, we haven't popped it up. */
+    if (!capture_child) {
       while (gtk_events_pending()) gtk_main_iteration();
     }
     snprintf(errmsg, sizeof errmsg,
@@ -337,14 +350,15 @@ capture(void)
     goto error;
   }
 
-  if (sync_mode) {
+  if (capture_child && sync_mode) {
     /* Well, we should be able to start capturing.
 
-       Sync out the capture file, so the header makes it to the file
-       system, and send a "capture started successfully and capture
-       file created" message to our parent so that they'll open the
-       capture file and update its windows to indicate that we have
-       a live capture in progress. */
+       This is the child process for a sync mode capture, so sync out
+       the capture file, so the header makes it to the file system,
+       and send a "capture started successfully and capture file created"
+       message to our parent so that they'll open the capture file and
+       update its windows to indicate that we have a live capture in
+       progress. */
     fflush(wtap_dump_file(ld.pdh));
     write(1, "0;", 2);
   }
@@ -447,7 +461,10 @@ capture(void)
 
       /* do sync here, too */
       fflush(wtap_dump_file(ld.pdh));
-      if (sync_mode && ld.sync_packets) {
+      if (capture_child && sync_mode && ld.sync_packets) {
+	/* This is the child process for a sync mode capture, so send
+	   our parent a message saying we've written out "ld.sync_packets"
+	   packets to the capture file. */
 	char tmp[20];
 	sprintf(tmp, "%d*", ld.sync_packets);
 	write(1, tmp, strlen(tmp));
@@ -515,8 +532,9 @@ error:
   /* We couldn't even start the capture, so get rid of the capture
      file. */
   unlink(cf.save_file); /* silently ignore error */
-  if (sync_mode) {
-    /* Send the error message to our parent, so they can display a
+  if (capture_child && sync_mode) {
+    /* This is the child process for a sync mode capture.
+       Send the error message to our parent, so they can display a
        dialog box containing it. */
     int msglen = strlen(errmsg);
     char lenbuf[10+1+1];
diff --git a/capture.h b/capture.h
index 2123a7c9ee..ff9e59519d 100644
--- a/capture.h
+++ b/capture.h
@@ -1,7 +1,7 @@
 /* capture.h
  * Definitions for packet capture windows
  *
- * $Id: capture.h,v 1.16 1999/09/30 06:11:44 guy Exp $
+ * $Id: capture.h,v 1.17 1999/09/30 06:49:54 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -51,7 +51,15 @@
 /* Name we give to the child process when doing a "-S" or "-F" capture. */
 #define	CHILD_NAME	"ethereal-capture"
 
+/* Create a temporary file and start a capture to it. */
 void   do_capture(void);
+
+/* Start a capture to a file we've opened; "cf.save_file" is the
+   pathname of the file, and "cf.save_file_fd" is the file descriptor
+   we got when we opened it. */
+void   run_capture(void);
+
+/* Do the low-level work of a capture. */
 void   capture(void);
 
 #endif /* HAVE_LIBPCAP */
diff --git a/globals.h b/globals.h
index bd4eaaa295..3fee9ae665 100644
--- a/globals.h
+++ b/globals.h
@@ -1,7 +1,7 @@
 /* globals.h
  * Global defines, etc.
  *
- * $Id: globals.h,v 1.8 1999/09/29 22:19:13 guy Exp $
+ * $Id: globals.h,v 1.9 1999/09/30 06:49:54 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -89,7 +89,6 @@ extern GtkWidget   *file_sel, *packet_list, *tree_view, *byte_view, *prog_bar,
             *info_bar;
 extern GdkFont     *m_r_font, *m_b_font;
 extern guint        main_ctx, file_ctx;
-extern gint         start_capture;
 extern gchar        comp_info_str[256];
 extern gchar       *ethereal_path;
 extern gchar       *medium_font;
@@ -107,6 +106,7 @@ extern int sync_mode;	/* allow sync */
 extern int sync_pipe[2]; /* used to sync father */
 extern int fork_mode;	/* fork a child to do the capture */
 extern int quit_after_cap; /* Makes a "capture only mode". Implies -k */
+extern gboolean capture_child;	/* if this is the child for "-F"/"-S" */
 #endif
 
 #define PF_DIR ".ethereal"
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