Customize 'permission denied' error.

From: Jan Safranek <jsafrane@redhat.com>

Add Fedora-specific message to error output when dumpcap cannot be started

because of permissions.

Signed-off-by: Jan Safranek <jsafrane@redhat.com>

diff -up wireshark-1.6.1/capture_sync.c.group-msg wireshark-1.6.1/capture_sync.c

--- wireshark-1.6.1/capture_sync.c.group-msg	2011-07-18 22:18:53.000000000 +0200

+++ wireshark-1.6.1/capture_sync.c	2011-07-21 10:52:28.962144991 +0200

@@ -351,6 +351,7 @@ sync_pipe_start(capture_options *capture

     gchar *signal_pipe_name;

 #else

     char errmsg[1024+1];

+    const char *securitymsg = "";

     int sync_pipe[2];                       /* pipe used to send messages from child to parent */

     enum PIPES { PIPE_READ, PIPE_WRITE };   /* Constants 0 and 1 for PIPE_READ and PIPE_WRITE */

 #endif

@@ -596,8 +597,10 @@ sync_pipe_start(capture_options *capture

       dup2(sync_pipe[PIPE_WRITE], 2);

       ws_close(sync_pipe[PIPE_READ]);

       execv(argv[0], (gpointer)argv);

-      g_snprintf(errmsg, sizeof errmsg, "Couldn't run %s in child process: %s",

-                argv[0], g_strerror(errno));

+      if (errno == EPERM || errno == EACCES)

+	      securitymsg = "\nAre you a member of the 'wireshark' group? Try running\n'usermod -a -G wireshark _your_username_' as root.";

+      g_snprintf(errmsg, sizeof errmsg, "Couldn't run %s in child process: %s%s",

+                argv[0], g_strerror(errno), securitymsg);

       sync_pipe_errmsg_to_parent(2, errmsg, "");

       /* Exit with "_exit()", so that we don't close the connection

@@ -687,6 +690,7 @@ sync_pipe_open_command(const char** argv

     int i;

 #else

     char errmsg[1024+1];

+    const char *securitymsg = "";

     int sync_pipe[2];                       /* pipe used to send messages from child to parent */

     int data_pipe[2];                       /* pipe used to send data from child to parent */

 #endif

@@ -811,8 +815,10 @@ sync_pipe_open_command(const char** argv

         ws_close(sync_pipe[PIPE_READ]);

         ws_close(sync_pipe[PIPE_WRITE]);

         execv(argv[0], (gpointer)argv);

-        g_snprintf(errmsg, sizeof errmsg, "Couldn't run %s in child process: %s",

-                   argv[0], g_strerror(errno));

+	if (errno == EPERM || errno == EACCES)

+		securitymsg = "\nAre you a member of the 'wireshark' group? Try running\n'usermod -a -G wireshark _your_username_' as root.";

+        g_snprintf(errmsg, sizeof errmsg, "Couldn't run %s in child process: %s%s",

+                   argv[0], g_strerror(errno), securitymsg);

         sync_pipe_errmsg_to_parent(2, errmsg, "");

         /* Exit with "_exit()", so that we don't close the connection