Pass two strings in capture child messages, so the child can send

primary and secondary error messages and let the parent worry about how
to display them.  This means dumpcap doesn't need stub routines for
generating the formatting tags for the primary and secondary messages.

Have a separate message for capture filter errors, so that the parent
can check whether the capture filter looks like a display filter and
report the appropriate message.  This means that dumpcap doesn't need a
stub routine for compiling display filters (a stub routine also means
that Ethereal won't do the check for capture filters that look like
display filters!).

svn path=/trunk/; revision=17465

1 files changed, 74 insertions, 52 deletions

diff --git a/tethereal.c b/tethereal.c
index b0775b0625..176607996b 100644
--- a/tethereal.c
+++ b/tethereal.c
@@ -136,6 +136,12 @@ static guint32 cum_bytes = 0;
 static print_format_e print_format = PR_FMT_TEXT;
 static print_stream_t *print_stream;
 
+/*
+ * Standard secondary message for unexpected errors.
+ */
+static const char please_report[] =
+    "Please report this to the Ethereal developers";
+
 #ifdef HAVE_LIBPCAP
 /*
  * TRUE if we're to print packet counts to keep track of captured packets.
@@ -1499,7 +1505,6 @@ capture(void)
   int         volatile volatile_err = 0;
   int         volatile inpkts = 0;
   int         pcap_cnt;
-  char        errmsg[1024+1];
   condition  *volatile cnd_autostop_size = NULL;
   condition  *volatile cnd_autostop_duration = NULL;
   char       *descr;
@@ -1510,6 +1515,9 @@ capture(void)
   struct pcap_stat stats;
   gboolean    write_ok;
   gboolean    close_ok;
+  gboolean    cfilter_error = FALSE;
+  char        errmsg[1024+1];
+  char        secondary_errmsg[4096+1];
   int         save_file_fd;
 
   /* Initialize all data structures used for dissection. */
@@ -1521,8 +1529,8 @@ capture(void)
 
 
   /* open the "input file" from network interface or capture pipe */
-  if (!capture_loop_open_input(&capture_opts, &ld, errmsg, sizeof(errmsg)))
-  {
+  if (!capture_loop_open_input(&capture_opts, &ld, errmsg, sizeof(errmsg),
+                               secondary_errmsg, sizeof(secondary_errmsg))) {
     goto error;
   }
 
@@ -1542,20 +1550,33 @@ capture(void)
 
   /* open the output file (temporary/specified name/ringbuffer/named pipe/stdout) */
   if (!capture_loop_open_output(&capture_opts, &save_file_fd, errmsg, sizeof(errmsg))) {
+    *secondary_errmsg = '\0';
     goto error;    
   }
 
   /* init the input filter from the network interface (capture pipe will do nothing) */
-  if(!capture_loop_init_filter(ld.pcap_h, ld.from_cap_pipe, 
-      capture_opts.iface, capture_opts.cfilter, errmsg, sizeof errmsg)) 
-  {
-      goto error;
+  switch (capture_loop_init_filter(ld.pcap_h, ld.from_cap_pipe, capture_opts.iface, capture_opts.cfilter)) {
+
+  case INITFILTER_NO_ERROR:
+    break;
+
+  case INITFILTER_BAD_FILTER:
+    cfilter_error = TRUE;
+    g_snprintf(errmsg, sizeof(errmsg), "%s", pcap_geterr(ld.pcap_h));
+    *secondary_errmsg = '\0';
+    goto error;
+
+  case INITFILTER_OTHER_ERROR:
+    g_snprintf(errmsg, sizeof(errmsg), "Can't install filter (%s).",
+               pcap_geterr(ld.pcap_h));
+    g_snprintf(secondary_errmsg, sizeof(secondary_errmsg), "%s", please_report);
+    goto error;
   }
 
   /* set up to write to the already-opened capture output file/files */
-  if(!capture_loop_init_output(&capture_opts, save_file_fd, &ld, errmsg, sizeof errmsg))
-  {
-      goto error;
+  if(!capture_loop_init_output(&capture_opts, save_file_fd, &ld, errmsg, sizeof errmsg)) {
+    *secondary_errmsg = '\0';
+    goto error;
   }
 
   ld.wtap_linktype = wtap_pcap_encap_to_wtap_encap(ld.linktype);
@@ -1793,7 +1814,36 @@ error:
   }
   g_free(capture_opts.save_file);
   capture_opts.save_file = NULL;
-  cmdarg_err("%s", errmsg);
+  if (cfilter_error) {
+    dfilter_t   *rfcode = NULL;
+    if (dfilter_compile(capture_opts.cfilter, &rfcode) && rfcode != NULL) {
+      cmdarg_err(
+        "Invalid capture filter: \"%s\"!\n"
+        "\n"
+        "That string looks like a valid display filter; however, it isn't a valid\n"
+        "capture filter (%s).\n"
+        "\n"
+        "Note that display filters and capture filters don't have the same syntax,\n"
+        "so you can't use most display filter expressions as capture filters.\n"
+        "\n"
+        "See the User's Guide for a description of the capture filter syntax.",
+        capture_opts.cfilter, errmsg);
+      dfilter_free(rfcode);
+    } else {
+      cmdarg_err(
+        "Invalid capture filter: \"%s\"!\n"
+        "\n"
+        "That string isn't a valid capture filter (%s).\n"
+        "See the User's Guide for a description of the capture filter syntax.",
+        capture_opts.cfilter, errmsg);
+    }
+  } else {
+    cmdarg_err("%s", errmsg);
+    if (*secondary_errmsg != '\0') {
+      fprintf(stderr, "\n");
+      cmdarg_err_cont("%s", secondary_errmsg);
+    }
+  }
 #ifndef _WIN32
   if (ld.from_cap_pipe) {
     if (ld.cap_pipe_fd >= 0)
@@ -2971,6 +3021,19 @@ sync_pipe_drops_to_parent(int drops)
     g_assert(0);
 }
 
+/** the child encountered an error with a capture filter, notify the parent */
+void
+sync_pipe_cfilter_error_to_parent(const char *cfilter, const char *errmsg)
+{
+
+    cmdarg_err(
+      "Invalid capture filter: \"%s\"!\n"
+      "\n"
+      "That string isn't a valid capture filter (%s).\n"
+      "See the User's Guide for a description of the capture filter syntax.",
+      cfilter, errmsg);
+}
+
 /** the child encountered an error, notify the parent */
 void 
 sync_pipe_errmsg_to_parent(const char *errmsg)
@@ -2996,44 +3059,3 @@ signal_pipe_check_running(void)
 #endif  /* _WIN32 */
 
 #endif /* HAVE_LIBPCAP */
-
-
-/****************************************************************************************************************/
-/* simple_dialog "dummies", needed for capture_loop.c */
-
-
-#ifdef HAVE_LIBPCAP
-
-char *simple_dialog_primary_start(void)
-{
-    return "";
-}
-
-char *simple_dialog_primary_end(void)
-{
-    return "";
-}
-
-
-/* XXX - do we need to convert the string for the console? */
-char *
-simple_dialog_format_message(const char *msg)
-{
-    char *str;
-
-
-    if (msg) {
-#if GTK_MAJOR_VERSION < 2
-	str = g_strdup(msg);
-#else
-	str = xml_escape(msg);
-#endif
-    } else {
-	str = NULL;
-    }
-    return str;
-}
-
-#endif /* HAVE_LIBPCAP */
-
-