Add new routines:

	tvb_get_string() - takes a tvbuff, an offset, and a length as
	arguments, allocates a buffer big enough to hold a string with
	the specified number of bytes plus an added null terminator
	(i.e., length+1), copies the specified number of bytes from the
	tvbuff, at the specified offset, to that buffer and puts in a
	null terminator, and returns a pointer to that buffer (or throws
	an exception before allocating the buffer if that many bytes
	aren't available in the tvbuff);

	tvb_get_stringz() - takes a tvbuff, an offset, and a pointer to
	a "gint" as arguments, gets the size of the null-terminated
	string starting at the specified offset in the tvbuff (throwing
	an exception if the null terminator isn't found), allocates a
	buffer big enough to hold that string, copies the string to that
	buffer, and returns a pointer to that buffer and stores the
	length of the string (including the terminating null) in the
	variable pointed to by the "gint" pointer.

Replace many pieces of code allocating a buffer and copying a string
with calls to "tvb_get_string()" (for one thing, "tvb_get_string()"
doesn't require you to remember that the argument to
"tvb_get_nstringz0()" is the size of the buffer into which you're
copying the string, which might be the length of the string to be copied
*plus 1*).

Don't use fixed-length buffers for null-terminated strings (even if the
code that generates those packets has a #define to limit the length of
the string).  Use "tvb_get_stringz()", instead.

In some cases where a value is fetched but is only used to pass an
argument to a "proto_tree_add_XXX" routine, use "proto_tree_add_item()"
instead.

svn path=/trunk/; revision=7859

1 files changed, 5 insertions, 7 deletions

diff --git a/packet-fix.c b/packet-fix.c
index 9a82d0fcab..fa5b245b50 100644
--- a/packet-fix.c
+++ b/packet-fix.c
@@ -2,7 +2,7 @@
  * Routines for Financial Information eXchange (FIX) Protocol dissection
  * Copyright 2000, PC Drew <drewpc@ibsncentral.com>
  *
- * $Id: packet-fix.c,v 1.5 2003/06/12 08:02:47 guy Exp $
+ * $Id: packet-fix.c,v 1.6 2003/06/12 08:33:29 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -867,8 +867,7 @@ dissect_fix(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
         col_clear(pinfo->cinfo, COL_INFO);
     }
 
-    value = g_malloc(value_len);
-    tvb_get_nstringz0(tvb, value_offset, value_len, value);
+    value = tvb_get_string(tvb, value_offset, value_len);
 
     if (check_col(pinfo->cinfo, COL_INFO)) {
         col_add_fstr(pinfo->cinfo, COL_INFO, "%s", (char *)g_datalist_get_data(&msg_types, value));
@@ -929,12 +928,10 @@ dissect_fix(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
                    packet. */
                 return TRUE;
             }
-            tag_str = g_malloc(tag_len);
-            tvb_get_nstringz0(tvb, field_offset, tag_len, tag_str);
+            tag_str = tvb_get_string(tvb, field_offset, tag_len);
             tag = atoi(tag_str);
 
-            value = g_malloc(value_len);
-            tvb_get_nstringz0(tvb, value_offset, value_len, value);
+            value = tvb_get_string(tvb, value_offset, value_len);
 
             switch(tag) {
                 case 1: /* Field Account */
@@ -2912,6 +2909,7 @@ dissect_fix(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
                     proto_tree_add_string(fix_tree, hf_fix_SideComplianceID, tvb, offset, field_len, value);
                     break;
                 default:
+                    /* XXX - it could be -1 if the tag isn't a number */
                     proto_tree_add_text(fix_tree, tvb, offset, field_len, "%i: %s", tag, value);
                     break;
             }