Add tvb_get and proto_tree_add for string-encoded byte arrays

This commit adds tvb_get_string_bytes and proto_tree_add_bytes_item routines for
getting GByteArrays fields from the tvb when they are encoded in ASCII hex string form.

The proto_tree_add_bytes_item routine is also usable for normal
binary encoded byte arrays, and has the advantage of retrieving
the array values even if there's no proto tree.

It also exposes the routines to Lua, both so that a Lua script can take
advantage of this, but also so I can write a testsuite to test the functions.

Change-Id: I112a038653df6482a5d0ebe7c95708f207319e20
Reviewed-on: https://code.wireshark.org/review/1158
Reviewed-by: Hadriel Kaplan <hadrielk@yahoo.com>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 29 insertions, 1 deletions

diff --git a/epan/strutil.h b/epan/strutil.h
index b9e8bdfcb7..f92136bbcd 100644
--- a/epan/strutil.h
+++ b/epan/strutil.h
@@ -112,6 +112,34 @@ WS_DLL_PUBLIC
 gboolean   hex_str_to_bytes(const char *hex_str, GByteArray *bytes,
     gboolean force_separators);
 
+/* Turn a string of hex digits with optional separators (defined by encoding)
+ * into a byte array. Unlike hex_str_to_bytes(), this will read as many hex-char
+ * pairs as possible and not error if it hits a non-hex-char; instead it just ends
+ * there. (i.e., like strtol()/atoi()/etc.) But it must see two hex chars at the
+ * beginning or it will return FALSE.
+ *
+ * @param hex_str The string of hex digits.
+ * @param bytes The GByteArray that will receive the bytes.  This
+ *        must be initialized by the caller.
+ * @param endptr if not NULL, is set to the char after the last hex character consumed.
+ * @param encoding set to one or more bitwise-or'ed ENC_SEP_* (see proto.h)
+ * @param fail_if_partial If set to TRUE, then the conversion fails if the whole
+ *    hex_str is not consumed.
+ * @return FALSE only if no bytes were generated; or if fail_if_partial is TRUE
+ *    and the entire hex_str was not consumed.
+ *
+ * If no ENC_SEP_* is set, then no separators are allowed. If multiple ENC_SEP_* are
+ * bit-or'ed, any of them can be a separator, but once the separator is seen then
+ * only its same type is accepted for the rest of the string. (i.e., it won't convert
+ * a "01:23-4567" even if ENC_SEP_COLON|ENC_SEP_DASH|ENC_SEP_NONE is passed in)
+ *
+ * This is done this way because it's likely a malformed scenario if they're mixed,
+ * and this routine is used by dissectors via tvb_get_string_XXX routines.
+ */
+WS_DLL_PUBLIC
+gboolean hex_str_to_bytes_encoding(const char *hex_str, GByteArray *bytes, const char **endptr,
+                                   const guint encoding, const gboolean fail_if_partial);
+
 /** Turn an RFC 3986 percent-encoded string into a byte array.
  *
  * @param uri_str The string of hex digits.
@@ -169,7 +197,7 @@ gboolean   oid_str_to_bytes(const char *oid_str, GByteArray *bytes);
  * @todo - Should this be in strutil.c?
  */
 WS_DLL_PUBLIC
-GByteArray *byte_array_dup(GByteArray *ba);
+GByteArray *byte_array_dup(const GByteArray *ba);
 
 /**
  * Compare the contents of two GByteArrays