[PATCH 1/2] wireshark: Switch to tvb_bytes_to_str()

[Michal Privoznik]

When the dissector sees a byte sequence that is either an opaque
data (xdr_opaque) or a byte sequence (xdr_bytes) it formats the
bytes as a hex numbers using our own implementation. But
wireshark already provides a function for it: tvb_bytes_to_str().
NB, the reason why it returns a const string is so that callers
don't try to free it - the string is allocated using an allocator
which will decide when to free it.

The wireshark formatter was introduced in wireshark commit of
v1.99.2~479 and thus is present in the version we require at
least (2.6.0).

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 tools/wireshark/src/packet-libvirt.c | 30 ++++++++--------------------
 1 file changed, 8 insertions(+), 22 deletions(-)

diff --git a/tools/wireshark/src/packet-libvirt.c b/tools/wireshark/src/packet-libvirt.c
index f43919b05d..cb922b8070 100644
--- a/tools/wireshark/src/packet-libvirt.c
+++ b/tools/wireshark/src/packet-libvirt.c
@@ -158,24 +158,6 @@ dissect_xdr_string(tvbuff_t *tvb, proto_tree *tree, XDR *xdrs, int hf,
     }
 }
 
-static const gchar *
-format_xdr_bytes(guint8 *bytes, guint32 length)
-{
-    gchar *buf;
-    guint32 i;
-
-    if (length == 0)
-        return "";
-    buf = wmem_alloc(wmem_packet_scope(), length*2 + 1);
-    for (i = 0; i < length; i++) {
-        /* We know that buf has enough size to contain
-           2 * length + '\0' characters. */
-        g_snprintf(buf, 2*(length - i) + 1, "%02x", bytes[i]);
-        buf += 2;
-    }
-    return buf - length*2;
-}
-
 static gboolean
 dissect_xdr_opaque(tvbuff_t *tvb, proto_tree *tree, XDR *xdrs, int hf,
                    guint32 size)
@@ -187,8 +169,10 @@ dissect_xdr_opaque(tvbuff_t *tvb, proto_tree *tree, XDR *xdrs, int hf,
     val = g_malloc(size);
     start = xdr_getpos(xdrs);
     if ((rc = xdr_opaque(xdrs, (caddr_t)val, size))) {
-        proto_tree_add_bytes_format_value(tree, hf, tvb, start, xdr_getpos(xdrs) - start,
-                                          NULL, "%s", format_xdr_bytes(val, size));
+        gint len = xdr_getpos(xdrs) - start;
+        const char *s = tvb_bytes_to_str(wmem_packet_scope(), tvb, start, len);
+
+        proto_tree_add_bytes_format_value(tree, hf, tvb, start, len, NULL, "%s", s);
     } else {
         proto_tree_add_item(tree, hf_libvirt_unknown, tvb, start, -1, ENC_NA);
     }
@@ -207,8 +191,10 @@ dissect_xdr_bytes(tvbuff_t *tvb, proto_tree *tree, XDR *xdrs, int hf,
 
     start = xdr_getpos(xdrs);
     if (xdr_bytes(xdrs, (char **)&val, &length, maxlen)) {
-        proto_tree_add_bytes_format_value(tree, hf, tvb, start, xdr_getpos(xdrs) - start,
-                                          NULL, "%s", format_xdr_bytes(val, length));
+        gint len = xdr_getpos(xdrs) - start;
+        const char *s = tvb_bytes_to_str(wmem_packet_scope(), tvb, start, len);
+
+        proto_tree_add_bytes_format_value(tree, hf, tvb, start, len, NULL, "%s", s);
         /* Seems I can't call xdr_free() for this case.
            It will raises SEGV by referencing out of bounds call stack */
         free(val);
-- 
2.32.0