bgpd: Remove unnecessary stream_new/stream_copies in bgp_open_make

The call into bgp_open_capability can return that it wrote more
than BGP_OPEN_NON_EXT_OPT_LEN bytes, in that case the open
part needs to be written again with ext_opt_params set to
true to allow extended parameters to be written thus keeping
the len < 255 bytes.  The code to do this was first creating
a new stream and then copying into it the stream, trying
to call bgp_open_capability() and if it succeeded recopying
the tmp stream back onto the original.

Let's change this around such that we save the current spot
in the stream of where we are writing and if the change does
not work reset the pointer and try again with the correct
parameter.  This removes the stream and multiple copies and
eventual free of the temporary stream.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>

diff --git a/bgpd/bgp_packet.c b/bgpd/bgp_packet.c
index ec8cc0465b4d1884405734628a5a01284545afe8..47c519326802271690e354e5dca672378bfbb47e 100644 (file)
--- a/bgpd/bgp_packet.c
+++ b/bgpd/bgp_packet.c
@@ -658,17 +658,12 @@ struct stream *bgp_open_make(struct peer *peer, uint16_t send_holdtime, as_t loc
                ext_opt_params = true;
                (void)bgp_open_capability(s, peer, ext_opt_params);
        } else {
-               struct stream *tmp = stream_new(STREAM_SIZE(s));
+               size_t endp = stream_get_endp(s);
 
-               stream_copy(tmp, s);
-               if (bgp_open_capability(tmp, peer, ext_opt_params) >
-                   BGP_OPEN_NON_EXT_OPT_LEN) {
-                       stream_free(tmp);
+               if (bgp_open_capability(s, peer, ext_opt_params) > BGP_OPEN_NON_EXT_OPT_LEN) {
+                       stream_set_endp(s, endp);
                        ext_opt_params = true;
                        (void)bgp_open_capability(s, peer, ext_opt_params);
-               } else {
-                       stream_copy(s, tmp);
-                       stream_free(tmp);
                }
        }