res_rtp_asterisk: Eliminate "type-punned pointer" build warning.

Removes "res_rtp_asterisk.c:706: warning: dereferencing type-punned pointer
will break strict-aliasing rules" warning from the build on 32-bit platforms.

The problem is that 'size' was referenced aliased to both (pj_size_t *) and
(pj_ssize_t *). Now just make a copy of size that is the right type so there
isn't any pointer aliasing happening.

It also adds comments and asserts regarding what looks like an inappropriate
use of pj_sock_sendto, but is actually totally fine.

(closes issue ASTERISK-20368)
Reported by: Shaun Ruffell
Tested by: Michael L. Young
Patches:
  0001-res_rtp_asterisk-Eliminate-type-punned-pointer-build.patch uploaded by Shaun Ruffell (license 5417)
    slightly modified by David M. Lee.
........

Merged revisions 372777 from http://svn.asterisk.org/svn/asterisk/branches/11

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@372787 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/res/res_rtp_asterisk.c b/res/res_rtp_asterisk.c
index 9a78dbd..9283f80 100644 (file)
--- a/res/res_rtp_asterisk.c
+++ b/res/res_rtp_asterisk.c
@@ -700,14 +700,19 @@ static pj_status_t ast_rtp_on_ice_tx_pkt(pj_ice_sess *ice, unsigned comp_id, uns
 {
        struct ast_rtp *rtp = ice->user_data;
        pj_status_t status = PJ_EINVALIDOP;
+       pj_ssize_t _size = (pj_ssize_t)size;
 
        if (transport_id == TRANSPORT_SOCKET_RTP) {
                /* Traffic is destined to go right out the RTP socket we already have */
-               status = pj_sock_sendto(rtp->s, pkt, (pj_ssize_t*)&size, 0, dst_addr, dst_addr_len);
+               status = pj_sock_sendto(rtp->s, pkt, &_size, 0, dst_addr, dst_addr_len);
+               /* sendto on a connectionless socket should send all the data, or none at all */
+               ast_assert(_size == size || status != PJ_SUCCESS);
        } else if (transport_id == TRANSPORT_SOCKET_RTCP) {
                /* Traffic is destined to go right out the RTCP socket we already have */
                if (rtp->rtcp) {
-                       status = pj_sock_sendto(rtp->rtcp->s, pkt, (pj_ssize_t*)&size, 0, dst_addr, dst_addr_len);
+                       status = pj_sock_sendto(rtp->rtcp->s, pkt, &_size, 0, dst_addr, dst_addr_len);
+                       /* sendto on a connectionless socket should send all the data, or none at all */
+                       ast_assert(_size == size || status != PJ_SUCCESS);
                } else {
                        status = PJ_SUCCESS;
                }