Fix SI95 transport header length bug

[ric-plt/lib/rmr.git] / src / rmr / si / src / mt_call_si_static.c

diff --git a/src/rmr/si/src/mt_call_si_static.c b/src/rmr/si/src/mt_call_si_static.c
index fbbffaf..76b56b2 100644 (file)
--- a/src/rmr/si/src/mt_call_si_static.c
+++ b/src/rmr/si/src/mt_call_si_static.c
@@ -110,14 +110,26 @@ static void buf2mbuf( uta_ctx_t* ctx, char *raw_msg, int msg_size, int sender_fd
        byte order. If <mark> is not present, we use <int1>. This allows
        old versions of RMR to continue to work with new versions that now
        do the right thing with byte ordering.
+
+       If the receiver of a message is a backlevel RMR, and it uses RTS to
+       return a message, it will only update the old size, but when the
+       message is received back at a new RMR application it will appear that
+       the message came from a new instance.  Therefore, we must compare
+       the old and new sizes and if they are different we must use the old
+       size assuming that this is the case.
 */
 static inline uint32_t extract_mlen( unsigned char* buf ) {
        uint32_t        size;           // adjusted (if needed) size for return
+       uint32_t        osize;          // old size
        uint32_t*       blen;           // length in the buffer to extract
 
        blen = (uint32_t *) buf;
        if( *(buf + sizeof( int ) * 2 ) == TP_SZ_MARKER ) {
+               osize = *blen;                                                  // old size
                size = ntohl( *(blen+1) );                              // pick up the second integer
+               if( osize != size ) {                                   // assume back level return to sender
+                       size = osize;                                           // MUST use old size
+               }
                if( DEBUG > 1 ) rmr_vlog( RMR_VL_DEBUG, "extract msg len converted from net order to: %d\n", size );
        } else {
                size = *blen;                                                   // old sender didn't encode size