13175 Add support for IP_RECVTOS
13182 CMSG_ macros should have man pages
Change-ID: I784aa36cfd3c17e3cccbf1fd329fa7e69b663ef9

@@ -1316,12 +1316,28 @@
                         if (oldflg)
                                 continue;
 
                         cmsg->cmsg_level = tohp->level;
                         cmsg->cmsg_type = tohp->name;
-                        cmsg->cmsg_len = (socklen_t)(_TPI_TOPT_DATALEN(tohp) +
-                            sizeof (struct cmsghdr));
+                        cmsg->cmsg_len = (socklen_t)sizeof (struct cmsghdr);
+                        if (tohp->level == IPPROTO_IP &&
+                            (tohp->name == IP_RECVTOS ||
+                            tohp->name == IP_RECVTTL)) {
+                                /*
+                                 * The data for these is a uint8_t but, in
+                                 * order to maintain alignment for any
+                                 * following TPI primitives in the message,
+                                 * there will be some trailing padding bytes
+                                 * which are included in the TPI_TOPT_DATALEN.
+                                 * For these types, we set the cmsg_len
+                                 * explicitly to the correct value.
+                                 */
+                                cmsg->cmsg_len += (socklen_t)sizeof (uint8_t);
+                        } else {
+                                cmsg->cmsg_len +=
+                                    (socklen_t)(_TPI_TOPT_DATALEN(tohp));
+                        }
 
                         /* copy content to control data part */
                         bcopy(&tohp[1], CMSG_CONTENT(cmsg),
                             CMSG_CONTENTLEN(cmsg));
                 }