Regression fix for last security fix. Set the iseqno correctly.

(closes issue #13918)
 Reported by: ffloimair
 Patches: 
       20081119__bug13918.diff.txt uploaded by Corydon76 (license 14)
 Tested by: ffloimair


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.2@159245 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_iax2.c

@@ -3102,7 +3102,7 @@ struct parsed_dial_string {
 static int send_apathetic_reply(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int command, int ts, unsigned char seqno)
 {
 	struct ast_iax2_full_hdr f = { .scallno = htons(0x8000 | callno), .dcallno = htons(dcallno),
-		.ts = htonl(ts), .iseqno = seqno, .oseqno = seqno, .type = AST_FRAME_IAX,
+		.ts = htonl(ts), .iseqno = seqno, .oseqno = 0, .type = AST_FRAME_IAX,
 		.csub = compress_subclass(command) };
 
 	return sendto(defaultsockfd, &f, sizeof(f), 0, (struct sockaddr *)sin, sizeof(*sin));
@@ -6842,7 +6842,7 @@ static int socket_read(int *id, int fd, short events, void *cbdata)
 		/* Deal with POKE/PONG without allocating a callno */
 		if (f.frametype == AST_FRAME_IAX && f.subclass == IAX_COMMAND_POKE) {
 			/* Reply back with a PONG, but don't care about the result. */
-			send_apathetic_reply(1, ntohs(fh->scallno), &sin, IAX_COMMAND_PONG, ntohs(fh->ts), fh->oseqno);
+			send_apathetic_reply(1, ntohs(fh->scallno), &sin, IAX_COMMAND_PONG, ntohs(fh->ts), fh->iseqno + 1);
 			return 1;
 		} else if (f.frametype == AST_FRAME_IAX && f.subclass == IAX_COMMAND_ACK && dcallno == 1) {
 			/* Ignore */