illumos gate

Consider the rmtcall test as it could be found in #4456. This test initiates remote call (type BCAST) for rpcbind at localhost asking to remotely call GETTIME procedure.

Here is the communication:

# snoop -r -d lo0 -V
Using device lo0 (promiscuous mode)
________________________________
   127.0.0.1 -> 127.0.0.1    IPNET src zone 0 dst zone 0
   127.0.0.1 -> 127.0.0.1    IP  D=127.0.0.1 S=127.0.0.1 LEN=84, ID=0, TOS=0x0, TTL=255
   127.0.0.1 -> 127.0.0.1    UDP D=111 S=47279 LEN=64
   127.0.0.1 -> 127.0.0.1    RPC C XID=1389445658 PROG=100000 (PMAP) VERS=4 PROC=5
   127.0.0.1 -> 127.0.0.1    RPCBIND C BCAST prog=PMAP vers=4 proc=6
   127.0.0.1 -> 127.0.0.1    RPCBIND C GETTIME
________________________________
   127.0.0.1 -> 127.0.0.1    IPNET src zone 0 dst zone 0
   127.0.0.1 -> 127.0.0.1    IP  D=127.0.0.1 S=127.0.0.1 LEN=68, ID=0, TOS=0x0, TTL=255
   127.0.0.1 -> 127.0.0.1    UDP D=111 S=37197 LEN=48
   127.0.0.1 -> 127.0.0.1    RPC C XID=3021490624 PROG=100000 (PMAP) VERS=4 PROC=6
   127.0.0.1 -> 127.0.0.1    RPCBIND C GETTIME
________________________________
   127.0.0.1 -> 127.0.0.1    IPNET src zone 0 dst zone 0
   127.0.0.1 -> 127.0.0.1    IP  D=127.0.0.1 S=127.0.0.1 LEN=56, ID=0, TOS=0x0, TTL=255
   127.0.0.1 -> 127.0.0.1    UDP D=37197 S=111 LEN=36
   127.0.0.1 -> 127.0.0.1    RPC R (#2) XID=3021490624 Success
   127.0.0.1 -> 127.0.0.1    RPCBIND R GETTIME 
________________________________
   127.0.0.1 -> 127.0.0.1    IPNET src zone 0 dst zone 0
   127.0.0.1 -> 127.0.0.1    IP  D=127.0.0.1 S=127.0.0.1 LEN=80, ID=0, TOS=0x0, TTL=255
   127.0.0.1 -> 127.0.0.1    UDP D=47279 S=37197 LEN=60
   127.0.0.1 -> 127.0.0.1    RPC R (#1) XID=1389445658 Success
   127.0.0.1 -> 127.0.0.1    RPCBIND R BCAST Uaddr=127.0.0.1.0.111 len=4
   127.0.0.1 -> 127.0.0.1    RPCBIND R GETTIME

The first packet is the BCAST call initiated by the rmtcall test program. The source port is 47279 and target port is 111 (rpcbind port).

The second packet is sent by rpcbind (source port 37197) back to rpcbind (target port 111). This is the actual GETTIME call.

The third packet is reply to the second packet. The source port is 111 and the target port is 37197. This is correct.

The problem is with the fourth packet. The fourth packet is a reply to the first packet (the BCAST). We would expect that the source port is 111 and the target port is 47279. But instead, we see the source port set to 37197. This is actually the port we saw in the second and third packet.