ipsec_setportof(3) on Linux
The text 3928311ffa62, as Debian 4.0 (Etch) shipped it.
get port field of an ip_address ipsec setportof - set port field of an ip_address ipsec sockaddrof - get pointer to internal sockaddr of an ip_address ipsec sockaddrlenof - get length of internal sockaddr of an ip_address