Rules of thumb (2)

Pointers: use struct sockaddr *
Memory allocation: use struct sockaddr_storage
sizeof sockaddr < sizeof sockaddr_in6

Be careful with sizeof()
sizeof(struct sockaddr_in)? sizeof(sa)?
Use sa_len where possible (on 4.4BSD-derived system)
pass around salen always (on 4.3BSD-derived systems)

Name resolution must use getaddrinfo()/getnameinfo()