I've been reading the source code of Erlang/OTP R15B to find out how it handles the IPv6-related functions.
Erlang VM has the most functions embedded into the inet_drv linked-in driver, so programmers don't really have to worry about many things except for the address tuple format difference between IPv4 ({192, 168, 0, 1}) and IPv6 ({8193,3512,4660,22136,51966,47806,57005,48879} for 2001:db8:1234:5678:cafe:babe:dead:beef). You can find a lot of gems by reading the kernel module source code.
Here is a list of notable functions inside the kernel module for IPv6 handling on Erlang/OTP R15B. I suggest you to read these functions before writing your own ones.
(Note: this is a work-in-progress article of my Erlang Factory SF Bay Area 2012 presentation.)
%%% A partial list of IPv6 keywords in Erlang/OTP R15B source code %%% atom "inet6" is an important keyword inet_parse:address/1 inet_parse:ipv6_address/1 inet_parse:ipv6strict_address/1 % review RFC4291 inet_parse:ntoa/1 inet_parse:hosts/2 % internal, now ignoring "%if" suffix -type inet:ip6_address() inet:getifaddrs/0 inet:getifaddrs/1 inet:gethostbyaddr/1 inet:getaddrs/2 % second arg: inet6 inet:gethostbyname_string/2 % second arg: inet6 inet:i/0 inet:i/1 %%% interesting module results %%% (no significant difference other than inet/inet6 flags): %%% diff --unified inet_tcp.erl inet6_tcp.erl %%% diff --unified inet_udp.erl inet6_udp.erl %%% diff --unified inet_sctp.erl inet6_sctp.erl %%% diff --unified inet_tcp_dist.erl inet6_tcp_dist.erl inet_config:set_hostname/0 % internal, dependent on inet_udp:open/2 %%% inet_db.erl has tcp/udp/sctp module config params %%% for the gen_server callbacks inet_db:set_inet6/1 inet_db:dn_ip6_int/8 % internal, for 8 elements of an IPv6 address tuple inet_db:make_hostent(Name, Addrs, Aliases, ?S_AAAA) inet_db:handle_call({add_host, IPv6address, Names}) inet_db:handle_call({del_host, IPv6address}) inet_dns.erl: ?S_AAAA related lines inet_dns.hrl: --define(T_AAAA), --define(S_AAAA) inet_int.hrl: --define(INET_AF_INET6), --define(SCTP_FLAG_PMTUD_*), --define(ip6(A,B,C,D,E,F,G,H) -type inet_res:res_option({inet6, boolean()}) -type inet_res:dns_data() % inet:ip6_address() inet_res:gethostbyaddr/1 inet_res:gethostbyaddr_tm/2 inet_res:gethostbyname/1 inet_res:gethostbyname_tm/3 inet_res:udp_open/2 % internal (record #sock) inet_res:udp_connect/2 % internal (record #sock) % There will be more...
