https://github.com/msantos/gen_unix
Erlang Unix socket interface
https://github.com/msantos/gen_unix
Last synced: about 1 month ago
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Erlang Unix socket interface
- Host: GitHub
- URL: https://github.com/msantos/gen_unix
- Owner: msantos
- Created: 2013-05-28T23:32:04.000Z (about 12 years ago)
- Default Branch: master
- Last Pushed: 2015-08-10T16:04:05.000Z (almost 10 years ago)
- Last Synced: 2025-03-30T11:41:41.546Z (2 months ago)
- Language: Erlang
- Size: 248 KB
- Stars: 30
- Watchers: 4
- Forks: 10
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
gen\_unix is an Erlang interface to Unix sockets. The main purpose of
gen\_unix is to allow access to socket ancillary data required for fd
and credential passing.
WARNING: gen\_unix is still under development and going through a lot
of change.
Examples
========
* File descriptor passing
Open 2 shell prompts and start an Erlang VM in each:
# VM 1
$ rebar shell
1> {ok, Ref} = gen_unix:start().
{ok,<0.35.0>}
2> {ok, Listen} = gen_unix:listen(Ref, "/tmp/test").
{ok,8}
# VM 2
$ sudo rebar shell
1> {ok, Ref} = gen_unix:start().
{ok,<0.35.0>}
2> {ok, Socket} = gen_unix:connect(Ref, "/tmp/test").
{ok,7}
2> {ok, FD1} = procket:socket(inet,raw,icmp).
{ok,8}
3> {ok, FD2} = procket:socket(inet6,raw,icmp6).
{ok,9}
4> {ok, Msg} = unixsock:msg({fdsend, [FD1,FD2]}).
{ok,{msghdr,<<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,160,114,0,
232,20,127,0,0,1,...>>,
[{msg_iov,<<>>},{msg_control,<<>>},{iov,[<<>>]}]}}
5> gen_unix:sendmsg(Ref, Socket, Msg).
ok
# Open another shell and send a few ping's
# Back in VM 1
2> {ok, Socket} = gen_unix:accept(Ref, Listen).
{ok,9}
3> {ok, Msg} = unixsock:msg({fdrecv, 2}).
{ok,{msghdr,<<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,160,114,0,
128,198,127,0,0,1,...>>,
[{msg_iov,<<>>},{msg_control,<<>>},{iov,[<<>>]}]}}
4> gen_unix:recvmsg(Ref, Socket, Msg).
{ok,1}
% [8,9]
5> {ok, [FD1, FD2]} = unixsock:msg(Msg).
{ok,"\t\n"}
5> procket:read(FD1, 1024).
{ok,<<69,0,0,84,236,114,0,0,56,1,38,238,173,194,43,69,
192,168,213,152,0,0,98,95,21,173,0,...>>}
* Credential passing
# VM 1
$ rebar shell
1> {ok, Ref} = gen_unix:start().
{ok,<0.35.0>}
2> {ok, Listen} = gen_unix:listen(Ref, "/tmp/test").
{ok,8}
# VM 2
$ rebar shell
1> {ok, Ref} = gen_unix:start().
{ok,<0.35.0>}
2> {ok, Socket} = gen_unix:connect(Ref, "/tmp/test").
{ok,7}
2> {ok, Msg} = unixsock:msg(credsend).
{ok,{msghdr,<<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,115,0,232,
20,127,0,0,1,...>>,
[{msg_iov,<<>>},{iov,[<<>>]}]}}
3> gen_unix:sendmsg(Ref, Socket, Msg).
ok
# Back in VM 1
2> {ok, Socket} = gen_unix:accept(Ref, Listen).
{ok,9}
3> {ok, Msg} = unixsock:msg(credrecv).
{ok,{msghdr,<<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,115,0,128,
198,127,0,0,1,...>>,
[{msg_iov,<<>>},{msg_control,<<>>},{iov,[<<>>]}]}}
4> unixsock:setsockopt(Socket, {credrecv, open}).
ok
5> gen_unix:recvmsg(Ref, Socket, Msg).
{ok,1}
6> unixsock:msg(Msg).
{ok, [{pid,12866},{uid,1000},{gid,1000}]}
7> unixsock:setsockopt(Socket, {credrecv, close}).
ok