diff options
| -rw-r--r-- | lib/kernel/doc/src/gen_sctp.xml | 113 | ||||
| -rw-r--r-- | lib/kernel/src/gen_sctp.erl | 36 | ||||
| -rw-r--r-- | lib/kernel/src/inet_sctp.erl | 20 | ||||
| -rw-r--r-- | lib/kernel/test/gen_sctp_SUITE.erl | 52 |
4 files changed, 202 insertions, 19 deletions
diff --git a/lib/kernel/doc/src/gen_sctp.xml b/lib/kernel/doc/src/gen_sctp.xml index de41178a17..40efba2bb7 100644 --- a/lib/kernel/doc/src/gen_sctp.xml +++ b/lib/kernel/doc/src/gen_sctp.xml @@ -170,10 +170,19 @@ <p>Establishes a new association for the socket <c>Socket</c>, with the peer (SCTP server socket) given by <c>Addr</c> and <c>Port</c>. The <c>Timeout</c>, - is expressed in milliseconds.</p> - <p>A socket can be associated with multiple peers. - <marker id="record-sctp_assoc_change"></marker> + is expressed in milliseconds. A socket can be associated with multiple peers.</p> + <p><b>WARNING:</b>Using a value of <c>Timeout</c> less than + the maximum time taken by the OS to establish an association (around 4.5 minutes + if the default values from RFC 4960 are used) can result in + inconsistent or incorrect return values. This is especially + relevant for associations sharing the same <c>Socket</c> + (i.e. source address and port) since the controlling process + blocks until <c>connect/*</c> returns. + <seealso marker="#connect_init/4">connect_init/*</seealso> + provides an alternative not subject to this limitation.</p> + + <p><marker id="record-sctp_assoc_change"></marker> The result of <c>connect/*</c> is an <c>#sctp_assoc_change{}</c> event which contains, in particular, the new <seealso marker="#type-assoc_id">Association ID:</seealso></p> @@ -233,6 +242,45 @@ </desc> </func> <func> + <name>connect_init(Socket, Addr, Port, Opts) -> ok | {error, posix()}</name> + <fsummary>Same as <c>connect_init(Socket, Addr, Port, Opts, infinity)</c>.</fsummary> + <desc> + <p>Same as <c>connect_init(Socket, Addr, Port, Opts, infinity)</c>.</p> + </desc> + </func> + <func> + <name>connect_init(Socket, Addr, Port, [Opt], Timeout) -> ok | {error, posix()}</name> + <fsummary>Initiate a new association for the socket <c>Socket</c>, with a peer (SCTP server socket)</fsummary> + <type> + <v>Socket = sctp_socket()</v> + <v>Addr = ip_address() | Host</v> + <v>Port = port_number()</v> + <v>Opt = sctp_option()</v> + <v>Timeout = timeout()</v> + <v>Host = atom() | string()</v> + </type> + <desc> + <p>Initiates a new association for the socket <c>Socket</c>, + with the peer (SCTP server socket) given by + <c>Addr</c> and <c>Port</c>.</p> + <p>The fundamental difference between this API + and <c>connect/*</c> is that the return value is that of the + underlying OS connect(2) system call. If <c>ok</c> is returned + then the result of the association establishement is received + by the calling process as + an <seealso marker="#record-sctp_assoc_change"> + #sctp_assoc_change{}</seealso> + event. The calling process must be prepared to receive this, or + poll for it using <c>recv/*</c> depending on the value of the + active option.</p> + <p>The parameters are as described + in <seealso marker="#connect/5">connect/*</seealso>, with the + exception of the <c>Timeout</c> value.</p> + <p>The timer associated with <c>Timeout</c> only supervises + IP resolution of <c>Addr</c></p> + </desc> + </func> + <func> <name>controlling_process(sctp_socket(), pid()) -> ok</name> <fsummary>Assign a new controlling process pid to the socket</fsummary> <desc> @@ -1058,6 +1106,65 @@ gen_sctp:close(S). </pre> <p></p> </item> + <item> + <p>A very simple Erlang SCTP Client which uses the + connect_init API.</p> + <pre> +-module(ex3). + +-export([client/4]). +-include_lib("kernel/include/inet.hrl"). +-include_lib("kernel/include/inet_sctp.hrl"). + +client(Peer1, Port1, Peer2, Port2) + when is_tuple(Peer1), is_integer(Port1), is_tuple(Peer2), is_integer(Port2) -> + {ok,S} = gen_sctp:open(), + SctpInitMsgOpt = {sctp_initmsg,#sctp_initmsg{num_ostreams=5}}, + ActiveOpt = {active, true}, + Opts = [SctpInitMsgOpt, ActiveOpt], + ok = gen_sctp:connect(S, Peer1, Port1, Opts), + ok = gen_sctp:connect(S, Peer2, Port2, Opts), + io:format("Connections initiated~n", []), + client_loop(S, Peer1, Port1, undefined, Peer2, Port2, undefined). + +client_loop(S, Peer1, Port1, AssocId1, Peer2, Port2, AssocId2) -> + receive + {sctp, S, Peer1, Port1, {_Anc, SAC}} + when is_record(SAC, sctp_assoc_change), AssocId1 == undefined -> + io:format("Association 1 connect result: ~p. AssocId: ~p~n", + [SAC#sctp_assoc_change.state, + SAC#sctp_assoc_change.assoc_id]), + client_loop(S, Peer1, Port1, SAC#sctp_assoc_change.assoc_id, + Peer2, Port2, AssocId2); + + {sctp, S, Peer2, Port2, {_Anc, SAC}} + when is_record(SAC, sctp_assoc_change), AssocId2 == undefined -> + io:format("Association 2 connect result: ~p. AssocId: ~p~n", + [SAC#sctp_assoc_change.state, SAC#sctp_assoc_change.assoc_id]), + client_loop(S, Peer1, Port1, AssocId1, Peer2, Port2, + SAC#sctp_assoc_change.assoc_id); + + {sctp, S, Peer1, Port1, Data} -> + io:format("Association 1: received ~p~n", [Data]), + client_loop(S, Peer1, Port1, AssocId1, + Peer2, Port2, AssocId2); + + {sctp, S, Peer2, Port2, Data} -> + io:format("Association 2: received ~p~n", [Data]), + client_loop(S, Peer1, Port1, AssocId1, + Peer2, Port2, AssocId2); + + Other -> + io:format("Other ~p~n", [Other]), + client_loop(S, Peer1, Port1, AssocId1, + Peer2, Port2, AssocId2) + + after 5000 -> + ok + end. +</pre> + <p></p> + </item> </list> </section> diff --git a/lib/kernel/src/gen_sctp.erl b/lib/kernel/src/gen_sctp.erl index fcd1d1564a..0665d2e14d 100644 --- a/lib/kernel/src/gen_sctp.erl +++ b/lib/kernel/src/gen_sctp.erl @@ -27,7 +27,7 @@ -include("inet_sctp.hrl"). -export([open/0,open/1,open/2,close/1]). --export([listen/2,connect/4,connect/5]). +-export([listen/2,connect/4,connect/5,connect_init/4,connect_init/5]). -export([eof/2,abort/2]). -export([send/3,send/4,recv/1,recv/2]). -export([error_string/1]). @@ -80,7 +80,26 @@ listen(S, Flag) -> connect(S, Addr, Port, Opts) -> connect(S, Addr, Port, Opts, infinity). -connect(S, Addr, Port, Opts, Timeout) when is_port(S), is_list(Opts) -> +connect(S, Addr, Port, Opts, Timeout) -> + case do_connect(S, Addr, Port, Opts, Timeout, true) of + badarg -> + erlang:error(badarg, [S,Addr,Port,Opts,Timeout]); + Result -> + Result + end. + +connect_init(S, Addr, Port, Opts) -> + connect_init(S, Addr, Port, Opts, infinity). + +connect_init(S, Addr, Port, Opts, Timeout) -> + case do_connect(S, Addr, Port, Opts, Timeout, false) of + badarg -> + erlang:error(badarg, [S,Addr,Port,Opts,Timeout]); + Result -> + Result + end. + +do_connect(S, Addr, Port, Opts, Timeout, ConnWait) when is_port(S), is_list(Opts) -> case inet_db:lookup_socket(S) of {ok,Mod} -> case Mod:getserv(Port) of @@ -89,21 +108,26 @@ connect(S, Addr, Port, Opts, Timeout) when is_port(S), is_list(Opts) -> Timer -> try Mod:getaddr(Addr, Timer) of {ok,IP} -> - Mod:connect(S, IP, Port, Opts, Timer); + ConnectTimer = if ConnWait == false -> + nowait; + true -> + Timer + end, + Mod:connect(S, IP, Port, Opts, ConnectTimer); Error -> Error after inet:stop_timer(Timer) end catch error:badarg -> - erlang:error(badarg, [S,Addr,Port,Opts,Timeout]) + badarg end; Error -> Error end; Error -> Error end; -connect(S, Addr, Port, Opts, Timeout) -> - erlang:error(badarg, [S,Addr,Port,Opts,Timeout]). +do_connect(_S, _Addr, _Port, _Opts, _Timeout, _ConnWait) -> + badarg. diff --git a/lib/kernel/src/inet_sctp.erl b/lib/kernel/src/inet_sctp.erl index 30c0e85dd9..6fdd4bf789 100644 --- a/lib/kernel/src/inet_sctp.erl +++ b/lib/kernel/src/inet_sctp.erl @@ -64,16 +64,22 @@ close(S) -> listen(S, Flag) -> prim_inet:listen(S, Flag). +%% A non-blocking connect is implemented when the initial call is to +%% gen_sctp:connect_init which passes the value nowait as the Timer connect(S, Addr, Port, Opts, Timer) -> case prim_inet:chgopts(S, Opts) of ok -> case prim_inet:getopt(S, active) of {ok,Active} -> - Timeout = inet:timeout(Timer), + Timeout = if Timer =:= nowait -> + infinity; %% don't start driver timer in inet_drv + true -> + inet:timeout(Timer) + end, case prim_inet:connect(S, Addr, Port, Timeout) of - ok -> + ok when Timer =/= nowait -> connect_get_assoc(S, Addr, Port, Active, Timer); - Err1 -> Err1 + OkOrErr1 -> OkOrErr1 end; Err2 -> Err2 end; @@ -89,10 +95,10 @@ connect(S, Addr, Port, Opts, Timer) -> %% connect_get_assoc/5 below mistakes it for an invalid response %% for a socket in {active,false} or {active,once} modes. %% -%% In {active,true} mode it probably gets right, but it is -%% a blocking connect that is implemented even for {active,true}, -%% and that may be a shortcoming. A non-blocking connect -%% would be nice to have. +%% In {active,true} mode the window of time for the race is smaller, +%% but it is possible and also it is a blocking connect that is +%% implemented even for {active,true}, and that may be a +%% shortcoming. connect_get_assoc(S, Addr, Port, false, Timer) -> case recv(S, inet:timeout(Timer)) of diff --git a/lib/kernel/test/gen_sctp_SUITE.erl b/lib/kernel/test/gen_sctp_SUITE.erl index dd7d5f111a..b19ce4d40b 100644 --- a/lib/kernel/test/gen_sctp_SUITE.erl +++ b/lib/kernel/test/gen_sctp_SUITE.erl @@ -24,10 +24,11 @@ %%-compile(export_all). -export([all/1,init_per_testcase/2,fin_per_testcase/2, - basic/1,xfer_min/1,xfer_active/1,api_open_close/1,api_listen/1]). + basic/1,api_open_close/1,api_listen/1,api_connect_init/1, + xfer_min/1,xfer_active/1]). all(suite) -> - [basic,xfer_min,xfer_active,api_open_close,api_listen]. + [basic,api_open_close,api_listen,api_connect_init,xfer_min,xfer_active]. init_per_testcase(_Func, Config) -> Dog = test_server:timetrap(test_server:seconds(15)), @@ -325,7 +326,7 @@ api_listen(Config) when is_list(Config) -> ?line {ok,{Localhost, Pb,[], #sctp_assoc_change{ - state = comm_lost}}} = + state=comm_lost}}} = gen_sctp:recv(Sa, infinity); {error,#sctp_assoc_change{state=cant_assoc}} -> ok end, @@ -336,3 +337,48 @@ api_listen(Config) when is_list(Config) -> ?line ok = gen_sctp:close(Sa), ?line ok = gen_sctp:close(Sb), ok. + +api_connect_init(doc) -> + "Test the API function connect_init/4"; +api_connect_init(suite) -> + []; +api_connect_init(Config) when is_list(Config) -> + ?line Localhost = {127,0,0,1}, + + ?line {ok,S} = gen_sctp:open(), + ?line {ok,Pb} = inet:port(S), + ?line try gen_sctp:connect_init(S, Localhost, not_allowed_for_port, []) + catch error:badarg -> ok + end, + ?line try gen_sctp:connect_init(S, Localhost, 12345, not_allowed_for_opts) + catch error:badarg -> ok + end, + ?line ok = gen_sctp:close(S), + ?line {error,closed} = gen_sctp:connect_init(S, Localhost, 12345, []), + + ?line {ok,Sb} = gen_sctp:open(Pb), + ?line {ok,Sa} = gen_sctp:open(), + ?line case gen_sctp:connect_init(Sa, localhost, Pb, []) of + {error,econnrefused} -> + ?line {ok,{Localhost, + Pb,[], + #sctp_assoc_change{state=comm_lost}}} = + gen_sctp:recv(Sa, infinity); + ok -> + ?line {ok,{Localhost, + Pb,[], + #sctp_assoc_change{state=cant_assoc}}} = + gen_sctp:recv(Sa, infinity) + end, + ?line ok = gen_sctp:listen(Sb, true), + ?line case gen_sctp:connect_init(Sa, localhost, Pb, []) of + ok -> + ?line {ok,{Localhost, + Pb,[], + #sctp_assoc_change{ + state = comm_up}}} = + gen_sctp:recv(Sa, infinity) + end, + ?line ok = gen_sctp:close(Sa), + ?line ok = gen_sctp:close(Sb), + ok. |