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-rw-r--r--lib/kernel/doc/src/Makefile1
-rw-r--r--lib/kernel/doc/src/erl_epmd.xml104
-rw-r--r--lib/kernel/doc/src/ref_man.xml1
-rw-r--r--lib/kernel/doc/src/specs.xml1
-rw-r--r--lib/kernel/src/erl_epmd.erl64
-rw-r--r--lib/kernel/src/inet_tcp_dist.erl148
6 files changed, 254 insertions, 65 deletions
diff --git a/lib/kernel/doc/src/Makefile b/lib/kernel/doc/src/Makefile
index 82869d7b15..29dc73a523 100644
--- a/lib/kernel/doc/src/Makefile
+++ b/lib/kernel/doc/src/Makefile
@@ -42,6 +42,7 @@ XML_REF3_FILES = application.xml \
disk_log.xml \
erl_boot_server.xml \
erl_ddll.xml \
+ erl_epmd.xml \
erl_prim_loader_stub.xml \
erlang_stub.xml \
error_handler.xml \
diff --git a/lib/kernel/doc/src/erl_epmd.xml b/lib/kernel/doc/src/erl_epmd.xml
new file mode 100644
index 0000000000..8b076cd2d7
--- /dev/null
+++ b/lib/kernel/doc/src/erl_epmd.xml
@@ -0,0 +1,104 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE erlref SYSTEM "erlref.dtd">
+
+<erlref>
+ <header>
+ <copyright>
+ <year>2018</year><year>2018</year>
+ <holder>Ericsson AB. All Rights Reserved.</holder>
+ </copyright>
+ <legalnotice>
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+ </legalnotice>
+
+ <title>erl_epmd</title>
+ <prepared>Timmo Verlaan</prepared>
+ <docno>1</docno>
+ <date>2018-02-19</date>
+ <rev>A</rev>
+ </header>
+ <module>erl_epmd</module>
+ <modulesummary>
+ Erlang interface towards epmd
+ </modulesummary>
+ <description>
+ <p>This module communicates with the EPMD daemon, see <seealso
+ marker="erts:epmd">epmd</seealso>. To implement your own epmd module please
+ see <seealso marker="erts:alt_disco">ERTS User's Guide: How to Implement an
+ Alternative Service Discovery for Erlang Distribution</seealso></p>
+ </description>
+
+ <funcs>
+ <func>
+ <name name="start_link" arity="0"/>
+ <fsummary>Callback for erl_distribution supervisor.</fsummary>
+ <desc>
+ <p>This function is invoked as this module is added as a child of the
+ <c>erl_distribution</c> supervisor.</p>
+ </desc>
+ </func>
+
+ <func>
+ <name name="register_node" arity="2"/>
+ <name name="register_node" arity="3"/>
+ <fsummary>Registers the node with <c>epmd</c>.</fsummary>
+ <desc>
+ <p>Registers the node with <c>epmd</c> and tells epmd what port will be
+ used for the current node. It returns a creation number. This number is
+ incremented on each register to help with identifying if a node is
+ reconnecting to epmd.</p>
+ </desc>
+ </func>
+
+ <func>
+ <name name="port_please" arity="2"/>
+ <name name="port_please" arity="3"/>
+ <fsummary>Returns the port number for a given node.</fsummary>
+ <desc>
+ <p>Requests the distribution port for the given node of an EPMD
+ instance. Together with the port it returns a distribution protocol
+ version which has been 5 since Erlang/OTP R6.</p>
+ </desc>
+ </func>
+
+ <func>
+ <name name="address_please" arity="3"/>
+ <fsummary>Returns address and port.</fsummary>
+ <desc>
+ <p>Called by the distribution module. Resolves the <c>Host</c> to an IP
+ address.</p>
+ <p>Another epmd module may return port and distribution protocol version
+ as well.</p>
+ </desc>
+ </func>
+
+ <func>
+ <name name="names" arity="1"/>
+ <fsummary>Names of Erlang nodes at a host.</fsummary>
+ <desc>
+ <p>Called by <seealso marker="net_adm"><c>net_adm:names/0</c></seealso>.
+ <c>Host</c> defaults to the localhost. Returns the names and associated
+ port numbers of the Erlang nodes that <c>epmd</c> registered at the
+ specified host. Returns <c>{error, address}</c> if <c>epmd</c> is not
+ operational.</p>
+ <p><em>Example:</em></p>
+ <pre>
+(arne@dunn)1> <input>erl_epmd:names(localhost).</input>
+{ok,[{"arne",40262}]}</pre>
+ </desc>
+ </func>
+ </funcs>
+
+</erlref>
+
diff --git a/lib/kernel/doc/src/ref_man.xml b/lib/kernel/doc/src/ref_man.xml
index c06914d23d..a633ae4832 100644
--- a/lib/kernel/doc/src/ref_man.xml
+++ b/lib/kernel/doc/src/ref_man.xml
@@ -38,6 +38,7 @@
<xi:include href="disk_log.xml"/>
<xi:include href="erl_boot_server.xml"/>
<xi:include href="erl_ddll.xml"/>
+ <xi:include href="erl_epmd.xml"/>
<xi:include href="erl_prim_loader_stub.xml"/>
<xi:include href="erlang_stub.xml"/>
<xi:include href="error_handler.xml"/>
diff --git a/lib/kernel/doc/src/specs.xml b/lib/kernel/doc/src/specs.xml
index bcc422930e..b8c25ca53b 100644
--- a/lib/kernel/doc/src/specs.xml
+++ b/lib/kernel/doc/src/specs.xml
@@ -6,6 +6,7 @@
<xi:include href="../specs/specs_disk_log.xml"/>
<xi:include href="../specs/specs_erl_boot_server.xml"/>
<xi:include href="../specs/specs_erl_ddll.xml"/>
+ <xi:include href="../specs/specs_erl_epmd.xml"/>
<xi:include href="../specs/specs_erl_prim_loader_stub.xml"/>
<xi:include href="../specs/specs_erlang_stub.xml"/>
<xi:include href="../specs/specs_error_handler.xml"/>
diff --git a/lib/kernel/src/erl_epmd.erl b/lib/kernel/src/erl_epmd.erl
index f96bc88913..9a0939972d 100644
--- a/lib/kernel/src/erl_epmd.erl
+++ b/lib/kernel/src/erl_epmd.erl
@@ -29,10 +29,20 @@
-define(port_please_failure2(Term), noop).
-endif.
+-ifndef(erlang_daemon_port).
+-define(erlang_daemon_port, 4369).
+-endif.
+-ifndef(epmd_dist_high).
+-define(epmd_dist_high, 4370).
+-endif.
+-ifndef(epmd_dist_low).
+-define(epmd_dist_low, 4370).
+-endif.
+
%% External exports
-export([start/0, start_link/0, stop/0, port_please/2,
port_please/3, names/0, names/1,
- register_node/2, register_node/3, open/0, open/1, open/2]).
+ register_node/2, register_node/3, address_please/3, open/0, open/1, open/2]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
@@ -53,7 +63,7 @@
start() ->
gen_server:start({local, erl_epmd}, ?MODULE, [], []).
-
+-spec start_link() -> {ok, pid()} | ignore | {error,term()}.
start_link() ->
gen_server:start_link({local, erl_epmd}, ?MODULE, [], []).
@@ -66,9 +76,22 @@ stop() ->
%% return {port, P, Version} | noport
%%
+-spec port_please(Name, Host) -> {ok, Port, Version} | noport when
+ Name :: string(),
+ Host :: inet:ip_address(),
+ Port :: non_neg_integer(),
+ Version :: non_neg_integer().
+
port_please(Node, Host) ->
port_please(Node, Host, infinity).
+-spec port_please(Name, Host, Timeout) -> {ok, Port, Version} | noport when
+ Name :: string(),
+ Host :: inet:ip_address(),
+ Timeout :: non_neg_integer() | infinity,
+ Port :: non_neg_integer(),
+ Version :: non_neg_integer().
+
port_please(Node,HostName, Timeout) when is_atom(HostName) ->
port_please1(Node,atom_to_list(HostName), Timeout);
port_please(Node,HostName, Timeout) when is_list(HostName) ->
@@ -92,10 +115,21 @@ port_please1(Node,HostName, Timeout) ->
Else
end.
+-spec names() -> {ok, [{Name, Port}]} | {error, Reason} when
+ Name :: string(),
+ Port :: non_neg_integer(),
+ Reason :: address | file:posix().
+
names() ->
{ok, H} = inet:gethostname(),
names(H).
+-spec names(Host) -> {ok, [{Name, Port}]} | {error, Reason} when
+ Host :: atom() | string() | inet:ip_address(),
+ Name :: string(),
+ Port :: non_neg_integer(),
+ Reason :: address | file:posix().
+
names(HostName) when is_atom(HostName); is_list(HostName) ->
case inet:gethostbyname(HostName) of
{ok,{hostent, _Name, _ , _Af, _Size, [EpmdAddr | _]}} ->
@@ -106,9 +140,22 @@ names(HostName) when is_atom(HostName); is_list(HostName) ->
names(EpmdAddr) ->
get_names(EpmdAddr).
+-spec register_node(Name, Port) -> Result when
+ Name :: string(),
+ Port :: non_neg_integer(),
+ Creation :: non_neg_integer(),
+ Result :: {ok, Creation} | {error, already_registered} | term().
register_node(Name, PortNo) ->
- register_node(Name, PortNo, inet).
+ register_node(Name, PortNo, inet).
+
+-spec register_node(Name, Port, Driver) -> Result when
+ Name :: string(),
+ Port :: non_neg_integer(),
+ Driver :: inet_tcp | inet6_tcp | inet | inet6,
+ Creation :: non_neg_integer(),
+ Result :: {ok, Creation} | {error, already_registered} | term().
+
register_node(Name, PortNo, inet_tcp) ->
register_node(Name, PortNo, inet);
register_node(Name, PortNo, inet6_tcp) ->
@@ -116,6 +163,17 @@ register_node(Name, PortNo, inet6_tcp) ->
register_node(Name, PortNo, Family) ->
gen_server:call(erl_epmd, {register, Name, PortNo, Family}, infinity).
+-spec address_please(Name, Host, AddressFamily) -> Success | {error, term()} when
+ Name :: string(),
+ Host :: string() | inet:ip_address(),
+ AddressFamily :: inet | inet6,
+ Port :: non_neg_integer(),
+ Version :: non_neg_integer(),
+ Success :: {ok, inet:ip_address()} | {ok, inet:ip_address(), Port, Version}.
+
+address_please(_Name, Host, AddressFamily) ->
+ inet:getaddr(Host, AddressFamily).
+
%%%----------------------------------------------------------------------
%%% Callback functions from gen_server
%%%----------------------------------------------------------------------
diff --git a/lib/kernel/src/inet_tcp_dist.erl b/lib/kernel/src/inet_tcp_dist.erl
index e3fdb1bb22..b4b50899f7 100644
--- a/lib/kernel/src/inet_tcp_dist.erl
+++ b/lib/kernel/src/inet_tcp_dist.erl
@@ -283,73 +283,22 @@ do_setup(Driver, Kernel, Node, Type, MyNode, LongOrShortNames, SetupTime) ->
?trace("~p~n",[{inet_tcp_dist,self(),setup,Node}]),
[Name, Address] = splitnode(Driver, Node, LongOrShortNames),
AddressFamily = Driver:family(),
- case inet:getaddr(Address, AddressFamily) of
+ ErlEpmd = net_kernel:epmd_module(),
+ {ARMod, ARFun} = get_address_resolver(ErlEpmd),
+ Timer = dist_util:start_timer(SetupTime),
+ case ARMod:ARFun(Name, Address, AddressFamily) of
+ {ok, Ip, TcpPort, Version} ->
+ ?trace("address_please(~p) -> version ~p~n",
+ [Node,Version]),
+ do_setup_connect(Driver, Kernel, Node, Address, AddressFamily,
+ Ip, TcpPort, Version, Type, MyNode, Timer);
{ok, Ip} ->
- Timer = dist_util:start_timer(SetupTime),
- ErlEpmd = net_kernel:epmd_module(),
case ErlEpmd:port_please(Name, Ip) of
{port, TcpPort, Version} ->
?trace("port_please(~p) -> version ~p~n",
[Node,Version]),
- dist_util:reset_timer(Timer),
- case
- Driver:connect(
- Ip, TcpPort,
- connect_options([{active, false}, {packet, 2}]))
- of
- {ok, Socket} ->
- HSData = #hs_data{
- kernel_pid = Kernel,
- other_node = Node,
- this_node = MyNode,
- socket = Socket,
- timer = Timer,
- this_flags = 0,
- other_version = Version,
- f_send = fun Driver:send/2,
- f_recv = fun Driver:recv/3,
- f_setopts_pre_nodeup =
- fun(S) ->
- inet:setopts
- (S,
- [{active, false},
- {packet, 4},
- nodelay()])
- end,
- f_setopts_post_nodeup =
- fun(S) ->
- inet:setopts
- (S,
- [{active, true},
- {deliver, port},
- {packet, 4},
- nodelay()])
- end,
-
- f_getll = fun inet:getll/1,
- f_address =
- fun(_,_) ->
- #net_address{
- address = {Ip,TcpPort},
- host = Address,
- protocol = tcp,
- family = AddressFamily}
- end,
- mf_tick = fun(S) -> ?MODULE:tick(Driver, S) end,
- mf_getstat = fun ?MODULE:getstat/1,
- request_type = Type,
- mf_setopts = fun ?MODULE:setopts/2,
- mf_getopts = fun ?MODULE:getopts/2
- },
- dist_util:handshake_we_started(HSData);
- _ ->
- %% Other Node may have closed since
- %% port_please !
- ?trace("other node (~p) "
- "closed since port_please.~n",
- [Node]),
- ?shutdown(Node)
- end;
+ do_setup_connect(Driver, Kernel, Node, Address, AddressFamily,
+ Ip, TcpPort, Version, Type, MyNode, Timer);
_ ->
?trace("port_please (~p) "
"failed.~n", [Node]),
@@ -361,6 +310,71 @@ do_setup(Driver, Kernel, Node, Type, MyNode, LongOrShortNames, SetupTime) ->
?shutdown(Node)
end.
+%%
+%% Actual setup of connection
+%%
+do_setup_connect(Driver, Kernel, Node, Address, AddressFamily,
+ Ip, TcpPort, Version, Type, MyNode, Timer) ->
+ dist_util:reset_timer(Timer),
+ case
+ Driver:connect(
+ Ip, TcpPort,
+ connect_options([{active, false}, {packet, 2}]))
+ of
+ {ok, Socket} ->
+ HSData = #hs_data{
+ kernel_pid = Kernel,
+ other_node = Node,
+ this_node = MyNode,
+ socket = Socket,
+ timer = Timer,
+ this_flags = 0,
+ other_version = Version,
+ f_send = fun Driver:send/2,
+ f_recv = fun Driver:recv/3,
+ f_setopts_pre_nodeup =
+ fun(S) ->
+ inet:setopts
+ (S,
+ [{active, false},
+ {packet, 4},
+ nodelay()])
+ end,
+ f_setopts_post_nodeup =
+ fun(S) ->
+ inet:setopts
+ (S,
+ [{active, true},
+ {deliver, port},
+ {packet, 4},
+ nodelay()])
+ end,
+
+ f_getll = fun inet:getll/1,
+ f_address =
+ fun(_,_) ->
+ #net_address{
+ address = {Ip,TcpPort},
+ host = Address,
+ protocol = tcp,
+ family = AddressFamily}
+ end,
+ mf_tick = fun(S) -> ?MODULE:tick(Driver, S) end,
+ mf_getstat = fun ?MODULE:getstat/1,
+ request_type = Type,
+ mf_setopts = fun ?MODULE:setopts/2,
+ mf_getopts = fun ?MODULE:getopts/2
+ },
+ dist_util:handshake_we_started(HSData);
+ _ ->
+ %% Other Node may have closed since
+ %% discovery !
+ ?trace("other node (~p) "
+ "closed since discovery (port_please).~n",
+ [Node]),
+ ?shutdown(Node)
+ end.
+
connect_options(Opts) ->
case application:get_env(kernel, inet_dist_connect_options) of
{ok,ConnectOpts} ->
@@ -430,6 +444,16 @@ get_tcp_address(Driver, Socket) ->
}.
%% ------------------------------------------------------------
+%% Determine if EPMD module supports address resolving. Default
+%% is to use inet:getaddr/2.
+%% ------------------------------------------------------------
+get_address_resolver(EpmdModule) ->
+ case erlang:function_exported(EpmdModule, address_please, 3) of
+ true -> {EpmdModule, address_please};
+ _ -> {inet, getaddr}
+ end.
+
+%% ------------------------------------------------------------
%% Do only accept new connection attempts from nodes at our
%% own LAN, if the check_ip environment parameter is true.
%% ------------------------------------------------------------
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-01 15:01:18 +0000