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diff --git a/erts/doc/src/socket.xml b/erts/doc/src/socket.xml new file mode 100644 index 0000000000..f6195a65b2 --- /dev/null +++ b/erts/doc/src/socket.xml @@ -0,0 +1,650 @@ +<?xml version="1.0" encoding="utf-8" ?> +<!DOCTYPE erlref SYSTEM "erlref.dtd"> + +<erlref> + <header> + <copyright> + <year>2018</year><year>2019</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>socket</title> + <prepared></prepared> + <docno></docno> + <date></date> + <rev></rev> + <file>socket.xml</file> + </header> + <module since="OTP @OTP-14831@">socket</module> + <modulesummary>Socket interface.</modulesummary> + <description> + <p>This module provides an API for the socket interface. + It is used to create, delete and manipulate sockets, + send and receive data.</p> + <p>The idea is that it shall be as "close as possible" to the OS + level socket interface. The only significant addition is that some of + the functions, + e.g. <seealso marker="#recv/3"><c>recv/3</c></seealso>, + has a timeout argument. </p> + <note> + <p>There is currently <em>no</em> support for Windows. </p> + <p>Support for IPv6 has been implemented but <em>not</em> tested. </p> + <p>SCTP has only been partly implemented (and not tested). </p> + </note> + </description> + + <datatypes> + <datatype> + <name name="domain"/> + </datatype> + <datatype> + <name name="type"/> + </datatype> + <datatype> + <name name="protocol"/> + </datatype> + <datatype> + <name>socket()</name> + <desc><p>As returned by + <seealso marker="#open/2"><c>open/2,3,4</c></seealso> and + <seealso marker="#accept/1"><c>accept/1,2</c></seealso>.</p> + </desc> + </datatype> + <datatype> + <name name="ip4_address"/> + </datatype> + <datatype> + <name name="ip6_address"/> + </datatype> + <datatype> + <name name="ip_address"/> + </datatype> + <datatype> + <name name="sockaddr"/> + </datatype> + <datatype> + <name name="sockaddr_in4"/> + </datatype> + <datatype> + <name name="sockaddr_in6"/> + </datatype> + <datatype> + <name name="sockaddr_un"/> + </datatype> + <datatype> + <name name="port_number"/> + </datatype> + <datatype> + <name name="in6_flow_info"/> + </datatype> + <datatype> + <name name="in6_scope_id"/> + </datatype> + <datatype> + <name name="accept_flags"/> + </datatype> + <datatype> + <name name="accept_flag"/> + </datatype> + <datatype> + <name name="send_flags"/> + </datatype> + <datatype> + <name name="send_flag"/> + </datatype> + <datatype> + <name name="recv_flags"/> + </datatype> + <datatype> + <name name="recv_flag"/> + </datatype> + <datatype> + <name name="shutdown_how"/> + </datatype> + <datatype> + <name name="sockopt_level"/> + </datatype> + <datatype> + <name name="otp_socket_option"/> + </datatype> + <datatype> + <name name="socket_option"/> + </datatype> + <datatype> + <name name="ip_socket_option"/> + </datatype> + <datatype> + <name name="ipv6_socket_option"/> + </datatype> + <datatype> + <name name="tcp_socket_option"/> + </datatype> + <datatype> + <name name="udp_socket_option"/> + </datatype> + <datatype> + <name name="sctp_socket_option"/> + </datatype> + <datatype> + <name name="timeval"/> + </datatype> + <datatype> + <name name="ip_tos"/> + </datatype> + <datatype> + <name name="ip_mreq"/> + </datatype> + <datatype> + <name name="ip_mreq_source"/> + </datatype> + <datatype> + <name name="ip_pmtudisc"/> + </datatype> + <datatype> + <name name="ip_msfilter_mode"/> + </datatype> + <datatype> + <name name="ip_msfilter"/> + </datatype> + <datatype> + <name name="ip_pktinfo"/> + </datatype> + <datatype> + <name name="ipv6_mreq"/> + </datatype> + <datatype> + <name name="ipv6_pmtudisc"/> + </datatype> + <datatype> + <name name="ipv6_pktinfo"/> + </datatype> + <datatype> + <name name="sctp_assoc_id"/> + </datatype> + <datatype> + <name name="sctp_sndrcvinfo"/> + </datatype> + <datatype> + <name name="sctp_event_subscribe"/> + </datatype> + <datatype> + <name name="sctp_assocparams"/> + </datatype> + <datatype> + <name name="sctp_initmsg"/> + </datatype> + <datatype> + <name name="sctp_rtoinfo"/> + </datatype> + <datatype> + <name name="msghdr_flag"/> + </datatype> + <datatype> + <name name="msghdr_flags"/> + </datatype> + <datatype> + <name name="msghdr"/> + </datatype> + <datatype> + <name name="cmsghdr_level"/> + </datatype> + <datatype> + <name name="cmsghdr_type"/> + </datatype> + <!-- + <datatype> + <name name="cmsghdr_data"/> + </datatype> + --> + <datatype> + <name name="cmsghdr_recv"/> + </datatype> + <datatype> + <name name="cmsghdr_send"/> + </datatype> + <datatype> + <name name="uint8"/> + </datatype> + <datatype> + <name name="uint16"/> + </datatype> + <datatype> + <name name="uint20"/> + </datatype> + <datatype> + <name name="uint32"/> + </datatype> + <datatype> + <name name="int32"/> + </datatype> + <datatype> + <name name="supports_options_socket"/> + </datatype> + <datatype> + <name name="supports_options_ip"/> + </datatype> + <datatype> + <name name="supports_options_ipv6"/> + </datatype> + <datatype> + <name name="supports_options_tcp"/> + </datatype> + <datatype> + <name name="supports_options_udp"/> + </datatype> + <datatype> + <name name="supports_options_sctp"/> + </datatype> + <datatype> + <name name="supports_options"/> + </datatype> + </datatypes> + + <funcs> + <func> + <name name="accept" arity="1" since="OTP @OTP-14831@"/> + <name name="accept" arity="2" since="OTP @OTP-14831@"/> + <fsummary>Accept a connection on a socket.</fsummary> + <desc> + <p>Accept a connection on a socket.</p> + <p>This call is used with connection-based socket types + (<c>stream</c> or <c>seqpacket</c>). It extracs the first pending + connection request for the listen socket and returns the (newly) + connected socket.</p> + </desc> + </func> + + <func> + <name name="bind" arity="2" since="OTP @OTP-14831@"/> + <fsummary>Bind a name to a socket.</fsummary> + <desc> + <p>Bind a name to a socket.</p> + <p>When a socket is created + (with <seealso marker="#open/2"><c>open</c></seealso>), + it has no address assigned to it. <c>bind</c> assigns the + address specified by the <c>Addr</c> argument.</p> + <p>The rules used for name binding vary between domains.</p> + </desc> + </func> + + <func> + <name name="close" arity="1" since="OTP @OTP-14831@"/> + <fsummary>Close a socket.</fsummary> + <desc> + <p>Closes the socket.</p> + + <note> + <p>Note that for e.g. <c>protocol</c> = <c>tcp</c>, most implementations + doing a close does not guarantee that any data sent is delivered to + the recipient before the close is detected at the remote side. </p> + <p>One way to handle this is to use the + <seealso marker="#shutdown/2"><c>shutdown</c></seealso> + function + (<c>socket:shutdown(Socket, write)</c>) to signal that no more data is + to be sent and then wait for the read side of the socket to be closed.</p> + </note> + </desc> + </func> + + <func> + <name name="connect" arity="2" since="OTP @OTP-14831@"/> + <name name="connect" arity="3" since="OTP @OTP-14831@"/> + <fsummary>Initiate a connection on a socket.</fsummary> + <desc> + <p>This function connects the socket to the address + specied by the <c>SockAddr</c> argument.</p> + </desc> + </func> + + <func> + <name name="getopt" arity="3" clause_i="1" since="OTP @OTP-14831@"/> + <name name="getopt" arity="3" clause_i="2" since="OTP @OTP-14831@"/> + <name name="getopt" arity="3" clause_i="3" since="OTP @OTP-14831@"/> + <name name="getopt" arity="3" clause_i="4" since="OTP @OTP-14831@"/> + <name name="getopt" arity="3" clause_i="5" since="OTP @OTP-14831@"/> + <name name="getopt" arity="3" clause_i="6" since="OTP @OTP-14831@"/> + <name name="getopt" arity="3" clause_i="7" since="OTP @OTP-14831@"/> + <fsummary>Get an option on a socket.</fsummary> + <desc> + <p>Get an option on a socket.</p> + <p>What properties are valid depend both on <c>Level</c> and + on what kind of socket it is (<c>domain</c>, <c>type</c> and + <c>protocol</c>).</p> + + <p>See the + <seealso marker="socket_usage#socket_options">socket options</seealso> + chapter of the users guide for more info. </p> + + <note><p>Not all options are valid on all platforms. That is, + even if "we" support an option, that does not mean that the + underlying OS does.</p></note> + + </desc> + </func> + + <func> + <name name="getopt" arity="3" clause_i="8" since="OTP @OTP-14831@"/> + <fsummary>Get an option on a socket.</fsummary> + <desc> + <p>Get an option on a socket.</p> + <p>What properties are valid depend both on <c>Level</c> and + on what kind of socket it is (<c>domain</c>, <c>type</c> and + <c>protocol</c>).</p> + <p>When specifying <c>Level</c> as an integer, and therefor + using "native mode", it is *currently* up to the caller to + know how to interpret the result.</p> + + <p>See the + <seealso marker="socket_usage#socket_options">socket options</seealso> + chapter of the users guide for more info. </p> + + <note><p>Not all options are valid on all platforms. That is, + even if "we" support an option, that does not mean that the + underlying OS does.</p></note> + </desc> + </func> + + <func> + <name name="listen" arity="1" since="OTP @OTP-14831@"/> + <name name="listen" arity="2" since="OTP @OTP-14831@"/> + <fsummary>Listen for connections on a socket.</fsummary> + <desc> + <p>Listen for connections on a socket.</p> + </desc> + </func> + + <func> + <name name="open" arity="2" since="OTP @OTP-14831@"/> + <name name="open" arity="3" since="OTP @OTP-14831@"/> + <name name="open" arity="4" since="OTP @OTP-14831@"/> + <fsummary>Create an endpoint for communication.</fsummary> + <desc> + <p>Creates an endpoint (socket) for communication.</p> + <p>For some <c>types</c> there is a default protocol, which will + be used if no protocol is specified: </p> + + <list> + <item><p><c>stream</c>: <c>tcp</c></p></item> + <item><p><c>dgram</c>: <c>udp</c></p></item> + <item><p><c>seqpacket</c>: <c>sctp</c></p></item> + </list> + + <p>The <c>Extra</c> argument is intended for "obscure" options. + Currently the only supported option is <c>netns</c>, which + is only supported on the linux platform.</p> + </desc> + </func> + + <func> + <name name="peername" arity="1" since="OTP @OTP-14831@"/> + <fsummary>Get name of connected socket peer.</fsummary> + <desc> + <p>Returns the address of the peer connected to the socket.</p> + </desc> + </func> + + <func> + <name name="recv" arity="1" since="OTP @OTP-14831@"/> + <name name="recv" arity="2" since="OTP @OTP-14831@"/> + <name name="recv" arity="3" clause_i="1" since="OTP @OTP-14831@"/> + <name name="recv" arity="3" clause_i="2" since="OTP @OTP-14831@"/> + <name name="recv" arity="4" since="OTP @OTP-14831@"/> + <fsummary>Receive a message from a socket.</fsummary> + <desc> + <p>Receive a message from a socket.</p> + <p>There is a special case for the argument <c>Length</c>. + If it is set to zero (0), it means "give me everything you + currently have".</p> + </desc> + </func> + + <func> + <name name="recvfrom" arity="1" since="OTP @OTP-14831@"/> + <name name="recvfrom" arity="2" since="OTP @OTP-14831@"/> + <name name="recvfrom" arity="3" clause_i="1" since="OTP @OTP-14831@"/> + <name name="recvfrom" arity="3" clause_i="2" since="OTP @OTP-14831@"/> + <name name="recvfrom" arity="3" clause_i="3" since="OTP @OTP-14831@"/> + <name name="recvfrom" arity="4" since="OTP @OTP-14831@"/> + <fsummary>Receive a message from a socket.</fsummary> + <desc> + <p>Receive a message from a socket.</p> + <p>This function reads "messages", which means that regardless of + how much we want to read, it returns when we get a message.</p> + <p>The <c>BufSz</c> argument basically defines the size of the + receive buffer. By setting the value to zero (0), the configured + size (setopt with <c>Level</c> = <c>otp</c> and <c>Key</c> = <c>rcvbuf</c>) + is used.</p> + <p>It may be impossible to know what (buffer) size is appropriate + "in advance", and in those cases it may be convenient to use the + (recv) 'peek' flag. When this flag is provided, the message is *not* + "consumed" from the underlying buffers, so another recvfrom call + is needed, possibly with a then adjusted buffer size.</p> + </desc> + </func> + + <func> + <name name="recvmsg" arity="1" since="OTP @OTP-14831@"/> + <name name="recvmsg" arity="2" clause_i="1" since="OTP @OTP-14831@"/> + <name name="recvmsg" arity="2" clause_i="2" since="OTP @OTP-14831@"/> + <name name="recvmsg" arity="3" clause_i="1" since="OTP @OTP-14831@"/> + <name name="recvmsg" arity="3" clause_i="2" since="OTP @OTP-14831@"/> + <name name="recvmsg" arity="5" since="OTP @OTP-14831@"/> + <fsummary>Receive a message from a socket.</fsummary> + <desc> + <p>Receive a message from a socket.</p> + <p>This function reads "messages", which means that regardless of + how much we want to read, it returns when we get a message.</p> + <p>The message will be delivered in the form of a <c>msghdr()</c>, + which may contain the source address (if socket not connected), + a list of <c>cmsghdr_recv()</c> (depends on what socket options have + been set and what the protocol and platform supports) and + also a set of flags, providing further info about the read. </p> + + <p>The <c>BufSz</c> argument basically defines the size of the + receive buffer. By setting the value to zero (0), the configured + size (setopt with <c>Level</c> = <c>otp</c> and <c>Key</c> = <c>rcvbuf</c>) + is used.</p> + + <p>The <c>CtrlSz</c> argument basically defines the size of the + receive buffer for the control messages. + By setting the value to zero (0), the configured size (setopt + with <c>Level</c> = <c>otp</c>) is used.</p> + + <p>It may be impossible to know what (buffer) size is appropriate + "in advance", and in those cases it may be convenient to use the + (recv) 'peek' flag. When this flag is provided, the message is *not* + "consumed" from the underlying buffers, so another recvmsg call + is needed, possibly with a then adjusted buffer size.</p> + </desc> + </func> + + <func> + <name name="send" arity="2" since="OTP @OTP-14831@"/> + <name name="send" arity="3" clause_i="1" since="OTP @OTP-14831@"/> + <name name="send" arity="3" clause_i="2" since="OTP @OTP-14831@"/> + <name name="send" arity="4" since="OTP @OTP-14831@"/> + <fsummary>Send a message on a socket.</fsummary> + <desc> + <p>Send a message on a connected socket.</p> + </desc> + </func> + + <func> + <name name="sendmsg" arity="2" since="OTP @OTP-14831@"/> + <name name="sendmsg" arity="3" clause_i="1" since="OTP @OTP-14831@"/> + <name name="sendmsg" arity="3" clause_i="2" since="OTP @OTP-14831@"/> + <name name="sendmsg" arity="4" since="OTP @OTP-14831@"/> + <fsummary>Send a message on a socket.</fsummary> + <desc> + <p>Send a message on a socket. The destination, if needed + (socket <em>not</em> connected) is provided in the <c>MsgHdr</c>, + which also contains the message to send, + The <c>MsgHdr</c> may also contain an list of optional <c>cmsghdr_send()</c> + (depends on what the protocol and platform supports).</p> + + <p>Unlike the <seealso marker="#send/2"><c>send</c></seealso> function, + this one sends <em>one message</em>. + This means that if, for whatever reason, its not possible to send the + message in one go, the function will instead return with the + <em>remaining</em> data (<c>{ok, Remaining}</c>). Thereby leaving it + up to the caller to decide what to do (retry with the remaining data + of give up). </p> + + </desc> + </func> + + <func> + <name name="sendto" arity="3" since="OTP @OTP-14831@"/> + <name name="sendto" arity="4" clause_i="1" since="OTP @OTP-14831@"/> + <name name="sendto" arity="4" clause_i="2" since="OTP @OTP-14831@"/> + <name name="sendto" arity="5" since="OTP @OTP-14831@"/> + <fsummary>Send a message on a socket.</fsummary> + <desc> + <p>Send a message on a socket, to the specified destination.</p> + </desc> + </func> + + <func> + <name name="setopt" arity="4" clause_i="1" since="OTP @OTP-14831@"/> + <name name="setopt" arity="4" clause_i="2" since="OTP @OTP-14831@"/> + <name name="setopt" arity="4" clause_i="3" since="OTP @OTP-14831@"/> + <name name="setopt" arity="4" clause_i="4" since="OTP @OTP-14831@"/> + <name name="setopt" arity="4" clause_i="5" since="OTP @OTP-14831@"/> + <name name="setopt" arity="4" clause_i="6" since="OTP @OTP-14831@"/> + <name name="setopt" arity="4" clause_i="7" since="OTP @OTP-14831@"/> + <fsummary>Set options on a socket.</fsummary> + <desc> + <p>Set options on a socket.</p> + <p>What properties are valid depend both on <c>Level</c> and on + what kind of socket it is (<c>domain</c>, <c>type</c> and + <c>protocol</c>).</p> + + <p>See the + <seealso marker="socket_usage#socket_options">socket options</seealso> + chapter of the users guide for more info. </p> + + <note><p>Not all options are valid on all platforms. That is, + even if "we" support an option, that does not mean that the + underlying OS does.</p></note> + + <note><p>Sockets are set 'non-blocking' when created, so this option + is *not* available (as it would adversely effect the Erlang VM + to set a socket 'blocking').</p></note> + </desc> + </func> + + <func> + <name name="setopt" arity="4" clause_i="8" since="OTP @OTP-14831@"/> + <fsummary>Set options on a socket.</fsummary> + <desc> + <p>Set options on a socket.</p> + <p>What properties are valid depend both on <c>Level</c> and on + what kind of socket it is (<c>domain</c>, <c>type</c> and + <c>protocol</c>).</p> + + <p>See the + <seealso marker="socket_usage#socket_options">socket options</seealso> + chapter of the users guide for more info. </p> + + <note><p>Not all options are valid on all platforms. That is, + even if "we" support an option, that does not mean that the + underlying OS does.</p></note> + + <note><p>Sockets are set 'non-blocking' when created, so this option + is *not* available (as it would adversely effect the Erlang VM + to set a socket 'blocking').</p></note> + </desc> + </func> + + <func> + <name name="shutdown" arity="2" since="OTP @OTP-14831@"/> + <fsummary>Shut down part of a full-duplex connection.</fsummary> + <desc> + <p>Shut down all or part of a full-duplex connection.</p> + </desc> + </func> + + <func> + <name name="sockname" arity="1" since="OTP @OTP-14831@"/> + <fsummary>Get socket name.</fsummary> + <desc> + <p>Returns the current address to which the socket is bound.</p> + </desc> + </func> + + <func> + <name name="supports" arity="0" since="OTP @OTP-14831@"/> + <name name="supports" arity="1" clause_i="1" since="OTP @OTP-14831@"/> + <name name="supports" arity="1" clause_i="2" since="OTP @OTP-14831@"/> + <name name="supports" arity="1" clause_i="3" since="OTP @OTP-14831@"/> + <name name="supports" arity="1" clause_i="4" since="OTP @OTP-14831@"/> + <name name="supports" arity="2" clause_i="1" since="OTP @OTP-14831@"/> + <name name="supports" arity="2" clause_i="2" since="OTP @OTP-14831@"/> + <name name="supports" arity="2" clause_i="3" since="OTP @OTP-14831@"/> + <name name="supports" arity="2" clause_i="4" since="OTP @OTP-14831@"/> + <name name="supports" arity="2" clause_i="5" since="OTP @OTP-14831@"/> + <name name="supports" arity="2" clause_i="6" since="OTP @OTP-14831@"/> + <name name="supports" arity="2" clause_i="7" since="OTP @OTP-14831@"/> + <name name="supports" arity="3" clause_i="1" since="OTP @OTP-14831@"/> + <name name="supports" arity="3" clause_i="2" since="OTP @OTP-14831@"/> + <name name="supports" arity="3" clause_i="3" since="OTP @OTP-14831@"/> + <name name="supports" arity="3" clause_i="4" since="OTP @OTP-14831@"/> + <name name="supports" arity="3" clause_i="5" since="OTP @OTP-14831@"/> + <name name="supports" arity="3" clause_i="6" since="OTP @OTP-14831@"/> + <name name="supports" arity="3" clause_i="7" since="OTP @OTP-14831@"/> + <fsummary>Report info about what the platform supports.</fsummary> + <desc> + <p>This function intends to retreive information about what the + platform supports. Such as if SCTP is supported. Or which socket + options are supported. </p> + </desc> + </func> + + </funcs> + <section> + <title>Examples</title> + <marker id="examples"></marker> + <code type="none"> +client(Addr, SAddr, SPort) -> + {ok, Sock} = socket:open(inet, stream, tcp), + {ok, _} = socket:bind(Sock, #{family => inet, + addr => Addr}), + ok = socket:connect(Sock, #{family => inet, + addr => SAddr, + port => SPort}), + Msg = list_to_binary("hello"), + ok = socket:send(Sock, Msg), + ok = socket:shutdown(Sock, write), + {ok, Msg} = socket:recv(Sock), + ok = socket:close(Sock). + +server(Addr, Port) -> + {ok, LSock} = socket:open(inet, stream, tcp), + {ok, _} = socket:bind(LSock, #{family => inet, + port => Port, + addr => Addr}), + ok = socket:listen(LSock), + {ok, Sock} = socket:accept(LSock), + {ok, Msg} = socket:recv(Sock), + ok = socket:send(Sock, Msg), + ok = socket:shutdown(Sock, write), + ok = socket:close(Sock), + ok = socket:close(LSock). + </code> + </section> +</erlref> + |