diff options
Diffstat (limited to 'lib/kernel/doc/src/inet.xml')
-rw-r--r-- | lib/kernel/doc/src/inet.xml | 460 |
1 files changed, 403 insertions, 57 deletions
diff --git a/lib/kernel/doc/src/inet.xml b/lib/kernel/doc/src/inet.xml index 4c4a5c39cb..87b08e4e36 100644 --- a/lib/kernel/doc/src/inet.xml +++ b/lib/kernel/doc/src/inet.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1997</year><year>2016</year> + <year>1997</year><year>2018</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -75,8 +75,8 @@ Address ip_address() ------- ------------ ::1 {0,0,0,0,0,0,0,1} ::192.168.42.2 {0,0,0,0,0,0,(192 bsl 8) bor 168,(42 bsl 8) bor 2} -FFFF::192.168.42.2 - {16#FFFF,0,0,0,0,0,(192 bsl 8) bor 168,(42 bsl 8) bor 2} +::FFFF:192.168.42.2 + {0,0,0,0,0,16#FFFF,(192 bsl 8) bor 168,(42 bsl 8) bor 2} 3ffe:b80:1f8d:2:204:acff:fe17:bf38 {16#3ffe,16#b80,16#1f8d,16#2,16#204,16#acff,16#fe17,16#bf38} fe80::204:acff:fe17:bf38 @@ -87,8 +87,8 @@ fe80::204:acff:fe17:bf38 <pre> 1> <input>inet:parse_address("192.168.42.2").</input> {ok,{192,168,42,2}} -2> <input>inet:parse_address("FFFF::192.168.42.2").</input> -{ok,{65535,0,0,0,0,0,49320,10754}}</pre> +2> <input>inet:parse_address("::FFFF:192.168.42.2").</input> +{ok,{0,0,0,0,0,65535,49320,10754}}</pre> </description> <datatypes> @@ -177,6 +177,100 @@ fe80::204:acff:fe17:bf38 </desc> </datatype> <datatype> + <name name="ancillary_data"/> + <desc> + <p> + Ancillary data received with the data packet + or read with the socket option + <seealso marker="gen_tcp#type-pktoptions_value"> + <c>pktoptions</c> + </seealso> + from a TCP socket. + </p> + <p> + The value(s) correspond to the currently active socket + <seealso marker="#type-socket_setopt">options</seealso> + <seealso marker="inet#option-recvtos"><c>recvtos</c></seealso>, + <seealso marker="inet#option-recvtclass"><c>recvtclass</c></seealso> + and + <seealso marker="inet#option-recvttl"><c>recvttl</c></seealso>. + </p> + </desc> + </datatype> + <datatype> + <name name="getifaddrs_ifopts"/> + <desc> + <p> + Interface address description list returned from + <seealso marker="#getifaddrs/0"><c>getifaddrs/0,1</c></seealso> + for a named interface, translated from the returned + data of the POSIX API function <c>getaddrinfo()</c>. + </p> + <p> + <c><anno>Hwaddr</anno></c> is hardware dependent, + for example, on Ethernet interfaces it is + the 6-byte Ethernet address (MAC address (EUI-48 address)). + </p> + <p> + The tuples <c>{addr,<anno>Addr</anno>}</c>, + <c>{netmask,<anno>Netmask</anno>}</c>, and possibly + <c>{broadaddr,<anno>Broadaddr</anno>}</c> or + <c>{dstaddr,<anno>Dstaddr</anno>}</c> + are repeated in the list + if the interface has got multiple addresses. + An interface may have multiple <c>{flag,_}</c> tuples + for example if it has different flags + for different address families. + Multiple <c>{hwaddr,<anno>Hwaddr</anno>}</c> tuples + is hard to say anything definite about, though. + The tuple <c>{flag,<anno>Flags</anno>}</c> is mandatory, + all others are optional. + </p> + <p> + Do not rely too much on the order + of <c><anno>Flags</anno></c> atoms + or the <c><anno>Ifopt</anno></c> tuples. + There are however some rules: + </p> + <list type="bulleted"> + <item><p> + A <c>{flag,_}</c> tuple applies to all other tuples that follow. + </p></item> + <item><p> + Immediately after <c>{addr,_}</c> follows <c>{netmask,_}</c>. + </p></item> + <item><p> + Immediately thereafter may <c>{broadaddr,_}</c> follow + if <c>broadcast</c> is member of <c><anno>Flags</anno></c>, + or <c>{dstaddr,_}</c> if <c>pointtopoint</c> + is member of <c><anno>Flags</anno></c>. + Both <c>{dstaddr,_}</c> and <c>{broadaddr,_}</c> + does not occur for the same <c>{addr,_}</c>. + </p></item> + <item><p> + Any <c>{netmask,_}</c>, <c>{broadaddr,_}</c>, or + <c>{dstaddr,_}</c> tuples that follow an + <c>{addr,<anno>Addr</anno>}</c> + tuple concerns the address <c><anno>Addr</anno></c>. + </p></item> + </list> + <p> + The tuple <c>{hwaddr,_}</c> is not returned on Solaris, as the + hardware address historically belongs to the link layer + and it is not returned by the Solaris API function + <c>getaddrinfo()</c>. + </p> + <warning> + <p> + On Windows, the data is fetched from different + OS API functions, so the <c><anno>Netmask</anno></c> + and <c><anno>Broadaddr</anno></c> values may be calculated, + just as some <c><anno>Flags</anno></c> values. + </p> + </warning> + </desc> + </datatype> + <datatype> <name name="posix"/> <desc> <p>An atom that is named from the POSIX error codes used in Unix, @@ -197,6 +291,9 @@ fe80::204:acff:fe17:bf38 <datatype> <name name="address_family"/> </datatype> + <datatype> + <name name="socket_protocol"/> + </datatype> </datatypes> <funcs> @@ -222,11 +319,18 @@ fe80::204:acff:fe17:bf38 <name name="get_rc" arity="0"/> <fsummary>Return a list of IP configuration parameters.</fsummary> <desc> - <p>Returns the state of the <c>Inet</c> configuration database in + <p> + Returns the state of the <c>Inet</c> configuration database in form of a list of recorded configuration parameters. For more information, see <seealso marker="erts:inet_cfg">ERTS User's Guide: Inet Configuration</seealso>. - Only parameters with other than default values are returned.</p> + </p> + <p> + Only actual parameters with other than default values + are returned, for example not directives that specify + other sources for configuration parameters nor + directives that clear parameters. + </p> </desc> </func> @@ -267,9 +371,7 @@ fe80::204:acff:fe17:bf38 <p>Returns a <c>hostent</c> record for the host with the specified hostname.</p> <p>If resolver option <c>inet6</c> is <c>true</c>, - an IPv6 address is looked up. If that fails, - the IPv4 address is looked up and returned on - IPv6-mapped IPv4 format.</p> + an IPv6 address is looked up.</p> </desc> </func> @@ -295,38 +397,64 @@ fe80::204:acff:fe17:bf38 <name name="getifaddrs" arity="0"/> <fsummary>Return a list of interfaces and their addresses.</fsummary> <desc> - <p>Returns a list of 2-tuples containing interface names and the - interface addresses. <c><anno>Ifname</anno></c> is a Unicode string. - <c><anno>Hwaddr</anno></c> is hardware dependent, for example, on - Ethernet interfaces - it is the 6-byte Ethernet address (MAC address (EUI-48 address)).</p> - <p>The tuples <c>{addr,<anno>Addr</anno>}</c>, <c>{netmask,_}</c>, and - <c>{broadaddr,_}</c> are repeated in the result list if the interface - has multiple addresses. If you come across an interface with - multiple <c>{flag,_}</c> or <c>{hwaddr,_}</c> tuples, you have - a strange interface or possibly a bug in this function. The tuple - <c>{flag,_}</c> is mandatory, all others are optional.</p> - <p>Do not rely too much on the order of <c><anno>Flag</anno></c> atoms - or <c><anno>Ifopt</anno></c> tuples. There are however some rules:</p> - <list type="bulleted"> - <item><p>Immediately after - <c>{addr,_}</c> follows <c>{netmask,_}</c>.</p></item> - <item><p>Immediately thereafter follows <c>{broadaddr,_}</c> if flag - <c>broadcast</c> is <em>not</em> set and flag - <c>pointtopoint</c> <em>is</em> set.</p></item> - <item><p>Any <c>{netmask,_}</c>, <c>{broadaddr,_}</c>, or - <c>{dstaddr,_}</c> tuples that follow an <c>{addr,_}</c> - tuple concerns that address.</p></item> - </list> - <p>The tuple <c>{hwaddr,_}</c> is not returned on Solaris, as the - hardware address historically belongs to the link layer and only - the superuser can read such addresses.</p> - <warning> - <p>On Windows, the data is fetched from different OS API functions, - so the <c><anno>Netmask</anno></c> and <c><anno>Broadaddr</anno></c> - values can be calculated, just as some <c><anno>Flag</anno></c> - values. Report flagrant bugs.</p> - </warning> + <p> + Returns a list of 2-tuples containing interface names and + the interfaces' addresses. <c><anno>Ifname</anno></c> + is a Unicode string and + <c><anno>Ifopts</anno></c> is a list of + interface address description tuples. + </p> + <p> + The interface address description tuples + are documented under the type of the + <seealso marker="#type-getifaddrs_ifopts"> + <c><anno>Ifopts</anno></c> + </seealso> + value. + </p> + </desc> + </func> + + <func> + <name>getifaddrs(Opts) -> + {ok, [{Ifname, Ifopts}]} | {error, Posix} + </name> + <fsummary>Return a list of interfaces and their addresses.</fsummary> + <type> + <v> + Opts = [{netns, Namespace}] + </v> + <v> + Namespace = + <seealso marker="file#type-filename_all"> + file:filename_all() + </seealso> + </v> + <v>Ifname = string()</v> + <v> + Ifopts = + <seealso marker="#type-getifaddrs_ifopts"> + getifaddrs_ifopts() + </seealso> + </v> + <v>Posix = <seealso marker="#type-posix">posix()</seealso></v> + </type> + <desc> + <p> + The same as + <seealso marker="#getifaddrs/0"><c>getifaddrs/0</c></seealso> + but the <c>Option</c> + <c>{netns, Namespace}</c> sets a network namespace + for the OS call, on platforms that supports that feature. + </p> + <p> + See the socket option + <seealso marker="#option-netns"> + <c>{netns, Namespace}</c> + </seealso> + under + <seealso marker="#setopts/2"><c>setopts/2</c></seealso>. + </p> </desc> </func> @@ -336,7 +464,11 @@ fe80::204:acff:fe17:bf38 <desc> <p>Gets one or more options for a socket. For a list of available options, see - <seealso marker="#setopts/2"><c>setopts/2</c></seealso>.</p> + <seealso marker="#setopts/2"><c>setopts/2</c></seealso>. + See also the description for the type + <seealso marker="gen_tcp#type-pktoptions_value"> + <c>gen_tcp:pktoptions_value()</c> + </seealso>.</p> <p>The number of elements in the returned <c><anno>OptionValues</anno></c> list does not necessarily correspond to the number of options @@ -352,7 +484,7 @@ fe80::204:acff:fe17:bf38 socket options not (explicitly) supported by the emulator. The use of raw socket options makes the code non-portable, but allows the Erlang programmer to take advantage of unusual features - present on the current platform.</p> + present on a particular platform.</p> <p><c>RawOptReq</c> consists of tag <c>raw</c> followed by the protocol level, the option number, and either a binary or the size, in bytes, of the @@ -454,6 +586,61 @@ get_tcpi_sacked(Sock) -> </func> <func> + <name name="i" arity="0" /> + <name name="i" arity="1" /> + <name name="i" arity="2" /> + <fsummary>Displays information and statistics about sockets on the terminal</fsummary> + <desc> + <p> + Lists all TCP, UDP and SCTP sockets, including those that the Erlang runtime system uses as well as + those created by the application. + </p> + <p> + The following options are available: + </p> + + <taglist> + <tag><c>port</c></tag> + <item> + <p>The internal index of the port.</p> + </item> + <tag><c>module</c></tag> + <item> + <p>The callback module of the socket.</p> + </item> + <tag><c>recv</c></tag> + <item> + <p>Number of bytes received by the socket.</p> + </item> + <tag><c>sent</c></tag> + <item> + <p>Number of bytes sent from the socket.</p> + </item> + <tag><c>owner</c></tag> + <item> + <p>The socket owner process.</p> + </item> + <tag><c>local_address</c></tag> + <item> + <p>The local address of the socket.</p> + </item> + <tag><c>foreign_address</c></tag> + <item> + <p>The address and port of the other end of the connection.</p> + </item> + <tag><c>state</c></tag> + <item> + <p>The connection state.</p> + </item> + <tag><c>type</c></tag> + <item> + <p>STREAM or DGRAM or SEQPACKET.</p> + </item> + </taglist> + </desc> + </func> + + <func> <name name="ntoa" arity="1" /> <fsummary>Convert IPv6/IPV4 address to ASCII.</fsummary> <desc> @@ -517,6 +704,19 @@ get_tcpi_sacked(Sock) -> </func> <func> + <name name="ipv4_mapped_ipv6_address" arity="1" /> + <fsummary>Convert to and from IPv4-mapped IPv6 address.</fsummary> + <desc> + <p> + Convert an IPv4 address to an IPv4-mapped IPv6 address + or the reverse. When converting from an IPv6 address + all but the 2 low words are ignored so this function also + works on some other types of addresses than IPv4-mapped. + </p> + </desc> + </func> + + <func> <name name="parse_strict_address" arity="1" /> <fsummary>Parse an IPv4 or IPv6 address strict.</fsummary> <desc> @@ -658,18 +858,23 @@ get_tcpi_sacked(Sock) -> </item> <tag><c>{buffer, Size}</c></tag> <item> - <p>The size of the user-level software buffer used by + <p>The size of the user-level buffer used by the driver. Not to be confused with options <c>sndbuf</c> and <c>recbuf</c>, which correspond to the - Kernel socket buffers. It is recommended - to have <c>val(buffer) >= max(val(sndbuf),val(recbuf))</c> to + Kernel socket buffers. For TCP it is recommended + to have <c>val(buffer) >= val(recbuf)</c> to avoid performance issues because of unnecessary copying. + For UDP the same recommendation applies, but the max should + not be larger than the MTU of the network path. <c>val(buffer)</c> is automatically set to the above - maximum when values <c>sndbuf</c> or <c>recbuf</c> are set. - However, as the sizes set for <c>sndbuf</c> and <c>recbuf</c> + maximum when <c>recbuf</c> is set. + However, as the size set for <c>recbuf</c> usually become larger, you are encouraged to use <seealso marker="#getopts/2"><c>getopts/2</c></seealso> to analyze the behavior of your operating system.</p> + <p>Note that this is also the maximum amount of data that can be + received from a single recv call. If you are using higher than + normal MTU consider setting buffer higher.</p> </item> <tag><c>{delay_send, Boolean}</c></tag> <item> @@ -844,20 +1049,29 @@ get_tcpi_sacked(Sock) -> </item> <tag><c>{mode, Mode :: binary | list}</c></tag> <item> - <p>Received <c>Packet</c> is delivered as defined by <c>Mode</c>. + <p> + Received <c>Packet</c> is delivered as defined by <c>Mode</c>. </p> </item> - <tag><c>{netns, Namespace :: file:filename_all()}</c></tag> + <tag> + <marker id="option-netns"/> + <c>{netns, Namespace :: file:filename_all()}</c> + </tag> <item> - <p>Sets a network namespace for the socket. Parameter + <p> + Sets a network namespace for the socket. Parameter <c>Namespace</c> is a filename defining the namespace, for example, <c>"/var/run/netns/example"</c>, typically created by command <c>ip netns add example</c>. This option must be used in a function call that creates a socket, that is, <seealso marker="gen_tcp#connect/3"><c>gen_tcp:connect/3,4</c></seealso>, <seealso marker="gen_tcp#listen/2"><c>gen_tcp:listen/2</c></seealso>, - <seealso marker="gen_udp#open/1"><c>gen_udp:open/1,2</c></seealso>, or - <seealso marker="gen_sctp#open/0"><c>gen_sctp:open/0,1,2</c></seealso>.</p> + <seealso marker="gen_udp#open/1"><c>gen_udp:open/1,2</c></seealso> + or + <seealso marker="gen_sctp#open/0"><c>gen_sctp:open/0,1,2</c></seealso>, + and also + <seealso marker="#getifaddrs/1"><c>getifaddrs/1</c></seealso>. + </p> <p>This option uses the Linux-specific syscall <c>setns()</c>, such as in Linux kernel 3.0 or later, and therefore only exists when the runtime system @@ -893,6 +1107,32 @@ setcap cap_sys_admin,cap_sys_ptrace,cap_dac_read_search+epi beam.smp</code> <seealso marker="file#native_name_encoding/0"><c>file:native_name_encoding/0</c></seealso>.</p></item> </list> </item> + <tag><c>{bind_to_device, Ifname :: binary()}</c></tag> + <item> + <p>Binds a socket to a specific network interface. This option + must be used in a function call that creates a socket, that is, + <seealso marker="gen_tcp#connect/3"><c>gen_tcp:connect/3,4</c></seealso>, + <seealso marker="gen_tcp#listen/2"><c>gen_tcp:listen/2</c></seealso>, + <seealso marker="gen_udp#open/1"><c>gen_udp:open/1,2</c></seealso>, or + <seealso marker="gen_sctp#open/0"><c>gen_sctp:open/0,1,2</c></seealso>.</p> + <p>Unlike <seealso marker="#getifaddrs/0"><c>getifaddrs/0</c></seealso>, Ifname + is encoded a binary. In the unlikely case that a system is using + non-7-bit-ASCII characters in network device names, special care + has to be taken when encoding this argument.</p> + <p>This option uses the Linux-specific socket option + <c>SO_BINDTODEVICE</c>, such as in Linux kernel 2.0.30 or later, + and therefore only exists when the runtime system + is compiled for such an operating system.</p> + <p>Before Linux 3.8, this socket option could be set, but could not retrieved + with <seealso marker="#getopts/2"><c>getopts/2</c></seealso>. Since Linux 3.8, + it is readable.</p> + <p>The virtual machine also needs elevated privileges, either + running as superuser or (for Linux) having capability + <c>CAP_NET_RAW</c>.</p> + <p>The primary use case for this option is to bind sockets into + <url href="http://www.kernel.org/doc/Documentation/networking/vrf.txt">Linux VRF instances</url>. + </p> + </item> <tag><c>list</c></tag> <item> <p>Received <c>Packet</c> is delivered as a list.</p> @@ -907,9 +1147,21 @@ setcap cap_sys_admin,cap_sys_ptrace,cap_dac_read_search+epi beam.smp</code> is turned on for the socket, which means that also small amounts of data are sent immediately.</p> </item> + <tag><c>{nopush, Boolean}</c>(TCP/IP sockets)</tag> + <item> + <p>This translates to <c>TCP_NOPUSH</c> on BSD and + to <c>TCP_CORK</c> on Linux.</p> + <p>If <c>Boolean == true</c>, the corresponding option + is turned on for the socket, which means that small + amounts of data are accumulated until a full MSS-worth + of data is available or this option is turned off.</p> + <p>Note that while <c>TCP_NOPUSH</c> socket option is available on OSX, its semantics + is very different (e.g., unsetting it does not cause immediate send + of accumulated data). Hence, <c>nopush</c> option is intentionally ignored on OSX.</p> + </item> <tag><c>{packet, PacketType}</c>(TCP/IP sockets)</tag> <item> - <p>Defines the type of packets to use for a socket. + <p><marker id="packet"/>Defines the type of packets to use for a socket. Possible values:</p> <taglist> <tag><c>raw | 0</c></tag> @@ -1008,6 +1260,100 @@ setcap cap_sys_admin,cap_sys_ptrace,cap_dac_read_search+epi beam.smp</code> the socket. You are encouraged to use <seealso marker="#getopts/2"><c>getopts/2</c></seealso> to retrieve the size set by your operating system.</p> + <marker id="option-recvtclass"></marker> + </item> + <tag><c>{recvtclass, Boolean}</c></tag> + <item> + <p> + If set to <c>true</c> activates returning the received + <c>TCLASS</c> value on platforms that implements + the protocol <c>IPPROTO_IPV6</c> + option <c>IPV6_RECVTCLASS</c> or <c>IPV6_2292RECVTCLASS</c> + for the socket. + The value is returned as a <c>{tclass,TCLASS}</c> tuple + regardless of if the platform returns an <c>IPV6_TCLASS</c> + or an <c>IPV6_RECVTCLASS</c> CMSG value. + </p> + <p> + For packet oriented sockets that supports receiving + ancillary data with the payload data + (<c>gen_udp</c> and <c>gen_sctp</c>), + the <c>TCLASS</c> value is returned + in an extended return tuple contained in an + <seealso marker="inet#type-ancillary_data"> + ancillary data + </seealso> + list. + For stream oriented sockets (<c>gen_tcp</c>) + the only way to get the <c>TCLASS</c> + value is if the platform supports the + <seealso marker="gen_tcp#type-pktoptions_value"> + <c>pktoptions</c> + </seealso> + option. + </p> + <marker id="option-recvtos"></marker> + </item> + <tag><c>{recvtos, Boolean}</c></tag> + <item> + <p> + If set to <c>true</c> activates returning the received + <c>TOS</c> value on platforms that implements + the protocol <c>IPPROTO_IP</c> option <c>IP_RECVTOS</c> + for the socket. + The value is returned as a <c>{tos,TOS}</c> tuple + regardless of if the platform returns an <c>IP_TOS</c> + or an <c>IP_RECVTOS</c> CMSG value. + </p> + <p> + For packet oriented sockets that supports receiving + ancillary data with the payload data + (<c>gen_udp</c> and <c>gen_sctp</c>), + the <c>TOS</c> value is returned + in an extended return tuple contained in an + <seealso marker="inet#type-ancillary_data"> + ancillary data + </seealso> + list. + For stream oriented sockets (<c>gen_tcp</c>) + the only way to get the <c>TOS</c> + value is if the platform supports the + <seealso marker="gen_tcp#type-pktoptions_value"> + <c>pktoptions</c> + </seealso> + option. + </p> + <marker id="option-recvttl"></marker> + </item> + <tag><c>{recvttl, Boolean}</c></tag> + <item> + <p> + If set to <c>true</c> activates returning the received + <c>TTL</c> value on platforms that implements + the protocol <c>IPPROTO_IP</c> option <c>IP_RECVTTL</c> + for the socket. + The value is returned as a <c>{ttl,TTL}</c> tuple + regardless of if the platform returns an <c>IP_TTL</c> + or an <c>IP_RECVTTL</c> CMSG value. + </p> + <p> + For packet oriented sockets that supports receiving + ancillary data with the payload data + (<c>gen_udp</c> and <c>gen_sctp</c>), + the <c>TTL</c> value is returned + in an extended return tuple contained in an + <seealso marker="inet#type-ancillary_data"> + ancillary data + </seealso> + list. + For stream oriented sockets (<c>gen_tcp</c>) + the only way to get the <c>TTL</c> + value is if the platform supports the + <seealso marker="gen_tcp#type-pktoptions_value"> + <c>pktoptions</c> + </seealso> + option. + </p> </item> <tag><c>{reuseaddr, Boolean}</c></tag> <item> @@ -1043,7 +1389,7 @@ setcap cap_sys_admin,cap_sys_ptrace,cap_dac_read_search+epi beam.smp</code> <seealso marker="gen_tcp#recv/2"><c>gen_tcp:recv/2</c></seealso> gets <c>{error, closed}</c>. In active mode, the controlling process receives a - <c>{tcp_close, Socket}</c> message, indicating that the + <c>{tcp_closed, Socket}</c> message, indicating that the peer has closed the connection.</p> <p>Setting this option to <c>true</c> allows you to distinguish between a connection that was closed normally, @@ -1177,7 +1523,7 @@ inet:setopts(Sock,[{raw,6,8,<<30:32/native>>}]),]]></code> For one-to-many style sockets, the special value <c>0</c> is defined to mean that the returned addresses must be without any particular association. - How different SCTP implementations interprets this varies somewhat. + How different SCTP implementations interpret this varies somewhat. </p> </desc> </func> |