diff options
Diffstat (limited to 'lib/kernel/doc/src/inet.xml')
| -rw-r--r-- | lib/kernel/doc/src/inet.xml | 447 |
1 files changed, 366 insertions, 81 deletions
diff --git a/lib/kernel/doc/src/inet.xml b/lib/kernel/doc/src/inet.xml index e6a7962c5a..86f76fc07f 100644 --- a/lib/kernel/doc/src/inet.xml +++ b/lib/kernel/doc/src/inet.xml @@ -28,7 +28,7 @@ <date>1998-02-04</date> <rev>A</rev> </header> - <module>inet</module> + <module since="">inet</module> <modulesummary>Access to TCP/IP protocols.</modulesummary> <description> <p>This module provides access to TCP/IP protocols.</p> @@ -118,6 +118,42 @@ fe80::204:acff:fe17:bf38 <name name="port_number"/> </datatype> <datatype> + <name name="family_address" since="OTP 21.3.8.4"/> + <desc> + <p> + A general address format on the form <c>{Family, Destination}</c> + where <c>Family</c> is an atom such as <c>local</c> + and the format of <c>Destination</c> depends on <c>Family</c>, + and is a complete address + (for example an IP address including port number). + </p> + </desc> + </datatype> + <datatype> + <name name="inet_address" since="OTP 21.3.8.4"/> + <desc> + <warning> + <p> + This address format is for now experimental + and for completeness to make all address families have a + <c>{Family, Destination}</c> representation. + </p> + </warning> + </desc> + </datatype> + <datatype> + <name name="inet6_address" since="OTP 21.3.8.4"/> + <desc> + <warning> + <p> + This address format is for now experimental + and for completeness to make all address families have a + <c>{Family, Destination}</c> representation. + </p> + </warning> + </desc> + </datatype> + <datatype> <name name="local_address"/> <desc> <p> @@ -177,6 +213,106 @@ fe80::204:acff:fe17:bf38 </desc> </datatype> <datatype> + <name name="ancillary_data"/> + <desc> + <p> + Ancillary data received with the data packet, + read with the socket option + <seealso marker="gen_tcp#type-pktoptions_value"> + <c>pktoptions</c> + </seealso> + from a TCP socket, + or to set in a call to + <seealso marker="gen_udp#send-4-AncData"><c>gen_udp:send/4</c></seealso> + or + <seealso marker="gen_udp#send/5"><c>gen_udp:send/5</c></seealso>. + </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>, + or for a single send operation the option(s) to override + the currently active socket option(s). + </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, @@ -200,11 +336,14 @@ fe80::204:acff:fe17:bf38 <datatype> <name name="socket_protocol"/> </datatype> + <datatype> + <name name="stat_option"/> + </datatype> </datatypes> <funcs> <func> - <name name="close" arity="1"/> + <name name="close" arity="1" since=""/> <fsummary>Close a socket of any type.</fsummary> <desc> <p>Closes a socket of any type.</p> @@ -212,7 +351,7 @@ fe80::204:acff:fe17:bf38 </func> <func> - <name name="format_error" arity="1"/> + <name name="format_error" arity="1" since=""/> <fsummary>Return a descriptive string for an error reason.</fsummary> <desc> <p>Returns a diagnostic error string. For possible POSIX values and @@ -222,7 +361,7 @@ fe80::204:acff:fe17:bf38 </func> <func> - <name name="get_rc" arity="0"/> + <name name="get_rc" arity="0" since=""/> <fsummary>Return a list of IP configuration parameters.</fsummary> <desc> <p> @@ -241,7 +380,7 @@ fe80::204:acff:fe17:bf38 </func> <func> - <name name="getaddr" arity="2"/> + <name name="getaddr" arity="2" since=""/> <fsummary>Return the IP address for a host.</fsummary> <desc> <p>Returns the IP address for <c><anno>Host</anno></c> as a tuple of @@ -251,7 +390,7 @@ fe80::204:acff:fe17:bf38 </func> <func> - <name name="getaddrs" arity="2"/> + <name name="getaddrs" arity="2" since=""/> <fsummary>Return the IP addresses for a host.</fsummary> <desc> <p>Returns a list of all IP addresses for <c><anno>Host</anno></c>. @@ -261,7 +400,7 @@ fe80::204:acff:fe17:bf38 </func> <func> - <name name="gethostbyaddr" arity="1"/> + <name name="gethostbyaddr" arity="1" since=""/> <fsummary>Return a hostent record for the host with the specified address.</fsummary> <desc> @@ -270,7 +409,7 @@ fe80::204:acff:fe17:bf38 </func> <func> - <name name="gethostbyname" arity="1"/> + <name name="gethostbyname" arity="1" since=""/> <fsummary>Return a hostent record for the host with the specified name. </fsummary> <desc> @@ -282,7 +421,7 @@ fe80::204:acff:fe17:bf38 </func> <func> - <name name="gethostbyname" arity="2"/> + <name name="gethostbyname" arity="2" since=""/> <fsummary>Return a hostent record for the host with the specified name. </fsummary> <desc> @@ -292,7 +431,7 @@ fe80::204:acff:fe17:bf38 </func> <func> - <name name="gethostname" arity="0"/> + <name name="gethostname" arity="0" since=""/> <fsummary>Return the local hostname.</fsummary> <desc> <p>Returns the local hostname. Never fails.</p> @@ -300,51 +439,81 @@ fe80::204:acff:fe17:bf38 </func> <func> - <name name="getifaddrs" arity="0"/> + <name name="getifaddrs" arity="0" since="OTP R14B01"/> <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 since="OTP 21.2">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> <func> - <name name="getopts" arity="2"/> + <name name="getopts" arity="2" since=""/> <fsummary>Get one or more options for a socket.</fsummary> <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 @@ -360,7 +529,7 @@ 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 @@ -405,8 +574,8 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="getstat" arity="1"/> - <name name="getstat" arity="2"/> + <name name="getstat" arity="1" since=""/> + <name name="getstat" arity="2" since=""/> <fsummary>Get one or more statistic options for a socket.</fsummary> <type name="stat_option"/> <desc> @@ -462,9 +631,9 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="i" arity="0" /> - <name name="i" arity="1" /> - <name name="i" arity="2" /> + <name name="i" arity="0" since="OTP 21.0"/> + <name name="i" arity="1" since="OTP 21.0"/> + <name name="i" arity="2" since="OTP 21.0"/> <fsummary>Displays information and statistics about sockets on the terminal</fsummary> <desc> <p> @@ -517,7 +686,7 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="ntoa" arity="1" /> + <name name="ntoa" arity="1" since="OTP R16B02"/> <fsummary>Convert IPv6/IPV4 address to ASCII.</fsummary> <desc> <p>Parses an @@ -527,7 +696,7 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="parse_address" arity="1" /> + <name name="parse_address" arity="1" since="OTP R16B"/> <fsummary>Parse an IPv4 or IPv6 address.</fsummary> <desc> <p>Parses an IPv4 or IPv6 address string and returns an @@ -538,7 +707,7 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="parse_ipv4_address" arity="1" /> + <name name="parse_ipv4_address" arity="1" since="OTP R16B"/> <fsummary>Parse an IPv4 address.</fsummary> <desc> <p>Parses an IPv4 address string and returns an @@ -548,7 +717,7 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="parse_ipv4strict_address" arity="1" /> + <name name="parse_ipv4strict_address" arity="1" since="OTP R16B"/> <fsummary>Parse an IPv4 address strict.</fsummary> <desc> <p>Parses an IPv4 address string containing four fields, that is, @@ -559,7 +728,7 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="parse_ipv6_address" arity="1" /> + <name name="parse_ipv6_address" arity="1" since="OTP R16B"/> <fsummary>Parse an IPv6 address.</fsummary> <desc> <p>Parses an IPv6 address string and returns an @@ -570,7 +739,7 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="parse_ipv6strict_address" arity="1" /> + <name name="parse_ipv6strict_address" arity="1" since="OTP R16B"/> <fsummary>Parse an IPv6 address strict.</fsummary> <desc> <p>Parses an IPv6 address string and returns an @@ -580,7 +749,7 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="ipv4_mapped_ipv6_address" arity="1" /> + <name name="ipv4_mapped_ipv6_address" arity="1" since="OTP 21.0"/> <fsummary>Convert to and from IPv4-mapped IPv6 address.</fsummary> <desc> <p> @@ -593,7 +762,7 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="parse_strict_address" arity="1" /> + <name name="parse_strict_address" arity="1" since="OTP R16B"/> <fsummary>Parse an IPv4 or IPv6 address strict.</fsummary> <desc> <p>Parses an IPv4 or IPv6 address string and returns an @@ -604,7 +773,7 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="peername" arity="1"/> + <name name="peername" arity="1" since=""/> <fsummary>Return the address and port for the other end of a connection. </fsummary> <desc> @@ -617,7 +786,7 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="peernames" arity="1"/> + <name name="peernames" arity="1" since="OTP R16B03"/> <fsummary>Return all address/port numbers for the other end of a connection.</fsummary> <desc> @@ -631,7 +800,7 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="peernames" arity="2"/> + <name name="peernames" arity="2" since="OTP R16B03"/> <fsummary>Return all address/port numbers for the other end of a connection.</fsummary> <desc> @@ -650,7 +819,7 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="port" arity="1"/> + <name name="port" arity="1" since=""/> <fsummary>Return the local port number for a socket.</fsummary> <desc> <p>Returns the local port number for a socket.</p> @@ -658,7 +827,7 @@ get_tcpi_sacked(Sock) -> </func> <func> - <name name="setopts" arity="2"/> + <name name="setopts" arity="2" since=""/> <fsummary>Set one or more options for a socket.</fsummary> <desc> <p>Sets one or more options for a socket.</p> @@ -734,22 +903,23 @@ get_tcpi_sacked(Sock) -> </item> <tag><c>{buffer, Size}</c></tag> <item> - <p>The size of the user-level software buffer used by - the driver. - Not to be confused with options <c>sndbuf</c> + <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> + 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> @@ -924,20 +1094,29 @@ 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 @@ -1013,6 +1192,18 @@ 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><marker id="packet"/>Defines the type of packets to use for a socket. @@ -1114,6 +1305,100 @@ 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> @@ -1246,7 +1531,7 @@ inet:setopts(Sock,[{raw,6,8,<<30:32/native>>}]),]]></code> </func> <func> - <name name="sockname" arity="1"/> + <name name="sockname" arity="1" since=""/> <fsummary>Return the local address and port number for a socket. </fsummary> <desc> @@ -1259,7 +1544,7 @@ inet:setopts(Sock,[{raw,6,8,<<30:32/native>>}]),]]></code> </func> <func> - <name name="socknames" arity="1"/> + <name name="socknames" arity="1" since="OTP R16B03"/> <fsummary>Return all local address/port numbers for a socket.</fsummary> <desc> <p>Equivalent to @@ -1269,7 +1554,7 @@ inet:setopts(Sock,[{raw,6,8,<<30:32/native>>}]),]]></code> </func> <func> - <name name="socknames" arity="2"/> + <name name="socknames" arity="2" since="OTP R16B03"/> <fsummary>Return all local address/port numbers for a socket.</fsummary> <desc> <p>Returns a list of all local address/port number pairs for a socket |