diff options
Diffstat (limited to 'lib/kernel/doc/src/inet.xml')
| -rw-r--r-- | lib/kernel/doc/src/inet.xml | 195 |
1 files changed, 178 insertions, 17 deletions
diff --git a/lib/kernel/doc/src/inet.xml b/lib/kernel/doc/src/inet.xml index 32b4a429dd..3d929a772e 100644 --- a/lib/kernel/doc/src/inet.xml +++ b/lib/kernel/doc/src/inet.xml @@ -323,8 +323,11 @@ fe80::204:acff:fe17:bf38 <type name="stat_option"/> <desc> <p>Gets one or more statistic options for a socket.</p> + <p><c>getstat(<anno>Socket</anno>)</c> is equivalent to - <c>getstat(<anno>Socket</anno>, [recv_avg, recv_cnt, recv_dvi, recv_max, recv_oct, send_avg, send_cnt, send_dvi, send_max, send_oct])</c></p> + <c>getstat(<anno>Socket</anno>, [recv_avg, recv_cnt, recv_dvi, + recv_max, recv_oct, send_avg, send_cnt, send_dvi, send_max, + send_oct])</c>.</p> <p>The following options are available:</p> <taglist> <tag><c>recv_avg</c></tag> @@ -371,7 +374,51 @@ fe80::204:acff:fe17:bf38 </taglist> </desc> </func> - + <func> + <name name="parse_ipv4_address" arity="1" /> + <fsummary>Parse an IPv4 address</fsummary> + <desc> + <p>Parses an IPv4 address string and returns an <a href="#type-ip4_address">ip4_address()</a>. + Accepts a shortened IPv4 shortened address string.</p> + </desc> + </func> + <func> + <name name="parse_ipv4strict_address" arity="1" /> + <fsummary>Parse an IPv4 address strict.</fsummary> + <desc> + <p>Parses an IPv4 address string containing four fields, i.e <b>not</b> shortened, and returns an <a href="#type-ip4_adress">ip4_address()</a>.</p> + </desc> + </func> + <func> + <name name="parse_ipv6_address" arity="1" /> + <fsummary>Parse an IPv6 address</fsummary> + <desc> + <p>Parses an IPv6 address string and returns an <a href="#type-ip6_address">ip6_address()</a>. + If an IPv4 address string is passed, an IPv4-mapped IPv6 address is returned.</p> + </desc> + </func> + <func> + <name name="parse_ipv6strict_address" arity="1" /> + <fsummary>Parse an IPv6 address strict.</fsummary> + <desc> + <p>Parses an IPv6 address string and returns an <a href="#type-ip6_address">ip6_address()</a>. + Does <b>not</b> accept IPv4 adresses.</p> + </desc> + </func> + <func> + <name name="parse_address" arity="1" /> + <fsummary>Parse an IPv4 or IPv6 address.</fsummary> + <desc> + <p>Parses an IPv4 or IPv6 address string and returns an <a href="#type-ip4_address">ip4_address()</a> or <a href="#type-ip6_address">ip6_address()</a>. Accepts a shortened IPv4 address string.</p> + </desc> + </func> + <func> + <name name="parse_strict_address" arity="1" /> + <fsummary>Parse an IPv4 or IPv6 address strict.</fsummary> + <desc> + <p>Parses an IPv4 or IPv6 address string and returns an <a href="#type-ip4_address">ip4_address()</a> or <a href="#type-ip6_adress">ip6_address()</a>. Does <b>not</b> accept a shortened IPv4 address string.</p> + </desc> + </func> <func> <name name="peername" arity="1"/> <fsummary>Return the address and port for the other end of a connection</fsummary> @@ -512,13 +559,100 @@ fe80::204:acff:fe17:bf38 <c>[Byte1,Byte2|Binary]</c>.</p> </item> - <tag><c>{high_watermark, Size}</c></tag> - <item> <p> - Sender is forced busy if sent and enqueued data - reaches the highwater mark. - <br /> Default: 8192 kB. - </p> - </item> + <tag><c>{high_msgq_watermark, Size}</c> (TCP/IP sockets)</tag> + <item> + <p>The socket message queue will be set into a busy + state when the amount of data queued on the message + queue reaches this limit. Note that this limit only + concerns data that have not yet reached the ERTS internal + socket implementation. Default value used is 8 kB.</p> + <p>Senders of data to the socket will be suspended if + either the socket message queue is busy, or the socket + itself is busy.</p> + <p>For more information see the <c>low_msgq_watermark</c>, + <c>high_watermark</c>, and <c>low_watermark</c> options.</p> + <p>Note that distribution sockets will disable the use of + <c>high_msgq_watermark</c> and <c>low_msgq_watermark</c>, + and will instead use the + <seealso marker="erts:erlang#system_info_dist_buf_busy_limit">distribution + buffer busy limit</seealso> which is a similar feature.</p> + </item> + + <tag><c>{high_watermark, Size}</c> (TCP/IP sockets)</tag> + <item> + <p>The socket will be set into a busy state when the amount + of data queued internally by the ERTS socket implementation + reaches this limit. Default value used is 8 kB.</p> + <p>Senders of data to the socket will be suspended if + either the socket message queue is busy, or the socket + itself is busy.</p> + <p>For more information see the <c>low_watermark</c>, + <c>high_msgq_watermark</c>, and <c>low_msqg_watermark</c> + options.</p> + </item> + + <tag><c>{ipv6_v6only, Boolean}</c></tag> + <item> + <p> + Restricts the socket to only use IPv6, prohibiting any + IPv4 connections. This is only applicable for + IPv6 sockets (option <c>inet6</c>). + </p> + <p> + On most platforms this option has to be set on the socket + before associating it to an address. Therefore it is only + reasonable to give it when creating the socket and not + to use it when calling the function + (<seealso marker="#setopts/2">setopts/2</seealso>) + containing this description. + </p> + <p> + The behaviour of a socket with this socket option set to + <c>true</c> is becoming the only portable one. The original + idea when IPv6 was new of using IPv6 for all traffic + is now not recommended by FreeBSD (you can use + <c>{ipv6_v6only,false}</c> to override the recommended + system default value), + forbidden by OpenBSD (the supported GENERIC kernel) + and impossible on Windows (that has separate + IPv4 and IPv6 protocol stacks). Most Linux distros + still have a system default value of <c>false</c>. + This policy shift among operating systems towards + separating IPv6 from IPv4 traffic has evolved since + it gradually proved hard and complicated to get + a dual stack implementation correct and secure. + </p> + <p> + On some platforms the only allowed value for this option + is <c>true</c>, e.g. OpenBSD and Windows. Trying to set + this option to <c>false</c> when creating the socket + will in this case fail. + </p> + <p> + Setting this option on platforms where it does not exist + is ignored and getting this option with + <seealso marker="#getopts/2">getopts/2</seealso> + returns no value i.e the returned list will not contain an + <c>{ipv6_v6only,_}</c> tuple. On Windows the option acually + does not exist, but it is emulated as being a + read-only option with the value <c>true</c>. + </p> + <p> + So it boils down to that setting this option to <c>true</c> + when creating a socket will never fail except possibly + (at the time of this writing) on a platform where you + have customized the kernel to only allow <c>false</c>, + which might be doable (but weird) on e.g. OpenBSD. + </p> + <p> + If you read back the option value using + <seealso marker="#getopts/2">getopts/2</seealso> + and get no value the option does not exist in the host OS + and all bets are off regarding the behaviour of both + an IPv6 and an IPv4 socket listening on the same port + as well as for an IPv6 socket getting IPv4 traffic. + </p> + </item> <tag><c>{keepalive, Boolean}</c>(TCP/IP sockets)</tag> <item> @@ -540,14 +674,41 @@ fe80::204:acff:fe17:bf38 the flushing time-out in seconds.</p> </item> - <tag><c>{low_watermark, Size}</c></tag> - <item> <p> - If the port has reached its <c>high_watermark</c> it will - force busy onto senders. When the port data queue reaches the - <c>low_watermark</c> callers are no longer forced busy. - <br /> Default: 4096 kB. - </p> - </item> + <tag><c>{low_msgq_watermark, Size}</c> (TCP/IP sockets)</tag> + <item> + <p>If the socket message queue is in a busy state, the + socket message queue will be set in a not busy state when + the amount of data queued in the message queue falls + below this limit. Note that this limit only concerns data + that have not yet reached the ERTS internal socket + implementation. Default value used is 4 kB.</p> + <p>Senders that have been suspended due to either a + busy message queue or a busy socket, will be resumed + when neither the socket message queue, nor the socket + are busy.</p> + <p>For more information see the <c>high_msgq_watermark</c>, + <c>high_watermark</c>, and <c>low_watermark</c> options.</p> + <p>Note that distribution sockets will disable the use of + <c>high_msgq_watermark</c> and <c>low_msgq_watermark</c>, + and will instead use the + <seealso marker="erts:erlang#system_info_dist_buf_busy_limit">distribution + buffer busy limit</seealso> which is a similar feature.</p> + </item> + + <tag><c>{low_watermark, Size}</c> (TCP/IP sockets)</tag> + <item> + <p>If the socket is in a busy state, the socket will + be set in a not busy state when the amount of data + queued internally by the ERTS socket implementation + falls below this limit. Default value used is 4 kB.</p> + <p>Senders that have been suspended due to either a + busy message queue or a busy socket, will be resumed + when neither the socket message queue, nor the socket + are busy.</p> + <p>For more information see the <c>high_watermark</c>, + <c>high_msgq_watermark</c>, and <c>low_msgq_watermark</c> + options.</p> + </item> <tag><c>{mode, Mode :: binary | list}</c></tag> <item> |