1inet(3) Erlang Module Definition inet(3)
2
6 inet - Access to TCP/IP protocols.
7
9 This module provides access to TCP/IP protocols.
10 See also ERTS User's Guide: Inet Configuration for more information
12 about how to configure an Erlang runtime system for IP communication.
13 The following two Kernel configuration parameters affect the behavior
15 of all sockets opened on an Erlang node:
16 * inet_default_connect_options can contain a list of default options
18 used for all sockets returned when doing connect.
19 * inet_default_listen_options can contain a list of default options
21 used when issuing a listen call.
22 When accept is issued, the values of the listening socket options are
24 inherited. No such application variable is therefore needed for accept.
25 Using the Kernel configuration parameters above, one can set default
27 options for all TCP sockets on a node, but use this with care. Options
28 such as {delay_send,true} can be specified in this way. The following
29 is an example of starting an Erlang node with all sockets using delayed
30 send:
31 $ erl -sname test -kernel \
33 inet_default_connect_options '[{delay_send,true}]' \
34 inet_default_listen_options '[{delay_send,true}]'
35 Notice that default option {active, true} cannot be changed, for inter‐
37 nal reasons.
38 Addresses as inputs to functions can be either a string or a tuple. For
40 example, the IP address 150.236.20.73 can be passed to gethostbyaddr/1,
41 either as string "150.236.20.73" or as tuple {150, 236, 20, 73}.
42 IPv4 address examples:
44 Address ip_address()
46 ------- ------------
47 127.0.0.1 {127,0,0,1}
48 192.168.42.2 {192,168,42,2}
49 IPv6 address examples:
51 Address ip_address()
53 ------- ------------
54 ::1 {0,0,0,0,0,0,0,1}
55 ::192.168.42.2 {0,0,0,0,0,0,(192 bsl 8) bor 168,(42 bsl 8) bor 2}
56 ::FFFF:192.168.42.2
57 {0,0,0,0,0,16#FFFF,(192 bsl 8) bor 168,(42 bsl 8) bor 2}
58 3ffe:b80:1f8d:2:204:acff:fe17:bf38
59 {16#3ffe,16#b80,16#1f8d,16#2,16#204,16#acff,16#fe17,16#bf38}
60 fe80::204:acff:fe17:bf38
61 {16#fe80,0,0,0,16#204,16#acff,16#fe17,16#bf38}
62 Function parse_address/1 can be useful:
64 1> inet:parse_address("192.168.42.2").
66 {ok,{192,168,42,2}}
67 2> inet:parse_address("::FFFF:192.168.42.2").
68 {ok,{0,0,0,0,0,65535,49320,10754}}
69
71 hostent() =
72 #hostent{h_name = inet:hostname(),
73 h_aliases = [inet:hostname()],
74 h_addrtype = inet | inet6,
75 h_length = integer() >= 0,
76 h_addr_list = [inet:ip_address()]}
77 The record is defined in the Kernel include file "inet.hrl".
79 Add the following directive to the module:
81 -include_lib("kernel/include/inet.hrl").
83 hostname() = atom() | string()
85 ip_address() = ip4_address() | ip6_address()
87 ip4_address() = {0..255, 0..255, 0..255, 0..255}
89 ip6_address() =
91 {0..65535,
92 0..65535,
93 0..65535,
94 0..65535,
95 0..65535,
96 0..65535,
97 0..65535,
98 0..65535}
99 port_number() = 0..65535
101 family_address() =
103 inet_address() | inet6_address() | local_address()
104 A general address format on the form {Family, Destination} where
106 Family is an atom such as local and the format of Destination
107 depends on Family, and is a complete address (for example an IP
108 address including port number).
109 inet_address() =
111 {inet, {ip4_address() | any | loopback, port_number()}}
112 Warning:
114 This address format is for now experimental and for completeness
115 to make all address families have a {Family, Destination} repre‐
116 sentation.
117 inet6_address() =
120 {inet6, {ip6_address() | any | loopback, port_number()}}
121 Warning:
123 This address format is for now experimental and for completeness
124 to make all address families have a {Family, Destination} repre‐
125 sentation.
126 local_address() = {local, File :: binary() | string()}
129 This address family only works on Unix-like systems.
131 File is normally a file pathname in a local filesystem. It is
133 limited in length by the operating system, traditionally to 108
134 bytes.
135 A binary() is passed as is to the operating system, but a
137 string() is encoded according to the system filename encoding
138 mode.
139 Other addresses are possible, for example Linux implements "Ab‐
141 stract Addresses". See the documentation for Unix Domain Sockets
142 on your system, normally unix in manual section 7.
143 In most API functions where you can use this address family the
145 port number must be 0.
146 socket_address() =
148 ip_address() | any | loopback | local_address()
149 socket_getopt() =
151 gen_sctp:option_name() |
152 gen_tcp:option_name() |
153 gen_udp:option_name()
154 socket_setopt() =
156 gen_sctp:option() | gen_tcp:option() | gen_udp:option()
157 returned_non_ip_address() =
159 {local, binary()} | {unspec, <<>>} | {undefined, any()}
160 Addresses besides ip_address() ones that are returned from
162 socket API functions. See in particular local_address(). The
163 unspec family corresponds to AF_UNSPEC and can occur if the
164 other side has no socket address. The undefined family can only
165 occur in the unlikely event of an address family that the VM
166 does not recognize.
167 ancillary_data() =
169 [{tos, byte()} | {tclass, byte()} | {ttl, byte()}]
170 Ancillary data received with the data packet, read with the
172 socket option pktoptions from a TCP socket, or to set in a call
173 to gen_udp:send/4 or gen_udp:send/5.
174 The value(s) correspond to the currently active socket options
176 recvtos, recvtclass and recvttl, or for a single send operation
177 the option(s) to override the currently active socket option(s).
178 getifaddrs_ifopts() =
180 [Ifopt ::
181 {flags,
182 Flags ::
183 [up | broadcast | loopback | pointtopoint |
184 running | multicast]} |
185 {addr, Addr :: ip_address()} |
186 {netmask, Netmask :: ip_address()} |
187 {broadaddr, Broadaddr :: ip_address()} |
188 {dstaddr, Dstaddr :: ip_address()} |
189 {hwaddr, Hwaddr :: [byte()]}]
190 Interface address description list returned from getifaddrs/0,1
192 for a named interface, translated from the returned data of the
193 POSIX API function getaddrinfo().
194 Hwaddr is hardware dependent, for example, on Ethernet inter‐
196 faces it is the 6-byte Ethernet address (MAC address (EUI-48 ad‐
197 dress)).
198 The tuples {addr,Addr}, {netmask,Netmask}, and possibly {broad‐
200 addr,Broadaddr} or {dstaddr,Dstaddr} are repeated in the list if
201 the interface has got multiple addresses. An interface may have
202 multiple {flag,_} tuples for example if it has different flags
203 for different address families. Multiple {hwaddr,Hwaddr} tuples
204 is hard to say anything definite about, though. The tuple
205 {flag,Flags} is mandatory, all others are optional.
206 Do not rely too much on the order of Flags atoms or the Ifopt
208 tuples. There are however some rules:
209 * A {flag,_} tuple applies to all other tuples that follow.
211 * Immediately after {addr,_} follows {netmask,_}.
213 * Immediately thereafter may {broadaddr,_} follow if broadcast
215 is member of Flags, or {dstaddr,_} if pointtopoint is member
216 of Flags. Both {dstaddr,_} and {broadaddr,_} does not occur
217 for the same {addr,_}.
218 * Any {netmask,_}, {broadaddr,_}, or {dstaddr,_} tuples that
220 follow an {addr,Addr} tuple concerns the address Addr.
221 The tuple {hwaddr,_} is not returned on Solaris, as the hardware
223 address historically belongs to the link layer and it is not re‐
224 turned by the Solaris API function getaddrinfo().
225 Warning:
227 On Windows, the data is fetched from different OS API functions,
228 so the Netmask and Broadaddr values may be calculated, just as
229 some Flags values.
230 posix() =
233 eaddrinuse | eaddrnotavail | eafnosupport | ealready |
234 econnaborted | econnrefused | econnreset | edestaddrreq |
235 ehostdown | ehostunreach | einprogress | eisconn | emsgsize |
236 enetdown | enetunreach | enopkg | enoprotoopt | enotconn |
237 enotty | enotsock | eproto | eprotonosupport | eprototype |
238 esocktnosupport | etimedout | ewouldblock | exbadport |
239 exbadseq |
240 file:posix()
241 An atom that is named from the POSIX error codes used in Unix,
243 and in the runtime libraries of most C compilers. See section
244 POSIX Error Codes.
245 socket()
247 See gen_tcp:type-socket and gen_udp:type-socket.
249 address_family() = inet | inet6 | local
251 socket_protocol() = tcp | udp | sctp
253 stat_option() =
255 recv_cnt | recv_max | recv_avg | recv_oct | recv_dvi |
256 send_cnt | send_max | send_avg | send_oct | send_pend
257
259 close(Socket) -> ok
260 Types:
262 Socket = socket()
264 Closes a socket of any type.
266 format_error(Reason) -> string()
268 Types:
270 Reason = posix() | system_limit
272 Returns a diagnostic error string. For possible POSIX values and
274 corresponding strings, see section POSIX Error Codes.
275 get_rc() ->
277 [{Par :: atom(), Val :: any()} |
278 {Par :: atom(), Val1 :: any(), Val2 :: any()}]
279 Returns the state of the Inet configuration database in form of
281 a list of recorded configuration parameters. For more informa‐
282 tion, see ERTS User's Guide: Inet Configuration.
283 Only actual parameters with other than default values are re‐
285 turned, for example not directives that specify other sources
286 for configuration parameters nor directives that clear parame‐
287 ters.
288 getaddr(Host, Family) -> {ok, Address} | {error, posix()}
290 Types:
292 Host = ip_address() | hostname()
294 Family = address_family()
295 Address = ip_address()
296 Returns the IP address for Host as a tuple of integers. Host can
298 be an IP address, a single hostname, or a fully qualified host‐
299 name.
300 getaddrs(Host, Family) -> {ok, Addresses} | {error, posix()}
302 Types:
304 Host = ip_address() | hostname()
306 Family = address_family()
307 Addresses = [ip_address()]
308 Returns a list of all IP addresses for Host. Host can be an IP
310 address, a single hostname, or a fully qualified hostname.
311 gethostbyaddr(Address) -> {ok, Hostent} | {error, posix()}
313 Types:
315 Address = string() | ip_address()
317 Hostent = hostent()
318 Returns a hostent record for the host with the specified ad‐
320 dress.
321 gethostbyname(Hostname) -> {ok, Hostent} | {error, posix()}
323 Types:
325 Hostname = hostname()
327 Hostent = hostent()
328 Returns a hostent record for the host with the specified host‐
330 name.
331 If resolver option inet6 is true, an IPv6 address is looked up.
333 gethostbyname(Hostname, Family) ->
335 {ok, Hostent} | {error, posix()}
336 Types:
338 Hostname = hostname()
340 Family = address_family()
341 Hostent = hostent()
342 Returns a hostent record for the host with the specified name,
344 restricted to the specified address family.
345 gethostname() -> {ok, Hostname}
347 Types:
349 Hostname = string()
351 Returns the local hostname. Never fails.
353 getifaddrs() ->
355 {ok,
356 [{Ifname :: string(),
357 Ifopts :: getifaddrs_ifopts()}]} |
358 {error, posix()}
359 Returns a list of 2-tuples containing interface names and the
361 interfaces' addresses. Ifname is a Unicode string and Ifopts is
362 a list of interface address description tuples.
363 The interface address description tuples are documented under
365 the type of the Ifopts value.
366 getifaddrs(Opts) -> {ok, [{Ifname, Ifopts}]} | {error, Posix}
368 Types:
370 Opts = [{netns, Namespace}]
372 Namespace = file:filename_all()
373 Ifname = string()
374 Ifopts = getifaddrs_ifopts()
375 Posix = posix()
376 The same as getifaddrs/0 but the Option {netns, Namespace} sets
378 a network namespace for the OS call, on platforms that supports
379 that feature.
380 See the socket option {netns, Namespace} under setopts/2.
382 getopts(Socket, Options) -> {ok, OptionValues} | {error, posix()}
384 Types:
386 Socket = socket()
388 Options = [socket_getopt()]
389 OptionValues = [socket_setopt() | gen_tcp:pktoptions_value()]
390 Gets one or more options for a socket. For a list of available
392 options, see setopts/2. See also the description for the type
393 gen_tcp:pktoptions_value().
394 The number of elements in the returned OptionValues list does
396 not necessarily correspond to the number of options asked for.
397 If the operating system fails to support an option, it is left
398 out in the returned list. An error tuple is returned only when
399 getting options for the socket is impossible (that is, the
400 socket is closed or the buffer size in a raw request is too
401 large). This behavior is kept for backward compatibility rea‐
402 sons.
403 A raw option request RawOptReq = {raw, Protocol, OptionNum, Val‐
405 ueSpec} can be used to get information about socket options not
406 (explicitly) supported by the emulator. The use of raw socket
407 options makes the code non-portable, but allows the Erlang pro‐
408 grammer to take advantage of unusual features present on a par‐
409 ticular platform.
410 RawOptReq consists of tag raw followed by the protocol level,
412 the option number, and either a binary or the size, in bytes, of
413 the buffer in which the option value is to be stored. A binary
414 is to be used when the underlying getsockopt requires input in
415 the argument field. In this case, the binary size is to corre‐
416 spond to the required buffer size of the return value. The sup‐
417 plied values in a RawOptReq correspond to the second, third, and
418 fourth/fifth parameters to the getsockopt call in the C socket
419 API. The value stored in the buffer is returned as a binary Val‐
420 ueBin, where all values are coded in the native endianess.
421 Asking for and inspecting raw socket options require low-level
423 information about the current operating system and TCP stack.
424 Example:
426 Consider a Linux machine where option TCP_INFO can be used to
428 collect TCP statistics for a socket. Assume you are interested
429 in field tcpi_sacked of struct tcp_info filled in when asking
430 for TCP_INFO. To be able to access this information, you need to
431 know the following:
432 * The numeric value of protocol level IPPROTO_TCP
434 * The numeric value of option TCP_INFO
436 * The size of struct tcp_info
438 * The size and offset of the specific field
440 By inspecting the headers or writing a small C program, it is
442 found that IPPROTO_TCP is 6, TCP_INFO is 11, the structure size
443 is 92 (bytes), the offset of tcpi_sacked is 28 bytes, and the
444 value is a 32-bit integer. The following code can be used to re‐
445 trieve the value:
446 get_tcpi_sacked(Sock) ->
448 {ok,[{raw,_,_,Info}]} = inet:getopts(Sock,[{raw,6,11,92}]),
449 <<_:28/binary,TcpiSacked:32/native,_/binary>> = Info,
450 TcpiSacked.
451 Preferably, you would check the machine type, the operating sys‐
453 tem, and the Kernel version before executing anything similar to
454 this code.
455 getstat(Socket) -> {ok, OptionValues} | {error, posix()}
457 getstat(Socket, Options) -> {ok, OptionValues} | {error, posix()}
459 Types:
461 Socket = socket()
463 Options = [stat_option()]
464 OptionValues = [{stat_option(), integer()}]
465 stat_option() =
466 recv_cnt | recv_max | recv_avg | recv_oct | recv_dvi |
467 send_cnt | send_max | send_avg | send_oct | send_pend
468 Gets one or more statistic options for a socket.
470 getstat(Socket) is equivalent to getstat(Socket, [recv_avg,
472 recv_cnt, recv_dvi, recv_max, recv_oct, send_avg, send_cnt,
473 send_pend, send_max, send_oct]).
474 The following options are available:
476 recv_avg:
478 Average size of packets, in bytes, received by the socket.
479 recv_cnt:
481 Number of packets received by the socket.
482 recv_dvi:
484 Average packet size deviation, in bytes, received by the
485 socket.
486 recv_max:
488 Size of the largest packet, in bytes, received by the
489 socket.
490 recv_oct:
492 Number of bytes received by the socket.
493 send_avg:
495 Average size of packets, in bytes, sent from the socket.
496 send_cnt:
498 Number of packets sent from the socket.
499 send_pend:
501 Number of bytes waiting to be sent by the socket.
502 send_max:
504 Size of the largest packet, in bytes, sent from the socket.
505 send_oct:
507 Number of bytes sent from the socket.
508 i() -> ok
510 i(Proto :: socket_protocol()) -> ok
512 i(X1 :: socket_protocol(), Fs :: [atom()]) -> ok
514 Lists all TCP, UDP and SCTP sockets, including those that the
516 Erlang runtime system uses as well as those created by the ap‐
517 plication.
518 The following options are available:
520 port:
522 The internal index of the port.
523 module:
525 The callback module of the socket.
526 recv:
528 Number of bytes received by the socket.
529 sent:
531 Number of bytes sent from the socket.
532 owner:
534 The socket owner process.
535 local_address:
537 The local address of the socket.
538 foreign_address:
540 The address and port of the other end of the connection.
541 state:
543 The connection state.
544 type:
546 STREAM or DGRAM or SEQPACKET.
547 ntoa(IpAddress) -> Address | {error, einval}
549 Types:
551 Address = string()
553 IpAddress = ip_address()
554 Parses an ip_address() and returns an IPv4 or IPv6 address
556 string.
557 parse_address(Address) -> {ok, IPAddress} | {error, einval}
559 Types:
561 Address = string()
563 IPAddress = ip_address()
564 Parses an IPv4 or IPv6 address string and returns an ip4_ad‐
566 dress() or ip6_address(). Accepts a shortened IPv4 address
567 string.
568 parse_ipv4_address(Address) -> {ok, IPv4Address} | {error, einval}
570 Types:
572 Address = string()
574 IPv4Address = ip_address()
575 Parses an IPv4 address string and returns an ip4_address(). Ac‐
577 cepts a shortened IPv4 address string.
578 parse_ipv4strict_address(Address) ->
580 {ok, IPv4Address} | {error, einval}
581 Types:
583 Address = string()
585 IPv4Address = ip_address()
586 Parses an IPv4 address string containing four fields, that is,
588 not shortened, and returns an ip4_address().
589 parse_ipv6_address(Address) -> {ok, IPv6Address} | {error, einval}
591 Types:
593 Address = string()
595 IPv6Address = ip_address()
596 Parses an IPv6 address string and returns an ip6_address(). If
598 an IPv4 address string is specified, an IPv4-mapped IPv6 address
599 is returned.
600 parse_ipv6strict_address(Address) ->
602 {ok, IPv6Address} | {error, einval}
603 Types:
605 Address = string()
607 IPv6Address = ip_address()
608 Parses an IPv6 address string and returns an ip6_address(). Does
610 not accept IPv4 addresses.
611 ipv4_mapped_ipv6_address(X1 :: ip_address()) -> ip_address()
613 Convert an IPv4 address to an IPv4-mapped IPv6 address or the
615 reverse. When converting from an IPv6 address all but the 2 low
616 words are ignored so this function also works on some other
617 types of addresses than IPv4-mapped.
618 parse_strict_address(Address) -> {ok, IPAddress} | {error, einval}
620 Types:
622 Address = string()
624 IPAddress = ip_address()
625 Parses an IPv4 or IPv6 address string and returns an ip4_ad‐
627 dress() or ip6_address(). Does not accept a shortened IPv4 ad‐
628 dress string.
629 peername(Socket :: socket()) ->
631 {ok,
632 {ip_address(), port_number()} |
633 returned_non_ip_address()} |
634 {error, posix()}
635 Returns the address and port for the other end of a connection.
637 Notice that for SCTP sockets, this function returns only one of
639 the peer addresses of the socket. Function peernames/1,2 returns
640 all.
641 peernames(Socket :: socket()) ->
643 {ok,
644 [{ip_address(), port_number()} |
645 returned_non_ip_address()]} |
646 {error, posix()}
647 Equivalent to peernames(Socket, 0).
649 Notice that the behavior of this function for an SCTP one-to-
651 many style socket is not defined by the SCTP Sockets API Exten‐
652 sions.
653 peernames(Socket, Assoc) ->
655 {ok, [{Address, Port}]} | {error, posix()}
656 Types:
658 Socket = socket()
660 Assoc = #sctp_assoc_change{} | gen_sctp:assoc_id()
661 Address = ip_address()
662 Port = integer() >= 0
663 Returns a list of all address/port number pairs for the other
665 end of an association Assoc of a socket.
666 This function can return multiple addresses for multihomed sock‐
668 ets, such as SCTP sockets. For other sockets it returns a one-
669 element list.
670 Notice that parameter Assoc is by the SCTP Sockets API Exten‐
672 sions defined to be ignored for one-to-one style sockets. What
673 the special value 0 means, hence its behavior for one-to-many
674 style sockets, is unfortunately undefined.
675 port(Socket) -> {ok, Port} | {error, any()}
677 Types:
679 Socket = socket()
681 Port = port_number()
682 Returns the local port number for a socket.
684 setopts(Socket, Options) -> ok | {error, posix()}
686 Types:
688 Socket = socket()
690 Options = [socket_setopt()]
691 Sets one or more options for a socket.
693 The following options are available:
695 {active, true | false | once | N}:
697 If the value is true, which is the default, everything re‐
698 ceived from the socket is sent as messages to the receiving
699 process.
700 If the value is false (passive mode), the process must ex‐
702 plicitly receive incoming data by calling gen_tcp:recv/2,3,
703 gen_udp:recv/2,3, or gen_sctp:recv/1,2 (depending on the
704 type of socket).
705 If the value is once ({active, once}), one data message from
707 the socket is sent to the process. To receive one more mes‐
708 sage, setopts/2 must be called again with option {active,
709 once}.
710 If the value is an integer N in the range -32768 to 32767
712 (inclusive), the value is added to the socket's count of
713 data messages sent to the controlling process. A socket's
714 default message count is 0. If a negative value is speci‐
715 fied, and its magnitude is equal to or greater than the
716 socket's current message count, the socket's message count
717 is set to 0. Once the socket's message count reaches 0, ei‐
718 ther because of sending received data messages to the
719 process or by being explicitly set, the process is then no‐
720 tified by a special message, specific to the type of socket,
721 that the socket has entered passive mode. Once the socket
722 enters passive mode, to receive more messages setopts/2 must
723 be called again to set the socket back into an active mode.
724 When using {active, once} or {active, N}, the socket changes
726 behavior automatically when data is received. This can be
727 confusing in combination with connection-oriented sockets
728 (that is, gen_tcp), as a socket with {active, false} behav‐
729 ior reports closing differently than a socket with {active,
730 true} behavior. To simplify programming, a socket where the
731 peer closed, and this is detected while in {active, false}
732 mode, still generates message {tcp_closed,Socket} when set
733 to {active, once}, {active, true}, or {active, N} mode. It
734 is therefore safe to assume that message
735 {tcp_closed,Socket}, possibly followed by socket port termi‐
736 nation (depending on option exit_on_close) eventually ap‐
737 pears when a socket changes back and forth between {active,
738 true} and {active, false} mode. However, when peer closing
739 is detected it is all up to the underlying TCP/IP stack and
740 protocol.
741 Notice that {active, true} mode provides no flow control; a
743 fast sender can easily overflow the receiver with incoming
744 messages. The same is true for {active, N} mode, while the
745 message count is greater than zero.
746 Use active mode only if your high-level protocol provides
748 its own flow control (for example, acknowledging received
749 messages) or the amount of data exchanged is small. {active,
750 false} mode, use of the {active, once} mode, or {active, N}
751 mode with values of N appropriate for the application pro‐
752 vides flow control. The other side cannot send faster than
753 the receiver can read.
754 {broadcast, Boolean} (UDP sockets):
756 Enables/disables permission to send broadcasts.
757 {buffer, Size}:
759 The size of the user-level buffer used by the driver. Not to
760 be confused with options sndbuf and recbuf, which correspond
761 to the Kernel socket buffers. For TCP it is recommended to
762 have val(buffer) >= val(recbuf) to avoid performance issues
763 because of unnecessary copying. For UDP the same recommenda‐
764 tion applies, but the max should not be larger than the MTU
765 of the network path. val(buffer) is automatically set to the
766 above maximum when recbuf is set. However, as the size set
767 for recbuf usually become larger, you are encouraged to use
768 getopts/2 to analyze the behavior of your operating system.
769 Note that this is also the maximum amount of data that can
771 be received from a single recv call. If you are using higher
772 than normal MTU consider setting buffer higher.
773 {delay_send, Boolean}:
775 Normally, when an Erlang process sends to a socket, the
776 driver tries to send the data immediately. If that fails,
777 the driver uses any means available to queue up the message
778 to be sent whenever the operating system says it can handle
779 it. Setting {delay_send, true} makes all messages queue up.
780 The messages sent to the network are then larger but fewer.
781 The option affects the scheduling of send requests versus
782 Erlang processes instead of changing any real property of
783 the socket. The option is implementation-specific. Defaults
784 to false.
785 {deliver, port | term}:
787 When {active, true}, data is delivered on the form port :
788 {S, {data, [H1,..Hsz | Data]}} or term : {tcp, S, [H1..Hsz |
789 Data]}.
790 {dontroute, Boolean}:
792 Enables/disables routing bypass for outgoing messages.
793 {exit_on_close, Boolean}:
795 This option is set to true by default.
796 The only reason to set it to false is if you want to con‐
798 tinue sending data to the socket after a close is detected,
799 for example, if the peer uses gen_tcp:shutdown/2 to shut
800 down the write side.
801 {header, Size}:
803 This option is only meaningful if option binary was speci‐
804 fied when the socket was created. If option header is speci‐
805 fied, the first Size number bytes of data received from the
806 socket are elements of a list, and the remaining data is a
807 binary specified as the tail of the same list. For example,
808 if Size == 2, the data received matches [Byte1,Byte2|Bi‐
809 nary].
810 {high_msgq_watermark, Size}:
812 The socket message queue is set to a busy state when the
813 amount of data on the message queue reaches this limit. No‐
814 tice that this limit only concerns data that has not yet
815 reached the ERTS internal socket implementation. Defaults to
816 8 kB.
817 Senders of data to the socket are suspended if either the
819 socket message queue is busy or the socket itself is busy.
820 For more information, see options low_msgq_watermark,
822 high_watermark, and low_watermark.
823 Notice that distribution sockets disable the use of
825 high_msgq_watermark and low_msgq_watermark. Instead use the
826 distribution buffer busy limit, which is a similar feature.
827 {high_watermark, Size} (TCP/IP sockets):
829 The socket is set to a busy state when the amount of data
830 queued internally by the ERTS socket implementation reaches
831 this limit. Defaults to 8 kB.
832 Senders of data to the socket are suspended if either the
834 socket message queue is busy or the socket itself is busy.
835 For more information, see options low_watermark,
837 high_msgq_watermark, and low_msqg_watermark.
838 {ipv6_v6only, Boolean}:
840 Restricts the socket to use only IPv6, prohibiting any IPv4
841 connections. This is only applicable for IPv6 sockets (op‐
842 tion inet6).
843 On most platforms this option must be set on the socket be‐
845 fore associating it to an address. It is therefore only rea‐
846 sonable to specify it when creating the socket and not to
847 use it when calling function (setopts/2) containing this de‐
848 scription.
849 The behavior of a socket with this option set to true is the
851 only portable one. The original idea when IPv6 was new of
852 using IPv6 for all traffic is now not recommended by FreeBSD
853 (you can use {ipv6_v6only,false} to override the recommended
854 system default value), forbidden by OpenBSD (the supported
855 GENERIC kernel), and impossible on Windows (which has sepa‐
856 rate IPv4 and IPv6 protocol stacks). Most Linux distros
857 still have a system default value of false. This policy
858 shift among operating systems to separate IPv6 from IPv4
859 traffic has evolved, as it gradually proved hard and compli‐
860 cated to get a dual stack implementation correct and secure.
861 On some platforms, the only allowed value for this option is
863 true, for example, OpenBSD and Windows. Trying to set this
864 option to false, when creating the socket, fails in this
865 case.
866 Setting this option on platforms where it does not exist is
868 ignored. Getting this option with getopts/2 returns no
869 value, that is, the returned list does not contain an
870 {ipv6_v6only,_} tuple. On Windows, the option does not ex‐
871 ist, but it is emulated as a read-only option with value
872 true.
873 Therefore, setting this option to true when creating a
875 socket never fails, except possibly on a platform where you
876 have customized the kernel to only allow false, which can be
877 doable (but awkward) on, for example, OpenBSD.
878 If you read back the option value using getopts/2 and get no
880 value, the option does not exist in the host operating sys‐
881 tem. The behavior of both an IPv6 and an IPv4 socket listen‐
882 ing on the same port, and for an IPv6 socket getting IPv4
883 traffic is then no longer predictable.
884 {keepalive, Boolean}(TCP/IP sockets):
886 Enables/disables periodic transmission on a connected socket
887 when no other data is exchanged. If the other end does not
888 respond, the connection is considered broken and an error
889 message is sent to the controlling process. Defaults to dis‐
890 abled.
891 {linger, {true|false, Seconds}}:
893 Determines the time-out, in seconds, for flushing unsent
894 data in the close/1 socket call.
895 The first component is if linger is enabled, the second com‐
897 ponent is the flushing time-out, in seconds. There are 3 al‐
898 ternatives:
899 {false, _}:
901 close/1 or shutdown/2 returns immediately, not waiting for
902 data to be flushed, with closing happening in the back‐
903 ground.
904 {true, 0}:
906 Aborts the connection when it is closed. Discards any data
907 still remaining in the send buffers and sends RST to the
908 peer.
909 This avoids TCP's TIME_WAIT state, but leaves open the
911 possibility that another "incarnation" of this connection
912 being created.
913 {true, Time} when Time > 0:
915 close/1 or shutdown/2 will not return until all queued
916 messages for the socket have been successfully sent or the
917 linger timeout (Time) has been reached.
918 {low_msgq_watermark, Size}:
920 If the socket message queue is in a busy state, the socket
921 message queue is set in a not busy state when the amount of
922 data queued in the message queue falls below this limit. No‐
923 tice that this limit only concerns data that has not yet
924 reached the ERTS internal socket implementation. Defaults to
925 4 kB.
926 Senders that are suspended because of either a busy message
928 queue or a busy socket are resumed when the socket message
929 queue and the socket are not busy.
930 For more information, see options high_msgq_watermark,
932 high_watermark, and low_watermark.
933 Notice that distribution sockets disable the use of
935 high_msgq_watermark and low_msgq_watermark. Instead they use
936 the distribution buffer busy limit, which is a similar fea‐
937 ture.
938 {low_watermark, Size} (TCP/IP sockets):
940 If the socket is in a busy state, the socket is set in a not
941 busy state when the amount of data queued internally by the
942 ERTS socket implementation falls below this limit. Defaults
943 to 4 kB.
944 Senders that are suspended because of a busy message queue
946 or a busy socket are resumed when the socket message queue
947 and the socket are not busy.
948 For more information, see options high_watermark,
950 high_msgq_watermark, and low_msgq_watermark.
951 {mode, Mode :: binary | list}:
953 Received Packet is delivered as defined by Mode.
954 {netns, Namespace :: file:filename_all()}:
956 Sets a network namespace for the socket. Parameter Namespace
957 is a filename defining the namespace, for example,
958 "/var/run/netns/example", typically created by command ip
959 netns add example. This option must be used in a function
960 call that creates a socket, that is, gen_tcp:connect/3,4,
961 gen_tcp:listen/2, gen_udp:open/1,2 or gen_sctp:open/0,1,2,
962 and also getifaddrs/1.
963 This option uses the Linux-specific syscall setns(), such as
965 in Linux kernel 3.0 or later, and therefore only exists when
966 the runtime system is compiled for such an operating system.
967 The virtual machine also needs elevated privileges, either
969 running as superuser or (for Linux) having capability
970 CAP_SYS_ADMIN according to the documentation for setns(2).
971 However, during testing also CAP_SYS_PTRACE and
972 CAP_DAC_READ_SEARCH have proven to be necessary.
973 Example:
975 setcap cap_sys_admin,cap_sys_ptrace,cap_dac_read_search+epi beam.smp
977 Notice that the filesystem containing the virtual machine
979 executable (beam.smp in the example) must be local, mounted
980 without flag nosetuid, support extended attributes, and the
981 kernel must support file capabilities. All this runs out of
982 the box on at least Ubuntu 12.04 LTS, except that SCTP sock‐
983 ets appear to not support network namespaces.
984 Namespace is a filename and is encoded and decoded as dis‐
986 cussed in module file, with the following exceptions:
987 * Emulator flag +fnu is ignored.
989 * getopts/2 for this option returns a binary for the file‐
991 name if the stored filename cannot be decoded. This is
992 only to occur if you set the option using a binary that
993 cannot be decoded with the emulator's filename encoding:
994 file:native_name_encoding/0.
995 {bind_to_device, Ifname :: binary()}:
997 Binds a socket to a specific network interface. This option
998 must be used in a function call that creates a socket, that
999 is, gen_tcp:connect/3,4, gen_tcp:listen/2, gen_udp:open/1,2,
1000 or gen_sctp:open/0,1,2.
1001 Unlike getifaddrs/0, Ifname is encoded a binary. In the un‐
1003 likely case that a system is using non-7-bit-ASCII charac‐
1004 ters in network device names, special care has to be taken
1005 when encoding this argument.
1006 This option uses the Linux-specific socket option SO_BIND‐
1008 TODEVICE, such as in Linux kernel 2.0.30 or later, and
1009 therefore only exists when the runtime system is compiled
1010 for such an operating system.
1011 Before Linux 3.8, this socket option could be set, but could
1013 not retrieved with getopts/2. Since Linux 3.8, it is read‐
1014 able.
1015 The virtual machine also needs elevated privileges, either
1017 running as superuser or (for Linux) having capability
1018 CAP_NET_RAW.
1019 The primary use case for this option is to bind sockets into
1021 Linux VRF instances.
1022 list:
1024 Received Packet is delivered as a list.
1025 binary:
1027 Received Packet is delivered as a binary.
1028 {nodelay, Boolean}(TCP/IP sockets):
1030 If Boolean == true, option TCP_NODELAY is turned on for the
1031 socket, which means that also small amounts of data are sent
1032 immediately.
1033 {nopush, Boolean}(TCP/IP sockets):
1035 This translates to TCP_NOPUSH on BSD and to TCP_CORK on
1036 Linux.
1037 If Boolean == true, the corresponding option is turned on
1039 for the socket, which means that small amounts of data are
1040 accumulated until a full MSS-worth of data is available or
1041 this option is turned off.
1042 Note that while TCP_NOPUSH socket option is available on
1044 OSX, its semantics is very different (e.g., unsetting it
1045 does not cause immediate send of accumulated data). Hence,
1046 nopush option is intentionally ignored on OSX.
1047 {packet, PacketType}(TCP/IP sockets):
1049 Defines the type of packets to use for a socket. Possible
1050 values:
1051 raw | 0:
1053 No packaging is done.
1054 1 | 2 | 4:
1056 Packets consist of a header specifying the number of bytes
1057 in the packet, followed by that number of bytes. The
1058 header length can be one, two, or four bytes, and contain‐
1059 ing an unsigned integer in big-endian byte order. Each
1060 send operation generates the header, and the header is
1061 stripped off on each receive operation.
1062 The 4-byte header is limited to 2Gb.
1064 asn1 | cdr | sunrm | fcgi | tpkt | line:
1066 These packet types only have effect on receiving. When
1067 sending a packet, it is the responsibility of the applica‐
1068 tion to supply a correct header. On receiving, however,
1069 one message is sent to the controlling process for each
1070 complete packet received, and, similarly, each call to
1071 gen_tcp:recv/2,3 returns one complete packet. The header
1072 is not stripped off.
1073 The meanings of the packet types are as follows:
1075 * asn1 - ASN.1 BER
1077 * sunrm - Sun's RPC encoding
1079 * cdr - CORBA (GIOP 1.1)
1081 * fcgi - Fast CGI
1083 * tpkt - TPKT format [RFC1006]
1085 * line - Line mode, a packet is a line-terminated with
1087 newline, lines longer than the receive buffer are trun‐
1088 cated
1089 http | http_bin:
1091 The Hypertext Transfer Protocol. The packets are returned
1092 with the format according to HttpPacket described in er‐
1093 lang:decode_packet/3 in ERTS. A socket in passive mode re‐
1094 turns {ok, HttpPacket} from gen_tcp:recv while an active
1095 socket sends messages like {http, Socket, HttpPacket}.
1096 httph | httph_bin:
1098 These two types are often not needed, as the socket auto‐
1099 matically switches from http/http_bin to httph/httph_bin
1100 internally after the first line is read. However, there
1101 can be occasions when they are useful, such as parsing
1102 trailers from chunked encoding.
1103 {packet_size, Integer}(TCP/IP sockets):
1105 Sets the maximum allowed length of the packet body. If the
1106 packet header indicates that the length of the packet is
1107 longer than the maximum allowed length, the packet is con‐
1108 sidered invalid. The same occurs if the packet header is too
1109 large for the socket receive buffer.
1110 For line-oriented protocols (line, http*), option
1112 packet_size also guarantees that lines up to the indicated
1113 length are accepted and not considered invalid because of
1114 internal buffer limitations.
1115 {line_delimiter, Char}(TCP/IP sockets):
1117 Sets the line delimiting character for line-oriented proto‐
1118 cols (line). Defaults to $\n.
1119 {raw, Protocol, OptionNum, ValueBin}:
1121 See below.
1122 {read_packets, Integer}(UDP sockets):
1124 Sets the maximum number of UDP packets to read without in‐
1125 tervention from the socket when data is available. When this
1126 many packets have been read and delivered to the destination
1127 process, new packets are not read until a new notification
1128 of available data has arrived. Defaults to 5. If this param‐
1129 eter is set too high, the system can become unresponsive be‐
1130 cause of UDP packet flooding.
1131 {recbuf, Size}:
1133 The minimum size of the receive buffer to use for the
1134 socket. You are encouraged to use getopts/2 to retrieve the
1135 size set by your operating system.
1136 {recvtclass, Boolean}:
1138 If set to true activates returning the received TCLASS value
1139 on platforms that implements the protocol IPPROTO_IPV6 op‐
1140 tion IPV6_RECVTCLASS or IPV6_2292RECVTCLASS for the socket.
1141 The value is returned as a {tclass,TCLASS} tuple regardless
1142 of if the platform returns an IPV6_TCLASS or an IPV6_RECVT‐
1143 CLASS CMSG value.
1144 For packet oriented sockets that supports receiving ancil‐
1146 lary data with the payload data (gen_udp and gen_sctp), the
1147 TCLASS value is returned in an extended return tuple con‐
1148 tained in an ancillary data list. For stream oriented
1149 sockets (gen_tcp) the only way to get the TCLASS value is if
1150 the platform supports the pktoptions option.
1151 {recvtos, Boolean}:
1153 If set to true activates returning the received TOS value on
1154 platforms that implements the protocol IPPROTO_IP option
1155 IP_RECVTOS for the socket. The value is returned as a
1156 {tos,TOS} tuple regardless of if the platform returns an
1157 IP_TOS or an IP_RECVTOS CMSG value.
1158 For packet oriented sockets that supports receiving ancil‐
1160 lary data with the payload data (gen_udp and gen_sctp), the
1161 TOS value is returned in an extended return tuple contained
1162 in an ancillary data list. For stream oriented sockets
1163 (gen_tcp) the only way to get the TOS value is if the plat‐
1164 form supports the pktoptions option.
1165 {recvttl, Boolean}:
1167 If set to true activates returning the received TTL value on
1168 platforms that implements the protocol IPPROTO_IP option
1169 IP_RECVTTL for the socket. The value is returned as a
1170 {ttl,TTL} tuple regardless of if the platform returns an
1171 IP_TTL or an IP_RECVTTL CMSG value.
1172 For packet oriented sockets that supports receiving ancil‐
1174 lary data with the payload data (gen_udp and gen_sctp), the
1175 TTL value is returned in an extended return tuple contained
1176 in an ancillary data list. For stream oriented sockets
1177 (gen_tcp) the only way to get the TTL value is if the plat‐
1178 form supports the pktoptions option.
1179 {reuseaddr, Boolean}:
1181 Allows or disallows local reuse of port numbers. By default,
1182 reuse is disallowed.
1183 {send_timeout, Integer}:
1185 Only allowed for connection-oriented sockets.
1186 Specifies a longest time to wait for a send operation to be
1188 accepted by the underlying TCP stack. When the limit is ex‐
1189 ceeded, the send operation returns {error,timeout}. How much
1190 of a packet that got sent is unknown; the socket is there‐
1191 fore to be closed whenever a time-out has occurred (see
1192 send_timeout_close below). Defaults to infinity.
1193 {send_timeout_close, Boolean}:
1195 Only allowed for connection-oriented sockets.
1196 Used together with send_timeout to specify whether the
1198 socket is to be automatically closed when the send operation
1199 returns {error,timeout}. The recommended setting is true,
1200 which automatically closes the socket. Defaults to false be‐
1201 cause of backward compatibility.
1202 {show_econnreset, Boolean}(TCP/IP sockets):
1204 When this option is set to false, which is default, an RST
1205 received from the TCP peer is treated as a normal close (as
1206 though an FIN was sent). A caller to gen_tcp:recv/2 gets
1207 {error, closed}. In active mode, the controlling process re‐
1208 ceives a {tcp_closed, Socket} message, indicating that the
1209 peer has closed the connection.
1210 Setting this option to true allows you to distinguish be‐
1212 tween a connection that was closed normally, and one that
1213 was aborted (intentionally or unintentionally) by the TCP
1214 peer. A call to gen_tcp:recv/2 returns {error, econnreset}.
1215 In active mode, the controlling process receives a {tcp_er‐
1216 ror, Socket, econnreset} message before the usual
1217 {tcp_closed, Socket}, as is the case for any other socket
1218 error. Calls to gen_tcp:send/2 also returns {error, econnre‐
1219 set} when it is detected that a TCP peer has sent an RST.
1220 A connected socket returned from gen_tcp:accept/1 inherits
1222 the show_econnreset setting from the listening socket.
1223 {sndbuf, Size}:
1225 The minimum size of the send buffer to use for the socket.
1226 You are encouraged to use getopts/2, to retrieve the size
1227 set by your operating system.
1228 {priority, Integer}:
1230 Sets the SO_PRIORITY socket level option on platforms where
1231 this is implemented. The behavior and allowed range varies
1232 between different systems. The option is ignored on plat‐
1233 forms where it is not implemented. Use with caution.
1234 {tos, Integer}:
1236 Sets IP_TOS IP level options on platforms where this is im‐
1237 plemented. The behavior and allowed range varies between
1238 different systems. The option is ignored on platforms where
1239 it is not implemented. Use with caution.
1240 {tclass, Integer}:
1242 Sets IPV6_TCLASS IP level options on platforms where this is
1243 implemented. The behavior and allowed range varies between
1244 different systems. The option is ignored on platforms where
1245 it is not implemented. Use with caution.
1246 In addition to these options, raw option specifications can be
1248 used. The raw options are specified as a tuple of arity four,
1249 beginning with tag raw, followed by the protocol level, the op‐
1250 tion number, and the option value specified as a binary. This
1251 corresponds to the second, third, and fourth arguments to the
1252 setsockopt call in the C socket API. The option value must be
1253 coded in the native endianess of the platform and, if a struc‐
1254 ture is required, must follow the structure alignment conven‐
1255 tions on the specific platform.
1256 Using raw socket options requires detailed knowledge about the
1258 current operating system and TCP stack.
1259 Example:
1261 This example concerns the use of raw options. Consider a Linux
1263 system where you want to set option TCP_LINGER2 on protocol
1264 level IPPROTO_TCP in the stack. You know that on this particular
1265 system it defaults to 60 (seconds), but you want to lower it to
1266 30 for a particular socket. Option TCP_LINGER2 is not explicitly
1267 supported by inet, but you know that the protocol level trans‐
1268 lates to number 6, the option number to number 8, and the value
1269 is to be specified as a 32-bit integer. You can use this code
1270 line to set the option for the socket named Sock:
1271 inet:setopts(Sock,[{raw,6,8,<<30:32/native>>}]),
1273 As many options are silently discarded by the stack if they are
1275 specified out of range; it can be a good idea to check that a
1276 raw option is accepted. The following code places the value in
1277 variable TcpLinger2:
1278 {ok,[{raw,6,8,<<TcpLinger2:32/native>>}]}=inet:getopts(Sock,[{raw,6,8,4}]),
1280 Code such as these examples is inherently non-portable, even
1282 different versions of the same OS on the same platform can re‐
1283 spond differently to this kind of option manipulation. Use with
1284 care.
1285 Notice that the default options for TCP/IP sockets can be
1287 changed with the Kernel configuration parameters mentioned in
1288 the beginning of this manual page.
1289 sockname(Socket :: socket()) ->
1291 {ok,
1292 {ip_address(), port_number()} |
1293 returned_non_ip_address()} |
1294 {error, posix()}
1295 Returns the local address and port number for a socket.
1297 Notice that for SCTP sockets this function returns only one of
1299 the socket addresses. Function socknames/1,2 returns all.
1300 socknames(Socket :: socket()) ->
1302 {ok,
1303 [{ip_address(), port_number()} |
1304 returned_non_ip_address()]} |
1305 {error, posix()}
1306 Equivalent to socknames(Socket, 0).
1308 socknames(Socket, Assoc) ->
1310 {ok, [{Address, Port}]} | {error, posix()}
1311 Types:
1313 Socket = socket()
1315 Assoc = #sctp_assoc_change{} | gen_sctp:assoc_id()
1316 Address = ip_address()
1317 Port = integer() >= 0
1318 Returns a list of all local address/port number pairs for a
1320 socket for the specified association Assoc.
1321 This function can return multiple addresses for multihomed sock‐
1323 ets, such as SCTP sockets. For other sockets it returns a one-
1324 element list.
1325 Notice that parameter Assoc is by the SCTP Sockets API Exten‐
1327 sions defined to be ignored for one-to-one style sockets. For
1328 one-to-many style sockets, the special value 0 is defined to
1329 mean that the returned addresses must be without any particular
1330 association. How different SCTP implementations interpret this
1331 varies somewhat.
1332
1334 * e2big - Too long argument list
1335 * eacces - Permission denied
1337 * eaddrinuse - Address already in use
1339 * eaddrnotavail - Cannot assign requested address
1341 * eadv - Advertise error
1343 * eafnosupport - Address family not supported by protocol family
1345 * eagain - Resource temporarily unavailable
1347 * ealign - EALIGN
1349 * ealready - Operation already in progress
1351 * ebade - Bad exchange descriptor
1353 * ebadf - Bad file number
1355 * ebadfd - File descriptor in bad state
1357 * ebadmsg - Not a data message
1359 * ebadr - Bad request descriptor
1361 * ebadrpc - Bad RPC structure
1363 * ebadrqc - Bad request code
1365 * ebadslt - Invalid slot
1367 * ebfont - Bad font file format
1369 * ebusy - File busy
1371 * echild - No children
1373 * echrng - Channel number out of range
1375 * ecomm - Communication error on send
1377 * econnaborted - Software caused connection abort
1379 * econnrefused - Connection refused
1381 * econnreset - Connection reset by peer
1383 * edeadlk - Resource deadlock avoided
1385 * edeadlock - Resource deadlock avoided
1387 * edestaddrreq - Destination address required
1389 * edirty - Mounting a dirty fs without force
1391 * edom - Math argument out of range
1393 * edotdot - Cross mount point
1395 * edquot - Disk quota exceeded
1397 * eduppkg - Duplicate package name
1399 * eexist - File already exists
1401 * efault - Bad address in system call argument
1403 * efbig - File too large
1405 * ehostdown - Host is down
1407 * ehostunreach - Host is unreachable
1409 * eidrm - Identifier removed
1411 * einit - Initialization error
1413 * einprogress - Operation now in progress
1415 * eintr - Interrupted system call
1417 * einval - Invalid argument
1419 * eio - I/O error
1421 * eisconn - Socket is already connected
1423 * eisdir - Illegal operation on a directory
1425 * eisnam - Is a named file
1427 * el2hlt - Level 2 halted
1429 * el2nsync - Level 2 not synchronized
1431 * el3hlt - Level 3 halted
1433 * el3rst - Level 3 reset
1435 * elbin - ELBIN
1437 * elibacc - Cannot access a needed shared library
1439 * elibbad - Accessing a corrupted shared library
1441 * elibexec - Cannot exec a shared library directly
1443 * elibmax - Attempting to link in more shared libraries than system
1445 limit
1446 * elibscn - .lib section in a.out corrupted
1448 * elnrng - Link number out of range
1450 * eloop - Too many levels of symbolic links
1452 * emfile - Too many open files
1454 * emlink - Too many links
1456 * emsgsize - Message too long
1458 * emultihop - Multihop attempted
1460 * enametoolong - Filename too long
1462 * enavail - Unavailable
1464 * enet - ENET
1466 * enetdown - Network is down
1468 * enetreset - Network dropped connection on reset
1470 * enetunreach - Network is unreachable
1472 * enfile - File table overflow
1474 * enoano - Anode table overflow
1476 * enobufs - No buffer space available
1478 * enocsi - No CSI structure available
1480 * enodata - No data available
1482 * enodev - No such device
1484 * enoent - No such file or directory
1486 * enoexec - Exec format error
1488 * enolck - No locks available
1490 * enolink - Link has been severed
1492 * enomem - Not enough memory
1494 * enomsg - No message of desired type
1496 * enonet - Machine is not on the network
1498 * enopkg - Package not installed
1500 * enoprotoopt - Bad protocol option
1502 * enospc - No space left on device
1504 * enosr - Out of stream resources or not a stream device
1506 * enosym - Unresolved symbol name
1508 * enosys - Function not implemented
1510 * enotblk - Block device required
1512 * enotconn - Socket is not connected
1514 * enotdir - Not a directory
1516 * enotempty - Directory not empty
1518 * enotnam - Not a named file
1520 * enotsock - Socket operation on non-socket
1522 * enotsup - Operation not supported
1524 * enotty - Inappropriate device for ioctl
1526 * enotuniq - Name not unique on network
1528 * enxio - No such device or address
1530 * eopnotsupp - Operation not supported on socket
1532 * eperm - Not owner
1534 * epfnosupport - Protocol family not supported
1536 * epipe - Broken pipe
1538 * eproclim - Too many processes
1540 * eprocunavail - Bad procedure for program
1542 * eprogmismatch - Wrong program version
1544 * eprogunavail - RPC program unavailable
1546 * eproto - Protocol error
1548 * eprotonosupport - Protocol not supported
1550 * eprototype - Wrong protocol type for socket
1552 * erange - Math result unrepresentable
1554 * erefused - EREFUSED
1556 * eremchg - Remote address changed
1558 * eremdev - Remote device
1560 * eremote - Pathname hit remote filesystem
1562 * eremoteio - Remote I/O error
1564 * eremoterelease - EREMOTERELEASE
1566 * erofs - Read-only filesystem
1568 * erpcmismatch - Wrong RPC version
1570 * erremote - Object is remote
1572 * eshutdown - Cannot send after socket shutdown
1574 * esocktnosupport - Socket type not supported
1576 * espipe - Invalid seek
1578 * esrch - No such process
1580 * esrmnt - Srmount error
1582 * estale - Stale remote file handle
1584 * esuccess - Error 0
1586 * etime - Timer expired
1588 * etimedout - Connection timed out
1590 * etoomanyrefs - Too many references
1592 * etxtbsy - Text file or pseudo-device busy
1594 * euclean - Structure needs cleaning
1596 * eunatch - Protocol driver not attached
1598 * eusers - Too many users
1600 * eversion - Version mismatch
1602 * ewouldblock - Operation would block
1604 * exdev - Cross-domain link
1606 * exfull - Message tables full
1608 * nxdomain - Hostname or domain name cannot be found
1610Ericsson AB kernel 7.3.1.1 inet(3)