| blob | 3c2400820627035d2fced0d9e49d61aa01e2d3f3 |
1 .\" Copyright (c) 2018 by Eugene Syromyatnikov <evgsyr@gmail.com>,
2 .\" and Copyright (c) 2018 Michael Kerrisk <mtk.manpages@gmail.com>
3 .\"
4 .\" SPDX-License-Identifier: Linux-man-pages-copyleft
5 .\"
6 .TH address_families 7 (date) "Linux man-pages (unreleased)"
7 .SH NAME
8 address_families \- socket address families (domains)
9 .SH SYNOPSIS
10 .nf
11 .BR "#include <sys/types.h>" " /* See NOTES */"
12 .B #include <sys/socket.h>
13 .P
14 .BI "int socket(int " domain ", int " type ", int " protocol );
15 .fi
16 .SH DESCRIPTION
17 The
18 .I domain
19 argument of the
20 .BR socket (2)
21 specifies a communication domain; this selects the protocol
22 family which will be used for communication.
23 These families are defined in
24 .IR <sys/socket.h> .
25 The formats currently understood by the Linux kernel include:
26 .TP
27 .B AF_UNIX
28 .TQ
29 .B AF_LOCAL
30 Local communication.
31 For further information, see
32 .BR unix (7).
33 .TP
34 .B AF_INET
35 IPv4 Internet protocols.
36 For further information, see
37 .BR ip (7).
38 .TP
39 .B AF_AX25
40 Amateur radio AX.25 protocol.
41 For further information, see
42 .BR ax25 (4).
43 .\" Part of ax25-tools
44 .TP
45 .B AF_IPX
46 IPX \- Novell protocols.
47 .TP
48 .B AF_APPLETALK
49 AppleTalk
50 For further information, see
51 .BR ddp (7).
52 .TP
53 .B AF_NETROM
54 AX.25 packet layer protocol.
55 For further information, see
56 .BR netrom (4),
57 .\" Part of ax25-tools package
58 .UR https://www.tldp.org/HOWTO/AX25-HOWTO/x61.html
59 .I The Packet Radio Protocols and Linux
60 .UE
61 and the
62 .IR AX.25 ", " NET/ROM ", and " "ROSE network programming"
63 chapters of the
64 .UR https://www.tldp.org/HOWTO/AX25-HOWTO/x2107.html
65 .I Linux Amateur Radio AX.25 HOWTO
66 .UE .
67 .TP
68 .B AF_BRIDGE
69 Can't be used for creating sockets;
70 mostly used for bridge links in
71 .BR rtnetlink (7)
72 protocol commands.
73 .TP
74 .B AF_ATMPVC
75 Access to raw ATM Permanent Virtual Circuits (PVCs).
76 For further information, see the
77 .UR https://www.tldp.org/HOWTO/text/ATM-Linux-HOWTO
78 .I ATM on Linux HOWTO
79 .UE .
80 .TP
81 .B AF_X25
82 ITU-T X.25 / ISO/IEC\~8208 protocol.
83 For further information, see
84 .BR x25 (7).
85 .TP
86 .B AF_INET6
87 IPv6 Internet protocols.
88 For further information, see
89 .BR ipv6 (7).
90 .TP
91 .B AF_ROSE
92 RATS (Radio Amateur Telecommunications Society).
93 Open Systems environment (ROSE) AX.25 packet layer protocol.
94 For further information, see the resources listed for
95 .BR AF_NETROM .
96 .TP
97 .B AF_DECnet
98 DECet protocol sockets.
99 See
100 .I Documentation/networking/decnet.txt
101 in the Linux kernel source tree for details.
102 .TP
103 .B AF_NETBEUI
104 Reserved for "802.2LLC project"; never used.
105 .TP
106 .B AF_SECURITY
107 This was a short-lived (between Linux 2.1.30 and 2.1.99pre2) protocol family
108 for firewall upcalls.
109 .TP
110 .B AF_KEY
111 Key management protocol, originally developed for usage with IPsec
112 (since Linux 2.1.38).
113 This has no relation to
114 .BR keyctl (2)
115 and the in-kernel key storage facility.
116 See
117 .UR https://tools.ietf.org/html/rfc2367
118 RFC 2367
119 .I PF_KEY Key Management API, Version 2
120 .UE
121 for details.
122 .TP
123 .B AF_NETLINK
124 Kernel user interface device.
125 For further information, see
126 .BR netlink (7).
127 .TP
128 .B AF_PACKET
129 Low-level packet interface.
130 For further information, see
131 .BR packet (7).
132 .\" .TP
133 .\" .B AF_ASH
134 .\" Asynchronous Serial Host protocol (?)
135 .\" Notes from Eugene Syromyatnikov:
136 .\" I haven't found any concrete information about this one;
137 .\" it never was implemented in Linux, at least, judging by historical
138 .\" repos. There is also this file (and its variations):
139 .\" https://github.com/ecki/net-tools/blob/master/lib/ash.c
140 .\" ( https://github.com/ecki/net-tools/commits/master/lib/ash.c )
141 .\" it mentions "NET-2 distribution" (BSD Net/2?), but, again, I failed
142 .\" to find any mentions of "ash" protocol there.
143 .\" (for the reference:
144 .\" ftp://pdp11.org.ru/pub/unix-archive/Distributions/UCB/Net2/net2.tar.gz )
145 .\" Another source that mentions it is
146 .\" https://www.silabs.com/documents/public/user-guides/ug101-uart-gateway-protocol-reference.pdf
147 .\" https://www.silabs.com/documents/public/user-guides/ug115-ashv3-protocol-reference.pdf
148 .\" but I doubt that it's related, as former files use 64-byte addresses and
149 .\" "Hamming-encode of hops", and that's barely combines with a protocol
150 .\" that is mainly used over serial connection.
151 .TP
152 .B AF_ECONET
153 .\" commit: 349f29d841dbae854bd7367be7c250401f974f47
154 Acorn Econet protocol (removed in Linux 3.5).
155 See the
156 .UR http://www.8bs.com/othrdnld/manuals/econet.shtml
157 Econet documentation
158 .UE
159 for details.
160 .TP
161 .B AF_ATMSVC
162 Access to ATM Switched Virtual Circuits (SVCs)
163 See the
164 .UR https://www.tldp.org/HOWTO/text/ATM-Linux-HOWTO
165 .I ATM on Linux HOWTO
166 .UE
167 for details.
168 .TP
169 .B AF_RDS
170 .\" commit: 639b321b4d8f4e412bfbb2a4a19bfebc1e68ace4
171 Reliable Datagram Sockets (RDS) protocol (since Linux 2.6.30).
172 RDS over RDMA has no relation to
173 .B AF_SMC
174 or
175 .BR AF_XDP .
176 For further information, see
177 .\" rds-tools: https://github.com/oracle/rds-tools/blob/master/rds.7
178 .\" rds-tools: https://github.com/oracle/rds-tools/blob/master/rds-rdma.7
179 .BR rds (7),
180 .BR rds\-rdma (7),
181 and
182 .I Documentation/networking/rds.txt
183 in the Linux kernel source tree.
184 .TP
185 .B AF_IRDA
186 .\" commits: 1ca163afb6fd569b, d64c2a76123f0300
187 Socket interface over IrDA
188 (moved to staging in Linux 4.14, removed in Linux 4.17).
189 .\" irda-utils: https://sourceforge.net/p/irda/code/HEAD/tree/tags/IRDAUTILS_0_9_18/irda-utils/man/irda.7.gz?format=raw
190 For further information, see
191 .BR irda (7).
192 .TP
193 .B AF_PPPOX
194 Generic PPP transport layer, for setting up L2 tunnels
195 (L2TP and PPPoE).
196 See
197 .I Documentation/networking/l2tp.txt
198 in the Linux kernel source tree for details.
199 .TP
200 .B AF_WANPIPE
201 .\" commits: ce0ecd594d78710422599918a608e96dd1ee6024
202 Legacy protocol for wide area network (WAN) connectivity
203 that was used by Sangoma WAN cards (called "WANPIPE");
204 removed in Linux 2.6.21.
205 .TP
206 .B AF_LLC
207 .\" linux-history commit: 34beb106cde7da233d4df35dd3d6cf4fee937caa
208 Logical link control (IEEE 802.2 LLC) protocol, upper part
209 of data link layer of ISO/OSI networking protocol stack
210 (since Linux 2.4);
211 has no relation to
212 .BR AF_PACKET .
213 See chapter
214 .I 13.5.3. Logical Link Control
215 in
216 .I Understanding Linux Kernel Internals
217 (O'Reilly Media, 2006)
218 and
219 .I IEEE Standards for Local Area Networks: Logical Link Control
220 (The Institute of Electronics and Electronics Engineers, Inc.,
221 New York, New York, 1985)
222 for details.
223 See also
224 .UR https://wiki.linuxfoundation.org/networking/llc
225 some historical notes
226 .UE
227 regarding its development.
228 .TP
229 .B AF_IB
230 .\" commits: 8d36eb01da5d371f..ce117ffac2e93334
231 InfiniBand native addressing (since Linux 3.11).
232 .TP
233 .B AF_MPLS
234 .\" commits: 0189197f441602acdca3f97750d392a895b778fd
235 Multiprotocol Label Switching (since Linux 4.1);
236 mostly used for configuring MPLS routing via
237 .BR netlink (7),
238 as it doesn't expose ability to create sockets to user space.
239 .TP
240 .B AF_CAN
241 .\" commits: 8dbde28d9711475a..5423dd67bd0108a1
242 Controller Area Network automotive bus protocol (since Linux 2.6.25).
243 See
244 .I Documentation/networking/can.rst
245 in the Linux kernel source tree for details.
246 .TP
247 .B AF_TIPC
248 .\" commits: b97bf3fd8f6a16966d4f18983b2c40993ff937d4
249 TIPC, "cluster domain sockets" protocol (since Linux 2.6.16).
250 See
251 .UR http://tipc.io/programming.html
252 .I TIPC Programmer's Guide
253 .UE
254 and the
255 .UR http://tipc.io/protocol.html
256 protocol description
257 .UE
258 for details.
259 .TP
260 .B AF_BLUETOOTH
261 .\" commits: 8d36eb01da5d371f..ce117ffac2e93334
262 Bluetooth low-level socket protocol (since Linux 3.11).
263 See
264 .UR https://git.kernel.org\:/pub/scm\:/bluetooth/bluez.git\:/tree/doc/mgmt-api.txt
265 .I Bluetooth Management API overview
266 .UE
267 and
268 .UR https://people.csail.mit.edu/albert/bluez-intro/
269 .I An Introduction to Bluetooth Programming
270 by Albert Huang
271 .UE
272 for details.
273 .TP
274 .B AF_IUCV
275 .\" commit: eac3731bd04c7131478722a3c148b78774553116
276 IUCV (inter-user communication vehicle) z/VM protocol
277 for hypervisor-guest interaction (since Linux 2.6.21);
278 has no relation to
279 .B AF_VSOCK
280 and/or
281 .B AF_SMC
282 See
283 .UR https://www.ibm.com\:/support\:/knowledgecenter\:/en\:/SSB27U_6.4.0\:/com.ibm.zvm.v640.hcpb4\:/iucv.htm
284 .I IUCV protocol overview
285 .UE
286 for details.
287 .TP
288 .B AF_RXRPC
289 .\" commit: 17926a79320afa9b95df6b977b40cca6d8713cea
290 .\" http://people.redhat.com/~dhowells/rxrpc/
291 .\" https://www.infradead.org/~dhowells/kafs/af_rxrpc_client.html
292 .\" http://workshop.openafs.org/afsbpw09/talks/thu_2/kafs.pdf
293 .\" http://pages.cs.wisc.edu/~remzi/OSTEP/dist-afs.pdf
294 .\" http://web.mit.edu/kolya/afs/rx/rx-spec
295 Rx, Andrew File System remote procedure call protocol
296 (since Linux 2.6.22).
297 See
298 .I Documentation/networking/rxrpc.txt
299 in the Linux kernel source tree for details.
300 .TP
301 .B AF_ISDN
302 .\" commit: 1b2b03f8e514e4f68e293846ba511a948b80243c
303 New "modular ISDN" driver interface protocol (since Linux 2.6.27).
304 See the
305 .UR http://www.misdn.eu/wiki/Main_Page/
306 mISDN wiki
307 .UE
308 for details.
309 .TP
310 .B AF_PHONET
311 .\" commit: 4b07b3f69a8471cdc142c51461a331226fef248a
312 Nokia cellular modem IPC/RPC interface (since Linux 2.6.31).
313 See
314 .I Documentation/networking/phonet.txt
315 in the Linux kernel source tree for details.
316 .TP
317 .B AF_IEEE802154
318 .\" commit: 9ec7671603573ede31207eb5b0b3e1aa211b2854
319 IEEE 802.15.4 WPAN (wireless personal area network) raw packet protocol
320 (since Linux 2.6.31).
321 See
322 .I Documentation/networking/ieee802154.txt
323 in the Linux kernel source tree for details.
324 .TP
325 .B AF_CAIF
326 .\" commit: 529d6dad5bc69de14cdd24831e2a14264e93daa4
327 .\" https://lwn.net/Articles/371017/
328 .\" http://read.pudn.com/downloads157/doc/comm/698729/Misc/caif/Com%20CPU%20to%20Appl%20CPU%20Interface%20DESCRIPTION_LZN901%202002_revR1C.pdf
329 .\" http://read.pudn.com/downloads157/doc/comm/698729/Misc/caif/Com%20CPU%20to%20Appl%20CPU%20Interface%20PROTOCOL%20SPECIFICATION_LZN901%201708_revR1A.pdf
330 Ericsson's Communication CPU to Application CPU interface (CAIF) protocol
331 (since Linux 2.6.36).
332 See
333 .I Documentation/networking/caif/Linux\-CAIF.txt
334 in the Linux kernel source tree for details.
335 .TP
336 .B AF_ALG
337 Interface to kernel crypto API (since Linux 2.6.38).
338 See
339 .I Documentation/crypto/userspace\-if.rst
340 in the Linux kernel source tree for details.
341 .TP
342 .B AF_VSOCK
343 .\" commit: d021c344051af91f42c5ba9fdedc176740cbd238
344 VMWare VSockets protocol for hypervisor-guest interaction (since Linux 3.9);
345 has no relation to
346 .B AF_IUCV
347 and
348 .BR AF_SMC .
349 For further information, see
350 .BR vsock (7).
351 .TP
352 .B AF_KCM
353 .\" commit: 03c8efc1ffeb6b82a22c1af8dd908af349563314
354 KCM (kernel connection multiplexer) interface (since Linux 4.6).
355 See
356 .I Documentation/networking/kcm.txt
357 in the Linux kernel source tree for details.
358 .TP
359 .B AF_QIPCRTR
360 .\" commit: bdabad3e363d825ddf9679dd431cca0b2c30f881
361 Qualcomm IPC router interface protocol (since Linux 4.7).
362 .TP
363 .B AF_SMC
364 .\" commit: f3a3e248f3f7cd9a4bed334022704d7e7fc781bf
365 SMC-R (shared memory communications over RDMA) protocol (since Linux 4.11),
366 and SMC-D (shared memory communications, direct memory access) protocol
367 for intra-node z/VM quest interaction (since Linux 4.19);
368 has no relation to
369 .BR AF_RDS ", " AF_IUCV
370 or
371 .BR AF_VSOCK .
372 See
373 .UR https://tools.ietf.org/html/rfc7609
374 RFC 7609
375 .I IBM's Shared Memory Communications over RDMA (SMC-R) Protocol
376 .UE
377 for details regarding SMC-R.
378 See
379 .UR https://www-01.ibm.com\:/software/network\:/commserver\:/SMC-D/index.html
380 .I SMC-D Reference Information
381 .UE
382 for details regarding SMC-D.
383 .TP
384 .B AF_XDP
385 .\" commit: c0c77d8fb787cfe0c3fca689c2a30d1dad4eaba7
386 XDP (express data path) interface (since Linux 4.18).
387 See
388 .I Documentation/networking/af_xdp.rst
389 in the Linux kernel source tree for details.
390 .SH SEE ALSO
391 .BR socket (2),
392 .BR socket (7)