[unix-history] / share / man / man4 / icmp.4

.\" Copyright (c) 1986, 1991 Regents of the University of California.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)icmp.4	6.6 (Berkeley) 3/28/91
.\"
.Dd March 28, 1991
.Dt ICMP 4
.Os BSD 4.3
.Sh NAME
.Nm icmp
.Nd Internet Control Message Protocol
.Sh SYNOPSIS
.Fd #include <sys/socket.h>
.Fd #include <netinet/in.h>
.Ft int
.Fn socket AF_INET SOCK_RAW proto
.Sh DESCRIPTION
.Tn ICMP
is the error and control message protocol used
by
.Tn IP
and the Internet protocol family.  It may be accessed
through a
.Dq raw socket
for network monitoring
and diagnostic functions.
The
.Fa proto
parameter to the socket call to create an
.Tn ICMP
socket
is obtained from
.Xr getprotobyname 3 .
.Tn ICMP
sockets are connectionless,
and are normally used with the
.Xr sendto
and
.Xr recvfrom
calls, though the
.Xr connect 2
call may also be used to fix the destination for future
packets (in which case the 
.Xr read 2
or
.Xr recv 2
and 
.Xr write 2
or
.Xr send 2
system calls may be used).
.Pp
Outgoing packets automatically have an
.Tn IP
header prepended to
them (based on the destination address).
Incoming packets are received with the
.Tn IP
header and options intact.
.Sh DIAGNOSTICS
A socket operation may fail with one of the following errors returned:
.Bl -tag -width [EADDRNOTAVAIL]
.It Bq Er EISCONN
when trying to establish a connection on a socket which
already has one, or when trying to send a datagram with the destination
address specified and the socket is already connected;
.It Bq Er ENOTCONN
when trying to send a datagram, but
no destination address is specified, and the socket hasn't been
connected;
.It Bq Er ENOBUFS
when the system runs out of memory for
an internal data structure;
.It Bq Er EADDRNOTAVAIL
when an attempt is made to create a 
socket with a network address for which no network interface
exists.
.El
.Sh SEE ALSO
.Xr send 2 ,
.Xr recv 2 ,
.Xr intro 4 ,
.Xr inet 4 ,
.Xr ip 4
.Sh HISTORY
The
.Nm
protocol appeared in
.Bx 4.3 .
Commit	Line	Data
15637ed4 RG	1	.\" Copyright (c) 1986, 1991 Regents of the University of California.
	2	.\" All rights reserved.
	3	.\"
	4	.\" Redistribution and use in source and binary forms, with or without
	5	.\" modification, are permitted provided that the following conditions
	6	.\" are met:
	7	.\" 1. Redistributions of source code must retain the above copyright
	8	.\" notice, this list of conditions and the following disclaimer.
	9	.\" 2. Redistributions in binary form must reproduce the above copyright
	10	.\" notice, this list of conditions and the following disclaimer in the
	11	.\" documentation and/or other materials provided with the distribution.
	12	.\" 3. All advertising materials mentioning features or use of this software
	13	.\" must display the following acknowledgement:
	14	.\" This product includes software developed by the University of
	15	.\" California, Berkeley and its contributors.
	16	.\" 4. Neither the name of the University nor the names of its contributors
	17	.\" may be used to endorse or promote products derived from this software
	18	.\" without specific prior written permission.
	19	.\"
	20	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	21	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	24	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	.\" SUCH DAMAGE.
	31	.\"
	32	.\" @(#)icmp.4 6.6 (Berkeley) 3/28/91
	33	.\"
	34	.Dd March 28, 1991
	35	.Dt ICMP 4
	36	.Os BSD 4.3
	37	.Sh NAME
	38	.Nm icmp
	39	.Nd Internet Control Message Protocol
	40	.Sh SYNOPSIS
	41	.Fd #include <sys/socket.h>
	42	.Fd #include <netinet/in.h>
	43	.Ft int
	44	.Fn socket AF_INET SOCK_RAW proto
	45	.Sh DESCRIPTION
	46	.Tn ICMP
	47	is the error and control message protocol used
	48	by
	49	.Tn IP
	50	and the Internet protocol family. It may be accessed
	51	through a
	52	.Dq raw socket
	53	for network monitoring
	54	and diagnostic functions.
	55	The
	56	.Fa proto
	57	parameter to the socket call to create an
	58	.Tn ICMP
	59	socket
	60	is obtained from
	61	.Xr getprotobyname 3 .
	62	.Tn ICMP
	63	sockets are connectionless,
	64	and are normally used with the
65	.Xr sendto
66	and
67	.Xr recvfrom
68	calls, though the
69	.Xr connect 2
70	call may also be used to fix the destination for future
71	packets (in which case the
72	.Xr read 2
73	or
74	.Xr recv 2
75	and
76	.Xr write 2
77	or
78	.Xr send 2
79	system calls may be used).
80	.Pp
81	Outgoing packets automatically have an
82	.Tn IP
83	header prepended to
84	them (based on the destination address).
85	Incoming packets are received with the
86	.Tn IP
87	header and options intact.
88	.Sh DIAGNOSTICS
89	A socket operation may fail with one of the following errors returned:
90	.Bl -tag -width [EADDRNOTAVAIL]
91	.It Bq Er EISCONN
92	when trying to establish a connection on a socket which
93	already has one, or when trying to send a datagram with the destination
94	address specified and the socket is already connected;
95	.It Bq Er ENOTCONN
96	when trying to send a datagram, but
97	no destination address is specified, and the socket hasn't been
98	connected;
99	.It Bq Er ENOBUFS
100	when the system runs out of memory for
101	an internal data structure;
102	.It Bq Er EADDRNOTAVAIL
103	when an attempt is made to create a
104	socket with a network address for which no network interface
105	exists.
106	.El
107	.Sh SEE ALSO
108	.Xr send 2 ,
109	.Xr recv 2 ,
110	.Xr intro 4 ,
111	.Xr inet 4 ,
112	.Xr ip 4
113	.Sh HISTORY
114	The
115	.Nm
116	protocol appeared in
117	.Bx 4.3 .