ICMP
Section: Devices and Network Interfaces (4)
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BSD mandoc
BSD 4.3
NAME
icmp
- Internet Control Message Protocol
SYNOPSIS
Fd #include <sys/socket.h>
Fd #include <netinet/in.h>
Ft int
Fn socket AF_INET SOCK_RAW proto
DESCRIPTION
ICMP
is the error and control message protocol used
by
IP
and the Internet protocol family. It may be accessed
through a
``raw socket''
for network monitoring
and diagnostic functions.
The
Fa proto
parameter to the socket call to create an
ICMP
socket
is obtained from
getprotobyname(3).
ICMP
sockets are connectionless,
and are normally used with the
sendto
and
recvfrom
calls, though the
connect(2)
call may also be used to fix the destination for future
packets (in which case the
read(2)
or
recv(2)
and
write(2)
or
send(2)
system calls may be used).
Outgoing packets automatically have an
IP
header prepended to
them (based on the destination address).
Incoming packets are received with the
IP
header and options intact.
DIAGNOSTICS
A socket operation may fail with one of the following errors returned:
- 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;
- Bq Er ENOTCONN
-
when trying to send a datagram, but
no destination address is specified, and the socket hasn't been
connected;
- Bq Er ENOBUFS
-
when the system runs out of memory for
an internal data structure;
- Bq Er EADDRNOTAVAIL
-
when an attempt is made to create a
socket with a network address for which no network interface
exists.
SEE ALSO
send(2),
recv(2),
intro(4),
inet(4),
ip(4)
HISTORY
The
protocol appeared in
BSD 4.3
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- DIAGNOSTICS
-
- SEE ALSO
-
- HISTORY
-
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Time: 16:28:56 GMT, April 18, 2022