ICMP(4) | Device Drivers Manual | ICMP(4) |
icmp
— Internet
Control Message Protocol
#include
<sys/socket.h>
#include <netinet/in.h>
int
socket
(AF_INET,
SOCK_RAW,
proto);
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 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(2) and recvfrom(2) 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.
A socket operation may fail with one of the following errors returned:
EISCONN
]ENOTCONN
]ENOBUFS
]EADDRNOTAVAIL
]recv(2), send(2), inet(4), intro(4), ip(4)
Internet Control Message Protocol, RFC, 792, September 1981.
Requirements for Internet Hosts -- Communication Layers, RFC, 1122, October 1989.
The icmp
protocol appeared in
4.3BSD.
June 5, 1993 | NetBSD 10.99 |