DragonFly On-Line Manual Pages

ICMP(4)               DragonFly Kernel Interfaces Manual               ICMP(4)

NAME
     icmp -- Internet Control Message Protocol

SYNOPSIS
     #include <sys/types.h>
     #include <sys/socket.h>
     #include <netinet/in.h>

     int
     socket(AF_INET, SOCK_RAW, proto);

DESCRIPTION
     ICMP is the error and control message protocol used by IP and the Inter-
     net 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.

ERRORS
     A socket operation may fail with one of the following errors returned:

     [EISCONN]          when trying to establish a connection on a socket
                        which already has one, or when trying to send a data-
                        gram with the destination address specified and the
                        socket is already connected;

     [ENOTCONN]         when trying to send a datagram, but no destination
                        address is specified, and the socket hasn't been con-
                        nected;

     [ENOBUFS]          when the system runs out of memory for an internal
                        data structure;

     [EADDRNOTAVAIL]    when an attempt is made to create a socket with a net-
                        work address for which no network interface exists.

SEE ALSO
     recv(2), send(2), inet(4), intro(4), ip(4)

HISTORY
     The icmp protocol appeared in 4.3BSD.

DragonFly 3.5                    June 5, 1993                    DragonFly 3.5