4.4BSD/usr/share/man/cat4/icmp.0

ICMP(4)                     BSD Programmer's Manual                    ICMP(4)

NNAAMMEE
     iiccmmpp - Internet Control Message Protocol

SSYYNNOOPPSSIISS
     ##iinncclluuddee <<ssyyss//ssoocckkeett..hh>>
     ##iinncclluuddee <<nneettiinneett//iinn..hh>>

     _i_n_t
     ssoocckkeett(_A_F___I_N_E_T, _S_O_C_K___R_A_W, _p_r_o_t_o);

DDEESSCCRRIIPPTTIIOONN
     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 _p_r_o_t_o 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.

DDIIAAGGNNOOSSTTIICCSS
     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 datagram with
                      the destination address specified and the socket is al-
                      ready connected;

     [ENOTCONN]       when trying to send a datagram, but no destination ad-
                      dress is specified, and the socket hasn't been connect-
                      ed;

     [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.

SSEEEE AALLSSOO
     send(2),  recv(2),  intro(4),  inet(4),  ip(4)

HHIISSTTOORRYY
     The iiccmmpp protocol appeared in 4.3BSD.

4.3 Berkeley Distribution        June 5, 1993                                1