projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| f29f3a8b | 1 | .\" Copyright (c) 1986 Regents of the University of California. |
| 97cd0d25 | 2 | .\" All rights reserved. |
| f29f3a8b | 3 | .\" |
| 91cff1e1 | 4 | .\" %sccs.include.redist.man% |
| 97cd0d25 | 5 | .\" |
| 91cff1e1 | 6 | .\" @(#)icmp.4 6.5 (Berkeley) %G% |
| f29f3a8b | 7 | .\" |
| 1324d254 | 8 | .TH ICMP 4 "" |
| f29f3a8b MK |
9 | .UC 6 |
| 10 | .SH NAME | |
| 11 | icmp \- Internet Control Message Protocol | |
| 12 | .SH SYNOPSIS | |
| 13 | .B #include <sys/socket.h> | |
| 14 | .br | |
| 15 | .B #include <netinet/in.h> | |
| 16 | .PP | |
| 17 | .B s = socket(AF_INET, SOCK_RAW, proto); | |
| 18 | .SH DESCRIPTION | |
| 19 | ICMP is the error and control message protocol used | |
| 20 | by IP and the Internet protocol family. It may be accessed | |
| 21 | through a \*(lqraw socket\*(rq for network monitoring | |
| 22 | and diagnostic functions. | |
| 23 | The | |
| 24 | .I proto | |
| 25 | parameter to the socket call to create an ICMP socket | |
| 26 | is obtained from | |
| 1324d254 | 27 | .IR getprotobyname (3). |
| f29f3a8b MK |
28 | ICMP sockets are connectionless, |
| 29 | and are normally used with the | |
| 30 | .I sendto | |
| 31 | and | |
| 32 | .I recvfrom | |
| 33 | calls, though the | |
| 34 | .IR connect (2) | |
| 35 | call may also be used to fix the destination for future | |
| 36 | packets (in which case the | |
| 37 | .IR read (2) | |
| 38 | or | |
| 39 | .IR recv (2) | |
| 40 | and | |
| 41 | .IR write (2) | |
| 42 | or | |
| 43 | .IR send (2) | |
| 44 | system calls may be used). | |
| 45 | .PP | |
| 46 | Outgoing packets automatically have an IP header prepended to | |
| 47 | them (based on the destination address). | |
| 48 | Incoming packets are received with the IP header and options intact. | |
| 49 | .SH DIAGNOSTICS | |
| 50 | A socket operation may fail with one of the following errors returned: | |
| 51 | .TP 15 | |
| 52 | [EISCONN] | |
| 53 | when trying to establish a connection on a socket which | |
| 54 | already has one, or when trying to send a datagram with the destination | |
| 55 | address specified and the socket is already connected; | |
| 56 | .TP 15 | |
| 57 | [ENOTCONN] | |
| 58 | when trying to send a datagram, but | |
| 59 | no destination address is specified, and the socket hasn't been | |
| 60 | connected; | |
| 61 | .TP 15 | |
| 62 | [ENOBUFS] | |
| 63 | when the system runs out of memory for | |
| 64 | an internal data structure; | |
| 65 | .TP 15 | |
| 66 | [EADDRNOTAVAIL] | |
| 67 | when an attempt is made to create a | |
| 68 | socket with a network address for which no network interface | |
| 69 | exists. | |
| 70 | .SH SEE ALSO | |
| 1324d254 | 71 | send(2), recv(2), intro(4), inet(4), ip(4) |