![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to tcp.4p CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Power 6/32 Unix Tahoe 4.2BSD] / cci / usr / src / man / man4|
Return to tcp.4p CVS log | Up to [Power 6/32 Unix Tahoe 4.2BSD] / cci / usr / src / man / man4 |
1.1 root 1: .TH TCP 4P "7 July 1983"
2: .UC 4
3: .SH NAME
4: tcp \- Internet Transmission Control Protocol
5: .SH SYNOPSIS
6: .B #include <sys/socket.h>
7: .br
8: .B #include <netinet/in.h>
9: .PP
10: .B s = socket(AF_INET, SOCK_STREAM, 0);
11: .SH DESCRIPTION
12: The TCP protocol provides reliable, flow-controlled, two-way
13: transmission of data. It is a byte-stream protocol used to
14: support the SOCK_STREAM abstraction. TCP uses the standard
15: Internet address format and, in addition, provides a per-host
16: collection of \*(lqport addresses\*(rq. Thus, each address is composed
17: of an Internet address specifying the host and network, with
18: a specific TCP port on the host identifying the peer entity.
19: .PP
20: Sockets utilizing the tcp protocol are either \*(lqactive\*(rq or
21: \*(lqpassive\*(rq. Active sockets initiate connections to passive
22: sockets. By default TCP sockets are created active; to create a
23: passive socket the
24: .IR listen (2)
25: system call must be used
26: after binding the socket with the
27: .IR bind (2)
28: system call. Only
29: passive sockets may use the
30: .IR accept (2)
31: call to accept incoming connections. Only active sockets may
32: use the
33: .IR connect (2)
34: call to initiate connections.
35: .PP
36: Passive sockets may \*(lqunderspecify\*(rq their location to match
37: incoming connection requests from multiple networks. This
38: technique, termed \*(lqwildcard addressing\*(rq, allows a single
39: server to provide service to clients on multiple networks.
40: To create a socket which listens on all networks, the Internet
41: address INADDR_ANY
42: must be bound. The TCP port may still be specified
43: at this time; if the port is not specified the system will assign one.
44: Once a connection has been established the socket's address is
45: fixed by the peer entity's location. The address assigned the
46: socket is the address associated with the network interface
47: through which packets are being transmitted and received. Normally
48: this address corresponds to the peer entity's network.
49: .SH DIAGNOSTICS
50: A socket operation may fail with one of the following errors returned:
51: .TP 20
52: [EISCONN]
53: when trying to establish a connection on a socket which
54: already has one;
55: .TP 20
56: [ENOBUFS]
57: when the system runs out of memory for
58: an internal data structure;
59: .TP 20
60: [ETIMEDOUT]
61: when a connection was dropped
62: due to excessive retransmissions;
63: .TP 20
64: [ECONNRESET]
65: when the remote peer
66: forces the connection to be closed;
67: .TP 20
68: [ECONNREFUSED]
69: when the remote
70: peer actively refuses connection establishment (usually because
71: no process is listening to the port);
72: .TP 20
73: [EADDRINUSE]
74: when an attempt
75: is made to create a socket with a port which has already been
76: allocated;
77: .TP 20
78: [EADDRNOTAVAIL]
79: when an attempt is made to create a
80: socket with a network address for which no network interface
81: exists.
82: .SH SEE ALSO
83: intro(4N), inet(4F)
84: .SH BUGS
85: It should be possible to send and receive TCP options.
86: The system always tries to negotiates the maximum TCP segment
87: size to be 1024 bytes. This can result in poor performance
88: if an intervening network performs excessive fragmentation.
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.