| tcp.4 (119893) | tcp.4 (125680) |
|---|---|
| 1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. --- 16 unchanged lines hidden (view full) --- 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" From: @(#)tcp.4 8.1 (Berkeley) 6/5/93 | 1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. --- 16 unchanged lines hidden (view full) --- 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" From: @(#)tcp.4 8.1 (Berkeley) 6/5/93 |
| 33.\" $FreeBSD: head/share/man/man4/tcp.4 119893 2003-09-08 19:57:22Z ru $ | 33.\" $FreeBSD: head/share/man/man4/tcp.4 125680 2004-02-11 04:26:04Z bms $ |
| 34.\" 35.Dd March 13, 2003 36.Dt TCP 4 37.Os 38.Sh NAME 39.Nm tcp 40.Nd Internet Transmission Control Protocol 41.Sh SYNOPSIS --- 74 unchanged lines hidden (view full) --- 116through which packets are being transmitted and received. 117Normally, this address corresponds to the peer entity's network. 118.Pp 119.Tn TCP 120supports a number of socket options which can be set with 121.Xr setsockopt 2 122and tested with 123.Xr getsockopt 2 : | 34.\" 35.Dd March 13, 2003 36.Dt TCP 4 37.Os 38.Sh NAME 39.Nm tcp 40.Nd Internet Transmission Control Protocol 41.Sh SYNOPSIS --- 74 unchanged lines hidden (view full) --- 116through which packets are being transmitted and received. 117Normally, this address corresponds to the peer entity's network. 118.Pp 119.Tn TCP 120supports a number of socket options which can be set with 121.Xr setsockopt 2 122and tested with 123.Xr getsockopt 2 : |
| 124.Bl -tag -width ".Dv TCP_NODELAY" | 124.Bl -tag -width ".Dv TCP_SIGNATURE_ENABLE" |
| 125.It Dv TCP_NODELAY 126Under most circumstances, 127.Tn TCP 128sends data when it is presented; 129when outstanding data has not yet been acknowledged, it gathers 130small amounts of output to be sent in a single packet once 131an acknowledgement is received. 132For a small number of clients, such as window systems --- 37 unchanged lines hidden (view full) --- 170option is provided to allow servers to easily make use of Transaction 171.Tn TCP 172(see 173.Xr ttcp 4 ) . 174When this option is set to a non-zero value, 175.Tn TCP 176will delay sending any data at all until either the socket is closed, 177or the internal send buffer is filled. | 125.It Dv TCP_NODELAY 126Under most circumstances, 127.Tn TCP 128sends data when it is presented; 129when outstanding data has not yet been acknowledged, it gathers 130small amounts of output to be sent in a single packet once 131an acknowledgement is received. 132For a small number of clients, such as window systems --- 37 unchanged lines hidden (view full) --- 170option is provided to allow servers to easily make use of Transaction 171.Tn TCP 172(see 173.Xr ttcp 4 ) . 174When this option is set to a non-zero value, 175.Tn TCP 176will delay sending any data at all until either the socket is closed, 177or the internal send buffer is filled. |
| 178.It Dv TCP_SIGNATURE_ENABLE 179This option enables the use of MD5 digests (also known as TCP-MD5) 180on writes to the specified socket. 181In the current release, only outgoing traffic is digested; 182digests on incoming traffic are not verified. 183The current default behavior for the system is to respond to a system 184advertising this option with TCP-MD5; this may change. 185.Pp 186One common use for this in a FreeBSD router deployment is to enable 187based routers to interwork with Cisco equipment at peering points. 188Support for this feature conforms to RFC 2385. 189Only IPv4 (AF_INET) sessions are supported. 190.Pp 191In order for this option to function correctly, it is necessary for the 192administrator to add a tcp-md5 key entry to the system's security 193associations database (SADB) using the 194.Xr setkey 8 195utility. 196This entry must have an SPI of 0x1000 and can therefore only be specified 197on a per-host basis at this time. 198.Pp 199If an SADB entry cannot be found for the destination, the outgoing traffic 200will have an invalid digest option prepended, and the following error message 201will be visible on the system console: 202.Em "tcpsignature_compute: SADB lookup failed for %d.%d.%d.%d" . |
|
| 178.El 179.Pp 180The option level for the 181.Xr setsockopt 2 182call is the protocol number for 183.Tn TCP , 184available from 185.Xr getprotobyname 3 , --- 298 unchanged lines hidden (view full) --- 484.Xr getsockopt 2 , 485.Xr socket 2 , 486.Xr sysctl 3 , 487.Xr blackhole 4 , 488.Xr inet 4 , 489.Xr intro 4 , 490.Xr ip 4 , 491.Xr syncache 4 , | 203.El 204.Pp 205The option level for the 206.Xr setsockopt 2 207call is the protocol number for 208.Tn TCP , 209available from 210.Xr getprotobyname 3 , --- 298 unchanged lines hidden (view full) --- 509.Xr getsockopt 2 , 510.Xr socket 2 , 511.Xr sysctl 3 , 512.Xr blackhole 4 , 513.Xr inet 4 , 514.Xr intro 4 , 515.Xr ip 4 , 516.Xr syncache 4 , |
| 492.Xr ttcp 4 | 517.Xr ttcp 4 , 518.Xr setkey 8 |
| 493.Rs 494.%A "V. Jacobson" 495.%A "R. Braden" 496.%A "D. Borman" 497.%T "TCP Extensions for High Performance" 498.%O "RFC 1323" 499.Re 500.Rs 501.%A "R. Braden" 502.%T "T/TCP \- TCP Extensions for Transactions" 503.%O "RFC 1644" 504.Re | 519.Rs 520.%A "V. Jacobson" 521.%A "R. Braden" 522.%A "D. Borman" 523.%T "TCP Extensions for High Performance" 524.%O "RFC 1323" 525.Re 526.Rs 527.%A "R. Braden" 528.%T "T/TCP \- TCP Extensions for Transactions" 529.%O "RFC 1644" 530.Re |
| 531.Rs 532.%A "A. Heffernan" 533.%T "Protection of BGP Sessions via the TCP MD5 Signature Option" 534.%O "RFC 2385" 535.Re |
|
| 505.Sh HISTORY 506The 507.Tn TCP 508protocol appeared in 509.Bx 4.2 . 510The RFC 1323 extensions for window scaling and timestamps were added 511in 512.Bx 4.4 . | 536.Sh HISTORY 537The 538.Tn TCP 539protocol appeared in 540.Bx 4.2 . 541The RFC 1323 extensions for window scaling and timestamps were added 542in 543.Bx 4.4 . |