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Improve comment to TCP_MINMSS by taking the wording from lstewart (with

a small difference in the last paragraph though) as suggested by jhb.

Clarify that the 'reviewed by' in r212653 by lstewart was for the
functional change, not the comments in the committed version.
This commit is contained in:
Andre Oppermann 2010-09-16 12:13:06 +00:00
parent 3c141a7e1d
commit 2c9879e8d3
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=212731

View File

@ -120,18 +120,18 @@ struct tcphdr {
#define TCP6_MSS 1220
/*
* Limit the lowest MSS we accept from path MTU discovery and the TCP SYN MSS
* option. Allowing too low values of MSS can consume significant amounts of
* resources and be used as a form of a resource exhaustion attack.
* Limit the lowest MSS we accept for path MTU discovery and the TCP SYN MSS
* option. Allowing low values of MSS can consume significant resources and
* be used to mount a resource exhaustion attack.
* Connections requesting lower MSS values will be rounded up to this value
* and the IP_DF flag is cleared to allow fragmentation along the path.
* and the IP_DF flag will be cleared to allow fragmentation along the path.
*
* See tcp_subr.c tcp_minmss SYSCTL declaration for more comments. Setting
* it to "0" disables the minmss check.
*
* The default value is fine for the smallest official link MTU (256 bytes,
* AX.25 packet radio) in the Internet. However it is very unlikely to come
* across such low MTU interfaces these days (anno domini 2003).
* The default value is fine for TCP across the Internet's smallest official
* link MTU (256 bytes for AX.25 packet radio). However, a connection is very
* unlikely to come across such low MTU interfaces these days (anno domini 2003).
*/
#define TCP_MINMSS 216