kern/108375: net.inet.raw.maxdgram shouldn't be less than MTU size.

[Vladimir Ivanov]

>Number:         108375
>Category:       kern
>Synopsis:       net.inet.raw.maxdgram shouldn't be less than MTU size.
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Jan 26 15:40:25 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator:     Vladimir Ivanov
>Release:        RELENG_5, RELENG_6
>Organization:
Yandex LLC
>Environment:
FreeBSD mimino.yandex.net 5.5-PRERELEASE FreeBSD 5.5-PRERELEASE #17: Tue May  2 00:33:08 MSD 2006     root at mimino.yandex.net:/usr/obj/usr/src/sys/CORE-RTR-RELENG_5  i386

>Description:

Big packets failed to transmit thru raw socket if datasize exceed net.inet.raw.maxdgram but still less than interface's MTU.

Tnat's why strange bugs appears if we use Jumbo packets more than 8KB.
E.g ospf daemon of Quagga fails to send route updates: 
Nov 23 18:59:42 multiped ospfd[16187]: *** sendmsg in ospf_write to 224.0.0.6 failed with Message too long

>How-To-Repeat:

>Fix:
Workaround: 
adjust net.inet.raw.maxdgram to bigger value.

It will be nice if committers will increase defult buffer size as hotfix.
>Release-Note:
>Audit-Trail:
>Unformatted: