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Handle PMTU discovery in syn-ack packets slightly differently;

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rely on syncache flags instead of directly accessing the route
entry.

MFC after:	3 days
This commit is contained in:
Mike Silbersack 2002-08-05 22:34:15 +00:00
parent f7a91b49b7
commit a9ce5e05b5
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=101405
1 changed files with 6 additions and 8 deletions
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14
sys/netinet/tcp_syncache.c
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@ -1141,16 +1141,14 @@ syncache_respond(sc, m)
ip->ip_tos = sc->sc_tp->t_inpcb->inp_ip_tos; /* XXX */
/*
* See if we should do MTU discovery. We do it only if the following
* are true:
* 1) we have a valid route to the destination
* 2) the MTU is not locked (if it is, then discovery has been
* disabled)
* See if we should do MTU discovery. Route lookups are expensive,
* so we will only unset the DF bit if:
*
* 1) path_mtu_discovery is disabled
* 2) the SCF_UNREACH flag has been set
*/
if (path_mtu_discovery
&& (rt != NULL)
&& rt->rt_flags & RTF_UP
&& !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
&& ((sc->sc_flags & SCF_UNREACH) == 0)) {
ip->ip_off |= IP_DF;
}