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- obey ip6po_minmtu.

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- notify a proper path MTU to applications.

Obtained from:	KAME
This commit is contained in:
Hajimu UMEMOTO 2004-02-08 18:22:27 +00:00
parent 777a986004
commit 8b00e59d89
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=125595
1 changed files with 30 additions and 3 deletions
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33
sys/netinet6/ip6_output.c
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@ -827,10 +827,28 @@ skip_ipsec2:;
goto bad;
/*
* advanced API (IPV6_USE_MIN_MTU) overrides mtu setting
* The caller of this function may specify to use the minimum MTU
* in some cases.
* An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
* setting. The logic is a bit complicated; by default, unicast
* packets will follow path MTU while multicast packets will be sent at
* the minimum MTU. If IP6PO_MINMTU_ALL is specified, all packets
* including unicast ones will be sent at the minimum MTU. Multicast
* packets will always be sent at the minimum MTU unless
* IP6PO_MINMTU_DISABLE is explicitly specified.
* See RFC 3542 for more details.
*/
if ((flags & IPV6_MINMTU) != 0 && mtu > IPV6_MMTU)
mtu = IPV6_MMTU;
if (mtu > IPV6_MMTU) {
if ((flags & IPV6_MINMTU))
mtu = IPV6_MMTU;
else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
mtu = IPV6_MMTU;
else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
(opt == NULL ||
opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
mtu = IPV6_MMTU;
}
}
/* Fake scoped addresses */
if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
@ -1032,6 +1050,8 @@ skip_ipsec2:;
u_int32_t id = htonl(ip6_id++);
#endif
u_char nextproto;
struct ip6ctlparam ip6cp;
u_int32_t mtu32;
/*
* Too large for the destination or interface;
@ -1042,6 +1062,13 @@ skip_ipsec2:;
if (mtu > IPV6_MAXPACKET)
mtu = IPV6_MAXPACKET;
/* Notify a proper path MTU to applications. */
mtu32 = (u_int32_t)mtu;
bzero(&ip6cp, sizeof(ip6cp));
ip6cp.ip6c_cmdarg = (void *)&mtu32;
pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
(void *)&ip6cp);
len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
if (len < 8) {
error = EMSGSIZE;