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Diffstat (limited to 'sys/netinet6/ip6_output.c')
-rw-r--r--sys/netinet6/ip6_output.c43
1 files changed, 10 insertions, 33 deletions
diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c
index bef6892f7ec..d6f620067db 100644
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ip6_output.c,v 1.220 2017/01/10 09:04:19 mpi Exp $ */
+/* $OpenBSD: ip6_output.c,v 1.221 2017/01/19 14:49:19 bluhm Exp $ */
/* $KAME: ip6_output.c,v 1.172 2001/03/25 09:55:56 itojun Exp $ */
/*
@@ -126,7 +126,7 @@ int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
struct ip6_frag **);
int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
-int ip6_getpmtu(struct rtentry *, struct ifnet *, u_long *, int *);
+int ip6_getpmtu(struct rtentry *, struct ifnet *, u_long *);
int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
static __inline u_int16_t __attribute__((__unused__))
in6_cksum_phdr(const struct in6_addr *, const struct in6_addr *,
@@ -160,7 +160,7 @@ ip6_output(struct mbuf *m0, struct ip6_pktopts *opt, struct route_in6 *ro,
struct sockaddr_in6 *dst, dstsock;
int error = 0;
u_long mtu;
- int alwaysfrag, dontfrag;
+ int dontfrag;
u_int16_t src_scope, dst_scope;
u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
struct ip6_exthdrs exthdrs;
@@ -555,7 +555,7 @@ reroute:
}
/* Determine path MTU. */
- if ((error = ip6_getpmtu(ro_pmtu->ro_rt, ifp, &mtu, &alwaysfrag)) != 0)
+ if ((error = ip6_getpmtu(ro_pmtu->ro_rt, ifp, &mtu)) != 0)
goto bad;
/*
@@ -654,19 +654,13 @@ reroute:
* If necessary, do IPv6 fragmentation before sending.
*
* the logic here is rather complex:
- * 1: normal case (dontfrag == 0, alwaysfrag == 0)
+ * 1: normal case (dontfrag == 0)
* 1-a: send as is if tlen <= path mtu
* 1-b: fragment if tlen > path mtu
*
* 2: if user asks us not to fragment (dontfrag == 1)
* 2-a: send as is if tlen <= interface mtu
* 2-b: error if tlen > interface mtu
- *
- * 3: if we always need to attach fragment header (alwaysfrag == 1)
- * always fragment
- *
- * 4: if dontfrag == 1 && alwaysfrag == 1
- * error, as we cannot handle this conflicting request
*/
tlen = m->m_pkthdr.len;
@@ -674,11 +668,6 @@ reroute:
dontfrag = 1;
else
dontfrag = 0;
- if (dontfrag && alwaysfrag) { /* case 4 */
- /* conflicting request - can't transmit */
- error = EMSGSIZE;
- goto bad;
- }
if (dontfrag && tlen > ifp->if_mtu) { /* case 2-b */
error = EMSGSIZE;
goto bad;
@@ -687,13 +676,13 @@ reroute:
/*
* transmit packet without fragmentation
*/
- if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
+ if (dontfrag || (tlen <= mtu)) { /* case 1-a and 2-a */
error = ifp->if_output(ifp, m, sin6tosa(dst), ro->ro_rt);
goto done;
}
/*
- * try to fragment the packet. case 1-b and 3
+ * try to fragment the packet. case 1-b
*/
if (mtu < IPV6_MMTU) {
/* path MTU cannot be less than IPV6_MMTU */
@@ -1021,11 +1010,9 @@ ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
}
int
-ip6_getpmtu(struct rtentry *rt, struct ifnet *ifp, u_long *mtup,
- int *alwaysfragp)
+ip6_getpmtu(struct rtentry *rt, struct ifnet *ifp, u_long *mtup)
{
u_int32_t mtu = 0;
- int alwaysfrag = 0;
int error = 0;
if (rt != NULL) {
@@ -1033,15 +1020,7 @@ ip6_getpmtu(struct rtentry *rt, struct ifnet *ifp, u_long *mtup,
if (mtu == 0)
mtu = ifp->if_mtu;
else if (mtu < IPV6_MMTU) {
- /*
- * RFC2460 section 5, last paragraph:
- * if we record ICMPv6 too big message with
- * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
- * or smaller, with fragment header attached.
- * (fragment header is needed regardless from the
- * packet size, for translators to identify packets)
- */
- alwaysfrag = 1;
+ /* RFC8021 IPv6 Atomic Fragments Considered Harmful */
mtu = IPV6_MMTU;
} else if (mtu > ifp->if_mtu) {
/*
@@ -1061,8 +1040,6 @@ ip6_getpmtu(struct rtentry *rt, struct ifnet *ifp, u_long *mtup,
}
*mtup = mtu;
- if (alwaysfragp)
- *alwaysfragp = alwaysfrag;
return (error);
}
@@ -1525,7 +1502,7 @@ do { \
* routing, or optional information to specify
* the outgoing interface.
*/
- error = ip6_getpmtu(rt, ifp, &pmtu, NULL);
+ error = ip6_getpmtu(rt, ifp, &pmtu);
if_put(ifp);
if (error)
break;