aboutsummaryrefslogtreecommitdiffstats
path: root/net
diff options
context:
space:
mode:
authorHerbert Xu <herbert@gondor.apana.org.au>2005-06-20 13:21:43 -0700
committerDavid S. Miller <davem@davemloft.net>2005-06-20 13:21:43 -0700
commitdd87147eed934eaff92869f3d158697c7239d1d2 (patch)
tree5a5d59c2678767530c2a3299a70ccfc14062b347 /net
parent[IPSEC]: Add xfrm_state_afinfo->init_flags (diff)
downloadlinux-dev-dd87147eed934eaff92869f3d158697c7239d1d2.tar.xz
linux-dev-dd87147eed934eaff92869f3d158697c7239d1d2.zip
[IPSEC]: Add XFRM_STATE_NOPMTUDISC flag
This patch adds the flag XFRM_STATE_NOPMTUDISC for xfrm states. It is similar to the nopmtudisc on IPIP/GRE tunnels. It only has an effect on IPv4 tunnel mode states. For these states, it will ensure that the DF flag is always cleared. This is primarily useful to work around ICMP blackholes. In future this flag could also allow a larger MTU to be set within the tunnel just like IPIP/GRE tunnels. This could be useful for short haul tunnels where temporary fragmentation outside the tunnel is desired over smaller fragments inside the tunnel. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: James Morris <jmorris@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/xfrm4_output.c8
-rw-r--r--net/ipv4/xfrm4_state.c9
-rw-r--r--net/key/af_key.c4
3 files changed, 19 insertions, 2 deletions
diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
index af2392ae5769..66620a95942a 100644
--- a/net/ipv4/xfrm4_output.c
+++ b/net/ipv4/xfrm4_output.c
@@ -33,6 +33,7 @@ static void xfrm4_encap(struct sk_buff *skb)
struct dst_entry *dst = skb->dst;
struct xfrm_state *x = dst->xfrm;
struct iphdr *iph, *top_iph;
+ int flags;
iph = skb->nh.iph;
skb->h.ipiph = iph;
@@ -51,10 +52,13 @@ static void xfrm4_encap(struct sk_buff *skb)
/* DS disclosed */
top_iph->tos = INET_ECN_encapsulate(iph->tos, iph->tos);
- if (x->props.flags & XFRM_STATE_NOECN)
+
+ flags = x->props.flags;
+ if (flags & XFRM_STATE_NOECN)
IP_ECN_clear(top_iph);
- top_iph->frag_off = iph->frag_off & htons(IP_DF);
+ top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
+ 0 : (iph->frag_off & htons(IP_DF));
if (!top_iph->frag_off)
__ip_select_ident(top_iph, dst, 0);
diff --git a/net/ipv4/xfrm4_state.c b/net/ipv4/xfrm4_state.c
index 223a2e83853f..050611d7a967 100644
--- a/net/ipv4/xfrm4_state.c
+++ b/net/ipv4/xfrm4_state.c
@@ -7,12 +7,20 @@
*
*/
+#include <net/ip.h>
#include <net/xfrm.h>
#include <linux/pfkeyv2.h>
#include <linux/ipsec.h>
static struct xfrm_state_afinfo xfrm4_state_afinfo;
+static int xfrm4_init_flags(struct xfrm_state *x)
+{
+ if (ipv4_config.no_pmtu_disc)
+ x->props.flags |= XFRM_STATE_NOPMTUDISC;
+ return 0;
+}
+
static void
__xfrm4_init_tempsel(struct xfrm_state *x, struct flowi *fl,
struct xfrm_tmpl *tmpl,
@@ -109,6 +117,7 @@ __xfrm4_find_acq(u8 mode, u32 reqid, u8 proto,
static struct xfrm_state_afinfo xfrm4_state_afinfo = {
.family = AF_INET,
.lock = RW_LOCK_UNLOCKED,
+ .init_flags = xfrm4_init_flags,
.init_tempsel = __xfrm4_init_tempsel,
.state_lookup = __xfrm4_state_lookup,
.find_acq = __xfrm4_find_acq,
diff --git a/net/key/af_key.c b/net/key/af_key.c
index 652dd09ccd3a..4879743b945a 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -690,6 +690,8 @@ static struct sk_buff * pfkey_xfrm_state2msg(struct xfrm_state *x, int add_keys,
sa->sadb_sa_flags |= SADB_SAFLAGS_NOECN;
if (x->props.flags & XFRM_STATE_DECAP_DSCP)
sa->sadb_sa_flags |= SADB_SAFLAGS_DECAP_DSCP;
+ if (x->props.flags & XFRM_STATE_NOPMTUDISC)
+ sa->sadb_sa_flags |= SADB_SAFLAGS_NOPMTUDISC;
/* hard time */
if (hsc & 2) {
@@ -974,6 +976,8 @@ static struct xfrm_state * pfkey_msg2xfrm_state(struct sadb_msg *hdr,
x->props.flags |= XFRM_STATE_NOECN;
if (sa->sadb_sa_flags & SADB_SAFLAGS_DECAP_DSCP)
x->props.flags |= XFRM_STATE_DECAP_DSCP;
+ if (sa->sadb_sa_flags & SADB_SAFLAGS_NOPMTUDISC)
+ x->props.flags |= XFRM_STATE_NOPMTUDISC;
lifetime = (struct sadb_lifetime*) ext_hdrs[SADB_EXT_LIFETIME_HARD-1];
if (lifetime != NULL) {