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authorNicolas Dichtel <nicolas.dichtel@6wind.com>2013-02-22 10:54:54 +0100
committerSteffen Klassert <steffen.klassert@secunet.com>2013-03-06 07:02:45 +0100
commita947b0a93efa9a25c012aa88848f4cf8d9b41280 (patch)
treeca5ccc41834e4c811e859724a184f223a3772ca7
parent6fac41157252220678b210fcb13e2c3dad7a912a (diff)
downloadlinux-a947b0a93efa9a25c012aa88848f4cf8d9b41280.tar.gz
xfrm: allow to avoid copying DSCP during encapsulation
By default, DSCP is copying during encapsulation. Copying the DSCP in IPsec tunneling may be a bit dangerous because packets with different DSCP may get reordered relative to each other in the network and then dropped by the remote IPsec GW if the reordering becomes too big compared to the replay window. It is possible to avoid this copy with netfilter rules, but it's very convenient to be able to configure it for each SA directly. This patch adds a toogle for this purpose. By default, it's not set to maintain backward compatibility. Field flags in struct xfrm_usersa_info is full, hence I add a new attribute. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
-rw-r--r--include/net/xfrm.h1
-rw-r--r--include/uapi/linux/xfrm.h3
-rw-r--r--net/ipv4/ipcomp.c1
-rw-r--r--net/ipv4/xfrm4_mode_tunnel.c8
-rw-r--r--net/ipv6/xfrm6_mode_tunnel.c7
-rw-r--r--net/xfrm/xfrm_state.c1
-rw-r--r--net/xfrm/xfrm_user.c13
7 files changed, 30 insertions, 4 deletions
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 24c8886fd96..ae16531d0d3 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -162,6 +162,7 @@ struct xfrm_state {
xfrm_address_t saddr;
int header_len;
int trailer_len;
+ u32 extra_flags;
} props;
struct xfrm_lifetime_cfg lft;
diff --git a/include/uapi/linux/xfrm.h b/include/uapi/linux/xfrm.h
index 28e493b5b94..a8cd6a4a297 100644
--- a/include/uapi/linux/xfrm.h
+++ b/include/uapi/linux/xfrm.h
@@ -297,6 +297,7 @@ enum xfrm_attr_type_t {
XFRMA_MARK, /* struct xfrm_mark */
XFRMA_TFCPAD, /* __u32 */
XFRMA_REPLAY_ESN_VAL, /* struct xfrm_replay_esn */
+ XFRMA_SA_EXTRA_FLAGS, /* __u32 */
__XFRMA_MAX
#define XFRMA_MAX (__XFRMA_MAX - 1)
@@ -367,6 +368,8 @@ struct xfrm_usersa_info {
#define XFRM_STATE_ESN 128
};
+#define XFRM_SA_XFLAG_DONT_ENCAP_DSCP 1
+
struct xfrm_usersa_id {
xfrm_address_t daddr;
__be32 spi;
diff --git a/net/ipv4/ipcomp.c b/net/ipv4/ipcomp.c
index f01d1b1aff7..59cb8c76905 100644
--- a/net/ipv4/ipcomp.c
+++ b/net/ipv4/ipcomp.c
@@ -75,6 +75,7 @@ static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x)
t->props.mode = x->props.mode;
t->props.saddr.a4 = x->props.saddr.a4;
t->props.flags = x->props.flags;
+ t->props.extra_flags = x->props.extra_flags;
memcpy(&t->mark, &x->mark, sizeof(t->mark));
if (xfrm_init_state(t))
diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index fe5189e2e11..eb1dd4d643f 100644
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -103,8 +103,12 @@ static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
top_iph->protocol = xfrm_af2proto(skb_dst(skb)->ops->family);
- /* DS disclosed */
- top_iph->tos = INET_ECN_encapsulate(XFRM_MODE_SKB_CB(skb)->tos,
+ /* DS disclosing depends on XFRM_SA_XFLAG_DONT_ENCAP_DSCP */
+ if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
+ top_iph->tos = 0;
+ else
+ top_iph->tos = XFRM_MODE_SKB_CB(skb)->tos;
+ top_iph->tos = INET_ECN_encapsulate(top_iph->tos,
XFRM_MODE_SKB_CB(skb)->tos);
flags = x->props.flags;
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index 9bf6a74a71d..4770d515c2c 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -49,8 +49,11 @@ static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
sizeof(top_iph->flow_lbl));
top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);
- dsfield = XFRM_MODE_SKB_CB(skb)->tos;
- dsfield = INET_ECN_encapsulate(dsfield, dsfield);
+ if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
+ dsfield = 0;
+ else
+ dsfield = XFRM_MODE_SKB_CB(skb)->tos;
+ dsfield = INET_ECN_encapsulate(dsfield, XFRM_MODE_SKB_CB(skb)->tos);
if (x->props.flags & XFRM_STATE_NOECN)
dsfield &= ~INET_ECN_MASK;
ipv6_change_dsfield(top_iph, 0, dsfield);
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 2c341bdaf47..78f66fa9244 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1187,6 +1187,7 @@ static struct xfrm_state *xfrm_state_clone(struct xfrm_state *orig, int *errp)
goto error;
x->props.flags = orig->props.flags;
+ x->props.extra_flags = orig->props.extra_flags;
x->curlft.add_time = orig->curlft.add_time;
x->km.state = orig->km.state;
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index fbd9e6cd0fd..204cba192af 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -515,6 +515,9 @@ static struct xfrm_state *xfrm_state_construct(struct net *net,
copy_from_user_state(x, p);
+ if (attrs[XFRMA_SA_EXTRA_FLAGS])
+ x->props.extra_flags = nla_get_u32(attrs[XFRMA_SA_EXTRA_FLAGS]);
+
if ((err = attach_aead(&x->aead, &x->props.ealgo,
attrs[XFRMA_ALG_AEAD])))
goto error;
@@ -779,6 +782,13 @@ static int copy_to_user_state_extra(struct xfrm_state *x,
copy_to_user_state(x, p);
+ if (x->props.extra_flags) {
+ ret = nla_put_u32(skb, XFRMA_SA_EXTRA_FLAGS,
+ x->props.extra_flags);
+ if (ret)
+ goto out;
+ }
+
if (x->coaddr) {
ret = nla_put(skb, XFRMA_COADDR, sizeof(*x->coaddr), x->coaddr);
if (ret)
@@ -2302,6 +2312,7 @@ static const struct nla_policy xfrma_policy[XFRMA_MAX+1] = {
[XFRMA_MARK] = { .len = sizeof(struct xfrm_mark) },
[XFRMA_TFCPAD] = { .type = NLA_U32 },
[XFRMA_REPLAY_ESN_VAL] = { .len = sizeof(struct xfrm_replay_state_esn) },
+ [XFRMA_SA_EXTRA_FLAGS] = { .type = NLA_U32 },
};
static struct xfrm_link {
@@ -2495,6 +2506,8 @@ static inline size_t xfrm_sa_len(struct xfrm_state *x)
x->security->ctx_len);
if (x->coaddr)
l += nla_total_size(sizeof(*x->coaddr));
+ if (x->props.extra_flags)
+ l += nla_total_size(sizeof(x->props.extra_flags));
/* Must count x->lastused as it may become non-zero behind our back. */
l += nla_total_size(sizeof(u64));