[MLSXFRM]: Flow based matching of xfrm policy and state
This implements a seemless mechanism for xfrm policy selection and
state matching based on the flow sid. This also includes the necessary
SELinux enforcement pieces.
Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/flow.c b/net/core/flow.c
index 2191af5..6452411 100644
--- a/net/core/flow.c
+++ b/net/core/flow.c
@@ -32,7 +32,6 @@
u8 dir;
struct flowi key;
u32 genid;
- u32 sk_sid;
void *object;
atomic_t *object_ref;
};
@@ -165,7 +164,7 @@
return 0;
}
-void *flow_cache_lookup(struct flowi *key, u32 sk_sid, u16 family, u8 dir,
+void *flow_cache_lookup(struct flowi *key, u16 family, u8 dir,
flow_resolve_t resolver)
{
struct flow_cache_entry *fle, **head;
@@ -189,7 +188,6 @@
for (fle = *head; fle; fle = fle->next) {
if (fle->family == family &&
fle->dir == dir &&
- fle->sk_sid == sk_sid &&
flow_key_compare(key, &fle->key) == 0) {
if (fle->genid == atomic_read(&flow_cache_genid)) {
void *ret = fle->object;
@@ -214,7 +212,6 @@
*head = fle;
fle->family = family;
fle->dir = dir;
- fle->sk_sid = sk_sid;
memcpy(&fle->key, key, sizeof(*key));
fle->object = NULL;
flow_count(cpu)++;
@@ -226,7 +223,7 @@
void *obj;
atomic_t *obj_ref;
- resolver(key, sk_sid, family, dir, &obj, &obj_ref);
+ resolver(key, family, dir, &obj, &obj_ref);
if (fle) {
fle->genid = atomic_read(&flow_cache_genid);
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 3da67ca..79405da 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -597,7 +597,7 @@
/* Find policy to apply to this flow. */
-static void xfrm_policy_lookup(struct flowi *fl, u32 sk_sid, u16 family, u8 dir,
+static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
void **objp, atomic_t **obj_refp)
{
struct xfrm_policy *pol;
@@ -613,7 +613,7 @@
match = xfrm_selector_match(sel, fl, family);
if (match) {
- if (!security_xfrm_policy_lookup(pol, sk_sid, dir)) {
+ if (!security_xfrm_policy_lookup(pol, fl->secid, dir)) {
xfrm_pol_hold(pol);
break;
}
@@ -641,7 +641,7 @@
};
}
-static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl, u32 sk_sid)
+static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
{
struct xfrm_policy *pol;
@@ -652,7 +652,7 @@
int err = 0;
if (match)
- err = security_xfrm_policy_lookup(pol, sk_sid, policy_to_flow_dir(dir));
+ err = security_xfrm_policy_lookup(pol, fl->secid, policy_to_flow_dir(dir));
if (match && !err)
xfrm_pol_hold(pol);
@@ -862,19 +862,20 @@
u32 genid;
u16 family;
u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
- u32 sk_sid = security_sk_sid(sk, fl, dir);
+
+ fl->secid = security_sk_sid(sk, fl, dir);
restart:
genid = atomic_read(&flow_cache_genid);
policy = NULL;
if (sk && sk->sk_policy[1])
- policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl, sk_sid);
+ policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
if (!policy) {
/* To accelerate a bit... */
if ((dst_orig->flags & DST_NOXFRM) || !xfrm_policy_list[XFRM_POLICY_OUT])
return 0;
- policy = flow_cache_lookup(fl, sk_sid, dst_orig->ops->family,
+ policy = flow_cache_lookup(fl, dst_orig->ops->family,
dir, xfrm_policy_lookup);
}
@@ -1032,13 +1033,15 @@
xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family)
{
struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
+ int err;
if (unlikely(afinfo == NULL))
return -EAFNOSUPPORT;
afinfo->decode_session(skb, fl);
+ err = security_xfrm_decode_session(skb, fl);
xfrm_policy_put_afinfo(afinfo);
- return 0;
+ return err;
}
EXPORT_SYMBOL(xfrm_decode_session);
@@ -1058,14 +1061,11 @@
struct xfrm_policy *pol;
struct flowi fl;
u8 fl_dir = policy_to_flow_dir(dir);
- u32 sk_sid;
if (xfrm_decode_session(skb, &fl, family) < 0)
return 0;
nf_nat_decode_session(skb, &fl, family);
- sk_sid = security_sk_sid(sk, &fl, fl_dir);
-
/* First, check used SA against their selectors. */
if (skb->sp) {
int i;
@@ -1079,10 +1079,10 @@
pol = NULL;
if (sk && sk->sk_policy[dir])
- pol = xfrm_sk_policy_lookup(sk, dir, &fl, sk_sid);
+ pol = xfrm_sk_policy_lookup(sk, dir, &fl);
if (!pol)
- pol = flow_cache_lookup(&fl, sk_sid, family, fl_dir,
+ pol = flow_cache_lookup(&fl, family, fl_dir,
xfrm_policy_lookup);
if (!pol)
@@ -1298,6 +1298,8 @@
if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
return 0;
+ if (fl && !security_xfrm_flow_state_match(fl, dst->xfrm))
+ return 0;
if (dst->xfrm->km.state != XFRM_STATE_VALID)
return 0;
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 0021aad..be02bd9 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -367,7 +367,7 @@
*/
if (x->km.state == XFRM_STATE_VALID) {
if (!xfrm_selector_match(&x->sel, fl, family) ||
- !xfrm_sec_ctx_match(pol->security, x->security))
+ !security_xfrm_state_pol_flow_match(x, pol, fl))
continue;
if (!best ||
best->km.dying > x->km.dying ||
@@ -379,7 +379,7 @@
} else if (x->km.state == XFRM_STATE_ERROR ||
x->km.state == XFRM_STATE_EXPIRED) {
if (xfrm_selector_match(&x->sel, fl, family) &&
- xfrm_sec_ctx_match(pol->security, x->security))
+ security_xfrm_state_pol_flow_match(x, pol, fl))
error = -ESRCH;
}
}
@@ -403,6 +403,14 @@
* to current session. */
xfrm_init_tempsel(x, fl, tmpl, daddr, saddr, family);
+ error = security_xfrm_state_alloc_acquire(x, pol->security, fl->secid);
+ if (error) {
+ x->km.state = XFRM_STATE_DEAD;
+ xfrm_state_put(x);
+ x = NULL;
+ goto out;
+ }
+
if (km_query(x, tmpl, pol) == 0) {
x->km.state = XFRM_STATE_ACQ;
list_add_tail(&x->bydst, xfrm_state_bydst+h);