[PATCHv3 net 1/4] openvswitch: Reject ct_state masks for unknown bits

Joe Stringer
2015-10-20T02:19:08Z

Currently, 0-bits are generated in ct_state where the bit position is
undefined, and matches are accepted on these bit-positions. If userspace
requests to match the 0-value for this bit then it may expect only a
subset of traffic to match this value, whereas currently all packets
will have this bit set to 0. Fix this by rejecting such masks.

Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
---
v2: Remove extraneous ovs_ct_supported() function declaration.
Acked.
v3: Acked.
---
net/openvswitch/conntrack.h | 16 +++++-----------
net/openvswitch/flow_netlink.c | 5 ++++-
2 files changed, 9 insertions(+), 12 deletions(-)

diff --git a/net/openvswitch/conntrack.h b/net/openvswitch/conntrack.h
index da8714942c95..82e0dfc66028 100644
--- a/net/openvswitch/conntrack.h
+++ b/net/openvswitch/conntrack.h
@@ -35,12 +35,9 @@ void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key);
int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb);
void ovs_ct_free_action(const struct nlattr *a);

-static inline bool ovs_ct_state_supported(u32 state)
-{
- return !(state & ~(OVS_CS_F_NEW | OVS_CS_F_ESTABLISHED |
- OVS_CS_F_RELATED | OVS_CS_F_REPLY_DIR |
- OVS_CS_F_INVALID | OVS_CS_F_TRACKED));
-}
+#define CT_SUPPORTED_MASK (OVS_CS_F_NEW | OVS_CS_F_ESTABLISHED | \
+ OVS_CS_F_RELATED | OVS_CS_F_REPLY_DIR | \
+ OVS_CS_F_INVALID | OVS_CS_F_TRACKED)
#else
#include <linux/errno.h>

@@ -53,11 +50,6 @@ static inline bool ovs_ct_verify(struct net *net, int attr)
return false;
}

-static inline bool ovs_ct_state_supported(u32 state)
-{
- return false;
-}
-
static inline int ovs_ct_copy_action(struct net *net, const struct nlattr *nla,
const struct sw_flow_key *key,
struct sw_flow_actions **acts, bool log)
@@ -94,5 +86,7 @@ static inline int ovs_ct_put_key(const struct sw_flow_key *key,
}

static inline void ovs_ct_free_action(const struct nlattr *a) { }
+
+#define CT_SUPPORTED_MASK 0
#endif /* CONFIG_NF_CONNTRACK */
#endif /* ovs_conntrack.h */
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index 171a691f1c32..bd710bc37469 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -816,7 +816,7 @@ static int metadata_from_nlattrs(struct net *net, struct sw_flow_match *match,
ovs_ct_verify(net, OVS_KEY_ATTR_CT_STATE)) {
u32 ct_state = nla_get_u32(a[OVS_KEY_ATTR_CT_STATE]);

- if (!is_mask && !ovs_ct_state_supported(ct_state)) {
+ if (ct_state & ~CT_SUPPORTED_MASK) {
OVS_NLERR(log, "ct_state flags %08x unsupported",
ct_state);
return -EINVAL;
@@ -1099,6 +1099,9 @@ static void nlattr_set(struct nlattr *attr, u8 val,
} else {
memset(nla_data(nla), val, nla_len(nla));
}
+
+ if (nla_type(nla) == OVS_KEY_ATTR_CT_STATE)
+ *(u32 *)nla_data(nla) &= CT_SUPPORTED_MASK;
}
}

--
2.1.4