[PATCH 5.4 53/54] netfilter: nftables_offload: set address type in control dissector

Greg Kroah-Hartman
2020-12-10T16:50:45Z

From: Pablo Neira Ayuso <pablo@netfilter.org>

commit 3c78e9e0d33a27ab8050e4492c03c6a1f8d0ed6b upstream.

This patch adds nft_flow_rule_set_addr_type() to set the address type
from the nft_payload expression accordingly.

If the address type is not set in the control dissector then a rule that
matches either on source or destination IP address does not work.

After this patch, nft hardware offload generates the flow dissector
configuration as tc-flower does to match on an IP address.

This patch has been also tested functionally to make sure packets are
filtered out by the NIC.

This is also getting the code aligned with the existing netfilter flow
offload infrastructure which is also setting the control dissector.

Fixes: c9626a2cbdb2 ("netfilter: nf_tables: add hardware offload support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
include/net/netfilter/nf_tables_offload.h | 4 ++++
net/netfilter/nf_tables_offload.c | 17 +++++++++++++++++
net/netfilter/nft_payload.c | 4 ++++
3 files changed, 25 insertions(+)

--- a/include/net/netfilter/nf_tables_offload.h
+++ b/include/net/netfilter/nf_tables_offload.h
@@ -37,6 +37,7 @@ void nft_offload_update_dependency(struc

struct nft_flow_key {
struct flow_dissector_key_basic basic;
+ struct flow_dissector_key_control control;
union {
struct flow_dissector_key_ipv4_addrs ipv4;
struct flow_dissector_key_ipv6_addrs ipv6;
@@ -61,6 +62,9 @@ struct nft_flow_rule {

#define NFT_OFFLOAD_F_ACTION (1 << 0)

+void nft_flow_rule_set_addr_type(struct nft_flow_rule *flow,
+ enum flow_dissector_key_id addr_type);
+
struct nft_rule;
struct nft_flow_rule *nft_flow_rule_create(struct net *net, const struct nft_rule *rule);
void nft_flow_rule_destroy(struct nft_flow_rule *flow);
--- a/net/netfilter/nf_tables_offload.c
+++ b/net/netfilter/nf_tables_offload.c
@@ -28,6 +28,23 @@ static struct nft_flow_rule *nft_flow_ru
return flow;
}

+void nft_flow_rule_set_addr_type(struct nft_flow_rule *flow,
+ enum flow_dissector_key_id addr_type)
+{
+ struct nft_flow_match *match = &flow->match;
+ struct nft_flow_key *mask = &match->mask;
+ struct nft_flow_key *key = &match->key;
+
+ if (match->dissector.used_keys & BIT(FLOW_DISSECTOR_KEY_CONTROL))
+ return;
+
+ key->control.addr_type = addr_type;
+ mask->control.addr_type = 0xffff;
+ match->dissector.used_keys |= BIT(FLOW_DISSECTOR_KEY_CONTROL);
+ match->dissector.offset[FLOW_DISSECTOR_KEY_CONTROL] =
+ offsetof(struct nft_flow_key, control);
+}
+
struct nft_flow_rule *nft_flow_rule_create(struct net *net,
const struct nft_rule *rule)
{
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -197,6 +197,7 @@ static int nft_payload_offload_ip(struct

NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4, src,
sizeof(struct in_addr), reg);
+ nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV4_ADDRS);
break;
case offsetof(struct iphdr, daddr):
if (priv->len != sizeof(struct in_addr))
@@ -204,6 +205,7 @@ static int nft_payload_offload_ip(struct

NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4, dst,
sizeof(struct in_addr), reg);
+ nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV4_ADDRS);
break;
case offsetof(struct iphdr, protocol):
if (priv->len != sizeof(__u8))
@@ -233,6 +235,7 @@ static int nft_payload_offload_ip6(struc

NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6, src,
sizeof(struct in6_addr), reg);
+ nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV6_ADDRS);
break;
case offsetof(struct ipv6hdr, daddr):
if (priv->len != sizeof(struct in6_addr))
@@ -240,6 +243,7 @@ static int nft_payload_offload_ip6(struc

NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6, dst,
sizeof(struct in6_addr), reg);
+ nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV6_ADDRS);
break;
case offsetof(struct ipv6hdr, nexthdr):
if (priv->len != sizeof(__u8))