netfilter: flowtable: use atomic bitwise operations for flow flags

Originally, all flow flag bits were set on only from the workqueue. With
the introduction of the flow teardown state and hardware offload this is
no longer true. Let's be safe and use atomic bitwise operation to
operation with flow flags.

Fixes: 59c466dd68e7 ("netfilter: nf_flow_table: add a new flow state for tearing down offloading")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index 4ad924d..5a10e28 100644 (file)
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -83,12 +83,14 @@ struct flow_offload_tuple_rhash {
        struct flow_offload_tuple       tuple;
 };
 
-#define FLOW_OFFLOAD_SNAT      0x1
-#define FLOW_OFFLOAD_DNAT      0x2
-#define FLOW_OFFLOAD_TEARDOWN  0x8
-#define FLOW_OFFLOAD_HW                0x10
-#define FLOW_OFFLOAD_HW_DYING  0x20
-#define FLOW_OFFLOAD_HW_DEAD   0x40
+enum nf_flow_flags {
+       NF_FLOW_SNAT,
+       NF_FLOW_DNAT,
+       NF_FLOW_TEARDOWN,
+       NF_FLOW_HW,
+       NF_FLOW_HW_DYING,
+       NF_FLOW_HW_DEAD,
+};
 
 enum flow_offload_type {
        NF_FLOW_OFFLOAD_UNSPEC  = 0,
@@ -98,7 +100,7 @@ enum flow_offload_type {
 struct flow_offload {
        struct flow_offload_tuple_rhash         tuplehash[FLOW_OFFLOAD_DIR_MAX];
        struct nf_conn                          *ct;
-       u16                                     flags;
+       unsigned long                           flags;
        u16                                     type;
        u32                                     timeout;
        struct rcu_head                         rcu_head;

diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index a9ed93a..9f134f4 100644 (file)
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -61,9 +61,9 @@ struct flow_offload *flow_offload_alloc(struct nf_conn *ct)
        flow_offload_fill_dir(flow, FLOW_OFFLOAD_DIR_REPLY);
 
        if (ct->status & IPS_SRC_NAT)
-               flow->flags |= FLOW_OFFLOAD_SNAT;
+               __set_bit(NF_FLOW_SNAT, &flow->flags);
        if (ct->status & IPS_DST_NAT)
-               flow->flags |= FLOW_OFFLOAD_DNAT;
+               __set_bit(NF_FLOW_DNAT, &flow->flags);
 
        return flow;
 
@@ -269,7 +269,7 @@ static void flow_offload_del(struct nf_flowtable *flow_table,
 
        if (nf_flow_has_expired(flow))
                flow_offload_fixup_ct(flow->ct);
-       else if (flow->flags & FLOW_OFFLOAD_TEARDOWN)
+       else if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
                flow_offload_fixup_ct_timeout(flow->ct);
 
        flow_offload_free(flow);
@@ -277,7 +277,7 @@ static void flow_offload_del(struct nf_flowtable *flow_table,
 
 void flow_offload_teardown(struct flow_offload *flow)
 {
-       flow->flags |= FLOW_OFFLOAD_TEARDOWN;
+       set_bit(NF_FLOW_TEARDOWN, &flow->flags);
 
        flow_offload_fixup_ct_state(flow->ct);
 }
@@ -298,7 +298,7 @@ flow_offload_lookup(struct nf_flowtable *flow_table,
 
        dir = tuplehash->tuple.dir;
        flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
-       if (flow->flags & FLOW_OFFLOAD_TEARDOWN)
+       if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
                return NULL;
 
        if (unlikely(nf_ct_is_dying(flow->ct)))
@@ -347,16 +347,16 @@ static void nf_flow_offload_gc_step(struct flow_offload *flow, void *data)
        struct nf_flowtable *flow_table = data;
 
        if (nf_flow_has_expired(flow) || nf_ct_is_dying(flow->ct) ||
-           (flow->flags & FLOW_OFFLOAD_TEARDOWN)) {
-               if (flow->flags & FLOW_OFFLOAD_HW) {
-                       if (!(flow->flags & FLOW_OFFLOAD_HW_DYING))
+           test_bit(NF_FLOW_TEARDOWN, &flow->flags)) {
+               if (test_bit(NF_FLOW_HW, &flow->flags)) {
+                       if (!test_bit(NF_FLOW_HW_DYING, &flow->flags))
                                nf_flow_offload_del(flow_table, flow);
-                       else if (flow->flags & FLOW_OFFLOAD_HW_DEAD)
+                       else if (test_bit(NF_FLOW_HW_DEAD, &flow->flags))
                                flow_offload_del(flow_table, flow);
                } else {
                        flow_offload_del(flow_table, flow);
                }
-       } else if (flow->flags & FLOW_OFFLOAD_HW) {
+       } else if (test_bit(NF_FLOW_HW, &flow->flags)) {
                nf_flow_offload_stats(flow_table, flow);
        }
 }

diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index 7ea2ddc..f4ccb5f 100644 (file)
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -144,11 +144,11 @@ static int nf_flow_nat_ip(const struct flow_offload *flow, struct sk_buff *skb,
 {
        struct iphdr *iph = ip_hdr(skb);
 
-       if (flow->flags & FLOW_OFFLOAD_SNAT &&
+       if (test_bit(NF_FLOW_SNAT, &flow->flags) &&
            (nf_flow_snat_port(flow, skb, thoff, iph->protocol, dir) < 0 ||
             nf_flow_snat_ip(flow, skb, iph, thoff, dir) < 0))
                return -1;
-       if (flow->flags & FLOW_OFFLOAD_DNAT &&
+       if (test_bit(NF_FLOW_DNAT, &flow->flags) &&
            (nf_flow_dnat_port(flow, skb, thoff, iph->protocol, dir) < 0 ||
             nf_flow_dnat_ip(flow, skb, iph, thoff, dir) < 0))
                return -1;
@@ -414,11 +414,11 @@ static int nf_flow_nat_ipv6(const struct flow_offload *flow,
        struct ipv6hdr *ip6h = ipv6_hdr(skb);
        unsigned int thoff = sizeof(*ip6h);
 
-       if (flow->flags & FLOW_OFFLOAD_SNAT &&
+       if (test_bit(NF_FLOW_SNAT, &flow->flags) &&
            (nf_flow_snat_port(flow, skb, thoff, ip6h->nexthdr, dir) < 0 ||
             nf_flow_snat_ipv6(flow, skb, ip6h, thoff, dir) < 0))
                return -1;
-       if (flow->flags & FLOW_OFFLOAD_DNAT &&
+       if (test_bit(NF_FLOW_DNAT, &flow->flags) &&
            (nf_flow_dnat_port(flow, skb, thoff, ip6h->nexthdr, dir) < 0 ||
             nf_flow_dnat_ipv6(flow, skb, ip6h, thoff, dir) < 0))
                return -1;

diff --git a/net/netfilter/nf_flow_table_offload.c b/net/netfilter/nf_flow_table_offload.c
index d161623..8a1fe39 100644 (file)
--- a/net/netfilter/nf_flow_table_offload.c
+++ b/net/netfilter/nf_flow_table_offload.c
@@ -450,16 +450,16 @@ int nf_flow_rule_route_ipv4(struct net *net, const struct flow_offload *flow,
            flow_offload_eth_dst(net, flow, dir, flow_rule) < 0)
                return -1;
 
-       if (flow->flags & FLOW_OFFLOAD_SNAT) {
+       if (test_bit(NF_FLOW_SNAT, &flow->flags)) {
                flow_offload_ipv4_snat(net, flow, dir, flow_rule);
                flow_offload_port_snat(net, flow, dir, flow_rule);
        }
-       if (flow->flags & FLOW_OFFLOAD_DNAT) {
+       if (test_bit(NF_FLOW_DNAT, &flow->flags)) {
                flow_offload_ipv4_dnat(net, flow, dir, flow_rule);
                flow_offload_port_dnat(net, flow, dir, flow_rule);
        }
-       if (flow->flags & FLOW_OFFLOAD_SNAT ||
-           flow->flags & FLOW_OFFLOAD_DNAT)
+       if (test_bit(NF_FLOW_SNAT, &flow->flags) ||
+           test_bit(NF_FLOW_DNAT, &flow->flags))
                flow_offload_ipv4_checksum(net, flow, flow_rule);
 
        flow_offload_redirect(flow, dir, flow_rule);
@@ -476,11 +476,11 @@ int nf_flow_rule_route_ipv6(struct net *net, const struct flow_offload *flow,
            flow_offload_eth_dst(net, flow, dir, flow_rule) < 0)
                return -1;
 
-       if (flow->flags & FLOW_OFFLOAD_SNAT) {
+       if (test_bit(NF_FLOW_SNAT, &flow->flags)) {
                flow_offload_ipv6_snat(net, flow, dir, flow_rule);
                flow_offload_port_snat(net, flow, dir, flow_rule);
        }
-       if (flow->flags & FLOW_OFFLOAD_DNAT) {
+       if (test_bit(NF_FLOW_DNAT, &flow->flags)) {
                flow_offload_ipv6_dnat(net, flow, dir, flow_rule);
                flow_offload_port_dnat(net, flow, dir, flow_rule);
        }
@@ -636,7 +636,7 @@ static void flow_offload_tuple_del(struct flow_offload_work *offload,
        list_for_each_entry(block_cb, &flowtable->flow_block.cb_list, list)
                block_cb->cb(TC_SETUP_CLSFLOWER, &cls_flow, block_cb->cb_priv);
 
-       offload->flow->flags |= FLOW_OFFLOAD_HW_DEAD;
+       set_bit(NF_FLOW_HW_DEAD, &offload->flow->flags);
 }
 
 static int flow_offload_rule_add(struct flow_offload_work *offload,
@@ -723,7 +723,7 @@ static void flow_offload_work_handler(struct work_struct *work)
                case FLOW_CLS_REPLACE:
                        ret = flow_offload_work_add(offload);
                        if (ret < 0)
-                               offload->flow->flags &= ~FLOW_OFFLOAD_HW;
+                               __clear_bit(NF_FLOW_HW, &offload->flow->flags);
                        break;
                case FLOW_CLS_DESTROY:
                        flow_offload_work_del(offload);
@@ -776,7 +776,7 @@ void nf_flow_offload_add(struct nf_flowtable *flowtable,
        if (!offload)
                return;
 
-       flow->flags |= FLOW_OFFLOAD_HW;
+       __set_bit(NF_FLOW_HW, &flow->flags);
        flow_offload_queue_work(offload);
 }
 
@@ -789,7 +789,7 @@ void nf_flow_offload_del(struct nf_flowtable *flowtable,
        if (!offload)
                return;
 
-       flow->flags |= FLOW_OFFLOAD_HW_DYING;
+       set_bit(NF_FLOW_HW_DYING, &flow->flags);
        flow_offload_queue_work(offload);
 }