net/sched: act_ct: Fix ipv6 lookup of offloaded connections

When checking the protocol number tcf_ct_flow_table_lookup() handles
the flow as if it's always ipv4, while it can be ipv6.

Instead, refactor the code to fetch the tcp header, if available,
in the relevant family (ipv4/ipv6) filler function, and do the
check on the returned tcp header.

Fixes: 46475bb20f4b ("net/sched: act_ct: Software offload of established flows")
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
index a2d5582a701e93b39a4430ff2ad14c8f9200076f..f434db750328fc421b1a37a45186f25a59f4db7f 100644 (file)
--- a/net/sched/act_ct.c
+++ b/net/sched/act_ct.c
@@ -188,7 +188,8 @@ static void tcf_ct_flow_table_process_conn(struct tcf_ct_flow_table *ct_ft,
 
 static bool
 tcf_ct_flow_table_fill_tuple_ipv4(struct sk_buff *skb,
-                                 struct flow_offload_tuple *tuple)
+                                 struct flow_offload_tuple *tuple,
+                                 struct tcphdr **tcph)
 {
        struct flow_ports *ports;
        unsigned int thoff;
@@ -211,11 +212,16 @@ tcf_ct_flow_table_fill_tuple_ipv4(struct sk_buff *skb,
        if (iph->ttl <= 1)
                return false;
 
-       if (!pskb_may_pull(skb, thoff + sizeof(*ports)))
+       if (!pskb_may_pull(skb, iph->protocol == IPPROTO_TCP ?
+                          thoff + sizeof(struct tcphdr) :
+                          thoff + sizeof(*ports)))
                return false;
 
-       ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
+       iph = ip_hdr(skb);
+       if (iph->protocol == IPPROTO_TCP)
+               *tcph = (void *)(skb_network_header(skb) + thoff);
 
+       ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
        tuple->src_v4.s_addr = iph->saddr;
        tuple->dst_v4.s_addr = iph->daddr;
        tuple->src_port = ports->source;
@@ -228,7 +234,8 @@ tcf_ct_flow_table_fill_tuple_ipv4(struct sk_buff *skb,
 
 static bool
 tcf_ct_flow_table_fill_tuple_ipv6(struct sk_buff *skb,
-                                 struct flow_offload_tuple *tuple)
+                                 struct flow_offload_tuple *tuple,
+                                 struct tcphdr **tcph)
 {
        struct flow_ports *ports;
        struct ipv6hdr *ip6h;
@@ -247,11 +254,16 @@ tcf_ct_flow_table_fill_tuple_ipv6(struct sk_buff *skb,
                return false;
 
        thoff = sizeof(*ip6h);
-       if (!pskb_may_pull(skb, thoff + sizeof(*ports)))
+       if (!pskb_may_pull(skb, ip6h->nexthdr == IPPROTO_TCP ?
+                          thoff + sizeof(struct tcphdr) :
+                          thoff + sizeof(*ports)))
                return false;
 
-       ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
+       ip6h = ipv6_hdr(skb);
+       if (ip6h->nexthdr == IPPROTO_TCP)
+               *tcph = (void *)(skb_network_header(skb) + thoff);
 
+       ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
        tuple->src_v6 = ip6h->saddr;
        tuple->dst_v6 = ip6h->daddr;
        tuple->src_port = ports->source;
@@ -262,24 +274,6 @@ tcf_ct_flow_table_fill_tuple_ipv6(struct sk_buff *skb,
        return true;
 }
 
-static bool tcf_ct_flow_table_check_tcp(struct flow_offload *flow,
-                                       struct sk_buff *skb,
-                                       unsigned int thoff)
-{
-       struct tcphdr *tcph;
-
-       if (!pskb_may_pull(skb, thoff + sizeof(*tcph)))
-               return false;
-
-       tcph = (void *)(skb_network_header(skb) + thoff);
-       if (unlikely(tcph->fin || tcph->rst)) {
-               flow_offload_teardown(flow);
-               return false;
-       }
-
-       return true;
-}
-
 static bool tcf_ct_flow_table_lookup(struct tcf_ct_params *p,
                                     struct sk_buff *skb,
                                     u8 family)
@@ -288,10 +282,9 @@ static bool tcf_ct_flow_table_lookup(struct tcf_ct_params *p,
        struct flow_offload_tuple_rhash *tuplehash;
        struct flow_offload_tuple tuple = {};
        enum ip_conntrack_info ctinfo;
+       struct tcphdr *tcph = NULL;
        struct flow_offload *flow;
        struct nf_conn *ct;
-       unsigned int thoff;
-       int ip_proto;
        u8 dir;
 
        /* Previously seen or loopback */
@@ -301,11 +294,11 @@ static bool tcf_ct_flow_table_lookup(struct tcf_ct_params *p,
 
        switch (family) {
        case NFPROTO_IPV4:
-               if (!tcf_ct_flow_table_fill_tuple_ipv4(skb, &tuple))
+               if (!tcf_ct_flow_table_fill_tuple_ipv4(skb, &tuple, &tcph))
                        return false;
                break;
        case NFPROTO_IPV6:
-               if (!tcf_ct_flow_table_fill_tuple_ipv6(skb, &tuple))
+               if (!tcf_ct_flow_table_fill_tuple_ipv6(skb, &tuple, &tcph))
                        return false;
                break;
        default:
@@ -320,15 +313,14 @@ static bool tcf_ct_flow_table_lookup(struct tcf_ct_params *p,
        flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
        ct = flow->ct;
 
+       if (tcph && (unlikely(tcph->fin || tcph->rst))) {
+               flow_offload_teardown(flow);
+               return false;
+       }
+
        ctinfo = dir == FLOW_OFFLOAD_DIR_ORIGINAL ? IP_CT_ESTABLISHED :
                                                    IP_CT_ESTABLISHED_REPLY;
 
-       thoff = ip_hdr(skb)->ihl * 4;
-       ip_proto = ip_hdr(skb)->protocol;
-       if (ip_proto == IPPROTO_TCP &&
-           !tcf_ct_flow_table_check_tcp(flow, skb, thoff))
-               return false;
-
        nf_conntrack_get(&ct->ct_general);
        nf_ct_set(skb, ct, ctinfo);