3 files changed, 50 insertions, 22 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index abde271c18ae..18ddf9684a27 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2567,20 +2567,26 @@ __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
                     __wsum csum);
 
-static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
-                                       int len, void *buffer)
+static inline void *__skb_header_pointer(const struct sk_buff *skb, int offset,
+                                         int len, void *data, int hlen, void *buffer)
 {
-        int hlen = skb_headlen(skb);
-
         if (hlen - offset >= len)
-                return skb->data + offset;
+                return data + offset;
 
-        if (skb_copy_bits(skb, offset, buffer, len) < 0)
+        if (!skb ||
+            skb_copy_bits(skb, offset, buffer, len) < 0)
                 return NULL;
 
         return buffer;
 }
 
+static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
+                                       int len, void *buffer)
+{
+        return __skb_header_pointer(skb, offset, len, skb->data,
+                                    skb_headlen(skb), buffer);
+}
+
 /**
  *      skb_needs_linearize - check if we need to linearize a given skb
  *                            depending on the given device features.
diff --git a/include/net/flow_keys.h b/include/net/flow_keys.h
index 6667a054763a..4040f63932c5 100644
--- a/include/net/flow_keys.h
+++ b/include/net/flow_keys.h
@@ -27,7 +27,17 @@ struct flow_keys {
         u8 ip_proto;
 };
 
-bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow);
-__be32 skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto);
+bool __skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow,
+                        void *data, int hlen);
+static inline bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow)
+{
+        return __skb_flow_dissect(skb, flow, NULL, 0);
+}
+__be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
+                            void *data, int hlen_proto);
+static inline __be32 skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto)
+{
+        return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0);
+}
 u32 flow_hash_from_keys(struct flow_keys *keys);
 #endif
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 5f362c1d0332..660c6492fb78 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -34,29 +34,40 @@ static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *i
  * The function will try to retrieve the ports at offset thoff + poff where poff
  * is the protocol port offset returned from proto_ports_offset
  */
-__be32 skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto)
+__be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
+                            void *data, int hlen)
 {
         int poff = proto_ports_offset(ip_proto);
 
+        if (!data) {
+                data = skb->data;
+                hlen = skb_headlen(skb);
+        }
+
         if (poff >= 0) {
                 __be32 *ports, _ports;
 
-                ports = skb_header_pointer(skb, thoff + poff,
-                                           sizeof(_ports), &_ports);
+                ports = __skb_header_pointer(skb, thoff + poff,
+                                             sizeof(_ports), data, hlen, &_ports);
                 if (ports)
                         return *ports;
         }
 
         return 0;
 }
-EXPORT_SYMBOL(skb_flow_get_ports);
+EXPORT_SYMBOL(__skb_flow_get_ports);
 
-bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow)
+bool __skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow, void *data, int hlen)
 {
         int nhoff = skb_network_offset(skb);
         u8 ip_proto;
         __be16 proto = skb->protocol;
 
+        if (!data) {
+                data = skb->data;
+                hlen = skb_headlen(skb);
+        }
+
         memset(flow, 0, sizeof(*flow));
 
 again:
@@ -65,7 +76,7 @@ again:
                 const struct iphdr *iph;
                 struct iphdr _iph;
 ip:
-                iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
+                iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
                 if (!iph || iph->ihl < 5)
                         return false;
                 nhoff += iph->ihl * 4;
@@ -83,7 +94,7 @@ ip:
                 __be32 flow_label;
 
 ipv6:
-                iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
+                iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
                 if (!iph)
                         return false;
 
@@ -113,7 +124,7 @@ ipv6:
                 const struct vlan_hdr *vlan;
                 struct vlan_hdr _vlan;
 
-                vlan = skb_header_pointer(skb, nhoff, sizeof(_vlan), &_vlan);
+                vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
                 if (!vlan)
                         return false;
 
@@ -126,7 +137,7 @@ ipv6:
                         struct pppoe_hdr hdr;
                         __be16 proto;
                 } *hdr, _hdr;
-                hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
+                hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
                 if (!hdr)
                         return false;
                 proto = hdr->proto;
@@ -151,7 +162,7 @@ ipv6:
                         __be16 proto;
                 } *hdr, _hdr;
 
-                hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
+                hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
                 if (!hdr)
                         return false;
                 /*
@@ -171,8 +182,9 @@ ipv6:
                                 const struct ethhdr *eth;
                                 struct ethhdr _eth;
 
-                                eth = skb_header_pointer(skb, nhoff,
-                                                         sizeof(_eth), &_eth);
+                                eth = __skb_header_pointer(skb, nhoff,
+                                                           sizeof(_eth),
+                                                           data, hlen, &_eth);
                                 if (!eth)
                                         return false;
                                 proto = eth->h_proto;
@@ -194,12 +206,12 @@ ipv6:
 
         flow->n_proto = proto;
         flow->ip_proto = ip_proto;
-        flow->ports = skb_flow_get_ports(skb, nhoff, ip_proto);
+        flow->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, data, hlen);
         flow->thoff = (u16) nhoff;
 
         return true;
 }
-EXPORT_SYMBOL(skb_flow_dissect);
+EXPORT_SYMBOL(__skb_flow_dissect);
 
 static u32 hashrnd __read_mostly;
 static __always_inline void __flow_hash_secret_init(void)