flow_dissector: factor out the ports extraction in skb_flow_get_ports

Factor out the code that extracts the ports from skb_flow_dissect and
add a new function skb_flow_get_ports which can be re-used.

Suggested-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Nikolay Aleksandrov 2013-10-02 13:39:24 +02:00 committed by David S. Miller
parent 5080546682
commit 357afe9c46
2 changed files with 29 additions and 11 deletions

View File

@ -14,4 +14,5 @@ struct flow_keys {
};
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);
#endif

View File

@ -25,9 +25,35 @@ static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *i
memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst));
}
/**
* skb_flow_get_ports - extract the upper layer ports and return them
* @skb: buffer to extract the ports from
* @thoff: transport header offset
* @ip_proto: protocol for which to get port offset
*
* 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)
{
int poff = proto_ports_offset(ip_proto);
if (poff >= 0) {
__be32 *ports, _ports;
ports = skb_header_pointer(skb, thoff + poff,
sizeof(_ports), &_ports);
if (ports)
return *ports;
}
return 0;
}
EXPORT_SYMBOL(skb_flow_get_ports);
bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow)
{
int poff, nhoff = skb_network_offset(skb);
int nhoff = skb_network_offset(skb);
u8 ip_proto;
__be16 proto = skb->protocol;
@ -150,16 +176,7 @@ ipv6:
}
flow->ip_proto = ip_proto;
poff = proto_ports_offset(ip_proto);
if (poff >= 0) {
__be32 *ports, _ports;
ports = skb_header_pointer(skb, nhoff + poff,
sizeof(_ports), &_ports);
if (ports)
flow->ports = *ports;
}
flow->ports = skb_flow_get_ports(skb, nhoff, ip_proto);
flow->thoff = (u16) nhoff;
return true;