From 357afe9c46c951c34769e39cabdf8d1637e2eecc Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Wed, 2 Oct 2013 13:39:24 +0200 Subject: 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 Signed-off-by: Nikolay Aleksandrov Acked-by: Eric Dumazet Reviewed-by: Veaceslav Falico Signed-off-by: David S. Miller --- net/core/flow_dissector.c | 39 ++++++++++++++++++++++++++++----------- 1 file changed, 28 insertions(+), 11 deletions(-) (limited to 'net/core') diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 8d7d0dd..f8e25ac 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -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; -- cgit v1.1