mirror of https://gitee.com/openkylin/linux.git
144 lines
3.0 KiB
C
144 lines
3.0 KiB
C
#include <linux/skbuff.h>
|
|
#include <linux/ip.h>
|
|
#include <linux/ipv6.h>
|
|
#include <linux/if_vlan.h>
|
|
#include <net/ip.h>
|
|
#include <linux/if_tunnel.h>
|
|
#include <linux/if_pppox.h>
|
|
#include <linux/ppp_defs.h>
|
|
#include <net/flow_keys.h>
|
|
|
|
/* copy saddr & daddr, possibly using 64bit load/store
|
|
* Equivalent to : flow->src = iph->saddr;
|
|
* flow->dst = iph->daddr;
|
|
*/
|
|
static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *iph)
|
|
{
|
|
BUILD_BUG_ON(offsetof(typeof(*flow), dst) !=
|
|
offsetof(typeof(*flow), src) + sizeof(flow->src));
|
|
memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst));
|
|
}
|
|
|
|
bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow)
|
|
{
|
|
int poff, nhoff = skb_network_offset(skb);
|
|
u8 ip_proto;
|
|
__be16 proto = skb->protocol;
|
|
|
|
memset(flow, 0, sizeof(*flow));
|
|
|
|
again:
|
|
switch (proto) {
|
|
case __constant_htons(ETH_P_IP): {
|
|
const struct iphdr *iph;
|
|
struct iphdr _iph;
|
|
ip:
|
|
iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
|
|
if (!iph)
|
|
return false;
|
|
|
|
if (ip_is_fragment(iph))
|
|
ip_proto = 0;
|
|
else
|
|
ip_proto = iph->protocol;
|
|
iph_to_flow_copy_addrs(flow, iph);
|
|
nhoff += iph->ihl * 4;
|
|
break;
|
|
}
|
|
case __constant_htons(ETH_P_IPV6): {
|
|
const struct ipv6hdr *iph;
|
|
struct ipv6hdr _iph;
|
|
ipv6:
|
|
iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
|
|
if (!iph)
|
|
return false;
|
|
|
|
ip_proto = iph->nexthdr;
|
|
flow->src = iph->saddr.s6_addr32[3];
|
|
flow->dst = iph->daddr.s6_addr32[3];
|
|
nhoff += sizeof(struct ipv6hdr);
|
|
break;
|
|
}
|
|
case __constant_htons(ETH_P_8021Q): {
|
|
const struct vlan_hdr *vlan;
|
|
struct vlan_hdr _vlan;
|
|
|
|
vlan = skb_header_pointer(skb, nhoff, sizeof(_vlan), &_vlan);
|
|
if (!vlan)
|
|
return false;
|
|
|
|
proto = vlan->h_vlan_encapsulated_proto;
|
|
nhoff += sizeof(*vlan);
|
|
goto again;
|
|
}
|
|
case __constant_htons(ETH_P_PPP_SES): {
|
|
struct {
|
|
struct pppoe_hdr hdr;
|
|
__be16 proto;
|
|
} *hdr, _hdr;
|
|
hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
|
|
if (!hdr)
|
|
return false;
|
|
proto = hdr->proto;
|
|
nhoff += PPPOE_SES_HLEN;
|
|
switch (proto) {
|
|
case __constant_htons(PPP_IP):
|
|
goto ip;
|
|
case __constant_htons(PPP_IPV6):
|
|
goto ipv6;
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
default:
|
|
return false;
|
|
}
|
|
|
|
switch (ip_proto) {
|
|
case IPPROTO_GRE: {
|
|
struct gre_hdr {
|
|
__be16 flags;
|
|
__be16 proto;
|
|
} *hdr, _hdr;
|
|
|
|
hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
|
|
if (!hdr)
|
|
return false;
|
|
/*
|
|
* Only look inside GRE if version zero and no
|
|
* routing
|
|
*/
|
|
if (!(hdr->flags & (GRE_VERSION|GRE_ROUTING))) {
|
|
proto = hdr->proto;
|
|
nhoff += 4;
|
|
if (hdr->flags & GRE_CSUM)
|
|
nhoff += 4;
|
|
if (hdr->flags & GRE_KEY)
|
|
nhoff += 4;
|
|
if (hdr->flags & GRE_SEQ)
|
|
nhoff += 4;
|
|
goto again;
|
|
}
|
|
break;
|
|
}
|
|
case IPPROTO_IPIP:
|
|
goto again;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
flow->ip_proto = ip_proto;
|
|
poff = proto_ports_offset(ip_proto);
|
|
if (poff >= 0) {
|
|
__be32 *ports, _ports;
|
|
|
|
nhoff += poff;
|
|
ports = skb_header_pointer(skb, nhoff, sizeof(_ports), &_ports);
|
|
if (ports)
|
|
flow->ports = *ports;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL(skb_flow_dissect);
|