linux/include/net/flow_dissector.h
Jiri Pirko fbff949e3b flow_dissector: introduce programable flow_dissector
Introduce dissector infrastructure which allows user to specify which
parts of skb he wants to dissect.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-13 15:19:47 -04:00

131 lines
3.7 KiB
C

#ifndef _NET_FLOW_DISSECTOR_H
#define _NET_FLOW_DISSECTOR_H
/**
* struct flow_dissector_key_basic:
* @thoff: Transport header offset
* @n_proto: Network header protocol (eg. IPv4/IPv6)
* @ip_proto: Transport header protocol (eg. TCP/UDP)
*/
struct flow_dissector_key_basic {
u16 thoff;
__be16 n_proto;
u8 ip_proto;
};
/**
* struct flow_dissector_key_addrs:
* @src: source ip address in case of IPv4
* For IPv6 it contains 32bit hash of src address
* @dst: destination ip address in case of IPv4
* For IPv6 it contains 32bit hash of dst address
*/
struct flow_dissector_key_addrs {
/* (src,dst) must be grouped, in the same way than in IP header */
__be32 src;
__be32 dst;
};
/**
* flow_dissector_key_tp_ports:
* @ports: port numbers of Transport header
* port16[0]: src port number
* port16[1]: dst port number
*/
struct flow_dissector_key_ports {
union {
__be32 ports;
__be16 port16[2];
};
};
enum flow_dissector_key_id {
FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_addrs */
FLOW_DISSECTOR_KEY_IPV6_HASH_ADDRS, /* struct flow_dissector_key_addrs */
FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
FLOW_DISSECTOR_KEY_MAX,
};
struct flow_dissector_key {
enum flow_dissector_key_id key_id;
size_t offset; /* offset of struct flow_dissector_key_*
in target the struct */
};
struct flow_dissector {
unsigned int used_keys; /* each bit repesents presence of one key id */
unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
};
/* struct flow_keys:
* @src: source ip address in case of IPv4
* For IPv6 it contains 32bit hash of src address
* @dst: destination ip address in case of IPv4
* For IPv6 it contains 32bit hash of dst address
* @ports: port numbers of Transport header
* port16[0]: src port number
* port16[1]: dst port number
* @thoff: Transport header offset
* @n_proto: Network header protocol (eg. IPv4/IPv6)
* @ip_proto: Transport header protocol (eg. TCP/UDP)
* All the members, except thoff, are in network byte order.
*/
struct flow_keys {
/* (src,dst) must be grouped, in the same way than in IP header */
__be32 src;
__be32 dst;
union {
__be32 ports;
__be16 port16[2];
};
u16 thoff;
__be16 n_proto;
u8 ip_proto;
};
void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
const struct flow_dissector_key *key,
unsigned int key_count);
bool __skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow,
void *data, __be16 proto, int nhoff, 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, 0, 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);
void __skb_get_hash(struct sk_buff *skb);
u32 skb_get_poff(const struct sk_buff *skb);
u32 __skb_get_poff(const struct sk_buff *skb, void *data,
const struct flow_keys *keys, int hlen);
/* struct flow_keys_digest:
*
* This structure is used to hold a digest of the full flow keys. This is a
* larger "hash" of a flow to allow definitively matching specific flows where
* the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
* that it can by used in CB of skb (see sch_choke for an example).
*/
#define FLOW_KEYS_DIGEST_LEN 16
struct flow_keys_digest {
u8 data[FLOW_KEYS_DIGEST_LEN];
};
void make_flow_keys_digest(struct flow_keys_digest *digest,
const struct flow_keys *flow);
#endif