include/net/flow_dissector.h

   1 #ifndef _NET_FLOW_DISSECTOR_H
   2 #define _NET_FLOW_DISSECTOR_H
   3
   4 #include <linux/types.h>
   5 #include <linux/skbuff.h>
   6 #include <linux/in6.h>
   7 #include <uapi/linux/if_ether.h>
   8
   9 /**
  10  * struct flow_dissector_key_basic:
  11  * @thoff: Transport header offset
  12  * @n_proto: Network header protocol (eg. IPv4/IPv6)
  13  * @ip_proto: Transport header protocol (eg. TCP/UDP)
  14  */
  15 struct flow_dissector_key_basic {
  16         u16     thoff;
  17         __be16  n_proto;
  18         u8      ip_proto;
  19 };
  20
  21 /**
  22  * struct flow_dissector_key_addrs:
  23  * @src: source ip address in case of IPv4
  24  *       For IPv6 it contains 32bit hash of src address
  25  * @dst: destination ip address in case of IPv4
  26  *       For IPv6 it contains 32bit hash of dst address
  27  */
  28 struct flow_dissector_key_addrs {
  29         /* (src,dst) must be grouped, in the same way than in IP header */
  30         __be32 src;
  31         __be32 dst;
  32 };
  33
  34 /**
  35  * flow_dissector_key_tp_ports:
  36  *      @ports: port numbers of Transport header
  37  *              port16[0]: src port number
  38  *              port16[1]: dst port number
  39  */
  40 struct flow_dissector_key_ports {
  41         union {
  42                 __be32 ports;
  43                 __be16 port16[2];
  44         };
  45 };
  46
  47 /**
  48  * struct flow_dissector_key_ipv6_addrs:
  49  * @src: source ip address
  50  * @dst: destination ip address
  51  */
  52 struct flow_dissector_key_ipv6_addrs {
  53         /* (src,dst) must be grouped, in the same way than in IP header */
  54         struct in6_addr src;
  55         struct in6_addr dst;
  56 };
  57
  58 /**
  59  * struct flow_dissector_key_eth_addrs:
  60  * @src: source Ethernet address
  61  * @dst: destination Ethernet address
  62  */
  63 struct flow_dissector_key_eth_addrs {
  64         /* (dst,src) must be grouped, in the same way than in ETH header */
  65         unsigned char dst[ETH_ALEN];
  66         unsigned char src[ETH_ALEN];
  67 };
  68
  69 enum flow_dissector_key_id {
  70         FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
  71         FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_addrs */
  72         FLOW_DISSECTOR_KEY_IPV6_HASH_ADDRS, /* struct flow_dissector_key_addrs */
  73         FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
  74         FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
  75         FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
  76
  77         FLOW_DISSECTOR_KEY_MAX,
  78 };
  79
  80 struct flow_dissector_key {
  81         enum flow_dissector_key_id key_id;
  82         size_t offset; /* offset of struct flow_dissector_key_*
  83                           in target the struct */
  84 };
  85
  86 struct flow_dissector {
  87         unsigned int used_keys; /* each bit repesents presence of one key id */
  88         unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
  89 };
  90
  91 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
  92                              const struct flow_dissector_key *key,
  93                              unsigned int key_count);
  94
  95 bool __skb_flow_dissect(const struct sk_buff *skb,
  96                         struct flow_dissector *flow_dissector,
  97                         void *target_container,
  98                         void *data, __be16 proto, int nhoff, int hlen);
  99
 100 static inline bool skb_flow_dissect(const struct sk_buff *skb,
 101                                     struct flow_dissector *flow_dissector,
 102                                     void *target_container)
 103 {
 104         return __skb_flow_dissect(skb, flow_dissector, target_container,
 105                                   NULL, 0, 0, 0);
 106 }
 107
 108 struct flow_keys {
 109         struct flow_dissector_key_addrs addrs;
 110         struct flow_dissector_key_ports ports;
 111         struct flow_dissector_key_basic basic;
 112 };
 113
 114 extern struct flow_dissector flow_keys_dissector;
 115 extern struct flow_dissector flow_keys_buf_dissector;
 116
 117 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb,
 118                                               struct flow_keys *flow)
 119 {
 120         memset(flow, 0, sizeof(*flow));
 121         return __skb_flow_dissect(skb, &flow_keys_dissector, flow,
 122                                   NULL, 0, 0, 0);
 123 }
 124
 125 static inline bool skb_flow_dissect_flow_keys_buf(struct flow_keys *flow,
 126                                                   void *data, __be16 proto,
 127                                                   int nhoff, int hlen)
 128 {
 129         memset(flow, 0, sizeof(*flow));
 130         return __skb_flow_dissect(NULL, &flow_keys_buf_dissector, flow,
 131                                   data, proto, nhoff, hlen);
 132 }
 133
 134 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
 135                             void *data, int hlen_proto);
 136
 137 static inline __be32 skb_flow_get_ports(const struct sk_buff *skb,
 138                                         int thoff, u8 ip_proto)
 139 {
 140         return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0);
 141 }
 142
 143 u32 flow_hash_from_keys(struct flow_keys *keys);
 144 void __skb_get_hash(struct sk_buff *skb);
 145 u32 skb_get_poff(const struct sk_buff *skb);
 146 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
 147                    const struct flow_keys *keys, int hlen);
 148
 149 /* struct flow_keys_digest:
 150  *
 151  * This structure is used to hold a digest of the full flow keys. This is a
 152  * larger "hash" of a flow to allow definitively matching specific flows where
 153  * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
 154  * that it can by used in CB of skb (see sch_choke for an example).
 155  */
 156 #define FLOW_KEYS_DIGEST_LEN    16
 157 struct flow_keys_digest {
 158         u8      data[FLOW_KEYS_DIGEST_LEN];
 159 };
 160
 161 void make_flow_keys_digest(struct flow_keys_digest *digest,
 162                            const struct flow_keys *flow);
 163
 164 #endif