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/in6.h>
   6 #include <uapi/linux/if_ether.h>
   7
   8 /**
   9  * struct flow_dissector_key_control:
  10  * @thoff: Transport header offset
  11  */
  12 struct flow_dissector_key_control {
  13         u16     thoff;
  14         u16     addr_type;
  15         u32     flags;
  16 };
  17
  18 #define FLOW_DIS_IS_FRAGMENT    BIT(0)
  19 #define FLOW_DIS_FIRST_FRAG     BIT(1)
  20 #define FLOW_DIS_ENCAPSULATION  BIT(2)
  21
  22 /**
  23  * struct flow_dissector_key_basic:
  24  * @thoff: Transport header offset
  25  * @n_proto: Network header protocol (eg. IPv4/IPv6)
  26  * @ip_proto: Transport header protocol (eg. TCP/UDP)
  27  */
  28 struct flow_dissector_key_basic {
  29         __be16  n_proto;
  30         u8      ip_proto;
  31         u8      padding;
  32 };
  33
  34 struct flow_dissector_key_tags {
  35         u32     vlan_id:12,
  36                 flow_label:20;
  37 };
  38
  39 struct flow_dissector_key_keyid {
  40         __be32  keyid;
  41 };
  42
  43 /**
  44  * struct flow_dissector_key_ipv4_addrs:
  45  * @src: source ip address
  46  * @dst: destination ip address
  47  */
  48 struct flow_dissector_key_ipv4_addrs {
  49         /* (src,dst) must be grouped, in the same way than in IP header */
  50         __be32 src;
  51         __be32 dst;
  52 };
  53
  54 /**
  55  * struct flow_dissector_key_ipv6_addrs:
  56  * @src: source ip address
  57  * @dst: destination ip address
  58  */
  59 struct flow_dissector_key_ipv6_addrs {
  60         /* (src,dst) must be grouped, in the same way than in IP header */
  61         struct in6_addr src;
  62         struct in6_addr dst;
  63 };
  64
  65 /**
  66  * struct flow_dissector_key_tipc_addrs:
  67  * @srcnode: source node address
  68  */
  69 struct flow_dissector_key_tipc_addrs {
  70         __be32 srcnode;
  71 };
  72
  73 /**
  74  * struct flow_dissector_key_addrs:
  75  * @v4addrs: IPv4 addresses
  76  * @v6addrs: IPv6 addresses
  77  */
  78 struct flow_dissector_key_addrs {
  79         union {
  80                 struct flow_dissector_key_ipv4_addrs v4addrs;
  81                 struct flow_dissector_key_ipv6_addrs v6addrs;
  82                 struct flow_dissector_key_tipc_addrs tipcaddrs;
  83         };
  84 };
  85
  86 /**
  87  * flow_dissector_key_tp_ports:
  88  *      @ports: port numbers of Transport header
  89  *              src: source port number
  90  *              dst: destination port number
  91  */
  92 struct flow_dissector_key_ports {
  93         union {
  94                 __be32 ports;
  95                 struct {
  96                         __be16 src;
  97                         __be16 dst;
  98                 };
  99         };
 100 };
 101
 102
 103 /**
 104  * struct flow_dissector_key_eth_addrs:
 105  * @src: source Ethernet address
 106  * @dst: destination Ethernet address
 107  */
 108 struct flow_dissector_key_eth_addrs {
 109         /* (dst,src) must be grouped, in the same way than in ETH header */
 110         unsigned char dst[ETH_ALEN];
 111         unsigned char src[ETH_ALEN];
 112 };
 113
 114 enum flow_dissector_key_id {
 115         FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
 116         FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
 117         FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
 118         FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 119         FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
 120         FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
 121         FLOW_DISSECTOR_KEY_TIPC_ADDRS, /* struct flow_dissector_key_tipc_addrs */
 122         FLOW_DISSECTOR_KEY_VLANID, /* struct flow_dissector_key_flow_tags */
 123         FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_flow_tags */
 124         FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */
 125         FLOW_DISSECTOR_KEY_MPLS_ENTROPY, /* struct flow_dissector_key_keyid */
 126
 127         FLOW_DISSECTOR_KEY_MAX,
 128 };
 129
 130 #define FLOW_DISSECTOR_F_PARSE_1ST_FRAG         BIT(0)
 131 #define FLOW_DISSECTOR_F_STOP_AT_L3             BIT(1)
 132 #define FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL     BIT(2)
 133 #define FLOW_DISSECTOR_F_STOP_AT_ENCAP          BIT(3)
 134
 135 struct flow_dissector_key {
 136         enum flow_dissector_key_id key_id;
 137         size_t offset; /* offset of struct flow_dissector_key_*
 138                           in target the struct */
 139 };
 140
 141 struct flow_dissector {
 142         unsigned int used_keys; /* each bit repesents presence of one key id */
 143         unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
 144 };
 145
 146 struct flow_keys {
 147         struct flow_dissector_key_control control;
 148 #define FLOW_KEYS_HASH_START_FIELD basic
 149         struct flow_dissector_key_basic basic;
 150         struct flow_dissector_key_tags tags;
 151         struct flow_dissector_key_keyid keyid;
 152         struct flow_dissector_key_ports ports;
 153         struct flow_dissector_key_addrs addrs;
 154 };
 155
 156 #define FLOW_KEYS_HASH_OFFSET           \
 157         offsetof(struct flow_keys, FLOW_KEYS_HASH_START_FIELD)
 158
 159 __be32 flow_get_u32_src(const struct flow_keys *flow);
 160 __be32 flow_get_u32_dst(const struct flow_keys *flow);
 161
 162 extern struct flow_dissector flow_keys_dissector;
 163 extern struct flow_dissector flow_keys_buf_dissector;
 164
 165 /* struct flow_keys_digest:
 166  *
 167  * This structure is used to hold a digest of the full flow keys. This is a
 168  * larger "hash" of a flow to allow definitively matching specific flows where
 169  * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
 170  * that it can by used in CB of skb (see sch_choke for an example).
 171  */
 172 #define FLOW_KEYS_DIGEST_LEN    16
 173 struct flow_keys_digest {
 174         u8      data[FLOW_KEYS_DIGEST_LEN];
 175 };
 176
 177 void make_flow_keys_digest(struct flow_keys_digest *digest,
 178                            const struct flow_keys *flow);
 179
 180 static inline bool flow_keys_have_l4(struct flow_keys *keys)
 181 {
 182         return (keys->ports.ports || keys->tags.flow_label);
 183 }
 184
 185 u32 flow_hash_from_keys(struct flow_keys *keys);
 186
 187 static inline bool dissector_uses_key(const struct flow_dissector *flow_dissector,
 188                                       enum flow_dissector_key_id key_id)
 189 {
 190         return flow_dissector->used_keys & (1 << key_id);
 191 }
 192
 193 static inline void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
 194                                               enum flow_dissector_key_id key_id,
 195                                               void *target_container)
 196 {
 197         return ((char *)target_container) + flow_dissector->offset[key_id];
 198 }
 199
 200 #endif