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     flow_label;
  36 };
  37
  38 struct flow_dissector_key_vlan {
  39         u16     vlan_id:12,
  40                 vlan_priority:3;
  41         u16     padding;
  42 };
  43
  44 struct flow_dissector_key_mpls {
  45         u32     mpls_ttl:8,
  46                 mpls_bos:1,
  47                 mpls_tc:3,
  48                 mpls_label:20;
  49 };
  50
  51 struct flow_dissector_key_keyid {
  52         __be32  keyid;
  53 };
  54
  55 /**
  56  * struct flow_dissector_key_ipv4_addrs:
  57  * @src: source ip address
  58  * @dst: destination ip address
  59  */
  60 struct flow_dissector_key_ipv4_addrs {
  61         /* (src,dst) must be grouped, in the same way than in IP header */
  62         __be32 src;
  63         __be32 dst;
  64 };
  65
  66 /**
  67  * struct flow_dissector_key_ipv6_addrs:
  68  * @src: source ip address
  69  * @dst: destination ip address
  70  */
  71 struct flow_dissector_key_ipv6_addrs {
  72         /* (src,dst) must be grouped, in the same way than in IP header */
  73         struct in6_addr src;
  74         struct in6_addr dst;
  75 };
  76
  77 /**
  78  * struct flow_dissector_key_tipc_addrs:
  79  * @srcnode: source node address
  80  */
  81 struct flow_dissector_key_tipc_addrs {
  82         __be32 srcnode;
  83 };
  84
  85 /**
  86  * struct flow_dissector_key_addrs:
  87  * @v4addrs: IPv4 addresses
  88  * @v6addrs: IPv6 addresses
  89  */
  90 struct flow_dissector_key_addrs {
  91         union {
  92                 struct flow_dissector_key_ipv4_addrs v4addrs;
  93                 struct flow_dissector_key_ipv6_addrs v6addrs;
  94                 struct flow_dissector_key_tipc_addrs tipcaddrs;
  95         };
  96 };
  97
  98 /**
  99  * flow_dissector_key_arp:
 100  *      @ports: Operation, source and target addresses for an ARP header
 101  *              for Ethernet hardware addresses and IPv4 protocol addresses
 102  *              sip: Sender IP address
 103  *              tip: Target IP address
 104  *              op:  Operation
 105  *              sha: Sender hardware address
 106  *              tpa: Target hardware address
 107  */
 108 struct flow_dissector_key_arp {
 109         __u32 sip;
 110         __u32 tip;
 111         __u8 op;
 112         unsigned char sha[ETH_ALEN];
 113         unsigned char tha[ETH_ALEN];
 114 };
 115
 116 /**
 117  * flow_dissector_key_tp_ports:
 118  *      @ports: port numbers of Transport header
 119  *              src: source port number
 120  *              dst: destination port number
 121  */
 122 struct flow_dissector_key_ports {
 123         union {
 124                 __be32 ports;
 125                 struct {
 126                         __be16 src;
 127                         __be16 dst;
 128                 };
 129         };
 130 };
 131
 132 /**
 133  * flow_dissector_key_icmp:
 134  *      @ports: type and code of ICMP header
 135  *              icmp: ICMP type (high) and code (low)
 136  *              type: ICMP type
 137  *              code: ICMP code
 138  */
 139 struct flow_dissector_key_icmp {
 140         union {
 141                 __be16 icmp;
 142                 struct {
 143                         u8 type;
 144                         u8 code;
 145                 };
 146         };
 147 };
 148
 149 /**
 150  * struct flow_dissector_key_eth_addrs:
 151  * @src: source Ethernet address
 152  * @dst: destination Ethernet address
 153  */
 154 struct flow_dissector_key_eth_addrs {
 155         /* (dst,src) must be grouped, in the same way than in ETH header */
 156         unsigned char dst[ETH_ALEN];
 157         unsigned char src[ETH_ALEN];
 158 };
 159
 160 enum flow_dissector_key_id {
 161         FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
 162         FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
 163         FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
 164         FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 165         FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
 166         FLOW_DISSECTOR_KEY_ICMP, /* struct flow_dissector_key_icmp */
 167         FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
 168         FLOW_DISSECTOR_KEY_TIPC_ADDRS, /* struct flow_dissector_key_tipc_addrs */
 169         FLOW_DISSECTOR_KEY_ARP, /* struct flow_dissector_key_arp */
 170         FLOW_DISSECTOR_KEY_VLAN, /* struct flow_dissector_key_flow_vlan */
 171         FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_flow_tags */
 172         FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */
 173         FLOW_DISSECTOR_KEY_MPLS_ENTROPY, /* struct flow_dissector_key_keyid */
 174         FLOW_DISSECTOR_KEY_ENC_KEYID, /* struct flow_dissector_key_keyid */
 175         FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
 176         FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 177         FLOW_DISSECTOR_KEY_ENC_CONTROL, /* struct flow_dissector_key_control */
 178         FLOW_DISSECTOR_KEY_ENC_PORTS, /* struct flow_dissector_key_ports */
 179         FLOW_DISSECTOR_KEY_MPLS, /* struct flow_dissector_key_mpls */
 180
 181         FLOW_DISSECTOR_KEY_MAX,
 182 };
 183
 184 #define FLOW_DISSECTOR_F_PARSE_1ST_FRAG         BIT(0)
 185 #define FLOW_DISSECTOR_F_STOP_AT_L3             BIT(1)
 186 #define FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL     BIT(2)
 187 #define FLOW_DISSECTOR_F_STOP_AT_ENCAP          BIT(3)
 188
 189 struct flow_dissector_key {
 190         enum flow_dissector_key_id key_id;
 191         size_t offset; /* offset of struct flow_dissector_key_*
 192                           in target the struct */
 193 };
 194
 195 struct flow_dissector {
 196         unsigned int used_keys; /* each bit repesents presence of one key id */
 197         unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
 198 };
 199
 200 struct flow_keys {
 201         struct flow_dissector_key_control control;
 202 #define FLOW_KEYS_HASH_START_FIELD basic
 203         struct flow_dissector_key_basic basic;
 204         struct flow_dissector_key_tags tags;
 205         struct flow_dissector_key_vlan vlan;
 206         struct flow_dissector_key_keyid keyid;
 207         struct flow_dissector_key_ports ports;
 208         struct flow_dissector_key_addrs addrs;
 209 };
 210
 211 #define FLOW_KEYS_HASH_OFFSET           \
 212         offsetof(struct flow_keys, FLOW_KEYS_HASH_START_FIELD)
 213
 214 __be32 flow_get_u32_src(const struct flow_keys *flow);
 215 __be32 flow_get_u32_dst(const struct flow_keys *flow);
 216
 217 extern struct flow_dissector flow_keys_dissector;
 218 extern struct flow_dissector flow_keys_buf_dissector;
 219
 220 /* struct flow_keys_digest:
 221  *
 222  * This structure is used to hold a digest of the full flow keys. This is a
 223  * larger "hash" of a flow to allow definitively matching specific flows where
 224  * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
 225  * that it can by used in CB of skb (see sch_choke for an example).
 226  */
 227 #define FLOW_KEYS_DIGEST_LEN    16
 228 struct flow_keys_digest {
 229         u8      data[FLOW_KEYS_DIGEST_LEN];
 230 };
 231
 232 void make_flow_keys_digest(struct flow_keys_digest *digest,
 233                            const struct flow_keys *flow);
 234
 235 static inline bool flow_keys_have_l4(const struct flow_keys *keys)
 236 {
 237         return (keys->ports.ports || keys->tags.flow_label);
 238 }
 239
 240 u32 flow_hash_from_keys(struct flow_keys *keys);
 241
 242 static inline bool dissector_uses_key(const struct flow_dissector *flow_dissector,
 243                                       enum flow_dissector_key_id key_id)
 244 {
 245         return flow_dissector->used_keys & (1 << key_id);
 246 }
 247
 248 static inline void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
 249                                               enum flow_dissector_key_id key_id,
 250                                               void *target_container)
 251 {
 252         return ((char *)target_container) + flow_dissector->offset[key_id];
 253 }
 254
 255 #endif