include/net/flow_dissector.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _NET_FLOW_DISSECTOR_H
   3 #define _NET_FLOW_DISSECTOR_H
   4
   5 #include <linux/types.h>
   6 #include <linux/in6.h>
   7 #include <uapi/linux/if_ether.h>
   8
   9 /**
  10  * struct flow_dissector_key_control:
  11  * @thoff: Transport header offset
  12  */
  13 struct flow_dissector_key_control {
  14         u16     thoff;
  15         u16     addr_type;
  16         u32     flags;
  17 };
  18
  19 #define FLOW_DIS_IS_FRAGMENT    BIT(0)
  20 #define FLOW_DIS_FIRST_FRAG     BIT(1)
  21 #define FLOW_DIS_ENCAPSULATION  BIT(2)
  22
  23 enum flow_dissect_ret {
  24         FLOW_DISSECT_RET_OUT_GOOD,
  25         FLOW_DISSECT_RET_OUT_BAD,
  26         FLOW_DISSECT_RET_PROTO_AGAIN,
  27         FLOW_DISSECT_RET_IPPROTO_AGAIN,
  28         FLOW_DISSECT_RET_CONTINUE,
  29 };
  30
  31 /**
  32  * struct flow_dissector_key_basic:
  33  * @thoff: Transport header offset
  34  * @n_proto: Network header protocol (eg. IPv4/IPv6)
  35  * @ip_proto: Transport header protocol (eg. TCP/UDP)
  36  */
  37 struct flow_dissector_key_basic {
  38         __be16  n_proto;
  39         u8      ip_proto;
  40         u8      padding;
  41 };
  42
  43 struct flow_dissector_key_tags {
  44         u32     flow_label;
  45 };
  46
  47 struct flow_dissector_key_vlan {
  48         u16     vlan_id:12,
  49                 vlan_priority:3;
  50         __be16  vlan_tpid;
  51 };
  52
  53 struct flow_dissector_key_mpls {
  54         u32     mpls_ttl:8,
  55                 mpls_bos:1,
  56                 mpls_tc:3,
  57                 mpls_label:20;
  58 };
  59
  60 #define FLOW_DIS_TUN_OPTS_MAX 255
  61 /**
  62  * struct flow_dissector_key_enc_opts:
  63  * @data: tunnel option data
  64  * @len: length of tunnel option data
  65  * @dst_opt_type: tunnel option type
  66  */
  67 struct flow_dissector_key_enc_opts {
  68         u8 data[FLOW_DIS_TUN_OPTS_MAX]; /* Using IP_TUNNEL_OPTS_MAX is desired
  69                                          * here but seems difficult to #include
  70                                          */
  71         u8 len;
  72         __be16 dst_opt_type;
  73 };
  74
  75 struct flow_dissector_key_keyid {
  76         __be32  keyid;
  77 };
  78
  79 /**
  80  * struct flow_dissector_key_ipv4_addrs:
  81  * @src: source ip address
  82  * @dst: destination ip address
  83  */
  84 struct flow_dissector_key_ipv4_addrs {
  85         /* (src,dst) must be grouped, in the same way than in IP header */
  86         __be32 src;
  87         __be32 dst;
  88 };
  89
  90 /**
  91  * struct flow_dissector_key_ipv6_addrs:
  92  * @src: source ip address
  93  * @dst: destination ip address
  94  */
  95 struct flow_dissector_key_ipv6_addrs {
  96         /* (src,dst) must be grouped, in the same way than in IP header */
  97         struct in6_addr src;
  98         struct in6_addr dst;
  99 };
 100
 101 /**
 102  * struct flow_dissector_key_tipc:
 103  * @key: source node address combined with selector
 104  */
 105 struct flow_dissector_key_tipc {
 106         __be32 key;
 107 };
 108
 109 /**
 110  * struct flow_dissector_key_addrs:
 111  * @v4addrs: IPv4 addresses
 112  * @v6addrs: IPv6 addresses
 113  */
 114 struct flow_dissector_key_addrs {
 115         union {
 116                 struct flow_dissector_key_ipv4_addrs v4addrs;
 117                 struct flow_dissector_key_ipv6_addrs v6addrs;
 118                 struct flow_dissector_key_tipc tipckey;
 119         };
 120 };
 121
 122 /**
 123  * flow_dissector_key_arp:
 124  *      @ports: Operation, source and target addresses for an ARP header
 125  *              for Ethernet hardware addresses and IPv4 protocol addresses
 126  *              sip: Sender IP address
 127  *              tip: Target IP address
 128  *              op:  Operation
 129  *              sha: Sender hardware address
 130  *              tpa: Target hardware address
 131  */
 132 struct flow_dissector_key_arp {
 133         __u32 sip;
 134         __u32 tip;
 135         __u8 op;
 136         unsigned char sha[ETH_ALEN];
 137         unsigned char tha[ETH_ALEN];
 138 };
 139
 140 /**
 141  * flow_dissector_key_tp_ports:
 142  *      @ports: port numbers of Transport header
 143  *              src: source port number
 144  *              dst: destination port number
 145  */
 146 struct flow_dissector_key_ports {
 147         union {
 148                 __be32 ports;
 149                 struct {
 150                         __be16 src;
 151                         __be16 dst;
 152                 };
 153         };
 154 };
 155
 156 /**
 157  * flow_dissector_key_icmp:
 158  *      @ports: type and code of ICMP header
 159  *              icmp: ICMP type (high) and code (low)
 160  *              type: ICMP type
 161  *              code: ICMP code
 162  */
 163 struct flow_dissector_key_icmp {
 164         union {
 165                 __be16 icmp;
 166                 struct {
 167                         u8 type;
 168                         u8 code;
 169                 };
 170         };
 171 };
 172
 173 /**
 174  * struct flow_dissector_key_eth_addrs:
 175  * @src: source Ethernet address
 176  * @dst: destination Ethernet address
 177  */
 178 struct flow_dissector_key_eth_addrs {
 179         /* (dst,src) must be grouped, in the same way than in ETH header */
 180         unsigned char dst[ETH_ALEN];
 181         unsigned char src[ETH_ALEN];
 182 };
 183
 184 /**
 185  * struct flow_dissector_key_tcp:
 186  * @flags: flags
 187  */
 188 struct flow_dissector_key_tcp {
 189         __be16 flags;
 190 };
 191
 192 /**
 193  * struct flow_dissector_key_ip:
 194  * @tos: tos
 195  * @ttl: ttl
 196  */
 197 struct flow_dissector_key_ip {
 198         __u8    tos;
 199         __u8    ttl;
 200 };
 201
 202 enum flow_dissector_key_id {
 203         FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
 204         FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
 205         FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
 206         FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 207         FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
 208         FLOW_DISSECTOR_KEY_ICMP, /* struct flow_dissector_key_icmp */
 209         FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
 210         FLOW_DISSECTOR_KEY_TIPC, /* struct flow_dissector_key_tipc */
 211         FLOW_DISSECTOR_KEY_ARP, /* struct flow_dissector_key_arp */
 212         FLOW_DISSECTOR_KEY_VLAN, /* struct flow_dissector_key_flow_vlan */
 213         FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_flow_tags */
 214         FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */
 215         FLOW_DISSECTOR_KEY_MPLS_ENTROPY, /* struct flow_dissector_key_keyid */
 216         FLOW_DISSECTOR_KEY_ENC_KEYID, /* struct flow_dissector_key_keyid */
 217         FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
 218         FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 219         FLOW_DISSECTOR_KEY_ENC_CONTROL, /* struct flow_dissector_key_control */
 220         FLOW_DISSECTOR_KEY_ENC_PORTS, /* struct flow_dissector_key_ports */
 221         FLOW_DISSECTOR_KEY_MPLS, /* struct flow_dissector_key_mpls */
 222         FLOW_DISSECTOR_KEY_TCP, /* struct flow_dissector_key_tcp */
 223         FLOW_DISSECTOR_KEY_IP, /* struct flow_dissector_key_ip */
 224         FLOW_DISSECTOR_KEY_CVLAN, /* struct flow_dissector_key_flow_vlan */
 225         FLOW_DISSECTOR_KEY_ENC_IP, /* struct flow_dissector_key_ip */
 226         FLOW_DISSECTOR_KEY_ENC_OPTS, /* struct flow_dissector_key_enc_opts */
 227
 228         FLOW_DISSECTOR_KEY_MAX,
 229 };
 230
 231 #define FLOW_DISSECTOR_F_PARSE_1ST_FRAG         BIT(0)
 232 #define FLOW_DISSECTOR_F_STOP_AT_L3             BIT(1)
 233 #define FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL     BIT(2)
 234 #define FLOW_DISSECTOR_F_STOP_AT_ENCAP          BIT(3)
 235
 236 struct flow_dissector_key {
 237         enum flow_dissector_key_id key_id;
 238         size_t offset; /* offset of struct flow_dissector_key_*
 239                           in target the struct */
 240 };
 241
 242 struct flow_dissector {
 243         unsigned int used_keys; /* each bit repesents presence of one key id */
 244         unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
 245 };
 246
 247 struct flow_keys_basic {
 248         struct flow_dissector_key_control control;
 249         struct flow_dissector_key_basic basic;
 250 };
 251
 252 struct flow_keys {
 253         struct flow_dissector_key_control control;
 254 #define FLOW_KEYS_HASH_START_FIELD basic
 255         struct flow_dissector_key_basic basic;
 256         struct flow_dissector_key_tags tags;
 257         struct flow_dissector_key_vlan vlan;
 258         struct flow_dissector_key_vlan cvlan;
 259         struct flow_dissector_key_keyid keyid;
 260         struct flow_dissector_key_ports ports;
 261         struct flow_dissector_key_addrs addrs;
 262 };
 263
 264 #define FLOW_KEYS_HASH_OFFSET           \
 265         offsetof(struct flow_keys, FLOW_KEYS_HASH_START_FIELD)
 266
 267 __be32 flow_get_u32_src(const struct flow_keys *flow);
 268 __be32 flow_get_u32_dst(const struct flow_keys *flow);
 269
 270 extern struct flow_dissector flow_keys_dissector;
 271 extern struct flow_dissector flow_keys_basic_dissector;
 272
 273 /* struct flow_keys_digest:
 274  *
 275  * This structure is used to hold a digest of the full flow keys. This is a
 276  * larger "hash" of a flow to allow definitively matching specific flows where
 277  * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
 278  * that it can be used in CB of skb (see sch_choke for an example).
 279  */
 280 #define FLOW_KEYS_DIGEST_LEN    16
 281 struct flow_keys_digest {
 282         u8      data[FLOW_KEYS_DIGEST_LEN];
 283 };
 284
 285 void make_flow_keys_digest(struct flow_keys_digest *digest,
 286                            const struct flow_keys *flow);
 287
 288 static inline bool flow_keys_have_l4(const struct flow_keys *keys)
 289 {
 290         return (keys->ports.ports || keys->tags.flow_label);
 291 }
 292
 293 u32 flow_hash_from_keys(struct flow_keys *keys);
 294
 295 static inline bool dissector_uses_key(const struct flow_dissector *flow_dissector,
 296                                       enum flow_dissector_key_id key_id)
 297 {
 298         return flow_dissector->used_keys & (1 << key_id);
 299 }
 300
 301 static inline void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
 302                                               enum flow_dissector_key_id key_id,
 303                                               void *target_container)
 304 {
 305         return ((char *)target_container) + flow_dissector->offset[key_id];
 306 }
 307
 308 #endif