root/include/net/flow_dissector.h

INCLUDED FROM

DEFINITIONS

1. flow_keys_have_l4
2. dissector_uses_key
3. skb_flow_dissector_target
4. flow_dissector_init_keys

   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 <linux/siphash.h>
   8 #include <linux/string.h>
   9 #include <uapi/linux/if_ether.h>
  10 
  11 /**
  12  * struct flow_dissector_key_control:
  13  * @thoff: Transport header offset
  14  */
  15 struct flow_dissector_key_control {
  16         u16     thoff;
  17         u16     addr_type;
  18         u32     flags;
  19 };
  20 
  21 #define FLOW_DIS_IS_FRAGMENT    BIT(0)
  22 #define FLOW_DIS_FIRST_FRAG     BIT(1)
  23 #define FLOW_DIS_ENCAPSULATION  BIT(2)
  24 
  25 enum flow_dissect_ret {
  26         FLOW_DISSECT_RET_OUT_GOOD,
  27         FLOW_DISSECT_RET_OUT_BAD,
  28         FLOW_DISSECT_RET_PROTO_AGAIN,
  29         FLOW_DISSECT_RET_IPPROTO_AGAIN,
  30         FLOW_DISSECT_RET_CONTINUE,
  31 };
  32 
  33 /**
  34  * struct flow_dissector_key_basic:
  35  * @thoff: Transport header offset
  36  * @n_proto: Network header protocol (eg. IPv4/IPv6)
  37  * @ip_proto: Transport header protocol (eg. TCP/UDP)
  38  */
  39 struct flow_dissector_key_basic {
  40         __be16  n_proto;
  41         u8      ip_proto;
  42         u8      padding;
  43 };
  44 
  45 struct flow_dissector_key_tags {
  46         u32     flow_label;
  47 };
  48 
  49 struct flow_dissector_key_vlan {
  50         u16     vlan_id:12,
  51                 vlan_dei:1,
  52                 vlan_priority:3;
  53         __be16  vlan_tpid;
  54 };
  55 
  56 struct flow_dissector_key_mpls {
  57         u32     mpls_ttl:8,
  58                 mpls_bos:1,
  59                 mpls_tc:3,
  60                 mpls_label:20;
  61 };
  62 
  63 #define FLOW_DIS_TUN_OPTS_MAX 255
  64 /**
  65  * struct flow_dissector_key_enc_opts:
  66  * @data: tunnel option data
  67  * @len: length of tunnel option data
  68  * @dst_opt_type: tunnel option type
  69  */
  70 struct flow_dissector_key_enc_opts {
  71         u8 data[FLOW_DIS_TUN_OPTS_MAX]; /* Using IP_TUNNEL_OPTS_MAX is desired
  72                                          * here but seems difficult to #include
  73                                          */
  74         u8 len;
  75         __be16 dst_opt_type;
  76 };
  77 
  78 struct flow_dissector_key_keyid {
  79         __be32  keyid;
  80 };
  81 
  82 /**
  83  * struct flow_dissector_key_ipv4_addrs:
  84  * @src: source ip address
  85  * @dst: destination ip address
  86  */
  87 struct flow_dissector_key_ipv4_addrs {
  88         /* (src,dst) must be grouped, in the same way than in IP header */
  89         __be32 src;
  90         __be32 dst;
  91 };
  92 
  93 /**
  94  * struct flow_dissector_key_ipv6_addrs:
  95  * @src: source ip address
  96  * @dst: destination ip address
  97  */
  98 struct flow_dissector_key_ipv6_addrs {
  99         /* (src,dst) must be grouped, in the same way than in IP header */
 100         struct in6_addr src;
 101         struct in6_addr dst;
 102 };
 103 
 104 /**
 105  * struct flow_dissector_key_tipc:
 106  * @key: source node address combined with selector
 107  */
 108 struct flow_dissector_key_tipc {
 109         __be32 key;
 110 };
 111 
 112 /**
 113  * struct flow_dissector_key_addrs:
 114  * @v4addrs: IPv4 addresses
 115  * @v6addrs: IPv6 addresses
 116  */
 117 struct flow_dissector_key_addrs {
 118         union {
 119                 struct flow_dissector_key_ipv4_addrs v4addrs;
 120                 struct flow_dissector_key_ipv6_addrs v6addrs;
 121                 struct flow_dissector_key_tipc tipckey;
 122         };
 123 };
 124 
 125 /**
 126  * flow_dissector_key_arp:
 127  *      @ports: Operation, source and target addresses for an ARP header
 128  *              for Ethernet hardware addresses and IPv4 protocol addresses
 129  *              sip: Sender IP address
 130  *              tip: Target IP address
 131  *              op:  Operation
 132  *              sha: Sender hardware address
 133  *              tpa: Target hardware address
 134  */
 135 struct flow_dissector_key_arp {
 136         __u32 sip;
 137         __u32 tip;
 138         __u8 op;
 139         unsigned char sha[ETH_ALEN];
 140         unsigned char tha[ETH_ALEN];
 141 };
 142 
 143 /**
 144  * flow_dissector_key_tp_ports:
 145  *      @ports: port numbers of Transport header
 146  *              src: source port number
 147  *              dst: destination port number
 148  */
 149 struct flow_dissector_key_ports {
 150         union {
 151                 __be32 ports;
 152                 struct {
 153                         __be16 src;
 154                         __be16 dst;
 155                 };
 156         };
 157 };
 158 
 159 /**
 160  * flow_dissector_key_icmp:
 161  *      @ports: type and code of ICMP header
 162  *              icmp: ICMP type (high) and code (low)
 163  *              type: ICMP type
 164  *              code: ICMP code
 165  */
 166 struct flow_dissector_key_icmp {
 167         union {
 168                 __be16 icmp;
 169                 struct {
 170                         u8 type;
 171                         u8 code;
 172                 };
 173         };
 174 };
 175 
 176 /**
 177  * struct flow_dissector_key_eth_addrs:
 178  * @src: source Ethernet address
 179  * @dst: destination Ethernet address
 180  */
 181 struct flow_dissector_key_eth_addrs {
 182         /* (dst,src) must be grouped, in the same way than in ETH header */
 183         unsigned char dst[ETH_ALEN];
 184         unsigned char src[ETH_ALEN];
 185 };
 186 
 187 /**
 188  * struct flow_dissector_key_tcp:
 189  * @flags: flags
 190  */
 191 struct flow_dissector_key_tcp {
 192         __be16 flags;
 193 };
 194 
 195 /**
 196  * struct flow_dissector_key_ip:
 197  * @tos: tos
 198  * @ttl: ttl
 199  */
 200 struct flow_dissector_key_ip {
 201         __u8    tos;
 202         __u8    ttl;
 203 };
 204 
 205 /**
 206  * struct flow_dissector_key_meta:
 207  * @ingress_ifindex: ingress ifindex
 208  */
 209 struct flow_dissector_key_meta {
 210         int ingress_ifindex;
 211 };
 212 
 213 /**
 214  * struct flow_dissector_key_ct:
 215  * @ct_state: conntrack state after converting with map
 216  * @ct_mark: conttrack mark
 217  * @ct_zone: conntrack zone
 218  * @ct_labels: conntrack labels
 219  */
 220 struct flow_dissector_key_ct {
 221         u16     ct_state;
 222         u16     ct_zone;
 223         u32     ct_mark;
 224         u32     ct_labels[4];
 225 };
 226 
 227 enum flow_dissector_key_id {
 228         FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
 229         FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
 230         FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
 231         FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 232         FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
 233         FLOW_DISSECTOR_KEY_PORTS_RANGE, /* struct flow_dissector_key_ports */
 234         FLOW_DISSECTOR_KEY_ICMP, /* struct flow_dissector_key_icmp */
 235         FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
 236         FLOW_DISSECTOR_KEY_TIPC, /* struct flow_dissector_key_tipc */
 237         FLOW_DISSECTOR_KEY_ARP, /* struct flow_dissector_key_arp */
 238         FLOW_DISSECTOR_KEY_VLAN, /* struct flow_dissector_key_vlan */
 239         FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_tags */
 240         FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */
 241         FLOW_DISSECTOR_KEY_MPLS_ENTROPY, /* struct flow_dissector_key_keyid */
 242         FLOW_DISSECTOR_KEY_ENC_KEYID, /* struct flow_dissector_key_keyid */
 243         FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
 244         FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 245         FLOW_DISSECTOR_KEY_ENC_CONTROL, /* struct flow_dissector_key_control */
 246         FLOW_DISSECTOR_KEY_ENC_PORTS, /* struct flow_dissector_key_ports */
 247         FLOW_DISSECTOR_KEY_MPLS, /* struct flow_dissector_key_mpls */
 248         FLOW_DISSECTOR_KEY_TCP, /* struct flow_dissector_key_tcp */
 249         FLOW_DISSECTOR_KEY_IP, /* struct flow_dissector_key_ip */
 250         FLOW_DISSECTOR_KEY_CVLAN, /* struct flow_dissector_key_vlan */
 251         FLOW_DISSECTOR_KEY_ENC_IP, /* struct flow_dissector_key_ip */
 252         FLOW_DISSECTOR_KEY_ENC_OPTS, /* struct flow_dissector_key_enc_opts */
 253         FLOW_DISSECTOR_KEY_META, /* struct flow_dissector_key_meta */
 254         FLOW_DISSECTOR_KEY_CT, /* struct flow_dissector_key_ct */
 255 
 256         FLOW_DISSECTOR_KEY_MAX,
 257 };
 258 
 259 #define FLOW_DISSECTOR_F_PARSE_1ST_FRAG         BIT(0)
 260 #define FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL     BIT(1)
 261 #define FLOW_DISSECTOR_F_STOP_AT_ENCAP          BIT(2)
 262 
 263 struct flow_dissector_key {
 264         enum flow_dissector_key_id key_id;
 265         size_t offset; /* offset of struct flow_dissector_key_*
 266                           in target the struct */
 267 };
 268 
 269 struct flow_dissector {
 270         unsigned int used_keys; /* each bit repesents presence of one key id */
 271         unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
 272 };
 273 
 274 struct flow_keys_basic {
 275         struct flow_dissector_key_control control;
 276         struct flow_dissector_key_basic basic;
 277 };
 278 
 279 struct flow_keys {
 280         struct flow_dissector_key_control control;
 281 #define FLOW_KEYS_HASH_START_FIELD basic
 282         struct flow_dissector_key_basic basic __aligned(SIPHASH_ALIGNMENT);
 283         struct flow_dissector_key_tags tags;
 284         struct flow_dissector_key_vlan vlan;
 285         struct flow_dissector_key_vlan cvlan;
 286         struct flow_dissector_key_keyid keyid;
 287         struct flow_dissector_key_ports ports;
 288         struct flow_dissector_key_addrs addrs;
 289 };
 290 
 291 #define FLOW_KEYS_HASH_OFFSET           \
 292         offsetof(struct flow_keys, FLOW_KEYS_HASH_START_FIELD)
 293 
 294 __be32 flow_get_u32_src(const struct flow_keys *flow);
 295 __be32 flow_get_u32_dst(const struct flow_keys *flow);
 296 
 297 extern struct flow_dissector flow_keys_dissector;
 298 extern struct flow_dissector flow_keys_basic_dissector;
 299 
 300 /* struct flow_keys_digest:
 301  *
 302  * This structure is used to hold a digest of the full flow keys. This is a
 303  * larger "hash" of a flow to allow definitively matching specific flows where
 304  * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
 305  * that it can be used in CB of skb (see sch_choke for an example).
 306  */
 307 #define FLOW_KEYS_DIGEST_LEN    16
 308 struct flow_keys_digest {
 309         u8      data[FLOW_KEYS_DIGEST_LEN];
 310 };
 311 
 312 void make_flow_keys_digest(struct flow_keys_digest *digest,
 313                            const struct flow_keys *flow);
 314 
 315 static inline bool flow_keys_have_l4(const struct flow_keys *keys)
 316 {
 317         return (keys->ports.ports || keys->tags.flow_label);
 318 }
 319 
 320 u32 flow_hash_from_keys(struct flow_keys *keys);
 321 
 322 static inline bool dissector_uses_key(const struct flow_dissector *flow_dissector,
 323                                       enum flow_dissector_key_id key_id)
 324 {
 325         return flow_dissector->used_keys & (1 << key_id);
 326 }
 327 
 328 static inline void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
 329                                               enum flow_dissector_key_id key_id,
 330                                               void *target_container)
 331 {
 332         return ((char *)target_container) + flow_dissector->offset[key_id];
 333 }
 334 
 335 struct bpf_flow_dissector {
 336         struct bpf_flow_keys    *flow_keys;
 337         const struct sk_buff    *skb;
 338         void                    *data;
 339         void                    *data_end;
 340 };
 341 
 342 static inline void
 343 flow_dissector_init_keys(struct flow_dissector_key_control *key_control,
 344                          struct flow_dissector_key_basic *key_basic)
 345 {
 346         memset(key_control, 0, sizeof(*key_control));
 347         memset(key_basic, 0, sizeof(*key_basic));
 348 }
 349 
 350 #endif