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 <linux/siphash.h>
   8 #include <linux/string.h>
   9 #include <uapi/linux/if_ether.h>
  10 #include <uapi/linux/pkt_cls.h>
  11
  12 struct bpf_prog;
  13 struct net;
  14 struct sk_buff;
  15
  16 /**
  17  * struct flow_dissector_key_control:
  18  * @thoff:     Transport header offset
  19  * @addr_type: Type of key. One of FLOW_DISSECTOR_KEY_*
  20  * @flags:     Key flags.
  21  *             Any of FLOW_DIS_(IS_FRAGMENT|FIRST_FRAG|ENCAPSULATION|F_*)
  22  */
  23 struct flow_dissector_key_control {
  24         u16     thoff;
  25         u16     addr_type;
  26         u32     flags;
  27 };
  28
  29 /* The control flags are kept in sync with TCA_FLOWER_KEY_FLAGS_*, as those
  30  * flags are exposed to userspace in some error paths, ie. unsupported flags.
  31  */
  32 enum flow_dissector_ctrl_flags {
  33         FLOW_DIS_IS_FRAGMENT            = TCA_FLOWER_KEY_FLAGS_IS_FRAGMENT,
  34         FLOW_DIS_FIRST_FRAG             = TCA_FLOWER_KEY_FLAGS_FRAG_IS_FIRST,
  35         FLOW_DIS_F_TUNNEL_CSUM          = TCA_FLOWER_KEY_FLAGS_TUNNEL_CSUM,
  36         FLOW_DIS_F_TUNNEL_DONT_FRAGMENT = TCA_FLOWER_KEY_FLAGS_TUNNEL_DONT_FRAGMENT,
  37         FLOW_DIS_F_TUNNEL_OAM           = TCA_FLOWER_KEY_FLAGS_TUNNEL_OAM,
  38         FLOW_DIS_F_TUNNEL_CRIT_OPT      = TCA_FLOWER_KEY_FLAGS_TUNNEL_CRIT_OPT,
  39
  40         /* These flags are internal to the kernel */
  41         FLOW_DIS_ENCAPSULATION          = (TCA_FLOWER_KEY_FLAGS_MAX << 1),
  42 };
  43
  44 enum flow_dissect_ret {
  45         FLOW_DISSECT_RET_OUT_GOOD,
  46         FLOW_DISSECT_RET_OUT_BAD,
  47         FLOW_DISSECT_RET_PROTO_AGAIN,
  48         FLOW_DISSECT_RET_IPPROTO_AGAIN,
  49         FLOW_DISSECT_RET_CONTINUE,
  50 };
  51
  52 /**
  53  * struct flow_dissector_key_basic:
  54  * @n_proto:  Network header protocol (eg. IPv4/IPv6)
  55  * @ip_proto: Transport header protocol (eg. TCP/UDP)
  56  * @padding:  Unused
  57  */
  58 struct flow_dissector_key_basic {
  59         __be16  n_proto;
  60         u8      ip_proto;
  61         u8      padding;
  62 };
  63
  64 struct flow_dissector_key_tags {
  65         u32     flow_label;
  66 };
  67
  68 struct flow_dissector_key_vlan {
  69         union {
  70                 struct {
  71                         u16     vlan_id:12,
  72                                 vlan_dei:1,
  73                                 vlan_priority:3;
  74                 };
  75                 __be16  vlan_tci;
  76         };
  77         __be16  vlan_tpid;
  78         __be16  vlan_eth_type;
  79         u16     padding;
  80 };
  81
  82 struct flow_dissector_mpls_lse {
  83         u32     mpls_ttl:8,
  84                 mpls_bos:1,
  85                 mpls_tc:3,
  86                 mpls_label:20;
  87 };
  88
  89 #define FLOW_DIS_MPLS_MAX 7
  90 struct flow_dissector_key_mpls {
  91         struct flow_dissector_mpls_lse ls[FLOW_DIS_MPLS_MAX]; /* Label Stack */
  92         u8 used_lses; /* One bit set for each Label Stack Entry in use */
  93 };
  94
  95 static inline void dissector_set_mpls_lse(struct flow_dissector_key_mpls *mpls,
  96                                           int lse_index)
  97 {
  98         mpls->used_lses |= 1 << lse_index;
  99 }
 100
 101 #define FLOW_DIS_TUN_OPTS_MAX 255
 102 /**
 103  * struct flow_dissector_key_enc_opts:
 104  * @data: tunnel option data
 105  * @len: length of tunnel option data
 106  * @dst_opt_type: tunnel option type
 107  */
 108 struct flow_dissector_key_enc_opts {
 109         u8 data[FLOW_DIS_TUN_OPTS_MAX]; /* Using IP_TUNNEL_OPTS_MAX is desired
 110                                          * here but seems difficult to #include
 111                                          */
 112         u8 len;
 113         u32 dst_opt_type;
 114 };
 115
 116 struct flow_dissector_key_keyid {
 117         __be32  keyid;
 118 };
 119
 120 /**
 121  * struct flow_dissector_key_ipv4_addrs:
 122  * @src: source ip address
 123  * @dst: destination ip address
 124  */
 125 struct flow_dissector_key_ipv4_addrs {
 126         /* (src,dst) must be grouped, in the same way than in IP header */
 127         __be32 src;
 128         __be32 dst;
 129 };
 130
 131 /**
 132  * struct flow_dissector_key_ipv6_addrs:
 133  * @src: source ip address
 134  * @dst: destination ip address
 135  */
 136 struct flow_dissector_key_ipv6_addrs {
 137         /* (src,dst) must be grouped, in the same way than in IP header */
 138         struct in6_addr src;
 139         struct in6_addr dst;
 140 };
 141
 142 /**
 143  * struct flow_dissector_key_tipc:
 144  * @key: source node address combined with selector
 145  */
 146 struct flow_dissector_key_tipc {
 147         __be32 key;
 148 };
 149
 150 /**
 151  * struct flow_dissector_key_addrs:
 152  * @v4addrs: IPv4 addresses
 153  * @v6addrs: IPv6 addresses
 154  * @tipckey: TIPC key
 155  */
 156 struct flow_dissector_key_addrs {
 157         union {
 158                 struct flow_dissector_key_ipv4_addrs v4addrs;
 159                 struct flow_dissector_key_ipv6_addrs v6addrs;
 160                 struct flow_dissector_key_tipc tipckey;
 161         };
 162 };
 163
 164 /**
 165  * struct flow_dissector_key_arp:
 166  * @sip: Sender IP address
 167  * @tip: Target IP address
 168  * @op:  Operation
 169  * @sha: Sender hardware address
 170  * @tha: Target hardware address
 171  */
 172 struct flow_dissector_key_arp {
 173         __u32 sip;
 174         __u32 tip;
 175         __u8 op;
 176         unsigned char sha[ETH_ALEN];
 177         unsigned char tha[ETH_ALEN];
 178 };
 179
 180 /**
 181  * struct flow_dissector_key_ports:
 182  * @ports: port numbers of Transport header
 183  * @src: source port number
 184  * @dst: destination port number
 185  */
 186 struct flow_dissector_key_ports {
 187         union {
 188                 __be32 ports;
 189                 struct {
 190                         __be16 src;
 191                         __be16 dst;
 192                 };
 193         };
 194 };
 195
 196 /**
 197  * struct flow_dissector_key_ports_range
 198  * @tp: port number from packet
 199  * @tp_min: min port number in range
 200  * @tp_max: max port number in range
 201  */
 202 struct flow_dissector_key_ports_range {
 203         union {
 204                 struct flow_dissector_key_ports tp;
 205                 struct {
 206                         struct flow_dissector_key_ports tp_min;
 207                         struct flow_dissector_key_ports tp_max;
 208                 };
 209         };
 210 };
 211
 212 /**
 213  * struct flow_dissector_key_icmp:
 214  * @type: ICMP type
 215  * @code: ICMP code
 216  * @id:   Session identifier
 217  */
 218 struct flow_dissector_key_icmp {
 219         struct {
 220                 u8 type;
 221                 u8 code;
 222         };
 223         u16 id;
 224 };
 225
 226 /**
 227  * struct flow_dissector_key_eth_addrs:
 228  * @src: source Ethernet address
 229  * @dst: destination Ethernet address
 230  */
 231 struct flow_dissector_key_eth_addrs {
 232         /* (dst,src) must be grouped, in the same way than in ETH header */
 233         unsigned char dst[ETH_ALEN];
 234         unsigned char src[ETH_ALEN];
 235 };
 236
 237 /**
 238  * struct flow_dissector_key_tcp:
 239  * @flags: flags
 240  */
 241 struct flow_dissector_key_tcp {
 242         __be16 flags;
 243 };
 244
 245 /**
 246  * struct flow_dissector_key_ip:
 247  * @tos: tos
 248  * @ttl: ttl
 249  */
 250 struct flow_dissector_key_ip {
 251         __u8    tos;
 252         __u8    ttl;
 253 };
 254
 255 /**
 256  * struct flow_dissector_key_meta:
 257  * @ingress_ifindex: ingress ifindex
 258  * @ingress_iftype: ingress interface type
 259  * @l2_miss: packet did not match an L2 entry during forwarding
 260  */
 261 struct flow_dissector_key_meta {
 262         int ingress_ifindex;
 263         u16 ingress_iftype;
 264         u8 l2_miss;
 265 };
 266
 267 /**
 268  * struct flow_dissector_key_ct:
 269  * @ct_state: conntrack state after converting with map
 270  * @ct_mark: conttrack mark
 271  * @ct_zone: conntrack zone
 272  * @ct_labels: conntrack labels
 273  */
 274 struct flow_dissector_key_ct {
 275         u16     ct_state;
 276         u16     ct_zone;
 277         u32     ct_mark;
 278         u32     ct_labels[4];
 279 };
 280
 281 /**
 282  * struct flow_dissector_key_hash:
 283  * @hash: hash value
 284  */
 285 struct flow_dissector_key_hash {
 286         u32 hash;
 287 };
 288
 289 /**
 290  * struct flow_dissector_key_num_of_vlans:
 291  * @num_of_vlans: num_of_vlans value
 292  */
 293 struct flow_dissector_key_num_of_vlans {
 294         u8 num_of_vlans;
 295 };
 296
 297 /**
 298  * struct flow_dissector_key_pppoe:
 299  * @session_id: pppoe session id
 300  * @ppp_proto: ppp protocol
 301  * @type: pppoe eth type
 302  */
 303 struct flow_dissector_key_pppoe {
 304         __be16 session_id;
 305         __be16 ppp_proto;
 306         __be16 type;
 307 };
 308
 309 /**
 310  * struct flow_dissector_key_l2tpv3:
 311  * @session_id: identifier for a l2tp session
 312  */
 313 struct flow_dissector_key_l2tpv3 {
 314         __be32 session_id;
 315 };
 316
 317 /**
 318  * struct flow_dissector_key_ipsec:
 319  * @spi: identifier for a ipsec connection
 320  */
 321 struct flow_dissector_key_ipsec {
 322         __be32 spi;
 323 };
 324
 325 /**
 326  * struct flow_dissector_key_cfm
 327  * @mdl_ver: maintenance domain level (mdl) and cfm protocol version
 328  * @opcode: code specifying a type of cfm protocol packet
 329  *
 330  * See 802.1ag, ITU-T G.8013/Y.1731
 331  *         1               2
 332  * |7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|
 333  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 334  * | mdl | version |     opcode    |
 335  * +-----+---------+-+-+-+-+-+-+-+-+
 336  */
 337 struct flow_dissector_key_cfm {
 338         u8      mdl_ver;
 339         u8      opcode;
 340 };
 341
 342 #define FLOW_DIS_CFM_MDL_MASK GENMASK(7, 5)
 343 #define FLOW_DIS_CFM_MDL_MAX 7
 344
 345 enum flow_dissector_key_id {
 346         FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
 347         FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
 348         FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
 349         FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 350         FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
 351         FLOW_DISSECTOR_KEY_PORTS_RANGE, /* struct flow_dissector_key_ports */
 352         FLOW_DISSECTOR_KEY_ICMP, /* struct flow_dissector_key_icmp */
 353         FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
 354         FLOW_DISSECTOR_KEY_TIPC, /* struct flow_dissector_key_tipc */
 355         FLOW_DISSECTOR_KEY_ARP, /* struct flow_dissector_key_arp */
 356         FLOW_DISSECTOR_KEY_VLAN, /* struct flow_dissector_key_vlan */
 357         FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_tags */
 358         FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */
 359         FLOW_DISSECTOR_KEY_MPLS_ENTROPY, /* struct flow_dissector_key_keyid */
 360         FLOW_DISSECTOR_KEY_ENC_KEYID, /* struct flow_dissector_key_keyid */
 361         FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
 362         FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 363         FLOW_DISSECTOR_KEY_ENC_CONTROL, /* struct flow_dissector_key_control */
 364         FLOW_DISSECTOR_KEY_ENC_PORTS, /* struct flow_dissector_key_ports */
 365         FLOW_DISSECTOR_KEY_MPLS, /* struct flow_dissector_key_mpls */
 366         FLOW_DISSECTOR_KEY_TCP, /* struct flow_dissector_key_tcp */
 367         FLOW_DISSECTOR_KEY_IP, /* struct flow_dissector_key_ip */
 368         FLOW_DISSECTOR_KEY_CVLAN, /* struct flow_dissector_key_vlan */
 369         FLOW_DISSECTOR_KEY_ENC_IP, /* struct flow_dissector_key_ip */
 370         FLOW_DISSECTOR_KEY_ENC_OPTS, /* struct flow_dissector_key_enc_opts */
 371         FLOW_DISSECTOR_KEY_META, /* struct flow_dissector_key_meta */
 372         FLOW_DISSECTOR_KEY_CT, /* struct flow_dissector_key_ct */
 373         FLOW_DISSECTOR_KEY_HASH, /* struct flow_dissector_key_hash */
 374         FLOW_DISSECTOR_KEY_NUM_OF_VLANS, /* struct flow_dissector_key_num_of_vlans */
 375         FLOW_DISSECTOR_KEY_PPPOE, /* struct flow_dissector_key_pppoe */
 376         FLOW_DISSECTOR_KEY_L2TPV3, /* struct flow_dissector_key_l2tpv3 */
 377         FLOW_DISSECTOR_KEY_CFM, /* struct flow_dissector_key_cfm */
 378         FLOW_DISSECTOR_KEY_IPSEC, /* struct flow_dissector_key_ipsec */
 379
 380         FLOW_DISSECTOR_KEY_MAX,
 381 };
 382
 383 #define FLOW_DISSECTOR_F_PARSE_1ST_FRAG         BIT(0)
 384 #define FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL     BIT(1)
 385 #define FLOW_DISSECTOR_F_STOP_AT_ENCAP          BIT(2)
 386 #define FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP      BIT(3)
 387
 388 struct flow_dissector_key {
 389         enum flow_dissector_key_id key_id;
 390         size_t offset; /* offset of struct flow_dissector_key_*
 391                           in target the struct */
 392 };
 393
 394 struct flow_dissector {
 395         unsigned long long  used_keys;
 396                 /* each bit represents presence of one key id */
 397         unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
 398 };
 399
 400 struct flow_keys_basic {
 401         struct flow_dissector_key_control control;
 402         struct flow_dissector_key_basic basic;
 403 };
 404
 405 struct flow_keys {
 406         struct flow_dissector_key_control control;
 407 #define FLOW_KEYS_HASH_START_FIELD basic
 408         struct flow_dissector_key_basic basic __aligned(SIPHASH_ALIGNMENT);
 409         struct flow_dissector_key_tags tags;
 410         struct flow_dissector_key_vlan vlan;
 411         struct flow_dissector_key_vlan cvlan;
 412         struct flow_dissector_key_keyid keyid;
 413         struct flow_dissector_key_ports ports;
 414         struct flow_dissector_key_icmp icmp;
 415         /* 'addrs' must be the last member */
 416         struct flow_dissector_key_addrs addrs;
 417 };
 418
 419 #define FLOW_KEYS_HASH_OFFSET           \
 420         offsetof(struct flow_keys, FLOW_KEYS_HASH_START_FIELD)
 421
 422 __be32 flow_get_u32_src(const struct flow_keys *flow);
 423 __be32 flow_get_u32_dst(const struct flow_keys *flow);
 424
 425 extern struct flow_dissector flow_keys_dissector;
 426 extern struct flow_dissector flow_keys_basic_dissector;
 427
 428 /* struct flow_keys_digest:
 429  *
 430  * This structure is used to hold a digest of the full flow keys. This is a
 431  * larger "hash" of a flow to allow definitively matching specific flows where
 432  * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
 433  * that it can be used in CB of skb (see sch_choke for an example).
 434  */
 435 #define FLOW_KEYS_DIGEST_LEN    16
 436 struct flow_keys_digest {
 437         u8      data[FLOW_KEYS_DIGEST_LEN];
 438 };
 439
 440 void make_flow_keys_digest(struct flow_keys_digest *digest,
 441                            const struct flow_keys *flow);
 442
 443 static inline bool flow_keys_have_l4(const struct flow_keys *keys)
 444 {
 445         return (keys->ports.ports || keys->tags.flow_label);
 446 }
 447
 448 u32 flow_hash_from_keys(struct flow_keys *keys);
 449 u32 flow_hash_from_keys_seed(struct flow_keys *keys,
 450                              const siphash_key_t *keyval);
 451 void skb_flow_get_icmp_tci(const struct sk_buff *skb,
 452                            struct flow_dissector_key_icmp *key_icmp,
 453                            const void *data, int thoff, int hlen);
 454
 455 static inline bool dissector_uses_key(const struct flow_dissector *flow_dissector,
 456                                       enum flow_dissector_key_id key_id)
 457 {
 458         return flow_dissector->used_keys & (1ULL << key_id);
 459 }
 460
 461 static inline void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
 462                                               enum flow_dissector_key_id key_id,
 463                                               void *target_container)
 464 {
 465         return ((char *)target_container) + flow_dissector->offset[key_id];
 466 }
 467
 468 struct bpf_flow_dissector {
 469         struct bpf_flow_keys    *flow_keys;
 470         const struct sk_buff    *skb;
 471         const void              *data;
 472         const void              *data_end;
 473 };
 474
 475 static inline void
 476 flow_dissector_init_keys(struct flow_dissector_key_control *key_control,
 477                          struct flow_dissector_key_basic *key_basic)
 478 {
 479         memset(key_control, 0, sizeof(*key_control));
 480         memset(key_basic, 0, sizeof(*key_basic));
 481 }
 482
 483 #ifdef CONFIG_BPF_SYSCALL
 484 int flow_dissector_bpf_prog_attach_check(struct net *net,
 485                                          struct bpf_prog *prog);
 486 #endif /* CONFIG_BPF_SYSCALL */
 487
 488 #endif