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
  11 struct bpf_prog;
  12 struct net;
  13 struct sk_buff;
  14
  15 /**
  16  * struct flow_dissector_key_control:
  17  * @thoff: Transport header offset
  18  */
  19 struct flow_dissector_key_control {
  20         u16     thoff;
  21         u16     addr_type;
  22         u32     flags;
  23 };
  24
  25 #define FLOW_DIS_IS_FRAGMENT    BIT(0)
  26 #define FLOW_DIS_FIRST_FRAG     BIT(1)
  27 #define FLOW_DIS_ENCAPSULATION  BIT(2)
  28
  29 enum flow_dissect_ret {
  30         FLOW_DISSECT_RET_OUT_GOOD,
  31         FLOW_DISSECT_RET_OUT_BAD,
  32         FLOW_DISSECT_RET_PROTO_AGAIN,
  33         FLOW_DISSECT_RET_IPPROTO_AGAIN,
  34         FLOW_DISSECT_RET_CONTINUE,
  35 };
  36
  37 /**
  38  * struct flow_dissector_key_basic:
  39  * @n_proto: Network header protocol (eg. IPv4/IPv6)
  40  * @ip_proto: Transport header protocol (eg. TCP/UDP)
  41  */
  42 struct flow_dissector_key_basic {
  43         __be16  n_proto;
  44         u8      ip_proto;
  45         u8      padding;
  46 };
  47
  48 struct flow_dissector_key_tags {
  49         u32     flow_label;
  50 };
  51
  52 struct flow_dissector_key_vlan {
  53         union {
  54                 struct {
  55                         u16     vlan_id:12,
  56                                 vlan_dei:1,
  57                                 vlan_priority:3;
  58                 };
  59                 __be16  vlan_tci;
  60         };
  61         __be16  vlan_tpid;
  62 };
  63
  64 struct flow_dissector_mpls_lse {
  65         u32     mpls_ttl:8,
  66                 mpls_bos:1,
  67                 mpls_tc:3,
  68                 mpls_label:20;
  69 };
  70
  71 #define FLOW_DIS_MPLS_MAX 7
  72 struct flow_dissector_key_mpls {
  73         struct flow_dissector_mpls_lse ls[FLOW_DIS_MPLS_MAX]; /* Label Stack */
  74         u8 used_lses; /* One bit set for each Label Stack Entry in use */
  75 };
  76
  77 static inline void dissector_set_mpls_lse(struct flow_dissector_key_mpls *mpls,
  78                                           int lse_index)
  79 {
  80         mpls->used_lses |= 1 << lse_index;
  81 }
  82
  83 #define FLOW_DIS_TUN_OPTS_MAX 255
  84 /**
  85  * struct flow_dissector_key_enc_opts:
  86  * @data: tunnel option data
  87  * @len: length of tunnel option data
  88  * @dst_opt_type: tunnel option type
  89  */
  90 struct flow_dissector_key_enc_opts {
  91         u8 data[FLOW_DIS_TUN_OPTS_MAX]; /* Using IP_TUNNEL_OPTS_MAX is desired
  92                                          * here but seems difficult to #include
  93                                          */
  94         u8 len;
  95         __be16 dst_opt_type;
  96 };
  97
  98 struct flow_dissector_key_keyid {
  99         __be32  keyid;
 100 };
 101
 102 /**
 103  * struct flow_dissector_key_ipv4_addrs:
 104  * @src: source ip address
 105  * @dst: destination ip address
 106  */
 107 struct flow_dissector_key_ipv4_addrs {
 108         /* (src,dst) must be grouped, in the same way than in IP header */
 109         __be32 src;
 110         __be32 dst;
 111 };
 112
 113 /**
 114  * struct flow_dissector_key_ipv6_addrs:
 115  * @src: source ip address
 116  * @dst: destination ip address
 117  */
 118 struct flow_dissector_key_ipv6_addrs {
 119         /* (src,dst) must be grouped, in the same way than in IP header */
 120         struct in6_addr src;
 121         struct in6_addr dst;
 122 };
 123
 124 /**
 125  * struct flow_dissector_key_tipc:
 126  * @key: source node address combined with selector
 127  */
 128 struct flow_dissector_key_tipc {
 129         __be32 key;
 130 };
 131
 132 /**
 133  * struct flow_dissector_key_addrs:
 134  * @v4addrs: IPv4 addresses
 135  * @v6addrs: IPv6 addresses
 136  */
 137 struct flow_dissector_key_addrs {
 138         union {
 139                 struct flow_dissector_key_ipv4_addrs v4addrs;
 140                 struct flow_dissector_key_ipv6_addrs v6addrs;
 141                 struct flow_dissector_key_tipc tipckey;
 142         };
 143 };
 144
 145 /**
 146  * flow_dissector_key_arp:
 147  *      @ports: Operation, source and target addresses for an ARP header
 148  *              for Ethernet hardware addresses and IPv4 protocol addresses
 149  *              sip: Sender IP address
 150  *              tip: Target IP address
 151  *              op:  Operation
 152  *              sha: Sender hardware address
 153  *              tpa: Target hardware address
 154  */
 155 struct flow_dissector_key_arp {
 156         __u32 sip;
 157         __u32 tip;
 158         __u8 op;
 159         unsigned char sha[ETH_ALEN];
 160         unsigned char tha[ETH_ALEN];
 161 };
 162
 163 /**
 164  * flow_dissector_key_tp_ports:
 165  *      @ports: port numbers of Transport header
 166  *              src: source port number
 167  *              dst: destination port number
 168  */
 169 struct flow_dissector_key_ports {
 170         union {
 171                 __be32 ports;
 172                 struct {
 173                         __be16 src;
 174                         __be16 dst;
 175                 };
 176         };
 177 };
 178
 179 /**
 180  * flow_dissector_key_icmp:
 181  *              type: ICMP type
 182  *              code: ICMP code
 183  *              id:   session identifier
 184  */
 185 struct flow_dissector_key_icmp {
 186         struct {
 187                 u8 type;
 188                 u8 code;
 189         };
 190         u16 id;
 191 };
 192
 193 /**
 194  * struct flow_dissector_key_eth_addrs:
 195  * @src: source Ethernet address
 196  * @dst: destination Ethernet address
 197  */
 198 struct flow_dissector_key_eth_addrs {
 199         /* (dst,src) must be grouped, in the same way than in ETH header */
 200         unsigned char dst[ETH_ALEN];
 201         unsigned char src[ETH_ALEN];
 202 };
 203
 204 /**
 205  * struct flow_dissector_key_tcp:
 206  * @flags: flags
 207  */
 208 struct flow_dissector_key_tcp {
 209         __be16 flags;
 210 };
 211
 212 /**
 213  * struct flow_dissector_key_ip:
 214  * @tos: tos
 215  * @ttl: ttl
 216  */
 217 struct flow_dissector_key_ip {
 218         __u8    tos;
 219         __u8    ttl;
 220 };
 221
 222 /**
 223  * struct flow_dissector_key_meta:
 224  * @ingress_ifindex: ingress ifindex
 225  * @ingress_iftype: ingress interface type
 226  */
 227 struct flow_dissector_key_meta {
 228         int ingress_ifindex;
 229         u16 ingress_iftype;
 230 };
 231
 232 /**
 233  * struct flow_dissector_key_ct:
 234  * @ct_state: conntrack state after converting with map
 235  * @ct_mark: conttrack mark
 236  * @ct_zone: conntrack zone
 237  * @ct_labels: conntrack labels
 238  */
 239 struct flow_dissector_key_ct {
 240         u16     ct_state;
 241         u16     ct_zone;
 242         u32     ct_mark;
 243         u32     ct_labels[4];
 244 };
 245
 246 enum flow_dissector_key_id {
 247         FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
 248         FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
 249         FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
 250         FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 251         FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
 252         FLOW_DISSECTOR_KEY_PORTS_RANGE, /* struct flow_dissector_key_ports */
 253         FLOW_DISSECTOR_KEY_ICMP, /* struct flow_dissector_key_icmp */
 254         FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
 255         FLOW_DISSECTOR_KEY_TIPC, /* struct flow_dissector_key_tipc */
 256         FLOW_DISSECTOR_KEY_ARP, /* struct flow_dissector_key_arp */
 257         FLOW_DISSECTOR_KEY_VLAN, /* struct flow_dissector_key_vlan */
 258         FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_tags */
 259         FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */
 260         FLOW_DISSECTOR_KEY_MPLS_ENTROPY, /* struct flow_dissector_key_keyid */
 261         FLOW_DISSECTOR_KEY_ENC_KEYID, /* struct flow_dissector_key_keyid */
 262         FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
 263         FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 264         FLOW_DISSECTOR_KEY_ENC_CONTROL, /* struct flow_dissector_key_control */
 265         FLOW_DISSECTOR_KEY_ENC_PORTS, /* struct flow_dissector_key_ports */
 266         FLOW_DISSECTOR_KEY_MPLS, /* struct flow_dissector_key_mpls */
 267         FLOW_DISSECTOR_KEY_TCP, /* struct flow_dissector_key_tcp */
 268         FLOW_DISSECTOR_KEY_IP, /* struct flow_dissector_key_ip */
 269         FLOW_DISSECTOR_KEY_CVLAN, /* struct flow_dissector_key_vlan */
 270         FLOW_DISSECTOR_KEY_ENC_IP, /* struct flow_dissector_key_ip */
 271         FLOW_DISSECTOR_KEY_ENC_OPTS, /* struct flow_dissector_key_enc_opts */
 272         FLOW_DISSECTOR_KEY_META, /* struct flow_dissector_key_meta */
 273         FLOW_DISSECTOR_KEY_CT, /* struct flow_dissector_key_ct */
 274
 275         FLOW_DISSECTOR_KEY_MAX,
 276 };
 277
 278 #define FLOW_DISSECTOR_F_PARSE_1ST_FRAG         BIT(0)
 279 #define FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL     BIT(1)
 280 #define FLOW_DISSECTOR_F_STOP_AT_ENCAP          BIT(2)
 281
 282 struct flow_dissector_key {
 283         enum flow_dissector_key_id key_id;
 284         size_t offset; /* offset of struct flow_dissector_key_*
 285                           in target the struct */
 286 };
 287
 288 struct flow_dissector {
 289         unsigned int used_keys; /* each bit repesents presence of one key id */
 290         unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
 291 };
 292
 293 struct flow_keys_basic {
 294         struct flow_dissector_key_control control;
 295         struct flow_dissector_key_basic basic;
 296 };
 297
 298 struct flow_keys {
 299         struct flow_dissector_key_control control;
 300 #define FLOW_KEYS_HASH_START_FIELD basic
 301         struct flow_dissector_key_basic basic __aligned(SIPHASH_ALIGNMENT);
 302         struct flow_dissector_key_tags tags;
 303         struct flow_dissector_key_vlan vlan;
 304         struct flow_dissector_key_vlan cvlan;
 305         struct flow_dissector_key_keyid keyid;
 306         struct flow_dissector_key_ports ports;
 307         struct flow_dissector_key_icmp icmp;
 308         /* 'addrs' must be the last member */
 309         struct flow_dissector_key_addrs addrs;
 310 };
 311
 312 #define FLOW_KEYS_HASH_OFFSET           \
 313         offsetof(struct flow_keys, FLOW_KEYS_HASH_START_FIELD)
 314
 315 __be32 flow_get_u32_src(const struct flow_keys *flow);
 316 __be32 flow_get_u32_dst(const struct flow_keys *flow);
 317
 318 extern struct flow_dissector flow_keys_dissector;
 319 extern struct flow_dissector flow_keys_basic_dissector;
 320
 321 /* struct flow_keys_digest:
 322  *
 323  * This structure is used to hold a digest of the full flow keys. This is a
 324  * larger "hash" of a flow to allow definitively matching specific flows where
 325  * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
 326  * that it can be used in CB of skb (see sch_choke for an example).
 327  */
 328 #define FLOW_KEYS_DIGEST_LEN    16
 329 struct flow_keys_digest {
 330         u8      data[FLOW_KEYS_DIGEST_LEN];
 331 };
 332
 333 void make_flow_keys_digest(struct flow_keys_digest *digest,
 334                            const struct flow_keys *flow);
 335
 336 static inline bool flow_keys_have_l4(const struct flow_keys *keys)
 337 {
 338         return (keys->ports.ports || keys->tags.flow_label);
 339 }
 340
 341 u32 flow_hash_from_keys(struct flow_keys *keys);
 342 void skb_flow_get_icmp_tci(const struct sk_buff *skb,
 343                            struct flow_dissector_key_icmp *key_icmp,
 344                            void *data, int thoff, int hlen);
 345
 346 static inline bool dissector_uses_key(const struct flow_dissector *flow_dissector,
 347                                       enum flow_dissector_key_id key_id)
 348 {
 349         return flow_dissector->used_keys & (1 << key_id);
 350 }
 351
 352 static inline void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
 353                                               enum flow_dissector_key_id key_id,
 354                                               void *target_container)
 355 {
 356         return ((char *)target_container) + flow_dissector->offset[key_id];
 357 }
 358
 359 struct bpf_flow_dissector {
 360         struct bpf_flow_keys    *flow_keys;
 361         const struct sk_buff    *skb;
 362         void                    *data;
 363         void                    *data_end;
 364 };
 365
 366 static inline void
 367 flow_dissector_init_keys(struct flow_dissector_key_control *key_control,
 368                          struct flow_dissector_key_basic *key_basic)
 369 {
 370         memset(key_control, 0, sizeof(*key_control));
 371         memset(key_basic, 0, sizeof(*key_basic));
 372 }
 373
 374 #ifdef CONFIG_BPF_SYSCALL
 375 int flow_dissector_bpf_prog_attach_check(struct net *net,
 376                                          struct bpf_prog *prog);
 377 #endif /* CONFIG_BPF_SYSCALL */
 378
 379 #endif