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         u16     padding;
  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 struct flow_dissector_key_keyid {
  61         __be32  keyid;
  62 };
  63
  64 /**
  65  * struct flow_dissector_key_ipv4_addrs:
  66  * @src: source ip address
  67  * @dst: destination ip address
  68  */
  69 struct flow_dissector_key_ipv4_addrs {
  70         /* (src,dst) must be grouped, in the same way than in IP header */
  71         __be32 src;
  72         __be32 dst;
  73 };
  74
  75 /**
  76  * struct flow_dissector_key_ipv6_addrs:
  77  * @src: source ip address
  78  * @dst: destination ip address
  79  */
  80 struct flow_dissector_key_ipv6_addrs {
  81         /* (src,dst) must be grouped, in the same way than in IP header */
  82         struct in6_addr src;
  83         struct in6_addr dst;
  84 };
  85
  86 /**
  87  * struct flow_dissector_key_tipc:
  88  * @key: source node address combined with selector
  89  */
  90 struct flow_dissector_key_tipc {
  91         __be32 key;
  92 };
  93
  94 /**
  95  * struct flow_dissector_key_addrs:
  96  * @v4addrs: IPv4 addresses
  97  * @v6addrs: IPv6 addresses
  98  */
  99 struct flow_dissector_key_addrs {
 100         union {
 101                 struct flow_dissector_key_ipv4_addrs v4addrs;
 102                 struct flow_dissector_key_ipv6_addrs v6addrs;
 103                 struct flow_dissector_key_tipc tipckey;
 104         };
 105 };
 106
 107 /**
 108  * flow_dissector_key_arp:
 109  *      @ports: Operation, source and target addresses for an ARP header
 110  *              for Ethernet hardware addresses and IPv4 protocol addresses
 111  *              sip: Sender IP address
 112  *              tip: Target IP address
 113  *              op:  Operation
 114  *              sha: Sender hardware address
 115  *              tpa: Target hardware address
 116  */
 117 struct flow_dissector_key_arp {
 118         __u32 sip;
 119         __u32 tip;
 120         __u8 op;
 121         unsigned char sha[ETH_ALEN];
 122         unsigned char tha[ETH_ALEN];
 123 };
 124
 125 /**
 126  * flow_dissector_key_tp_ports:
 127  *      @ports: port numbers of Transport header
 128  *              src: source port number
 129  *              dst: destination port number
 130  */
 131 struct flow_dissector_key_ports {
 132         union {
 133                 __be32 ports;
 134                 struct {
 135                         __be16 src;
 136                         __be16 dst;
 137                 };
 138         };
 139 };
 140
 141 /**
 142  * flow_dissector_key_icmp:
 143  *      @ports: type and code of ICMP header
 144  *              icmp: ICMP type (high) and code (low)
 145  *              type: ICMP type
 146  *              code: ICMP code
 147  */
 148 struct flow_dissector_key_icmp {
 149         union {
 150                 __be16 icmp;
 151                 struct {
 152                         u8 type;
 153                         u8 code;
 154                 };
 155         };
 156 };
 157
 158 /**
 159  * struct flow_dissector_key_eth_addrs:
 160  * @src: source Ethernet address
 161  * @dst: destination Ethernet address
 162  */
 163 struct flow_dissector_key_eth_addrs {
 164         /* (dst,src) must be grouped, in the same way than in ETH header */
 165         unsigned char dst[ETH_ALEN];
 166         unsigned char src[ETH_ALEN];
 167 };
 168
 169 /**
 170  * struct flow_dissector_key_tcp:
 171  * @flags: flags
 172  */
 173 struct flow_dissector_key_tcp {
 174         __be16 flags;
 175 };
 176
 177 /**
 178  * struct flow_dissector_key_ip:
 179  * @tos: tos
 180  * @ttl: ttl
 181  */
 182 struct flow_dissector_key_ip {
 183         __u8    tos;
 184         __u8    ttl;
 185 };
 186
 187 enum flow_dissector_key_id {
 188         FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
 189         FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
 190         FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
 191         FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 192         FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
 193         FLOW_DISSECTOR_KEY_ICMP, /* struct flow_dissector_key_icmp */
 194         FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
 195         FLOW_DISSECTOR_KEY_TIPC, /* struct flow_dissector_key_tipc */
 196         FLOW_DISSECTOR_KEY_ARP, /* struct flow_dissector_key_arp */
 197         FLOW_DISSECTOR_KEY_VLAN, /* struct flow_dissector_key_flow_vlan */
 198         FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_flow_tags */
 199         FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */
 200         FLOW_DISSECTOR_KEY_MPLS_ENTROPY, /* struct flow_dissector_key_keyid */
 201         FLOW_DISSECTOR_KEY_ENC_KEYID, /* struct flow_dissector_key_keyid */
 202         FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
 203         FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 204         FLOW_DISSECTOR_KEY_ENC_CONTROL, /* struct flow_dissector_key_control */
 205         FLOW_DISSECTOR_KEY_ENC_PORTS, /* struct flow_dissector_key_ports */
 206         FLOW_DISSECTOR_KEY_MPLS, /* struct flow_dissector_key_mpls */
 207         FLOW_DISSECTOR_KEY_TCP, /* struct flow_dissector_key_tcp */
 208         FLOW_DISSECTOR_KEY_IP, /* struct flow_dissector_key_ip */
 209
 210         FLOW_DISSECTOR_KEY_MAX,
 211 };
 212
 213 #define FLOW_DISSECTOR_F_PARSE_1ST_FRAG         BIT(0)
 214 #define FLOW_DISSECTOR_F_STOP_AT_L3             BIT(1)
 215 #define FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL     BIT(2)
 216 #define FLOW_DISSECTOR_F_STOP_AT_ENCAP          BIT(3)
 217
 218 struct flow_dissector_key {
 219         enum flow_dissector_key_id key_id;
 220         size_t offset; /* offset of struct flow_dissector_key_*
 221                           in target the struct */
 222 };
 223
 224 struct flow_dissector {
 225         unsigned int used_keys; /* each bit repesents presence of one key id */
 226         unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
 227 };
 228
 229 struct flow_keys {
 230         struct flow_dissector_key_control control;
 231 #define FLOW_KEYS_HASH_START_FIELD basic
 232         struct flow_dissector_key_basic basic;
 233         struct flow_dissector_key_tags tags;
 234         struct flow_dissector_key_vlan vlan;
 235         struct flow_dissector_key_keyid keyid;
 236         struct flow_dissector_key_ports ports;
 237         struct flow_dissector_key_addrs addrs;
 238 };
 239
 240 #define FLOW_KEYS_HASH_OFFSET           \
 241         offsetof(struct flow_keys, FLOW_KEYS_HASH_START_FIELD)
 242
 243 __be32 flow_get_u32_src(const struct flow_keys *flow);
 244 __be32 flow_get_u32_dst(const struct flow_keys *flow);
 245
 246 extern struct flow_dissector flow_keys_dissector;
 247 extern struct flow_dissector flow_keys_buf_dissector;
 248
 249 /* struct flow_keys_digest:
 250  *
 251  * This structure is used to hold a digest of the full flow keys. This is a
 252  * larger "hash" of a flow to allow definitively matching specific flows where
 253  * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
 254  * that it can by used in CB of skb (see sch_choke for an example).
 255  */
 256 #define FLOW_KEYS_DIGEST_LEN    16
 257 struct flow_keys_digest {
 258         u8      data[FLOW_KEYS_DIGEST_LEN];
 259 };
 260
 261 void make_flow_keys_digest(struct flow_keys_digest *digest,
 262                            const struct flow_keys *flow);
 263
 264 static inline bool flow_keys_have_l4(const struct flow_keys *keys)
 265 {
 266         return (keys->ports.ports || keys->tags.flow_label);
 267 }
 268
 269 u32 flow_hash_from_keys(struct flow_keys *keys);
 270
 271 static inline bool dissector_uses_key(const struct flow_dissector *flow_dissector,
 272                                       enum flow_dissector_key_id key_id)
 273 {
 274         return flow_dissector->used_keys & (1 << key_id);
 275 }
 276
 277 static inline void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
 278                                               enum flow_dissector_key_id key_id,
 279                                               void *target_container)
 280 {
 281         return ((char *)target_container) + flow_dissector->offset[key_id];
 282 }
 283
 284 #endif