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