xref: /linux/include/net/flow_dissector.h (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 #ifndef _NET_FLOW_DISSECTOR_H
2 #define _NET_FLOW_DISSECTOR_H
3 
4 #include <linux/types.h>
5 #include <linux/in6.h>
6 #include <uapi/linux/if_ether.h>
7 
8 /**
9  * struct flow_dissector_key_control:
10  * @thoff: Transport header offset
11  */
12 struct flow_dissector_key_control {
13 	u16	thoff;
14 	u16	addr_type;
15 	u32	flags;
16 };
17 
18 #define FLOW_DIS_IS_FRAGMENT	BIT(0)
19 #define FLOW_DIS_FIRST_FRAG	BIT(1)
20 #define FLOW_DIS_ENCAPSULATION	BIT(2)
21 
22 /**
23  * struct flow_dissector_key_basic:
24  * @thoff: Transport header offset
25  * @n_proto: Network header protocol (eg. IPv4/IPv6)
26  * @ip_proto: Transport header protocol (eg. TCP/UDP)
27  */
28 struct flow_dissector_key_basic {
29 	__be16	n_proto;
30 	u8	ip_proto;
31 	u8	padding;
32 };
33 
34 struct flow_dissector_key_tags {
35 	u32	flow_label;
36 };
37 
38 struct flow_dissector_key_vlan {
39 	u16	vlan_id:12,
40 		vlan_priority:3;
41 	u16	padding;
42 };
43 
44 struct flow_dissector_key_keyid {
45 	__be32	keyid;
46 };
47 
48 /**
49  * struct flow_dissector_key_ipv4_addrs:
50  * @src: source ip address
51  * @dst: destination ip address
52  */
53 struct flow_dissector_key_ipv4_addrs {
54 	/* (src,dst) must be grouped, in the same way than in IP header */
55 	__be32 src;
56 	__be32 dst;
57 };
58 
59 /**
60  * struct flow_dissector_key_ipv6_addrs:
61  * @src: source ip address
62  * @dst: destination ip address
63  */
64 struct flow_dissector_key_ipv6_addrs {
65 	/* (src,dst) must be grouped, in the same way than in IP header */
66 	struct in6_addr src;
67 	struct in6_addr dst;
68 };
69 
70 /**
71  * struct flow_dissector_key_tipc_addrs:
72  * @srcnode: source node address
73  */
74 struct flow_dissector_key_tipc_addrs {
75 	__be32 srcnode;
76 };
77 
78 /**
79  * struct flow_dissector_key_addrs:
80  * @v4addrs: IPv4 addresses
81  * @v6addrs: IPv6 addresses
82  */
83 struct flow_dissector_key_addrs {
84 	union {
85 		struct flow_dissector_key_ipv4_addrs v4addrs;
86 		struct flow_dissector_key_ipv6_addrs v6addrs;
87 		struct flow_dissector_key_tipc_addrs tipcaddrs;
88 	};
89 };
90 
91 /**
92  * flow_dissector_key_arp:
93  *	@ports: Operation, source and target addresses for an ARP header
94  *              for Ethernet hardware addresses and IPv4 protocol addresses
95  *		sip: Sender IP address
96  *		tip: Target IP address
97  *		op:  Operation
98  *		sha: Sender hardware address
99  *		tpa: Target hardware address
100  */
101 struct flow_dissector_key_arp {
102 	__u32 sip;
103 	__u32 tip;
104 	__u8 op;
105 	unsigned char sha[ETH_ALEN];
106 	unsigned char tha[ETH_ALEN];
107 };
108 
109 /**
110  * flow_dissector_key_tp_ports:
111  *	@ports: port numbers of Transport header
112  *		src: source port number
113  *		dst: destination port number
114  */
115 struct flow_dissector_key_ports {
116 	union {
117 		__be32 ports;
118 		struct {
119 			__be16 src;
120 			__be16 dst;
121 		};
122 	};
123 };
124 
125 /**
126  * flow_dissector_key_icmp:
127  *	@ports: type and code of ICMP header
128  *		icmp: ICMP type (high) and code (low)
129  *		type: ICMP type
130  *		code: ICMP code
131  */
132 struct flow_dissector_key_icmp {
133 	union {
134 		__be16 icmp;
135 		struct {
136 			u8 type;
137 			u8 code;
138 		};
139 	};
140 };
141 
142 /**
143  * struct flow_dissector_key_eth_addrs:
144  * @src: source Ethernet address
145  * @dst: destination Ethernet address
146  */
147 struct flow_dissector_key_eth_addrs {
148 	/* (dst,src) must be grouped, in the same way than in ETH header */
149 	unsigned char dst[ETH_ALEN];
150 	unsigned char src[ETH_ALEN];
151 };
152 
153 enum flow_dissector_key_id {
154 	FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
155 	FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
156 	FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
157 	FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
158 	FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
159 	FLOW_DISSECTOR_KEY_ICMP, /* struct flow_dissector_key_icmp */
160 	FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
161 	FLOW_DISSECTOR_KEY_TIPC_ADDRS, /* struct flow_dissector_key_tipc_addrs */
162 	FLOW_DISSECTOR_KEY_ARP, /* struct flow_dissector_key_arp */
163 	FLOW_DISSECTOR_KEY_VLAN, /* struct flow_dissector_key_flow_vlan */
164 	FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_flow_tags */
165 	FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */
166 	FLOW_DISSECTOR_KEY_MPLS_ENTROPY, /* struct flow_dissector_key_keyid */
167 	FLOW_DISSECTOR_KEY_ENC_KEYID, /* struct flow_dissector_key_keyid */
168 	FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
169 	FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
170 	FLOW_DISSECTOR_KEY_ENC_CONTROL, /* struct flow_dissector_key_control */
171 	FLOW_DISSECTOR_KEY_ENC_PORTS, /* struct flow_dissector_key_ports */
172 
173 	FLOW_DISSECTOR_KEY_MAX,
174 };
175 
176 #define FLOW_DISSECTOR_F_PARSE_1ST_FRAG		BIT(0)
177 #define FLOW_DISSECTOR_F_STOP_AT_L3		BIT(1)
178 #define FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL	BIT(2)
179 #define FLOW_DISSECTOR_F_STOP_AT_ENCAP		BIT(3)
180 
181 struct flow_dissector_key {
182 	enum flow_dissector_key_id key_id;
183 	size_t offset; /* offset of struct flow_dissector_key_*
184 			  in target the struct */
185 };
186 
187 struct flow_dissector {
188 	unsigned int used_keys; /* each bit repesents presence of one key id */
189 	unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
190 };
191 
192 struct flow_keys {
193 	struct flow_dissector_key_control control;
194 #define FLOW_KEYS_HASH_START_FIELD basic
195 	struct flow_dissector_key_basic basic;
196 	struct flow_dissector_key_tags tags;
197 	struct flow_dissector_key_vlan vlan;
198 	struct flow_dissector_key_keyid keyid;
199 	struct flow_dissector_key_ports ports;
200 	struct flow_dissector_key_addrs addrs;
201 };
202 
203 #define FLOW_KEYS_HASH_OFFSET		\
204 	offsetof(struct flow_keys, FLOW_KEYS_HASH_START_FIELD)
205 
206 __be32 flow_get_u32_src(const struct flow_keys *flow);
207 __be32 flow_get_u32_dst(const struct flow_keys *flow);
208 
209 extern struct flow_dissector flow_keys_dissector;
210 extern struct flow_dissector flow_keys_buf_dissector;
211 
212 /* struct flow_keys_digest:
213  *
214  * This structure is used to hold a digest of the full flow keys. This is a
215  * larger "hash" of a flow to allow definitively matching specific flows where
216  * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
217  * that it can by used in CB of skb (see sch_choke for an example).
218  */
219 #define FLOW_KEYS_DIGEST_LEN	16
220 struct flow_keys_digest {
221 	u8	data[FLOW_KEYS_DIGEST_LEN];
222 };
223 
224 void make_flow_keys_digest(struct flow_keys_digest *digest,
225 			   const struct flow_keys *flow);
226 
227 static inline bool flow_keys_have_l4(const struct flow_keys *keys)
228 {
229 	return (keys->ports.ports || keys->tags.flow_label);
230 }
231 
232 u32 flow_hash_from_keys(struct flow_keys *keys);
233 
234 static inline bool dissector_uses_key(const struct flow_dissector *flow_dissector,
235 				      enum flow_dissector_key_id key_id)
236 {
237 	return flow_dissector->used_keys & (1 << key_id);
238 }
239 
240 static inline void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
241 					      enum flow_dissector_key_id key_id,
242 					      void *target_container)
243 {
244 	return ((char *)target_container) + flow_dissector->offset[key_id];
245 }
246 
247 #endif
248