xref: /openbmc/linux/include/net/flow_dissector.h (revision 293d5b43)
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	vlan_id:12,
36 		flow_label:20;
37 };
38 
39 struct flow_dissector_key_keyid {
40 	__be32	keyid;
41 };
42 
43 /**
44  * struct flow_dissector_key_ipv4_addrs:
45  * @src: source ip address
46  * @dst: destination ip address
47  */
48 struct flow_dissector_key_ipv4_addrs {
49 	/* (src,dst) must be grouped, in the same way than in IP header */
50 	__be32 src;
51 	__be32 dst;
52 };
53 
54 /**
55  * struct flow_dissector_key_ipv6_addrs:
56  * @src: source ip address
57  * @dst: destination ip address
58  */
59 struct flow_dissector_key_ipv6_addrs {
60 	/* (src,dst) must be grouped, in the same way than in IP header */
61 	struct in6_addr src;
62 	struct in6_addr dst;
63 };
64 
65 /**
66  * struct flow_dissector_key_tipc_addrs:
67  * @srcnode: source node address
68  */
69 struct flow_dissector_key_tipc_addrs {
70 	__be32 srcnode;
71 };
72 
73 /**
74  * struct flow_dissector_key_addrs:
75  * @v4addrs: IPv4 addresses
76  * @v6addrs: IPv6 addresses
77  */
78 struct flow_dissector_key_addrs {
79 	union {
80 		struct flow_dissector_key_ipv4_addrs v4addrs;
81 		struct flow_dissector_key_ipv6_addrs v6addrs;
82 		struct flow_dissector_key_tipc_addrs tipcaddrs;
83 	};
84 };
85 
86 /**
87  * flow_dissector_key_tp_ports:
88  *	@ports: port numbers of Transport header
89  *		src: source port number
90  *		dst: destination port number
91  */
92 struct flow_dissector_key_ports {
93 	union {
94 		__be32 ports;
95 		struct {
96 			__be16 src;
97 			__be16 dst;
98 		};
99 	};
100 };
101 
102 
103 /**
104  * struct flow_dissector_key_eth_addrs:
105  * @src: source Ethernet address
106  * @dst: destination Ethernet address
107  */
108 struct flow_dissector_key_eth_addrs {
109 	/* (dst,src) must be grouped, in the same way than in ETH header */
110 	unsigned char dst[ETH_ALEN];
111 	unsigned char src[ETH_ALEN];
112 };
113 
114 enum flow_dissector_key_id {
115 	FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
116 	FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
117 	FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
118 	FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
119 	FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
120 	FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
121 	FLOW_DISSECTOR_KEY_TIPC_ADDRS, /* struct flow_dissector_key_tipc_addrs */
122 	FLOW_DISSECTOR_KEY_VLANID, /* struct flow_dissector_key_flow_tags */
123 	FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_flow_tags */
124 	FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */
125 	FLOW_DISSECTOR_KEY_MPLS_ENTROPY, /* struct flow_dissector_key_keyid */
126 
127 	FLOW_DISSECTOR_KEY_MAX,
128 };
129 
130 #define FLOW_DISSECTOR_F_PARSE_1ST_FRAG		BIT(0)
131 #define FLOW_DISSECTOR_F_STOP_AT_L3		BIT(1)
132 #define FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL	BIT(2)
133 #define FLOW_DISSECTOR_F_STOP_AT_ENCAP		BIT(3)
134 
135 struct flow_dissector_key {
136 	enum flow_dissector_key_id key_id;
137 	size_t offset; /* offset of struct flow_dissector_key_*
138 			  in target the struct */
139 };
140 
141 struct flow_dissector {
142 	unsigned int used_keys; /* each bit repesents presence of one key id */
143 	unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
144 };
145 
146 struct flow_keys {
147 	struct flow_dissector_key_control control;
148 #define FLOW_KEYS_HASH_START_FIELD basic
149 	struct flow_dissector_key_basic basic;
150 	struct flow_dissector_key_tags tags;
151 	struct flow_dissector_key_keyid keyid;
152 	struct flow_dissector_key_ports ports;
153 	struct flow_dissector_key_addrs addrs;
154 };
155 
156 #define FLOW_KEYS_HASH_OFFSET		\
157 	offsetof(struct flow_keys, FLOW_KEYS_HASH_START_FIELD)
158 
159 __be32 flow_get_u32_src(const struct flow_keys *flow);
160 __be32 flow_get_u32_dst(const struct flow_keys *flow);
161 
162 extern struct flow_dissector flow_keys_dissector;
163 extern struct flow_dissector flow_keys_buf_dissector;
164 
165 /* struct flow_keys_digest:
166  *
167  * This structure is used to hold a digest of the full flow keys. This is a
168  * larger "hash" of a flow to allow definitively matching specific flows where
169  * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
170  * that it can by used in CB of skb (see sch_choke for an example).
171  */
172 #define FLOW_KEYS_DIGEST_LEN	16
173 struct flow_keys_digest {
174 	u8	data[FLOW_KEYS_DIGEST_LEN];
175 };
176 
177 void make_flow_keys_digest(struct flow_keys_digest *digest,
178 			   const struct flow_keys *flow);
179 
180 static inline bool flow_keys_have_l4(struct flow_keys *keys)
181 {
182 	return (keys->ports.ports || keys->tags.flow_label);
183 }
184 
185 u32 flow_hash_from_keys(struct flow_keys *keys);
186 
187 static inline bool dissector_uses_key(const struct flow_dissector *flow_dissector,
188 				      enum flow_dissector_key_id key_id)
189 {
190 	return flow_dissector->used_keys & (1 << key_id);
191 }
192 
193 static inline void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
194 					      enum flow_dissector_key_id key_id,
195 					      void *target_container)
196 {
197 	return ((char *)target_container) + flow_dissector->offset[key_id];
198 }
199 
200 #endif
201