1 | #ifndef __LINUX_ERSPAN_H |
2 | #define __LINUX_ERSPAN_H |
3 | |
4 | /* |
5 | * GRE header for ERSPAN type I encapsulation (4 octets [34:37]) |
6 | * 0 1 2 3 |
7 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
8 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
9 | * |0|0|0|0|0|00000|000000000|00000| Protocol Type for ERSPAN | |
10 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
11 | * |
12 | * The Type I ERSPAN frame format is based on the barebones IP + GRE |
13 | * encapsulation (as described above) on top of the raw mirrored frame. |
14 | * There is no extra ERSPAN header. |
15 | * |
16 | * |
17 | * GRE header for ERSPAN type II and II encapsulation (8 octets [34:41]) |
18 | * 0 1 2 3 |
19 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
20 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
21 | * |0|0|0|1|0|00000|000000000|00000| Protocol Type for ERSPAN | |
22 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
23 | * | Sequence Number (increments per packet per session) | |
24 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
25 | * |
26 | * Note that in the above GRE header [RFC1701] out of the C, R, K, S, |
27 | * s, Recur, Flags, Version fields only S (bit 03) is set to 1. The |
28 | * other fields are set to zero, so only a sequence number follows. |
29 | * |
30 | * ERSPAN Version 1 (Type II) header (8 octets [42:49]) |
31 | * 0 1 2 3 |
32 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
33 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
34 | * | Ver | VLAN | COS | En|T| Session ID | |
35 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
36 | * | Reserved | Index | |
37 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
38 | * |
39 | * |
40 | * ERSPAN Version 2 (Type III) header (12 octets [42:49]) |
41 | * 0 1 2 3 |
42 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
43 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
44 | * | Ver | VLAN | COS |BSO|T| Session ID | |
45 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
46 | * | Timestamp | |
47 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
48 | * | SGT |P| FT | Hw ID |D|Gra|O| |
49 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
50 | * |
51 | * Platform Specific SubHeader (8 octets, optional) |
52 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
53 | * | Platf ID | Platform Specific Info | |
54 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
55 | * | Platform Specific Info | |
56 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
57 | * |
58 | * GRE proto ERSPAN type I/II = 0x88BE, type III = 0x22EB |
59 | */ |
60 | |
61 | #include <linux/ip.h> |
62 | #include <linux/ipv6.h> |
63 | #include <linux/skbuff.h> |
64 | #include <uapi/linux/erspan.h> |
65 | |
66 | #define ERSPAN_VERSION 0x1 /* ERSPAN type II */ |
67 | #define VER_MASK 0xf000 |
68 | #define VLAN_MASK 0x0fff |
69 | #define COS_MASK 0xe000 |
70 | #define EN_MASK 0x1800 |
71 | #define T_MASK 0x0400 |
72 | #define ID_MASK 0x03ff |
73 | #define INDEX_MASK 0xfffff |
74 | |
75 | #define ERSPAN_VERSION2 0x2 /* ERSPAN type III*/ |
76 | #define BSO_MASK EN_MASK |
77 | #define SGT_MASK 0xffff0000 |
78 | #define P_MASK 0x8000 |
79 | #define FT_MASK 0x7c00 |
80 | #define HWID_MASK 0x03f0 |
81 | #define DIR_MASK 0x0008 |
82 | #define GRA_MASK 0x0006 |
83 | #define O_MASK 0x0001 |
84 | |
85 | #define HWID_OFFSET 4 |
86 | #define DIR_OFFSET 3 |
87 | |
88 | enum erspan_encap_type { |
89 | ERSPAN_ENCAP_NOVLAN = 0x0, /* originally without VLAN tag */ |
90 | ERSPAN_ENCAP_ISL = 0x1, /* originally ISL encapsulated */ |
91 | ERSPAN_ENCAP_8021Q = 0x2, /* originally 802.1Q encapsulated */ |
92 | ERSPAN_ENCAP_INFRAME = 0x3, /* VLAN tag perserved in frame */ |
93 | }; |
94 | |
95 | #define ERSPAN_V1_MDSIZE 4 |
96 | #define ERSPAN_V2_MDSIZE 8 |
97 | |
98 | struct erspan_base_hdr { |
99 | #if defined(__LITTLE_ENDIAN_BITFIELD) |
100 | __u8 vlan_upper:4, |
101 | ver:4; |
102 | __u8 vlan:8; |
103 | __u8 session_id_upper:2, |
104 | t:1, |
105 | en:2, |
106 | cos:3; |
107 | __u8 session_id:8; |
108 | #elif defined(__BIG_ENDIAN_BITFIELD) |
109 | __u8 ver: 4, |
110 | vlan_upper:4; |
111 | __u8 vlan:8; |
112 | __u8 cos:3, |
113 | en:2, |
114 | t:1, |
115 | session_id_upper:2; |
116 | __u8 session_id:8; |
117 | #else |
118 | #error "Please fix <asm/byteorder.h>" |
119 | #endif |
120 | }; |
121 | |
122 | static inline void set_session_id(struct erspan_base_hdr *ershdr, u16 id) |
123 | { |
124 | ershdr->session_id = id & 0xff; |
125 | ershdr->session_id_upper = (id >> 8) & 0x3; |
126 | } |
127 | |
128 | static inline u16 get_session_id(const struct erspan_base_hdr *ershdr) |
129 | { |
130 | return (ershdr->session_id_upper << 8) + ershdr->session_id; |
131 | } |
132 | |
133 | static inline void set_vlan(struct erspan_base_hdr *ershdr, u16 vlan) |
134 | { |
135 | ershdr->vlan = vlan & 0xff; |
136 | ershdr->vlan_upper = (vlan >> 8) & 0xf; |
137 | } |
138 | |
139 | static inline u16 get_vlan(const struct erspan_base_hdr *ershdr) |
140 | { |
141 | return (ershdr->vlan_upper << 8) + ershdr->vlan; |
142 | } |
143 | |
144 | static inline void set_hwid(struct erspan_md2 *md2, u8 hwid) |
145 | { |
146 | md2->hwid = hwid & 0xf; |
147 | md2->hwid_upper = (hwid >> 4) & 0x3; |
148 | } |
149 | |
150 | static inline u8 get_hwid(const struct erspan_md2 *md2) |
151 | { |
152 | return (md2->hwid_upper << 4) + md2->hwid; |
153 | } |
154 | |
155 | static inline int erspan_hdr_len(int version) |
156 | { |
157 | if (version == 0) |
158 | return 0; |
159 | |
160 | return sizeof(struct erspan_base_hdr) + |
161 | (version == 1 ? ERSPAN_V1_MDSIZE : ERSPAN_V2_MDSIZE); |
162 | } |
163 | |
164 | static inline u8 tos_to_cos(u8 tos) |
165 | { |
166 | u8 dscp, cos; |
167 | |
168 | dscp = tos >> 2; |
169 | cos = dscp >> 3; |
170 | return cos; |
171 | } |
172 | |
173 | static inline void (struct sk_buff *skb, |
174 | u32 id, u32 index, |
175 | bool truncate, bool is_ipv4) |
176 | { |
177 | struct ethhdr *eth = (struct ethhdr *)skb->data; |
178 | enum erspan_encap_type enc_type; |
179 | struct erspan_base_hdr *ershdr; |
180 | struct qtag_prefix { |
181 | __be16 eth_type; |
182 | __be16 tci; |
183 | } *qp; |
184 | u16 vlan_tci = 0; |
185 | u8 tos; |
186 | __be32 *idx; |
187 | |
188 | tos = is_ipv4 ? ip_hdr(skb)->tos : |
189 | (ipv6_hdr(skb)->priority << 4) + |
190 | (ipv6_hdr(skb)->flow_lbl[0] >> 4); |
191 | |
192 | enc_type = ERSPAN_ENCAP_NOVLAN; |
193 | |
194 | /* If mirrored packet has vlan tag, extract tci and |
195 | * perserve vlan header in the mirrored frame. |
196 | */ |
197 | if (eth->h_proto == htons(ETH_P_8021Q)) { |
198 | qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN); |
199 | vlan_tci = ntohs(qp->tci); |
200 | enc_type = ERSPAN_ENCAP_INFRAME; |
201 | } |
202 | |
203 | skb_push(skb, len: sizeof(*ershdr) + ERSPAN_V1_MDSIZE); |
204 | ershdr = (struct erspan_base_hdr *)skb->data; |
205 | memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V1_MDSIZE); |
206 | |
207 | /* Build base header */ |
208 | ershdr->ver = ERSPAN_VERSION; |
209 | ershdr->cos = tos_to_cos(tos); |
210 | ershdr->en = enc_type; |
211 | ershdr->t = truncate; |
212 | set_vlan(ershdr, vlan: vlan_tci); |
213 | set_session_id(ershdr, id); |
214 | |
215 | /* Build metadata */ |
216 | idx = (__be32 *)(ershdr + 1); |
217 | *idx = htonl(index & INDEX_MASK); |
218 | } |
219 | |
220 | /* ERSPAN GRA: timestamp granularity |
221 | * 00b --> granularity = 100 microseconds |
222 | * 01b --> granularity = 100 nanoseconds |
223 | * 10b --> granularity = IEEE 1588 |
224 | * Here we only support 100 microseconds. |
225 | */ |
226 | static inline __be32 erspan_get_timestamp(void) |
227 | { |
228 | u64 h_usecs; |
229 | ktime_t kt; |
230 | |
231 | kt = ktime_get_real(); |
232 | h_usecs = ktime_divns(kt, div: 100 * NSEC_PER_USEC); |
233 | |
234 | /* ERSPAN base header only has 32-bit, |
235 | * so it wraps around 4 days. |
236 | */ |
237 | return htonl((u32)h_usecs); |
238 | } |
239 | |
240 | /* ERSPAN BSO (Bad/Short/Oversized), see RFC1757 |
241 | * 00b --> Good frame with no error, or unknown integrity |
242 | * 01b --> Payload is a Short Frame |
243 | * 10b --> Payload is an Oversized Frame |
244 | * 11b --> Payload is a Bad Frame with CRC or Alignment Error |
245 | */ |
246 | enum erspan_bso { |
247 | BSO_NOERROR = 0x0, |
248 | BSO_SHORT = 0x1, |
249 | BSO_OVERSIZED = 0x2, |
250 | BSO_BAD = 0x3, |
251 | }; |
252 | |
253 | static inline u8 erspan_detect_bso(struct sk_buff *skb) |
254 | { |
255 | /* BSO_BAD is not handled because the frame CRC |
256 | * or alignment error information is in FCS. |
257 | */ |
258 | if (skb->len < ETH_ZLEN) |
259 | return BSO_SHORT; |
260 | |
261 | if (skb->len > ETH_FRAME_LEN) |
262 | return BSO_OVERSIZED; |
263 | |
264 | return BSO_NOERROR; |
265 | } |
266 | |
267 | static inline void (struct sk_buff *skb, |
268 | u32 id, u8 direction, u16 hwid, |
269 | bool truncate, bool is_ipv4) |
270 | { |
271 | struct ethhdr *eth = (struct ethhdr *)skb->data; |
272 | struct erspan_base_hdr *ershdr; |
273 | struct erspan_md2 *md2; |
274 | struct qtag_prefix { |
275 | __be16 eth_type; |
276 | __be16 tci; |
277 | } *qp; |
278 | u16 vlan_tci = 0; |
279 | u8 gra = 0; /* 100 usec */ |
280 | u8 bso = 0; /* Bad/Short/Oversized */ |
281 | u8 sgt = 0; |
282 | u8 tos; |
283 | |
284 | tos = is_ipv4 ? ip_hdr(skb)->tos : |
285 | (ipv6_hdr(skb)->priority << 4) + |
286 | (ipv6_hdr(skb)->flow_lbl[0] >> 4); |
287 | |
288 | /* Unlike v1, v2 does not have En field, |
289 | * so only extract vlan tci field. |
290 | */ |
291 | if (eth->h_proto == htons(ETH_P_8021Q)) { |
292 | qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN); |
293 | vlan_tci = ntohs(qp->tci); |
294 | } |
295 | |
296 | bso = erspan_detect_bso(skb); |
297 | skb_push(skb, len: sizeof(*ershdr) + ERSPAN_V2_MDSIZE); |
298 | ershdr = (struct erspan_base_hdr *)skb->data; |
299 | memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V2_MDSIZE); |
300 | |
301 | /* Build base header */ |
302 | ershdr->ver = ERSPAN_VERSION2; |
303 | ershdr->cos = tos_to_cos(tos); |
304 | ershdr->en = bso; |
305 | ershdr->t = truncate; |
306 | set_vlan(ershdr, vlan: vlan_tci); |
307 | set_session_id(ershdr, id); |
308 | |
309 | /* Build metadata */ |
310 | md2 = (struct erspan_md2 *)(ershdr + 1); |
311 | md2->timestamp = erspan_get_timestamp(); |
312 | md2->sgt = htons(sgt); |
313 | md2->p = 1; |
314 | md2->ft = 0; |
315 | md2->dir = direction; |
316 | md2->gra = gra; |
317 | md2->o = 0; |
318 | set_hwid(md2, hwid); |
319 | } |
320 | |
321 | #endif |
322 | |