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 <uapi/linux/erspan.h> 62 63 #define ERSPAN_VERSION 0x1 /* ERSPAN type II */ 64 #define VER_MASK 0xf000 65 #define VLAN_MASK 0x0fff 66 #define COS_MASK 0xe000 67 #define EN_MASK 0x1800 68 #define T_MASK 0x0400 69 #define ID_MASK 0x03ff 70 #define INDEX_MASK 0xfffff 71 72 #define ERSPAN_VERSION2 0x2 /* ERSPAN type III*/ 73 #define BSO_MASK EN_MASK 74 #define SGT_MASK 0xffff0000 75 #define P_MASK 0x8000 76 #define FT_MASK 0x7c00 77 #define HWID_MASK 0x03f0 78 #define DIR_MASK 0x0008 79 #define GRA_MASK 0x0006 80 #define O_MASK 0x0001 81 82 #define HWID_OFFSET 4 83 #define DIR_OFFSET 3 84 85 enum erspan_encap_type { 86 ERSPAN_ENCAP_NOVLAN = 0x0, /* originally without VLAN tag */ 87 ERSPAN_ENCAP_ISL = 0x1, /* originally ISL encapsulated */ 88 ERSPAN_ENCAP_8021Q = 0x2, /* originally 802.1Q encapsulated */ 89 ERSPAN_ENCAP_INFRAME = 0x3, /* VLAN tag perserved in frame */ 90 }; 91 92 #define ERSPAN_V1_MDSIZE 4 93 #define ERSPAN_V2_MDSIZE 8 94 95 struct erspan_base_hdr { 96 #if defined(__LITTLE_ENDIAN_BITFIELD) 97 __u8 vlan_upper:4, 98 ver:4; 99 __u8 vlan:8; 100 __u8 session_id_upper:2, 101 t:1, 102 en:2, 103 cos:3; 104 __u8 session_id:8; 105 #elif defined(__BIG_ENDIAN_BITFIELD) 106 __u8 ver: 4, 107 vlan_upper:4; 108 __u8 vlan:8; 109 __u8 cos:3, 110 en:2, 111 t:1, 112 session_id_upper:2; 113 __u8 session_id:8; 114 #else 115 #error "Please fix <asm/byteorder.h>" 116 #endif 117 }; 118 119 static inline void set_session_id(struct erspan_base_hdr *ershdr, u16 id) 120 { 121 ershdr->session_id = id & 0xff; 122 ershdr->session_id_upper = (id >> 8) & 0x3; 123 } 124 125 static inline u16 get_session_id(const struct erspan_base_hdr *ershdr) 126 { 127 return (ershdr->session_id_upper << 8) + ershdr->session_id; 128 } 129 130 static inline void set_vlan(struct erspan_base_hdr *ershdr, u16 vlan) 131 { 132 ershdr->vlan = vlan & 0xff; 133 ershdr->vlan_upper = (vlan >> 8) & 0xf; 134 } 135 136 static inline u16 get_vlan(const struct erspan_base_hdr *ershdr) 137 { 138 return (ershdr->vlan_upper << 8) + ershdr->vlan; 139 } 140 141 static inline void set_hwid(struct erspan_md2 *md2, u8 hwid) 142 { 143 md2->hwid = hwid & 0xf; 144 md2->hwid_upper = (hwid >> 4) & 0x3; 145 } 146 147 static inline u8 get_hwid(const struct erspan_md2 *md2) 148 { 149 return (md2->hwid_upper << 4) + md2->hwid; 150 } 151 152 static inline int erspan_hdr_len(int version) 153 { 154 if (version == 0) 155 return 0; 156 157 return sizeof(struct erspan_base_hdr) + 158 (version == 1 ? ERSPAN_V1_MDSIZE : ERSPAN_V2_MDSIZE); 159 } 160 161 static inline u8 tos_to_cos(u8 tos) 162 { 163 u8 dscp, cos; 164 165 dscp = tos >> 2; 166 cos = dscp >> 3; 167 return cos; 168 } 169 170 static inline void erspan_build_header(struct sk_buff *skb, 171 u32 id, u32 index, 172 bool truncate, bool is_ipv4) 173 { 174 struct ethhdr *eth = (struct ethhdr *)skb->data; 175 enum erspan_encap_type enc_type; 176 struct erspan_base_hdr *ershdr; 177 struct qtag_prefix { 178 __be16 eth_type; 179 __be16 tci; 180 } *qp; 181 u16 vlan_tci = 0; 182 u8 tos; 183 __be32 *idx; 184 185 tos = is_ipv4 ? ip_hdr(skb)->tos : 186 (ipv6_hdr(skb)->priority << 4) + 187 (ipv6_hdr(skb)->flow_lbl[0] >> 4); 188 189 enc_type = ERSPAN_ENCAP_NOVLAN; 190 191 /* If mirrored packet has vlan tag, extract tci and 192 * perserve vlan header in the mirrored frame. 193 */ 194 if (eth->h_proto == htons(ETH_P_8021Q)) { 195 qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN); 196 vlan_tci = ntohs(qp->tci); 197 enc_type = ERSPAN_ENCAP_INFRAME; 198 } 199 200 skb_push(skb, sizeof(*ershdr) + ERSPAN_V1_MDSIZE); 201 ershdr = (struct erspan_base_hdr *)skb->data; 202 memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V1_MDSIZE); 203 204 /* Build base header */ 205 ershdr->ver = ERSPAN_VERSION; 206 ershdr->cos = tos_to_cos(tos); 207 ershdr->en = enc_type; 208 ershdr->t = truncate; 209 set_vlan(ershdr, vlan_tci); 210 set_session_id(ershdr, id); 211 212 /* Build metadata */ 213 idx = (__be32 *)(ershdr + 1); 214 *idx = htonl(index & INDEX_MASK); 215 } 216 217 /* ERSPAN GRA: timestamp granularity 218 * 00b --> granularity = 100 microseconds 219 * 01b --> granularity = 100 nanoseconds 220 * 10b --> granularity = IEEE 1588 221 * Here we only support 100 microseconds. 222 */ 223 static inline __be32 erspan_get_timestamp(void) 224 { 225 u64 h_usecs; 226 ktime_t kt; 227 228 kt = ktime_get_real(); 229 h_usecs = ktime_divns(kt, 100 * NSEC_PER_USEC); 230 231 /* ERSPAN base header only has 32-bit, 232 * so it wraps around 4 days. 233 */ 234 return htonl((u32)h_usecs); 235 } 236 237 /* ERSPAN BSO (Bad/Short/Oversized), see RFC1757 238 * 00b --> Good frame with no error, or unknown integrity 239 * 01b --> Payload is a Short Frame 240 * 10b --> Payload is an Oversized Frame 241 * 11b --> Payload is a Bad Frame with CRC or Alignment Error 242 */ 243 enum erspan_bso { 244 BSO_NOERROR = 0x0, 245 BSO_SHORT = 0x1, 246 BSO_OVERSIZED = 0x2, 247 BSO_BAD = 0x3, 248 }; 249 250 static inline u8 erspan_detect_bso(struct sk_buff *skb) 251 { 252 /* BSO_BAD is not handled because the frame CRC 253 * or alignment error information is in FCS. 254 */ 255 if (skb->len < ETH_ZLEN) 256 return BSO_SHORT; 257 258 if (skb->len > ETH_FRAME_LEN) 259 return BSO_OVERSIZED; 260 261 return BSO_NOERROR; 262 } 263 264 static inline void erspan_build_header_v2(struct sk_buff *skb, 265 u32 id, u8 direction, u16 hwid, 266 bool truncate, bool is_ipv4) 267 { 268 struct ethhdr *eth = (struct ethhdr *)skb->data; 269 struct erspan_base_hdr *ershdr; 270 struct erspan_md2 *md2; 271 struct qtag_prefix { 272 __be16 eth_type; 273 __be16 tci; 274 } *qp; 275 u16 vlan_tci = 0; 276 u8 gra = 0; /* 100 usec */ 277 u8 bso = 0; /* Bad/Short/Oversized */ 278 u8 sgt = 0; 279 u8 tos; 280 281 tos = is_ipv4 ? ip_hdr(skb)->tos : 282 (ipv6_hdr(skb)->priority << 4) + 283 (ipv6_hdr(skb)->flow_lbl[0] >> 4); 284 285 /* Unlike v1, v2 does not have En field, 286 * so only extract vlan tci field. 287 */ 288 if (eth->h_proto == htons(ETH_P_8021Q)) { 289 qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN); 290 vlan_tci = ntohs(qp->tci); 291 } 292 293 bso = erspan_detect_bso(skb); 294 skb_push(skb, sizeof(*ershdr) + ERSPAN_V2_MDSIZE); 295 ershdr = (struct erspan_base_hdr *)skb->data; 296 memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V2_MDSIZE); 297 298 /* Build base header */ 299 ershdr->ver = ERSPAN_VERSION2; 300 ershdr->cos = tos_to_cos(tos); 301 ershdr->en = bso; 302 ershdr->t = truncate; 303 set_vlan(ershdr, vlan_tci); 304 set_session_id(ershdr, id); 305 306 /* Build metadata */ 307 md2 = (struct erspan_md2 *)(ershdr + 1); 308 md2->timestamp = erspan_get_timestamp(); 309 md2->sgt = htons(sgt); 310 md2->p = 1; 311 md2->ft = 0; 312 md2->dir = direction; 313 md2->gra = gra; 314 md2->o = 0; 315 set_hwid(md2, hwid); 316 } 317 318 #endif 319