1 #ifndef __LINUX_ERSPAN_H 2 #define __LINUX_ERSPAN_H 3 4 /* 5 * GRE header for ERSPAN encapsulation (8 octets [34:41]) -- 8 bytes 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|1|0|00000|000000000|00000| Protocol Type for ERSPAN | 10 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 11 * | Sequence Number (increments per packet per session) | 12 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 13 * 14 * Note that in the above GRE header [RFC1701] out of the C, R, K, S, 15 * s, Recur, Flags, Version fields only S (bit 03) is set to 1. The 16 * other fields are set to zero, so only a sequence number follows. 17 * 18 * ERSPAN Version 1 (Type II) header (8 octets [42:49]) 19 * 0 1 2 3 20 * 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 21 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 22 * | Ver | VLAN | COS | En|T| Session ID | 23 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 24 * | Reserved | Index | 25 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 26 * 27 * 28 * ERSPAN Version 2 (Type III) header (12 octets [42:49]) 29 * 0 1 2 3 30 * 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 31 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 32 * | Ver | VLAN | COS |BSO|T| Session ID | 33 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 34 * | Timestamp | 35 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 36 * | SGT |P| FT | Hw ID |D|Gra|O| 37 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 38 * 39 * Platform Specific SubHeader (8 octets, optional) 40 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 41 * | Platf ID | Platform Specific Info | 42 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 43 * | Platform Specific Info | 44 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 45 * 46 * GRE proto ERSPAN type II = 0x88BE, type III = 0x22EB 47 */ 48 49 #include <uapi/linux/erspan.h> 50 51 #define ERSPAN_VERSION 0x1 /* ERSPAN type II */ 52 #define VER_MASK 0xf000 53 #define VLAN_MASK 0x0fff 54 #define COS_MASK 0xe000 55 #define EN_MASK 0x1800 56 #define T_MASK 0x0400 57 #define ID_MASK 0x03ff 58 #define INDEX_MASK 0xfffff 59 60 #define ERSPAN_VERSION2 0x2 /* ERSPAN type III*/ 61 #define BSO_MASK EN_MASK 62 #define SGT_MASK 0xffff0000 63 #define P_MASK 0x8000 64 #define FT_MASK 0x7c00 65 #define HWID_MASK 0x03f0 66 #define DIR_MASK 0x0008 67 #define GRA_MASK 0x0006 68 #define O_MASK 0x0001 69 70 #define HWID_OFFSET 4 71 #define DIR_OFFSET 3 72 73 enum erspan_encap_type { 74 ERSPAN_ENCAP_NOVLAN = 0x0, /* originally without VLAN tag */ 75 ERSPAN_ENCAP_ISL = 0x1, /* originally ISL encapsulated */ 76 ERSPAN_ENCAP_8021Q = 0x2, /* originally 802.1Q encapsulated */ 77 ERSPAN_ENCAP_INFRAME = 0x3, /* VLAN tag perserved in frame */ 78 }; 79 80 #define ERSPAN_V1_MDSIZE 4 81 #define ERSPAN_V2_MDSIZE 8 82 83 struct erspan_base_hdr { 84 #if defined(__LITTLE_ENDIAN_BITFIELD) 85 __u8 vlan_upper:4, 86 ver:4; 87 __u8 vlan:8; 88 __u8 session_id_upper:2, 89 t:1, 90 en:2, 91 cos:3; 92 __u8 session_id:8; 93 #elif defined(__BIG_ENDIAN_BITFIELD) 94 __u8 ver: 4, 95 vlan_upper:4; 96 __u8 vlan:8; 97 __u8 cos:3, 98 en:2, 99 t:1, 100 session_id_upper:2; 101 __u8 session_id:8; 102 #else 103 #error "Please fix <asm/byteorder.h>" 104 #endif 105 }; 106 107 static inline void set_session_id(struct erspan_base_hdr *ershdr, u16 id) 108 { 109 ershdr->session_id = id & 0xff; 110 ershdr->session_id_upper = (id >> 8) & 0x3; 111 } 112 113 static inline u16 get_session_id(const struct erspan_base_hdr *ershdr) 114 { 115 return (ershdr->session_id_upper << 8) + ershdr->session_id; 116 } 117 118 static inline void set_vlan(struct erspan_base_hdr *ershdr, u16 vlan) 119 { 120 ershdr->vlan = vlan & 0xff; 121 ershdr->vlan_upper = (vlan >> 8) & 0xf; 122 } 123 124 static inline u16 get_vlan(const struct erspan_base_hdr *ershdr) 125 { 126 return (ershdr->vlan_upper << 8) + ershdr->vlan; 127 } 128 129 static inline void set_hwid(struct erspan_md2 *md2, u8 hwid) 130 { 131 md2->hwid = hwid & 0xf; 132 md2->hwid_upper = (hwid >> 4) & 0x3; 133 } 134 135 static inline u8 get_hwid(const struct erspan_md2 *md2) 136 { 137 return (md2->hwid_upper << 4) + md2->hwid; 138 } 139 140 static inline int erspan_hdr_len(int version) 141 { 142 return sizeof(struct erspan_base_hdr) + 143 (version == 1 ? ERSPAN_V1_MDSIZE : ERSPAN_V2_MDSIZE); 144 } 145 146 static inline u8 tos_to_cos(u8 tos) 147 { 148 u8 dscp, cos; 149 150 dscp = tos >> 2; 151 cos = dscp >> 3; 152 return cos; 153 } 154 155 static inline void erspan_build_header(struct sk_buff *skb, 156 u32 id, u32 index, 157 bool truncate, bool is_ipv4) 158 { 159 struct ethhdr *eth = (struct ethhdr *)skb->data; 160 enum erspan_encap_type enc_type; 161 struct erspan_base_hdr *ershdr; 162 struct qtag_prefix { 163 __be16 eth_type; 164 __be16 tci; 165 } *qp; 166 u16 vlan_tci = 0; 167 u8 tos; 168 __be32 *idx; 169 170 tos = is_ipv4 ? ip_hdr(skb)->tos : 171 (ipv6_hdr(skb)->priority << 4) + 172 (ipv6_hdr(skb)->flow_lbl[0] >> 4); 173 174 enc_type = ERSPAN_ENCAP_NOVLAN; 175 176 /* If mirrored packet has vlan tag, extract tci and 177 * perserve vlan header in the mirrored frame. 178 */ 179 if (eth->h_proto == htons(ETH_P_8021Q)) { 180 qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN); 181 vlan_tci = ntohs(qp->tci); 182 enc_type = ERSPAN_ENCAP_INFRAME; 183 } 184 185 skb_push(skb, sizeof(*ershdr) + ERSPAN_V1_MDSIZE); 186 ershdr = (struct erspan_base_hdr *)skb->data; 187 memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V1_MDSIZE); 188 189 /* Build base header */ 190 ershdr->ver = ERSPAN_VERSION; 191 ershdr->cos = tos_to_cos(tos); 192 ershdr->en = enc_type; 193 ershdr->t = truncate; 194 set_vlan(ershdr, vlan_tci); 195 set_session_id(ershdr, id); 196 197 /* Build metadata */ 198 idx = (__be32 *)(ershdr + 1); 199 *idx = htonl(index & INDEX_MASK); 200 } 201 202 /* ERSPAN GRA: timestamp granularity 203 * 00b --> granularity = 100 microseconds 204 * 01b --> granularity = 100 nanoseconds 205 * 10b --> granularity = IEEE 1588 206 * Here we only support 100 microseconds. 207 */ 208 static inline __be32 erspan_get_timestamp(void) 209 { 210 u64 h_usecs; 211 ktime_t kt; 212 213 kt = ktime_get_real(); 214 h_usecs = ktime_divns(kt, 100 * NSEC_PER_USEC); 215 216 /* ERSPAN base header only has 32-bit, 217 * so it wraps around 4 days. 218 */ 219 return htonl((u32)h_usecs); 220 } 221 222 /* ERSPAN BSO (Bad/Short/Oversized), see RFC1757 223 * 00b --> Good frame with no error, or unknown integrity 224 * 01b --> Payload is a Short Frame 225 * 10b --> Payload is an Oversized Frame 226 * 11b --> Payload is a Bad Frame with CRC or Alignment Error 227 */ 228 enum erspan_bso { 229 BSO_NOERROR = 0x0, 230 BSO_SHORT = 0x1, 231 BSO_OVERSIZED = 0x2, 232 BSO_BAD = 0x3, 233 }; 234 235 static inline u8 erspan_detect_bso(struct sk_buff *skb) 236 { 237 /* BSO_BAD is not handled because the frame CRC 238 * or alignment error information is in FCS. 239 */ 240 if (skb->len < ETH_ZLEN) 241 return BSO_SHORT; 242 243 if (skb->len > ETH_FRAME_LEN) 244 return BSO_OVERSIZED; 245 246 return BSO_NOERROR; 247 } 248 249 static inline void erspan_build_header_v2(struct sk_buff *skb, 250 u32 id, u8 direction, u16 hwid, 251 bool truncate, bool is_ipv4) 252 { 253 struct ethhdr *eth = (struct ethhdr *)skb->data; 254 struct erspan_base_hdr *ershdr; 255 struct erspan_md2 *md2; 256 struct qtag_prefix { 257 __be16 eth_type; 258 __be16 tci; 259 } *qp; 260 u16 vlan_tci = 0; 261 u8 gra = 0; /* 100 usec */ 262 u8 bso = 0; /* Bad/Short/Oversized */ 263 u8 sgt = 0; 264 u8 tos; 265 266 tos = is_ipv4 ? ip_hdr(skb)->tos : 267 (ipv6_hdr(skb)->priority << 4) + 268 (ipv6_hdr(skb)->flow_lbl[0] >> 4); 269 270 /* Unlike v1, v2 does not have En field, 271 * so only extract vlan tci field. 272 */ 273 if (eth->h_proto == htons(ETH_P_8021Q)) { 274 qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN); 275 vlan_tci = ntohs(qp->tci); 276 } 277 278 bso = erspan_detect_bso(skb); 279 skb_push(skb, sizeof(*ershdr) + ERSPAN_V2_MDSIZE); 280 ershdr = (struct erspan_base_hdr *)skb->data; 281 memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V2_MDSIZE); 282 283 /* Build base header */ 284 ershdr->ver = ERSPAN_VERSION2; 285 ershdr->cos = tos_to_cos(tos); 286 ershdr->en = bso; 287 ershdr->t = truncate; 288 set_vlan(ershdr, vlan_tci); 289 set_session_id(ershdr, id); 290 291 /* Build metadata */ 292 md2 = (struct erspan_md2 *)(ershdr + 1); 293 md2->timestamp = erspan_get_timestamp(); 294 md2->sgt = htons(sgt); 295 md2->p = 1; 296 md2->ft = 0; 297 md2->dir = direction; 298 md2->gra = gra; 299 md2->o = 0; 300 set_hwid(md2, hwid); 301 } 302 303 #endif 304