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-rw-r--r--include/net/erspan.h321
1 files changed, 321 insertions, 0 deletions
diff --git a/include/net/erspan.h b/include/net/erspan.h
new file mode 100644
index 000000000..6cb4cbd6a
--- /dev/null
+++ b/include/net/erspan.h
@@ -0,0 +1,321 @@
+#ifndef __LINUX_ERSPAN_H
+#define __LINUX_ERSPAN_H
+
+/*
+ * GRE header for ERSPAN type I encapsulation (4 octets [34:37])
+ * 0 1 2 3
+ * 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
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |0|0|0|0|0|00000|000000000|00000| Protocol Type for ERSPAN |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * The Type I ERSPAN frame format is based on the barebones IP + GRE
+ * encapsulation (as described above) on top of the raw mirrored frame.
+ * There is no extra ERSPAN header.
+ *
+ *
+ * GRE header for ERSPAN type II and II encapsulation (8 octets [34:41])
+ * 0 1 2 3
+ * 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
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |0|0|0|1|0|00000|000000000|00000| Protocol Type for ERSPAN |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Sequence Number (increments per packet per session) |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Note that in the above GRE header [RFC1701] out of the C, R, K, S,
+ * s, Recur, Flags, Version fields only S (bit 03) is set to 1. The
+ * other fields are set to zero, so only a sequence number follows.
+ *
+ * ERSPAN Version 1 (Type II) header (8 octets [42:49])
+ * 0 1 2 3
+ * 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
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Ver | VLAN | COS | En|T| Session ID |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Reserved | Index |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ *
+ * ERSPAN Version 2 (Type III) header (12 octets [42:49])
+ * 0 1 2 3
+ * 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
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Ver | VLAN | COS |BSO|T| Session ID |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Timestamp |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | SGT |P| FT | Hw ID |D|Gra|O|
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Platform Specific SubHeader (8 octets, optional)
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Platf ID | Platform Specific Info |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Platform Specific Info |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * GRE proto ERSPAN type I/II = 0x88BE, type III = 0x22EB
+ */
+
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/skbuff.h>
+#include <uapi/linux/erspan.h>
+
+#define ERSPAN_VERSION 0x1 /* ERSPAN type II */
+#define VER_MASK 0xf000
+#define VLAN_MASK 0x0fff
+#define COS_MASK 0xe000
+#define EN_MASK 0x1800
+#define T_MASK 0x0400
+#define ID_MASK 0x03ff
+#define INDEX_MASK 0xfffff
+
+#define ERSPAN_VERSION2 0x2 /* ERSPAN type III*/
+#define BSO_MASK EN_MASK
+#define SGT_MASK 0xffff0000
+#define P_MASK 0x8000
+#define FT_MASK 0x7c00
+#define HWID_MASK 0x03f0
+#define DIR_MASK 0x0008
+#define GRA_MASK 0x0006
+#define O_MASK 0x0001
+
+#define HWID_OFFSET 4
+#define DIR_OFFSET 3
+
+enum erspan_encap_type {
+ ERSPAN_ENCAP_NOVLAN = 0x0, /* originally without VLAN tag */
+ ERSPAN_ENCAP_ISL = 0x1, /* originally ISL encapsulated */
+ ERSPAN_ENCAP_8021Q = 0x2, /* originally 802.1Q encapsulated */
+ ERSPAN_ENCAP_INFRAME = 0x3, /* VLAN tag perserved in frame */
+};
+
+#define ERSPAN_V1_MDSIZE 4
+#define ERSPAN_V2_MDSIZE 8
+
+struct erspan_base_hdr {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+ __u8 vlan_upper:4,
+ ver:4;
+ __u8 vlan:8;
+ __u8 session_id_upper:2,
+ t:1,
+ en:2,
+ cos:3;
+ __u8 session_id:8;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+ __u8 ver: 4,
+ vlan_upper:4;
+ __u8 vlan:8;
+ __u8 cos:3,
+ en:2,
+ t:1,
+ session_id_upper:2;
+ __u8 session_id:8;
+#else
+#error "Please fix <asm/byteorder.h>"
+#endif
+};
+
+static inline void set_session_id(struct erspan_base_hdr *ershdr, u16 id)
+{
+ ershdr->session_id = id & 0xff;
+ ershdr->session_id_upper = (id >> 8) & 0x3;
+}
+
+static inline u16 get_session_id(const struct erspan_base_hdr *ershdr)
+{
+ return (ershdr->session_id_upper << 8) + ershdr->session_id;
+}
+
+static inline void set_vlan(struct erspan_base_hdr *ershdr, u16 vlan)
+{
+ ershdr->vlan = vlan & 0xff;
+ ershdr->vlan_upper = (vlan >> 8) & 0xf;
+}
+
+static inline u16 get_vlan(const struct erspan_base_hdr *ershdr)
+{
+ return (ershdr->vlan_upper << 8) + ershdr->vlan;
+}
+
+static inline void set_hwid(struct erspan_md2 *md2, u8 hwid)
+{
+ md2->hwid = hwid & 0xf;
+ md2->hwid_upper = (hwid >> 4) & 0x3;
+}
+
+static inline u8 get_hwid(const struct erspan_md2 *md2)
+{
+ return (md2->hwid_upper << 4) + md2->hwid;
+}
+
+static inline int erspan_hdr_len(int version)
+{
+ if (version == 0)
+ return 0;
+
+ return sizeof(struct erspan_base_hdr) +
+ (version == 1 ? ERSPAN_V1_MDSIZE : ERSPAN_V2_MDSIZE);
+}
+
+static inline u8 tos_to_cos(u8 tos)
+{
+ u8 dscp, cos;
+
+ dscp = tos >> 2;
+ cos = dscp >> 3;
+ return cos;
+}
+
+static inline void erspan_build_header(struct sk_buff *skb,
+ u32 id, u32 index,
+ bool truncate, bool is_ipv4)
+{
+ struct ethhdr *eth = (struct ethhdr *)skb->data;
+ enum erspan_encap_type enc_type;
+ struct erspan_base_hdr *ershdr;
+ struct qtag_prefix {
+ __be16 eth_type;
+ __be16 tci;
+ } *qp;
+ u16 vlan_tci = 0;
+ u8 tos;
+ __be32 *idx;
+
+ tos = is_ipv4 ? ip_hdr(skb)->tos :
+ (ipv6_hdr(skb)->priority << 4) +
+ (ipv6_hdr(skb)->flow_lbl[0] >> 4);
+
+ enc_type = ERSPAN_ENCAP_NOVLAN;
+
+ /* If mirrored packet has vlan tag, extract tci and
+ * perserve vlan header in the mirrored frame.
+ */
+ if (eth->h_proto == htons(ETH_P_8021Q)) {
+ qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN);
+ vlan_tci = ntohs(qp->tci);
+ enc_type = ERSPAN_ENCAP_INFRAME;
+ }
+
+ skb_push(skb, sizeof(*ershdr) + ERSPAN_V1_MDSIZE);
+ ershdr = (struct erspan_base_hdr *)skb->data;
+ memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V1_MDSIZE);
+
+ /* Build base header */
+ ershdr->ver = ERSPAN_VERSION;
+ ershdr->cos = tos_to_cos(tos);
+ ershdr->en = enc_type;
+ ershdr->t = truncate;
+ set_vlan(ershdr, vlan_tci);
+ set_session_id(ershdr, id);
+
+ /* Build metadata */
+ idx = (__be32 *)(ershdr + 1);
+ *idx = htonl(index & INDEX_MASK);
+}
+
+/* ERSPAN GRA: timestamp granularity
+ * 00b --> granularity = 100 microseconds
+ * 01b --> granularity = 100 nanoseconds
+ * 10b --> granularity = IEEE 1588
+ * Here we only support 100 microseconds.
+ */
+static inline __be32 erspan_get_timestamp(void)
+{
+ u64 h_usecs;
+ ktime_t kt;
+
+ kt = ktime_get_real();
+ h_usecs = ktime_divns(kt, 100 * NSEC_PER_USEC);
+
+ /* ERSPAN base header only has 32-bit,
+ * so it wraps around 4 days.
+ */
+ return htonl((u32)h_usecs);
+}
+
+/* ERSPAN BSO (Bad/Short/Oversized), see RFC1757
+ * 00b --> Good frame with no error, or unknown integrity
+ * 01b --> Payload is a Short Frame
+ * 10b --> Payload is an Oversized Frame
+ * 11b --> Payload is a Bad Frame with CRC or Alignment Error
+ */
+enum erspan_bso {
+ BSO_NOERROR = 0x0,
+ BSO_SHORT = 0x1,
+ BSO_OVERSIZED = 0x2,
+ BSO_BAD = 0x3,
+};
+
+static inline u8 erspan_detect_bso(struct sk_buff *skb)
+{
+ /* BSO_BAD is not handled because the frame CRC
+ * or alignment error information is in FCS.
+ */
+ if (skb->len < ETH_ZLEN)
+ return BSO_SHORT;
+
+ if (skb->len > ETH_FRAME_LEN)
+ return BSO_OVERSIZED;
+
+ return BSO_NOERROR;
+}
+
+static inline void erspan_build_header_v2(struct sk_buff *skb,
+ u32 id, u8 direction, u16 hwid,
+ bool truncate, bool is_ipv4)
+{
+ struct ethhdr *eth = (struct ethhdr *)skb->data;
+ struct erspan_base_hdr *ershdr;
+ struct erspan_md2 *md2;
+ struct qtag_prefix {
+ __be16 eth_type;
+ __be16 tci;
+ } *qp;
+ u16 vlan_tci = 0;
+ u8 gra = 0; /* 100 usec */
+ u8 bso = 0; /* Bad/Short/Oversized */
+ u8 sgt = 0;
+ u8 tos;
+
+ tos = is_ipv4 ? ip_hdr(skb)->tos :
+ (ipv6_hdr(skb)->priority << 4) +
+ (ipv6_hdr(skb)->flow_lbl[0] >> 4);
+
+ /* Unlike v1, v2 does not have En field,
+ * so only extract vlan tci field.
+ */
+ if (eth->h_proto == htons(ETH_P_8021Q)) {
+ qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN);
+ vlan_tci = ntohs(qp->tci);
+ }
+
+ bso = erspan_detect_bso(skb);
+ skb_push(skb, sizeof(*ershdr) + ERSPAN_V2_MDSIZE);
+ ershdr = (struct erspan_base_hdr *)skb->data;
+ memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V2_MDSIZE);
+
+ /* Build base header */
+ ershdr->ver = ERSPAN_VERSION2;
+ ershdr->cos = tos_to_cos(tos);
+ ershdr->en = bso;
+ ershdr->t = truncate;
+ set_vlan(ershdr, vlan_tci);
+ set_session_id(ershdr, id);
+
+ /* Build metadata */
+ md2 = (struct erspan_md2 *)(ershdr + 1);
+ md2->timestamp = erspan_get_timestamp();
+ md2->sgt = htons(sgt);
+ md2->p = 1;
+ md2->ft = 0;
+ md2->dir = direction;
+ md2->gra = gra;
+ md2->o = 0;
+ set_hwid(md2, hwid);
+}
+
+#endif
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