mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-23 11:04:44 +08:00
f989d546a2
The Type I ERSPAN frame format is based on the barebones
IP + GRE(4-byte) encapsulation on top of the raw mirrored frame.
Both type I and II use 0x88BE as protocol type. Unlike type II
and III, no sequence number or key is required.
To creat a type I erspan tunnel device:
$ ip link add dev erspan11 type erspan \
local 172.16.1.100 remote 172.16.1.200 \
erspan_ver 0
Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
319 lines
9.0 KiB
C
319 lines
9.0 KiB
C
#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 <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
|