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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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1d7e2ed22f
The patch refactors the existing erspan implementation in order to support erspan version 2, which has additional metadata. So, in stead of having one 'struct erspanhdr' holding erspan version 1, breaks it into 'struct erspan_base_hdr' and 'struct erspan_metadata'. Signed-off-by: William Tu <u9012063@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
126 lines
3.8 KiB
C
126 lines
3.8 KiB
C
#ifndef __LINUX_ERSPAN_H
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#define __LINUX_ERSPAN_H
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/*
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* GRE header for ERSPAN encapsulation (8 octets [34:41]) -- 8 bytes
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* 0 1 2 3
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* 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
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* |0|0|0|1|0|00000|000000000|00000| Protocol Type for ERSPAN |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Sequence Number (increments per packet per session) |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*
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* Note that in the above GRE header [RFC1701] out of the C, R, K, S,
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* s, Recur, Flags, Version fields only S (bit 03) is set to 1. The
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* other fields are set to zero, so only a sequence number follows.
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*
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* ERSPAN Version 1 (Type II) header (8 octets [42:49])
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* 0 1 2 3
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* 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
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Ver | VLAN | COS | En|T| Session ID |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Reserved | Index |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*
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* GRE proto ERSPAN type II = 0x88BE, type III = 0x22EB
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*/
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#define ERSPAN_VERSION 0x1 /* ERSPAN type II */
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#define VER_MASK 0xf000
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#define VLAN_MASK 0x0fff
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#define COS_MASK 0xe000
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#define EN_MASK 0x1800
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#define T_MASK 0x0400
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#define ID_MASK 0x03ff
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#define INDEX_MASK 0xfffff
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enum erspan_encap_type {
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ERSPAN_ENCAP_NOVLAN = 0x0, /* originally without VLAN tag */
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ERSPAN_ENCAP_ISL = 0x1, /* originally ISL encapsulated */
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ERSPAN_ENCAP_8021Q = 0x2, /* originally 802.1Q encapsulated */
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ERSPAN_ENCAP_INFRAME = 0x3, /* VLAN tag perserved in frame */
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};
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#define ERSPAN_V1_MDSIZE 4
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#define ERSPAN_V2_MDSIZE 8
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struct erspan_metadata {
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union {
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__be32 index; /* Version 1 (type II)*/
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} u;
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};
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struct erspan_base_hdr {
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__be16 ver_vlan;
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#define VER_OFFSET 12
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__be16 session_id;
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#define COS_OFFSET 13
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#define EN_OFFSET 11
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#define T_OFFSET 10
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};
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static inline int erspan_hdr_len(int version)
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{
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return sizeof(struct erspan_base_hdr) +
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(version == 1 ? ERSPAN_V1_MDSIZE : ERSPAN_V2_MDSIZE);
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}
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static inline u8 tos_to_cos(u8 tos)
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{
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u8 dscp, cos;
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dscp = tos >> 2;
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cos = dscp >> 3;
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return cos;
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}
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static inline void erspan_build_header(struct sk_buff *skb,
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__be32 id, u32 index,
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bool truncate, bool is_ipv4)
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{
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struct ethhdr *eth = eth_hdr(skb);
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enum erspan_encap_type enc_type;
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struct erspan_base_hdr *ershdr;
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struct erspan_metadata *ersmd;
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struct qtag_prefix {
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__be16 eth_type;
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__be16 tci;
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} *qp;
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u16 vlan_tci = 0;
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u8 tos;
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tos = is_ipv4 ? ip_hdr(skb)->tos :
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(ipv6_hdr(skb)->priority << 4) +
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(ipv6_hdr(skb)->flow_lbl[0] >> 4);
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enc_type = ERSPAN_ENCAP_NOVLAN;
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/* If mirrored packet has vlan tag, extract tci and
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* perserve vlan header in the mirrored frame.
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*/
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if (eth->h_proto == htons(ETH_P_8021Q)) {
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qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN);
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vlan_tci = ntohs(qp->tci);
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enc_type = ERSPAN_ENCAP_INFRAME;
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}
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skb_push(skb, sizeof(*ershdr) + ERSPAN_V1_MDSIZE);
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ershdr = (struct erspan_base_hdr *)skb->data;
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memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V1_MDSIZE);
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/* Build base header */
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ershdr->ver_vlan = htons((vlan_tci & VLAN_MASK) |
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(ERSPAN_VERSION << VER_OFFSET));
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ershdr->session_id = htons((u16)(ntohl(id) & ID_MASK) |
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((tos_to_cos(tos) << COS_OFFSET) & COS_MASK) |
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(enc_type << EN_OFFSET & EN_MASK) |
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((truncate << T_OFFSET) & T_MASK));
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/* Build metadata */
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ersmd = (struct erspan_metadata *)(ershdr + 1);
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ersmd->u.index = htonl(index & INDEX_MASK);
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}
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#endif
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