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erspan: Add type I version 0 support.

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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>
This commit is contained in:
William Tu 2020-05-05 09:05:06 -07:00 committed by David S. Miller
parent 730f135104
commit f989d546a2
2 changed files with 60 additions and 17 deletions
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19
include/net/erspan.h
View File

@ -2,7 +2,19 @@
#define __LINUX_ERSPAN_H
/*
* GRE header for ERSPAN encapsulation (8 octets [34:41]) -- 8 bytes
* 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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
@ -43,7 +55,7 @@
* | Platform Specific Info |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* GRE proto ERSPAN type II = 0x88BE, type III = 0x22EB
* GRE proto ERSPAN type I/II = 0x88BE, type III = 0x22EB
*/
#include <uapi/linux/erspan.h>
@ -139,6 +151,9 @@ static inline u8 get_hwid(const struct erspan_md2 *md2)
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);
}

46
net/ipv4/ip_gre.c
View File

@ -248,6 +248,15 @@ static void gre_err(struct sk_buff *skb, u32 info)
ipgre_err(skb, info, &tpi);
}
static bool is_erspan_type1(int gre_hdr_len)
{
/* Both ERSPAN type I (version 0) and type II (version 1) use
* protocol 0x88BE, but the type I has only 4-byte GRE header,
* while type II has 8-byte.
*/
return gre_hdr_len == 4;
}
static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
int gre_hdr_len)
{
@ -262,17 +271,26 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
int len;
itn = net_generic(net, erspan_net_id);
iph = ip_hdr(skb);
if (is_erspan_type1(gre_hdr_len)) {
ver = 0;
tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
tpi->flags | TUNNEL_NO_KEY,
iph->saddr, iph->daddr, 0);
} else {
ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
ver = ershdr->ver;
tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
tpi->flags | TUNNEL_KEY,
iph->saddr, iph->daddr, tpi->key);
}
if (tunnel) {
if (is_erspan_type1(gre_hdr_len))
len = gre_hdr_len;
else
len = gre_hdr_len + erspan_hdr_len(ver);
if (unlikely(!pskb_may_pull(skb, len)))
return PACKET_REJECT;
@ -665,7 +683,10 @@ static netdev_tx_t erspan_xmit(struct sk_buff *skb,
}
/* Push ERSPAN header */
if (tunnel->erspan_ver == 1) {
if (tunnel->erspan_ver == 0) {
proto = htons(ETH_P_ERSPAN);
tunnel->parms.o_flags &= ~TUNNEL_SEQ;
} else if (tunnel->erspan_ver == 1) {
erspan_build_header(skb, ntohl(tunnel->parms.o_key),
tunnel->index,
truncate, true);
@ -1066,7 +1087,10 @@ static int erspan_validate(struct nlattr *tb[], struct nlattr *data[],
if (ret)
return ret;
/* ERSPAN should only have GRE sequence and key flag */
if (nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0)
return 0;
/* ERSPAN type II/III should only have GRE sequence and key flag */
if (data[IFLA_GRE_OFLAGS])
flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
if (data[IFLA_GRE_IFLAGS])
@ -1174,7 +1198,7 @@ static int erspan_netlink_parms(struct net_device *dev,
if (data[IFLA_GRE_ERSPAN_VER]) {
t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
if (t->erspan_ver != 1 && t->erspan_ver != 2)
if (t->erspan_ver > 2)
return -EINVAL;
}
@ -1259,7 +1283,11 @@ static int erspan_tunnel_init(struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
tunnel->tun_hlen = 8;
if (tunnel->erspan_ver == 0)
tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */
else
tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */
tunnel->parms.iph.protocol = IPPROTO_GRE;
tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
erspan_hdr_len(tunnel->erspan_ver);
@ -1456,8 +1484,8 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
struct ip_tunnel_parm *p = &t->parms;
__be16 o_flags = p->o_flags;
if (t->erspan_ver == 1 || t->erspan_ver == 2) {
if (!t->collect_md)
if (t->erspan_ver <= 2) {
if (t->erspan_ver != 0 && !t->collect_md)
o_flags |= TUNNEL_KEY;
if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
@ -1466,7 +1494,7 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
if (t->erspan_ver == 1) {
if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
goto nla_put_failure;
} else {
} else if (t->erspan_ver == 2) {
if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
goto nla_put_failure;
if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))