Commit f989d546 authored by William Tu's avatar William Tu Committed by David S. Miller
Browse files

erspan: Add type I version 0 support. 



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: default avatarWilliam Tu <u9012063@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 730f1351

include/net/erspan.h

+17 −2
Original line number Diff line number Diff line
@@ -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);

}

net/ipv4/ip_gre.c

+43 −15
Original line number Diff line number Diff line
@@ -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))

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