Commit d5a915b9 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'gre-add-collect_md-mode-for-ERSPAN-tunnel' 



William Tu says:

====================
gre: add collect_md mode for ERSPAN tunnel

This patch series provide collect_md mode for ERSPAN tunnel.  The fist patch
refactors the existing gre_fb_xmit function by exacting the route cache
portion into a new function called prepare_fb_xmit.  The second patch
introduces the collect_md mode for ERSPAN tunnel, by calling the
prepare_fb_xmit function and adding ERSPAN specific logic.  The final patch
adds the test case using bpf_skb_{set,get}_tunnel_{key,opt}.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 03157937 ef88f89c

include/net/ip_tunnels.h

+3 −1
Original line number Diff line number Diff line
@@ -154,8 +154,10 @@ struct ip_tunnel { 
#define TUNNEL_GENEVE_OPT	__cpu_to_be16(0x0800)

#define TUNNEL_VXLAN_OPT	__cpu_to_be16(0x1000)

#define TUNNEL_NOCACHE		__cpu_to_be16(0x2000)

#define TUNNEL_ERSPAN_OPT	__cpu_to_be16(0x4000)



#define TUNNEL_OPTIONS_PRESENT	(TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT)

#define TUNNEL_OPTIONS_PRESENT \

		(TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT | TUNNEL_ERSPAN_OPT)



struct tnl_ptk_info {

	__be16 flags;

net/ipv4/ip_gre.c

+138 −19
Original line number Diff line number Diff line
@@ -113,6 +113,8 @@ MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 


static struct rtnl_link_ops ipgre_link_ops __read_mostly;

static int ipgre_tunnel_init(struct net_device *dev);

static void erspan_build_header(struct sk_buff *skb,

				__be32 id, u32 index, bool truncate);



static unsigned int ipgre_net_id __read_mostly;

static unsigned int gre_tap_net_id __read_mostly;
@@ -287,7 +289,33 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi, 
					   false, false) < 0)

			goto drop;



		if (tunnel->collect_md) {

			struct ip_tunnel_info *info;

			struct erspan_metadata *md;

			__be64 tun_id;

			__be16 flags;



			tpi->flags |= TUNNEL_KEY;

			flags = tpi->flags;

			tun_id = key32_to_tunnel_id(tpi->key);



			tun_dst = ip_tun_rx_dst(skb, flags,

						tun_id, sizeof(*md));

			if (!tun_dst)

				return PACKET_REJECT;



			md = ip_tunnel_info_opts(&tun_dst->u.tun_info);

			if (!md)

				return PACKET_REJECT;



			md->index = index;

			info = &tun_dst->u.tun_info;

			info->key.tun_flags |= TUNNEL_ERSPAN_OPT;

			info->options_len = sizeof(*md);

		} else {

			tunnel->index = ntohl(index);

		}



		skb_reset_mac_header(skb);

		ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);

		return PACKET_RCVD;
@@ -432,39 +460,33 @@ static struct rtable *gre_get_rt(struct sk_buff *skb, 
	return ip_route_output_key(net, fl);

}



static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,

			__be16 proto)

static struct rtable *prepare_fb_xmit(struct sk_buff *skb,

				      struct net_device *dev,

				      struct flowi4 *fl,

				      int tunnel_hlen)

{

	struct ip_tunnel_info *tun_info;

	const struct ip_tunnel_key *key;

	struct rtable *rt = NULL;

	struct flowi4 fl;

	int min_headroom;

	int tunnel_hlen;

	__be16 df, flags;

	bool use_cache;

	int err;



	tun_info = skb_tunnel_info(skb);

	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||

		     ip_tunnel_info_af(tun_info) != AF_INET))

		goto err_free_skb;



	key = &tun_info->key;

	use_cache = ip_tunnel_dst_cache_usable(skb, tun_info);



	if (use_cache)

		rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl.saddr);

		rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl->saddr);

	if (!rt) {

		rt = gre_get_rt(skb, dev, &fl, key);

		rt = gre_get_rt(skb, dev, fl, key);

		if (IS_ERR(rt))

			goto err_free_skb;

		if (use_cache)

			dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst,

					  fl.saddr);

					  fl->saddr);

	}



	tunnel_hlen = gre_calc_hlen(key->tun_flags);



	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len

			+ tunnel_hlen + sizeof(struct iphdr);

	if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
@@ -476,6 +498,37 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, 
		if (unlikely(err))

			goto err_free_rt;

	}

	return rt;



err_free_rt:

	ip_rt_put(rt);

err_free_skb:

	kfree_skb(skb);

	dev->stats.tx_dropped++;

	return NULL;

}



static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,

			__be16 proto)

{

	struct ip_tunnel_info *tun_info;

	const struct ip_tunnel_key *key;

	struct rtable *rt = NULL;

	struct flowi4 fl;

	int tunnel_hlen;

	__be16 df, flags;



	tun_info = skb_tunnel_info(skb);

	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||

		     ip_tunnel_info_af(tun_info) != AF_INET))

		goto err_free_skb;



	key = &tun_info->key;

	tunnel_hlen = gre_calc_hlen(key->tun_flags);



	rt = prepare_fb_xmit(skb, dev, &fl, tunnel_hlen);

	if (!rt)

		return;



	/* Push Tunnel header. */

	if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM)))
@@ -498,6 +551,64 @@ err_free_skb: 
	dev->stats.tx_dropped++;

}



static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev,

			   __be16 proto)

{

	struct ip_tunnel *tunnel = netdev_priv(dev);

	struct ip_tunnel_info *tun_info;

	const struct ip_tunnel_key *key;

	struct erspan_metadata *md;

	struct rtable *rt = NULL;

	bool truncate = false;

	struct flowi4 fl;

	int tunnel_hlen;

	__be16 df;



	tun_info = skb_tunnel_info(skb);

	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||

		     ip_tunnel_info_af(tun_info) != AF_INET))

		goto err_free_skb;



	key = &tun_info->key;



	/* ERSPAN has fixed 8 byte GRE header */

	tunnel_hlen = 8 + sizeof(struct erspanhdr);



	rt = prepare_fb_xmit(skb, dev, &fl, tunnel_hlen);

	if (!rt)

		return;



	if (gre_handle_offloads(skb, false))

		goto err_free_rt;



	if (skb->len > dev->mtu) {

		pskb_trim(skb, dev->mtu);

		truncate = true;

	}



	md = ip_tunnel_info_opts(tun_info);

	if (!md)

		goto err_free_rt;



	erspan_build_header(skb, tunnel_id_to_key32(key->tun_id),

			    ntohl(md->index), truncate);



	gre_build_header(skb, 8, TUNNEL_SEQ,

			 htons(ETH_P_ERSPAN), 0, htonl(tunnel->o_seqno++));



	df = key->tun_flags & TUNNEL_DONT_FRAGMENT ?  htons(IP_DF) : 0;



	iptunnel_xmit(skb->sk, rt, skb, fl.saddr, key->u.ipv4.dst, IPPROTO_GRE,

		      key->tos, key->ttl, df, false);

	return;



err_free_rt:

	ip_rt_put(rt);

err_free_skb:

	kfree_skb(skb);

	dev->stats.tx_dropped++;

}



static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)

{

	struct ip_tunnel_info *info = skb_tunnel_info(skb);
@@ -611,6 +722,11 @@ static netdev_tx_t erspan_xmit(struct sk_buff *skb, 
	struct ip_tunnel *tunnel = netdev_priv(dev);

	bool truncate = false;



	if (tunnel->collect_md) {

		erspan_fb_xmit(skb, dev, skb->protocol);

		return NETDEV_TX_OK;

	}



	if (gre_handle_offloads(skb, false))

		goto free_skb;
@@ -973,9 +1089,12 @@ static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 
		return ret;



	/* ERSPAN 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])

		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);

	if (flags != (GRE_SEQ | GRE_KEY))

	if (!data[IFLA_GRE_COLLECT_METADATA] &&

	    flags != (GRE_SEQ | GRE_KEY))

		return -EINVAL;



	/* ERSPAN Session ID only has 10-bit. Since we reuse

samples/bpf/tcbpf2_kern.c

+62 −1
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <uapi/linux/pkt_cls.h>

#include <net/ipv6.h>

#include "bpf_helpers.h"

#include "bpf_endian.h"



#define _htonl __builtin_bswap32

#define ERROR(ret) do {\
@@ -38,6 +39,10 @@ struct vxlan_metadata { 
	u32     gbp;

};



struct erspan_metadata {

	__be32 index;

};



SEC("gre_set_tunnel")

int _gre_set_tunnel(struct __sk_buff *skb)

{
@@ -76,6 +81,63 @@ int _gre_get_tunnel(struct __sk_buff *skb) 
	return TC_ACT_OK;

}



SEC("erspan_set_tunnel")

int _erspan_set_tunnel(struct __sk_buff *skb)

{

	struct bpf_tunnel_key key;

	struct erspan_metadata md;

	int ret;



	__builtin_memset(&key, 0x0, sizeof(key));

	key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */

	key.tunnel_id = 2;

	key.tunnel_tos = 0;

	key.tunnel_ttl = 64;



	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key), BPF_F_ZERO_CSUM_TX);

	if (ret < 0) {

		ERROR(ret);

		return TC_ACT_SHOT;

	}



	md.index = htonl(123);

	ret = bpf_skb_set_tunnel_opt(skb, &md, sizeof(md));

	if (ret < 0) {

		ERROR(ret);

		return TC_ACT_SHOT;

	}



	return TC_ACT_OK;

}



SEC("erspan_get_tunnel")

int _erspan_get_tunnel(struct __sk_buff *skb)

{

	char fmt[] = "key %d remote ip 0x%x erspan index 0x%x\n";

	struct bpf_tunnel_key key;

	struct erspan_metadata md;

	u32 index;

	int ret;



	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);

	if (ret < 0) {

		ERROR(ret);

		return TC_ACT_SHOT;

	}



	ret = bpf_skb_get_tunnel_opt(skb, &md, sizeof(md));

	if (ret < 0) {

		ERROR(ret);

		return TC_ACT_SHOT;

	}



	index = bpf_ntohl(md.index);

	bpf_trace_printk(fmt, sizeof(fmt),

			key.tunnel_id, key.remote_ipv4, index);



	return TC_ACT_OK;

}



SEC("vxlan_set_tunnel")

int _vxlan_set_tunnel(struct __sk_buff *skb)

{
@@ -378,5 +440,4 @@ int _ip6ip6_get_tunnel(struct __sk_buff *skb) 
	return TC_ACT_OK;

}





char _license[] SEC("license") = "GPL";

samples/bpf/test_tunnel_bpf.sh

+29 −0
Original line number Diff line number Diff line
@@ -32,6 +32,19 @@ function add_gre_tunnel { 
	ip addr add dev $DEV 10.1.1.200/24

}



function add_erspan_tunnel {

	# in namespace

	ip netns exec at_ns0 \

		ip link add dev $DEV_NS type $TYPE seq key 2 local 172.16.1.100 remote 172.16.1.200 erspan 123

	ip netns exec at_ns0 ip link set dev $DEV_NS up

	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24



	# out of namespace

	ip link add dev $DEV type $TYPE external

	ip link set dev $DEV up

	ip addr add dev $DEV 10.1.1.200/24

}



function add_vxlan_tunnel {

	# Set static ARP entry here because iptables set-mark works

	# on L3 packet, as a result not applying to ARP packets,
@@ -99,6 +112,18 @@ function test_gre { 
	cleanup

}



function test_erspan {

	TYPE=erspan

	DEV_NS=erspan00

	DEV=erspan11

	config_device

	add_erspan_tunnel

	attach_bpf $DEV erspan_set_tunnel erspan_get_tunnel

	ping -c 1 10.1.1.100

	ip netns exec at_ns0 ping -c 1 10.1.1.200

	cleanup

}



function test_vxlan {

	TYPE=vxlan

	DEV_NS=vxlan00
@@ -151,14 +176,18 @@ function cleanup { 
	ip link del gretap11

	ip link del vxlan11

	ip link del geneve11

	ip link del erspan11

	pkill tcpdump

	pkill cat

	set -ex

}



trap cleanup 0 2 3 6 9

cleanup

echo "Testing GRE tunnel..."

test_gre

echo "Testing ERSPAN tunnel..."

test_erspan

echo "Testing VXLAN tunnel..."

test_vxlan

echo "Testing GENEVE tunnel..."

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