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Commit 2e15ea39 authored by Pravin B Shelar's avatar Pravin B Shelar Committed by David S. Miller
Browse files

ip_gre: Add support to collect tunnel metadata. 



Following patch create new tunnel flag which enable
tunnel metadata collection on given device.

Signed-off-by: default avatarPravin B Shelar <pshelar@nicira.com>
Acked-by: default avatarThomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a9020fde

include/net/ip_tunnels.h

+6 −1
Original line number Diff line number Diff line
@@ -82,6 +82,8 @@ struct ip_tunnel_dst { 
	__be32				 saddr;

};



struct metadata_dst;



struct ip_tunnel {

	struct ip_tunnel __rcu	*next;

	struct hlist_node hash_node;
@@ -115,6 +117,7 @@ struct ip_tunnel { 
	unsigned int		prl_count;	/* # of entries in PRL */

	int			ip_tnl_net_id;

	struct gro_cells	gro_cells;

	bool			collect_md;

};



#define TUNNEL_CSUM		__cpu_to_be16(0x01)
@@ -149,6 +152,7 @@ struct tnl_ptk_info { 
struct ip_tunnel_net {

	struct net_device *fb_tunnel_dev;

	struct hlist_head tunnels[IP_TNL_HASH_SIZE];

	struct ip_tunnel __rcu *collect_md_tun;

};



struct ip_tunnel_encap_ops {
@@ -235,7 +239,8 @@ struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, 
				   __be32 key);



int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,

		  const struct tnl_ptk_info *tpi, bool log_ecn_error);

		  const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,

		  bool log_ecn_error);

int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],

			 struct ip_tunnel_parm *p);

int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],

include/uapi/linux/if_tunnel.h

+1 −0
Original line number Diff line number Diff line
@@ -112,6 +112,7 @@ enum { 
	IFLA_GRE_ENCAP_FLAGS,

	IFLA_GRE_ENCAP_SPORT,

	IFLA_GRE_ENCAP_DPORT,

	IFLA_GRE_COLLECT_METADATA,

	__IFLA_GRE_MAX,

};

net/ipv4/ip_gre.c

+179 −16
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/udp.h>

#include <linux/if_arp.h>

#include <linux/mroute.h>

#include <linux/if_vlan.h>

#include <linux/init.h>

#include <linux/in6.h>

#include <linux/inetdevice.h>
@@ -47,6 +48,7 @@ 
#include <net/netns/generic.h>

#include <net/rtnetlink.h>

#include <net/gre.h>

#include <net/dst_metadata.h>



#if IS_ENABLED(CONFIG_IPV6)

#include <net/ipv6.h>
@@ -200,9 +202,29 @@ static int ipgre_err(struct sk_buff *skb, u32 info, 
	return PACKET_RCVD;

}



static __be64 key_to_tunnel_id(__be32 key)

{

#ifdef __BIG_ENDIAN

	return (__force __be64)((__force u32)key);

#else

	return (__force __be64)((__force u64)key << 32);

#endif

}



/* Returns the least-significant 32 bits of a __be64. */

static __be32 tunnel_id_to_key(__be64 x)

{

#ifdef __BIG_ENDIAN

	return (__force __be32)x;

#else

	return (__force __be32)((__force u64)x >> 32);

#endif

}



static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)

{

	struct net *net = dev_net(skb->dev);

	struct metadata_dst *tun_dst = NULL;

	struct ip_tunnel_net *itn;

	const struct iphdr *iph;

	struct ip_tunnel *tunnel;
@@ -218,40 +240,162 @@ static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi) 


	if (tunnel) {

		skb_pop_mac_header(skb);

		ip_tunnel_rcv(tunnel, skb, tpi, log_ecn_error);

		if (tunnel->collect_md) {

			struct ip_tunnel_info *info;



			tun_dst = metadata_dst_alloc(0, GFP_ATOMIC);

			if (!tun_dst)

				return PACKET_REJECT;



			info = &tun_dst->u.tun_info;

			info->key.ipv4_src = iph->saddr;

			info->key.ipv4_dst = iph->daddr;

			info->key.ipv4_tos = iph->tos;

			info->key.ipv4_ttl = iph->ttl;



			info->mode = IP_TUNNEL_INFO_RX;

			info->key.tun_flags = tpi->flags &

					      (TUNNEL_CSUM | TUNNEL_KEY);

			info->key.tun_id = key_to_tunnel_id(tpi->key);



			info->key.tp_src = 0;

			info->key.tp_dst = 0;

		}



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

		return PACKET_RCVD;

	}

	return PACKET_REJECT;

}



static void build_header(struct sk_buff *skb, int hdr_len, __be16 flags,

			 __be16 proto, __be32 key, __be32 seq)

{

	struct gre_base_hdr *greh;



	skb_push(skb, hdr_len);



	skb_reset_transport_header(skb);

	greh = (struct gre_base_hdr *)skb->data;

	greh->flags = tnl_flags_to_gre_flags(flags);

	greh->protocol = proto;



	if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) {

		__be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4);



		if (flags & TUNNEL_SEQ) {

			*ptr = seq;

			ptr--;

		}

		if (flags & TUNNEL_KEY) {

			*ptr = key;

			ptr--;

		}

		if (flags & TUNNEL_CSUM &&

		    !(skb_shinfo(skb)->gso_type &

		      (SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) {

			*ptr = 0;

			*(__sum16 *)ptr = csum_fold(skb_checksum(skb, 0,

								 skb->len, 0));

		}

	}

}



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

		       const struct iphdr *tnl_params,

		       __be16 proto)

{

	struct ip_tunnel *tunnel = netdev_priv(dev);

	struct tnl_ptk_info tpi;



	tpi.flags = tunnel->parms.o_flags;

	tpi.proto = proto;

	tpi.key = tunnel->parms.o_key;

	if (tunnel->parms.o_flags & TUNNEL_SEQ)

		tunnel->o_seqno++;

	tpi.seq = htonl(tunnel->o_seqno);



	/* Push GRE header. */

	gre_build_header(skb, &tpi, tunnel->tun_hlen);



	skb_set_inner_protocol(skb, tpi.proto);

	build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,

		     proto, tunnel->parms.o_key, htonl(tunnel->o_seqno));



	skb_set_inner_protocol(skb, proto);

	ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);

}



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

{

	struct ip_tunnel_info *tun_info;

	struct net *net = dev_net(dev);

	const struct ip_tunnel_key *key;

	struct flowi4 fl;

	struct rtable *rt;

	int min_headroom;

	int tunnel_hlen;

	__be16 df, flags;

	int err;



	tun_info = skb_tunnel_info(skb, AF_INET);

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

		goto err_free_skb;



	key = &tun_info->key;

	memset(&fl, 0, sizeof(fl));

	fl.daddr = key->ipv4_dst;

	fl.saddr = key->ipv4_src;

	fl.flowi4_tos = RT_TOS(key->ipv4_tos);

	fl.flowi4_mark = skb->mark;

	fl.flowi4_proto = IPPROTO_GRE;



	rt = ip_route_output_key(net, &fl);

	if (IS_ERR(rt))

		goto err_free_skb;



	tunnel_hlen = ip_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)) {

		int head_delta = SKB_DATA_ALIGN(min_headroom -

						skb_headroom(skb) +

						16);

		err = pskb_expand_head(skb, max_t(int, head_delta, 0),

				       0, GFP_ATOMIC);

		if (unlikely(err))

			goto err_free_rt;

	}



	/* Push Tunnel header. */

	skb = gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM));

	if (IS_ERR(skb)) {

		skb = NULL;

		goto err_free_rt;

	}



	flags = tun_info->key.tun_flags & (TUNNEL_CSUM | TUNNEL_KEY);

	build_header(skb, tunnel_hlen, flags, htons(ETH_P_TEB),

		     tunnel_id_to_key(tun_info->key.tun_id), 0);



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

	err = iptunnel_xmit(skb->sk, rt, skb, fl.saddr,

			    key->ipv4_dst, IPPROTO_GRE,

			    key->ipv4_tos, key->ipv4_ttl, df, false);

	iptunnel_xmit_stats(err, &dev->stats, dev->tstats);

	return;



err_free_rt:

	ip_rt_put(rt);

err_free_skb:

	kfree_skb(skb);

	dev->stats.tx_dropped++;

}



static netdev_tx_t ipgre_xmit(struct sk_buff *skb,

			      struct net_device *dev)

{

	struct ip_tunnel *tunnel = netdev_priv(dev);

	const struct iphdr *tnl_params;



	if (tunnel->collect_md) {

		gre_fb_xmit(skb, dev);

		return NETDEV_TX_OK;

	}



	if (dev->header_ops) {

		/* Need space for new headers */

		if (skb_cow_head(skb, dev->needed_headroom -
@@ -277,7 +421,6 @@ static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 
		goto out;



	__gre_xmit(skb, dev, tnl_params, skb->protocol);



	return NETDEV_TX_OK;



free_skb:
@@ -292,6 +435,11 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 
{

	struct ip_tunnel *tunnel = netdev_priv(dev);



	if (tunnel->collect_md) {

		gre_fb_xmit(skb, dev);

		return NETDEV_TX_OK;

	}



	skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM));

	if (IS_ERR(skb))

		goto out;
@@ -300,7 +448,6 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 
		goto free_skb;



	__gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB));



	return NETDEV_TX_OK;



free_skb:
@@ -596,7 +743,9 @@ static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[]) 
	return ipgre_tunnel_validate(tb, data);

}



static void ipgre_netlink_parms(struct nlattr *data[], struct nlattr *tb[],

static void ipgre_netlink_parms(struct net_device *dev,

				struct nlattr *data[],

				struct nlattr *tb[],

				struct ip_tunnel_parm *parms)

{

	memset(parms, 0, sizeof(*parms));
@@ -635,6 +784,12 @@ static void ipgre_netlink_parms(struct nlattr *data[], struct nlattr *tb[], 


	if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))

		parms->iph.frag_off = htons(IP_DF);



	if (data[IFLA_GRE_COLLECT_METADATA]) {

		struct ip_tunnel *t = netdev_priv(dev);



		t->collect_md = true;

	}

}



/* This function returns true when ENCAP attributes are present in the nl msg */
@@ -712,7 +867,7 @@ static int ipgre_newlink(struct net *src_net, struct net_device *dev, 
			return err;

	}



	ipgre_netlink_parms(data, tb, &p);

	ipgre_netlink_parms(dev, data, tb, &p);

	return ip_tunnel_newlink(dev, tb, &p);

}
@@ -730,7 +885,7 @@ static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 
			return err;

	}



	ipgre_netlink_parms(data, tb, &p);

	ipgre_netlink_parms(dev, data, tb, &p);

	return ip_tunnel_changelink(dev, tb, &p);

}
@@ -765,6 +920,8 @@ static size_t ipgre_get_size(const struct net_device *dev) 
		nla_total_size(2) +

		/* IFLA_GRE_ENCAP_DPORT */

		nla_total_size(2) +

		/* IFLA_GRE_COLLECT_METADATA */

		nla_total_size(0) +

		0;

}
@@ -796,6 +953,11 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 
			t->encap.flags))

		goto nla_put_failure;



	if (t->collect_md) {

		if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))

			goto nla_put_failure;

	}



	return 0;



nla_put_failure:
@@ -817,6 +979,7 @@ static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 
	[IFLA_GRE_ENCAP_FLAGS]	= { .type = NLA_U16 },

	[IFLA_GRE_ENCAP_SPORT]	= { .type = NLA_U16 },

	[IFLA_GRE_ENCAP_DPORT]	= { .type = NLA_U16 },

	[IFLA_GRE_COLLECT_METADATA]	= { .type = NLA_FLAG },

};



static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
@@ -851,7 +1014,7 @@ static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 


static int __net_init ipgre_tap_init_net(struct net *net)

{

	return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, NULL);

	return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0");

}



static void __net_exit ipgre_tap_exit_net(struct net *net)

net/ipv4/ip_tunnel.c

+28 −9
Original line number Diff line number Diff line
@@ -230,10 +230,13 @@ struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, 
	if (cand)

		return cand;



	t = rcu_dereference(itn->collect_md_tun);

	if (t)

		return t;



	if (itn->fb_tunnel_dev && itn->fb_tunnel_dev->flags & IFF_UP)

		return netdev_priv(itn->fb_tunnel_dev);





	return NULL;

}

EXPORT_SYMBOL_GPL(ip_tunnel_lookup);
@@ -261,11 +264,15 @@ static void ip_tunnel_add(struct ip_tunnel_net *itn, struct ip_tunnel *t) 
{

	struct hlist_head *head = ip_bucket(itn, &t->parms);



	if (t->collect_md)

		rcu_assign_pointer(itn->collect_md_tun, t);

	hlist_add_head_rcu(&t->hash_node, head);

}



static void ip_tunnel_del(struct ip_tunnel *t)

static void ip_tunnel_del(struct ip_tunnel_net *itn, struct ip_tunnel *t)

{

	if (t->collect_md)

		rcu_assign_pointer(itn->collect_md_tun, NULL);

	hlist_del_init_rcu(&t->hash_node);

}
@@ -419,7 +426,8 @@ static struct ip_tunnel *ip_tunnel_create(struct net *net, 
}



int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,

		  const struct tnl_ptk_info *tpi, bool log_ecn_error)

		  const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,

		  bool log_ecn_error)

{

	struct pcpu_sw_netstats *tstats;

	const struct iphdr *iph = ip_hdr(skb);
@@ -478,6 +486,9 @@ int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, 
		skb->dev = tunnel->dev;

	}



	if (tun_dst)

		skb_dst_set(skb, (struct dst_entry *)tun_dst);



	gro_cells_receive(&tunnel->gro_cells, skb);

	return 0;
@@ -806,7 +817,7 @@ static void ip_tunnel_update(struct ip_tunnel_net *itn, 
			     struct ip_tunnel_parm *p,

			     bool set_mtu)

{

	ip_tunnel_del(t);

	ip_tunnel_del(itn, t);

	t->parms.iph.saddr = p->iph.saddr;

	t->parms.iph.daddr = p->iph.daddr;

	t->parms.i_key = p->i_key;
@@ -967,7 +978,7 @@ void ip_tunnel_dellink(struct net_device *dev, struct list_head *head) 
	itn = net_generic(tunnel->net, tunnel->ip_tnl_net_id);



	if (itn->fb_tunnel_dev != dev) {

		ip_tunnel_del(netdev_priv(dev));

		ip_tunnel_del(itn, netdev_priv(dev));

		unregister_netdevice_queue(dev, head);

	}

}
@@ -1072,8 +1083,13 @@ int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], 
	nt = netdev_priv(dev);

	itn = net_generic(net, nt->ip_tnl_net_id);



	if (nt->collect_md) {

		if (rtnl_dereference(itn->collect_md_tun))

			return -EEXIST;

	} else {

		if (ip_tunnel_find(itn, p, dev->type))

			return -EEXIST;

	}



	nt->net = net;

	nt->parms = *p;
@@ -1089,7 +1105,6 @@ int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], 
		dev->mtu = mtu;



	ip_tunnel_add(itn, nt);



out:

	return err;

}
@@ -1163,6 +1178,10 @@ int ip_tunnel_init(struct net_device *dev) 
	iph->version		= 4;

	iph->ihl		= 5;



	if (tunnel->collect_md) {

		dev->features |= NETIF_F_NETNS_LOCAL;

		netif_keep_dst(dev);

	}

	return 0;

}

EXPORT_SYMBOL_GPL(ip_tunnel_init);
@@ -1176,7 +1195,7 @@ void ip_tunnel_uninit(struct net_device *dev) 
	itn = net_generic(net, tunnel->ip_tnl_net_id);

	/* fb_tunnel_dev will be unregisted in net-exit call. */

	if (itn->fb_tunnel_dev != dev)

		ip_tunnel_del(netdev_priv(dev));

		ip_tunnel_del(itn, netdev_priv(dev));



	ip_tunnel_dst_reset_all(tunnel);

}

net/ipv4/ipip.c

+1 −1
Original line number Diff line number Diff line
@@ -198,7 +198,7 @@ static int ipip_rcv(struct sk_buff *skb) 
			goto drop;

		if (iptunnel_pull_header(skb, 0, tpi.proto))

			goto drop;

		return ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error);

		return ip_tunnel_rcv(tunnel, skb, &tpi, NULL, log_ecn_error);

	}



	return -1;