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Commit 4565e991 authored by Tom Herbert's avatar Tom Herbert Committed by David S. Miller
Browse files

gre: Setup and TX path for gre/UDP foo-over-udp encapsulation 



Added netlink attrs to configure FOU encapsulation for GRE, netlink
handling of these flags, and properly adjust MTU for encapsulation.
ip_tunnel_encap is called from ip_tunnel_xmit to actually perform FOU
encapsulation.

Signed-off-by: default avatarTom Herbert <therbert@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 473ab820

include/uapi/linux/if_tunnel.h

+4 −0
Original line number Diff line number Diff line
@@ -106,6 +106,10 @@ enum { 
	IFLA_GRE_ENCAP_LIMIT,

	IFLA_GRE_FLOWINFO,

	IFLA_GRE_FLAGS,

	IFLA_GRE_ENCAP_TYPE,

	IFLA_GRE_ENCAP_FLAGS,

	IFLA_GRE_ENCAP_SPORT,

	IFLA_GRE_ENCAP_DPORT,

	__IFLA_GRE_MAX,

};

net/ipv4/ip_gre.c

+85 −5
Original line number Diff line number Diff line
@@ -239,7 +239,7 @@ static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 
	tpi.seq = htonl(tunnel->o_seqno);



	/* Push GRE header. */

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

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



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

}
@@ -310,7 +310,7 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 
static int ipgre_tunnel_ioctl(struct net_device *dev,

			      struct ifreq *ifr, int cmd)

{

	int err = 0;

	int err;

	struct ip_tunnel_parm p;



	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
@@ -470,13 +470,18 @@ static void ipgre_tunnel_setup(struct net_device *dev) 
static void __gre_tunnel_init(struct net_device *dev)

{

	struct ip_tunnel *tunnel;

	int t_hlen;



	tunnel = netdev_priv(dev);

	tunnel->hlen = ip_gre_calc_hlen(tunnel->parms.o_flags);

	tunnel->tun_hlen = ip_gre_calc_hlen(tunnel->parms.o_flags);

	tunnel->parms.iph.protocol = IPPROTO_GRE;



	dev->needed_headroom	= LL_MAX_HEADER + sizeof(struct iphdr) + 4;

	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 4;

	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;



	t_hlen = tunnel->hlen + sizeof(struct iphdr);



	dev->needed_headroom	= LL_MAX_HEADER + t_hlen + 4;

	dev->mtu		= ETH_DATA_LEN - t_hlen - 4;



	dev->features		|= GRE_FEATURES;

	dev->hw_features	|= GRE_FEATURES;
@@ -628,6 +633,40 @@ static void ipgre_netlink_parms(struct nlattr *data[], struct nlattr *tb[], 
		parms->iph.frag_off = htons(IP_DF);

}



/* This function returns true when ENCAP attributes are present in the nl msg */

static bool ipgre_netlink_encap_parms(struct nlattr *data[],

				      struct ip_tunnel_encap *ipencap)

{

	bool ret = false;



	memset(ipencap, 0, sizeof(*ipencap));



	if (!data)

		return ret;



	if (data[IFLA_GRE_ENCAP_TYPE]) {

		ret = true;

		ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);

	}



	if (data[IFLA_GRE_ENCAP_FLAGS]) {

		ret = true;

		ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);

	}



	if (data[IFLA_GRE_ENCAP_SPORT]) {

		ret = true;

		ipencap->sport = nla_get_u16(data[IFLA_GRE_ENCAP_SPORT]);

	}



	if (data[IFLA_GRE_ENCAP_DPORT]) {

		ret = true;

		ipencap->dport = nla_get_u16(data[IFLA_GRE_ENCAP_DPORT]);

	}



	return ret;

}



static int gre_tap_init(struct net_device *dev)

{

	__gre_tunnel_init(dev);
@@ -657,6 +696,15 @@ static int ipgre_newlink(struct net *src_net, struct net_device *dev, 
			 struct nlattr *tb[], struct nlattr *data[])

{

	struct ip_tunnel_parm p;

	struct ip_tunnel_encap ipencap;



	if (ipgre_netlink_encap_parms(data, &ipencap)) {

		struct ip_tunnel *t = netdev_priv(dev);

		int err = ip_tunnel_encap_setup(t, &ipencap);



		if (err < 0)

			return err;

	}



	ipgre_netlink_parms(data, tb, &p);

	return ip_tunnel_newlink(dev, tb, &p);
@@ -666,6 +714,15 @@ static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 
			    struct nlattr *data[])

{

	struct ip_tunnel_parm p;

	struct ip_tunnel_encap ipencap;



	if (ipgre_netlink_encap_parms(data, &ipencap)) {

		struct ip_tunnel *t = netdev_priv(dev);

		int err = ip_tunnel_encap_setup(t, &ipencap);



		if (err < 0)

			return err;

	}



	ipgre_netlink_parms(data, tb, &p);

	return ip_tunnel_changelink(dev, tb, &p);
@@ -694,6 +751,14 @@ static size_t ipgre_get_size(const struct net_device *dev) 
		nla_total_size(1) +

		/* IFLA_GRE_PMTUDISC */

		nla_total_size(1) +

		/* IFLA_GRE_ENCAP_TYPE */

		nla_total_size(2) +

		/* IFLA_GRE_ENCAP_FLAGS */

		nla_total_size(2) +

		/* IFLA_GRE_ENCAP_SPORT */

		nla_total_size(2) +

		/* IFLA_GRE_ENCAP_DPORT */

		nla_total_size(2) +

		0;

}
@@ -714,6 +779,17 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 
	    nla_put_u8(skb, IFLA_GRE_PMTUDISC,

		       !!(p->iph.frag_off & htons(IP_DF))))

		goto nla_put_failure;



	if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,

			t->encap.type) ||

	    nla_put_u16(skb, IFLA_GRE_ENCAP_SPORT,

			t->encap.sport) ||

	    nla_put_u16(skb, IFLA_GRE_ENCAP_DPORT,

			t->encap.dport) ||

	    nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,

			t->encap.dport))

		goto nla_put_failure;



	return 0;



nla_put_failure:
@@ -731,6 +807,10 @@ static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 
	[IFLA_GRE_TTL]		= { .type = NLA_U8 },

	[IFLA_GRE_TOS]		= { .type = NLA_U8 },

	[IFLA_GRE_PMTUDISC]	= { .type = NLA_U8 },

	[IFLA_GRE_ENCAP_TYPE]	= { .type = NLA_U16 },

	[IFLA_GRE_ENCAP_FLAGS]	= { .type = NLA_U16 },

	[IFLA_GRE_ENCAP_SPORT]	= { .type = NLA_U16 },

	[IFLA_GRE_ENCAP_DPORT]	= { .type = NLA_U16 },

};



static struct rtnl_link_ops ipgre_link_ops __read_mostly = {