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Commit 5b861f6b authored by Girish Moodalbail's avatar Girish Moodalbail Committed by David S. Miller
Browse files

geneve: add rtnl changelink support 



This patch adds changelink rtnl operation support for geneve devices
and the code changes involve:

  - added geneve_quiesce() which quiesces the geneve device data path
    for both TX and RX. This lets us perform the changelink operation
    atomically w.r.t data path. Also added geneve_unquiesce() to
    reverse the operation of geneve_quiesce().

  - refactor geneve_newlink into geneve_nl2info to be used by both
    geneve_newlink and geneve_changelink

  - geneve_nl2info takes a changelink boolean argument to isolate
    changelink checks.

  - Allow changing only a few attributes (ttl, tos, and remote tunnel
    endpoint IP address (within the same address family)):
    - return -EOPNOTSUPP for attributes that cannot be changed for
      now. Incremental patches can make the non-supported one
      available in the future if needed.

Signed-off-by: default avatarGirish Moodalbail <girish.moodalbail@oracle.com>
Acked-by: default avatarPravin B Shelar <pshelar@ovn.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f7ce9103

drivers/net/geneve.c

+176 −42
Original line number Diff line number Diff line
@@ -715,6 +715,7 @@ static int geneve_build_skb(struct dst_entry *dst, struct sk_buff *skb, 


static struct rtable *geneve_get_v4_rt(struct sk_buff *skb,

				       struct net_device *dev,

				       struct geneve_sock *gs4,

				       struct flowi4 *fl4,

				       const struct ip_tunnel_info *info)

{
@@ -724,7 +725,7 @@ static struct rtable *geneve_get_v4_rt(struct sk_buff *skb, 
	struct rtable *rt = NULL;

	__u8 tos;



	if (!rcu_dereference(geneve->sock4))

	if (!gs4)

		return ERR_PTR(-EIO);



	memset(fl4, 0, sizeof(*fl4));
@@ -764,6 +765,7 @@ static struct rtable *geneve_get_v4_rt(struct sk_buff *skb, 
#if IS_ENABLED(CONFIG_IPV6)

static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb,

					   struct net_device *dev,

					   struct geneve_sock *gs6,

					   struct flowi6 *fl6,

					   const struct ip_tunnel_info *info)

{
@@ -771,10 +773,8 @@ static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb, 
	struct geneve_dev *geneve = netdev_priv(dev);

	struct dst_entry *dst = NULL;

	struct dst_cache *dst_cache;

	struct geneve_sock *gs6;

	__u8 prio;



	gs6 = rcu_dereference(geneve->sock6);

	if (!gs6)

		return ERR_PTR(-EIO);
@@ -827,7 +827,7 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev, 
	__be16 df;

	int err;



	rt = geneve_get_v4_rt(skb, dev, &fl4, info);

	rt = geneve_get_v4_rt(skb, dev, gs4, &fl4, info);

	if (IS_ERR(rt))

		return PTR_ERR(rt);
@@ -866,7 +866,7 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev, 
	__be16 sport;

	int err;



	dst = geneve_get_v6_dst(skb, dev, &fl6, info);

	dst = geneve_get_v6_dst(skb, dev, gs6, &fl6, info);

	if (IS_ERR(dst))

		return PTR_ERR(dst);
@@ -951,8 +951,9 @@ static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 
	if (ip_tunnel_info_af(info) == AF_INET) {

		struct rtable *rt;

		struct flowi4 fl4;

		struct geneve_sock *gs4 = rcu_dereference(geneve->sock4);



		rt = geneve_get_v4_rt(skb, dev, &fl4, info);

		rt = geneve_get_v4_rt(skb, dev, gs4, &fl4, info);

		if (IS_ERR(rt))

			return PTR_ERR(rt);
@@ -962,8 +963,9 @@ static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 
	} else if (ip_tunnel_info_af(info) == AF_INET6) {

		struct dst_entry *dst;

		struct flowi6 fl6;

		struct geneve_sock *gs6 = rcu_dereference(geneve->sock6);



		dst = geneve_get_v6_dst(skb, dev, &fl6, info);

		dst = geneve_get_v6_dst(skb, dev, gs6, &fl6, info);

		if (IS_ERR(dst))

			return PTR_ERR(dst);
@@ -1140,6 +1142,15 @@ static bool is_tnl_info_zero(const struct ip_tunnel_info *info) 
		return true;

}



static bool geneve_dst_addr_equal(struct ip_tunnel_info *a,

				  struct ip_tunnel_info *b)

{

	if (ip_tunnel_info_af(a) == AF_INET)

		return a->key.u.ipv4.dst == b->key.u.ipv4.dst;

	else

		return ipv6_addr_equal(&a->key.u.ipv6.dst, &b->key.u.ipv6.dst);

}



static int geneve_configure(struct net *net, struct net_device *dev,

			    const struct ip_tunnel_info *info,

			    bool metadata, bool ipv6_rx_csum)
@@ -1197,24 +1208,22 @@ static void init_tnl_info(struct ip_tunnel_info *info, __u16 dst_port) 
	info->key.tp_dst = htons(dst_port);

}



static int geneve_newlink(struct net *net, struct net_device *dev,

			  struct nlattr *tb[], struct nlattr *data[],

			  struct netlink_ext_ack *extack)

static int geneve_nl2info(struct net_device *dev, struct nlattr *tb[],

			  struct nlattr *data[], struct ip_tunnel_info *info,

			  bool *metadata, bool *use_udp6_rx_checksums,

			  bool changelink)

{

	bool use_udp6_rx_checksums = false;

	struct ip_tunnel_info info;

	bool metadata = false;



	init_tnl_info(&info, GENEVE_UDP_PORT);



	if (data[IFLA_GENEVE_REMOTE] && data[IFLA_GENEVE_REMOTE6])

		return -EINVAL;



	if (data[IFLA_GENEVE_REMOTE]) {

		info.key.u.ipv4.dst =

		if (changelink && (ip_tunnel_info_af(info) == AF_INET6))

			return -EOPNOTSUPP;



		info->key.u.ipv4.dst =

			nla_get_in_addr(data[IFLA_GENEVE_REMOTE]);



		if (IN_MULTICAST(ntohl(info.key.u.ipv4.dst))) {

		if (IN_MULTICAST(ntohl(info->key.u.ipv4.dst))) {

			netdev_dbg(dev, "multicast remote is unsupported\n");

			return -EINVAL;

		}
@@ -1222,21 +1231,24 @@ static int geneve_newlink(struct net *net, struct net_device *dev, 


	if (data[IFLA_GENEVE_REMOTE6]) {

 #if IS_ENABLED(CONFIG_IPV6)

		info.mode = IP_TUNNEL_INFO_IPV6;

		info.key.u.ipv6.dst =

		if (changelink && (ip_tunnel_info_af(info) == AF_INET))

			return -EOPNOTSUPP;



		info->mode = IP_TUNNEL_INFO_IPV6;

		info->key.u.ipv6.dst =

			nla_get_in6_addr(data[IFLA_GENEVE_REMOTE6]);



		if (ipv6_addr_type(&info.key.u.ipv6.dst) &

		if (ipv6_addr_type(&info->key.u.ipv6.dst) &

		    IPV6_ADDR_LINKLOCAL) {

			netdev_dbg(dev, "link-local remote is unsupported\n");

			return -EINVAL;

		}

		if (ipv6_addr_is_multicast(&info.key.u.ipv6.dst)) {

		if (ipv6_addr_is_multicast(&info->key.u.ipv6.dst)) {

			netdev_dbg(dev, "multicast remote is unsupported\n");

			return -EINVAL;

		}

		info.key.tun_flags |= TUNNEL_CSUM;

		use_udp6_rx_checksums = true;

		info->key.tun_flags |= TUNNEL_CSUM;

		*use_udp6_rx_checksums = true;

#else

		return -EPFNOSUPPORT;

#endif
@@ -1245,48 +1257,169 @@ static int geneve_newlink(struct net *net, struct net_device *dev, 
	if (data[IFLA_GENEVE_ID]) {

		__u32 vni;

		__u8 tvni[3];

		__be64 tunid;



		vni = nla_get_u32(data[IFLA_GENEVE_ID]);

		tvni[0] = (vni & 0x00ff0000) >> 16;

		tvni[1] = (vni & 0x0000ff00) >> 8;

		tvni[2] =  vni & 0x000000ff;



		info.key.tun_id = vni_to_tunnel_id(tvni);

		tunid = vni_to_tunnel_id(tvni);

		if (changelink && (tunid != info->key.tun_id))

			return -EOPNOTSUPP;

		info->key.tun_id = tunid;

	}



	if (data[IFLA_GENEVE_TTL])

		info.key.ttl = nla_get_u8(data[IFLA_GENEVE_TTL]);

		info->key.ttl = nla_get_u8(data[IFLA_GENEVE_TTL]);



	if (data[IFLA_GENEVE_TOS])

		info.key.tos = nla_get_u8(data[IFLA_GENEVE_TOS]);

		info->key.tos = nla_get_u8(data[IFLA_GENEVE_TOS]);



	if (data[IFLA_GENEVE_LABEL]) {

		info.key.label = nla_get_be32(data[IFLA_GENEVE_LABEL]) &

		info->key.label = nla_get_be32(data[IFLA_GENEVE_LABEL]) &

				  IPV6_FLOWLABEL_MASK;

		if (info.key.label && (!(info.mode & IP_TUNNEL_INFO_IPV6)))

		if (info->key.label && (!(info->mode & IP_TUNNEL_INFO_IPV6)))

			return -EINVAL;

	}



	if (data[IFLA_GENEVE_PORT])

		info.key.tp_dst = nla_get_be16(data[IFLA_GENEVE_PORT]);

	if (data[IFLA_GENEVE_PORT]) {

		if (changelink)

			return -EOPNOTSUPP;

		info->key.tp_dst = nla_get_be16(data[IFLA_GENEVE_PORT]);

	}



	if (data[IFLA_GENEVE_COLLECT_METADATA])

		metadata = true;

	if (data[IFLA_GENEVE_COLLECT_METADATA]) {

		if (changelink)

			return -EOPNOTSUPP;

		*metadata = true;

	}



	if (data[IFLA_GENEVE_UDP_CSUM]) {

		if (changelink)

			return -EOPNOTSUPP;

		if (nla_get_u8(data[IFLA_GENEVE_UDP_CSUM]))

			info->key.tun_flags |= TUNNEL_CSUM;

	}



	if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX]) {

		if (changelink)

			return -EOPNOTSUPP;

		if (nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX]))

			info->key.tun_flags &= ~TUNNEL_CSUM;

	}



	if (data[IFLA_GENEVE_UDP_CSUM] &&

	    nla_get_u8(data[IFLA_GENEVE_UDP_CSUM]))

		info.key.tun_flags |= TUNNEL_CSUM;

	if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX]) {

		if (changelink)

			return -EOPNOTSUPP;

		if (nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX]))

			*use_udp6_rx_checksums = false;

	}



	return 0;

}



	if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX] &&

	    nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX]))

		info.key.tun_flags &= ~TUNNEL_CSUM;

static int geneve_newlink(struct net *net, struct net_device *dev,

			  struct nlattr *tb[], struct nlattr *data[],

			  struct netlink_ext_ack *extack)

{

	bool use_udp6_rx_checksums = false;

	struct ip_tunnel_info info;

	bool metadata = false;

	int err;



	if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX] &&

	    nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX]))

		use_udp6_rx_checksums = false;

	init_tnl_info(&info, GENEVE_UDP_PORT);

	err = geneve_nl2info(dev, tb, data, &info, &metadata,

			     &use_udp6_rx_checksums, false);

	if (err)

		return err;



	return geneve_configure(net, dev, &info, metadata, use_udp6_rx_checksums);

}



/* Quiesces the geneve device data path for both TX and RX.

 *

 * On transmit geneve checks for non-NULL geneve_sock before it proceeds.

 * So, if we set that socket to NULL under RCU and wait for synchronize_net()

 * to complete for the existing set of in-flight packets to be transmitted,

 * then we would have quiesced the transmit data path. All the future packets

 * will get dropped until we unquiesce the data path.

 *

 * On receive geneve dereference the geneve_sock stashed in the socket. So,

 * if we set that to NULL under RCU and wait for synchronize_net() to

 * complete, then we would have quiesced the receive data path.

 */

static void geneve_quiesce(struct geneve_dev *geneve, struct geneve_sock **gs4,

			   struct geneve_sock **gs6)

{

	*gs4 = rtnl_dereference(geneve->sock4);

	rcu_assign_pointer(geneve->sock4, NULL);

	if (*gs4)

		rcu_assign_sk_user_data((*gs4)->sock->sk, NULL);

#if IS_ENABLED(CONFIG_IPV6)

	*gs6 = rtnl_dereference(geneve->sock6);

	rcu_assign_pointer(geneve->sock6, NULL);

	if (*gs6)

		rcu_assign_sk_user_data((*gs6)->sock->sk, NULL);

#else

	*gs6 = NULL;

#endif

	synchronize_net();

}



/* Resumes the geneve device data path for both TX and RX. */

static void geneve_unquiesce(struct geneve_dev *geneve, struct geneve_sock *gs4,

			     struct geneve_sock __maybe_unused *gs6)

{

	rcu_assign_pointer(geneve->sock4, gs4);

	if (gs4)

		rcu_assign_sk_user_data(gs4->sock->sk, gs4);

#if IS_ENABLED(CONFIG_IPV6)

	rcu_assign_pointer(geneve->sock6, gs6);

	if (gs6)

		rcu_assign_sk_user_data(gs6->sock->sk, gs6);

#endif

	synchronize_net();

}



static int geneve_changelink(struct net_device *dev, struct nlattr *tb[],

			     struct nlattr *data[],

			     struct netlink_ext_ack *extack)

{

	struct geneve_dev *geneve = netdev_priv(dev);

	struct geneve_sock *gs4, *gs6;

	struct ip_tunnel_info info;

	bool metadata;

	bool use_udp6_rx_checksums;

	int err;



	/* If the geneve device is configured for metadata (or externally

	 * controlled, for example, OVS), then nothing can be changed.

	 */

	if (geneve->collect_md)

		return -EOPNOTSUPP;



	/* Start with the existing info. */

	memcpy(&info, &geneve->info, sizeof(info));

	metadata = geneve->collect_md;

	use_udp6_rx_checksums = geneve->use_udp6_rx_checksums;

	err = geneve_nl2info(dev, tb, data, &info, &metadata,

			     &use_udp6_rx_checksums, true);

	if (err)

		return err;



	if (!geneve_dst_addr_equal(&geneve->info, &info))

		dst_cache_reset(&info.dst_cache);



	geneve_quiesce(geneve, &gs4, &gs6);

	geneve->info = info;

	geneve->collect_md = metadata;

	geneve->use_udp6_rx_checksums = use_udp6_rx_checksums;

	geneve_unquiesce(geneve, gs4, gs6);



	return 0;

}



static void geneve_dellink(struct net_device *dev, struct list_head *head)

{

	struct geneve_dev *geneve = netdev_priv(dev);
@@ -1375,6 +1508,7 @@ static struct rtnl_link_ops geneve_link_ops __read_mostly = { 
	.setup		= geneve_setup,

	.validate	= geneve_validate,

	.newlink	= geneve_newlink,

	.changelink	= geneve_changelink,

	.dellink	= geneve_dellink,

	.get_size	= geneve_get_size,

	.fill_info	= geneve_fill_info,