diff mbox series

[v3,net-next,2/2] Special handling for IP & MPLS.

Message ID 24ec93937d65fa2afc636a2887c78ae48736a649.1573872264.git.martin.varghese@nokia.com
State Changes Requested
Delegated to: David Miller
Headers show
Series Bare UDP L3 Encapsulation Module | expand

Commit Message

Martin Varghese Nov. 16, 2019, 5:45 a.m. UTC 
From: Martin Varghese <martin.varghese@nokia.com>

Special handling is needed in bareudp module for IP & MPLS as they support
more than one ethertypes.

MPLS has 2 ethertypes. 0x8847 for MPLS unicast and 0x8848 for MPLS multicast.
While decapsulating MPLS packet from UDP packet the tunnel destination IP
address is checked to determine the ethertype. The ethertype of the packet
will be set to 0x8848 if the  tunnel destination IP address is a multicast
IP address. The ethertype of the packet will be set to 0x8847 if the
tunnel destination IP address is a unicast IP address.

IP has 2 ethertypes.0x0800 for IPV4 and 0x86dd for IPv6. The version field
of the IP header tunnelled will be checked to determine the ethertype.

This special handling to tunnel additional ethertypes will be disabled by
default and can be enabled using a flag called ext mode. This flag can be
used only with ethertypes 0x8847 and 0x0800.

Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
---
Changes in v2:
    - Fixed documentation errors.
    - Changed commit message.

Changes in v3:
    - Re-sending the patch.

 Documentation/networking/bareudp.rst | 18 ++++++++
 drivers/net/bareudp.c                | 82 +++++++++++++++++++++++++++++++++---
 include/net/bareudp.h                |  1 +
 include/uapi/linux/if_link.h         |  1 +
 4 files changed, 95 insertions(+), 7 deletions(-)

Comments

Willem de Bruijn Nov. 18, 2019, 5:30 p.m. UTC | #1 
On Sat, Nov 16, 2019 at 12:45 AM Martin Varghese
<martinvarghesenokia@gmail.com> wrote:
>
> From: Martin Varghese <martin.varghese@nokia.com>
>
> Special handling is needed in bareudp module for IP & MPLS as they support
> more than one ethertypes.
>
> MPLS has 2 ethertypes. 0x8847 for MPLS unicast and 0x8848 for MPLS multicast.
> While decapsulating MPLS packet from UDP packet the tunnel destination IP
> address is checked to determine the ethertype. The ethertype of the packet
> will be set to 0x8848 if the  tunnel destination IP address is a multicast
> IP address. The ethertype of the packet will be set to 0x8847 if the
> tunnel destination IP address is a unicast IP address.
>
> IP has 2 ethertypes.0x0800 for IPV4 and 0x86dd for IPv6. The version field
> of the IP header tunnelled will be checked to determine the ethertype.

If using ipv6 dual stack, it might make more sense to use extended
mode with the ipv6 device instead of the ipv4 device.

Also, the term extended mode is not self describing. Dual stack as
term would be, but is not relevant to MPLS. Maybe "dual_proto"?

> diff --git a/Documentation/networking/bareudp.rst b/Documentation/networking/bareudp.rst
> index 2828521..1f01dfd 100644
> --- a/Documentation/networking/bareudp.rst
> +++ b/Documentation/networking/bareudp.rst
> @@ -12,6 +12,15 @@ The Bareudp tunnel module provides a generic L3 encapsulation tunnelling
>  support for tunnelling different L3 protocols like MPLS, IP, NSH etc. inside
>  a UDP tunnel.
>
> +Special Handling
> +----------------
> +The bareudp device supports special handling for MPLS & IP as they can have
> +multiple ethertypes.
> +MPLS procotcol can have ethertypes ETH_P_MPLS_UC  (unicast) & ETH_P_MPLS_MC (multicast).
> +IP proctocol can have ethertypes ETH_P_IP (v4) & ETH_P_IPV6 (v6).

proctocol -> protocol
Martin Varghese Nov. 28, 2019, 4:12 p.m. UTC | #2 
On Mon, Nov 18, 2019 at 12:30:11PM -0500, Willem de Bruijn wrote:
> On Sat, Nov 16, 2019 at 12:45 AM Martin Varghese
> <martinvarghesenokia@gmail.com> wrote:
> >
> > From: Martin Varghese <martin.varghese@nokia.com>
> >
> > Special handling is needed in bareudp module for IP & MPLS as they support
> > more than one ethertypes.
> >
> > MPLS has 2 ethertypes. 0x8847 for MPLS unicast and 0x8848 for MPLS multicast.
> > While decapsulating MPLS packet from UDP packet the tunnel destination IP
> > address is checked to determine the ethertype. The ethertype of the packet
> > will be set to 0x8848 if the  tunnel destination IP address is a multicast
> > IP address. The ethertype of the packet will be set to 0x8847 if the
> > tunnel destination IP address is a unicast IP address.
> >
> > IP has 2 ethertypes.0x0800 for IPV4 and 0x86dd for IPv6. The version field
> > of the IP header tunnelled will be checked to determine the ethertype.
> 
> If using ipv6 dual stack, it might make more sense to use extended
> mode with the ipv6 device instead of the ipv4 device.
>
ipv6 dual stack (v6 socket) is for the tunnel.the ethertype mentioned above
is for the inner protocol being tunnelled


 
> Also, the term extended mode is not self describing. Dual stack as
> term would be, but is not relevant to MPLS. Maybe "dual_proto"?
>
multi_proto ?

> > diff --git a/Documentation/networking/bareudp.rst b/Documentation/networking/bareudp.rst
> > index 2828521..1f01dfd 100644
> > --- a/Documentation/networking/bareudp.rst
> > +++ b/Documentation/networking/bareudp.rst
> > @@ -12,6 +12,15 @@ The Bareudp tunnel module provides a generic L3 encapsulation tunnelling
> >  support for tunnelling different L3 protocols like MPLS, IP, NSH etc. inside
> >  a UDP tunnel.
> >
> > +Special Handling
> > +----------------
> > +The bareudp device supports special handling for MPLS & IP as they can have
> > +multiple ethertypes.
> > +MPLS procotcol can have ethertypes ETH_P_MPLS_UC  (unicast) & ETH_P_MPLS_MC (multicast).
> > +IP proctocol can have ethertypes ETH_P_IP (v4) & ETH_P_IPV6 (v6).
> 
> proctocol -> protocol

Noted.

Thanks for your time
Willem de Bruijn Nov. 29, 2019, 6:20 p.m. UTC | #3 
On Thu, Nov 28, 2019 at 11:13 AM Martin Varghese
<martinvarghesenokia@gmail.com> wrote:
>
> On Mon, Nov 18, 2019 at 12:30:11PM -0500, Willem de Bruijn wrote:
> > On Sat, Nov 16, 2019 at 12:45 AM Martin Varghese
> > <martinvarghesenokia@gmail.com> wrote:
> > >
> > > From: Martin Varghese <martin.varghese@nokia.com>
> > >
> > > Special handling is needed in bareudp module for IP & MPLS as they support
> > > more than one ethertypes.
> > >
> > > MPLS has 2 ethertypes. 0x8847 for MPLS unicast and 0x8848 for MPLS multicast.
> > > While decapsulating MPLS packet from UDP packet the tunnel destination IP
> > > address is checked to determine the ethertype. The ethertype of the packet
> > > will be set to 0x8848 if the  tunnel destination IP address is a multicast
> > > IP address. The ethertype of the packet will be set to 0x8847 if the
> > > tunnel destination IP address is a unicast IP address.
> > >
> > > IP has 2 ethertypes.0x0800 for IPV4 and 0x86dd for IPv6. The version field
> > > of the IP header tunnelled will be checked to determine the ethertype.
> >
> > If using ipv6 dual stack, it might make more sense to use extended
> > mode with the ipv6 device instead of the ipv4 device.
> >
> ipv6 dual stack (v6 socket) is for the tunnel.the ethertype mentioned above
> is for the inner protocol being tunnelled
>
> > Also, the term extended mode is not self describing. Dual stack as
> > term would be, but is not relevant to MPLS. Maybe "dual_proto"?
> >
> multi_proto ?

Sounds good to me, thanks.
diff mbox series

Patch

diff --git a/Documentation/networking/bareudp.rst b/Documentation/networking/bareudp.rst
index 2828521..1f01dfd 100644
--- a/Documentation/networking/bareudp.rst
+++ b/Documentation/networking/bareudp.rst
@@ -12,6 +12,15 @@  The Bareudp tunnel module provides a generic L3 encapsulation tunnelling
 support for tunnelling different L3 protocols like MPLS, IP, NSH etc. inside
 a UDP tunnel.
 
+Special Handling
+----------------
+The bareudp device supports special handling for MPLS & IP as they can have
+multiple ethertypes.
+MPLS procotcol can have ethertypes ETH_P_MPLS_UC  (unicast) & ETH_P_MPLS_MC (multicast).
+IP proctocol can have ethertypes ETH_P_IP (v4) & ETH_P_IPV6 (v6).
+This special handling can be enabled only for ethertypes ETH_P_IP & ETH_P_MPLS_UC
+with a flag called extended mode.
+
 Usage
 ------
 
@@ -24,3 +33,12 @@  Usage
        6635.The device will listen on UDP port 6635 to receive traffic.
 
     b) ip link delete bareudp0
+
+2) Device creation with extended mode enabled
+
+There are two ways to create a bareudp device for MPLS & IP with extended mode
+enabled.
+
+    a) ip link add dev  bareudp0 type bareudp dstport 6635 ethertype 0x8847 extmode
+
+    b) ip link add dev  bareudp0 type bareudp dstport 6635 ethertype mpls
diff --git a/drivers/net/bareudp.c b/drivers/net/bareudp.c
index 5a8e64a..636127a 100644
--- a/drivers/net/bareudp.c
+++ b/drivers/net/bareudp.c
@@ -50,6 +50,7 @@  struct bareudp_dev {
 	struct net_device  *dev;        /* netdev for bareudp tunnel */
 	__be16		   ethertype;
 	u16	           sport_min;
+	bool               ext_mode;
 	struct bareudp_conf conf;
 	struct bareudp_sock __rcu *sock;
 	struct list_head   next;        /* bareudp node  on namespace list */
@@ -81,15 +82,64 @@  static int bareudp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 		goto drop;
 
 	bareudp = bs->bareudp;
-	proto = bareudp->ethertype;
+	if (!bareudp)
+		goto drop;
+
+	if (bareudp->ethertype == htons(ETH_P_IP)) {
+		struct iphdr *iphdr;
+
+		iphdr = (struct iphdr *)(skb->data + BAREUDP_BASE_HLEN);
+		if (iphdr->version == 4) {
+			proto = bareudp->ethertype;
+		} else if (bareudp->ext_mode && (iphdr->version == 6)) {
+			proto = htons(ETH_P_IPV6);
+		} else {
+			bareudp->dev->stats.rx_dropped++;
+			goto drop;
+		}
+	} else if (bareudp->ethertype == htons(ETH_P_MPLS_UC)) {
+		struct iphdr *tunnel_hdr;
+
+		tunnel_hdr = (struct iphdr *)skb_network_header(skb);
+		if (tunnel_hdr->version == 4) {
+			if (!ipv4_is_multicast(tunnel_hdr->daddr)) {
+				proto = bareudp->ethertype;
+			} else if (bareudp->ext_mode &&
+				   ipv4_is_multicast(tunnel_hdr->daddr)) {
+				proto = htons(ETH_P_MPLS_MC);
+			} else {
+				bareudp->dev->stats.rx_dropped++;
+				goto drop;
+			}
+		} else {
+			int addr_type;
+			struct ipv6hdr *tunnel_hdr_v6;
+
+			tunnel_hdr_v6 = (struct ipv6hdr *)skb_network_header(skb);
+			addr_type =
+			ipv6_addr_type((struct in6_addr *)&tunnel_hdr_v6->daddr);
+			if (!(addr_type & IPV6_ADDR_MULTICAST)) {
+				proto = bareudp->ethertype;
+			} else if (bareudp->ext_mode &&
+				   (addr_type & IPV6_ADDR_MULTICAST)) {
+				proto = htons(ETH_P_MPLS_MC);
+			} else {
+				bareudp->dev->stats.rx_dropped++;
+				goto drop;
+			}
+		}
+	} else {
+		proto = bareudp->ethertype;
+	}
 
 	if (iptunnel_pull_header(skb, BAREUDP_BASE_HLEN,
-				 proto,
-				 !net_eq(bareudp->net,
-					 dev_net(bareudp->dev)))) {
+				proto,
+				!net_eq(bareudp->net,
+					dev_net(bareudp->dev)))) {
 		bareudp->dev->stats.rx_dropped++;
 		goto drop;
 	}
+
 	tun_dst = udp_tun_rx_dst(skb, bareudp_get_sk_family(bs), TUNNEL_KEY,
 				 0, 0);
 	if (!tun_dst) {
@@ -421,10 +471,13 @@  static netdev_tx_t bareudp_xmit(struct sk_buff *skb, struct net_device *dev)
 	int err;
 
 	if (skb->protocol != bareudp->ethertype) {
-		err = -EINVAL;
-		goto tx_error;
+		if (!bareudp->ext_mode ||
+		    (skb->protocol !=  htons(ETH_P_MPLS_MC) &&
+		     skb->protocol !=  htons(ETH_P_IPV6))) {
+			err = -EINVAL;
+			goto tx_error;
+		}
 	}
-
 	info = skb_tunnel_info(skb);
 	if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
 		err = -EINVAL;
@@ -520,6 +573,7 @@  static int bareudp_change_mtu(struct net_device *dev, int new_mtu)
 	[IFLA_BAREUDP_PORT]                = { .type = NLA_U16 },
 	[IFLA_BAREUDP_ETHERTYPE]	   = { .type = NLA_U16 },
 	[IFLA_BAREUDP_SRCPORT_MIN]         = { .type = NLA_U16 },
+	[IFLA_BAREUDP_EXTMODE]             = { .type = NLA_FLAG },
 };
 
 static int bareudp_validate(struct nlattr *tb[], struct nlattr *data[],
@@ -602,9 +656,15 @@  static int bareudp_configure(struct net *net, struct net_device *dev,
 	if (t)
 		return -EBUSY;
 
+	if (conf->ext_mode &&
+	    (conf->ethertype != htons(ETH_P_MPLS_UC) &&
+	     conf->ethertype != htons(ETH_P_IP)))
+		return -EINVAL;
+
 	bareudp->conf = *conf;
 	bareudp->ethertype = conf->ethertype;
 	bareudp->sport_min = conf->sport_min;
+	bareudp->ext_mode = conf->ext_mode;
 	err = register_netdevice(dev);
 	if (err)
 		return err;
@@ -627,6 +687,11 @@  static int bareudp2info(struct nlattr *data[], struct bareudp_conf *conf)
 	if (data[IFLA_BAREUDP_SRCPORT_MIN])
 		conf->sport_min =  nla_get_u16(data[IFLA_BAREUDP_SRCPORT_MIN]);
 
+	if (data[IFLA_BAREUDP_EXTMODE])
+		conf->ext_mode = true;
+	else
+		conf->ext_mode = false;
+
 	return 0;
 }
 
@@ -669,6 +734,7 @@  static size_t bareudp_get_size(const struct net_device *dev)
 	return  nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_PORT */
 		nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_ETHERTYPE */
 		nla_total_size(sizeof(__u16))  +  /* IFLA_BAREUDP_SRCPORT_MIN */
+		nla_total_size(0)              +  /* IFLA_BAREUDP_EXTMODE */
 		0;
 }
 
@@ -682,6 +748,8 @@  static int bareudp_fill_info(struct sk_buff *skb, const struct net_device *dev)
 		goto nla_put_failure;
 	if (nla_put_u16(skb, IFLA_BAREUDP_SRCPORT_MIN, bareudp->conf.sport_min))
 		goto nla_put_failure;
+	if (bareudp->ext_mode && nla_put_flag(skb, IFLA_BAREUDP_EXTMODE))
+		goto nla_put_failure;
 
 	return 0;
 
diff --git a/include/net/bareudp.h b/include/net/bareudp.h
index 513fae6..2c121d8 100644
--- a/include/net/bareudp.h
+++ b/include/net/bareudp.h
@@ -10,6 +10,7 @@  struct bareudp_conf {
 	__be16 ethertype;
 	__be16 port;
 	u16 sport_min;
+	bool ext_mode;
 };
 
 struct net_device *bareudp_dev_create(struct net *net, const char *name,
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 012f7e8..2b91c872 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -586,6 +586,7 @@  enum {
 	IFLA_BAREUDP_PORT,
 	IFLA_BAREUDP_ETHERTYPE,
 	IFLA_BAREUDP_SRCPORT_MIN,
+	IFLA_BAREUDP_EXTMODE,
 	__IFLA_BAREUDP_MAX
 };