[PATCH net-next v5 0/1] Bareudp Device Support

[PATCH net-next v5 0/1] Bareudp Device Support

[Martin Varghese]

From: Martin Varghese <martin.varghese@nokia.com>

There are various L3 encapsulation standards using UDP being discussed to
leverage the UDP based load balancing capability of different networks.
MPLSoUDP (__ https://tools.ietf.org/html/rfc7510) is one among them.

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 protocol 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 multiproto mode.

Usage
------

1) Device creation & deletion

    a) ip link add dev bareudp0 type bareudp dstport 6635 ethertype 0x8847.

       This creates a bareudp tunnel device which tunnels L3 traffic with ethertype
       0x8847 (MPLS traffic). The destination port of the UDP header will be set to
       6635.The device will listen on UDP port 6635 to receive traffic.

    b) ip link delete bareudp0

2) Device creation with multiple proto mode enabled

There are two ways to create a bareudp device for MPLS & IP with multiproto mode
enabled.

    a) ip link add dev  bareudp0 type bareudp dstport 6635 ethertype 0x8847 multiproto

    b) ip link add dev  bareudp0 type bareudp dstport 6635 ethertype mpls

3) Device Usage

The bareudp device could be used along with OVS or flower filter in TC.
The OVS or TC flower layer must set the tunnel information in SKB dst field before
sending packet buffer to the bareudp device for transmission. On reception the
bareudp device extracts and stores the tunnel information in SKB dst field before
passing the packet buffer to the network stack.


Martin Varghese (1):
  Bareudp device support

 include/uapi/linux/if_link.h |  12 ++++
 ip/Makefile                  |   2 +-
 ip/iplink.c                  |   2 +-
 ip/iplink_bareudp.c          | 157 +++++++++++++++++++++++++++++++++++++++++++
 man/man8/ip-link.8.in        |  38 +++++++++++
 5 files changed, 209 insertions(+), 2 deletions(-)
 create mode 100644 ip/iplink_bareudp.c

-- 
1.8.3.1

[PATCH net-next v5 1/1] Bareudp device support

[Martin Varghese]

From: Martin Varghese <martin.varghese@nokia.com>

The Bareudp device provides a generic L3 encapsulation for tunnelling
different protocols like MPLS,IP,NSH, etc. inside a UDP tunnel.

Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
---
Changes in v2:
    - Man Pages added.

Changes in v3:
    - Re-sending the patch.

Changes in v4:
    - renamed extmode flag to multiproto.

Changes in v5:
    - resending the patch.
 
 include/uapi/linux/if_link.h |  12 ++++
 ip/Makefile                  |   2 +-
 ip/iplink.c                  |   2 +-
 ip/iplink_bareudp.c          | 157 +++++++++++++++++++++++++++++++++++++++++++
 man/man8/ip-link.8.in        |  38 +++++++++++
 5 files changed, 209 insertions(+), 2 deletions(-)
 create mode 100644 ip/iplink_bareudp.c

diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index d36919f..05c97ae 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -578,6 +578,18 @@ enum ifla_geneve_df {
 	GENEVE_DF_MAX = __GENEVE_DF_END - 1,
 };
 
+/* Bareudp section  */
+enum {
+	IFLA_BAREUDP_UNSPEC,
+	IFLA_BAREUDP_PORT,
+	IFLA_BAREUDP_ETHERTYPE,
+	IFLA_BAREUDP_SRCPORT_MIN,
+	IFLA_BAREUDP_MULTIPROTO_MODE,
+	__IFLA_BAREUDP_MAX
+};
+
+#define IFLA_BAREUDP_MAX (__IFLA_BAREUDP_MAX - 1)
+
 /* PPP section */
 enum {
 	IFLA_PPP_UNSPEC,
diff --git a/ip/Makefile b/ip/Makefile
index 5ab78d7..784d852 100644
--- a/ip/Makefile
+++ b/ip/Makefile
@@ -11,7 +11,7 @@ IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o ipnetns.o \
     iplink_bridge.o iplink_bridge_slave.o ipfou.o iplink_ipvlan.o \
     iplink_geneve.o iplink_vrf.o iproute_lwtunnel.o ipmacsec.o ipila.o \
     ipvrf.o iplink_xstats.o ipseg6.o iplink_netdevsim.o iplink_rmnet.o \
-    ipnexthop.o
+    ipnexthop.o iplink_bareudp.o
 
 RTMONOBJ=rtmon.o
 
diff --git a/ip/iplink.c b/ip/iplink.c
index 212a088..325fd0f 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -122,7 +122,7 @@ void iplink_usage(void)
 			"	   bridge | bond | team | ipoib | ip6tnl | ipip | sit | vxlan |\n"
 			"	   gre | gretap | erspan | ip6gre | ip6gretap | ip6erspan |\n"
 			"	   vti | nlmon | team_slave | bond_slave | bridge_slave |\n"
-			"	   ipvlan | ipvtap | geneve | vrf | macsec | netdevsim | rmnet |\n"
+			"	   ipvlan | ipvtap | geneve | bareudp | vrf | macsec | netdevsim | rmnet |\n"
 			"	   xfrm }\n");
 	}
 	exit(-1);
diff --git a/ip/iplink_bareudp.c b/ip/iplink_bareudp.c
new file mode 100644
index 0000000..5798199
--- /dev/null
+++ b/ip/iplink_bareudp.c
@@ -0,0 +1,157 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <stdio.h>
+
+#include "rt_names.h"
+#include "utils.h"
+#include "ip_common.h"
+
+#define BAREUDP_ATTRSET(attrs, type) (((attrs) & (1L << (type))) != 0)
+
+static void print_explain(FILE *f)
+{
+	fprintf(f,
+			"Usage: ........ bareudp dstport PORT\n"
+			"                ethertype ETHERTYPE|PROTOCOL\n"
+			"                [multiproto]\n"
+			"                [srcportmin SRCPORTMIN]\n"
+			"\n"
+			"Where: PORT   := 0-65535\n"
+			"     : ETHERTYPE|PROTOCOL := 0-65535|ip|mpls\n"
+			"     : SRCPORTMIN : = 0-65535\n"
+	       );
+}
+
+static void explain(void)
+{
+	print_explain(stderr);
+}
+
+static void check_duparg(__u64 *attrs, int type, const char *key,
+		const char *argv)
+{
+	if (!BAREUDP_ATTRSET(*attrs, type)) {
+		*attrs |= (1L << type);
+		return;
+	}
+	duparg2(key, argv);
+}
+
+static int bareudp_parse_opt(struct link_util *lu, int argc, char **argv,
+		struct nlmsghdr *n)
+{
+	__u16 dstport = 0;
+	__u16 ethertype = 0;
+	__u16 srcportmin = 0;
+	bool multiproto = 0;
+	__u64 attrs = 0;
+
+	while (argc > 0) {
+		if (!matches(*argv, "dstport")) {
+			NEXT_ARG();
+			check_duparg(&attrs, IFLA_BAREUDP_PORT, "dstport",
+					*argv);
+			if (get_u16(&dstport, *argv, 0))
+				invarg("dstport", *argv);
+		} else if (!matches(*argv, "multiproto")) {
+			check_duparg(&attrs, IFLA_BAREUDP_MULTIPROTO_MODE,
+					*argv, *argv);
+			multiproto = true;
+		} else if (!matches(*argv, "ethertype"))  {
+			NEXT_ARG();
+			check_duparg(&attrs, IFLA_BAREUDP_ETHERTYPE,
+					*argv, *argv);
+			if (!matches(*argv, "mpls")) {
+				ethertype = 0x8847;
+				check_duparg(&attrs, IFLA_BAREUDP_MULTIPROTO_MODE,
+						*argv, *argv);
+				multiproto = true;
+			} else if (!matches(*argv, "ip")) {
+				ethertype = 0x0800;
+				check_duparg(&attrs, IFLA_BAREUDP_MULTIPROTO_MODE,
+						*argv, *argv);
+				multiproto = true;
+			} else {
+				if (get_u16(&ethertype, *argv, 0))
+					invarg("ethertype", *argv);
+			}
+		} else if (!matches(*argv, "srcportmin")) {
+			NEXT_ARG();
+			check_duparg(&attrs, IFLA_BAREUDP_SRCPORT_MIN,
+					*argv, *argv);
+			if (get_u16(&srcportmin, *argv, 0))
+				invarg("srcportmin", *argv);
+
+		} else if (matches(*argv, "help") == 0) {
+			explain();
+			return -1;
+		} else {
+			fprintf(stderr, "bareudp: unknown command \"%s\"?\n", *argv);
+			explain();
+			return -1;
+		}
+	argc--, argv++;
+	}
+
+	if (!dstport || !ethertype)  {
+		fprintf(stderr, "bareudp : Missing mandatory params\n");
+		return -1;
+	}
+
+	if (dstport)
+		addattr16(n, 1024, IFLA_BAREUDP_PORT, htons(dstport));
+	if (ethertype)
+		addattr16(n, 1024, IFLA_BAREUDP_ETHERTYPE, htons(ethertype));
+	if (multiproto)
+		addattr(n, 1024, IFLA_BAREUDP_MULTIPROTO_MODE);
+	if (srcportmin)
+		addattr16(n, 1024, IFLA_BAREUDP_PORT, srcportmin);
+
+	return 0;
+}
+
+static void bareudp_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
+{
+
+	if (!tb)
+		return;
+
+	if (tb[IFLA_BAREUDP_PORT])
+		print_uint(PRINT_ANY, "port", "dstport %u ",
+				rta_getattr_be16(tb[IFLA_BAREUDP_PORT]));
+
+	if (tb[IFLA_BAREUDP_ETHERTYPE])
+		print_uint(PRINT_ANY, "port", "ethertype %u ",
+				rta_getattr_be16(tb[IFLA_BAREUDP_ETHERTYPE]));
+	if (tb[IFLA_BAREUDP_SRCPORT_MIN])
+		print_uint(PRINT_ANY, "port", "srcportmin %u ",
+				rta_getattr_u16(tb[IFLA_BAREUDP_SRCPORT_MIN]));
+
+	if (tb[IFLA_BAREUDP_MULTIPROTO_MODE]) {
+		 if (is_json_context()) {
+                        print_bool(PRINT_JSON,
+                                   "multiproto",
+                                   NULL,
+                                   rta_getattr_u8(tb[IFLA_BAREUDP_MULTIPROTO_MODE]));
+                } else {
+                        if (!rta_getattr_u8(tb[IFLA_BAREUDP_MULTIPROTO_MODE]))
+                                fputs("no", f);
+                        fputs("multiproto ", f);
+                }
+
+	}
+}
+
+static void bareudp_print_help(struct link_util *lu, int argc, char **argv,
+		FILE *f)
+{
+	print_explain(f);
+}
+
+struct link_util bareudp_link_util = {
+	.id		= "bareudp",
+	.maxattr	= IFLA_BAREUDP_MAX,
+	.parse_opt	= bareudp_parse_opt,
+	.print_opt	= bareudp_print_opt,
+	.print_help	= bareudp_print_help,
+};
diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index a8ae72d..7e79f30 100644
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -223,6 +223,7 @@ ip-link \- network device configuration
 .BR ipvtap " |"
 .BR lowpan " |"
 .BR geneve " |"
+.BR bareudp " |"
 .BR vrf " |"
 .BR macsec " |"
 .BR netdevsim " |"
@@ -345,6 +346,9 @@ Link types:
 .BR geneve
 - GEneric NEtwork Virtualization Encapsulation
 .sp
+.BR bareudp
+- Bare UDP L3 encapsulation support
+.sp
 .BR macsec
 - Interface for IEEE 802.1AE MAC Security (MACsec)
 .sp
@@ -1283,6 +1287,40 @@ options.
 .in -8
 
 .TP
+Bareudp Type Support
+For a link of type
+.I Bareudp
+the following additional arguments are supported:
+
+.BI "ip link add " DEVICE
+.BI type " bareudp " dstport " PORT " ethertype " ETHERTYPE"
+[
+.RB [ no ] multiproto
+][
+.BI srcportmin " SRCPORTMIN "
+]
+
+.in +8
+.sp
+.BI  dstport " PORT " 
+- Selects the destination port for the UDP tunnel.
+
+.sp
+.BI  ethertype " ETHERTYPE "
+- Selects the ethertype of the L3 protocol being tunnelled.
+
+.sp
+.RB [ no ] multiproto
+- Enables special handling for certain ethertypes ( Supported only for ethertypes 0x8847 & 0x0800)
+multiproto when configured with ethertype 0x8847(MPLS Unicast) enables the device to tunnel ethertype
+0x8848 (MPLS multicast) also.Multiproto when configured with ethertype 0x0800 (IPV4) enables the device
+to tunnel 0x86dd (IPv6) also.
+
+.sp
+.BI srcportmin " SRCPORTMIN "
+- selecs the lowest value of the UDP tunnel source port range.
+
+.TP
 MACVLAN and MACVTAP Type Support
 For a link of type
 .I MACVLAN
-- 
1.8.3.1