Merge branch 'net-erspan-add-support-for-openvswitch'

William Tu says:

====================
net: erspan: add support for openvswitch

The first patch refactors the erspan header definitions.
Originally, the erspan fields are defined as a group into a __be16 field,
and use mask and offset to access each field.  This is more costly due to
calling ntohs/htons and error-prone.  The first patch changes it to use
bitfields.  The second patch creates erspan.h in UAPI and move the definition
'struct erspan_metadata' to it for later openvswitch to use.  The final patch
introduces the new OVS tunnel key attribute, OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS,
to program both v1 and v2 erspan tunnel for openvswitch.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 209 insertions, 93 deletions

diff --git a/include/net/erspan.h b/include/net/erspan.h
index 712ea1b1f4db..5daa4866412b 100644
--- a/include/net/erspan.h
+++ b/include/net/erspan.h
@@ -46,6 +46,8 @@
  * GRE proto ERSPAN type II = 0x88BE, type III = 0x22EB
  */
 
+#include <uapi/linux/erspan.h>
+
 #define ERSPAN_VERSION	0x1	/* ERSPAN type II */
 #define VER_MASK	0xf000
 #define VLAN_MASK	0x0fff
@@ -65,17 +67,8 @@
 #define GRA_MASK	0x0006
 #define O_MASK		0x0001
 
-/* ERSPAN version 2 metadata header */
-struct erspan_md2 {
-	__be32 timestamp;
-	__be16 sgt;	/* security group tag */
-	__be16 flags;
-#define P_OFFSET	15
-#define FT_OFFSET	10
-#define HWID_OFFSET	4
-#define DIR_OFFSET	3
-#define GRA_OFFSET	1
-};
+#define HWID_OFFSET    4
+#define DIR_OFFSET     3
 
 enum erspan_encap_type {
 	ERSPAN_ENCAP_NOVLAN = 0x0,	/* originally without VLAN tag */
@@ -86,24 +79,64 @@ enum erspan_encap_type {
 
 #define ERSPAN_V1_MDSIZE	4
 #define ERSPAN_V2_MDSIZE	8
-struct erspan_metadata {
-	union {
-		__be32 index;		/* Version 1 (type II)*/
-		struct erspan_md2 md2;	/* Version 2 (type III) */
-	} u;
-	int version;
-};
 
 struct erspan_base_hdr {
-	__be16 ver_vlan;
-#define VER_OFFSET  12
-	__be16 session_id;
-#define COS_OFFSET  13
-#define EN_OFFSET   11
-#define BSO_OFFSET  EN_OFFSET
-#define T_OFFSET    10
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+	__u8	vlan_upper:4,
+		ver:4;
+	__u8	vlan:8;
+	__u8	session_id_upper:2,
+		t:1,
+		en:2,
+		cos:3;
+	__u8	session_id:8;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+	__u8	ver: 4,
+		vlan_upper:4;
+	__u8	vlan:8;
+	__u8	cos:3,
+		en:2,
+		t:1,
+		session_id_upper:2;
+	__u8	session_id:8;
+#else
+#error "Please fix <asm/byteorder.h>"
+#endif
 };
 
+static inline void set_session_id(struct erspan_base_hdr *ershdr, u16 id)
+{
+	ershdr->session_id = id & 0xff;
+	ershdr->session_id_upper = (id >> 8) & 0x3;
+}
+
+static inline u16 get_session_id(const struct erspan_base_hdr *ershdr)
+{
+	return (ershdr->session_id_upper << 8) + ershdr->session_id;
+}
+
+static inline void set_vlan(struct erspan_base_hdr *ershdr, u16 vlan)
+{
+	ershdr->vlan = vlan & 0xff;
+	ershdr->vlan_upper = (vlan >> 8) & 0xf;
+}
+
+static inline u16 get_vlan(const struct erspan_base_hdr *ershdr)
+{
+	return (ershdr->vlan_upper << 8) + ershdr->vlan;
+}
+
+static inline void set_hwid(struct erspan_md2 *md2, u8 hwid)
+{
+	md2->hwid = hwid & 0xf;
+	md2->hwid_upper = (hwid >> 4) & 0x3;
+}
+
+static inline u8 get_hwid(const struct erspan_md2 *md2)
+{
+	return (md2->hwid_upper << 4) + md2->hwid;
+}
+
 static inline int erspan_hdr_len(int version)
 {
 	return sizeof(struct erspan_base_hdr) +
@@ -120,7 +153,7 @@ static inline u8 tos_to_cos(u8 tos)
 }
 
 static inline void erspan_build_header(struct sk_buff *skb,
-				__be32 id, u32 index,
+				u32 id, u32 index,
 				bool truncate, bool is_ipv4)
 {
 	struct ethhdr *eth = (struct ethhdr *)skb->data;
@@ -154,12 +187,12 @@ static inline void erspan_build_header(struct sk_buff *skb,
 	memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V1_MDSIZE);
 
 	/* Build base header */
-	ershdr->ver_vlan = htons((vlan_tci & VLAN_MASK) |
-				 (ERSPAN_VERSION << VER_OFFSET));
-	ershdr->session_id = htons((u16)(ntohl(id) & ID_MASK) |
-			   ((tos_to_cos(tos) << COS_OFFSET) & COS_MASK) |
-			   (enc_type << EN_OFFSET & EN_MASK) |
-			   ((truncate << T_OFFSET) & T_MASK));
+	ershdr->ver = ERSPAN_VERSION;
+	ershdr->cos = tos_to_cos(tos);
+	ershdr->en = enc_type;
+	ershdr->t = truncate;
+	set_vlan(ershdr, vlan_tci);
+	set_session_id(ershdr, id);
 
 	/* Build metadata */
 	ersmd = (struct erspan_metadata *)(ershdr + 1);
@@ -187,7 +220,7 @@ static inline __be32 erspan_get_timestamp(void)
 }
 
 static inline void erspan_build_header_v2(struct sk_buff *skb,
-					  __be32 id, u8 direction, u16 hwid,
+					  u32 id, u8 direction, u16 hwid,
 					  bool truncate, bool is_ipv4)
 {
 	struct ethhdr *eth = (struct ethhdr *)skb->data;
@@ -198,7 +231,6 @@ static inline void erspan_build_header_v2(struct sk_buff *skb,
 		__be16 tci;
 	} *qp;
 	u16 vlan_tci = 0;
-	u16 session_id;
 	u8 gra = 0; /* 100 usec */
 	u8 bso = 0; /* Bad/Short/Oversized */
 	u8 sgt = 0;
@@ -221,22 +253,23 @@ static inline void erspan_build_header_v2(struct sk_buff *skb,
 	memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V2_MDSIZE);
 
 	/* Build base header */
-	ershdr->ver_vlan = htons((vlan_tci & VLAN_MASK) |
-				 (ERSPAN_VERSION2 << VER_OFFSET));
-	session_id = (u16)(ntohl(id) & ID_MASK) |
-		     ((tos_to_cos(tos) << COS_OFFSET) & COS_MASK) |
-		     (bso << BSO_OFFSET & BSO_MASK) |
-		     ((truncate << T_OFFSET) & T_MASK);
-	ershdr->session_id = htons(session_id);
+	ershdr->ver = ERSPAN_VERSION2;
+	ershdr->cos = tos_to_cos(tos);
+	ershdr->en = bso;
+	ershdr->t = truncate;
+	set_vlan(ershdr, vlan_tci);
+	set_session_id(ershdr, id);
 
 	/* Build metadata */
 	md = (struct erspan_metadata *)(ershdr + 1);
 	md->u.md2.timestamp = erspan_get_timestamp();
 	md->u.md2.sgt = htons(sgt);
-	md->u.md2.flags = htons(((1 << P_OFFSET) & P_MASK) |
-				((hwid << HWID_OFFSET) & HWID_MASK) |
-				((direction << DIR_OFFSET) & DIR_MASK) |
-				((gra << GRA_OFFSET) & GRA_MASK));
+	md->u.md2.p = 1;
+	md->u.md2.ft = 0;
+	md->u.md2.dir = direction;
+	md->u.md2.gra = gra;
+	md->u.md2.o = 0;
+	set_hwid(&md->u.md2, hwid);
 }
 
 #endif
diff --git a/include/uapi/linux/erspan.h b/include/uapi/linux/erspan.h
new file mode 100644
index 000000000000..841573019ae1
--- /dev/null
+++ b/include/uapi/linux/erspan.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * ERSPAN Tunnel Metadata
+ *
+ * Copyright (c) 2018 VMware
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * Userspace API for metadata mode ERSPAN tunnel
+ */
+#ifndef _UAPI_ERSPAN_H
+#define _UAPI_ERSPAN_H
+
+#include <linux/types.h>	/* For __beXX in userspace */
+#include <asm/byteorder.h>
+
+/* ERSPAN version 2 metadata header */
+struct erspan_md2 {
+	__be32 timestamp;
+	__be16 sgt;	/* security group tag */
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+	__u8	hwid_upper:2,
+		ft:5,
+		p:1;
+	__u8	o:1,
+		gra:2,
+		dir:1,
+		hwid:4;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+	__u8	p:1,
+		ft:5,
+		hwid_upper:2;
+	__u8	hwid:4,
+		dir:1,
+		gra:2,
+		o:1;
+#else
+#error "Please fix <asm/byteorder.h>"
+#endif
+};
+
+struct erspan_metadata {
+	int version;
+	union {
+		__be32 index;		/* Version 1 (type II)*/
+		struct erspan_md2 md2;	/* Version 2 (type III) */
+	} u;
+};
+
+#endif /* _UAPI_ERSPAN_H */
diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
index dcfab5e3b55c..713e56ce681f 100644
--- a/include/uapi/linux/openvswitch.h
+++ b/include/uapi/linux/openvswitch.h
@@ -363,6 +363,7 @@ enum ovs_tunnel_key_attr {
 	OVS_TUNNEL_KEY_ATTR_IPV6_SRC,		/* struct in6_addr src IPv6 address. */
 	OVS_TUNNEL_KEY_ATTR_IPV6_DST,		/* struct in6_addr dst IPv6 address. */
 	OVS_TUNNEL_KEY_ATTR_PAD,
+	OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS,	/* struct erspan_metadata */
 	__OVS_TUNNEL_KEY_ATTR_MAX
 };
 
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index b61f2285816d..6ec670fbbbdd 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -114,7 +114,7 @@ MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
 static int ipgre_tunnel_init(struct net_device *dev);
 static void erspan_build_header(struct sk_buff *skb,
-				__be32 id, u32 index,
+				u32 id, u32 index,
 				bool truncate, bool is_ipv4);
 
 static unsigned int ipgre_net_id __read_mostly;
@@ -273,12 +273,12 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 
 	iph = ip_hdr(skb);
 	ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
-	ver = (ntohs(ershdr->ver_vlan) & VER_MASK) >> VER_OFFSET;
+	ver = ershdr->ver;
 
 	/* The original GRE header does not have key field,
 	 * Use ERSPAN 10-bit session ID as key.
 	 */
-	tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK);
+	tpi->key = cpu_to_be32(get_session_id(ershdr));
 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
 				  tpi->flags | TUNNEL_KEY,
 				  iph->saddr, iph->daddr, tpi->key);
@@ -324,14 +324,8 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 			if (ver == 1) {
 				tunnel->index = ntohl(pkt_md->u.index);
 			} else {
-				u16 md2_flags;
-				u16 dir, hwid;
-
-				md2_flags = ntohs(pkt_md->u.md2.flags);
-				dir = (md2_flags & DIR_MASK) >> DIR_OFFSET;
-				hwid = (md2_flags & HWID_MASK) >> HWID_OFFSET;
-				tunnel->dir = dir;
-				tunnel->hwid = hwid;
+				tunnel->dir = pkt_md->u.md2.dir;
+				tunnel->hwid = get_hwid(&pkt_md->u.md2);
 			}
 
 		}
@@ -615,19 +609,14 @@ static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev,
 	}
 
 	if (version == 1) {
-		erspan_build_header(skb, tunnel_id_to_key32(key->tun_id),
+		erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
 				    ntohl(md->u.index), truncate, true);
 	} else if (version == 2) {
-		u16 md2_flags;
-		u8 direction;
-		u16 hwid;
-
-		md2_flags = ntohs(md->u.md2.flags);
-		direction = (md2_flags & DIR_MASK) >> DIR_OFFSET;
-		hwid = (md2_flags & HWID_MASK) >> HWID_OFFSET;
-
-		erspan_build_header_v2(skb, tunnel_id_to_key32(key->tun_id),
-				       direction, hwid,	truncate, true);
+		erspan_build_header_v2(skb,
+				       ntohl(tunnel_id_to_key32(key->tun_id)),
+				       md->u.md2.dir,
+				       get_hwid(&md->u.md2),
+				       truncate, true);
 	} else {
 		goto err_free_rt;
 	}
@@ -733,10 +722,11 @@ static netdev_tx_t erspan_xmit(struct sk_buff *skb,
 
 	/* Push ERSPAN header */
 	if (tunnel->erspan_ver == 1)
-		erspan_build_header(skb, tunnel->parms.o_key, tunnel->index,
+		erspan_build_header(skb, ntohl(tunnel->parms.o_key),
+				    tunnel->index,
 				    truncate, true);
 	else
-		erspan_build_header_v2(skb, tunnel->parms.o_key,
+		erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key),
 				       tunnel->dir, tunnel->hwid,
 				       truncate, true);
 
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index a88480193d77..05f070e123e4 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -513,8 +513,8 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
 
 	ipv6h = ipv6_hdr(skb);
 	ershdr = (struct erspan_base_hdr *)skb->data;
-	ver = (ntohs(ershdr->ver_vlan) & VER_MASK) >> VER_OFFSET;
-	tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK);
+	ver = ershdr->ver;
+	tpi->key = cpu_to_be32(get_session_id(ershdr));
 
 	tunnel = ip6gre_tunnel_lookup(skb->dev,
 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
@@ -565,14 +565,8 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
 			if (ver == 1) {
 				tunnel->parms.index = ntohl(pkt_md->u.index);
 			} else {
-				u16 md2_flags;
-				u16 dir, hwid;
-
-				md2_flags = ntohs(pkt_md->u.md2.flags);
-				dir = (md2_flags & DIR_MASK) >> DIR_OFFSET;
-				hwid = (md2_flags & HWID_MASK) >> HWID_OFFSET;
-				tunnel->parms.dir = dir;
-				tunnel->parms.hwid = hwid;
+				tunnel->parms.dir = pkt_md->u.md2.dir;
+				tunnel->parms.hwid = get_hwid(&pkt_md->u.md2);
 			}
 
 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
@@ -925,6 +919,7 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
 		struct ip_tunnel_info *tun_info;
 		const struct ip_tunnel_key *key;
 		struct erspan_metadata *md;
+		__be32 tun_id;
 
 		tun_info = skb_tunnel_info(skb);
 		if (unlikely(!tun_info ||
@@ -944,23 +939,18 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
 		if (!md)
 			goto tx_err;
 
+		tun_id = tunnel_id_to_key32(key->tun_id);
 		if (md->version == 1) {
 			erspan_build_header(skb,
-					    tunnel_id_to_key32(key->tun_id),
+					    ntohl(tun_id),
 					    ntohl(md->u.index), truncate,
 					    false);
 		} else if (md->version == 2) {
-			u16 md2_flags;
-			u16 dir, hwid;
-
-			md2_flags = ntohs(md->u.md2.flags);
-			dir = (md2_flags & DIR_MASK) >> DIR_OFFSET;
-			hwid = (md2_flags & HWID_MASK) >> HWID_OFFSET;
-
 			erspan_build_header_v2(skb,
-					       tunnel_id_to_key32(key->tun_id),
-					       dir, hwid, truncate,
-					       false);
+					       ntohl(tun_id),
+					       md->u.md2.dir,
+					       get_hwid(&md->u.md2),
+					       truncate, false);
 		}
 	} else {
 		switch (skb->protocol) {
@@ -982,11 +972,11 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
 		}
 
 		if (t->parms.erspan_ver == 1)
-			erspan_build_header(skb, t->parms.o_key,
+			erspan_build_header(skb, ntohl(t->parms.o_key),
 					    t->parms.index,
 					    truncate, false);
 		else
-			erspan_build_header_v2(skb, t->parms.o_key,
+			erspan_build_header_v2(skb, ntohl(t->parms.o_key),
 					       t->parms.dir,
 					       t->parms.hwid,
 					       truncate, false);
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index eb55f1b3d047..7322aa1e382e 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -49,6 +49,7 @@
 #include <net/mpls.h>
 #include <net/vxlan.h>
 #include <net/tun_proto.h>
+#include <net/erspan.h>
 
 #include "flow_netlink.h"
 
@@ -329,7 +330,8 @@ size_t ovs_tun_key_attr_size(void)
 		+ nla_total_size(0)    /* OVS_TUNNEL_KEY_ATTR_CSUM */
 		+ nla_total_size(0)    /* OVS_TUNNEL_KEY_ATTR_OAM */
 		+ nla_total_size(256)  /* OVS_TUNNEL_KEY_ATTR_GENEVE_OPTS */
-		/* OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS is mutually exclusive with
+		/* OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS and
+		 * OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS is mutually exclusive with
 		 * OVS_TUNNEL_KEY_ATTR_GENEVE_OPTS and covered by it.
 		 */
 		+ nla_total_size(2)    /* OVS_TUNNEL_KEY_ATTR_TP_SRC */
@@ -400,6 +402,7 @@ static const struct ovs_len_tbl ovs_tunnel_key_lens[OVS_TUNNEL_KEY_ATTR_MAX + 1]
 						.next = ovs_vxlan_ext_key_lens },
 	[OVS_TUNNEL_KEY_ATTR_IPV6_SRC]      = { .len = sizeof(struct in6_addr) },
 	[OVS_TUNNEL_KEY_ATTR_IPV6_DST]      = { .len = sizeof(struct in6_addr) },
+	[OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS]   = { .len = OVS_ATTR_VARIABLE },
 };
 
 static const struct ovs_len_tbl
@@ -631,6 +634,33 @@ static int vxlan_tun_opt_from_nlattr(const struct nlattr *attr,
 	return 0;
 }
 
+static int erspan_tun_opt_from_nlattr(const struct nlattr *a,
+				      struct sw_flow_match *match, bool is_mask,
+				      bool log)
+{
+	unsigned long opt_key_offset;
+
+	BUILD_BUG_ON(sizeof(struct erspan_metadata) >
+		     sizeof(match->key->tun_opts));
+
+	if (nla_len(a) > sizeof(match->key->tun_opts)) {
+		OVS_NLERR(log, "ERSPAN option length err (len %d, max %zu).",
+			  nla_len(a), sizeof(match->key->tun_opts));
+		return -EINVAL;
+	}
+
+	if (!is_mask)
+		SW_FLOW_KEY_PUT(match, tun_opts_len,
+				sizeof(struct erspan_metadata), false);
+	else
+		SW_FLOW_KEY_PUT(match, tun_opts_len, 0xff, true);
+
+	opt_key_offset = TUN_METADATA_OFFSET(nla_len(a));
+	SW_FLOW_KEY_MEMCPY_OFFSET(match, opt_key_offset, nla_data(a),
+				  nla_len(a), is_mask);
+	return 0;
+}
+
 static int ip_tun_from_nlattr(const struct nlattr *attr,
 			      struct sw_flow_match *match, bool is_mask,
 			      bool log)
@@ -738,6 +768,20 @@ static int ip_tun_from_nlattr(const struct nlattr *attr,
 			break;
 		case OVS_TUNNEL_KEY_ATTR_PAD:
 			break;
+		case OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS:
+			if (opts_type) {
+				OVS_NLERR(log, "Multiple metadata blocks provided");
+				return -EINVAL;
+			}
+
+			err = erspan_tun_opt_from_nlattr(a, match, is_mask,
+							 log);
+			if (err)
+				return err;
+
+			tun_flags |= TUNNEL_ERSPAN_OPT;
+			opts_type = type;
+			break;
 		default:
 			OVS_NLERR(log, "Unknown IP tunnel attribute %d",
 				  type);
@@ -862,6 +906,10 @@ static int __ip_tun_to_nlattr(struct sk_buff *skb,
 		else if (output->tun_flags & TUNNEL_VXLAN_OPT &&
 			 vxlan_opt_to_nlattr(skb, tun_opts, swkey_tun_opts_len))
 			return -EMSGSIZE;
+		else if (output->tun_flags & TUNNEL_ERSPAN_OPT &&
+			 nla_put(skb, OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS,
+				 swkey_tun_opts_len, tun_opts))
+			return -EMSGSIZE;
 	}
 
 	return 0;
@@ -2486,6 +2534,8 @@ static int validate_and_copy_set_tun(const struct nlattr *attr,
 			break;
 		case OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS:
 			break;
+		case OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS:
+			break;
 		}
 	}