[PATCH net 0/3] net: erspan fixes

[PATCH net 0/3] net: erspan fixes

[William Tu]

The first patch fixes erspan metadata extraction issue from packet
header due to commit d350a823020e ("net: erspan: create erspan metadata
uapi header").  The commit moves the erspan 'version' in
'struct erspan_metadata' in front of 'struct erspan_md2' for later
extensibility, but breaks the existing metadata extraction code due
to extra 4-byte size 'version'.  The second patch fixes the case where
tunnel device receives an erspan packet with different tunnel metadata
(ex: version, index, hwid, direction), existing code overwrites the
tunnel device's erspan configuration.  The third patch fixes the bpf
tests due to the above patches.

William Tu (3):
  net: erspan: fix metadata extraction
  net: erspan: fix erspan config overwrite
  sample/bpf: fix erspan metadata

 include/net/erspan.h           | 26 +++++++++++++-------------
 net/ipv4/ip_gre.c              | 14 ++++----------
 net/ipv6/ip6_gre.c             | 15 ++++-----------
 samples/bpf/tcbpf2_kern.c      | 41 ++++++++++++++++-------------------------
 samples/bpf/test_tunnel_bpf.sh |  4 ++--
 5 files changed, 39 insertions(+), 61 deletions(-)

-- 
2.7.4

[PATCH net 1/3] net: erspan: fix metadata extraction

[William Tu]

Commit d350a823020e ("net: erspan: create erspan metadata uapi header")
moves the erspan 'version' in front of the 'struct erspan_md2' for
later extensibility reason.  This breaks the existing erspan metadata
extraction code because the erspan_md2 then has a 4-byte offset
to between the erspan_metadata and erspan_base_hdr.  This patch
fixes it.

Fixes: 1a66a836da63 ("gre: add collect_md mode to ERSPAN tunnel")
Fixes: ef7baf5e083c ("ip6_gre: add ip6 erspan collect_md mode")
Fixes: 1d7e2ed22f8d ("net: erspan: refactor existing erspan code")
Signed-off-by: William Tu <u9012063@gmail.com>
---
 include/net/erspan.h | 26 +++++++++++++-------------
 net/ipv4/ip_gre.c    |  5 ++++-
 net/ipv6/ip6_gre.c   |  6 ++++--
 3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/include/net/erspan.h b/include/net/erspan.h
index 5daa4866412b..d044aa60cc76 100644
--- a/include/net/erspan.h
+++ b/include/net/erspan.h
@@ -159,13 +159,13 @@ static inline void erspan_build_header(struct sk_buff *skb,
 	struct ethhdr *eth = (struct ethhdr *)skb->data;
 	enum erspan_encap_type enc_type;
 	struct erspan_base_hdr *ershdr;
-	struct erspan_metadata *ersmd;
 	struct qtag_prefix {
 		__be16 eth_type;
 		__be16 tci;
 	} *qp;
 	u16 vlan_tci = 0;
 	u8 tos;
+	__be32 *idx;
 
 	tos = is_ipv4 ? ip_hdr(skb)->tos :
 			(ipv6_hdr(skb)->priority << 4) +
@@ -195,8 +195,8 @@ static inline void erspan_build_header(struct sk_buff *skb,
 	set_session_id(ershdr, id);
 
 	/* Build metadata */
-	ersmd = (struct erspan_metadata *)(ershdr + 1);
-	ersmd->u.index = htonl(index & INDEX_MASK);
+	idx = (__be32 *)(ershdr + 1);
+	*idx = htonl(index & INDEX_MASK);
 }
 
 /* ERSPAN GRA: timestamp granularity
@@ -225,7 +225,7 @@ static inline void erspan_build_header_v2(struct sk_buff *skb,
 {
 	struct ethhdr *eth = (struct ethhdr *)skb->data;
 	struct erspan_base_hdr *ershdr;
-	struct erspan_metadata *md;
+	struct erspan_md2 *md2;
 	struct qtag_prefix {
 		__be16 eth_type;
 		__be16 tci;
@@ -261,15 +261,15 @@ static inline void erspan_build_header_v2(struct sk_buff *skb,
 	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.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);
+	md2 = (struct erspan_md2 *)(ershdr + 1);
+	md2->timestamp = erspan_get_timestamp();
+	md2->sgt = htons(sgt);
+	md2->p = 1;
+	md2->ft = 0;
+	md2->dir = direction;
+	md2->gra = gra;
+	md2->o = 0;
+	set_hwid(md2, hwid);
 }
 
 #endif
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 6ec670fbbbdd..9b50eddd1882 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -261,6 +261,7 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 	struct ip_tunnel_net *itn;
 	struct ip_tunnel *tunnel;
 	const struct iphdr *iph;
+	struct erspan_md2 *md2;
 	int ver;
 	int len;
 
@@ -313,8 +314,10 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 				return PACKET_REJECT;
 
 			md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
-			memcpy(md, pkt_md, sizeof(*md));
 			md->version = ver;
+			md2 = &md->u.md2;
+			memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
+						       ERSPAN_V2_MDSIZE);
 
 			info = &tun_dst->u.tun_info;
 			info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 05f070e123e4..50913dbd0612 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -505,6 +505,7 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
 	struct erspan_base_hdr *ershdr;
 	struct erspan_metadata *pkt_md;
 	const struct ipv6hdr *ipv6h;
+	struct erspan_md2 *md2;
 	struct ip6_tnl *tunnel;
 	u8 ver;
 
@@ -551,9 +552,10 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
 
 			info = &tun_dst->u.tun_info;
 			md = ip_tunnel_info_opts(info);
-
-			memcpy(md, pkt_md, sizeof(*md));
 			md->version = ver;
+			md2 = &md->u.md2;
+			memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
+						       ERSPAN_V2_MDSIZE);
 			info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
 			info->options_len = sizeof(*md);
 
-- 
2.7.4

[PATCH net 2/3] net: erspan: fix erspan config overwrite

[William Tu]

When an erspan tunnel device receives an erpsan packet with different
tunnel metadata (ex: version, index, hwid, direction), existing code
overwrites the tunnel device's erspan configuration with the received
packet's metadata.  The patch fixes it.

Fixes: 1a66a836da63 ("gre: add collect_md mode to ERSPAN tunnel")
Fixes: f551c91de262 ("net: erspan: introduce erspan v2 for ip_gre")
Fixes: ef7baf5e083c ("ip6_gre: add ip6 erspan collect_md mode")
Fixes: 94d7d8f29287 ("ip6_gre: add erspan v2 support")
Signed-off-by: William Tu <u9012063@gmail.com>
---
 net/ipv4/ip_gre.c  | 9 ---------
 net/ipv6/ip6_gre.c | 9 ---------
 2 files changed, 18 deletions(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 9b50eddd1882..45d97e9b2759 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -322,15 +322,6 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 			info = &tun_dst->u.tun_info;
 			info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
 			info->options_len = sizeof(*md);
-		} else {
-			tunnel->erspan_ver = ver;
-			if (ver == 1) {
-				tunnel->index = ntohl(pkt_md->u.index);
-			} else {
-				tunnel->dir = pkt_md->u.md2.dir;
-				tunnel->hwid = get_hwid(&pkt_md->u.md2);
-			}
-
 		}
 
 		skb_reset_mac_header(skb);
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 50913dbd0612..3c353125546d 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -562,15 +562,6 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
 
 		} else {
-			tunnel->parms.erspan_ver = ver;
-
-			if (ver == 1) {
-				tunnel->parms.index = ntohl(pkt_md->u.index);
-			} else {
-				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);
 		}
 
-- 
2.7.4

[PATCH net 3/3] sample/bpf: fix erspan metadata

[William Tu]

The commit c69de58ba84f ("net: erspan: use bitfield instead of
mask and offset") changes the erspan header to use bitfield, and
commit d350a823020e ("net: erspan: create erspan metadata uapi header")
creates a uapi header file.  The above two commit breaks the current
erspan test.  This patch fixes it by adapting the above two changes.

Fixes: ac80c2a165af ("samples/bpf: add erspan v2 sample code")
Fixes: ef88f89c830f ("samples/bpf: extend test_tunnel_bpf.sh with ERSPAN")
Signed-off-by: William Tu <u9012063@gmail.com>
---
 samples/bpf/tcbpf2_kern.c      | 41 ++++++++++++++++-------------------------
 samples/bpf/test_tunnel_bpf.sh |  4 ++--
 2 files changed, 18 insertions(+), 27 deletions(-)

diff --git a/samples/bpf/tcbpf2_kern.c b/samples/bpf/tcbpf2_kern.c
index f6bbf8f50da3..efdc16d195ff 100644
--- a/samples/bpf/tcbpf2_kern.c
+++ b/samples/bpf/tcbpf2_kern.c
@@ -15,6 +15,7 @@
 #include <uapi/linux/tcp.h>
 #include <uapi/linux/filter.h>
 #include <uapi/linux/pkt_cls.h>
+#include <uapi/linux/erspan.h>
 #include <net/ipv6.h>
 #include "bpf_helpers.h"
 #include "bpf_endian.h"
@@ -35,24 +36,10 @@ struct geneve_opt {
 	u8	opt_data[8]; /* hard-coded to 8 byte */
 };
 
-struct erspan_md2 {
-	__be32 timestamp;
-	__be16 sgt;
-	__be16 flags;
-};
-
 struct vxlan_metadata {
 	u32     gbp;
 };
 
-struct erspan_metadata {
-	union {
-		__be32 index;
-		struct erspan_md2 md2;
-	} u;
-	int version;
-};
-
 SEC("gre_set_tunnel")
 int _gre_set_tunnel(struct __sk_buff *skb)
 {
@@ -156,13 +143,15 @@ int _erspan_set_tunnel(struct __sk_buff *skb)
 	__builtin_memset(&md, 0, sizeof(md));
 #ifdef ERSPAN_V1
 	md.version = 1;
-	md.u.index = htonl(123);
+	md.u.index = bpf_htonl(123);
 #else
 	u8 direction = 1;
-	u16 hwid = 7;
+	u8 hwid = 7;
 
 	md.version = 2;
-	md.u.md2.flags = htons((direction << 3) | (hwid << 4));
+	md.u.md2.dir = direction;
+	md.u.md2.hwid = hwid & 0xf;
+	md.u.md2.hwid_upper = (hwid >> 4) & 0x3;
 #endif
 
 	ret = bpf_skb_set_tunnel_opt(skb, &md, sizeof(md));
@@ -207,9 +196,9 @@ int _erspan_get_tunnel(struct __sk_buff *skb)
 	char fmt2[] = "\tdirection %d hwid %x timestamp %u\n";
 
 	bpf_trace_printk(fmt2, sizeof(fmt2),
-		(ntohs(md.u.md2.flags) >> 3) & 0x1,
-		(ntohs(md.u.md2.flags) >> 4) & 0x3f,
-		bpf_ntohl(md.u.md2.timestamp));
+			 md.u.md2.dir,
+			 (md.u.md2.hwid_upper << 4) + md.u.md2.hwid,
+			 bpf_ntohl(md.u.md2.timestamp));
 #endif
 
 	return TC_ACT_OK;
@@ -242,10 +231,12 @@ int _ip4ip6erspan_set_tunnel(struct __sk_buff *skb)
 	md.version = 1;
 #else
 	u8 direction = 0;
-	u16 hwid = 17;
+	u8 hwid = 17;
 
 	md.version = 2;
-	md.u.md2.flags = htons((direction << 3) | (hwid << 4));
+	md.u.md2.dir = direction;
+	md.u.md2.hwid = hwid & 0xf;
+	md.u.md2.hwid_upper = (hwid >> 4) & 0x3;
 #endif
 
 	ret = bpf_skb_set_tunnel_opt(skb, &md, sizeof(md));
@@ -290,9 +281,9 @@ int _ip4ip6erspan_get_tunnel(struct __sk_buff *skb)
 	char fmt2[] = "\tdirection %d hwid %x timestamp %u\n";
 
 	bpf_trace_printk(fmt2, sizeof(fmt2),
-		(ntohs(md.u.md2.flags) >> 3) & 0x1,
-		(ntohs(md.u.md2.flags) >> 4) & 0x3f,
-		bpf_ntohl(md.u.md2.timestamp));
+			 md.u.md2.dir,
+			 (md.u.md2.hwid_upper << 4) + md.u.md2.hwid,
+			 bpf_ntohl(md.u.md2.timestamp));
 #endif
 
 	return TC_ACT_OK;
diff --git a/samples/bpf/test_tunnel_bpf.sh b/samples/bpf/test_tunnel_bpf.sh
index ae7f7c38309b..43ce049996ee 100755
--- a/samples/bpf/test_tunnel_bpf.sh
+++ b/samples/bpf/test_tunnel_bpf.sh
@@ -68,7 +68,7 @@ function add_erspan_tunnel {
 		ip netns exec at_ns0 \
 		ip link add dev $DEV_NS type $TYPE seq key 2 \
 		local 172.16.1.100 remote 172.16.1.200 \
-		erspan_ver 2 erspan_dir 1 erspan_hwid 3
+		erspan_ver 2 erspan_dir egress erspan_hwid 3
 	fi
 	ip netns exec at_ns0 ip link set dev $DEV_NS up
 	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
@@ -97,7 +97,7 @@ function add_ip6erspan_tunnel {
 		ip netns exec at_ns0 \
 		ip link add dev $DEV_NS type $TYPE seq key 2 \
 		local ::11 remote ::22 \
-		erspan_ver 2 erspan_dir 1 erspan_hwid 7
+		erspan_ver 2 erspan_dir egress erspan_hwid 7
 	fi
 	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
 	ip netns exec at_ns0 ip link set dev $DEV_NS up
-- 
2.7.4

Re: [PATCH net 0/3] net: erspan fixes

[David Miller]

From: William Tu <u9012063@gmail.com>
Date: Mon,  5 Feb 2018 13:35:33 -0800

> The first patch fixes erspan metadata extraction issue from packet
> header due to commit d350a823020e ("net: erspan: create erspan metadata
> uapi header").  The commit moves the erspan 'version' in
> 'struct erspan_metadata' in front of 'struct erspan_md2' for later
> extensibility, but breaks the existing metadata extraction code due
> to extra 4-byte size 'version'.  The second patch fixes the case where
> tunnel device receives an erspan packet with different tunnel metadata
> (ex: version, index, hwid, direction), existing code overwrites the
> tunnel device's erspan configuration.  The third patch fixes the bpf
> tests due to the above patches.

Applied, thanks William.