5.4-stable review patch. If anyone has any objections, please let me know.
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From: William Tu u9012063@gmail.com
[ Upstream commit f989d546a2d5a9f001f6f8be49d98c10ab9b1897 ]
The Type I ERSPAN frame format is based on the barebones IP + GRE(4-byte) encapsulation on top of the raw mirrored frame. Both type I and II use 0x88BE as protocol type. Unlike type II and III, no sequence number or key is required. To creat a type I erspan tunnel device: $ ip link add dev erspan11 type erspan \ local 172.16.1.100 remote 172.16.1.200 \ erspan_ver 0
Signed-off-by: William Tu u9012063@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: 17af420545a7 ("erspan: make sure erspan_base_hdr is present in skb->head") Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/erspan.h | 19 +++++++++++++-- net/ipv4/ip_gre.c | 58 ++++++++++++++++++++++++++++++++------------ 2 files changed, 60 insertions(+), 17 deletions(-)
diff --git a/include/net/erspan.h b/include/net/erspan.h index b39643ef4c95f..0d9e86bd98934 100644 --- a/include/net/erspan.h +++ b/include/net/erspan.h @@ -2,7 +2,19 @@ #define __LINUX_ERSPAN_H
/* - * GRE header for ERSPAN encapsulation (8 octets [34:41]) -- 8 bytes + * GRE header for ERSPAN type I encapsulation (4 octets [34:37]) + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |0|0|0|0|0|00000|000000000|00000| Protocol Type for ERSPAN | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * The Type I ERSPAN frame format is based on the barebones IP + GRE + * encapsulation (as described above) on top of the raw mirrored frame. + * There is no extra ERSPAN header. + * + * + * GRE header for ERSPAN type II and II encapsulation (8 octets [34:41]) * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ @@ -43,7 +55,7 @@ * | Platform Specific Info | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * - * GRE proto ERSPAN type II = 0x88BE, type III = 0x22EB + * GRE proto ERSPAN type I/II = 0x88BE, type III = 0x22EB */
#include <uapi/linux/erspan.h> @@ -139,6 +151,9 @@ static inline u8 get_hwid(const struct erspan_md2 *md2)
static inline int erspan_hdr_len(int version) { + if (version == 0) + return 0; + return sizeof(struct erspan_base_hdr) + (version == 1 ? ERSPAN_V1_MDSIZE : ERSPAN_V2_MDSIZE); } diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index db48dec61f305..f8369580ea273 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -248,6 +248,15 @@ static void gre_err(struct sk_buff *skb, u32 info) ipgre_err(skb, info, &tpi); }
+static bool is_erspan_type1(int gre_hdr_len) +{ + /* Both ERSPAN type I (version 0) and type II (version 1) use + * protocol 0x88BE, but the type I has only 4-byte GRE header, + * while type II has 8-byte. + */ + return gre_hdr_len == 4; +} + static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi, int gre_hdr_len) { @@ -262,17 +271,26 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi, int len;
itn = net_generic(net, erspan_net_id); - iph = ip_hdr(skb); - ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len); - ver = ershdr->ver; - - tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, - tpi->flags | TUNNEL_KEY, - iph->saddr, iph->daddr, tpi->key); + if (is_erspan_type1(gre_hdr_len)) { + ver = 0; + tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, + tpi->flags | TUNNEL_NO_KEY, + iph->saddr, iph->daddr, 0); + } else { + ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len); + ver = ershdr->ver; + tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, + tpi->flags | TUNNEL_KEY, + iph->saddr, iph->daddr, tpi->key); + }
if (tunnel) { - len = gre_hdr_len + erspan_hdr_len(ver); + if (is_erspan_type1(gre_hdr_len)) + len = gre_hdr_len; + else + len = gre_hdr_len + erspan_hdr_len(ver); + if (unlikely(!pskb_may_pull(skb, len))) return PACKET_REJECT;
@@ -670,7 +688,10 @@ static netdev_tx_t erspan_xmit(struct sk_buff *skb, }
/* Push ERSPAN header */ - if (tunnel->erspan_ver == 1) { + if (tunnel->erspan_ver == 0) { + proto = htons(ETH_P_ERSPAN); + tunnel->parms.o_flags &= ~TUNNEL_SEQ; + } else if (tunnel->erspan_ver == 1) { erspan_build_header(skb, ntohl(tunnel->parms.o_key), tunnel->index, truncate, true); @@ -1080,7 +1101,10 @@ static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], if (ret) return ret;
- /* ERSPAN should only have GRE sequence and key flag */ + if (nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0) + return 0; + + /* ERSPAN type II/III should only have GRE sequence and key flag */ if (data[IFLA_GRE_OFLAGS]) flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); if (data[IFLA_GRE_IFLAGS]) @@ -1188,7 +1212,7 @@ static int erspan_netlink_parms(struct net_device *dev, if (data[IFLA_GRE_ERSPAN_VER]) { t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
- if (t->erspan_ver != 1 && t->erspan_ver != 2) + if (t->erspan_ver > 2) return -EINVAL; }
@@ -1273,7 +1297,11 @@ static int erspan_tunnel_init(struct net_device *dev) { struct ip_tunnel *tunnel = netdev_priv(dev);
- tunnel->tun_hlen = 8; + if (tunnel->erspan_ver == 0) + tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */ + else + tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */ + tunnel->parms.iph.protocol = IPPROTO_GRE; tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + erspan_hdr_len(tunnel->erspan_ver); @@ -1470,8 +1498,8 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) struct ip_tunnel_parm *p = &t->parms; __be16 o_flags = p->o_flags;
- if (t->erspan_ver == 1 || t->erspan_ver == 2) { - if (!t->collect_md) + if (t->erspan_ver <= 2) { + if (t->erspan_ver != 0 && !t->collect_md) o_flags |= TUNNEL_KEY;
if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) @@ -1480,7 +1508,7 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) if (t->erspan_ver == 1) { if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) goto nla_put_failure; - } else { + } else if (t->erspan_ver == 2) { if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) goto nla_put_failure; if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))