[ovs-dev] [ERSPAN RFC 04/25] compat/gre: add collect_md mode
Greg Rose
gvrose8192 at gmail.com
Thu Mar 22 22:07:20 UTC 2018
From: William Tu <u9012063 at gmail.com>
commit 1a66a836da630cd70f3639208da549b549ce576b
Author: William Tu <u9012063 at gmail.com>
Date: Fri Aug 25 09:21:28 2017 -0700
gre: add collect_md mode to ERSPAN tunnel
Similar to gre, vxlan, geneve, ipip tunnels, allow ERSPAN tunnels to
operate in 'collect metadata' mode. bpf_skb_[gs]et_tunnel_key() helpers
can make use of it right away. OVS can use it as well in the future.
Signed-off-by: William Tu <u9012063 at gmail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
With some adjustments for compatibility layer.
Cc: William Tu <u9012063 at gmail.com>
Signed-off-by: Greg Rose <gvrose8192 at gmail.com>
---
datapath/linux/compat/include/net/ip_tunnels.h | 68 ++++++++------
datapath/linux/compat/ip_gre.c | 117 ++++++++++++++++++++++---
2 files changed, 146 insertions(+), 39 deletions(-)
diff --git a/datapath/linux/compat/include/net/ip_tunnels.h b/datapath/linux/compat/include/net/ip_tunnels.h
index e3fb13b..159eb48 100644
--- a/datapath/linux/compat/include/net/ip_tunnels.h
+++ b/datapath/linux/compat/include/net/ip_tunnels.h
@@ -74,14 +74,25 @@ void rpl_ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
#ifndef TUNNEL_CSUM
-#define TUNNEL_CSUM __cpu_to_be16(0x01)
-#define TUNNEL_ROUTING __cpu_to_be16(0x02)
-#define TUNNEL_KEY __cpu_to_be16(0x04)
-#define TUNNEL_SEQ __cpu_to_be16(0x08)
-#define TUNNEL_STRICT __cpu_to_be16(0x10)
-#define TUNNEL_REC __cpu_to_be16(0x20)
-#define TUNNEL_VERSION __cpu_to_be16(0x40)
-#define TUNNEL_NO_KEY __cpu_to_be16(0x80)
+#define TUNNEL_CSUM __cpu_to_be16(0x01)
+#define TUNNEL_ROUTING __cpu_to_be16(0x02)
+#define TUNNEL_KEY __cpu_to_be16(0x04)
+#define TUNNEL_SEQ __cpu_to_be16(0x08)
+#define TUNNEL_STRICT __cpu_to_be16(0x10)
+#define TUNNEL_REC __cpu_to_be16(0x20)
+#define TUNNEL_VERSION __cpu_to_be16(0x40)
+#define TUNNEL_NO_KEY __cpu_to_be16(0x80)
+#define TUNNEL_DONT_FRAGMENT __cpu_to_be16(0x0100)
+#define TUNNEL_OAM __cpu_to_be16(0x0200)
+#define TUNNEL_CRIT_OPT __cpu_to_be16(0x0400)
+#define TUNNEL_GENEVE_OPT __cpu_to_be16(0x0800)
+#define TUNNEL_VXLAN_OPT __cpu_to_be16(0x1000)
+#define TUNNEL_NOCACHE __cpu_to_be16(0x2000)
+#define TUNNEL_ERSPAN_OPT __cpu_to_be16(0x4000)
+
+#undef TUNNEL_OPTIONS_PRESENT
+#define TUNNEL_OPTIONS_PRESENT \
+ (TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT | TUNNEL_ERSPAN_OPT)
struct tnl_ptk_info {
__be16 flags;
@@ -100,27 +111,6 @@ struct tnl_ptk_info {
#define IP_TNL_HASH_BITS 7
#define IP_TNL_HASH_SIZE (1 << IP_TNL_HASH_BITS)
-#ifndef TUNNEL_DONT_FRAGMENT
-#define TUNNEL_DONT_FRAGMENT __cpu_to_be16(0x0100)
-#endif
-
-#ifndef TUNNEL_OAM
-#define TUNNEL_OAM __cpu_to_be16(0x0200)
-#define TUNNEL_CRIT_OPT __cpu_to_be16(0x0400)
-#endif
-
-#ifndef TUNNEL_GENEVE_OPT
-#define TUNNEL_GENEVE_OPT __cpu_to_be16(0x0800)
-#endif
-
-#ifndef TUNNEL_VXLAN_OPT
-#define TUNNEL_VXLAN_OPT __cpu_to_be16(0x1000)
-#endif
-
-/* Older kernels defined TUNNEL_OPTIONS_PRESENT to GENEVE only */
-#undef TUNNEL_OPTIONS_PRESENT
-#define TUNNEL_OPTIONS_PRESENT (TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT)
-
/* Keep error state on tunnel for 30 sec */
#define IPTUNNEL_ERR_TIMEO (30*HZ)
@@ -243,6 +233,7 @@ static inline void ip_tunnel_key_init(struct ip_tunnel_key *key,
#define ip_tunnel_collect_metadata() true
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
+#undef TUNNEL_NOCACHE
#define TUNNEL_NOCACHE 0
static inline bool
@@ -420,6 +411,25 @@ static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
}
}
+static inline __be64 key32_to_tunnel_id(__be32 key)
+{
+#ifdef __BIG_ENDIAN
+ return (__force __be64)key;
+#else
+ return (__force __be64)((__force u64)key << 32);
+#endif
+}
+
+/* Returns the least-significant 32 bits of a __be64. */
+static inline __be32 tunnel_id_to_key32(__be64 tun_id)
+{
+#ifdef __BIG_ENDIAN
+ return (__force __be32)tun_id;
+#else
+ return (__force __be32)((__force u64)tun_id >> 32);
+#endif
+}
+
#define ip_tunnel_init rpl_ip_tunnel_init
int rpl_ip_tunnel_init(struct net_device *dev);
diff --git a/datapath/linux/compat/ip_gre.c b/datapath/linux/compat/ip_gre.c
index d25d2df..d0f112d 100644
--- a/datapath/linux/compat/ip_gre.c
+++ b/datapath/linux/compat/ip_gre.c
@@ -122,6 +122,9 @@ static __be32 tunnel_id_to_key(__be64 x)
#endif
}
+static void erspan_build_header(struct sk_buff *skb,
+ __be32 id, u32 index, bool truncate);
+
/* Called with rcu_read_lock and BH disabled. */
static int gre_err(struct sk_buff *skb, u32 info,
const struct tnl_ptk_info *tpi)
@@ -133,7 +136,7 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
int gre_hdr_len)
{
struct net *net = dev_net(skb->dev);
- struct metadata_dst *tun_dst = NULL;
+ struct metadata_dst tun_dst;
struct ip_tunnel_net *itn;
struct ip_tunnel *tunnel;
struct erspanhdr *ershdr;
@@ -169,9 +172,33 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
false, false) < 0)
goto drop;
- tunnel->index = ntohl(index);
+ if (tunnel->collect_md) {
+ struct ip_tunnel_info *info;
+ struct erspan_metadata *md;
+ __be64 tun_id;
+ __be16 flags;
+
+ tpi->flags |= TUNNEL_KEY;
+ flags = tpi->flags;
+ tun_id = key32_to_tunnel_id(tpi->key);
+
+ ovs_ip_tun_rx_dst(&tun_dst, skb, flags,
+ tun_id, sizeof(*md));
+
+ md = ip_tunnel_info_opts(&tun_dst.u.tun_info);
+ if (!md)
+ return PACKET_REJECT;
+
+ md->index = index;
+ info = &tun_dst.u.tun_info;
+ info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
+ info->options_len = sizeof(*md);
+ } else {
+ tunnel->index = ntohl(index);
+ }
+
skb_reset_mac_header(skb);
- ovs_ip_tunnel_rcv(tunnel->dev, skb, tun_dst);
+ ovs_ip_tunnel_rcv(tunnel->dev, skb, &tun_dst);
return PACKET_RCVD;
}
drop:
@@ -484,6 +511,72 @@ err_free_skb:
}
EXPORT_SYMBOL(rpl_gre_fb_xmit);
+
+
+static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev,
+ __be16 proto)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ struct ip_tunnel_info *tun_info;
+ const struct ip_tunnel_key *key;
+ struct erspan_metadata *md;
+ struct rtable *rt = NULL;
+ struct tnl_ptk_info tpi;
+ bool truncate = false;
+ struct flowi4 fl;
+ int tunnel_hlen;
+ __be16 df;
+
+ tun_info = skb_tunnel_info(skb);
+ if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
+ ip_tunnel_info_af(tun_info) != AF_INET))
+ goto err_free_skb;
+
+ key = &tun_info->key;
+
+ /* ERSPAN has fixed 8 byte GRE header */
+ tunnel_hlen = 8 + sizeof(struct erspanhdr);
+
+ rt = prepare_fb_xmit(skb, dev, &fl, tunnel_hlen);
+ if (!rt)
+ return;
+
+ if (gre_handle_offloads(skb, false))
+ goto err_free_rt;
+
+ if (skb->len > dev->mtu) {
+ pskb_trim(skb, dev->mtu);
+ truncate = true;
+ }
+
+ md = ip_tunnel_info_opts(tun_info);
+ if (!md)
+ goto err_free_rt;
+
+ erspan_build_header(skb, tunnel_id_to_key32(key->tun_id),
+ ntohl(md->index), truncate);
+
+ tpi.flags = (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ);
+ tpi.proto = htons(ETH_P_ERSPAN);
+ tpi.key = tunnel_id_to_key32(key->tun_id);
+ tpi.seq = htonl(tunnel->o_seqno++);
+ tpi.hdr_len = 8;
+
+ gre_build_header(skb, &tpi, 8);
+
+ df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
+
+ iptunnel_xmit(skb->sk, rt, skb, fl.saddr, key->u.ipv4.dst, IPPROTO_GRE,
+ key->tos, key->ttl, df, false);
+ return;
+
+err_free_rt:
+ ip_rt_put(rt);
+err_free_skb:
+ kfree_skb(skb);
+ dev->stats.tx_dropped++;
+}
+
#define GRE_FEATURES (NETIF_F_SG | \
NETIF_F_FRAGLIST | \
NETIF_F_HIGHDMA | \
@@ -608,18 +701,17 @@ static int erspan_validate(struct nlattr *tb[], struct nlattr *data[])
return ret;
/* ERSPAN should only have GRE sequence and key flag */
- flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
- flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
- if (flags != (GRE_SEQ | GRE_KEY))
+ if (data[IFLA_GRE_OFLAGS])
+ flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
+ if (data[IFLA_GRE_IFLAGS])
+ flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
+ if (!data[IFLA_GRE_COLLECT_METADATA] &&
+ flags != (GRE_SEQ | GRE_KEY))
return -EINVAL;
/* ERSPAN Session ID only has 10-bit. Since we reuse
* 32-bit key field as ID, check it's range.
*/
- if (data[IFLA_GRE_IKEY] &&
- (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
- return -EINVAL;
-
if (data[IFLA_GRE_OKEY] &&
(ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
return -EINVAL;
@@ -708,6 +800,11 @@ static netdev_tx_t erspan_xmit(struct sk_buff *skb,
struct ip_tunnel *tunnel = netdev_priv(dev);
bool truncate = false;
+ if (tunnel->collect_md) {
+ erspan_fb_xmit(skb, dev, skb->protocol);
+ return NETDEV_TX_OK;
+ }
+
if (gre_handle_offloads(skb, false))
goto free_skb;
--
1.8.3.1
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