openvswitch: add erspan version I and II support

The patch adds support for openvswitch to configure erspan
v1 and v2.  The OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS attr is added
to uapi as a binary blob to support all ERSPAN v1 and v2's
fields.  Note that Previous commit "openvswitch: Add erspan tunnel
support." was reverted since it does not design properly.

Signed-off-by: William Tu <u9012063@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 52 insertions, 1 deletions

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/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;
                 }
         }