openvswitch: Allow each vport to have an array of 'port_id's.

In order to allow handlers directly read upcalls from datapath,
we need to support per-handler netlink socket for each vport in
datapath.  This commit makes this happen.  Also, it is guaranteed
to be backward compatible with previous branch.

Signed-off-by: Alex Wang <alexw@nicira.com>
Acked-by: Thomas Graf <tgraf@redhat.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>

4 files changed, 148 insertions, 16 deletions

diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
index 0b979ee4bfc0..a794d1dd7b40 100644
--- a/include/uapi/linux/openvswitch.h
+++ b/include/uapi/linux/openvswitch.h
@@ -118,6 +118,9 @@ struct ovs_vport_stats {
 /* Allow last Netlink attribute to be unaligned */
 #define OVS_DP_F_UNALIGNED      (1 << 0)
 
+/* Allow datapath to associate multiple Netlink PIDs to each vport */
+#define OVS_DP_F_VPORT_PIDS     (1 << 1)
+
 /* Fixed logical ports. */
 #define OVSP_LOCAL      ((__u32)0)
 
@@ -203,9 +206,10 @@ enum ovs_vport_type {
  * this is the name of the network device.  Maximum length %IFNAMSIZ-1 bytes
  * plus a null terminator.
  * @OVS_VPORT_ATTR_OPTIONS: Vport-specific configuration information.
- * @OVS_VPORT_ATTR_UPCALL_PID: The Netlink socket in userspace that
- * OVS_PACKET_CMD_MISS upcalls will be directed to for packets received on
- * this port.  A value of zero indicates that upcalls should not be sent.
+ * @OVS_VPORT_ATTR_UPCALL_PID: The array of Netlink socket pids in userspace
+ * among which OVS_PACKET_CMD_MISS upcalls will be distributed for packets
+ * received on this port.  If this is a single-element array of value 0,
+ * upcalls should not be sent.
  * @OVS_VPORT_ATTR_STATS: A &struct ovs_vport_stats giving statistics for
  * packets sent or received through the vport.
  *
@@ -228,7 +232,8 @@ enum ovs_vport_attr {
         OVS_VPORT_ATTR_TYPE,    /* u32 OVS_VPORT_TYPE_* constant. */
         OVS_VPORT_ATTR_NAME,    /* string name, up to IFNAMSIZ bytes long */
         OVS_VPORT_ATTR_OPTIONS, /* nested attributes, varies by vport type */
-        OVS_VPORT_ATTR_UPCALL_PID, /* u32 Netlink PID to receive upcalls */
+        OVS_VPORT_ATTR_UPCALL_PID, /* array of u32 Netlink socket PIDs for */
+                                /* receiving upcalls */
         OVS_VPORT_ATTR_STATS,   /* struct ovs_vport_stats */
         __OVS_VPORT_ATTR_MAX
 };
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 20f59b62721a..65a8e5c089e4 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -266,7 +266,7 @@ void ovs_dp_process_received_packet(struct vport *p, struct sk_buff *skb)
                 upcall.cmd = OVS_PACKET_CMD_MISS;
                 upcall.key = &key;
                 upcall.userdata = NULL;
-                upcall.portid = p->upcall_portid;
+                upcall.portid = ovs_vport_find_upcall_portid(p, skb);
                 ovs_dp_upcall(dp, skb, &upcall);
                 consume_skb(skb);
                 stats_counter = &stats->n_missed;
@@ -1373,7 +1373,7 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
         parms.options = NULL;
         parms.dp = dp;
         parms.port_no = OVSP_LOCAL;
-        parms.upcall_portid = nla_get_u32(a[OVS_DP_ATTR_UPCALL_PID]);
+        parms.upcall_portids = a[OVS_DP_ATTR_UPCALL_PID];
 
         ovs_dp_change(dp, a);
 
@@ -1632,8 +1632,8 @@ static int ovs_vport_cmd_fill_info(struct vport *vport, struct sk_buff *skb,
 
         if (nla_put_u32(skb, OVS_VPORT_ATTR_PORT_NO, vport->port_no) ||
             nla_put_u32(skb, OVS_VPORT_ATTR_TYPE, vport->ops->type) ||
-            nla_put_string(skb, OVS_VPORT_ATTR_NAME, vport->ops->get_name(vport)) ||
-            nla_put_u32(skb, OVS_VPORT_ATTR_UPCALL_PID, vport->upcall_portid))
+            nla_put_string(skb, OVS_VPORT_ATTR_NAME,
+                           vport->ops->get_name(vport)))
                 goto nla_put_failure;
 
         ovs_vport_get_stats(vport, &vport_stats);
@@ -1641,6 +1641,9 @@ static int ovs_vport_cmd_fill_info(struct vport *vport, struct sk_buff *skb,
                     &vport_stats))
                 goto nla_put_failure;
 
+        if (ovs_vport_get_upcall_portids(vport, skb))
+                goto nla_put_failure;
+
         err = ovs_vport_get_options(vport, skb);
         if (err == -EMSGSIZE)
                 goto error;
@@ -1762,7 +1765,7 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
         parms.options = a[OVS_VPORT_ATTR_OPTIONS];
         parms.dp = dp;
         parms.port_no = port_no;
-        parms.upcall_portid = nla_get_u32(a[OVS_VPORT_ATTR_UPCALL_PID]);
+        parms.upcall_portids = a[OVS_VPORT_ATTR_UPCALL_PID];
 
         vport = new_vport(&parms);
         err = PTR_ERR(vport);
@@ -1812,8 +1815,14 @@ static int ovs_vport_cmd_set(struct sk_buff *skb, struct genl_info *info)
                         goto exit_unlock_free;
         }
 
-        if (a[OVS_VPORT_ATTR_UPCALL_PID])
-                vport->upcall_portid = nla_get_u32(a[OVS_VPORT_ATTR_UPCALL_PID]);
+
+        if (a[OVS_VPORT_ATTR_UPCALL_PID]) {
+                struct nlattr *ids = a[OVS_VPORT_ATTR_UPCALL_PID];
+
+                err = ovs_vport_set_upcall_portids(vport, ids);
+                if (err)
+                        goto exit_unlock_free;
+        }
 
         err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
                                       info->snd_seq, 0, OVS_VPORT_CMD_NEW);
diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index 42c0f4a0b78c..702fb21bfe15 100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c
@@ -134,10 +134,12 @@ struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
 
         vport->dp = parms->dp;
         vport->port_no = parms->port_no;
-        vport->upcall_portid = parms->upcall_portid;
         vport->ops = ops;
         INIT_HLIST_NODE(&vport->dp_hash_node);
 
+        if (ovs_vport_set_upcall_portids(vport, parms->upcall_portids))
+                return ERR_PTR(-EINVAL);
+
         vport->percpu_stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
         if (!vport->percpu_stats) {
                 kfree(vport);
@@ -161,6 +163,10 @@ struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
  */
 void ovs_vport_free(struct vport *vport)
 {
+        /* vport is freed from RCU callback or error path, Therefore
+         * it is safe to use raw dereference.
+         */
+        kfree(rcu_dereference_raw(vport->upcall_portids));
         free_percpu(vport->percpu_stats);
         kfree(vport);
 }
@@ -327,6 +333,99 @@ int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
 }
 
 /**
+ *      ovs_vport_set_upcall_portids - set upcall portids of @vport.
+ *
+ * @vport: vport to modify.
+ * @ids: new configuration, an array of port ids.
+ *
+ * Sets the vport's upcall_portids to @ids.
+ *
+ * Returns 0 if successful, -EINVAL if @ids is zero length or cannot be parsed
+ * as an array of U32.
+ *
+ * Must be called with ovs_mutex.
+ */
+int ovs_vport_set_upcall_portids(struct vport *vport,  struct nlattr *ids)
+{
+        struct vport_portids *old, *vport_portids;
+
+        if (!nla_len(ids) || nla_len(ids) % sizeof(u32))
+                return -EINVAL;
+
+        old = ovsl_dereference(vport->upcall_portids);
+
+        vport_portids = kmalloc(sizeof(*vport_portids) + nla_len(ids),