datapath: reliable interface indentification in port dumps

Upstream commit:
    commit 9354d452034273a50a4fd703bea31e5d6b1fc20b
    Author: Jiri Benc <[email protected]>
    Date:   Thu Nov 2 17:04:37 2017 -0200

    openvswitch: reliable interface indentification in port dumps

    This patch allows reliable identification of netdevice interfaces connected
    to openvswitch bridges. In particular, user space queries the netdev
    interfaces belonging to the ports for statistics, up/down state, etc.
    Datapath dump needs to provide enough information for the user space to be
    able to do that.

    Currently, only interface names are returned. This is not sufficient, as
    openvswitch allows its ports to be in different name spaces and the
    interface name is valid only in its name space. What is needed and generally
    used in other netlink APIs, is the pair ifindex+netnsid.

    The solution is addition of the ifindex+netnsid pair (or only ifindex if in
    the same name space) to vport get/dump operation.

    On request side, ideally the ifindex+netnsid pair could be used to
    get/set/del the corresponding vport. This is not implemented by this patch
    and can be added later if needed.

    Signed-off-by: Jiri Benc <[email protected]>
    Signed-off-by: David S. Miller <[email protected]>

Added compat fixup for peernet2id.

Cc: Jiri Benc <[email protected]>
Signed-off-by: Greg Rose <[email protected]>
Acked-by: Pravin B Shelar <[email protected]>

acinclude.m4

@@ -805,6 +805,9 @@ AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
   OVS_GREP_IFELSE([$KSRC/include/linux/timekeeping.h],
                   [ktime_get_ts64],
                   [OVS_DEFINE([HAVE_KTIME_GET_TS64])])
+  OVS_GREP_IFELSE([$KSRC/include/net/net_namespace.h],
+                  [EXPORT_SYMBOL_GPL(peernet2id_alloc)],
+                  [OVS_DEFINE([HAVE_PEERNET2ID_ALLOC])])
 
   if cmp -s datapath/linux/kcompat.h.new \
             datapath/linux/kcompat.h >/dev/null 2>&1; then

datapath/datapath.c

@@ -1848,7 +1848,8 @@ static struct genl_family dp_datapath_genl_family __ro_after_init = {
 
 /* Called with ovs_mutex or RCU read lock. */
 static int ovs_vport_cmd_fill_info(struct vport *vport, struct sk_buff *skb,
-				   u32 portid, u32 seq, u32 flags, u8 cmd)
+				   struct net *net, u32 portid, u32 seq,
+				   u32 flags, u8 cmd)
 {
 	struct ovs_header *ovs_header;
 	struct ovs_vport_stats vport_stats;
@@ -1864,9 +1865,19 @@ 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,
-			   ovs_vport_name(vport)))
+			   ovs_vport_name(vport)) ||
+	    nla_put_u32(skb, OVS_VPORT_ATTR_IFINDEX, vport->dev->ifindex))
 		goto nla_put_failure;
 
+#ifdef HAVE_PEERNET2ID_ALLOC
+	if (!net_eq(net, dev_net(vport->dev))) {
+		int id = peernet2id_alloc(net, dev_net(vport->dev));
+
+		if (nla_put_s32(skb, OVS_VPORT_ATTR_NETNSID, id))
+			goto nla_put_failure;
+	}
+
+#endif
 	ovs_vport_get_stats(vport, &vport_stats);
 	if (nla_put_64bit(skb, OVS_VPORT_ATTR_STATS,
 			  sizeof(struct ovs_vport_stats), &vport_stats,
@@ -1896,8 +1907,8 @@ static struct sk_buff *ovs_vport_cmd_alloc_info(void)
 }
 
 /* Called with ovs_mutex, only via ovs_dp_notify_wq(). */
-struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, u32 portid,
-					 u32 seq, u8 cmd)
+struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, struct net *net,
+					 u32 portid, u32 seq, u8 cmd)
 {
 	struct sk_buff *skb;
 	int retval;
@@ -1906,7 +1917,7 @@ struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, u32 portid,
 	if (!skb)
 		return ERR_PTR(-ENOMEM);
 
-	retval = ovs_vport_cmd_fill_info(vport, skb, portid, seq, 0, cmd);
+	retval = ovs_vport_cmd_fill_info(vport, skb, net, portid, seq, 0, cmd);
 	BUG_ON(retval < 0);
 
 	return skb;
@@ -1920,6 +1931,8 @@ static struct vport *lookup_vport(struct net *net,
 	struct datapath *dp;
 	struct vport *vport;
 
+	if (a[OVS_VPORT_ATTR_IFINDEX])
+		return ERR_PTR(-EOPNOTSUPP);
 	if (a[OVS_VPORT_ATTR_NAME]) {
 		vport = ovs_vport_locate(net, nla_data(a[OVS_VPORT_ATTR_NAME]));
 		if (!vport)
@@ -1944,6 +1957,7 @@ static struct vport *lookup_vport(struct net *net,
 		return vport;
 	} else
 		return ERR_PTR(-EINVAL);
+
 }
 
 /* Called with ovs_mutex */
@@ -1983,6 +1997,8 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
 	if (!a[OVS_VPORT_ATTR_NAME] || !a[OVS_VPORT_ATTR_TYPE] ||
 	    !a[OVS_VPORT_ATTR_UPCALL_PID])
 		return -EINVAL;
+	if (a[OVS_VPORT_ATTR_IFINDEX])
+		return -EOPNOTSUPP;
 
 	port_no = a[OVS_VPORT_ATTR_PORT_NO]
 		? nla_get_u32(a[OVS_VPORT_ATTR_PORT_NO]) : 0;
@@ -2032,8 +2048,9 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
 		goto exit_unlock_free;
 	}
 
-	err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
-				      info->snd_seq, 0, OVS_VPORT_CMD_NEW);
+	err = ovs_vport_cmd_fill_info(vport, reply, genl_info_net(info),
+				      info->snd_portid, info->snd_seq, 0,
+				      OVS_VPORT_CMD_NEW);
 	BUG_ON(err < 0);
 
 	if (netdev_get_fwd_headroom(vport->dev) > dp->max_headroom)
@@ -2089,8 +2106,9 @@ static int ovs_vport_cmd_set(struct sk_buff *skb, struct genl_info *info)
 			goto exit_unlock_free;
 	}
 
-	err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
-				      info->snd_seq, 0, OVS_VPORT_CMD_NEW);
+	err = ovs_vport_cmd_fill_info(vport, reply, genl_info_net(info),
+				      info->snd_portid, info->snd_seq, 0,
+				      OVS_VPORT_CMD_NEW);
 	BUG_ON(err < 0);
 	ovs_unlock();
 
@@ -2127,8 +2145,9 @@ static int ovs_vport_cmd_del(struct sk_buff *skb, struct genl_info *info)
 		goto exit_unlock_free;
 	}
 
-	err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
-				      info->snd_seq, 0, OVS_VPORT_CMD_DEL);
+	err = ovs_vport_cmd_fill_info(vport, reply, genl_info_net(info),
+				      info->snd_portid, info->snd_seq, 0,
+				      OVS_VPORT_CMD_DEL);
 	BUG_ON(err < 0);
 
 	/* the vport deletion may trigger dp headroom update */
@@ -2169,8 +2188,9 @@ static int ovs_vport_cmd_get(struct sk_buff *skb, struct genl_info *info)
 	err = PTR_ERR(vport);
 	if (IS_ERR(vport))
 		goto exit_unlock_free;
-	err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
-				      info->snd_seq, 0, OVS_VPORT_CMD_NEW);
+	err = ovs_vport_cmd_fill_info(vport, reply, genl_info_net(info),
+				      info->snd_portid, info->snd_seq, 0,
+				      OVS_VPORT_CMD_NEW);
 	BUG_ON(err < 0);
 	rcu_read_unlock();
 
@@ -2202,6 +2222,7 @@ static int ovs_vport_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb)
 		hlist_for_each_entry_rcu(vport, &dp->ports[i], dp_hash_node) {
 			if (j >= skip &&
 			    ovs_vport_cmd_fill_info(vport, skb,
+						    sock_net(skb->sk),
 						    NETLINK_CB(cb->skb).portid,
 						    cb->nlh->nlmsg_seq,
 						    NLM_F_MULTI,
@@ -2228,6 +2249,8 @@ static const struct nla_policy vport_policy[OVS_VPORT_ATTR_MAX + 1] = {
 	[OVS_VPORT_ATTR_TYPE] = { .type = NLA_U32 },
 	[OVS_VPORT_ATTR_UPCALL_PID] = { .type = NLA_U32 },
 	[OVS_VPORT_ATTR_OPTIONS] = { .type = NLA_NESTED },
+	[OVS_VPORT_ATTR_IFINDEX] = { .type = NLA_U32 },
+	[OVS_VPORT_ATTR_NETNSID] = { .type = NLA_S32 },
 };
 
 static struct genl_ops dp_vport_genl_ops[] = {

datapath/datapath.h

@@ -239,8 +239,8 @@ int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 		  uint32_t cutlen);
 
 const char *ovs_dp_name(const struct datapath *dp);
-struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
-					 u8 cmd);
+struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, struct net *net,
+					 u32 portid, u32 seq, u8 cmd);
 
 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
 			const struct sw_flow_actions *, struct sw_flow_key *);

datapath/dp_notify.c

@@ -31,7 +31,8 @@ static void dp_detach_port_notify(struct vport *vport)
 	struct datapath *dp;
 
 	dp = vport->dp;
-	notify = ovs_vport_cmd_build_info(vport, 0, 0, OVS_VPORT_CMD_DEL);
+	notify = ovs_vport_cmd_build_info(vport, ovs_dp_get_net(dp),
+					  0, 0, OVS_VPORT_CMD_DEL);
 	ovs_dp_detach_port(vport);
 	if (IS_ERR(notify)) {
 		genl_set_err(&dp_vport_genl_family, ovs_dp_get_net(dp), 0,

datapath/linux/compat/include/linux/openvswitch.h

@@ -283,6 +283,8 @@ enum ovs_vport_attr {
 				/* receiving upcalls */
 	OVS_VPORT_ATTR_STATS,	/* struct ovs_vport_stats */
 	OVS_VPORT_ATTR_PAD,
+	OVS_VPORT_ATTR_IFINDEX,
+	OVS_VPORT_ATTR_NETNSID,
 	__OVS_VPORT_ATTR_MAX
 };