net: Add lease info to queue-get response

Populate nested lease info to the queue-get response that returns the
ifindex, queue id with type and optionally netns id if the device
resides in a different netns.

Example with ynl client when using AF_XDP via queue leasing:

  # ip a
  [...]
  4: enp10s0f0np0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp/id:24 qdisc mq state UP group default qlen 1000
    link/ether e8:eb:d3:a3:43:f6 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.2/24 scope global enp10s0f0np0
       valid_lft forever preferred_lft forever
    inet6 fe80::eaeb:d3ff:fea3:43f6/64 scope link proto kernel_ll
       valid_lft forever preferred_lft forever
  [...]

  # ethtool -i enp10s0f0np0
  driver: mlx5_core
  [...]

  # ynl --family netdev --output-json --do queue-get \
        --json '{"ifindex": 4, "id": 15, "type": "rx"}'
  {'id': 15,
   'ifindex': 4,
   'lease': {'ifindex': 8, 'netns-id': 0, 'queue': {'id': 1, 'type': 'rx'}},
   'napi-id': 8227,
   'type': 'rx',
   'xsk': {}}

  # ip netns list
  foo (id: 0)

  # ip netns exec foo ip a
  [...]
  8: nk@NONE: <BROADCAST,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
      link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
      inet6 fe80::200:ff:fe00:0/64 scope link proto kernel_ll
         valid_lft forever preferred_lft forever
  [...]

  # ip netns exec foo ethtool -i nk
  driver: netkit
  [...]

  # ip netns exec foo ls /sys/class/net/nk/queues/
  rx-0  rx-1  tx-0

  # ip netns exec foo ynl --family netdev --output-json --do queue-get \
        --json '{"ifindex": 8, "id": 1, "type": "rx"}'
  {"id": 1, "type": "rx", "ifindex": 8, "xsk": {}}

Note that the caller of netdev_nl_queue_fill_one() holds the netdevice
lock. For the queue-get we do not lock both devices. When queues get
{un,}leased, both devices are locked, thus if __netif_get_rx_queue_lease()
returns a lease pointer, it points to a valid device. The netns-id is
fetched via peernet2id_alloc() similarly as done in OVS.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: David Wei <dw@davidwei.uk>
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260402231031.447597-4-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/net/netdev_rx_queue.h b/include/net/netdev_rx_queue.h
index 1d41c253f0a32c7f3f821070e450f32ed05c7a1f..7e98c679ea84f49aa0cc299ce9045062cc668a0d 100644 (file)
--- a/include/net/netdev_rx_queue.h
+++ b/include/net/netdev_rx_queue.h
@@ -67,6 +67,20 @@ get_netdev_rx_queue_index(struct netdev_rx_queue *queue)
        return index;
 }
 
+enum netif_lease_dir {
+       NETIF_VIRT_TO_PHYS,
+       NETIF_PHYS_TO_VIRT,
+};
+
+struct netdev_rx_queue *
+__netif_get_rx_queue_lease(struct net_device **dev, unsigned int *rxq,
+                          enum netif_lease_dir dir);
+
+struct netdev_rx_queue *
+netif_get_rx_queue_lease_locked(struct net_device **dev, unsigned int *rxq);
+void netif_put_rx_queue_lease_locked(struct net_device *orig_dev,
+                                    struct net_device *dev);
+
 int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq);
 void netdev_rx_queue_lease(struct netdev_rx_queue *rxq_dst,
                           struct netdev_rx_queue *rxq_src);

diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 5d5e5b9a8af056f8b3db9eed85c1e0abc824ea67..515832854251f4d29a2820f111d8b888fe628ff9 100644 (file)
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -386,12 +386,63 @@ static int nla_put_napi_id(struct sk_buff *skb, const struct napi_struct *napi)
        return 0;
 }
 
+static int
+netdev_nl_queue_fill_lease(struct sk_buff *rsp, struct net_device *netdev,
+                          u32 q_idx, u32 q_type)
+{
+       struct net_device *orig_netdev = netdev;
+       struct nlattr *nest_lease, *nest_queue;
+       struct netdev_rx_queue *rxq;
+       struct net *net, *peer_net;
+
+       rxq = __netif_get_rx_queue_lease(&netdev, &q_idx,
+                                        NETIF_PHYS_TO_VIRT);
+       if (!rxq || orig_netdev == netdev)
+               return 0;
+
+       nest_lease = nla_nest_start(rsp, NETDEV_A_QUEUE_LEASE);
+       if (!nest_lease)
+               goto nla_put_failure;
+
+       nest_queue = nla_nest_start(rsp, NETDEV_A_LEASE_QUEUE);
+       if (!nest_queue)
+               goto nla_put_failure;
+       if (nla_put_u32(rsp, NETDEV_A_QUEUE_ID, q_idx))
+               goto nla_put_failure;
+       if (nla_put_u32(rsp, NETDEV_A_QUEUE_TYPE, q_type))
+               goto nla_put_failure;
+       nla_nest_end(rsp, nest_queue);
+
+       if (nla_put_u32(rsp, NETDEV_A_LEASE_IFINDEX,
+                       READ_ONCE(netdev->ifindex)))
+               goto nla_put_failure;
+
+       rcu_read_lock();
+       peer_net = dev_net_rcu(netdev);
+       net = dev_net_rcu(orig_netdev);
+       if (!net_eq(net, peer_net)) {
+               s32 id = peernet2id_alloc(net, peer_net, GFP_ATOMIC);
+
+               if (nla_put_s32(rsp, NETDEV_A_LEASE_NETNS_ID, id))
+                       goto nla_put_failure_unlock;
+       }
+       rcu_read_unlock();
+       nla_nest_end(rsp, nest_lease);
+       return 0;
+
+nla_put_failure_unlock:
+       rcu_read_unlock();
+nla_put_failure:
+       return -ENOMEM;
+}
+
 static int
 netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
                         u32 q_idx, u32 q_type, const struct genl_info *info)
 {
        struct pp_memory_provider_params *params;
-       struct netdev_rx_queue *rxq;
+       struct net_device *orig_netdev = netdev;
+       struct netdev_rx_queue *rxq, *rxq_lease;
        struct netdev_queue *txq;
        void *hdr;
 
@@ -409,17 +460,22 @@ netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
                rxq = __netif_get_rx_queue(netdev, q_idx);
                if (nla_put_napi_id(rsp, rxq->napi))
                        goto nla_put_failure;
+               if (netdev_nl_queue_fill_lease(rsp, netdev, q_idx, q_type))
+                       goto nla_put_failure;
 
+               rxq_lease = netif_get_rx_queue_lease_locked(&netdev, &q_idx);
+               if (rxq_lease)
+                       rxq = rxq_lease;
                params = &rxq->mp_params;
                if (params->mp_ops &&
                    params->mp_ops->nl_fill(params->mp_priv, rsp, rxq))
-                       goto nla_put_failure;
+                       goto nla_put_failure_lease;
 #ifdef CONFIG_XDP_SOCKETS
                if (rxq->pool)
                        if (nla_put_empty_nest(rsp, NETDEV_A_QUEUE_XSK))
-                               goto nla_put_failure;
+                               goto nla_put_failure_lease;
 #endif
-
+               netif_put_rx_queue_lease_locked(orig_netdev, netdev);
                break;
        case NETDEV_QUEUE_TYPE_TX:
                txq = netdev_get_tx_queue(netdev, q_idx);
@@ -437,6 +493,8 @@ netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
 
        return 0;
 
+nla_put_failure_lease:
+       netif_put_rx_queue_lease_locked(orig_netdev, netdev);
 nla_put_failure:
        genlmsg_cancel(rsp, hdr);
        return -EMSGSIZE;

diff --git a/net/core/netdev_rx_queue.c b/net/core/netdev_rx_queue.c
index a1f23c2c96d48803d6d1f623121c5bba8a7413eb..a4d8cad6db746f793d3745da476d77640fcb4f41 100644 (file)
--- a/net/core/netdev_rx_queue.c
+++ b/net/core/netdev_rx_queue.c
@@ -41,6 +41,60 @@ bool netif_rxq_is_leased(struct net_device *dev, unsigned int rxq_idx)
        return false;
 }
 
+/* Virtual devices eligible for leasing have no dev->dev.parent, while
+ * physical devices always have one. Use this to enforce the correct
+ * lease traversal direction.
+ */
+static bool netif_lease_dir_ok(const struct net_device *dev,
+                              enum netif_lease_dir dir)
+{
+       if (dir == NETIF_VIRT_TO_PHYS && !dev->dev.parent)
+               return true;
+       if (dir == NETIF_PHYS_TO_VIRT && dev->dev.parent)
+               return true;
+       return false;
+}
+
+struct netdev_rx_queue *
+__netif_get_rx_queue_lease(struct net_device **dev, unsigned int *rxq_idx,
+                          enum netif_lease_dir dir)
+{
+       struct net_device *orig_dev = *dev;
+       struct netdev_rx_queue *rxq = __netif_get_rx_queue(orig_dev, *rxq_idx);
+
+       if (rxq->lease) {
+               if (!netif_lease_dir_ok(orig_dev, dir))
+                       return NULL;
+               rxq = rxq->lease;
+               *rxq_idx = get_netdev_rx_queue_index(rxq);
+               *dev = rxq->dev;
+       }
+       return rxq;
+}
+
+struct netdev_rx_queue *
+netif_get_rx_queue_lease_locked(struct net_device **dev, unsigned int *rxq_idx)
+{
+       struct net_device *orig_dev = *dev;
+       struct netdev_rx_queue *rxq;
+
+       /* Locking order is always from the virtual to the physical device
+        * see netdev_nl_queue_create_doit().
+        */
+       netdev_ops_assert_locked(orig_dev);
+       rxq = __netif_get_rx_queue_lease(dev, rxq_idx, NETIF_VIRT_TO_PHYS);
+       if (rxq && orig_dev != *dev)
+               netdev_lock(*dev);
+       return rxq;
+}
+
+void netif_put_rx_queue_lease_locked(struct net_device *orig_dev,
+                                    struct net_device *dev)
+{
+       if (orig_dev != dev)
+               netdev_unlock(dev);
+}
+
 /* See also page_pool_is_unreadable() */
 bool netif_rxq_has_unreadable_mp(struct net_device *dev, unsigned int rxq_idx)
 {