kernel: backport support for renaming netdevs while up

Will be used in upcoming hostapd changes

Signed-off-by: Felix Fietkau <nbd@nbd.name>
(cherry picked from commit 77c45ddd86b0dff7765e30f7846cbdef34fa93ce)

4 files changed, 159 insertions, 23 deletions

diff --git a/target/linux/generic/backport-5.15/794-v6.2-net-core-Allow-live-renaming-when-an-interface-is-up.patch b/target/linux/generic/backport-5.15/794-v6.2-net-core-Allow-live-renaming-when-an-interface-is-up.patch
new file mode 100644
index 0000000000..bd58db2e77
--- /dev/null
+++ b/target/linux/generic/backport-5.15/794-v6.2-net-core-Allow-live-renaming-when-an-interface-is-up.patch
@@ -0,0 +1,136 @@
+From: Andy Ren <andy.ren@getcruise.com>
+Date: Mon, 7 Nov 2022 09:42:42 -0800
+Subject: [PATCH] net/core: Allow live renaming when an interface is up
+
+Allow a network interface to be renamed when the interface
+is up.
+
+As described in the netconsole documentation [1], when netconsole is
+used as a built-in, it will bring up the specified interface as soon as
+possible. As a result, user space will not be able to rename the
+interface since the kernel disallows renaming of interfaces that are
+administratively up unless the 'IFF_LIVE_RENAME_OK' private flag was set
+by the kernel.
+
+The original solution [2] to this problem was to add a new parameter to
+the netconsole configuration parameters that allows renaming of
+the interface used by netconsole while it is administratively up.
+However, during the discussion that followed, it became apparent that we
+have no reason to keep the current restriction and instead we should
+allow user space to rename interfaces regardless of their administrative
+state:
+
+1. The restriction was put in place over 20 years ago when renaming was
+only possible via IOCTL and before rtnetlink started notifying user
+space about such changes like it does today.
+
+2. The 'IFF_LIVE_RENAME_OK' flag was added over 3 years ago in version
+5.2 and no regressions were reported.
+
+3. In-kernel listeners to 'NETDEV_CHANGENAME' do not seem to care about
+the administrative state of interface.
+
+Therefore, allow user space to rename running interfaces by removing the
+restriction and the associated 'IFF_LIVE_RENAME_OK' flag. Help in
+possible triage by emitting a message to the kernel log that an
+interface was renamed while UP.
+
+[1] https://www.kernel.org/doc/Documentation/networking/netconsole.rst
+[2] https://lore.kernel.org/netdev/20221102002420.2613004-1-andy.ren@getcruise.com/
+
+Signed-off-by: Andy Ren <andy.ren@getcruise.com>
+Reviewed-by: Ido Schimmel <idosch@nvidia.com>
+Reviewed-by: David Ahern <dsahern@kernel.org>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/include/linux/netdevice.h
++++ b/include/linux/netdevice.h
+@@ -1642,7 +1642,6 @@ struct net_device_ops {
+  * @IFF_FAILOVER: device is a failover master device
+  * @IFF_FAILOVER_SLAVE: device is lower dev of a failover master device
+  * @IFF_L3MDEV_RX_HANDLER: only invoke the rx handler of L3 master device
+- * @IFF_LIVE_RENAME_OK: rename is allowed while device is up and running
+  * @IFF_TX_SKB_NO_LINEAR: device/driver is capable of xmitting frames with
+  *	skb_headlen(skb) == 0 (data starts from frag0)
+  */
+@@ -1677,7 +1676,7 @@ enum netdev_priv_flags {
+ 	IFF_FAILOVER			= 1<<27,
+ 	IFF_FAILOVER_SLAVE		= 1<<28,
+ 	IFF_L3MDEV_RX_HANDLER		= 1<<29,
+-	IFF_LIVE_RENAME_OK		= 1<<30,
++	/* was IFF_LIVE_RENAME_OK */
+ 	IFF_TX_SKB_NO_LINEAR		= BIT_ULL(31),
+ };
+ 
+@@ -1711,7 +1710,6 @@ enum netdev_priv_flags {
+ #define IFF_FAILOVER			IFF_FAILOVER
+ #define IFF_FAILOVER_SLAVE		IFF_FAILOVER_SLAVE
+ #define IFF_L3MDEV_RX_HANDLER		IFF_L3MDEV_RX_HANDLER
+-#define IFF_LIVE_RENAME_OK		IFF_LIVE_RENAME_OK
+ #define IFF_TX_SKB_NO_LINEAR		IFF_TX_SKB_NO_LINEAR
+ 
+ /* Specifies the type of the struct net_device::ml_priv pointer */
+--- a/net/core/dev.c
++++ b/net/core/dev.c
+@@ -1222,22 +1222,6 @@ int dev_change_name(struct net_device *d
+ 
+ 	net = dev_net(dev);
+ 
+-	/* Some auto-enslaved devices e.g. failover slaves are
+-	 * special, as userspace might rename the device after
+-	 * the interface had been brought up and running since
+-	 * the point kernel initiated auto-enslavement. Allow
+-	 * live name change even when these slave devices are
+-	 * up and running.
+-	 *
+-	 * Typically, users of these auto-enslaving devices
+-	 * don't actually care about slave name change, as
+-	 * they are supposed to operate on master interface
+-	 * directly.
+-	 */
+-	if (dev->flags & IFF_UP &&
+-	    likely(!(dev->priv_flags & IFF_LIVE_RENAME_OK)))
+-		return -EBUSY;
+-
+ 	down_write(&devnet_rename_sem);
+ 
+ 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
+@@ -1254,7 +1238,8 @@ int dev_change_name(struct net_device *d
+ 	}
+ 
+ 	if (oldname[0] && !strchr(oldname, '%'))
+-		netdev_info(dev, "renamed from %s\n", oldname);
++		netdev_info(dev, "renamed from %s%s\n", oldname,
++			    dev->flags & IFF_UP ? " (while UP)" : "");
+ 
+ 	old_assign_type = dev->name_assign_type;
+ 	dev->name_assign_type = NET_NAME_RENAMED;
+--- a/net/core/failover.c
++++ b/net/core/failover.c
+@@ -80,14 +80,14 @@ static int failover_slave_register(struc
+ 		goto err_upper_link;
+ 	}
+ 
+-	slave_dev->priv_flags |= (IFF_FAILOVER_SLAVE | IFF_LIVE_RENAME_OK);
++	slave_dev->priv_flags |= IFF_FAILOVER_SLAVE;
+ 
+ 	if (fops && fops->slave_register &&
+ 	    !fops->slave_register(slave_dev, failover_dev))
+ 		return NOTIFY_OK;
+ 
+ 	netdev_upper_dev_unlink(slave_dev, failover_dev);
+-	slave_dev->priv_flags &= ~(IFF_FAILOVER_SLAVE | IFF_LIVE_RENAME_OK);
++	slave_dev->priv_flags &= ~IFF_FAILOVER_SLAVE;
+ err_upper_link:
+ 	netdev_rx_handler_unregister(slave_dev);
+ done:
+@@ -121,7 +121,7 @@ int failover_slave_unregister(struct net
+ 
+ 	netdev_rx_handler_unregister(slave_dev);
+ 	netdev_upper_dev_unlink(slave_dev, failover_dev);
+-	slave_dev->priv_flags &= ~(IFF_FAILOVER_SLAVE | IFF_LIVE_RENAME_OK);
++	slave_dev->priv_flags &= ~IFF_FAILOVER_SLAVE;
+ 
+ 	if (fops && fops->slave_unregister &&
+ 	    !fops->slave_unregister(slave_dev, failover_dev))
diff --git a/target/linux/generic/hack-5.15/721-net-add-packet-mangeling.patch b/target/linux/generic/hack-5.15/721-net-add-packet-mangeling.patch
index 69771cef39..fcaed01cad 100644
--- a/target/linux/generic/hack-5.15/721-net-add-packet-mangeling.patch
+++ b/target/linux/generic/hack-5.15/721-net-add-packet-mangeling.patch
@@ -19,7 +19,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 
 --- a/include/linux/netdevice.h
 +++ b/include/linux/netdevice.h
-@@ -1682,6 +1682,10 @@ enum netdev_priv_flags {
+@@ -1681,6 +1681,10 @@ enum netdev_priv_flags {
  	IFF_TX_SKB_NO_LINEAR		= BIT_ULL(31),
  };
  
@@ -30,15 +30,15 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  #define IFF_802_1Q_VLAN			IFF_802_1Q_VLAN
  #define IFF_EBRIDGE			IFF_EBRIDGE
  #define IFF_BONDING			IFF_BONDING
-@@ -1714,6 +1718,7 @@ enum netdev_priv_flags {
+@@ -1712,6 +1716,7 @@ enum netdev_priv_flags {
+ #define IFF_FAILOVER_SLAVE		IFF_FAILOVER_SLAVE
  #define IFF_L3MDEV_RX_HANDLER		IFF_L3MDEV_RX_HANDLER
- #define IFF_LIVE_RENAME_OK		IFF_LIVE_RENAME_OK
  #define IFF_TX_SKB_NO_LINEAR		IFF_TX_SKB_NO_LINEAR
 +#define IFF_NO_IP_ALIGN			IFF_NO_IP_ALIGN
  
  /* Specifies the type of the struct net_device::ml_priv pointer */
  enum netdev_ml_priv_type {
-@@ -2014,6 +2019,7 @@ struct net_device {
+@@ -2012,6 +2017,7 @@ struct net_device {
  	/* Read-mostly cache-line for fast-path access */
  	unsigned int		flags;
  	unsigned int		priv_flags;
@@ -46,7 +46,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	const struct net_device_ops *netdev_ops;
  	int			ifindex;
  	unsigned short		gflags;
-@@ -2074,6 +2080,11 @@ struct net_device {
+@@ -2072,6 +2078,11 @@ struct net_device {
  	const struct tlsdev_ops *tlsdev_ops;
  #endif
  
@@ -58,7 +58,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	const struct header_ops *header_ops;
  
  	unsigned char		operstate;
-@@ -2145,6 +2156,10 @@ struct net_device {
+@@ -2143,6 +2154,10 @@ struct net_device {
  	struct mctp_dev __rcu	*mctp_ptr;
  #endif
  
@@ -116,7 +116,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	help
 --- a/net/core/dev.c
 +++ b/net/core/dev.c
-@@ -3592,6 +3592,11 @@ static int xmit_one(struct sk_buff *skb,
+@@ -3577,6 +3577,11 @@ static int xmit_one(struct sk_buff *skb,
  	if (dev_nit_active(dev))
  		dev_queue_xmit_nit(skb, dev);
  
diff --git a/target/linux/generic/pending-5.15/680-NET-skip-GRO-for-foreign-MAC-addresses.patch b/target/linux/generic/pending-5.15/680-NET-skip-GRO-for-foreign-MAC-addresses.patch
index f01348d349..71b3aac846 100644
--- a/target/linux/generic/pending-5.15/680-NET-skip-GRO-for-foreign-MAC-addresses.patch
+++ b/target/linux/generic/pending-5.15/680-NET-skip-GRO-for-foreign-MAC-addresses.patch
@@ -11,7 +11,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 
 --- a/include/linux/netdevice.h
 +++ b/include/linux/netdevice.h
-@@ -2100,6 +2100,8 @@ struct net_device {
+@@ -2098,6 +2098,8 @@ struct net_device {
  	struct netdev_hw_addr_list	mc;
  	struct netdev_hw_addr_list	dev_addrs;
  
@@ -32,7 +32,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	__u8			inner_protocol_type:1;
 --- a/net/core/dev.c
 +++ b/net/core/dev.c
-@@ -6069,6 +6069,9 @@ static enum gro_result dev_gro_receive(s
+@@ -6054,6 +6054,9 @@ static enum gro_result dev_gro_receive(s
  	int same_flow;
  	int grow;
  
@@ -42,7 +42,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	if (netif_elide_gro(skb->dev))
  		goto normal;
  
-@@ -8083,6 +8086,48 @@ static void __netdev_adjacent_dev_unlink
+@@ -8068,6 +8071,48 @@ static void __netdev_adjacent_dev_unlink
  					   &upper_dev->adj_list.lower);
  }
  
@@ -91,7 +91,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  static int __netdev_upper_dev_link(struct net_device *dev,
  				   struct net_device *upper_dev, bool master,
  				   void *upper_priv, void *upper_info,
-@@ -8134,6 +8179,7 @@ static int __netdev_upper_dev_link(struc
+@@ -8119,6 +8164,7 @@ static int __netdev_upper_dev_link(struc
  	if (ret)
  		return ret;
  
@@ -99,7 +99,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
  					    &changeupper_info.info);
  	ret = notifier_to_errno(ret);
-@@ -8230,6 +8276,7 @@ static void __netdev_upper_dev_unlink(st
+@@ -8215,6 +8261,7 @@ static void __netdev_upper_dev_unlink(st
  
  	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
  
@@ -107,7 +107,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
  				      &changeupper_info.info);
  
-@@ -9049,6 +9096,7 @@ int dev_set_mac_address(struct net_devic
+@@ -9034,6 +9081,7 @@ int dev_set_mac_address(struct net_devic
  	if (err)
  		return err;
  	dev->addr_assign_type = NET_ADDR_SET;
diff --git a/target/linux/generic/pending-5.15/760-net-core-add-optional-threading-for-backlog-processi.patch b/target/linux/generic/pending-5.15/760-net-core-add-optional-threading-for-backlog-processi.patch
index 1ccdea6d99..8a65cbe021 100644
--- a/target/linux/generic/pending-5.15/760-net-core-add-optional-threading-for-backlog-processi.patch
+++ b/target/linux/generic/pending-5.15/760-net-core-add-optional-threading-for-backlog-processi.patch
@@ -20,7 +20,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  
  /**
   *	napi_disable - prevent NAPI from scheduling
-@@ -3364,6 +3365,7 @@ struct softnet_data {
+@@ -3362,6 +3363,7 @@ struct softnet_data {
  	unsigned int		processed;
  	unsigned int		time_squeeze;
  	unsigned int		received_rps;
@@ -30,7 +30,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  #endif
 --- a/net/core/dev.c
 +++ b/net/core/dev.c
-@@ -4578,7 +4578,7 @@ static int rps_ipi_queued(struct softnet
+@@ -4563,7 +4563,7 @@ static int rps_ipi_queued(struct softnet
  #ifdef CONFIG_RPS
  	struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
  
@@ -39,7 +39,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  		sd->rps_ipi_next = mysd->rps_ipi_list;
  		mysd->rps_ipi_list = sd;
  
-@@ -5759,6 +5759,8 @@ static DEFINE_PER_CPU(struct work_struct
+@@ -5744,6 +5744,8 @@ static DEFINE_PER_CPU(struct work_struct
  /* Network device is going away, flush any packets still pending */
  static void flush_backlog(struct work_struct *work)
  {
@@ -48,7 +48,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	struct sk_buff *skb, *tmp;
  	struct softnet_data *sd;
  
-@@ -5774,9 +5776,18 @@ static void flush_backlog(struct work_st
+@@ -5759,9 +5761,18 @@ static void flush_backlog(struct work_st
  			input_queue_head_incr(sd);
  		}
  	}
@@ -67,7 +67,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
  		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
  			__skb_unlink(skb, &sd->process_queue);
-@@ -5784,7 +5795,18 @@ static void flush_backlog(struct work_st
+@@ -5769,7 +5780,18 @@ static void flush_backlog(struct work_st
  			input_queue_head_incr(sd);
  		}
  	}
@@ -86,7 +86,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  }
  
  static bool flush_required(int cpu)
-@@ -6467,6 +6489,7 @@ static int process_backlog(struct napi_s
+@@ -6452,6 +6474,7 @@ static int process_backlog(struct napi_s
  
  		local_irq_disable();
  		rps_lock(sd);
@@ -94,7 +94,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  		if (skb_queue_empty(&sd->input_pkt_queue)) {
  			/*
  			 * Inline a custom version of __napi_complete().
-@@ -6476,7 +6499,8 @@ static int process_backlog(struct napi_s
+@@ -6461,7 +6484,8 @@ static int process_backlog(struct napi_s
  			 * We can use a plain write instead of clear_bit(),
  			 * and we dont need an smp_mb() memory barrier.
  			 */
@@ -104,7 +104,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  			again = false;
  		} else {
  			skb_queue_splice_tail_init(&sd->input_pkt_queue,
-@@ -6893,6 +6917,57 @@ int dev_set_threaded(struct net_device *
+@@ -6878,6 +6902,57 @@ int dev_set_threaded(struct net_device *
  }
  EXPORT_SYMBOL(dev_set_threaded);
  
@@ -162,7 +162,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
  		    int (*poll)(struct napi_struct *, int), int weight)
  {
-@@ -11369,6 +11444,9 @@ static int dev_cpu_dead(unsigned int old
+@@ -11354,6 +11429,9 @@ static int dev_cpu_dead(unsigned int old
  	raise_softirq_irqoff(NET_TX_SOFTIRQ);
  	local_irq_enable();
  
@@ -172,7 +172,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  #ifdef CONFIG_RPS
  	remsd = oldsd->rps_ipi_list;
  	oldsd->rps_ipi_list = NULL;
-@@ -11708,6 +11786,7 @@ static int __init net_dev_init(void)
+@@ -11693,6 +11771,7 @@ static int __init net_dev_init(void)
  		sd->cpu = i;
  #endif