Merge branch 'dsa_master_ioctl-notifier'

Vladimir Oltean says:

====================
net: Convert dsa_master_ioctl() to netdev notifier

This is preparatory work in order for Maxim Georgiev to be able to start
the API conversion process of hardware timestamping from ndo_eth_ioctl()
to ndo_hwtstamp_set():
https://lore.kernel.org/netdev/20230331045619.40256-1-glipus@gmail.com/

In turn, Maxim Georgiev's work is a preparation so that Köry Maincent is
able to make the active hardware timestamping layer selectable by user
space.
https://lore.kernel.org/netdev/20230308135936.761794-1-kory.maincent@bootlin.com/

So, quite some dependency chain.

Before this patch set, DSA prevented the conversion of any networking
driver from the ndo_eth_ioctl() API to the ndo_hwtstamp_set() API,
because it wanted to validate the hwtstamping settings on the DSA
master, and it was only coded up to do this using the old API.

After this patch set, a new netdev notifier exists, which does not
depend on anything that would constitute the "soon-to-be-legacy" API,
but rather, it uses a newly introduced struct kernel_hwtstamp_config,
and it doesn't issue any ioctl at all, being thus compatible both with
ndo_eth_ioctl(), and with the not-yet-introduced, but now possible,
ndo_hwtstamp_set().
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 70 insertions, 48 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 0c4b21291348..7ce5985be84b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -160,8 +160,6 @@ struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
 struct list_head ptype_all __read_mostly;	/* Taps */
 
 static int netif_rx_internal(struct sk_buff *skb);
-static int call_netdevice_notifiers_info(unsigned long val,
-					 struct netdev_notifier_info *info);
 static int call_netdevice_notifiers_extack(unsigned long val,
 					   struct net_device *dev,
 					   struct netlink_ext_ack *extack);
@@ -1614,7 +1612,7 @@ const char *netdev_cmd_to_name(enum netdev_cmd cmd)
 	N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
 	N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
 	N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
-	N(XDP_FEAT_CHANGE)
+	N(XDP_FEAT_CHANGE) N(PRE_CHANGE_HWTSTAMP)
 	}
 #undef N
 	return "UNKNOWN_NETDEV_EVENT";
@@ -1919,8 +1917,8 @@ static void move_netdevice_notifiers_dev_net(struct net_device *dev,
  *	are as for raw_notifier_call_chain().
  */
 
-static int call_netdevice_notifiers_info(unsigned long val,
-					 struct netdev_notifier_info *info)
+int call_netdevice_notifiers_info(unsigned long val,
+				  struct netdev_notifier_info *info)
 {
 	struct net *net = dev_net(info->dev);
 	int ret;
diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c
index 846669426236..6d772837eb3f 100644
--- a/net/core/dev_ioctl.c
+++ b/net/core/dev_ioctl.c
@@ -183,22 +183,18 @@ static int dev_ifsioc_locked(struct net *net, struct ifreq *ifr, unsigned int cm
 	return err;
 }
 
-static int net_hwtstamp_validate(struct ifreq *ifr)
+static int net_hwtstamp_validate(const struct kernel_hwtstamp_config *cfg)
 {
-	struct hwtstamp_config cfg;
 	enum hwtstamp_tx_types tx_type;
 	enum hwtstamp_rx_filters rx_filter;
 	int tx_type_valid = 0;
 	int rx_filter_valid = 0;
 
-	if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
-		return -EFAULT;
-
-	if (cfg.flags & ~HWTSTAMP_FLAG_MASK)
+	if (cfg->flags & ~HWTSTAMP_FLAG_MASK)
 		return -EINVAL;
 
-	tx_type = cfg.tx_type;
-	rx_filter = cfg.rx_filter;
+	tx_type = cfg->tx_type;
+	rx_filter = cfg->rx_filter;
 
 	switch (tx_type) {
 	case HWTSTAMP_TX_OFF:
@@ -246,20 +242,53 @@ static int dev_eth_ioctl(struct net_device *dev,
 			 struct ifreq *ifr, unsigned int cmd)
 {
 	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (!ops->ndo_eth_ioctl)
+		return -EOPNOTSUPP;
+
+	if (!netif_device_present(dev))
+		return -ENODEV;
+
+	return ops->ndo_eth_ioctl(dev, ifr, cmd);
+}
+
+static int dev_get_hwtstamp(struct net_device *dev, struct ifreq *ifr)
+{
+	return dev_eth_ioctl(dev, ifr, SIOCGHWTSTAMP);
+}
+
+static int dev_set_hwtstamp(struct net_device *dev, struct ifreq *ifr)
+{
+	struct netdev_notifier_hwtstamp_info info = {
+		.info.dev = dev,
+	};
+	struct kernel_hwtstamp_config kernel_cfg;
+	struct netlink_ext_ack extack = {};
+	struct hwtstamp_config cfg;
 	int err;
 
-	err = dsa_ndo_eth_ioctl(dev, ifr, cmd);
-	if (err == 0 || err != -EOPNOTSUPP)
+	if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
+		return -EFAULT;
+
+	hwtstamp_config_to_kernel(&kernel_cfg, &cfg);
+
+	err = net_hwtstamp_validate(&kernel_cfg);
+	if (err)
 		return err;
 
-	if (ops->ndo_eth_ioctl) {
-		if (netif_device_present(dev))
-			err = ops->ndo_eth_ioctl(dev, ifr, cmd);
-		else
-			err = -ENODEV;
+	info.info.extack = &extack;
+	info.config = &kernel_cfg;
+
+	err = call_netdevice_notifiers_info(NETDEV_PRE_CHANGE_HWTSTAMP,
+					    &info.info);
+	err = notifier_to_errno(err);
+	if (err) {
+		if (extack._msg)
+			netdev_err(dev, "%s\n", extack._msg);
+		return err;
 	}
 
-	return err;
+	return dev_eth_ioctl(dev, ifr, SIOCSHWTSTAMP);
 }
 
 static int dev_siocbond(struct net_device *dev,
@@ -391,36 +420,31 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data,
 		rtnl_lock();
 		return err;
 
+	case SIOCDEVPRIVATE ... SIOCDEVPRIVATE + 15:
+		return dev_siocdevprivate(dev, ifr, data, cmd);
+
 	case SIOCSHWTSTAMP:
-		err = net_hwtstamp_validate(ifr);
-		if (err)
-			return err;
-		fallthrough;
+		return dev_set_hwtstamp(dev, ifr);
 
-	/*
-	 *	Unknown or private ioctl
-	 */
-	default:
-		if (cmd >= SIOCDEVPRIVATE &&
-		    cmd <= SIOCDEVPRIVATE + 15)
-			return dev_siocdevprivate(dev, ifr, data, cmd);
-
-		if (cmd == SIOCGMIIPHY ||
-		    cmd == SIOCGMIIREG ||
-		    cmd == SIOCSMIIREG ||
-		    cmd == SIOCSHWTSTAMP ||
-		    cmd == SIOCGHWTSTAMP) {
-			err = dev_eth_ioctl(dev, ifr, cmd);
-		} else if (cmd == SIOCBONDENSLAVE ||
-		    cmd == SIOCBONDRELEASE ||
-		    cmd == SIOCBONDSETHWADDR ||
-		    cmd == SIOCBONDSLAVEINFOQUERY ||
-		    cmd == SIOCBONDINFOQUERY ||
-		    cmd == SIOCBONDCHANGEACTIVE) {
-			err = dev_siocbond(dev, ifr, cmd);
-		} else
-			err = -EINVAL;
+	case SIOCGHWTSTAMP:
+		return dev_get_hwtstamp(dev, ifr);
 
+	case SIOCGMIIPHY:
+	case SIOCGMIIREG:
+	case SIOCSMIIREG:
+		return dev_eth_ioctl(dev, ifr, cmd);
+
+	case SIOCBONDENSLAVE:
+	case SIOCBONDRELEASE:
+	case SIOCBONDSETHWADDR:
+	case SIOCBONDSLAVEINFOQUERY:
+	case SIOCBONDINFOQUERY:
+	case SIOCBONDCHANGEACTIVE:
+		return dev_siocbond(dev, ifr, cmd);
+
+	/* Unknown ioctl */
+	default:
+		err = -EINVAL;
 	}
 	return err;
 }