From b9067f5dc4a07c8e24e01a1b277c6722d91be39e Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 27 Jul 2021 15:44:47 +0200 Subject: net: split out SIOCDEVPRIVATE handling from dev_ioctl SIOCDEVPRIVATE ioctl commands are mainly used in really old drivers, and they have a number of problems: - They hide behind the normal .ndo_do_ioctl function that is also used for other things in modern drivers, so it's hard to spot a driver that actually uses one of these - Since drivers use a number different calling conventions, it is impossible to support compat mode for them in a generic way. - With all drivers using the same 16 commands codes, there is no way to introspect the data being passed through things like strace. Add a new net_device_ops callback pointer, to address the first two of these. Separating them from .ndo_do_ioctl makes it easy to grep for drivers with a .ndo_siocdevprivate callback, and the unwieldy name hopefully makes it easier to spot in code review. By passing the ifreq structure and the ifr_data pointer separately, it is no longer necessary to overload these, and the driver can use either one for a given command. Cc: Cong Wang Signed-off-by: Arnd Bergmann Signed-off-by: David S. Miller --- Documentation/networking/netdevices.rst | 7 +++++++ include/linux/netdevice.h | 3 +++ net/core/dev_ioctl.c | 25 ++++++++++++++++++++++--- 3 files changed, 32 insertions(+), 3 deletions(-) diff --git a/Documentation/networking/netdevices.rst b/Documentation/networking/netdevices.rst index 17bdcb746dcf..02f1faac839a 100644 --- a/Documentation/networking/netdevices.rst +++ b/Documentation/networking/netdevices.rst @@ -222,6 +222,13 @@ ndo_do_ioctl: Synchronization: rtnl_lock() semaphore. Context: process +ndo_siocdevprivate: + Synchronization: rtnl_lock() semaphore. + Context: process + + This is used to implement SIOCDEVPRIVATE ioctl helpers. + These should not be added to new drivers, so don't use. + ndo_get_stats: Synchronization: rtnl_lock() semaphore, dev_base_lock rwlock, or RCU. Context: atomic (can't sleep under rwlock or RCU) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index c871dc223dfa..670e1a8e5928 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1361,6 +1361,9 @@ struct net_device_ops { int (*ndo_validate_addr)(struct net_device *dev); int (*ndo_do_ioctl)(struct net_device *dev, struct ifreq *ifr, int cmd); + int (*ndo_siocdevprivate)(struct net_device *dev, + struct ifreq *ifr, + void __user *data, int cmd); int (*ndo_set_config)(struct net_device *dev, struct ifmap *map); int (*ndo_change_mtu)(struct net_device *dev, diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c index 950e2fe5d56a..75e3e340d884 100644 --- a/net/core/dev_ioctl.c +++ b/net/core/dev_ioctl.c @@ -259,6 +259,23 @@ static int dev_do_ioctl(struct net_device *dev, return err; } +static int dev_siocdevprivate(struct net_device *dev, + struct ifreq *ifr, unsigned int cmd) +{ + const struct net_device_ops *ops = dev->netdev_ops; + void __user *data = ifr->ifr_data; + + if (ops->ndo_siocdevprivate) { + if (netif_device_present(dev)) + return ops->ndo_siocdevprivate(dev, ifr, data, cmd); + else + return -ENODEV; + } + + /* fall back to do_ioctl for drivers not yet converted */ + return dev_do_ioctl(dev, ifr, cmd); +} + /* * Perform the SIOCxIFxxx calls, inside rtnl_lock() */ @@ -336,9 +353,11 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd) * Unknown or private ioctl */ default: - if ((cmd >= SIOCDEVPRIVATE && - cmd <= SIOCDEVPRIVATE + 15) || - cmd == SIOCBONDENSLAVE || + if (cmd >= SIOCDEVPRIVATE && + cmd <= SIOCDEVPRIVATE + 15) + return dev_siocdevprivate(dev, ifr, cmd); + + if (cmd == SIOCBONDENSLAVE || cmd == SIOCBONDRELEASE || cmd == SIOCBONDSETHWADDR || cmd == SIOCBONDSLAVEINFOQUERY || -- cgit v1.2.3-58-ga151