From 6eda357564b21f9142c8f0fe0b6fcc6fceb42bfe Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Thu, 3 Dec 2015 21:12:31 +0100 Subject: [PATCH] WAN: HDLC: Call notifiers before and after changing device type An HDLC device can change type when the protocol driver is changed. Calling the notifier change allows potential users of the interface know about this planned change, and even block it. After the change has occurred, send a second notification to users can evaluate the new device type etc. Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/wan/hdlc.c | 19 +++++++++++++++++-- drivers/net/wan/hdlc_cisco.c | 1 + drivers/net/wan/hdlc_fr.c | 1 + drivers/net/wan/hdlc_ppp.c | 1 + drivers/net/wan/hdlc_raw.c | 1 + drivers/net/wan/hdlc_raw_eth.c | 1 + drivers/net/wan/hdlc_x25.c | 1 + include/linux/hdlc.h | 2 +- 8 files changed, 24 insertions(+), 3 deletions(-) diff --git a/drivers/net/wan/hdlc.c b/drivers/net/wan/hdlc.c index 2a6595b4ae158..9bd4aa8083ce7 100644 --- a/drivers/net/wan/hdlc.c +++ b/drivers/net/wan/hdlc.c @@ -276,7 +276,11 @@ void unregister_hdlc_device(struct net_device *dev) int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto, size_t size) { - detach_hdlc_protocol(dev); + int err; + + err = detach_hdlc_protocol(dev); + if (err) + return err; if (!try_module_get(proto->module)) return -ENOSYS; @@ -289,15 +293,24 @@ int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto, } } dev_to_hdlc(dev)->proto = proto; + return 0; } -void detach_hdlc_protocol(struct net_device *dev) +int detach_hdlc_protocol(struct net_device *dev) { hdlc_device *hdlc = dev_to_hdlc(dev); + int err; if (hdlc->proto) { + err = call_netdevice_notifiers(NETDEV_PRE_TYPE_CHANGE, dev); + err = notifier_to_errno(err); + if (err) { + netdev_err(dev, "Refused to change device type\n"); + return err; + } + if (hdlc->proto->detach) hdlc->proto->detach(dev); module_put(hdlc->proto->module); @@ -306,6 +319,8 @@ void detach_hdlc_protocol(struct net_device *dev) kfree(hdlc->state); hdlc->state = NULL; hdlc_setup_dev(dev); + + return 0; } diff --git a/drivers/net/wan/hdlc_cisco.c b/drivers/net/wan/hdlc_cisco.c index 3f20808b5ff82..a408abc25512a 100644 --- a/drivers/net/wan/hdlc_cisco.c +++ b/drivers/net/wan/hdlc_cisco.c @@ -378,6 +378,7 @@ static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr) spin_lock_init(&state(hdlc)->lock); dev->header_ops = &cisco_header_ops; dev->type = ARPHRD_CISCO; + call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev); netif_dormant_on(dev); return 0; } diff --git a/drivers/net/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c index 89541cc90e877..b6e0cfb095d35 100644 --- a/drivers/net/wan/hdlc_fr.c +++ b/drivers/net/wan/hdlc_fr.c @@ -1240,6 +1240,7 @@ static int fr_ioctl(struct net_device *dev, struct ifreq *ifr) } memcpy(&state(hdlc)->settings, &new_settings, size); dev->type = ARPHRD_FRAD; + call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev); return 0; case IF_PROTO_FR_ADD_PVC: diff --git a/drivers/net/wan/hdlc_ppp.c b/drivers/net/wan/hdlc_ppp.c index 0d7645581f912..47fdb87d3567c 100644 --- a/drivers/net/wan/hdlc_ppp.c +++ b/drivers/net/wan/hdlc_ppp.c @@ -687,6 +687,7 @@ static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr) dev->hard_header_len = sizeof(struct hdlc_header); dev->header_ops = &ppp_header_ops; dev->type = ARPHRD_PPP; + call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev); netif_dormant_on(dev); return 0; } diff --git a/drivers/net/wan/hdlc_raw.c b/drivers/net/wan/hdlc_raw.c index 5dc153e8a29d1..4feb45001aacf 100644 --- a/drivers/net/wan/hdlc_raw.c +++ b/drivers/net/wan/hdlc_raw.c @@ -84,6 +84,7 @@ static int raw_ioctl(struct net_device *dev, struct ifreq *ifr) return result; memcpy(hdlc->state, &new_settings, size); dev->type = ARPHRD_RAWHDLC; + call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev); netif_dormant_off(dev); return 0; } diff --git a/drivers/net/wan/hdlc_raw_eth.c b/drivers/net/wan/hdlc_raw_eth.c index 3ab72b3082dee..2f11836078ab5 100644 --- a/drivers/net/wan/hdlc_raw_eth.c +++ b/drivers/net/wan/hdlc_raw_eth.c @@ -102,6 +102,7 @@ static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr) ether_setup(dev); dev->tx_queue_len = old_qlen; eth_hw_addr_random(dev); + call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev); netif_dormant_off(dev); return 0; } diff --git a/drivers/net/wan/hdlc_x25.c b/drivers/net/wan/hdlc_x25.c index a49aec5efd207..e867638067a65 100644 --- a/drivers/net/wan/hdlc_x25.c +++ b/drivers/net/wan/hdlc_x25.c @@ -213,6 +213,7 @@ static int x25_ioctl(struct net_device *dev, struct ifreq *ifr) if ((result = attach_hdlc_protocol(dev, &proto, 0))) return result; dev->type = ARPHRD_X25; + call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev); netif_dormant_off(dev); return 0; } diff --git a/include/linux/hdlc.h b/include/linux/hdlc.h index 1acb1445e05fe..e31bcd4c7859e 100644 --- a/include/linux/hdlc.h +++ b/include/linux/hdlc.h @@ -101,7 +101,7 @@ netdev_tx_t hdlc_start_xmit(struct sk_buff *skb, struct net_device *dev); int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto, size_t size); /* May be used by hardware driver to gain control over HDLC device */ -void detach_hdlc_protocol(struct net_device *dev); +int detach_hdlc_protocol(struct net_device *dev); static __inline__ __be16 hdlc_type_trans(struct sk_buff *skb, struct net_device *dev) -- 2.39.5