From ff3516442768f0babe7ea2db62e34aee1d76e969 Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Thu, 3 Dec 2015 21:12:30 +0100 Subject: [PATCH 1/4] WAN: HDLC: Detach protocol before unregistering device The current code first unregisters the device, and then detaches the protocol from it. This should be performed the other way around, since the detach may try to use state which has been freed by the unregister. Swap the order, so that we first detach and then remove the netdev. Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/wan/hdlc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wan/hdlc.c b/drivers/net/wan/hdlc.c index 51f6cee8aab2..2a6595b4ae15 100644 --- a/drivers/net/wan/hdlc.c +++ b/drivers/net/wan/hdlc.c @@ -266,8 +266,8 @@ struct net_device *alloc_hdlcdev(void *priv) void unregister_hdlc_device(struct net_device *dev) { rtnl_lock(); - unregister_netdevice(dev); detach_hdlc_protocol(dev); + unregister_netdevice(dev); rtnl_unlock(); } From 2f8364a291e8adde25c93f97a76abbcaf4b1ed3f Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Thu, 3 Dec 2015 21:12:31 +0100 Subject: [PATCH 2/4] 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 2a6595b4ae15..9bd4aa8083ce 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 3f20808b5ff8..a408abc25512 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 89541cc90e87..b6e0cfb095d3 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 0d7645581f91..47fdb87d3567 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 5dc153e8a29d..4feb45001aac 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 3ab72b3082de..2f11836078ab 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 a49aec5efd20..e867638067a6 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 1acb1445e05f..e31bcd4c7859 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) From 3ef0952ca85e28226b09a6d833c30e3e604a63c8 Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Thu, 3 Dec 2015 21:12:32 +0100 Subject: [PATCH 3/4] ipv6: Only act upon NETDEV_*_TYPE_CHANGE if we have ipv6 addresses An interface changing type may not have IPv6 addresses. Don't call the address configuration type change in this case. Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 6936d0d8c6b1..5e9111da449d 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3287,7 +3287,8 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, case NETDEV_PRE_TYPE_CHANGE: case NETDEV_POST_TYPE_CHANGE: - addrconf_type_change(dev, event); + if (idev) + addrconf_type_change(dev, event); break; } From a1a66b1100373ead1fa2383bc3dee42c508bb504 Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Thu, 3 Dec 2015 21:12:33 +0100 Subject: [PATCH 4/4] batman-adv: Act on NETDEV_*_TYPE_CHANGE events A network interface can change type. It may change from a type which batman does not support, e.g. hdlc, to one it does, e.g. hdlc-eth. When an interface changes type, it sends two notifications. Handle these notifications. Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller --- net/batman-adv/hard-interface.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index aa8867e1d983..a58184fdf5fd 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -709,7 +709,8 @@ static int batadv_hard_if_event(struct notifier_block *this, } hard_iface = batadv_hardif_get_by_netdev(net_dev); - if (!hard_iface && event == NETDEV_REGISTER) + if (!hard_iface && (event == NETDEV_REGISTER || + event == NETDEV_POST_TYPE_CHANGE)) hard_iface = batadv_hardif_add_interface(net_dev); if (!hard_iface) @@ -724,6 +725,7 @@ static int batadv_hard_if_event(struct notifier_block *this, batadv_hardif_deactivate_interface(hard_iface); break; case NETDEV_UNREGISTER: + case NETDEV_PRE_TYPE_CHANGE: list_del_rcu(&hard_iface->list); batadv_hardif_remove_interface(hard_iface);