From b325fddb7f869e6c95a88dc6573220f162e5b89f Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Thu, 26 Feb 2009 06:55:31 +0000 Subject: ipv6: Fix sysctl unregistration deadlock Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index f9afb452249c..40fabdee42ae 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -493,15 +493,17 @@ static void addrconf_forward_change(struct net *net, __s32 newf) read_unlock(&dev_base_lock); } -static void addrconf_fixup_forwarding(struct ctl_table *table, int *p, int old) +static int addrconf_fixup_forwarding(struct ctl_table *table, int *p, int old) { struct net *net; net = (struct net *)table->extra2; if (p == &net->ipv6.devconf_dflt->forwarding) - return; + return 0; + + if (!rtnl_trylock()) + return -ERESTARTSYS; - rtnl_lock(); if (p == &net->ipv6.devconf_all->forwarding) { __s32 newf = net->ipv6.devconf_all->forwarding; net->ipv6.devconf_dflt->forwarding = newf; @@ -512,6 +514,7 @@ static void addrconf_fixup_forwarding(struct ctl_table *table, int *p, int old) if (*p) rt6_purge_dflt_routers(net); + return 1; } #endif @@ -3983,7 +3986,7 @@ int addrconf_sysctl_forward(ctl_table *ctl, int write, struct file * filp, ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos); if (write) - addrconf_fixup_forwarding(ctl, valp, val); + ret = addrconf_fixup_forwarding(ctl, valp, val); return ret; } @@ -4019,8 +4022,7 @@ static int addrconf_sysctl_forward_strategy(ctl_table *table, } *valp = new; - addrconf_fixup_forwarding(table, valp, val); - return 1; + return addrconf_fixup_forwarding(table, valp, val); } static struct addrconf_sysctl_table -- cgit v1.2.3 From 176c39af29bc4edaf37f663553eeaacd47b5bc9c Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Tue, 3 Mar 2009 01:06:45 -0800 Subject: netns: fix addrconf_ifdown kernel panic When a network namespace is destroyed the network interfaces are all unregistered, making addrconf_ifdown called by the netdevice notifier. In the other hand, the addrconf exit method does a loop on the network devices and does addrconf_ifdown on each of them. But the ordering of the netns subsystem is not right because it uses the register_pernet_device instead of register_pernet_subsys. If we handle the loopback as any network device, we can safely use register_pernet_subsys. But if we use register_pernet_subsys, the addrconf exit method will do exactly what was already done with the unregistering of the network devices. So in definitive, this code is pointless. I removed the netns addrconf exit method and moved the code to the addrconf cleanup function. Signed-off-by: Daniel Lezcano Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 39 +++++++++------------------------------ 1 file changed, 9 insertions(+), 30 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 40fabdee42ae..1220e2c7831e 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2611,9 +2611,6 @@ static int addrconf_ifdown(struct net_device *dev, int how) ASSERT_RTNL(); - if ((dev->flags & IFF_LOOPBACK) && how == 1) - how = 0; - rt6_ifdown(net, dev); neigh_ifdown(&nd_tbl, dev); @@ -4448,25 +4445,6 @@ int unregister_inet6addr_notifier(struct notifier_block *nb) EXPORT_SYMBOL(unregister_inet6addr_notifier); -static void addrconf_net_exit(struct net *net) -{ - struct net_device *dev; - - rtnl_lock(); - /* clean dev list */ - for_each_netdev(net, dev) { - if (__in6_dev_get(dev) == NULL) - continue; - addrconf_ifdown(dev, 1); - } - addrconf_ifdown(net->loopback_dev, 2); - rtnl_unlock(); -} - -static struct pernet_operations addrconf_net_ops = { - .exit = addrconf_net_exit, -}; - /* * Init / cleanup code */ @@ -4508,10 +4486,6 @@ int __init addrconf_init(void) if (err) goto errlo; - err = register_pernet_device(&addrconf_net_ops); - if (err) - return err; - register_netdevice_notifier(&ipv6_dev_notf); addrconf_verify(0); @@ -4541,15 +4515,22 @@ errlo: void addrconf_cleanup(void) { struct inet6_ifaddr *ifa; + struct net_device *dev; int i; unregister_netdevice_notifier(&ipv6_dev_notf); - unregister_pernet_device(&addrconf_net_ops); - unregister_pernet_subsys(&addrconf_ops); rtnl_lock(); + /* clean dev list */ + for_each_netdev(&init_net, dev) { + if (__in6_dev_get(dev) == NULL) + continue; + addrconf_ifdown(dev, 1); + } + addrconf_ifdown(init_net.loopback_dev, 2); + /* * Check hash table. */ @@ -4570,6 +4551,4 @@ void addrconf_cleanup(void) del_timer(&addr_chk_timer); rtnl_unlock(); - - unregister_pernet_subsys(&addrconf_net_ops); } -- cgit v1.2.3 From fe7ca2e1e847b65c12d245cbf402af89da96888a Mon Sep 17 00:00:00 2001 From: Brian Haley Date: Wed, 4 Mar 2009 03:18:11 -0800 Subject: IPv6: add "disable" module parameter support to ipv6.ko Add "disable" module parameter support to ipv6.ko by specifying "disable=1" on module load. We just do the minimum of initializing inetsw6[] so calls from other modules to inet6_register_protosw() won't OOPs, then bail out. No IPv6 addresses or sockets can be created as a result, and a reboot is required to enable IPv6. Signed-off-by: Brian Haley Signed-off-by: David S. Miller --- Documentation/networking/ipv6.txt | 35 +++++++++++++++++++++++++++++++++++ net/ipv6/af_inet6.c | 21 ++++++++++++++++----- 2 files changed, 51 insertions(+), 5 deletions(-) create mode 100644 Documentation/networking/ipv6.txt (limited to 'net/ipv6') diff --git a/Documentation/networking/ipv6.txt b/Documentation/networking/ipv6.txt new file mode 100644 index 000000000000..268e5c103dd8 --- /dev/null +++ b/Documentation/networking/ipv6.txt @@ -0,0 +1,35 @@ + +Options for the ipv6 module are supplied as parameters at load time. + +Module options may be given as command line arguments to the insmod +or modprobe command, but are usually specified in either the +/etc/modules.conf or /etc/modprobe.conf configuration file, or in a +distro-specific configuration file. + +The available ipv6 module parameters are listed below. If a parameter +is not specified the default value is used. + +The parameters are as follows: + +disable + + Specifies whether to load the IPv6 module, but disable all + its functionality. This might be used when another module + has a dependency on the IPv6 module being loaded, but no + IPv6 addresses or operations are desired. + + The possible values and their effects are: + + 0 + IPv6 is enabled. + + This is the default value. + + 1 + IPv6 is disabled. + + No IPv6 addresses will be added to interfaces, and + it will not be possible to open an IPv6 socket. + + A reboot is required to enable IPv6. + diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index c802bc1658a8..da944eca2ca6 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -72,6 +72,10 @@ MODULE_LICENSE("GPL"); static struct list_head inetsw6[SOCK_MAX]; static DEFINE_SPINLOCK(inetsw6_lock); +static int disable_ipv6 = 0; +module_param_named(disable, disable_ipv6, int, 0); +MODULE_PARM_DESC(disable, "Disable IPv6 such that it is non-functional"); + static __inline__ struct ipv6_pinfo *inet6_sk_generic(struct sock *sk) { const int offset = sk->sk_prot->obj_size - sizeof(struct ipv6_pinfo); @@ -991,10 +995,21 @@ static int __init inet6_init(void) { struct sk_buff *dummy_skb; struct list_head *r; - int err; + int err = 0; BUILD_BUG_ON(sizeof(struct inet6_skb_parm) > sizeof(dummy_skb->cb)); + /* Register the socket-side information for inet6_create. */ + for(r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r) + INIT_LIST_HEAD(r); + + if (disable_ipv6) { + printk(KERN_INFO + "IPv6: Loaded, but administratively disabled, " + "reboot required to enable\n"); + goto out; + } + err = proto_register(&tcpv6_prot, 1); if (err) goto out; @@ -1012,10 +1027,6 @@ static int __init inet6_init(void) goto out_unregister_udplite_proto; - /* Register the socket-side information for inet6_create. */ - for(r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r) - INIT_LIST_HEAD(r); - /* We MUST register RAW sockets before we create the ICMP6, * IGMP6, or NDISC control sockets. */ -- cgit v1.2.3