From 56d417b12e57dfe11c9b7ba4bea3882c62a55815 Mon Sep 17 00:00:00 2001 From: Brian Haley Date: Mon, 1 Jun 2009 03:07:33 -0700 Subject: [PATCH] IPv6: Add 'autoconf' and 'disable_ipv6' module parameters Add 'autoconf' and 'disable_ipv6' parameters to the IPv6 module. The first controls if IPv6 addresses are autoconfigured from prefixes received in Router Advertisements. The IPv6 loopback (::1) and link-local addresses are still configured. The second controls if IPv6 addresses are desired at all. No IPv6 addresses will be added to any interfaces. Signed-off-by: Brian Haley Signed-off-by: David S. Miller --- Documentation/networking/ip-sysctl.txt | 7 +++ Documentation/networking/ipv6.txt | 37 ++++++++++++ include/linux/ipv6.h | 6 ++ net/ipv6/addrconf.c | 83 ++++++++++++++++++++++++-- net/ipv6/af_inet6.c | 22 +++++-- 5 files changed, 145 insertions(+), 10 deletions(-) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 3ffd233c369c..8be76235fe67 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -1057,6 +1057,13 @@ disable_ipv6 - BOOLEAN address. Default: FALSE (enable IPv6 operation) + When this value is changed from 1 to 0 (IPv6 is being enabled), + it will dynamically create a link-local address on the given + interface and start Duplicate Address Detection, if necessary. + + When this value is changed from 0 to 1 (IPv6 is being disabled), + it will dynamically delete all address on the given interface. + accept_dad - INTEGER Whether to accept DAD (Duplicate Address Detection). 0: Disable DAD diff --git a/Documentation/networking/ipv6.txt b/Documentation/networking/ipv6.txt index 268e5c103dd8..9fd7e21296c8 100644 --- a/Documentation/networking/ipv6.txt +++ b/Documentation/networking/ipv6.txt @@ -33,3 +33,40 @@ disable A reboot is required to enable IPv6. +autoconf + + Specifies whether to enable IPv6 address autoconfiguration + on all interfaces. This might be used when one does not wish + for addresses to be automatically generated from prefixes + received in Router Advertisements. + + The possible values and their effects are: + + 0 + IPv6 address autoconfiguration is disabled on all interfaces. + + Only the IPv6 loopback address (::1) and link-local addresses + will be added to interfaces. + + 1 + IPv6 address autoconfiguration is enabled on all interfaces. + + This is the default value. + +disable_ipv6 + + Specifies whether to disable IPv6 on all interfaces. + This might be used when no IPv6 addresses are desired. + + The possible values and their effects are: + + 0 + IPv6 is enabled on all interfaces. + + This is the default value. + + 1 + IPv6 is disabled on all interfaces. + + No IPv6 addresses will be added to interfaces. + diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index 476d9464ac82..c662efa68289 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -169,6 +169,12 @@ struct ipv6_devconf { __s32 accept_dad; void *sysctl; }; + +struct ipv6_params { + __s32 disable_ipv6; + __s32 autoconf; +}; +extern struct ipv6_params ipv6_defaults; #endif /* index values for the variables in ipv6_devconf */ diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 31938e5fb220..c3488372f12d 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -591,7 +591,6 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen, { struct inet6_ifaddr *ifa = NULL; struct rt6_info *rt; - struct net *net = dev_net(idev->dev); int hash; int err = 0; int addr_type = ipv6_addr_type(addr); @@ -608,7 +607,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen, goto out2; } - if (idev->cnf.disable_ipv6 || net->ipv6.devconf_all->disable_ipv6) { + if (idev->cnf.disable_ipv6) { err = -EACCES; goto out2; } @@ -1752,6 +1751,7 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len) __u32 prefered_lft; int addr_type; struct inet6_dev *in6_dev; + struct net *net = dev_net(dev); pinfo = (struct prefix_info *) opt; @@ -1809,7 +1809,7 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len) if (addrconf_finite_timeout(rt_expires)) rt_expires *= HZ; - rt = rt6_lookup(dev_net(dev), &pinfo->prefix, NULL, + rt = rt6_lookup(net, &pinfo->prefix, NULL, dev->ifindex, 1); if (rt && addrconf_is_prefix_route(rt)) { @@ -1846,7 +1846,6 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len) struct inet6_ifaddr * ifp; struct in6_addr addr; int create = 0, update_lft = 0; - struct net *net = dev_net(dev); if (pinfo->prefix_len == 64) { memcpy(&addr, &pinfo->prefix, 8); @@ -3988,6 +3987,75 @@ static int addrconf_sysctl_forward_strategy(ctl_table *table, return addrconf_fixup_forwarding(table, valp, val); } +static void dev_disable_change(struct inet6_dev *idev) +{ + if (!idev || !idev->dev) + return; + + if (idev->cnf.disable_ipv6) + addrconf_notify(NULL, NETDEV_DOWN, idev->dev); + else + addrconf_notify(NULL, NETDEV_UP, idev->dev); +} + +static void addrconf_disable_change(struct net *net, __s32 newf) +{ + struct net_device *dev; + struct inet6_dev *idev; + + read_lock(&dev_base_lock); + for_each_netdev(net, dev) { + rcu_read_lock(); + idev = __in6_dev_get(dev); + if (idev) { + int changed = (!idev->cnf.disable_ipv6) ^ (!newf); + idev->cnf.disable_ipv6 = newf; + if (changed) + dev_disable_change(idev); + } + rcu_read_unlock(); + } + read_unlock(&dev_base_lock); +} + +static int addrconf_disable_ipv6(struct ctl_table *table, int *p, int old) +{ + struct net *net; + + net = (struct net *)table->extra2; + + if (p == &net->ipv6.devconf_dflt->disable_ipv6) + return 0; + + if (!rtnl_trylock()) + return restart_syscall(); + + if (p == &net->ipv6.devconf_all->disable_ipv6) { + __s32 newf = net->ipv6.devconf_all->disable_ipv6; + net->ipv6.devconf_dflt->disable_ipv6 = newf; + addrconf_disable_change(net, newf); + } else if ((!*p) ^ (!old)) + dev_disable_change((struct inet6_dev *)table->extra1); + + rtnl_unlock(); + return 0; +} + +static +int addrconf_sysctl_disable(ctl_table *ctl, int write, struct file * filp, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + int *valp = ctl->data; + int val = *valp; + int ret; + + ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos); + + if (write) + ret = addrconf_disable_ipv6(ctl, valp, val); + return ret; +} + static struct addrconf_sysctl_table { struct ctl_table_header *sysctl_header; @@ -4225,7 +4293,8 @@ static struct addrconf_sysctl_table .data = &ipv6_devconf.disable_ipv6, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec, + .proc_handler = addrconf_sysctl_disable, + .strategy = sysctl_intvec, }, { .ctl_name = CTL_UNNUMBERED, @@ -4346,6 +4415,10 @@ static int addrconf_init_net(struct net *net) dflt = kmemdup(dflt, sizeof(ipv6_devconf_dflt), GFP_KERNEL); if (dflt == NULL) goto err_alloc_dflt; + } else { + /* these will be inherited by all namespaces */ + dflt->autoconf = ipv6_defaults.autoconf; + dflt->disable_ipv6 = ipv6_defaults.disable_ipv6; } net->ipv6.devconf_all = all; diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index b6215be0963f..85b3d0036afd 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -72,9 +72,21 @@ 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"); +struct ipv6_params ipv6_defaults = { + .disable_ipv6 = 0, + .autoconf = 1, +}; + +static int disable_ipv6_mod = 0; + +module_param_named(disable, disable_ipv6_mod, int, 0444); +MODULE_PARM_DESC(disable, "Disable IPv6 module such that it is non-functional"); + +module_param_named(disable_ipv6, ipv6_defaults.disable_ipv6, int, 0444); +MODULE_PARM_DESC(disable_ipv6, "Disable IPv6 on all interfaces"); + +module_param_named(autoconf, ipv6_defaults.autoconf, int, 0444); +MODULE_PARM_DESC(autoconf, "Enable IPv6 address autoconfiguration on all interfaces"); static __inline__ struct ipv6_pinfo *inet6_sk_generic(struct sock *sk) { @@ -1038,7 +1050,7 @@ static int __init inet6_init(void) for(r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r) INIT_LIST_HEAD(r); - if (disable_ipv6) { + if (disable_ipv6_mod) { printk(KERN_INFO "IPv6: Loaded, but administratively disabled, " "reboot required to enable\n"); @@ -1227,7 +1239,7 @@ module_init(inet6_init); static void __exit inet6_exit(void) { - if (disable_ipv6) + if (disable_ipv6_mod) return; /* First of all disallow new sockets creation. */