linux/net/ipv6/addrconf_core.c
David Ahern ff7883ea60 net: ipv6: Make inet6addr_validator a blocking notifier
inet6addr_validator chain was added by commit 3ad7d2468f ("Ipvlan
should return an error when an address is already in use") to allow
address validation before changes are committed and to be able to
fail the address change with an error back to the user. The address
validation is not done for addresses received from router
advertisements.

Handling RAs in softirq context is the only reason for the notifier
chain to be atomic versus blocking. Since the only current user, ipvlan,
of the validator chain ignores softirq context, the notifier can be made
blocking and simply not invoked for softirq path.

The blocking option is needed by spectrum for example to validate
resources for an adding an address to an interface.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20 13:15:07 +01:00

194 lines
6.0 KiB
C

/*
* IPv6 library code, needed by static components when full IPv6 support is
* not configured or static.
*/
#include <linux/export.h>
#include <net/ipv6.h>
#include <net/addrconf.h>
#include <net/ip.h>
/* if ipv6 module registers this function is used by xfrm to force all
* sockets to relookup their nodes - this is fairly expensive, be
* careful
*/
void (*__fib6_flush_trees)(struct net *);
EXPORT_SYMBOL(__fib6_flush_trees);
#define IPV6_ADDR_SCOPE_TYPE(scope) ((scope) << 16)
static inline unsigned int ipv6_addr_scope2type(unsigned int scope)
{
switch (scope) {
case IPV6_ADDR_SCOPE_NODELOCAL:
return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_NODELOCAL) |
IPV6_ADDR_LOOPBACK);
case IPV6_ADDR_SCOPE_LINKLOCAL:
return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL) |
IPV6_ADDR_LINKLOCAL);
case IPV6_ADDR_SCOPE_SITELOCAL:
return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL) |
IPV6_ADDR_SITELOCAL);
}
return IPV6_ADDR_SCOPE_TYPE(scope);
}
int __ipv6_addr_type(const struct in6_addr *addr)
{
__be32 st;
st = addr->s6_addr32[0];
/* Consider all addresses with the first three bits different of
000 and 111 as unicasts.
*/
if ((st & htonl(0xE0000000)) != htonl(0x00000000) &&
(st & htonl(0xE0000000)) != htonl(0xE0000000))
return (IPV6_ADDR_UNICAST |
IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));
if ((st & htonl(0xFF000000)) == htonl(0xFF000000)) {
/* multicast */
/* addr-select 3.1 */
return (IPV6_ADDR_MULTICAST |
ipv6_addr_scope2type(IPV6_ADDR_MC_SCOPE(addr)));
}
if ((st & htonl(0xFFC00000)) == htonl(0xFE800000))
return (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST |
IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL)); /* addr-select 3.1 */
if ((st & htonl(0xFFC00000)) == htonl(0xFEC00000))
return (IPV6_ADDR_SITELOCAL | IPV6_ADDR_UNICAST |
IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL)); /* addr-select 3.1 */
if ((st & htonl(0xFE000000)) == htonl(0xFC000000))
return (IPV6_ADDR_UNICAST |
IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL)); /* RFC 4193 */
if ((addr->s6_addr32[0] | addr->s6_addr32[1]) == 0) {
if (addr->s6_addr32[2] == 0) {
if (addr->s6_addr32[3] == 0)
return IPV6_ADDR_ANY;
if (addr->s6_addr32[3] == htonl(0x00000001))
return (IPV6_ADDR_LOOPBACK | IPV6_ADDR_UNICAST |
IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL)); /* addr-select 3.4 */
return (IPV6_ADDR_COMPATv4 | IPV6_ADDR_UNICAST |
IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL)); /* addr-select 3.3 */
}
if (addr->s6_addr32[2] == htonl(0x0000ffff))
return (IPV6_ADDR_MAPPED |
IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL)); /* addr-select 3.3 */
}
return (IPV6_ADDR_UNICAST |
IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL)); /* addr-select 3.4 */
}
EXPORT_SYMBOL(__ipv6_addr_type);
static ATOMIC_NOTIFIER_HEAD(inet6addr_chain);
static BLOCKING_NOTIFIER_HEAD(inet6addr_validator_chain);
int register_inet6addr_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_register(&inet6addr_chain, nb);
}
EXPORT_SYMBOL(register_inet6addr_notifier);
int unregister_inet6addr_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&inet6addr_chain, nb);
}
EXPORT_SYMBOL(unregister_inet6addr_notifier);
int inet6addr_notifier_call_chain(unsigned long val, void *v)
{
return atomic_notifier_call_chain(&inet6addr_chain, val, v);
}
EXPORT_SYMBOL(inet6addr_notifier_call_chain);
int register_inet6addr_validator_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&inet6addr_validator_chain, nb);
}
EXPORT_SYMBOL(register_inet6addr_validator_notifier);
int unregister_inet6addr_validator_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&inet6addr_validator_chain,
nb);
}
EXPORT_SYMBOL(unregister_inet6addr_validator_notifier);
int inet6addr_validator_notifier_call_chain(unsigned long val, void *v)
{
return blocking_notifier_call_chain(&inet6addr_validator_chain, val, v);
}
EXPORT_SYMBOL(inet6addr_validator_notifier_call_chain);
static int eafnosupport_ipv6_dst_lookup(struct net *net, struct sock *u1,
struct dst_entry **u2,
struct flowi6 *u3)
{
return -EAFNOSUPPORT;
}
const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
.ipv6_dst_lookup = eafnosupport_ipv6_dst_lookup,
};
EXPORT_SYMBOL_GPL(ipv6_stub);
/* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
EXPORT_SYMBOL(in6addr_loopback);
const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
EXPORT_SYMBOL(in6addr_any);
const struct in6_addr in6addr_linklocal_allnodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
EXPORT_SYMBOL(in6addr_linklocal_allnodes);
const struct in6_addr in6addr_linklocal_allrouters = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
EXPORT_SYMBOL(in6addr_linklocal_allrouters);
const struct in6_addr in6addr_interfacelocal_allnodes = IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
const struct in6_addr in6addr_interfacelocal_allrouters = IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
const struct in6_addr in6addr_sitelocal_allrouters = IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
static void snmp6_free_dev(struct inet6_dev *idev)
{
kfree(idev->stats.icmpv6msgdev);
kfree(idev->stats.icmpv6dev);
free_percpu(idev->stats.ipv6);
}
static void in6_dev_finish_destroy_rcu(struct rcu_head *head)
{
struct inet6_dev *idev = container_of(head, struct inet6_dev, rcu);
snmp6_free_dev(idev);
kfree(idev);
}
/* Nobody refers to this device, we may destroy it. */
void in6_dev_finish_destroy(struct inet6_dev *idev)
{
struct net_device *dev = idev->dev;
WARN_ON(!list_empty(&idev->addr_list));
WARN_ON(idev->mc_list);
WARN_ON(timer_pending(&idev->rs_timer));
#ifdef NET_REFCNT_DEBUG
pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
#endif
dev_put(dev);
if (!idev->dead) {
pr_warn("Freeing alive inet6 device %p\n", idev);
return;
}
call_rcu(&idev->rcu, in6_dev_finish_destroy_rcu);
}
EXPORT_SYMBOL(in6_dev_finish_destroy);