linux/net/ipv6/anycast.c
Daniel Lezcano bfeade0870 [NETNS][IPV6]: inet6_addr - check ipv6 address per namespace
When a new address is added, we must check if the new address does not
already exists.  This patch makes this check to be aware of a network
namespace, so the check will look if the address already exists for
the specified network namespace. While the addresses are browsed, the
addresses which do not belong to the namespace are discarded.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 15:01:44 -08:00

580 lines
12 KiB
C

/*
* Anycast support for IPv6
* Linux INET6 implementation
*
* Authors:
* David L Stevens (dlstevens@us.ibm.com)
*
* based heavily on net/ipv6/mcast.c
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/capability.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/random.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/route.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/snmp.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/if_inet6.h>
#include <net/ndisc.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>
#include <net/checksum.h>
static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr);
/* Big ac list lock for all the sockets */
static DEFINE_RWLOCK(ipv6_sk_ac_lock);
static int
ip6_onlink(struct in6_addr *addr, struct net_device *dev)
{
struct inet6_dev *idev;
struct inet6_ifaddr *ifa;
int onlink;
onlink = 0;
rcu_read_lock();
idev = __in6_dev_get(dev);
if (idev) {
read_lock_bh(&idev->lock);
for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
onlink = ipv6_prefix_equal(addr, &ifa->addr,
ifa->prefix_len);
if (onlink)
break;
}
read_unlock_bh(&idev->lock);
}
rcu_read_unlock();
return onlink;
}
/*
* socket join an anycast group
*/
int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
{
struct ipv6_pinfo *np = inet6_sk(sk);
struct net_device *dev = NULL;
struct inet6_dev *idev;
struct ipv6_ac_socklist *pac;
int ishost = !ipv6_devconf.forwarding;
int err = 0;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (ipv6_addr_is_multicast(addr))
return -EINVAL;
if (ipv6_chk_addr(&init_net, addr, NULL, 0))
return -EINVAL;
pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
if (pac == NULL)
return -ENOMEM;
pac->acl_next = NULL;
ipv6_addr_copy(&pac->acl_addr, addr);
if (ifindex == 0) {
struct rt6_info *rt;
rt = rt6_lookup(addr, NULL, 0, 0);
if (rt) {
dev = rt->rt6i_dev;
dev_hold(dev);
dst_release(&rt->u.dst);
} else if (ishost) {
err = -EADDRNOTAVAIL;
goto out_free_pac;
} else {
/* router, no matching interface: just pick one */
dev = dev_get_by_flags(&init_net, IFF_UP, IFF_UP|IFF_LOOPBACK);
}
} else
dev = dev_get_by_index(&init_net, ifindex);
if (dev == NULL) {
err = -ENODEV;
goto out_free_pac;
}
idev = in6_dev_get(dev);
if (!idev) {
if (ifindex)
err = -ENODEV;
else
err = -EADDRNOTAVAIL;
goto out_dev_put;
}
/* reset ishost, now that we have a specific device */
ishost = !idev->cnf.forwarding;
in6_dev_put(idev);
pac->acl_ifindex = dev->ifindex;
/* XXX
* For hosts, allow link-local or matching prefix anycasts.
* This obviates the need for propagating anycast routes while
* still allowing some non-router anycast participation.
*/
if (!ip6_onlink(addr, dev)) {
if (ishost)
err = -EADDRNOTAVAIL;
if (err)
goto out_dev_put;
}
err = ipv6_dev_ac_inc(dev, addr);
if (err)
goto out_dev_put;
write_lock_bh(&ipv6_sk_ac_lock);
pac->acl_next = np->ipv6_ac_list;
np->ipv6_ac_list = pac;
write_unlock_bh(&ipv6_sk_ac_lock);
dev_put(dev);
return 0;
out_dev_put:
dev_put(dev);
out_free_pac:
sock_kfree_s(sk, pac, sizeof(*pac));
return err;
}
/*
* socket leave an anycast group
*/
int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
{
struct ipv6_pinfo *np = inet6_sk(sk);
struct net_device *dev;
struct ipv6_ac_socklist *pac, *prev_pac;
write_lock_bh(&ipv6_sk_ac_lock);
prev_pac = NULL;
for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
ipv6_addr_equal(&pac->acl_addr, addr))
break;
prev_pac = pac;
}
if (!pac) {
write_unlock_bh(&ipv6_sk_ac_lock);
return -ENOENT;
}
if (prev_pac)
prev_pac->acl_next = pac->acl_next;
else
np->ipv6_ac_list = pac->acl_next;
write_unlock_bh(&ipv6_sk_ac_lock);
dev = dev_get_by_index(&init_net, pac->acl_ifindex);
if (dev) {
ipv6_dev_ac_dec(dev, &pac->acl_addr);
dev_put(dev);
}
sock_kfree_s(sk, pac, sizeof(*pac));
return 0;
}
void ipv6_sock_ac_close(struct sock *sk)
{
struct ipv6_pinfo *np = inet6_sk(sk);
struct net_device *dev = NULL;
struct ipv6_ac_socklist *pac;
int prev_index;
write_lock_bh(&ipv6_sk_ac_lock);
pac = np->ipv6_ac_list;
np->ipv6_ac_list = NULL;
write_unlock_bh(&ipv6_sk_ac_lock);
prev_index = 0;
while (pac) {
struct ipv6_ac_socklist *next = pac->acl_next;
if (pac->acl_ifindex != prev_index) {
if (dev)
dev_put(dev);
dev = dev_get_by_index(&init_net, pac->acl_ifindex);
prev_index = pac->acl_ifindex;
}
if (dev)
ipv6_dev_ac_dec(dev, &pac->acl_addr);
sock_kfree_s(sk, pac, sizeof(*pac));
pac = next;
}
if (dev)
dev_put(dev);
}
#if 0
/* The function is not used, which is funny. Apparently, author
* supposed to use it to filter out datagrams inside udp/raw but forgot.
*
* It is OK, anycasts are not special comparing to delivery to unicasts.
*/
int inet6_ac_check(struct sock *sk, struct in6_addr *addr, int ifindex)
{
struct ipv6_ac_socklist *pac;
struct ipv6_pinfo *np = inet6_sk(sk);
int found;
found = 0;
read_lock(&ipv6_sk_ac_lock);
for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) {
if (ifindex && pac->acl_ifindex != ifindex)
continue;
found = ipv6_addr_equal(&pac->acl_addr, addr);
if (found)
break;
}
read_unlock(&ipv6_sk_ac_lock);
return found;
}
#endif
static void aca_put(struct ifacaddr6 *ac)
{
if (atomic_dec_and_test(&ac->aca_refcnt)) {
in6_dev_put(ac->aca_idev);
dst_release(&ac->aca_rt->u.dst);
kfree(ac);
}
}
/*
* device anycast group inc (add if not found)
*/
int ipv6_dev_ac_inc(struct net_device *dev, struct in6_addr *addr)
{
struct ifacaddr6 *aca;
struct inet6_dev *idev;
struct rt6_info *rt;
int err;
idev = in6_dev_get(dev);
if (idev == NULL)
return -EINVAL;
write_lock_bh(&idev->lock);
if (idev->dead) {
err = -ENODEV;
goto out;
}
for (aca = idev->ac_list; aca; aca = aca->aca_next) {
if (ipv6_addr_equal(&aca->aca_addr, addr)) {
aca->aca_users++;
err = 0;
goto out;
}
}
/*
* not found: create a new one.
*/
aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
if (aca == NULL) {
err = -ENOMEM;
goto out;
}
rt = addrconf_dst_alloc(idev, addr, 1);
if (IS_ERR(rt)) {
kfree(aca);
err = PTR_ERR(rt);
goto out;
}
ipv6_addr_copy(&aca->aca_addr, addr);
aca->aca_idev = idev;
aca->aca_rt = rt;
aca->aca_users = 1;
/* aca_tstamp should be updated upon changes */
aca->aca_cstamp = aca->aca_tstamp = jiffies;
atomic_set(&aca->aca_refcnt, 2);
spin_lock_init(&aca->aca_lock);
aca->aca_next = idev->ac_list;
idev->ac_list = aca;
write_unlock_bh(&idev->lock);
dst_hold(&rt->u.dst);
if (ip6_ins_rt(rt))
dst_release(&rt->u.dst);
addrconf_join_solict(dev, &aca->aca_addr);
aca_put(aca);
return 0;
out:
write_unlock_bh(&idev->lock);
in6_dev_put(idev);
return err;
}
/*
* device anycast group decrement
*/
int __ipv6_dev_ac_dec(struct inet6_dev *idev, struct in6_addr *addr)
{
struct ifacaddr6 *aca, *prev_aca;
write_lock_bh(&idev->lock);
prev_aca = NULL;
for (aca = idev->ac_list; aca; aca = aca->aca_next) {
if (ipv6_addr_equal(&aca->aca_addr, addr))
break;
prev_aca = aca;
}
if (!aca) {
write_unlock_bh(&idev->lock);
return -ENOENT;
}
if (--aca->aca_users > 0) {
write_unlock_bh(&idev->lock);
return 0;
}
if (prev_aca)
prev_aca->aca_next = aca->aca_next;
else
idev->ac_list = aca->aca_next;
write_unlock_bh(&idev->lock);
addrconf_leave_solict(idev, &aca->aca_addr);
dst_hold(&aca->aca_rt->u.dst);
if (ip6_del_rt(aca->aca_rt))
dst_free(&aca->aca_rt->u.dst);
else
dst_release(&aca->aca_rt->u.dst);
aca_put(aca);
return 0;
}
static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr)
{
int ret;
struct inet6_dev *idev = in6_dev_get(dev);
if (idev == NULL)
return -ENODEV;
ret = __ipv6_dev_ac_dec(idev, addr);
in6_dev_put(idev);
return ret;
}
/*
* check if the interface has this anycast address
*/
static int ipv6_chk_acast_dev(struct net_device *dev, struct in6_addr *addr)
{
struct inet6_dev *idev;
struct ifacaddr6 *aca;
idev = in6_dev_get(dev);
if (idev) {
read_lock_bh(&idev->lock);
for (aca = idev->ac_list; aca; aca = aca->aca_next)
if (ipv6_addr_equal(&aca->aca_addr, addr))
break;
read_unlock_bh(&idev->lock);
in6_dev_put(idev);
return aca != NULL;
}
return 0;
}
/*
* check if given interface (or any, if dev==0) has this anycast address
*/
int ipv6_chk_acast_addr(struct net_device *dev, struct in6_addr *addr)
{
int found = 0;
if (dev)
return ipv6_chk_acast_dev(dev, addr);
read_lock(&dev_base_lock);
for_each_netdev(&init_net, dev)
if (ipv6_chk_acast_dev(dev, addr)) {
found = 1;
break;
}
read_unlock(&dev_base_lock);
return found;
}
#ifdef CONFIG_PROC_FS
struct ac6_iter_state {
struct net_device *dev;
struct inet6_dev *idev;
};
#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
{
struct ifacaddr6 *im = NULL;
struct ac6_iter_state *state = ac6_seq_private(seq);
state->idev = NULL;
for_each_netdev(&init_net, state->dev) {
struct inet6_dev *idev;
idev = in6_dev_get(state->dev);
if (!idev)
continue;
read_lock_bh(&idev->lock);
im = idev->ac_list;
if (im) {
state->idev = idev;
break;
}
read_unlock_bh(&idev->lock);
in6_dev_put(idev);
}
return im;
}
static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
{
struct ac6_iter_state *state = ac6_seq_private(seq);
im = im->aca_next;
while (!im) {
if (likely(state->idev != NULL)) {
read_unlock_bh(&state->idev->lock);
in6_dev_put(state->idev);
}
state->dev = next_net_device(state->dev);
if (!state->dev) {
state->idev = NULL;
break;
}
state->idev = in6_dev_get(state->dev);
if (!state->idev)
continue;
read_lock_bh(&state->idev->lock);
im = state->idev->ac_list;
}
return im;
}
static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
{
struct ifacaddr6 *im = ac6_get_first(seq);
if (im)
while (pos && (im = ac6_get_next(seq, im)) != NULL)
--pos;
return pos ? NULL : im;
}
static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(dev_base_lock)
{
read_lock(&dev_base_lock);
return ac6_get_idx(seq, *pos);
}
static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct ifacaddr6 *im;
im = ac6_get_next(seq, v);
++*pos;
return im;
}
static void ac6_seq_stop(struct seq_file *seq, void *v)
__releases(dev_base_lock)
{
struct ac6_iter_state *state = ac6_seq_private(seq);
if (likely(state->idev != NULL)) {
read_unlock_bh(&state->idev->lock);
in6_dev_put(state->idev);
}
read_unlock(&dev_base_lock);
}
static int ac6_seq_show(struct seq_file *seq, void *v)
{
struct ifacaddr6 *im = (struct ifacaddr6 *)v;
struct ac6_iter_state *state = ac6_seq_private(seq);
seq_printf(seq,
"%-4d %-15s " NIP6_SEQFMT " %5d\n",
state->dev->ifindex, state->dev->name,
NIP6(im->aca_addr),
im->aca_users);
return 0;
}
static const struct seq_operations ac6_seq_ops = {
.start = ac6_seq_start,
.next = ac6_seq_next,
.stop = ac6_seq_stop,
.show = ac6_seq_show,
};
static int ac6_seq_open(struct inode *inode, struct file *file)
{
return seq_open_private(file, &ac6_seq_ops,
sizeof(struct ac6_iter_state));
}
static const struct file_operations ac6_seq_fops = {
.owner = THIS_MODULE,
.open = ac6_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
};
int __init ac6_proc_init(void)
{
if (!proc_net_fops_create(&init_net, "anycast6", S_IRUGO, &ac6_seq_fops))
return -ENOMEM;
return 0;
}
void ac6_proc_exit(void)
{
proc_net_remove(&init_net, "anycast6");
}
#endif