linux/net/ipv6/anycast.c
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00

556 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 <linux/slab.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);
/*
* 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;
struct net *net = sock_net(sk);
int ishost = !net->ipv6.devconf_all->forwarding;
int err = 0;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (ipv6_addr_is_multicast(addr))
return -EINVAL;
if (ipv6_chk_addr(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(net, 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(net, IFF_UP, IFF_UP|IFF_LOOPBACK);
}
} else
dev = dev_get_by_index(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 (!ipv6_chk_prefix(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;
struct net *net = sock_net(sk);
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(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;
struct net *net = sock_net(sk);
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(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);
ip6_ins_rt(rt);
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);
ip6_del_rt(aca->aca_rt);
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 *net, struct net_device *dev,
struct in6_addr *addr)
{
int found = 0;
if (dev)
return ipv6_chk_acast_dev(dev, addr);
rcu_read_lock();
for_each_netdev_rcu(net, dev)
if (ipv6_chk_acast_dev(dev, addr)) {
found = 1;
break;
}
rcu_read_unlock();
return found;
}
#ifdef CONFIG_PROC_FS
struct ac6_iter_state {
struct seq_net_private p;
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);
struct net *net = seq_file_net(seq);
state->idev = NULL;
for_each_netdev_rcu(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);
}
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);
state->dev = next_net_device_rcu(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(RCU)
{
rcu_read_lock();
return ac6_get_idx(seq, *pos);
}
static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct ifacaddr6 *im = ac6_get_next(seq, v);
++*pos;
return im;
}
static void ac6_seq_stop(struct seq_file *seq, void *v)
__releases(RCU)
{
struct ac6_iter_state *state = ac6_seq_private(seq);
if (likely(state->idev != NULL)) {
read_unlock_bh(&state->idev->lock);
state->idev = NULL;
}
rcu_read_unlock();
}
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 %pi6 %5d\n",
state->dev->ifindex, state->dev->name,
&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_net(inode, 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_net,
};
int __net_init ac6_proc_init(struct net *net)
{
if (!proc_net_fops_create(net, "anycast6", S_IRUGO, &ac6_seq_fops))
return -ENOMEM;
return 0;
}
void ac6_proc_exit(struct net *net)
{
proc_net_remove(net, "anycast6");
}
#endif