kernel_optimize_test/include/net/neighbour.h
Simon Kelley bd89efc532 [NEIGH]: Fix IP-over-ATM and ARP interaction.
The classical IP over ATM code maintains its own IPv4 <-> <ATM stuff>
ARP table, using the standard neighbour-table code. The
neigh_table_init function adds this neighbour table to a linked list
of all neighbor tables which is used by the functions neigh_delete()
neigh_add() and neightbl_set(), all called by the netlink code.

Once the ATM neighbour table is added to the list, there are two
tables with family == AF_INET there, and ARP entries sent via netlink
go into the first table with matching family. This is indeterminate
and often wrong.

To see the bug, on a kernel with CLIP enabled, create a standard IPv4
ARP entry by pinging an unused address on a local subnet. Then attempt
to complete that entry by doing

ip neigh replace <ip address> lladdr <some mac address> nud reachable

Looking at the ARP tables by using 

ip neigh show

will reveal two ARP entries for the same address. One of these can be
found in /proc/net/arp, and the other in /proc/net/atm/arp.

This patch adds a new function, neigh_table_init_no_netlink() which
does everything the neigh_table_init() does, except add the table to
the netlink all-arp-tables chain. In addition neigh_table_init() has a
check that all tables on the chain have a distinct address family.
The init call in clip.c is changed to call
neigh_table_init_no_netlink().

Since ATM ARP tables are rather more complicated than can currently be
handled by the available rtattrs in the netlink protocol, no
functionality is lost by this patch, and non-ATM ARP manipulation via
netlink is rescued. A more complete solution would involve a rtattr
for ATM ARP entries and some way for the netlink code to give
neigh_add and friends more information than just address family with
which to find the correct ARP table.

[ I've changed the assertion checking in neigh_table_init() to not
  use BUG_ON() while holding neigh_tbl_lock.  Instead we remember that
  we found an existing tbl with the same family, and after dropping
  the lock we'll give a diagnostic kernel log message and a stack dump.
  -DaveM ]

Signed-off-by: Simon Kelley <simon@thekelleys.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-05-12 14:56:08 -07:00

380 lines
10 KiB
C

#ifndef _NET_NEIGHBOUR_H
#define _NET_NEIGHBOUR_H
/*
* Generic neighbour manipulation
*
* Authors:
* Pedro Roque <roque@di.fc.ul.pt>
* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
*
* Changes:
*
* Harald Welte: <laforge@gnumonks.org>
* - Add neighbour cache statistics like rtstat
*/
/* The following flags & states are exported to user space,
so that they should be moved to include/linux/ directory.
*/
/*
* Neighbor Cache Entry Flags
*/
#define NTF_PROXY 0x08 /* == ATF_PUBL */
#define NTF_ROUTER 0x80
/*
* Neighbor Cache Entry States.
*/
#define NUD_INCOMPLETE 0x01
#define NUD_REACHABLE 0x02
#define NUD_STALE 0x04
#define NUD_DELAY 0x08
#define NUD_PROBE 0x10
#define NUD_FAILED 0x20
/* Dummy states */
#define NUD_NOARP 0x40
#define NUD_PERMANENT 0x80
#define NUD_NONE 0x00
/* NUD_NOARP & NUD_PERMANENT are pseudostates, they never change
and make no address resolution or NUD.
NUD_PERMANENT is also cannot be deleted by garbage collectors.
*/
#ifdef __KERNEL__
#include <asm/atomic.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/rcupdate.h>
#include <linux/seq_file.h>
#include <linux/err.h>
#include <linux/sysctl.h>
#define NUD_IN_TIMER (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
#define NUD_VALID (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
#define NUD_CONNECTED (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
struct neighbour;
struct neigh_parms
{
struct net_device *dev;
struct neigh_parms *next;
int (*neigh_setup)(struct neighbour *);
void (*neigh_destructor)(struct neighbour *);
struct neigh_table *tbl;
void *sysctl_table;
int dead;
atomic_t refcnt;
struct rcu_head rcu_head;
int base_reachable_time;
int retrans_time;
int gc_staletime;
int reachable_time;
int delay_probe_time;
int queue_len;
int ucast_probes;
int app_probes;
int mcast_probes;
int anycast_delay;
int proxy_delay;
int proxy_qlen;
int locktime;
};
struct neigh_statistics
{
unsigned long allocs; /* number of allocated neighs */
unsigned long destroys; /* number of destroyed neighs */
unsigned long hash_grows; /* number of hash resizes */
unsigned long res_failed; /* nomber of failed resolutions */
unsigned long lookups; /* number of lookups */
unsigned long hits; /* number of hits (among lookups) */
unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */
unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
unsigned long periodic_gc_runs; /* number of periodic GC runs */
unsigned long forced_gc_runs; /* number of forced GC runs */
};
#define NEIGH_CACHE_STAT_INC(tbl, field) \
do { \
preempt_disable(); \
(per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \
preempt_enable(); \
} while (0)
struct neighbour
{
struct neighbour *next;
struct neigh_table *tbl;
struct neigh_parms *parms;
struct net_device *dev;
unsigned long used;
unsigned long confirmed;
unsigned long updated;
__u8 flags;
__u8 nud_state;
__u8 type;
__u8 dead;
atomic_t probes;
rwlock_t lock;
unsigned char ha[(MAX_ADDR_LEN+sizeof(unsigned long)-1)&~(sizeof(unsigned long)-1)];
struct hh_cache *hh;
atomic_t refcnt;
int (*output)(struct sk_buff *skb);
struct sk_buff_head arp_queue;
struct timer_list timer;
struct neigh_ops *ops;
u8 primary_key[0];
};
struct neigh_ops
{
int family;
void (*solicit)(struct neighbour *, struct sk_buff*);
void (*error_report)(struct neighbour *, struct sk_buff*);
int (*output)(struct sk_buff*);
int (*connected_output)(struct sk_buff*);
int (*hh_output)(struct sk_buff*);
int (*queue_xmit)(struct sk_buff*);
};
struct pneigh_entry
{
struct pneigh_entry *next;
struct net_device *dev;
u8 key[0];
};
/*
* neighbour table manipulation
*/
struct neigh_table
{
struct neigh_table *next;
int family;
int entry_size;
int key_len;
__u32 (*hash)(const void *pkey, const struct net_device *);
int (*constructor)(struct neighbour *);
int (*pconstructor)(struct pneigh_entry *);
void (*pdestructor)(struct pneigh_entry *);
void (*proxy_redo)(struct sk_buff *skb);
char *id;
struct neigh_parms parms;
/* HACK. gc_* shoul follow parms without a gap! */
int gc_interval;
int gc_thresh1;
int gc_thresh2;
int gc_thresh3;
unsigned long last_flush;
struct timer_list gc_timer;
struct timer_list proxy_timer;
struct sk_buff_head proxy_queue;
atomic_t entries;
rwlock_t lock;
unsigned long last_rand;
kmem_cache_t *kmem_cachep;
struct neigh_statistics *stats;
struct neighbour **hash_buckets;
unsigned int hash_mask;
__u32 hash_rnd;
unsigned int hash_chain_gc;
struct pneigh_entry **phash_buckets;
#ifdef CONFIG_PROC_FS
struct proc_dir_entry *pde;
#endif
};
/* flags for neigh_update() */
#define NEIGH_UPDATE_F_OVERRIDE 0x00000001
#define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002
#define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004
#define NEIGH_UPDATE_F_ISROUTER 0x40000000
#define NEIGH_UPDATE_F_ADMIN 0x80000000
extern void neigh_table_init(struct neigh_table *tbl);
extern void neigh_table_init_no_netlink(struct neigh_table *tbl);
extern int neigh_table_clear(struct neigh_table *tbl);
extern struct neighbour * neigh_lookup(struct neigh_table *tbl,
const void *pkey,
struct net_device *dev);
extern struct neighbour * neigh_lookup_nodev(struct neigh_table *tbl,
const void *pkey);
extern struct neighbour * neigh_create(struct neigh_table *tbl,
const void *pkey,
struct net_device *dev);
extern void neigh_destroy(struct neighbour *neigh);
extern int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
extern int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
u32 flags);
extern void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
extern int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
extern int neigh_resolve_output(struct sk_buff *skb);
extern int neigh_connected_output(struct sk_buff *skb);
extern int neigh_compat_output(struct sk_buff *skb);
extern struct neighbour *neigh_event_ns(struct neigh_table *tbl,
u8 *lladdr, void *saddr,
struct net_device *dev);
extern struct neigh_parms *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
extern void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);
extern void neigh_parms_destroy(struct neigh_parms *parms);
extern unsigned long neigh_rand_reach_time(unsigned long base);
extern void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
struct sk_buff *skb);
extern struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, const void *key, struct net_device *dev, int creat);
extern int pneigh_delete(struct neigh_table *tbl, const void *key, struct net_device *dev);
struct netlink_callback;
struct nlmsghdr;
extern int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
extern int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
extern int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
extern void neigh_app_ns(struct neighbour *n);
extern int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb);
extern int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);
extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
struct neigh_seq_state {
struct neigh_table *tbl;
void *(*neigh_sub_iter)(struct neigh_seq_state *state,
struct neighbour *n, loff_t *pos);
unsigned int bucket;
unsigned int flags;
#define NEIGH_SEQ_NEIGH_ONLY 0x00000001
#define NEIGH_SEQ_IS_PNEIGH 0x00000002
#define NEIGH_SEQ_SKIP_NOARP 0x00000004
};
extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
extern void neigh_seq_stop(struct seq_file *, void *);
extern int neigh_sysctl_register(struct net_device *dev,
struct neigh_parms *p,
int p_id, int pdev_id,
char *p_name,
proc_handler *proc_handler,
ctl_handler *strategy);
extern void neigh_sysctl_unregister(struct neigh_parms *p);
static inline void __neigh_parms_put(struct neigh_parms *parms)
{
atomic_dec(&parms->refcnt);
}
static inline void neigh_parms_put(struct neigh_parms *parms)
{
if (atomic_dec_and_test(&parms->refcnt))
neigh_parms_destroy(parms);
}
static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
{
atomic_inc(&parms->refcnt);
return parms;
}
/*
* Neighbour references
*/
static inline void neigh_release(struct neighbour *neigh)
{
if (atomic_dec_and_test(&neigh->refcnt))
neigh_destroy(neigh);
}
static inline struct neighbour * neigh_clone(struct neighbour *neigh)
{
if (neigh)
atomic_inc(&neigh->refcnt);
return neigh;
}
#define neigh_hold(n) atomic_inc(&(n)->refcnt)
static inline void neigh_confirm(struct neighbour *neigh)
{
if (neigh)
neigh->confirmed = jiffies;
}
static inline int neigh_is_connected(struct neighbour *neigh)
{
return neigh->nud_state&NUD_CONNECTED;
}
static inline int neigh_is_valid(struct neighbour *neigh)
{
return neigh->nud_state&NUD_VALID;
}
static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
{
neigh->used = jiffies;
if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
return __neigh_event_send(neigh, skb);
return 0;
}
static inline struct neighbour *
__neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
{
struct neighbour *n = neigh_lookup(tbl, pkey, dev);
if (n || !creat)
return n;
n = neigh_create(tbl, pkey, dev);
return IS_ERR(n) ? NULL : n;
}
static inline struct neighbour *
__neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
struct net_device *dev)
{
struct neighbour *n = neigh_lookup(tbl, pkey, dev);
if (n)
return n;
return neigh_create(tbl, pkey, dev);
}
struct neighbour_cb {
unsigned long sched_next;
unsigned int flags;
};
#define LOCALLY_ENQUEUED 0x1
#define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb)
#endif
#endif