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NetBSD/sys/net/if_llatbl.h
ozaki-r ecd5b23eef Use lltable/llentry for NDP 
lltable and llentry were introduced to replace ARP cache data structure
for further restructuring of the routing table: L2 nexthop cache
separation. This change replaces the NDP cache data structure
(llinfo_nd6) with them as well as ARP.

One noticeable change is for neighbor cache GC mechanism that was
introduced to prevent IPv6 DoS attacks. net.inet6.ip6.neighborgcthresh
was the max number of caches that we store in the system. After
introducing lltable/llentry, the value is changed to be per-interface
basis because lltable/llentry stores neighbor caches in each interface
separately. And the change brings one degradation; the old GC mechanism
dropped exceeded packets based on LRU while the new implementation drops
packets in order from the beginning of lltable (a hash table + linked
lists). It would be improved in the future.

Added functions in in6.c come from FreeBSD (as of r286629) and are
tweaked for NetBSD.

Proposed on tech-kern and tech-net.
2015-11-25 06:21:26 +00:00

345 lines
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/* $NetBSD: if_llatbl.h,v 1.6 2015/11/25 06:21:26 ozaki-r Exp $ */
/*
* Copyright (c) 2004 Luigi Rizzo, Alessandro Cerri. All rights reserved.
* Copyright (c) 2004-2008 Qing Li. All rights reserved.
* Copyright (c) 2008 Kip Macy. All rights reserved.
* Copyright (c) 2015 The NetBSD Foundation, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef _NET_IF_LLATBL_H_
#define _NET_IF_LLATBL_H_
#if defined(_KERNEL_OPT)
#include "opt_gateway.h"
#endif
#include <sys/rwlock.h>
#ifdef GATEWAY
#include <sys/mutex.h>
#endif
#include <netinet/in.h>
struct ifnet;
struct sysctl_req;
struct rt_msghdr;
struct rt_addrinfo;
struct llentry;
LIST_HEAD(llentries, llentry);
extern krwlock_t lltable_rwlock;
#define LLTABLE_RLOCK() rw_enter(&lltable_rwlock, RW_READER)
#define LLTABLE_RUNLOCK() rw_exit(&lltable_rwlock)
#define LLTABLE_WLOCK() rw_enter(&lltable_rwlock, RW_WRITER)
#define LLTABLE_WUNLOCK() rw_exit(&lltable_rwlock)
#define LLTABLE_LOCK_ASSERT() KASSERT(rw_lock_held(&lltable_rwlock))
/*
* Code referencing llentry must at least hold
* a shared lock
*/
struct llentry {
LIST_ENTRY(llentry) lle_next;
union {
struct in_addr addr4;
struct in6_addr addr6;
} r_l3addr;
union {
uint64_t mac_aligned;
uint16_t mac16[3];
uint8_t mac8[20]; /* IB needs 20 bytes. */
} ll_addr;
uint32_t spare0;
uint64_t spare1;
struct lltable *lle_tbl;
struct llentries *lle_head;
void (*lle_free)(struct llentry *);
struct mbuf *la_hold;
int la_numheld; /* # of packets currently held */
time_t la_expire;
uint16_t la_flags;
uint16_t la_asked;
uint16_t la_preempt;
uint16_t ln_byhint;
int16_t ln_state; /* IPv6 has ND6_LLINFO_NOSTATE == -2 */
uint16_t ln_router;
time_t ln_ntick;
int lle_refcnt;
LIST_ENTRY(llentry) lle_chain; /* chain of deleted items */
struct callout lle_timer;
#ifdef GATEWAY
kmutex_t lle_lock;
#else
krwlock_t lle_lock;
#endif
#ifdef __NetBSD__
#define la_timer lle_timer
#define ln_timer_ch lle_timer
#define ln_expire la_expire
#define ln_asked la_asked
#define ln_hold la_hold
struct rtentry *la_rt;
#define ln_rt la_rt
void *la_opaque; /* For tokenring */
#endif
};
#if 0
#define LLE_LOCK_TRACE(t, lle) aprint_normal( \
"%s:%d: LOCK(" #t "): lle=%p\n", \
__func__, __LINE__, (lle))
#else
#define LLE_LOCK_TRACE(t, lle) do {} while (0)
#endif
#ifdef GATEWAY
#define LLE_WLOCK(lle) do { \
LLE_LOCK_TRACE(WL, (lle)); \
mutex_enter(&(lle)->lle_lock); \
} while (0)
#define LLE_RLOCK(lle) do { \
LLE_LOCK_TRACE(RL, (lle)); \
mutex_enter(&(lle)->lle_lock); \
} while (0)
#define LLE_WUNLOCK(lle) do { \
LLE_LOCK_TRACE(WU, (lle)); \
mutex_exit(&(lle)->lle_lock); \
} while (0)
#define LLE_RUNLOCK(lle) do { \
LLE_LOCK_TRACE(RU, (lle)); \
mutex_exit(&(lle)->lle_lock); \
} while (0)
#define LLE_DOWNGRADE(lle) do {} while (0)
#define LLE_TRY_UPGRADE(lle) (1)
#define LLE_LOCK_INIT(lle) mutex_init(&(lle)->lle_lock, MUTEX_DEFAULT, \
IPL_NET)
#define LLE_LOCK_DESTROY(lle) mutex_destroy(&(lle)->lle_lock)
#define LLE_WLOCK_ASSERT(lle) KASSERT(mutex_owned(&(lle)->lle_lock))
#else /* GATEWAY */
#define LLE_WLOCK(lle) do { \
LLE_LOCK_TRACE(WL, (lle)); \
rw_enter(&(lle)->lle_lock, RW_WRITER); \
} while (0)
#define LLE_RLOCK(lle) do { \
LLE_LOCK_TRACE(RL, (lle)); \
rw_enter(&(lle)->lle_lock, RW_READER); \
} while (0)
#define LLE_WUNLOCK(lle) do { \
LLE_LOCK_TRACE(WU, (lle)); \
rw_exit(&(lle)->lle_lock); \
} while (0)
#define LLE_RUNLOCK(lle) do { \
LLE_LOCK_TRACE(RU, (lle)); \
rw_exit(&(lle)->lle_lock); \
} while (0)
#define LLE_DOWNGRADE(lle) rw_downgrade(&(lle)->lle_lock)
#define LLE_TRY_UPGRADE(lle) rw_tryupgrade(&(lle)->lle_lock)
#ifdef __FreeBSD__
#define LLE_LOCK_INIT(lle) rw_init_flags(&(lle)->lle_lock, "lle", RW_DUPOK)
#else /* XXX */
#define LLE_LOCK_INIT(lle) rw_init(&(lle)->lle_lock)
#endif
#define LLE_LOCK_DESTROY(lle) rw_destroy(&(lle)->lle_lock)
#define LLE_WLOCK_ASSERT(lle) KASSERT(rw_write_held(&(lle)->lle_lock))
#endif /* GATEWAY */
#define LLE_IS_VALID(lle) (((lle) != NULL) && ((lle) != (void *)-1))
#if 0
#define LLE_REF_TRACE(t, n) aprint_normal("%s:%d: REF(" #t "): refcnt=%d\n", \
__func__, __LINE__, (n))
#else
#define LLE_REF_TRACE(t, n) do {} while (0)
#endif
#define LLE_ADDREF(lle) do { \
LLE_WLOCK_ASSERT(lle); \
LLE_REF_TRACE(ADD, (lle)->lle_refcnt); \
KASSERTMSG((lle)->lle_refcnt >= 0, \
"negative refcnt %d on lle %p", \
(lle)->lle_refcnt, (lle)); \
(lle)->lle_refcnt++; \
} while (0)
#define LLE_REMREF(lle) do { \
LLE_WLOCK_ASSERT(lle); \
LLE_REF_TRACE(REM, (lle)->lle_refcnt); \
KASSERTMSG((lle)->lle_refcnt > 0, \
"bogus refcnt %d on lle %p", \
(lle)->lle_refcnt, (lle)); \
(lle)->lle_refcnt--; \
if ((lle)->lle_refcnt == 0) \
LLE_REF_TRACE(ZERO, (lle)->lle_refcnt); \
} while (0)
#define LLE_FREE_LOCKED(lle) do { \
if ((lle)->lle_refcnt == 1) \
(lle)->lle_free(lle); \
else { \
LLE_REMREF(lle); \
LLE_WUNLOCK(lle); \
} \
/* guard against invalid refs */ \
(lle) = NULL; \
} while (0)
#define LLE_FREE(lle) do { \
LLE_WLOCK(lle); \
LLE_FREE_LOCKED(lle); \
} while (0)
typedef struct llentry *(llt_lookup_t)(struct lltable *, u_int flags,
const struct sockaddr *l3addr);
typedef struct llentry *(llt_create_t)(struct lltable *, u_int flags,
const struct sockaddr *l3addr);
typedef int (llt_delete_t)(struct lltable *, u_int flags,
const struct sockaddr *l3addr);
typedef void (llt_prefix_free_t)(struct lltable *,
const struct sockaddr *prefix, const struct sockaddr *mask, u_int flags);
typedef int (llt_dump_entry_t)(struct lltable *, struct llentry *,
struct sysctl_req *);
typedef uint32_t (llt_hash_t)(const struct llentry *, uint32_t);
typedef int (llt_match_prefix_t)(const struct sockaddr *,
const struct sockaddr *, u_int, struct llentry *);
typedef void (llt_free_entry_t)(struct lltable *, struct llentry *);
typedef void (llt_fill_sa_entry_t)(const struct llentry *, struct sockaddr *);
typedef void (llt_free_tbl_t)(struct lltable *);
typedef void (llt_link_entry_t)(struct lltable *, struct llentry *);
typedef void (llt_unlink_entry_t)(struct llentry *);
typedef int (llt_foreach_cb_t)(struct lltable *, struct llentry *, void *);
typedef int (llt_foreach_entry_t)(struct lltable *, llt_foreach_cb_t *, void *);
struct lltable {
SLIST_ENTRY(lltable) llt_link;
int llt_af;
int llt_hsize;
struct llentries *lle_head;
unsigned int llt_lle_count;
struct ifnet *llt_ifp;
llt_lookup_t *llt_lookup;
llt_create_t *llt_create;
llt_delete_t *llt_delete;
llt_prefix_free_t *llt_prefix_free;
llt_dump_entry_t *llt_dump_entry;
llt_hash_t *llt_hash;
llt_match_prefix_t *llt_match_prefix;
llt_free_entry_t *llt_free_entry;
llt_foreach_entry_t *llt_foreach_entry;
llt_link_entry_t *llt_link_entry;
llt_unlink_entry_t *llt_unlink_entry;
llt_fill_sa_entry_t *llt_fill_sa_entry;
llt_free_tbl_t *llt_free_tbl;
};
MALLOC_DECLARE(M_LLTABLE);
/*
* LLentry flags
*/
#define LLE_DELETED 0x0001 /* entry must be deleted */
#define LLE_STATIC 0x0002 /* entry is static */
#define LLE_IFADDR 0x0004 /* entry is interface addr */
#define LLE_VALID 0x0008 /* ll_addr is valid */
#define LLE_PUB 0x0020 /* publish entry ??? */
#define LLE_LINKED 0x0040 /* linked to lookup structure */
/* LLE request flags */
#define LLE_EXCLUSIVE 0x2000 /* return lle xlocked */
#define LLATBL_HASH(key, mask) \
(((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)
void lltableinit(void);
struct lltable *lltable_allocate_htbl(uint32_t hsize);
void lltable_free(struct lltable *);
void lltable_link(struct lltable *llt);
void lltable_prefix_free(int, struct sockaddr *,
struct sockaddr *, u_int);
void lltable_drain(int);
void lltable_purge_entries(struct lltable *);
int lltable_sysctl_dumparp(int, struct sysctl_req *);
size_t llentry_free(struct llentry *);
struct llentry *llentry_alloc(struct ifnet *, struct lltable *,
struct sockaddr_storage *);
/* helper functions */
size_t lltable_drop_entry_queue(struct llentry *);
struct llentry *lltable_create_lle(struct lltable *llt, u_int flags,
const void *paddr);
void lltable_link_entry(struct lltable *llt, struct llentry *lle);
void lltable_unlink_entry(struct lltable *llt, struct llentry *lle);
void lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa);
struct ifnet *lltable_get_ifp(const struct lltable *llt);
int lltable_get_af(const struct lltable *llt);
static inline unsigned int
lltable_get_entry_count(struct lltable *llt)
{
return llt->llt_lle_count;
}
int lltable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f,
void *farg);
/*
* Generic link layer address lookup function.
*/
static __inline struct llentry *
lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
{
return (llt->llt_lookup(llt, flags, l3addr));
}
static __inline struct llentry *
lla_create(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
{
return (llt->llt_create(llt, flags, l3addr));
}
static __inline int
lla_delete(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
{
return (llt->llt_delete(llt, flags, l3addr));
}
int lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
#endif /* _NET_IF_LLATBL_H_ */
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