freebsd-nq/sys/net/if_llatbl.c
Alexander V. Chernikov d3cdb71655 * Require explicitl lle unlink prior to calling llentry_delete().
This one slightly decreases time of holding afdata wlock.
* While here, make nd6_free() return void. No one has used its return value
  since r186119.
2015-09-15 06:48:19 +00:00

832 lines
18 KiB
C

/*
* 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.
*
* 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>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/syslog.h>
#include <sys/sysctl.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#ifdef DDB
#include <ddb/ddb.h>
#endif
#include <vm/uma.h>
#include <netinet/in.h>
#include <net/if_llatbl.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_var.h>
#include <net/route.h>
#include <net/vnet.h>
#include <netinet/if_ether.h>
#include <netinet6/in6_var.h>
#include <netinet6/nd6.h>
MALLOC_DEFINE(M_LLTABLE, "lltable", "link level address tables");
static VNET_DEFINE(SLIST_HEAD(, lltable), lltables);
#define V_lltables VNET(lltables)
static void vnet_lltable_init(void);
struct rwlock lltable_rwlock;
RW_SYSINIT(lltable_rwlock, &lltable_rwlock, "lltable_rwlock");
static void lltable_unlink(struct lltable *llt);
static void llentries_unlink(struct lltable *llt, struct llentries *head);
static void htable_unlink_entry(struct llentry *lle);
static void htable_link_entry(struct lltable *llt, struct llentry *lle);
static int htable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f,
void *farg);
/*
* Dump lle state for a specific address family.
*/
static int
lltable_dump_af(struct lltable *llt, struct sysctl_req *wr)
{
int error;
LLTABLE_LOCK_ASSERT();
if (llt->llt_ifp->if_flags & IFF_LOOPBACK)
return (0);
error = 0;
IF_AFDATA_RLOCK(llt->llt_ifp);
error = lltable_foreach_lle(llt,
(llt_foreach_cb_t *)llt->llt_dump_entry, wr);
IF_AFDATA_RUNLOCK(llt->llt_ifp);
return (error);
}
/*
* Dump arp state for a specific address family.
*/
int
lltable_sysctl_dumparp(int af, struct sysctl_req *wr)
{
struct lltable *llt;
int error = 0;
LLTABLE_RLOCK();
SLIST_FOREACH(llt, &V_lltables, llt_link) {
if (llt->llt_af == af) {
error = lltable_dump_af(llt, wr);
if (error != 0)
goto done;
}
}
done:
LLTABLE_RUNLOCK();
return (error);
}
/*
* Common function helpers for chained hash table.
*/
/*
* Runs specified callback for each entry in @llt.
* Caller does the locking.
*
*/
static int
htable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f, void *farg)
{
struct llentry *lle, *next;
int i, error;
error = 0;
for (i = 0; i < llt->llt_hsize; i++) {
LIST_FOREACH_SAFE(lle, &llt->lle_head[i], lle_next, next) {
error = f(llt, lle, farg);
if (error != 0)
break;
}
}
return (error);
}
static void
htable_link_entry(struct lltable *llt, struct llentry *lle)
{
struct llentries *lleh;
uint32_t hashidx;
if ((lle->la_flags & LLE_LINKED) != 0)
return;
IF_AFDATA_WLOCK_ASSERT(llt->llt_ifp);
hashidx = llt->llt_hash(lle, llt->llt_hsize);
lleh = &llt->lle_head[hashidx];
lle->lle_tbl = llt;
lle->lle_head = lleh;
lle->la_flags |= LLE_LINKED;
LIST_INSERT_HEAD(lleh, lle, lle_next);
}
static void
htable_unlink_entry(struct llentry *lle)
{
if ((lle->la_flags & LLE_LINKED) != 0) {
IF_AFDATA_WLOCK_ASSERT(lle->lle_tbl->llt_ifp);
LIST_REMOVE(lle, lle_next);
lle->la_flags &= ~(LLE_VALID | LLE_LINKED);
#if 0
lle->lle_tbl = NULL;
lle->lle_head = NULL;
#endif
}
}
struct prefix_match_data {
const struct sockaddr *addr;
const struct sockaddr *mask;
struct llentries dchain;
u_int flags;
};
static int
htable_prefix_free_cb(struct lltable *llt, struct llentry *lle, void *farg)
{
struct prefix_match_data *pmd;
pmd = (struct prefix_match_data *)farg;
if (llt->llt_match_prefix(pmd->addr, pmd->mask, pmd->flags, lle)) {
LLE_WLOCK(lle);
LIST_INSERT_HEAD(&pmd->dchain, lle, lle_chain);
}
return (0);
}
static void
htable_prefix_free(struct lltable *llt, const struct sockaddr *addr,
const struct sockaddr *mask, u_int flags)
{
struct llentry *lle, *next;
struct prefix_match_data pmd;
bzero(&pmd, sizeof(pmd));
pmd.addr = addr;
pmd.mask = mask;
pmd.flags = flags;
LIST_INIT(&pmd.dchain);
IF_AFDATA_WLOCK(llt->llt_ifp);
/* Push matching lles to chain */
lltable_foreach_lle(llt, htable_prefix_free_cb, &pmd);
llentries_unlink(llt, &pmd.dchain);
IF_AFDATA_WUNLOCK(llt->llt_ifp);
LIST_FOREACH_SAFE(lle, &pmd.dchain, lle_chain, next)
lltable_free_entry(llt, lle);
}
static void
htable_free_tbl(struct lltable *llt)
{
free(llt->lle_head, M_LLTABLE);
free(llt, M_LLTABLE);
}
static void
llentries_unlink(struct lltable *llt, struct llentries *head)
{
struct llentry *lle, *next;
LIST_FOREACH_SAFE(lle, head, lle_chain, next)
llt->llt_unlink_entry(lle);
}
/*
* Helper function used to drop all mbufs in hold queue.
*
* Returns the number of held packets, if any, that were dropped.
*/
size_t
lltable_drop_entry_queue(struct llentry *lle)
{
size_t pkts_dropped;
struct mbuf *next;
LLE_WLOCK_ASSERT(lle);
pkts_dropped = 0;
while ((lle->la_numheld > 0) && (lle->la_hold != NULL)) {
next = lle->la_hold->m_nextpkt;
m_freem(lle->la_hold);
lle->la_hold = next;
lle->la_numheld--;
pkts_dropped++;
}
KASSERT(lle->la_numheld == 0,
("%s: la_numheld %d > 0, pkts_droped %zd", __func__,
lle->la_numheld, pkts_dropped));
return (pkts_dropped);
}
/*
*
* Performes generic cleanup routines and frees lle.
*
* Called for non-linked entries, with callouts and
* other AF-specific cleanups performed.
*
* @lle must be passed WLOCK'ed
*
* Returns the number of held packets, if any, that were dropped.
*/
size_t
llentry_free(struct llentry *lle)
{
size_t pkts_dropped;
LLE_WLOCK_ASSERT(lle);
KASSERT((lle->la_flags & LLE_LINKED) == 0, ("freeing linked lle"));
pkts_dropped = lltable_drop_entry_queue(lle);
LLE_FREE_LOCKED(lle);
return (pkts_dropped);
}
/*
* (al)locate an llentry for address dst (equivalent to rtalloc for new-arp).
*
* If found the llentry * is returned referenced and unlocked.
*/
struct llentry *
llentry_alloc(struct ifnet *ifp, struct lltable *lt,
struct sockaddr_storage *dst)
{
struct llentry *la, *la_tmp;
IF_AFDATA_RLOCK(ifp);
la = lla_lookup(lt, LLE_EXCLUSIVE, (struct sockaddr *)dst);
IF_AFDATA_RUNLOCK(ifp);
if (la != NULL) {
LLE_ADDREF(la);
LLE_WUNLOCK(la);
return (la);
}
if ((ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0) {
la = lltable_alloc_entry(lt, 0, (struct sockaddr *)dst);
if (la == NULL)
return (NULL);
IF_AFDATA_WLOCK(ifp);
LLE_WLOCK(la);
/* Prefer any existing LLE over newly-created one */
la_tmp = lla_lookup(lt, LLE_EXCLUSIVE, (struct sockaddr *)dst);
if (la_tmp == NULL)
lltable_link_entry(lt, la);
IF_AFDATA_WUNLOCK(ifp);
if (la_tmp != NULL) {
lltable_free_entry(lt, la);
la = la_tmp;
}
LLE_ADDREF(la);
LLE_WUNLOCK(la);
}
return (la);
}
/*
* Free all entries from given table and free itself.
*/
static int
lltable_free_cb(struct lltable *llt, struct llentry *lle, void *farg)
{
struct llentries *dchain;
dchain = (struct llentries *)farg;
LLE_WLOCK(lle);
LIST_INSERT_HEAD(dchain, lle, lle_chain);
return (0);
}
/*
* Free all entries from given table and free itself.
*/
void
lltable_free(struct lltable *llt)
{
struct llentry *lle, *next;
struct llentries dchain;
KASSERT(llt != NULL, ("%s: llt is NULL", __func__));
lltable_unlink(llt);
LIST_INIT(&dchain);
IF_AFDATA_WLOCK(llt->llt_ifp);
/* Push all lles to @dchain */
lltable_foreach_lle(llt, lltable_free_cb, &dchain);
llentries_unlink(llt, &dchain);
IF_AFDATA_WUNLOCK(llt->llt_ifp);
LIST_FOREACH_SAFE(lle, &dchain, lle_chain, next) {
if (callout_stop(&lle->lle_timer))
LLE_REMREF(lle);
llentry_free(lle);
}
llt->llt_free_tbl(llt);
}
#if 0
void
lltable_drain(int af)
{
struct lltable *llt;
struct llentry *lle;
register int i;
LLTABLE_RLOCK();
SLIST_FOREACH(llt, &V_lltables, llt_link) {
if (llt->llt_af != af)
continue;
for (i=0; i < llt->llt_hsize; i++) {
LIST_FOREACH(lle, &llt->lle_head[i], lle_next) {
LLE_WLOCK(lle);
if (lle->la_hold) {
m_freem(lle->la_hold);
lle->la_hold = NULL;
}
LLE_WUNLOCK(lle);
}
}
}
LLTABLE_RUNLOCK();
}
#endif
/*
* Deletes an address from given lltable.
* Used for userland interaction to remove
* individual entries. Skips entries added by OS.
*/
int
lltable_delete_addr(struct lltable *llt, u_int flags,
const struct sockaddr *l3addr)
{
struct llentry *lle;
struct ifnet *ifp;
ifp = llt->llt_ifp;
IF_AFDATA_WLOCK(ifp);
lle = lla_lookup(llt, LLE_EXCLUSIVE, l3addr);
if (lle == NULL) {
IF_AFDATA_WUNLOCK(ifp);
return (ENOENT);
}
if ((lle->la_flags & LLE_IFADDR) != 0 && (flags & LLE_IFADDR) == 0) {
IF_AFDATA_WUNLOCK(ifp);
LLE_WUNLOCK(lle);
return (EPERM);
}
lltable_unlink_entry(llt, lle);
IF_AFDATA_WUNLOCK(ifp);
llt->llt_delete_entry(llt, lle);
return (0);
}
void
lltable_prefix_free(int af, struct sockaddr *addr, struct sockaddr *mask,
u_int flags)
{
struct lltable *llt;
LLTABLE_RLOCK();
SLIST_FOREACH(llt, &V_lltables, llt_link) {
if (llt->llt_af != af)
continue;
llt->llt_prefix_free(llt, addr, mask, flags);
}
LLTABLE_RUNLOCK();
}
struct lltable *
lltable_allocate_htbl(uint32_t hsize)
{
struct lltable *llt;
int i;
llt = malloc(sizeof(struct lltable), M_LLTABLE, M_WAITOK | M_ZERO);
llt->llt_hsize = hsize;
llt->lle_head = malloc(sizeof(struct llentries) * hsize,
M_LLTABLE, M_WAITOK | M_ZERO);
for (i = 0; i < llt->llt_hsize; i++)
LIST_INIT(&llt->lle_head[i]);
/* Set some default callbacks */
llt->llt_link_entry = htable_link_entry;
llt->llt_unlink_entry = htable_unlink_entry;
llt->llt_prefix_free = htable_prefix_free;
llt->llt_foreach_entry = htable_foreach_lle;
llt->llt_free_tbl = htable_free_tbl;
return (llt);
}
/*
* Links lltable to global llt list.
*/
void
lltable_link(struct lltable *llt)
{
LLTABLE_WLOCK();
SLIST_INSERT_HEAD(&V_lltables, llt, llt_link);
LLTABLE_WUNLOCK();
}
static void
lltable_unlink(struct lltable *llt)
{
LLTABLE_WLOCK();
SLIST_REMOVE(&V_lltables, llt, lltable, llt_link);
LLTABLE_WUNLOCK();
}
/*
* External methods used by lltable consumers
*/
int
lltable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f, void *farg)
{
return (llt->llt_foreach_entry(llt, f, farg));
}
struct llentry *
lltable_alloc_entry(struct lltable *llt, u_int flags,
const struct sockaddr *l3addr)
{
return (llt->llt_alloc_entry(llt, flags, l3addr));
}
void
lltable_free_entry(struct lltable *llt, struct llentry *lle)
{
llt->llt_free_entry(llt, lle);
}
void
lltable_link_entry(struct lltable *llt, struct llentry *lle)
{
llt->llt_link_entry(llt, lle);
}
void
lltable_unlink_entry(struct lltable *llt, struct llentry *lle)
{
llt->llt_unlink_entry(lle);
}
void
lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa)
{
struct lltable *llt;
llt = lle->lle_tbl;
llt->llt_fill_sa_entry(lle, sa);
}
struct ifnet *
lltable_get_ifp(const struct lltable *llt)
{
return (llt->llt_ifp);
}
int
lltable_get_af(const struct lltable *llt)
{
return (llt->llt_af);
}
/*
* Called in route_output when rtm_flags contains RTF_LLDATA.
*/
int
lla_rt_output(struct rt_msghdr *rtm, struct rt_addrinfo *info)
{
struct sockaddr_dl *dl =
(struct sockaddr_dl *)info->rti_info[RTAX_GATEWAY];
struct sockaddr *dst = (struct sockaddr *)info->rti_info[RTAX_DST];
struct ifnet *ifp;
struct lltable *llt;
struct llentry *lle, *lle_tmp;
u_int laflags = 0;
int error;
KASSERT(dl != NULL && dl->sdl_family == AF_LINK,
("%s: invalid dl\n", __func__));
ifp = ifnet_byindex(dl->sdl_index);
if (ifp == NULL) {
log(LOG_INFO, "%s: invalid ifp (sdl_index %d)\n",
__func__, dl->sdl_index);
return EINVAL;
}
/* XXX linked list may be too expensive */
LLTABLE_RLOCK();
SLIST_FOREACH(llt, &V_lltables, llt_link) {
if (llt->llt_af == dst->sa_family &&
llt->llt_ifp == ifp)
break;
}
LLTABLE_RUNLOCK();
KASSERT(llt != NULL, ("Yep, ugly hacks are bad\n"));
error = 0;
switch (rtm->rtm_type) {
case RTM_ADD:
/* Add static LLE */
laflags = 0;
if (rtm->rtm_rmx.rmx_expire == 0)
laflags = LLE_STATIC;
lle = lltable_alloc_entry(llt, laflags, dst);
if (lle == NULL)
return (ENOMEM);
bcopy(LLADDR(dl), &lle->ll_addr, ifp->if_addrlen);
if ((rtm->rtm_flags & RTF_ANNOUNCE))
lle->la_flags |= LLE_PUB;
lle->la_flags |= LLE_VALID;
lle->la_expire = rtm->rtm_rmx.rmx_expire;
laflags = lle->la_flags;
/* Try to link new entry */
lle_tmp = NULL;
IF_AFDATA_WLOCK(ifp);
LLE_WLOCK(lle);
lle_tmp = lla_lookup(llt, LLE_EXCLUSIVE, dst);
if (lle_tmp != NULL) {
/* Check if we are trying to replace immutable entry */
if ((lle_tmp->la_flags & LLE_IFADDR) != 0) {
IF_AFDATA_WUNLOCK(ifp);
LLE_WUNLOCK(lle_tmp);
lltable_free_entry(llt, lle);
return (EPERM);
}
/* Unlink existing entry from table */
lltable_unlink_entry(llt, lle_tmp);
}
lltable_link_entry(llt, lle);
IF_AFDATA_WUNLOCK(ifp);
if (lle_tmp != NULL) {
EVENTHANDLER_INVOKE(lle_event, lle_tmp,LLENTRY_EXPIRED);
lltable_free_entry(llt, lle_tmp);
}
/*
* By invoking LLE handler here we might get
* two events on static LLE entry insertion
* in routing socket. However, since we might have
* other subscribers we need to generate this event.
*/
EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_RESOLVED);
LLE_WUNLOCK(lle);
#ifdef INET
/* gratuitous ARP */
if ((laflags & LLE_PUB) && dst->sa_family == AF_INET)
arprequest(ifp,
&((struct sockaddr_in *)dst)->sin_addr,
&((struct sockaddr_in *)dst)->sin_addr,
(u_char *)LLADDR(dl));
#endif
break;
case RTM_DELETE:
return (lltable_delete_addr(llt, 0, dst));
default:
error = EINVAL;
}
return (error);
}
static void
vnet_lltable_init()
{
SLIST_INIT(&V_lltables);
}
VNET_SYSINIT(vnet_lltable_init, SI_SUB_PSEUDO, SI_ORDER_FIRST,
vnet_lltable_init, NULL);
#ifdef DDB
struct llentry_sa {
struct llentry base;
struct sockaddr l3_addr;
};
static void
llatbl_lle_show(struct llentry_sa *la)
{
struct llentry *lle;
uint8_t octet[6];
lle = &la->base;
db_printf("lle=%p\n", lle);
db_printf(" lle_next=%p\n", lle->lle_next.le_next);
db_printf(" lle_lock=%p\n", &lle->lle_lock);
db_printf(" lle_tbl=%p\n", lle->lle_tbl);
db_printf(" lle_head=%p\n", lle->lle_head);
db_printf(" la_hold=%p\n", lle->la_hold);
db_printf(" la_numheld=%d\n", lle->la_numheld);
db_printf(" la_expire=%ju\n", (uintmax_t)lle->la_expire);
db_printf(" la_flags=0x%04x\n", lle->la_flags);
db_printf(" la_asked=%u\n", lle->la_asked);
db_printf(" la_preempt=%u\n", lle->la_preempt);
db_printf(" ln_byhint=%u\n", lle->ln_byhint);
db_printf(" ln_state=%d\n", lle->ln_state);
db_printf(" ln_router=%u\n", lle->ln_router);
db_printf(" ln_ntick=%ju\n", (uintmax_t)lle->ln_ntick);
db_printf(" lle_refcnt=%d\n", lle->lle_refcnt);
bcopy(&lle->ll_addr.mac16, octet, sizeof(octet));
db_printf(" ll_addr=%02x:%02x:%02x:%02x:%02x:%02x\n",
octet[0], octet[1], octet[2], octet[3], octet[4], octet[5]);
db_printf(" lle_timer=%p\n", &lle->lle_timer);
switch (la->l3_addr.sa_family) {
#ifdef INET
case AF_INET:
{
struct sockaddr_in *sin;
char l3s[INET_ADDRSTRLEN];
sin = (struct sockaddr_in *)&la->l3_addr;
inet_ntoa_r(sin->sin_addr, l3s);
db_printf(" l3_addr=%s\n", l3s);
break;
}
#endif
#ifdef INET6
case AF_INET6:
{
struct sockaddr_in6 *sin6;
char l3s[INET6_ADDRSTRLEN];
sin6 = (struct sockaddr_in6 *)&la->l3_addr;
ip6_sprintf(l3s, &sin6->sin6_addr);
db_printf(" l3_addr=%s\n", l3s);
break;
}
#endif
default:
db_printf(" l3_addr=N/A (af=%d)\n", la->l3_addr.sa_family);
break;
}
}
DB_SHOW_COMMAND(llentry, db_show_llentry)
{
if (!have_addr) {
db_printf("usage: show llentry <struct llentry *>\n");
return;
}
llatbl_lle_show((struct llentry_sa *)addr);
}
static void
llatbl_llt_show(struct lltable *llt)
{
int i;
struct llentry *lle;
db_printf("llt=%p llt_af=%d llt_ifp=%p\n",
llt, llt->llt_af, llt->llt_ifp);
for (i = 0; i < llt->llt_hsize; i++) {
LIST_FOREACH(lle, &llt->lle_head[i], lle_next) {
llatbl_lle_show((struct llentry_sa *)lle);
if (db_pager_quit)
return;
}
}
}
DB_SHOW_COMMAND(lltable, db_show_lltable)
{
if (!have_addr) {
db_printf("usage: show lltable <struct lltable *>\n");
return;
}
llatbl_llt_show((struct lltable *)addr);
}
DB_SHOW_ALL_COMMAND(lltables, db_show_all_lltables)
{
VNET_ITERATOR_DECL(vnet_iter);
struct lltable *llt;
VNET_FOREACH(vnet_iter) {
CURVNET_SET_QUIET(vnet_iter);
#ifdef VIMAGE
db_printf("vnet=%p\n", curvnet);
#endif
SLIST_FOREACH(llt, &V_lltables, llt_link) {
db_printf("llt=%p llt_af=%d llt_ifp=%p(%s)\n",
llt, llt->llt_af, llt->llt_ifp,
(llt->llt_ifp != NULL) ?
llt->llt_ifp->if_xname : "?");
if (have_addr && addr != 0) /* verbose */
llatbl_llt_show(llt);
if (db_pager_quit) {
CURVNET_RESTORE();
return;
}
}
CURVNET_RESTORE();
}
}
#endif