freebsd-skq/sys/netinet/libalias/alias_mod.c
piso 9ddea13291 o made in kernel libalias mpsafe
o fixed a comment
o made in kernel libalias a bit less verbose (disabled automatic
  logging everytime a new link is added or deleted)

Approved by: glebius (mentor)
2006-12-15 12:50:06 +00:00

285 lines
5.9 KiB
C

/*-
* Copyright (c) 2005 Paolo Pisati <piso@FreeBSD.org>
* 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 THE 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 THE 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("$FreeBSD$");
#ifdef _KERNEL
#include <sys/libkern.h>
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/rwlock.h>
#else
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <errno.h>
#endif
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#ifdef _KERNEL
#include <netinet/libalias/alias_local.h>
#include <netinet/libalias/alias_mod.h>
#else
#include "alias_local.h"
#include "alias_mod.h"
#endif
/* Protocol and userland module handlers chains. */
LIST_HEAD(handler_chain, proto_handler) handler_chain = LIST_HEAD_INITIALIZER(foo);
#ifdef _KERNEL
struct rwlock handler_rw;
#endif
SLIST_HEAD(dll_chain, dll) dll_chain = SLIST_HEAD_INITIALIZER(foo);
#ifdef _KERNEL
#define LIBALIAS_RWLOCK_INIT() \
rw_init(&handler_rw, "Libalias_modules_rwlock")
#define LIBALIAS_RWLOCK_DESTROY() rw_destroy(&handler_rw)
#define LIBALIAS_WLOCK_ASSERT() \
rw_assert(&handler_rw, RA_WLOCKED)
static __inline void
LIBALIAS_RLOCK(void)
{
rw_rlock(&handler_rw);
}
static __inline void
LIBALIAS_RUNLOCK(void)
{
rw_runlock(&handler_rw);
}
static __inline void
LIBALIAS_WLOCK(void)
{
rw_wlock(&handler_rw);
}
static __inline void
LIBALIAS_WUNLOCK(void)
{
rw_wunlock(&handler_rw);
}
static void
_handler_chain_init(void)
{
if (!rw_initialized(&handler_rw))
LIBALIAS_RWLOCK_INIT();
}
static void
_handler_chain_destroy(void)
{
if (rw_initialized(&handler_rw))
LIBALIAS_RWLOCK_DESTROY();
}
#else
#define LIBALIAS_RWLOCK_INIT() ;
#define LIBALIAS_RWLOCK_DESTROY() ;
#define LIBALIAS_WLOCK_ASSERT() ;
#define LIBALIAS_RLOCK() ;
#define LIBALIAS_RUNLOCK() ;
#define LIBALIAS_WLOCK() ;
#define LIBALIAS_WUNLOCK() ;
#define _handler_chain_init() ;
#define _handler_chain_destroy() ;
#endif
void
handler_chain_init(void)
{
_handler_chain_init();
}
void
handler_chain_destroy(void)
{
_handler_chain_destroy();
}
static int
_attach_handler(struct proto_handler *p)
{
struct proto_handler *b = NULL;
LIBALIAS_WLOCK_ASSERT();
LIST_FOREACH(b, &handler_chain, entries) {
if ((b->pri == p->pri) &&
(b->dir == p->dir) &&
(b->proto == p->proto))
return (EEXIST); /* Priority conflict. */
if (b->pri > p->pri) {
LIST_INSERT_BEFORE(b, p, entries);
return (0);
}
}
/* End of list or found right position, inserts here. */
if (b)
LIST_INSERT_AFTER(b, p, entries);
else
LIST_INSERT_HEAD(&handler_chain, p, entries);
return (0);
}
static int
_detach_handler(struct proto_handler *p)
{
struct proto_handler *b, *b_tmp;;
LIBALIAS_WLOCK_ASSERT();
LIST_FOREACH_SAFE(b, &handler_chain, entries, b_tmp) {
if (b == p) {
LIST_REMOVE(b, entries);
return (0);
}
}
return (ENOENT); /* Handler not found. */
}
int
LibAliasAttachHandlers(struct proto_handler *_p)
{
int i, error = -1;
LIBALIAS_WLOCK();
for (i=0; 1; i++) {
if (*((int *)&_p[i]) == EOH)
break;
error = _attach_handler(&_p[i]);
if (error != 0)
break;
}
LIBALIAS_WUNLOCK();
return (error);
}
int
LibAliasDetachHandlers(struct proto_handler *_p)
{
int i, error = -1;
LIBALIAS_WLOCK();
for (i=0; 1; i++) {
if (*((int *)&_p[i]) == EOH)
break;
error = _detach_handler(&_p[i]);
if (error != 0)
break;
}
LIBALIAS_WUNLOCK();
return (error);
}
int
detach_handler(struct proto_handler *_p)
{
int error = -1;
LIBALIAS_WLOCK();
error = _detach_handler(_p);
LIBALIAS_WUNLOCK();
return (error);
}
int
find_handler(int8_t dir, int8_t proto, struct libalias *la, struct ip *pip,
struct alias_data *ad)
{
struct proto_handler *p;
int error = ENOENT;
LIBALIAS_RLOCK();
LIST_FOREACH(p, &handler_chain, entries) {
if ((p->dir & dir) && (p->proto & proto))
if (p->fingerprint(la, pip, ad) == 0) {
error = p->protohandler(la, pip, ad);
break;
}
}
LIBALIAS_RUNLOCK();
return (error);
}
struct proto_handler *
first_handler(void)
{
return (LIST_FIRST(&handler_chain));
}
/* Dll manipulation code - this code is not thread safe... */
int
attach_dll(struct dll *p)
{
struct dll *b;
SLIST_FOREACH(b, &dll_chain, next) {
if (!strncmp(b->name, p->name, DLL_LEN))
return (EEXIST); /* Dll name conflict. */
}
SLIST_INSERT_HEAD(&dll_chain, p, next);
return (0);
}
void *
detach_dll(char *p)
{
struct dll *b = NULL, *b_tmp;
void *error = NULL;
SLIST_FOREACH_SAFE(b, &dll_chain, next, b_tmp)
if (!strncmp(b->name, p, DLL_LEN)) {
SLIST_REMOVE(&dll_chain, b, dll, next);
error = b;
break;
}
return (error);
}
struct dll *
walk_dll_chain(void)
{
struct dll *t;
t = SLIST_FIRST(&dll_chain);
if (t == NULL)
return (NULL);
SLIST_REMOVE_HEAD(&dll_chain, next);
return (t);
}