#include <machine/rtems-bsd-kernel-space.h>
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2010,2013 Lawrence Stewart <lstewart@freebsd.org>
* Copyright (c) 2010 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Lawrence Stewart while studying at the Centre
* for Advanced Internet Architectures, Swinburne University of Technology,
* made possible in part by grants from the FreeBSD Foundation and Cisco
* University Research Program Fund at Community Foundation Silicon Valley.
*
* Portions of this software were developed at the Centre for Advanced
* Internet Architectures, Swinburne University of Technology, Melbourne,
* Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation.
*
* 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("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/hhook.h>
#include <sys/khelp.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/module_khelp.h>
#include <sys/osd.h>
#include <sys/queue.h>
#include <sys/refcount.h>
#include <sys/rwlock.h>
#include <sys/systm.h>
static struct rwlock khelp_list_lock;
RW_SYSINIT(khelplistlock, &khelp_list_lock, "helper list lock");
static TAILQ_HEAD(helper_head, helper) helpers = TAILQ_HEAD_INITIALIZER(helpers);
/* Private function prototypes. */
static inline void khelp_remove_osd(struct helper *h, struct osd *hosd);
void khelp_new_hhook_registered(struct hhook_head *hhh, uint32_t flags);
#define KHELP_LIST_WLOCK() rw_wlock(&khelp_list_lock)
#define KHELP_LIST_WUNLOCK() rw_wunlock(&khelp_list_lock)
#define KHELP_LIST_RLOCK() rw_rlock(&khelp_list_lock)
#define KHELP_LIST_RUNLOCK() rw_runlock(&khelp_list_lock)
#define KHELP_LIST_LOCK_ASSERT() rw_assert(&khelp_list_lock, RA_LOCKED)
int
khelp_register_helper(struct helper *h)
{
struct helper *tmph;
int error, i, inserted;
error = inserted = 0;
refcount_init(&h->h_refcount, 0);
h->h_id = osd_register(OSD_KHELP, NULL, NULL);
/* It's only safe to add the hooks after osd_register(). */
for (i = 0; i < h->h_nhooks && !error; i++) {
/* We don't require the module to assign hook_helper. */
h->h_hooks[i].hook_helper = h;
error = hhook_add_hook_lookup(&h->h_hooks[i], HHOOK_WAITOK);
if (error)
printf("%s: \"%s\" khelp module unable to "
"hook type %d id %d due to error %d\n", __func__,
h->h_name, h->h_hooks[i].hook_type,
h->h_hooks[i].hook_id, error);
}
if (error) {
for (i--; i >= 0; i--)
hhook_remove_hook_lookup(&h->h_hooks[i]);
osd_deregister(OSD_KHELP, h->h_id);
} else {
KHELP_LIST_WLOCK();
/*
* Keep list of helpers sorted in descending h_id order. Due to
* the way osd_set() works, a sorted list ensures
* khelp_init_osd() will operate with improved efficiency.
*/
TAILQ_FOREACH(tmph, &helpers, h_next) {
if (tmph->h_id < h->h_id) {
TAILQ_INSERT_BEFORE(tmph, h, h_next);
inserted = 1;
break;
}
}
if (!inserted)
TAILQ_INSERT_TAIL(&helpers, h, h_next);
KHELP_LIST_WUNLOCK();
}
return (error);
}
int
khelp_deregister_helper(struct helper *h)
{
struct helper *tmph;
int error, i;
KHELP_LIST_WLOCK();
if (h->h_refcount > 0)
error = EBUSY;
else {
error = ENOENT;
TAILQ_FOREACH(tmph, &helpers, h_next) {
if (tmph == h) {
TAILQ_REMOVE(&helpers, h, h_next);
error = 0;
break;
}
}
}
KHELP_LIST_WUNLOCK();
if (!error) {
for (i = 0; i < h->h_nhooks; i++)
hhook_remove_hook_lookup(&h->h_hooks[i]);
osd_deregister(OSD_KHELP, h->h_id);
}
return (error);
}
int
khelp_init_osd(uint32_t classes, struct osd *hosd)
{
struct helper *h;
void *hdata;
int error;
KASSERT(hosd != NULL, ("struct osd not initialised!"));
error = 0;
KHELP_LIST_RLOCK();
TAILQ_FOREACH(h, &helpers, h_next) {
/* If helper is correct class and needs to store OSD... */
if (h->h_classes & classes && h->h_flags & HELPER_NEEDS_OSD) {
hdata = uma_zalloc(h->h_zone, M_NOWAIT);
if (hdata == NULL) {
error = ENOMEM;
break;
}
osd_set(OSD_KHELP, hosd, h->h_id, hdata);
refcount_acquire(&h->h_refcount);
}
}
if (error) {
/* Delete OSD that was assigned prior to the error. */
TAILQ_FOREACH(h, &helpers, h_next) {
if (h->h_classes & classes)
khelp_remove_osd(h, hosd);
}
}
KHELP_LIST_RUNLOCK();
return (error);
}
int
khelp_destroy_osd(struct osd *hosd)
{
struct helper *h;
int error;
KASSERT(hosd != NULL, ("struct osd not initialised!"));
error = 0;
KHELP_LIST_RLOCK();
/*
* Clean up all khelp related OSD.
*
* XXXLAS: Would be nice to use something like osd_exit() here but it
* doesn't have the right semantics for this purpose.
*/
TAILQ_FOREACH(h, &helpers, h_next)
khelp_remove_osd(h, hosd);
KHELP_LIST_RUNLOCK();
return (error);
}
static inline void
khelp_remove_osd(struct helper *h, struct osd *hosd)
{
void *hdata;
if (h->h_flags & HELPER_NEEDS_OSD) {
/*
* If the current helper uses OSD and calling osd_get()
* on the helper's h_id returns non-NULL, the helper has
* OSD attached to 'hosd' which needs to be cleaned up.
*/
hdata = osd_get(OSD_KHELP, hosd, h->h_id);
if (hdata != NULL) {
uma_zfree(h->h_zone, hdata);
osd_del(OSD_KHELP, hosd, h->h_id);
refcount_release(&h->h_refcount);
}
}
}
void *
khelp_get_osd(struct osd *hosd, int32_t id)
{
return (osd_get(OSD_KHELP, hosd, id));
}
int32_t
khelp_get_id(char *hname)
{
struct helper *h;
int32_t id;
id = -1;
KHELP_LIST_RLOCK();
TAILQ_FOREACH(h, &helpers, h_next) {
if (strncmp(h->h_name, hname, HELPER_NAME_MAXLEN) == 0) {
id = h->h_id;
break;
}
}
KHELP_LIST_RUNLOCK();
return (id);
}
int
khelp_add_hhook(struct hookinfo *hki, uint32_t flags)
{
int error;
/*
* XXXLAS: Should probably include the functionality to update the
* helper's h_hooks struct member.
*/
error = hhook_add_hook_lookup(hki, flags);
return (error);
}
int
khelp_remove_hhook(struct hookinfo *hki)
{
int error;
/*
* XXXLAS: Should probably include the functionality to update the
* helper's h_hooks struct member.
*/
error = hhook_remove_hook_lookup(hki);
return (error);
}
/*
* Private KPI between hhook and khelp that allows khelp modules to insert hook
* functions into hhook points which register after the modules were loaded.
*/
void
khelp_new_hhook_registered(struct hhook_head *hhh, uint32_t flags)
{
struct helper *h;
int error, i;
KHELP_LIST_RLOCK();
TAILQ_FOREACH(h, &helpers, h_next) {
for (i = 0; i < h->h_nhooks; i++) {
if (hhh->hhh_type != h->h_hooks[i].hook_type ||
hhh->hhh_id != h->h_hooks[i].hook_id)
continue;
error = hhook_add_hook(hhh, &h->h_hooks[i], flags);
if (error) {
printf("%s: \"%s\" khelp module unable to "
"hook type %d id %d due to error %d\n",
__func__, h->h_name,
h->h_hooks[i].hook_type,
h->h_hooks[i].hook_id, error);
error = 0;
}
}
}
KHELP_LIST_RUNLOCK();
}
#ifndef __rtems__
int
khelp_modevent(module_t mod, int event_type, void *data)
{
struct khelp_modevent_data *kmd;
int error;
kmd = (struct khelp_modevent_data *)data;
error = 0;
switch(event_type) {
case MOD_LOAD:
if (kmd->helper->h_flags & HELPER_NEEDS_OSD) {
if (kmd->uma_zsize <= 0) {
printf("Use KHELP_DECLARE_MOD_UMA() instead!\n");
error = EDOOFUS;
break;
}
kmd->helper->h_zone = uma_zcreate(kmd->name,
kmd->uma_zsize, kmd->umactor, kmd->umadtor, NULL,
NULL, 0, 0);
if (kmd->helper->h_zone == NULL) {
error = ENOMEM;
break;
}
}
strlcpy(kmd->helper->h_name, kmd->name, HELPER_NAME_MAXLEN);
kmd->helper->h_hooks = kmd->hooks;
kmd->helper->h_nhooks = kmd->nhooks;
if (kmd->helper->mod_init != NULL)
error = kmd->helper->mod_init();
if (!error)
error = khelp_register_helper(kmd->helper);
break;
case MOD_QUIESCE:
case MOD_SHUTDOWN:
case MOD_UNLOAD:
error = khelp_deregister_helper(kmd->helper);
if (!error) {
if (kmd->helper->h_flags & HELPER_NEEDS_OSD)
uma_zdestroy(kmd->helper->h_zone);
if (kmd->helper->mod_destroy != NULL)
kmd->helper->mod_destroy();
} else if (error == ENOENT)
/* Do nothing and allow unload if helper not in list. */
error = 0;
else if (error == EBUSY)
printf("Khelp module \"%s\" can't unload until its "
"refcount drops from %d to 0.\n", kmd->name,
kmd->helper->h_refcount);
break;
default:
error = EINVAL;
break;
}
return (error);
}
#endif /* __rtems__ */
