2 * SPDX-License-Identifier: BSD-2-Clause
4 * Copyright (c) 2010,2013 Lawrence Stewart <lstewart@freebsd.org>
5 * Copyright (c) 2010 The FreeBSD Foundation
8 * This software was developed by Lawrence Stewart while studying at the Centre
9 * for Advanced Internet Architectures, Swinburne University of Technology,
10 * made possible in part by grants from the FreeBSD Foundation and Cisco
11 * University Research Program Fund at Community Foundation Silicon Valley.
13 * Portions of this software were developed at the Centre for Advanced
14 * Internet Architectures, Swinburne University of Technology, Melbourne,
15 * Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation.
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 #include <sys/param.h>
40 #include <sys/kernel.h>
41 #include <sys/hhook.h>
42 #include <sys/khelp.h>
44 #include <sys/malloc.h>
45 #include <sys/module.h>
46 #include <sys/module_khelp.h>
48 #include <sys/queue.h>
49 #include <sys/refcount.h>
50 #include <sys/rwlock.h>
51 #include <sys/systm.h>
53 static struct rwlock khelp_list_lock;
54 RW_SYSINIT(khelplistlock, &khelp_list_lock, "helper list lock");
56 static TAILQ_HEAD(helper_head, helper) helpers = TAILQ_HEAD_INITIALIZER(helpers);
58 /* Private function prototypes. */
59 static inline void khelp_remove_osd(struct helper *h, struct osd *hosd);
60 void khelp_new_hhook_registered(struct hhook_head *hhh, uint32_t flags);
62 #define KHELP_LIST_WLOCK() rw_wlock(&khelp_list_lock)
63 #define KHELP_LIST_WUNLOCK() rw_wunlock(&khelp_list_lock)
64 #define KHELP_LIST_RLOCK() rw_rlock(&khelp_list_lock)
65 #define KHELP_LIST_RUNLOCK() rw_runlock(&khelp_list_lock)
66 #define KHELP_LIST_LOCK_ASSERT() rw_assert(&khelp_list_lock, RA_LOCKED)
69 khelp_register_helper(struct helper *h)
72 int error, i, inserted;
75 refcount_init(&h->h_refcount, 0);
76 h->h_id = osd_register(OSD_KHELP, NULL, NULL);
78 /* It's only safe to add the hooks after osd_register(). */
79 for (i = 0; i < h->h_nhooks && !error; i++) {
80 /* We don't require the module to assign hook_helper. */
81 h->h_hooks[i].hook_helper = h;
82 error = hhook_add_hook_lookup(&h->h_hooks[i], HHOOK_WAITOK);
84 printf("%s: \"%s\" khelp module unable to "
85 "hook type %d id %d due to error %d\n", __func__,
86 h->h_name, h->h_hooks[i].hook_type,
87 h->h_hooks[i].hook_id, error);
91 for (i--; i >= 0; i--)
92 hhook_remove_hook_lookup(&h->h_hooks[i]);
93 osd_deregister(OSD_KHELP, h->h_id);
97 * Keep list of helpers sorted in descending h_id order. Due to
98 * the way osd_set() works, a sorted list ensures
99 * khelp_init_osd() will operate with improved efficiency.
101 TAILQ_FOREACH(tmph, &helpers, h_next) {
102 if (tmph->h_id < h->h_id) {
103 TAILQ_INSERT_BEFORE(tmph, h, h_next);
110 TAILQ_INSERT_TAIL(&helpers, h, h_next);
111 KHELP_LIST_WUNLOCK();
118 khelp_deregister_helper(struct helper *h)
124 if (h->h_refcount > 0)
128 TAILQ_FOREACH(tmph, &helpers, h_next) {
130 TAILQ_REMOVE(&helpers, h, h_next);
136 KHELP_LIST_WUNLOCK();
139 for (i = 0; i < h->h_nhooks; i++)
140 hhook_remove_hook_lookup(&h->h_hooks[i]);
141 osd_deregister(OSD_KHELP, h->h_id);
148 khelp_init_osd(uint32_t classes, struct osd *hosd)
154 KASSERT(hosd != NULL, ("struct osd not initialised!"));
159 TAILQ_FOREACH(h, &helpers, h_next) {
160 /* If helper is correct class and needs to store OSD... */
161 if (h->h_classes & classes && h->h_flags & HELPER_NEEDS_OSD) {
162 hdata = uma_zalloc(h->h_zone, M_NOWAIT);
167 osd_set(OSD_KHELP, hosd, h->h_id, hdata);
168 refcount_acquire(&h->h_refcount);
173 /* Delete OSD that was assigned prior to the error. */
174 TAILQ_FOREACH(h, &helpers, h_next) {
175 if (h->h_classes & classes)
176 khelp_remove_osd(h, hosd);
179 KHELP_LIST_RUNLOCK();
185 khelp_destroy_osd(struct osd *hosd)
190 KASSERT(hosd != NULL, ("struct osd not initialised!"));
196 * Clean up all khelp related OSD.
198 * XXXLAS: Would be nice to use something like osd_exit() here but it
199 * doesn't have the right semantics for this purpose.
201 TAILQ_FOREACH(h, &helpers, h_next)
202 khelp_remove_osd(h, hosd);
203 KHELP_LIST_RUNLOCK();
209 khelp_remove_osd(struct helper *h, struct osd *hosd)
213 if (h->h_flags & HELPER_NEEDS_OSD) {
215 * If the current helper uses OSD and calling osd_get()
216 * on the helper's h_id returns non-NULL, the helper has
217 * OSD attached to 'hosd' which needs to be cleaned up.
219 hdata = osd_get(OSD_KHELP, hosd, h->h_id);
221 uma_zfree(h->h_zone, hdata);
222 osd_del(OSD_KHELP, hosd, h->h_id);
223 refcount_release(&h->h_refcount);
229 khelp_get_osd(struct osd *hosd, int32_t id)
232 return (osd_get(OSD_KHELP, hosd, id));
236 khelp_get_id(char *hname)
244 TAILQ_FOREACH(h, &helpers, h_next) {
245 if (strncmp(h->h_name, hname, HELPER_NAME_MAXLEN) == 0) {
250 KHELP_LIST_RUNLOCK();
256 khelp_add_hhook(struct hookinfo *hki, uint32_t flags)
261 * XXXLAS: Should probably include the functionality to update the
262 * helper's h_hooks struct member.
264 error = hhook_add_hook_lookup(hki, flags);
270 khelp_remove_hhook(struct hookinfo *hki)
275 * XXXLAS: Should probably include the functionality to update the
276 * helper's h_hooks struct member.
278 error = hhook_remove_hook_lookup(hki);
284 * Private KPI between hhook and khelp that allows khelp modules to insert hook
285 * functions into hhook points which register after the modules were loaded.
288 khelp_new_hhook_registered(struct hhook_head *hhh, uint32_t flags)
294 TAILQ_FOREACH(h, &helpers, h_next) {
295 for (i = 0; i < h->h_nhooks; i++) {
296 if (hhh->hhh_type != h->h_hooks[i].hook_type ||
297 hhh->hhh_id != h->h_hooks[i].hook_id)
299 error = hhook_add_hook(hhh, &h->h_hooks[i], flags);
301 printf("%s: \"%s\" khelp module unable to "
302 "hook type %d id %d due to error %d\n",
304 h->h_hooks[i].hook_type,
305 h->h_hooks[i].hook_id, error);
310 KHELP_LIST_RUNLOCK();
314 khelp_modevent(module_t mod, int event_type, void *data)
316 struct khelp_modevent_data *kmd;
319 kmd = (struct khelp_modevent_data *)data;
324 if (kmd->helper->h_flags & HELPER_NEEDS_OSD) {
325 if (kmd->uma_zsize <= 0) {
326 printf("Use KHELP_DECLARE_MOD_UMA() instead!\n");
330 kmd->helper->h_zone = uma_zcreate(kmd->name,
331 kmd->uma_zsize, kmd->umactor, kmd->umadtor, NULL,
333 if (kmd->helper->h_zone == NULL) {
338 strlcpy(kmd->helper->h_name, kmd->name, HELPER_NAME_MAXLEN);
339 kmd->helper->h_hooks = kmd->hooks;
340 kmd->helper->h_nhooks = kmd->nhooks;
341 if (kmd->helper->mod_init != NULL)
342 error = kmd->helper->mod_init();
344 error = khelp_register_helper(kmd->helper);
350 error = khelp_deregister_helper(kmd->helper);
352 if (kmd->helper->h_flags & HELPER_NEEDS_OSD)
353 uma_zdestroy(kmd->helper->h_zone);
354 if (kmd->helper->mod_destroy != NULL)
355 kmd->helper->mod_destroy();
356 } else if (error == ENOENT)
357 /* Do nothing and allow unload if helper not in list. */
359 else if (error == EBUSY && event_type != MOD_SHUTDOWN)
360 printf("Khelp module \"%s\" can't unload until its "
361 "refcount drops from %d to 0.\n", kmd->name,
362 kmd->helper->h_refcount);