From af5333e0a02b2295304d4e029b15ee15a4fe2b3a Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Mon, 4 Nov 2013 11:33:00 +0100 Subject: Update to FreeBSD 8.4 --- freebsd/sys/kern/kern_hhook.c | 456 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 456 insertions(+) create mode 100644 freebsd/sys/kern/kern_hhook.c (limited to 'freebsd/sys/kern/kern_hhook.c') diff --git a/freebsd/sys/kern/kern_hhook.c b/freebsd/sys/kern/kern_hhook.c new file mode 100644 index 00000000..3a5503a6 --- /dev/null +++ b/freebsd/sys/kern/kern_hhook.c @@ -0,0 +1,456 @@ +#include + +/*- + * Copyright (c) 2010 Lawrence Stewart + * 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 +__FBSDID("$FreeBSD$"); + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +struct hhook { + hhook_func_t hhk_func; + struct helper *hhk_helper; + void *hhk_udata; + STAILQ_ENTRY(hhook) hhk_next; +}; + +static MALLOC_DEFINE(M_HHOOK, "hhook", "Helper hooks are linked off hhook_head lists"); + +LIST_HEAD(hhookheadhead, hhook_head); +VNET_DEFINE(struct hhookheadhead, hhook_head_list); +#define V_hhook_head_list VNET(hhook_head_list) + +static struct mtx hhook_head_list_lock; +MTX_SYSINIT(hhookheadlistlock, &hhook_head_list_lock, "hhook_head list lock", + MTX_DEF); + +/* Private function prototypes. */ +static void hhook_head_destroy(struct hhook_head *hhh); + +#define HHHLIST_LOCK() mtx_lock(&hhook_head_list_lock) +#define HHHLIST_UNLOCK() mtx_unlock(&hhook_head_list_lock) +#define HHHLIST_LOCK_ASSERT() mtx_assert(&hhook_head_list_lock, MA_OWNED) + +#define HHH_LOCK_INIT(hhh) rm_init(&(hhh)->hhh_lock, "hhook_head rm lock") +#define HHH_LOCK_DESTROY(hhh) rm_destroy(&(hhh)->hhh_lock) +#define HHH_WLOCK(hhh) rm_wlock(&(hhh)->hhh_lock) +#define HHH_WUNLOCK(hhh) rm_wunlock(&(hhh)->hhh_lock) +#define HHH_RLOCK(hhh, rmpt) rm_rlock(&(hhh)->hhh_lock, (rmpt)) +#define HHH_RUNLOCK(hhh, rmpt) rm_runlock(&(hhh)->hhh_lock, (rmpt)) + +/* + * Run all helper hook functions for a given hook point. + */ +void +hhook_run_hooks(struct hhook_head *hhh, void *ctx_data, struct osd *hosd) +{ + struct hhook *hhk; + void *hdata; + struct rm_priotracker rmpt; + + KASSERT(hhh->hhh_refcount > 0, ("hhook_head %p refcount is 0", hhh)); + + HHH_RLOCK(hhh, &rmpt); + STAILQ_FOREACH(hhk, &hhh->hhh_hooks, hhk_next) { + if (hhk->hhk_helper->h_flags & HELPER_NEEDS_OSD) { + hdata = osd_get(OSD_KHELP, hosd, hhk->hhk_helper->h_id); + if (hdata == NULL) + continue; + } else + hdata = NULL; + + /* + * XXXLAS: We currently ignore the int returned by the hook, + * but will likely want to handle it in future to allow hhook to + * be used like pfil and effect changes at the hhook calling + * site e.g. we could define a new hook type of HHOOK_TYPE_PFIL + * and standardise what particular return values mean and set + * the context data to pass exactly the same information as pfil + * hooks currently receive, thus replicating pfil with hhook. + */ + hhk->hhk_func(hhh->hhh_type, hhh->hhh_id, hhk->hhk_udata, + ctx_data, hdata, hosd); + } + HHH_RUNLOCK(hhh, &rmpt); +} + +/* + * Register a new helper hook function with a helper hook point. + */ +int +hhook_add_hook(struct hhook_head *hhh, struct hookinfo *hki, uint32_t flags) +{ + struct hhook *hhk, *tmp; + int error; + + error = 0; + + if (hhh == NULL) + return (ENOENT); + + hhk = malloc(sizeof(struct hhook), M_HHOOK, + M_ZERO | ((flags & HHOOK_WAITOK) ? M_WAITOK : M_NOWAIT)); + + if (hhk == NULL) + return (ENOMEM); + + hhk->hhk_helper = hki->hook_helper; + hhk->hhk_func = hki->hook_func; + hhk->hhk_udata = hki->hook_udata; + + HHH_WLOCK(hhh); + STAILQ_FOREACH(tmp, &hhh->hhh_hooks, hhk_next) { + if (tmp->hhk_func == hki->hook_func && + tmp->hhk_udata == hki->hook_udata) { + /* The helper hook function is already registered. */ + error = EEXIST; + break; + } + } + + if (!error) { + STAILQ_INSERT_TAIL(&hhh->hhh_hooks, hhk, hhk_next); + hhh->hhh_nhooks++; + } else + free(hhk, M_HHOOK); + + HHH_WUNLOCK(hhh); + + return (error); +} + +/* + * Lookup a helper hook point and register a new helper hook function with it. + */ +int +hhook_add_hook_lookup(struct hookinfo *hki, uint32_t flags) +{ + struct hhook_head *hhh; + int error; + + hhh = hhook_head_get(hki->hook_type, hki->hook_id); + + if (hhh == NULL) + return (ENOENT); + + error = hhook_add_hook(hhh, hki, flags); + hhook_head_release(hhh); + + return (error); +} + +/* + * Remove a helper hook function from a helper hook point. + */ +int +hhook_remove_hook(struct hhook_head *hhh, struct hookinfo *hki) +{ + struct hhook *tmp; + + if (hhh == NULL) + return (ENOENT); + + HHH_WLOCK(hhh); + STAILQ_FOREACH(tmp, &hhh->hhh_hooks, hhk_next) { + if (tmp->hhk_func == hki->hook_func && + tmp->hhk_udata == hki->hook_udata) { + STAILQ_REMOVE(&hhh->hhh_hooks, tmp, hhook, hhk_next); + free(tmp, M_HHOOK); + hhh->hhh_nhooks--; + break; + } + } + HHH_WUNLOCK(hhh); + + return (0); +} + +/* + * Lookup a helper hook point and remove a helper hook function from it. + */ +int +hhook_remove_hook_lookup(struct hookinfo *hki) +{ + struct hhook_head *hhh; + + hhh = hhook_head_get(hki->hook_type, hki->hook_id); + + if (hhh == NULL) + return (ENOENT); + + hhook_remove_hook(hhh, hki); + hhook_head_release(hhh); + + return (0); +} + +/* + * Register a new helper hook point. + */ +int +hhook_head_register(int32_t hhook_type, int32_t hhook_id, struct hhook_head **hhh, + uint32_t flags) +{ + struct hhook_head *tmphhh; + + tmphhh = hhook_head_get(hhook_type, hhook_id); + + if (tmphhh != NULL) { + /* Hook point previously registered. */ + hhook_head_release(tmphhh); + return (EEXIST); + } + + /* XXXLAS: Need to implement support for non-virtualised hooks. */ + if ((flags & HHOOK_HEADISINVNET) == 0) { + printf("%s: only vnet-style virtualised hooks can be used\n", + __func__); + return (EINVAL); + } + + tmphhh = malloc(sizeof(struct hhook_head), M_HHOOK, + M_ZERO | ((flags & HHOOK_WAITOK) ? M_WAITOK : M_NOWAIT)); + + if (tmphhh == NULL) + return (ENOMEM); + + tmphhh->hhh_type = hhook_type; + tmphhh->hhh_id = hhook_id; + tmphhh->hhh_nhooks = 0; + STAILQ_INIT(&tmphhh->hhh_hooks); + HHH_LOCK_INIT(tmphhh); + + if (hhh != NULL) + refcount_init(&tmphhh->hhh_refcount, 1); + else + refcount_init(&tmphhh->hhh_refcount, 0); + + if (flags & HHOOK_HEADISINVNET) { + tmphhh->hhh_flags |= HHH_ISINVNET; + HHHLIST_LOCK(); + LIST_INSERT_HEAD(&V_hhook_head_list, tmphhh, hhh_next); + HHHLIST_UNLOCK(); + } else { + /* XXXLAS: Add tmphhh to the non-virtualised list. */ + } + + *hhh = tmphhh; + + return (0); +} + +static void +hhook_head_destroy(struct hhook_head *hhh) +{ + struct hhook *tmp, *tmp2; + + HHHLIST_LOCK_ASSERT(); + + LIST_REMOVE(hhh, hhh_next); + HHH_WLOCK(hhh); + STAILQ_FOREACH_SAFE(tmp, &hhh->hhh_hooks, hhk_next, tmp2) + free(tmp, M_HHOOK); + HHH_WUNLOCK(hhh); + HHH_LOCK_DESTROY(hhh); + free(hhh, M_HHOOK); +} + +/* + * Remove a helper hook point. + */ +int +hhook_head_deregister(struct hhook_head *hhh) +{ + int error; + + error = 0; + + HHHLIST_LOCK(); + if (hhh == NULL) + error = ENOENT; + else if (hhh->hhh_refcount > 1) + error = EBUSY; + else + hhook_head_destroy(hhh); + HHHLIST_UNLOCK(); + + return (error); +} + +/* + * Remove a helper hook point via a hhook_head lookup. + */ +int +hhook_head_deregister_lookup(int32_t hhook_type, int32_t hhook_id) +{ + struct hhook_head *hhh; + int error; + + hhh = hhook_head_get(hhook_type, hhook_id); + error = hhook_head_deregister(hhh); + + if (error == EBUSY) + hhook_head_release(hhh); + + return (error); +} + +/* + * Lookup and return the hhook_head struct associated with the specified type + * and id, or NULL if not found. If found, the hhook_head's refcount is bumped. + */ +struct hhook_head * +hhook_head_get(int32_t hhook_type, int32_t hhook_id) +{ + struct hhook_head *hhh; + + /* XXXLAS: Pick hhook_head_list based on hhook_head flags. */ + HHHLIST_LOCK(); + LIST_FOREACH(hhh, &V_hhook_head_list, hhh_next) { + if (hhh->hhh_type == hhook_type && hhh->hhh_id == hhook_id) { + refcount_acquire(&hhh->hhh_refcount); + break; + } + } + HHHLIST_UNLOCK(); + + return (hhh); +} + +void +hhook_head_release(struct hhook_head *hhh) +{ + + refcount_release(&hhh->hhh_refcount); +} + +/* + * Check the hhook_head private flags and return the appropriate public + * representation of the flag to the caller. The function is implemented in a + * way that allows us to cope with other subsystems becoming virtualised in the + * future. + */ +uint32_t +hhook_head_is_virtualised(struct hhook_head *hhh) +{ + uint32_t ret; + + ret = 0; + + if (hhh != NULL) { + if (hhh->hhh_flags & HHH_ISINVNET) + ret = HHOOK_HEADISINVNET; + } + + return (ret); +} + +uint32_t +hhook_head_is_virtualised_lookup(int32_t hook_type, int32_t hook_id) +{ + struct hhook_head *hhh; + uint32_t ret; + + hhh = hhook_head_get(hook_type, hook_id); + + if (hhh == NULL) + return (0); + + ret = hhook_head_is_virtualised(hhh); + hhook_head_release(hhh); + + return (ret); +} + +/* + * Vnet created and being initialised. + */ +static void +hhook_vnet_init(const void *unused __unused) +{ + + LIST_INIT(&V_hhook_head_list); +} + +/* + * Vnet being torn down and destroyed. + */ +static void +hhook_vnet_uninit(const void *unused __unused) +{ + struct hhook_head *hhh, *tmphhh; + + /* + * If subsystems which export helper hook points use the hhook KPI + * correctly, the loop below should have no work to do because the + * subsystem should have already called hhook_head_deregister(). + */ + HHHLIST_LOCK(); + LIST_FOREACH_SAFE(hhh, &V_hhook_head_list, hhh_next, tmphhh) { + printf("%s: hhook_head type=%d, id=%d cleanup required\n", + __func__, hhh->hhh_type, hhh->hhh_id); + hhook_head_destroy(hhh); + } + HHHLIST_UNLOCK(); +} + + +/* + * When a vnet is created and being initialised, init the V_hhook_head_list. + */ +VNET_SYSINIT(hhook_vnet_init, SI_SUB_PROTO_BEGIN, SI_ORDER_FIRST, + hhook_vnet_init, NULL); + +/* + * The hhook KPI provides a mechanism for subsystems which export helper hook + * points to clean up on vnet tear down, but in case the KPI is misused, + * provide a function to clean up and free memory for a vnet being destroyed. + */ +VNET_SYSUNINIT(hhook_vnet_uninit, SI_SUB_PROTO_BEGIN, SI_ORDER_FIRST, + hhook_vnet_uninit, NULL); -- cgit v1.2.3