833 lines
22 KiB
C
833 lines
22 KiB
C
/*-
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* Copyright (c) 2002 Dima Dorfman.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/*
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* DEVFS ruleset implementation.
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*
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* A note on terminology: To "run" a rule on a dirent is to take the
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* prescribed action; to "apply" a rule is to check whether it matches
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* a dirent and run if if it does.
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*
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* A note on locking: Only foreign entry points (non-static functions)
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* should deal with locking. Everything else assumes we already hold
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* the required kind of lock.
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*
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* A note on namespace: devfs_rules_* are the non-static functions for
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* the entire "ruleset" subsystem, devfs_rule_* are the static
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* functions that operate on rules, and devfs_ruleset_* are the static
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* functions that operate on rulesets. The line between the last two
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* isn't always clear, but the guideline is still useful.
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*
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* A note on "special" identifiers: Ruleset 0 is the NULL, or empty,
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* ruleset; it cannot be deleted or changed in any way. This may be
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* assumed inside the code; e.g., a ruleset of 0 may be interpeted to
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* mean "no ruleset". The interpretation of rule 0 is
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* command-dependent, but in no case is there a real rule with number
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* 0.
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*
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* A note on errno codes: To make it easier for the userland to tell
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* what went wrong, we sometimes use errno codes that are not entirely
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* appropriate for the error but that would be less ambiguous than the
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* appropriate "generic" code. For example, when we can't find a
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* ruleset, we return ESRCH instead of ENOENT (except in
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* DEVFSIO_{R,S}GETNEXT, where a nonexistent ruleset means "end of
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* list", and the userland expects ENOENT to be this indicator); this
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* way, when an operation fails, it's clear that what couldn't be
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* found is a ruleset and not a rule (well, it's clear to those who
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* know the convention).
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*/
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#include "opt_devfs.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/conf.h>
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#include <sys/kernel.h>
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#include <sys/malloc.h>
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#include <sys/dirent.h>
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#include <sys/vnode.h>
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#include <sys/mount.h>
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#include <sys/ioccom.h>
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#include <fs/devfs/devfs.h>
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/*
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* Kernel version of devfs_rule.
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*/
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struct devfs_krule {
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SLIST_ENTRY(devfs_krule) dk_list;
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struct devfs_ruleset *dk_ruleset;
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struct devfs_rule dk_rule;
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};
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/*
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* Structure to describe a ruleset.
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*/
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struct devfs_ruleset {
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SLIST_ENTRY(devfs_ruleset) ds_list;
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devfs_rsnum ds_number;
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SLIST_HEAD(, devfs_krule) ds_rules;
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int ds_refcount;
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int ds_flags;
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#define DS_IMMUTABLE 0x001
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int ds_running;
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};
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static devfs_rid devfs_rid_input(devfs_rid rid, struct devfs_mount *dm);
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static void devfs_rule_applyde(struct devfs_krule *dk,struct devfs_dirent *de);
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static void devfs_rule_applyde_recursive(struct devfs_krule *dk,
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struct devfs_dirent *de);
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static void devfs_rule_applydm(struct devfs_krule *dk, struct devfs_mount *dm);
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static int devfs_rule_autonumber(struct devfs_ruleset *ds, devfs_rnum *rnp);
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static struct devfs_krule *devfs_rule_byid(devfs_rid rid);
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static int devfs_rule_delete(struct devfs_krule **dkp);
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static struct cdev *devfs_rule_getdev(struct devfs_dirent *de);
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static int devfs_rule_input(struct devfs_rule *dr, struct devfs_mount *dm);
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static int devfs_rule_insert(struct devfs_rule *dr);
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static int devfs_rule_match(struct devfs_krule *dk, struct devfs_dirent *de);
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static int devfs_rule_matchpath(struct devfs_krule *dk,
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struct devfs_dirent *de);
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static void devfs_rule_run(struct devfs_krule *dk, struct devfs_dirent *de);
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static void devfs_ruleset_applyde(struct devfs_ruleset *ds,
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struct devfs_dirent *de);
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static void devfs_ruleset_applydm(struct devfs_ruleset *ds,
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struct devfs_mount *dm);
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static struct devfs_ruleset *devfs_ruleset_bynum(devfs_rsnum rsnum);
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static struct devfs_ruleset *devfs_ruleset_create(devfs_rsnum rsnum);
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static void devfs_ruleset_destroy(struct devfs_ruleset **dsp);
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static void devfs_ruleset_reap(struct devfs_ruleset **dsp);
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static int devfs_ruleset_use(devfs_rsnum rsnum, struct devfs_mount *dm);
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static SLIST_HEAD(, devfs_ruleset) devfs_rulesets;
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/*
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* Called to apply the proper rules for de before the latter can be
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* exposed to the userland. This should be called with an exclusive
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* lock on dm in case we need to run anything.
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*/
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void
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devfs_rules_apply(struct devfs_mount *dm, struct devfs_dirent *de)
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{
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struct devfs_ruleset *ds;
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ds = devfs_ruleset_bynum(dm->dm_ruleset);
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KASSERT(ds != NULL, ("mount-point has NULL ruleset"));
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devfs_ruleset_applyde(ds, de);
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}
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/*
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* Rule subsystem SYSINIT hook.
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*/
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static void
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devfs_rules_init(void *junk __unused)
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{
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struct devfs_ruleset *ds;
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SLIST_INIT(&devfs_rulesets);
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ds = devfs_ruleset_create(0);
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ds->ds_flags |= DS_IMMUTABLE;
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ds->ds_refcount = 1; /* Prevent reaping. */
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}
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SYSINIT(devfs_rules, SI_SUB_DEVFS, SI_ORDER_FIRST, devfs_rules_init, NULL);
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/*
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* Rule subsystem ioctl hook.
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*/
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int
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devfs_rules_ioctl(struct mount *mp, u_long cmd, caddr_t data, struct thread *td)
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{
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struct devfs_mount *dm = VFSTODEVFS(mp);
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struct devfs_ruleset *ds;
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struct devfs_krule *dk;
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struct devfs_rule *dr;
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devfs_rsnum rsnum;
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devfs_rnum rnum;
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devfs_rid rid;
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int error;
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/*
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* XXX: This returns an error regardless of whether we
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* actually support the cmd or not.
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*/
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error = suser(td);
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if (error != 0)
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return (error);
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lockmgr(&dm->dm_lock, LK_SHARED, 0, td);
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switch (cmd) {
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case DEVFSIO_RADD:
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dr = (struct devfs_rule *)data;
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error = devfs_rule_input(dr, dm);
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if (error != 0)
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goto out;
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dk = devfs_rule_byid(dr->dr_id);
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if (dk != NULL) {
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error = EEXIST;
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goto out;
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}
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lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td);
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error = devfs_rule_insert(dr);
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break;
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case DEVFSIO_RAPPLY:
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dr = (struct devfs_rule *)data;
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error = devfs_rule_input(dr, dm);
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if (error != 0)
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goto out;
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/*
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* This is one of many possible hackish
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* implementations. The primary contender is an
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* implementation where the rule we read in is
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* temporarily inserted into some ruleset, perhaps
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* with a hypothetical DRO_NOAUTO flag so that it
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* doesn't get used where it isn't intended, and
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* applied in the normal way. This can be done in the
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* userland (DEVFSIO_ADD, DEVFSIO_APPLYID,
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* DEVFSIO_DEL) or in the kernel; either way it breaks
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* some corner case assumptions in other parts of the
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* code (not that this implementation doesn't do
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* that).
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*/
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if (dr->dr_iacts & DRA_INCSET &&
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devfs_ruleset_bynum(dr->dr_incset) == NULL) {
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error = ESRCH;
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goto out;
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}
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dk = malloc(sizeof(*dk), M_TEMP, M_WAITOK | M_ZERO);
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memcpy(&dk->dk_rule, dr, sizeof(*dr));
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lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td);
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devfs_rule_applydm(dk, dm);
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lockmgr(&dm->dm_lock, LK_DOWNGRADE, 0, td);
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free(dk, M_TEMP);
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error = 0;
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break;
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case DEVFSIO_RAPPLYID:
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rid = *(devfs_rid *)data;
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rid = devfs_rid_input(rid, dm);
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dk = devfs_rule_byid(rid);
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if (dk == NULL) {
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error = ENOENT;
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goto out;
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}
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lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td);
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devfs_rule_applydm(dk, dm);
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error = 0;
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break;
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case DEVFSIO_RDEL:
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rid = *(devfs_rid *)data;
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rid = devfs_rid_input(rid, dm);
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dk = devfs_rule_byid(rid);
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if (dk == NULL) {
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error = ENOENT;
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goto out;
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}
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ds = dk->dk_ruleset;
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lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td);
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error = devfs_rule_delete(&dk);
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devfs_ruleset_reap(&ds);
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break;
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case DEVFSIO_RGETNEXT:
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dr = (struct devfs_rule *)data;
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error = devfs_rule_input(dr, dm);
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if (error != 0)
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goto out;
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/*
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* We can't use devfs_rule_byid() here since that
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* requires the rule specified to exist, but we want
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* getnext(N) to work whether there is a rule N or not
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* (specifically, getnext(0) must work, but we should
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* never have a rule 0 since the add command
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* interprets 0 to mean "auto-number").
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*/
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ds = devfs_ruleset_bynum(rid2rsn(dr->dr_id));
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if (ds == NULL) {
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error = ENOENT;
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goto out;
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}
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rnum = rid2rn(dr->dr_id);
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SLIST_FOREACH(dk, &ds->ds_rules, dk_list) {
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if (rid2rn(dk->dk_rule.dr_id) > rnum)
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break;
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}
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if (dk == NULL) {
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error = ENOENT;
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goto out;
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}
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memcpy(dr, &dk->dk_rule, sizeof(*dr));
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error = 0;
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break;
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case DEVFSIO_SUSE:
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rsnum = *(devfs_rsnum *)data;
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lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td);
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error = devfs_ruleset_use(rsnum, dm);
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break;
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case DEVFSIO_SAPPLY:
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rsnum = *(devfs_rsnum *)data;
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rsnum = rid2rsn(devfs_rid_input(mkrid(rsnum, 0), dm));
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ds = devfs_ruleset_bynum(rsnum);
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if (ds == NULL) {
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error = ESRCH;
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goto out;
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}
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lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td);
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devfs_ruleset_applydm(ds, dm);
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error = 0;
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break;
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case DEVFSIO_SGETNEXT:
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rsnum = *(devfs_rsnum *)data;
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SLIST_FOREACH(ds, &devfs_rulesets, ds_list) {
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if (ds->ds_number > rsnum)
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break;
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}
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if (ds == NULL)
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error = ENOENT;
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else {
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*(devfs_rsnum *)data = ds->ds_number;
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error = 0;
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}
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break;
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default:
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error = ENOIOCTL;
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break;
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}
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out:
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lockmgr(&dm->dm_lock, LK_RELEASE, 0, td);
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return (error);
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}
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/*
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* Called to initialize dm_ruleset when there is a new mount-point.
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*/
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void
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devfs_rules_newmount(struct devfs_mount *dm, struct thread *td)
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{
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struct devfs_ruleset *ds;
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lockmgr(&dm->dm_lock, LK_EXCLUSIVE, 0, td);
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/*
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* We can't use devfs_ruleset_use() since it will try to
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* decrement the refcount for the old ruleset, and there is no
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* old ruleset. Making some value of ds_ruleset "special" to
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* mean "don't decrement refcount" is uglier than this.
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*/
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ds = devfs_ruleset_bynum(0);
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KASSERT(ds != NULL, ("no ruleset 0"));
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++ds->ds_refcount;
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dm->dm_ruleset = 0;
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lockmgr(&dm->dm_lock, LK_RELEASE, 0, td);
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}
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/*
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* Adjust the rule identifier to use the ruleset of dm if one isn't
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* explicitly specified.
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*
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* Note that after this operation, rid2rsn(rid) might still be 0, and
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* that's okay; ruleset 0 is a valid ruleset, but when it's read in
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* from the userland, it means "current ruleset for this mount-point".
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*/
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static devfs_rid
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devfs_rid_input(devfs_rid rid, struct devfs_mount *dm)
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{
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if (rid2rsn(rid) == 0)
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return (mkrid(dm->dm_ruleset, rid2rn(rid)));
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else
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return (rid);
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}
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/*
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* Apply dk to de.
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*/
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static void
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devfs_rule_applyde(struct devfs_krule *dk, struct devfs_dirent *de)
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{
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if (devfs_rule_match(dk, de))
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devfs_rule_run(dk, de);
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}
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/*
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* Apply dk to de and everything under de.
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*
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* XXX: This method needs a function call for every nested
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* subdirectory in a devfs mount. If we plan to have many of these,
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* we might eventually run out of kernel stack space.
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*/
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static void
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devfs_rule_applyde_recursive(struct devfs_krule *dk, struct devfs_dirent *de)
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{
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struct devfs_dirent *de2;
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/* XXX: Should we apply to ourselves first or last? Does it matter? */
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TAILQ_FOREACH(de2, &de->de_dlist, de_list) {
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devfs_rule_applyde_recursive(dk, de2);
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}
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devfs_rule_applyde(dk, de);
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}
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/*
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* Apply dk to all entires in dm.
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*/
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static void
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devfs_rule_applydm(struct devfs_krule *dk, struct devfs_mount *dm)
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{
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devfs_rule_applyde_recursive(dk, dm->dm_rootdir);
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}
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/*
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* Automatically select a number for a new rule in ds, and write the
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* result into rnump.
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*/
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static int
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devfs_rule_autonumber(struct devfs_ruleset *ds, devfs_rnum *rnump)
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{
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struct devfs_krule *dk;
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/* Find the last rule. */
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SLIST_FOREACH(dk, &ds->ds_rules, dk_list) {
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if (SLIST_NEXT(dk, dk_list) == NULL)
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break;
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}
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if (dk == NULL)
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*rnump = 100;
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else {
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*rnump = rid2rn(dk->dk_rule.dr_id) + 100;
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/* Detect overflow. */
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if (*rnump < rid2rn(dk->dk_rule.dr_id))
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return (ERANGE);
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}
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KASSERT(devfs_rule_byid(mkrid(ds->ds_number, *rnump)) == NULL,
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("autonumbering resulted in an already existing rule"));
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return (0);
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}
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/*
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* Find a krule by id.
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*/
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static struct devfs_krule *
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devfs_rule_byid(devfs_rid rid)
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{
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struct devfs_ruleset *ds;
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struct devfs_krule *dk;
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devfs_rnum rn;
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rn = rid2rn(rid);
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ds = devfs_ruleset_bynum(rid2rsn(rid));
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if (ds == NULL)
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return (NULL);
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SLIST_FOREACH(dk, &ds->ds_rules, dk_list) {
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if (rid2rn(dk->dk_rule.dr_id) == rn)
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return (dk);
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else if (rid2rn(dk->dk_rule.dr_id) > rn)
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break;
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}
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return (NULL);
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}
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/*
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* Remove dkp from any lists it may be on and remove memory associated
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* with it.
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*/
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static int
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devfs_rule_delete(struct devfs_krule **dkp)
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{
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struct devfs_krule *dk = *dkp;
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struct devfs_ruleset *ds;
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if (dk->dk_rule.dr_iacts & DRA_INCSET) {
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ds = devfs_ruleset_bynum(dk->dk_rule.dr_incset);
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KASSERT(ds != NULL, ("DRA_INCSET but bad dr_incset"));
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--ds->ds_refcount;
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devfs_ruleset_reap(&ds);
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}
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SLIST_REMOVE(&dk->dk_ruleset->ds_rules, dk, devfs_krule, dk_list);
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free(dk, M_DEVFS);
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*dkp = NULL;
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return (0);
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}
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/*
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* Get a struct cdev *corresponding to de so we can try to match rules based
|
|
* on it. If this routine returns NULL, there is no struct cdev *associated
|
|
* with the dirent (symlinks and directories don't have dev_ts), and
|
|
* the caller should assume that any critera dependent on a dev_t
|
|
* don't match.
|
|
*/
|
|
static struct cdev *
|
|
devfs_rule_getdev(struct devfs_dirent *de)
|
|
{
|
|
struct cdev **devp, *dev;
|
|
|
|
devp = devfs_itod(de->de_inode);
|
|
if (devp != NULL)
|
|
dev = *devp;
|
|
else
|
|
dev = NULL;
|
|
/* If we think this dirent should have a struct cdev *, alert the user. */
|
|
if (dev == NULL && de->de_dirent->d_type != DT_LNK &&
|
|
de->de_dirent->d_type != DT_DIR)
|
|
printf("Warning: no struct cdev *for %s\n", de->de_dirent->d_name);
|
|
return (dev);
|
|
}
|
|
|
|
/*
|
|
* Do what we need to do to a rule that we just loaded from the
|
|
* userland. In particular, we need to check the magic, and adjust
|
|
* the ruleset appropriate if desired.
|
|
*/
|
|
static int
|
|
devfs_rule_input(struct devfs_rule *dr, struct devfs_mount *dm)
|
|
{
|
|
|
|
if (dr->dr_magic != DEVFS_MAGIC)
|
|
return (ERPCMISMATCH);
|
|
dr->dr_id = devfs_rid_input(dr->dr_id, dm);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Import dr into the appropriate place in the kernel (i.e., make a
|
|
* krule). The value of dr is copied, so the pointer may be destroyed
|
|
* after this call completes.
|
|
*/
|
|
static int
|
|
devfs_rule_insert(struct devfs_rule *dr)
|
|
{
|
|
struct devfs_ruleset *ds, *dsi;
|
|
struct devfs_krule *k1, *k2;
|
|
struct devfs_krule *dk;
|
|
devfs_rsnum rsnum;
|
|
devfs_rnum dkrn;
|
|
int error;
|
|
|
|
/*
|
|
* This stuff seems out of place here, but we want to do it as
|
|
* soon as possible so that if it fails, we don't have to roll
|
|
* back any changes we already made (e.g., ruleset creation).
|
|
*/
|
|
if (dr->dr_iacts & DRA_INCSET) {
|
|
dsi = devfs_ruleset_bynum(dr->dr_incset);
|
|
if (dsi == NULL)
|
|
return (ESRCH);
|
|
} else
|
|
dsi = NULL;
|
|
|
|
rsnum = rid2rsn(dr->dr_id);
|
|
ds = devfs_ruleset_bynum(rsnum);
|
|
if (ds == NULL)
|
|
ds = devfs_ruleset_create(rsnum);
|
|
if (ds->ds_flags & DS_IMMUTABLE)
|
|
return (EIO);
|
|
dkrn = rid2rn(dr->dr_id);
|
|
if (dkrn == 0) {
|
|
error = devfs_rule_autonumber(ds, &dkrn);
|
|
if (error != 0)
|
|
return (error);
|
|
}
|
|
|
|
dk = malloc(sizeof(*dk), M_DEVFS, M_WAITOK);
|
|
dk->dk_ruleset = ds;
|
|
if (dsi != NULL)
|
|
++dsi->ds_refcount;
|
|
/* XXX: Inspect dr? */
|
|
memcpy(&dk->dk_rule, dr, sizeof(*dr));
|
|
dk->dk_rule.dr_id = mkrid(rid2rsn(dk->dk_rule.dr_id), dkrn);
|
|
|
|
k1 = SLIST_FIRST(&ds->ds_rules);
|
|
if (k1 == NULL || rid2rn(k1->dk_rule.dr_id) > dkrn)
|
|
SLIST_INSERT_HEAD(&ds->ds_rules, dk, dk_list);
|
|
else {
|
|
SLIST_FOREACH(k1, &ds->ds_rules, dk_list) {
|
|
k2 = SLIST_NEXT(k1, dk_list);
|
|
if (k2 == NULL || rid2rn(k2->dk_rule.dr_id) > dkrn) {
|
|
SLIST_INSERT_AFTER(k1, dk, dk_list);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Determine whether dk matches de. Returns 1 if dk should be run on
|
|
* de; 0, otherwise.
|
|
*/
|
|
static int
|
|
devfs_rule_match(struct devfs_krule *dk, struct devfs_dirent *de)
|
|
{
|
|
struct devfs_rule *dr = &dk->dk_rule;
|
|
struct cdev *dev;
|
|
|
|
dev = devfs_rule_getdev(de);
|
|
/*
|
|
* At this point, if dev is NULL, we should assume that any
|
|
* criteria that depend on it don't match. We should *not*
|
|
* just ignore them (i.e., act like they weren't specified),
|
|
* since that makes a rule that only has criteria dependent on
|
|
* the struct cdev *match all symlinks and directories.
|
|
*
|
|
* Note also that the following tests are somewhat reversed:
|
|
* They're actually testing to see whether the condition does
|
|
* *not* match, since the default is to assume the rule should
|
|
* be run (such as if there are no conditions).
|
|
*
|
|
* XXX: lacks threadref on dev
|
|
*/
|
|
if (dr->dr_icond & DRC_DSWFLAGS)
|
|
if (dev == NULL ||
|
|
(dev->si_devsw->d_flags & dr->dr_dswflags) == 0)
|
|
goto nomatch;
|
|
if (dr->dr_icond & DRC_PATHPTRN)
|
|
if (!devfs_rule_matchpath(dk, de))
|
|
goto nomatch;
|
|
|
|
return (1);
|
|
|
|
nomatch:
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Determine whether dk matches de on account of dr_pathptrn.
|
|
*/
|
|
static int
|
|
devfs_rule_matchpath(struct devfs_krule *dk, struct devfs_dirent *de)
|
|
{
|
|
struct devfs_rule *dr = &dk->dk_rule;
|
|
char *pname;
|
|
struct cdev *dev;
|
|
|
|
dev = devfs_rule_getdev(de);
|
|
if (dev != NULL)
|
|
pname = dev->si_name;
|
|
else if (de->de_dirent->d_type == DT_LNK ||
|
|
de->de_dirent->d_type == DT_DIR)
|
|
pname = de->de_dirent->d_name;
|
|
else
|
|
return (0);
|
|
KASSERT(pname != NULL, ("devfs_rule_matchpath: NULL pname"));
|
|
|
|
return (fnmatch(dr->dr_pathptrn, pname, 0) == 0);
|
|
}
|
|
|
|
/*
|
|
* Run dk on de.
|
|
*/
|
|
static void
|
|
devfs_rule_run(struct devfs_krule *dk, struct devfs_dirent *de)
|
|
{
|
|
struct devfs_rule *dr = &dk->dk_rule;
|
|
struct devfs_ruleset *ds;
|
|
|
|
if (dr->dr_iacts & DRA_BACTS) {
|
|
if (dr->dr_bacts & DRB_HIDE)
|
|
de->de_flags |= DE_WHITEOUT;
|
|
if (dr->dr_bacts & DRB_UNHIDE)
|
|
de->de_flags &= ~DE_WHITEOUT;
|
|
}
|
|
if (dr->dr_iacts & DRA_UID)
|
|
de->de_uid = dr->dr_uid;
|
|
if (dr->dr_iacts & DRA_GID)
|
|
de->de_gid = dr->dr_gid;
|
|
if (dr->dr_iacts & DRA_MODE)
|
|
de->de_mode = dr->dr_mode;
|
|
if (dr->dr_iacts & DRA_INCSET) {
|
|
ds = devfs_ruleset_bynum(dk->dk_rule.dr_incset);
|
|
KASSERT(ds != NULL, ("DRA_INCSET but bad dr_incset"));
|
|
if (ds->ds_running)
|
|
printf("Warning: avoiding loop through ruleset %d\n",
|
|
ds->ds_number);
|
|
else
|
|
devfs_ruleset_applyde(ds, de);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Apply all the rules in ds to de.
|
|
*/
|
|
static void
|
|
devfs_ruleset_applyde(struct devfs_ruleset *ds, struct devfs_dirent *de)
|
|
{
|
|
struct devfs_krule *dk;
|
|
|
|
KASSERT(!ds->ds_running,("ruleset %d already running", ds->ds_number));
|
|
ds->ds_running = 1;
|
|
SLIST_FOREACH(dk, &ds->ds_rules, dk_list) {
|
|
devfs_rule_applyde(dk, de);
|
|
}
|
|
ds->ds_running = 0;
|
|
}
|
|
|
|
/*
|
|
* Apply all the rules in ds to all the entires in dm.
|
|
*/
|
|
static void
|
|
devfs_ruleset_applydm(struct devfs_ruleset *ds, struct devfs_mount *dm)
|
|
{
|
|
struct devfs_krule *dk;
|
|
|
|
KASSERT(!ds->ds_running,("ruleset %d already running", ds->ds_number));
|
|
ds->ds_running = 1;
|
|
/*
|
|
* XXX: Does it matter whether we do
|
|
*
|
|
* foreach(dk in ds)
|
|
* foreach(de in dm)
|
|
* apply(dk to de)
|
|
*
|
|
* as opposed to
|
|
*
|
|
* foreach(de in dm)
|
|
* foreach(dk in ds)
|
|
* apply(dk to de)
|
|
*
|
|
* The end result is obviously the same, but does the order
|
|
* matter?
|
|
*/
|
|
SLIST_FOREACH(dk, &ds->ds_rules, dk_list) {
|
|
devfs_rule_applydm(dk, dm);
|
|
}
|
|
ds->ds_running = 0;
|
|
}
|
|
|
|
/*
|
|
* Find a ruleset by number.
|
|
*/
|
|
static struct devfs_ruleset *
|
|
devfs_ruleset_bynum(devfs_rsnum rsnum)
|
|
{
|
|
struct devfs_ruleset *ds;
|
|
|
|
SLIST_FOREACH(ds, &devfs_rulesets, ds_list) {
|
|
if (ds->ds_number == rsnum)
|
|
return (ds);
|
|
}
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* Create a new ruleset.
|
|
*/
|
|
static struct devfs_ruleset *
|
|
devfs_ruleset_create(devfs_rsnum rsnum)
|
|
{
|
|
struct devfs_ruleset *s1, *s2;
|
|
struct devfs_ruleset *ds;
|
|
|
|
KASSERT(devfs_ruleset_bynum(rsnum) == NULL,
|
|
("creating already existent ruleset %d", rsnum));
|
|
|
|
ds = malloc(sizeof(*ds), M_DEVFS, M_WAITOK | M_ZERO);
|
|
ds->ds_number = rsnum;
|
|
ds->ds_refcount = ds->ds_flags = 0;
|
|
SLIST_INIT(&ds->ds_rules);
|
|
|
|
s1 = SLIST_FIRST(&devfs_rulesets);
|
|
if (s1 == NULL || s1->ds_number > rsnum)
|
|
SLIST_INSERT_HEAD(&devfs_rulesets, ds, ds_list);
|
|
else {
|
|
SLIST_FOREACH(s1, &devfs_rulesets, ds_list) {
|
|
s2 = SLIST_NEXT(s1, ds_list);
|
|
if (s2 == NULL || s2->ds_number > rsnum) {
|
|
SLIST_INSERT_AFTER(s1, ds, ds_list);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
return (ds);
|
|
}
|
|
|
|
/*
|
|
* Remove a ruleset form the system. The ruleset specified must be
|
|
* empty and not in use.
|
|
*/
|
|
static void
|
|
devfs_ruleset_destroy(struct devfs_ruleset **dsp)
|
|
{
|
|
struct devfs_ruleset *ds = *dsp;
|
|
|
|
KASSERT(SLIST_EMPTY(&ds->ds_rules), ("destroying non-empty ruleset"));
|
|
KASSERT(ds->ds_refcount == 0, ("destroying busy ruleset"));
|
|
KASSERT((ds->ds_flags & DS_IMMUTABLE) == 0,
|
|
("destroying immutable ruleset"));
|
|
|
|
SLIST_REMOVE(&devfs_rulesets, ds, devfs_ruleset, ds_list);
|
|
free(ds, M_DEVFS);
|
|
*dsp = NULL;
|
|
}
|
|
|
|
/*
|
|
* Remove a ruleset from the system if it's empty and not used
|
|
* anywhere. This should be called after every time a rule is deleted
|
|
* from this ruleset or the reference count is decremented.
|
|
*/
|
|
static void
|
|
devfs_ruleset_reap(struct devfs_ruleset **dsp)
|
|
{
|
|
struct devfs_ruleset *ds = *dsp;
|
|
|
|
if (SLIST_EMPTY(&ds->ds_rules) && ds->ds_refcount == 0) {
|
|
devfs_ruleset_destroy(&ds);
|
|
*dsp = ds;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Make rsnum the active ruleset for dm.
|
|
*/
|
|
static int
|
|
devfs_ruleset_use(devfs_rsnum rsnum, struct devfs_mount *dm)
|
|
{
|
|
struct devfs_ruleset *cds, *ds;
|
|
|
|
ds = devfs_ruleset_bynum(rsnum);
|
|
if (ds == NULL)
|
|
ds = devfs_ruleset_create(rsnum);
|
|
cds = devfs_ruleset_bynum(dm->dm_ruleset);
|
|
KASSERT(cds != NULL, ("mount-point has NULL ruleset"));
|
|
|
|
/* These should probably be made atomic somehow. */
|
|
--cds->ds_refcount;
|
|
++ds->ds_refcount;
|
|
dm->dm_ruleset = rsnum;
|
|
|
|
devfs_ruleset_reap(&cds);
|
|
return (0);
|
|
}
|
|
|