devfs_rule.c revision 124804
1100206Sdd/*- 2100206Sdd * Copyright (c) 2002 Dima Dorfman. 3100206Sdd * All rights reserved. 4100206Sdd * 5100206Sdd * Redistribution and use in source and binary forms, with or without 6100206Sdd * modification, are permitted provided that the following conditions 7100206Sdd * are met: 8100206Sdd * 1. Redistributions of source code must retain the above copyright 9100206Sdd * notice, this list of conditions and the following disclaimer. 10100206Sdd * 2. Redistributions in binary form must reproduce the above copyright 11100206Sdd * notice, this list of conditions and the following disclaimer in the 12100206Sdd * documentation and/or other materials provided with the distribution. 13100206Sdd * 14100206Sdd * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15100206Sdd * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16100206Sdd * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17100206Sdd * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18100206Sdd * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19100206Sdd * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20100206Sdd * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21100206Sdd * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22100206Sdd * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23100206Sdd * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24100206Sdd * SUCH DAMAGE. 25100206Sdd * 26100206Sdd * $FreeBSD: head/sys/fs/devfs/devfs_rule.c 124804 2004-01-21 18:03:54Z cperciva $ 27100206Sdd */ 28100206Sdd 29100206Sdd/* 30100206Sdd * DEVFS ruleset implementation. 31100206Sdd * 32100206Sdd * A note on terminology: To "run" a rule on a dirent is to take the 33100206Sdd * prescribed action; to "apply" a rule is to check whether it matches 34100206Sdd * a dirent and run if if it does. 35100206Sdd * 36100206Sdd * A note on locking: Only foreign entry points (non-static functions) 37100206Sdd * should deal with locking. Everything else assumes we already hold 38100206Sdd * the required kind of lock. 39100206Sdd * 40100206Sdd * A note on namespace: devfs_rules_* are the non-static functions for 41100206Sdd * the entire "ruleset" subsystem, devfs_rule_* are the static 42100206Sdd * functions that operate on rules, and devfs_ruleset_* are the static 43100206Sdd * functions that operate on rulesets. The line between the last two 44100206Sdd * isn't always clear, but the guideline is still useful. 45100206Sdd * 46100206Sdd * A note on "special" identifiers: Ruleset 0 is the NULL, or empty, 47100206Sdd * ruleset; it cannot be deleted or changed in any way. This may be 48100206Sdd * assumed inside the code; e.g., a ruleset of 0 may be interpeted to 49100206Sdd * mean "no ruleset". The interpretation of rule 0 is 50100206Sdd * command-dependent, but in no case is there a real rule with number 51100206Sdd * 0. 52100206Sdd * 53100206Sdd * A note on errno codes: To make it easier for the userland to tell 54100206Sdd * what went wrong, we sometimes use errno codes that are not entirely 55100206Sdd * appropriate for the error but that would be less ambiguous than the 56100206Sdd * appropriate "generic" code. For example, when we can't find a 57100206Sdd * ruleset, we return ESRCH instead of ENOENT (except in 58100206Sdd * DEVFSIO_{R,S}GETNEXT, where a nonexistent ruleset means "end of 59100206Sdd * list", and the userland expects ENOENT to be this indicator); this 60100206Sdd * way, when an operation fails, it's clear that what couldn't be 61100206Sdd * found is a ruleset and not a rule (well, it's clear to those who 62100206Sdd * know the convention). 63100206Sdd */ 64100206Sdd 65100206Sdd#include "opt_devfs.h" 66100206Sdd 67100206Sdd#include <sys/param.h> 68100206Sdd#include <sys/systm.h> 69100206Sdd#include <sys/conf.h> 70100206Sdd#include <sys/kernel.h> 71100206Sdd#include <sys/malloc.h> 72100206Sdd#include <sys/dirent.h> 73100206Sdd#include <sys/vnode.h> 74100206Sdd#include <sys/mount.h> 75100206Sdd#include <sys/ioccom.h> 76100206Sdd 77100206Sdd#include <fs/devfs/devfs.h> 78100206Sdd 79100206Sdd 80100206Sdd/* 81100206Sdd * Kernel version of devfs_rule. 82100206Sdd */ 83100206Sddstruct devfs_krule { 84100206Sdd SLIST_ENTRY(devfs_krule) dk_list; 85100206Sdd struct devfs_ruleset *dk_ruleset; 86100206Sdd struct devfs_rule dk_rule; 87100206Sdd}; 88100206Sdd 89100206Sdd/* 90100206Sdd * Structure to describe a ruleset. 91100206Sdd */ 92100206Sddstruct devfs_ruleset { 93100206Sdd SLIST_ENTRY(devfs_ruleset) ds_list; 94100206Sdd devfs_rsnum ds_number; 95100206Sdd SLIST_HEAD(, devfs_krule) ds_rules; 96100206Sdd int ds_refcount; 97100206Sdd int ds_flags; 98100206Sdd#define DS_IMMUTABLE 0x001 99100793Sdd int ds_running; 100100206Sdd}; 101100206Sdd 102100206Sddstatic devfs_rid devfs_rid_input(devfs_rid rid, struct devfs_mount *dm); 103100206Sdd 104100206Sddstatic void devfs_rule_applyde(struct devfs_krule *dk,struct devfs_dirent *de); 105100206Sddstatic void devfs_rule_applyde_recursive(struct devfs_krule *dk, 106100206Sdd struct devfs_dirent *de); 107100206Sddstatic void devfs_rule_applydm(struct devfs_krule *dk, struct devfs_mount *dm); 108100206Sddstatic int devfs_rule_autonumber(struct devfs_ruleset *ds, devfs_rnum *rnp); 109100206Sddstatic struct devfs_krule *devfs_rule_byid(devfs_rid rid); 110100206Sddstatic int devfs_rule_delete(struct devfs_krule **dkp); 111100206Sddstatic dev_t devfs_rule_getdev(struct devfs_dirent *de); 112100206Sddstatic int devfs_rule_input(struct devfs_rule *dr, struct devfs_mount *dm); 113100206Sddstatic int devfs_rule_insert(struct devfs_rule *dr); 114100206Sddstatic int devfs_rule_match(struct devfs_krule *dk, struct devfs_dirent *de); 115100206Sddstatic int devfs_rule_matchpath(struct devfs_krule *dk, 116100206Sdd struct devfs_dirent *de); 117100206Sddstatic void devfs_rule_run(struct devfs_krule *dk, struct devfs_dirent *de); 118100206Sdd 119100206Sddstatic void devfs_ruleset_applyde(struct devfs_ruleset *ds, 120100206Sdd struct devfs_dirent *de); 121100206Sddstatic void devfs_ruleset_applydm(struct devfs_ruleset *ds, 122100206Sdd struct devfs_mount *dm); 123100206Sddstatic struct devfs_ruleset *devfs_ruleset_bynum(devfs_rsnum rsnum); 124100206Sddstatic struct devfs_ruleset *devfs_ruleset_create(devfs_rsnum rsnum); 125100206Sddstatic void devfs_ruleset_destroy(struct devfs_ruleset **dsp); 126100206Sddstatic void devfs_ruleset_reap(struct devfs_ruleset **dsp); 127100206Sddstatic int devfs_ruleset_use(devfs_rsnum rsnum, struct devfs_mount *dm); 128100206Sdd 129100206Sddstatic SLIST_HEAD(, devfs_ruleset) devfs_rulesets; 130100206Sdd 131100206Sdd/* 132100206Sdd * Called to apply the proper rules for de before the latter can be 133100206Sdd * exposed to the userland. This should be called with an exclusive 134100206Sdd * lock on dm in case we need to run anything. 135100206Sdd */ 136100206Sddvoid 137100206Sdddevfs_rules_apply(struct devfs_mount *dm, struct devfs_dirent *de) 138100206Sdd{ 139100206Sdd struct devfs_ruleset *ds; 140100206Sdd 141100206Sdd ds = devfs_ruleset_bynum(dm->dm_ruleset); 142100206Sdd KASSERT(ds != NULL, ("mount-point has NULL ruleset")); 143100206Sdd devfs_ruleset_applyde(ds, de); 144100206Sdd} 145100206Sdd 146100206Sdd/* 147100206Sdd * Rule subsystem SYSINIT hook. 148100206Sdd */ 149100206Sddvoid 150100206Sdddevfs_rules_init(void) 151100206Sdd{ 152100206Sdd struct devfs_ruleset *ds; 153100206Sdd 154100206Sdd SLIST_INIT(&devfs_rulesets); 155100206Sdd 156100206Sdd ds = devfs_ruleset_create(0); 157100206Sdd ds->ds_flags |= DS_IMMUTABLE; 158100206Sdd ds->ds_refcount = 1; /* Prevent reaping. */ 159100206Sdd} 160100206Sdd 161100206Sdd/* 162100206Sdd * Rule subsystem ioctl hook. 163100206Sdd */ 164100206Sddint 165105212Sphkdevfs_rules_ioctl(struct mount *mp, u_long cmd, caddr_t data, struct thread *td) 166100206Sdd{ 167100206Sdd struct devfs_mount *dm = VFSTODEVFS(mp); 168100206Sdd struct devfs_ruleset *ds; 169100206Sdd struct devfs_krule *dk; 170100206Sdd struct devfs_rule *dr; 171100206Sdd devfs_rsnum rsnum; 172100206Sdd devfs_rnum rnum; 173100206Sdd devfs_rid rid; 174100206Sdd int error; 175100206Sdd 176100206Sdd /* 177100206Sdd * XXX: This returns an error regardless of whether we 178100206Sdd * actually support the cmd or not. 179100206Sdd */ 180100206Sdd error = suser(td); 181100206Sdd if (error != 0) 182100206Sdd return (error); 183100206Sdd 184100206Sdd lockmgr(&dm->dm_lock, LK_SHARED, 0, td); 185100206Sdd 186100206Sdd switch (cmd) { 187100206Sdd case DEVFSIO_RADD: 188100206Sdd dr = (struct devfs_rule *)data; 189100206Sdd error = devfs_rule_input(dr, dm); 190100206Sdd if (error != 0) 191100206Sdd goto out; 192100206Sdd dk = devfs_rule_byid(dr->dr_id); 193100206Sdd if (dk != NULL) { 194100206Sdd error = EEXIST; 195100206Sdd goto out; 196100206Sdd } 197100206Sdd lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td); 198100206Sdd error = devfs_rule_insert(dr); 199100206Sdd break; 200100206Sdd case DEVFSIO_RAPPLY: 201100206Sdd dr = (struct devfs_rule *)data; 202100206Sdd error = devfs_rule_input(dr, dm); 203100206Sdd if (error != 0) 204100206Sdd goto out; 205100206Sdd 206100206Sdd /* 207100206Sdd * This is one of many possible hackish 208100206Sdd * implementations. The primary contender is an 209100206Sdd * implementation where the rule we read in is 210100206Sdd * temporarily inserted into some ruleset, perhaps 211100206Sdd * with a hypothetical DRO_NOAUTO flag so that it 212100206Sdd * doesn't get used where it isn't intended, and 213100206Sdd * applied in the normal way. This can be done in the 214100206Sdd * userland (DEVFSIO_ADD, DEVFSIO_APPLYID, 215100206Sdd * DEVFSIO_DEL) or in the kernel; either way it breaks 216100206Sdd * some corner case assumptions in other parts of the 217100206Sdd * code (not that this implementation doesn't do 218100206Sdd * that). 219100206Sdd */ 220100206Sdd if (dr->dr_iacts & DRA_INCSET && 221100206Sdd devfs_ruleset_bynum(dr->dr_incset) == NULL) { 222100206Sdd error = ESRCH; 223100206Sdd goto out; 224100206Sdd } 225111119Simp dk = malloc(sizeof(*dk), M_TEMP, M_WAITOK | M_ZERO); 226100206Sdd memcpy(&dk->dk_rule, dr, sizeof(*dr)); 227100206Sdd lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td); 228100206Sdd devfs_rule_applydm(dk, dm); 229100206Sdd lockmgr(&dm->dm_lock, LK_DOWNGRADE, 0, td); 230100206Sdd free(dk, M_TEMP); 231100206Sdd error = 0; 232100206Sdd break; 233100206Sdd case DEVFSIO_RAPPLYID: 234100206Sdd rid = *(devfs_rid *)data; 235100206Sdd rid = devfs_rid_input(rid, dm); 236100206Sdd dk = devfs_rule_byid(rid); 237100206Sdd if (dk == NULL) { 238100206Sdd error = ENOENT; 239100206Sdd goto out; 240100206Sdd } 241100206Sdd lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td); 242100206Sdd devfs_rule_applydm(dk, dm); 243100206Sdd error = 0; 244100206Sdd break; 245100206Sdd case DEVFSIO_RDEL: 246100206Sdd rid = *(devfs_rid *)data; 247100206Sdd rid = devfs_rid_input(rid, dm); 248100206Sdd dk = devfs_rule_byid(rid); 249100206Sdd if (dk == NULL) { 250100206Sdd error = ENOENT; 251100206Sdd goto out; 252100206Sdd } 253100206Sdd ds = dk->dk_ruleset; 254100206Sdd lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td); 255100206Sdd error = devfs_rule_delete(&dk); 256100206Sdd devfs_ruleset_reap(&ds); 257100206Sdd break; 258100206Sdd case DEVFSIO_RGETNEXT: 259100206Sdd dr = (struct devfs_rule *)data; 260100206Sdd error = devfs_rule_input(dr, dm); 261100206Sdd if (error != 0) 262100206Sdd goto out; 263100206Sdd /* 264100206Sdd * We can't use devfs_rule_byid() here since that 265100206Sdd * requires the rule specified to exist, but we want 266100206Sdd * getnext(N) to work whether there is a rule N or not 267100206Sdd * (specifically, getnext(0) must work, but we should 268100206Sdd * never have a rule 0 since the add command 269100206Sdd * interprets 0 to mean "auto-number"). 270100206Sdd */ 271100206Sdd ds = devfs_ruleset_bynum(rid2rsn(dr->dr_id)); 272100206Sdd if (ds == NULL) { 273100206Sdd error = ENOENT; 274100206Sdd goto out; 275100206Sdd } 276100206Sdd rnum = rid2rn(dr->dr_id); 277100206Sdd SLIST_FOREACH(dk, &ds->ds_rules, dk_list) { 278100206Sdd if (rid2rn(dk->dk_rule.dr_id) > rnum) 279100206Sdd break; 280100206Sdd } 281100206Sdd if (dk == NULL) { 282100206Sdd error = ENOENT; 283100206Sdd goto out; 284100206Sdd } 285100206Sdd memcpy(dr, &dk->dk_rule, sizeof(*dr)); 286100206Sdd error = 0; 287100206Sdd break; 288100206Sdd case DEVFSIO_SUSE: 289100206Sdd rsnum = *(devfs_rsnum *)data; 290100206Sdd lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td); 291100206Sdd error = devfs_ruleset_use(rsnum, dm); 292100206Sdd break; 293100206Sdd case DEVFSIO_SAPPLY: 294100206Sdd rsnum = *(devfs_rsnum *)data; 295100206Sdd rsnum = rid2rsn(devfs_rid_input(mkrid(rsnum, 0), dm)); 296100206Sdd ds = devfs_ruleset_bynum(rsnum); 297100206Sdd if (ds == NULL) { 298100206Sdd error = ESRCH; 299100206Sdd goto out; 300100206Sdd } 301100206Sdd lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td); 302100206Sdd devfs_ruleset_applydm(ds, dm); 303100206Sdd error = 0; 304100206Sdd break; 305100206Sdd case DEVFSIO_SGETNEXT: 306100206Sdd rsnum = *(devfs_rsnum *)data; 307100206Sdd SLIST_FOREACH(ds, &devfs_rulesets, ds_list) { 308100206Sdd if (ds->ds_number > rsnum) 309100206Sdd break; 310100206Sdd } 311100206Sdd if (ds == NULL) 312100206Sdd error = ENOENT; 313100206Sdd else { 314100206Sdd *(devfs_rsnum *)data = ds->ds_number; 315100206Sdd error = 0; 316100206Sdd } 317100206Sdd break; 318100206Sdd default: 319100206Sdd error = ENOIOCTL; 320100206Sdd break; 321100206Sdd } 322100206Sdd 323100206Sddout: 324100206Sdd lockmgr(&dm->dm_lock, LK_RELEASE, 0, td); 325100206Sdd return (error); 326100206Sdd} 327100206Sdd 328100206Sdd/* 329100206Sdd * Called to initialize dm_ruleset when there is a new mount-point. 330100206Sdd */ 331100206Sddvoid 332100206Sdddevfs_rules_newmount(struct devfs_mount *dm, struct thread *td) 333100206Sdd{ 334100206Sdd struct devfs_ruleset *ds; 335100206Sdd 336100206Sdd lockmgr(&dm->dm_lock, LK_EXCLUSIVE, 0, td); 337100206Sdd /* 338100206Sdd * We can't use devfs_ruleset_use() since it will try to 339100206Sdd * decrement the refcount for the old ruleset, and there is no 340100206Sdd * old ruleset. Making some value of ds_ruleset "special" to 341100206Sdd * mean "don't decrement refcount" is uglier than this. 342100206Sdd */ 343100206Sdd ds = devfs_ruleset_bynum(0); 344100206Sdd KASSERT(ds != NULL, ("no ruleset 0")); 345100206Sdd ++ds->ds_refcount; 346100206Sdd dm->dm_ruleset = 0; 347100206Sdd lockmgr(&dm->dm_lock, LK_RELEASE, 0, td); 348100206Sdd} 349100206Sdd 350100206Sdd/* 351100206Sdd * Adjust the rule identifier to use the ruleset of dm if one isn't 352100206Sdd * explicitly specified. 353100206Sdd * 354100206Sdd * Note that after this operation, rid2rsn(rid) might still be 0, and 355100206Sdd * that's okay; ruleset 0 is a valid ruleset, but when it's read in 356100206Sdd * from the userland, it means "current ruleset for this mount-point". 357100206Sdd */ 358100206Sddstatic devfs_rid 359100206Sdddevfs_rid_input(devfs_rid rid, struct devfs_mount *dm) 360100206Sdd{ 361100206Sdd 362100206Sdd if (rid2rsn(rid) == 0) 363100206Sdd return (mkrid(dm->dm_ruleset, rid2rn(rid))); 364100206Sdd else 365100206Sdd return (rid); 366100206Sdd} 367100206Sdd 368100206Sdd/* 369100206Sdd * Apply dk to de. 370100206Sdd */ 371100206Sddstatic void 372100206Sdddevfs_rule_applyde(struct devfs_krule *dk, struct devfs_dirent *de) 373100206Sdd{ 374100206Sdd 375100206Sdd if (devfs_rule_match(dk, de)) 376100206Sdd devfs_rule_run(dk, de); 377100206Sdd} 378100206Sdd 379100206Sdd/* 380100206Sdd * Apply dk to de and everything under de. 381100206Sdd * 382100206Sdd * XXX: This method needs a function call for every nested 383100206Sdd * subdirectory in a devfs mount. If we plan to have many of these, 384100206Sdd * we might eventually run out of kernel stack space. 385100206Sdd */ 386100206Sddstatic void 387100206Sdddevfs_rule_applyde_recursive(struct devfs_krule *dk, struct devfs_dirent *de) 388100206Sdd{ 389100206Sdd struct devfs_dirent *de2; 390100206Sdd 391100206Sdd /* XXX: Should we apply to ourselves first or last? Does it matter? */ 392100206Sdd TAILQ_FOREACH(de2, &de->de_dlist, de_list) { 393100206Sdd devfs_rule_applyde_recursive(dk, de2); 394100206Sdd } 395100206Sdd devfs_rule_applyde(dk, de); 396100206Sdd} 397100206Sdd 398100206Sdd/* 399100206Sdd * Apply dk to all entires in dm. 400100206Sdd */ 401100206Sddstatic void 402100206Sdddevfs_rule_applydm(struct devfs_krule *dk, struct devfs_mount *dm) 403100206Sdd{ 404100206Sdd 405100206Sdd devfs_rule_applyde_recursive(dk, dm->dm_basedir); 406100206Sdd} 407100206Sdd 408100206Sdd/* 409100206Sdd * Automatically select a number for a new rule in ds, and write the 410100206Sdd * result into rnump. 411100206Sdd */ 412100206Sddstatic int 413100206Sdddevfs_rule_autonumber(struct devfs_ruleset *ds, devfs_rnum *rnump) 414100206Sdd{ 415100206Sdd struct devfs_krule *dk; 416100206Sdd 417100206Sdd /* Find the last rule. */ 418100206Sdd SLIST_FOREACH(dk, &ds->ds_rules, dk_list) { 419100206Sdd if (SLIST_NEXT(dk, dk_list) == NULL) 420100206Sdd break; 421100206Sdd } 422100206Sdd if (dk == NULL) 423100206Sdd *rnump = 100; 424100206Sdd else { 425100206Sdd *rnump = rid2rn(dk->dk_rule.dr_id) + 100; 426100206Sdd /* Detect overflow. */ 427100206Sdd if (*rnump < rid2rn(dk->dk_rule.dr_id)) 428100206Sdd return (ERANGE); 429100206Sdd } 430100206Sdd KASSERT(devfs_rule_byid(mkrid(ds->ds_number, *rnump)) == NULL, 431100206Sdd ("autonumbering resulted in an already existing rule")); 432100206Sdd return (0); 433100206Sdd} 434100206Sdd 435100206Sdd/* 436100206Sdd * Find a krule by id. 437100206Sdd */ 438100206Sddstatic struct devfs_krule * 439100206Sdddevfs_rule_byid(devfs_rid rid) 440100206Sdd{ 441100206Sdd struct devfs_ruleset *ds; 442100206Sdd struct devfs_krule *dk; 443100206Sdd devfs_rnum rn; 444100206Sdd 445100206Sdd rn = rid2rn(rid); 446100206Sdd ds = devfs_ruleset_bynum(rid2rsn(rid)); 447100206Sdd if (ds == NULL) 448100206Sdd return (NULL); 449100206Sdd SLIST_FOREACH(dk, &ds->ds_rules, dk_list) { 450100206Sdd if (rid2rn(dk->dk_rule.dr_id) == rn) 451100206Sdd return (dk); 452100206Sdd else if (rid2rn(dk->dk_rule.dr_id) > rn) 453100206Sdd break; 454100206Sdd } 455100206Sdd return (NULL); 456100206Sdd} 457100206Sdd 458100206Sdd/* 459100206Sdd * Remove dkp from any lists it may be on and remove memory associated 460100206Sdd * with it. 461100206Sdd */ 462100206Sddstatic int 463100206Sdddevfs_rule_delete(struct devfs_krule **dkp) 464100206Sdd{ 465100206Sdd struct devfs_krule *dk = *dkp; 466100206Sdd struct devfs_ruleset *ds; 467100206Sdd 468100206Sdd if (dk->dk_rule.dr_iacts & DRA_INCSET) { 469100206Sdd ds = devfs_ruleset_bynum(dk->dk_rule.dr_incset); 470100206Sdd KASSERT(ds != NULL, ("DRA_INCSET but bad dr_incset")); 471100206Sdd --ds->ds_refcount; 472100206Sdd devfs_ruleset_reap(&ds); 473100206Sdd } 474100206Sdd SLIST_REMOVE(&dk->dk_ruleset->ds_rules, dk, devfs_krule, dk_list); 475100206Sdd free(dk, M_DEVFS); 476100206Sdd *dkp = NULL; 477100206Sdd return (0); 478100206Sdd} 479100206Sdd 480100206Sdd/* 481100206Sdd * Get a dev_t corresponding to de so we can try to match rules based 482100206Sdd * on it. If this routine returns NULL, there is no dev_t associated 483100206Sdd * with the dirent (symlinks and directories don't have dev_ts), and 484100206Sdd * the caller should assume that any critera dependent on a dev_t 485100206Sdd * don't match. 486100206Sdd */ 487100206Sddstatic dev_t 488100206Sdddevfs_rule_getdev(struct devfs_dirent *de) 489100206Sdd{ 490100206Sdd dev_t *devp, dev; 491100206Sdd 492100206Sdd devp = devfs_itod(de->de_inode); 493100206Sdd if (devp != NULL) 494100206Sdd dev = *devp; 495100206Sdd else 496100206Sdd dev = NULL; 497100206Sdd /* If we think this dirent should have a dev_t, alert the user. */ 498100206Sdd if (dev == NULL && de->de_dirent->d_type != DT_LNK && 499100206Sdd de->de_dirent->d_type != DT_DIR) 500100206Sdd printf("Warning: no dev_t for %s\n", de->de_dirent->d_name); 501100206Sdd return (dev); 502100206Sdd} 503100206Sdd 504100206Sdd/* 505100206Sdd * Do what we need to do to a rule that we just loaded from the 506100206Sdd * userland. In particular, we need to check the magic, and adjust 507100206Sdd * the ruleset appropriate if desired. 508100206Sdd */ 509100206Sddstatic int 510100206Sdddevfs_rule_input(struct devfs_rule *dr, struct devfs_mount *dm) 511100206Sdd{ 512100206Sdd 513100206Sdd if (dr->dr_magic != DEVFS_MAGIC) 514100206Sdd return (ERPCMISMATCH); 515100206Sdd dr->dr_id = devfs_rid_input(dr->dr_id, dm); 516100206Sdd return (0); 517100206Sdd} 518100206Sdd 519100206Sdd/* 520100206Sdd * Import dr into the appropriate place in the kernel (i.e., make a 521100206Sdd * krule). The value of dr is copied, so the pointer may be destroyed 522100206Sdd * after this call completes. 523100206Sdd */ 524100206Sddstatic int 525100206Sdddevfs_rule_insert(struct devfs_rule *dr) 526100206Sdd{ 527100206Sdd struct devfs_ruleset *ds, *dsi; 528100206Sdd struct devfs_krule *k1, *k2; 529100206Sdd struct devfs_krule *dk; 530100206Sdd devfs_rsnum rsnum; 531100206Sdd devfs_rnum dkrn; 532100206Sdd int error; 533100206Sdd 534100206Sdd /* 535100206Sdd * This stuff seems out of place here, but we want to do it as 536100206Sdd * soon as possible so that if it fails, we don't have to roll 537100206Sdd * back any changes we already made (e.g., ruleset creation). 538100206Sdd */ 539100206Sdd if (dr->dr_iacts & DRA_INCSET) { 540100206Sdd dsi = devfs_ruleset_bynum(dr->dr_incset); 541100206Sdd if (dsi == NULL) 542100206Sdd return (ESRCH); 543100206Sdd } else 544100206Sdd dsi = NULL; 545100206Sdd 546100206Sdd rsnum = rid2rsn(dr->dr_id); 547100206Sdd ds = devfs_ruleset_bynum(rsnum); 548100206Sdd if (ds == NULL) 549100206Sdd ds = devfs_ruleset_create(rsnum); 550100206Sdd if (ds->ds_flags & DS_IMMUTABLE) 551100206Sdd return (EIO); 552100206Sdd dkrn = rid2rn(dr->dr_id); 553100206Sdd if (dkrn == 0) { 554100206Sdd error = devfs_rule_autonumber(ds, &dkrn); 555100206Sdd if (error != 0) 556100206Sdd return (error); 557100206Sdd } 558100206Sdd 559111119Simp dk = malloc(sizeof(*dk), M_DEVFS, M_WAITOK); 560100206Sdd dk->dk_ruleset = ds; 561100206Sdd if (dsi != NULL) 562100206Sdd ++dsi->ds_refcount; 563100206Sdd /* XXX: Inspect dr? */ 564100206Sdd memcpy(&dk->dk_rule, dr, sizeof(*dr)); 565100206Sdd dk->dk_rule.dr_id = mkrid(rid2rsn(dk->dk_rule.dr_id), dkrn); 566100206Sdd 567100206Sdd k1 = SLIST_FIRST(&ds->ds_rules); 568100206Sdd if (k1 == NULL || rid2rn(k1->dk_rule.dr_id) > dkrn) 569100206Sdd SLIST_INSERT_HEAD(&ds->ds_rules, dk, dk_list); 570100206Sdd else { 571100206Sdd SLIST_FOREACH(k1, &ds->ds_rules, dk_list) { 572100206Sdd k2 = SLIST_NEXT(k1, dk_list); 573100206Sdd if (k2 == NULL || rid2rn(k2->dk_rule.dr_id) > dkrn) { 574100206Sdd SLIST_INSERT_AFTER(k1, dk, dk_list); 575100206Sdd break; 576100206Sdd } 577100206Sdd } 578100206Sdd } 579100206Sdd 580100206Sdd return (0); 581100206Sdd} 582100206Sdd 583100206Sdd/* 584100206Sdd * Determine whether dk matches de. Returns 1 if dk should be run on 585100206Sdd * de; 0, otherwise. 586100206Sdd */ 587100206Sddstatic int 588100206Sdddevfs_rule_match(struct devfs_krule *dk, struct devfs_dirent *de) 589100206Sdd{ 590100206Sdd struct devfs_rule *dr = &dk->dk_rule; 591100206Sdd dev_t dev; 592100206Sdd 593100206Sdd dev = devfs_rule_getdev(de); 594100206Sdd /* 595100206Sdd * At this point, if dev is NULL, we should assume that any 596100206Sdd * criteria that depend on it don't match. We should *not* 597100206Sdd * just ignore them (i.e., act like they weren't specified), 598100206Sdd * since that makes a rule that only has criteria dependent on 599100206Sdd * the dev_t match all symlinks and directories. 600100206Sdd * 601100206Sdd * Note also that the following tests are somewhat reversed: 602100206Sdd * They're actually testing to see whether the condition does 603100206Sdd * *not* match, since the default is to assume the rule should 604100206Sdd * be run (such as if there are no conditions). 605100206Sdd */ 606100206Sdd if (dr->dr_icond & DRC_DSWFLAGS) 607100206Sdd if (dev == NULL || 608100206Sdd (dev->si_devsw->d_flags & dr->dr_dswflags) == 0) 609100206Sdd goto nomatch; 610100206Sdd if (dr->dr_icond & DRC_PATHPTRN) 611100206Sdd if (!devfs_rule_matchpath(dk, de)) 612100206Sdd goto nomatch; 613100206Sdd if (dr->dr_icond & DRC_MAJOR) 614100206Sdd if (dev == NULL || major(dev) != dr->dr_major) 615100206Sdd goto nomatch; 616100206Sdd 617100206Sdd return (1); 618100206Sdd 619100206Sddnomatch: 620100206Sdd return (0); 621100206Sdd} 622100206Sdd 623100206Sdd/* 624100206Sdd * Determine whether dk matches de on account of dr_pathptrn. 625100206Sdd */ 626100206Sddstatic int 627100206Sdddevfs_rule_matchpath(struct devfs_krule *dk, struct devfs_dirent *de) 628100206Sdd{ 629100206Sdd struct devfs_rule *dr = &dk->dk_rule; 630100206Sdd char *pname; 631100206Sdd dev_t dev; 632100206Sdd 633100206Sdd dev = devfs_rule_getdev(de); 634100206Sdd if (dev != NULL) 635100206Sdd pname = dev->si_name; 636124798Scperciva else if (de->de_dirent->d_type == DT_LNK || 637124804Scperciva de->de_dirent->d_type == DT_DIR) 638109090Sdd pname = de->de_dirent->d_name; 639100206Sdd else 640100206Sdd return (0); 641100206Sdd KASSERT(pname != NULL, ("devfs_rule_matchpath: NULL pname")); 642100206Sdd 643104653Sdd return (fnmatch(dr->dr_pathptrn, pname, 0) == 0); 644100206Sdd} 645100206Sdd 646100206Sdd/* 647100206Sdd * Run dk on de. 648100206Sdd */ 649100206Sddstatic void 650100206Sdddevfs_rule_run(struct devfs_krule *dk, struct devfs_dirent *de) 651100206Sdd{ 652100206Sdd struct devfs_rule *dr = &dk->dk_rule; 653100206Sdd struct devfs_ruleset *ds; 654100206Sdd 655100206Sdd if (dr->dr_iacts & DRA_BACTS) { 656100206Sdd if (dr->dr_bacts & DRB_HIDE) 657100206Sdd de->de_flags |= DE_WHITEOUT; 658100206Sdd if (dr->dr_bacts & DRB_UNHIDE) 659100206Sdd de->de_flags &= ~DE_WHITEOUT; 660100206Sdd } 661100206Sdd if (dr->dr_iacts & DRA_UID) 662100206Sdd de->de_uid = dr->dr_uid; 663100206Sdd if (dr->dr_iacts & DRA_GID) 664100206Sdd de->de_gid = dr->dr_gid; 665100206Sdd if (dr->dr_iacts & DRA_MODE) 666100206Sdd de->de_mode = dr->dr_mode; 667100206Sdd if (dr->dr_iacts & DRA_INCSET) { 668100206Sdd ds = devfs_ruleset_bynum(dk->dk_rule.dr_incset); 669100206Sdd KASSERT(ds != NULL, ("DRA_INCSET but bad dr_incset")); 670100793Sdd if (ds->ds_running) 671100793Sdd printf("Warning: avoiding loop through ruleset %d\n", 672100793Sdd ds->ds_number); 673100793Sdd else 674100206Sdd devfs_ruleset_applyde(ds, de); 675100206Sdd } 676100206Sdd} 677100206Sdd 678100206Sdd/* 679100206Sdd * Apply all the rules in ds to de. 680100206Sdd */ 681100206Sddstatic void 682100206Sdddevfs_ruleset_applyde(struct devfs_ruleset *ds, struct devfs_dirent *de) 683100206Sdd{ 684100206Sdd struct devfs_krule *dk; 685100206Sdd 686100793Sdd KASSERT(!ds->ds_running,("ruleset %d already running", ds->ds_number)); 687100793Sdd ds->ds_running = 1; 688100206Sdd SLIST_FOREACH(dk, &ds->ds_rules, dk_list) { 689100206Sdd devfs_rule_applyde(dk, de); 690100206Sdd } 691100793Sdd ds->ds_running = 0; 692100206Sdd} 693100206Sdd 694100206Sdd/* 695100206Sdd * Apply all the rules in ds to all the entires in dm. 696100206Sdd */ 697100206Sddstatic void 698100206Sdddevfs_ruleset_applydm(struct devfs_ruleset *ds, struct devfs_mount *dm) 699100206Sdd{ 700100206Sdd struct devfs_krule *dk; 701100206Sdd 702100793Sdd KASSERT(!ds->ds_running,("ruleset %d already running", ds->ds_number)); 703100793Sdd ds->ds_running = 1; 704100206Sdd /* 705100206Sdd * XXX: Does it matter whether we do 706100206Sdd * 707100206Sdd * foreach(dk in ds) 708100206Sdd * foreach(de in dm) 709100206Sdd * apply(dk to de) 710100206Sdd * 711100206Sdd * as opposed to 712100206Sdd * 713100206Sdd * foreach(de in dm) 714100206Sdd * foreach(dk in ds) 715100206Sdd * apply(dk to de) 716100206Sdd * 717100206Sdd * The end result is obviously the same, but does the order 718100206Sdd * matter? 719100206Sdd */ 720100206Sdd SLIST_FOREACH(dk, &ds->ds_rules, dk_list) { 721100206Sdd devfs_rule_applydm(dk, dm); 722100206Sdd } 723100793Sdd ds->ds_running = 0; 724100206Sdd} 725100206Sdd 726100206Sdd/* 727100206Sdd * Find a ruleset by number. 728100206Sdd */ 729100206Sddstatic struct devfs_ruleset * 730100206Sdddevfs_ruleset_bynum(devfs_rsnum rsnum) 731100206Sdd{ 732100206Sdd struct devfs_ruleset *ds; 733100206Sdd 734100206Sdd SLIST_FOREACH(ds, &devfs_rulesets, ds_list) { 735100206Sdd if (ds->ds_number == rsnum) 736100206Sdd return (ds); 737100206Sdd } 738100206Sdd return (NULL); 739100206Sdd} 740100206Sdd 741100206Sdd/* 742100206Sdd * Create a new ruleset. 743100206Sdd */ 744100206Sddstatic struct devfs_ruleset * 745100206Sdddevfs_ruleset_create(devfs_rsnum rsnum) 746100206Sdd{ 747100206Sdd struct devfs_ruleset *s1, *s2; 748100206Sdd struct devfs_ruleset *ds; 749100206Sdd 750100206Sdd KASSERT(devfs_ruleset_bynum(rsnum) == NULL, 751100206Sdd ("creating already existent ruleset %d", rsnum)); 752100206Sdd 753111119Simp ds = malloc(sizeof(*ds), M_DEVFS, M_WAITOK | M_ZERO); 754100206Sdd ds->ds_number = rsnum; 755100206Sdd ds->ds_refcount = ds->ds_flags = 0; 756100206Sdd SLIST_INIT(&ds->ds_rules); 757100206Sdd 758100206Sdd s1 = SLIST_FIRST(&devfs_rulesets); 759100206Sdd if (s1 == NULL || s1->ds_number > rsnum) 760100206Sdd SLIST_INSERT_HEAD(&devfs_rulesets, ds, ds_list); 761100206Sdd else { 762100206Sdd SLIST_FOREACH(s1, &devfs_rulesets, ds_list) { 763100206Sdd s2 = SLIST_NEXT(s1, ds_list); 764100206Sdd if (s2 == NULL || s2->ds_number > rsnum) { 765100206Sdd SLIST_INSERT_AFTER(s1, ds, ds_list); 766100206Sdd break; 767100206Sdd } 768100206Sdd } 769100206Sdd } 770100206Sdd 771100206Sdd return (ds); 772100206Sdd} 773100206Sdd 774100206Sdd/* 775100206Sdd * Remove a ruleset form the system. The ruleset specified must be 776100206Sdd * empty and not in use. 777100206Sdd */ 778100206Sddstatic void 779100206Sdddevfs_ruleset_destroy(struct devfs_ruleset **dsp) 780100206Sdd{ 781100206Sdd struct devfs_ruleset *ds = *dsp; 782100206Sdd 783100206Sdd KASSERT(SLIST_EMPTY(&ds->ds_rules), ("destroying non-empty ruleset")); 784100206Sdd KASSERT(ds->ds_refcount == 0, ("destroying busy ruleset")); 785100206Sdd KASSERT((ds->ds_flags & DS_IMMUTABLE) == 0, 786100206Sdd ("destroying immutable ruleset")); 787100206Sdd 788100206Sdd SLIST_REMOVE(&devfs_rulesets, ds, devfs_ruleset, ds_list); 789100206Sdd free(ds, M_DEVFS); 790100206Sdd *dsp = NULL; 791100206Sdd} 792100206Sdd 793100206Sdd/* 794100206Sdd * Remove a ruleset from the system if it's empty and not used 795100206Sdd * anywhere. This should be called after every time a rule is deleted 796100206Sdd * from this ruleset or the reference count is decremented. 797100206Sdd */ 798100206Sddstatic void 799100206Sdddevfs_ruleset_reap(struct devfs_ruleset **dsp) 800100206Sdd{ 801100206Sdd struct devfs_ruleset *ds = *dsp; 802100206Sdd 803100206Sdd if (SLIST_EMPTY(&ds->ds_rules) && ds->ds_refcount == 0) { 804100206Sdd devfs_ruleset_destroy(&ds); 805100206Sdd *dsp = ds; 806100206Sdd } 807100206Sdd} 808100206Sdd 809100206Sdd/* 810100206Sdd * Make rsnum the active ruleset for dm. 811100206Sdd */ 812100206Sddstatic int 813100206Sdddevfs_ruleset_use(devfs_rsnum rsnum, struct devfs_mount *dm) 814100206Sdd{ 815100206Sdd struct devfs_ruleset *cds, *ds; 816100206Sdd 817100206Sdd ds = devfs_ruleset_bynum(rsnum); 818100206Sdd if (ds == NULL) 819100206Sdd ds = devfs_ruleset_create(rsnum); 820100206Sdd cds = devfs_ruleset_bynum(dm->dm_ruleset); 821100206Sdd KASSERT(cds != NULL, ("mount-point has NULL ruleset")); 822100206Sdd 823100206Sdd /* These should probably be made atomic somehow. */ 824100206Sdd --cds->ds_refcount; 825100206Sdd ++ds->ds_refcount; 826100206Sdd dm->dm_ruleset = rsnum; 827100206Sdd 828100206Sdd devfs_ruleset_reap(&cds); 829100206Sdd return (0); 830100206Sdd} 831100206Sdd 832