devfs_rule.c revision 227489
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 227489 2011-11-13 17:06:33Z eadler $ 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 <sys/param.h> 66100206Sdd#include <sys/systm.h> 67100206Sdd#include <sys/conf.h> 68100206Sdd#include <sys/kernel.h> 69100206Sdd#include <sys/malloc.h> 70164033Srwatson#include <sys/priv.h> 71100206Sdd#include <sys/dirent.h> 72100206Sdd#include <sys/ioccom.h> 73150342Sphk#include <sys/lock.h> 74150150Sphk#include <sys/sx.h> 75100206Sdd 76100206Sdd#include <fs/devfs/devfs.h> 77150342Sphk#include <fs/devfs/devfs_int.h> 78100206Sdd 79100206Sdd/* 80100206Sdd * Kernel version of devfs_rule. 81100206Sdd */ 82100206Sddstruct devfs_krule { 83150501Sphk TAILQ_ENTRY(devfs_krule) dk_list; 84150501Sphk struct devfs_ruleset *dk_ruleset; 85150501Sphk struct devfs_rule dk_rule; 86100206Sdd}; 87100206Sdd 88150501SphkTAILQ_HEAD(rulehead, devfs_krule); 89150501Sphkstatic MALLOC_DEFINE(M_DEVFSRULE, "DEVFS_RULE", "DEVFS rule storage"); 90150501Sphk 91100206Sdd/* 92100206Sdd * Structure to describe a ruleset. 93100206Sdd */ 94100206Sddstruct devfs_ruleset { 95150501Sphk TAILQ_ENTRY(devfs_ruleset) ds_list; 96150501Sphk struct rulehead ds_rules; 97150501Sphk devfs_rsnum ds_number; 98150501Sphk int ds_refcount; 99100206Sdd}; 100100206Sdd 101100206Sddstatic devfs_rid devfs_rid_input(devfs_rid rid, struct devfs_mount *dm); 102100206Sdd 103100206Sddstatic void devfs_rule_applyde_recursive(struct devfs_krule *dk, 104100206Sdd struct devfs_dirent *de); 105100206Sddstatic void devfs_rule_applydm(struct devfs_krule *dk, struct devfs_mount *dm); 106100206Sddstatic int devfs_rule_autonumber(struct devfs_ruleset *ds, devfs_rnum *rnp); 107100206Sddstatic struct devfs_krule *devfs_rule_byid(devfs_rid rid); 108150501Sphkstatic int devfs_rule_delete(struct devfs_krule *dkp); 109130585Sphkstatic struct cdev *devfs_rule_getdev(struct devfs_dirent *de); 110100206Sddstatic int devfs_rule_input(struct devfs_rule *dr, struct devfs_mount *dm); 111100206Sddstatic int devfs_rule_insert(struct devfs_rule *dr); 112100206Sddstatic int devfs_rule_match(struct devfs_krule *dk, struct devfs_dirent *de); 113100206Sddstatic int devfs_rule_matchpath(struct devfs_krule *dk, 114100206Sdd struct devfs_dirent *de); 115150147Sphkstatic void devfs_rule_run(struct devfs_krule *dk, struct devfs_dirent *de, unsigned depth); 116100206Sdd 117100206Sddstatic void devfs_ruleset_applyde(struct devfs_ruleset *ds, 118150147Sphk struct devfs_dirent *de, unsigned depth); 119100206Sddstatic void devfs_ruleset_applydm(struct devfs_ruleset *ds, 120100206Sdd struct devfs_mount *dm); 121100206Sddstatic struct devfs_ruleset *devfs_ruleset_bynum(devfs_rsnum rsnum); 122100206Sddstatic struct devfs_ruleset *devfs_ruleset_create(devfs_rsnum rsnum); 123150501Sphkstatic void devfs_ruleset_reap(struct devfs_ruleset *dsp); 124100206Sddstatic int devfs_ruleset_use(devfs_rsnum rsnum, struct devfs_mount *dm); 125100206Sdd 126150150Sphkstatic struct sx sx_rules; 127150501SphkSX_SYSINIT(sx_rules, &sx_rules, "DEVFS ruleset lock"); 128100206Sdd 129150501Sphkstatic TAILQ_HEAD(, devfs_ruleset) devfs_rulesets = 130150501Sphk TAILQ_HEAD_INITIALIZER(devfs_rulesets); 131150501Sphk 132100206Sdd/* 133150147Sphk * Called to apply the proper rules for 'de' before it can be 134100206Sdd * exposed to the userland. This should be called with an exclusive 135100206Sdd * lock on dm in case we need to run anything. 136100206Sdd */ 137100206Sddvoid 138100206Sdddevfs_rules_apply(struct devfs_mount *dm, struct devfs_dirent *de) 139100206Sdd{ 140100206Sdd struct devfs_ruleset *ds; 141100206Sdd 142216461Sjh sx_assert(&dm->dm_lock, SX_XLOCKED); 143216461Sjh 144150501Sphk if (dm->dm_ruleset == 0) 145150501Sphk return; 146150150Sphk sx_slock(&sx_rules); 147100206Sdd ds = devfs_ruleset_bynum(dm->dm_ruleset); 148100206Sdd KASSERT(ds != NULL, ("mount-point has NULL ruleset")); 149150147Sphk devfs_ruleset_applyde(ds, de, devfs_rule_depth); 150150150Sphk sx_sunlock(&sx_rules); 151100206Sdd} 152100206Sdd 153100206Sdd/* 154100206Sdd * Rule subsystem ioctl hook. 155100206Sdd */ 156100206Sddint 157150149Sphkdevfs_rules_ioctl(struct devfs_mount *dm, u_long cmd, caddr_t data, struct thread *td) 158100206Sdd{ 159100206Sdd struct devfs_ruleset *ds; 160100206Sdd struct devfs_krule *dk; 161100206Sdd struct devfs_rule *dr; 162100206Sdd devfs_rsnum rsnum; 163100206Sdd devfs_rnum rnum; 164100206Sdd devfs_rid rid; 165100206Sdd int error; 166100206Sdd 167150342Sphk sx_assert(&dm->dm_lock, SX_XLOCKED); 168150342Sphk 169100206Sdd /* 170164033Srwatson * XXX: This returns an error regardless of whether we actually 171164033Srwatson * support the cmd or not. 172164033Srwatson * 173164033Srwatson * We could make this privileges finer grained if desired. 174100206Sdd */ 175164033Srwatson error = priv_check(td, PRIV_DEVFS_RULE); 176164033Srwatson if (error) 177100206Sdd return (error); 178100206Sdd 179150150Sphk sx_xlock(&sx_rules); 180150342Sphk 181100206Sdd switch (cmd) { 182100206Sdd case DEVFSIO_RADD: 183100206Sdd dr = (struct devfs_rule *)data; 184100206Sdd error = devfs_rule_input(dr, dm); 185100206Sdd if (error != 0) 186150501Sphk break; 187100206Sdd dk = devfs_rule_byid(dr->dr_id); 188100206Sdd if (dk != NULL) { 189100206Sdd error = EEXIST; 190150501Sphk break; 191100206Sdd } 192153986Srwatson if (rid2rsn(dr->dr_id) == 0) { 193153986Srwatson error = EIO; 194153986Srwatson break; 195153986Srwatson } 196100206Sdd error = devfs_rule_insert(dr); 197100206Sdd break; 198100206Sdd case DEVFSIO_RAPPLY: 199100206Sdd dr = (struct devfs_rule *)data; 200100206Sdd error = devfs_rule_input(dr, dm); 201100206Sdd if (error != 0) 202150501Sphk break; 203100206Sdd 204100206Sdd /* 205100206Sdd * This is one of many possible hackish 206100206Sdd * implementations. The primary contender is an 207100206Sdd * implementation where the rule we read in is 208100206Sdd * temporarily inserted into some ruleset, perhaps 209100206Sdd * with a hypothetical DRO_NOAUTO flag so that it 210100206Sdd * doesn't get used where it isn't intended, and 211100206Sdd * applied in the normal way. This can be done in the 212100206Sdd * userland (DEVFSIO_ADD, DEVFSIO_APPLYID, 213100206Sdd * DEVFSIO_DEL) or in the kernel; either way it breaks 214100206Sdd * some corner case assumptions in other parts of the 215100206Sdd * code (not that this implementation doesn't do 216100206Sdd * that). 217100206Sdd */ 218100206Sdd if (dr->dr_iacts & DRA_INCSET && 219100206Sdd devfs_ruleset_bynum(dr->dr_incset) == NULL) { 220100206Sdd error = ESRCH; 221150501Sphk break; 222100206Sdd } 223111119Simp dk = malloc(sizeof(*dk), M_TEMP, M_WAITOK | M_ZERO); 224100206Sdd memcpy(&dk->dk_rule, dr, sizeof(*dr)); 225100206Sdd devfs_rule_applydm(dk, dm); 226100206Sdd free(dk, M_TEMP); 227100206Sdd break; 228100206Sdd case DEVFSIO_RAPPLYID: 229100206Sdd rid = *(devfs_rid *)data; 230100206Sdd rid = devfs_rid_input(rid, dm); 231100206Sdd dk = devfs_rule_byid(rid); 232100206Sdd if (dk == NULL) { 233100206Sdd error = ENOENT; 234150501Sphk break; 235100206Sdd } 236100206Sdd devfs_rule_applydm(dk, dm); 237100206Sdd break; 238100206Sdd case DEVFSIO_RDEL: 239100206Sdd rid = *(devfs_rid *)data; 240100206Sdd rid = devfs_rid_input(rid, dm); 241100206Sdd dk = devfs_rule_byid(rid); 242100206Sdd if (dk == NULL) { 243100206Sdd error = ENOENT; 244150501Sphk break; 245100206Sdd } 246100206Sdd ds = dk->dk_ruleset; 247150501Sphk error = devfs_rule_delete(dk); 248100206Sdd break; 249100206Sdd case DEVFSIO_RGETNEXT: 250100206Sdd dr = (struct devfs_rule *)data; 251100206Sdd error = devfs_rule_input(dr, dm); 252100206Sdd if (error != 0) 253150501Sphk break; 254100206Sdd /* 255100206Sdd * We can't use devfs_rule_byid() here since that 256100206Sdd * requires the rule specified to exist, but we want 257100206Sdd * getnext(N) to work whether there is a rule N or not 258100206Sdd * (specifically, getnext(0) must work, but we should 259100206Sdd * never have a rule 0 since the add command 260100206Sdd * interprets 0 to mean "auto-number"). 261100206Sdd */ 262100206Sdd ds = devfs_ruleset_bynum(rid2rsn(dr->dr_id)); 263100206Sdd if (ds == NULL) { 264100206Sdd error = ENOENT; 265150501Sphk break; 266100206Sdd } 267100206Sdd rnum = rid2rn(dr->dr_id); 268150501Sphk TAILQ_FOREACH(dk, &ds->ds_rules, dk_list) { 269100206Sdd if (rid2rn(dk->dk_rule.dr_id) > rnum) 270100206Sdd break; 271100206Sdd } 272100206Sdd if (dk == NULL) { 273100206Sdd error = ENOENT; 274150501Sphk break; 275100206Sdd } 276100206Sdd memcpy(dr, &dk->dk_rule, sizeof(*dr)); 277100206Sdd break; 278100206Sdd case DEVFSIO_SUSE: 279100206Sdd rsnum = *(devfs_rsnum *)data; 280100206Sdd error = devfs_ruleset_use(rsnum, dm); 281100206Sdd break; 282100206Sdd case DEVFSIO_SAPPLY: 283100206Sdd rsnum = *(devfs_rsnum *)data; 284100206Sdd rsnum = rid2rsn(devfs_rid_input(mkrid(rsnum, 0), dm)); 285100206Sdd ds = devfs_ruleset_bynum(rsnum); 286100206Sdd if (ds == NULL) { 287100206Sdd error = ESRCH; 288150501Sphk break; 289100206Sdd } 290100206Sdd devfs_ruleset_applydm(ds, dm); 291100206Sdd break; 292100206Sdd case DEVFSIO_SGETNEXT: 293100206Sdd rsnum = *(devfs_rsnum *)data; 294150501Sphk TAILQ_FOREACH(ds, &devfs_rulesets, ds_list) { 295100206Sdd if (ds->ds_number > rsnum) 296100206Sdd break; 297100206Sdd } 298150501Sphk if (ds == NULL) { 299100206Sdd error = ENOENT; 300150501Sphk break; 301100206Sdd } 302150501Sphk *(devfs_rsnum *)data = ds->ds_number; 303100206Sdd break; 304100206Sdd default: 305100206Sdd error = ENOIOCTL; 306100206Sdd break; 307100206Sdd } 308100206Sdd 309150150Sphk sx_xunlock(&sx_rules); 310100206Sdd return (error); 311100206Sdd} 312100206Sdd 313100206Sdd/* 314100206Sdd * Adjust the rule identifier to use the ruleset of dm if one isn't 315100206Sdd * explicitly specified. 316100206Sdd * 317100206Sdd * Note that after this operation, rid2rsn(rid) might still be 0, and 318100206Sdd * that's okay; ruleset 0 is a valid ruleset, but when it's read in 319100206Sdd * from the userland, it means "current ruleset for this mount-point". 320100206Sdd */ 321100206Sddstatic devfs_rid 322100206Sdddevfs_rid_input(devfs_rid rid, struct devfs_mount *dm) 323100206Sdd{ 324100206Sdd 325100206Sdd if (rid2rsn(rid) == 0) 326100206Sdd return (mkrid(dm->dm_ruleset, rid2rn(rid))); 327100206Sdd else 328100206Sdd return (rid); 329100206Sdd} 330100206Sdd 331100206Sdd/* 332100206Sdd * Apply dk to de and everything under de. 333100206Sdd * 334100206Sdd * XXX: This method needs a function call for every nested 335100206Sdd * subdirectory in a devfs mount. If we plan to have many of these, 336100206Sdd * we might eventually run out of kernel stack space. 337150342Sphk * XXX: a linear search could be done through the cdev list instead. 338100206Sdd */ 339100206Sddstatic void 340100206Sdddevfs_rule_applyde_recursive(struct devfs_krule *dk, struct devfs_dirent *de) 341100206Sdd{ 342100206Sdd struct devfs_dirent *de2; 343100206Sdd 344150147Sphk TAILQ_FOREACH(de2, &de->de_dlist, de_list) 345100206Sdd devfs_rule_applyde_recursive(dk, de2); 346150147Sphk devfs_rule_run(dk, de, devfs_rule_depth); 347100206Sdd} 348100206Sdd 349100206Sdd/* 350100206Sdd * Apply dk to all entires in dm. 351100206Sdd */ 352100206Sddstatic void 353100206Sdddevfs_rule_applydm(struct devfs_krule *dk, struct devfs_mount *dm) 354100206Sdd{ 355100206Sdd 356149107Sphk devfs_rule_applyde_recursive(dk, dm->dm_rootdir); 357100206Sdd} 358100206Sdd 359100206Sdd/* 360100206Sdd * Automatically select a number for a new rule in ds, and write the 361100206Sdd * result into rnump. 362100206Sdd */ 363100206Sddstatic int 364100206Sdddevfs_rule_autonumber(struct devfs_ruleset *ds, devfs_rnum *rnump) 365100206Sdd{ 366100206Sdd struct devfs_krule *dk; 367100206Sdd 368100206Sdd /* Find the last rule. */ 369150501Sphk dk = TAILQ_LAST(&ds->ds_rules, rulehead); 370100206Sdd if (dk == NULL) 371100206Sdd *rnump = 100; 372100206Sdd else { 373100206Sdd *rnump = rid2rn(dk->dk_rule.dr_id) + 100; 374100206Sdd /* Detect overflow. */ 375100206Sdd if (*rnump < rid2rn(dk->dk_rule.dr_id)) 376100206Sdd return (ERANGE); 377100206Sdd } 378100206Sdd KASSERT(devfs_rule_byid(mkrid(ds->ds_number, *rnump)) == NULL, 379100206Sdd ("autonumbering resulted in an already existing rule")); 380100206Sdd return (0); 381100206Sdd} 382100206Sdd 383100206Sdd/* 384100206Sdd * Find a krule by id. 385100206Sdd */ 386100206Sddstatic struct devfs_krule * 387100206Sdddevfs_rule_byid(devfs_rid rid) 388100206Sdd{ 389100206Sdd struct devfs_ruleset *ds; 390100206Sdd struct devfs_krule *dk; 391100206Sdd devfs_rnum rn; 392100206Sdd 393100206Sdd rn = rid2rn(rid); 394100206Sdd ds = devfs_ruleset_bynum(rid2rsn(rid)); 395100206Sdd if (ds == NULL) 396100206Sdd return (NULL); 397150501Sphk TAILQ_FOREACH(dk, &ds->ds_rules, dk_list) { 398100206Sdd if (rid2rn(dk->dk_rule.dr_id) == rn) 399100206Sdd return (dk); 400100206Sdd else if (rid2rn(dk->dk_rule.dr_id) > rn) 401100206Sdd break; 402100206Sdd } 403100206Sdd return (NULL); 404100206Sdd} 405100206Sdd 406100206Sdd/* 407100206Sdd * Remove dkp from any lists it may be on and remove memory associated 408100206Sdd * with it. 409100206Sdd */ 410100206Sddstatic int 411150501Sphkdevfs_rule_delete(struct devfs_krule *dk) 412100206Sdd{ 413100206Sdd struct devfs_ruleset *ds; 414100206Sdd 415100206Sdd if (dk->dk_rule.dr_iacts & DRA_INCSET) { 416100206Sdd ds = devfs_ruleset_bynum(dk->dk_rule.dr_incset); 417100206Sdd KASSERT(ds != NULL, ("DRA_INCSET but bad dr_incset")); 418100206Sdd --ds->ds_refcount; 419150501Sphk devfs_ruleset_reap(ds); 420100206Sdd } 421150501Sphk ds = dk->dk_ruleset; 422150501Sphk TAILQ_REMOVE(&ds->ds_rules, dk, dk_list); 423150501Sphk devfs_ruleset_reap(ds); 424150501Sphk free(dk, M_DEVFSRULE); 425100206Sdd return (0); 426100206Sdd} 427100206Sdd 428100206Sdd/* 429130585Sphk * Get a struct cdev *corresponding to de so we can try to match rules based 430130585Sphk * on it. If this routine returns NULL, there is no struct cdev *associated 431100206Sdd * with the dirent (symlinks and directories don't have dev_ts), and 432100206Sdd * the caller should assume that any critera dependent on a dev_t 433100206Sdd * don't match. 434100206Sdd */ 435130585Sphkstatic struct cdev * 436100206Sdddevfs_rule_getdev(struct devfs_dirent *de) 437100206Sdd{ 438100206Sdd 439150342Sphk if (de->de_cdp == NULL) 440150342Sphk return (NULL); 441150342Sphk if (de->de_cdp->cdp_flags & CDP_ACTIVE) 442150342Sphk return (&de->de_cdp->cdp_c); 443100206Sdd else 444150342Sphk return (NULL); 445100206Sdd} 446100206Sdd 447100206Sdd/* 448100206Sdd * Do what we need to do to a rule that we just loaded from the 449100206Sdd * userland. In particular, we need to check the magic, and adjust 450100206Sdd * the ruleset appropriate if desired. 451100206Sdd */ 452100206Sddstatic int 453100206Sdddevfs_rule_input(struct devfs_rule *dr, struct devfs_mount *dm) 454100206Sdd{ 455100206Sdd 456100206Sdd if (dr->dr_magic != DEVFS_MAGIC) 457100206Sdd return (ERPCMISMATCH); 458100206Sdd dr->dr_id = devfs_rid_input(dr->dr_id, dm); 459100206Sdd return (0); 460100206Sdd} 461100206Sdd 462100206Sdd/* 463100206Sdd * Import dr into the appropriate place in the kernel (i.e., make a 464100206Sdd * krule). The value of dr is copied, so the pointer may be destroyed 465100206Sdd * after this call completes. 466100206Sdd */ 467100206Sddstatic int 468100206Sdddevfs_rule_insert(struct devfs_rule *dr) 469100206Sdd{ 470100206Sdd struct devfs_ruleset *ds, *dsi; 471150501Sphk struct devfs_krule *k1; 472100206Sdd struct devfs_krule *dk; 473100206Sdd devfs_rsnum rsnum; 474100206Sdd devfs_rnum dkrn; 475100206Sdd int error; 476100206Sdd 477100206Sdd /* 478100206Sdd * This stuff seems out of place here, but we want to do it as 479100206Sdd * soon as possible so that if it fails, we don't have to roll 480100206Sdd * back any changes we already made (e.g., ruleset creation). 481100206Sdd */ 482100206Sdd if (dr->dr_iacts & DRA_INCSET) { 483100206Sdd dsi = devfs_ruleset_bynum(dr->dr_incset); 484100206Sdd if (dsi == NULL) 485100206Sdd return (ESRCH); 486100206Sdd } else 487100206Sdd dsi = NULL; 488100206Sdd 489100206Sdd rsnum = rid2rsn(dr->dr_id); 490150501Sphk KASSERT(rsnum != 0, ("Inserting into ruleset zero")); 491150501Sphk 492100206Sdd ds = devfs_ruleset_bynum(rsnum); 493100206Sdd if (ds == NULL) 494100206Sdd ds = devfs_ruleset_create(rsnum); 495100206Sdd dkrn = rid2rn(dr->dr_id); 496100206Sdd if (dkrn == 0) { 497100206Sdd error = devfs_rule_autonumber(ds, &dkrn); 498150501Sphk if (error != 0) { 499150501Sphk devfs_ruleset_reap(ds); 500100206Sdd return (error); 501150501Sphk } 502100206Sdd } 503100206Sdd 504150501Sphk dk = malloc(sizeof(*dk), M_DEVFSRULE, M_WAITOK | M_ZERO); 505100206Sdd dk->dk_ruleset = ds; 506100206Sdd if (dsi != NULL) 507100206Sdd ++dsi->ds_refcount; 508100206Sdd /* XXX: Inspect dr? */ 509100206Sdd memcpy(&dk->dk_rule, dr, sizeof(*dr)); 510100206Sdd dk->dk_rule.dr_id = mkrid(rid2rsn(dk->dk_rule.dr_id), dkrn); 511100206Sdd 512150501Sphk TAILQ_FOREACH(k1, &ds->ds_rules, dk_list) { 513150501Sphk if (rid2rn(k1->dk_rule.dr_id) > dkrn) { 514150501Sphk TAILQ_INSERT_BEFORE(k1, dk, dk_list); 515150501Sphk break; 516100206Sdd } 517100206Sdd } 518150501Sphk if (k1 == NULL) 519150501Sphk TAILQ_INSERT_TAIL(&ds->ds_rules, dk, dk_list); 520100206Sdd return (0); 521100206Sdd} 522100206Sdd 523100206Sdd/* 524100206Sdd * Determine whether dk matches de. Returns 1 if dk should be run on 525100206Sdd * de; 0, otherwise. 526100206Sdd */ 527100206Sddstatic int 528100206Sdddevfs_rule_match(struct devfs_krule *dk, struct devfs_dirent *de) 529100206Sdd{ 530100206Sdd struct devfs_rule *dr = &dk->dk_rule; 531130585Sphk struct cdev *dev; 532177458Skib struct cdevsw *dsw; 533210923Skib int ref; 534100206Sdd 535100206Sdd dev = devfs_rule_getdev(de); 536100206Sdd /* 537100206Sdd * At this point, if dev is NULL, we should assume that any 538100206Sdd * criteria that depend on it don't match. We should *not* 539100206Sdd * just ignore them (i.e., act like they weren't specified), 540100206Sdd * since that makes a rule that only has criteria dependent on 541130585Sphk * the struct cdev *match all symlinks and directories. 542100206Sdd * 543100206Sdd * Note also that the following tests are somewhat reversed: 544100206Sdd * They're actually testing to see whether the condition does 545100206Sdd * *not* match, since the default is to assume the rule should 546100206Sdd * be run (such as if there are no conditions). 547100206Sdd */ 548177458Skib if (dr->dr_icond & DRC_DSWFLAGS) { 549177458Skib if (dev == NULL) 550150147Sphk return (0); 551210923Skib dsw = dev_refthread(dev, &ref); 552177458Skib if (dsw == NULL) 553177458Skib return (0); 554177458Skib if ((dsw->d_flags & dr->dr_dswflags) == 0) { 555210923Skib dev_relthread(dev, ref); 556177458Skib return (0); 557177458Skib } 558210923Skib dev_relthread(dev, ref); 559177458Skib } 560100206Sdd if (dr->dr_icond & DRC_PATHPTRN) 561100206Sdd if (!devfs_rule_matchpath(dk, de)) 562150147Sphk return (0); 563100206Sdd 564100206Sdd return (1); 565100206Sdd} 566100206Sdd 567100206Sdd/* 568100206Sdd * Determine whether dk matches de on account of dr_pathptrn. 569100206Sdd */ 570100206Sddstatic int 571100206Sdddevfs_rule_matchpath(struct devfs_krule *dk, struct devfs_dirent *de) 572100206Sdd{ 573100206Sdd struct devfs_rule *dr = &dk->dk_rule; 574100206Sdd char *pname; 575130585Sphk struct cdev *dev; 576100206Sdd 577100206Sdd dev = devfs_rule_getdev(de); 578100206Sdd if (dev != NULL) 579100206Sdd pname = dev->si_name; 580124798Scperciva else if (de->de_dirent->d_type == DT_LNK || 581124804Scperciva de->de_dirent->d_type == DT_DIR) 582109090Sdd pname = de->de_dirent->d_name; 583100206Sdd else 584100206Sdd return (0); 585100206Sdd KASSERT(pname != NULL, ("devfs_rule_matchpath: NULL pname")); 586100206Sdd 587104653Sdd return (fnmatch(dr->dr_pathptrn, pname, 0) == 0); 588100206Sdd} 589100206Sdd 590100206Sdd/* 591100206Sdd * Run dk on de. 592100206Sdd */ 593100206Sddstatic void 594150147Sphkdevfs_rule_run(struct devfs_krule *dk, struct devfs_dirent *de, unsigned depth) 595100206Sdd{ 596100206Sdd struct devfs_rule *dr = &dk->dk_rule; 597100206Sdd struct devfs_ruleset *ds; 598100206Sdd 599150147Sphk if (!devfs_rule_match(dk, de)) 600150147Sphk return; 601100206Sdd if (dr->dr_iacts & DRA_BACTS) { 602100206Sdd if (dr->dr_bacts & DRB_HIDE) 603100206Sdd de->de_flags |= DE_WHITEOUT; 604100206Sdd if (dr->dr_bacts & DRB_UNHIDE) 605100206Sdd de->de_flags &= ~DE_WHITEOUT; 606100206Sdd } 607100206Sdd if (dr->dr_iacts & DRA_UID) 608100206Sdd de->de_uid = dr->dr_uid; 609100206Sdd if (dr->dr_iacts & DRA_GID) 610100206Sdd de->de_gid = dr->dr_gid; 611100206Sdd if (dr->dr_iacts & DRA_MODE) 612100206Sdd de->de_mode = dr->dr_mode; 613100206Sdd if (dr->dr_iacts & DRA_INCSET) { 614150147Sphk /* 615150147Sphk * XXX: we should tell the user if the depth is exceeded here 616150147Sphk * XXX: but it is not obvious how to. A return value will 617150147Sphk * XXX: not work as this is called when devices are created 618150147Sphk * XXX: long time after the rules were instantiated. 619150147Sphk * XXX: a printf() would probably give too much noise, or 620227489Seadler * XXX: DoS the machine. I guess a rate-limited message 621150147Sphk * XXX: might work. 622150147Sphk */ 623150147Sphk if (depth > 0) { 624150147Sphk ds = devfs_ruleset_bynum(dk->dk_rule.dr_incset); 625150147Sphk KASSERT(ds != NULL, ("DRA_INCSET but bad dr_incset")); 626150147Sphk devfs_ruleset_applyde(ds, de, depth - 1); 627150147Sphk } 628100206Sdd } 629100206Sdd} 630100206Sdd 631100206Sdd/* 632100206Sdd * Apply all the rules in ds to de. 633100206Sdd */ 634100206Sddstatic void 635150147Sphkdevfs_ruleset_applyde(struct devfs_ruleset *ds, struct devfs_dirent *de, unsigned depth) 636100206Sdd{ 637100206Sdd struct devfs_krule *dk; 638100206Sdd 639150501Sphk TAILQ_FOREACH(dk, &ds->ds_rules, dk_list) 640150147Sphk devfs_rule_run(dk, de, depth); 641100206Sdd} 642100206Sdd 643100206Sdd/* 644100206Sdd * Apply all the rules in ds to all the entires in dm. 645100206Sdd */ 646100206Sddstatic void 647100206Sdddevfs_ruleset_applydm(struct devfs_ruleset *ds, struct devfs_mount *dm) 648100206Sdd{ 649100206Sdd struct devfs_krule *dk; 650100206Sdd 651100206Sdd /* 652100206Sdd * XXX: Does it matter whether we do 653100206Sdd * 654100206Sdd * foreach(dk in ds) 655100206Sdd * foreach(de in dm) 656100206Sdd * apply(dk to de) 657100206Sdd * 658100206Sdd * as opposed to 659100206Sdd * 660100206Sdd * foreach(de in dm) 661100206Sdd * foreach(dk in ds) 662100206Sdd * apply(dk to de) 663100206Sdd * 664100206Sdd * The end result is obviously the same, but does the order 665100206Sdd * matter? 666100206Sdd */ 667150501Sphk TAILQ_FOREACH(dk, &ds->ds_rules, dk_list) 668100206Sdd devfs_rule_applydm(dk, dm); 669100206Sdd} 670100206Sdd 671100206Sdd/* 672100206Sdd * Find a ruleset by number. 673100206Sdd */ 674100206Sddstatic struct devfs_ruleset * 675100206Sdddevfs_ruleset_bynum(devfs_rsnum rsnum) 676100206Sdd{ 677100206Sdd struct devfs_ruleset *ds; 678100206Sdd 679150501Sphk TAILQ_FOREACH(ds, &devfs_rulesets, ds_list) { 680100206Sdd if (ds->ds_number == rsnum) 681100206Sdd return (ds); 682100206Sdd } 683100206Sdd return (NULL); 684100206Sdd} 685100206Sdd 686100206Sdd/* 687100206Sdd * Create a new ruleset. 688100206Sdd */ 689100206Sddstatic struct devfs_ruleset * 690100206Sdddevfs_ruleset_create(devfs_rsnum rsnum) 691100206Sdd{ 692150501Sphk struct devfs_ruleset *s1; 693100206Sdd struct devfs_ruleset *ds; 694100206Sdd 695150501Sphk KASSERT(rsnum != 0, ("creating ruleset zero")); 696150501Sphk 697100206Sdd KASSERT(devfs_ruleset_bynum(rsnum) == NULL, 698100206Sdd ("creating already existent ruleset %d", rsnum)); 699100206Sdd 700150501Sphk ds = malloc(sizeof(*ds), M_DEVFSRULE, M_WAITOK | M_ZERO); 701100206Sdd ds->ds_number = rsnum; 702150501Sphk TAILQ_INIT(&ds->ds_rules); 703100206Sdd 704150501Sphk TAILQ_FOREACH(s1, &devfs_rulesets, ds_list) { 705150501Sphk if (s1->ds_number > rsnum) { 706150501Sphk TAILQ_INSERT_BEFORE(s1, ds, ds_list); 707150501Sphk break; 708100206Sdd } 709100206Sdd } 710150501Sphk if (s1 == NULL) 711150501Sphk TAILQ_INSERT_TAIL(&devfs_rulesets, ds, ds_list); 712100206Sdd return (ds); 713100206Sdd} 714100206Sdd 715100206Sdd/* 716100206Sdd * Remove a ruleset from the system if it's empty and not used 717100206Sdd * anywhere. This should be called after every time a rule is deleted 718100206Sdd * from this ruleset or the reference count is decremented. 719100206Sdd */ 720100206Sddstatic void 721150501Sphkdevfs_ruleset_reap(struct devfs_ruleset *ds) 722100206Sdd{ 723100206Sdd 724150501Sphk KASSERT(ds->ds_number != 0, ("reaping ruleset zero ")); 725150501Sphk 726150501Sphk if (!TAILQ_EMPTY(&ds->ds_rules) || ds->ds_refcount != 0) 727150501Sphk return; 728150501Sphk 729150501Sphk TAILQ_REMOVE(&devfs_rulesets, ds, ds_list); 730150501Sphk free(ds, M_DEVFSRULE); 731100206Sdd} 732100206Sdd 733100206Sdd/* 734100206Sdd * Make rsnum the active ruleset for dm. 735100206Sdd */ 736100206Sddstatic int 737100206Sdddevfs_ruleset_use(devfs_rsnum rsnum, struct devfs_mount *dm) 738100206Sdd{ 739100206Sdd struct devfs_ruleset *cds, *ds; 740100206Sdd 741150501Sphk if (dm->dm_ruleset != 0) { 742150501Sphk cds = devfs_ruleset_bynum(dm->dm_ruleset); 743150501Sphk --cds->ds_refcount; 744150501Sphk devfs_ruleset_reap(cds); 745150501Sphk } 746100206Sdd 747216391Sjh if (rsnum == 0) { 748216391Sjh dm->dm_ruleset = 0; 749216391Sjh return (0); 750216391Sjh } 751216391Sjh 752179926Sgonzo ds = devfs_ruleset_bynum(rsnum); 753179926Sgonzo if (ds == NULL) 754179926Sgonzo ds = devfs_ruleset_create(rsnum); 755100206Sdd /* These should probably be made atomic somehow. */ 756100206Sdd ++ds->ds_refcount; 757100206Sdd dm->dm_ruleset = rsnum; 758100206Sdd 759100206Sdd return (0); 760100206Sdd} 761150501Sphk 762150501Sphkvoid 763150501Sphkdevfs_rules_cleanup(struct devfs_mount *dm) 764150501Sphk{ 765150501Sphk struct devfs_ruleset *ds; 766150501Sphk 767150501Sphk sx_assert(&dm->dm_lock, SX_XLOCKED); 768150501Sphk if (dm->dm_ruleset != 0) { 769150501Sphk ds = devfs_ruleset_bynum(dm->dm_ruleset); 770150501Sphk --ds->ds_refcount; 771150501Sphk devfs_ruleset_reap(ds); 772150501Sphk } 773150501Sphk} 774