audit_bsm_klib.c revision 184660
1155192Srwatson/* 2184482Srwatson * Copyright (c) 1999-2008 Apple Inc. 3155192Srwatson * Copyright (c) 2005 Robert N. M. Watson 4155192Srwatson * All rights reserved. 5155192Srwatson * 6155192Srwatson * Redistribution and use in source and binary forms, with or without 7155192Srwatson * modification, are permitted provided that the following conditions 8155192Srwatson * are met: 9155192Srwatson * 1. Redistributions of source code must retain the above copyright 10155192Srwatson * notice, this list of conditions and the following disclaimer. 11155192Srwatson * 2. Redistributions in binary form must reproduce the above copyright 12155192Srwatson * notice, this list of conditions and the following disclaimer in the 13155192Srwatson * documentation and/or other materials provided with the distribution. 14180701Srwatson * 3. Neither the name of Apple Inc. ("Apple") nor the names of 15155192Srwatson * its contributors may be used to endorse or promote products derived 16155192Srwatson * from this software without specific prior written permission. 17155192Srwatson * 18155192Srwatson * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND 19155192Srwatson * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20155192Srwatson * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21155192Srwatson * ARE DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR 22155192Srwatson * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23155192Srwatson * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24155192Srwatson * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25155192Srwatson * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 26155192Srwatson * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 27155192Srwatson * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28155192Srwatson * POSSIBILITY OF SUCH DAMAGE. 29155192Srwatson */ 30155192Srwatson 31178186Srwatson#include <sys/cdefs.h> 32178186Srwatson__FBSDID("$FreeBSD: head/sys/security/audit/audit_bsm_klib.c 184660 2008-11-04 22:30:24Z jhb $"); 33178186Srwatson 34155192Srwatson#include <sys/param.h> 35155192Srwatson#include <sys/fcntl.h> 36155192Srwatson#include <sys/filedesc.h> 37155192Srwatson#include <sys/libkern.h> 38155192Srwatson#include <sys/malloc.h> 39155192Srwatson#include <sys/mount.h> 40155192Srwatson#include <sys/proc.h> 41184482Srwatson#include <sys/rwlock.h> 42155192Srwatson#include <sys/sem.h> 43181060Scsjp#include <sys/sbuf.h> 44155192Srwatson#include <sys/syscall.h> 45155192Srwatson#include <sys/sysctl.h> 46155192Srwatson#include <sys/sysent.h> 47155192Srwatson#include <sys/vnode.h> 48155192Srwatson 49155192Srwatson#include <bsm/audit.h> 50155192Srwatson#include <bsm/audit_kevents.h> 51155192Srwatson#include <security/audit/audit.h> 52155192Srwatson#include <security/audit/audit_private.h> 53155192Srwatson 54155192Srwatson/* 55155192Srwatson * Hash table functions for the audit event number to event class mask 56155192Srwatson * mapping. 57155192Srwatson */ 58180735Srwatson#define EVCLASSMAP_HASH_TABLE_SIZE 251 59155192Srwatsonstruct evclass_elem { 60155192Srwatson au_event_t event; 61155192Srwatson au_class_t class; 62155192Srwatson LIST_ENTRY(evclass_elem) entry; 63155192Srwatson}; 64155192Srwatsonstruct evclass_list { 65155192Srwatson LIST_HEAD(, evclass_elem) head; 66155192Srwatson}; 67155192Srwatson 68155192Srwatsonstatic MALLOC_DEFINE(M_AUDITEVCLASS, "audit_evclass", "Audit event class"); 69184482Srwatsonstatic struct rwlock evclass_lock; 70156889Srwatsonstatic struct evclass_list evclass_hash[EVCLASSMAP_HASH_TABLE_SIZE]; 71155192Srwatson 72184482Srwatson#define EVCLASS_LOCK_INIT() rw_init(&evclass_lock, "evclass_lock") 73184482Srwatson#define EVCLASS_RLOCK() rw_rlock(&evclass_lock) 74184482Srwatson#define EVCLASS_RUNLOCK() rw_runlock(&evclass_lock) 75184482Srwatson#define EVCLASS_WLOCK() rw_wlock(&evclass_lock) 76184482Srwatson#define EVCLASS_WUNLOCK() rw_wunlock(&evclass_lock) 77184482Srwatson 78155192Srwatson/* 79155192Srwatson * Look up the class for an audit event in the class mapping table. 80155192Srwatson */ 81155192Srwatsonau_class_t 82155192Srwatsonau_event_class(au_event_t event) 83155192Srwatson{ 84155192Srwatson struct evclass_list *evcl; 85155192Srwatson struct evclass_elem *evc; 86155192Srwatson au_class_t class; 87155192Srwatson 88184482Srwatson EVCLASS_RLOCK(); 89155192Srwatson evcl = &evclass_hash[event % EVCLASSMAP_HASH_TABLE_SIZE]; 90173142Srwatson class = 0; 91155192Srwatson LIST_FOREACH(evc, &evcl->head, entry) { 92155192Srwatson if (evc->event == event) { 93155192Srwatson class = evc->class; 94155192Srwatson goto out; 95155192Srwatson } 96155192Srwatson } 97155192Srwatsonout: 98184482Srwatson EVCLASS_RUNLOCK(); 99155192Srwatson return (class); 100155192Srwatson} 101155192Srwatson 102156889Srwatson/* 103155192Srwatson * Insert a event to class mapping. If the event already exists in the 104155192Srwatson * mapping, then replace the mapping with the new one. 105156889Srwatson * 106155192Srwatson * XXX There is currently no constraints placed on the number of mappings. 107156889Srwatson * May want to either limit to a number, or in terms of memory usage. 108155192Srwatson */ 109155192Srwatsonvoid 110156889Srwatsonau_evclassmap_insert(au_event_t event, au_class_t class) 111155192Srwatson{ 112155192Srwatson struct evclass_list *evcl; 113155192Srwatson struct evclass_elem *evc, *evc_new; 114155192Srwatson 115155192Srwatson /* 116155192Srwatson * Pessimistically, always allocate storage before acquiring mutex. 117155192Srwatson * Free if there is already a mapping for this event. 118155192Srwatson */ 119155192Srwatson evc_new = malloc(sizeof(*evc), M_AUDITEVCLASS, M_WAITOK); 120155192Srwatson 121184482Srwatson EVCLASS_WLOCK(); 122155192Srwatson evcl = &evclass_hash[event % EVCLASSMAP_HASH_TABLE_SIZE]; 123155192Srwatson LIST_FOREACH(evc, &evcl->head, entry) { 124155192Srwatson if (evc->event == event) { 125155192Srwatson evc->class = class; 126184482Srwatson EVCLASS_WUNLOCK(); 127155192Srwatson free(evc_new, M_AUDITEVCLASS); 128155192Srwatson return; 129155192Srwatson } 130155192Srwatson } 131155192Srwatson evc = evc_new; 132155192Srwatson evc->event = event; 133155192Srwatson evc->class = class; 134155192Srwatson LIST_INSERT_HEAD(&evcl->head, evc, entry); 135184482Srwatson EVCLASS_WUNLOCK(); 136155192Srwatson} 137155192Srwatson 138155192Srwatsonvoid 139156889Srwatsonau_evclassmap_init(void) 140155192Srwatson{ 141155192Srwatson int i; 142155192Srwatson 143184482Srwatson EVCLASS_LOCK_INIT(); 144155192Srwatson for (i = 0; i < EVCLASSMAP_HASH_TABLE_SIZE; i++) 145155192Srwatson LIST_INIT(&evclass_hash[i].head); 146155192Srwatson 147155192Srwatson /* 148155192Srwatson * Set up the initial event to class mapping for system calls. 149155192Srwatson * 150155192Srwatson * XXXRW: Really, this should walk all possible audit events, not all 151155192Srwatson * native ABI system calls, as there may be audit events reachable 152155192Srwatson * only through non-native system calls. It also seems a shame to 153155192Srwatson * frob the mutex this early. 154156889Srwatson */ 155155192Srwatson for (i = 0; i < SYS_MAXSYSCALL; i++) { 156155192Srwatson if (sysent[i].sy_auevent != AUE_NULL) 157173142Srwatson au_evclassmap_insert(sysent[i].sy_auevent, 0); 158155192Srwatson } 159155192Srwatson} 160155192Srwatson 161155192Srwatson/* 162155192Srwatson * Check whether an event is aditable by comparing the mask of classes this 163155192Srwatson * event is part of against the given mask. 164155192Srwatson */ 165155192Srwatsonint 166159269Srwatsonau_preselect(au_event_t event, au_class_t class, au_mask_t *mask_p, int sorf) 167155192Srwatson{ 168155192Srwatson au_class_t effmask = 0; 169155192Srwatson 170155192Srwatson if (mask_p == NULL) 171155192Srwatson return (-1); 172155192Srwatson 173156889Srwatson /* 174155192Srwatson * Perform the actual check of the masks against the event. 175155192Srwatson */ 176155192Srwatson if (sorf & AU_PRS_SUCCESS) 177159269Srwatson effmask |= (mask_p->am_success & class); 178156889Srwatson 179155192Srwatson if (sorf & AU_PRS_FAILURE) 180159269Srwatson effmask |= (mask_p->am_failure & class); 181156889Srwatson 182155192Srwatson if (effmask) 183155192Srwatson return (1); 184156889Srwatson else 185155192Srwatson return (0); 186155192Srwatson} 187155192Srwatson 188155192Srwatson/* 189156889Srwatson * Convert sysctl names and present arguments to events. 190155192Srwatson */ 191155192Srwatsonau_event_t 192176690Srwatsonaudit_ctlname_to_sysctlevent(int name[], uint64_t valid_arg) 193155192Srwatson{ 194155192Srwatson 195155192Srwatson /* can't parse it - so return the worst case */ 196156889Srwatson if ((valid_arg & (ARG_CTLNAME | ARG_LEN)) != (ARG_CTLNAME | ARG_LEN)) 197155192Srwatson return (AUE_SYSCTL); 198155192Srwatson 199155192Srwatson switch (name[0]) { 200155192Srwatson /* non-admin "lookups" treat them special */ 201155192Srwatson case KERN_OSTYPE: 202155192Srwatson case KERN_OSRELEASE: 203155192Srwatson case KERN_OSREV: 204155192Srwatson case KERN_VERSION: 205155192Srwatson case KERN_ARGMAX: 206155192Srwatson case KERN_CLOCKRATE: 207155192Srwatson case KERN_BOOTTIME: 208155192Srwatson case KERN_POSIX1: 209155192Srwatson case KERN_NGROUPS: 210155192Srwatson case KERN_JOB_CONTROL: 211155192Srwatson case KERN_SAVED_IDS: 212155192Srwatson case KERN_OSRELDATE: 213155192Srwatson case KERN_DUMMY: 214155192Srwatson return (AUE_SYSCTL_NONADMIN); 215155192Srwatson 216155192Srwatson /* only treat the changeable controls as admin */ 217155192Srwatson case KERN_MAXVNODES: 218155192Srwatson case KERN_MAXPROC: 219155192Srwatson case KERN_MAXFILES: 220155192Srwatson case KERN_MAXPROCPERUID: 221155192Srwatson case KERN_MAXFILESPERPROC: 222155192Srwatson case KERN_HOSTID: 223155192Srwatson case KERN_SECURELVL: 224155192Srwatson case KERN_HOSTNAME: 225155192Srwatson case KERN_VNODE: 226155192Srwatson case KERN_PROC: 227155192Srwatson case KERN_FILE: 228155192Srwatson case KERN_PROF: 229155192Srwatson case KERN_NISDOMAINNAME: 230155192Srwatson case KERN_UPDATEINTERVAL: 231155192Srwatson case KERN_NTP_PLL: 232155192Srwatson case KERN_BOOTFILE: 233155192Srwatson case KERN_DUMPDEV: 234155192Srwatson case KERN_IPC: 235155192Srwatson case KERN_PS_STRINGS: 236155192Srwatson case KERN_USRSTACK: 237155192Srwatson case KERN_LOGSIGEXIT: 238155192Srwatson case KERN_IOV_MAX: 239155192Srwatson case KERN_MAXID: 240155192Srwatson return ((valid_arg & ARG_VALUE) ? 241181053Srwatson AUE_SYSCTL : AUE_SYSCTL_NONADMIN); 242155192Srwatson 243155192Srwatson default: 244155192Srwatson return (AUE_SYSCTL); 245155192Srwatson } 246155192Srwatson /* NOTREACHED */ 247155192Srwatson} 248155192Srwatson 249155192Srwatson/* 250156889Srwatson * Convert an open flags specifier into a specific type of open event for 251155192Srwatson * auditing purposes. 252155192Srwatson */ 253155192Srwatsonau_event_t 254176690Srwatsonaudit_flags_and_error_to_openevent(int oflags, int error) 255156889Srwatson{ 256155192Srwatson au_event_t aevent; 257155192Srwatson 258156889Srwatson /* 259156889Srwatson * Need to check only those flags we care about. 260156889Srwatson */ 261155192Srwatson oflags = oflags & (O_RDONLY | O_CREAT | O_TRUNC | O_RDWR | O_WRONLY); 262155192Srwatson 263155192Srwatson /* 264155192Srwatson * These checks determine what flags are on with the condition that 265155192Srwatson * ONLY that combination is on, and no other flags are on. 266155192Srwatson */ 267155192Srwatson switch (oflags) { 268155192Srwatson case O_RDONLY: 269155192Srwatson aevent = AUE_OPEN_R; 270155192Srwatson break; 271155192Srwatson 272155192Srwatson case (O_RDONLY | O_CREAT): 273155192Srwatson aevent = AUE_OPEN_RC; 274155192Srwatson break; 275155192Srwatson 276155192Srwatson case (O_RDONLY | O_CREAT | O_TRUNC): 277155192Srwatson aevent = AUE_OPEN_RTC; 278155192Srwatson break; 279155192Srwatson 280155192Srwatson case (O_RDONLY | O_TRUNC): 281155192Srwatson aevent = AUE_OPEN_RT; 282155192Srwatson break; 283155192Srwatson 284155192Srwatson case O_RDWR: 285155192Srwatson aevent = AUE_OPEN_RW; 286155192Srwatson break; 287155192Srwatson 288155192Srwatson case (O_RDWR | O_CREAT): 289155192Srwatson aevent = AUE_OPEN_RWC; 290155192Srwatson break; 291155192Srwatson 292155192Srwatson case (O_RDWR | O_CREAT | O_TRUNC): 293155192Srwatson aevent = AUE_OPEN_RWTC; 294155192Srwatson break; 295155192Srwatson 296155192Srwatson case (O_RDWR | O_TRUNC): 297155192Srwatson aevent = AUE_OPEN_RWT; 298155192Srwatson break; 299155192Srwatson 300155192Srwatson case O_WRONLY: 301155192Srwatson aevent = AUE_OPEN_W; 302155192Srwatson break; 303155192Srwatson 304155192Srwatson case (O_WRONLY | O_CREAT): 305155192Srwatson aevent = AUE_OPEN_WC; 306155192Srwatson break; 307155192Srwatson 308155192Srwatson case (O_WRONLY | O_CREAT | O_TRUNC): 309155192Srwatson aevent = AUE_OPEN_WTC; 310155192Srwatson break; 311155192Srwatson 312155192Srwatson case (O_WRONLY | O_TRUNC): 313155192Srwatson aevent = AUE_OPEN_WT; 314155192Srwatson break; 315155192Srwatson 316155192Srwatson default: 317155192Srwatson aevent = AUE_OPEN; 318155192Srwatson break; 319155192Srwatson } 320155192Srwatson 321155192Srwatson#if 0 322156889Srwatson /* 323170196Srwatson * Convert chatty errors to better matching events. Failures to 324170196Srwatson * find a file are really just attribute events -- so recast them as 325170196Srwatson * such. 326155192Srwatson * 327155192Srwatson * XXXAUDIT: Solaris defines that AUE_OPEN will never be returned, it 328155192Srwatson * is just a placeholder. However, in Darwin we return that in 329155192Srwatson * preference to other events. For now, comment this out as we don't 330155192Srwatson * have a BSM conversion routine for AUE_OPEN. 331155192Srwatson */ 332155192Srwatson switch (aevent) { 333155192Srwatson case AUE_OPEN_R: 334155192Srwatson case AUE_OPEN_RT: 335155192Srwatson case AUE_OPEN_RW: 336155192Srwatson case AUE_OPEN_RWT: 337155192Srwatson case AUE_OPEN_W: 338155192Srwatson case AUE_OPEN_WT: 339155192Srwatson if (error == ENOENT) 340155192Srwatson aevent = AUE_OPEN; 341155192Srwatson } 342155192Srwatson#endif 343155192Srwatson return (aevent); 344155192Srwatson} 345155192Srwatson 346155192Srwatson/* 347155192Srwatson * Convert a MSGCTL command to a specific event. 348155192Srwatson */ 349155192Srwatsonint 350176565Srwatsonaudit_msgctl_to_event(int cmd) 351155192Srwatson{ 352155192Srwatson 353155192Srwatson switch (cmd) { 354155192Srwatson case IPC_RMID: 355155192Srwatson return (AUE_MSGCTL_RMID); 356155192Srwatson 357155192Srwatson case IPC_SET: 358155192Srwatson return (AUE_MSGCTL_SET); 359155192Srwatson 360155192Srwatson case IPC_STAT: 361155192Srwatson return (AUE_MSGCTL_STAT); 362155192Srwatson 363155192Srwatson default: 364170196Srwatson /* We will audit a bad command. */ 365155192Srwatson return (AUE_MSGCTL); 366155192Srwatson } 367155192Srwatson} 368155192Srwatson 369155192Srwatson/* 370155192Srwatson * Convert a SEMCTL command to a specific event. 371155192Srwatson */ 372155192Srwatsonint 373176565Srwatsonaudit_semctl_to_event(int cmd) 374155192Srwatson{ 375155192Srwatson 376155192Srwatson switch (cmd) { 377155192Srwatson case GETALL: 378155192Srwatson return (AUE_SEMCTL_GETALL); 379155192Srwatson 380155192Srwatson case GETNCNT: 381155192Srwatson return (AUE_SEMCTL_GETNCNT); 382155192Srwatson 383155192Srwatson case GETPID: 384155192Srwatson return (AUE_SEMCTL_GETPID); 385155192Srwatson 386155192Srwatson case GETVAL: 387155192Srwatson return (AUE_SEMCTL_GETVAL); 388155192Srwatson 389155192Srwatson case GETZCNT: 390155192Srwatson return (AUE_SEMCTL_GETZCNT); 391155192Srwatson 392155192Srwatson case IPC_RMID: 393155192Srwatson return (AUE_SEMCTL_RMID); 394155192Srwatson 395155192Srwatson case IPC_SET: 396155192Srwatson return (AUE_SEMCTL_SET); 397155192Srwatson 398155192Srwatson case SETALL: 399155192Srwatson return (AUE_SEMCTL_SETALL); 400155192Srwatson 401155192Srwatson case SETVAL: 402155192Srwatson return (AUE_SEMCTL_SETVAL); 403155192Srwatson 404155192Srwatson case IPC_STAT: 405155192Srwatson return (AUE_SEMCTL_STAT); 406155192Srwatson 407155192Srwatson default: 408181053Srwatson /* We will audit a bad command. */ 409155192Srwatson return (AUE_SEMCTL); 410155192Srwatson } 411155192Srwatson} 412155192Srwatson 413155192Srwatson/* 414155192Srwatson * Convert a command for the auditon() system call to a audit event. 415155192Srwatson */ 416155192Srwatsonint 417155192Srwatsonauditon_command_event(int cmd) 418155192Srwatson{ 419155192Srwatson 420155192Srwatson switch(cmd) { 421155192Srwatson case A_GETPOLICY: 422155192Srwatson return (AUE_AUDITON_GPOLICY); 423155192Srwatson 424155192Srwatson case A_SETPOLICY: 425155192Srwatson return (AUE_AUDITON_SPOLICY); 426155192Srwatson 427155192Srwatson case A_GETKMASK: 428155192Srwatson return (AUE_AUDITON_GETKMASK); 429155192Srwatson 430155192Srwatson case A_SETKMASK: 431155192Srwatson return (AUE_AUDITON_SETKMASK); 432155192Srwatson 433155192Srwatson case A_GETQCTRL: 434155192Srwatson return (AUE_AUDITON_GQCTRL); 435155192Srwatson 436155192Srwatson case A_SETQCTRL: 437155192Srwatson return (AUE_AUDITON_SQCTRL); 438155192Srwatson 439155192Srwatson case A_GETCWD: 440155192Srwatson return (AUE_AUDITON_GETCWD); 441155192Srwatson 442155192Srwatson case A_GETCAR: 443155192Srwatson return (AUE_AUDITON_GETCAR); 444155192Srwatson 445155192Srwatson case A_GETSTAT: 446155192Srwatson return (AUE_AUDITON_GETSTAT); 447155192Srwatson 448155192Srwatson case A_SETSTAT: 449155192Srwatson return (AUE_AUDITON_SETSTAT); 450155192Srwatson 451155192Srwatson case A_SETUMASK: 452155192Srwatson return (AUE_AUDITON_SETUMASK); 453155192Srwatson 454155192Srwatson case A_SETSMASK: 455155192Srwatson return (AUE_AUDITON_SETSMASK); 456155192Srwatson 457155192Srwatson case A_GETCOND: 458155192Srwatson return (AUE_AUDITON_GETCOND); 459155192Srwatson 460155192Srwatson case A_SETCOND: 461155192Srwatson return (AUE_AUDITON_SETCOND); 462155192Srwatson 463155192Srwatson case A_GETCLASS: 464155192Srwatson return (AUE_AUDITON_GETCLASS); 465155192Srwatson 466155192Srwatson case A_SETCLASS: 467155192Srwatson return (AUE_AUDITON_SETCLASS); 468155192Srwatson 469155192Srwatson case A_GETPINFO: 470155192Srwatson case A_SETPMASK: 471155192Srwatson case A_SETFSIZE: 472155192Srwatson case A_GETFSIZE: 473155192Srwatson case A_GETPINFO_ADDR: 474155192Srwatson case A_GETKAUDIT: 475155192Srwatson case A_SETKAUDIT: 476155192Srwatson default: 477155192Srwatson return (AUE_AUDITON); /* No special record */ 478155192Srwatson } 479155192Srwatson} 480155192Srwatson 481156889Srwatson/* 482156889Srwatson * Create a canonical path from given path by prefixing either the root 483156889Srwatson * directory, or the current working directory. If the process working 484170196Srwatson * directory is NULL, we could use 'rootvnode' to obtain the root directory, 485156889Srwatson * but this results in a volfs name written to the audit log. So we will 486156889Srwatson * leave the filename starting with '/' in the audit log in this case. 487155192Srwatson */ 488155192Srwatsonvoid 489176565Srwatsonaudit_canon_path(struct thread *td, char *path, char *cpath) 490155192Srwatson{ 491181060Scsjp struct vnode *cvnp, *rvnp; 492181060Scsjp char *rbuf, *fbuf, *copy; 493155192Srwatson struct filedesc *fdp; 494181060Scsjp struct sbuf sbf; 495184660Sjhb int error, cwir; 496155192Srwatson 497181060Scsjp WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "%s: at %s:%d", 498181060Scsjp __func__, __FILE__, __LINE__); 499165621Srwatson 500181060Scsjp copy = path; 501181060Scsjp rvnp = cvnp = NULL; 502155192Srwatson fdp = td->td_proc->p_fd; 503168355Srwatson FILEDESC_SLOCK(fdp); 504181060Scsjp /* 505181060Scsjp * Make sure that we handle the chroot(2) case. If there is an 506181060Scsjp * alternate root directory, prepend it to the audited pathname. 507181060Scsjp */ 508181060Scsjp if (fdp->fd_rdir != NULL && fdp->fd_rdir != rootvnode) { 509181060Scsjp rvnp = fdp->fd_rdir; 510181060Scsjp vhold(rvnp); 511155192Srwatson } 512181060Scsjp /* 513181060Scsjp * If the supplied path is relative, make sure we capture the current 514181060Scsjp * working directory so we can prepend it to the supplied relative 515181060Scsjp * path. 516181060Scsjp */ 517181060Scsjp if (*path != '/') { 518181060Scsjp cvnp = fdp->fd_cdir; 519181060Scsjp vhold(cvnp); 520181060Scsjp } 521181060Scsjp cwir = (fdp->fd_rdir == fdp->fd_cdir); 522168355Srwatson FILEDESC_SUNLOCK(fdp); 523181060Scsjp /* 524181060Scsjp * NB: We require that the supplied array be at least MAXPATHLEN bytes 525181060Scsjp * long. If this is not the case, then we can run into serious trouble. 526181060Scsjp */ 527181060Scsjp (void) sbuf_new(&sbf, cpath, MAXPATHLEN, SBUF_FIXEDLEN); 528181060Scsjp /* 529181060Scsjp * Strip leading forward slashes. 530181060Scsjp */ 531181060Scsjp while (*copy == '/') 532181060Scsjp copy++; 533181060Scsjp /* 534181060Scsjp * Make sure we handle chroot(2) and prepend the global path to these 535181060Scsjp * environments. 536181060Scsjp * 537181060Scsjp * NB: vn_fullpath(9) on FreeBSD is less reliable than vn_getpath(9) 538181060Scsjp * on Darwin. As a result, this may need some additional attention 539181060Scsjp * in the future. 540181060Scsjp */ 541181060Scsjp if (rvnp != NULL) { 542184660Sjhb error = vn_fullpath_global(td, rvnp, &rbuf, &fbuf); 543181060Scsjp vdrop(rvnp); 544181060Scsjp if (error) { 545155192Srwatson cpath[0] = '\0'; 546181060Scsjp if (cvnp != NULL) 547181060Scsjp vdrop(cvnp); 548181060Scsjp return; 549181060Scsjp } 550181060Scsjp (void) sbuf_cat(&sbf, rbuf); 551181060Scsjp free(fbuf, M_TEMP); 552181060Scsjp } 553181060Scsjp if (cvnp != NULL) { 554184660Sjhb error = vn_fullpath(td, cvnp, &rbuf, &fbuf); 555181060Scsjp vdrop(cvnp); 556181060Scsjp if (error) { 557181060Scsjp cpath[0] = '\0'; 558181060Scsjp return; 559181060Scsjp } 560181060Scsjp (void) sbuf_cat(&sbf, rbuf); 561181060Scsjp free(fbuf, M_TEMP); 562181060Scsjp } 563181060Scsjp if (cwir == 0 || (cwir != 0 && cvnp == NULL)) 564182090Scsjp (void) sbuf_putc(&sbf, '/'); 565181060Scsjp /* 566181060Scsjp * Now that we have processed any alternate root and relative path 567181060Scsjp * names, add the supplied pathname. 568181060Scsjp */ 569181060Scsjp (void) sbuf_cat(&sbf, copy); 570181060Scsjp /* 571181060Scsjp * One or more of the previous sbuf operations could have resulted in 572181060Scsjp * the supplied buffer being overflowed. Check to see if this is the 573181060Scsjp * case. 574181060Scsjp */ 575181060Scsjp if (sbuf_overflowed(&sbf) != 0) { 576181060Scsjp cpath[0] = '\0'; 577181060Scsjp return; 578181060Scsjp } 579181060Scsjp sbuf_finish(&sbf); 580155192Srwatson} 581