audit_worker.c revision 162380
1148456Spjd/* 2161220Spjd * Copyright (c) 1999-2005 Apple Computer, Inc. 3148456Spjd * Copyright (c) 2006 Robert N. M. Watson 4148456Spjd * All rights reserved. 5148456Spjd * 6148456Spjd * Redistribution and use in source and binary forms, with or without 7148456Spjd * modification, are permitted provided that the following conditions 8148456Spjd * are met: 9148456Spjd * 1. Redistributions of source code must retain the above copyright 10148456Spjd * notice, this list of conditions and the following disclaimer. 11148456Spjd * 2. Redistributions in binary form must reproduce the above copyright 12148456Spjd * notice, this list of conditions and the following disclaimer in the 13155174Spjd * documentation and/or other materials provided with the distribution. 14148456Spjd * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of 15148456Spjd * its contributors may be used to endorse or promote products derived 16148456Spjd * from this software without specific prior written permission. 17148456Spjd * 18148456Spjd * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND 19148456Spjd * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20148456Spjd * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21148456Spjd * ARE DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR 22148456Spjd * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23148456Spjd * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24148456Spjd * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25148456Spjd * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 26148456Spjd * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 27148456Spjd * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28148456Spjd * POSSIBILITY OF SUCH DAMAGE. 29148456Spjd * 30148456Spjd * $FreeBSD: head/sys/security/audit/audit_worker.c 162380 2006-09-17 17:52:57Z csjp $ 31148456Spjd */ 32148456Spjd 33148456Spjd#include <sys/param.h> 34148456Spjd#include <sys/condvar.h> 35148456Spjd#include <sys/conf.h> 36148456Spjd#include <sys/file.h> 37148456Spjd#include <sys/filedesc.h> 38148456Spjd#include <sys/fcntl.h> 39148456Spjd#include <sys/ipc.h> 40148456Spjd#include <sys/kernel.h> 41148456Spjd#include <sys/kthread.h> 42148456Spjd#include <sys/malloc.h> 43148456Spjd#include <sys/mount.h> 44148867Spjd#include <sys/namei.h> 45148456Spjd#include <sys/proc.h> 46148456Spjd#include <sys/queue.h> 47148456Spjd#include <sys/socket.h> 48148456Spjd#include <sys/socketvar.h> 49148456Spjd#include <sys/protosw.h> 50148456Spjd#include <sys/domain.h> 51148456Spjd#include <sys/sysproto.h> 52148456Spjd#include <sys/sysent.h> 53148456Spjd#include <sys/systm.h> 54148456Spjd#include <sys/ucred.h> 55148456Spjd#include <sys/uio.h> 56148456Spjd#include <sys/un.h> 57159307Spjd#include <sys/unistd.h> 58159307Spjd#include <sys/vnode.h> 59161217Spjd 60161220Spjd#include <bsm/audit.h> 61161220Spjd#include <bsm/audit_internal.h> 62148456Spjd#include <bsm/audit_kevents.h> 63161217Spjd 64148456Spjd#include <netinet/in.h> 65161127Spjd#include <netinet/in_pcb.h> 66148456Spjd 67161220Spjd#include <security/audit/audit.h> 68148456Spjd#include <security/audit/audit_private.h> 69161220Spjd 70148456Spjd#include <vm/uma.h> 71161220Spjd 72148456Spjd/* 73161220Spjd * Worker thread that will schedule disk I/O, etc. 74159307Spjd */ 75161220Spjdstatic struct proc *audit_thread; 76161127Spjd 77161220Spjd/* 78161127Spjd * When an audit log is rotated, the actual rotation must be performed by the 79148456Spjd * audit worker thread, as it may have outstanding writes on the current 80161220Spjd * audit log. audit_replacement_vp holds the vnode replacing the current 81148456Spjd * vnode. We can't let more than one replacement occur at a time, so if more 82161220Spjd * than one thread requests a replacement, only one can have the replacement 83161220Spjd * "in progress" at any given moment. If a thread tries to replace the audit 84161220Spjd * vnode and discovers a replacement is already in progress (i.e., 85148456Spjd * audit_replacement_flag != 0), then it will sleep on audit_replacement_cv 86148456Spjd * waiting its turn to perform a replacement. When a replacement is 87159307Spjd * completed, this cv is signalled by the worker thread so a waiting thread 88148456Spjd * can start another replacement. We also store a credential to perform 89148456Spjd * audit log write operations with. 90148456Spjd * 91148456Spjd * The current credential and vnode are thread-local to audit_worker. 92148456Spjd */ 93159307Spjdstatic struct cv audit_replacement_cv; 94148456Spjd 95148456Spjdstatic int audit_replacement_flag; 96148456Spjdstatic struct vnode *audit_replacement_vp; 97148456Spjdstatic struct ucred *audit_replacement_cred; 98148456Spjd 99148456Spjd/* 100148456Spjd * Flags related to Kernel->user-space communication. 101148456Spjd */ 102148456Spjdstatic int audit_file_rotate_wait; 103159307Spjd 104148456Spjd/* 105148456Spjd * XXXAUDIT: Should adjust comments below to make it clear that we get to 106148456Spjd * this point only if we believe we have storage, so not having space here is 107148456Spjd * a violation of invariants derived from administrative procedures. I.e., 108148456Spjd * someone else has written to the audit partition, leaving less space than 109148456Spjd * we accounted for. 110148456Spjd */ 111148456Spjdstatic int 112148456Spjdaudit_record_write(struct vnode *vp, struct ucred *cred, struct thread *td, 113148456Spjd void *data, size_t len) 114148456Spjd{ 115148456Spjd int ret; 116148456Spjd long temp; 117148456Spjd struct vattr vattr; 118148456Spjd struct statfs *mnt_stat; 119148456Spjd int vfslocked; 120148456Spjd 121148456Spjd if (vp == NULL) 122148456Spjd return (0); 123148456Spjd 124148456Spjd mnt_stat = &vp->v_mount->mnt_stat; 125148456Spjd vfslocked = VFS_LOCK_GIANT(vp->v_mount); 126148456Spjd 127148456Spjd /* 128148456Spjd * First, gather statistics on the audit log file and file system so 129148456Spjd * that we know how we're doing on space. In both cases, if we're 130148456Spjd * unable to perform the operation, we drop the record and return. 131148456Spjd * However, this is arguably an assertion failure. 132148456Spjd * XXX Need a FreeBSD equivalent. 133148456Spjd */ 134148456Spjd ret = VFS_STATFS(vp->v_mount, mnt_stat, td); 135148456Spjd if (ret) 136148456Spjd goto out; 137148456Spjd 138148456Spjd vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 139148456Spjd ret = VOP_GETATTR(vp, &vattr, cred, td); 140148456Spjd VOP_UNLOCK(vp, 0, td); 141148456Spjd if (ret) 142159307Spjd goto out; 143159307Spjd 144159307Spjd /* update the global stats struct */ 145159307Spjd audit_fstat.af_currsz = vattr.va_size; 146159307Spjd 147159307Spjd /* 148159307Spjd * XXX Need to decide what to do if the trigger to the audit daemon 149159307Spjd * fails. 150159307Spjd */ 151148456Spjd 152148456Spjd /* 153148456Spjd * If we fall below minimum free blocks (hard limit), tell the audit 154148456Spjd * daemon to force a rotation off of the file system. We also stop 155159307Spjd * writing, which means this audit record is probably lost. If we 156159307Spjd * fall below the minimum percent free blocks (soft limit), then 157148456Spjd * kindly suggest to the audit daemon to do something. 158148456Spjd */ 159148456Spjd if (mnt_stat->f_bfree < AUDIT_HARD_LIMIT_FREE_BLOCKS) { 160148456Spjd (void)send_trigger(AUDIT_TRIGGER_NO_SPACE); 161148456Spjd /* 162148456Spjd * Hopefully userspace did something about all the previous 163148456Spjd * triggers that were sent prior to this critical condition. 164148456Spjd * If fail-stop is set, then we're done; goodnight Gracie. 165148456Spjd */ 166148456Spjd if (audit_fail_stop) 167148456Spjd panic("Audit log space exhausted and fail-stop set."); 168148456Spjd else { 169148456Spjd audit_suspended = 1; 170159307Spjd ret = ENOSPC; 171148456Spjd goto out; 172159307Spjd } 173148456Spjd } else 174148456Spjd /* 175148456Spjd * Send a message to the audit daemon that disk space is 176149303Spjd * getting low. 177148456Spjd * 178148456Spjd * XXXAUDIT: Check math and block size calculation here. 179148456Spjd */ 180148456Spjd if (audit_qctrl.aq_minfree != 0) { 181149323Spjd temp = mnt_stat->f_blocks / (100 / 182148456Spjd audit_qctrl.aq_minfree); 183148456Spjd if (mnt_stat->f_bfree < temp) 184148456Spjd (void)send_trigger(AUDIT_TRIGGER_LOW_SPACE); 185148456Spjd } 186148456Spjd 187148456Spjd /* 188148456Spjd * Check if the current log file is full; if so, call for a log 189148456Spjd * rotate. This is not an exact comparison; we may write some records 190148456Spjd * over the limit. If that's not acceptable, then add a fudge factor 191148456Spjd * here. 192148456Spjd */ 193159307Spjd if ((audit_fstat.af_filesz != 0) && 194148456Spjd (audit_file_rotate_wait == 0) && 195159307Spjd (vattr.va_size >= audit_fstat.af_filesz)) { 196148456Spjd audit_file_rotate_wait = 1; 197148456Spjd (void)send_trigger(AUDIT_TRIGGER_OPEN_NEW); 198148456Spjd } 199148456Spjd 200148456Spjd /* 201148456Spjd * If the estimated amount of audit data in the audit event queue 202148456Spjd * (plus records allocated but not yet queued) has reached the amount 203148456Spjd * of free space on the disk, then we need to go into an audit fail 204157305Spjd * stop state, in which we do not permit the allocation/committing of 205148456Spjd * any new audit records. We continue to process packets but don't 206148456Spjd * allow any activities that might generate new records. In the 207148456Spjd * future, we might want to detect when space is available again and 208148456Spjd * allow operation to continue, but this behavior is sufficient to 209148456Spjd * meet fail stop requirements in CAPP. 210148456Spjd */ 211148456Spjd if (audit_fail_stop && 212148456Spjd (unsigned long) 213148456Spjd ((audit_q_len + audit_pre_q_len + 1) * MAX_AUDIT_RECORD_SIZE) / 214148456Spjd mnt_stat->f_bsize >= (unsigned long)(mnt_stat->f_bfree)) { 215159307Spjd printf("audit_record_write: free space below size of audit " 216148456Spjd "queue, failing stop\n"); 217148456Spjd audit_in_failure = 1; 218148456Spjd } 219148456Spjd 220148456Spjd ret = vn_rdwr(UIO_WRITE, vp, data, len, (off_t)0, UIO_SYSSPACE, 221148456Spjd IO_APPEND|IO_UNIT, cred, NULL, NULL, td); 222148456Spjd 223148456Spjdout: 224148456Spjd /* 225157305Spjd * When we're done processing the current record, we have to check to 226148456Spjd * see if we're in a failure mode, and if so, whether this was the 227148456Spjd * last record left to be drained. If we're done draining, then we 228148456Spjd * fsync the vnode and panic. 229148456Spjd */ 230148456Spjd if (audit_in_failure && audit_q_len == 0 && audit_pre_q_len == 0) { 231161217Spjd VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 232159307Spjd (void)VOP_FSYNC(vp, MNT_WAIT, td); 233159307Spjd VOP_UNLOCK(vp, 0, td); 234159307Spjd panic("Audit store overflow; record queue drained."); 235159307Spjd } 236159307Spjd 237159307Spjd VFS_UNLOCK_GIANT(vfslocked); 238159307Spjd 239159307Spjd return (ret); 240159307Spjd} 241159307Spjd 242159307Spjd/* 243159307Spjd * If an appropriate signal has been received rotate the audit log based on 244159307Spjd * the global replacement variables. Signal consumers as needed that the 245159307Spjd * rotation has taken place. 246159307Spjd * 247159307Spjd * XXXRW: The global variables and CVs used to signal the audit_worker to 248159307Spjd * perform a rotation are essentially a message queue of depth 1. It would 249159307Spjd * be much nicer to actually use a message queue. 250159307Spjd */ 251159307Spjdstatic void 252159307Spjdaudit_worker_rotate(struct ucred **audit_credp, struct vnode **audit_vpp, 253159307Spjd struct thread *audit_td) 254159307Spjd{ 255148456Spjd int do_replacement_signal, vfslocked; 256148456Spjd struct ucred *old_cred; 257148456Spjd struct vnode *old_vp; 258148456Spjd 259148456Spjd mtx_assert(&audit_mtx, MA_OWNED); 260148456Spjd 261148456Spjd do_replacement_signal = 0; 262148456Spjd while (audit_replacement_flag != 0) { 263148456Spjd old_cred = *audit_credp; 264148456Spjd old_vp = *audit_vpp; 265159307Spjd *audit_credp = audit_replacement_cred; 266161217Spjd *audit_vpp = audit_replacement_vp; 267161217Spjd audit_replacement_cred = NULL; 268159307Spjd audit_replacement_vp = NULL; 269148456Spjd audit_replacement_flag = 0; 270148456Spjd 271148456Spjd audit_enabled = (*audit_vpp != NULL); 272148456Spjd 273148456Spjd /* 274148456Spjd * XXX: What to do about write failures here? 275148456Spjd */ 276148456Spjd if (old_vp != NULL) { 277148456Spjd AUDIT_PRINTF(("Closing old audit file\n")); 278159307Spjd mtx_unlock(&audit_mtx); 279148456Spjd vfslocked = VFS_LOCK_GIANT(old_vp->v_mount); 280148456Spjd vn_close(old_vp, AUDIT_CLOSE_FLAGS, old_cred, 281148867Spjd audit_td); 282148456Spjd VFS_UNLOCK_GIANT(vfslocked); 283148867Spjd crfree(old_cred); 284148456Spjd mtx_lock(&audit_mtx); 285148867Spjd old_cred = NULL; 286148456Spjd old_vp = NULL; 287148867Spjd AUDIT_PRINTF(("Audit file closed\n")); 288148456Spjd } 289148456Spjd if (*audit_vpp != NULL) { 290148456Spjd AUDIT_PRINTF(("Opening new audit file\n")); 291148456Spjd } 292159307Spjd do_replacement_signal = 1; 293159307Spjd } 294159307Spjd 295159307Spjd /* 296159307Spjd * Signal that replacement have occurred to wake up and 297159307Spjd * start any other replacements started in parallel. We can 298159307Spjd * continue about our business in the mean time. We 299159307Spjd * broadcast so that both new replacements can be inserted, 300159307Spjd * but also so that the source(s) of replacement can return 301159307Spjd * successfully. 302159307Spjd */ 303159307Spjd if (do_replacement_signal) 304159307Spjd cv_broadcast(&audit_replacement_cv); 305159307Spjd} 306159307Spjd 307159307Spjd/* 308159307Spjd * Given a kernel audit record, process as required. Kernel audit records 309159307Spjd * are converted to one, or possibly two, BSM records, depending on whether 310159307Spjd * there is a user audit record present also. Kernel records need be 311148456Spjd * converted to BSM before they can be written out. Both types will be 312148456Spjd * written to disk, and audit pipes. 313148456Spjd */ 314148456Spjdstatic void 315148456Spjdaudit_worker_process_record(struct vnode *audit_vp, struct ucred *audit_cred, 316148456Spjd struct thread *audit_td, struct kaudit_record *ar) 317148456Spjd{ 318148456Spjd struct au_record *bsm; 319159307Spjd au_class_t class; 320148456Spjd au_event_t event; 321159307Spjd int error, ret; 322148456Spjd au_id_t auid; 323159307Spjd int sorf; 324159307Spjd 325159307Spjd if ((ar->k_ar_commit & AR_COMMIT_USER) && 326159307Spjd (ar->k_ar_commit & AR_PRESELECT_USER_TRAIL)) { 327159307Spjd error = audit_record_write(audit_vp, audit_cred, audit_td, 328159307Spjd ar->k_udata, ar->k_ulen); 329159307Spjd if (error && audit_panic_on_write_fail) 330159307Spjd panic("audit_worker: write error %d\n", error); 331159307Spjd else if (error) 332159307Spjd printf("audit_worker: write error %d\n", error); 333159307Spjd } 334159307Spjd 335159307Spjd if ((ar->k_ar_commit & AR_COMMIT_USER) && 336148456Spjd (ar->k_ar_commit & AR_PRESELECT_USER_PIPE)) 337148456Spjd audit_pipe_submit_user(ar->k_udata, ar->k_ulen); 338148456Spjd 339148456Spjd if (!(ar->k_ar_commit & AR_COMMIT_KERNEL) || 340148456Spjd ((ar->k_ar_commit & AR_PRESELECT_PIPE) == 0 && 341148456Spjd (ar->k_ar_commit & AR_PRESELECT_TRAIL) == 0)) 342148456Spjd return; 343148456Spjd 344148456Spjd auid = ar->k_ar.ar_subj_auid; 345148456Spjd event = ar->k_ar.ar_event; 346148456Spjd class = au_event_class(event); 347148456Spjd if (ar->k_ar.ar_errno == 0) 348148456Spjd sorf = AU_PRS_SUCCESS; 349148456Spjd else 350159307Spjd sorf = AU_PRS_FAILURE; 351148456Spjd 352159307Spjd ret = kaudit_to_bsm(ar, &bsm); 353159307Spjd switch (ret) { 354148456Spjd case BSM_NOAUDIT: 355148456Spjd return; 356148456Spjd 357148456Spjd case BSM_FAILURE: 358148456Spjd printf("audit_worker_process_record: BSM_FAILURE\n"); 359148456Spjd return; 360148456Spjd 361148456Spjd case BSM_SUCCESS: 362148456Spjd break; 363149303Spjd 364148456Spjd default: 365148456Spjd panic("kaudit_to_bsm returned %d", ret); 366148456Spjd } 367148456Spjd 368148456Spjd if (ar->k_ar_commit & AR_PRESELECT_TRAIL) { 369148456Spjd error = audit_record_write(audit_vp, audit_cred, 370148456Spjd audit_td, bsm->data, bsm->len); 371148456Spjd if (error && audit_panic_on_write_fail) 372148456Spjd panic("audit_worker: write error %d\n", 373148456Spjd error); 374148456Spjd else if (error) 375149303Spjd printf("audit_worker: write error %d\n", 376148456Spjd error); 377148456Spjd } 378148456Spjd 379148456Spjd if (ar->k_ar_commit & AR_PRESELECT_PIPE) 380148456Spjd audit_pipe_submit(auid, event, class, sorf, 381148456Spjd ar->k_ar_commit & AR_PRESELECT_TRAIL, bsm->data, 382148456Spjd bsm->len); 383148456Spjd kau_free(bsm); 384148456Spjd} 385148456Spjd 386148456Spjd/* 387148456Spjd * The audit_worker thread is responsible for watching the event queue, 388148456Spjd * dequeueing records, converting them to BSM format, and committing them to 389148456Spjd * disk. In order to minimize lock thrashing, records are dequeued in sets 390148456Spjd * to a thread-local work queue. In addition, the audit_work performs the 391148456Spjd * actual exchange of audit log vnode pointer, as audit_vp is a thread-local 392148456Spjd * variable. 393148456Spjd */ 394148456Spjdstatic void 395148456Spjdaudit_worker(void *arg) 396148456Spjd{ 397148456Spjd struct kaudit_queue ar_worklist; 398148456Spjd struct kaudit_record *ar; 399148456Spjd struct ucred *audit_cred; 400148456Spjd struct thread *audit_td; 401148456Spjd struct vnode *audit_vp; 402148456Spjd int lowater_signal; 403148456Spjd 404148456Spjd AUDIT_PRINTF(("audit_worker starting\n")); 405148456Spjd 406148456Spjd /* 407148456Spjd * These are thread-local variables requiring no synchronization. 408148456Spjd */ 409148456Spjd TAILQ_INIT(&ar_worklist); 410148456Spjd audit_cred = NULL; 411148456Spjd audit_td = curthread; 412148456Spjd audit_vp = NULL; 413148456Spjd 414148456Spjd mtx_lock(&audit_mtx); 415148456Spjd while (1) { 416148456Spjd mtx_assert(&audit_mtx, MA_OWNED); 417148456Spjd 418148456Spjd /* 419159307Spjd * Wait for record or rotation events. 420159307Spjd */ 421159307Spjd while (!audit_replacement_flag && TAILQ_EMPTY(&audit_q)) { 422159307Spjd AUDIT_PRINTF(("audit_worker waiting\n")); 423159307Spjd cv_wait(&audit_worker_cv, &audit_mtx); 424159307Spjd AUDIT_PRINTF(("audit_worker woken up\n")); 425159307Spjd AUDIT_PRINTF(("audit_worker: new vp = %p; value of " 426159307Spjd "flag %d\n", audit_replacement_vp, 427159307Spjd audit_replacement_flag)); 428159307Spjd } 429159307Spjd 430159307Spjd /* 431159307Spjd * First priority: replace the audit log target if requested. 432159307Spjd */ 433159307Spjd audit_worker_rotate(&audit_cred, &audit_vp, audit_td); 434159307Spjd 435159307Spjd /* 436159307Spjd * If there are records in the global audit record queue, 437159307Spjd * transfer them to a thread-local queue and process them 438159307Spjd * one by one. If we cross the low watermark threshold, 439159307Spjd * signal any waiting processes that they may wake up and 440148456Spjd * continue generating records. 441148456Spjd */ 442148456Spjd lowater_signal = 0; 443148456Spjd while ((ar = TAILQ_FIRST(&audit_q))) { 444148456Spjd TAILQ_REMOVE(&audit_q, ar, k_q); 445148456Spjd audit_q_len--; 446148456Spjd if (audit_q_len == audit_qctrl.aq_lowater) 447148456Spjd lowater_signal++; 448148456Spjd TAILQ_INSERT_TAIL(&ar_worklist, ar, k_q); 449148456Spjd } 450159307Spjd if (lowater_signal) 451159307Spjd cv_broadcast(&audit_watermark_cv); 452159307Spjd 453159307Spjd mtx_unlock(&audit_mtx); 454159307Spjd while ((ar = TAILQ_FIRST(&ar_worklist))) { 455159307Spjd TAILQ_REMOVE(&ar_worklist, ar, k_q); 456159307Spjd audit_worker_process_record(audit_vp, audit_cred, 457159307Spjd audit_td, ar); 458159307Spjd audit_free(ar); 459159307Spjd } 460159307Spjd mtx_lock(&audit_mtx); 461148456Spjd } 462148456Spjd} 463148456Spjd 464148456Spjd/* 465148456Spjd * audit_rotate_vnode() is called by a user or kernel thread to configure or 466148456Spjd * de-configure auditing on a vnode. The arguments are the replacement 467148456Spjd * credential and vnode to substitute for the current credential and vnode, 468159307Spjd * if any. If either is set to NULL, both should be NULL, and this is used 469159307Spjd * to indicate that audit is being disabled. The real work is done in the 470159307Spjd * audit_worker thread, but audit_rotate_vnode() waits synchronously for that 471148456Spjd * to complete. 472148456Spjd * 473148456Spjd * The vnode should be referenced and opened by the caller. The credential 474148456Spjd * should be referenced. audit_rotate_vnode() will own both references as of 475148456Spjd * this call, so the caller should not release either. 476148456Spjd * 477148456Spjd * XXXAUDIT: Review synchronize communication logic. Really, this is a 478148456Spjd * message queue of depth 1. 479148456Spjd * 480148456Spjd * XXXAUDIT: Enhance the comments below to indicate that we are basically 481148456Spjd * acquiring ownership of the communications queue, inserting our message, 482148456Spjd * and waiting for an acknowledgement. 483148456Spjd */ 484148456Spjdvoid 485148456Spjdaudit_rotate_vnode(struct ucred *cred, struct vnode *vp) 486148456Spjd{ 487148456Spjd 488148456Spjd /* 489148456Spjd * If other parallel log replacements have been requested, we wait 490 * until they've finished before continuing. 491 */ 492 mtx_lock(&audit_mtx); 493 while (audit_replacement_flag != 0) { 494 AUDIT_PRINTF(("audit_rotate_vnode: sleeping to wait for " 495 "flag\n")); 496 cv_wait(&audit_replacement_cv, &audit_mtx); 497 AUDIT_PRINTF(("audit_rotate_vnode: woken up (flag %d)\n", 498 audit_replacement_flag)); 499 } 500 audit_replacement_cred = cred; 501 audit_replacement_flag = 1; 502 audit_replacement_vp = vp; 503 504 /* 505 * Wake up the audit worker to perform the exchange once we 506 * release the mutex. 507 */ 508 cv_signal(&audit_worker_cv); 509 510 /* 511 * Wait for the audit_worker to broadcast that a replacement has 512 * taken place; we know that once this has happened, our vnode 513 * has been replaced in, so we can return successfully. 514 */ 515 AUDIT_PRINTF(("audit_rotate_vnode: waiting for news of " 516 "replacement\n")); 517 cv_wait(&audit_replacement_cv, &audit_mtx); 518 AUDIT_PRINTF(("audit_rotate_vnode: change acknowledged by " 519 "audit_worker (flag " "now %d)\n", audit_replacement_flag)); 520 mtx_unlock(&audit_mtx); 521 522 audit_file_rotate_wait = 0; /* We can now request another rotation */ 523} 524 525void 526audit_worker_init(void) 527{ 528 int error; 529 530 cv_init(&audit_replacement_cv, "audit_replacement_cv"); 531 error = kthread_create(audit_worker, NULL, &audit_thread, RFHIGHPID, 532 0, "audit_worker"); 533 if (error) 534 panic("audit_worker_init: kthread_create returned %d", error); 535} 536