audit.c revision 170196
1155192Srwatson/* 2155192Srwatson * Copyright (c) 1999-2005 Apple Computer, Inc. 3155406Srwatson * Copyright (c) 2006 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. 14155192Srwatson * 3. Neither the name of Apple Computer, 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 * $FreeBSD: head/sys/security/audit/audit.c 170196 2007-06-01 21:58:59Z rwatson $ 31155192Srwatson */ 32155192Srwatson 33155192Srwatson#include <sys/param.h> 34155192Srwatson#include <sys/condvar.h> 35155192Srwatson#include <sys/conf.h> 36155192Srwatson#include <sys/file.h> 37155192Srwatson#include <sys/filedesc.h> 38155192Srwatson#include <sys/fcntl.h> 39155192Srwatson#include <sys/ipc.h> 40155192Srwatson#include <sys/kernel.h> 41155192Srwatson#include <sys/kthread.h> 42155192Srwatson#include <sys/malloc.h> 43155192Srwatson#include <sys/mount.h> 44155192Srwatson#include <sys/namei.h> 45164033Srwatson#include <sys/priv.h> 46155192Srwatson#include <sys/proc.h> 47155192Srwatson#include <sys/queue.h> 48155192Srwatson#include <sys/socket.h> 49155192Srwatson#include <sys/socketvar.h> 50155192Srwatson#include <sys/protosw.h> 51155192Srwatson#include <sys/domain.h> 52155192Srwatson#include <sys/sysproto.h> 53155192Srwatson#include <sys/sysent.h> 54155192Srwatson#include <sys/systm.h> 55155192Srwatson#include <sys/ucred.h> 56155192Srwatson#include <sys/uio.h> 57155192Srwatson#include <sys/un.h> 58155192Srwatson#include <sys/unistd.h> 59155192Srwatson#include <sys/vnode.h> 60155192Srwatson 61155406Srwatson#include <bsm/audit.h> 62156291Srwatson#include <bsm/audit_internal.h> 63155406Srwatson#include <bsm/audit_kevents.h> 64155406Srwatson 65155192Srwatson#include <netinet/in.h> 66155192Srwatson#include <netinet/in_pcb.h> 67155192Srwatson 68155192Srwatson#include <security/audit/audit.h> 69155192Srwatson#include <security/audit/audit_private.h> 70155192Srwatson 71155406Srwatson#include <vm/uma.h> 72155406Srwatson 73156888Srwatsonstatic uma_zone_t audit_record_zone; 74155192Srwatsonstatic MALLOC_DEFINE(M_AUDITPROC, "audit_proc", "Audit process storage"); 75155192SrwatsonMALLOC_DEFINE(M_AUDITDATA, "audit_data", "Audit data storage"); 76155192SrwatsonMALLOC_DEFINE(M_AUDITPATH, "audit_path", "Audit path storage"); 77155192SrwatsonMALLOC_DEFINE(M_AUDITTEXT, "audit_text", "Audit text storage"); 78155192Srwatson 79155192Srwatson/* 80170196Srwatson * Audit control settings that are set/read by system calls and are hence 81170196Srwatson * non-static. 82170196Srwatson * 83155192Srwatson * Define the audit control flags. 84155192Srwatson */ 85156889Srwatsonint audit_enabled; 86156889Srwatsonint audit_suspended; 87155192Srwatson 88155192Srwatson/* 89162176Srwatson * Flags controlling behavior in low storage situations. Should we panic if 90162176Srwatson * a write fails? Should we fail stop if we're out of disk space? 91155192Srwatson */ 92156889Srwatsonint audit_panic_on_write_fail; 93156889Srwatsonint audit_fail_stop; 94161813Swsalamonint audit_argv; 95161813Swsalamonint audit_arge; 96155192Srwatson 97155192Srwatson/* 98155192Srwatson * Are we currently "failing stop" due to out of disk space? 99155192Srwatson */ 100156889Srwatsonint audit_in_failure; 101155192Srwatson 102155192Srwatson/* 103156889Srwatson * Global audit statistiscs. 104155192Srwatson */ 105156889Srwatsonstruct audit_fstat audit_fstat; 106155192Srwatson 107155192Srwatson/* 108155192Srwatson * Preselection mask for non-attributable events. 109155192Srwatson */ 110156889Srwatsonstruct au_mask audit_nae_mask; 111155192Srwatson 112155192Srwatson/* 113155192Srwatson * Mutex to protect global variables shared between various threads and 114155192Srwatson * processes. 115155192Srwatson */ 116156889Srwatsonstruct mtx audit_mtx; 117155192Srwatson 118155192Srwatson/* 119170196Srwatson * Queue of audit records ready for delivery to disk. We insert new records 120170196Srwatson * at the tail, and remove records from the head. Also, a count of the 121170196Srwatson * number of records used for checking queue depth. In addition, a counter 122170196Srwatson * of records that we have allocated but are not yet in the queue, which is 123170196Srwatson * needed to estimate the total size of the combined set of records 124170196Srwatson * outstanding in the system. 125155192Srwatson */ 126156889Srwatsonstruct kaudit_queue audit_q; 127156889Srwatsonint audit_q_len; 128156889Srwatsonint audit_pre_q_len; 129155192Srwatson 130155192Srwatson/* 131155192Srwatson * Audit queue control settings (minimum free, low/high water marks, etc.) 132155192Srwatson */ 133156889Srwatsonstruct au_qctrl audit_qctrl; 134155192Srwatson 135155192Srwatson/* 136170196Srwatson * Condition variable to signal to the worker that it has work to do: either 137170196Srwatson * new records are in the queue, or a log replacement is taking place. 138155192Srwatson */ 139159261Srwatsonstruct cv audit_worker_cv; 140155192Srwatson 141155192Srwatson/* 142159261Srwatson * Condition variable to flag when crossing the low watermark, meaning that 143159261Srwatson * threads blocked due to hitting the high watermark can wake up and continue 144159261Srwatson * to commit records. 145155192Srwatson */ 146159261Srwatsonstruct cv audit_watermark_cv; 147155192Srwatson 148156889Srwatson/* 149156889Srwatson * Condition variable for auditing threads wait on when in fail-stop mode. 150170196Srwatson * Threads wait on this CV forever (and ever), never seeing the light of day 151170196Srwatson * again. 152155192Srwatson */ 153156889Srwatsonstatic struct cv audit_fail_cv; 154155192Srwatson 155155192Srwatson/* 156155406Srwatson * Construct an audit record for the passed thread. 157155192Srwatson */ 158155406Srwatsonstatic int 159155406Srwatsonaudit_record_ctor(void *mem, int size, void *arg, int flags) 160155406Srwatson{ 161155406Srwatson struct kaudit_record *ar; 162155406Srwatson struct thread *td; 163155406Srwatson 164155406Srwatson KASSERT(sizeof(*ar) == size, ("audit_record_ctor: wrong size")); 165155406Srwatson 166155406Srwatson td = arg; 167155406Srwatson ar = mem; 168155406Srwatson bzero(ar, sizeof(*ar)); 169155406Srwatson ar->k_ar.ar_magic = AUDIT_RECORD_MAGIC; 170155406Srwatson nanotime(&ar->k_ar.ar_starttime); 171155406Srwatson 172155406Srwatson /* 173155406Srwatson * Export the subject credential. 174155406Srwatson */ 175155406Srwatson cru2x(td->td_ucred, &ar->k_ar.ar_subj_cred); 176155406Srwatson ar->k_ar.ar_subj_ruid = td->td_ucred->cr_ruid; 177155406Srwatson ar->k_ar.ar_subj_rgid = td->td_ucred->cr_rgid; 178155406Srwatson ar->k_ar.ar_subj_egid = td->td_ucred->cr_groups[0]; 179159415Srwatson PROC_LOCK(td->td_proc); 180155406Srwatson ar->k_ar.ar_subj_auid = td->td_proc->p_au->ai_auid; 181155406Srwatson ar->k_ar.ar_subj_asid = td->td_proc->p_au->ai_asid; 182155406Srwatson ar->k_ar.ar_subj_pid = td->td_proc->p_pid; 183155406Srwatson ar->k_ar.ar_subj_amask = td->td_proc->p_au->ai_mask; 184168688Scsjp ar->k_ar.ar_subj_term_addr = td->td_proc->p_au->ai_termid; 185159415Srwatson PROC_UNLOCK(td->td_proc); 186155406Srwatson return (0); 187155406Srwatson} 188155406Srwatson 189155192Srwatsonstatic void 190155406Srwatsonaudit_record_dtor(void *mem, int size, void *arg) 191155192Srwatson{ 192155406Srwatson struct kaudit_record *ar; 193155192Srwatson 194155406Srwatson KASSERT(sizeof(*ar) == size, ("audit_record_dtor: wrong size")); 195155406Srwatson 196155406Srwatson ar = mem; 197155406Srwatson if (ar->k_ar.ar_arg_upath1 != NULL) 198155192Srwatson free(ar->k_ar.ar_arg_upath1, M_AUDITPATH); 199155406Srwatson if (ar->k_ar.ar_arg_upath2 != NULL) 200155192Srwatson free(ar->k_ar.ar_arg_upath2, M_AUDITPATH); 201155406Srwatson if (ar->k_ar.ar_arg_text != NULL) 202155192Srwatson free(ar->k_ar.ar_arg_text, M_AUDITTEXT); 203155406Srwatson if (ar->k_udata != NULL) 204155192Srwatson free(ar->k_udata, M_AUDITDATA); 205161813Swsalamon if (ar->k_ar.ar_arg_argv != NULL) 206161813Swsalamon free(ar->k_ar.ar_arg_argv, M_AUDITTEXT); 207161813Swsalamon if (ar->k_ar.ar_arg_envv != NULL) 208161813Swsalamon free(ar->k_ar.ar_arg_envv, M_AUDITTEXT); 209155192Srwatson} 210155192Srwatson 211155192Srwatson/* 212155192Srwatson * Initialize the Audit subsystem: configuration state, work queue, 213155192Srwatson * synchronization primitives, worker thread, and trigger device node. Also 214155192Srwatson * call into the BSM assembly code to initialize it. 215155192Srwatson */ 216155192Srwatsonstatic void 217155192Srwatsonaudit_init(void) 218155192Srwatson{ 219155192Srwatson 220155192Srwatson printf("Security auditing service present\n"); 221155192Srwatson audit_enabled = 0; 222155192Srwatson audit_suspended = 0; 223155192Srwatson audit_panic_on_write_fail = 0; 224155192Srwatson audit_fail_stop = 0; 225155192Srwatson audit_in_failure = 0; 226161813Swsalamon audit_argv = 0; 227161813Swsalamon audit_arge = 0; 228155192Srwatson 229170196Srwatson audit_fstat.af_filesz = 0; /* '0' means unset, unbounded. */ 230156889Srwatson audit_fstat.af_currsz = 0; 231155192Srwatson audit_nae_mask.am_success = AU_NULL; 232155192Srwatson audit_nae_mask.am_failure = AU_NULL; 233155192Srwatson 234155192Srwatson TAILQ_INIT(&audit_q); 235155192Srwatson audit_q_len = 0; 236155192Srwatson audit_pre_q_len = 0; 237155192Srwatson audit_qctrl.aq_hiwater = AQ_HIWATER; 238155192Srwatson audit_qctrl.aq_lowater = AQ_LOWATER; 239155192Srwatson audit_qctrl.aq_bufsz = AQ_BUFSZ; 240155192Srwatson audit_qctrl.aq_minfree = AU_FS_MINFREE; 241155192Srwatson 242155192Srwatson mtx_init(&audit_mtx, "audit_mtx", NULL, MTX_DEF); 243159261Srwatson cv_init(&audit_worker_cv, "audit_worker_cv"); 244159261Srwatson cv_init(&audit_watermark_cv, "audit_watermark_cv"); 245155192Srwatson cv_init(&audit_fail_cv, "audit_fail_cv"); 246155192Srwatson 247159266Srwatson audit_record_zone = uma_zcreate("audit_record", 248155406Srwatson sizeof(struct kaudit_record), audit_record_ctor, 249155406Srwatson audit_record_dtor, NULL, NULL, UMA_ALIGN_PTR, 0); 250155406Srwatson 251155192Srwatson /* Initialize the BSM audit subsystem. */ 252155192Srwatson kau_init(); 253155192Srwatson 254155192Srwatson audit_trigger_init(); 255155192Srwatson 256155192Srwatson /* Register shutdown handler. */ 257155192Srwatson EVENTHANDLER_REGISTER(shutdown_pre_sync, audit_shutdown, NULL, 258155192Srwatson SHUTDOWN_PRI_FIRST); 259155192Srwatson 260156888Srwatson /* Start audit worker thread. */ 261156888Srwatson audit_worker_init(); 262155192Srwatson} 263155192Srwatson 264155192SrwatsonSYSINIT(audit_init, SI_SUB_AUDIT, SI_ORDER_FIRST, audit_init, NULL) 265155192Srwatson 266155192Srwatson/* 267155192Srwatson * Drain the audit queue and close the log at shutdown. Note that this can 268155192Srwatson * be called both from the system shutdown path and also from audit 269155192Srwatson * configuration syscalls, so 'arg' and 'howto' are ignored. 270155192Srwatson */ 271155192Srwatsonvoid 272155192Srwatsonaudit_shutdown(void *arg, int howto) 273155192Srwatson{ 274155192Srwatson 275155192Srwatson audit_rotate_vnode(NULL, NULL); 276155192Srwatson} 277155192Srwatson 278155192Srwatson/* 279155192Srwatson * Return the current thread's audit record, if any. 280155192Srwatson */ 281169896Srwatsonstruct kaudit_record * 282155192Srwatsoncurrecord(void) 283155192Srwatson{ 284155192Srwatson 285155192Srwatson return (curthread->td_ar); 286155192Srwatson} 287155192Srwatson 288155192Srwatson/* 289155192Srwatson * XXXAUDIT: There are a number of races present in the code below due to 290155192Srwatson * release and re-grab of the mutex. The code should be revised to become 291155192Srwatson * slightly less racy. 292155192Srwatson * 293155192Srwatson * XXXAUDIT: Shouldn't there be logic here to sleep waiting on available 294155192Srwatson * pre_q space, suspending the system call until there is room? 295155192Srwatson */ 296155192Srwatsonstruct kaudit_record * 297155192Srwatsonaudit_new(int event, struct thread *td) 298155192Srwatson{ 299155192Srwatson struct kaudit_record *ar; 300155192Srwatson int no_record; 301155192Srwatson 302155406Srwatson mtx_lock(&audit_mtx); 303155406Srwatson no_record = (audit_suspended || !audit_enabled); 304155406Srwatson mtx_unlock(&audit_mtx); 305155406Srwatson if (no_record) 306155406Srwatson return (NULL); 307155192Srwatson 308155192Srwatson /* 309165604Srwatson * Note: the number of outstanding uncommitted audit records is 310165604Srwatson * limited to the number of concurrent threads servicing system calls 311165604Srwatson * in the kernel. 312155192Srwatson */ 313155406Srwatson ar = uma_zalloc_arg(audit_record_zone, td, M_WAITOK); 314155406Srwatson ar->k_ar.ar_event = event; 315155192Srwatson 316155192Srwatson mtx_lock(&audit_mtx); 317155192Srwatson audit_pre_q_len++; 318155192Srwatson mtx_unlock(&audit_mtx); 319155192Srwatson 320155192Srwatson return (ar); 321155192Srwatson} 322155192Srwatson 323156888Srwatsonvoid 324156888Srwatsonaudit_free(struct kaudit_record *ar) 325156888Srwatson{ 326156888Srwatson 327156888Srwatson uma_zfree(audit_record_zone, ar); 328156888Srwatson} 329156888Srwatson 330155192Srwatsonvoid 331155192Srwatsonaudit_commit(struct kaudit_record *ar, int error, int retval) 332155192Srwatson{ 333159269Srwatson au_event_t event; 334159269Srwatson au_class_t class; 335159269Srwatson au_id_t auid; 336155192Srwatson int sorf; 337155192Srwatson struct au_mask *aumask; 338155192Srwatson 339155192Srwatson if (ar == NULL) 340155192Srwatson return; 341155192Srwatson 342155192Srwatson /* 343170196Srwatson * Decide whether to commit the audit record by checking the error 344170196Srwatson * value from the system call and using the appropriate audit mask. 345155192Srwatson * 346155192Srwatson * XXXAUDIT: Synchronize access to audit_nae_mask? 347155192Srwatson */ 348155192Srwatson if (ar->k_ar.ar_subj_auid == AU_DEFAUDITID) 349155192Srwatson aumask = &audit_nae_mask; 350155192Srwatson else 351155192Srwatson aumask = &ar->k_ar.ar_subj_amask; 352156889Srwatson 353155192Srwatson if (error) 354155192Srwatson sorf = AU_PRS_FAILURE; 355155192Srwatson else 356155192Srwatson sorf = AU_PRS_SUCCESS; 357155192Srwatson 358155192Srwatson switch(ar->k_ar.ar_event) { 359155192Srwatson case AUE_OPEN_RWTC: 360170196Srwatson /* 361170196Srwatson * The open syscall always writes a AUE_OPEN_RWTC event; 362170196Srwatson * change it to the proper type of event based on the flags 363170196Srwatson * and the error value. 364155192Srwatson */ 365155192Srwatson ar->k_ar.ar_event = flags_and_error_to_openevent( 366155192Srwatson ar->k_ar.ar_arg_fflags, error); 367155192Srwatson break; 368155192Srwatson 369155192Srwatson case AUE_SYSCTL: 370155192Srwatson ar->k_ar.ar_event = ctlname_to_sysctlevent( 371155192Srwatson ar->k_ar.ar_arg_ctlname, ar->k_ar.ar_valid_arg); 372155192Srwatson break; 373155192Srwatson 374155192Srwatson case AUE_AUDITON: 375155192Srwatson /* Convert the auditon() command to an event */ 376155192Srwatson ar->k_ar.ar_event = auditon_command_event(ar->k_ar.ar_arg_cmd); 377155192Srwatson break; 378155192Srwatson } 379155192Srwatson 380159269Srwatson auid = ar->k_ar.ar_subj_auid; 381159269Srwatson event = ar->k_ar.ar_event; 382159269Srwatson class = au_event_class(event); 383155192Srwatson 384159269Srwatson ar->k_ar_commit |= AR_COMMIT_KERNEL; 385159269Srwatson if (au_preselect(event, class, aumask, sorf) != 0) 386159269Srwatson ar->k_ar_commit |= AR_PRESELECT_TRAIL; 387159269Srwatson if (audit_pipe_preselect(auid, event, class, sorf, 388159269Srwatson ar->k_ar_commit & AR_PRESELECT_TRAIL) != 0) 389159269Srwatson ar->k_ar_commit |= AR_PRESELECT_PIPE; 390162380Scsjp if ((ar->k_ar_commit & (AR_PRESELECT_TRAIL | AR_PRESELECT_PIPE | 391162380Scsjp AR_PRESELECT_USER_TRAIL | AR_PRESELECT_USER_PIPE)) == 0) { 392155192Srwatson mtx_lock(&audit_mtx); 393155192Srwatson audit_pre_q_len--; 394155192Srwatson mtx_unlock(&audit_mtx); 395159275Srwatson audit_free(ar); 396155192Srwatson return; 397155192Srwatson } 398155192Srwatson 399155192Srwatson ar->k_ar.ar_errno = error; 400155192Srwatson ar->k_ar.ar_retval = retval; 401155192Srwatson 402155192Srwatson /* 403170196Srwatson * We might want to do some system-wide post-filtering here at some 404170196Srwatson * point. 405155192Srwatson */ 406155192Srwatson 407155192Srwatson /* 408155192Srwatson * Timestamp system call end. 409155192Srwatson */ 410155192Srwatson nanotime(&ar->k_ar.ar_endtime); 411155192Srwatson 412155192Srwatson /* 413155192Srwatson * Note: it could be that some records initiated while audit was 414155192Srwatson * enabled should still be committed? 415155192Srwatson */ 416170196Srwatson mtx_lock(&audit_mtx); 417155192Srwatson if (audit_suspended || !audit_enabled) { 418155192Srwatson audit_pre_q_len--; 419155192Srwatson mtx_unlock(&audit_mtx); 420159275Srwatson audit_free(ar); 421155192Srwatson return; 422155192Srwatson } 423156889Srwatson 424155192Srwatson /* 425170182Srwatson * Constrain the number of committed audit records based on the 426170182Srwatson * configurable parameter. 427155192Srwatson */ 428170182Srwatson while (audit_q_len >= audit_qctrl.aq_hiwater) 429159261Srwatson cv_wait(&audit_watermark_cv, &audit_mtx); 430155192Srwatson 431155192Srwatson TAILQ_INSERT_TAIL(&audit_q, ar, k_q); 432155192Srwatson audit_q_len++; 433155192Srwatson audit_pre_q_len--; 434159261Srwatson cv_signal(&audit_worker_cv); 435155192Srwatson mtx_unlock(&audit_mtx); 436155192Srwatson} 437155192Srwatson 438155192Srwatson/* 439155192Srwatson * audit_syscall_enter() is called on entry to each system call. It is 440155192Srwatson * responsible for deciding whether or not to audit the call (preselection), 441155192Srwatson * and if so, allocating a per-thread audit record. audit_new() will fill in 442155192Srwatson * basic thread/credential properties. 443155192Srwatson */ 444155192Srwatsonvoid 445155192Srwatsonaudit_syscall_enter(unsigned short code, struct thread *td) 446155192Srwatson{ 447155192Srwatson struct au_mask *aumask; 448159269Srwatson au_class_t class; 449159269Srwatson au_event_t event; 450159269Srwatson au_id_t auid; 451155192Srwatson 452155192Srwatson KASSERT(td->td_ar == NULL, ("audit_syscall_enter: td->td_ar != NULL")); 453155192Srwatson 454155192Srwatson /* 455155192Srwatson * In FreeBSD, each ABI has its own system call table, and hence 456155192Srwatson * mapping of system call codes to audit events. Convert the code to 457155192Srwatson * an audit event identifier using the process system call table 458155192Srwatson * reference. In Darwin, there's only one, so we use the global 459162950Srwatson * symbol for the system call table. No audit record is generated 460162950Srwatson * for bad system calls, as no operation has been performed. 461155192Srwatson */ 462155192Srwatson if (code >= td->td_proc->p_sysent->sv_size) 463155192Srwatson return; 464155192Srwatson 465159269Srwatson event = td->td_proc->p_sysent->sv_table[code].sy_auevent; 466159269Srwatson if (event == AUE_NULL) 467155192Srwatson return; 468155192Srwatson 469155192Srwatson /* 470155192Srwatson * Check which audit mask to use; either the kernel non-attributable 471155192Srwatson * event mask or the process audit mask. 472155192Srwatson */ 473159269Srwatson auid = td->td_proc->p_au->ai_auid; 474159269Srwatson if (auid == AU_DEFAUDITID) 475155192Srwatson aumask = &audit_nae_mask; 476155192Srwatson else 477155192Srwatson aumask = &td->td_proc->p_au->ai_mask; 478156889Srwatson 479155192Srwatson /* 480170196Srwatson * Allocate an audit record, if preselection allows it, and store in 481170196Srwatson * the thread for later use. 482155192Srwatson */ 483159269Srwatson class = au_event_class(event); 484159269Srwatson if (au_preselect(event, class, aumask, AU_PRS_BOTH)) { 485155192Srwatson /* 486155192Srwatson * If we're out of space and need to suspend unprivileged 487155192Srwatson * processes, do that here rather than trying to allocate 488155192Srwatson * another audit record. 489155192Srwatson * 490165604Srwatson * Note: we might wish to be able to continue here in the 491155192Srwatson * future, if the system recovers. That should be possible 492155192Srwatson * by means of checking the condition in a loop around 493155192Srwatson * cv_wait(). It might be desirable to reevaluate whether an 494155192Srwatson * audit record is still required for this event by 495155192Srwatson * re-calling au_preselect(). 496155192Srwatson */ 497164033Srwatson if (audit_in_failure && 498164033Srwatson priv_check(td, PRIV_AUDIT_FAILSTOP) != 0) { 499155192Srwatson cv_wait(&audit_fail_cv, &audit_mtx); 500155192Srwatson panic("audit_failing_stop: thread continued"); 501155192Srwatson } 502159269Srwatson td->td_ar = audit_new(event, td); 503159269Srwatson } else if (audit_pipe_preselect(auid, event, class, AU_PRS_BOTH, 0)) 504159269Srwatson td->td_ar = audit_new(event, td); 505159269Srwatson else 506155192Srwatson td->td_ar = NULL; 507155192Srwatson} 508155192Srwatson 509155192Srwatson/* 510155192Srwatson * audit_syscall_exit() is called from the return of every system call, or in 511155192Srwatson * the event of exit1(), during the execution of exit1(). It is responsible 512155192Srwatson * for committing the audit record, if any, along with return condition. 513155192Srwatson */ 514155192Srwatsonvoid 515155192Srwatsonaudit_syscall_exit(int error, struct thread *td) 516155192Srwatson{ 517155192Srwatson int retval; 518155192Srwatson 519155192Srwatson /* 520170196Srwatson * Commit the audit record as desired; once we pass the record into 521170196Srwatson * audit_commit(), the memory is owned by the audit subsystem. The 522170196Srwatson * return value from the system call is stored on the user thread. 523170196Srwatson * If there was an error, the return value is set to -1, imitating 524170196Srwatson * the behavior of the cerror routine. 525155192Srwatson */ 526155192Srwatson if (error) 527155192Srwatson retval = -1; 528155192Srwatson else 529155192Srwatson retval = td->td_retval[0]; 530155192Srwatson 531155192Srwatson audit_commit(td->td_ar, error, retval); 532155192Srwatson td->td_ar = NULL; 533155192Srwatson} 534155192Srwatson 535155192Srwatson/* 536155192Srwatson * Allocate storage for a new process (init, or otherwise). 537155192Srwatson */ 538155192Srwatsonvoid 539155192Srwatsonaudit_proc_alloc(struct proc *p) 540155192Srwatson{ 541155192Srwatson 542155192Srwatson KASSERT(p->p_au == NULL, ("audit_proc_alloc: p->p_au != NULL (%d)", 543155192Srwatson p->p_pid)); 544155192Srwatson p->p_au = malloc(sizeof(*(p->p_au)), M_AUDITPROC, M_WAITOK); 545155192Srwatson} 546155192Srwatson 547155195Srwatson/* 548155195Srwatson * Allocate storage for a new thread. 549155195Srwatson */ 550155195Srwatsonvoid 551155195Srwatsonaudit_thread_alloc(struct thread *td) 552155195Srwatson{ 553155195Srwatson 554155195Srwatson td->td_ar = NULL; 555155195Srwatson} 556155195Srwatson 557155353Srwatson/* 558155353Srwatson * Thread destruction. 559155353Srwatson */ 560155353Srwatsonvoid 561155353Srwatsonaudit_thread_free(struct thread *td) 562155353Srwatson{ 563155353Srwatson 564155353Srwatson KASSERT(td->td_ar == NULL, ("audit_thread_free: td_ar != NULL")); 565155353Srwatson} 566155353Srwatson 567156889Srwatson/* 568162950Srwatson * Initialize audit information for the first kernel process (proc 0) and for 569162950Srwatson * the first user process (init). 570162950Srwatson * 571156889Srwatson * XXX It is not clear what the initial values should be for audit ID, 572156889Srwatson * session ID, etc. 573155192Srwatson */ 574155192Srwatsonvoid 575155192Srwatsonaudit_proc_kproc0(struct proc *p) 576155192Srwatson{ 577155192Srwatson 578155192Srwatson KASSERT(p->p_au != NULL, ("audit_proc_kproc0: p->p_au == NULL (%d)", 579155192Srwatson p->p_pid)); 580170196Srwatson 581155192Srwatson bzero(p->p_au, sizeof(*(p)->p_au)); 582155192Srwatson} 583155192Srwatson 584155192Srwatsonvoid 585155192Srwatsonaudit_proc_init(struct proc *p) 586155192Srwatson{ 587155192Srwatson 588155192Srwatson KASSERT(p->p_au != NULL, ("audit_proc_init: p->p_au == NULL (%d)", 589155192Srwatson p->p_pid)); 590170196Srwatson 591155192Srwatson bzero(p->p_au, sizeof(*(p)->p_au)); 592155558Srwatson p->p_au->ai_auid = AU_DEFAUDITID; 593155192Srwatson} 594155192Srwatson 595156889Srwatson/* 596170196Srwatson * Copy the audit info from the parent process to the child process when a 597170196Srwatson * fork takes place. 598155192Srwatson */ 599155192Srwatsonvoid 600155192Srwatsonaudit_proc_fork(struct proc *parent, struct proc *child) 601155192Srwatson{ 602155192Srwatson 603155192Srwatson PROC_LOCK_ASSERT(parent, MA_OWNED); 604155192Srwatson PROC_LOCK_ASSERT(child, MA_OWNED); 605155192Srwatson KASSERT(parent->p_au != NULL, 606155192Srwatson ("audit_proc_fork: parent->p_au == NULL (%d)", parent->p_pid)); 607155192Srwatson KASSERT(child->p_au != NULL, 608155192Srwatson ("audit_proc_fork: child->p_au == NULL (%d)", child->p_pid)); 609170196Srwatson 610155192Srwatson bcopy(parent->p_au, child->p_au, sizeof(*child->p_au)); 611155192Srwatson} 612155192Srwatson 613155192Srwatson/* 614156889Srwatson * Free the auditing structure for the process. 615155192Srwatson */ 616155192Srwatsonvoid 617155192Srwatsonaudit_proc_free(struct proc *p) 618155192Srwatson{ 619155192Srwatson 620155192Srwatson KASSERT(p->p_au != NULL, ("p->p_au == NULL (%d)", p->p_pid)); 621170196Srwatson 622155192Srwatson free(p->p_au, M_AUDITPROC); 623155192Srwatson p->p_au = NULL; 624155192Srwatson} 625