audit.c revision 189570
1181053Srwatson/*- 2180701Srwatson * Copyright (c) 1999-2005 Apple Inc. 3170407Srwatson * Copyright (c) 2006-2007 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.c 189570 2009-03-09 10:45:58Z rwatson $"); 33178186Srwatson 34155192Srwatson#include <sys/param.h> 35155192Srwatson#include <sys/condvar.h> 36155192Srwatson#include <sys/conf.h> 37155192Srwatson#include <sys/file.h> 38155192Srwatson#include <sys/filedesc.h> 39155192Srwatson#include <sys/fcntl.h> 40155192Srwatson#include <sys/ipc.h> 41155192Srwatson#include <sys/kernel.h> 42155192Srwatson#include <sys/kthread.h> 43155192Srwatson#include <sys/malloc.h> 44155192Srwatson#include <sys/mount.h> 45155192Srwatson#include <sys/namei.h> 46164033Srwatson#include <sys/priv.h> 47155192Srwatson#include <sys/proc.h> 48155192Srwatson#include <sys/queue.h> 49155192Srwatson#include <sys/socket.h> 50155192Srwatson#include <sys/socketvar.h> 51155192Srwatson#include <sys/protosw.h> 52155192Srwatson#include <sys/domain.h> 53171144Srwatson#include <sys/sysctl.h> 54155192Srwatson#include <sys/sysproto.h> 55155192Srwatson#include <sys/sysent.h> 56155192Srwatson#include <sys/systm.h> 57155192Srwatson#include <sys/ucred.h> 58155192Srwatson#include <sys/uio.h> 59155192Srwatson#include <sys/un.h> 60155192Srwatson#include <sys/unistd.h> 61155192Srwatson#include <sys/vnode.h> 62155192Srwatson 63155406Srwatson#include <bsm/audit.h> 64156291Srwatson#include <bsm/audit_internal.h> 65155406Srwatson#include <bsm/audit_kevents.h> 66155406Srwatson 67155192Srwatson#include <netinet/in.h> 68155192Srwatson#include <netinet/in_pcb.h> 69155192Srwatson 70155192Srwatson#include <security/audit/audit.h> 71155192Srwatson#include <security/audit/audit_private.h> 72155192Srwatson 73155406Srwatson#include <vm/uma.h> 74155406Srwatson 75156888Srwatsonstatic uma_zone_t audit_record_zone; 76170407Srwatsonstatic MALLOC_DEFINE(M_AUDITCRED, "audit_cred", "Audit cred storage"); 77155192SrwatsonMALLOC_DEFINE(M_AUDITDATA, "audit_data", "Audit data storage"); 78155192SrwatsonMALLOC_DEFINE(M_AUDITPATH, "audit_path", "Audit path storage"); 79155192SrwatsonMALLOC_DEFINE(M_AUDITTEXT, "audit_text", "Audit text storage"); 80155192Srwatson 81171144SrwatsonSYSCTL_NODE(_security, OID_AUTO, audit, CTLFLAG_RW, 0, 82171144Srwatson "TrustedBSD audit controls"); 83171144Srwatson 84155192Srwatson/* 85170196Srwatson * Audit control settings that are set/read by system calls and are hence 86170196Srwatson * non-static. 87170196Srwatson * 88155192Srwatson * Define the audit control flags. 89155192Srwatson */ 90156889Srwatsonint audit_enabled; 91156889Srwatsonint audit_suspended; 92155192Srwatson 93155192Srwatson/* 94162176Srwatson * Flags controlling behavior in low storage situations. Should we panic if 95162176Srwatson * a write fails? Should we fail stop if we're out of disk space? 96155192Srwatson */ 97156889Srwatsonint audit_panic_on_write_fail; 98156889Srwatsonint audit_fail_stop; 99161813Swsalamonint audit_argv; 100161813Swsalamonint audit_arge; 101155192Srwatson 102155192Srwatson/* 103155192Srwatson * Are we currently "failing stop" due to out of disk space? 104155192Srwatson */ 105156889Srwatsonint audit_in_failure; 106155192Srwatson 107155192Srwatson/* 108170691Srwatson * Global audit statistics. 109155192Srwatson */ 110156889Srwatsonstruct audit_fstat audit_fstat; 111155192Srwatson 112155192Srwatson/* 113155192Srwatson * Preselection mask for non-attributable events. 114155192Srwatson */ 115156889Srwatsonstruct au_mask audit_nae_mask; 116155192Srwatson 117155192Srwatson/* 118155192Srwatson * Mutex to protect global variables shared between various threads and 119155192Srwatson * processes. 120155192Srwatson */ 121156889Srwatsonstruct mtx audit_mtx; 122155192Srwatson 123155192Srwatson/* 124170196Srwatson * Queue of audit records ready for delivery to disk. We insert new records 125170196Srwatson * at the tail, and remove records from the head. Also, a count of the 126170196Srwatson * number of records used for checking queue depth. In addition, a counter 127170196Srwatson * of records that we have allocated but are not yet in the queue, which is 128170196Srwatson * needed to estimate the total size of the combined set of records 129170196Srwatson * outstanding in the system. 130155192Srwatson */ 131156889Srwatsonstruct kaudit_queue audit_q; 132184904Srwatsonsize_t audit_q_len; 133184904Srwatsonsize_t audit_pre_q_len; 134155192Srwatson 135155192Srwatson/* 136155192Srwatson * Audit queue control settings (minimum free, low/high water marks, etc.) 137155192Srwatson */ 138156889Srwatsonstruct au_qctrl audit_qctrl; 139155192Srwatson 140155192Srwatson/* 141170196Srwatson * Condition variable to signal to the worker that it has work to do: either 142170196Srwatson * new records are in the queue, or a log replacement is taking place. 143155192Srwatson */ 144159261Srwatsonstruct cv audit_worker_cv; 145155192Srwatson 146155192Srwatson/* 147159261Srwatson * Condition variable to flag when crossing the low watermark, meaning that 148159261Srwatson * threads blocked due to hitting the high watermark can wake up and continue 149159261Srwatson * to commit records. 150155192Srwatson */ 151159261Srwatsonstruct cv audit_watermark_cv; 152155192Srwatson 153156889Srwatson/* 154156889Srwatson * Condition variable for auditing threads wait on when in fail-stop mode. 155170196Srwatson * Threads wait on this CV forever (and ever), never seeing the light of day 156170196Srwatson * again. 157155192Srwatson */ 158156889Srwatsonstatic struct cv audit_fail_cv; 159155192Srwatson 160155192Srwatson/* 161184856Scsjp * Kernel audit information. This will store the current audit address 162184856Scsjp * or host information that the kernel will use when it's generating 163184856Scsjp * audit records. This data is modified by the A_GET{SET}KAUDIT auditon(2) 164184856Scsjp * command. 165184856Scsjp */ 166184856Scsjpstatic struct auditinfo_addr audit_kinfo; 167184856Scsjpstatic struct rwlock audit_kinfo_lock; 168184856Scsjp 169184857Srwatson#define KINFO_LOCK_INIT() rw_init(&audit_kinfo_lock, \ 170184857Srwatson "audit_kinfo_lock") 171184856Scsjp#define KINFO_RLOCK() rw_rlock(&audit_kinfo_lock) 172184856Scsjp#define KINFO_WLOCK() rw_wlock(&audit_kinfo_lock) 173184856Scsjp#define KINFO_RUNLOCK() rw_runlock(&audit_kinfo_lock) 174184856Scsjp#define KINFO_WUNLOCK() rw_wunlock(&audit_kinfo_lock) 175184856Scsjp 176184856Scsjpvoid 177184856Scsjpaudit_set_kinfo(struct auditinfo_addr *ak) 178184856Scsjp{ 179184856Scsjp 180184856Scsjp KASSERT(ak->ai_termid.at_type == AU_IPv4 || 181184856Scsjp ak->ai_termid.at_type == AU_IPv6, 182184856Scsjp ("audit_set_kinfo: invalid address type")); 183184857Srwatson 184184856Scsjp KINFO_WLOCK(); 185184856Scsjp audit_kinfo = *ak; 186184856Scsjp KINFO_WUNLOCK(); 187184856Scsjp} 188184856Scsjp 189184856Scsjpvoid 190184856Scsjpaudit_get_kinfo(struct auditinfo_addr *ak) 191184856Scsjp{ 192184856Scsjp 193184856Scsjp KASSERT(audit_kinfo.ai_termid.at_type == AU_IPv4 || 194184856Scsjp audit_kinfo.ai_termid.at_type == AU_IPv6, 195184856Scsjp ("audit_set_kinfo: invalid address type")); 196184857Srwatson 197184856Scsjp KINFO_RLOCK(); 198184856Scsjp *ak = audit_kinfo; 199184856Scsjp KINFO_RUNLOCK(); 200184856Scsjp} 201184856Scsjp 202184856Scsjp/* 203155406Srwatson * Construct an audit record for the passed thread. 204155192Srwatson */ 205155406Srwatsonstatic int 206155406Srwatsonaudit_record_ctor(void *mem, int size, void *arg, int flags) 207155406Srwatson{ 208155406Srwatson struct kaudit_record *ar; 209155406Srwatson struct thread *td; 210184948Srwatson struct ucred *cred; 211155406Srwatson 212155406Srwatson KASSERT(sizeof(*ar) == size, ("audit_record_ctor: wrong size")); 213155406Srwatson 214155406Srwatson td = arg; 215155406Srwatson ar = mem; 216155406Srwatson bzero(ar, sizeof(*ar)); 217155406Srwatson ar->k_ar.ar_magic = AUDIT_RECORD_MAGIC; 218155406Srwatson nanotime(&ar->k_ar.ar_starttime); 219155406Srwatson 220155406Srwatson /* 221155406Srwatson * Export the subject credential. 222155406Srwatson */ 223184948Srwatson cred = td->td_ucred; 224184948Srwatson cru2x(cred, &ar->k_ar.ar_subj_cred); 225184948Srwatson ar->k_ar.ar_subj_ruid = cred->cr_ruid; 226184948Srwatson ar->k_ar.ar_subj_rgid = cred->cr_rgid; 227184948Srwatson ar->k_ar.ar_subj_egid = cred->cr_groups[0]; 228184948Srwatson ar->k_ar.ar_subj_auid = cred->cr_audit.ai_auid; 229184948Srwatson ar->k_ar.ar_subj_asid = cred->cr_audit.ai_asid; 230155406Srwatson ar->k_ar.ar_subj_pid = td->td_proc->p_pid; 231184948Srwatson ar->k_ar.ar_subj_amask = cred->cr_audit.ai_mask; 232184948Srwatson ar->k_ar.ar_subj_term_addr = cred->cr_audit.ai_termid; 233155406Srwatson return (0); 234155406Srwatson} 235155406Srwatson 236155192Srwatsonstatic void 237155406Srwatsonaudit_record_dtor(void *mem, int size, void *arg) 238155192Srwatson{ 239155406Srwatson struct kaudit_record *ar; 240155192Srwatson 241155406Srwatson KASSERT(sizeof(*ar) == size, ("audit_record_dtor: wrong size")); 242155406Srwatson 243155406Srwatson ar = mem; 244155406Srwatson if (ar->k_ar.ar_arg_upath1 != NULL) 245155192Srwatson free(ar->k_ar.ar_arg_upath1, M_AUDITPATH); 246155406Srwatson if (ar->k_ar.ar_arg_upath2 != NULL) 247155192Srwatson free(ar->k_ar.ar_arg_upath2, M_AUDITPATH); 248155406Srwatson if (ar->k_ar.ar_arg_text != NULL) 249155192Srwatson free(ar->k_ar.ar_arg_text, M_AUDITTEXT); 250155406Srwatson if (ar->k_udata != NULL) 251155192Srwatson free(ar->k_udata, M_AUDITDATA); 252161813Swsalamon if (ar->k_ar.ar_arg_argv != NULL) 253161813Swsalamon free(ar->k_ar.ar_arg_argv, M_AUDITTEXT); 254161813Swsalamon if (ar->k_ar.ar_arg_envv != NULL) 255161813Swsalamon free(ar->k_ar.ar_arg_envv, M_AUDITTEXT); 256155192Srwatson} 257155192Srwatson 258155192Srwatson/* 259155192Srwatson * Initialize the Audit subsystem: configuration state, work queue, 260155192Srwatson * synchronization primitives, worker thread, and trigger device node. Also 261155192Srwatson * call into the BSM assembly code to initialize it. 262155192Srwatson */ 263155192Srwatsonstatic void 264155192Srwatsonaudit_init(void) 265155192Srwatson{ 266155192Srwatson 267155192Srwatson audit_enabled = 0; 268155192Srwatson audit_suspended = 0; 269155192Srwatson audit_panic_on_write_fail = 0; 270155192Srwatson audit_fail_stop = 0; 271155192Srwatson audit_in_failure = 0; 272161813Swsalamon audit_argv = 0; 273161813Swsalamon audit_arge = 0; 274155192Srwatson 275170196Srwatson audit_fstat.af_filesz = 0; /* '0' means unset, unbounded. */ 276156889Srwatson audit_fstat.af_currsz = 0; 277173142Srwatson audit_nae_mask.am_success = 0; 278173142Srwatson audit_nae_mask.am_failure = 0; 279155192Srwatson 280155192Srwatson TAILQ_INIT(&audit_q); 281155192Srwatson audit_q_len = 0; 282155192Srwatson audit_pre_q_len = 0; 283155192Srwatson audit_qctrl.aq_hiwater = AQ_HIWATER; 284155192Srwatson audit_qctrl.aq_lowater = AQ_LOWATER; 285155192Srwatson audit_qctrl.aq_bufsz = AQ_BUFSZ; 286155192Srwatson audit_qctrl.aq_minfree = AU_FS_MINFREE; 287155192Srwatson 288184856Scsjp audit_kinfo.ai_termid.at_type = AU_IPv4; 289184856Scsjp audit_kinfo.ai_termid.at_addr[0] = INADDR_ANY; 290184856Scsjp 291155192Srwatson mtx_init(&audit_mtx, "audit_mtx", NULL, MTX_DEF); 292184856Scsjp KINFO_LOCK_INIT(); 293159261Srwatson cv_init(&audit_worker_cv, "audit_worker_cv"); 294159261Srwatson cv_init(&audit_watermark_cv, "audit_watermark_cv"); 295155192Srwatson cv_init(&audit_fail_cv, "audit_fail_cv"); 296155192Srwatson 297159266Srwatson audit_record_zone = uma_zcreate("audit_record", 298155406Srwatson sizeof(struct kaudit_record), audit_record_ctor, 299155406Srwatson audit_record_dtor, NULL, NULL, UMA_ALIGN_PTR, 0); 300155406Srwatson 301155192Srwatson /* Initialize the BSM audit subsystem. */ 302155192Srwatson kau_init(); 303155192Srwatson 304155192Srwatson audit_trigger_init(); 305155192Srwatson 306155192Srwatson /* Register shutdown handler. */ 307155192Srwatson EVENTHANDLER_REGISTER(shutdown_pre_sync, audit_shutdown, NULL, 308155192Srwatson SHUTDOWN_PRI_FIRST); 309155192Srwatson 310156888Srwatson /* Start audit worker thread. */ 311156888Srwatson audit_worker_init(); 312155192Srwatson} 313155192Srwatson 314177253SrwatsonSYSINIT(audit_init, SI_SUB_AUDIT, SI_ORDER_FIRST, audit_init, NULL); 315155192Srwatson 316155192Srwatson/* 317155192Srwatson * Drain the audit queue and close the log at shutdown. Note that this can 318155192Srwatson * be called both from the system shutdown path and also from audit 319155192Srwatson * configuration syscalls, so 'arg' and 'howto' are ignored. 320179517Srwatson * 321179517Srwatson * XXXRW: In FreeBSD 7.x and 8.x, this fails to wait for the record queue to 322179517Srwatson * drain before returning, which could lead to lost records on shutdown. 323155192Srwatson */ 324155192Srwatsonvoid 325155192Srwatsonaudit_shutdown(void *arg, int howto) 326155192Srwatson{ 327155192Srwatson 328155192Srwatson audit_rotate_vnode(NULL, NULL); 329155192Srwatson} 330155192Srwatson 331155192Srwatson/* 332155192Srwatson * Return the current thread's audit record, if any. 333155192Srwatson */ 334169896Srwatsonstruct kaudit_record * 335155192Srwatsoncurrecord(void) 336155192Srwatson{ 337155192Srwatson 338155192Srwatson return (curthread->td_ar); 339155192Srwatson} 340155192Srwatson 341155192Srwatson/* 342155192Srwatson * XXXAUDIT: There are a number of races present in the code below due to 343155192Srwatson * release and re-grab of the mutex. The code should be revised to become 344155192Srwatson * slightly less racy. 345155192Srwatson * 346155192Srwatson * XXXAUDIT: Shouldn't there be logic here to sleep waiting on available 347155192Srwatson * pre_q space, suspending the system call until there is room? 348155192Srwatson */ 349155192Srwatsonstruct kaudit_record * 350155192Srwatsonaudit_new(int event, struct thread *td) 351155192Srwatson{ 352155192Srwatson struct kaudit_record *ar; 353155192Srwatson int no_record; 354155192Srwatson 355155406Srwatson mtx_lock(&audit_mtx); 356155406Srwatson no_record = (audit_suspended || !audit_enabled); 357155406Srwatson mtx_unlock(&audit_mtx); 358155406Srwatson if (no_record) 359155406Srwatson return (NULL); 360155192Srwatson 361155192Srwatson /* 362165604Srwatson * Note: the number of outstanding uncommitted audit records is 363165604Srwatson * limited to the number of concurrent threads servicing system calls 364165604Srwatson * in the kernel. 365155192Srwatson */ 366155406Srwatson ar = uma_zalloc_arg(audit_record_zone, td, M_WAITOK); 367155406Srwatson ar->k_ar.ar_event = event; 368155192Srwatson 369155192Srwatson mtx_lock(&audit_mtx); 370155192Srwatson audit_pre_q_len++; 371155192Srwatson mtx_unlock(&audit_mtx); 372155192Srwatson 373155192Srwatson return (ar); 374155192Srwatson} 375155192Srwatson 376156888Srwatsonvoid 377156888Srwatsonaudit_free(struct kaudit_record *ar) 378156888Srwatson{ 379156888Srwatson 380156888Srwatson uma_zfree(audit_record_zone, ar); 381156888Srwatson} 382156888Srwatson 383155192Srwatsonvoid 384155192Srwatsonaudit_commit(struct kaudit_record *ar, int error, int retval) 385155192Srwatson{ 386159269Srwatson au_event_t event; 387159269Srwatson au_class_t class; 388159269Srwatson au_id_t auid; 389155192Srwatson int sorf; 390155192Srwatson struct au_mask *aumask; 391155192Srwatson 392155192Srwatson if (ar == NULL) 393155192Srwatson return; 394155192Srwatson 395155192Srwatson /* 396170196Srwatson * Decide whether to commit the audit record by checking the error 397170196Srwatson * value from the system call and using the appropriate audit mask. 398155192Srwatson */ 399155192Srwatson if (ar->k_ar.ar_subj_auid == AU_DEFAUDITID) 400155192Srwatson aumask = &audit_nae_mask; 401155192Srwatson else 402155192Srwatson aumask = &ar->k_ar.ar_subj_amask; 403156889Srwatson 404155192Srwatson if (error) 405155192Srwatson sorf = AU_PRS_FAILURE; 406155192Srwatson else 407155192Srwatson sorf = AU_PRS_SUCCESS; 408155192Srwatson 409155192Srwatson switch(ar->k_ar.ar_event) { 410155192Srwatson case AUE_OPEN_RWTC: 411170196Srwatson /* 412170196Srwatson * The open syscall always writes a AUE_OPEN_RWTC event; 413170196Srwatson * change it to the proper type of event based on the flags 414170196Srwatson * and the error value. 415155192Srwatson */ 416176690Srwatson ar->k_ar.ar_event = audit_flags_and_error_to_openevent( 417155192Srwatson ar->k_ar.ar_arg_fflags, error); 418155192Srwatson break; 419155192Srwatson 420155192Srwatson case AUE_SYSCTL: 421176690Srwatson ar->k_ar.ar_event = audit_ctlname_to_sysctlevent( 422155192Srwatson ar->k_ar.ar_arg_ctlname, ar->k_ar.ar_valid_arg); 423155192Srwatson break; 424155192Srwatson 425155192Srwatson case AUE_AUDITON: 426170585Srwatson /* Convert the auditon() command to an event. */ 427155192Srwatson ar->k_ar.ar_event = auditon_command_event(ar->k_ar.ar_arg_cmd); 428155192Srwatson break; 429155192Srwatson } 430155192Srwatson 431159269Srwatson auid = ar->k_ar.ar_subj_auid; 432159269Srwatson event = ar->k_ar.ar_event; 433159269Srwatson class = au_event_class(event); 434155192Srwatson 435159269Srwatson ar->k_ar_commit |= AR_COMMIT_KERNEL; 436159269Srwatson if (au_preselect(event, class, aumask, sorf) != 0) 437159269Srwatson ar->k_ar_commit |= AR_PRESELECT_TRAIL; 438159269Srwatson if (audit_pipe_preselect(auid, event, class, sorf, 439159269Srwatson ar->k_ar_commit & AR_PRESELECT_TRAIL) != 0) 440159269Srwatson ar->k_ar_commit |= AR_PRESELECT_PIPE; 441162380Scsjp if ((ar->k_ar_commit & (AR_PRESELECT_TRAIL | AR_PRESELECT_PIPE | 442162380Scsjp AR_PRESELECT_USER_TRAIL | AR_PRESELECT_USER_PIPE)) == 0) { 443155192Srwatson mtx_lock(&audit_mtx); 444155192Srwatson audit_pre_q_len--; 445155192Srwatson mtx_unlock(&audit_mtx); 446159275Srwatson audit_free(ar); 447155192Srwatson return; 448155192Srwatson } 449155192Srwatson 450155192Srwatson ar->k_ar.ar_errno = error; 451155192Srwatson ar->k_ar.ar_retval = retval; 452155192Srwatson nanotime(&ar->k_ar.ar_endtime); 453155192Srwatson 454155192Srwatson /* 455155192Srwatson * Note: it could be that some records initiated while audit was 456155192Srwatson * enabled should still be committed? 457155192Srwatson */ 458170196Srwatson mtx_lock(&audit_mtx); 459155192Srwatson if (audit_suspended || !audit_enabled) { 460155192Srwatson audit_pre_q_len--; 461155192Srwatson mtx_unlock(&audit_mtx); 462159275Srwatson audit_free(ar); 463155192Srwatson return; 464155192Srwatson } 465156889Srwatson 466155192Srwatson /* 467170182Srwatson * Constrain the number of committed audit records based on the 468170182Srwatson * configurable parameter. 469155192Srwatson */ 470170182Srwatson while (audit_q_len >= audit_qctrl.aq_hiwater) 471159261Srwatson cv_wait(&audit_watermark_cv, &audit_mtx); 472155192Srwatson 473155192Srwatson TAILQ_INSERT_TAIL(&audit_q, ar, k_q); 474155192Srwatson audit_q_len++; 475155192Srwatson audit_pre_q_len--; 476159261Srwatson cv_signal(&audit_worker_cv); 477155192Srwatson mtx_unlock(&audit_mtx); 478155192Srwatson} 479155192Srwatson 480155192Srwatson/* 481155192Srwatson * audit_syscall_enter() is called on entry to each system call. It is 482155192Srwatson * responsible for deciding whether or not to audit the call (preselection), 483155192Srwatson * and if so, allocating a per-thread audit record. audit_new() will fill in 484155192Srwatson * basic thread/credential properties. 485155192Srwatson */ 486155192Srwatsonvoid 487155192Srwatsonaudit_syscall_enter(unsigned short code, struct thread *td) 488155192Srwatson{ 489155192Srwatson struct au_mask *aumask; 490159269Srwatson au_class_t class; 491159269Srwatson au_event_t event; 492159269Srwatson au_id_t auid; 493155192Srwatson 494155192Srwatson KASSERT(td->td_ar == NULL, ("audit_syscall_enter: td->td_ar != NULL")); 495189570Srwatson KASSERT((td->td_pflags & TDP_AUDITREC) == 0, 496189570Srwatson ("audit_syscall_enter: TDP_AUDITREC set")); 497155192Srwatson 498155192Srwatson /* 499155192Srwatson * In FreeBSD, each ABI has its own system call table, and hence 500155192Srwatson * mapping of system call codes to audit events. Convert the code to 501155192Srwatson * an audit event identifier using the process system call table 502155192Srwatson * reference. In Darwin, there's only one, so we use the global 503162950Srwatson * symbol for the system call table. No audit record is generated 504162950Srwatson * for bad system calls, as no operation has been performed. 505155192Srwatson */ 506155192Srwatson if (code >= td->td_proc->p_sysent->sv_size) 507155192Srwatson return; 508155192Srwatson 509159269Srwatson event = td->td_proc->p_sysent->sv_table[code].sy_auevent; 510159269Srwatson if (event == AUE_NULL) 511155192Srwatson return; 512155192Srwatson 513155192Srwatson /* 514155192Srwatson * Check which audit mask to use; either the kernel non-attributable 515155192Srwatson * event mask or the process audit mask. 516155192Srwatson */ 517170407Srwatson auid = td->td_ucred->cr_audit.ai_auid; 518159269Srwatson if (auid == AU_DEFAUDITID) 519155192Srwatson aumask = &audit_nae_mask; 520155192Srwatson else 521170407Srwatson aumask = &td->td_ucred->cr_audit.ai_mask; 522156889Srwatson 523155192Srwatson /* 524170196Srwatson * Allocate an audit record, if preselection allows it, and store in 525170196Srwatson * the thread for later use. 526155192Srwatson */ 527159269Srwatson class = au_event_class(event); 528159269Srwatson if (au_preselect(event, class, aumask, AU_PRS_BOTH)) { 529155192Srwatson /* 530155192Srwatson * If we're out of space and need to suspend unprivileged 531155192Srwatson * processes, do that here rather than trying to allocate 532155192Srwatson * another audit record. 533155192Srwatson * 534165604Srwatson * Note: we might wish to be able to continue here in the 535155192Srwatson * future, if the system recovers. That should be possible 536155192Srwatson * by means of checking the condition in a loop around 537155192Srwatson * cv_wait(). It might be desirable to reevaluate whether an 538155192Srwatson * audit record is still required for this event by 539155192Srwatson * re-calling au_preselect(). 540155192Srwatson */ 541164033Srwatson if (audit_in_failure && 542164033Srwatson priv_check(td, PRIV_AUDIT_FAILSTOP) != 0) { 543155192Srwatson cv_wait(&audit_fail_cv, &audit_mtx); 544155192Srwatson panic("audit_failing_stop: thread continued"); 545155192Srwatson } 546159269Srwatson td->td_ar = audit_new(event, td); 547189570Srwatson if (td->td_ar != NULL) 548189570Srwatson td->td_pflags |= TDP_AUDITREC; 549189570Srwatson } else if (audit_pipe_preselect(auid, event, class, AU_PRS_BOTH, 0)) { 550159269Srwatson td->td_ar = audit_new(event, td); 551189570Srwatson if (td->td_ar != NULL) 552189570Srwatson td->td_pflags |= TDP_AUDITREC; 553189570Srwatson } else 554155192Srwatson td->td_ar = NULL; 555155192Srwatson} 556155192Srwatson 557155192Srwatson/* 558155192Srwatson * audit_syscall_exit() is called from the return of every system call, or in 559155192Srwatson * the event of exit1(), during the execution of exit1(). It is responsible 560155192Srwatson * for committing the audit record, if any, along with return condition. 561155192Srwatson */ 562155192Srwatsonvoid 563155192Srwatsonaudit_syscall_exit(int error, struct thread *td) 564155192Srwatson{ 565155192Srwatson int retval; 566155192Srwatson 567155192Srwatson /* 568170196Srwatson * Commit the audit record as desired; once we pass the record into 569170196Srwatson * audit_commit(), the memory is owned by the audit subsystem. The 570170196Srwatson * return value from the system call is stored on the user thread. 571170196Srwatson * If there was an error, the return value is set to -1, imitating 572170196Srwatson * the behavior of the cerror routine. 573155192Srwatson */ 574155192Srwatson if (error) 575155192Srwatson retval = -1; 576155192Srwatson else 577155192Srwatson retval = td->td_retval[0]; 578155192Srwatson 579155192Srwatson audit_commit(td->td_ar, error, retval); 580155192Srwatson td->td_ar = NULL; 581189570Srwatson td->td_pflags &= ~TDP_AUDITREC; 582155192Srwatson} 583155192Srwatson 584155192Srwatsonvoid 585170407Srwatsonaudit_cred_copy(struct ucred *src, struct ucred *dest) 586155192Srwatson{ 587155192Srwatson 588170407Srwatson bcopy(&src->cr_audit, &dest->cr_audit, sizeof(dest->cr_audit)); 589155192Srwatson} 590155192Srwatson 591155195Srwatsonvoid 592170407Srwatsonaudit_cred_destroy(struct ucred *cred) 593155195Srwatson{ 594155195Srwatson 595155195Srwatson} 596155195Srwatson 597155353Srwatsonvoid 598170407Srwatsonaudit_cred_init(struct ucred *cred) 599155353Srwatson{ 600155353Srwatson 601170407Srwatson bzero(&cred->cr_audit, sizeof(cred->cr_audit)); 602155353Srwatson} 603155353Srwatson 604156889Srwatson/* 605162950Srwatson * Initialize audit information for the first kernel process (proc 0) and for 606162950Srwatson * the first user process (init). 607155192Srwatson */ 608155192Srwatsonvoid 609170407Srwatsonaudit_cred_kproc0(struct ucred *cred) 610155192Srwatson{ 611155192Srwatson 612170585Srwatson cred->cr_audit.ai_auid = AU_DEFAUDITID; 613175763Scsjp cred->cr_audit.ai_termid.at_type = AU_IPv4; 614155192Srwatson} 615155192Srwatson 616155192Srwatsonvoid 617170407Srwatsonaudit_cred_proc1(struct ucred *cred) 618155192Srwatson{ 619155192Srwatson 620170407Srwatson cred->cr_audit.ai_auid = AU_DEFAUDITID; 621175763Scsjp cred->cr_audit.ai_termid.at_type = AU_IPv4; 622155192Srwatson} 623155192Srwatson 624155192Srwatsonvoid 625170407Srwatsonaudit_thread_alloc(struct thread *td) 626155192Srwatson{ 627155192Srwatson 628170407Srwatson td->td_ar = NULL; 629155192Srwatson} 630155192Srwatson 631155192Srwatsonvoid 632170407Srwatsonaudit_thread_free(struct thread *td) 633155192Srwatson{ 634155192Srwatson 635170407Srwatson KASSERT(td->td_ar == NULL, ("audit_thread_free: td_ar != NULL")); 636189570Srwatson KASSERT((td->td_pflags & TDP_AUDITREC) == 0, 637189570Srwatson ("audit_thread_free: TDP_AUDITREC set")); 638155192Srwatson} 639172995Scsjp 640172995Scsjpvoid 641172995Scsjpaudit_proc_coredump(struct thread *td, char *path, int errcode) 642172995Scsjp{ 643172995Scsjp struct kaudit_record *ar; 644172995Scsjp struct au_mask *aumask; 645184948Srwatson struct ucred *cred; 646172995Scsjp au_class_t class; 647172995Scsjp int ret, sorf; 648172995Scsjp char **pathp; 649172995Scsjp au_id_t auid; 650172995Scsjp 651174267Swkoszek ret = 0; 652174267Swkoszek 653172995Scsjp /* 654172995Scsjp * Make sure we are using the correct preselection mask. 655172995Scsjp */ 656184948Srwatson cred = td->td_ucred; 657184948Srwatson auid = cred->cr_audit.ai_auid; 658172995Scsjp if (auid == AU_DEFAUDITID) 659172995Scsjp aumask = &audit_nae_mask; 660172995Scsjp else 661184948Srwatson aumask = &cred->cr_audit.ai_mask; 662172995Scsjp /* 663172995Scsjp * It's possible for coredump(9) generation to fail. Make sure that 664172995Scsjp * we handle this case correctly for preselection. 665172995Scsjp */ 666172995Scsjp if (errcode != 0) 667172995Scsjp sorf = AU_PRS_FAILURE; 668172995Scsjp else 669172995Scsjp sorf = AU_PRS_SUCCESS; 670172995Scsjp class = au_event_class(AUE_CORE); 671181604Scsjp if (au_preselect(AUE_CORE, class, aumask, sorf) == 0 && 672181604Scsjp audit_pipe_preselect(auid, AUE_CORE, class, sorf, 0) == 0) 673172995Scsjp return; 674184948Srwatson 675172995Scsjp /* 676172995Scsjp * If we are interested in seeing this audit record, allocate it. 677172995Scsjp * Where possible coredump records should contain a pathname and arg32 678172995Scsjp * (signal) tokens. 679172995Scsjp */ 680172995Scsjp ar = audit_new(AUE_CORE, td); 681172995Scsjp if (path != NULL) { 682172995Scsjp pathp = &ar->k_ar.ar_arg_upath1; 683172995Scsjp *pathp = malloc(MAXPATHLEN, M_AUDITPATH, M_WAITOK); 684176565Srwatson audit_canon_path(td, path, *pathp); 685172995Scsjp ARG_SET_VALID(ar, ARG_UPATH1); 686172995Scsjp } 687172995Scsjp ar->k_ar.ar_arg_signum = td->td_proc->p_sig; 688172995Scsjp ARG_SET_VALID(ar, ARG_SIGNUM); 689172995Scsjp if (errcode != 0) 690172995Scsjp ret = 1; 691172995Scsjp audit_commit(ar, errcode, ret); 692172995Scsjp} 693