audit.c revision 195177
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 195177 2009-06-29 20:19:19Z sson $"); 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"); 80195177SssonMALLOC_DEFINE(M_AUDITGIDSET, "audit_gidset", "Audit GID set storage"); 81155192Srwatson 82171144SrwatsonSYSCTL_NODE(_security, OID_AUTO, audit, CTLFLAG_RW, 0, 83171144Srwatson "TrustedBSD audit controls"); 84171144Srwatson 85155192Srwatson/* 86170196Srwatson * Audit control settings that are set/read by system calls and are hence 87170196Srwatson * non-static. 88170196Srwatson * 89155192Srwatson * Define the audit control flags. 90155192Srwatson */ 91156889Srwatsonint audit_enabled; 92156889Srwatsonint audit_suspended; 93155192Srwatson 94155192Srwatson/* 95162176Srwatson * Flags controlling behavior in low storage situations. Should we panic if 96162176Srwatson * a write fails? Should we fail stop if we're out of disk space? 97155192Srwatson */ 98156889Srwatsonint audit_panic_on_write_fail; 99156889Srwatsonint audit_fail_stop; 100161813Swsalamonint audit_argv; 101161813Swsalamonint audit_arge; 102155192Srwatson 103155192Srwatson/* 104155192Srwatson * Are we currently "failing stop" due to out of disk space? 105155192Srwatson */ 106156889Srwatsonint audit_in_failure; 107155192Srwatson 108155192Srwatson/* 109170691Srwatson * Global audit statistics. 110155192Srwatson */ 111156889Srwatsonstruct audit_fstat audit_fstat; 112155192Srwatson 113155192Srwatson/* 114155192Srwatson * Preselection mask for non-attributable events. 115155192Srwatson */ 116156889Srwatsonstruct au_mask audit_nae_mask; 117155192Srwatson 118155192Srwatson/* 119155192Srwatson * Mutex to protect global variables shared between various threads and 120155192Srwatson * processes. 121155192Srwatson */ 122156889Srwatsonstruct mtx audit_mtx; 123155192Srwatson 124155192Srwatson/* 125170196Srwatson * Queue of audit records ready for delivery to disk. We insert new records 126170196Srwatson * at the tail, and remove records from the head. Also, a count of the 127170196Srwatson * number of records used for checking queue depth. In addition, a counter 128170196Srwatson * of records that we have allocated but are not yet in the queue, which is 129170196Srwatson * needed to estimate the total size of the combined set of records 130170196Srwatson * outstanding in the system. 131155192Srwatson */ 132156889Srwatsonstruct kaudit_queue audit_q; 133191270Srwatsonint audit_q_len; 134191270Srwatsonint audit_pre_q_len; 135155192Srwatson 136155192Srwatson/* 137155192Srwatson * Audit queue control settings (minimum free, low/high water marks, etc.) 138155192Srwatson */ 139156889Srwatsonstruct au_qctrl audit_qctrl; 140155192Srwatson 141155192Srwatson/* 142170196Srwatson * Condition variable to signal to the worker that it has work to do: either 143170196Srwatson * new records are in the queue, or a log replacement is taking place. 144155192Srwatson */ 145159261Srwatsonstruct cv audit_worker_cv; 146155192Srwatson 147155192Srwatson/* 148159261Srwatson * Condition variable to flag when crossing the low watermark, meaning that 149159261Srwatson * threads blocked due to hitting the high watermark can wake up and continue 150159261Srwatson * to commit records. 151155192Srwatson */ 152159261Srwatsonstruct cv audit_watermark_cv; 153155192Srwatson 154156889Srwatson/* 155156889Srwatson * Condition variable for auditing threads wait on when in fail-stop mode. 156170196Srwatson * Threads wait on this CV forever (and ever), never seeing the light of day 157170196Srwatson * again. 158155192Srwatson */ 159156889Srwatsonstatic struct cv audit_fail_cv; 160155192Srwatson 161155192Srwatson/* 162184856Scsjp * Kernel audit information. This will store the current audit address 163184856Scsjp * or host information that the kernel will use when it's generating 164184856Scsjp * audit records. This data is modified by the A_GET{SET}KAUDIT auditon(2) 165184856Scsjp * command. 166184856Scsjp */ 167184856Scsjpstatic struct auditinfo_addr audit_kinfo; 168184856Scsjpstatic struct rwlock audit_kinfo_lock; 169184856Scsjp 170184857Srwatson#define KINFO_LOCK_INIT() rw_init(&audit_kinfo_lock, \ 171184857Srwatson "audit_kinfo_lock") 172184856Scsjp#define KINFO_RLOCK() rw_rlock(&audit_kinfo_lock) 173184856Scsjp#define KINFO_WLOCK() rw_wlock(&audit_kinfo_lock) 174184856Scsjp#define KINFO_RUNLOCK() rw_runlock(&audit_kinfo_lock) 175184856Scsjp#define KINFO_WUNLOCK() rw_wunlock(&audit_kinfo_lock) 176184856Scsjp 177184856Scsjpvoid 178184856Scsjpaudit_set_kinfo(struct auditinfo_addr *ak) 179184856Scsjp{ 180184856Scsjp 181184856Scsjp KASSERT(ak->ai_termid.at_type == AU_IPv4 || 182184856Scsjp ak->ai_termid.at_type == AU_IPv6, 183184856Scsjp ("audit_set_kinfo: invalid address type")); 184184857Srwatson 185184856Scsjp KINFO_WLOCK(); 186184856Scsjp audit_kinfo = *ak; 187184856Scsjp KINFO_WUNLOCK(); 188184856Scsjp} 189184856Scsjp 190184856Scsjpvoid 191184856Scsjpaudit_get_kinfo(struct auditinfo_addr *ak) 192184856Scsjp{ 193184856Scsjp 194184856Scsjp KASSERT(audit_kinfo.ai_termid.at_type == AU_IPv4 || 195184856Scsjp audit_kinfo.ai_termid.at_type == AU_IPv6, 196184856Scsjp ("audit_set_kinfo: invalid address type")); 197184857Srwatson 198184856Scsjp KINFO_RLOCK(); 199184856Scsjp *ak = audit_kinfo; 200184856Scsjp KINFO_RUNLOCK(); 201184856Scsjp} 202184856Scsjp 203184856Scsjp/* 204155406Srwatson * Construct an audit record for the passed thread. 205155192Srwatson */ 206155406Srwatsonstatic int 207155406Srwatsonaudit_record_ctor(void *mem, int size, void *arg, int flags) 208155406Srwatson{ 209155406Srwatson struct kaudit_record *ar; 210155406Srwatson struct thread *td; 211184948Srwatson struct ucred *cred; 212155406Srwatson 213155406Srwatson KASSERT(sizeof(*ar) == size, ("audit_record_ctor: wrong size")); 214155406Srwatson 215155406Srwatson td = arg; 216155406Srwatson ar = mem; 217155406Srwatson bzero(ar, sizeof(*ar)); 218155406Srwatson ar->k_ar.ar_magic = AUDIT_RECORD_MAGIC; 219155406Srwatson nanotime(&ar->k_ar.ar_starttime); 220155406Srwatson 221155406Srwatson /* 222155406Srwatson * Export the subject credential. 223155406Srwatson */ 224184948Srwatson cred = td->td_ucred; 225184948Srwatson cru2x(cred, &ar->k_ar.ar_subj_cred); 226184948Srwatson ar->k_ar.ar_subj_ruid = cred->cr_ruid; 227184948Srwatson ar->k_ar.ar_subj_rgid = cred->cr_rgid; 228184948Srwatson ar->k_ar.ar_subj_egid = cred->cr_groups[0]; 229184948Srwatson ar->k_ar.ar_subj_auid = cred->cr_audit.ai_auid; 230184948Srwatson ar->k_ar.ar_subj_asid = cred->cr_audit.ai_asid; 231155406Srwatson ar->k_ar.ar_subj_pid = td->td_proc->p_pid; 232184948Srwatson ar->k_ar.ar_subj_amask = cred->cr_audit.ai_mask; 233184948Srwatson ar->k_ar.ar_subj_term_addr = cred->cr_audit.ai_termid; 234155406Srwatson return (0); 235155406Srwatson} 236155406Srwatson 237155192Srwatsonstatic void 238155406Srwatsonaudit_record_dtor(void *mem, int size, void *arg) 239155192Srwatson{ 240155406Srwatson struct kaudit_record *ar; 241155192Srwatson 242155406Srwatson KASSERT(sizeof(*ar) == size, ("audit_record_dtor: wrong size")); 243155406Srwatson 244155406Srwatson ar = mem; 245155406Srwatson if (ar->k_ar.ar_arg_upath1 != NULL) 246155192Srwatson free(ar->k_ar.ar_arg_upath1, M_AUDITPATH); 247155406Srwatson if (ar->k_ar.ar_arg_upath2 != NULL) 248155192Srwatson free(ar->k_ar.ar_arg_upath2, M_AUDITPATH); 249155406Srwatson if (ar->k_ar.ar_arg_text != NULL) 250155192Srwatson free(ar->k_ar.ar_arg_text, M_AUDITTEXT); 251155406Srwatson if (ar->k_udata != NULL) 252155192Srwatson free(ar->k_udata, M_AUDITDATA); 253161813Swsalamon if (ar->k_ar.ar_arg_argv != NULL) 254161813Swsalamon free(ar->k_ar.ar_arg_argv, M_AUDITTEXT); 255161813Swsalamon if (ar->k_ar.ar_arg_envv != NULL) 256161813Swsalamon free(ar->k_ar.ar_arg_envv, M_AUDITTEXT); 257195177Ssson if (ar->k_ar.ar_arg_groups.gidset != NULL) 258195177Ssson free(ar->k_ar.ar_arg_groups.gidset, M_AUDITGIDSET); 259155192Srwatson} 260155192Srwatson 261155192Srwatson/* 262155192Srwatson * Initialize the Audit subsystem: configuration state, work queue, 263155192Srwatson * synchronization primitives, worker thread, and trigger device node. Also 264155192Srwatson * call into the BSM assembly code to initialize it. 265155192Srwatson */ 266155192Srwatsonstatic void 267155192Srwatsonaudit_init(void) 268155192Srwatson{ 269155192Srwatson 270155192Srwatson audit_enabled = 0; 271155192Srwatson audit_suspended = 0; 272155192Srwatson audit_panic_on_write_fail = 0; 273155192Srwatson audit_fail_stop = 0; 274155192Srwatson audit_in_failure = 0; 275161813Swsalamon audit_argv = 0; 276161813Swsalamon audit_arge = 0; 277155192Srwatson 278170196Srwatson audit_fstat.af_filesz = 0; /* '0' means unset, unbounded. */ 279156889Srwatson audit_fstat.af_currsz = 0; 280173142Srwatson audit_nae_mask.am_success = 0; 281173142Srwatson audit_nae_mask.am_failure = 0; 282155192Srwatson 283155192Srwatson TAILQ_INIT(&audit_q); 284155192Srwatson audit_q_len = 0; 285155192Srwatson audit_pre_q_len = 0; 286155192Srwatson audit_qctrl.aq_hiwater = AQ_HIWATER; 287155192Srwatson audit_qctrl.aq_lowater = AQ_LOWATER; 288155192Srwatson audit_qctrl.aq_bufsz = AQ_BUFSZ; 289155192Srwatson audit_qctrl.aq_minfree = AU_FS_MINFREE; 290155192Srwatson 291184856Scsjp audit_kinfo.ai_termid.at_type = AU_IPv4; 292184856Scsjp audit_kinfo.ai_termid.at_addr[0] = INADDR_ANY; 293184856Scsjp 294155192Srwatson mtx_init(&audit_mtx, "audit_mtx", NULL, MTX_DEF); 295184856Scsjp KINFO_LOCK_INIT(); 296159261Srwatson cv_init(&audit_worker_cv, "audit_worker_cv"); 297159261Srwatson cv_init(&audit_watermark_cv, "audit_watermark_cv"); 298155192Srwatson cv_init(&audit_fail_cv, "audit_fail_cv"); 299155192Srwatson 300159266Srwatson audit_record_zone = uma_zcreate("audit_record", 301155406Srwatson sizeof(struct kaudit_record), audit_record_ctor, 302155406Srwatson audit_record_dtor, NULL, NULL, UMA_ALIGN_PTR, 0); 303155406Srwatson 304155192Srwatson /* Initialize the BSM audit subsystem. */ 305155192Srwatson kau_init(); 306155192Srwatson 307155192Srwatson audit_trigger_init(); 308155192Srwatson 309155192Srwatson /* Register shutdown handler. */ 310155192Srwatson EVENTHANDLER_REGISTER(shutdown_pre_sync, audit_shutdown, NULL, 311155192Srwatson SHUTDOWN_PRI_FIRST); 312155192Srwatson 313156888Srwatson /* Start audit worker thread. */ 314156888Srwatson audit_worker_init(); 315155192Srwatson} 316155192Srwatson 317177253SrwatsonSYSINIT(audit_init, SI_SUB_AUDIT, SI_ORDER_FIRST, audit_init, NULL); 318155192Srwatson 319155192Srwatson/* 320155192Srwatson * Drain the audit queue and close the log at shutdown. Note that this can 321155192Srwatson * be called both from the system shutdown path and also from audit 322155192Srwatson * configuration syscalls, so 'arg' and 'howto' are ignored. 323179517Srwatson * 324179517Srwatson * XXXRW: In FreeBSD 7.x and 8.x, this fails to wait for the record queue to 325179517Srwatson * drain before returning, which could lead to lost records on shutdown. 326155192Srwatson */ 327155192Srwatsonvoid 328155192Srwatsonaudit_shutdown(void *arg, int howto) 329155192Srwatson{ 330155192Srwatson 331155192Srwatson audit_rotate_vnode(NULL, NULL); 332155192Srwatson} 333155192Srwatson 334155192Srwatson/* 335155192Srwatson * Return the current thread's audit record, if any. 336155192Srwatson */ 337169896Srwatsonstruct kaudit_record * 338155192Srwatsoncurrecord(void) 339155192Srwatson{ 340155192Srwatson 341155192Srwatson return (curthread->td_ar); 342155192Srwatson} 343155192Srwatson 344155192Srwatson/* 345155192Srwatson * XXXAUDIT: There are a number of races present in the code below due to 346155192Srwatson * release and re-grab of the mutex. The code should be revised to become 347155192Srwatson * slightly less racy. 348155192Srwatson * 349155192Srwatson * XXXAUDIT: Shouldn't there be logic here to sleep waiting on available 350155192Srwatson * pre_q space, suspending the system call until there is room? 351155192Srwatson */ 352155192Srwatsonstruct kaudit_record * 353155192Srwatsonaudit_new(int event, struct thread *td) 354155192Srwatson{ 355155192Srwatson struct kaudit_record *ar; 356155192Srwatson int no_record; 357155192Srwatson 358155406Srwatson mtx_lock(&audit_mtx); 359155406Srwatson no_record = (audit_suspended || !audit_enabled); 360155406Srwatson mtx_unlock(&audit_mtx); 361155406Srwatson if (no_record) 362155406Srwatson return (NULL); 363155192Srwatson 364155192Srwatson /* 365165604Srwatson * Note: the number of outstanding uncommitted audit records is 366165604Srwatson * limited to the number of concurrent threads servicing system calls 367165604Srwatson * in the kernel. 368155192Srwatson */ 369155406Srwatson ar = uma_zalloc_arg(audit_record_zone, td, M_WAITOK); 370155406Srwatson ar->k_ar.ar_event = event; 371155192Srwatson 372155192Srwatson mtx_lock(&audit_mtx); 373155192Srwatson audit_pre_q_len++; 374155192Srwatson mtx_unlock(&audit_mtx); 375155192Srwatson 376155192Srwatson return (ar); 377155192Srwatson} 378155192Srwatson 379156888Srwatsonvoid 380156888Srwatsonaudit_free(struct kaudit_record *ar) 381156888Srwatson{ 382156888Srwatson 383156888Srwatson uma_zfree(audit_record_zone, ar); 384156888Srwatson} 385156888Srwatson 386155192Srwatsonvoid 387155192Srwatsonaudit_commit(struct kaudit_record *ar, int error, int retval) 388155192Srwatson{ 389159269Srwatson au_event_t event; 390159269Srwatson au_class_t class; 391159269Srwatson au_id_t auid; 392155192Srwatson int sorf; 393155192Srwatson struct au_mask *aumask; 394155192Srwatson 395155192Srwatson if (ar == NULL) 396155192Srwatson return; 397155192Srwatson 398155192Srwatson /* 399170196Srwatson * Decide whether to commit the audit record by checking the error 400170196Srwatson * value from the system call and using the appropriate audit mask. 401155192Srwatson */ 402155192Srwatson if (ar->k_ar.ar_subj_auid == AU_DEFAUDITID) 403155192Srwatson aumask = &audit_nae_mask; 404155192Srwatson else 405155192Srwatson aumask = &ar->k_ar.ar_subj_amask; 406156889Srwatson 407155192Srwatson if (error) 408155192Srwatson sorf = AU_PRS_FAILURE; 409155192Srwatson else 410155192Srwatson sorf = AU_PRS_SUCCESS; 411155192Srwatson 412155192Srwatson switch(ar->k_ar.ar_event) { 413155192Srwatson case AUE_OPEN_RWTC: 414170196Srwatson /* 415170196Srwatson * The open syscall always writes a AUE_OPEN_RWTC event; 416170196Srwatson * change it to the proper type of event based on the flags 417170196Srwatson * and the error value. 418155192Srwatson */ 419176690Srwatson ar->k_ar.ar_event = audit_flags_and_error_to_openevent( 420155192Srwatson ar->k_ar.ar_arg_fflags, error); 421155192Srwatson break; 422155192Srwatson 423155192Srwatson case AUE_SYSCTL: 424176690Srwatson ar->k_ar.ar_event = audit_ctlname_to_sysctlevent( 425155192Srwatson ar->k_ar.ar_arg_ctlname, ar->k_ar.ar_valid_arg); 426155192Srwatson break; 427155192Srwatson 428155192Srwatson case AUE_AUDITON: 429170585Srwatson /* Convert the auditon() command to an event. */ 430155192Srwatson ar->k_ar.ar_event = auditon_command_event(ar->k_ar.ar_arg_cmd); 431155192Srwatson break; 432155192Srwatson } 433155192Srwatson 434159269Srwatson auid = ar->k_ar.ar_subj_auid; 435159269Srwatson event = ar->k_ar.ar_event; 436159269Srwatson class = au_event_class(event); 437155192Srwatson 438159269Srwatson ar->k_ar_commit |= AR_COMMIT_KERNEL; 439159269Srwatson if (au_preselect(event, class, aumask, sorf) != 0) 440159269Srwatson ar->k_ar_commit |= AR_PRESELECT_TRAIL; 441159269Srwatson if (audit_pipe_preselect(auid, event, class, sorf, 442159269Srwatson ar->k_ar_commit & AR_PRESELECT_TRAIL) != 0) 443159269Srwatson ar->k_ar_commit |= AR_PRESELECT_PIPE; 444162380Scsjp if ((ar->k_ar_commit & (AR_PRESELECT_TRAIL | AR_PRESELECT_PIPE | 445162380Scsjp AR_PRESELECT_USER_TRAIL | AR_PRESELECT_USER_PIPE)) == 0) { 446155192Srwatson mtx_lock(&audit_mtx); 447155192Srwatson audit_pre_q_len--; 448155192Srwatson mtx_unlock(&audit_mtx); 449159275Srwatson audit_free(ar); 450155192Srwatson return; 451155192Srwatson } 452155192Srwatson 453155192Srwatson ar->k_ar.ar_errno = error; 454155192Srwatson ar->k_ar.ar_retval = retval; 455155192Srwatson nanotime(&ar->k_ar.ar_endtime); 456155192Srwatson 457155192Srwatson /* 458155192Srwatson * Note: it could be that some records initiated while audit was 459155192Srwatson * enabled should still be committed? 460155192Srwatson */ 461170196Srwatson mtx_lock(&audit_mtx); 462155192Srwatson if (audit_suspended || !audit_enabled) { 463155192Srwatson audit_pre_q_len--; 464155192Srwatson mtx_unlock(&audit_mtx); 465159275Srwatson audit_free(ar); 466155192Srwatson return; 467155192Srwatson } 468156889Srwatson 469155192Srwatson /* 470170182Srwatson * Constrain the number of committed audit records based on the 471170182Srwatson * configurable parameter. 472155192Srwatson */ 473170182Srwatson while (audit_q_len >= audit_qctrl.aq_hiwater) 474159261Srwatson cv_wait(&audit_watermark_cv, &audit_mtx); 475155192Srwatson 476155192Srwatson TAILQ_INSERT_TAIL(&audit_q, ar, k_q); 477155192Srwatson audit_q_len++; 478155192Srwatson audit_pre_q_len--; 479159261Srwatson cv_signal(&audit_worker_cv); 480155192Srwatson mtx_unlock(&audit_mtx); 481155192Srwatson} 482155192Srwatson 483155192Srwatson/* 484155192Srwatson * audit_syscall_enter() is called on entry to each system call. It is 485155192Srwatson * responsible for deciding whether or not to audit the call (preselection), 486155192Srwatson * and if so, allocating a per-thread audit record. audit_new() will fill in 487155192Srwatson * basic thread/credential properties. 488155192Srwatson */ 489155192Srwatsonvoid 490155192Srwatsonaudit_syscall_enter(unsigned short code, struct thread *td) 491155192Srwatson{ 492155192Srwatson struct au_mask *aumask; 493159269Srwatson au_class_t class; 494159269Srwatson au_event_t event; 495159269Srwatson au_id_t auid; 496155192Srwatson 497155192Srwatson KASSERT(td->td_ar == NULL, ("audit_syscall_enter: td->td_ar != NULL")); 498189570Srwatson KASSERT((td->td_pflags & TDP_AUDITREC) == 0, 499189570Srwatson ("audit_syscall_enter: TDP_AUDITREC set")); 500155192Srwatson 501155192Srwatson /* 502155192Srwatson * In FreeBSD, each ABI has its own system call table, and hence 503155192Srwatson * mapping of system call codes to audit events. Convert the code to 504155192Srwatson * an audit event identifier using the process system call table 505155192Srwatson * reference. In Darwin, there's only one, so we use the global 506162950Srwatson * symbol for the system call table. No audit record is generated 507162950Srwatson * for bad system calls, as no operation has been performed. 508155192Srwatson */ 509155192Srwatson if (code >= td->td_proc->p_sysent->sv_size) 510155192Srwatson return; 511155192Srwatson 512159269Srwatson event = td->td_proc->p_sysent->sv_table[code].sy_auevent; 513159269Srwatson if (event == AUE_NULL) 514155192Srwatson return; 515155192Srwatson 516155192Srwatson /* 517155192Srwatson * Check which audit mask to use; either the kernel non-attributable 518155192Srwatson * event mask or the process audit mask. 519155192Srwatson */ 520170407Srwatson auid = td->td_ucred->cr_audit.ai_auid; 521159269Srwatson if (auid == AU_DEFAUDITID) 522155192Srwatson aumask = &audit_nae_mask; 523155192Srwatson else 524170407Srwatson aumask = &td->td_ucred->cr_audit.ai_mask; 525156889Srwatson 526155192Srwatson /* 527170196Srwatson * Allocate an audit record, if preselection allows it, and store in 528170196Srwatson * the thread for later use. 529155192Srwatson */ 530159269Srwatson class = au_event_class(event); 531159269Srwatson if (au_preselect(event, class, aumask, AU_PRS_BOTH)) { 532155192Srwatson /* 533155192Srwatson * If we're out of space and need to suspend unprivileged 534155192Srwatson * processes, do that here rather than trying to allocate 535155192Srwatson * another audit record. 536155192Srwatson * 537165604Srwatson * Note: we might wish to be able to continue here in the 538155192Srwatson * future, if the system recovers. That should be possible 539155192Srwatson * by means of checking the condition in a loop around 540155192Srwatson * cv_wait(). It might be desirable to reevaluate whether an 541155192Srwatson * audit record is still required for this event by 542155192Srwatson * re-calling au_preselect(). 543155192Srwatson */ 544164033Srwatson if (audit_in_failure && 545164033Srwatson priv_check(td, PRIV_AUDIT_FAILSTOP) != 0) { 546155192Srwatson cv_wait(&audit_fail_cv, &audit_mtx); 547155192Srwatson panic("audit_failing_stop: thread continued"); 548155192Srwatson } 549159269Srwatson td->td_ar = audit_new(event, td); 550189570Srwatson if (td->td_ar != NULL) 551189570Srwatson td->td_pflags |= TDP_AUDITREC; 552189570Srwatson } else if (audit_pipe_preselect(auid, event, class, AU_PRS_BOTH, 0)) { 553159269Srwatson td->td_ar = audit_new(event, td); 554189570Srwatson if (td->td_ar != NULL) 555189570Srwatson td->td_pflags |= TDP_AUDITREC; 556189570Srwatson } else 557155192Srwatson td->td_ar = NULL; 558155192Srwatson} 559155192Srwatson 560155192Srwatson/* 561155192Srwatson * audit_syscall_exit() is called from the return of every system call, or in 562155192Srwatson * the event of exit1(), during the execution of exit1(). It is responsible 563155192Srwatson * for committing the audit record, if any, along with return condition. 564155192Srwatson */ 565155192Srwatsonvoid 566155192Srwatsonaudit_syscall_exit(int error, struct thread *td) 567155192Srwatson{ 568155192Srwatson int retval; 569155192Srwatson 570155192Srwatson /* 571170196Srwatson * Commit the audit record as desired; once we pass the record into 572170196Srwatson * audit_commit(), the memory is owned by the audit subsystem. The 573170196Srwatson * return value from the system call is stored on the user thread. 574170196Srwatson * If there was an error, the return value is set to -1, imitating 575170196Srwatson * the behavior of the cerror routine. 576155192Srwatson */ 577155192Srwatson if (error) 578155192Srwatson retval = -1; 579155192Srwatson else 580155192Srwatson retval = td->td_retval[0]; 581155192Srwatson 582155192Srwatson audit_commit(td->td_ar, error, retval); 583155192Srwatson td->td_ar = NULL; 584189570Srwatson td->td_pflags &= ~TDP_AUDITREC; 585155192Srwatson} 586155192Srwatson 587155192Srwatsonvoid 588170407Srwatsonaudit_cred_copy(struct ucred *src, struct ucred *dest) 589155192Srwatson{ 590155192Srwatson 591170407Srwatson bcopy(&src->cr_audit, &dest->cr_audit, sizeof(dest->cr_audit)); 592155192Srwatson} 593155192Srwatson 594155195Srwatsonvoid 595170407Srwatsonaudit_cred_destroy(struct ucred *cred) 596155195Srwatson{ 597155195Srwatson 598155195Srwatson} 599155195Srwatson 600155353Srwatsonvoid 601170407Srwatsonaudit_cred_init(struct ucred *cred) 602155353Srwatson{ 603155353Srwatson 604170407Srwatson bzero(&cred->cr_audit, sizeof(cred->cr_audit)); 605155353Srwatson} 606155353Srwatson 607156889Srwatson/* 608162950Srwatson * Initialize audit information for the first kernel process (proc 0) and for 609162950Srwatson * the first user process (init). 610155192Srwatson */ 611155192Srwatsonvoid 612170407Srwatsonaudit_cred_kproc0(struct ucred *cred) 613155192Srwatson{ 614155192Srwatson 615170585Srwatson cred->cr_audit.ai_auid = AU_DEFAUDITID; 616175763Scsjp cred->cr_audit.ai_termid.at_type = AU_IPv4; 617155192Srwatson} 618155192Srwatson 619155192Srwatsonvoid 620170407Srwatsonaudit_cred_proc1(struct ucred *cred) 621155192Srwatson{ 622155192Srwatson 623170407Srwatson cred->cr_audit.ai_auid = AU_DEFAUDITID; 624175763Scsjp cred->cr_audit.ai_termid.at_type = AU_IPv4; 625155192Srwatson} 626155192Srwatson 627155192Srwatsonvoid 628170407Srwatsonaudit_thread_alloc(struct thread *td) 629155192Srwatson{ 630155192Srwatson 631170407Srwatson td->td_ar = NULL; 632155192Srwatson} 633155192Srwatson 634155192Srwatsonvoid 635170407Srwatsonaudit_thread_free(struct thread *td) 636155192Srwatson{ 637155192Srwatson 638170407Srwatson KASSERT(td->td_ar == NULL, ("audit_thread_free: td_ar != NULL")); 639189570Srwatson KASSERT((td->td_pflags & TDP_AUDITREC) == 0, 640189570Srwatson ("audit_thread_free: TDP_AUDITREC set")); 641155192Srwatson} 642172995Scsjp 643172995Scsjpvoid 644172995Scsjpaudit_proc_coredump(struct thread *td, char *path, int errcode) 645172995Scsjp{ 646172995Scsjp struct kaudit_record *ar; 647172995Scsjp struct au_mask *aumask; 648184948Srwatson struct ucred *cred; 649172995Scsjp au_class_t class; 650172995Scsjp int ret, sorf; 651172995Scsjp char **pathp; 652172995Scsjp au_id_t auid; 653172995Scsjp 654174267Swkoszek ret = 0; 655174267Swkoszek 656172995Scsjp /* 657172995Scsjp * Make sure we are using the correct preselection mask. 658172995Scsjp */ 659184948Srwatson cred = td->td_ucred; 660184948Srwatson auid = cred->cr_audit.ai_auid; 661172995Scsjp if (auid == AU_DEFAUDITID) 662172995Scsjp aumask = &audit_nae_mask; 663172995Scsjp else 664184948Srwatson aumask = &cred->cr_audit.ai_mask; 665172995Scsjp /* 666172995Scsjp * It's possible for coredump(9) generation to fail. Make sure that 667172995Scsjp * we handle this case correctly for preselection. 668172995Scsjp */ 669172995Scsjp if (errcode != 0) 670172995Scsjp sorf = AU_PRS_FAILURE; 671172995Scsjp else 672172995Scsjp sorf = AU_PRS_SUCCESS; 673172995Scsjp class = au_event_class(AUE_CORE); 674181604Scsjp if (au_preselect(AUE_CORE, class, aumask, sorf) == 0 && 675181604Scsjp audit_pipe_preselect(auid, AUE_CORE, class, sorf, 0) == 0) 676172995Scsjp return; 677184948Srwatson 678172995Scsjp /* 679172995Scsjp * If we are interested in seeing this audit record, allocate it. 680172995Scsjp * Where possible coredump records should contain a pathname and arg32 681172995Scsjp * (signal) tokens. 682172995Scsjp */ 683172995Scsjp ar = audit_new(AUE_CORE, td); 684172995Scsjp if (path != NULL) { 685172995Scsjp pathp = &ar->k_ar.ar_arg_upath1; 686172995Scsjp *pathp = malloc(MAXPATHLEN, M_AUDITPATH, M_WAITOK); 687176565Srwatson audit_canon_path(td, path, *pathp); 688172995Scsjp ARG_SET_VALID(ar, ARG_UPATH1); 689172995Scsjp } 690172995Scsjp ar->k_ar.ar_arg_signum = td->td_proc->p_sig; 691172995Scsjp ARG_SET_VALID(ar, ARG_SIGNUM); 692172995Scsjp if (errcode != 0) 693172995Scsjp ret = 1; 694172995Scsjp audit_commit(ar, errcode, ret); 695172995Scsjp} 696