audit.c revision 219028
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 219028 2011-02-25 10:11:01Z netchild $"); 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 75219028SnetchildFEATURE(audit, "BSM audit support"); 76219028Snetchild 77156888Srwatsonstatic uma_zone_t audit_record_zone; 78170407Srwatsonstatic MALLOC_DEFINE(M_AUDITCRED, "audit_cred", "Audit cred storage"); 79155192SrwatsonMALLOC_DEFINE(M_AUDITDATA, "audit_data", "Audit data storage"); 80155192SrwatsonMALLOC_DEFINE(M_AUDITPATH, "audit_path", "Audit path storage"); 81155192SrwatsonMALLOC_DEFINE(M_AUDITTEXT, "audit_text", "Audit text storage"); 82195177SssonMALLOC_DEFINE(M_AUDITGIDSET, "audit_gidset", "Audit GID set storage"); 83155192Srwatson 84171144SrwatsonSYSCTL_NODE(_security, OID_AUTO, audit, CTLFLAG_RW, 0, 85171144Srwatson "TrustedBSD audit controls"); 86171144Srwatson 87155192Srwatson/* 88170196Srwatson * Audit control settings that are set/read by system calls and are hence 89170196Srwatson * non-static. 90170196Srwatson * 91155192Srwatson * Define the audit control flags. 92155192Srwatson */ 93156889Srwatsonint audit_enabled; 94156889Srwatsonint audit_suspended; 95155192Srwatson 96155192Srwatson/* 97162176Srwatson * Flags controlling behavior in low storage situations. Should we panic if 98162176Srwatson * a write fails? Should we fail stop if we're out of disk space? 99155192Srwatson */ 100156889Srwatsonint audit_panic_on_write_fail; 101156889Srwatsonint audit_fail_stop; 102161813Swsalamonint audit_argv; 103161813Swsalamonint audit_arge; 104155192Srwatson 105155192Srwatson/* 106155192Srwatson * Are we currently "failing stop" due to out of disk space? 107155192Srwatson */ 108156889Srwatsonint audit_in_failure; 109155192Srwatson 110155192Srwatson/* 111170691Srwatson * Global audit statistics. 112155192Srwatson */ 113156889Srwatsonstruct audit_fstat audit_fstat; 114155192Srwatson 115155192Srwatson/* 116155192Srwatson * Preselection mask for non-attributable events. 117155192Srwatson */ 118156889Srwatsonstruct au_mask audit_nae_mask; 119155192Srwatson 120155192Srwatson/* 121155192Srwatson * Mutex to protect global variables shared between various threads and 122155192Srwatson * processes. 123155192Srwatson */ 124156889Srwatsonstruct mtx audit_mtx; 125155192Srwatson 126155192Srwatson/* 127170196Srwatson * Queue of audit records ready for delivery to disk. We insert new records 128170196Srwatson * at the tail, and remove records from the head. Also, a count of the 129170196Srwatson * number of records used for checking queue depth. In addition, a counter 130170196Srwatson * of records that we have allocated but are not yet in the queue, which is 131170196Srwatson * needed to estimate the total size of the combined set of records 132170196Srwatson * outstanding in the system. 133155192Srwatson */ 134156889Srwatsonstruct kaudit_queue audit_q; 135191270Srwatsonint audit_q_len; 136191270Srwatsonint audit_pre_q_len; 137155192Srwatson 138155192Srwatson/* 139155192Srwatson * Audit queue control settings (minimum free, low/high water marks, etc.) 140155192Srwatson */ 141156889Srwatsonstruct au_qctrl audit_qctrl; 142155192Srwatson 143155192Srwatson/* 144170196Srwatson * Condition variable to signal to the worker that it has work to do: either 145170196Srwatson * new records are in the queue, or a log replacement is taking place. 146155192Srwatson */ 147159261Srwatsonstruct cv audit_worker_cv; 148155192Srwatson 149155192Srwatson/* 150159261Srwatson * Condition variable to flag when crossing the low watermark, meaning that 151159261Srwatson * threads blocked due to hitting the high watermark can wake up and continue 152159261Srwatson * to commit records. 153155192Srwatson */ 154159261Srwatsonstruct cv audit_watermark_cv; 155155192Srwatson 156156889Srwatson/* 157156889Srwatson * Condition variable for auditing threads wait on when in fail-stop mode. 158170196Srwatson * Threads wait on this CV forever (and ever), never seeing the light of day 159170196Srwatson * again. 160155192Srwatson */ 161156889Srwatsonstatic struct cv audit_fail_cv; 162155192Srwatson 163155192Srwatson/* 164184856Scsjp * Kernel audit information. This will store the current audit address 165184856Scsjp * or host information that the kernel will use when it's generating 166184856Scsjp * audit records. This data is modified by the A_GET{SET}KAUDIT auditon(2) 167184856Scsjp * command. 168184856Scsjp */ 169184856Scsjpstatic struct auditinfo_addr audit_kinfo; 170184856Scsjpstatic struct rwlock audit_kinfo_lock; 171184856Scsjp 172184857Srwatson#define KINFO_LOCK_INIT() rw_init(&audit_kinfo_lock, \ 173184857Srwatson "audit_kinfo_lock") 174184856Scsjp#define KINFO_RLOCK() rw_rlock(&audit_kinfo_lock) 175184856Scsjp#define KINFO_WLOCK() rw_wlock(&audit_kinfo_lock) 176184856Scsjp#define KINFO_RUNLOCK() rw_runlock(&audit_kinfo_lock) 177184856Scsjp#define KINFO_WUNLOCK() rw_wunlock(&audit_kinfo_lock) 178184856Scsjp 179184856Scsjpvoid 180184856Scsjpaudit_set_kinfo(struct auditinfo_addr *ak) 181184856Scsjp{ 182184856Scsjp 183184856Scsjp KASSERT(ak->ai_termid.at_type == AU_IPv4 || 184184856Scsjp ak->ai_termid.at_type == AU_IPv6, 185184856Scsjp ("audit_set_kinfo: invalid address type")); 186184857Srwatson 187184856Scsjp KINFO_WLOCK(); 188184856Scsjp audit_kinfo = *ak; 189184856Scsjp KINFO_WUNLOCK(); 190184856Scsjp} 191184856Scsjp 192184856Scsjpvoid 193184856Scsjpaudit_get_kinfo(struct auditinfo_addr *ak) 194184856Scsjp{ 195184856Scsjp 196184856Scsjp KASSERT(audit_kinfo.ai_termid.at_type == AU_IPv4 || 197184856Scsjp audit_kinfo.ai_termid.at_type == AU_IPv6, 198184856Scsjp ("audit_set_kinfo: invalid address type")); 199184857Srwatson 200184856Scsjp KINFO_RLOCK(); 201184856Scsjp *ak = audit_kinfo; 202184856Scsjp KINFO_RUNLOCK(); 203184856Scsjp} 204184856Scsjp 205184856Scsjp/* 206155406Srwatson * Construct an audit record for the passed thread. 207155192Srwatson */ 208155406Srwatsonstatic int 209155406Srwatsonaudit_record_ctor(void *mem, int size, void *arg, int flags) 210155406Srwatson{ 211155406Srwatson struct kaudit_record *ar; 212155406Srwatson struct thread *td; 213184948Srwatson struct ucred *cred; 214155406Srwatson 215155406Srwatson KASSERT(sizeof(*ar) == size, ("audit_record_ctor: wrong size")); 216155406Srwatson 217155406Srwatson td = arg; 218155406Srwatson ar = mem; 219155406Srwatson bzero(ar, sizeof(*ar)); 220155406Srwatson ar->k_ar.ar_magic = AUDIT_RECORD_MAGIC; 221155406Srwatson nanotime(&ar->k_ar.ar_starttime); 222155406Srwatson 223155406Srwatson /* 224155406Srwatson * Export the subject credential. 225155406Srwatson */ 226184948Srwatson cred = td->td_ucred; 227184948Srwatson cru2x(cred, &ar->k_ar.ar_subj_cred); 228184948Srwatson ar->k_ar.ar_subj_ruid = cred->cr_ruid; 229184948Srwatson ar->k_ar.ar_subj_rgid = cred->cr_rgid; 230184948Srwatson ar->k_ar.ar_subj_egid = cred->cr_groups[0]; 231184948Srwatson ar->k_ar.ar_subj_auid = cred->cr_audit.ai_auid; 232184948Srwatson ar->k_ar.ar_subj_asid = cred->cr_audit.ai_asid; 233155406Srwatson ar->k_ar.ar_subj_pid = td->td_proc->p_pid; 234184948Srwatson ar->k_ar.ar_subj_amask = cred->cr_audit.ai_mask; 235184948Srwatson ar->k_ar.ar_subj_term_addr = cred->cr_audit.ai_termid; 236155406Srwatson return (0); 237155406Srwatson} 238155406Srwatson 239155192Srwatsonstatic void 240155406Srwatsonaudit_record_dtor(void *mem, int size, void *arg) 241155192Srwatson{ 242155406Srwatson struct kaudit_record *ar; 243155192Srwatson 244155406Srwatson KASSERT(sizeof(*ar) == size, ("audit_record_dtor: wrong size")); 245155406Srwatson 246155406Srwatson ar = mem; 247155406Srwatson if (ar->k_ar.ar_arg_upath1 != NULL) 248155192Srwatson free(ar->k_ar.ar_arg_upath1, M_AUDITPATH); 249155406Srwatson if (ar->k_ar.ar_arg_upath2 != NULL) 250155192Srwatson free(ar->k_ar.ar_arg_upath2, M_AUDITPATH); 251155406Srwatson if (ar->k_ar.ar_arg_text != NULL) 252155192Srwatson free(ar->k_ar.ar_arg_text, M_AUDITTEXT); 253155406Srwatson if (ar->k_udata != NULL) 254155192Srwatson free(ar->k_udata, M_AUDITDATA); 255161813Swsalamon if (ar->k_ar.ar_arg_argv != NULL) 256161813Swsalamon free(ar->k_ar.ar_arg_argv, M_AUDITTEXT); 257161813Swsalamon if (ar->k_ar.ar_arg_envv != NULL) 258161813Swsalamon free(ar->k_ar.ar_arg_envv, M_AUDITTEXT); 259195177Ssson if (ar->k_ar.ar_arg_groups.gidset != NULL) 260195177Ssson free(ar->k_ar.ar_arg_groups.gidset, M_AUDITGIDSET); 261155192Srwatson} 262155192Srwatson 263155192Srwatson/* 264155192Srwatson * Initialize the Audit subsystem: configuration state, work queue, 265155192Srwatson * synchronization primitives, worker thread, and trigger device node. Also 266155192Srwatson * call into the BSM assembly code to initialize it. 267155192Srwatson */ 268155192Srwatsonstatic void 269155192Srwatsonaudit_init(void) 270155192Srwatson{ 271155192Srwatson 272155192Srwatson audit_enabled = 0; 273155192Srwatson audit_suspended = 0; 274155192Srwatson audit_panic_on_write_fail = 0; 275155192Srwatson audit_fail_stop = 0; 276155192Srwatson audit_in_failure = 0; 277161813Swsalamon audit_argv = 0; 278161813Swsalamon audit_arge = 0; 279155192Srwatson 280170196Srwatson audit_fstat.af_filesz = 0; /* '0' means unset, unbounded. */ 281156889Srwatson audit_fstat.af_currsz = 0; 282173142Srwatson audit_nae_mask.am_success = 0; 283173142Srwatson audit_nae_mask.am_failure = 0; 284155192Srwatson 285155192Srwatson TAILQ_INIT(&audit_q); 286155192Srwatson audit_q_len = 0; 287155192Srwatson audit_pre_q_len = 0; 288155192Srwatson audit_qctrl.aq_hiwater = AQ_HIWATER; 289155192Srwatson audit_qctrl.aq_lowater = AQ_LOWATER; 290155192Srwatson audit_qctrl.aq_bufsz = AQ_BUFSZ; 291155192Srwatson audit_qctrl.aq_minfree = AU_FS_MINFREE; 292155192Srwatson 293184856Scsjp audit_kinfo.ai_termid.at_type = AU_IPv4; 294184856Scsjp audit_kinfo.ai_termid.at_addr[0] = INADDR_ANY; 295184856Scsjp 296155192Srwatson mtx_init(&audit_mtx, "audit_mtx", NULL, MTX_DEF); 297184856Scsjp KINFO_LOCK_INIT(); 298159261Srwatson cv_init(&audit_worker_cv, "audit_worker_cv"); 299159261Srwatson cv_init(&audit_watermark_cv, "audit_watermark_cv"); 300155192Srwatson cv_init(&audit_fail_cv, "audit_fail_cv"); 301155192Srwatson 302159266Srwatson audit_record_zone = uma_zcreate("audit_record", 303155406Srwatson sizeof(struct kaudit_record), audit_record_ctor, 304155406Srwatson audit_record_dtor, NULL, NULL, UMA_ALIGN_PTR, 0); 305155406Srwatson 306155192Srwatson /* Initialize the BSM audit subsystem. */ 307155192Srwatson kau_init(); 308155192Srwatson 309155192Srwatson audit_trigger_init(); 310155192Srwatson 311155192Srwatson /* Register shutdown handler. */ 312155192Srwatson EVENTHANDLER_REGISTER(shutdown_pre_sync, audit_shutdown, NULL, 313155192Srwatson SHUTDOWN_PRI_FIRST); 314155192Srwatson 315156888Srwatson /* Start audit worker thread. */ 316156888Srwatson audit_worker_init(); 317155192Srwatson} 318155192Srwatson 319177253SrwatsonSYSINIT(audit_init, SI_SUB_AUDIT, SI_ORDER_FIRST, audit_init, NULL); 320155192Srwatson 321155192Srwatson/* 322155192Srwatson * Drain the audit queue and close the log at shutdown. Note that this can 323155192Srwatson * be called both from the system shutdown path and also from audit 324155192Srwatson * configuration syscalls, so 'arg' and 'howto' are ignored. 325179517Srwatson * 326179517Srwatson * XXXRW: In FreeBSD 7.x and 8.x, this fails to wait for the record queue to 327179517Srwatson * drain before returning, which could lead to lost records on shutdown. 328155192Srwatson */ 329155192Srwatsonvoid 330155192Srwatsonaudit_shutdown(void *arg, int howto) 331155192Srwatson{ 332155192Srwatson 333155192Srwatson audit_rotate_vnode(NULL, NULL); 334155192Srwatson} 335155192Srwatson 336155192Srwatson/* 337155192Srwatson * Return the current thread's audit record, if any. 338155192Srwatson */ 339169896Srwatsonstruct kaudit_record * 340155192Srwatsoncurrecord(void) 341155192Srwatson{ 342155192Srwatson 343155192Srwatson return (curthread->td_ar); 344155192Srwatson} 345155192Srwatson 346155192Srwatson/* 347155192Srwatson * XXXAUDIT: There are a number of races present in the code below due to 348155192Srwatson * release and re-grab of the mutex. The code should be revised to become 349155192Srwatson * slightly less racy. 350155192Srwatson * 351155192Srwatson * XXXAUDIT: Shouldn't there be logic here to sleep waiting on available 352155192Srwatson * pre_q space, suspending the system call until there is room? 353155192Srwatson */ 354155192Srwatsonstruct kaudit_record * 355155192Srwatsonaudit_new(int event, struct thread *td) 356155192Srwatson{ 357155192Srwatson struct kaudit_record *ar; 358155192Srwatson int no_record; 359155192Srwatson 360155406Srwatson mtx_lock(&audit_mtx); 361155406Srwatson no_record = (audit_suspended || !audit_enabled); 362155406Srwatson mtx_unlock(&audit_mtx); 363155406Srwatson if (no_record) 364155406Srwatson return (NULL); 365155192Srwatson 366155192Srwatson /* 367165604Srwatson * Note: the number of outstanding uncommitted audit records is 368165604Srwatson * limited to the number of concurrent threads servicing system calls 369165604Srwatson * in the kernel. 370155192Srwatson */ 371155406Srwatson ar = uma_zalloc_arg(audit_record_zone, td, M_WAITOK); 372155406Srwatson ar->k_ar.ar_event = event; 373155192Srwatson 374155192Srwatson mtx_lock(&audit_mtx); 375155192Srwatson audit_pre_q_len++; 376155192Srwatson mtx_unlock(&audit_mtx); 377155192Srwatson 378155192Srwatson return (ar); 379155192Srwatson} 380155192Srwatson 381156888Srwatsonvoid 382156888Srwatsonaudit_free(struct kaudit_record *ar) 383156888Srwatson{ 384156888Srwatson 385156888Srwatson uma_zfree(audit_record_zone, ar); 386156888Srwatson} 387156888Srwatson 388155192Srwatsonvoid 389155192Srwatsonaudit_commit(struct kaudit_record *ar, int error, int retval) 390155192Srwatson{ 391159269Srwatson au_event_t event; 392159269Srwatson au_class_t class; 393159269Srwatson au_id_t auid; 394155192Srwatson int sorf; 395155192Srwatson struct au_mask *aumask; 396155192Srwatson 397155192Srwatson if (ar == NULL) 398155192Srwatson return; 399155192Srwatson 400155192Srwatson /* 401170196Srwatson * Decide whether to commit the audit record by checking the error 402170196Srwatson * value from the system call and using the appropriate audit mask. 403155192Srwatson */ 404155192Srwatson if (ar->k_ar.ar_subj_auid == AU_DEFAUDITID) 405155192Srwatson aumask = &audit_nae_mask; 406155192Srwatson else 407155192Srwatson aumask = &ar->k_ar.ar_subj_amask; 408156889Srwatson 409155192Srwatson if (error) 410155192Srwatson sorf = AU_PRS_FAILURE; 411155192Srwatson else 412155192Srwatson sorf = AU_PRS_SUCCESS; 413155192Srwatson 414195925Srwatson /* 415195925Srwatson * syscalls.master sometimes contains a prototype event number, which 416195925Srwatson * we will transform into a more specific event number now that we 417195925Srwatson * have more complete information gathered during the system call. 418195925Srwatson */ 419155192Srwatson switch(ar->k_ar.ar_event) { 420155192Srwatson case AUE_OPEN_RWTC: 421176690Srwatson ar->k_ar.ar_event = audit_flags_and_error_to_openevent( 422155192Srwatson ar->k_ar.ar_arg_fflags, error); 423155192Srwatson break; 424155192Srwatson 425195925Srwatson case AUE_OPENAT_RWTC: 426195925Srwatson ar->k_ar.ar_event = audit_flags_and_error_to_openatevent( 427195925Srwatson ar->k_ar.ar_arg_fflags, error); 428195925Srwatson break; 429195925Srwatson 430155192Srwatson case AUE_SYSCTL: 431176690Srwatson ar->k_ar.ar_event = audit_ctlname_to_sysctlevent( 432155192Srwatson ar->k_ar.ar_arg_ctlname, ar->k_ar.ar_valid_arg); 433155192Srwatson break; 434155192Srwatson 435155192Srwatson case AUE_AUDITON: 436170585Srwatson /* Convert the auditon() command to an event. */ 437155192Srwatson ar->k_ar.ar_event = auditon_command_event(ar->k_ar.ar_arg_cmd); 438155192Srwatson break; 439155192Srwatson } 440155192Srwatson 441159269Srwatson auid = ar->k_ar.ar_subj_auid; 442159269Srwatson event = ar->k_ar.ar_event; 443159269Srwatson class = au_event_class(event); 444155192Srwatson 445159269Srwatson ar->k_ar_commit |= AR_COMMIT_KERNEL; 446159269Srwatson if (au_preselect(event, class, aumask, sorf) != 0) 447159269Srwatson ar->k_ar_commit |= AR_PRESELECT_TRAIL; 448159269Srwatson if (audit_pipe_preselect(auid, event, class, sorf, 449159269Srwatson ar->k_ar_commit & AR_PRESELECT_TRAIL) != 0) 450159269Srwatson ar->k_ar_commit |= AR_PRESELECT_PIPE; 451162380Scsjp if ((ar->k_ar_commit & (AR_PRESELECT_TRAIL | AR_PRESELECT_PIPE | 452162380Scsjp AR_PRESELECT_USER_TRAIL | AR_PRESELECT_USER_PIPE)) == 0) { 453155192Srwatson mtx_lock(&audit_mtx); 454155192Srwatson audit_pre_q_len--; 455155192Srwatson mtx_unlock(&audit_mtx); 456159275Srwatson audit_free(ar); 457155192Srwatson return; 458155192Srwatson } 459155192Srwatson 460155192Srwatson ar->k_ar.ar_errno = error; 461155192Srwatson ar->k_ar.ar_retval = retval; 462155192Srwatson nanotime(&ar->k_ar.ar_endtime); 463155192Srwatson 464155192Srwatson /* 465155192Srwatson * Note: it could be that some records initiated while audit was 466155192Srwatson * enabled should still be committed? 467155192Srwatson */ 468170196Srwatson mtx_lock(&audit_mtx); 469155192Srwatson if (audit_suspended || !audit_enabled) { 470155192Srwatson audit_pre_q_len--; 471155192Srwatson mtx_unlock(&audit_mtx); 472159275Srwatson audit_free(ar); 473155192Srwatson return; 474155192Srwatson } 475156889Srwatson 476155192Srwatson /* 477170182Srwatson * Constrain the number of committed audit records based on the 478170182Srwatson * configurable parameter. 479155192Srwatson */ 480170182Srwatson while (audit_q_len >= audit_qctrl.aq_hiwater) 481159261Srwatson cv_wait(&audit_watermark_cv, &audit_mtx); 482155192Srwatson 483155192Srwatson TAILQ_INSERT_TAIL(&audit_q, ar, k_q); 484155192Srwatson audit_q_len++; 485155192Srwatson audit_pre_q_len--; 486159261Srwatson cv_signal(&audit_worker_cv); 487155192Srwatson mtx_unlock(&audit_mtx); 488155192Srwatson} 489155192Srwatson 490155192Srwatson/* 491155192Srwatson * audit_syscall_enter() is called on entry to each system call. It is 492155192Srwatson * responsible for deciding whether or not to audit the call (preselection), 493155192Srwatson * and if so, allocating a per-thread audit record. audit_new() will fill in 494155192Srwatson * basic thread/credential properties. 495155192Srwatson */ 496155192Srwatsonvoid 497155192Srwatsonaudit_syscall_enter(unsigned short code, struct thread *td) 498155192Srwatson{ 499155192Srwatson struct au_mask *aumask; 500159269Srwatson au_class_t class; 501159269Srwatson au_event_t event; 502159269Srwatson au_id_t auid; 503155192Srwatson 504155192Srwatson KASSERT(td->td_ar == NULL, ("audit_syscall_enter: td->td_ar != NULL")); 505189570Srwatson KASSERT((td->td_pflags & TDP_AUDITREC) == 0, 506189570Srwatson ("audit_syscall_enter: TDP_AUDITREC set")); 507155192Srwatson 508155192Srwatson /* 509155192Srwatson * In FreeBSD, each ABI has its own system call table, and hence 510155192Srwatson * mapping of system call codes to audit events. Convert the code to 511155192Srwatson * an audit event identifier using the process system call table 512155192Srwatson * reference. In Darwin, there's only one, so we use the global 513162950Srwatson * symbol for the system call table. No audit record is generated 514162950Srwatson * for bad system calls, as no operation has been performed. 515155192Srwatson */ 516155192Srwatson if (code >= td->td_proc->p_sysent->sv_size) 517155192Srwatson return; 518155192Srwatson 519159269Srwatson event = td->td_proc->p_sysent->sv_table[code].sy_auevent; 520159269Srwatson if (event == AUE_NULL) 521155192Srwatson return; 522155192Srwatson 523155192Srwatson /* 524155192Srwatson * Check which audit mask to use; either the kernel non-attributable 525155192Srwatson * event mask or the process audit mask. 526155192Srwatson */ 527170407Srwatson auid = td->td_ucred->cr_audit.ai_auid; 528159269Srwatson if (auid == AU_DEFAUDITID) 529155192Srwatson aumask = &audit_nae_mask; 530155192Srwatson else 531170407Srwatson aumask = &td->td_ucred->cr_audit.ai_mask; 532156889Srwatson 533155192Srwatson /* 534170196Srwatson * Allocate an audit record, if preselection allows it, and store in 535170196Srwatson * the thread for later use. 536155192Srwatson */ 537159269Srwatson class = au_event_class(event); 538159269Srwatson if (au_preselect(event, class, aumask, AU_PRS_BOTH)) { 539155192Srwatson /* 540155192Srwatson * If we're out of space and need to suspend unprivileged 541155192Srwatson * processes, do that here rather than trying to allocate 542155192Srwatson * another audit record. 543155192Srwatson * 544165604Srwatson * Note: we might wish to be able to continue here in the 545155192Srwatson * future, if the system recovers. That should be possible 546155192Srwatson * by means of checking the condition in a loop around 547155192Srwatson * cv_wait(). It might be desirable to reevaluate whether an 548155192Srwatson * audit record is still required for this event by 549155192Srwatson * re-calling au_preselect(). 550155192Srwatson */ 551164033Srwatson if (audit_in_failure && 552164033Srwatson priv_check(td, PRIV_AUDIT_FAILSTOP) != 0) { 553155192Srwatson cv_wait(&audit_fail_cv, &audit_mtx); 554155192Srwatson panic("audit_failing_stop: thread continued"); 555155192Srwatson } 556159269Srwatson td->td_ar = audit_new(event, td); 557189570Srwatson if (td->td_ar != NULL) 558189570Srwatson td->td_pflags |= TDP_AUDITREC; 559189570Srwatson } else if (audit_pipe_preselect(auid, event, class, AU_PRS_BOTH, 0)) { 560159269Srwatson td->td_ar = audit_new(event, td); 561189570Srwatson if (td->td_ar != NULL) 562189570Srwatson td->td_pflags |= TDP_AUDITREC; 563189570Srwatson } else 564155192Srwatson td->td_ar = NULL; 565155192Srwatson} 566155192Srwatson 567155192Srwatson/* 568155192Srwatson * audit_syscall_exit() is called from the return of every system call, or in 569155192Srwatson * the event of exit1(), during the execution of exit1(). It is responsible 570155192Srwatson * for committing the audit record, if any, along with return condition. 571155192Srwatson */ 572155192Srwatsonvoid 573155192Srwatsonaudit_syscall_exit(int error, struct thread *td) 574155192Srwatson{ 575155192Srwatson int retval; 576155192Srwatson 577155192Srwatson /* 578170196Srwatson * Commit the audit record as desired; once we pass the record into 579170196Srwatson * audit_commit(), the memory is owned by the audit subsystem. The 580170196Srwatson * return value from the system call is stored on the user thread. 581170196Srwatson * If there was an error, the return value is set to -1, imitating 582170196Srwatson * the behavior of the cerror routine. 583155192Srwatson */ 584155192Srwatson if (error) 585155192Srwatson retval = -1; 586155192Srwatson else 587155192Srwatson retval = td->td_retval[0]; 588155192Srwatson 589155192Srwatson audit_commit(td->td_ar, error, retval); 590155192Srwatson td->td_ar = NULL; 591189570Srwatson td->td_pflags &= ~TDP_AUDITREC; 592155192Srwatson} 593155192Srwatson 594155192Srwatsonvoid 595170407Srwatsonaudit_cred_copy(struct ucred *src, struct ucred *dest) 596155192Srwatson{ 597155192Srwatson 598170407Srwatson bcopy(&src->cr_audit, &dest->cr_audit, sizeof(dest->cr_audit)); 599155192Srwatson} 600155192Srwatson 601155195Srwatsonvoid 602170407Srwatsonaudit_cred_destroy(struct ucred *cred) 603155195Srwatson{ 604155195Srwatson 605155195Srwatson} 606155195Srwatson 607155353Srwatsonvoid 608170407Srwatsonaudit_cred_init(struct ucred *cred) 609155353Srwatson{ 610155353Srwatson 611170407Srwatson bzero(&cred->cr_audit, sizeof(cred->cr_audit)); 612155353Srwatson} 613155353Srwatson 614156889Srwatson/* 615162950Srwatson * Initialize audit information for the first kernel process (proc 0) and for 616162950Srwatson * the first user process (init). 617155192Srwatson */ 618155192Srwatsonvoid 619170407Srwatsonaudit_cred_kproc0(struct ucred *cred) 620155192Srwatson{ 621155192Srwatson 622170585Srwatson cred->cr_audit.ai_auid = AU_DEFAUDITID; 623175763Scsjp cred->cr_audit.ai_termid.at_type = AU_IPv4; 624155192Srwatson} 625155192Srwatson 626155192Srwatsonvoid 627170407Srwatsonaudit_cred_proc1(struct ucred *cred) 628155192Srwatson{ 629155192Srwatson 630170407Srwatson cred->cr_audit.ai_auid = AU_DEFAUDITID; 631175763Scsjp cred->cr_audit.ai_termid.at_type = AU_IPv4; 632155192Srwatson} 633155192Srwatson 634155192Srwatsonvoid 635170407Srwatsonaudit_thread_alloc(struct thread *td) 636155192Srwatson{ 637155192Srwatson 638170407Srwatson td->td_ar = NULL; 639155192Srwatson} 640155192Srwatson 641155192Srwatsonvoid 642170407Srwatsonaudit_thread_free(struct thread *td) 643155192Srwatson{ 644155192Srwatson 645170407Srwatson KASSERT(td->td_ar == NULL, ("audit_thread_free: td_ar != NULL")); 646189570Srwatson KASSERT((td->td_pflags & TDP_AUDITREC) == 0, 647189570Srwatson ("audit_thread_free: TDP_AUDITREC set")); 648155192Srwatson} 649172995Scsjp 650172995Scsjpvoid 651172995Scsjpaudit_proc_coredump(struct thread *td, char *path, int errcode) 652172995Scsjp{ 653172995Scsjp struct kaudit_record *ar; 654172995Scsjp struct au_mask *aumask; 655184948Srwatson struct ucred *cred; 656172995Scsjp au_class_t class; 657172995Scsjp int ret, sorf; 658172995Scsjp char **pathp; 659172995Scsjp au_id_t auid; 660172995Scsjp 661174267Swkoszek ret = 0; 662174267Swkoszek 663172995Scsjp /* 664172995Scsjp * Make sure we are using the correct preselection mask. 665172995Scsjp */ 666184948Srwatson cred = td->td_ucred; 667184948Srwatson auid = cred->cr_audit.ai_auid; 668172995Scsjp if (auid == AU_DEFAUDITID) 669172995Scsjp aumask = &audit_nae_mask; 670172995Scsjp else 671184948Srwatson aumask = &cred->cr_audit.ai_mask; 672172995Scsjp /* 673172995Scsjp * It's possible for coredump(9) generation to fail. Make sure that 674172995Scsjp * we handle this case correctly for preselection. 675172995Scsjp */ 676172995Scsjp if (errcode != 0) 677172995Scsjp sorf = AU_PRS_FAILURE; 678172995Scsjp else 679172995Scsjp sorf = AU_PRS_SUCCESS; 680172995Scsjp class = au_event_class(AUE_CORE); 681181604Scsjp if (au_preselect(AUE_CORE, class, aumask, sorf) == 0 && 682181604Scsjp audit_pipe_preselect(auid, AUE_CORE, class, sorf, 0) == 0) 683172995Scsjp return; 684184948Srwatson 685172995Scsjp /* 686172995Scsjp * If we are interested in seeing this audit record, allocate it. 687172995Scsjp * Where possible coredump records should contain a pathname and arg32 688172995Scsjp * (signal) tokens. 689172995Scsjp */ 690172995Scsjp ar = audit_new(AUE_CORE, td); 691172995Scsjp if (path != NULL) { 692172995Scsjp pathp = &ar->k_ar.ar_arg_upath1; 693172995Scsjp *pathp = malloc(MAXPATHLEN, M_AUDITPATH, M_WAITOK); 694176565Srwatson audit_canon_path(td, path, *pathp); 695172995Scsjp ARG_SET_VALID(ar, ARG_UPATH1); 696172995Scsjp } 697172995Scsjp ar->k_ar.ar_arg_signum = td->td_proc->p_sig; 698172995Scsjp ARG_SET_VALID(ar, ARG_SIGNUM); 699172995Scsjp if (errcode != 0) 700172995Scsjp ret = 1; 701172995Scsjp audit_commit(ar, errcode, ret); 702172995Scsjp} 703