audit.c revision 162950
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 162950 2006-10-02 11:32:23Z 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> 45155192Srwatson#include <sys/proc.h> 46155192Srwatson#include <sys/queue.h> 47155192Srwatson#include <sys/socket.h> 48155192Srwatson#include <sys/socketvar.h> 49155192Srwatson#include <sys/protosw.h> 50155192Srwatson#include <sys/domain.h> 51155192Srwatson#include <sys/sysproto.h> 52155192Srwatson#include <sys/sysent.h> 53155192Srwatson#include <sys/systm.h> 54155192Srwatson#include <sys/ucred.h> 55155192Srwatson#include <sys/uio.h> 56155192Srwatson#include <sys/un.h> 57155192Srwatson#include <sys/unistd.h> 58155192Srwatson#include <sys/vnode.h> 59155192Srwatson 60155406Srwatson#include <bsm/audit.h> 61156291Srwatson#include <bsm/audit_internal.h> 62155406Srwatson#include <bsm/audit_kevents.h> 63155406Srwatson 64155192Srwatson#include <netinet/in.h> 65155192Srwatson#include <netinet/in_pcb.h> 66155192Srwatson 67155192Srwatson#include <security/audit/audit.h> 68155192Srwatson#include <security/audit/audit_private.h> 69155192Srwatson 70155406Srwatson#include <vm/uma.h> 71155406Srwatson 72156888Srwatsonstatic uma_zone_t audit_record_zone; 73155192Srwatsonstatic MALLOC_DEFINE(M_AUDITPROC, "audit_proc", "Audit process storage"); 74155192SrwatsonMALLOC_DEFINE(M_AUDITDATA, "audit_data", "Audit data storage"); 75155192SrwatsonMALLOC_DEFINE(M_AUDITPATH, "audit_path", "Audit path storage"); 76155192SrwatsonMALLOC_DEFINE(M_AUDITTEXT, "audit_text", "Audit text storage"); 77155192Srwatson 78155192Srwatson/* 79156889Srwatson * Audit control settings that are set/read by system calls and are 80155192Srwatson * hence non-static. 81155192Srwatson */ 82156889Srwatson/* 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/* 119155192Srwatson * Queue of audit records ready for delivery to disk. We insert new 120155192Srwatson * records at the tail, and remove records from the head. Also, 121155192Srwatson * a count of the number of records used for checking queue depth. 122155192Srwatson * In addition, a counter of records that we have allocated but are 123155192Srwatson * not yet in the queue, which is needed to estimate the total 124155192Srwatson * size of the combined set of records 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/* 136155192Srwatson * Condition variable to signal to the worker that it has work to do: 137155192Srwatson * either new records are in the queue, or a log replacement is taking 138155192Srwatson * place. 139155192Srwatson */ 140159261Srwatsonstruct cv audit_worker_cv; 141155192Srwatson 142155192Srwatson/* 143159261Srwatson * Condition variable to flag when crossing the low watermark, meaning that 144159261Srwatson * threads blocked due to hitting the high watermark can wake up and continue 145159261Srwatson * to commit records. 146155192Srwatson */ 147159261Srwatsonstruct cv audit_watermark_cv; 148155192Srwatson 149156889Srwatson/* 150156889Srwatson * Condition variable for auditing threads wait on when in fail-stop mode. 151156889Srwatson * Threads wait on this CV forever (and ever), never seeing the light of 152155192Srwatson * day again. 153155192Srwatson */ 154156889Srwatsonstatic struct cv audit_fail_cv; 155155192Srwatson 156155192Srwatson/* 157155406Srwatson * Construct an audit record for the passed thread. 158155192Srwatson */ 159155406Srwatsonstatic int 160155406Srwatsonaudit_record_ctor(void *mem, int size, void *arg, int flags) 161155406Srwatson{ 162155406Srwatson struct kaudit_record *ar; 163155406Srwatson struct thread *td; 164155406Srwatson 165155406Srwatson KASSERT(sizeof(*ar) == size, ("audit_record_ctor: wrong size")); 166155406Srwatson 167155406Srwatson td = arg; 168155406Srwatson ar = mem; 169155406Srwatson bzero(ar, sizeof(*ar)); 170155406Srwatson ar->k_ar.ar_magic = AUDIT_RECORD_MAGIC; 171155406Srwatson nanotime(&ar->k_ar.ar_starttime); 172155406Srwatson 173155406Srwatson /* 174155406Srwatson * Export the subject credential. 175155406Srwatson */ 176155406Srwatson cru2x(td->td_ucred, &ar->k_ar.ar_subj_cred); 177155406Srwatson ar->k_ar.ar_subj_ruid = td->td_ucred->cr_ruid; 178155406Srwatson ar->k_ar.ar_subj_rgid = td->td_ucred->cr_rgid; 179155406Srwatson ar->k_ar.ar_subj_egid = td->td_ucred->cr_groups[0]; 180159415Srwatson PROC_LOCK(td->td_proc); 181155406Srwatson ar->k_ar.ar_subj_auid = td->td_proc->p_au->ai_auid; 182155406Srwatson ar->k_ar.ar_subj_asid = td->td_proc->p_au->ai_asid; 183155406Srwatson ar->k_ar.ar_subj_pid = td->td_proc->p_pid; 184155406Srwatson ar->k_ar.ar_subj_amask = td->td_proc->p_au->ai_mask; 185155406Srwatson ar->k_ar.ar_subj_term = td->td_proc->p_au->ai_termid; 186155406Srwatson bcopy(td->td_proc->p_comm, ar->k_ar.ar_subj_comm, MAXCOMLEN); 187159415Srwatson PROC_UNLOCK(td->td_proc); 188155406Srwatson 189155406Srwatson return (0); 190155406Srwatson} 191155406Srwatson 192155192Srwatsonstatic void 193155406Srwatsonaudit_record_dtor(void *mem, int size, void *arg) 194155192Srwatson{ 195155406Srwatson struct kaudit_record *ar; 196155192Srwatson 197155406Srwatson KASSERT(sizeof(*ar) == size, ("audit_record_dtor: wrong size")); 198155406Srwatson 199155406Srwatson ar = mem; 200155406Srwatson if (ar->k_ar.ar_arg_upath1 != NULL) 201155192Srwatson free(ar->k_ar.ar_arg_upath1, M_AUDITPATH); 202155406Srwatson if (ar->k_ar.ar_arg_upath2 != NULL) 203155192Srwatson free(ar->k_ar.ar_arg_upath2, M_AUDITPATH); 204155406Srwatson if (ar->k_ar.ar_arg_text != NULL) 205155192Srwatson free(ar->k_ar.ar_arg_text, M_AUDITTEXT); 206155406Srwatson if (ar->k_udata != NULL) 207155192Srwatson free(ar->k_udata, M_AUDITDATA); 208161813Swsalamon if (ar->k_ar.ar_arg_argv != NULL) 209161813Swsalamon free(ar->k_ar.ar_arg_argv, M_AUDITTEXT); 210161813Swsalamon if (ar->k_ar.ar_arg_envv != NULL) 211161813Swsalamon free(ar->k_ar.ar_arg_envv, M_AUDITTEXT); 212155192Srwatson} 213155192Srwatson 214155192Srwatson/* 215155192Srwatson * Initialize the Audit subsystem: configuration state, work queue, 216155192Srwatson * synchronization primitives, worker thread, and trigger device node. Also 217155192Srwatson * call into the BSM assembly code to initialize it. 218155192Srwatson */ 219155192Srwatsonstatic void 220155192Srwatsonaudit_init(void) 221155192Srwatson{ 222155192Srwatson 223155192Srwatson printf("Security auditing service present\n"); 224155192Srwatson audit_enabled = 0; 225155192Srwatson audit_suspended = 0; 226155192Srwatson audit_panic_on_write_fail = 0; 227155192Srwatson audit_fail_stop = 0; 228155192Srwatson audit_in_failure = 0; 229161813Swsalamon audit_argv = 0; 230161813Swsalamon audit_arge = 0; 231155192Srwatson 232155192Srwatson audit_fstat.af_filesz = 0; /* '0' means unset, unbounded */ 233156889Srwatson audit_fstat.af_currsz = 0; 234155192Srwatson audit_nae_mask.am_success = AU_NULL; 235155192Srwatson audit_nae_mask.am_failure = AU_NULL; 236155192Srwatson 237155192Srwatson TAILQ_INIT(&audit_q); 238155192Srwatson audit_q_len = 0; 239155192Srwatson audit_pre_q_len = 0; 240155192Srwatson audit_qctrl.aq_hiwater = AQ_HIWATER; 241155192Srwatson audit_qctrl.aq_lowater = AQ_LOWATER; 242155192Srwatson audit_qctrl.aq_bufsz = AQ_BUFSZ; 243155192Srwatson audit_qctrl.aq_minfree = AU_FS_MINFREE; 244155192Srwatson 245155192Srwatson mtx_init(&audit_mtx, "audit_mtx", NULL, MTX_DEF); 246159261Srwatson cv_init(&audit_worker_cv, "audit_worker_cv"); 247159261Srwatson cv_init(&audit_watermark_cv, "audit_watermark_cv"); 248155192Srwatson cv_init(&audit_fail_cv, "audit_fail_cv"); 249155192Srwatson 250159266Srwatson audit_record_zone = uma_zcreate("audit_record", 251155406Srwatson sizeof(struct kaudit_record), audit_record_ctor, 252155406Srwatson audit_record_dtor, NULL, NULL, UMA_ALIGN_PTR, 0); 253155406Srwatson 254155192Srwatson /* Initialize the BSM audit subsystem. */ 255155192Srwatson kau_init(); 256155192Srwatson 257155192Srwatson audit_trigger_init(); 258155192Srwatson 259155192Srwatson /* Register shutdown handler. */ 260155192Srwatson EVENTHANDLER_REGISTER(shutdown_pre_sync, audit_shutdown, NULL, 261155192Srwatson SHUTDOWN_PRI_FIRST); 262155192Srwatson 263156888Srwatson /* Start audit worker thread. */ 264156888Srwatson audit_worker_init(); 265155192Srwatson} 266155192Srwatson 267155192SrwatsonSYSINIT(audit_init, SI_SUB_AUDIT, SI_ORDER_FIRST, audit_init, NULL) 268155192Srwatson 269155192Srwatson/* 270155192Srwatson * Drain the audit queue and close the log at shutdown. Note that this can 271155192Srwatson * be called both from the system shutdown path and also from audit 272155192Srwatson * configuration syscalls, so 'arg' and 'howto' are ignored. 273155192Srwatson */ 274155192Srwatsonvoid 275155192Srwatsonaudit_shutdown(void *arg, int howto) 276155192Srwatson{ 277155192Srwatson 278155192Srwatson audit_rotate_vnode(NULL, NULL); 279155192Srwatson} 280155192Srwatson 281155192Srwatson/* 282155192Srwatson * Return the current thread's audit record, if any. 283155192Srwatson */ 284155192Srwatson__inline__ struct kaudit_record * 285155192Srwatsoncurrecord(void) 286155192Srwatson{ 287155192Srwatson 288155192Srwatson return (curthread->td_ar); 289155192Srwatson} 290155192Srwatson 291155192Srwatson/* 292155192Srwatson * MPSAFE 293155192Srwatson * 294155192Srwatson * XXXAUDIT: There are a number of races present in the code below due to 295155192Srwatson * release and re-grab of the mutex. The code should be revised to become 296155192Srwatson * slightly less racy. 297155192Srwatson * 298155192Srwatson * XXXAUDIT: Shouldn't there be logic here to sleep waiting on available 299155192Srwatson * pre_q space, suspending the system call until there is room? 300155192Srwatson */ 301155192Srwatsonstruct kaudit_record * 302155192Srwatsonaudit_new(int event, struct thread *td) 303155192Srwatson{ 304155192Srwatson struct kaudit_record *ar; 305155192Srwatson int no_record; 306155192Srwatson 307155406Srwatson mtx_lock(&audit_mtx); 308155406Srwatson no_record = (audit_suspended || !audit_enabled); 309155406Srwatson mtx_unlock(&audit_mtx); 310155406Srwatson if (no_record) 311155406Srwatson return (NULL); 312155192Srwatson 313155192Srwatson /* 314155192Srwatson * XXX: The number of outstanding uncommitted audit records is 315155406Srwatson * limited to the number of concurrent threads servicing system 316155192Srwatson * calls in the kernel. 317155192Srwatson */ 318155406Srwatson ar = uma_zalloc_arg(audit_record_zone, td, M_WAITOK); 319155406Srwatson ar->k_ar.ar_event = event; 320155192Srwatson 321155192Srwatson mtx_lock(&audit_mtx); 322155192Srwatson audit_pre_q_len++; 323155192Srwatson mtx_unlock(&audit_mtx); 324155192Srwatson 325155192Srwatson return (ar); 326155192Srwatson} 327155192Srwatson 328156888Srwatsonvoid 329156888Srwatsonaudit_free(struct kaudit_record *ar) 330156888Srwatson{ 331156888Srwatson 332156888Srwatson uma_zfree(audit_record_zone, ar); 333156888Srwatson} 334156888Srwatson 335155192Srwatson/* 336155192Srwatson * MPSAFE 337155192Srwatson */ 338155192Srwatsonvoid 339155192Srwatsonaudit_commit(struct kaudit_record *ar, int error, int retval) 340155192Srwatson{ 341159269Srwatson au_event_t event; 342159269Srwatson au_class_t class; 343159269Srwatson au_id_t auid; 344155192Srwatson int sorf; 345155192Srwatson struct au_mask *aumask; 346155192Srwatson 347155192Srwatson if (ar == NULL) 348155192Srwatson return; 349155192Srwatson 350155192Srwatson /* 351155192Srwatson * Decide whether to commit the audit record by checking the 352155192Srwatson * error value from the system call and using the appropriate 353155192Srwatson * audit mask. 354155192Srwatson * 355155192Srwatson * XXXAUDIT: Synchronize access to audit_nae_mask? 356155192Srwatson */ 357155192Srwatson if (ar->k_ar.ar_subj_auid == AU_DEFAUDITID) 358155192Srwatson aumask = &audit_nae_mask; 359155192Srwatson else 360155192Srwatson aumask = &ar->k_ar.ar_subj_amask; 361156889Srwatson 362155192Srwatson if (error) 363155192Srwatson sorf = AU_PRS_FAILURE; 364155192Srwatson else 365155192Srwatson sorf = AU_PRS_SUCCESS; 366155192Srwatson 367155192Srwatson switch(ar->k_ar.ar_event) { 368155192Srwatson 369155192Srwatson case AUE_OPEN_RWTC: 370155192Srwatson /* The open syscall always writes a AUE_OPEN_RWTC event; change 371156889Srwatson * it to the proper type of event based on the flags and the 372155192Srwatson * error value. 373155192Srwatson */ 374155192Srwatson ar->k_ar.ar_event = flags_and_error_to_openevent( 375155192Srwatson ar->k_ar.ar_arg_fflags, error); 376155192Srwatson break; 377155192Srwatson 378155192Srwatson case AUE_SYSCTL: 379155192Srwatson ar->k_ar.ar_event = ctlname_to_sysctlevent( 380155192Srwatson ar->k_ar.ar_arg_ctlname, ar->k_ar.ar_valid_arg); 381155192Srwatson break; 382155192Srwatson 383155192Srwatson case AUE_AUDITON: 384155192Srwatson /* Convert the auditon() command to an event */ 385155192Srwatson ar->k_ar.ar_event = auditon_command_event(ar->k_ar.ar_arg_cmd); 386155192Srwatson break; 387155192Srwatson } 388155192Srwatson 389159269Srwatson auid = ar->k_ar.ar_subj_auid; 390159269Srwatson event = ar->k_ar.ar_event; 391159269Srwatson class = au_event_class(event); 392155192Srwatson 393159269Srwatson ar->k_ar_commit |= AR_COMMIT_KERNEL; 394159269Srwatson if (au_preselect(event, class, aumask, sorf) != 0) 395159269Srwatson ar->k_ar_commit |= AR_PRESELECT_TRAIL; 396159269Srwatson if (audit_pipe_preselect(auid, event, class, sorf, 397159269Srwatson ar->k_ar_commit & AR_PRESELECT_TRAIL) != 0) 398159269Srwatson ar->k_ar_commit |= AR_PRESELECT_PIPE; 399162380Scsjp if ((ar->k_ar_commit & (AR_PRESELECT_TRAIL | AR_PRESELECT_PIPE | 400162380Scsjp AR_PRESELECT_USER_TRAIL | AR_PRESELECT_USER_PIPE)) == 0) { 401155192Srwatson mtx_lock(&audit_mtx); 402155192Srwatson audit_pre_q_len--; 403155192Srwatson mtx_unlock(&audit_mtx); 404159275Srwatson audit_free(ar); 405155192Srwatson return; 406155192Srwatson } 407155192Srwatson 408155192Srwatson ar->k_ar.ar_errno = error; 409155192Srwatson ar->k_ar.ar_retval = retval; 410155192Srwatson 411155192Srwatson /* 412155192Srwatson * We might want to do some system-wide post-filtering 413155192Srwatson * here at some point. 414155192Srwatson */ 415155192Srwatson 416155192Srwatson /* 417155192Srwatson * Timestamp system call end. 418155192Srwatson */ 419155192Srwatson nanotime(&ar->k_ar.ar_endtime); 420155192Srwatson 421155192Srwatson mtx_lock(&audit_mtx); 422155192Srwatson 423155192Srwatson /* 424155192Srwatson * Note: it could be that some records initiated while audit was 425155192Srwatson * enabled should still be committed? 426155192Srwatson */ 427155192Srwatson if (audit_suspended || !audit_enabled) { 428155192Srwatson audit_pre_q_len--; 429155192Srwatson mtx_unlock(&audit_mtx); 430159275Srwatson audit_free(ar); 431155192Srwatson return; 432155192Srwatson } 433156889Srwatson 434155192Srwatson /* 435155192Srwatson * Constrain the number of committed audit records based on 436155192Srwatson * the configurable parameter. 437155192Srwatson */ 438155192Srwatson while (audit_q_len >= audit_qctrl.aq_hiwater) { 439155192Srwatson AUDIT_PRINTF(("audit_commit: sleeping to wait for " 440155192Srwatson "audit queue to drain below high water mark\n")); 441159261Srwatson cv_wait(&audit_watermark_cv, &audit_mtx); 442155192Srwatson AUDIT_PRINTF(("audit_commit: woke up waiting for " 443155192Srwatson "audit queue draining\n")); 444155192Srwatson } 445155192Srwatson 446155192Srwatson TAILQ_INSERT_TAIL(&audit_q, ar, k_q); 447155192Srwatson audit_q_len++; 448155192Srwatson audit_pre_q_len--; 449159261Srwatson cv_signal(&audit_worker_cv); 450155192Srwatson mtx_unlock(&audit_mtx); 451155192Srwatson} 452155192Srwatson 453155192Srwatson/* 454155192Srwatson * audit_syscall_enter() is called on entry to each system call. It is 455155192Srwatson * responsible for deciding whether or not to audit the call (preselection), 456155192Srwatson * and if so, allocating a per-thread audit record. audit_new() will fill in 457155192Srwatson * basic thread/credential properties. 458155192Srwatson */ 459155192Srwatsonvoid 460155192Srwatsonaudit_syscall_enter(unsigned short code, struct thread *td) 461155192Srwatson{ 462155192Srwatson struct au_mask *aumask; 463159269Srwatson au_class_t class; 464159269Srwatson au_event_t event; 465159269Srwatson au_id_t auid; 466155192Srwatson 467155192Srwatson KASSERT(td->td_ar == NULL, ("audit_syscall_enter: td->td_ar != NULL")); 468155192Srwatson 469155192Srwatson /* 470155192Srwatson * In FreeBSD, each ABI has its own system call table, and hence 471155192Srwatson * mapping of system call codes to audit events. Convert the code to 472155192Srwatson * an audit event identifier using the process system call table 473155192Srwatson * reference. In Darwin, there's only one, so we use the global 474162950Srwatson * symbol for the system call table. No audit record is generated 475162950Srwatson * for bad system calls, as no operation has been performed. 476155192Srwatson */ 477155192Srwatson if (code >= td->td_proc->p_sysent->sv_size) 478155192Srwatson return; 479155192Srwatson 480159269Srwatson event = td->td_proc->p_sysent->sv_table[code].sy_auevent; 481159269Srwatson if (event == AUE_NULL) 482155192Srwatson return; 483155192Srwatson 484155192Srwatson /* 485155192Srwatson * Check which audit mask to use; either the kernel non-attributable 486155192Srwatson * event mask or the process audit mask. 487155192Srwatson */ 488159269Srwatson auid = td->td_proc->p_au->ai_auid; 489159269Srwatson if (auid == AU_DEFAUDITID) 490155192Srwatson aumask = &audit_nae_mask; 491155192Srwatson else 492155192Srwatson aumask = &td->td_proc->p_au->ai_mask; 493156889Srwatson 494155192Srwatson /* 495156889Srwatson * Allocate an audit record, if preselection allows it, and store 496155192Srwatson * in the thread for later use. 497155192Srwatson */ 498159269Srwatson class = au_event_class(event); 499159269Srwatson if (au_preselect(event, class, aumask, AU_PRS_BOTH)) { 500155192Srwatson /* 501155192Srwatson * If we're out of space and need to suspend unprivileged 502155192Srwatson * processes, do that here rather than trying to allocate 503155192Srwatson * another audit record. 504155192Srwatson * 505155192Srwatson * XXXRW: We might wish to be able to continue here in the 506155192Srwatson * future, if the system recovers. That should be possible 507155192Srwatson * by means of checking the condition in a loop around 508155192Srwatson * cv_wait(). It might be desirable to reevaluate whether an 509155192Srwatson * audit record is still required for this event by 510155192Srwatson * re-calling au_preselect(). 511155192Srwatson */ 512155192Srwatson if (audit_in_failure && suser(td) != 0) { 513155192Srwatson cv_wait(&audit_fail_cv, &audit_mtx); 514155192Srwatson panic("audit_failing_stop: thread continued"); 515155192Srwatson } 516159269Srwatson td->td_ar = audit_new(event, td); 517159269Srwatson } else if (audit_pipe_preselect(auid, event, class, AU_PRS_BOTH, 0)) 518159269Srwatson td->td_ar = audit_new(event, td); 519159269Srwatson else 520155192Srwatson td->td_ar = NULL; 521155192Srwatson} 522155192Srwatson 523155192Srwatson/* 524155192Srwatson * audit_syscall_exit() is called from the return of every system call, or in 525155192Srwatson * the event of exit1(), during the execution of exit1(). It is responsible 526155192Srwatson * for committing the audit record, if any, along with return condition. 527155192Srwatson */ 528155192Srwatsonvoid 529155192Srwatsonaudit_syscall_exit(int error, struct thread *td) 530155192Srwatson{ 531155192Srwatson int retval; 532155192Srwatson 533155192Srwatson /* 534155192Srwatson * Commit the audit record as desired; once we pass the record 535155192Srwatson * into audit_commit(), the memory is owned by the audit 536155192Srwatson * subsystem. 537155192Srwatson * The return value from the system call is stored on the user 538155192Srwatson * thread. If there was an error, the return value is set to -1, 539155192Srwatson * imitating the behavior of the cerror routine. 540155192Srwatson */ 541155192Srwatson if (error) 542155192Srwatson retval = -1; 543155192Srwatson else 544155192Srwatson retval = td->td_retval[0]; 545155192Srwatson 546155192Srwatson audit_commit(td->td_ar, error, retval); 547155192Srwatson if (td->td_ar != NULL) 548156889Srwatson AUDIT_PRINTF(("audit record committed by pid %d\n", 549155192Srwatson td->td_proc->p_pid)); 550155192Srwatson td->td_ar = NULL; 551155192Srwatson 552155192Srwatson} 553155192Srwatson 554155192Srwatson/* 555155192Srwatson * Allocate storage for a new process (init, or otherwise). 556155192Srwatson */ 557155192Srwatsonvoid 558155192Srwatsonaudit_proc_alloc(struct proc *p) 559155192Srwatson{ 560155192Srwatson 561155192Srwatson KASSERT(p->p_au == NULL, ("audit_proc_alloc: p->p_au != NULL (%d)", 562155192Srwatson p->p_pid)); 563155192Srwatson p->p_au = malloc(sizeof(*(p->p_au)), M_AUDITPROC, M_WAITOK); 564155192Srwatson} 565155192Srwatson 566155195Srwatson/* 567155195Srwatson * Allocate storage for a new thread. 568155195Srwatson */ 569155195Srwatsonvoid 570155195Srwatsonaudit_thread_alloc(struct thread *td) 571155195Srwatson{ 572155195Srwatson 573155195Srwatson td->td_ar = NULL; 574155195Srwatson} 575155195Srwatson 576155353Srwatson/* 577155353Srwatson * Thread destruction. 578155353Srwatson */ 579155353Srwatsonvoid 580155353Srwatsonaudit_thread_free(struct thread *td) 581155353Srwatson{ 582155353Srwatson 583155353Srwatson KASSERT(td->td_ar == NULL, ("audit_thread_free: td_ar != NULL")); 584155353Srwatson} 585155353Srwatson 586156889Srwatson/* 587162950Srwatson * Initialize audit information for the first kernel process (proc 0) and for 588162950Srwatson * the first user process (init). 589162950Srwatson * 590156889Srwatson * XXX It is not clear what the initial values should be for audit ID, 591156889Srwatson * session ID, etc. 592155192Srwatson */ 593155192Srwatsonvoid 594155192Srwatsonaudit_proc_kproc0(struct proc *p) 595155192Srwatson{ 596155192Srwatson 597155192Srwatson KASSERT(p->p_au != NULL, ("audit_proc_kproc0: p->p_au == NULL (%d)", 598155192Srwatson p->p_pid)); 599155192Srwatson bzero(p->p_au, sizeof(*(p)->p_au)); 600155192Srwatson} 601155192Srwatson 602155192Srwatsonvoid 603155192Srwatsonaudit_proc_init(struct proc *p) 604155192Srwatson{ 605155192Srwatson 606155192Srwatson KASSERT(p->p_au != NULL, ("audit_proc_init: p->p_au == NULL (%d)", 607155192Srwatson p->p_pid)); 608155192Srwatson bzero(p->p_au, sizeof(*(p)->p_au)); 609155558Srwatson p->p_au->ai_auid = AU_DEFAUDITID; 610155192Srwatson} 611155192Srwatson 612156889Srwatson/* 613155192Srwatson * Copy the audit info from the parent process to the child process when 614155192Srwatson * a fork takes place. 615155192Srwatson */ 616155192Srwatsonvoid 617155192Srwatsonaudit_proc_fork(struct proc *parent, struct proc *child) 618155192Srwatson{ 619155192Srwatson 620155192Srwatson PROC_LOCK_ASSERT(parent, MA_OWNED); 621155192Srwatson PROC_LOCK_ASSERT(child, MA_OWNED); 622155192Srwatson KASSERT(parent->p_au != NULL, 623155192Srwatson ("audit_proc_fork: parent->p_au == NULL (%d)", parent->p_pid)); 624155192Srwatson KASSERT(child->p_au != NULL, 625155192Srwatson ("audit_proc_fork: child->p_au == NULL (%d)", child->p_pid)); 626155192Srwatson bcopy(parent->p_au, child->p_au, sizeof(*child->p_au)); 627155192Srwatson} 628155192Srwatson 629155192Srwatson/* 630156889Srwatson * Free the auditing structure for the process. 631155192Srwatson */ 632155192Srwatsonvoid 633155192Srwatsonaudit_proc_free(struct proc *p) 634155192Srwatson{ 635155192Srwatson 636155192Srwatson KASSERT(p->p_au != NULL, ("p->p_au == NULL (%d)", p->p_pid)); 637155192Srwatson free(p->p_au, M_AUDITPROC); 638155192Srwatson p->p_au = NULL; 639155192Srwatson} 640