Date: Thu, 6 Oct 2005 01:10:18 GMT From: Wayne Salamon <wsalamon@FreeBSD.org> To: Perforce Change Reviews <perforce@freebsd.org> Subject: PERFORCE change 84875 for review Message-ID: <200510060110.j961AIo8094337@repoman.freebsd.org>
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http://perforce.freebsd.org/chv.cgi?CH=84875 Change 84875 by wsalamon@gretsch on 2005/10/06 01:09:55 Move the audit_arg_xxx() functions into the new source file and add the new file to the config. Affected files ... .. //depot/projects/trustedbsd/audit3/sys/conf/files#9 edit .. //depot/projects/trustedbsd/audit3/sys/security/audit/audit_arg.c#2 edit .. //depot/projects/trustedbsd/audit3/sys/security/audit/kern_audit.c#45 edit Differences ... ==== //depot/projects/trustedbsd/audit3/sys/conf/files#9 (text+ko) ==== @@ -1843,8 +1843,9 @@ posix4/p1003_1b.c standard posix4/posix4_mib.c standard rpc/rpcclnt.c optional nfsclient +security/audit/audit_arg.c optional audit +security/audit/audit_syscalls.c standard security/audit/audit_trigger.c optional audit -security/audit/audit_syscalls.c standard security/audit/kern_audit.c optional audit security/audit/kern_bsm_audit.c optional audit security/audit/kern_bsm_klib.c optional audit ==== //depot/projects/trustedbsd/audit3/sys/security/audit/audit_arg.c#2 (text+ko) ==== @@ -21,985 +21,25 @@ */ #include <sys/param.h> -#include <sys/condvar.h> -#include <sys/conf.h> -#include <sys/file.h> #include <sys/filedesc.h> -#include <sys/fcntl.h> #include <sys/ipc.h> -#include <sys/kernel.h> -#include <sys/kthread.h> -#include <sys/malloc.h> #include <sys/mount.h> -#include <sys/namei.h> #include <sys/proc.h> -#include <sys/queue.h> #include <sys/socket.h> #include <sys/socketvar.h> #include <sys/protosw.h> #include <sys/domain.h> -#include <sys/sysproto.h> -#include <sys/sysent.h> #include <sys/systm.h> -#include <sys/ucred.h> -#include <sys/uio.h> #include <sys/un.h> -#include <sys/unistd.h> #include <sys/vnode.h> #include <netinet/in.h> #include <netinet/in_pcb.h> -#include <bsm/audit.h> -#include <bsm/audit_kevents.h> #include <security/audit/audit.h> #include <security/audit/audit_private.h> /* - * The AUDIT_EXCESSIVELY_VERBOSE define enables a number of - * gratuitously noisy printf's to the console. Due to the - * volume, it should be left off unless you want your system - * to churn a lot whenever the audit record flow gets high. - */ -//#define AUDIT_EXCESSIVELY_VERBOSE -#ifdef AUDIT_EXCESSIVELY_VERBOSE -#define AUDIT_PRINTF(x) printf x -#else -#define AUDIT_PRINTF(X) -#endif - -#if 0 -#if DIAGNOSTIC -#if defined(assert) -#undef assert() -#endif -#define assert(cond) \ - ((void) ((cond) ? 0 : panic("%s:%d (%s)", __FILE__, __LINE__, # cond))) -#else -#include <kern/assert.h> -#endif /* DIAGNOSTIC */ -#endif -#define assert(x) KASSERT(x, x) - -MALLOC_DEFINE(M_AUDIT, "audit", "Audit event records"); - -/* - * Audit control settings that are set/read by system calls and are - * hence non-static. - */ -/* - * Define the audit control flags. - */ -int audit_enabled; -int audit_suspended; - -/* - * Flags controlling behavior in low storage situations. - * Should we panic if a write fails? Should we fail stop - * if we're out of disk space? - */ -int audit_panic_on_write_fail; -int audit_fail_stop; - -/* - * Audit queue control settings (minimum free, low/high water marks, etc.) - */ -struct au_qctrl audit_qctrl; - -/* - * Global audit statistiscs. - */ -struct audit_fstat audit_fstat; - -/* - * Preselection mask for non-attributable events. - */ -struct au_mask audit_nae_mask; - -/* - * Mutex to protect global variables shared between various threads and - * processes. - */ -static struct mtx audit_mtx; - -/* - * Queue of audit records ready for delivery to disk. We insert new - * records at the tail, and remove records from the head. Also, - * a count of the number of records used for checking queue depth. - * In addition, a counter of records that we have allocated but are - * not yet in the queue, which is needed to estimate the total - * size of the combined set of records outstanding in the system. - */ -static TAILQ_HEAD(, kaudit_record) audit_q; -static int audit_q_len; -static int audit_pre_q_len; - -/* - * Condition variable to signal to the worker that it has work to do: - * either new records are in the queue, or a log replacement is taking - * place. - */ -static struct cv audit_cv; - -/* - * Worker thread that will schedule disk I/O, etc. - */ -static struct proc *audit_thread; - -/* - * When an audit log is rotated, the actual rotation must be performed - * by the audit worker thread, as it may have outstanding writes on the - * current audit log. audit_replacement_vp holds the vnode replacing - * the current vnode. We can't let more than one replacement occur - * at a time, so if more than one thread requests a replacement, only - * one can have the replacement "in progress" at any given moment. If - * a thread tries to replace the audit vnode and discovers a replacement - * is already in progress (i.e., audit_replacement_flag != 0), then it - * will sleep on audit_replacement_cv waiting its turn to perform a - * replacement. When a replacement is completed, this cv is signalled - * by the worker thread so a waiting thread can start another replacement. - * We also store a credential to perform audit log write operations with. - * - * The current credential and vnode are thread-local to audit_worker. - */ -static struct cv audit_replacement_cv; - -static int audit_replacement_flag; -static struct vnode *audit_replacement_vp; -static struct ucred *audit_replacement_cred; - -/* - * Condition variable to signal to the worker that it has work to do: - * either new records are in the queue, or a log replacement is taking - * place. - */ -static struct cv audit_commit_cv; - -/* - * Condition variable for auditing threads wait on when in fail-stop mode. - * Threads wait on this CV forever (and ever), never seeing the light of - * day again. - */ -static struct cv audit_fail_cv; - -/* - * Flags related to Kernel->user-space communication. - */ -static int audit_file_rotate_wait; - -/* - * Are we currently "failing stop" due to out of disk space? - */ -static int audit_in_failure; - -/* - * Perform a deep free of an audit record (core record and referenced objects) - */ -static void -audit_record_free(struct kaudit_record *ar) -{ - - if (ar->k_ar.ar_arg_upath1 != NULL) { - free(ar->k_ar.ar_arg_upath1, M_AUDIT); - } - if (ar->k_ar.ar_arg_upath2 != NULL) { - free(ar->k_ar.ar_arg_upath2, M_AUDIT); - } - if (ar->k_ar.ar_arg_kpath1 != NULL) { - free(ar->k_ar.ar_arg_kpath1, M_AUDIT); - } - if (ar->k_ar.ar_arg_kpath2 != NULL) { - free(ar->k_ar.ar_arg_kpath2, M_AUDIT); - } - if (ar->k_ar.ar_arg_text != NULL) { - free(ar->k_ar.ar_arg_text, M_AUDIT); - } - if (ar->k_udata != NULL) { - free(ar->k_udata, M_AUDIT); - } - free(ar, M_AUDIT); -} - -/* - * XXXAUDIT: Should adjust comments below to make it clear that we get to - * this point only if we believe we have storage, so not having space here - * is a violation of invariants derived from administrative procedures. - * I.e., someone else has written to the audit partition, leaving less space - * than we accounted for. - */ -static int -audit_record_write(struct vnode *vp, struct kaudit_record *ar, - struct ucred *cred, struct thread *td) -{ - int ret; - long temp; - struct au_record *bsm; - struct vattr vattr; - struct statfs *mnt_stat = &vp->v_mount->mnt_stat; - int vfslocked; - - vfslocked = VFS_LOCK_GIANT(vp->v_mount); - - /* - * First, gather statistics on the audit log file and file system - * so that we know how we're doing on space. In both cases, - * if we're unable to perform the operation, we drop the record - * and return. However, this is arguably an assertion failure. - * XXX Need a FreeBSD equivalent. - */ - ret = VFS_STATFS(vp->v_mount, mnt_stat, td); - if (ret) - goto out; - - ret = VOP_GETATTR(vp, &vattr, cred, td); - if (ret) - goto out; - - /* update the global stats struct */ - audit_fstat.af_currsz = vattr.va_size; - - /* - * XXX Need to decide what to do if the trigger to the audit daemon - * fails. - */ - - /* - * If we fall below minimum free blocks (hard limit), tell the audit - * daemon to force a rotation off of the file system. We also stop - * writing, which means this audit record is probably lost. - * If we fall below the minimum percent free blocks (soft limit), - * then kindly suggest to the audit daemon to do something. - */ - if (mnt_stat->f_bfree < AUDIT_HARD_LIMIT_FREE_BLOCKS) { - send_trigger(AUDIT_TRIGGER_NO_SPACE); - /* Hopefully userspace did something about all the previous - * triggers that were sent prior to this critical condition. - * If fail-stop is set, then we're done; goodnight Gracie. - */ - if (audit_fail_stop) - panic("Audit log space exhausted and fail-stop set."); - else { - audit_suspended = 1; - ret = ENOSPC; - goto out; - } - } else - /* - * Send a message to the audit daemon that disk space - * is getting low. - * - * XXXAUDIT: Check math and block size calculation here. - */ - if (audit_qctrl.aq_minfree != 0) { - temp = mnt_stat->f_blocks / (100 / - audit_qctrl.aq_minfree); - if (mnt_stat->f_bfree < temp) - send_trigger(AUDIT_TRIGGER_LOW_SPACE); - } - - /* Check if the current log file is full; if so, call for - * a log rotate. This is not an exact comparison; we may - * write some records over the limit. If that's not - * acceptable, then add a fudge factor here. - */ - if ((audit_fstat.af_filesz != 0) && - (audit_file_rotate_wait == 0) && - (vattr.va_size >= audit_fstat.af_filesz)) { - audit_file_rotate_wait = 1; - send_trigger(AUDIT_TRIGGER_OPEN_NEW); - } - - /* - * If the estimated amount of audit data in the audit event queue - * (plus records allocated but not yet queued) has reached the - * amount of free space on the disk, then we need to go into an - * audit fail stop state, in which we do not permit the - * allocation/committing of any new audit records. We continue to - * process packets but don't allow any activities that might - * generate new records. In the future, we might want to detect - * when space is available again and allow operation to continue, - * but this behavior is sufficient to meet fail stop requirements - * in CAPP. - */ - if (audit_fail_stop && - (unsigned long) - ((audit_q_len + audit_pre_q_len + 1) * MAX_AUDIT_RECORD_SIZE) / - mnt_stat->f_bsize >= (unsigned long)(mnt_stat->f_bfree)) { - printf( - "audit_worker: free space below size of audit queue, failing stop\n"); - audit_in_failure = 1; - } - - /* - * If there is a user audit record attached to the kernel record, - * then write the user record. - */ - /* XXX Need to decide a few things here: IF the user audit - * record is written, but the write of the kernel record fails, - * what to do? Should the kernel record come before or after the - * user record? For now, we write the user record first, and - * we ignore errors. - */ - if (ar->k_ar_commit & AR_COMMIT_USER) { - ret = vn_rdwr(UIO_WRITE, vp, (void *)ar->k_udata, ar->k_ulen, - (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, cred, NULL, - NULL, td); - if (ret) - goto out; - } - - /* - * Convert the internal kernel record to BSM format and write it - * out if everything's OK. - */ - if (!(ar->k_ar_commit & AR_COMMIT_KERNEL)) { - ret = 0; - goto out; - } - - /* - * XXXAUDIT: Should we actually allow this conversion to fail? With - * sleeping memory allocation and invariants checks, perhaps not. - */ - ret = kaudit_to_bsm(ar, &bsm); - if (ret == BSM_NOAUDIT) { - ret = 0; - goto out; - } - - /* - * XXX: We drop the record on BSM conversion failure, but really - * this is an assertion failure. - */ - if (ret == BSM_FAILURE) { - AUDIT_PRINTF(("BSM conversion failure\n")); - ret = EINVAL; - goto out; - } - - /* - * XXX - * We should break the write functionality away from the BSM record - * generation and have the BSM generation done before this function - * is called. This function will then take the BSM record as a - * parameter. - */ - ret = (vn_rdwr(UIO_WRITE, vp, (void *)bsm->data, bsm->len, - (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, cred, NULL, NULL, td)); - - kau_free(bsm); - -out: - /* - * When we're done processing the current record, we have to - * check to see if we're in a failure mode, and if so, whether - * this was the last record left to be drained. If we're done - * draining, then we fsync the vnode and panic. - */ - if (audit_in_failure && - audit_q_len == 0 && audit_pre_q_len == 0) { - VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); - (void)VOP_FSYNC(vp, MNT_WAIT, td); - VOP_UNLOCK(vp, 0, td); - panic("Audit store overflow; record queue drained."); - } - - VFS_UNLOCK_GIANT(vfslocked); - - return (ret); -} - -/* - * The audit_worker thread is responsible for watching the event queue, - * dequeueing records, converting them to BSM format, and committing them to - * disk. In order to minimize lock thrashing, records are dequeued in sets - * to a thread-local work queue. In addition, the audit_work performs the - * actual exchange of audit log vnode pointer, as audit_vp is a thread-local - * variable. - */ -static void -audit_worker(void *arg) -{ - int do_replacement_signal, error; - TAILQ_HEAD(, kaudit_record) ar_worklist; - struct kaudit_record *ar; - struct vnode *audit_vp, *old_vp; - int vfslocked; - - struct ucred *audit_cred, *old_cred; - struct thread *audit_td; - - AUDIT_PRINTF(("audit_worker starting\n")); - - /* - * These are thread-local variables requiring no synchronization. - */ - TAILQ_INIT(&ar_worklist); - audit_cred = NULL; - audit_td = curthread; - audit_vp = NULL; - - mtx_lock(&audit_mtx); - while (1) { - /* - * First priority: replace the audit log target if requested. - * Accessing the vnode here requires dropping the audit_mtx; - * in case another replacement was scheduled while the mutex - * was released, we loop. - * - * XXX It could well be we should drain existing records - * first to ensure that the timestamps and ordering - * are right. - */ - do_replacement_signal = 0; - while (audit_replacement_flag != 0) { - old_cred = audit_cred; - old_vp = audit_vp; - audit_cred = audit_replacement_cred; - audit_vp = audit_replacement_vp; - audit_replacement_cred = NULL; - audit_replacement_vp = NULL; - audit_replacement_flag = 0; - - audit_enabled = (audit_vp != NULL); - - /* - * XXX: What to do about write failures here? - */ - if (old_vp != NULL) { - AUDIT_PRINTF(("Closing old audit file\n")); - mtx_unlock(&audit_mtx); - vfslocked = VFS_LOCK_GIANT(old_vp->v_mount); - vn_close(old_vp, AUDIT_CLOSE_FLAGS, old_cred, - audit_td); - VFS_UNLOCK_GIANT(vfslocked); - crfree(old_cred); - mtx_lock(&audit_mtx); - old_cred = NULL; - old_vp = NULL; - AUDIT_PRINTF(("Audit file closed\n")); - } - if (audit_vp != NULL) { - AUDIT_PRINTF(("Opening new audit file\n")); - } - do_replacement_signal = 1; - } - /* - * Signal that replacement have occurred to wake up and - * start any other replacements started in parallel. We can - * continue about our business in the mean time. We - * broadcast so that both new replacements can be inserted, - * but also so that the source(s) of replacement can return - * successfully. - */ - if (do_replacement_signal) - cv_broadcast(&audit_replacement_cv); - - /* - * Next, check to see if we have any records to drain into - * the vnode. If not, go back to waiting for an event. - */ - if (TAILQ_EMPTY(&audit_q)) { - AUDIT_PRINTF(("audit_worker waiting\n")); - cv_wait(&audit_cv, &audit_mtx); - AUDIT_PRINTF(("audit_worker woken up\n")); - AUDIT_PRINTF(("audit_worker: new vp = %p; value of flag %d\n", - audit_replacement_vp, audit_replacement_flag)); - continue; - } - - /* - * If we have records, but there's no active vnode to - * write to, drain the record queue. Generally, we - * prevent the unnecessary allocation of records - * elsewhere, but we need to allow for races between - * conditional allocation and queueing. Go back to - * waiting when we're done. - * - * XXX: We go out of our way to avoid calling - * audit_record_free(). - * with the audit_mtx held, to avoid a lock order reversal - * as free() may grab Giant. This should be fixed at - * some point. - */ - if (audit_vp == NULL) { - while ((ar = TAILQ_FIRST(&audit_q))) { - TAILQ_REMOVE(&audit_q, ar, k_q); - audit_q_len--; - if (audit_q_len <= audit_qctrl.aq_lowater) - cv_broadcast(&audit_commit_cv); - - TAILQ_INSERT_TAIL(&ar_worklist, ar, k_q); - } - mtx_unlock(&audit_mtx); - while ((ar = TAILQ_FIRST(&ar_worklist))) { - TAILQ_REMOVE(&ar_worklist, ar, k_q); - audit_record_free(ar); - } - mtx_lock(&audit_mtx); - continue; - } - - /* - * We have both records to write and an active vnode - * to write to. Dequeue a record, and start the write. - * Eventually, it might make sense to dequeue several - * records and perform our own clustering, if the lower - * layers aren't doing it automatically enough. - * - * XXX: We go out of our way to avoid calling - * audit_record_free() - * with the audit_mtx held, to avoid a lock order reversal - * as free() may grab Giant. This should be fixed at - * some point. - * - * XXXAUDIT: free() no longer grabs Giant. - */ - while ((ar = TAILQ_FIRST(&audit_q))) { - TAILQ_REMOVE(&audit_q, ar, k_q); - audit_q_len--; - if (audit_q_len <= audit_qctrl.aq_lowater) - cv_broadcast(&audit_commit_cv); - - TAILQ_INSERT_TAIL(&ar_worklist, ar, k_q); - } - - mtx_unlock(&audit_mtx); - while ((ar = TAILQ_FIRST(&ar_worklist))) { - TAILQ_REMOVE(&ar_worklist, ar, k_q); - if (audit_vp != NULL) { - error = audit_record_write(audit_vp, ar, - audit_cred, audit_td); - if (error && audit_panic_on_write_fail) - panic("audit_worker: write error %d\n", - error); - else if (error) - printf("audit_worker: write error %d\n", - error); - } - audit_record_free(ar); - } - mtx_lock(&audit_mtx); - } -} - -/* - * Initialize the Audit subsystem: configuration state, work queue, - * synchronization primitives, worker thread, and trigger device node. Also - * call into the BSM assembly code to initialize it. - */ -static void -audit_init(void) -{ - int error; - - printf("Security auditing service present\n"); - TAILQ_INIT(&audit_q); - audit_q_len = 0; - audit_pre_q_len = 0; - audit_enabled = 0; - audit_suspended = 0; - audit_replacement_cred = NULL; - audit_replacement_flag = 0; - audit_file_rotate_wait = 0; - audit_replacement_vp = NULL; - audit_fstat.af_filesz = 0; /* '0' means unset, unbounded */ - audit_fstat.af_currsz = 0; - audit_qctrl.aq_hiwater = AQ_HIWATER; - audit_qctrl.aq_lowater = AQ_LOWATER; - audit_qctrl.aq_bufsz = AQ_BUFSZ; - audit_qctrl.aq_minfree = AU_FS_MINFREE; - - mtx_init(&audit_mtx, "audit_mtx", NULL, MTX_DEF); - cv_init(&audit_cv, "audit_cv"); - cv_init(&audit_replacement_cv, "audit_replacement_cv"); - cv_init(&audit_commit_cv, "audit_commit_cv"); - cv_init(&audit_fail_cv, "audit_fail_cv"); - - /* Initialize the BSM audit subsystem. */ - kau_init(); - - audit_trigger_init(); - - /* Register shutdown handler. */ - EVENTHANDLER_REGISTER(shutdown_pre_sync, audit_shutdown, NULL, - SHUTDOWN_PRI_FIRST); - - error = kthread_create(audit_worker, NULL, &audit_thread, RFHIGHPID, - 0, "audit_worker"); - if (error != 0) - panic("audit_init: kthread_create returned %d", error); -} - -SYSINIT(audit_init, SI_SUB_AUDIT, SI_ORDER_FIRST, audit_init, NULL) - -/* - * audit_rotate_vnode() is called by a user or kernel thread to configure or - * de-configure auditing on a vnode. The arguments are the replacement - * credential and vnode to substitute for the current credential and vnode, - * if any. If either is set to NULL, both should be NULL, and this is used - * to indicate that audit is being disabled. The real work is done in the - * audit_worker thread, but audit_rotate_vnode() waits synchronously for that - * to complete. - * - * The vnode should be referenced and opened by the caller. The credential - * should be referenced. audit_rotate_vnode() will own both references as of - * this call, so the caller should not release either. - * - * XXXAUDIT: Review synchronize communication logic. Really, this is a - * message queue of depth 1. - * - * XXXAUDIT: Enhance the comments below to indicate that we are basically - * acquiring ownership of the communications queue, inserting our message, - * and waiting for an acknowledgement. - */ -void -audit_rotate_vnode(struct ucred *cred, struct vnode *vp) -{ - - /* - * If other parallel log replacements have been requested, we wait - * until they've finished before continuing. - */ - mtx_lock(&audit_mtx); - while (audit_replacement_flag != 0) { - AUDIT_PRINTF(("audit_rotate_vnode: sleeping to wait for " - "flag\n")); - cv_wait(&audit_replacement_cv, &audit_mtx); - AUDIT_PRINTF(("audit_rotate_vnode: woken up (flag %d)\n", - audit_replacement_flag)); - } - audit_replacement_cred = cred; - audit_replacement_flag = 1; - audit_replacement_vp = vp; - - /* - * Wake up the audit worker to perform the exchange once we - * release the mutex. - */ - cv_signal(&audit_cv); - - /* - * Wait for the audit_worker to broadcast that a replacement has - * taken place; we know that once this has happened, our vnode - * has been replaced in, so we can return successfully. - */ - AUDIT_PRINTF(("audit_rotate_vnode: waiting for news of " - "replacement\n")); - cv_wait(&audit_replacement_cv, &audit_mtx); - AUDIT_PRINTF(("audit_rotate_vnode: change acknowledged by " - "audit_worker (flag " "now %d)\n", audit_replacement_flag)); - mtx_unlock(&audit_mtx); - - audit_file_rotate_wait = 0; /* We can now request another rotation */ -} - -/* - * Drain the audit queue and close the log at shutdown. Note that this can - * be called both from the system shutdown path and also from audit - * configuration syscalls, so 'arg' and 'howto' are ignored. - */ -void -audit_shutdown(void *arg, int howto) -{ - - audit_rotate_vnode(NULL, NULL); -} - -/* - * Return the current thread's audit record, if any. - */ -__inline__ struct kaudit_record * -currecord(void) -{ - - return (curthread->td_ar); -} - -/* - * MPSAFE - * - * XXXAUDIT: There are a number of races present in the code below due to - * release and re-grab of the mutex. The code should be revised to become - * slightly less racy. - * - * XXXAUDIT: Shouldn't there be logic here to sleep waiting on available - * pre_q space, suspending the system call until there is room? - */ -struct kaudit_record * -audit_new(int event, struct thread *td) -{ - struct kaudit_record *ar; - int no_record; - - /* - * Eventually, there may be certain classes of events that - * we will audit regardless of the audit state at the time - * the record is created. These events will generally - * correspond to changes in the audit state. The dummy - * code below is from our first prototype, but may also - * be used in the final version (with modified event numbers). - */ -#if 0 - if (event != AUDIT_EVENT_FILESTOP && event != AUDIT_EVENT_FILESTART) { -#endif - mtx_lock(&audit_mtx); - no_record = (audit_suspended || !audit_enabled); - mtx_unlock(&audit_mtx); - if (no_record) - return (NULL); -#if 0 - } -#endif - - /* - * Initialize the audit record header. - * XXX: We may want to fail-stop if allocation fails. - * XXX: The number of outstanding uncommitted audit records is - * limited by the number of concurrent threads servicing system - * calls in the kernel. - */ - - ar = malloc(sizeof(*ar), M_AUDIT, M_WAITOK); - if (ar == NULL) - return NULL; - - mtx_lock(&audit_mtx); - audit_pre_q_len++; - mtx_unlock(&audit_mtx); - - bzero(ar, sizeof(*ar)); - ar->k_ar.ar_magic = AUDIT_RECORD_MAGIC; - ar->k_ar.ar_event = event; - nanotime(&ar->k_ar.ar_starttime); - - /* - * Export the subject credential. - * - * XXXAUDIT: td_ucred access is OK without proc lock, but some other - * fields here may require the proc lock. - */ - cru2x(td->td_ucred, &ar->k_ar.ar_subj_cred); - ar->k_ar.ar_subj_ruid = td->td_ucred->cr_ruid; - ar->k_ar.ar_subj_rgid = td->td_ucred->cr_rgid; - ar->k_ar.ar_subj_egid = td->td_ucred->cr_groups[0]; - ar->k_ar.ar_subj_auid = td->td_proc->p_au->ai_auid; - ar->k_ar.ar_subj_asid = td->td_proc->p_au->ai_asid; - ar->k_ar.ar_subj_pid = td->td_proc->p_pid; - ar->k_ar.ar_subj_amask = td->td_proc->p_au->ai_mask; - ar->k_ar.ar_subj_term = td->td_proc->p_au->ai_termid; - - bcopy(td->td_proc->p_comm, ar->k_ar.ar_subj_comm, MAXCOMLEN); - - return (ar); -} - -/* - * MPSAFE - */ -void -audit_commit(struct kaudit_record *ar, int error, int retval) -{ - int sorf; - struct au_mask *aumask; - - if (ar == NULL) - return; - - /* - * Decide whether to commit the audit record by checking the - * error value from the system call and using the appropriate - * audit mask. - * - * XXXAUDIT: Synchronize access to audit_nae_mask? - */ - if (ar->k_ar.ar_subj_auid == AU_DEFAUDITID) - aumask = &audit_nae_mask; - else - aumask = &ar->k_ar.ar_subj_amask; - - if (error) - sorf = AU_PRS_FAILURE; - else - sorf = AU_PRS_SUCCESS; - - switch(ar->k_ar.ar_event) { - - case AUE_OPEN_RWTC: - /* The open syscall always writes a AUE_OPEN_RWTC event; change - * it to the proper type of event based on the flags and the - * error value. - */ - ar->k_ar.ar_event = flags_and_error_to_openevent( - ar->k_ar.ar_arg_fflags, error); - break; - - case AUE_SYSCTL: - ar->k_ar.ar_event = ctlname_to_sysctlevent( - ar->k_ar.ar_arg_ctlname, ar->k_ar.ar_valid_arg); - break; - - case AUE_AUDITON: - /* Convert the auditon() command to an event */ - ar->k_ar.ar_event = auditon_command_event(ar->k_ar.ar_arg_cmd); - break; - } - - if (au_preselect(ar->k_ar.ar_event, aumask, sorf) != 0) - ar->k_ar_commit |= AR_COMMIT_KERNEL; - - if ((ar->k_ar_commit & (AR_COMMIT_USER | AR_COMMIT_KERNEL)) == 0) { - mtx_lock(&audit_mtx); - audit_pre_q_len--; - mtx_unlock(&audit_mtx); - audit_record_free(ar); - return; - } - - ar->k_ar.ar_errno = error; - ar->k_ar.ar_retval = retval; - - /* - * We might want to do some system-wide post-filtering - * here at some point. - */ - - /* - * Timestamp system call end. - */ - nanotime(&ar->k_ar.ar_endtime); - - mtx_lock(&audit_mtx); - - /* - * Note: it could be that some records initiated while audit was - * enabled should still be committed? - */ - if (audit_suspended || !audit_enabled) { - audit_pre_q_len--; - mtx_unlock(&audit_mtx); - audit_record_free(ar); - return; - } - - /* - * Constrain the number of committed audit records based on - * the configurable parameter. - */ - while (audit_q_len >= audit_qctrl.aq_hiwater) { - AUDIT_PRINTF(("audit_commit: sleeping to wait for " - "audit queue to drain below high water mark\n")); - cv_wait(&audit_commit_cv, &audit_mtx); - AUDIT_PRINTF(("audit_commit: woke up waiting for " - "audit queue draining\n")); - } - - TAILQ_INSERT_TAIL(&audit_q, ar, k_q); - audit_q_len++; - audit_pre_q_len--; - cv_signal(&audit_cv); - mtx_unlock(&audit_mtx); -} - -/* - * audit_syscall_enter() is called on entry to eatch system call. It is - * responsible for deciding whether or not to audit the call (preselection), - * and if so, allocating a per-thread audit record. audit_new() will fill in - * basic thread/credential properties. - */ -void -audit_syscall_enter(unsigned short code, struct thread *td) -{ - int audit_event; - struct au_mask *aumask; - - KASSERT(td->td_ar == NULL, ("audit_syscall_enter: td->td_ar != NULL")); - - /* - * In FreeBSD, each ABI has its own system call table, and hence - * mapping of system call codes to audit events. Convert the code to - * an audit event identifier using the process system call table - * reference. In Darwin, there's only one, so we use the global - * symbol for the system call table. - * - * XXXAUDIT: Should we audit that a bad system call was made, and if - * so, how? - */ - if (code >= td->td_proc->p_sysent->sv_size) - return; - - audit_event = td->td_proc->p_sysent->sv_table[code].sy_auevent; - if (audit_event == AUE_NULL) - return; - - /* - * Check which audit mask to use; either the kernel non-attributable - * event mask or the process audit mask. - */ - if (td->td_proc->p_au->ai_auid == AU_DEFAUDITID) - aumask = &audit_nae_mask; - else - aumask = &td->td_proc->p_au->ai_mask; - - /* - * Allocate an audit record, if preselection allows it, and store - * in the thread for later use. - */ - if (au_preselect(audit_event, aumask, - AU_PRS_FAILURE | AU_PRS_SUCCESS)) { - /* - * If we're out of space and need to suspend unprivileged - * processes, do that here rather than trying to allocate - * another audit record. - * - * XXXRW: We might wish to be able to continue here in the - * future, if the system recovers. That should be possible - * by means of checking the condition in a loop around - * cv_wait(). It might be desirable to reevaluate whether an - * audit record is still required for this event by - * re-calling au_preselect(). - */ - if (audit_in_failure && suser(td) != 0) { - cv_wait(&audit_fail_cv, &audit_mtx); - panic("audit_failing_stop: thread continued"); - } - td->td_ar = audit_new(audit_event, td); - } else - td->td_ar = NULL; -} - -/* - * audit_syscall_exit() is called from the return of every system call, or in - * the event of exit1(), during the execution of exit1(). It is responsible - * for committing the audit record, if any, along with return condition. - */ -void -audit_syscall_exit(int error, struct thread *td) -{ - int retval; - - /* - * Commit the audit record as desired; once we pass the record - * into audit_commit(), the memory is owned by the audit - * subsystem. - * The return value from the system call is stored on the user - * thread. If there was an error, the return value is set to -1, - * imitating the behavior of the cerror routine. - */ - if (error) - retval = -1; >>> TRUNCATED FOR MAIL (1000 lines) <<<
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