[apple/xnu.git] / bsd / kern / kern_audit.c

/*
 * Copyright (c) 2003-2004 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
#include <sys/param.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/namei.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/ucred.h>
#include <sys/uio.h>
#include <sys/unistd.h>
#include <sys/file_internal.h>
#include <sys/vnode_internal.h>
#include <sys/user.h>
#include <sys/syscall.h>
#include <sys/malloc.h>
#include <sys/un.h>
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/vfs_context.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socketvar.h>

#include <bsm/audit.h>
#include <bsm/audit_kevents.h>
#include <bsm/audit_klib.h>
#include <bsm/audit_kernel.h>

#include <mach/host_priv.h>
#include <mach/host_special_ports.h>
#include <mach/audit_triggers_server.h>

#include <kern/host.h>
#include <kern/kalloc.h>
#include <kern/zalloc.h>
#include <kern/lock.h>
#include <kern/wait_queue.h>
#include <kern/sched_prim.h>

#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_pcb.h>

#ifdef AUDIT

/*
 * 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_ONLY
#define AUDIT_PRINTF(x) printf x
#else
#define AUDIT_PRINTF_ONLY __unused
#define AUDIT_PRINTF(X)
#endif

#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 */

/* 
 * Define the audit control flags.
 */
int     audit_enabled;
int     audit_suspended;

/*
 * Mutex to protect global variables shared between various threads and
 * processes.
 */
static mutex_t                          *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 size_t                           audit_q_len;
static size_t                           audit_pre_q_len;

static wait_queue_t                     audit_wait_queue;
static zone_t                           audit_zone;

/*
 * 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 int audit_worker_event;
#define    AUDIT_WORKER_EVENT   ((event_t)&audit_worker_event)

/*
 * The audit worker thread (which is lazy started when we first
 * rotate the audit log.
 */
static thread_t audit_worker_thread = THREAD_NULL;

/*
 * 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.
 */
static int audit_replacement_event;
#define    AUDIT_REPLACEMENT_EVENT ((event_t)&audit_replacement_event)

static int                               audit_replacement_flag;
static struct vnode                     *audit_replacement_vp;
static kauth_cred_t             audit_replacement_cred;

/*
 * Wait queue for auditing threads that cannot commit the audit
 * record at the present time. Also, the queue control parameter
 * structure.
 */
static int audit_commit_event;
#define    AUDIT_COMMIT_EVENT ((event_t)&audit_commit_event)

static struct au_qctrl                  audit_qctrl;

/*
 * Flags to use on audit files when opening and closing.
 */
static const int                 audit_open_flags = FWRITE | O_APPEND;
static const int                 audit_close_flags = FWRITE | O_APPEND;

/*
 * Global audit statistiscs. 
 */
static struct audit_fstat       audit_fstat;

/*
 Preselection mask for non-attributable events.
 */
static struct au_mask           audit_nae_mask;

/* 
 * Flags related to Kernel->user-space communication.
 */
static int                       audit_file_rotate_wait;

/*
 * 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?  Are we currently "failing
 * stop" due to out of disk space?
 */
static int                       audit_panic_on_write_fail;
static int                       audit_fail_stop;
static int                       audit_in_failure;

/*
 * When in a fail-stop mode, threads will drop into this wait queue
 * rather than perform auditable events.  They won't ever get woken
 * up.
 */
static int audit_failure_event;
#define    AUDIT_FAILURE_EVENT ((event_t)&audit_failure_event)

/*
 * XXX: Couldn't find the include file for this, so copied kern_exec.c's
 * behavior.
 */
extern task_t kernel_task;

static void
audit_free(struct kaudit_record *ar)
{
        if (ar->k_ar.ar_arg_upath1 != NULL) {
                kfree(ar->k_ar.ar_arg_upath1, MAXPATHLEN);
        }
        if (ar->k_ar.ar_arg_upath2 != NULL) {
                kfree(ar->k_ar.ar_arg_upath2, MAXPATHLEN);

        }
        if (ar->k_ar.ar_arg_kpath1 != NULL) {
                kfree(ar->k_ar.ar_arg_kpath1, MAXPATHLEN);

        }
        if (ar->k_ar.ar_arg_kpath2 != NULL) {
                kfree(ar->k_ar.ar_arg_kpath2, MAXPATHLEN);

        }
        if (ar->k_ar.ar_arg_text != NULL) {
                kfree(ar->k_ar.ar_arg_text, MAXPATHLEN);

        }
        if (ar->k_udata != NULL) {
                kfree(ar->k_udata, ar->k_ulen);

        }
        zfree(audit_zone, ar);
}

static int
audit_write(struct vnode *vp, struct kaudit_record *ar, kauth_cred_t cred,
    struct proc *p)
{
        struct vfsstatfs *mnt_stat = &vp->v_mount->mnt_vfsstat;
        int ret;
        struct au_record *bsm;
        /* KVV maybe we should take a context as a param to audit_write? */
        struct vfs_context context;
        off_t file_size;

        mach_port_t audit_port;

        /* 
         * 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.
         */
        context.vc_proc = p;
        context.vc_ucred = cred;
        ret = vfs_update_vfsstat(vp->v_mount, &context);
        if (ret)
                goto out;

        /* update the global stats struct */
        if ((ret = vnode_size(vp, &file_size, &context)) != 0)
                goto out;
        audit_fstat.af_currsz = file_size;
        
        /* 
         * Send a message to the audit daemon when disk space is getting
         * low.
         * XXX Need to decide what to do if the trigger to the audit daemon
         * fails.
         */
        if(host_get_audit_control_port(host_priv_self(), &audit_port) 
                != KERN_SUCCESS)
                printf("Cannot get audit control port\n");

        if (audit_port != MACH_PORT_NULL) {
                uint64_t temp;

                /* 
                 * If we fall below percent free blocks, then trigger the
                 * audit daemon to do something about it.
                 */
                if (audit_qctrl.aq_minfree != 0) {
                        temp = mnt_stat->f_blocks / (100 / audit_qctrl.aq_minfree);
                        if (mnt_stat->f_bfree < temp) {
                                ret = audit_triggers(audit_port, 
                                        AUDIT_TRIGGER_LOW_SPACE); 
                                if (ret != KERN_SUCCESS) {
                                        printf(
    "Failed audit_triggers(AUDIT_TRIGGER_LOW_SPACE): %d\n", ret);
                                /*
                                 * XXX: What to do here? Disable auditing?
                                 * panic?
                                 */
                                }
                        }
                }
                /* 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) && 
                    (file_size >= audit_fstat.af_filesz)) {
                        audit_file_rotate_wait = 1;
                        ret = audit_triggers(audit_port, 
                                AUDIT_TRIGGER_FILE_FULL); 
                        if (ret != KERN_SUCCESS) {
                                printf(
    "Failed audit_triggers(AUDIT_TRIGGER_FILE_FULL): %d\n", ret);
                        /* XXX what to do here? */
                        }
                }
        }

        /*
         * 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) {
                if (vnode_getwithref(vp) == 0) {
                        ret = vn_rdwr(UIO_WRITE, vp, (void *)ar->k_udata, ar->k_ulen,
                                (off_t)0, UIO_SYSSPACE32, IO_APPEND|IO_UNIT, cred, NULL, p);
                        vnode_put(vp);
                        if (ret)
                                goto out;
                } else {
                        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;
        }

        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 This function can be called with the kernel funnel held,
         * which is not optimal. 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.
         */
        if ((ret = vnode_getwithref(vp)) == 0) {
                ret = (vn_rdwr(UIO_WRITE, vp, (void *)bsm->data, bsm->len,
                               (off_t)0, UIO_SYSSPACE32, IO_APPEND|IO_UNIT, cred, NULL, p));
                vnode_put(vp);
        }
        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) {
                (void)VNOP_FSYNC(vp, MNT_WAIT, &context);
                panic("Audit store overflow; record queue drained.");
        }

        return (ret);
}

static void
audit_worker(void)
{
        int do_replacement_signal, error, release_funnel;
        TAILQ_HEAD(, kaudit_record) ar_worklist;
        struct kaudit_record *ar;
        struct vnode *audit_vp, *old_vp;
        kauth_cred_t audit_cred;
        kauth_cred_t old_cred;
        struct proc *audit_p;

        AUDIT_PRINTF(("audit_worker starting\n"));

        TAILQ_INIT(&ar_worklist);
        audit_cred = NULL;
        audit_p = current_proc();
        audit_vp = NULL;

        /*
         * XXX: Presumably we can assume Mach threads are started without
         * holding the BSD kernel funnel?
         */
        thread_funnel_set(kernel_flock, FALSE);

        mutex_lock(audit_mtx);
        while (1) {
                /*
                 * First priority: replace the audit log target if requested.
                 * As we actually close the vnode in the worker thread, we
                 * need to grab the funnel, which means releasing audit_mtx.
                 * In case another replacement was scheduled while the mutex
                 * we 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);

                        if (old_vp != NULL || audit_vp != NULL) {
                                mutex_unlock(audit_mtx);
                                thread_funnel_set(kernel_flock, TRUE);
                                release_funnel = 1;
                        } else
                                release_funnel = 0;
                        /*
                         * XXX: What to do about write failures here?
                         */
                        if (old_vp != NULL) {
                                AUDIT_PRINTF(("Closing old audit file\n"));
                                vn_close(old_vp, audit_close_flags, old_cred,
                                    audit_p);
                                kauth_cred_rele(old_cred);
                                old_cred = NOCRED;
                                old_vp = NULL;
                                AUDIT_PRINTF(("Audit file closed\n"));
                        }
                        if (audit_vp != NULL) {
                                AUDIT_PRINTF(("Opening new audit file\n"));
                        }
                        if (release_funnel) {
                                thread_funnel_set(kernel_flock, FALSE);
                                mutex_lock(audit_mtx);
                        }
                        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)
                        wait_queue_wakeup_all(audit_wait_queue,
                            AUDIT_REPLACEMENT_EVENT, THREAD_AWAKENED);

                /*
                 * 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)) {
                        int ret;

                        AUDIT_PRINTF(("audit_worker waiting\n"));
                        ret = wait_queue_assert_wait(audit_wait_queue,
                                                     AUDIT_WORKER_EVENT,
                                                     THREAD_UNINT,
                                                     0);
                        mutex_unlock(audit_mtx);

                        assert(ret == THREAD_WAITING);
                        ret = thread_block(THREAD_CONTINUE_NULL);
                        assert(ret == THREAD_AWAKENED);
                        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));

                        mutex_lock(audit_mtx);
                        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_free()
                 * with the audit_mtx held, to avoid a lock order reversal
                 * as free() may grab the funnel.  This will 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)
                                        wait_queue_wakeup_one(
                                                audit_wait_queue,
                                                AUDIT_COMMIT_EVENT, 
                                                THREAD_AWAKENED);

                                TAILQ_INSERT_TAIL(&ar_worklist, ar, k_q);
                        }
                        mutex_unlock(audit_mtx);
                        while ((ar = TAILQ_FIRST(&ar_worklist))) {
                                TAILQ_REMOVE(&ar_worklist, ar, k_q);
                                audit_free(ar);
                        }
                        mutex_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_free()
                 * with the audit_mtx held, to avoid a lock order reversal
                 * as free() may grab the funnel.  This will be fixed at
                 * some point.
                 */
                while ((ar = TAILQ_FIRST(&audit_q))) {
                        TAILQ_REMOVE(&audit_q, ar, k_q);
                        audit_q_len--;
                        if (audit_q_len <= audit_qctrl.aq_lowater) {
                                wait_queue_wakeup_one(audit_wait_queue,
                                         AUDIT_COMMIT_EVENT, THREAD_AWAKENED);
                        }

                        TAILQ_INSERT_TAIL(&ar_worklist, ar, k_q);
                }
                mutex_unlock(audit_mtx);
                release_funnel = 0;
                while ((ar = TAILQ_FIRST(&ar_worklist))) {
                        TAILQ_REMOVE(&ar_worklist, ar, k_q);
                        if (audit_vp != NULL) {
                                /*
                                 * XXX: What should happen if there's a write
                                 * error here?
                                 */
                                if (!release_funnel) {
                                        thread_funnel_set(kernel_flock, TRUE);
                                        release_funnel = 1;
                                }
                                error = audit_write(audit_vp, ar, audit_cred,
                                    audit_p);
                                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_free(ar);
                }
                if (release_funnel)
                        thread_funnel_set(kernel_flock, FALSE);
                mutex_lock(audit_mtx);
        }
}

void
audit_init(void)
{

        /* Verify that the syscall to audit event table is the same
         * size as the system call table.
         */
        if (nsys_au_event != nsysent) {
                printf("Security auditing service initialization failed, ");
                printf("audit event table doesn't match syscall table.\n");
                return;
        }

        printf("Security auditing service present\n");
        TAILQ_INIT(&audit_q);
        audit_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;

        audit_mtx = mutex_alloc(0);
        audit_wait_queue = wait_queue_alloc(SYNC_POLICY_FIFO);
        audit_zone = zinit(sizeof(struct kaudit_record), 
                           AQ_HIWATER*sizeof(struct kaudit_record),
                           8192,
                           "audit_zone");

        /* Initialize the BSM audit subsystem. */
        kau_init();
}

static void
audit_rotate_vnode(kauth_cred_t cred, struct vnode *vp)
{
        int ret;

        /*
         * If other parallel log replacements have been requested, we wait
         * until they've finished before continuing.
         */
        mutex_lock(audit_mtx);
        while (audit_replacement_flag != 0) {

                AUDIT_PRINTF(("audit_rotate_vnode: sleeping to wait for "
                    "flag\n"));
                ret = wait_queue_assert_wait(audit_wait_queue,
                                             AUDIT_REPLACEMENT_EVENT,
                                             THREAD_UNINT,
                                             0);
                mutex_unlock(audit_mtx);

                assert(ret == THREAD_WAITING);
                ret = thread_block(THREAD_CONTINUE_NULL);
                assert(ret == THREAD_AWAKENED);
                AUDIT_PRINTF(("audit_rotate_vnode: woken up (flag %d)\n",
                    audit_replacement_flag));

                mutex_lock(audit_mtx);
        }
        audit_replacement_cred = cred;
        audit_replacement_flag = 1;
        audit_replacement_vp = vp;

        /*
         * Start or wake up the audit worker to perform the exchange.
         * It will have to wait until we release the mutex.
         */
        if (audit_worker_thread == THREAD_NULL)
                audit_worker_thread = kernel_thread(kernel_task,
                                                    audit_worker);
        else 
                wait_queue_wakeup_one(audit_wait_queue,
                                      AUDIT_WORKER_EVENT,
                                      THREAD_AWAKENED);

        /*
         * 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"));
        ret = wait_queue_assert_wait(audit_wait_queue, 
                                     AUDIT_REPLACEMENT_EVENT,
                                     THREAD_UNINT,
                                     0);
        mutex_unlock(audit_mtx);

        assert(ret == THREAD_WAITING);
        ret = thread_block(THREAD_CONTINUE_NULL);
        assert(ret == THREAD_AWAKENED);
        AUDIT_PRINTF(("audit_rotate_vnode: change acknowledged by "
            "audit_worker (flag " "now %d)\n", audit_replacement_flag));

        audit_file_rotate_wait = 0; /* We can now request another rotation */
}

/*
 * Drain the audit queue and close the log at shutdown.
 */
void
audit_shutdown(void)
{
        audit_rotate_vnode(NULL, NULL);
}

static __inline__ struct uthread *
curuthread(void)
{
        return (get_bsdthread_info(current_thread()));
}

static __inline__ struct kaudit_record *
currecord(void)
{
        return (curuthread()->uu_ar);
}

/**********************************
 * Begin system calls.            *
 **********************************/
/*
 * System call to allow a user space application to submit a BSM audit
 * record to the kernel for inclusion in the audit log. This function
 * does little verification on the audit record that is submitted.
 *
 * XXXAUDIT: Audit preselection for user records does not currently
 * work, since we pre-select only based on the AUE_audit event type,
 * not the event type submitted as part of the user audit data.
 */
/* ARGSUSED */
int
audit(struct proc *p, struct audit_args *uap, __unused register_t *retval)
{
        int error;
        void * rec;
        struct kaudit_record *ar;
        struct uthread *uthr;

        error = suser(kauth_cred_get(), &p->p_acflag);
        if (error)
                return (error);

        if ((uap->length <= 0) || (uap->length > (int)audit_qctrl.aq_bufsz))
                return (EINVAL);

        ar = currecord();

        /* If there's no current audit record (audit() itself not audited)
         * commit the user audit record.
         */
        if (ar == NULL) {
                uthr = curuthread();
                if (uthr == NULL)       /* can this happen? */
                return (ENOTSUP);

                /* This is not very efficient; we're required to allocate
                 * a complete kernel audit record just so the user record
                 * can tag along.
                 */
                uthr->uu_ar = audit_new(AUE_NULL, p, uthr);
                if (uthr->uu_ar == NULL) /* auditing not on, or memory error */
                        return (ENOTSUP);
                ar = uthr->uu_ar;
        }

        if (uap->length > MAX_AUDIT_RECORD_SIZE) 
                return (EINVAL);

        rec = (void *)kalloc((vm_size_t)uap->length);

        error = copyin(uap->record, rec, uap->length);
        if (error)
                goto free_out;

        /* Verify the record */
        if (bsm_rec_verify(rec) == 0) {
                error = EINVAL;
                goto free_out;
        }

        /* Attach the user audit record to the kernel audit record. Because
         * this system call is an auditable event, we will write the user
         * record along with the record for this audit event.
         */
        ar->k_udata = rec;
        ar->k_ar_commit |= AR_COMMIT_USER;
        ar->k_ulen  = uap->length;
        return (0);

free_out:
        /* audit_syscall_exit() will free the audit record on the thread
         * even if we allocated it above.
         */
        kfree(rec, uap->length);
        return (error);
}

/*
 *  System call to manipulate auditing.
 */
/* ARGSUSED */
int
auditon(struct proc *p, __unused struct auditon_args *uap, __unused register_t *retval)
{
        int ret;
        int len;
        union auditon_udata udata;
        struct proc *tp;

        AUDIT_ARG(cmd, uap->cmd);
        ret = suser(kauth_cred_get(), &p->p_acflag);
        if (ret)
                return (ret);

        len = uap->length;
        if ((len <= 0) || (len > (int)sizeof(union auditon_udata)))
                return (EINVAL);

        memset((void *)&udata, 0, sizeof(udata));

        switch (uap->cmd) {
        /* Some of the GET commands use the arguments too */
        case A_SETPOLICY:
        case A_SETKMASK:
        case A_SETQCTRL:
        case A_SETSTAT:
        case A_SETUMASK:
        case A_SETSMASK:
        case A_SETCOND:
        case A_SETCLASS:
        case A_SETPMASK:
        case A_SETFSIZE:
        case A_SETKAUDIT:
        case A_GETCLASS:
        case A_GETPINFO:
        case A_GETPINFO_ADDR:
                ret = copyin(uap->data, (void *)&udata, uap->length);
                if (ret)
                        return (ret);
                AUDIT_ARG(auditon, &udata);
                break;
}

        /* XXX Need to implement these commands by accessing the global
         * values associated with the commands.
         */
        switch (uap->cmd) {
        case A_GETPOLICY:
                if (!audit_fail_stop)
                        udata.au_policy |= AUDIT_CNT;
                if (audit_panic_on_write_fail)
                        udata.au_policy |= AUDIT_AHLT;
                break;
        case A_SETPOLICY:
                if (udata.au_policy & ~(AUDIT_CNT|AUDIT_AHLT))
                        return (EINVAL);
/*
                 * XXX - Need to wake up waiters if the policy relaxes?
 */
                audit_fail_stop = ((udata.au_policy & AUDIT_CNT) == 0);
                audit_panic_on_write_fail = (udata.au_policy & AUDIT_AHLT);
                break;
        case A_GETKMASK:
                udata.au_mask = audit_nae_mask;
                break;
        case A_SETKMASK:
                audit_nae_mask = udata.au_mask;
                break;
        case A_GETQCTRL:
                udata.au_qctrl = audit_qctrl;
                break;
        case A_SETQCTRL:
                if ((udata.au_qctrl.aq_hiwater > AQ_MAXHIGH) ||
                    (udata.au_qctrl.aq_lowater >= udata.au_qctrl.aq_hiwater) ||
                    (udata.au_qctrl.aq_bufsz > AQ_MAXBUFSZ) ||
                    (udata.au_qctrl.aq_minfree < 0) ||
                    (udata.au_qctrl.aq_minfree > 100))
                        return (EINVAL);

                audit_qctrl = udata.au_qctrl;
                /* XXX The queue delay value isn't used with the kernel. */
                audit_qctrl.aq_delay = -1;
                break;
        case A_GETCWD:
                return (ENOSYS);
                break;
        case A_GETCAR:
                return (ENOSYS);
                break;
        case A_GETSTAT:
                return (ENOSYS);
                break;
        case A_SETSTAT:
                return (ENOSYS);
                break;
        case A_SETUMASK:
                return (ENOSYS);
                break;
        case A_SETSMASK:
                return (ENOSYS);
                break;
        case A_GETCOND:
                if (audit_enabled && !audit_suspended)
                        udata.au_cond = AUC_AUDITING;
                else
                        udata.au_cond = AUC_NOAUDIT;
                break;
        case A_SETCOND:
                if (udata.au_cond == AUC_NOAUDIT) 
                        audit_suspended = 1;
                if (udata.au_cond == AUC_AUDITING) 
                        audit_suspended = 0;
                if (udata.au_cond == AUC_DISABLED) {
                        audit_suspended = 1;
                        audit_shutdown();
                }
                break;
        case A_GETCLASS:
                udata.au_evclass.ec_class = 
                        au_event_class(udata.au_evclass.ec_number);
                break;
        case A_SETCLASS:
                au_evclassmap_insert(udata.au_evclass.ec_number,
                                        udata.au_evclass.ec_class);
                break;
        case A_GETPINFO:
                if (udata.au_aupinfo.ap_pid < 1) 
                        return (EINVAL);
                if ((tp = pfind(udata.au_aupinfo.ap_pid)) == NULL)
                        return (EINVAL);

                udata.au_aupinfo.ap_auid = tp->p_ucred->cr_au.ai_auid;
                udata.au_aupinfo.ap_mask.am_success = 
                        tp->p_ucred->cr_au.ai_mask.am_success;
                udata.au_aupinfo.ap_mask.am_failure = 
                        tp->p_ucred->cr_au.ai_mask.am_failure;
                udata.au_aupinfo.ap_termid.machine = 
                        tp->p_ucred->cr_au.ai_termid.machine;
                udata.au_aupinfo.ap_termid.port = 
                        tp->p_ucred->cr_au.ai_termid.port;
                udata.au_aupinfo.ap_asid = tp->p_ucred->cr_au.ai_asid;
                break;
        case A_SETPMASK:
                if (udata.au_aupinfo.ap_pid < 1) 
                        return (EINVAL);
                if ((tp = pfind(udata.au_aupinfo.ap_pid)) == NULL)
                        return (EINVAL);

                /*
                 * we are modifying the audit info in a credential so we need a new
                 * credential (or take another reference on an existing credential that
                 * matches our new one).  We must do this because the audit info in the 
                 * credential is used as part of our hash key.  Get current credential 
                 * in the target process and take a reference while we muck with it.
                 */
                for (;;) {
                        kauth_cred_t my_cred, my_new_cred;
                        struct auditinfo temp_auditinfo;
                        
                        my_cred = kauth_cred_proc_ref(tp);
                        /* 
                         * set the credential with new info.  If there is no change we get back 
                         * the same credential we passed in.
                         */
                        temp_auditinfo = my_cred->cr_au;
                        temp_auditinfo.ai_mask.am_success = 
                                        udata.au_aupinfo.ap_mask.am_success;
                        temp_auditinfo.ai_mask.am_failure = 
                                        udata.au_aupinfo.ap_mask.am_failure;
                        my_new_cred = kauth_cred_setauditinfo(my_cred, &temp_auditinfo);
                
                        if (my_cred != my_new_cred) {
                                proc_lock(tp);
                                /* need to protect for a race where another thread also changed
                                 * the credential after we took our reference.  If p_ucred has 
                                 * changed then we should restart this again with the new cred.
                                 */
                                if (tp->p_ucred != my_cred) {
                                        proc_unlock(tp);
                                        kauth_cred_rele(my_cred);
                                        kauth_cred_rele(my_new_cred);
                                        /* try again */
                                        continue;
                                }
                                tp->p_ucred = my_new_cred;
                                proc_unlock(tp);
                        }
                        /* drop our extra reference */
                        kauth_cred_rele(my_cred);
                        break;
                }
                break;
        case A_SETFSIZE:
                if ((udata.au_fstat.af_filesz != 0) &&
                   (udata.au_fstat.af_filesz < MIN_AUDIT_FILE_SIZE))
                        return (EINVAL);
                audit_fstat.af_filesz = udata.au_fstat.af_filesz;
                break;
        case A_GETFSIZE:
                udata.au_fstat.af_filesz = audit_fstat.af_filesz;
                udata.au_fstat.af_currsz = audit_fstat.af_currsz;
                break;
        case A_GETPINFO_ADDR:
                return (ENOSYS);
                break;
        case A_GETKAUDIT:
                return (ENOSYS);
                break;
        case A_SETKAUDIT:
        return (ENOSYS);
                break;
}
        /* Copy data back to userspace for the GET comands */
        switch (uap->cmd) {
        case A_GETPOLICY:
        case A_GETKMASK:
        case A_GETQCTRL:
        case A_GETCWD:
        case A_GETCAR:
        case A_GETSTAT:
        case A_GETCOND:
        case A_GETCLASS:
        case A_GETPINFO:
        case A_GETFSIZE:
        case A_GETPINFO_ADDR:
        case A_GETKAUDIT:
                ret = copyout((void *)&udata, uap->data, uap->length);
                if (ret)
                        return (ret);
                break;
        }

        return (0);
}

/* 
 * System calls to manage the user audit information.
 * XXXAUDIT May need to lock the proc structure.
 */
/* ARGSUSED */
int
getauid(struct proc *p, struct getauid_args *uap, __unused register_t *retval)
{
        int error;

        error = copyout((void *)&kauth_cred_get()->cr_au.ai_auid,
                        uap->auid, sizeof(au_id_t));
        if (error)
                return (error);

        return (0);
}

/* ARGSUSED */
int
setauid(struct proc *p, struct setauid_args *uap, __unused register_t *retval)
{
        int error;
        au_id_t temp_au_id;

        error = suser(kauth_cred_get(), &p->p_acflag);
        if (error)
                return (error);

        error = copyin(uap->auid,
                        (void *)&temp_au_id, 
                        sizeof(au_id_t));
        if (error)
                return (error);

        /*
         * we are modifying the audit info in a credential so we need a new
         * credential (or take another reference on an existing credential that
         * matches our new one).  We must do this because the audit info in the 
         * credential is used as part of our hash key.  Get current credential 
         * in the target process and take a reference while we muck with it.
         */
        for (;;) {
                kauth_cred_t my_cred, my_new_cred;
                struct auditinfo temp_auditinfo;
                
                my_cred = kauth_cred_proc_ref(p);
                /* 
                 * set the credential with new info.  If there is no change we get back 
                 * the same credential we passed in.
                 */
                temp_auditinfo = my_cred->cr_au;
                temp_auditinfo.ai_auid = temp_au_id;
                my_new_cred = kauth_cred_setauditinfo(my_cred, &temp_auditinfo);
        
                if (my_cred != my_new_cred) {
                        proc_lock(p);
                        /* need to protect for a race where another thread also changed
                         * the credential after we took our reference.  If p_ucred has 
                         * changed then we should restart this again with the new cred.
                         */
                        if (p->p_ucred != my_cred) {
                                proc_unlock(p);
                                kauth_cred_rele(my_cred);
                                kauth_cred_rele(my_new_cred);
                                /* try again */
                                continue;
                        }
                        p->p_ucred = my_new_cred;
                        proc_unlock(p);
                }
                /* drop our extra reference */
                kauth_cred_rele(my_cred);
                break;
        }

        /* propagate the change from the process to Mach task */
        set_security_token(p);

        audit_arg_auid(kauth_cred_get()->cr_au.ai_auid);
        return (0);
}

/*
 *  System calls to get and set process audit information.
 *  If the caller is privileged, they get the whole set of
 *  audit information.  Otherwise, the real audit mask is
 *  filtered out - but the rest of the information is
 *  returned.
 */
/* ARGSUSED */
int
getaudit(struct proc *p, struct getaudit_args *uap, __unused register_t *retval)
{
        struct auditinfo ai;
        int error;

        ai = kauth_cred_get()->cr_au;

        /* only superuser gets to see the real mask */
        error = suser(kauth_cred_get(), &p->p_acflag);
        if (error) {
                ai.ai_mask.am_success = ~0;
                ai.ai_mask.am_failure = ~0;
        }

        error = copyout(&ai, uap->auditinfo, sizeof(ai));
        if (error)
                return (error);

        return (0);
}

/* ARGSUSED */
int
setaudit(struct proc *p, struct setaudit_args *uap, __unused register_t *retval)
{
        int error;
        struct auditinfo temp_auditinfo;

        error = suser(kauth_cred_get(), &p->p_acflag);
        if (error)
                return (error);
                
        error = copyin(uap->auditinfo,
                       (void *)&temp_auditinfo, 
                       sizeof(temp_auditinfo));
        if (error)
                return (error);

        /*
         * we are modifying the audit info in a credential so we need a new
         * credential (or take another reference on an existing credential that
         * matches our new one).  We must do this because the audit info in the 
         * credential is used as part of our hash key.  Get current credential 
         * in the target process and take a reference while we muck with it.
         */
        for (;;) {
                kauth_cred_t my_cred, my_new_cred;
                
                my_cred = kauth_cred_proc_ref(p);
                /* 
                 * set the credential with new info.  If there is no change we get back 
                 * the same credential we passed in.
                 */
                my_new_cred = kauth_cred_setauditinfo(my_cred, &temp_auditinfo);
        
                if (my_cred != my_new_cred) {
                        proc_lock(p);
                        /* need to protect for a race where another thread also changed
                         * the credential after we took our reference.  If p_ucred has 
                         * changed then we should restart this again with the new cred.
                         */
                        if (p->p_ucred != my_cred) {
                                proc_unlock(p);
                                kauth_cred_rele(my_cred);
                                kauth_cred_rele(my_new_cred);
                                /* try again */
                                continue;
                        }
                        p->p_ucred = my_new_cred;
                        proc_unlock(p);
                }
                /* drop our extra reference */
                kauth_cred_rele(my_cred);
                break;
        }

        /* propagate the change from the process to Mach task */
        set_security_token(p);

        audit_arg_auditinfo(&p->p_ucred->cr_au);

        return (0);
}

/* ARGSUSED */
int
getaudit_addr(struct proc *p, __unused struct getaudit_addr_args *uap, __unused register_t *retval)
{
        return (ENOSYS);
}

/* ARGSUSED */
int
setaudit_addr(struct proc *p, __unused struct setaudit_addr_args *uap, __unused register_t *retval)
{
        int error;

        error = suser(kauth_cred_get(), &p->p_acflag);
        if (error)
                return (error);
        return (ENOSYS);
}

/*
 * Syscall to manage audit files.
 *
 */
/* ARGSUSED */
int
auditctl(struct proc *p, struct auditctl_args *uap, __unused register_t *retval)
{
        struct nameidata nd;
        kauth_cred_t cred;
        struct vnode *vp;
        int error, flags;
        struct vfs_context context;

        context.vc_proc = p;
        context.vc_ucred = kauth_cred_get();

        error = suser(kauth_cred_get(), &p->p_acflag);
        if (error)
                return (error);

        vp = NULL;
        cred = NULL;

        /*
         * If a path is specified, open the replacement vnode, perform
         * validity checks, and grab another reference to the current
         * credential.
         */
        if (uap->path != 0) {
                NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1, 
                        (IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32),
                        uap->path, &context);
                flags = audit_open_flags;
                error = vn_open(&nd, flags, 0);
                if (error)
                        goto out;
                vp = nd.ni_vp;
                if (vp->v_type != VREG) {
                        vn_close(vp, audit_close_flags, kauth_cred_get(), p);
                        vnode_put(vp);
                        error = EINVAL;
                        goto out;
                }
                cred = kauth_cred_get_with_ref();
                audit_suspended = 0;
        }
        /*
         * a vp and cred of NULL is valid at this point
         * and indicates we're to turn off auditing...
         */
        audit_rotate_vnode(cred, vp);
        if (vp)
                vnode_put(vp);
out:
        return (error);
}

/**********************************
 * End of system calls.           *
 **********************************/

/*
 * MPSAFE
 */
struct kaudit_record *
audit_new(int event, struct proc *p, __unused struct uthread *uthread)
{
        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
                mutex_lock(audit_mtx);
                no_record = (audit_suspended || !audit_enabled);
                mutex_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 = (struct kaudit_record *)zalloc(audit_zone);
        if (ar == NULL)
                return NULL;

        mutex_lock(audit_mtx);
        audit_pre_q_len++;
        mutex_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. */
        cru2x(p->p_ucred, &ar->k_ar.ar_subj_cred);
        ar->k_ar.ar_subj_ruid = p->p_ucred->cr_ruid;
        ar->k_ar.ar_subj_rgid = p->p_ucred->cr_rgid;
        ar->k_ar.ar_subj_egid = p->p_ucred->cr_groups[0];
        ar->k_ar.ar_subj_auid = p->p_ucred->cr_au.ai_auid;
        ar->k_ar.ar_subj_asid = p->p_ucred->cr_au.ai_asid;
        ar->k_ar.ar_subj_pid = p->p_pid;
        ar->k_ar.ar_subj_amask = p->p_ucred->cr_au.ai_mask;
        ar->k_ar.ar_subj_term = p->p_ucred->cr_au.ai_termid;
        bcopy(p->p_comm, ar->k_ar.ar_subj_comm, MAXCOMLEN);

        return (ar);
}

/*
 * MPSAFE
 * XXXAUDIT: So far, this is unused, and should probably be GC'd.
 */
void
audit_abort(struct kaudit_record *ar)
{
        mutex_lock(audit_mtx);
        audit_pre_q_len--;
        mutex_unlock(audit_mtx);
        audit_free(ar);
}

/*
 * MPSAFE
 */
void
audit_commit(struct kaudit_record *ar, int error, int retval)
{
        int ret;
        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. 
         */
        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 OPEN_RWTC event; limit the
                 * 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) {
                mutex_lock(audit_mtx);
                audit_pre_q_len--;
                mutex_unlock(audit_mtx);
                audit_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);

        mutex_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--;
                mutex_unlock(audit_mtx);
                audit_free(ar);
                return;
        }

        /*
         * Constrain the number of committed audit records based on
         * the configurable parameter.
         */
        while (audit_q_len >= audit_qctrl.aq_hiwater) {

                ret = wait_queue_assert_wait(audit_wait_queue,
                                             AUDIT_COMMIT_EVENT,
                                             THREAD_UNINT,
                                             0);
                mutex_unlock(audit_mtx);

                assert(ret == THREAD_WAITING);

                ret = thread_block(THREAD_CONTINUE_NULL);
                assert(ret == THREAD_AWAKENED);
                mutex_lock(audit_mtx);
        }

        TAILQ_INSERT_TAIL(&audit_q, ar, k_q);
        audit_q_len++;
        audit_pre_q_len--;
        wait_queue_wakeup_one(audit_wait_queue, AUDIT_WORKER_EVENT, THREAD_AWAKENED);
        mutex_unlock(audit_mtx);
}

/*
 * Calls to set up and tear down audit structures associated with
 * each system call.
 */
void
audit_syscall_enter(unsigned short code, struct proc *proc, 
                        struct uthread *uthread)
{
        int audit_event;
        struct au_mask *aumask;

        audit_event = sys_au_event[code];
        if (audit_event == AUE_NULL)
                return;

        assert(uthread->uu_ar == NULL);

        /* Check which audit mask to use; either the kernel non-attributable
         * event mask or the process audit mask.
         */
        if (proc->p_ucred->cr_au.ai_auid == AU_DEFAUDITID)
                aumask = &audit_nae_mask;
        else
                aumask = &proc->p_ucred->cr_au.ai_mask;

        /*
         * Allocate an audit record, if preselection allows it, and store 
         * in the BSD 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.
                 */
                if (audit_in_failure &&
                    suser(kauth_cred_get(), &proc->p_acflag) != 0) {
                        int ret;

                        assert(audit_worker_thread != THREAD_NULL);
                        ret = wait_queue_assert_wait(audit_wait_queue,
                            AUDIT_FAILURE_EVENT, THREAD_UNINT, 0);
                        assert(ret == THREAD_WAITING);
                        (void)thread_block(THREAD_CONTINUE_NULL);
                        panic("audit_failing_stop: thread continued");
                }
                        uthread->uu_ar = audit_new(audit_event, proc, uthread);
                } else {
                        uthread->uu_ar = NULL;
                }
        }

void
audit_syscall_exit(int error, AUDIT_PRINTF_ONLY struct proc *proc, struct uthread *uthread)
{
        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;
        else
                retval = uthread->uu_rval[0];

        audit_commit(uthread->uu_ar, error, retval);
        if (uthread->uu_ar != NULL) {
                AUDIT_PRINTF(("audit record committed by pid %d\n", proc->p_pid));
        }
        uthread->uu_ar = NULL;

}

/*
 * Calls to set up and tear down audit structures used during Mach 
 * system calls.
 */
void
audit_mach_syscall_enter(unsigned short audit_event)
{
        struct uthread *uthread;
        struct proc *proc;
        struct au_mask *aumask;

        if (audit_event == AUE_NULL)
                return;

        uthread = curuthread();
        if (uthread == NULL)
                return;

        proc = current_proc();
        if (proc == NULL) 
                return;

        assert(uthread->uu_ar == NULL);

        /* Check which audit mask to use; either the kernel non-attributable
         * event mask or the process audit mask.
         */
        if (proc->p_ucred->cr_au.ai_auid == AU_DEFAUDITID)
                aumask = &audit_nae_mask;
        else
                aumask = &proc->p_ucred->cr_au.ai_mask;
        
        /*
         * Allocate an audit record, if desired, and store in the BSD
         * thread for later use.
         */
        if (au_preselect(audit_event, aumask,
                        AU_PRS_FAILURE | AU_PRS_SUCCESS)) {
                uthread->uu_ar = audit_new(audit_event, proc, uthread);
        } else {
                uthread->uu_ar = NULL;
        }
}

void
audit_mach_syscall_exit(int retval, struct uthread *uthread)
{
        /* The error code from Mach system calls is the same as the
         * return value  
         */
        /* XXX Is the above statement always true? */
        audit_commit(uthread->uu_ar, retval, retval);
        uthread->uu_ar = NULL;

}

/*
 * Calls to manipulate elements of the audit record structure from system
 * call code.  Macro wrappers will prevent this functions from being
 * entered if auditing is disabled, avoiding the function call cost.  We
 * check the thread audit record pointer anyway, as the audit condition
 * could change, and pre-selection may not have allocated an audit
 * record for this event.
 */
void
audit_arg_addr(user_addr_t addr)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_addr = CAST_DOWN(void *, addr);  /* XXX */
        ar->k_ar.ar_valid_arg |= ARG_ADDR;
}

void
audit_arg_len(user_size_t len)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_len = CAST_DOWN(int, len);  /* XXX */
        ar->k_ar.ar_valid_arg |= ARG_LEN;
}

void
audit_arg_fd(int fd)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_fd = fd;
        ar->k_ar.ar_valid_arg |= ARG_FD;
}

void
audit_arg_fflags(int fflags)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_fflags = fflags;
        ar->k_ar.ar_valid_arg |= ARG_FFLAGS;
}

void
audit_arg_gid(gid_t gid, gid_t egid, gid_t rgid, gid_t sgid)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_gid = gid;
        ar->k_ar.ar_arg_egid = egid;
        ar->k_ar.ar_arg_rgid = rgid;
        ar->k_ar.ar_arg_sgid = sgid;
        ar->k_ar.ar_valid_arg |= (ARG_GID | ARG_EGID | ARG_RGID | ARG_SGID);
}

void
audit_arg_uid(uid_t uid, uid_t euid, uid_t ruid, uid_t suid)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_uid = uid;
        ar->k_ar.ar_arg_euid = euid;
        ar->k_ar.ar_arg_ruid = ruid;
        ar->k_ar.ar_arg_suid = suid;
        ar->k_ar.ar_valid_arg |= (ARG_UID | ARG_EUID | ARG_RUID | ARG_SUID);
}

void
audit_arg_groupset(const gid_t *gidset, u_int gidset_size)
{
        uint i;
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        for (i = 0; i < gidset_size; i++)
                ar->k_ar.ar_arg_groups.gidset[i] = gidset[i];
        ar->k_ar.ar_arg_groups.gidset_size = gidset_size;
        ar->k_ar.ar_valid_arg |= ARG_GROUPSET;
}

void
audit_arg_login(const char *login)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

#if 0
        /*
         * XXX: Add strlcpy() to Darwin for improved safety.
         */
        strlcpy(ar->k_ar.ar_arg_login, login, MAXLOGNAME);
#else
        strcpy(ar->k_ar.ar_arg_login, login);
#endif

        ar->k_ar.ar_valid_arg |= ARG_LOGIN;
}

void
audit_arg_ctlname(const int *name, int namelen)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        bcopy(name, &ar->k_ar.ar_arg_ctlname, namelen * sizeof(int));
        ar->k_ar.ar_arg_len = namelen;
        ar->k_ar.ar_valid_arg |= (ARG_CTLNAME | ARG_LEN);
}

void
audit_arg_mask(int mask)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_mask = mask;
        ar->k_ar.ar_valid_arg |= ARG_MASK;
}

void
audit_arg_mode(mode_t mode)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_mode = mode;
        ar->k_ar.ar_valid_arg |= ARG_MODE;
}

void
audit_arg_dev(int dev)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_dev = dev;
        ar->k_ar.ar_valid_arg |= ARG_DEV;
}

void
audit_arg_value(long value)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_value = value;
        ar->k_ar.ar_valid_arg |= ARG_VALUE;
}

void
audit_arg_owner(uid_t uid, gid_t gid)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_uid = uid;
        ar->k_ar.ar_arg_gid = gid;
        ar->k_ar.ar_valid_arg |= (ARG_UID | ARG_GID);
}

void
audit_arg_pid(pid_t pid)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_pid = pid;
        ar->k_ar.ar_valid_arg |= ARG_PID;
}

void
audit_arg_process(struct proc *p)
{
        struct kaudit_record *ar;

        ar = currecord();
        if ((ar == NULL) || (p == NULL))
                return;

        ar->k_ar.ar_arg_auid = p->p_ucred->cr_au.ai_auid;
        ar->k_ar.ar_arg_euid = p->p_ucred->cr_uid;
        ar->k_ar.ar_arg_egid = p->p_ucred->cr_groups[0];
        ar->k_ar.ar_arg_ruid = p->p_ucred->cr_ruid;
        ar->k_ar.ar_arg_rgid = p->p_ucred->cr_rgid;
        ar->k_ar.ar_arg_asid = p->p_ucred->cr_au.ai_asid;
        ar->k_ar.ar_arg_termid = p->p_ucred->cr_au.ai_termid;

        ar->k_ar.ar_valid_arg |= ARG_AUID | ARG_EUID | ARG_EGID | ARG_RUID | 
                ARG_RGID | ARG_ASID | ARG_TERMID | ARG_PROCESS;
}

void
audit_arg_signum(u_int signum)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_signum = signum;
        ar->k_ar.ar_valid_arg |= ARG_SIGNUM;
}

void
audit_arg_socket(int sodomain, int sotype, int soprotocol)
{

        struct kaudit_record *ar;
 
        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_sockinfo.so_domain = sodomain;
        ar->k_ar.ar_arg_sockinfo.so_type = sotype;
        ar->k_ar.ar_arg_sockinfo.so_protocol = soprotocol;
        ar->k_ar.ar_valid_arg |= ARG_SOCKINFO;
}

void
audit_arg_sockaddr(struct proc *p, struct sockaddr *so)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL || p == NULL || so == NULL)
                return;

        bcopy(so, &ar->k_ar.ar_arg_sockaddr, sizeof(ar->k_ar.ar_arg_sockaddr));
        switch (so->sa_family) {
        case AF_INET:
                ar->k_ar.ar_valid_arg |= ARG_SADDRINET;
                break;
        case AF_INET6:
                ar->k_ar.ar_valid_arg |= ARG_SADDRINET6;
                break;
        case AF_UNIX:
                audit_arg_upath(p, ((struct sockaddr_un *)so)->sun_path, 
                                ARG_UPATH1);
                ar->k_ar.ar_valid_arg |= ARG_SADDRUNIX;
                break;
        }
}

void
audit_arg_auid(uid_t auid)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_auid = auid;
        ar->k_ar.ar_valid_arg |= ARG_AUID;
}

void
audit_arg_auditinfo(const struct auditinfo *au_info)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_auid = au_info->ai_auid;
        ar->k_ar.ar_arg_asid = au_info->ai_asid;
        ar->k_ar.ar_arg_amask.am_success = au_info->ai_mask.am_success;
        ar->k_ar.ar_arg_amask.am_failure = au_info->ai_mask.am_failure;
        ar->k_ar.ar_arg_termid.port = au_info->ai_termid.port;
        ar->k_ar.ar_arg_termid.machine = au_info->ai_termid.machine;
        ar->k_ar.ar_valid_arg |= ARG_AUID | ARG_ASID | ARG_AMASK | ARG_TERMID;
}

void
audit_arg_text(const char *text)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        /* Invalidate the text string */
        ar->k_ar.ar_valid_arg &= (ARG_ALL ^ ARG_TEXT);
        if (text == NULL)
                return; 

        if (ar->k_ar.ar_arg_text == NULL) {
                ar->k_ar.ar_arg_text = (char *)kalloc(MAXPATHLEN);
                if (ar->k_ar.ar_arg_text == NULL)
                        return; 
        }

        strncpy(ar->k_ar.ar_arg_text, text, MAXPATHLEN);
        ar->k_ar.ar_valid_arg |= ARG_TEXT;
}

void
audit_arg_cmd(int cmd)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_cmd = cmd;
        ar->k_ar.ar_valid_arg |= ARG_CMD;
}

void
audit_arg_svipc_cmd(int cmd)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_svipc_cmd = cmd;
        ar->k_ar.ar_valid_arg |= ARG_SVIPC_CMD;
}

void
audit_arg_svipc_perm(const struct ipc_perm *perm)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        bcopy(perm, &ar->k_ar.ar_arg_svipc_perm, 
                sizeof(ar->k_ar.ar_arg_svipc_perm));
        ar->k_ar.ar_valid_arg |= ARG_SVIPC_PERM;
}

void
audit_arg_svipc_id(int id)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_svipc_id = id;
        ar->k_ar.ar_valid_arg |= ARG_SVIPC_ID;
}

void
audit_arg_svipc_addr(void * addr)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_svipc_addr = addr;
        ar->k_ar.ar_valid_arg |= ARG_SVIPC_ADDR;
}

void
audit_arg_posix_ipc_perm(uid_t uid, gid_t gid, mode_t mode)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_pipc_perm.pipc_uid = uid;
        ar->k_ar.ar_arg_pipc_perm.pipc_gid = gid;
        ar->k_ar.ar_arg_pipc_perm.pipc_mode = mode;
        ar->k_ar.ar_valid_arg |= ARG_POSIX_IPC_PERM;
}

void
audit_arg_auditon(const union auditon_udata *udata)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        bcopy((const void *)udata, &ar->k_ar.ar_arg_auditon, 
                sizeof(ar->k_ar.ar_arg_auditon));
        ar->k_ar.ar_valid_arg |= ARG_AUDITON;
}

/* 
 * Audit information about a file, either the file's vnode info, or its
 * socket address info.
 */
void
audit_arg_file(__unused struct proc *p, const struct fileproc *fp)
{
        struct kaudit_record *ar;
        struct socket *so;
        struct inpcb *pcb;

        if (fp->f_fglob->fg_type == DTYPE_VNODE) {
                audit_arg_vnpath_withref((struct vnode *)fp->f_fglob->fg_data, ARG_VNODE1);
                return;
        }

        if (fp->f_fglob->fg_type == DTYPE_SOCKET) {
                ar = currecord();
                if (ar == NULL)
                        return;
                so = (struct socket *)fp->f_fglob->fg_data;
                if (INP_CHECK_SOCKAF(so, PF_INET)) {
                        if (so->so_pcb == NULL)
                                return;
                        ar->k_ar.ar_arg_sockinfo.so_type =
                                so->so_type;
                        ar->k_ar.ar_arg_sockinfo.so_domain =
                                INP_SOCKAF(so);
                        ar->k_ar.ar_arg_sockinfo.so_protocol =
                                so->so_proto->pr_protocol;
                        pcb = (struct inpcb *)so->so_pcb;
                        ar->k_ar.ar_arg_sockinfo.so_raddr =
                                pcb->inp_faddr.s_addr;
                        ar->k_ar.ar_arg_sockinfo.so_laddr =
                                pcb->inp_laddr.s_addr;
                        ar->k_ar.ar_arg_sockinfo.so_rport =
                                pcb->inp_fport;
                        ar->k_ar.ar_arg_sockinfo.so_lport =
                                pcb->inp_lport;
                        ar->k_ar.ar_valid_arg |= ARG_SOCKINFO;
                }
        }

}


/* 
 * Store a path as given by the user process for auditing into the audit 
 * record stored on the user thread. This function will allocate the memory to 
 * store the path info if not already available. This memory will be 
 * freed when the audit record is freed.
 */
void
audit_arg_upath(struct proc *p, char *upath, u_int64_t flags)
{
        struct kaudit_record *ar;
        char **pathp;

        if (p == NULL || upath == NULL) 
                return;         /* nothing to do! */

        if ((flags & (ARG_UPATH1 | ARG_UPATH2)) == 0)
                return;

        ar = currecord();
        if (ar == NULL) /* This will be the case for unaudited system calls */
                return;

        if (flags & ARG_UPATH1) {
                ar->k_ar.ar_valid_arg &= (ARG_ALL ^ ARG_UPATH1);
                pathp = &ar->k_ar.ar_arg_upath1;
        }
        else {
                ar->k_ar.ar_valid_arg &= (ARG_ALL ^ ARG_UPATH2);
                pathp = &ar->k_ar.ar_arg_upath2;
        }

        if (*pathp == NULL) {
                *pathp = (char *)kalloc(MAXPATHLEN);
                if (*pathp == NULL)
                        return;
        }

        if (canon_path(p, upath, *pathp) == 0) {
                if (flags & ARG_UPATH1)
                        ar->k_ar.ar_valid_arg |= ARG_UPATH1;
                else
                        ar->k_ar.ar_valid_arg |= ARG_UPATH2;
                } else {
                        kfree(*pathp, MAXPATHLEN);
                        *pathp = NULL;
        }
}

/*
 * Function to save the path and vnode attr information into the audit 
 * record. 
 *
 * It is assumed that the caller will hold any vnode locks necessary to
 * perform a VNOP_GETATTR() on the passed vnode.
 *
 * XXX: The attr code is very similar to vfs_vnops.c:vn_stat(), but
 * always provides access to the generation number as we need that
 * to construct the BSM file ID.
 * XXX: We should accept the process argument from the caller, since
 * it's very likely they already have a reference.
 * XXX: Error handling in this function is poor.
 */
void
audit_arg_vnpath(struct vnode *vp, u_int64_t flags)
{
        struct kaudit_record *ar;
        struct vnode_attr va;
        int error;
        int len;
        char **pathp;
        struct vnode_au_info *vnp;
        struct proc *p;
        struct vfs_context context;

        if (vp == NULL)
                return;

        ar = currecord();
        if (ar == NULL) /* This will be the case for unaudited system calls */
                return;

        if ((flags & (ARG_VNODE1 | ARG_VNODE2)) == 0)
                return;

        p = current_proc();

        if (flags & ARG_VNODE1) {
                ar->k_ar.ar_valid_arg &= (ARG_ALL ^ ARG_KPATH1);
                ar->k_ar.ar_valid_arg &= (ARG_ALL ^ ARG_VNODE1);
                pathp = &ar->k_ar.ar_arg_kpath1;
                vnp = &ar->k_ar.ar_arg_vnode1;
        }
        else {
                ar->k_ar.ar_valid_arg &= (ARG_ALL ^ ARG_KPATH2);
                ar->k_ar.ar_valid_arg &= (ARG_ALL ^ ARG_VNODE2);
                pathp = &ar->k_ar.ar_arg_kpath2;
                vnp = &ar->k_ar.ar_arg_vnode2;
        }

        if (*pathp == NULL) {
                *pathp = (char *)kalloc(MAXPATHLEN);
                if (*pathp == NULL)
                        return;
        }

        /*
         * If vn_getpath() succeeds, place it in a string buffer
         * attached to the audit record, and set a flag indicating
         * it is present.
         */
        len = MAXPATHLEN;
        if (vn_getpath(vp, *pathp, &len) == 0) {
        if (flags & ARG_VNODE1)
                ar->k_ar.ar_valid_arg |= ARG_KPATH1;
        else
                ar->k_ar.ar_valid_arg |= ARG_KPATH2;
        } else {
                kfree(*pathp, MAXPATHLEN);
                *pathp = NULL;
        }

        context.vc_proc = p;
        context.vc_ucred = kauth_cred_get();

        VATTR_INIT(&va);
        VATTR_WANTED(&va, va_mode);
        VATTR_WANTED(&va, va_uid);
        VATTR_WANTED(&va, va_gid);
        VATTR_WANTED(&va, va_rdev);
        VATTR_WANTED(&va, va_fsid);
        VATTR_WANTED(&va, va_fileid);
        VATTR_WANTED(&va, va_gen);
        error = vnode_getattr(vp, &va, &context);
        if (error) {
                /* XXX: How to handle this case? */
                return;
        }

        /* XXX do we want to fall back here when these aren't supported? */
        vnp->vn_mode = va.va_mode;
        vnp->vn_uid = va.va_uid;
        vnp->vn_gid = va.va_gid;
        vnp->vn_dev = va.va_rdev;
        vnp->vn_fsid = va.va_fsid;
        vnp->vn_fileid = (u_long)va.va_fileid;
        vnp->vn_gen = va.va_gen;
        if (flags & ARG_VNODE1)
                ar->k_ar.ar_valid_arg |= ARG_VNODE1;
        else
                ar->k_ar.ar_valid_arg |= ARG_VNODE2;

}

void
audit_arg_vnpath_withref(struct vnode *vp, u_int64_t flags)
{
        if (vp == NULL || vnode_getwithref(vp))
                return;
        audit_arg_vnpath(vp, flags);
        (void)vnode_put(vp);
}

void
audit_arg_mach_port1(mach_port_name_t port)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_mach_port1 = port;
        ar->k_ar.ar_valid_arg |= ARG_MACHPORT1;
}

void
audit_arg_mach_port2(mach_port_name_t port)
{
        struct kaudit_record *ar;

        ar = currecord();
        if (ar == NULL)
                return;

        ar->k_ar.ar_arg_mach_port2 = port;
        ar->k_ar.ar_valid_arg |= ARG_MACHPORT2;
}

/*
 * The close() system call uses it's own audit call to capture the 
 * path/vnode information because those pieces are not easily obtained
 * within the system call itself.
 */
void
audit_sysclose(struct proc *p, int fd)
{
        struct fileproc *fp;
        struct vnode *vp;

        audit_arg_fd(fd);

        if (fp_getfvp(p, fd, &fp, &vp) != 0)
                return;

        audit_arg_vnpath_withref((struct vnode *)fp->f_fglob->fg_data, ARG_VNODE1);
        file_drop(fd);
} 

#else /* !AUDIT */

void
audit_init(void)
{

}

void
audit_shutdown(void)
{

}

int
audit(struct proc *p, struct audit_args *uap, register_t *retval)
{
        return (ENOSYS);
}

int
auditon(struct proc *p, struct auditon_args *uap, register_t *retval)
{
        return (ENOSYS);
}

int
getauid(struct proc *p, struct getauid_args *uap, register_t *retval)
{
        return (ENOSYS);
}

int
setauid(struct proc *p, struct setauid_args *uap, register_t *retval)
{
        return (ENOSYS);
}

int
getaudit(struct proc *p, struct getaudit_args *uap, register_t *retval)
{
        return (ENOSYS);
}

int
setaudit(struct proc *p, struct setaudit_args *uap, register_t *retval)
{
        return (ENOSYS);
}

int
getaudit_addr(struct proc *p, struct getaudit_addr_args *uap, register_t *retval)
{
        return (ENOSYS);
}

int
setaudit_addr(struct proc *p, struct setaudit_addr_args *uap, register_t *retval)
{
        return (ENOSYS);
}

int
auditctl(struct proc *p, struct auditctl_args *uap, register_t *retval)
{
        return (ENOSYS);
}

#endif /* AUDIT */