/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
 *
 * write binary audit records directly to a file.
 */

#define DEBUG   0

#if DEBUG
#define DPRINT(x) { (void) fprintf x; }
#else
#define DPRINT(x)
#endif

/*
 * auditd_plugin_open(), auditd_plugin() and auditd_plugin_close()
 * implement a replacable library for use by auditd; they are a
 * project private interface and may change without notice.
 *
 */

#include <assert.h>
#include <bsm/audit.h>
#include <bsm/audit_record.h>
#include <bsm/libbsm.h>
#include <errno.h>
#include <fcntl.h>
#include <libintl.h>
#include <netdb.h>
#include <pthread.h>
#include <secdb.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/param.h>
#include <sys/types.h>
#include <time.h>
#include <tzfile.h>
#include <unistd.h>
#include <sys/vfs.h>
#include <limits.h>
#include <syslog.h>
#include <security/auditd.h>
#include <audit_plugin.h>

#define AUDIT_DATE_SZ   14
#define AUDIT_FNAME_SZ  2 * AUDIT_DATE_SZ + 2 + MAXHOSTNAMELEN

                        /* per-directory status */
#define SOFT_SPACE      0       /* minfree or less space available      */
#define PLENTY_SPACE    1       /* more than minfree available          */
#define SPACE_FULL      2       /* out of space                         */

#define AVAIL_MIN       50      /* If there are less that this number   */
                                /* of blocks avail, the filesystem is   */
                                /* presumed full.                       */

#define ALLHARD_DELAY   20      /* Call audit_warn(allhard) every 20 seconds */

/* minimum reasonable size in bytes to roll over an audit file */
#define FSIZE_MIN       512000

/*
 * The directory list is a circular linked list.  It is pointed into by
 * activeDir.  Each element contains the pointer to the next
 * element, the directory pathname, a flag for how much space there is
 * in the directory's filesystem, and a file handle.  Since a new
 * directory list can be created from auditd_plugin_open() while the
 * current list is in use, activeDir is protected by log_mutex.
 */
typedef struct dirlist_s dirlist_t;
struct dirlist_s {
        dirlist_t       *dl_next;
        int             dl_space;
        int             dl_flags;
        char            *dl_dirname;
        char            *dl_filename;   /* file name (not path) if open */
        int             dl_fd;          /* file handle, -1 unless open */
};
/*
 * Defines for dl_flags
 */
#define SOFT_WARNED     0x0001  /* already did soft warning for this dir */
#define HARD_WARNED     0x0002  /* already did hard warning for this dir */

#if DEBUG
static FILE             *dbfp;                  /* debug file */
#endif

static pthread_mutex_t  log_mutex;
static int              binfile_is_open = 0;

static int              minfree = -1;
static int              minfreeblocks;          /* minfree in blocks */

static dirlist_t        *lastOpenDir = NULL;    /* last activeDir */
static dirlist_t        *activeDir = NULL;      /* to be current directory */
static dirlist_t        *startdir;              /* first dir in the ring */
static int              activeCount = 0;        /* number of dirs in the ring */

static int              openNewFile = 0;        /* need to open a new file */
static int              hung_count = 0;         /* count of audit_warn hard */

/* flag from audit_plugin_open to audit_plugin_close */
static int              am_open = 0;
/* preferred dir state */
static int              fullness_state = PLENTY_SPACE;

/*
 * These are used to implement a maximum size for the auditing
 * file. binfile_maxsize is set via the 'p_fsize' parameter to the
 * audit_binfile plugin.
 */
static uint_t           binfile_cursize = 0;
static uint_t           binfile_maxsize = 0;

static int open_log(dirlist_t *);

static void
freedirlist(dirlist_t *head)
{
        dirlist_t        *n1, *n2;
        /*
         * Free up the old directory list if any
         */
        if (head != NULL) {
                n1 = head;
                do {
                        n2 = n1->dl_next;
                        free(n1->dl_dirname);
                        free(n1->dl_filename);
                        free(n1);
                        n1 = n2;
                } while (n1 != head);
        }
}

dirlist_t *
dupdirnode(dirlist_t *node_orig)
{
        dirlist_t       *node_new;

        if ((node_new = calloc(1, sizeof (dirlist_t))) == NULL) {
                return (NULL);
        }

        if (node_orig->dl_dirname != NULL &&
            (node_new->dl_dirname = strdup(node_orig->dl_dirname)) == NULL ||
            node_orig->dl_filename != NULL &&
            (node_new->dl_filename = strdup(node_orig->dl_filename)) == NULL) {
                freedirlist(node_new);
                return (NULL);
        }

        node_new->dl_next = node_new;
        node_new->dl_space = node_orig->dl_space;
        node_new->dl_flags = node_orig->dl_flags;
        node_new->dl_fd = node_orig->dl_fd;

        return (node_new);
}

/*
 * add to a linked list of directories available for writing
 *
 */
static int
growauditlist(dirlist_t **listhead, char *dirlist,
    dirlist_t *endnode, int *count)
{
        dirlist_t       *node;
        char            *bs, *be;
        dirlist_t       **node_p;
        char            *dirname;
        char            *remainder;

        DPRINT((dbfp, "binfile: dirlist=%s\n", dirlist));

        if (*listhead == NULL)
                node_p = listhead;
        else
                node_p = &(endnode->dl_next);

        node = NULL;
        while ((dirname = strtok_r(dirlist, ",", &remainder)) != NULL) {
                dirlist = NULL;

                DPRINT((dbfp, "binfile: p_dir = %s\n", dirname));

                (*count)++;
                node = malloc(sizeof (dirlist_t));
                if (node == NULL)
                        return (AUDITD_NO_MEMORY);

                node->dl_flags = 0;
                node->dl_filename = NULL;
                node->dl_fd = -1;
                node->dl_space = PLENTY_SPACE;

                node->dl_dirname = malloc((unsigned)strlen(dirname) + 1);
                if (node->dl_dirname == NULL)
                        return (AUDITD_NO_MEMORY);

                bs = dirname;
                while ((*bs == ' ') || (*bs == '\t'))   /* trim blanks */
                        bs++;
                be = bs + strlen(bs) - 1;
                while (be > bs) {       /* trim trailing blanks */
                        if ((*bs != ' ') && (*bs != '\t'))
                                break;
                        be--;
                }
                *(be + 1) = '\0';
                (void) strlcpy(node->dl_dirname, bs, AUDIT_FNAME_SZ);

                if (*listhead != NULL)
                        node->dl_next = *listhead;
                else
                        node->dl_next = node;
                *node_p = node;
                node_p = &(node->dl_next);

        }
        return (0);
}

/*
 * create a linked list of directories available for writing
 *
 * if a list already exists, the two are compared and the new one is
 * used only if it is different than the old.
 *
 * returns -2 for new or changed list, 0 for unchanged list and -1 for
 * error.  (Positive returns are for AUDITD_<error code> values)
 *
 */
static int
loadauditlist(char *dirstr, char *minfreestr)
{
        dirlist_t       *n1, *n2;
        dirlist_t       *listhead = NULL;
        dirlist_t       *thisdir;
        int             node_count = 0;
        int             rc;
        int             temp_minfree = 0;

        static dirlist_t        *activeList = NULL;     /* directory list */

        DPRINT((dbfp, "binfile: Loading audit list from audit service "
            "(audit_binfile)\n"));

        if (dirstr == NULL || minfreestr == NULL) {
                DPRINT((dbfp, "binfile: internal error"));
                return (-1);
        }
        if ((rc = growauditlist(&listhead, dirstr, NULL, &node_count)) != 0) {
                return (rc);
        }
        if (node_count == 0) {
                /*
                 * there was a problem getting the directory
                 * list or remote host info from the audit_binfile
                 * configuration even though auditd thought there was
                 * at least 1 good entry
                 */
                DPRINT((dbfp, "binfile: "
                    "problem getting directory / libpath list "
                    "from audit_binfile configuration.\n"));
                return (-1);
        }

#if DEBUG
        /* print out directory list */
        if (listhead != NULL) {
                (void) fprintf(dbfp, "Directory list:\n\t%s\n",
                    listhead->dl_dirname);
                thisdir = listhead->dl_next;

                while (thisdir != listhead) {
                        (void) fprintf(dbfp, "\t%s\n", thisdir->dl_dirname);
                        thisdir = thisdir->dl_next;
                }
        }
#endif  /* DEBUG */

        thisdir = listhead;

        /* See if the list has changed (rc = 0 if no change, else 1) */
        rc = 0;
        if (node_count == activeCount) {
                n1 = listhead;
                n2 = activeList;
                do {
                        if (strcmp(n1->dl_dirname, n2->dl_dirname) != 0) {
                                DPRINT((dbfp,
                                    "binfile: new dirname = %s\n"
                                    "binfile: old dirname = %s\n",
                                    n1->dl_dirname,
                                    n2->dl_dirname));
                                rc = -2;
                                break;
                        }
                        n1 = n1->dl_next;
                        n2 = n2->dl_next;
                } while ((n1 != listhead) && (n2 != activeList));
        } else {
                DPRINT((dbfp, "binfile: dir counts differs\n"
                    "binfile:  old dir count = %d\n"
                    "binfile:  new dir count = %d\n",
                    activeCount, node_count));
                rc = -2;
        }
        if (rc == -2) {
                (void) pthread_mutex_lock(&log_mutex);
                DPRINT((dbfp, "loadauditlist:  close / open audit.log(5)\n"));
                if (open_log(listhead) == 0) {
                        openNewFile = 1;        /* try again later */
                } else {
                        openNewFile = 0;
                }
                freedirlist(activeList);        /* old list */
                activeList = listhead;          /* new list */
                activeDir = startdir = thisdir;
                activeCount = node_count;
                (void) pthread_mutex_unlock(&log_mutex);
        } else {
                freedirlist(listhead);
        }

        /* Get the minfree value. */
        if (minfreestr != NULL)
                temp_minfree = atoi(minfreestr);

        if ((temp_minfree < 0) || (temp_minfree > 100))
                temp_minfree = 0;

        if (minfree != temp_minfree) {
                DPRINT((dbfp, "minfree:  old = %d, new = %d\n",
                    minfree, temp_minfree));
                rc = -2;                /* data change */
                minfree = temp_minfree;
        }

        return (rc);
}

/*
 * getauditdate - get the current time (GMT) and put it in the form
 *                yyyymmddHHMMSS .
 */
static void
getauditdate(char *date)
{
        struct timeval tp;
        struct timezone tzp;
        struct tm tm;

        (void) gettimeofday(&tp, &tzp);
        tm = *gmtime(&tp.tv_sec);
        /*
         * NOTE:  if we want to use gmtime, we have to be aware that the
         *      structure only keeps the year as an offset from TM_YEAR_BASE.
         *      I have used TM_YEAR_BASE in this code so that if they change
         *      this base from 1900 to 2000, it will hopefully mean that this
         *      code does not have to change.  TM_YEAR_BASE is defined in
         *      tzfile.h .
         */
        (void) sprintf(date, "%.4d%.2d%.2d%.2d%.2d%.2d",
            tm.tm_year + TM_YEAR_BASE, tm.tm_mon + 1, tm.tm_mday,
            tm.tm_hour, tm.tm_min, tm.tm_sec);
}



/*
 * write_file_token - put the file token into the audit log
 */
static int
write_file_token(int fd, char *name)
{
        adr_t adr;                                      /* xdr ptr */
        struct timeval tv;                              /* time now */
        char for_adr[AUDIT_FNAME_SZ + AUDIT_FNAME_SZ];  /* plenty of room */
        char    token_id;
        short   i;

        (void) gettimeofday(&tv, (struct timezone *)0);
        i = strlen(name) + 1;
        adr_start(&adr, for_adr);
#ifdef _LP64
                token_id = AUT_OTHER_FILE64;
                adr_char(&adr, &token_id, 1);
                adr_int64(&adr, (int64_t *)& tv, 2);
#else
                token_id = AUT_OTHER_FILE32;
                adr_char(&adr, &token_id, 1);
                adr_int32(&adr, (int32_t *)& tv, 2);
#endif

        adr_short(&adr, &i, 1);
        adr_char(&adr, name, i);

        if (write(fd, for_adr, adr_count(&adr)) < 0) {
                DPRINT((dbfp, "binfile: Bad write\n"));
                return (errno);
        }
        return (0);
}

/*
 * close_log - close the file if open.  Also put the name of the
 *      new log file in the trailer, and rename the old file
 *      to oldname.  The caller must hold log_mutext while calling
 *      close_log since any change to activeDir is a complete redo
 *      of all it points to.
 * arguments -
 *      oldname - the new name for the file to be closed
 *      newname - the name of the new log file (for the trailer)
 */
static void
close_log(dirlist_t **lastOpenDir_ptr, char *oname, char *newname)
{
        char            auditdate[AUDIT_DATE_SZ+1];
        char            *name;
        char            oldname[AUDIT_FNAME_SZ+1];
        dirlist_t       *currentdir = *lastOpenDir_ptr;

        if ((currentdir == NULL) || (currentdir->dl_fd == -1))
                return;
        /*
         * If oldname is blank, we were called by auditd_plugin_close()
         * instead of by open_log, so we need to update our name.
         */
        (void) strlcpy(oldname, oname, AUDIT_FNAME_SZ);

        if (strcmp(oldname, "") == 0) {
                getauditdate(auditdate);

                assert(currentdir->dl_filename != NULL);

                (void) strlcpy(oldname, currentdir->dl_filename,
                    AUDIT_FNAME_SZ);

                name = strrchr(oldname, '/') + 1;
                (void) memcpy(name + AUDIT_DATE_SZ + 1, auditdate,
                    AUDIT_DATE_SZ);
        }
        /*
         * Write the trailer record and rename and close the file.
         * If any of the write, rename, or close fail, ignore it
         * since there is not much else we can do and the next open()
         * will trigger the necessary full directory logic.
         *
         * newname is "" if binfile is being closed down.
         */
        (void) write_file_token(currentdir->dl_fd, newname);
        if (currentdir->dl_fd >= 0) {
                (void) fsync(currentdir->dl_fd);
                (void) close(currentdir->dl_fd);
        }
        currentdir->dl_fd = -1;
        (void) rename(currentdir->dl_filename, oldname);

        DPRINT((dbfp, "binfile: Log closed %s\n", oldname));

        freedirlist(currentdir);
        *lastOpenDir_ptr = NULL;
}


/*
 * open_log - open a new file in the current directory.  If a
 *      file is already open, close it.
 *
 *      return 1 if ok, 0 if all directories are full.
 *
 *      lastOpenDir - used to get the oldfile name (and change it),
 *              to close the oldfile.
 *
 * The caller must hold log_mutex while calling open_log.
 *
 */
static int
open_log(dirlist_t *current_dir)
{
        char    auditdate[AUDIT_DATE_SZ + 1];
        char    oldname[AUDIT_FNAME_SZ + 1] = "";
        char    newname[AUDIT_FNAME_SZ + 1];
        char    *name;                  /* pointer into oldname */
        int     opened = 0;
        int     error = 0;
        int     newfd = 0;

        static char             host[MAXHOSTNAMELEN + 1] = "";
        /* previous directory with open log file */

        if (host[0] == '\0')
                (void) gethostname(host, MAXHOSTNAMELEN);

        /* Get a filename which does not already exist */
        while (!opened) {
                getauditdate(auditdate);
                (void) snprintf(newname, AUDIT_FNAME_SZ,
                    "%s/%s.not_terminated.%s",
                    current_dir->dl_dirname, auditdate, host);
                newfd = open(newname,
                    O_RDWR | O_APPEND | O_CREAT | O_EXCL, 0640);
                if (newfd < 0) {
                        switch (errno) {
                        case EEXIST:
                                DPRINT((dbfp,
                                    "open_log says duplicate for %s "
                                    "(will try another)\n", newname));
                                (void) sleep(1);
                                break;
                        case ENOENT: {
                                /* invalid path */
                                char    *msg;
                                (void) asprintf(&msg,
                                    gettext("No such p_dir: %s\n"),
                                    current_dir->dl_dirname);
                                DPRINT((dbfp,
                                    "open_log says about %s: %s\n",
                                    newname, strerror(errno)));
                                __audit_syslog("audit_binfile.so",
                                    LOG_CONS | LOG_NDELAY,
                                    LOG_DAEMON, LOG_ERR, msg);
                                free(msg);
                                current_dir = current_dir->dl_next;
                                return (0);
                        }
                        default:
                                /* open failed */
                                DPRINT((dbfp,
                                    "open_log says full for %s: %s\n",
                                    newname, strerror(errno)));
                                current_dir->dl_space = SPACE_FULL;
                                current_dir = current_dir->dl_next;
                                return (0);
                        } /* switch */
                } else
                        opened = 1;
        } /* while */

        /*
         * When we get here, we have opened our new log file.
         * Now we need to update the name of the old file to
         * store in this file's header.  lastOpenDir may point
         * to current_dir if the list is only one entry long and
         * there is only one list.
         */
        if ((lastOpenDir != NULL) && (lastOpenDir->dl_filename != NULL)) {
                (void) strlcpy(oldname, lastOpenDir->dl_filename,
                    AUDIT_FNAME_SZ);
                name = (char *)strrchr(oldname, '/') + 1;

                (void) memcpy(name + AUDIT_DATE_SZ + 1, auditdate,
                    AUDIT_DATE_SZ);

                close_log(&lastOpenDir, oldname, newname);
        }
        error = write_file_token(newfd, oldname);
        if (error) {
                /* write token failed */
                (void) close(newfd);

                current_dir->dl_space = SPACE_FULL;
                current_dir->dl_fd = -1;
                free(current_dir->dl_filename);
                current_dir->dl_filename = NULL;
                current_dir = current_dir->dl_next;
                return (0);
        } else {
                if (current_dir->dl_filename != NULL) {
                        free(current_dir->dl_filename);
                }
                current_dir->dl_filename = strdup(newname);
                current_dir->dl_fd = newfd;

                if (lastOpenDir == NULL) {
                        freedirlist(lastOpenDir);
                        if ((lastOpenDir = dupdirnode(current_dir)) == NULL) {
                                __audit_syslog("audit_binfile.so",
                                    LOG_CONS | LOG_NDELAY,
                                    LOG_DAEMON, LOG_ERR, gettext("no memory"));
                                return (0);
                        }
                        DPRINT((dbfp, "open_log created new lastOpenDir "
                            "(%s, %s [fd: %d])\n",
                            lastOpenDir->dl_dirname == NULL ? "" :
                            lastOpenDir->dl_dirname,
                            lastOpenDir->dl_filename == NULL ? "" :
                            lastOpenDir->dl_filename, lastOpenDir->dl_fd));
                }

                /*
                 * New file opened, so reset file size statistic (used
                 * to ensure audit log does not grow above size limit
                 * set by p_fsize).
                 */
                binfile_cursize = 0;

                (void) __logpost(newname);

                DPRINT((dbfp, "binfile: Log opened: %s\n", newname));
                return (1);
        }
}

#define IGNORE_SIZE     8192
/*
 * spacecheck - determine whether the given directory's filesystem
 *      has the at least the space requested.  Also set the space
 *      value in the directory list structure.  If the caller
 *      passes other than PLENTY_SPACE or SOFT_SPACE, the caller should
 *      ignore the return value.  Otherwise, 0 = less than the
 *      requested space is available, 1 = at least the requested space
 *      is available.
 *
 *      log_mutex must be held by the caller
 *
 *      -1 is returned if stat fails
 *
 * IGNORE_SIZE is one page (Sol 9 / 10 timeframe) and is the default
 * buffer size written for Sol 9 and earlier.  To keep the same accuracy
 * for the soft limit check as before, spacecheck checks for space
 * remaining IGNORE_SIZE bytes.  This reduces the number of statvfs()
 * calls and related math.
 *
 * globals -
 *      minfree - the soft limit, i.e., the % of filesystem to reserve
 */
static int
spacecheck(dirlist_t *thisdir, int test_limit, size_t next_buf_size)
{
        struct statvfs  sb;
        static int      ignore_size = 0;

        ignore_size += next_buf_size;

        if ((test_limit == PLENTY_SPACE) && (ignore_size < IGNORE_SIZE))
                return (1);

        assert(thisdir != NULL);

        if (statvfs(thisdir->dl_dirname, &sb) < 0) {
                thisdir->dl_space = SPACE_FULL;
                minfreeblocks = AVAIL_MIN;
                return (-1);
        } else {
                minfreeblocks = ((minfree * sb.f_blocks) / 100) + AVAIL_MIN;

                if (sb.f_bavail < AVAIL_MIN)
                        thisdir->dl_space = SPACE_FULL;
                else if (sb.f_bavail > minfreeblocks) {
                        thisdir->dl_space = fullness_state = PLENTY_SPACE;
                        ignore_size = 0;
                } else
                        thisdir->dl_space = SOFT_SPACE;
        }
        if (thisdir->dl_space == PLENTY_SPACE)
                return (1);

        return (thisdir->dl_space == test_limit);
}

/*
 * Parses p_fsize value and contains it within the range FSIZE_MIN and
 * INT_MAX so using uints won't cause an undetected overflow of
 * INT_MAX.  Defaults to 0 if the value is invalid or is missing.
 */
static void
save_maxsize(char *maxsize)
{
        /*
         * strtol() returns a long which could be larger than int so
         * store here for sanity checking first
         */
        long proposed_maxsize;

        if (maxsize != NULL) {
                /*
                 * There is no explicit error return from strtol() so
                 * we may need to depend on the value of errno.
                 */
                errno = 0;
                proposed_maxsize = strtol(maxsize, (char **)NULL, 10);

                /*
                 * If sizeof(long) is greater than sizeof(int) on this
                 * platform, proposed_maxsize might be greater than
                 * INT_MAX without it being reported as ERANGE.
                 */
                if ((errno == ERANGE) ||
                    ((proposed_maxsize != 0) &&
                    (proposed_maxsize < FSIZE_MIN)) ||
                    (proposed_maxsize > INT_MAX)) {
                        binfile_maxsize = 0;
                        DPRINT((dbfp, "binfile: p_fsize parameter out of "
                            "range: %s\n", maxsize));
                        /*
                         * Inform administrator of the error via
                         * syslog
                         */
                        __audit_syslog("audit_binfile.so",
                            LOG_CONS | LOG_NDELAY,
                            LOG_DAEMON, LOG_ERR,
                            gettext("p_fsize parameter out of range\n"));
                } else {
                        binfile_maxsize = proposed_maxsize;
                }
        } else { /* p_fsize string was not present */
                binfile_maxsize = 0;
        }

        DPRINT((dbfp, "binfile: set maxsize to %d\n", binfile_maxsize));
}

/*
 * auditd_plugin() writes a buffer to the currently open file. The
 * global "openNewFile" is used to force a new log file for cases such
 * as the initial open, when minfree is reached, the p_fsize value is
 * exceeded or the current file system fills up, and "audit -s" with
 * changed parameters.  For "audit -n" a new log file is opened
 * immediately in auditd_plugin_open().
 *
 * This function manages one or more audit directories as follows:
 *
 *      If the current open file is in a directory that has not
 *      reached the soft limit, write the input data and return.
 *
 *      Scan the list of directories for one which has not reached
 *      the soft limit; if one is found, write and return.  Such
 *      a writable directory is in "PLENTY_SPACE" state.
 *
 *      Scan the list of directories for one which has not reached
 *      the hard limit; if one is found, write and return.  This
 *      directory in in "SOFT_SPACE" state.
 *
 * Oh, and if a write fails, handle it like a hard space limit.
 *
 * audit_warn (via __audit_dowarn()) is used to alert an operator
 * at various levels of fullness.
 */
/* ARGSUSED */
auditd_rc_t
auditd_plugin(const char *input, size_t in_len, uint64_t sequence, char **error)
{
        auditd_rc_t     rc = AUDITD_FAIL;
        int             open_status;
        size_t          out_len;
        /* avoid excess audit_warnage */
        static int      allsoftfull_warning = 0;
        static int      allhard_pause = 0;
        static struct timeval   next_allhard;
        struct timeval  now;
#if DEBUG
        int             statrc;
        static char     *last_file_written_to = NULL;
        static uint64_t last_sequence = 0;
        static uint64_t write_count = 0;

        if ((last_sequence > 0) && (sequence != last_sequence + 1))
                (void) fprintf(dbfp,
                    "binfile: buffer sequence=%llu but prev=%llu=n",
                    sequence, last_sequence);
        last_sequence = sequence;

        (void) fprintf(dbfp, "binfile: input seq=%llu, len=%d\n",
            sequence, in_len);
#endif
        *error = NULL;
        /*
         * lock is for activeDir, referenced by open_log() and close_log()
         */
        (void) pthread_mutex_lock(&log_mutex);

        /*
         * If this would take us over the maximum size, open a new
         * file, unless maxsize is 0, in which case growth of the
         * audit log is unrestricted.
         */
        if ((binfile_maxsize != 0) &&
            ((binfile_cursize + in_len) > binfile_maxsize)) {
                DPRINT((dbfp, "binfile: maxsize exceeded, opening new audit "
                    "file.\n"));
                openNewFile = 1;
        }

        while (rc == AUDITD_FAIL) {
                open_status = 1;
                if (openNewFile) {
                        open_status = open_log(activeDir);
                        if (open_status == 1)   /* ok */
                                openNewFile = 0;
                }
                /*
                 * consider "space ok" return and error return the same;
                 * a -1 means spacecheck couldn't check for space.
                 */
#if !DEBUG
                if ((open_status == 1) &&
                    (spacecheck(activeDir, fullness_state, in_len) != 0)) {
#else
                if ((open_status == 1) &&
                    (statrc = spacecheck(activeDir, fullness_state,
                    in_len) != 0)) {
                        DPRINT((dbfp, "binfile: returned from spacecheck\n"));
                        /*
                         * The last copy of last_file_written_to is
                         * never free'd, so there will be one open
                         * memory reference on exit.  It's debug only.
                         */
                        if ((last_file_written_to != NULL) &&
                            (strcmp(last_file_written_to,
                            activeDir->dl_filename) != 0)) {
                                DPRINT((dbfp, "binfile:  now writing to %s\n",
                                    activeDir->dl_filename));
                                free(last_file_written_to);
                        }
                        DPRINT((dbfp, "binfile:  finished some debug stuff\n"));
                        last_file_written_to =
                            strdup(activeDir->dl_filename);
#endif
                        out_len = write(activeDir->dl_fd, input, in_len);
                        DPRINT((dbfp, "binfile:  finished the write\n"));

                        binfile_cursize += out_len;

                        if (out_len == in_len) {
                                DPRINT((dbfp,
                                    "binfile: write_count=%llu, sequence=%llu,"
                                    " l=%u\n",
                                    ++write_count, sequence, out_len));
                                allsoftfull_warning = 0;
                                activeDir->dl_flags = 0;

                                rc = AUDITD_SUCCESS;
                                break;
                        } else if (!(activeDir->dl_flags & HARD_WARNED)) {
                                DPRINT((dbfp,
                                    "binfile: write failed, sequence=%llu, "
                                    "l=%u\n", sequence, out_len));
                                DPRINT((dbfp, "hard warning sent.\n"));
                                __audit_dowarn("hard", activeDir->dl_dirname,
                                    0);

                                activeDir->dl_flags |= HARD_WARNED;
                        }
                } else {
                        DPRINT((dbfp, "binfile: statrc=%d, fullness_state=%d\n",
                            statrc, fullness_state));
                        if (!(activeDir->dl_flags & SOFT_WARNED) &&
                            (activeDir->dl_space == SOFT_SPACE)) {
                                DPRINT((dbfp, "soft warning sent\n"));
                                __audit_dowarn("soft",
                                    activeDir->dl_dirname, 0);
                                activeDir->dl_flags |= SOFT_WARNED;
                        }
                        if (!(activeDir->dl_flags & HARD_WARNED) &&
                            (activeDir->dl_space == SPACE_FULL)) {
                                DPRINT((dbfp, "hard warning sent.\n"));
                                __audit_dowarn("hard",
                                    activeDir->dl_dirname, 0);
                                activeDir->dl_flags |= HARD_WARNED;
                        }
                }
                DPRINT((dbfp, "binfile: activeDir=%s, next=%s\n",
                    activeDir->dl_dirname, activeDir->dl_next->dl_dirname));

                activeDir = activeDir->dl_next;
                openNewFile = 1;

                if (activeDir == startdir) {            /* full circle */
                        if (fullness_state == PLENTY_SPACE) {   /* once */
                                fullness_state = SOFT_SPACE;
                                if (allsoftfull_warning == 0) {
                                        allsoftfull_warning++;
                                        __audit_dowarn("allsoft", "", 0);
                                }
                        } else {                        /* full circle twice */
                                if ((hung_count > 0) && !allhard_pause) {
                                        allhard_pause = 1;
                                        (void) gettimeofday(&next_allhard,
                                            NULL);
                                        next_allhard.tv_sec += ALLHARD_DELAY;
                                }

                                if (allhard_pause) {
                                        (void) gettimeofday(&now, NULL);
                                        if (now.tv_sec >= next_allhard.tv_sec) {
                                                allhard_pause = 0;
                                                __audit_dowarn("allhard", "",
                                                    ++hung_count);
                                        }
                                } else {
                                        __audit_dowarn("allhard", "",
                                            ++hung_count);
                                }
                                minfreeblocks = AVAIL_MIN;
                                rc = AUDITD_RETRY;
                                *error = strdup(gettext(
                                    "all partitions full\n"));
                                (void) __logpost("");
                        }
                }
        }
        (void) pthread_mutex_unlock(&log_mutex);

        return (rc);
}


/*
 * It may be called multiple times as auditd handles SIGHUP and SIGUSR1
 * corresponding to the audit(8) flags -s and -n
 *
 * kvlist is NULL only if auditd caught a SIGUSR1 (audit -n), so after the first
 * time open is called; the reason is -s if kvlist != NULL and -n otherwise.
 *
 */
auditd_rc_t
auditd_plugin_open(const kva_t *kvlist, char **ret_list, char **error)
{
        int             rc = 0;
        int             status;
        int             reason;
        char            *dirlist;
        char            *minfree;
        char            *maxsize;
        kva_t           *kv;

        *error = NULL;
        *ret_list = NULL;
        kv = (kva_t *)kvlist;

        if (am_open) {
                if (kvlist == NULL)
                        reason = 1;     /* audit -n */
                else
                        reason = 2;     /* audit -s */
        } else {
                reason = 0;             /* initial open */
#if DEBUG
                dbfp = __auditd_debug_file_open();
#endif
        }
        DPRINT((dbfp, "binfile: am_open=%d, reason=%d\n", am_open, reason));

        am_open = 1;

        if (kvlist == NULL) {
                dirlist = NULL;
                minfree = NULL;
                maxsize = NULL;
        } else {
                dirlist = kva_match(kv, "p_dir");
                minfree = kva_match(kv, "p_minfree");
                maxsize = kva_match(kv, "p_fsize");
        }
        switch (reason) {
        case 0:                 /* initial open */
                if (!binfile_is_open)
                        (void) pthread_mutex_init(&log_mutex, NULL);
                binfile_is_open = 1;
                openNewFile = 1;
                /* FALLTHRU */
        case 2:                 /* audit -s */
                /* handle p_fsize parameter */
                save_maxsize(maxsize);

                fullness_state = PLENTY_SPACE;
                status = loadauditlist(dirlist, minfree);

                if (status == -1) {
                        (void) __logpost("");
                        *error = strdup(gettext("no directories configured"));
                        return (AUDITD_RETRY);
                } else if (status == AUDITD_NO_MEMORY) {
                        (void) __logpost("");
                        *error = strdup(gettext("no memory"));
                        return (status);
                } else {        /* status is 0 or -2 (no change or changed) */
                        hung_count = 0;
                        DPRINT((dbfp, "binfile: loadauditlist returned %d\n",
                            status));
                }
                break;
        case 1:                 /* audit -n */
                (void) pthread_mutex_lock(&log_mutex);
                if (open_log(activeDir) == 1)   /* ok */
                        openNewFile = 0;
                (void) pthread_mutex_unlock(&log_mutex);
                break;
        }

        rc = AUDITD_SUCCESS;
        *ret_list = NULL;

        return (rc);
}

auditd_rc_t
auditd_plugin_close(char **error)
{
        *error = NULL;

        (void) pthread_mutex_lock(&log_mutex);
        close_log(&lastOpenDir, "", "");
        freedirlist(activeDir);
        activeDir = NULL;
        (void) pthread_mutex_unlock(&log_mutex);

        DPRINT((dbfp, "binfile:  closed\n"));

        (void) __logpost("");

        if (binfile_is_open) {
                (void) pthread_mutex_destroy(&log_mutex);
                binfile_is_open = 0;
#if DEBUG
        } else {
                (void) fprintf(dbfp,
                    "auditd_plugin_close() called when already closed.");
#endif
        }
        am_open = 0;
        return (AUDITD_SUCCESS);
}