/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/queue.h>

#include <ufs/ufs/dinode.h>

#include <protocols/dumprestore.h>

#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <timeconv.h>

#include "dump.h"

struct dumptime {
        struct  dumpdates dt_value;
        SLIST_ENTRY(dumptime) dt_list;
};
SLIST_HEAD(dthead, dumptime) dthead = SLIST_HEAD_INITIALIZER(dthead);
int     nddates = 0;            /* number of records (might be zero) */
struct  dumpdates **ddatev;     /* the arrayfied version */
char    *dumpdates;             /* name of the file containing dump date info */
int     lastlevel;              /* dump level of previous dump */

static  void dumprecout(FILE *, const struct dumpdates *);
static  int getrecord(FILE *, struct dumpdates *);
static  int makedumpdate(struct dumpdates *, const char *);
static  void readdumptimes(FILE *);

void
initdumptimes(void)
{
        FILE *df;

        if ((df = fopen(dumpdates, "r")) == NULL) {
                if (errno != ENOENT) {
                        msg("WARNING: cannot read %s: %s\n", dumpdates,
                            strerror(errno));
                        return;
                }
                /*
                 * Dumpdates does not exist, make an empty one.
                 */
                msg("WARNING: no file `%s', making an empty one\n", dumpdates);
                if ((df = fopen(dumpdates, "w")) == NULL) {
                        msg("WARNING: cannot create %s: %s\n", dumpdates,
                            strerror(errno));
                        return;
                }
                (void) fclose(df);
                if ((df = fopen(dumpdates, "r")) == NULL) {
                        quit("cannot read %s even after creating it: %s\n",
                            dumpdates, strerror(errno));
                        /* NOTREACHED */
                }
        }
        (void) flock(fileno(df), LOCK_SH);
        readdumptimes(df);
        (void) fclose(df);
}

static void
readdumptimes(FILE *df)
{
        int i;
        struct  dumptime *dtwalk;

        for (;;) {
                dtwalk = (struct dumptime *)calloc(1, sizeof (struct dumptime));
                if (getrecord(df, &(dtwalk->dt_value)) < 0) {
                        free(dtwalk);
                        break;
                }
                nddates++;
                SLIST_INSERT_HEAD(&dthead, dtwalk, dt_list);
        }

        /*
         *      arrayify the list, leaving enough room for the additional
         *      record that we may have to add to the ddate structure
         */
        ddatev = calloc((unsigned) (nddates + 1), sizeof (struct dumpdates *));
        dtwalk = SLIST_FIRST(&dthead);
        for (i = nddates - 1; i >= 0; i--, dtwalk = SLIST_NEXT(dtwalk, dt_list))
                ddatev[i] = &dtwalk->dt_value;
}

void
getdumptime(void)
{
        struct dumpdates *ddp;
        int i;
        char *fname;

        fname = disk;
#ifdef FDEBUG
        msg("Looking for name %s in dumpdates = %s for level = %d\n",
                fname, dumpdates, level);
#endif
        spcl.c_ddate = 0;
        lastlevel = 0;

        initdumptimes();
        /*
         *      Go find the entry with the same name for a lower increment
         *      and older date
         */
        ITITERATE(i, ddp) {
                if (strncmp(fname, ddp->dd_name, sizeof (ddp->dd_name)) != 0)
                        continue;
                if (ddp->dd_level >= level)
                        continue;
                if (ddp->dd_ddate <= _time64_to_time(spcl.c_ddate))
                        continue;
                spcl.c_ddate = _time_to_time64(ddp->dd_ddate);
                lastlevel = ddp->dd_level;
        }
}

void
putdumptime(void)
{
        FILE *df;
        struct dumpdates *dtwalk;
        int i;
        int fd;
        char *fname;
        char *tmsg;

        if(uflag == 0)
                return;
        if ((df = fopen(dumpdates, "r+")) == NULL)
                quit("cannot rewrite %s: %s\n", dumpdates, strerror(errno));
        fd = fileno(df);
        (void) flock(fd, LOCK_EX);
        fname = disk;
        free(ddatev);
        ddatev = NULL;
        nddates = 0;
        readdumptimes(df);
        if (fseek(df, 0L, 0) < 0)
                quit("fseek: %s\n", strerror(errno));
        spcl.c_ddate = 0;
        ITITERATE(i, dtwalk) {
                if (strncmp(fname, dtwalk->dd_name,
                                sizeof (dtwalk->dd_name)) != 0)
                        continue;
                if (dtwalk->dd_level != level)
                        continue;
                goto found;
        }
        /*
         *      construct the new upper bound;
         *      Enough room has been allocated.
         */
        dtwalk = ddatev[nddates] =
                (struct dumpdates *)calloc(1, sizeof (struct dumpdates));
        nddates += 1;
  found:
        (void) strncpy(dtwalk->dd_name, fname, sizeof (dtwalk->dd_name));
        dtwalk->dd_level = level;
        dtwalk->dd_ddate = _time64_to_time(spcl.c_date);

        ITITERATE(i, dtwalk) {
                dumprecout(df, dtwalk);
        }
        if (fflush(df))
                quit("%s: %s\n", dumpdates, strerror(errno));
        if (ftruncate(fd, ftell(df)))
                quit("ftruncate (%s): %s\n", dumpdates, strerror(errno));
        (void) fclose(df);
        if (spcl.c_date == 0) {
                tmsg = "the epoch\n";
        } else {
                time_t t = _time64_to_time(spcl.c_date);
                tmsg = ctime(&t);
        }
        msg("level %d dump on %s", level, tmsg);
}

static void
dumprecout(FILE *file, const struct dumpdates *what)
{

        if (strlen(what->dd_name) > DUMPFMTLEN)
                quit("Name '%s' exceeds DUMPFMTLEN (%d) bytes\n",
                    what->dd_name, DUMPFMTLEN);
        if (fprintf(file, DUMPOUTFMT, DUMPFMTLEN, what->dd_name,
              what->dd_level, ctime(&what->dd_ddate)) < 0)
                quit("%s: %s\n", dumpdates, strerror(errno));
}

int     recno;

static int
getrecord(FILE *df, struct dumpdates *ddatep)
{
        char tbuf[BUFSIZ];

        recno = 0;
        if ( (fgets(tbuf, sizeof (tbuf), df)) != tbuf)
                return(-1);
        recno++;
        if (makedumpdate(ddatep, tbuf) < 0)
                msg("Unknown intermediate format in %s, line %d\n",
                        dumpdates, recno);

#ifdef FDEBUG
        msg("getrecord: %s %d %s", ddatep->dd_name, ddatep->dd_level,
            ddatep->dd_ddate == 0 ? "the epoch\n" : ctime(&ddatep->dd_ddate));
#endif
        return(0);
}

static int
makedumpdate(struct dumpdates *ddp, const char *tbuf)
{
        char un_buf[128];

        (void) sscanf(tbuf, DUMPINFMT, ddp->dd_name, &ddp->dd_level, un_buf);
        ddp->dd_ddate = unctime(un_buf);
        if (ddp->dd_ddate < 0)
                return(-1);
        return(0);
}