/*      $OpenBSD: tape.c,v 1.54 2024/05/09 08:35:40 florian Exp $       */
/*      $NetBSD: tape.c,v 1.26 1997/04/15 07:12:25 lukem Exp $  */

/*
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * 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>  /* MAXBSIZE */
#include <sys/ioctl.h>
#include <sys/mtio.h>
#include <sys/stat.h>

#include <ufs/ufs/dinode.h>
#include <protocols/dumprestore.h>

#include <err.h>
#include <fcntl.h>
#include <paths.h>
#include <setjmp.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>

#include "restore.h"
#include "extern.h"

static long     fssize = MAXBSIZE;
static int      mt = -1;
static int      pipein = 0;
static char     magtape[BUFSIZ];
static int      blkcnt;
static int      numtrec;
static char     *tapebuf;
static union    u_spcl endoftapemark;
static long     blksread;               /* blocks read since last header */
static long     tpblksread = 0;         /* TP_BSIZE blocks read */
static long     tapesread;
static jmp_buf  restart;
static int      gettingfile = 0;        /* restart has a valid frame */
#ifdef RRESTORE
static char     *host = NULL;
#endif

static int      ofile;
static char     *map;
static char     lnkbuf[PATH_MAX + 1];
static size_t   pathlen;

struct context  curfile;        /* describes next file available on the tape */
union u_spcl    u_spcl;         /* mapping of variables in a control block */
int             oldinofmt;      /* old inode format conversion required */
int             Bcvt;           /* Swap Bytes (for CCI or sun) */

#define FLUSHTAPEBUF()  blkcnt = ntrec + 1

union u_ospcl {
        char dummy[TP_BSIZE];
        struct  s_ospcl {
                int32_t   c_type;
                int32_t   c_date;
                int32_t   c_ddate;
                int32_t   c_volume;
                int32_t   c_tapea;
                u_int16_t c_inumber;
                int32_t   c_magic;
                int32_t   c_checksum;
                struct odinode {
                        unsigned short odi_mode;
                        u_int16_t odi_nlink;
                        u_int16_t odi_uid;
                        u_int16_t odi_gid;
                        int32_t   odi_size;
                        int32_t   odi_rdev;
                        char      odi_addr[36];
                        int32_t   odi_atime;
                        int32_t   odi_mtime;
                        int32_t   odi_ctime;
                } c_odinode;
                int32_t c_count;
                char    c_addr[256];
        } s_ospcl;
};

static void      accthdr(struct s_spcl *);
static int       checksum(int *);
static void      findinode(struct s_spcl *);
static void      findtapeblksize(void);
static int       gethead(struct s_spcl *);
static void      readtape(char *);
static void      setdumpnum(void);
static void      swap_header(struct s_spcl *);
static void      swap_old_header(struct s_ospcl *);
static void      terminateinput(void);
static void      xtrlnkfile(char *, size_t);
static void      xtrlnkskip(char *, size_t);
static void      xtrmap(char *, size_t);
static void      xtrmapskip(char *, size_t);
static void      xtrskip(char *, size_t);

/*
 * Set up an input source
 */
void
setinput(char *source)
{
        FLUSHTAPEBUF();
        if (bflag)
                newtapebuf(ntrec);
        else
                /* Max out buffer size, let findtapeblksize() set ntrec. */
                newtapebuf(MAXBSIZE / TP_BSIZE);
        terminal = stdin;

#ifdef RRESTORE
        if (strchr(source, ':')) {
                host = source;
                source = strchr(host, ':');
                *source++ = '\0';
                if (rmthost(host) == 0)
                        exit(1);
        } else
#endif
        if (strcmp(source, "-") == 0) {
                /*
                 * Since input is coming from a pipe we must establish
                 * our own connection to the terminal.
                 */
                terminal = fopen(_PATH_TTY, "r");
                if (terminal == NULL) {
                        warn("cannot open %s", _PATH_TTY);
                        terminal = fopen(_PATH_DEVNULL, "r");
                        if (terminal == NULL)
                                err(1, "cannot open %s", _PATH_DEVNULL);
                }
                pipein++;
        }
        (void)strlcpy(magtape, source, sizeof magtape);
}

void
newtapebuf(long size)
{
        static long tapebufsize = -1;

        ntrec = size;
        if (size <= tapebufsize)
                return;
        free(tapebuf);
        tapebuf = calloc(size, TP_BSIZE);
        if (tapebuf == NULL)
                errx(1, "Cannot allocate space for tape buffer");
        tapebufsize = size;
}

/*
 * Verify that the tape drive can be accessed and
 * that it actually is a dump tape.
 */
void
setup(void)
{
        int i, j, *ip;
        struct stat stbuf;

        Vprintf(stdout, "Verify tape and initialize maps\n");
#ifdef RRESTORE
        if (host)
                mt = rmtopen(magtape, O_RDONLY);
        else
#endif
        if (pipein)
                mt = 0;
        else
                mt = open(magtape, O_RDONLY);
        if (mt == -1)
                err(1, "%s", magtape);
        volno = 1;
        setdumpnum();
        FLUSHTAPEBUF();
        if (!pipein && !bflag)
                findtapeblksize();
        if (gethead(&spcl) == FAIL) {
                blkcnt--; /* push back this block */
                blksread--;
                tpblksread--;
                cvtflag++;
                if (gethead(&spcl) == FAIL)
                        errx(1, "Tape is not a dump tape");
                (void)fputs("Converting to new file system format.\n", stderr);
        }
        if (pipein) {
                endoftapemark.s_spcl.c_magic = cvtflag ? OFS_MAGIC :
                    FS_UFS2_MAGIC;
                endoftapemark.s_spcl.c_type = TS_END;
                ip = (int *)&endoftapemark;
                j = sizeof(union u_spcl) / sizeof(int);
                i = 0;
                do
                        i += *ip++;
                while (--j);
                endoftapemark.s_spcl.c_checksum = CHECKSUM - i;
        }
        if (vflag || command == 't')
                printdumpinfo();
        dumptime = (time_t)spcl.c_ddate;
        dumpdate = (time_t)spcl.c_date;
        if (stat(".", &stbuf) == -1)
                err(1, "cannot stat .");
        if (stbuf.st_blksize > 0 && stbuf.st_blksize < TP_BSIZE )
                fssize = TP_BSIZE;
        if (stbuf.st_blksize >= TP_BSIZE && stbuf.st_blksize <= MAXBSIZE)
                fssize = stbuf.st_blksize;
        if (((fssize - 1) & fssize) != 0)
                errx(1, "bad block size %ld", fssize);
        if (spcl.c_volume != 1)
                errx(1, "Tape is not volume 1 of the dump");
        if (gethead(&spcl) == FAIL) {
                Dprintf(stdout, "header read failed at %ld blocks\n", blksread);
                panic("no header after volume mark!\n");
        }
        findinode(&spcl);
        if (spcl.c_type != TS_CLRI)
                errx(1, "Cannot find file removal list");
        maxino = (spcl.c_count * TP_BSIZE * NBBY) + 1;
        Dprintf(stdout, "maxino = %llu\n", (unsigned long long)maxino);
        map = calloc(1, howmany(maxino, NBBY));
        if (map == NULL)
                panic("no memory for active inode map\n");
        usedinomap = map;
        curfile.action = USING;
        getfile(xtrmap, xtrmapskip);
        if (spcl.c_type != TS_BITS)
                errx(1, "Cannot find file dump list");
        map = calloc(1, howmany(maxino, NBBY));
        if (map == NULL)
                panic("no memory for file dump list\n");
        dumpmap = map;
        curfile.action = USING;
        getfile(xtrmap, xtrmapskip);
}

/*
 * Prompt user to load a new dump volume.
 * "Nextvol" is the next suggested volume to use.
 * This suggested volume is enforced when doing full
 * or incremental restores, but can be overrridden by
 * the user when only extracting a subset of the files.
 */
void
getvol(long nextvol)
{
        long newvol = 0, savecnt = 0, wantnext = 0, i;
        union u_spcl tmpspcl;
#       define tmpbuf tmpspcl.s_spcl
        char buf[TP_BSIZE];
        const char *errstr;

        if (nextvol == 1) {
                tapesread = 0;
                gettingfile = 0;
        }
        if (pipein) {
                if (nextvol != 1)
                        panic("Changing volumes on pipe input?\n");
                if (volno == 1)
                        return;
                goto gethdr;
        }
        savecnt = blksread;
again:
        if (pipein)
                exit(1); /* pipes do not get a second chance */
        if (command == 'R' || command == 'r' || curfile.action != SKIP) {
                newvol = nextvol;
                wantnext = 1;
        } else {
                newvol = 0;
                wantnext = 0;
        }
        while (newvol <= 0) {
                if (tapesread == 0) {
                        fprintf(stderr, "%s%s%s%s%s",
                            "You have not read any tapes yet.\n",
                            "Unless you know which volume your",
                            " file(s) are on you should start\n",
                            "with the last volume and work",
                            " towards the first.\n");
                } else {
                        fprintf(stderr, "You have read volumes");
                        strlcpy(buf, ": ", sizeof buf);
                        for (i = 1; i < 32; i++)
                                if (tapesread & (1 << i)) {
                                        fprintf(stderr, "%s%ld", buf, i);
                                        strlcpy(buf, ", ", sizeof buf);
                                }
                        fprintf(stderr, "\n");
                }
                do      {
                        fprintf(stderr, "Specify next volume #: ");
                        (void)fflush(stderr);
                        if (fgets(buf, sizeof buf, terminal) == NULL)
                                exit(1);
                        buf[strcspn(buf, "\n")] = '\0';

                        newvol = strtonum(buf, 1, INT_MAX, &errstr);
                        if (errstr)
                                fprintf(stderr, "Volume number %s: %s\n", errstr, buf);
                } while (errstr);
        }
        if (newvol == volno) {
                tapesread |= 1 << volno;
                return;
        }
        closemt();
        fprintf(stderr, "Mount tape volume %ld\n", newvol);
        fprintf(stderr, "Enter ``none'' if there are no more tapes\n");
        fprintf(stderr, "otherwise enter tape name (default: %s) ", magtape);
        (void)fflush(stderr);
        if (fgets(buf, sizeof buf, terminal) == NULL || feof(terminal))
                exit(1);
        buf[strcspn(buf, "\n")] = '\0';
        if (strcmp(buf, "none") == 0) {
                terminateinput();
                return;
        }
        if (buf[0] != '\0')
                (void)strlcpy(magtape, buf, sizeof magtape);

#ifdef RRESTORE
        if (host)
                mt = rmtopen(magtape, O_RDONLY);
        else
#endif
                mt = open(magtape, O_RDONLY);

        if (mt == -1) {
                fprintf(stderr, "Cannot open %s\n", magtape);
                volno = -1;
                goto again;
        }
gethdr:
        volno = newvol;
        setdumpnum();
        FLUSHTAPEBUF();
        if (gethead(&tmpbuf) == FAIL) {
                Dprintf(stdout, "header read failed at %ld blocks\n", blksread);
                fprintf(stderr, "tape is not dump tape\n");
                volno = 0;
                goto again;
        }
        if (tmpbuf.c_volume != volno) {
                fprintf(stderr, "Wrong volume (%d)\n", tmpbuf.c_volume);
                volno = 0;
                goto again;
        }
        if (tmpbuf.c_date != dumpdate || tmpbuf.c_ddate != dumptime) {
                time_t t = (time_t)tmpbuf.c_date;
                char ct1buf[26], ct2buf[26];
                char *ct1, *ct2;

                ct1 = ctime_r(&t, ct1buf);
                ct2 = ctime_r(&dumpdate, ct2buf);
                if (ct1 && ct2) {
                        fprintf(stderr, "Wrong dump date\n\tgot: %s", ct1);
                        fprintf(stderr, "\twanted: %s", ct2);
                } else {
                        fprintf(stderr, "Wrong dump date\n\tgot: %lld\n", t);
                        fprintf(stderr, "\twanted: %lld\n", dumpdate);
                }
                volno = 0;
                goto again;
        }
        tapesread |= 1 << volno;
        blksread = savecnt;
        /*
         * If continuing from the previous volume, skip over any
         * blocks read already at the end of the previous volume.
         *
         * If coming to this volume at random, skip to the beginning
         * of the next record.
         */
        Dprintf(stdout, "read %ld recs, tape starts with %lld\n",
                tpblksread, tmpbuf.c_firstrec);
        if (tmpbuf.c_type == TS_TAPE && (tmpbuf.c_flags & DR_NEWHEADER)) {
                if (!wantnext) {
                        tpblksread = tmpbuf.c_firstrec;
                        for (i = tmpbuf.c_count; i > 0; i--)
                                readtape(buf);
                } else if (tmpbuf.c_firstrec > 0 &&
                           tmpbuf.c_firstrec < tpblksread - 1) {
                        /*
                         * -1 since we've read the volume header
                         */
                        i = tpblksread - tmpbuf.c_firstrec - 1;
                        Dprintf(stderr, "Skipping %ld duplicate record%s.\n",
                                i, (i == 1) ? "" : "s");
                        while (--i >= 0)
                                readtape(buf);
                }
        }
        if (curfile.action == USING) {
                if (volno == 1)
                        panic("active file into volume 1\n");
                return;
        }
        /*
         * Skip up to the beginning of the next record
         */
        if (tmpbuf.c_type == TS_TAPE && (tmpbuf.c_flags & DR_NEWHEADER))
                for (i = tmpbuf.c_count; i > 0; i--)
                        readtape(buf);
        (void)gethead(&spcl);
        findinode(&spcl);
        if (gettingfile) {
                gettingfile = 0;
                longjmp(restart, 1);
        }
}

/*
 * Handle unexpected EOF.
 */
static void
terminateinput(void)
{

        if (gettingfile && curfile.action == USING) {
                printf("Warning: %s %s\n",
                    "End-of-input encountered while extracting", curfile.name);
        }
        curfile.name = "<name unknown>";
        curfile.action = UNKNOWN;
        curfile.mode = 0;
        curfile.ino = maxino;
        if (gettingfile) {
                gettingfile = 0;
                longjmp(restart, 1);
        }
}

/*
 * handle multiple dumps per tape by skipping forward to the
 * appropriate one.
 */
static void
setdumpnum(void)
{
        struct mtop tcom;

        if (dumpnum == 1 || volno != 1)
                return;
        if (pipein)
                errx(1, "Cannot have multiple dumps on pipe input");
        tcom.mt_op = MTFSF;
        tcom.mt_count = dumpnum - 1;
#ifdef RRESTORE
        if (host)
                rmtioctl(MTFSF, dumpnum - 1);
        else
#endif
                if (ioctl(mt, MTIOCTOP, (char *)&tcom) == -1)
                        warn("ioctl MTFSF");
}

void
printdumpinfo(void)
{
        time_t t;
        char *ct;

        t = (time_t)spcl.c_date;
        ct = ctime(&t);
        if (ct)
                fprintf(stdout, "Dump   date: %s", ct);
        else
                fprintf(stdout, "Dump   date: %lld\n", t);
        t = (time_t)spcl.c_ddate;
        ct = ctime(&t);
        if (ct)
                fprintf(stdout, "Dumped from: %s",
                    (spcl.c_ddate == 0) ? "the epoch\n" : ct);
        else
                fprintf(stdout, "Dumped from: %lld\n", t);
        if (spcl.c_host[0] == '\0')
                return;
        fprintf(stderr, "Level %d dump of %s on %s:%s\n",
                spcl.c_level, spcl.c_filesys, spcl.c_host, spcl.c_dev);
        fprintf(stderr, "Label: %s\n", spcl.c_label);
}

int
extractfile(char *name)
{
        u_int flags;
        uid_t uid;
        gid_t gid;
        mode_t mode;
        struct timespec mtimep[2], ctimep[2];
        struct entry *ep;
        int setbirth;

        curfile.name = name;
        curfile.action = USING;
        mtimep[0].tv_sec = curfile.atime_sec;
        mtimep[0].tv_nsec = curfile.atime_nsec;
        mtimep[1].tv_sec = curfile.mtime_sec;
        mtimep[1].tv_nsec = curfile.mtime_nsec;

        setbirth = curfile.birthtime_sec != 0;
        if (setbirth) {
                ctimep[0].tv_sec = curfile.atime_sec;
                ctimep[0].tv_nsec = curfile.atime_nsec;
                ctimep[1].tv_sec = curfile.birthtime_sec;
                ctimep[1].tv_nsec = curfile.birthtime_nsec;
        }
        uid = curfile.uid;
        gid = curfile.gid;
        mode = curfile.mode;
        flags = curfile.file_flags;
        switch (mode & IFMT) {

        default:
                fprintf(stderr, "%s: unknown file mode 0%o\n", name, mode);
                skipfile();
                return (FAIL);

        case IFSOCK:
                Vprintf(stdout, "skipped socket %s\n", name);
                skipfile();
                return (GOOD);

        case IFDIR:
                if (mflag) {
                        ep = lookupname(name);
                        if (ep == NULL || ep->e_flags & EXTRACT)
                                panic("unextracted directory %s\n", name);
                        skipfile();
                        return (GOOD);
                }
                Vprintf(stdout, "extract file %s\n", name);
                return (genliteraldir(name, curfile.ino));

        case IFLNK: {
                        lnkbuf[0] = '\0';
                        pathlen = 0;
                        getfile(xtrlnkfile, xtrlnkskip);
                        if (pathlen == 0) {
                                Vprintf(stdout,
                                    "%s: zero length symbolic link (ignored)\n",
                                     name);
                                return (GOOD);
                        }
                        if (linkit(lnkbuf, name, SYMLINK) == FAIL)
                                return (FAIL);
                        (void)lchown(name, uid, gid);
                        (void)fchmodat(AT_FDCWD, name, mode,
                            AT_SYMLINK_NOFOLLOW);
                        return (GOOD);
                }

        case IFCHR:
        case IFBLK:
                Vprintf(stdout, "extract special file %s\n", name);
                if (Nflag) {
                        skipfile();
                        return (GOOD);
                }
                if (mknod(name, mode, (int)curfile.rdev) == -1) {
                        warn("%s: cannot create special file", name);
                        skipfile();
                        return (FAIL);
                }
                (void)chown(name, uid, gid);
                (void)chmod(name, mode);
                (void)chflags(name, flags);
                skipfile();
                if (setbirth)
                        (void)utimensat(AT_FDCWD, name, ctimep, 0);
                (void)utimensat(AT_FDCWD, name, mtimep, 0);
                return (GOOD);

        case IFIFO:
                Vprintf(stdout, "extract fifo %s\n", name);
                if (Nflag) {
                        skipfile();
                        return (GOOD);
                }
                if (mkfifo(name, mode) == -1) {
                        warn("%s: cannot create fifo", name);
                        skipfile();
                        return (FAIL);
                }
                (void)chown(name, uid, gid);
                (void)chmod(name, mode);
                (void)chflags(name, flags);
                skipfile();
                if (setbirth)
                        (void)utimensat(AT_FDCWD, name, ctimep, 0);
                (void)utimensat(AT_FDCWD, name, mtimep, 0);
                return (GOOD);

        case IFREG:
                Vprintf(stdout, "extract file %s\n", name);
                if (Nflag) {
                        skipfile();
                        return (GOOD);
                }
                if ((ofile = open(name, O_WRONLY | O_CREAT | O_TRUNC,
                    0666)) == -1) {
                        warn("%s: cannot create file", name);
                        skipfile();
                        return (FAIL);
                }
                (void)fchown(ofile, curfile.uid, curfile.gid);
                (void)fchmod(ofile, mode);
                (void)fchflags(ofile, flags);
                getfile(xtrfile, xtrskip);
                (void)close(ofile);
                if (setbirth)
                        (void)utimensat(AT_FDCWD, name, ctimep, 0);
                (void)utimensat(AT_FDCWD, name, mtimep, 0);
                return (GOOD);
        }
        /* NOTREACHED */
}

/*
 * skip over bit maps on the tape
 */
void
skipmaps(void)
{

        while (spcl.c_type == TS_BITS || spcl.c_type == TS_CLRI)
                skipfile();
}

/*
 * skip over a file on the tape
 */
void
skipfile(void)
{

        curfile.action = SKIP;
        getfile(xtrnull, xtrnull);
}

/*
 * Extract a file from the tape.
 * When an allocated block is found it is passed to the fill function;
 * when an unallocated block (hole) is found, a zeroed buffer is passed
 * to the skip function.
 *
 * For some block types (TS_BITS, TS_CLRI), the c_addr map is not meaningful
 * and no blocks should be skipped.
 */
void
getfile(void (*fill)(char *, size_t), void (*skip)(char *, size_t))
{
        int i;
        volatile int curblk = 0;
        volatile off_t size = spcl.c_size;
        static char clearedbuf[MAXBSIZE];
        char buf[MAXBSIZE / TP_BSIZE][TP_BSIZE];
        char junk[TP_BSIZE];
        volatile int noskip = (spcl.c_type == TS_BITS || spcl.c_type == TS_CLRI);

        if (spcl.c_type == TS_END)
                panic("ran off end of tape\n");
        if (spcl.c_magic != FS_UFS2_MAGIC)
                panic("not at beginning of a file\n");
        if (!gettingfile && setjmp(restart) != 0)
                return;
        gettingfile++;
loop:
        for (i = 0; i < spcl.c_count; i++) {
                if (noskip || spcl.c_addr[i]) {
                        readtape(&buf[curblk++][0]);
                        if (curblk == fssize / TP_BSIZE) {
                                (*fill)((char *)buf, size > TP_BSIZE ?
                                     fssize :
                                     ((off_t)curblk - 1) * TP_BSIZE + size);
                                curblk = 0;
                        }
                } else {
                        if (curblk > 0) {
                                (*fill)((char *)buf, size > TP_BSIZE ?
                                     (curblk * TP_BSIZE) :
                                     ((off_t)curblk - 1) * TP_BSIZE + size);
                                curblk = 0;
                        }
                        (*skip)(clearedbuf, size > TP_BSIZE ?
                                TP_BSIZE : size);
                }
                if ((size -= TP_BSIZE) <= 0) {
                        for (i++; i < spcl.c_count; i++)
                                if (noskip || spcl.c_addr[i])
                                        readtape(junk);
                        break;
                }
        }
        if (gethead(&spcl) == GOOD && size > 0) {
                if (spcl.c_type == TS_ADDR)
                        goto loop;
                Dprintf(stdout,
                        "Missing address (header) block for %s at %ld blocks\n",
                        curfile.name, blksread);
        }
        if (curblk > 0)
                (*fill)((char *)buf, ((off_t)curblk * TP_BSIZE) + size);
        findinode(&spcl);
        gettingfile = 0;
}

/*
 * Write out the next block of a file.
 */
void
xtrfile(char *buf, size_t size)
{

        if (Nflag)
                return;
        if (write(ofile, buf, size) == -1)
                err(1, "write error extracting inode %llu, name %s\nwrite",
                    (unsigned long long)curfile.ino, curfile.name);
}

/*
 * Skip over a hole in a file.
 */
static void
xtrskip(char *buf, size_t size)
{

        if (lseek(ofile, (off_t)size, SEEK_CUR) == -1)
                err(1, "seek error extracting inode %llu, name %s\nlseek",
                    (unsigned long long)curfile.ino, curfile.name);
}

/*
 * Collect the next block of a symbolic link.
 */
static void
xtrlnkfile(char *buf, size_t size)
{

        pathlen += size;
        if (pathlen > PATH_MAX)
                errx(1, "symbolic link name: %s->%s%s; too long %lu",
                    curfile.name, lnkbuf, buf, (u_long)pathlen);
        (void)strlcat(lnkbuf, buf, sizeof(lnkbuf));
}

/*
 * Skip over a hole in a symbolic link (should never happen).
 */
static void
xtrlnkskip(char *buf, size_t size)
{

        errx(1, "unallocated block in symbolic link %s", curfile.name);
}

/*
 * Collect the next block of a bit map.
 */
static void
xtrmap(char *buf, size_t size)
{

        memcpy(map, buf, size);
        map += size;
}

/*
 * Skip over a hole in a bit map (should never happen).
 */
static void
xtrmapskip(char *buf, size_t size)
{

        panic("hole in map\n");
        map += size;
}

/*
 * Noop, when an extraction function is not needed.
 */
void
xtrnull(char *buf, size_t size)
{

        return;
}

/*
 * Read TP_BSIZE blocks from the input.
 * Handle read errors, and end of media.
 */
static void
readtape(char *buf)
{
        long rd, newvol, i;
        int cnt, seek_failed;

        if (blkcnt < numtrec) {
                memcpy(buf, &tapebuf[(blkcnt++ * TP_BSIZE)], TP_BSIZE);
                blksread++;
                tpblksread++;
                return;
        }
        for (i = 0; i < ntrec; i++)
                ((struct s_spcl *)&tapebuf[i * TP_BSIZE])->c_magic = 0;
        if (numtrec == 0)
                numtrec = ntrec;
        cnt = ntrec * TP_BSIZE;
        rd = 0;
getmore:
#ifdef RRESTORE
        if (host)
                i = rmtread(&tapebuf[rd], cnt);
        else
#endif
                i = read(mt, &tapebuf[rd], cnt);
        /*
         * Check for mid-tape short read error.
         * If found, skip rest of buffer and start with the next.
         */
        if (!pipein && numtrec < ntrec && i > 0) {
                Dprintf(stdout, "mid-media short read error.\n");
                numtrec = ntrec;
        }
        /*
         * Handle partial block read.
         */
        if (pipein && i == 0 && rd > 0)
                i = rd;
        else if (i > 0 && i != ntrec * TP_BSIZE) {
                if (pipein) {
                        rd += i;
                        cnt -= i;
                        if (cnt > 0)
                                goto getmore;
                        i = rd;
                } else {
                        /*
                         * Short read. Process the blocks read.
                         */
                        if (i % TP_BSIZE != 0)
                                Vprintf(stdout,
                                    "partial block read: %ld should be %ld\n",
                                    i, ntrec * TP_BSIZE);
                        numtrec = i / TP_BSIZE;
                }
        }
        /*
         * Handle read error.
         */
        if (i < 0) {
                fprintf(stderr, "Tape read error while ");
                switch (curfile.action) {
                default:
                        fprintf(stderr, "trying to set up tape\n");
                        break;
                case UNKNOWN:
                        fprintf(stderr, "trying to resynchronize\n");
                        break;
                case USING:
                        fprintf(stderr, "restoring %s\n", curfile.name);
                        break;
                case SKIP:
                        fprintf(stderr, "skipping over inode %llu\n",
                            (unsigned long long)curfile.ino);
                        break;
                }
                if (!yflag && !reply("continue"))
                        exit(1);
                i = ntrec * TP_BSIZE;
                memset(tapebuf, 0, i);
#ifdef RRESTORE
                if (host)
                        seek_failed = (rmtseek(i, 1) < 0);
                else
#endif
                        seek_failed = (lseek(mt, i, SEEK_CUR) == (off_t)-1);

                if (seek_failed)
                        err(1, "continuation failed");
        }
        /*
         * Handle end of tape.
         */
        if (i == 0) {
                Vprintf(stdout, "End-of-tape encountered\n");
                if (!pipein) {
                        newvol = volno + 1;
                        volno = 0;
                        numtrec = 0;
                        getvol(newvol);
                        readtape(buf);
                        return;
                }
                if (rd % TP_BSIZE != 0)
                        panic("partial block read: %ld should be %ld\n",
                                rd, ntrec * TP_BSIZE);
                terminateinput();
                memcpy(&tapebuf[rd], &endoftapemark, TP_BSIZE);
        }
        blkcnt = 0;
        memcpy(buf, &tapebuf[(blkcnt++ * TP_BSIZE)], TP_BSIZE);
        blksread++;
        tpblksread++;
}

static void
findtapeblksize(void)
{
        long i;

        for (i = 0; i < ntrec; i++)
                ((struct s_spcl *)&tapebuf[i * TP_BSIZE])->c_magic = 0;
        blkcnt = 0;
#ifdef RRESTORE
        if (host)
                i = rmtread(tapebuf, ntrec * TP_BSIZE);
        else
#endif
                i = read(mt, tapebuf, ntrec * TP_BSIZE);

        if (i <= 0)
                err(1, "tape read error");
        if (i % TP_BSIZE != 0) {
                errx(1,
                    "Tape block size (%ld) is not a multiple of dump block size (%d)",
                    i, TP_BSIZE);
        }
        ntrec = i / TP_BSIZE;
        numtrec = ntrec;
        Vprintf(stdout, "Tape block size is %ld\n", ntrec);
}

void
closemt(void)
{

        if (mt < 0)
                return;
#ifdef RRESTORE
        if (host)
                rmtclose();
        else
#endif
                (void)close(mt);
}

/*
 * Read the next block from the tape.
 * Check to see if it is one of several vintage headers.
 * If it is an old style header, convert it to a new style header.
 * If it is not any valid header, return an error.
 */
static int
gethead(struct s_spcl *buf)
{
        union u_ospcl u_ospcl;

        if (!cvtflag) {
                readtape((char *)buf);
                if (buf->c_magic != NFS_MAGIC &&
                    buf->c_magic != FS_UFS2_MAGIC) {
                        if (swap32(buf->c_magic) != NFS_MAGIC &&
                            swap32(buf->c_magic) != FS_UFS2_MAGIC)
                                return (FAIL);
                        if (!Bcvt) {
                                Vprintf(stdout, "Note: Doing Byte swapping\n");
                                Bcvt = 1;
                        }
                }
                if (checksum((int *)buf) == FAIL)
                        return (FAIL);
                if (Bcvt)
                        swap_header(buf);
                goto good;
        }

        readtape((char *)(&u_ospcl.s_ospcl));
        if (checksum((int *)(&u_ospcl.s_ospcl)) == FAIL)
                return (FAIL);
        if (u_ospcl.s_ospcl.c_magic != OFS_MAGIC) {
                if (swap32(u_ospcl.s_ospcl.c_magic) != OFS_MAGIC)
                        return (FAIL);
                if (!Bcvt) {
                        fprintf(stdout, "Note: Doing Byte swapping\n");
                        Bcvt = 1;
                }
                swap_old_header(&u_ospcl.s_ospcl);
        }

        memset(buf, 0, TP_BSIZE);
        buf->c_type = u_ospcl.s_ospcl.c_type;
        buf->c_date = u_ospcl.s_ospcl.c_date;
        buf->c_ddate = u_ospcl.s_ospcl.c_ddate;
        buf->c_volume = u_ospcl.s_ospcl.c_volume;
        buf->c_tapea = u_ospcl.s_ospcl.c_tapea;
        buf->c_inumber = u_ospcl.s_ospcl.c_inumber;
        buf->c_checksum = u_ospcl.s_ospcl.c_checksum;
        buf->c_mode = u_ospcl.s_ospcl.c_odinode.odi_mode;
        buf->c_uid = u_ospcl.s_ospcl.c_odinode.odi_uid;
        buf->c_gid = u_ospcl.s_ospcl.c_odinode.odi_gid;
        buf->c_size = u_ospcl.s_ospcl.c_odinode.odi_size;
        buf->c_rdev = u_ospcl.s_ospcl.c_odinode.odi_rdev;
        buf->c_atime = u_ospcl.s_ospcl.c_odinode.odi_atime;
        buf->c_mtime = u_ospcl.s_ospcl.c_odinode.odi_mtime;
        buf->c_count = u_ospcl.s_ospcl.c_count;
        memcpy(buf->c_addr, u_ospcl.s_ospcl.c_addr, 256);
        buf->c_magic = FS_UFS2_MAGIC;
good:
        switch (buf->c_type) {

        case TS_CLRI:
        case TS_BITS:
                /*
                 * Have to patch up missing information in bit map headers
                 */
                buf->c_inumber = 0;
                buf->c_size = buf->c_count * TP_BSIZE;
                break;

        case TS_TAPE:
                if ((buf->c_flags & DR_NEWINODEFMT) == 0)
                        oldinofmt = 1;
                /* fall through */
        case TS_END:
                buf->c_inumber = 0;
                break;

        case TS_INODE:
                if (buf->c_magic == NFS_MAGIC) {
                        buf->c_tapea = buf->c_old_tapea;
                        buf->c_firstrec = buf->c_old_firstrec;
                        buf->c_date = buf->c_old_date;
                        buf->c_ddate = buf->c_old_ddate;
                        buf->c_atime = buf->c_old_atime;
                        buf->c_mtime = buf->c_old_mtime;
                        buf->c_birthtime = 0;
                        buf->c_birthtimensec = 0;
                        buf->c_atimensec = buf->c_mtimensec = 0;
                }

        case TS_ADDR:
                break;

        default:
                panic("gethead: unknown inode type %d\n", buf->c_type);
                break;
        }

        buf->c_magic = FS_UFS2_MAGIC;

        /*
         * If we are restoring a filesystem with old format inodes,
         * copy the uid/gid to the new location.
         */
        if (oldinofmt) {
                buf->c_uid = buf->c_spare1[1];
                buf->c_gid = buf->c_spare1[2];
        }
        if (dflag)
                accthdr(buf);
        return(GOOD);
}

/*
 * Check that a header is where it belongs and predict the next header
 */
static void
accthdr(struct s_spcl *header)
{
        static ino_t previno = (ino_t)-1;
        static int prevtype;
        static long predict;
        long blks, i;

        if (header->c_type == TS_TAPE) {
                fprintf(stderr, "Volume header (%s inode format) ",
                    oldinofmt ? "old" : "new");
                if (header->c_firstrec)
                        fprintf(stderr, "begins with record %lld",
                                (long long)header->c_firstrec);
                fprintf(stderr, "\n");
                previno = (ino_t)-1;
                return;
        }
        if (previno == (ino_t)-1)
                goto newcalc;
        switch (prevtype) {
        case TS_BITS:
                fprintf(stderr, "Dumped inodes map header");
                break;
        case TS_CLRI:
                fprintf(stderr, "Used inodes map header");
                break;
        case TS_INODE:
                fprintf(stderr, "File header, ino %llu",
                    (unsigned long long)previno);
                break;
        case TS_ADDR:
                fprintf(stderr, "File continuation header, ino %llu",
                    (unsigned long long)previno);
                break;
        case TS_END:
                fprintf(stderr, "End of tape header");
                break;
        }
        if (predict != blksread - 1)
                fprintf(stderr, "; predicted %ld blocks, got %ld blocks",
                        predict, blksread - 1);
        fprintf(stderr, "\n");
newcalc:
        blks = 0;
        switch (header->c_type) {

        case TS_BITS:
        case TS_CLRI:
                blks = header->c_count;
                break;

        case TS_END:
                break;

        default:
                for (i = 0; i < header->c_count; i++)
                        if (header->c_addr[i] != 0)
                                blks++;
        }
        predict = blks;
        blksread = 0;
        prevtype = header->c_type;
        previno = header->c_inumber;
}

/*
 * Find an inode header.
 * Complain if had to skip, and complain is set.
 */
static void
findinode(struct s_spcl *header)
{
        static long skipcnt = 0;
        long i;
        char buf[TP_BSIZE];

        curfile.name = "<name unknown>";
        curfile.action = UNKNOWN;
        curfile.mode = 0;
        curfile.ino = 0;
        do {
                if (header->c_magic != FS_UFS2_MAGIC) {
                        skipcnt++;
                        while (gethead(header) == FAIL ||
                            header->c_date != dumpdate)
                                skipcnt++;
                }
                switch (header->c_type) {

                case TS_ADDR:
                        /*
                         * Skip up to the beginning of the next record
                         */
                        for (i = 0; i < header->c_count; i++)
                                if (header->c_addr[i])
                                        readtape(buf);
                        while (gethead(header) == FAIL ||
                            header->c_date != dumpdate)
                                skipcnt++;
                        break;

                case TS_INODE:
                        curfile.mode = header->c_mode;
                        curfile.uid = header->c_uid;
                        curfile.gid = header->c_gid;
                        curfile.file_flags = header->c_file_flags;
                        curfile.rdev = header->c_rdev;
                        curfile.atime_sec = header->c_atime;
                        curfile.atime_nsec = header->c_atimensec;
                        curfile.mtime_sec = header->c_mtime;
                        curfile.mtime_nsec = header->c_mtimensec;
                        curfile.birthtime_sec = header->c_birthtime;
                        curfile.birthtime_nsec = header->c_birthtimensec;
                        curfile.size = header->c_size;
                        curfile.ino = header->c_inumber;
                        break;

                case TS_END:
                        curfile.ino = maxino;
                        break;

                case TS_CLRI:
                        curfile.name = "<file removal list>";
                        break;

                case TS_BITS:
                        curfile.name = "<file dump list>";
                        break;

                case TS_TAPE:
                        panic("unexpected tape header\n");
                        /* NOTREACHED */

                default:
                        panic("unknown tape header type %d\n", spcl.c_type);
                        /* NOTREACHED */

                }
        } while (header->c_type == TS_ADDR);
        if (skipcnt > 0)
                fprintf(stderr, "resync restore, skipped %ld blocks\n", skipcnt);
        skipcnt = 0;
}

static int
checksum(int *buf)
{
        int i, j;

        j = sizeof(union u_spcl) / sizeof(int);
        i = 0;
        if (!Bcvt) {
                do
                        i += *buf++;
                while (--j);
        } else {
                do
                        i += swap32(*buf++);
                while (--j);
        }

        if (i != CHECKSUM) {
                fprintf(stderr, "Checksum error %o, inode %llu file %s\n", i,
                    (unsigned long long)curfile.ino, curfile.name);
                return(FAIL);
        }
        return(GOOD);
}

#ifdef RRESTORE
#include <stdarg.h>

void
msg(const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        (void)vfprintf(stderr, fmt, ap);
        va_end(ap);
}
#endif /* RRESTORE */

static void
swap_header(struct s_spcl *s)
{
        s->c_type = swap32(s->c_type);
        s->c_old_date = swap32(s->c_old_date);
        s->c_old_ddate = swap32(s->c_old_ddate);
        s->c_volume = swap32(s->c_volume);
        s->c_old_tapea = swap32(s->c_old_tapea);
        s->c_inumber = swap32(s->c_inumber);
        s->c_magic = swap32(s->c_magic);
        s->c_checksum = swap32(s->c_checksum);

        s->c_mode = swap16(s->c_mode);
        s->c_size = swap64(s->c_size);
        s->c_old_atime = swap32(s->c_old_atime);
        s->c_atimensec = swap32(s->c_atimensec);
        s->c_old_mtime = swap32(s->c_old_mtime);
        s->c_mtimensec = swap32(s->c_mtimensec);
        s->c_rdev = swap32(s->c_rdev);
        s->c_birthtimensec = swap32(s->c_birthtimensec);
        s->c_birthtime = swap64(s->c_birthtime);
        s->c_atime = swap64(s->c_atime);
        s->c_mtime = swap64(s->c_mtime);
        s->c_file_flags = swap32(s->c_file_flags);
        s->c_uid = swap32(s->c_uid);
        s->c_gid = swap32(s->c_gid);

        s->c_count = swap32(s->c_count);
        s->c_level = swap32(s->c_level);
        s->c_flags = swap32(s->c_flags);
        s->c_old_firstrec = swap32(s->c_old_firstrec);

        s->c_date = swap64(s->c_date);
        s->c_ddate = swap64(s->c_ddate);
        s->c_tapea = swap64(s->c_tapea);
        s->c_firstrec = swap64(s->c_firstrec);

        /*
         * These are ouid and ogid.
         */
        s->c_spare1[1] = swap16(s->c_spare1[1]);
        s->c_spare1[2] = swap16(s->c_spare1[2]);
}

static void
swap_old_header(struct s_ospcl *os)
{
        os->c_type = swap32(os->c_type);
        os->c_date = swap32(os->c_date);
        os->c_ddate = swap32(os->c_ddate);
        os->c_volume = swap32(os->c_volume);
        os->c_tapea = swap32(os->c_tapea);
        os->c_inumber = swap16(os->c_inumber);
        os->c_magic = swap32(os->c_magic);
        os->c_checksum = swap32(os->c_checksum);

        os->c_odinode.odi_mode = swap16(os->c_odinode.odi_mode);
        os->c_odinode.odi_nlink = swap16(os->c_odinode.odi_nlink);
        os->c_odinode.odi_uid = swap16(os->c_odinode.odi_uid);
        os->c_odinode.odi_gid = swap16(os->c_odinode.odi_gid);

        os->c_odinode.odi_size = swap32(os->c_odinode.odi_size);
        os->c_odinode.odi_rdev = swap32(os->c_odinode.odi_rdev);
        os->c_odinode.odi_atime = swap32(os->c_odinode.odi_atime);
        os->c_odinode.odi_mtime = swap32(os->c_odinode.odi_mtime);
        os->c_odinode.odi_ctime = swap32(os->c_odinode.odi_ctime);

        os->c_count = swap32(os->c_count);
}