/*      $OpenBSD: restore.c,v 1.18 2023/03/08 04:43:07 guenther Exp $   */
/*      $NetBSD: restore.c,v 1.9 1997/06/18 07:10:16 lukem Exp $        */

/*
 * Copyright (c) 1983, 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/types.h>
#include <sys/stat.h>

#include <ufs/ufs/dinode.h>

#include <stdio.h>
#include <string.h>

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

static char *keyval(int);

/*
 * This implements the 't' option.
 * List entries on the tape.
 */
long
listfile(char *name, ino_t ino, int type)
{
        long descend = hflag ? GOOD : FAIL;

        if (TSTINO(ino, dumpmap) == 0)
                return (descend);
        Vprintf(stdout, "%s", type == LEAF ? "leaf" : "dir ");
        fprintf(stdout, "%10llu\t%s\n", (unsigned long long)ino, name);
        return (descend);
}

/*
 * This implements the 'x' option.
 * Request that new entries be extracted.
 */
long
addfile(char *name, ino_t ino, int type)
{
        struct entry *ep;
        long descend = hflag ? GOOD : FAIL;
        char buf[100];

        if (TSTINO(ino, dumpmap) == 0) {
                Dprintf(stdout, "%s: not on the tape\n", name);
                return (descend);
        }
        if (!mflag) {
                (void)snprintf(buf, sizeof(buf), "./%llu",
                    (unsigned long long)ino);
                name = buf;
                if (type == NODE) {
                        (void)genliteraldir(name, ino);
                        return (descend);
                }
        }
        ep = lookupino(ino);
        if (ep != NULL) {
                if (strcmp(name, myname(ep)) == 0) {
                        ep->e_flags |= NEW;
                        return (descend);
                }
                type |= LINK;
        }
        ep = addentry(name, ino, type);
        if (type == NODE)
                newnode(ep);
        ep->e_flags |= NEW;
        return (descend);
}

/*
 * This is used by the 'i' option to undo previous requests made by addfile.
 * Delete entries from the request queue.
 */
long
deletefile(char *name, ino_t ino, int type)
{
        long descend = hflag ? GOOD : FAIL;
        struct entry *ep;

        if (TSTINO(ino, dumpmap) == 0)
                return (descend);
        ep = lookupname(name);
        if (ep != NULL) {
                ep->e_flags &= ~NEW;
                ep->e_flags |= REMOVED;
                if (ep->e_type != NODE)
                        freeentry(ep);
        }
        return (descend);
}

/*
 * The following four routines implement the incremental
 * restore algorithm. The first removes old entries, the second
 * does renames and calculates the extraction list, the third
 * cleans up link names missed by the first two, and the final
 * one deletes old directories.
 *
 * Directories cannot be immediately deleted, as they may have
 * other files in them which need to be moved out first. As
 * directories to be deleted are found, they are put on the
 * following deletion list. After all deletions and renames
 * are done, this list is actually deleted.
 */
static struct entry *removelist;

/*
 *      Remove unneeded leaves from the old tree.
 *      Remove directories from the lookup chains.
 */
void
removeoldleaves(void)
{
        struct entry *ep;
        ino_t i;

        Vprintf(stdout, "Mark entries to be removed.\n");
        for (i = ROOTINO + 1; i < maxino; i++) {
                ep = lookupino(i);
                if (ep == NULL)
                        continue;
                if (TSTINO(i, usedinomap))
                        continue;
                for ( ; ep != NULL; ep = ep->e_links) {
                        Dprintf(stdout, "%s: REMOVE\n", myname(ep));
                        if (ep->e_type == LEAF) {
                                removeleaf(ep);
                                freeentry(ep);
                        } else {
                                mktempname(ep);
                                deleteino(ep->e_ino);
                                ep->e_next = removelist;
                                removelist = ep;
                        }
                }
        }
}

/*
 *      For each directory entry on the incremental tape, determine which
 *      category it falls into as follows:
 *      KEEP - entries that are to be left alone.
 *      NEW - new entries to be added.
 *      EXTRACT - files that must be updated with new contents.
 *      LINK - new links to be added.
 *      Renames are done at the same time.
 */
long
nodeupdates(char *name, ino_t ino, int type)
{
        struct entry *ep, *np, *ip;
        long descend = GOOD;
        int lookuptype = 0;
        int key = 0;
                /* key values */
#               define ONTAPE   0x1     /* inode is on the tape */
#               define INOFND   0x2     /* inode already exists */
#               define NAMEFND  0x4     /* name already exists */
#               define MODECHG  0x8     /* mode of inode changed */

        /*
         * This routine is called once for each element in the
         * directory hierarchy, with a full path name.
         * The "type" value is incorrectly specified as LEAF for
         * directories that are not on the dump tape.
         *
         * Check to see if the file is on the tape.
         */
        if (TSTINO(ino, dumpmap))
                key |= ONTAPE;
        /*
         * Check to see if the name exists, and if the name is a link.
         */
        np = lookupname(name);
        if (np != NULL) {
                key |= NAMEFND;
                ip = lookupino(np->e_ino);
                if (ip == NULL)
                        panic("corrupted symbol table\n");
                if (ip != np)
                        lookuptype = LINK;
        }
        /*
         * Check to see if the inode exists, and if one of its links
         * corresponds to the name (if one was found).
         */
        ip = lookupino(ino);
        if (ip != NULL) {
                key |= INOFND;
                for (ep = ip->e_links; ep != NULL; ep = ep->e_links) {
                        if (ep == np) {
                                ip = ep;
                                break;
                        }
                }
        }
        /*
         * If both a name and an inode are found, but they do not
         * correspond to the same file, then both the inode that has
         * been found and the inode corresponding to the name that
         * has been found need to be renamed. The current pathname
         * is the new name for the inode that has been found. Since
         * all files to be deleted have already been removed, the
         * named file is either a now unneeded link, or it must live
         * under a new name in this dump level. If it is a link, it
         * can be removed. If it is not a link, it is given a
         * temporary name in anticipation that it will be renamed
         * when it is later found by inode number.
         */
        if (((key & (INOFND|NAMEFND)) == (INOFND|NAMEFND)) && ip != np) {
                if (lookuptype == LINK) {
                        removeleaf(np);
                        freeentry(np);
                } else {
                        Dprintf(stdout, "name/inode conflict, mktempname %s\n",
                                myname(np));
                        mktempname(np);
                }
                np = NULL;
                key &= ~NAMEFND;
        }
        if ((key & ONTAPE) &&
          (((key & INOFND) && ip->e_type != type) ||
           ((key & NAMEFND) && np->e_type != type)))
                key |= MODECHG;

        /*
         * Decide on the disposition of the file based on its flags.
         * Note that we have already handled the case in which
         * a name and inode are found that correspond to different files.
         * Thus if both NAMEFND and INOFND are set then ip == np.
         */
        switch (key) {

        /*
         * A previously existing file has been found.
         * Mark it as KEEP so that other links to the inode can be
         * detected, and so that it will not be reclaimed by the search
         * for unreferenced names.
         */
        case INOFND|NAMEFND:
                ip->e_flags |= KEEP;
                Dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
                        flagvalues(ip));
                break;

        /*
         * A file on the tape has a name which is the same as a name
         * corresponding to a different file in the previous dump.
         * Since all files to be deleted have already been removed,
         * this file is either a now unneeded link, or it must live
         * under a new name in this dump level. If it is a link, it
         * can simply be removed. If it is not a link, it is given a
         * temporary name in anticipation that it will be renamed
         * when it is later found by inode number (see INOFND case
         * below). The entry is then treated as a new file.
         */
        case ONTAPE|NAMEFND:
        case ONTAPE|NAMEFND|MODECHG:
                if (lookuptype == LINK) {
                        removeleaf(np);
                        freeentry(np);
                } else {
                        mktempname(np);
                }
                /* fall through */

        /*
         * A previously non-existent file.
         * Add it to the file system, and request its extraction.
         * If it is a directory, create it immediately.
         * (Since the name is unused there can be no conflict)
         */
        case ONTAPE:
                ep = addentry(name, ino, type);
                if (type == NODE)
                        newnode(ep);
                ep->e_flags |= NEW|KEEP;
                Dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
                        flagvalues(ep));
                break;

        /*
         * A file with the same inode number, but a different
         * name has been found. If the other name has not already
         * been found (indicated by the KEEP flag, see above) then
         * this must be a new name for the file, and it is renamed.
         * If the other name has been found then this must be a
         * link to the file. Hard links to directories are not
         * permitted, and are either deleted or converted to
         * symbolic links. Finally, if the file is on the tape,
         * a request is made to extract it.
         */
        case ONTAPE|INOFND:
                if (type == LEAF && (ip->e_flags & KEEP) == 0)
                        ip->e_flags |= EXTRACT;
                /* fall through */
        case INOFND:
                if ((ip->e_flags & KEEP) == 0) {
                        renameit(myname(ip), name);
                        moveentry(ip, name);
                        ip->e_flags |= KEEP;
                        Dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
                                flagvalues(ip));
                        break;
                }
                if (ip->e_type == NODE) {
                        descend = FAIL;
                        fprintf(stderr,
                                "deleted hard link %s to directory %s\n",
                                name, myname(ip));
                        break;
                }
                ep = addentry(name, ino, type|LINK);
                ep->e_flags |= NEW;
                Dprintf(stdout, "[%s] %s: %s|LINK\n", keyval(key), name,
                        flagvalues(ep));
                break;

        /*
         * A previously known file which is to be updated. If it is a link,
         * then all names referring to the previous file must be removed
         * so that the subset of them that remain can be recreated.
         */
        case ONTAPE|INOFND|NAMEFND:
                if (lookuptype == LINK) {
                        removeleaf(np);
                        freeentry(np);
                        ep = addentry(name, ino, type|LINK);
                        if (type == NODE)
                                newnode(ep);
                        ep->e_flags |= NEW|KEEP;
                        Dprintf(stdout, "[%s] %s: %s|LINK\n", keyval(key), name,
                                flagvalues(ep));
                        break;
                }
                if (type == LEAF && lookuptype != LINK)
                        np->e_flags |= EXTRACT;
                np->e_flags |= KEEP;
                Dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
                        flagvalues(np));
                break;

        /*
         * An inode is being reused in a completely different way.
         * Normally an extract can simply do an "unlink" followed
         * by a "creat". Here we must do effectively the same
         * thing. The complications arise because we cannot really
         * delete a directory since it may still contain files
         * that we need to rename, so we delete it from the symbol
         * table, and put it on the list to be deleted eventually.
         * Conversely if a directory is to be created, it must be
         * done immediately, rather than waiting until the
         * extraction phase.
         */
        case ONTAPE|INOFND|MODECHG:
        case ONTAPE|INOFND|NAMEFND|MODECHG:
                if (ip->e_flags & KEEP) {
                        badentry(ip, "cannot KEEP and change modes");
                        break;
                }
                if (ip->e_type == LEAF) {
                        /* changing from leaf to node */
                        for ( ; ip != NULL; ip = ip->e_links) {
                                if (ip->e_type != LEAF)
                                        badentry(ip,
                                           "NODE and LEAF links to same inode");
                                removeleaf(ip);
                                freeentry(ip);
                        }
                        ip = addentry(name, ino, type);
                        newnode(ip);
                } else {
                        /* changing from node to leaf */
                        if ((ip->e_flags & TMPNAME) == 0)
                                mktempname(ip);
                        deleteino(ip->e_ino);
                        ip->e_next = removelist;
                        removelist = ip;
                        ip = addentry(name, ino, type);
                }
                ip->e_flags |= NEW|KEEP;
                Dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
                        flagvalues(ip));
                break;

        /*
         * A hard link to a diirectory that has been removed.
         * Ignore it.
         */
        case NAMEFND:
                Dprintf(stdout, "[%s] %s: Extraneous name\n", keyval(key),
                        name);
                descend = FAIL;
                break;

        /*
         * If we find a directory entry for a file that is not on
         * the tape, then we must have found a file that was created
         * while the dump was in progress. Since we have no contents
         * for it, we discard the name knowing that it will be on the
         * next incremental tape.
         */
        case 0:
                fprintf(stderr, "%s: (inode %llu) not found on tape\n",
                        name, (unsigned long long)ino);
                break;

        /*
         * If any of these arise, something is grievously wrong with
         * the current state of the symbol table.
         */
        case INOFND|NAMEFND|MODECHG:
        case NAMEFND|MODECHG:
        case INOFND|MODECHG:
                fprintf(stderr, "[%s] %s: inconsistent state\n", keyval(key),
                        name);
                break;

        /*
         * These states "cannot" arise for any state of the symbol table.
         */
        case ONTAPE|MODECHG:
        case MODECHG:
        default:
                panic("[%s] %s: impossible state\n", keyval(key), name);
                break;
        }
        return (descend);
}

/*
 * Calculate the active flags in a key.
 */
static char *
keyval(int key)
{
        static char keybuf[32];

        (void)strlcpy(keybuf, "|NIL", sizeof keybuf);
        keybuf[0] = '\0';
        if (key & ONTAPE)
                (void)strlcat(keybuf, "|ONTAPE", sizeof keybuf);
        if (key & INOFND)
                (void)strlcat(keybuf, "|INOFND", sizeof keybuf);
        if (key & NAMEFND)
                (void)strlcat(keybuf, "|NAMEFND", sizeof keybuf);
        if (key & MODECHG)
                (void)strlcat(keybuf, "|MODECHG", sizeof keybuf);
        return (&keybuf[1]);
}

/*
 * Find unreferenced link names.
 */
void
findunreflinks(void)
{
        struct entry *ep, *np;
        ino_t i;

        Vprintf(stdout, "Find unreferenced names.\n");
        for (i = ROOTINO; i < maxino; i++) {
                ep = lookupino(i);
                if (ep == NULL || ep->e_type == LEAF || TSTINO(i, dumpmap) == 0)
                        continue;
                for (np = ep->e_entries; np != NULL; np = np->e_sibling) {
                        if (np->e_flags == 0) {
                                Dprintf(stdout,
                                    "%s: remove unreferenced name\n",
                                    myname(np));
                                removeleaf(np);
                                freeentry(np);
                        }
                }
        }
        /*
         * Any leaves remaining in removed directories is unreferenced.
         */
        for (ep = removelist; ep != NULL; ep = ep->e_next) {
                for (np = ep->e_entries; np != NULL; np = np->e_sibling) {
                        if (np->e_type == LEAF) {
                                if (np->e_flags != 0)
                                        badentry(np, "unreferenced with flags");
                                Dprintf(stdout,
                                    "%s: remove unreferenced name\n",
                                    myname(np));
                                removeleaf(np);
                                freeentry(np);
                        }
                }
        }
}

/*
 * Remove old nodes (directories).
 * Note that this routine runs in O(N*D) where:
 *      N is the number of directory entries to be removed.
 *      D is the maximum depth of the tree.
 * If N == D this can be quite slow. If the list were
 * topologically sorted, the deletion could be done in
 * time O(N).
 */
void
removeoldnodes(void)
{
        struct entry *ep, **prev;
        long change;

        Vprintf(stdout, "Remove old nodes (directories).\n");
        do      {
                change = 0;
                prev = &removelist;
                for (ep = removelist; ep != NULL; ep = *prev) {
                        if (ep->e_entries != NULL) {
                                prev = &ep->e_next;
                                continue;
                        }
                        *prev = ep->e_next;
                        removenode(ep);
                        freeentry(ep);
                        change++;
                }
        } while (change);
        for (ep = removelist; ep != NULL; ep = ep->e_next)
                badentry(ep, "cannot remove, non-empty");
}

/*
 * This is the routine used to extract files for the 'r' command.
 * Extract new leaves.
 */
void
createleaves(char *symtabfile)
{
        struct entry *ep;
        ino_t first;
        long curvol;

        if (command == 'R') {
                Vprintf(stdout, "Continue extraction of new leaves\n");
        } else {
                Vprintf(stdout, "Extract new leaves.\n");
                dumpsymtable(symtabfile, volno);
        }
        first = lowerbnd(ROOTINO);
        curvol = volno;
        while (curfile.ino < maxino) {
                first = lowerbnd(first);
                /*
                 * If the next available file is not the one which we
                 * expect then we have missed one or more files. Since
                 * we do not request files that were not on the tape,
                 * the lost files must have been due to a tape read error,
                 * or a file that was removed while the dump was in progress.
                 */
                while (first < curfile.ino) {
                        ep = lookupino(first);
                        if (ep == NULL)
                                panic("%llu: bad first\n",
                            (unsigned long long)first);
                        fprintf(stderr, "%s: not found on tape\n", myname(ep));
                        ep->e_flags &= ~(NEW|EXTRACT);
                        first = lowerbnd(first);
                }
                /*
                 * If we find files on the tape that have no corresponding
                 * directory entries, then we must have found a file that
                 * was created while the dump was in progress. Since we have
                 * no name for it, we discard it knowing that it will be
                 * on the next incremental tape.
                 */
                if (first != curfile.ino) {
                        fprintf(stderr, "expected next file %llu, got %llu\n",
                            (unsigned long long)first,
                            (unsigned long long)curfile.ino);
                        skipfile();
                        goto next;
                }
                ep = lookupino(curfile.ino);
                if (ep == NULL)
                        panic("unknown file on tape\n");
                if ((ep->e_flags & (NEW|EXTRACT)) == 0)
                        badentry(ep, "unexpected file on tape");
                /*
                 * If the file is to be extracted, then the old file must
                 * be removed since its type may change from one leaf type
                 * to another (eg "file" to "character special").
                 */
                if ((ep->e_flags & EXTRACT) != 0) {
                        removeleaf(ep);
                        ep->e_flags &= ~REMOVED;
                }
                (void)extractfile(myname(ep));
                ep->e_flags &= ~(NEW|EXTRACT);
                /*
                 * We checkpoint the restore after every tape reel, so
                 * as to simplify the amount of work re quired by the
                 * 'R' command.
                 */
        next:
                if (curvol != volno) {
                        dumpsymtable(symtabfile, volno);
                        skipmaps();
                        curvol = volno;
                }
        }
}

/*
 * This is the routine used to extract files for the 'x' and 'i' commands.
 * Efficiently extract a subset of the files on a tape.
 */
void
createfiles(void)
{
        ino_t first, next, last;
        struct entry *ep;
        long curvol;

        Vprintf(stdout, "Extract requested files\n");
        curfile.action = SKIP;
        getvol((long)1);
        skipmaps();
        skipdirs();
        first = lowerbnd(ROOTINO);
        last = upperbnd(maxino - 1);
        for (;;) {
                first = lowerbnd(first);
                last = upperbnd(last);
                /*
                 * Check to see if any files remain to be extracted
                 */
                if (first > last)
                        return;
                /*
                 * Reject any volumes with inodes greater
                 * than the last one needed
                 */
                while (curfile.ino > last) {
                        curfile.action = SKIP;
                        getvol((long)0);
                        skipmaps();
                        skipdirs();
                }
                /*
                 * Decide on the next inode needed.
                 * Skip across the inodes until it is found
                 * or an out of order volume change is encountered
                 */
                next = lowerbnd(curfile.ino);
                do      {
                        curvol = volno;
                        while (next > curfile.ino && volno == curvol)
                                skipfile();
                        skipmaps();
                        skipdirs();
                } while (volno == curvol + 1);
                /*
                 * If volume change out of order occurred the
                 * current state must be recalculated
                 */
                if (volno != curvol)
                        continue;
                /*
                 * If the current inode is greater than the one we were
                 * looking for then we missed the one we were looking for.
                 * Since we only attempt to extract files listed in the
                 * dump map, the lost files must have been due to a tape
                 * read error, or a file that was removed while the dump
                 * was in progress. Thus we report all requested files
                 * between the one we were looking for, and the one we
                 * found as missing, and delete their request flags.
                 */
                while (next < curfile.ino) {
                        ep = lookupino(next);
                        if (ep == NULL)
                                panic("corrupted symbol table\n");
                        fprintf(stderr, "%s: not found on tape\n", myname(ep));
                        ep->e_flags &= ~NEW;
                        next = lowerbnd(next);
                }
                /*
                 * The current inode is the one that we are looking for,
                 * so extract it per its requested name.
                 */
                if (next == curfile.ino && next <= last) {
                        ep = lookupino(next);
                        if (ep == NULL)
                                panic("corrupted symbol table\n");
                        (void)extractfile(myname(ep));
                        ep->e_flags &= ~NEW;
                        if (volno != curvol)
                                skipmaps();
                }
        }
}

/*
 * Add links.
 */
void
createlinks(void)
{
        struct entry *np, *ep;
        ino_t i;
        char name[BUFSIZ];

        Vprintf(stdout, "Add links\n");
        for (i = ROOTINO; i < maxino; i++) {
                ep = lookupino(i);
                if (ep == NULL)
                        continue;
                for (np = ep->e_links; np != NULL; np = np->e_links) {
                        if ((np->e_flags & NEW) == 0)
                                continue;
                        (void)strlcpy(name, myname(ep), sizeof name);
                        if (ep->e_type == NODE) {
                                (void)linkit(name, myname(np), SYMLINK);
                        } else {
                                (void)linkit(name, myname(np), HARDLINK);
                        }
                        np->e_flags &= ~NEW;
                }
        }
}

/*
 * Check the symbol table.
 * We do this to insure that all the requested work was done, and
 * that no temporary names remain.
 */
void
checkrestore(void)
{
        struct entry *ep;
        ino_t i;

        Vprintf(stdout, "Check the symbol table.\n");
        for (i = ROOTINO; i < maxino; i++) {
                for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
                        ep->e_flags &= ~KEEP;
                        if (ep->e_type == NODE)
                                ep->e_flags &= ~(NEW|EXISTED);
                        if (ep->e_flags != 0)
                                badentry(ep, "incomplete operations");
                }
        }
}

/*
 * Compare with the directory structure on the tape
 * A paranoid check that things are as they should be.
 */
long
verifyfile(char *name, ino_t ino, int type)
{
        struct entry *np, *ep;
        long descend = GOOD;

        ep = lookupname(name);
        if (ep == NULL) {
                fprintf(stderr, "Warning: missing name %s\n", name);
                return (FAIL);
        }
        np = lookupino(ino);
        if (np != ep)
                descend = FAIL;
        for ( ; np != NULL; np = np->e_links)
                if (np == ep)
                        break;
        if (np == NULL)
                panic("missing inumber %llu\n", (unsigned long long)ino);
        if (ep->e_type == LEAF && type != LEAF)
                badentry(ep, "type should be LEAF");
        return (descend);
}