/* $NetBSD: utils.c,v 1.50 2024/01/15 17:41:06 christos Exp $ */

/*-
 * Copyright (c) 1991, 1993, 1994
 *      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/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)utils.c     8.3 (Berkeley) 4/1/94";
#else
__RCSID("$NetBSD: utils.c,v 1.50 2024/01/15 17:41:06 christos Exp $");
#endif
#endif /* not lint */

#define _ACL_PRIVATE
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/time.h>
#ifndef SMALL
#include <sys/acl.h>
#endif
#include <sys/extattr.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <fts.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "extern.h"

#define MMAP_MAX_SIZE   (8 * 1048576)
#define MMAP_MAX_WRITE  (64 * 1024)

int
set_utimes(const char *file, struct stat *fs)
{
    struct timespec ts[2];

    ts[0] = fs->st_atimespec;
    ts[1] = fs->st_mtimespec;

    if (lutimens(file, ts)) {
        warn("lutimens: %s", file);
        return (1);
    }
    return (0);
}

struct finfo {
        const char *from;
        const char *to;
        off_t size;
};

static void
progress(const struct finfo *fi, off_t written)
{
        int pcent = (int)((100.0 * written) / fi->size);

        pinfo = 0;
        (void)fprintf(stderr, "%s => %s %llu/%llu bytes %d%% written\n",
            fi->from, fi->to, (unsigned long long)written,
            (unsigned long long)fi->size, pcent);
}

int
copy_file(FTSENT *entp, int dne)
{
        static char buf[MAXBSIZE];
        struct stat to_stat, *fs;
        int ch, checkch, from_fd, rcount, rval, to_fd, tolnk, wcount;
        char *p;
        off_t ptotal = 0;

        /* if hard linking then simply link and return */
        if (lflag) {
                (void)unlink(to.p_path);
                if (link(entp->fts_path, to.p_path)) {
                        warn("%s", to.p_path);
                        return (1);
                }
                return (0);
        }

        if ((from_fd = open(entp->fts_path, O_RDONLY, 0)) == -1) {
                warn("%s", entp->fts_path);
                return (1);
        }

        to_fd = -1;
        fs = entp->fts_statp;
        tolnk = ((Rflag && !(Lflag || Hflag)) || Pflag);

        /*
         * If the file exists and we're interactive, verify with the user.
         * If the file DNE, set the mode to be the from file, minus setuid
         * bits, modified by the umask; arguably wrong, but it makes copying
         * executables work right and it's been that way forever.  (The
         * other choice is 666 or'ed with the execute bits on the from file
         * modified by the umask.)
         */
        if (!dne) {
                struct stat sb;
                int sval;

                if (iflag) {
                        (void)fprintf(stderr, "overwrite %s? ", to.p_path);
                        checkch = ch = getchar();
                        while (ch != '\n' && ch != EOF)
                                ch = getchar();
                        if (checkch != 'y' && checkch != 'Y') {
                                (void)close(from_fd);
                                return (0);
                        }
                }

                sval = tolnk ?
                        lstat(to.p_path, &sb) : stat(to.p_path, &sb);
                if (sval == -1) {
                        warn("stat: %s", to.p_path);
                        (void)close(from_fd);
                        return (1);
                }

                if (!(tolnk && S_ISLNK(sb.st_mode)))
                        to_fd = open(to.p_path, O_WRONLY | O_TRUNC, 0);
        } else
                to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
                    fs->st_mode & ~(S_ISUID | S_ISGID));

        if (to_fd == -1 && (fflag || tolnk)) {
                /*
                 * attempt to remove existing destination file name and
                 * create a new file
                 */
                (void)unlink(to.p_path);
                to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
                             fs->st_mode & ~(S_ISUID | S_ISGID));
        }

        if (to_fd == -1) {
                warn("%s", to.p_path);
                (void)close(from_fd);
                return (1);
        }

        rval = 0;

        /* 
         * We always copy regular files, even if they appear to be 0-sized
         * because kernfs and procfs don't return file sizes.
         */
        bool need_copy = S_ISREG(fs->st_mode) || fs->st_size > 0;

        struct finfo fi;

        fi.from = entp->fts_path;
        fi.to = to.p_path;
        fi.size = fs->st_size;

        /*
         * Mmap and write if less than 8M (the limit is so
         * we don't totally trash memory on big files).
         * This is really a minor hack, but it wins some CPU back.
         */
        if (S_ISREG(fs->st_mode) && fs->st_size && fs->st_size <= MMAP_MAX_SIZE) {
                size_t fsize = (size_t)fs->st_size;
                p = mmap(NULL, fsize, PROT_READ, MAP_FILE|MAP_SHARED,
                    from_fd, (off_t)0);
                if (p != MAP_FAILED) {
                        size_t remainder;

                        need_copy = false;

                        (void) madvise(p, (size_t)fs->st_size, MADV_SEQUENTIAL);

                        /*
                         * Write out the data in small chunks to
                         * avoid locking the output file for a
                         * long time if the reading the data from
                         * the source is slow.
                         */
                        remainder = fsize;
                        do {
                                ssize_t chunk;

                                chunk = (remainder > MMAP_MAX_WRITE) ?
                                    MMAP_MAX_WRITE : remainder;
                                if (write(to_fd, &p[fsize - remainder],
                                    chunk) != chunk) {
                                        warn("%s", to.p_path);
                                        rval = 1;
                                        break;
                                }
                                remainder -= chunk;
                                ptotal += chunk;
                                if (pinfo)
                                        progress(&fi, ptotal);
                        } while (remainder > 0);

                        if (munmap(p, fsize) < 0) {
                                warn("%s", entp->fts_path);
                                rval = 1;
                        }
                }
        }

        if (need_copy) {
                while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
                        wcount = write(to_fd, buf, (size_t)rcount);
                        if (rcount != wcount || wcount == -1) {
                                warn("%s", to.p_path);
                                rval = 1;
                                break;
                        }
                        ptotal += wcount;
                        if (pinfo)
                                progress(&fi, ptotal);
                }
                if (rcount < 0) {
                        warn("%s", entp->fts_path);
                        rval = 1;
                }
        }

        if (pflag && (fcpxattr(from_fd, to_fd) != 0))
                warn("%s: error copying extended attributes", to.p_path);

#ifndef SMALL
        if (pflag && preserve_fd_acls(from_fd, to_fd) != 0)
                rval = 1;
#endif

        (void)close(from_fd);

        if (rval == 1) {
                (void)close(to_fd);
                return (1);
        }

        if (pflag && setfile(fs, to_fd))
                rval = 1;
        /*
         * If the source was setuid or setgid, lose the bits unless the
         * copy is owned by the same user and group.
         */
#define RETAINBITS \
        (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
        if (!pflag && dne
            && fs->st_mode & (S_ISUID | S_ISGID) && fs->st_uid == myuid) {
                if (fstat(to_fd, &to_stat)) {
                        warn("%s", to.p_path);
                        rval = 1;
                } else if (fs->st_gid == to_stat.st_gid &&
                    fchmod(to_fd, fs->st_mode & RETAINBITS & ~myumask)) {
                        warn("%s", to.p_path);
                        rval = 1;
                }
        }
        if (close(to_fd)) {
                warn("%s", to.p_path);
                rval = 1;
        }
        /* set the mod/access times now after close of the fd */
        if (pflag && set_utimes(to.p_path, fs)) { 
            rval = 1;
        }
        return (rval);
}

int
copy_link(FTSENT *p, int exists)
{
        int len;
        char target[MAXPATHLEN];

        if ((len = readlink(p->fts_path, target, sizeof(target)-1)) == -1) {
                warn("readlink: %s", p->fts_path);
                return (1);
        }
        target[len] = '\0';
        if (exists && unlink(to.p_path)) {
                warn("unlink: %s", to.p_path);
                return (1);
        }
        if (symlink(target, to.p_path)) {
                warn("symlink: %s", target);
                return (1);
        }
        return (pflag ? setfile(p->fts_statp, 0) : 0);
}

int
copy_fifo(struct stat *from_stat, int exists)
{
        if (exists && unlink(to.p_path)) {
                warn("unlink: %s", to.p_path);
                return (1);
        }
        if (mkfifo(to.p_path, from_stat->st_mode)) {
                warn("mkfifo: %s", to.p_path);
                return (1);
        }
        return (pflag ? setfile(from_stat, 0) : 0);
}

int
copy_special(struct stat *from_stat, int exists)
{
        if (exists && unlink(to.p_path)) {
                warn("unlink: %s", to.p_path);
                return (1);
        }
        if (mknod(to.p_path, from_stat->st_mode, from_stat->st_rdev)) {
                warn("mknod: %s", to.p_path);
                return (1);
        }
        return (pflag ? setfile(from_stat, 0) : 0);
}


/*
 * Function: setfile
 *
 * Purpose:
 *   Set the owner/group/permissions for the "to" file to the information
 *   in the stat structure.  If fd is zero, also call set_utimes() to set
 *   the mod/access times.  If fd is non-zero, the caller must do a utimes
 *   itself after close(fd).
 */
int
setfile(struct stat *fs, int fd)
{
        int rval, islink;

        rval = 0;
        islink = S_ISLNK(fs->st_mode);
        fs->st_mode &= S_ISUID | S_ISGID | S_IRWXU | S_IRWXG | S_IRWXO;

        /*
         * Changing the ownership probably won't succeed, unless we're root
         * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
         * the mode; current BSD behavior is to remove all setuid bits on
         * chown.  If chown fails, lose setuid/setgid bits.
         */
        if (fd ? fchown(fd, fs->st_uid, fs->st_gid) :
            lchown(to.p_path, fs->st_uid, fs->st_gid)) {
                if (errno != EPERM) {
                        warn("chown: %s", to.p_path);
                        rval = 1;
                }
                fs->st_mode &= ~(S_ISUID | S_ISGID);
        }
        if (fd ? fchmod(fd, fs->st_mode) : lchmod(to.p_path, fs->st_mode)) {
                warn("chmod: %s", to.p_path);
                rval = 1;
        }

        if (!islink && !Nflag) {
                unsigned long fflags = fs->st_flags;
                /*
                 * XXX
                 * NFS doesn't support chflags; ignore errors unless
                 * there's reason to believe we're losing bits.
                 * (Note, this still won't be right if the server
                 * supports flags and we were trying to *remove* flags
                 * on a file that we copied, i.e., that we didn't create.)
                 */
                errno = 0;
                if ((fd ? fchflags(fd, fflags) :
                    chflags(to.p_path, fflags)) == -1)
                        if (errno != EOPNOTSUPP || fs->st_flags != 0) {
                                warn("chflags: %s", to.p_path);
                                rval = 1;
                        }
        }
        /* if fd is non-zero, caller must call set_utimes() after close() */
        if (fd == 0 && set_utimes(to.p_path, fs))
            rval = 1;
        return (rval);
}

#ifndef SMALL
int
preserve_fd_acls(int source_fd, int dest_fd)
{
        acl_t acl;
        acl_type_t acl_type;
        int acl_supported = 0, ret, trivial;

        ret = fpathconf(source_fd, _PC_ACL_NFS4);
        if (ret > 0 ) {
                acl_supported = 1;
                acl_type = ACL_TYPE_NFS4;
        } else if (ret < 0 && errno != EINVAL) {
                warn("fpathconf(..., _PC_ACL_NFS4) failed for %s", to.p_path);
                return (1);
        }
        if (acl_supported == 0) {
                ret = fpathconf(source_fd, _PC_ACL_EXTENDED);
                if (ret > 0 ) {
                        acl_supported = 1;
                        acl_type = ACL_TYPE_ACCESS;
                } else if (ret < 0 && errno != EINVAL) {
                        warn("fpathconf(..., _PC_ACL_EXTENDED) failed for %s",
                            to.p_path);
                        return (1);
                }
        }
        if (acl_supported == 0)
                return (0);

        acl = acl_get_fd_np(source_fd, acl_type);
        if (acl == NULL) {
                warn("failed to get acl entries while setting %s", to.p_path);
                return (1);
        }
        if (acl_is_trivial_np(acl, &trivial)) {
                warn("acl_is_trivial() failed for %s", to.p_path);
                acl_free(acl);
                return (1);
        }
        if (trivial) {
                acl_free(acl);
                return (0);
        }
        if (acl_set_fd_np(dest_fd, acl, acl_type) < 0) {
                warn("failed to set acl entries for %s", to.p_path);
                acl_free(acl);
                return (1);
        }
        acl_free(acl);
        return (0);
}

int
preserve_dir_acls(struct stat *fs, char *source_dir, char *dest_dir)
{
        acl_t (*aclgetf)(const char *, acl_type_t);
        int (*aclsetf)(const char *, acl_type_t, acl_t);
        struct acl *aclp;
        acl_t acl;
        acl_type_t acl_type;
        int acl_supported = 0, ret, trivial;

        ret = pathconf(source_dir, _PC_ACL_NFS4);
        if (ret > 0) {
                acl_supported = 1;
                acl_type = ACL_TYPE_NFS4;
        } else if (ret < 0 && errno != EINVAL) {
                warn("fpathconf(..., _PC_ACL_NFS4) failed for %s", source_dir);
                return (1);
        }
        if (acl_supported == 0) {
                ret = pathconf(source_dir, _PC_ACL_EXTENDED);
                if (ret > 0) {
                        acl_supported = 1;
                        acl_type = ACL_TYPE_ACCESS;
                } else if (ret < 0 && errno != EINVAL) {
                        warn("fpathconf(..., _PC_ACL_EXTENDED) failed for %s",
                            source_dir);
                        return (1);
                }
        }
        if (acl_supported == 0)
                return (0);

        /*
         * If the file is a link we will not follow it.
         */
        if (S_ISLNK(fs->st_mode)) {
                aclgetf = acl_get_link_np;
                aclsetf = acl_set_link_np;
        } else {
                aclgetf = acl_get_file;
                aclsetf = acl_set_file;
        }
        if (acl_type == ACL_TYPE_ACCESS) {
                /*
                 * Even if there is no ACL_TYPE_DEFAULT entry here, a zero
                 * size ACL will be returned. So it is not safe to simply
                 * check the pointer to see if the default ACL is present.
                 */
                acl = aclgetf(source_dir, ACL_TYPE_DEFAULT);
                if (acl == NULL) {
                        warn("failed to get default acl entries on %s",
                            source_dir);
                        return (1);
                }
                aclp = &acl->ats_acl;
                if (aclp->acl_cnt != 0 && aclsetf(dest_dir,
                    ACL_TYPE_DEFAULT, acl) < 0) {
                        warn("failed to set default acl entries on %s",
                            dest_dir);
                        acl_free(acl);
                        return (1);
                }
                acl_free(acl);
        }
        acl = aclgetf(source_dir, acl_type);
        if (acl == NULL) {
                warn("failed to get acl entries on %s", source_dir);
                return (1);
        }
        if (acl_is_trivial_np(acl, &trivial)) {
                warn("acl_is_trivial() failed on %s", source_dir);
                acl_free(acl);
                return (1);
        }
        if (trivial) {
                acl_free(acl);
                return (0);
        }
        if (aclsetf(dest_dir, acl_type, acl) < 0) {
                warn("failed to set acl entries on %s", dest_dir);
                acl_free(acl);
                return (1);
        }
        acl_free(acl);
        return (0);
}
#endif

void
usage(void)
{
        (void)fprintf(stderr,
            "usage: %s [-R [-H | -L | -P]] [-f | -i] [-alNpv] src target\n"
            "       %s [-R [-H | -L | -P]] [-f | -i] [-alNpv] src1 ... srcN directory\n",
            getprogname(), getprogname());
        exit(1);
        /* NOTREACHED */
}