usr/src/bin/cp/utils.c

/*-
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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.
 */

#ifndef lint
static char sccsid[] = "@(#)utils.c     8.3 (Berkeley) 4/1/94";
#endif /* not lint */

#include <sys/param.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/time.h>

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

#include "extern.h"

int
copy_file(entp, dne)
        FTSENT *entp;
        int dne;
{
        static char buf[MAXBSIZE];
        struct stat to_stat, *fs;
        int ch, checkch, from_fd, rcount, rval, to_fd, wcount;
#ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
        char *p;
#endif

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

        fs = entp->fts_statp;

        /*
         * 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) {
                if (iflag) {
                        (void)fprintf(stderr, "overwrite %s? ", to.p_path);
                        checkch = ch = getchar();
                        while (ch != '\n' && ch != EOF)
                                ch = getchar();
                        if (checkch != 'y') {
                                (void)close(from_fd);
                                return (0);
                        }
                }
                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) {
                warn("%s", to.p_path);
                (void)close(from_fd);
                return (1);;
        }

        rval = 0;

        /*
         * 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.
         */
#ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
        if (fs->st_size <= 8 * 1048576) {
                if ((p = mmap(NULL, (size_t)fs->st_size, PROT_READ,
                    0, from_fd, (off_t)0)) == (char *)-1) {
                        warn("%s", entp->fts_path);
                        rval = 1;
                } else {
                        if (write(to_fd, p, fs->st_size) != fs->st_size) {
                                warn("%s", to.p_path);
                                rval = 1;
                        }
                        /* Some systems don't unmap on close(2). */
                        if (munmap(p, fs->st_size) < 0) {
                                warn("%s", entp->fts_path);
                                rval = 1;
                        }
                }
        } else
#endif
        {
                while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
                        wcount = write(to_fd, buf, rcount);
                        if (rcount != wcount || wcount == -1) {
                                warn("%s", to.p_path);
                                rval = 1;
                                break;
                        }
                }
                if (rcount < 0) {
                        warn("%s", entp->fts_path);
                        rval = 1;
                }
        }

        /* If the copy went bad, lose the file. */
        if (rval == 1) {
                (void)unlink(to.p_path);
                (void)close(from_fd);
                (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)
        else if (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;
                }
        (void)close(from_fd);
        if (close(to_fd)) {
                warn("%s", to.p_path);
                rval = 1;
        }
        return (rval);
}

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

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

int
copy_fifo(from_stat, exists)
        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(from_stat, exists)
        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);
}


int
setfile(fs, fd)
        register struct stat *fs;
        int fd;
{
        static struct timeval tv[2];
        int rval;

        rval = 0;
        fs->st_mode &= S_ISUID | S_ISGID | S_IRWXU | S_IRWXG | S_IRWXO;

        TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
        TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
        if (utimes(to.p_path, tv)) {
                warn("utimes: %s", to.p_path);
                rval = 1;
        }
        /*
         * 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) :
            chown(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) : chmod(to.p_path, fs->st_mode)) {
                warn("chown: %s", to.p_path);
                rval = 1;
        }

        if (fd ?
            fchflags(fd, fs->st_flags) : chflags(to.p_path, fs->st_flags)) {
                warn("chflags: %s", to.p_path);
                rval = 1;
        }
        return (rval);
}

void
usage()
{
        (void)fprintf(stderr, "%s\n%s\n",
"usage: cp [-R [-H | -L | -P] [-fip] src target",
"       cp [-R [-H | -L | -P] [-fip] src1 ... srcN directory");
        exit(1);
}