/*-
 * 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/param.h>
#include <sys/stat.h>
#include <sys/time.h>
#ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
#include <sys/mman.h>
#endif

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

#include "extern.h"

#define cp_pct(x, y)    ((y == 0) ? 0 : (int)(100.0 * (x) / (y)))


int
copy_file(const FTSENT *entp, int dne)
{
        static char buf[MAXBSIZE];
        struct stat *fs;
        ssize_t wcount, rcount;
        size_t wresid;
        off_t wtotal;
        int ch, checkch, from_fd = 0, rval, to_fd = 0;
        char *bufp;
#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) {
#define YESNO "(y/n [n]) "
                if (nflag) {
                        if (vflag)
                                printf("%s not overwritten\n", to.p_path);
                        close(from_fd);
                        return (0);
                } else if (iflag) {
                        fprintf(stderr, "overwrite %s? %s",
                                        to.p_path, YESNO);
                        checkch = ch = getchar();
                        while (ch != '\n' && ch != EOF)
                                ch = getchar();
                        if (checkch != 'y' && checkch != 'Y') {
                                close(from_fd);
                                fprintf(stderr, "not overwritten\n");
                                return (1);
                        }
                }
                
                if (fflag) {
                    /* remove existing destination file name, 
                     * create a new file  */
                    unlink(to.p_path);
                    if (!lflag)
                        to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
                            fs->st_mode & ~(S_ISUID | S_ISGID));
                } else {
                    if (!lflag)
                        /* overwrite existing destination file name */
                            to_fd = open(to.p_path, O_WRONLY | O_TRUNC, 0);
                }
        } else {
                if (!lflag)
                        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);
                close(from_fd);
                return (1);
        }

        rval = 0;

        if (!lflag) {
        /*
                 * 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.
                 * Some filesystems, such as smbnetfs, don't support mmap,
                 * so this is a best-effort attempt.
         */
#ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
                if (S_ISREG(fs->st_mode) && fs->st_size > 0 &&
                    fs->st_size <= 8 * 1024 * 1024 &&
                    (p = mmap(NULL, (size_t)fs->st_size, PROT_READ,
                    MAP_SHARED, from_fd, (off_t)0)) != MAP_FAILED) {
                        wtotal = 0;
                        for (bufp = p, wresid = fs->st_size; ;
                            bufp += wcount, wresid -= (size_t)wcount) {
                                wcount = write(to_fd, bufp, wresid);
                                if (wcount <= 0)
                                        break;
                                wtotal += wcount;
                                if (info) {
                                        info = 0;
                                        fprintf(stderr,
                                            "%s -> %s %3d%%\n",
                                            entp->fts_path, to.p_path,
                                            cp_pct(wtotal, fs->st_size));
                                }
                                if (wcount >= (ssize_t)wresid)
                                        break;
                        }
                        if (wcount != (ssize_t)wresid) {
                                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
                {
                        wtotal = 0;
                        while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
                                for (bufp = buf, wresid = rcount; ;
                                    bufp += wcount, wresid -= wcount) {
                                        wcount = write(to_fd, bufp, wresid);
                                        if (wcount <= 0)
                                                break;
                                        wtotal += wcount;
                                        if (info) {
                                                info = 0;
                                                fprintf(stderr,
                                                    "%s -> %s %3d%%\n",
                                                    entp->fts_path, to.p_path,
                                                    cp_pct(wtotal, fs->st_size));
                                        }
                                        if (wcount >= (ssize_t)wresid)
                                                break;
                                }
                                if (wcount != (ssize_t)wresid) {
                                        warn("%s", to.p_path);
                                        rval = 1;
                                        break;
                                }
                        }
                        if (rcount < 0) {
                                warn("%s", entp->fts_path);
                                rval = 1;
                        }
                }
        } else {
                if (link(entp->fts_path, to.p_path)) {
                        warn("%s", to.p_path);
                        rval = 1;
                }
        }

        /*
         * Don't remove the target even after an error.  The target might
         * not be a regular file, or its attributes might be important,
         * or its contents might be irreplaceable.  It would only be safe
         * to remove it if we created it and its length is 0.
         */

        if (!lflag) {
                if (pflag && setfile(fs, to_fd))
                        rval = 1;
                if (close(to_fd)) {
                        warn("%s", to.p_path);
                        rval = 1;
                }
        }

        close(from_fd);

        return (rval);
}

int
copy_link(const FTSENT *p, int exists)
{
        int len;
        char llink[PATH_MAX];

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

int
setfile(struct stat *fs, int fd)
{
        static struct timeval tv[2];
        struct stat ts;
        int rval, gotstat, islink, fdval;

        rval = 0;
        fdval = fd != -1;
        islink = !fdval && S_ISLNK(fs->st_mode);
        fs->st_mode &= S_ISUID | S_ISGID | S_ISVTX |
                       S_IRWXU | S_IRWXG | S_IRWXO;

        TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
        TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
        if (islink ? lutimes(to.p_path, tv) : utimes(to.p_path, tv)) {
                warn("%sutimes: %s", islink ? "l" : "", to.p_path);
                rval = 1;
        }
        if (fdval ? fstat(fd, &ts) :
            (islink ? lstat(to.p_path, &ts) : stat(to.p_path, &ts)))
                gotstat = 0;
        else {
                gotstat = 1;
                ts.st_mode &= S_ISUID | S_ISGID | S_ISVTX |
                              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 (!gotstat || fs->st_uid != ts.st_uid || fs->st_gid != ts.st_gid)
                if (fdval ? fchown(fd, fs->st_uid, fs->st_gid) :
                    (islink ? lchown(to.p_path, 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 (!gotstat || fs->st_mode != ts.st_mode)
                if (fdval ? fchmod(fd, fs->st_mode) :
                    (islink ? lchmod(to.p_path, fs->st_mode) :
                    chmod(to.p_path, fs->st_mode))) {
                        warn("chmod: %s", to.p_path);
                        rval = 1;
                }

#ifdef _ST_FLAGS_PRESENT_
        if (!gotstat || fs->st_flags != ts.st_flags)
                if (fdval ?
                    fchflags(fd, fs->st_flags) :
                    (islink ? lchflags(to.p_path, fs->st_flags) :
                    chflags(to.p_path, fs->st_flags))) {
                        warn("chflags: %s", to.p_path);
                        rval = 1;
                }
#endif

        return (rval);
}

void
usage(void)
{

        fprintf(stderr, "%s\n%s\n",
"usage: cp [-R [-H | -L | -P]] [-f | -i | -n] [-alpvx] source_file target_file",
"       cp [-R [-H | -L | -P]] [-f | -i | -n] [-alpvx] source_file ... "
"target_directory");
        exit(EX_USAGE);
}