cp/utils.c

   1 /*-
   2  * Copyright (c) 1991, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifndef lint
  35 #if 0
  36 static char sccsid[] = "@(#)utils.c     8.3 (Berkeley) 4/1/94";
  37 #endif
  38 #endif /* not lint */
  39 #include <sys/cdefs.h>
  40 __RCSID("$FreeBSD: src/bin/cp/utils.c,v 1.38 2002/07/31 16:52:16 markm Exp $");
  41
  42 #include <sys/param.h>
  43 #include <sys/stat.h>
  44 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
  45 #include <sys/mman.h>
  46 #endif
  47
  48 #include <err.h>
  49 #include <errno.h>
  50 #include <fcntl.h>
  51 #include <fts.h>
  52 #include <limits.h>
  53 #include <stdio.h>
  54 #include <stdlib.h>
  55 #include <sysexits.h>
  56 #include <unistd.h>
  57
  58 #include "extern.h"
  59
  60 int
  61 copy_file(FTSENT *entp, int dne)
  62 {
  63         static char buf[MAXBSIZE];
  64         struct stat *fs;
  65         int ch, checkch, from_fd, rcount, rval, to_fd;
  66         ssize_t wcount;
  67         size_t wresid;
  68         char *bufp;
  69 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
  70         char *p;
  71 #endif
  72
  73         if ((from_fd = open(entp->fts_path, O_RDONLY, 0)) == -1) {
  74                 warn("%s", entp->fts_path);
  75                 return (1);
  76         }
  77
  78         fs = entp->fts_statp;
  79
  80         /*
  81          * If the file exists and we're interactive, verify with the user.
  82          * If the file DNE, set the mode to be the from file, minus setuid
  83          * bits, modified by the umask; arguably wrong, but it makes copying
  84          * executables work right and it's been that way forever.  (The
  85          * other choice is 666 or'ed with the execute bits on the from file
  86          * modified by the umask.)
  87          */
  88         if (!dne) {
  89 #define YESNO "(y/n [n]) "
  90                 if (nflag) {
  91                         if (vflag)
  92                                 printf("%s not overwritten\n", to.p_path);
  93                         return (0);
  94                 } else if (iflag) {
  95                         (void)fprintf(stderr, "overwrite %s? %s",
  96                                         to.p_path, YESNO);
  97                         checkch = ch = getchar();
  98                         while (ch != '\n' && ch != EOF)
  99                                 ch = getchar();
 100                         if (checkch != 'y' && checkch != 'Y') {
 101                                 (void)close(from_fd);
 102                                 (void)fprintf(stderr, "not overwritten\n");
 103                                 return (1);
 104                         }
 105                 }
 106
 107                 if (fflag) {
 108                     /* remove existing destination file name,
 109                      * create a new file  */
 110                     (void)unlink(to.p_path);
 111                     to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
 112                                  fs->st_mode & ~(S_ISUID | S_ISGID));
 113                 } else
 114                     /* overwrite existing destination file name */
 115                     to_fd = open(to.p_path, O_WRONLY | O_TRUNC, 0);
 116         } else
 117                 to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
 118                     fs->st_mode & ~(S_ISUID | S_ISGID));
 119
 120         if (to_fd == -1) {
 121                 warn("%s", to.p_path);
 122                 (void)close(from_fd);
 123                 return (1);
 124         }
 125
 126         rval = 0;
 127
 128         /*
 129          * Mmap and write if less than 8M (the limit is so we don't totally
 130          * trash memory on big files.  This is really a minor hack, but it
 131          * wins some CPU back.
 132          */
 133 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
 134         if (S_ISREG(fs->st_mode) && fs->st_size <= 8 * 1048576) {
 135                 if ((p = mmap(NULL, (size_t)fs->st_size, PROT_READ,
 136                     MAP_SHARED, from_fd, (off_t)0)) == MAP_FAILED) {
 137                         warn("%s", entp->fts_path);
 138                         rval = 1;
 139                 } else {
 140                         for (bufp = p, wresid = fs->st_size; ;
 141                             bufp += wcount, wresid -= (size_t)wcount) {
 142                                 wcount = write(to_fd, bufp, wresid);
 143                                 if (wcount >= (ssize_t)wresid || wcount <= 0)
 144                                         break;
 145                         }
 146                         if (wcount != (ssize_t)wresid) {
 147                                 warn("%s", to.p_path);
 148                                 rval = 1;
 149                         }
 150                         /* Some systems don't unmap on close(2). */
 151                         if (munmap(p, fs->st_size) < 0) {
 152                                 warn("%s", entp->fts_path);
 153                                 rval = 1;
 154                         }
 155                 }
 156         } else
 157 #endif
 158         {
 159                 while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
 160                         for (bufp = buf, wresid = rcount; ;
 161                             bufp += wcount, wresid -= wcount) {
 162                                 wcount = write(to_fd, bufp, wresid);
 163                                 if (wcount >= (ssize_t)wresid || wcount <= 0)
 164                                         break;
 165                         }
 166                         if (wcount != (ssize_t)wresid) {
 167                                 warn("%s", to.p_path);
 168                                 rval = 1;
 169                                 break;
 170                         }
 171                 }
 172                 if (rcount < 0) {
 173                         warn("%s", entp->fts_path);
 174                         rval = 1;
 175                 }
 176         }
 177
 178         /*
 179          * Don't remove the target even after an error.  The target might
 180          * not be a regular file, or its attributes might be important,
 181          * or its contents might be irreplaceable.  It would only be safe
 182          * to remove it if we created it and its length is 0.
 183          */
 184
 185         if (pflag && setfile(fs, to_fd))
 186                 rval = 1;
 187         (void)close(from_fd);
 188         if (close(to_fd)) {
 189                 warn("%s", to.p_path);
 190                 rval = 1;
 191         }
 192         return (rval);
 193 }
 194
 195 int
 196 copy_link(FTSENT *p, int exists)
 197 {
 198         int len;
 199         char llink[PATH_MAX];
 200
 201         if ((len = readlink(p->fts_path, llink, sizeof(llink) - 1)) == -1) {
 202                 warn("readlink: %s", p->fts_path);
 203                 return (1);
 204         }
 205         llink[len] = '\0';
 206         if (exists && unlink(to.p_path)) {
 207                 warn("unlink: %s", to.p_path);
 208                 return (1);
 209         }
 210         if (symlink(llink, to.p_path)) {
 211                 warn("symlink: %s", llink);
 212                 return (1);
 213         }
 214         return (0);
 215 }
 216
 217 int
 218 copy_fifo(struct stat *from_stat, int exists)
 219 {
 220         if (exists && unlink(to.p_path)) {
 221                 warn("unlink: %s", to.p_path);
 222                 return (1);
 223         }
 224         if (mkfifo(to.p_path, from_stat->st_mode)) {
 225                 warn("mkfifo: %s", to.p_path);
 226                 return (1);
 227         }
 228         return (pflag ? setfile(from_stat, 0) : 0);
 229 }
 230
 231 int
 232 copy_special(struct stat *from_stat, int exists)
 233 {
 234         if (exists && unlink(to.p_path)) {
 235                 warn("unlink: %s", to.p_path);
 236                 return (1);
 237         }
 238         if (mknod(to.p_path, from_stat->st_mode, from_stat->st_rdev)) {
 239                 warn("mknod: %s", to.p_path);
 240                 return (1);
 241         }
 242         return (pflag ? setfile(from_stat, 0) : 0);
 243 }
 244
 245 int
 246 setfile(struct stat *fs, int fd)
 247 {
 248         static struct timeval tv[2];
 249         struct stat ts;
 250         int rval;
 251         int gotstat;
 252
 253         rval = 0;
 254         fs->st_mode &= S_ISUID | S_ISGID | S_ISVTX |
 255                        S_IRWXU | S_IRWXG | S_IRWXO;
 256
 257         TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
 258         TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
 259         if (utimes(to.p_path, tv)) {
 260                 warn("utimes: %s", to.p_path);
 261                 rval = 1;
 262         }
 263         if (fd ? fstat(fd, &ts) : stat(to.p_path, &ts))
 264                 gotstat = 0;
 265         else {
 266                 gotstat = 1;
 267                 ts.st_mode &= S_ISUID | S_ISGID | S_ISVTX |
 268                               S_IRWXU | S_IRWXG | S_IRWXO;
 269         }
 270         /*
 271          * Changing the ownership probably won't succeed, unless we're root
 272          * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
 273          * the mode; current BSD behavior is to remove all setuid bits on
 274          * chown.  If chown fails, lose setuid/setgid bits.
 275          */
 276         if (!gotstat || fs->st_uid != ts.st_uid || fs->st_gid != ts.st_gid)
 277                 if (fd ? fchown(fd, fs->st_uid, fs->st_gid) :
 278                     chown(to.p_path, fs->st_uid, fs->st_gid)) {
 279                         if (errno != EPERM) {
 280                                 warn("chown: %s", to.p_path);
 281                                 rval = 1;
 282                         }
 283                         fs->st_mode &= ~(S_ISUID | S_ISGID);
 284                 }
 285
 286         if (!gotstat || fs->st_mode != ts.st_mode)
 287                 if (fd ? fchmod(fd, fs->st_mode) : chmod(to.p_path, fs->st_mode)) {
 288                         warn("chmod: %s", to.p_path);
 289                         rval = 1;
 290                 }
 291
 292         if (!gotstat || fs->st_flags != ts.st_flags)
 293                 if (fd ?
 294                     fchflags(fd, fs->st_flags) : chflags(to.p_path, fs->st_flags)) {
 295                         warn("chflags: %s", to.p_path);
 296                         rval = 1;
 297                 }
 298
 299         return (rval);
 300 }
 301
 302 void
 303 usage(void)
 304 {
 305
 306         (void)fprintf(stderr, "%s\n%s\n",
 307 "usage: cp [-R [-H | -L | -P]] [-f | -i | -n] [-pv] src target",
 308 "       cp [-R [-H | -L | -P]] [-f | -i | -n] [-pv] src1 ... srcN directory");
 309         exit(EX_USAGE);
 310 }