bin/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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include <sys/param.h>
  31 #include <sys/stat.h>
  32 #include <sys/time.h>
  33 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
  34 #include <sys/mman.h>
  35 #endif
  36
  37 #include <err.h>
  38 #include <errno.h>
  39 #include <fcntl.h>
  40 #include <fts.h>
  41 #include <limits.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <sysexits.h>
  45 #include <unistd.h>
  46
  47 #include "extern.h"
  48
  49 #define cp_pct(x, y)    ((y == 0) ? 0 : (int)(100.0 * (x) / (y)))
  50
  51
  52 int
  53 copy_file(const FTSENT *entp, int dne)
  54 {
  55         static char buf[MAXBSIZE];
  56         struct stat *fs;
  57         ssize_t wcount, rcount;
  58         size_t wresid;
  59         off_t wtotal;
  60         int ch, checkch, from_fd = 0, rval, to_fd = 0;
  61         char *bufp;
  62 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
  63         char *p;
  64 #endif
  65
  66         if ((from_fd = open(entp->fts_path, O_RDONLY, 0)) == -1) {
  67                 warn("%s", entp->fts_path);
  68                 return (1);
  69         }
  70
  71         fs = entp->fts_statp;
  72
  73         /*
  74          * If the file exists and we're interactive, verify with the user.
  75          * If the file DNE, set the mode to be the from file, minus setuid
  76          * bits, modified by the umask; arguably wrong, but it makes copying
  77          * executables work right and it's been that way forever.  (The
  78          * other choice is 666 or'ed with the execute bits on the from file
  79          * modified by the umask.)
  80          */
  81         if (!dne) {
  82 #define YESNO "(y/n [n]) "
  83                 if (nflag) {
  84                         if (vflag)
  85                                 printf("%s not overwritten\n", to.p_path);
  86                         close(from_fd);
  87                         return (0);
  88                 } else if (iflag) {
  89                         fprintf(stderr, "overwrite %s? %s",
  90                                         to.p_path, YESNO);
  91                         checkch = ch = getchar();
  92                         while (ch != '\n' && ch != EOF)
  93                                 ch = getchar();
  94                         if (checkch != 'y' && checkch != 'Y') {
  95                                 close(from_fd);
  96                                 fprintf(stderr, "not overwritten\n");
  97                                 return (1);
  98                         }
  99                 }
 100
 101                 if (fflag) {
 102                     /* remove existing destination file name,
 103                      * create a new file  */
 104                     unlink(to.p_path);
 105                     if (!lflag)
 106                         to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
 107                             fs->st_mode & ~(S_ISUID | S_ISGID));
 108                 } else {
 109                     if (!lflag)
 110                         /* overwrite existing destination file name */
 111                             to_fd = open(to.p_path, O_WRONLY | O_TRUNC, 0);
 112                 }
 113         } else {
 114                 if (!lflag)
 115                         to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
 116                             fs->st_mode & ~(S_ISUID | S_ISGID));
 117         }
 118
 119         if (to_fd == -1) {
 120                 warn("%s", to.p_path);
 121                 close(from_fd);
 122                 return (1);
 123         }
 124
 125         rval = 0;
 126
 127         if (!lflag) {
 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                  * Some filesystems, such as smbnetfs, don't support mmap,
 133                  * so this is a best-effort attempt.
 134          */
 135 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
 136                 if (S_ISREG(fs->st_mode) && fs->st_size > 0 &&
 137                     fs->st_size <= 8 * 1024 * 1024 &&
 138                     (p = mmap(NULL, (size_t)fs->st_size, PROT_READ,
 139                     MAP_SHARED, from_fd, (off_t)0)) != MAP_FAILED) {
 140                         wtotal = 0;
 141                         for (bufp = p, wresid = fs->st_size; ;
 142                             bufp += wcount, wresid -= (size_t)wcount) {
 143                                 wcount = write(to_fd, bufp, wresid);
 144                                 if (wcount <= 0)
 145                                         break;
 146                                 wtotal += wcount;
 147                                 if (info) {
 148                                         info = 0;
 149                                         fprintf(stderr,
 150                                             "%s -> %s %3d%%\n",
 151                                             entp->fts_path, to.p_path,
 152                                             cp_pct(wtotal, fs->st_size));
 153                                 }
 154                                 if (wcount >= (ssize_t)wresid)
 155                                         break;
 156                         }
 157                         if (wcount != (ssize_t)wresid) {
 158                                 warn("%s", to.p_path);
 159                                 rval = 1;
 160                         }
 161                         /* Some systems don't unmap on close(2). */
 162                         if (munmap(p, fs->st_size) < 0) {
 163                                 warn("%s", entp->fts_path);
 164                                 rval = 1;
 165                         }
 166                 } else
 167 #endif
 168                 {
 169                         wtotal = 0;
 170                         while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
 171                                 for (bufp = buf, wresid = rcount; ;
 172                                     bufp += wcount, wresid -= wcount) {
 173                                         wcount = write(to_fd, bufp, wresid);
 174                                         if (wcount <= 0)
 175                                                 break;
 176                                         wtotal += wcount;
 177                                         if (info) {
 178                                                 info = 0;
 179                                                 fprintf(stderr,
 180                                                     "%s -> %s %3d%%\n",
 181                                                     entp->fts_path, to.p_path,
 182                                                     cp_pct(wtotal, fs->st_size));
 183                                         }
 184                                         if (wcount >= (ssize_t)wresid)
 185                                                 break;
 186                                 }
 187                                 if (wcount != (ssize_t)wresid) {
 188                                         warn("%s", to.p_path);
 189                                         rval = 1;
 190                                         break;
 191                                 }
 192                         }
 193                         if (rcount < 0) {
 194                                 warn("%s", entp->fts_path);
 195                                 rval = 1;
 196                         }
 197                 }
 198         } else {
 199                 if (link(entp->fts_path, to.p_path)) {
 200                         warn("%s", to.p_path);
 201                         rval = 1;
 202                 }
 203         }
 204
 205         /*
 206          * Don't remove the target even after an error.  The target might
 207          * not be a regular file, or its attributes might be important,
 208          * or its contents might be irreplaceable.  It would only be safe
 209          * to remove it if we created it and its length is 0.
 210          */
 211
 212         if (!lflag) {
 213                 if (pflag && setfile(fs, to_fd))
 214                         rval = 1;
 215                 if (close(to_fd)) {
 216                         warn("%s", to.p_path);
 217                         rval = 1;
 218                 }
 219         }
 220
 221         close(from_fd);
 222
 223         return (rval);
 224 }
 225
 226 int
 227 copy_link(const FTSENT *p, int exists)
 228 {
 229         int len;
 230         char llink[PATH_MAX];
 231
 232         if ((len = readlink(p->fts_path, llink, sizeof(llink) - 1)) == -1) {
 233                 warn("readlink: %s", p->fts_path);
 234                 return (1);
 235         }
 236         llink[len] = '\0';
 237         if (exists && unlink(to.p_path)) {
 238                 warn("unlink: %s", to.p_path);
 239                 return (1);
 240         }
 241         if (symlink(llink, to.p_path)) {
 242                 warn("symlink: %s", llink);
 243                 return (1);
 244         }
 245         return (pflag ? setfile(p->fts_statp, -1) : 0);
 246 }
 247
 248 int
 249 copy_fifo(struct stat *from_stat, int exists)
 250 {
 251         if (exists && unlink(to.p_path)) {
 252                 warn("unlink: %s", to.p_path);
 253                 return (1);
 254         }
 255         if (mkfifo(to.p_path, from_stat->st_mode)) {
 256                 warn("mkfifo: %s", to.p_path);
 257                 return (1);
 258         }
 259         return (pflag ? setfile(from_stat, -1) : 0);
 260 }
 261
 262 int
 263 copy_special(struct stat *from_stat, int exists)
 264 {
 265         if (exists && unlink(to.p_path)) {
 266                 warn("unlink: %s", to.p_path);
 267                 return (1);
 268         }
 269         if (mknod(to.p_path, from_stat->st_mode, from_stat->st_rdev)) {
 270                 warn("mknod: %s", to.p_path);
 271                 return (1);
 272         }
 273         return (pflag ? setfile(from_stat, -1) : 0);
 274 }
 275
 276 int
 277 setfile(struct stat *fs, int fd)
 278 {
 279         static struct timeval tv[2];
 280         struct stat ts;
 281         int rval, gotstat, islink, fdval;
 282
 283         rval = 0;
 284         fdval = fd != -1;
 285         islink = !fdval && S_ISLNK(fs->st_mode);
 286         fs->st_mode &= S_ISUID | S_ISGID | S_ISVTX |
 287                        S_IRWXU | S_IRWXG | S_IRWXO;
 288
 289         TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
 290         TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
 291         if (islink ? lutimes(to.p_path, tv) : utimes(to.p_path, tv)) {
 292                 warn("%sutimes: %s", islink ? "l" : "", to.p_path);
 293                 rval = 1;
 294         }
 295         if (fdval ? fstat(fd, &ts) :
 296             (islink ? lstat(to.p_path, &ts) : stat(to.p_path, &ts)))
 297                 gotstat = 0;
 298         else {
 299                 gotstat = 1;
 300                 ts.st_mode &= S_ISUID | S_ISGID | S_ISVTX |
 301                               S_IRWXU | S_IRWXG | S_IRWXO;
 302         }
 303         /*
 304          * Changing the ownership probably won't succeed, unless we're root
 305          * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
 306          * the mode; current BSD behavior is to remove all setuid bits on
 307          * chown.  If chown fails, lose setuid/setgid bits.
 308          */
 309         if (!gotstat || fs->st_uid != ts.st_uid || fs->st_gid != ts.st_gid)
 310                 if (fdval ? fchown(fd, fs->st_uid, fs->st_gid) :
 311                     (islink ? lchown(to.p_path, fs->st_uid, fs->st_gid) :
 312                     chown(to.p_path, fs->st_uid, fs->st_gid))) {
 313                         if (errno != EPERM) {
 314                                 warn("chown: %s", to.p_path);
 315                                 rval = 1;
 316                         }
 317                         fs->st_mode &= ~(S_ISUID | S_ISGID);
 318                 }
 319
 320         if (!gotstat || fs->st_mode != ts.st_mode)
 321                 if (fdval ? fchmod(fd, fs->st_mode) :
 322                     (islink ? lchmod(to.p_path, fs->st_mode) :
 323                     chmod(to.p_path, fs->st_mode))) {
 324                         warn("chmod: %s", to.p_path);
 325                         rval = 1;
 326                 }
 327
 328         if (!gotstat || fs->st_flags != ts.st_flags)
 329                 if (fdval ?
 330                     fchflags(fd, fs->st_flags) :
 331                     (islink ? lchflags(to.p_path, fs->st_flags) :
 332                     chflags(to.p_path, fs->st_flags))) {
 333                         warn("chflags: %s", to.p_path);
 334                         rval = 1;
 335                 }
 336
 337         return (rval);
 338 }
 339
 340 void
 341 usage(void)
 342 {
 343
 344         fprintf(stderr, "%s\n%s\n",
 345 "usage: cp [-R [-H | -L | -P]] [-f | -i | -n] [-alpvx] source_file target_file",
 346 "       cp [-R [-H | -L | -P]] [-f | -i | -n] [-alpvx] source_file ... "
 347 "target_directory");
 348         exit(EX_USAGE);
 349 }