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                         close(from_fd);
  94                         return (0);
  95                 } else if (iflag) {
  96                         (void)fprintf(stderr, "overwrite %s? %s",
  97                                         to.p_path, YESNO);
  98                         checkch = ch = getchar();
  99                         while (ch != '\n' && ch != EOF)
 100                                 ch = getchar();
 101                         if (checkch != 'y' && checkch != 'Y') {
 102                                 (void)close(from_fd);
 103                                 (void)fprintf(stderr, "not overwritten\n");
 104                                 return (1);
 105                         }
 106                 }
 107
 108                 if (fflag) {
 109                     /* remove existing destination file name,
 110                      * create a new file  */
 111                     (void)unlink(to.p_path);
 112                     to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
 113                                  fs->st_mode & ~(S_ISUID | S_ISGID));
 114                 } else
 115                     /* overwrite existing destination file name */
 116                     to_fd = open(to.p_path, O_WRONLY | O_TRUNC, 0);
 117         } else
 118                 to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
 119                     fs->st_mode & ~(S_ISUID | S_ISGID));
 120
 121         if (to_fd == -1) {
 122                 warn("%s", to.p_path);
 123                 (void)close(from_fd);
 124                 return (1);
 125         }
 126
 127         rval = 0;
 128
 129         /*
 130          * Mmap and write if less than 8M (the limit is so we don't totally
 131          * trash memory on big files.  This is really a minor hack, but it
 132          * wins some CPU back.
 133          */
 134 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
 135         if (S_ISREG(fs->st_mode) && fs->st_size <= 8 * 1048576) {
 136                 if ((p = mmap(NULL, (size_t)fs->st_size, PROT_READ,
 137                     MAP_SHARED, from_fd, (off_t)0)) == MAP_FAILED) {
 138                         warn("%s", entp->fts_path);
 139                         rval = 1;
 140                 } else {
 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 >= (ssize_t)wresid || wcount <= 0)
 145                                         break;
 146                         }
 147                         if (wcount != (ssize_t)wresid) {
 148                                 warn("%s", to.p_path);
 149                                 rval = 1;
 150                         }
 151                         /* Some systems don't unmap on close(2). */
 152                         if (munmap(p, fs->st_size) < 0) {
 153                                 warn("%s", entp->fts_path);
 154                                 rval = 1;
 155                         }
 156                 }
 157         } else
 158 #endif
 159         {
 160                 while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
 161                         for (bufp = buf, wresid = rcount; ;
 162                             bufp += wcount, wresid -= wcount) {
 163                                 wcount = write(to_fd, bufp, wresid);
 164                                 if (wcount >= (ssize_t)wresid || wcount <= 0)
 165                                         break;
 166                         }
 167                         if (wcount != (ssize_t)wresid) {
 168                                 warn("%s", to.p_path);
 169                                 rval = 1;
 170                                 break;
 171                         }
 172                 }
 173                 if (rcount < 0) {
 174                         warn("%s", entp->fts_path);
 175                         rval = 1;
 176                 }
 177         }
 178
 179         /*
 180          * Don't remove the target even after an error.  The target might
 181          * not be a regular file, or its attributes might be important,
 182          * or its contents might be irreplaceable.  It would only be safe
 183          * to remove it if we created it and its length is 0.
 184          */
 185
 186         if (pflag && setfile(fs, to_fd))
 187                 rval = 1;
 188         (void)close(from_fd);
 189         if (close(to_fd)) {
 190                 warn("%s", to.p_path);
 191                 rval = 1;
 192         }
 193         return (rval);
 194 }
 195
 196 int
 197 copy_link(FTSENT *p, int exists)
 198 {
 199         int len;
 200         char llink[PATH_MAX];
 201
 202         if ((len = readlink(p->fts_path, llink, sizeof(llink) - 1)) == -1) {
 203                 warn("readlink: %s", p->fts_path);
 204                 return (1);
 205         }
 206         llink[len] = '\0';
 207         if (exists && unlink(to.p_path)) {
 208                 warn("unlink: %s", to.p_path);
 209                 return (1);
 210         }
 211         if (symlink(llink, to.p_path)) {
 212                 warn("symlink: %s", llink);
 213                 return (1);
 214         }
 215         return (0);
 216 }
 217
 218 int
 219 copy_fifo(struct stat *from_stat, int exists)
 220 {
 221         if (exists && unlink(to.p_path)) {
 222                 warn("unlink: %s", to.p_path);
 223                 return (1);
 224         }
 225         if (mkfifo(to.p_path, from_stat->st_mode)) {
 226                 warn("mkfifo: %s", to.p_path);
 227                 return (1);
 228         }
 229         return (pflag ? setfile(from_stat, 0) : 0);
 230 }
 231
 232 int
 233 copy_special(struct stat *from_stat, int exists)
 234 {
 235         if (exists && unlink(to.p_path)) {
 236                 warn("unlink: %s", to.p_path);
 237                 return (1);
 238         }
 239         if (mknod(to.p_path, from_stat->st_mode, from_stat->st_rdev)) {
 240                 warn("mknod: %s", to.p_path);
 241                 return (1);
 242         }
 243         return (pflag ? setfile(from_stat, 0) : 0);
 244 }
 245
 246 int
 247 setfile(struct stat *fs, int fd)
 248 {
 249         static struct timeval tv[2];
 250         struct stat ts;
 251         int rval;
 252         int gotstat;
 253
 254         rval = 0;
 255         fs->st_mode &= S_ISUID | S_ISGID | S_ISVTX |
 256                        S_IRWXU | S_IRWXG | S_IRWXO;
 257
 258         TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
 259         TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
 260         if (utimes(to.p_path, tv)) {
 261                 warn("utimes: %s", to.p_path);
 262                 rval = 1;
 263         }
 264         if (fd ? fstat(fd, &ts) : stat(to.p_path, &ts))
 265                 gotstat = 0;
 266         else {
 267                 gotstat = 1;
 268                 ts.st_mode &= S_ISUID | S_ISGID | S_ISVTX |
 269                               S_IRWXU | S_IRWXG | S_IRWXO;
 270         }
 271         /*
 272          * Changing the ownership probably won't succeed, unless we're root
 273          * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
 274          * the mode; current BSD behavior is to remove all setuid bits on
 275          * chown.  If chown fails, lose setuid/setgid bits.
 276          */
 277         if (!gotstat || fs->st_uid != ts.st_uid || fs->st_gid != ts.st_gid)
 278                 if (fd ? fchown(fd, fs->st_uid, fs->st_gid) :
 279                     chown(to.p_path, fs->st_uid, fs->st_gid)) {
 280                         if (errno != EPERM) {
 281                                 warn("chown: %s", to.p_path);
 282                                 rval = 1;
 283                         }
 284                         fs->st_mode &= ~(S_ISUID | S_ISGID);
 285                 }
 286
 287         if (!gotstat || fs->st_mode != ts.st_mode)
 288                 if (fd ? fchmod(fd, fs->st_mode) : chmod(to.p_path, fs->st_mode)) {
 289                         warn("chmod: %s", to.p_path);
 290                         rval = 1;
 291                 }
 292
 293         if (!gotstat || fs->st_flags != ts.st_flags)
 294                 if (fd ?
 295                     fchflags(fd, fs->st_flags) : chflags(to.p_path, fs->st_flags)) {
 296                         warn("chflags: %s", to.p_path);
 297                         rval = 1;
 298                 }
 299
 300         return (rval);
 301 }
 302
 303 void
 304 usage(void)
 305 {
 306
 307         (void)fprintf(stderr, "%s\n%s\n",
 308 "usage: cp [-R [-H | -L | -P]] [-f | -i | -n] [-pv] src target",
 309 "       cp [-R [-H | -L | -P]] [-f | -i | -n] [-pv] src1 ... srcN directory");
 310         exit(EX_USAGE);
 311 }