aboutsummaryrefslogtreecommitdiff
path: root/toys/posix/cp.c
blob: 5e7d99e4e46aaed79cd9eb116a6dfd0051459553 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
/* Copyright 2008 Rob Landley <rob@landley.net>
 *
 * See http://opengroup.org/onlinepubs/9699919799/utilities/cp.html
 * And http://opengroup.org/onlinepubs/9699919799/utilities/mv.html
 * And http://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic.html#INSTALL
 *
 * Posix says "cp -Rf dir file" shouldn't delete file, but our -f does.
 *
 * Deviations from posix: -adlnrsvF, --preserve... about half the
 * functionality in this cp isn't in posix. Posix is stuck in the 1970's.
 *
 * TODO: --preserve=links
 * TODO: what's this _CP_mode system.posix_acl_ business? We chmod()?

// options shared between mv/cp must be in same order (right to left)
// for FLAG macros to work out right in shared infrastructure.

USE_CP(NEWTOY(cp, "<2"USE_CP_PRESERVE("(preserve):;")"D(parents)RHLPprdaslvnF(remove-destination)fi[-HLPd][-ni]", TOYFLAG_BIN))
USE_MV(NEWTOY(mv, "<2vnF(remove-destination)fi[-ni]", TOYFLAG_BIN))
USE_INSTALL(NEWTOY(install, "<1cdDpsvm:o:g:", TOYFLAG_USR|TOYFLAG_BIN))

config CP
  bool "cp"
  default y
  help
    usage: cp [-adlnrsvfipRHLP] SOURCE... DEST

    Copy files from SOURCE to DEST.  If more than one SOURCE, DEST must
    be a directory.

    -D	Create leading dirs under DEST (--parents)
    -f	Delete destination files we can't write to
    -F	Delete any existing destination file first (--remove-destination)
    -i	Interactive, prompt before overwriting existing DEST
    -p	Preserve timestamps, ownership, and mode
    -R	Recurse into subdirectories (DEST must be a directory)
    -H	Follow symlinks listed on command line
    -L	Follow all symlinks
    -P	Do not follow symlinks [default]
    -a	Same as -dpr
    -d	Don't dereference symlinks
    -l	Hard link instead of copy
    -n	No clobber (don't overwrite DEST)
    -r	Synonym for -R
    -s	Symlink instead of copy
    -v	Verbose

config CP_PRESERVE
  bool "cp --preserve support"
  default y
  depends on CP
  help
    usage: cp [--preserve=motcxa]

    --preserve takes either a comma separated list of attributes, or the first
    letter(s) of:

            mode - permissions (ignore umask for rwx, copy suid and sticky bit)
       ownership - user and group
      timestamps - file creation, modification, and access times.
         context - security context
           xattr - extended attributes
             all - all of the above

config MV
  bool "mv"
  default y
  help
    usage: mv [-fivn] SOURCE... DEST

    -f	Force copy by deleting destination file
    -i	Interactive, prompt before overwriting existing DEST
    -v	Verbose
    -n	No clobber (don't overwrite DEST)

config INSTALL
  bool "install"
  default y
  help
    usage: install [-dDpsv] [-o USER] [-g GROUP] [-m MODE] [SOURCE...] DEST

    Copy files and set attributes.

    -d	Act like mkdir -p
    -D	Create leading directories for DEST
    -g	Make copy belong to GROUP
    -m	Set permissions to MODE
    -o	Make copy belong to USER
    -p	Preserve timestamps
    -s	Call "strip -p"
    -v	Verbose
*/

#define FORCE_FLAGS
#define FOR_cp
#include "toys.h"

GLOBALS(
  union {
    // install's options
    struct {
      char *g, *o, *m;
    } i;
    // cp's options
    struct {
      char *preserve;
    } c;
  };

  char *destname;
  struct stat top;
  int (*callback)(struct dirtree *try);
  uid_t uid;
  gid_t gid;
  int pflags;
)

struct cp_preserve {
  char *name;
} static const cp_preserve[] = TAGGED_ARRAY(CP,
  {"mode"}, {"ownership"}, {"timestamps"}, {"context"}, {"xattr"},
);

// Callback from dirtree_read() for each file/directory under a source dir.

static int cp_node(struct dirtree *try)
{
  int fdout = -1, cfd = try->parent ? try->parent->extra : AT_FDCWD,
      tfd = dirtree_parentfd(try);
  unsigned flags = toys.optflags;
  char *catch = try->parent ? try->name : TT.destname, *err = "%s";
  struct stat cst;

  if (!dirtree_notdotdot(try)) return 0;

  // If returning from COMEAGAIN, jump straight to -p logic at end.
  if (S_ISDIR(try->st.st_mode) && try->again) {
    fdout = try->extra;
    err = 0;
  } else {

    // -d is only the same as -r for symlinks, not for directories
    if (S_ISLNK(try->st.st_mode) && (flags & FLAG_d)) flags |= FLAG_r;

    // Detect recursive copies via repeated top node (cp -R .. .) or
    // identical source/target (fun with hardlinks).
    if ((TT.top.st_dev == try->st.st_dev && TT.top.st_ino == try->st.st_ino
         && (catch = TT.destname))
        || (!fstatat(cfd, catch, &cst, 0) && cst.st_dev == try->st.st_dev
         && cst.st_ino == try->st.st_ino))
    {
      error_msg("'%s' is '%s'", catch, err = dirtree_path(try, 0));
      free(err);

      return 0;
    }

    // Handle -invF

    if (!faccessat(cfd, catch, F_OK, 0) && !S_ISDIR(cst.st_mode)) {
      char *s;

      if (S_ISDIR(try->st.st_mode)) {
        error_msg("dir at '%s'", s = dirtree_path(try, 0));
        free(s);
        return 0;
      } else if ((flags & FLAG_F) && unlinkat(cfd, catch, 0)) {
        error_msg("unlink '%s'", catch);
        return 0;
      } else if (flags & FLAG_n) return 0;
      else if (flags & FLAG_i) {
        fprintf(stderr, "%s: overwrite '%s'", toys.which->name,
          s = dirtree_path(try, 0));
        free(s);
        if (!yesno(1)) return 0;
      }
    }

    if (flags & FLAG_v) {
      char *s = dirtree_path(try, 0);
      printf("%s '%s'\n", toys.which->name, s);
      free(s);
    }

    // Loop for -f retry after unlink
    do {

      // directory, hardlink, symlink, mknod (char, block, fifo, socket), file

      // Copy directory

      if (S_ISDIR(try->st.st_mode)) {
        struct stat st2;

        if (!(flags & (FLAG_a|FLAG_r|FLAG_R))) {
          err = "Skipped dir '%s'";
          catch = try->name;
          break;
        }

        // Always make directory writeable to us, so we can create files in it.
        //
        // Yes, there's a race window between mkdir() and open() so it's
        // possible that -p can be made to chown a directory other than the one
        // we created. The closest we can do to closing this is make sure
        // that what we open _is_ a directory rather than something else.

        if (!mkdirat(cfd, catch, try->st.st_mode | 0200) || errno == EEXIST)
          if (-1 != (try->extra = openat(cfd, catch, O_NOFOLLOW)))
            if (!fstat(try->extra, &st2) && S_ISDIR(st2.st_mode))
              return DIRTREE_COMEAGAIN | (DIRTREE_SYMFOLLOW*!!FLAG(L));

      // Hardlink

      } else if (flags & FLAG_l) {
        if (!linkat(tfd, try->name, cfd, catch, 0)) err = 0;

      // Copy tree as symlinks. For non-absolute paths this involves
      // appending the right number of .. entries as you go down the tree.

      } else if (flags & FLAG_s) {
        char *s;
        struct dirtree *or;
        int dotdots = 0;

        s = dirtree_path(try, 0);
        for (or = try; or->parent; or = or->parent) dotdots++;

        if (*or->name == '/') dotdots = 0;
        if (dotdots) {
          char *s2 = xmprintf("%*c%s", 3*dotdots, ' ', s);
          free(s);
          s = s2;
          while(dotdots--) {
            memcpy(s2, "../", 3);
            s2 += 3;
          }
        }
        if (!symlinkat(s, cfd, catch)) {
          err = 0;
          fdout = AT_FDCWD;
        }
        free(s);

      // Do something _other_ than copy contents of a file?
      } else if (!S_ISREG(try->st.st_mode)
                 && (try->parent || (flags & (FLAG_a|FLAG_r))))
      {
        int i;

        // make symlink, or make block/char/fifo/socket
        if (S_ISLNK(try->st.st_mode)
            ? ((i = readlinkat0(tfd, try->name, toybuf, sizeof(toybuf))) &&
               ((!unlinkat(cfd, catch, 0) || ENOENT == errno) &&
                !symlinkat(toybuf, cfd, catch)))
            : !mknodat(cfd, catch, try->st.st_mode, try->st.st_rdev))
        {
          err = 0;
          fdout = AT_FDCWD;
        }

      // Copy contents of file.
      } else {
        int fdin;

        fdin = openat(tfd, try->name, O_RDONLY);
        if (fdin < 0) {
          catch = try->name;
          break;
        }
        // When copying contents use symlink target's attributes
        if (S_ISLNK(try->st.st_mode)) fstat(fdin, &try->st);
        fdout = openat(cfd, catch, O_RDWR|O_CREAT|O_TRUNC, try->st.st_mode);
        if (fdout >= 0) {
          xsendfile(fdin, fdout);
          err = 0;
        }

        // We only copy xattrs for files because there's no flistxattrat()
        if (TT.pflags&(_CP_xattr|_CP_context)) {
          ssize_t listlen = xattr_flist(fdin, 0, 0), len;
          char *name, *value, *list;

          if (listlen>0) {
            list = xmalloc(listlen);
            xattr_flist(fdin, list, listlen);
            list[listlen-1] = 0; // I do not trust this API.
            for (name = list; name-list < listlen; name += strlen(name)+1) {
              if (!(TT.pflags&_CP_xattr) && strncmp(name, "security.", 9))
                continue;
              if ((len = xattr_fget(fdin, name, 0, 0))>0) {
                value = xmalloc(len);
                if (len == xattr_fget(fdin, name, value, len))
                  if (xattr_fset(fdout, name, value, len, 0))
                    perror_msg("%s setxattr(%s=%s)", catch, name, value);
                free(value);
              }
            }
            free(list);
          }
        }

        close(fdin);
      }
    } while (err && (flags & (FLAG_f|FLAG_n)) && !unlinkat(cfd, catch, 0));
  }

  // Did we make a thing?
  if (fdout != -1) {
    int rc;

    // Inability to set --preserve isn't fatal, some require root access.

    // ownership
    if (TT.pflags & _CP_ownership) {

      // permission bits already correct for mknod and don't apply to symlink
      // If we can't get a filehandle to the actual object, use racy functions
      if (fdout == AT_FDCWD)
        rc = fchownat(cfd, catch, try->st.st_uid, try->st.st_gid,
                      AT_SYMLINK_NOFOLLOW);
      else rc = fchown(fdout, try->st.st_uid, try->st.st_gid);
      if (rc && !geteuid()) {
        char *pp;

        perror_msg("chown '%s'", pp = dirtree_path(try, 0));
        free(pp);
      }
    }

    // timestamp
    if (TT.pflags & _CP_timestamps) {
      struct timespec times[] = {try->st.st_atim, try->st.st_mtim};

      if (fdout == AT_FDCWD) utimensat(cfd, catch, times, AT_SYMLINK_NOFOLLOW);
      else futimens(fdout, times);
    }

    // mode comes last because other syscalls can strip suid bit
    if (fdout != AT_FDCWD) {
      if (TT.pflags & _CP_mode) fchmod(fdout, try->st.st_mode);
      xclose(fdout);
    }

    if (CFG_MV && toys.which->name[0] == 'm')
      if (unlinkat(tfd, try->name, S_ISDIR(try->st.st_mode) ? AT_REMOVEDIR :0))
        err = "%s";
  }

  if (err) {
    char *f = 0;

    if (catch == try->name) {
      f = dirtree_path(try, 0);
      while (try->parent) try = try->parent;
      catch = xmprintf("%s%s", TT.destname, f+strlen(try->name));
      free(f);
      f = catch;
    }
    perror_msg(err, catch);
    free(f);
  }
  return 0;
}

void cp_main(void)
{
  char *destname = toys.optargs[--toys.optc];
  int i, destdir = !stat(destname, &TT.top) && S_ISDIR(TT.top.st_mode);

  if ((toys.optc>1 || FLAG(D)) && !destdir)
    error_exit("'%s' not directory", destname);

  if (FLAG(a)||FLAG(p)) TT.pflags = _CP_mode|_CP_ownership|_CP_timestamps;

  // Not using comma_args() (yet?) because interpeting as letters.
  if (CFG_CP_PRESERVE && FLAG(preserve)) {
    char *pre = xstrdup(TT.c.preserve ? TT.c.preserve : "mot"), *s;

    if (comma_scan(pre, "all", 1)) TT.pflags = ~0;
    for (i=0; i<ARRAY_LEN(cp_preserve); i++)
      if (comma_scan(pre, cp_preserve[i].name, 1)) TT.pflags |= 1<<i;
    if (*pre) {

      // Try to interpret as letters, commas won't set anything this doesn't.
      for (s = pre; *s; s++) {
        for (i=0; i<ARRAY_LEN(cp_preserve); i++)
          if (*s == *cp_preserve[i].name) break;
        if (i == ARRAY_LEN(cp_preserve)) {
          if (*s == 'a') TT.pflags = ~0;
          else break;
        } else TT.pflags |= 1<<i;
      }

      if (*s) error_exit("bad --preserve=%s", pre);
    }
    free(pre);
  }
  if (TT.pflags & _CP_mode) umask(0);
  if (!TT.callback) TT.callback = cp_node;

  // Loop through sources
  for (i=0; i<toys.optc; i++) {
    char *src = toys.optargs[i], *trail = src;
    int rc = 1;

    if (CFG_MV && toys.which->name[0] == 'm') {
      while (*++trail);
      if (*--trail == '/') *trail = 0;
    }

    if (destdir) {
      char *s = FLAG(D) ? getdirname(src) : getbasename(src);

      TT.destname = xmprintf("%s/%s", destname, s);
      if (FLAG(D)) {
        free(s);
        if (!(s = fileunderdir(TT.destname, destname))) {
          error_msg("%s not under %s", TT.destname, destname);
          continue;
        }
        // TODO: .. follows abspath, not links...
        free(s);
        mkpath(TT.destname);
      }
    } else TT.destname = destname;

    errno = EXDEV;
    if (CFG_MV && toys.which->name[0] == 'm') {
      int force = FLAG(f), no_clobber = FLAG(n);

      if (!force || no_clobber) {
        struct stat st;
        int exists = !stat(TT.destname, &st);

        // Prompt if -i or file isn't writable.  Technically "is writable" is
        // more complicated (022 is not writeable by the owner, just everybody
        // _else_) but I don't care.
        if (exists && (FLAG(i) || !(st.st_mode & 0222))) {
          fprintf(stderr, "%s: overwrite '%s'", toys.which->name, TT.destname);
          if (!yesno(1)) rc = 0;
          else unlink(TT.destname);
        }
        // if -n and dest exists, don't try to rename() or copy
        if (exists && no_clobber) rc = 0;
      }
      if (rc) rc = rename(src, TT.destname);
      if (errno && !*trail) *trail = '/';
    }

    // Copy if we didn't mv, skipping nonexistent sources
    if (rc) {
      if (errno!=EXDEV || dirtree_flagread(src, DIRTREE_SHUTUP+
        DIRTREE_SYMFOLLOW*!!(FLAG(H)||FLAG(L)), TT.callback))
          perror_msg("bad '%s'", src);
    }
    if (destdir) free(TT.destname);
  }
}

void mv_main(void)
{
  toys.optflags |= FLAG_d|FLAG_p|FLAG_R;

  cp_main();
}

// Export cp flags into install's flag context.

static inline int cp_flag_F(void) { return FLAG_F; };
static inline int cp_flag_p(void) { return FLAG_p; };
static inline int cp_flag_v(void) { return FLAG_v; };

// Switch to install's flag context
#define CLEANUP_cp
#define FOR_install
#include <generated/flags.h>

static int install_node(struct dirtree *try)
{
  try->st.st_mode = TT.i.m ? string_to_mode(TT.i.m, try->st.st_mode) : 0755;
  if (TT.i.g) try->st.st_gid = TT.gid;
  if (TT.i.o) try->st.st_uid = TT.uid;

  // Always returns 0 because no -r
  cp_node(try);

  // No -r so always one level deep, so destname as set by cp_node() is correct
  if (FLAG(s) && xrun((char *[]){"strip", "-p", TT.destname, 0}))
    toys.exitval = 1;

  return 0;
}

void install_main(void)
{
  char **ss;
  int flags = toys.optflags;

  TT.uid = TT.i.o ? xgetuid(TT.i.o) : -1;
  TT.gid = TT.i.g ? xgetgid(TT.i.g) : -1;

  if (flags & FLAG_d) {
    for (ss = toys.optargs; *ss; ss++) {
      if (mkpathat(AT_FDCWD, *ss, 0777, MKPATHAT_MKLAST | MKPATHAT_MAKE)) perror_msg_raw(*ss);
      if (flags & (FLAG_g|FLAG_o))
        if (lchown(*ss, TT.uid, TT.gid)) perror_msg("chown '%s'", *ss);
      if (flags & FLAG_v) printf("%s\n", *ss);
    }

    return;
  }

  if (FLAG(D)) {
    TT.destname = toys.optargs[toys.optc-1];
    if (mkpathat(AT_FDCWD, TT.destname, 0, MKPATHAT_MAKE))
      perror_exit("-D '%s'", TT.destname);
    if (toys.optc == 1) return;
  }
  if (toys.optc < 2) error_exit("needs 2 args");

  // Translate flags from install to cp
  toys.optflags = cp_flag_F();
  if (flags & FLAG_v) toys.optflags |= cp_flag_v();
  if (flags & (FLAG_p|FLAG_o|FLAG_g)) toys.optflags |= cp_flag_p();

  TT.callback = install_node;
  cp_main();
}