CopyFile.c revision 636c1c4a44261ac05b2bcdf035df412b6773eabb 
1/*
2 * Copyright 2005 The Android Open Source Project
3 *
4 * Android "cp" replacement.
5 *
6 * The GNU/Linux "cp" uses O_LARGEFILE in its open() calls, utimes() instead
7 * of utime(), and getxattr()/setxattr() instead of chmod().  These are
8 * probably "better", but are non-portable, and not necessary for our
9 * purposes.
10 */
11#include <host/CopyFile.h>
12
13#include <stdlib.h>
14#include <stdio.h>
15#include <string.h>
16#include <unistd.h>
17#include <sys/types.h>
18#include <sys/stat.h>
19#include <getopt.h>
20#include <dirent.h>
21#include <fcntl.h>
22#include <utime.h>
23#include <limits.h>
24#include <errno.h>
25#include <assert.h>
26
27#if defined(_WIN32)
28#include <direct.h>  /* For _mkdir() */
29#  define mkdir(path,mode)   _mkdir(path)
30#  define S_ISLNK(s) 0
31#  define lstat stat
32#  ifndef EACCESS   /* seems to be missing from the Mingw headers */
33#    define  EACCESS            13
34#  endif
35#endif
36
37#ifndef O_BINARY
38#  define  O_BINARY  0
39#endif
40
41/*#define DEBUG_MSGS*/
42#ifdef DEBUG_MSGS
43# define DBUG(x) printf x
44#else
45# define DBUG(x) ((void)0)
46#endif
47
48#define FSSEP '/'       /* filename separator char */
49
50static int copyFileRecursive(const char* src, const char* dst, bool isCmdLine, unsigned int options);
51
52/*
53 * Returns true if the source file is newer than the destination file.
54 *
55 * The check is based on the modification date, whole seconds only.  This
56 * also returns true if the file sizes don't match.
57 */
58static bool isSourceNewer(const struct stat* pSrcStat, const struct stat* pDstStat)
59{
60    return (pSrcStat->st_mtime > pDstStat->st_mtime) ||
61           (pSrcStat->st_size != pDstStat->st_size);
62}
63
64/*
65 * Returns true if the source file has high resolution modification
66 * date. Cygwin/Mingw doesn't support st_mtim and always returns false.
67 */
68static bool isHiresMtime(const struct stat* pSrcStat)
69{
70#if defined(_WIN32)
71    return 0;
72#elif defined(__APPLE__)
73    return pSrcStat->st_mtimespec.tv_nsec > 0;
74#else
75    return pSrcStat->st_mtim.tv_nsec > 0;
76#endif
77}
78
79/*
80 * Returns true if the source and destination files are actually the
81 * same thing.  We detect this by checking the inode numbers, which seems
82 * to work on Cygwin.
83 */
84static bool isSameFile(const struct stat* pSrcStat, const struct stat* pDstStat)
85{
86#if defined(_WIN32)
87  (void)pSrcStat;
88  (void)pDstStat;
89    /* with MSVCRT.DLL, stat always sets st_ino to 0, and there is no simple way to */
90	/* get the equivalent information with Win32 (Cygwin does some weird stuff in   */
91	/* its winsup/cygwin/fhandler_disk_file.cc to emulate this, too complex for us) */
92	return 0;
93#else
94    return (pSrcStat->st_ino == pDstStat->st_ino);
95#endif
96}
97
98static void printCopyMsg(const char* src, const char* dst, unsigned int options)
99{
100    if ((options & COPY_VERBOSE_MASK) > 0)
101        printf("    '%s' --> '%s'\n", src, dst);
102}
103
104static void printNotNewerMsg(const char* src, const char* dst, unsigned int options)
105{
106    (void)src;
107    if ((options & COPY_VERBOSE_MASK) > 1)
108        printf("    '%s' is up-to-date\n", dst);
109}
110
111/*
112 * Copy the contents of one file to another.
113 *
114 * The files are assumed to be seeked to the start.
115 */
116static int copyFileContents(const char* dst, int dstFd, const char* src, int srcFd)
117{
118    unsigned char buf[8192];
119    ssize_t readCount, writeCount;
120
121    /*
122     * Read a chunk, write it, and repeat.
123     */
124    while (1) {
125        readCount = read(srcFd, buf, sizeof(buf));
126        if (readCount < 0) {
127            fprintf(stderr,
128                "acp: failed reading '%s': %s\n", src, strerror(errno));
129            return -1;
130        }
131
132        if (readCount > 0) {
133            writeCount = write(dstFd, buf, readCount);
134            if (writeCount < 0) {
135                fprintf(stderr,
136                    "acp: failed writing '%s': %s\n", dst, strerror(errno));
137                return -1;
138            }
139            if (writeCount != readCount) {
140                fprintf(stderr, "acp: partial write to '%s' (%zd of %zd)\n",
141                    dst, writeCount, readCount);
142                return -1;
143            }
144        }
145
146        if (readCount < (ssize_t) sizeof(buf))
147            break;
148    }
149
150    return 0;
151}
152
153/*
154 * Set the permissions, owner, and timestamps on the destination file
155 * equal to those of the source file.
156 *
157 * Failures here are "soft"; they don't produce warning messages and don't
158 * cause the cp command to report a failure.
159 */
160static int setPermissions(const char* dst, const struct stat* pSrcStat, unsigned int options)
161{
162    struct utimbuf ut;
163
164    if (options & COPY_TIMESTAMPS) {
165        /*
166         * Start with timestamps.  The access and mod dates are not affected
167         * by the next operations.
168         */
169        ut.actime = pSrcStat->st_atime;
170        ut.modtime = pSrcStat->st_mtime;
171        if (isHiresMtime(pSrcStat))
172            ut.modtime += 1;
173        if (utime(dst, &ut) != 0) {
174            DBUG(("---   unable to set timestamps on '%s': %s\n",
175                dst, strerror(errno)));
176        }
177    }
178
179    if (options & COPY_PERMISSIONS) {
180        /*
181         * Set the permissions.
182         */
183        if (chmod(dst, pSrcStat->st_mode & ~(S_IFMT)) != 0) {
184            DBUG(("---   unable to set perms on '%s' to 0%o: %s\n",
185                dst, pSrcStat->st_mode & ~(S_IFMT), strerror(errno)));
186        }
187#ifndef _WIN32
188        /*
189         * Set the owner.
190         */
191        if (chown(dst, pSrcStat->st_uid, pSrcStat->st_gid) != 0) {
192            DBUG(("---   unable to set owner of '%s' to %d/%d: %s\n",
193                dst, pSrcStat->st_uid, pSrcStat->st_gid, strerror(errno)));
194        }
195#endif
196    }
197
198    return 0;
199}
200
201/*
202 * Copy a regular file.  If the destination file exists and is not a
203 * regular file, we fail.  However, we use stat() rather than lstat(),
204 * because it's okay to write through a symlink (the noDereference stuff
205 * only applies to the source file).
206 *
207 * If the file doesn't exist, create it.  If it does exist, truncate it.
208 */
209static int copyRegular(const char* src, const char* dst, const struct stat* pSrcStat, unsigned int options)
210{
211    struct stat dstStat;
212    int srcFd, dstFd, statResult, copyResult;
213
214    DBUG(("--- copying regular '%s' to '%s'\n", src, dst));
215
216    statResult = stat(dst, &dstStat);
217    if (statResult == 0 && !S_ISREG(dstStat.st_mode)) {
218        fprintf(stderr,
219            "acp: destination '%s' exists and is not regular file\n",
220            dst);
221        return -1;
222    } else if (statResult != 0 && errno != ENOENT) {
223        fprintf(stderr, "acp: unable to stat destination '%s'\n", dst);
224        return -1;
225    }
226
227    if (statResult == 0) {
228        if (isSameFile(pSrcStat, &dstStat)) {
229            fprintf(stderr, "acp: '%s' and '%s' are the same file\n",
230                src, dst);
231            return -1;
232        }
233        if (options & COPY_UPDATE_ONLY) {
234            if (!isSourceNewer(pSrcStat, &dstStat)) {
235                DBUG(("---  source is not newer: '%s'\n", src));
236                printNotNewerMsg(src, dst, options);
237                return 0;
238            }
239        }
240    }
241
242    /* open src */
243    srcFd = open(src, O_RDONLY | O_BINARY, 0);
244    if (srcFd < 0) {
245        fprintf(stderr, "acp: unable to open '%s': %s\n", src, strerror(errno));
246        return -1;
247    }
248
249    /* open dest with O_CREAT | O_TRUNC */
250    DBUG(("---  opening '%s'\n", dst));
251    dstFd = open(dst, O_CREAT | O_TRUNC | O_WRONLY | O_BINARY, 0644);
252
253    if (dstFd < 0) {
254        if (errno == ENOENT) {
255            /* this happens if the target directory doesn't exist */
256            fprintf(stderr,
257                "acp: cannot create '%s': %s\n", dst, strerror(errno));
258            (void) close(srcFd);
259            return -1;
260        }
261
262        /* if "force" is set, try removing the destination file and retry */
263        if (options & COPY_FORCE) {
264            if (unlink(dst) != 0) {
265#ifdef _WIN32
266				/* MSVCRT.DLL unlink will fail with EACCESS if the file is set read-only */
267				/* so try to change its mode, and unlink again                           */
268				if (errno == EACCESS) {
269					if (chmod(dst, S_IWRITE|S_IREAD) == 0 && unlink(dst) == 0)
270						goto Open_File;
271				}
272#endif
273                fprintf(stderr, "acp: unable to remove '%s': %s\n",
274                    dst, strerror(errno));
275                (void) close(srcFd);
276                return -1;
277            }
278#ifdef _WIN32
279        Open_File:
280#endif
281            dstFd = open(dst, O_CREAT | O_TRUNC | O_WRONLY | O_BINARY, 0644);
282        }
283    }
284    if (dstFd < 0) {
285        fprintf(stderr, "acp: unable to open '%s': %s\n",
286            dst, strerror(errno));
287        (void) close(srcFd);
288        return -1;
289    }
290
291    copyResult = copyFileContents(dst, dstFd, src, srcFd);
292
293    (void) close(srcFd);
294    (void) close(dstFd);
295    if (copyResult != 0)
296        return -1;
297
298#if defined(__APPLE__)
299    // Copy Mac OS X resource forks too.
300    {
301        char* srcRsrcName = NULL;
302        char* dstRsrcName = NULL;
303        struct stat rsrcStat;
304
305        srcRsrcName = malloc(strlen(src) + 5 + 1);
306        strcpy(srcRsrcName, src);
307        strcat(srcRsrcName, "/rsrc");
308
309        dstRsrcName = malloc(strlen(dst) + 5 + 1);
310        strcpy(dstRsrcName, dst);
311        strcat(dstRsrcName, "/rsrc");
312
313        if (stat(srcRsrcName, &rsrcStat) == 0 && rsrcStat.st_size > 0) {
314            DBUG(("---  RSRC: %s --> %s\n", srcRsrcName, dstRsrcName));
315
316            srcFd = open(srcRsrcName, O_RDONLY);
317            dstFd = open(dstRsrcName, O_TRUNC | O_WRONLY, 0);
318            copyResult = -1;
319            if (srcFd >= 0 && dstFd >= 0) {
320                copyResult = copyFileContents(dstRsrcName, dstFd,
321                    srcRsrcName, srcFd);
322                (void) close(srcFd);
323                (void) close(dstFd);
324            }
325
326            if (copyResult != 0)
327                return -1;
328        }
329
330        free(srcRsrcName);
331        free(dstRsrcName);
332    }
333#endif
334
335    setPermissions(dst, pSrcStat, options);
336
337    printCopyMsg(src, dst, options);
338
339    return 0;
340}
341
342
343/*
344 * Copy a symlink.  This only happens if we're in "no derefence" mode,
345 * in which we copy the links rather than the files that are pointed at.
346 *
347 * We always discard the destination file.  If it's a symlink already,
348 * we want to throw it out and replace it.  If it's not a symlink, we
349 * need to trash it so we can create one.
350 */
351#if defined(_WIN32)
352extern int copySymlink(const char* src, const char* dst, const struct stat* pSrcStat, unsigned int options) __attribute__((error("no symlinks on Windows")));
353#else
354static int copySymlink(const char* src, const char* dst, const struct stat* pSrcStat, unsigned int options)
355{
356    struct stat dstStat;
357    char linkBuf[PATH_MAX+1];
358    int statResult, nameLen;
359
360    assert(options & COPY_NO_DEREFERENCE);
361    DBUG(("--- copying symlink '%s' to '%s'\n", src, dst));
362
363    /* NOTE: we use lstat() here */
364    statResult = lstat(dst, &dstStat);
365    if (statResult == 0 && !S_ISREG(dstStat.st_mode)
366                         && !S_ISLNK(dstStat.st_mode)
367						 )
368    {
369        fprintf(stderr,
370            "acp: destination '%s' exists and is not regular or symlink\n",
371            dst);
372        return -1;
373    }
374
375    if (statResult == 0) {
376        if (isSameFile(pSrcStat, &dstStat)) {
377            fprintf(stderr, "acp: '%s' and '%s' are the same file\n",
378                src, dst);
379            return -1;
380        }
381        if (options & COPY_UPDATE_ONLY) {
382            if (!isSourceNewer(pSrcStat, &dstStat)) {
383                DBUG(("---  source is not newer: '%s'\n", src));
384                printNotNewerMsg(src, dst, options);
385                return 0;
386            }
387        }
388    }
389
390    /* extract the symlink contents */
391    nameLen = readlink(src, linkBuf, sizeof(linkBuf)-1);
392    if (nameLen <= 0) {
393        fprintf(stderr, "acp: unable to read symlink '%s': %s\n",
394            src, strerror(errno));
395        return -1;
396    }
397    linkBuf[nameLen] = '\0';
398    DBUG(("--- creating symlink file '%s' (--> %s)\n", dst, linkBuf));
399
400    if (statResult == 0) {
401        DBUG(("---  removing '%s'\n", dst));
402        if (unlink(dst) != 0) {
403            fprintf(stderr, "acp: unable to remove '%s': %s\n",
404                dst, strerror(errno));
405            return -1;
406        }
407    }
408
409    if (symlink(linkBuf, dst) != 0) {
410        fprintf(stderr, "acp: unable to create symlink '%s' [%s]: %s\n",
411            dst, linkBuf, strerror(errno));
412        return -1;
413    }
414
415    /*
416     * There's no way to set the file date or access permissions, but
417     * it is possible to set the owner.
418     */
419    if (options & COPY_PERMISSIONS) {
420        if (lchown(dst, pSrcStat->st_uid, pSrcStat->st_gid) != 0)
421            DBUG(("---  lchown failed: %s\n", strerror(errno)));
422    }
423
424    printCopyMsg(src, dst, options);
425
426    return 0;
427}
428#endif
429
430/*
431 * Copy the contents of one directory to another.  Both "src" and "dst"
432 * must be directories.  We will create "dst" if it does not exist.
433 */
434int copyDirectory(const char* src, const char* dst, const struct stat* pSrcStat, unsigned int options)
435{
436    int retVal = 0;
437    struct stat dstStat;
438    DIR* dir;
439    int cc, statResult;
440
441    DBUG(("--- copy dir '%s' to '%s'\n", src, dst));
442
443    statResult = stat(dst, &dstStat);
444    if (statResult == 0 && !S_ISDIR(dstStat.st_mode)) {
445        fprintf(stderr,
446            "acp: destination '%s' exists and is not a directory\n", dst);
447        return -1;
448    } else if (statResult != 0 && errno != ENOENT) {
449        fprintf(stderr, "acp: unable to stat destination '%s'\n", dst);
450        return -1;
451    }
452
453    if (statResult == 0) {
454        if (isSameFile(pSrcStat, &dstStat)) {
455            fprintf(stderr,
456                "acp: cannot copy directory into itself ('%s' and '%s')\n",
457                src, dst);
458            return -1;
459        }
460    } else {
461        DBUG(("---  creating dir '%s'\n", dst));
462        cc = mkdir(dst, 0755);
463        if (cc != 0) {
464            fprintf(stderr, "acp: unable to create directory '%s': %s\n",
465                dst, strerror(errno));
466            return -1;
467        }
468
469        /* only print on mkdir */
470        printCopyMsg(src, dst, options);
471    }
472
473    /*
474     * Open the directory, and plow through its contents.
475     */
476    dir = opendir(src);
477    if (dir == NULL) {
478        fprintf(stderr, "acp: unable to open directory '%s': %s\n",
479            src, strerror(errno));
480        return -1;
481    }
482
483    while (1) {
484        struct dirent* ent;
485        char* srcFile;
486        char* dstFile;
487        int srcLen, dstLen, nameLen;
488
489        ent = readdir(dir);
490        if (ent == NULL)
491            break;
492
493        if (strcmp(ent->d_name, ".") == 0 ||
494            strcmp(ent->d_name, "..") == 0)
495        {
496            continue;
497        }
498
499        nameLen = strlen(ent->d_name);
500        srcLen = strlen(src);
501        dstLen = strlen(dst);
502
503        srcFile = malloc(srcLen +1 + nameLen +1);
504        memcpy(srcFile, src, srcLen);
505        srcFile[srcLen] = FSSEP;
506        memcpy(srcFile + srcLen+1, ent->d_name, nameLen +1);
507
508        dstFile = malloc(dstLen +1 + nameLen +1);
509        memcpy(dstFile, dst, dstLen);
510        dstFile[dstLen] = FSSEP;
511        memcpy(dstFile + dstLen+1, ent->d_name, nameLen +1);
512
513        if (copyFileRecursive(srcFile, dstFile, false, options) != 0)
514            retVal = -1;        /* note failure and keep going */
515
516        free(srcFile);
517        free(dstFile);
518    }
519    closedir(dir);
520
521    setPermissions(dst, pSrcStat, options);
522
523    return retVal;
524}
525
526/*
527 * Do the actual copy.  This is called recursively from copyDirectory().
528 *
529 * "dst" should only be a directory if "src" is also a directory.
530 *
531 * Returns 0 on success.
532 */
533static int copyFileRecursive(const char* src, const char* dst, bool isCmdLine, unsigned int options)
534{
535    char* srcExe = NULL;
536    char* dstExe = NULL;
537    char* dstDir = NULL;
538    struct stat srcStat;
539    int retVal = 0;
540    int statResult, statErrno;
541    (void)isCmdLine;
542
543    /*
544     * Stat the source file.  If it doesn't exist, fail.
545     */
546    if (options & COPY_NO_DEREFERENCE)
547        statResult = lstat(src, &srcStat);
548    else
549        statResult = stat(src, &srcStat);
550    statErrno = errno;        /* preserve across .exe attempt */
551
552    if (statResult < 0) {
553        if (statErrno == ENOENT)
554            fprintf(stderr, "acp: file '%s' does not exist\n", src);
555        else
556            fprintf(stderr, "acp: unable to stat '%s': %s\n",
557                src, strerror(statErrno));
558        retVal = -1;
559        goto bail;
560    }
561
562    /*
563     * If "src" is a directory, ignore it if "recursive" isn't set.
564     *
565     * We want to create "dst" as a directory (or verify that it already
566     * exists as a directory), and then copy its contents.
567     */
568    if (S_ISDIR(srcStat.st_mode)) {
569        if (!(options & COPY_RECURSIVE)) {
570            fprintf(stderr, "acp: omitting directory '%s'\n", src);
571        } else {
572            retVal = copyDirectory(src, dst, &srcStat, options);
573        }
574    } else if (S_ISLNK(srcStat.st_mode)) {
575        retVal = copySymlink(src, dst, &srcStat, options);
576    } else if (S_ISREG(srcStat.st_mode)) {
577        retVal = copyRegular(src, dst, &srcStat, options);
578    } else {
579        fprintf(stderr, "acp: skipping unusual file '%s' (mode=0%o)\n",
580            src, srcStat.st_mode);
581        retVal = -1;
582    }
583
584bail:
585    free(srcExe);
586    free(dstExe);
587    free(dstDir);
588    return retVal;
589}
590
591int copyFile(const char* src, const char* dst, unsigned int options)
592{
593    return copyFileRecursive(src, dst, true, options);
594}
595
596
597