diff options
Diffstat (limited to 'libbb/copy_file.c')
-rw-r--r-- | libbb/copy_file.c | 282 |
1 files changed, 282 insertions, 0 deletions
diff --git a/libbb/copy_file.c b/libbb/copy_file.c new file mode 100644 index 000000000..0135831fe --- /dev/null +++ b/libbb/copy_file.c | |||
@@ -0,0 +1,282 @@ | |||
1 | /* vi: set sw=4 ts=4: */ | ||
2 | /* | ||
3 | * Mini copy_file implementation for busybox | ||
4 | * | ||
5 | * Copyright (C) 2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu> | ||
6 | * | ||
7 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. | ||
8 | * | ||
9 | */ | ||
10 | |||
11 | #include "libbb.h" | ||
12 | |||
13 | static int retry_overwrite(const char *dest, int flags) | ||
14 | { | ||
15 | if (!(flags & (FILEUTILS_FORCE|FILEUTILS_INTERACTIVE))) { | ||
16 | fprintf(stderr, "'%s' exists\n", dest); | ||
17 | return -1; | ||
18 | } | ||
19 | if (flags & FILEUTILS_INTERACTIVE) { | ||
20 | fprintf(stderr, "%s: overwrite '%s'? ", applet_name, dest); | ||
21 | if (!bb_ask_confirmation()) | ||
22 | return 0; // not allowed to overwrite | ||
23 | } | ||
24 | if (unlink(dest) < 0) { | ||
25 | bb_perror_msg("cannot remove '%s'", dest); | ||
26 | return -1; // error | ||
27 | } | ||
28 | return 1; // ok (to try again) | ||
29 | } | ||
30 | |||
31 | int copy_file(const char *source, const char *dest, int flags) | ||
32 | { | ||
33 | struct stat source_stat; | ||
34 | struct stat dest_stat; | ||
35 | int status = 0; | ||
36 | signed char dest_exists = 0; | ||
37 | signed char ovr; | ||
38 | |||
39 | #define FLAGS_DEREF (flags & FILEUTILS_DEREFERENCE) | ||
40 | |||
41 | if ((FLAGS_DEREF ? stat : lstat)(source, &source_stat) < 0) { | ||
42 | // This may be a dangling symlink. | ||
43 | // Making [sym]links to dangling symlinks works, so... | ||
44 | if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) | ||
45 | goto make_links; | ||
46 | bb_perror_msg("cannot stat '%s'", source); | ||
47 | return -1; | ||
48 | } | ||
49 | |||
50 | if (lstat(dest, &dest_stat) < 0) { | ||
51 | if (errno != ENOENT) { | ||
52 | bb_perror_msg("cannot stat '%s'", dest); | ||
53 | return -1; | ||
54 | } | ||
55 | } else { | ||
56 | if (source_stat.st_dev == dest_stat.st_dev | ||
57 | && source_stat.st_ino == dest_stat.st_ino | ||
58 | ) { | ||
59 | bb_error_msg("'%s' and '%s' are the same file", source, dest); | ||
60 | return -1; | ||
61 | } | ||
62 | dest_exists = 1; | ||
63 | } | ||
64 | |||
65 | if (S_ISDIR(source_stat.st_mode)) { | ||
66 | DIR *dp; | ||
67 | struct dirent *d; | ||
68 | mode_t saved_umask = 0; | ||
69 | |||
70 | if (!(flags & FILEUTILS_RECUR)) { | ||
71 | bb_error_msg("omitting directory '%s'", source); | ||
72 | return -1; | ||
73 | } | ||
74 | |||
75 | /* Create DEST. */ | ||
76 | if (dest_exists) { | ||
77 | if (!S_ISDIR(dest_stat.st_mode)) { | ||
78 | bb_error_msg("target '%s' is not a directory", dest); | ||
79 | return -1; | ||
80 | } | ||
81 | } else { | ||
82 | mode_t mode; | ||
83 | saved_umask = umask(0); | ||
84 | |||
85 | mode = source_stat.st_mode; | ||
86 | if (!(flags & FILEUTILS_PRESERVE_STATUS)) | ||
87 | mode = source_stat.st_mode & ~saved_umask; | ||
88 | mode |= S_IRWXU; | ||
89 | |||
90 | if (mkdir(dest, mode) < 0) { | ||
91 | umask(saved_umask); | ||
92 | bb_perror_msg("cannot create directory '%s'", dest); | ||
93 | return -1; | ||
94 | } | ||
95 | |||
96 | umask(saved_umask); | ||
97 | } | ||
98 | |||
99 | /* Recursively copy files in SOURCE. */ | ||
100 | dp = opendir(source); | ||
101 | if (dp == NULL) { | ||
102 | status = -1; | ||
103 | goto preserve_status; | ||
104 | } | ||
105 | |||
106 | while ((d = readdir(dp)) != NULL) { | ||
107 | char *new_source, *new_dest; | ||
108 | |||
109 | new_source = concat_subpath_file(source, d->d_name); | ||
110 | if (new_source == NULL) | ||
111 | continue; | ||
112 | new_dest = concat_path_file(dest, d->d_name); | ||
113 | if (copy_file(new_source, new_dest, flags) < 0) | ||
114 | status = -1; | ||
115 | free(new_source); | ||
116 | free(new_dest); | ||
117 | } | ||
118 | closedir(dp); | ||
119 | |||
120 | if (!dest_exists | ||
121 | && chmod(dest, source_stat.st_mode & ~saved_umask) < 0 | ||
122 | ) { | ||
123 | bb_perror_msg("cannot change permissions of '%s'", dest); | ||
124 | status = -1; | ||
125 | } | ||
126 | |||
127 | } else if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) { | ||
128 | int (*lf)(const char *oldpath, const char *newpath); | ||
129 | make_links: | ||
130 | // Hmm... maybe | ||
131 | // if (DEREF && MAKE_SOFTLINK) source = realpath(source) ? | ||
132 | // (but realpath returns NULL on dangling symlinks...) | ||
133 | lf = (flags & FILEUTILS_MAKE_SOFTLINK) ? symlink : link; | ||
134 | if (lf(source, dest) < 0) { | ||
135 | ovr = retry_overwrite(dest, flags); | ||
136 | if (ovr <= 0) | ||
137 | return ovr; | ||
138 | if (lf(source, dest) < 0) { | ||
139 | bb_perror_msg("cannot create link '%s'", dest); | ||
140 | return -1; | ||
141 | } | ||
142 | } | ||
143 | return 0; | ||
144 | |||
145 | } else if (S_ISREG(source_stat.st_mode) | ||
146 | // Huh? DEREF uses stat, which never returns links IIRC... | ||
147 | || (FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) | ||
148 | ) { | ||
149 | int src_fd; | ||
150 | int dst_fd; | ||
151 | if (ENABLE_FEATURE_PRESERVE_HARDLINKS) { | ||
152 | char *link_name; | ||
153 | |||
154 | if (!FLAGS_DEREF | ||
155 | && is_in_ino_dev_hashtable(&source_stat, &link_name) | ||
156 | ) { | ||
157 | if (link(link_name, dest) < 0) { | ||
158 | ovr = retry_overwrite(dest, flags); | ||
159 | if (ovr <= 0) | ||
160 | return ovr; | ||
161 | if (link(link_name, dest) < 0) { | ||
162 | bb_perror_msg("cannot create link '%s'", dest); | ||
163 | return -1; | ||
164 | } | ||
165 | } | ||
166 | return 0; | ||
167 | } | ||
168 | // TODO: probably is_in_.. and add_to_... | ||
169 | // can be combined: find_or_add_... | ||
170 | add_to_ino_dev_hashtable(&source_stat, dest); | ||
171 | } | ||
172 | |||
173 | src_fd = open(source, O_RDONLY); | ||
174 | if (src_fd == -1) { | ||
175 | bb_perror_msg("cannot open '%s'", source); | ||
176 | return -1; | ||
177 | } | ||
178 | |||
179 | // POSIX: if exists and -i, ask (w/o -i assume yes). | ||
180 | // Then open w/o EXCL. | ||
181 | // If open still fails and -f, try unlink, then try open again. | ||
182 | // Result: a mess: | ||
183 | // If dest is a softlink, we overwrite softlink's destination! | ||
184 | // (or fail, if it points to dir/nonexistent location/etc). | ||
185 | // This is strange, but POSIX-correct. | ||
186 | // coreutils cp has --remove-destination to override this... | ||
187 | dst_fd = open(dest, (flags & FILEUTILS_INTERACTIVE) | ||
188 | ? O_WRONLY|O_CREAT|O_TRUNC|O_EXCL | ||
189 | : O_WRONLY|O_CREAT|O_TRUNC, source_stat.st_mode); | ||
190 | if (dst_fd == -1) { | ||
191 | // We would not do POSIX insanity. -i asks, | ||
192 | // then _unlinks_ the offender. Presto. | ||
193 | // Or else we will end up having 3 open()s! | ||
194 | ovr = retry_overwrite(dest, flags); | ||
195 | if (ovr <= 0) { | ||
196 | close(src_fd); | ||
197 | return ovr; | ||
198 | } | ||
199 | dst_fd = open(dest, O_WRONLY|O_CREAT|O_TRUNC, source_stat.st_mode); | ||
200 | if (dst_fd == -1) { | ||
201 | bb_perror_msg("cannot open '%s'", dest); | ||
202 | close(src_fd); | ||
203 | return -1; | ||
204 | } | ||
205 | } | ||
206 | |||
207 | if (bb_copyfd_eof(src_fd, dst_fd) == -1) | ||
208 | status = -1; | ||
209 | if (close(dst_fd) < 0) { | ||
210 | bb_perror_msg("cannot close '%s'", dest); | ||
211 | status = -1; | ||
212 | } | ||
213 | if (close(src_fd) < 0) { | ||
214 | bb_perror_msg("cannot close '%s'", source); | ||
215 | status = -1; | ||
216 | } | ||
217 | |||
218 | } else if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode) | ||
219 | || S_ISSOCK(source_stat.st_mode) || S_ISFIFO(source_stat.st_mode) | ||
220 | || S_ISLNK(source_stat.st_mode) | ||
221 | ) { | ||
222 | // We are lazy here, a bit lax with races... | ||
223 | if (dest_exists) { | ||
224 | ovr = retry_overwrite(dest, flags); | ||
225 | if (ovr <= 0) | ||
226 | return ovr; | ||
227 | } | ||
228 | if (S_ISFIFO(source_stat.st_mode)) { | ||
229 | if (mkfifo(dest, source_stat.st_mode) < 0) { | ||
230 | bb_perror_msg("cannot create fifo '%s'", dest); | ||
231 | return -1; | ||
232 | } | ||
233 | } else if (S_ISLNK(source_stat.st_mode)) { | ||
234 | char *lpath; | ||
235 | |||
236 | lpath = xreadlink(source); | ||
237 | if (symlink(lpath, dest) < 0) { | ||
238 | bb_perror_msg("cannot create symlink '%s'", dest); | ||
239 | free(lpath); | ||
240 | return -1; | ||
241 | } | ||
242 | free(lpath); | ||
243 | |||
244 | if (flags & FILEUTILS_PRESERVE_STATUS) | ||
245 | if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0) | ||
246 | bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest); | ||
247 | |||
248 | return 0; | ||
249 | |||
250 | } else { | ||
251 | if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) { | ||
252 | bb_perror_msg("cannot create '%s'", dest); | ||
253 | return -1; | ||
254 | } | ||
255 | } | ||
256 | } else { | ||
257 | bb_error_msg("internal error: unrecognized file type"); | ||
258 | return -1; | ||
259 | } | ||
260 | |||
261 | preserve_status: | ||
262 | |||
263 | if (flags & FILEUTILS_PRESERVE_STATUS | ||
264 | /* Cannot happen: */ | ||
265 | /* && !(flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) */ | ||
266 | ) { | ||
267 | struct utimbuf times; | ||
268 | |||
269 | times.actime = source_stat.st_atime; | ||
270 | times.modtime = source_stat.st_mtime; | ||
271 | if (utime(dest, ×) < 0) | ||
272 | bb_perror_msg("cannot preserve %s of '%s'", "times", dest); | ||
273 | if (chown(dest, source_stat.st_uid, source_stat.st_gid) < 0) { | ||
274 | source_stat.st_mode &= ~(S_ISUID | S_ISGID); | ||
275 | bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest); | ||
276 | } | ||
277 | if (chmod(dest, source_stat.st_mode) < 0) | ||
278 | bb_perror_msg("cannot preserve %s of '%s'", "permissions", dest); | ||
279 | } | ||
280 | |||
281 | return status; | ||
282 | } | ||