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
|
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2014 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <sys/sendfile.h>
#include "util.h"
#include "copy.h"
int copy_bytes(int fdf, int fdt, off_t max_bytes) {
bool try_sendfile = true;
assert(fdf >= 0);
assert(fdt >= 0);
for (;;) {
size_t m = PIPE_BUF;
ssize_t n;
if (max_bytes != (off_t) -1) {
if (max_bytes <= 0)
return -EFBIG;
if ((off_t) m > max_bytes)
m = (size_t) max_bytes;
}
/* First try sendfile(), unless we already tried */
if (try_sendfile) {
n = sendfile(fdt, fdf, NULL, m);
if (n < 0) {
if (errno != EINVAL && errno != ENOSYS)
return -errno;
try_sendfile = false;
/* use fallback below */
} else if (n == 0) /* EOF */
break;
else if (n > 0)
/* Succcess! */
goto next;
}
/* As a fallback just copy bits by hand */
{
char buf[m];
int r;
n = read(fdf, buf, m);
if (n < 0)
return -errno;
if (n == 0) /* EOF */
break;
r = loop_write(fdt, buf, n, false);
if (r < 0)
return r;
}
next:
if (max_bytes != (off_t) -1) {
assert(max_bytes >= n);
max_bytes -= n;
}
}
return 0;
}
static int fd_copy_symlink(int df, const char *from, const struct stat *st, int dt, const char *to) {
_cleanup_free_ char *target = NULL;
int r;
assert(from);
assert(st);
assert(to);
r = readlinkat_malloc(df, from, &target);
if (r < 0)
return r;
if (symlinkat(target, dt, to) < 0)
return -errno;
if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
return -errno;
return 0;
}
static int fd_copy_regular(int df, const char *from, const struct stat *st, int dt, const char *to) {
_cleanup_close_ int fdf = -1, fdt = -1;
int r, q;
assert(from);
assert(st);
assert(to);
fdf = openat(df, from, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
if (fdf < 0)
return -errno;
fdt = openat(dt, to, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, st->st_mode & 07777);
if (fdt < 0)
return -errno;
r = copy_bytes(fdf, fdt, (off_t) -1);
if (r < 0) {
unlinkat(dt, to, 0);
return r;
}
if (fchown(fdt, st->st_uid, st->st_gid) < 0)
r = -errno;
if (fchmod(fdt, st->st_mode & 07777) < 0)
r = -errno;
q = close(fdt);
fdt = -1;
if (q < 0) {
r = -errno;
unlinkat(dt, to, 0);
}
return r;
}
static int fd_copy_fifo(int df, const char *from, const struct stat *st, int dt, const char *to) {
int r;
assert(from);
assert(st);
assert(to);
r = mkfifoat(dt, to, st->st_mode & 07777);
if (r < 0)
return -errno;
if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
r = -errno;
if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
r = -errno;
return r;
}
static int fd_copy_node(int df, const char *from, const struct stat *st, int dt, const char *to) {
int r;
assert(from);
assert(st);
assert(to);
r = mknodat(dt, to, st->st_mode, st->st_rdev);
if (r < 0)
return -errno;
if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
r = -errno;
if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
r = -errno;
return r;
}
static int fd_copy_directory(int df, const char *from, const struct stat *st, int dt, const char *to, dev_t original_device, bool merge) {
_cleanup_close_ int fdf = -1, fdt = -1;
_cleanup_closedir_ DIR *d = NULL;
struct dirent *de;
bool created;
int r;
assert(from);
assert(st);
assert(to);
fdf = openat(df, from, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
if (fdf < 0)
return -errno;
d = fdopendir(fdf);
if (!d)
return -errno;
fdf = -1;
r = mkdirat(dt, to, st->st_mode & 07777);
if (r >= 0)
created = true;
else if (errno == EEXIST && merge)
created = false;
else
return -errno;
fdt = openat(dt, to, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
if (fdt < 0)
return -errno;
r = 0;
if (created) {
if (fchown(fdt, st->st_uid, st->st_gid) < 0)
r = -errno;
if (fchmod(fdt, st->st_mode & 07777) < 0)
r = -errno;
}
FOREACH_DIRENT(de, d, return -errno) {
struct stat buf;
int q;
if (fstatat(dirfd(d), de->d_name, &buf, AT_SYMLINK_NOFOLLOW) < 0) {
r = -errno;
continue;
}
if (buf.st_dev != original_device)
continue;
if (S_ISREG(buf.st_mode))
q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name);
else if (S_ISDIR(buf.st_mode))
q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, merge);
else if (S_ISLNK(buf.st_mode))
q = fd_copy_symlink(dirfd(d), de->d_name, &buf, fdt, de->d_name);
else if (S_ISFIFO(buf.st_mode))
q = fd_copy_fifo(dirfd(d), de->d_name, &buf, fdt, de->d_name);
else if (S_ISBLK(buf.st_mode) || S_ISCHR(buf.st_mode))
q = fd_copy_node(dirfd(d), de->d_name, &buf, fdt, de->d_name);
else
q = -ENOTSUP;
if (q == -EEXIST && merge)
q = 0;
if (q < 0)
r = q;
}
return r;
}
int copy_tree(const char *from, const char *to, bool merge) {
struct stat st;
assert(from);
assert(to);
if (lstat(from, &st) < 0)
return -errno;
if (S_ISREG(st.st_mode))
return fd_copy_regular(AT_FDCWD, from, &st, AT_FDCWD, to);
else if (S_ISDIR(st.st_mode))
return fd_copy_directory(AT_FDCWD, from, &st, AT_FDCWD, to, st.st_dev, merge);
else if (S_ISLNK(st.st_mode))
return fd_copy_symlink(AT_FDCWD, from, &st, AT_FDCWD, to);
else if (S_ISFIFO(st.st_mode))
return fd_copy_fifo(AT_FDCWD, from, &st, AT_FDCWD, to);
else if (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode))
return fd_copy_node(AT_FDCWD, from, &st, AT_FDCWD, to);
else
return -ENOTSUP;
}
int copy_file_fd(const char *from, int fdt) {
_cleanup_close_ int fdf = -1;
assert(from);
assert(fdt >= 0);
fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (fdf < 0)
return -errno;
return copy_bytes(fdf, fdt, (off_t) -1);
}
int copy_file(const char *from, const char *to, int flags, mode_t mode) {
int fdt, r;
assert(from);
assert(to);
fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode);
if (fdt < 0)
return -errno;
r = copy_file_fd(from, fdt);
if (r < 0) {
close(fdt);
unlink(to);
return r;
}
if (close(fdt) < 0) {
unlink_noerrno(to);
return -errno;
}
return 0;
}
|
