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37ef15bb CB |
1 | /* liblxcapi |
2 | * | |
3 | * Copyright © 2018 Christian Brauner <christian.brauner@ubuntu.com>. | |
4 | * Copyright © 2018 Canonical Ltd. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2, as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License along | |
16 | * with this program; if not, write to the Free Software Foundation, Inc., | |
17 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 | */ | |
19 | ||
d38dd64a CB |
20 | #ifndef _GNU_SOURCE |
21 | #define _GNU_SOURCE 1 | |
22 | #endif | |
37ef15bb CB |
23 | #include <errno.h> |
24 | #include <fcntl.h> | |
25 | #include <linux/magic.h> | |
26 | #include <stdlib.h> | |
27 | #include <sys/stat.h> | |
7c4d9466 | 28 | #include <sys/sendfile.h> |
37ef15bb CB |
29 | #include <sys/types.h> |
30 | ||
d38dd64a | 31 | #include "config.h" |
37ef15bb CB |
32 | #include "file_utils.h" |
33 | #include "log.h" | |
34 | #include "macro.h" | |
35 | #include "string.h" | |
36 | ||
37ef15bb | 37 | lxc_log_define(file_utils, lxc); |
37ef15bb CB |
38 | |
39 | int lxc_write_to_file(const char *filename, const void *buf, size_t count, | |
40 | bool add_newline, mode_t mode) | |
41 | { | |
42 | int fd, saved_errno; | |
43 | ssize_t ret; | |
44 | ||
45 | fd = open(filename, O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode); | |
46 | if (fd < 0) | |
47 | return -1; | |
48 | ||
49 | ret = lxc_write_nointr(fd, buf, count); | |
50 | if (ret < 0) | |
51 | goto out_error; | |
52 | ||
53 | if ((size_t)ret != count) | |
54 | goto out_error; | |
55 | ||
56 | if (add_newline) { | |
57 | ret = lxc_write_nointr(fd, "\n", 1); | |
58 | if (ret != 1) | |
59 | goto out_error; | |
60 | } | |
61 | ||
62 | close(fd); | |
63 | return 0; | |
64 | ||
65 | out_error: | |
66 | saved_errno = errno; | |
67 | close(fd); | |
68 | errno = saved_errno; | |
69 | return -1; | |
70 | } | |
71 | ||
72 | int lxc_read_from_file(const char *filename, void *buf, size_t count) | |
73 | { | |
74 | int fd = -1, saved_errno; | |
75 | ssize_t ret; | |
76 | ||
77 | fd = open(filename, O_RDONLY | O_CLOEXEC); | |
78 | if (fd < 0) | |
79 | return -1; | |
80 | ||
81 | if (!buf || !count) { | |
82 | char buf2[100]; | |
83 | size_t count2 = 0; | |
84 | ||
85 | while ((ret = lxc_read_nointr(fd, buf2, 100)) > 0) | |
86 | count2 += ret; | |
87 | ||
88 | if (ret >= 0) | |
89 | ret = count2; | |
90 | } else { | |
91 | memset(buf, 0, count); | |
92 | ret = lxc_read_nointr(fd, buf, count); | |
93 | } | |
94 | ||
95 | saved_errno = errno; | |
96 | close(fd); | |
97 | errno = saved_errno; | |
98 | return ret; | |
99 | } | |
100 | ||
101 | ssize_t lxc_write_nointr(int fd, const void *buf, size_t count) | |
102 | { | |
103 | ssize_t ret; | |
104 | again: | |
105 | ret = write(fd, buf, count); | |
106 | if (ret < 0 && errno == EINTR) | |
107 | goto again; | |
108 | ||
109 | return ret; | |
110 | } | |
111 | ||
28143f88 CB |
112 | ssize_t lxc_send_nointr(int sockfd, void *buf, size_t len, int flags) |
113 | { | |
114 | ssize_t ret; | |
115 | again: | |
116 | ret = send(sockfd, buf, len, flags); | |
117 | if (ret < 0 && errno == EINTR) | |
118 | goto again; | |
119 | ||
120 | return ret; | |
121 | } | |
122 | ||
37ef15bb CB |
123 | ssize_t lxc_read_nointr(int fd, void *buf, size_t count) |
124 | { | |
125 | ssize_t ret; | |
126 | again: | |
127 | ret = read(fd, buf, count); | |
128 | if (ret < 0 && errno == EINTR) | |
129 | goto again; | |
130 | ||
131 | return ret; | |
132 | } | |
133 | ||
de69edd1 CB |
134 | ssize_t lxc_recv_nointr(int sockfd, void *buf, size_t len, int flags) |
135 | { | |
136 | ssize_t ret; | |
137 | again: | |
138 | ret = recv(sockfd, buf, len, flags); | |
139 | if (ret < 0 && errno == EINTR) | |
140 | goto again; | |
141 | ||
142 | return ret; | |
143 | } | |
144 | ||
37ef15bb CB |
145 | ssize_t lxc_read_nointr_expect(int fd, void *buf, size_t count, const void *expected_buf) |
146 | { | |
147 | ssize_t ret; | |
148 | ||
149 | ret = lxc_read_nointr(fd, buf, count); | |
150 | if (ret <= 0) | |
151 | return ret; | |
152 | ||
153 | if ((size_t)ret != count) | |
154 | return -1; | |
155 | ||
156 | if (expected_buf && memcmp(buf, expected_buf, count) != 0) { | |
157 | errno = EINVAL; | |
158 | return -1; | |
159 | } | |
160 | ||
161 | return ret; | |
162 | } | |
163 | ||
164 | bool file_exists(const char *f) | |
165 | { | |
166 | struct stat statbuf; | |
167 | ||
168 | return stat(f, &statbuf) == 0; | |
169 | } | |
170 | ||
171 | int print_to_file(const char *file, const char *content) | |
172 | { | |
173 | FILE *f; | |
174 | int ret = 0; | |
175 | ||
176 | f = fopen(file, "w"); | |
177 | if (!f) | |
178 | return -1; | |
179 | ||
180 | if (fprintf(f, "%s", content) != strlen(content)) | |
181 | ret = -1; | |
182 | ||
183 | fclose(f); | |
184 | return ret; | |
185 | } | |
186 | ||
187 | int is_dir(const char *path) | |
188 | { | |
189 | struct stat statbuf; | |
190 | int ret; | |
191 | ||
192 | ret = stat(path, &statbuf); | |
193 | if (ret == 0 && S_ISDIR(statbuf.st_mode)) | |
194 | return 1; | |
195 | ||
196 | return 0; | |
197 | } | |
198 | ||
199 | /* | |
200 | * Return the number of lines in file @fn, or -1 on error | |
201 | */ | |
202 | int lxc_count_file_lines(const char *fn) | |
203 | { | |
204 | FILE *f; | |
205 | char *line = NULL; | |
206 | size_t sz = 0; | |
207 | int n = 0; | |
208 | ||
209 | f = fopen_cloexec(fn, "r"); | |
210 | if (!f) | |
211 | return -1; | |
212 | ||
213 | while (getline(&line, &sz, f) != -1) { | |
214 | n++; | |
215 | } | |
216 | ||
217 | free(line); | |
218 | fclose(f); | |
219 | return n; | |
220 | } | |
221 | ||
222 | int lxc_make_tmpfile(char *template, bool rm) | |
223 | { | |
224 | int fd, ret; | |
225 | mode_t msk; | |
226 | ||
227 | msk = umask(0022); | |
228 | fd = mkstemp(template); | |
229 | umask(msk); | |
230 | if (fd < 0) | |
231 | return -1; | |
232 | ||
233 | if (!rm) | |
234 | return fd; | |
235 | ||
236 | ret = unlink(template); | |
237 | if (ret < 0) { | |
238 | close(fd); | |
239 | return -1; | |
240 | } | |
241 | ||
242 | return fd; | |
243 | } | |
244 | ||
37ef15bb CB |
245 | bool is_fs_type(const struct statfs *fs, fs_type_magic magic_val) |
246 | { | |
247 | return (fs->f_type == (fs_type_magic)magic_val); | |
248 | } | |
249 | ||
250 | bool has_fs_type(const char *path, fs_type_magic magic_val) | |
251 | { | |
37ef15bb CB |
252 | int ret; |
253 | struct statfs sb; | |
254 | ||
255 | ret = statfs(path, &sb); | |
256 | if (ret < 0) | |
257 | return false; | |
258 | ||
259 | return is_fs_type(&sb, magic_val); | |
260 | } | |
261 | ||
262 | bool fhas_fs_type(int fd, fs_type_magic magic_val) | |
263 | { | |
264 | int ret; | |
265 | struct statfs sb; | |
266 | ||
267 | ret = fstatfs(fd, &sb); | |
268 | if (ret < 0) | |
269 | return false; | |
270 | ||
271 | return is_fs_type(&sb, magic_val); | |
272 | } | |
273 | ||
274 | FILE *fopen_cloexec(const char *path, const char *mode) | |
275 | { | |
276 | int open_mode = 0; | |
277 | int step = 0; | |
278 | int fd; | |
279 | int saved_errno = 0; | |
280 | FILE *ret; | |
281 | ||
282 | if (!strncmp(mode, "r+", 2)) { | |
283 | open_mode = O_RDWR; | |
284 | step = 2; | |
285 | } else if (!strncmp(mode, "r", 1)) { | |
286 | open_mode = O_RDONLY; | |
287 | step = 1; | |
288 | } else if (!strncmp(mode, "w+", 2)) { | |
289 | open_mode = O_RDWR | O_TRUNC | O_CREAT; | |
290 | step = 2; | |
291 | } else if (!strncmp(mode, "w", 1)) { | |
292 | open_mode = O_WRONLY | O_TRUNC | O_CREAT; | |
293 | step = 1; | |
294 | } else if (!strncmp(mode, "a+", 2)) { | |
295 | open_mode = O_RDWR | O_CREAT | O_APPEND; | |
296 | step = 2; | |
297 | } else if (!strncmp(mode, "a", 1)) { | |
298 | open_mode = O_WRONLY | O_CREAT | O_APPEND; | |
299 | step = 1; | |
300 | } | |
301 | for (; mode[step]; step++) | |
302 | if (mode[step] == 'x') | |
303 | open_mode |= O_EXCL; | |
304 | open_mode |= O_CLOEXEC; | |
305 | ||
3e9bde7e | 306 | fd = open(path, open_mode, 0660); |
37ef15bb CB |
307 | if (fd < 0) |
308 | return NULL; | |
309 | ||
310 | ret = fdopen(fd, mode); | |
311 | saved_errno = errno; | |
312 | if (!ret) | |
313 | close(fd); | |
314 | errno = saved_errno; | |
315 | return ret; | |
316 | } | |
7c4d9466 CB |
317 | |
318 | ssize_t lxc_sendfile_nointr(int out_fd, int in_fd, off_t *offset, size_t count) | |
319 | { | |
320 | ssize_t ret; | |
321 | ||
322 | again: | |
323 | ret = sendfile(out_fd, in_fd, offset, count); | |
324 | if (ret < 0) { | |
325 | if (errno == EINTR) | |
326 | goto again; | |
327 | ||
328 | return -1; | |
329 | } | |
330 | ||
331 | return ret; | |
332 | } |