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Commit | Line | Data |
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758ad80c SH |
1 | /* lxcfs |
2 | * | |
b11c6ec0 | 3 | * Copyright © 2014-2016 Canonical, Inc |
758ad80c SH |
4 | * Author: Serge Hallyn <serge.hallyn@ubuntu.com> |
5 | * | |
f2799430 | 6 | * See COPYING file for details. |
758ad80c SH |
7 | */ |
8 | ||
758ad80c SH |
9 | #define FUSE_USE_VERSION 26 |
10 | ||
2183082c | 11 | #include <stdio.h> |
758ad80c SH |
12 | #include <dirent.h> |
13 | #include <fcntl.h> | |
14 | #include <fuse.h> | |
15 | #include <unistd.h> | |
16 | #include <errno.h> | |
17 | #include <stdbool.h> | |
18 | #include <time.h> | |
19 | #include <string.h> | |
20 | #include <stdlib.h> | |
21 | #include <libgen.h> | |
41bb9357 | 22 | #include <sched.h> |
b11c6ec0 | 23 | #include <pthread.h> |
237e200e | 24 | #include <dlfcn.h> |
41bb9357 | 25 | #include <linux/sched.h> |
a05660a6 | 26 | #include <sys/socket.h> |
41bb9357 | 27 | #include <sys/mount.h> |
5b2dfd85 | 28 | #include <sys/epoll.h> |
41bb9357 | 29 | #include <wait.h> |
758ad80c | 30 | |
2e9c0b32 | 31 | #include "config.h" // for VERSION |
237e200e | 32 | #include "bindings.h" |
758ad80c | 33 | |
237e200e | 34 | void *dlopen_handle; |
b11c6ec0 | 35 | |
237e200e | 36 | /* Functions to keep track of number of threads using the library */ |
6d1308cb | 37 | |
237e200e SH |
38 | static int users_count; |
39 | static pthread_mutex_t user_count_mutex = PTHREAD_MUTEX_INITIALIZER; | |
b11c6ec0 | 40 | static void lock_mutex(pthread_mutex_t *l) |
2c51f8dd | 41 | { |
b11c6ec0 | 42 | int ret; |
2c51f8dd | 43 | |
b11c6ec0 SH |
44 | if ((ret = pthread_mutex_lock(l)) != 0) { |
45 | fprintf(stderr, "pthread_mutex_lock returned:%d %s\n", ret, strerror(ret)); | |
46 | exit(1); | |
47 | } | |
48 | } | |
2c51f8dd | 49 | |
237e200e | 50 | static void unlock_mutex(pthread_mutex_t *l) |
23ce2127 | 51 | { |
237e200e | 52 | int ret; |
2dc17609 | 53 | |
237e200e SH |
54 | if ((ret = pthread_mutex_unlock(l)) != 0) { |
55 | fprintf(stderr, "pthread_mutex_unlock returned:%d %s\n", ret, strerror(ret)); | |
56 | exit(1); | |
97f1f27b | 57 | } |
237e200e | 58 | } |
2dc17609 | 59 | |
237e200e SH |
60 | static void users_lock(void) |
61 | { | |
62 | lock_mutex(&user_count_mutex); | |
63 | } | |
b731895e | 64 | |
237e200e SH |
65 | static void users_unlock(void) |
66 | { | |
67 | unlock_mutex(&user_count_mutex); | |
68 | } | |
e1068397 | 69 | |
81d17d8f | 70 | static volatile sig_atomic_t need_reload; |
59120f04 | 71 | |
237e200e SH |
72 | /* do_reload - reload the dynamic library. Done under |
73 | * lock and when we know the user_count was 0 */ | |
74 | static void do_reload(void) | |
75 | { | |
76 | if (dlopen_handle) | |
77 | dlclose(dlopen_handle); | |
e1068397 | 78 | |
59120f04 | 79 | /* First try loading using ld.so */ |
237e200e | 80 | dlopen_handle = dlopen("liblxcfs.so", RTLD_LAZY); |
59120f04 SH |
81 | if (dlopen_handle) |
82 | goto good; | |
83 | ||
7c82d95e | 84 | dlopen_handle = dlopen("/usr/lib/lxcfs/liblxcfs.so", RTLD_LAZY); |
237e200e SH |
85 | if (!dlopen_handle) { |
86 | fprintf(stderr, "Failed to open liblxcfs\n"); | |
87 | _exit(1); | |
2dc17609 | 88 | } |
59120f04 SH |
89 | |
90 | good: | |
91 | if (need_reload) | |
92 | fprintf(stderr, "lxcfs: reloaded\n"); | |
237e200e | 93 | need_reload = 0; |
23ce2127 SH |
94 | } |
95 | ||
237e200e | 96 | static void up_users(void) |
23ce2127 | 97 | { |
237e200e SH |
98 | users_lock(); |
99 | if (users_count == 0 && need_reload) | |
100 | do_reload(); | |
101 | users_count++; | |
102 | users_unlock(); | |
103 | } | |
23ce2127 | 104 | |
237e200e SH |
105 | static void down_users(void) |
106 | { | |
107 | users_lock(); | |
108 | users_count--; | |
109 | users_unlock(); | |
23ce2127 SH |
110 | } |
111 | ||
237e200e SH |
112 | static void reload_handler(int sig) |
113 | { | |
237e200e | 114 | need_reload = 1; |
237e200e | 115 | } |
23ce2127 | 116 | |
237e200e SH |
117 | /* Functions to run the library methods */ |
118 | static int do_cg_getattr(const char *path, struct stat *sb) | |
aeb56147 | 119 | { |
237e200e SH |
120 | int (*cg_getattr)(const char *path, struct stat *sb); |
121 | char *error; | |
122 | dlerror(); /* Clear any existing error */ | |
123 | cg_getattr = (int (*)(const char *, struct stat *)) dlsym(dlopen_handle, "cg_getattr"); | |
124 | error = dlerror(); | |
125 | if (error != NULL) { | |
126 | fprintf(stderr, "cg_getattr: %s\n", error); | |
127 | return -1; | |
128 | } | |
aeb56147 | 129 | |
237e200e | 130 | return cg_getattr(path, sb); |
aeb56147 SH |
131 | } |
132 | ||
237e200e | 133 | static int do_proc_getattr(const char *path, struct stat *sb) |
23ce2127 | 134 | { |
237e200e SH |
135 | int (*proc_getattr)(const char *path, struct stat *sb); |
136 | char *error; | |
137 | dlerror(); /* Clear any existing error */ | |
138 | proc_getattr = (int (*)(const char *, struct stat *)) dlsym(dlopen_handle, "proc_getattr"); | |
139 | error = dlerror(); | |
140 | if (error != NULL) { | |
141 | fprintf(stderr, "proc_getattr: %s\n", error); | |
142 | return -1; | |
143 | } | |
23ce2127 | 144 | |
237e200e | 145 | return proc_getattr(path, sb); |
23ce2127 SH |
146 | } |
147 | ||
237e200e | 148 | static int do_cg_read(const char *path, char *buf, size_t size, off_t offset, |
23ce2127 SH |
149 | struct fuse_file_info *fi) |
150 | { | |
237e200e SH |
151 | int (*cg_read)(const char *path, char *buf, size_t size, off_t offset, |
152 | struct fuse_file_info *fi); | |
153 | char *error; | |
23ce2127 | 154 | |
237e200e SH |
155 | dlerror(); /* Clear any existing error */ |
156 | cg_read = (int (*)(const char *, char *, size_t, off_t, struct fuse_file_info *)) dlsym(dlopen_handle, "cg_read"); | |
157 | error = dlerror(); | |
158 | if (error != NULL) { | |
159 | fprintf(stderr, "cg_read: %s\n", error); | |
160 | return -1; | |
23ce2127 SH |
161 | } |
162 | ||
237e200e | 163 | return cg_read(path, buf, size, offset, fi); |
23ce2127 SH |
164 | } |
165 | ||
237e200e | 166 | static int do_proc_read(const char *path, char *buf, size_t size, off_t offset, |
23ce2127 SH |
167 | struct fuse_file_info *fi) |
168 | { | |
237e200e SH |
169 | int (*proc_read)(const char *path, char *buf, size_t size, off_t offset, |
170 | struct fuse_file_info *fi); | |
171 | char *error; | |
aeb56147 | 172 | |
237e200e SH |
173 | dlerror(); /* Clear any existing error */ |
174 | proc_read = (int (*)(const char *, char *, size_t, off_t, struct fuse_file_info *)) dlsym(dlopen_handle, "proc_read"); | |
175 | error = dlerror(); | |
176 | if (error != NULL) { | |
177 | fprintf(stderr, "proc_read: %s\n", error); | |
178 | return -1; | |
97f1f27b YY |
179 | } |
180 | ||
237e200e SH |
181 | return proc_read(path, buf, size, offset, fi); |
182 | } | |
97f1f27b | 183 | |
237e200e SH |
184 | static int do_cg_write(const char *path, const char *buf, size_t size, off_t offset, |
185 | struct fuse_file_info *fi) | |
186 | { | |
187 | int (*cg_write)(const char *path, const char *buf, size_t size, off_t offset, | |
188 | struct fuse_file_info *fi); | |
189 | char *error; | |
190 | dlerror(); /* Clear any existing error */ | |
191 | cg_write = (int (*)(const char *, const char *, size_t, off_t, struct fuse_file_info *)) dlsym(dlopen_handle, "cg_write"); | |
192 | error = dlerror(); | |
193 | if (error != NULL) { | |
194 | fprintf(stderr, "cg_write: %s\n", error); | |
195 | return -1; | |
97f1f27b YY |
196 | } |
197 | ||
237e200e | 198 | return cg_write(path, buf, size, offset, fi); |
23ce2127 SH |
199 | } |
200 | ||
237e200e | 201 | static int do_cg_mkdir(const char *path, mode_t mode) |
41bb9357 | 202 | { |
237e200e SH |
203 | int (*cg_mkdir)(const char *path, mode_t mode); |
204 | char *error; | |
205 | dlerror(); /* Clear any existing error */ | |
206 | cg_mkdir = (int (*)(const char *, mode_t)) dlsym(dlopen_handle, "cg_mkdir"); | |
207 | error = dlerror(); | |
208 | if (error != NULL) { | |
209 | fprintf(stderr, "cg_mkdir: %s\n", error); | |
210 | return -1; | |
211 | } | |
41bb9357 | 212 | |
237e200e | 213 | return cg_mkdir(path, mode); |
41bb9357 SH |
214 | } |
215 | ||
237e200e | 216 | static int do_cg_chown(const char *path, uid_t uid, gid_t gid) |
0b6af11b | 217 | { |
237e200e SH |
218 | int (*cg_chown)(const char *path, uid_t uid, gid_t gid); |
219 | char *error; | |
220 | dlerror(); /* Clear any existing error */ | |
221 | cg_chown = (int (*)(const char *, uid_t, gid_t)) dlsym(dlopen_handle, "cg_chown"); | |
222 | error = dlerror(); | |
223 | if (error != NULL) { | |
224 | fprintf(stderr, "cg_chown: %s\n", error); | |
225 | return -1; | |
226 | } | |
0b6af11b | 227 | |
237e200e | 228 | return cg_chown(path, uid, gid); |
41bb9357 SH |
229 | } |
230 | ||
237e200e | 231 | static int do_cg_rmdir(const char *path) |
23ce2127 | 232 | { |
237e200e SH |
233 | int (*cg_rmdir)(const char *path); |
234 | char *error; | |
235 | dlerror(); /* Clear any existing error */ | |
236 | cg_rmdir = (int (*)(const char *path)) dlsym(dlopen_handle, "cg_rmdir"); | |
237 | error = dlerror(); | |
238 | if (error != NULL) { | |
239 | fprintf(stderr, "cg_rmdir: %s\n", error); | |
240 | return -1; | |
97f1f27b YY |
241 | } |
242 | ||
237e200e SH |
243 | return cg_rmdir(path); |
244 | } | |
f6c0b279 | 245 | |
237e200e SH |
246 | static int do_cg_chmod(const char *path, mode_t mode) |
247 | { | |
248 | int (*cg_chmod)(const char *path, mode_t mode); | |
249 | char *error; | |
250 | dlerror(); /* Clear any existing error */ | |
251 | cg_chmod = (int (*)(const char *, mode_t)) dlsym(dlopen_handle, "cg_chmod"); | |
252 | error = dlerror(); | |
253 | if (error != NULL) { | |
254 | fprintf(stderr, "cg_chmod: %s\n", error); | |
255 | return -1; | |
e1068397 | 256 | } |
cdcdb29b | 257 | |
237e200e | 258 | return cg_chmod(path, mode); |
23ce2127 SH |
259 | } |
260 | ||
237e200e | 261 | static int do_cg_readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset, |
49878439 YY |
262 | struct fuse_file_info *fi) |
263 | { | |
237e200e SH |
264 | int (*cg_readdir)(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset, |
265 | struct fuse_file_info *fi); | |
266 | char *error; | |
49878439 | 267 | |
237e200e SH |
268 | dlerror(); /* Clear any existing error */ |
269 | cg_readdir = (int (*)(const char *, void *, fuse_fill_dir_t, off_t, struct fuse_file_info *)) dlsym(dlopen_handle, "cg_readdir"); | |
270 | error = dlerror(); | |
271 | if (error != NULL) { | |
272 | fprintf(stderr, "cg_readdir: %s\n", error); | |
273 | return -1; | |
97f1f27b | 274 | } |
49878439 | 275 | |
237e200e SH |
276 | return cg_readdir(path, buf, filler, offset, fi); |
277 | } | |
49878439 | 278 | |
237e200e SH |
279 | static int do_proc_readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset, |
280 | struct fuse_file_info *fi) | |
281 | { | |
282 | int (*proc_readdir)(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset, | |
283 | struct fuse_file_info *fi); | |
284 | char *error; | |
49878439 | 285 | |
237e200e SH |
286 | dlerror(); /* Clear any existing error */ |
287 | proc_readdir = (int (*)(const char *, void *, fuse_fill_dir_t, off_t, struct fuse_file_info *)) dlsym(dlopen_handle, "proc_readdir"); | |
288 | error = dlerror(); | |
289 | if (error != NULL) { | |
290 | fprintf(stderr, "proc_readdir: %s\n", error); | |
291 | return -1; | |
49878439 YY |
292 | } |
293 | ||
237e200e | 294 | return proc_readdir(path, buf, filler, offset, fi); |
49878439 YY |
295 | } |
296 | ||
237e200e | 297 | static int do_cg_open(const char *path, struct fuse_file_info *fi) |
23ce2127 | 298 | { |
237e200e SH |
299 | int (*cg_open)(const char *path, struct fuse_file_info *fi); |
300 | char *error; | |
301 | dlerror(); /* Clear any existing error */ | |
302 | cg_open = (int (*)(const char *, struct fuse_file_info *)) dlsym(dlopen_handle, "cg_open"); | |
303 | error = dlerror(); | |
304 | if (error != NULL) { | |
305 | fprintf(stderr, "cg_open: %s\n", error); | |
306 | return -1; | |
307 | } | |
23ce2127 | 308 | |
237e200e | 309 | return cg_open(path, fi); |
23ce2127 SH |
310 | } |
311 | ||
bddbb106 SH |
312 | static int do_cg_access(const char *path, int mode) |
313 | { | |
314 | int (*cg_access)(const char *path, int mode); | |
315 | char *error; | |
316 | dlerror(); /* Clear any existing error */ | |
317 | cg_access = (int (*)(const char *, int mode)) dlsym(dlopen_handle, "cg_access"); | |
318 | error = dlerror(); | |
319 | if (error != NULL) { | |
320 | fprintf(stderr, "cg_access: %s\n", error); | |
321 | return -1; | |
322 | } | |
323 | ||
324 | return cg_access(path, mode); | |
325 | } | |
326 | ||
237e200e | 327 | static int do_proc_open(const char *path, struct fuse_file_info *fi) |
758ad80c | 328 | { |
237e200e SH |
329 | int (*proc_open)(const char *path, struct fuse_file_info *fi); |
330 | char *error; | |
331 | dlerror(); /* Clear any existing error */ | |
332 | proc_open = (int (*)(const char *path, struct fuse_file_info *fi)) dlsym(dlopen_handle, "proc_open"); | |
333 | error = dlerror(); | |
334 | if (error != NULL) { | |
335 | fprintf(stderr, "proc_open: %s\n", error); | |
336 | return -1; | |
35629743 SH |
337 | } |
338 | ||
237e200e | 339 | return proc_open(path, fi); |
35629743 SH |
340 | } |
341 | ||
bddbb106 SH |
342 | static int do_proc_access(const char *path, int mode) |
343 | { | |
344 | int (*proc_access)(const char *path, int mode); | |
345 | char *error; | |
346 | dlerror(); /* Clear any existing error */ | |
347 | proc_access = (int (*)(const char *, int mode)) dlsym(dlopen_handle, "proc_access"); | |
348 | error = dlerror(); | |
349 | if (error != NULL) { | |
350 | fprintf(stderr, "proc_access: %s\n", error); | |
351 | return -1; | |
352 | } | |
353 | ||
354 | return proc_access(path, mode); | |
355 | } | |
356 | ||
237e200e | 357 | static int do_cg_release(const char *path, struct fuse_file_info *fi) |
35629743 | 358 | { |
237e200e SH |
359 | int (*cg_release)(const char *path, struct fuse_file_info *fi); |
360 | char *error; | |
361 | dlerror(); /* Clear any existing error */ | |
362 | cg_release = (int (*)(const char *path, struct fuse_file_info *)) dlsym(dlopen_handle, "cg_release"); | |
363 | error = dlerror(); | |
364 | if (error != NULL) { | |
365 | fprintf(stderr, "cg_release: %s\n", error); | |
366 | return -1; | |
367 | } | |
368 | ||
369 | return cg_release(path, fi); | |
758ad80c SH |
370 | } |
371 | ||
237e200e | 372 | static int do_proc_release(const char *path, struct fuse_file_info *fi) |
35629743 | 373 | { |
237e200e SH |
374 | int (*proc_release)(const char *path, struct fuse_file_info *fi); |
375 | char *error; | |
376 | dlerror(); /* Clear any existing error */ | |
377 | proc_release = (int (*)(const char *path, struct fuse_file_info *)) dlsym(dlopen_handle, "proc_release"); | |
378 | error = dlerror(); | |
379 | if (error != NULL) { | |
380 | fprintf(stderr, "proc_release: %s\n", error); | |
381 | return -1; | |
382 | } | |
97f1f27b | 383 | |
237e200e | 384 | return proc_release(path, fi); |
96fc5ee6 SH |
385 | } |
386 | ||
237e200e | 387 | static int do_cg_opendir(const char *path, struct fuse_file_info *fi) |
96fc5ee6 | 388 | { |
237e200e SH |
389 | int (*cg_opendir)(const char *path, struct fuse_file_info *fi); |
390 | char *error; | |
391 | dlerror(); /* Clear any existing error */ | |
392 | cg_opendir = (int (*)(const char *path, struct fuse_file_info *fi)) dlsym(dlopen_handle, "cg_opendir"); | |
393 | error = dlerror(); | |
394 | if (error != NULL) { | |
395 | fprintf(stderr, "cg_opendir: %s\n", error); | |
396 | return -1; | |
397 | } | |
96fc5ee6 | 398 | |
237e200e | 399 | return cg_opendir(path, fi); |
35629743 SH |
400 | } |
401 | ||
237e200e | 402 | static int do_cg_releasedir(const char *path, struct fuse_file_info *fi) |
35629743 | 403 | { |
237e200e SH |
404 | int (*cg_releasedir)(const char *path, struct fuse_file_info *fi); |
405 | char *error; | |
406 | dlerror(); /* Clear any existing error */ | |
407 | cg_releasedir = (int (*)(const char *path, struct fuse_file_info *)) dlsym(dlopen_handle, "cg_releasedir"); | |
408 | error = dlerror(); | |
409 | if (error != NULL) { | |
410 | fprintf(stderr, "cg_releasedir: %s\n", error); | |
411 | return -1; | |
96fc5ee6 | 412 | } |
237e200e SH |
413 | |
414 | return cg_releasedir(path, fi); | |
35629743 SH |
415 | } |
416 | ||
2ad6d2bd SH |
417 | /* |
418 | * FUSE ops for / | |
419 | * these just delegate to the /proc and /cgroup ops as | |
420 | * needed | |
421 | */ | |
758ad80c SH |
422 | |
423 | static int lxcfs_getattr(const char *path, struct stat *sb) | |
424 | { | |
237e200e | 425 | int ret; |
758ad80c SH |
426 | if (strcmp(path, "/") == 0) { |
427 | sb->st_mode = S_IFDIR | 00755; | |
428 | sb->st_nlink = 2; | |
429 | return 0; | |
430 | } | |
431 | if (strncmp(path, "/cgroup", 7) == 0) { | |
237e200e SH |
432 | up_users(); |
433 | ret = do_cg_getattr(path, sb); | |
434 | down_users(); | |
435 | return ret; | |
758ad80c | 436 | } |
35629743 | 437 | if (strncmp(path, "/proc", 5) == 0) { |
237e200e SH |
438 | up_users(); |
439 | ret = do_proc_getattr(path, sb); | |
440 | down_users(); | |
441 | return ret; | |
758ad80c SH |
442 | } |
443 | return -EINVAL; | |
444 | } | |
445 | ||
446 | static int lxcfs_opendir(const char *path, struct fuse_file_info *fi) | |
447 | { | |
237e200e | 448 | int ret; |
758ad80c SH |
449 | if (strcmp(path, "/") == 0) |
450 | return 0; | |
451 | ||
452 | if (strncmp(path, "/cgroup", 7) == 0) { | |
237e200e SH |
453 | up_users(); |
454 | ret = do_cg_opendir(path, fi); | |
455 | down_users(); | |
456 | return ret; | |
758ad80c | 457 | } |
35629743 SH |
458 | if (strcmp(path, "/proc") == 0) |
459 | return 0; | |
460 | return -ENOENT; | |
758ad80c SH |
461 | } |
462 | ||
463 | static int lxcfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset, | |
464 | struct fuse_file_info *fi) | |
465 | { | |
237e200e | 466 | int ret; |
758ad80c SH |
467 | if (strcmp(path, "/") == 0) { |
468 | if (filler(buf, "proc", NULL, 0) != 0 || | |
469 | filler(buf, "cgroup", NULL, 0) != 0) | |
470 | return -EINVAL; | |
471 | return 0; | |
472 | } | |
237e200e SH |
473 | if (strncmp(path, "/cgroup", 7) == 0) { |
474 | up_users(); | |
475 | ret = do_cg_readdir(path, buf, filler, offset, fi); | |
476 | down_users(); | |
477 | return ret; | |
478 | } | |
479 | if (strcmp(path, "/proc") == 0) { | |
480 | up_users(); | |
481 | ret = do_proc_readdir(path, buf, filler, offset, fi); | |
482 | down_users(); | |
483 | return ret; | |
484 | } | |
758ad80c SH |
485 | return -EINVAL; |
486 | } | |
487 | ||
bddbb106 SH |
488 | static int lxcfs_access(const char *path, int mode) |
489 | { | |
490 | int ret; | |
491 | if (strncmp(path, "/cgroup", 7) == 0) { | |
492 | up_users(); | |
493 | ret = do_cg_access(path, mode); | |
494 | down_users(); | |
495 | return ret; | |
496 | } | |
497 | if (strncmp(path, "/proc", 5) == 0) { | |
498 | up_users(); | |
499 | ret = do_proc_access(path, mode); | |
500 | down_users(); | |
501 | return ret; | |
502 | } | |
503 | ||
504 | return -EINVAL; | |
505 | } | |
506 | ||
758ad80c SH |
507 | static int lxcfs_releasedir(const char *path, struct fuse_file_info *fi) |
508 | { | |
237e200e | 509 | int ret; |
758ad80c SH |
510 | if (strcmp(path, "/") == 0) |
511 | return 0; | |
512 | if (strncmp(path, "/cgroup", 7) == 0) { | |
237e200e SH |
513 | up_users(); |
514 | ret = do_cg_releasedir(path, fi); | |
515 | down_users(); | |
516 | return ret; | |
758ad80c | 517 | } |
35629743 SH |
518 | if (strcmp(path, "/proc") == 0) |
519 | return 0; | |
758ad80c SH |
520 | return -EINVAL; |
521 | } | |
522 | ||
99978832 SH |
523 | static int lxcfs_open(const char *path, struct fuse_file_info *fi) |
524 | { | |
237e200e SH |
525 | int ret; |
526 | if (strncmp(path, "/cgroup", 7) == 0) { | |
527 | up_users(); | |
528 | ret = do_cg_open(path, fi); | |
529 | down_users(); | |
530 | return ret; | |
531 | } | |
532 | if (strncmp(path, "/proc", 5) == 0) { | |
533 | up_users(); | |
534 | ret = do_proc_open(path, fi); | |
535 | down_users(); | |
536 | return ret; | |
537 | } | |
99978832 SH |
538 | |
539 | return -EINVAL; | |
540 | } | |
541 | ||
542 | static int lxcfs_read(const char *path, char *buf, size_t size, off_t offset, | |
543 | struct fuse_file_info *fi) | |
544 | { | |
237e200e SH |
545 | int ret; |
546 | if (strncmp(path, "/cgroup", 7) == 0) { | |
547 | up_users(); | |
548 | ret = do_cg_read(path, buf, size, offset, fi); | |
549 | down_users(); | |
550 | return ret; | |
551 | } | |
552 | if (strncmp(path, "/proc", 5) == 0) { | |
553 | up_users(); | |
554 | ret = do_proc_read(path, buf, size, offset, fi); | |
555 | down_users(); | |
556 | return ret; | |
557 | } | |
99978832 SH |
558 | |
559 | return -EINVAL; | |
560 | } | |
561 | ||
2ad6d2bd SH |
562 | int lxcfs_write(const char *path, const char *buf, size_t size, off_t offset, |
563 | struct fuse_file_info *fi) | |
564 | { | |
237e200e | 565 | int ret; |
2ad6d2bd | 566 | if (strncmp(path, "/cgroup", 7) == 0) { |
237e200e SH |
567 | up_users(); |
568 | ret = do_cg_write(path, buf, size, offset, fi); | |
569 | down_users(); | |
570 | return ret; | |
2ad6d2bd SH |
571 | } |
572 | ||
573 | return -EINVAL; | |
574 | } | |
575 | ||
99978832 SH |
576 | static int lxcfs_flush(const char *path, struct fuse_file_info *fi) |
577 | { | |
578 | return 0; | |
579 | } | |
580 | ||
581 | static int lxcfs_release(const char *path, struct fuse_file_info *fi) | |
758ad80c | 582 | { |
237e200e SH |
583 | int ret; |
584 | if (strncmp(path, "/cgroup", 7) == 0) { | |
585 | up_users(); | |
586 | ret = do_cg_release(path, fi); | |
587 | down_users(); | |
588 | return ret; | |
589 | } | |
590 | if (strncmp(path, "/proc", 5) == 0) { | |
591 | up_users(); | |
592 | ret = do_proc_release(path, fi); | |
593 | down_users(); | |
594 | return ret; | |
595 | } | |
8f6e8f5e SH |
596 | |
597 | return -EINVAL; | |
99978832 SH |
598 | } |
599 | ||
600 | static int lxcfs_fsync(const char *path, int datasync, struct fuse_file_info *fi) | |
601 | { | |
602 | return 0; | |
758ad80c SH |
603 | } |
604 | ||
ab54b798 SH |
605 | int lxcfs_mkdir(const char *path, mode_t mode) |
606 | { | |
237e200e SH |
607 | int ret; |
608 | if (strncmp(path, "/cgroup", 7) == 0) { | |
609 | up_users(); | |
610 | ret = do_cg_mkdir(path, mode); | |
611 | down_users(); | |
612 | return ret; | |
613 | } | |
ab54b798 SH |
614 | |
615 | return -EINVAL; | |
616 | } | |
617 | ||
341b21ad SH |
618 | int lxcfs_chown(const char *path, uid_t uid, gid_t gid) |
619 | { | |
237e200e SH |
620 | int ret; |
621 | if (strncmp(path, "/cgroup", 7) == 0) { | |
622 | up_users(); | |
623 | ret = do_cg_chown(path, uid, gid); | |
624 | down_users(); | |
625 | return ret; | |
626 | } | |
341b21ad SH |
627 | |
628 | return -EINVAL; | |
629 | } | |
630 | ||
2ad6d2bd SH |
631 | /* |
632 | * cat first does a truncate before doing ops->write. This doesn't | |
633 | * really make sense for cgroups. So just return 0 always but do | |
634 | * nothing. | |
635 | */ | |
636 | int lxcfs_truncate(const char *path, off_t newsize) | |
637 | { | |
638 | if (strncmp(path, "/cgroup", 7) == 0) | |
639 | return 0; | |
640 | return -EINVAL; | |
641 | } | |
642 | ||
50d8d5b5 SH |
643 | int lxcfs_rmdir(const char *path) |
644 | { | |
237e200e SH |
645 | int ret; |
646 | if (strncmp(path, "/cgroup", 7) == 0) { | |
647 | up_users(); | |
648 | ret = do_cg_rmdir(path); | |
649 | down_users(); | |
650 | return ret; | |
651 | } | |
50d8d5b5 SH |
652 | return -EINVAL; |
653 | } | |
654 | ||
fd2e4e03 SH |
655 | int lxcfs_chmod(const char *path, mode_t mode) |
656 | { | |
237e200e SH |
657 | int ret; |
658 | if (strncmp(path, "/cgroup", 7) == 0) { | |
659 | up_users(); | |
660 | ret = do_cg_chmod(path, mode); | |
661 | down_users(); | |
662 | return ret; | |
663 | } | |
fd2e4e03 SH |
664 | return -EINVAL; |
665 | } | |
666 | ||
758ad80c SH |
667 | const struct fuse_operations lxcfs_ops = { |
668 | .getattr = lxcfs_getattr, | |
669 | .readlink = NULL, | |
670 | .getdir = NULL, | |
671 | .mknod = NULL, | |
ab54b798 | 672 | .mkdir = lxcfs_mkdir, |
758ad80c | 673 | .unlink = NULL, |
50d8d5b5 | 674 | .rmdir = lxcfs_rmdir, |
758ad80c SH |
675 | .symlink = NULL, |
676 | .rename = NULL, | |
677 | .link = NULL, | |
fd2e4e03 | 678 | .chmod = lxcfs_chmod, |
341b21ad | 679 | .chown = lxcfs_chown, |
2ad6d2bd | 680 | .truncate = lxcfs_truncate, |
758ad80c | 681 | .utime = NULL, |
99978832 SH |
682 | |
683 | .open = lxcfs_open, | |
684 | .read = lxcfs_read, | |
685 | .release = lxcfs_release, | |
2ad6d2bd | 686 | .write = lxcfs_write, |
99978832 | 687 | |
758ad80c | 688 | .statfs = NULL, |
99978832 SH |
689 | .flush = lxcfs_flush, |
690 | .fsync = lxcfs_fsync, | |
758ad80c SH |
691 | |
692 | .setxattr = NULL, | |
693 | .getxattr = NULL, | |
694 | .listxattr = NULL, | |
695 | .removexattr = NULL, | |
696 | ||
697 | .opendir = lxcfs_opendir, | |
698 | .readdir = lxcfs_readdir, | |
699 | .releasedir = lxcfs_releasedir, | |
700 | ||
701 | .fsyncdir = NULL, | |
702 | .init = NULL, | |
703 | .destroy = NULL, | |
bddbb106 | 704 | .access = lxcfs_access, |
758ad80c SH |
705 | .create = NULL, |
706 | .ftruncate = NULL, | |
707 | .fgetattr = NULL, | |
708 | }; | |
709 | ||
99978832 | 710 | static void usage(const char *me) |
758ad80c SH |
711 | { |
712 | fprintf(stderr, "Usage:\n"); | |
713 | fprintf(stderr, "\n"); | |
e190ee91 SH |
714 | fprintf(stderr, "%s [-p pidfile] mountpoint\n", me); |
715 | fprintf(stderr, " Default pidfile is %s/lxcfs.pid\n", RUNTIME_PATH); | |
0b0f73db | 716 | fprintf(stderr, "%s -h\n", me); |
758ad80c SH |
717 | exit(1); |
718 | } | |
719 | ||
99978832 | 720 | static bool is_help(char *w) |
758ad80c SH |
721 | { |
722 | if (strcmp(w, "-h") == 0 || | |
723 | strcmp(w, "--help") == 0 || | |
724 | strcmp(w, "-help") == 0 || | |
725 | strcmp(w, "help") == 0) | |
726 | return true; | |
727 | return false; | |
728 | } | |
729 | ||
0b0f73db SH |
730 | void swallow_arg(int *argcp, char *argv[], char *which) |
731 | { | |
732 | int i; | |
733 | ||
734 | for (i = 1; argv[i]; i++) { | |
735 | if (strcmp(argv[i], which) != 0) | |
736 | continue; | |
737 | for (; argv[i]; i++) { | |
738 | argv[i] = argv[i+1]; | |
739 | } | |
740 | (*argcp)--; | |
741 | return; | |
742 | } | |
743 | } | |
744 | ||
e190ee91 | 745 | bool swallow_option(int *argcp, char *argv[], char *opt, char **v) |
0b0f73db SH |
746 | { |
747 | int i; | |
748 | ||
749 | for (i = 1; argv[i]; i++) { | |
750 | if (!argv[i+1]) | |
751 | continue; | |
752 | if (strcmp(argv[i], opt) != 0) | |
753 | continue; | |
e190ee91 SH |
754 | do { |
755 | *v = strdup(argv[i+1]); | |
756 | } while (!*v); | |
0b0f73db SH |
757 | for (; argv[i+1]; i++) { |
758 | argv[i] = argv[i+2]; | |
759 | } | |
760 | (*argcp) -= 2; | |
e190ee91 | 761 | return true; |
0b0f73db | 762 | } |
e190ee91 | 763 | return false; |
0b0f73db SH |
764 | } |
765 | ||
237e200e SH |
766 | static bool mkdir_p(const char *dir, mode_t mode) |
767 | { | |
768 | const char *tmp = dir; | |
769 | const char *orig = dir; | |
770 | char *makeme; | |
771 | ||
772 | do { | |
773 | dir = tmp + strspn(tmp, "/"); | |
774 | tmp = dir + strcspn(dir, "/"); | |
775 | makeme = strndup(orig, dir - orig); | |
776 | if (!makeme) | |
777 | return false; | |
778 | if (mkdir(makeme, mode) && errno != EEXIST) { | |
779 | fprintf(stderr, "failed to create directory '%s': %s", | |
780 | makeme, strerror(errno)); | |
781 | free(makeme); | |
782 | return false; | |
783 | } | |
784 | free(makeme); | |
785 | } while(tmp != dir); | |
786 | ||
787 | return true; | |
788 | } | |
789 | ||
790 | static bool umount_if_mounted(void) | |
791 | { | |
792 | if (umount2(basedir, MNT_DETACH) < 0 && errno != EINVAL) { | |
793 | fprintf(stderr, "failed to umount %s: %s\n", basedir, | |
794 | strerror(errno)); | |
795 | return false; | |
796 | } | |
797 | return true; | |
798 | } | |
799 | ||
800 | static bool setup_cgfs_dir(void) | |
801 | { | |
802 | if (!mkdir_p(basedir, 0700)) { | |
803 | fprintf(stderr, "Failed to create lxcfs cgdir\n"); | |
804 | return false; | |
805 | } | |
806 | if (!umount_if_mounted()) { | |
807 | fprintf(stderr, "Failed to clean up old lxcfs cgdir\n"); | |
808 | return false; | |
809 | } | |
810 | if (mount("tmpfs", basedir, "tmpfs", 0, "size=100000,mode=700") < 0) { | |
811 | fprintf(stderr, "Failed to mount tmpfs for private controllers\n"); | |
812 | return false; | |
813 | } | |
814 | return true; | |
815 | } | |
816 | ||
817 | static bool do_mount_cgroup(char *controller) | |
818 | { | |
819 | char *target; | |
820 | size_t len; | |
821 | int ret; | |
822 | ||
823 | len = strlen(basedir) + strlen(controller) + 2; | |
824 | target = alloca(len); | |
825 | ret = snprintf(target, len, "%s/%s", basedir, controller); | |
826 | if (ret < 0 || ret >= len) | |
827 | return false; | |
828 | if (mkdir(target, 0755) < 0 && errno != EEXIST) | |
829 | return false; | |
830 | if (mount(controller, target, "cgroup", 0, controller) < 0) { | |
831 | fprintf(stderr, "Failed mounting cgroup %s\n", controller); | |
832 | return false; | |
833 | } | |
834 | return true; | |
835 | } | |
836 | ||
837 | static bool do_mount_cgroups(void) | |
838 | { | |
839 | bool ret; | |
840 | FILE *f; | |
841 | char *line = NULL; | |
842 | size_t len = 0; | |
843 | ||
844 | if ((f = fopen("/proc/self/cgroup", "r")) == NULL) { | |
845 | fprintf(stderr, "Error opening /proc/self/cgroup: %s\n", strerror(errno)); | |
846 | return false; | |
847 | } | |
848 | ||
849 | while (getline(&line, &len, f) != -1) { | |
850 | char *p, *p2; | |
851 | ||
852 | p = strchr(line, ':'); | |
853 | if (!p) | |
854 | goto out; | |
855 | *(p++) = '\0'; | |
856 | ||
857 | p2 = strrchr(p, ':'); | |
858 | if (!p2) | |
859 | goto out; | |
860 | *p2 = '\0'; | |
861 | ||
862 | if (!do_mount_cgroup(p)) | |
863 | goto out; | |
864 | } | |
865 | ret = true; | |
866 | ||
867 | out: | |
868 | free(line); | |
869 | fclose(f); | |
870 | return ret; | |
871 | } | |
872 | ||
873 | static bool cgfs_setup_controllers(void) | |
874 | { | |
875 | if (!setup_cgfs_dir()) { | |
876 | return false; | |
877 | } | |
878 | ||
879 | if (!do_mount_cgroups()) { | |
880 | fprintf(stderr, "Failed to set up cgroup mounts\n"); | |
881 | return false; | |
882 | } | |
883 | ||
884 | return true; | |
885 | } | |
886 | ||
e190ee91 SH |
887 | static int set_pidfile(char *pidfile) |
888 | { | |
889 | int fd; | |
890 | char buf[50]; | |
891 | struct flock fl; | |
892 | ||
893 | fl.l_type = F_WRLCK; | |
894 | fl.l_whence = SEEK_SET; | |
895 | fl.l_start = 0; | |
896 | fl.l_len = 0; | |
897 | ||
898 | fd = open(pidfile, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR); | |
899 | if (fd == -1) { | |
900 | fprintf(stderr, "Could not open pidfile %s: %m", pidfile); | |
901 | return -1; | |
902 | } | |
903 | ||
904 | if (fcntl(fd, F_SETLK, &fl) == -1) { | |
905 | if (errno == EAGAIN || errno == EACCES) { | |
906 | fprintf(stderr, "PID file '%s' is already locked.\n", pidfile); | |
907 | close(fd); | |
908 | return -1; | |
909 | } | |
910 | fprintf(stderr, "Warning; unable to lock PID file, proceeding.\n"); | |
911 | } | |
912 | ||
913 | if (ftruncate(fd, 0) == -1) { | |
914 | fprintf(stderr, "Error truncating PID file '%s': %m", pidfile); | |
915 | close(fd); | |
916 | return -1; | |
917 | } | |
918 | ||
919 | snprintf(buf, 50, "%ld\n", (long) getpid()); | |
920 | if (write(fd, buf, strlen(buf)) != strlen(buf)) { | |
921 | fprintf(stderr, "Error writing to PID file '%s': %m", pidfile); | |
922 | close(fd); | |
923 | return -1; | |
924 | } | |
925 | ||
926 | return fd; | |
927 | } | |
928 | ||
758ad80c SH |
929 | int main(int argc, char *argv[]) |
930 | { | |
e190ee91 SH |
931 | int ret = -1, pidfd; |
932 | char *pidfile = NULL, *v = NULL; | |
933 | size_t pidfile_len; | |
0b0f73db SH |
934 | /* |
935 | * what we pass to fuse_main is: | |
936 | * argv[0] -s -f -o allow_other,directio argv[1] NULL | |
937 | */ | |
2c51f8dd SH |
938 | int nargs = 5, cnt = 0; |
939 | char *newargv[6]; | |
758ad80c | 940 | |
0b0f73db SH |
941 | /* accomodate older init scripts */ |
942 | swallow_arg(&argc, argv, "-s"); | |
943 | swallow_arg(&argc, argv, "-f"); | |
e190ee91 SH |
944 | if (swallow_option(&argc, argv, "-o", &v)) { |
945 | if (strcmp(v, "allow_other") != 0) { | |
946 | fprintf(stderr, "Warning: unexpected fuse option %s\n", v); | |
947 | exit(1); | |
948 | } | |
949 | free(v); | |
950 | v = NULL; | |
951 | } | |
952 | if (swallow_option(&argc, argv, "-p", &v)) | |
953 | pidfile = v; | |
0b0f73db | 954 | |
2e9c0b32 SH |
955 | if (argc == 2 && strcmp(argv[1], "--version") == 0) { |
956 | fprintf(stderr, "%s\n", VERSION); | |
957 | exit(0); | |
958 | } | |
0b0f73db | 959 | if (argc != 2 || is_help(argv[1])) |
758ad80c SH |
960 | usage(argv[0]); |
961 | ||
59120f04 | 962 | do_reload(); |
8fad16cd | 963 | if (signal(SIGUSR1, reload_handler) == SIG_ERR) { |
8dcde249 | 964 | fprintf(stderr, "Error setting USR1 signal handler: %m\n"); |
8fad16cd SH |
965 | exit(1); |
966 | } | |
e190ee91 | 967 | |
38a76a91 | 968 | newargv[cnt++] = argv[0]; |
38a76a91 SH |
969 | newargv[cnt++] = "-f"; |
970 | newargv[cnt++] = "-o"; | |
f466a31e | 971 | newargv[cnt++] = "allow_other,direct_io,entry_timeout=0.5,attr_timeout=0.5"; |
38a76a91 SH |
972 | newargv[cnt++] = argv[1]; |
973 | newargv[cnt++] = NULL; | |
758ad80c | 974 | |
35482f91 | 975 | if (!cgfs_setup_controllers()) |
c0adec85 | 976 | goto out; |
758ad80c | 977 | |
e190ee91 SH |
978 | if (!pidfile) { |
979 | pidfile_len = strlen(RUNTIME_PATH) + strlen("/lxcfs.pid") + 1; | |
980 | pidfile = alloca(pidfile_len); | |
981 | snprintf(pidfile, pidfile_len, "%s/lxcfs.pid", RUNTIME_PATH); | |
982 | } | |
983 | if ((pidfd = set_pidfile(pidfile)) < 0) | |
984 | goto out; | |
985 | ||
35482f91 | 986 | ret = fuse_main(nargs, newargv, &lxcfs_ops, NULL); |
758ad80c | 987 | |
237e200e | 988 | dlclose(dlopen_handle); |
e190ee91 SH |
989 | unlink(pidfile); |
990 | close(pidfd); | |
237e200e | 991 | |
c0adec85 | 992 | out: |
758ad80c | 993 | return ret; |
2183082c | 994 | } |