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