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1 | /* lxcfs | |
2 | * | |
3 | * Copyright © 2014 Canonical, Inc | |
4 | * Author: Serge Hallyn <serge.hallyn@ubuntu.com> | |
5 | * | |
6 | * See COPYING file for details. | |
7 | */ | |
8 | ||
9 | /* | |
10 | * NOTES - make sure to run this as -s to avoid threading. | |
11 | * TODO - can we enforce that here from the code? | |
12 | */ | |
13 | #define FUSE_USE_VERSION 26 | |
14 | ||
15 | #include <stdio.h> | |
16 | #include <dirent.h> | |
17 | #include <fcntl.h> | |
18 | #include <fuse.h> | |
19 | #include <unistd.h> | |
20 | #include <errno.h> | |
21 | #include <stdbool.h> | |
22 | #include <time.h> | |
23 | #include <string.h> | |
24 | #include <stdlib.h> | |
25 | #include <libgen.h> | |
26 | #include <sched.h> | |
27 | #include <linux/sched.h> | |
28 | #include <sys/socket.h> | |
29 | #include <sys/mount.h> | |
30 | #include <wait.h> | |
31 | ||
32 | #include <nih/alloc.h> | |
33 | #include <nih/string.h> | |
34 | ||
35 | #include "cgmanager.h" | |
36 | ||
37 | struct lxcfs_state { | |
38 | /* | |
39 | * a null-terminated, nih-allocated list of the mounted subsystems. We | |
40 | * detect this at startup. | |
41 | */ | |
42 | char **subsystems; | |
43 | }; | |
44 | #define LXCFS_DATA ((struct lxcfs_state *) fuse_get_context()->private_data) | |
45 | ||
46 | /* | |
47 | * TODO - return value should denote whether child exited with failure | |
48 | * so callers can return errors. Esp read/write of tasks and cgroup.procs | |
49 | */ | |
50 | static int wait_for_pid(pid_t pid) | |
51 | { | |
52 | int status, ret; | |
53 | ||
54 | again: | |
55 | ret = waitpid(pid, &status, 0); | |
56 | if (ret == -1) { | |
57 | if (errno == EINTR) | |
58 | goto again; | |
59 | return -1; | |
60 | } | |
61 | if (ret != pid) | |
62 | goto again; | |
63 | if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) | |
64 | return -1; | |
65 | return 0; | |
66 | } | |
67 | ||
68 | /* | |
69 | * Given a open file * to /proc/pid/{u,g}id_map, and an id | |
70 | * valid in the caller's namespace, return the id mapped into | |
71 | * pid's namespace. | |
72 | * Returns the mapped id, or -1 on error. | |
73 | */ | |
74 | unsigned int | |
75 | convert_id_to_ns(FILE *idfile, unsigned int in_id) | |
76 | { | |
77 | unsigned int nsuid, // base id for a range in the idfile's namespace | |
78 | hostuid, // base id for a range in the caller's namespace | |
79 | count; // number of ids in this range | |
80 | char line[400]; | |
81 | int ret; | |
82 | ||
83 | fseek(idfile, 0L, SEEK_SET); | |
84 | while (fgets(line, 400, idfile)) { | |
85 | ret = sscanf(line, "%u %u %u\n", &nsuid, &hostuid, &count); | |
86 | if (ret != 3) | |
87 | continue; | |
88 | if (hostuid + count < hostuid || nsuid + count < nsuid) { | |
89 | /* | |
90 | * uids wrapped around - unexpected as this is a procfile, | |
91 | * so just bail. | |
92 | */ | |
93 | fprintf(stderr, "pid wrapparound at entry %u %u %u in %s\n", | |
94 | nsuid, hostuid, count, line); | |
95 | return -1; | |
96 | } | |
97 | if (hostuid <= in_id && hostuid+count > in_id) { | |
98 | /* | |
99 | * now since hostuid <= in_id < hostuid+count, and | |
100 | * hostuid+count and nsuid+count do not wrap around, | |
101 | * we know that nsuid+(in_id-hostuid) which must be | |
102 | * less that nsuid+(count) must not wrap around | |
103 | */ | |
104 | return (in_id - hostuid) + nsuid; | |
105 | } | |
106 | } | |
107 | ||
108 | // no answer found | |
109 | return -1; | |
110 | } | |
111 | ||
112 | /* | |
113 | * for is_privileged_over, | |
114 | * specify whether we require the calling uid to be root in his | |
115 | * namespace | |
116 | */ | |
117 | #define NS_ROOT_REQD true | |
118 | #define NS_ROOT_OPT false | |
119 | ||
120 | static bool is_privileged_over(pid_t pid, uid_t uid, uid_t victim, bool req_ns_root) | |
121 | { | |
122 | nih_local char *fpath = NULL; | |
123 | bool answer = false; | |
124 | uid_t nsuid; | |
125 | ||
126 | if (victim == -1 || uid == -1) | |
127 | return false; | |
128 | ||
129 | /* | |
130 | * If the request is one not requiring root in the namespace, | |
131 | * then having the same uid suffices. (i.e. uid 1000 has write | |
132 | * access to files owned by uid 1000 | |
133 | */ | |
134 | if (!req_ns_root && uid == victim) | |
135 | return true; | |
136 | ||
137 | fpath = NIH_MUST( nih_sprintf(NULL, "/proc/%d/uid_map", pid) ); | |
138 | FILE *f = fopen(fpath, "r"); | |
139 | if (!f) | |
140 | return false; | |
141 | ||
142 | /* if caller's not root in his namespace, reject */ | |
143 | nsuid = convert_id_to_ns(f, uid); | |
144 | if (nsuid) | |
145 | goto out; | |
146 | ||
147 | /* | |
148 | * If victim is not mapped into caller's ns, reject. | |
149 | * XXX I'm not sure this check is needed given that fuse | |
150 | * will be sending requests where the vfs has converted | |
151 | */ | |
152 | nsuid = convert_id_to_ns(f, victim); | |
153 | if (nsuid == -1) | |
154 | goto out; | |
155 | ||
156 | answer = true; | |
157 | ||
158 | out: | |
159 | fclose(f); | |
160 | return answer; | |
161 | } | |
162 | ||
163 | static bool perms_include(int fmode, mode_t req_mode) | |
164 | { | |
165 | mode_t r; | |
166 | ||
167 | switch (req_mode & O_ACCMODE) { | |
168 | case O_RDONLY: | |
169 | r = S_IROTH; | |
170 | break; | |
171 | case O_WRONLY: | |
172 | r = S_IWOTH; | |
173 | break; | |
174 | case O_RDWR: | |
175 | r = S_IROTH | S_IWOTH; | |
176 | break; | |
177 | default: | |
178 | return false; | |
179 | } | |
180 | return ((fmode & r) == r); | |
181 | } | |
182 | ||
183 | static char *get_next_cgroup_dir(const char *taskcg, const char *querycg) | |
184 | { | |
185 | char *start, *end; | |
186 | ||
187 | if (strlen(taskcg) <= strlen(querycg)) { | |
188 | fprintf(stderr, "%s: I was fed bad input\n", __func__); | |
189 | return NULL; | |
190 | } | |
191 | ||
192 | if (strcmp(querycg, "/") == 0) | |
193 | start = NIH_MUST( nih_strdup(NULL, taskcg + 1) ); | |
194 | else | |
195 | start = NIH_MUST( nih_strdup(NULL, taskcg + strlen(querycg) + 1) ); | |
196 | end = strchr(start, '/'); | |
197 | if (end) | |
198 | *end = '\0'; | |
199 | return start; | |
200 | } | |
201 | ||
202 | /* | |
203 | * check whether a fuse context may access a cgroup dir or file | |
204 | * | |
205 | * If file is not null, it is a cgroup file to check under cg. | |
206 | * If file is null, then we are checking perms on cg itself. | |
207 | * | |
208 | * For files we can check the mode of the list_keys result. | |
209 | * For cgroups, we must make assumptions based on the files under the | |
210 | * cgroup, because cgmanager doesn't tell us ownership/perms of cgroups | |
211 | * yet. | |
212 | */ | |
213 | static bool fc_may_access(struct fuse_context *fc, const char *contrl, const char *cg, const char *file, mode_t mode) | |
214 | { | |
215 | nih_local struct cgm_keys **list = NULL; | |
216 | int i; | |
217 | ||
218 | if (!file) | |
219 | file = "tasks"; | |
220 | ||
221 | if (*file == '/') | |
222 | file++; | |
223 | ||
224 | if (!cgm_list_keys(contrl, cg, &list)) | |
225 | return false; | |
226 | for (i = 0; list[i]; i++) { | |
227 | if (strcmp(list[i]->name, file) == 0) { | |
228 | struct cgm_keys *k = list[i]; | |
229 | if (is_privileged_over(fc->pid, fc->uid, k->uid, NS_ROOT_OPT)) { | |
230 | if (perms_include(k->mode >> 6, mode)) | |
231 | return true; | |
232 | } | |
233 | if (fc->gid == k->gid) { | |
234 | if (perms_include(k->mode >> 3, mode)) | |
235 | return true; | |
236 | } | |
237 | return perms_include(k->mode, mode); | |
238 | } | |
239 | } | |
240 | ||
241 | return false; | |
242 | } | |
243 | ||
244 | static void stripnewline(char *x) | |
245 | { | |
246 | size_t l = strlen(x); | |
247 | if (l && x[l-1] == '\n') | |
248 | x[l-1] = '\0'; | |
249 | } | |
250 | ||
251 | /* | |
252 | * If caller is in /a/b/c/d, he may only act on things under cg=/a/b/c/d. | |
253 | * If caller is in /a, he may act on /a/b, but not on /b. | |
254 | * if the answer is false and nextcg is not NULL, then *nextcg will point | |
255 | * to a nih_alloc'd string containing the next cgroup directory under cg | |
256 | */ | |
257 | static bool caller_is_in_ancestor(pid_t pid, const char *contrl, const char *cg, char **nextcg) | |
258 | { | |
259 | nih_local char *fnam = NULL; | |
260 | FILE *f; | |
261 | bool answer = false; | |
262 | char *line = NULL; | |
263 | size_t len = 0; | |
264 | ||
265 | fnam = NIH_MUST( nih_sprintf(NULL, "/proc/%d/cgroup", pid) ); | |
266 | if (!(f = fopen(fnam, "r"))) | |
267 | return false; | |
268 | ||
269 | while (getline(&line, &len, f) != -1) { | |
270 | char *c1, *c2, *linecmp; | |
271 | if (!line[0]) | |
272 | continue; | |
273 | c1 = strchr(line, ':'); | |
274 | if (!c1) | |
275 | goto out; | |
276 | c1++; | |
277 | c2 = strchr(c1, ':'); | |
278 | if (!c2) | |
279 | goto out; | |
280 | *c2 = '\0'; | |
281 | if (strcmp(c1, contrl) != 0) | |
282 | continue; | |
283 | c2++; | |
284 | stripnewline(c2); | |
285 | /* | |
286 | * callers pass in '/' for root cgroup, otherwise they pass | |
287 | * in a cgroup without leading '/' | |
288 | */ | |
289 | linecmp = *cg == '/' ? c2 : c2+1; | |
290 | if (strncmp(linecmp, cg, strlen(linecmp)) != 0) { | |
291 | if (nextcg) | |
292 | *nextcg = get_next_cgroup_dir(linecmp, cg); | |
293 | goto out; | |
294 | } | |
295 | answer = true; | |
296 | goto out; | |
297 | } | |
298 | ||
299 | out: | |
300 | fclose(f); | |
301 | free(line); | |
302 | return answer; | |
303 | } | |
304 | ||
305 | /* | |
306 | * given /cgroup/freezer/a/b, return "freezer". this will be nih-allocated | |
307 | * and needs to be nih_freed. | |
308 | */ | |
309 | static char *pick_controller_from_path(struct fuse_context *fc, const char *path) | |
310 | { | |
311 | const char *p1; | |
312 | char *ret, *slash; | |
313 | ||
314 | if (strlen(path) < 9) | |
315 | return NULL; | |
316 | p1 = path+8; | |
317 | ret = nih_strdup(NULL, p1); | |
318 | if (!ret) | |
319 | return ret; | |
320 | slash = strstr(ret, "/"); | |
321 | if (slash) | |
322 | *slash = '\0'; | |
323 | ||
324 | /* verify that it is a subsystem */ | |
325 | char **list = LXCFS_DATA ? LXCFS_DATA->subsystems : NULL; | |
326 | int i; | |
327 | if (!list) { | |
328 | nih_free(ret); | |
329 | return NULL; | |
330 | } | |
331 | for (i = 0; list[i]; i++) { | |
332 | if (strcmp(list[i], ret) == 0) | |
333 | return ret; | |
334 | } | |
335 | nih_free(ret); | |
336 | return NULL; | |
337 | } | |
338 | ||
339 | /* | |
340 | * Find the start of cgroup in /cgroup/controller/the/cgroup/path | |
341 | * Note that the returned value may include files (keynames) etc | |
342 | */ | |
343 | static const char *find_cgroup_in_path(const char *path) | |
344 | { | |
345 | const char *p1; | |
346 | ||
347 | if (strlen(path) < 9) | |
348 | return NULL; | |
349 | p1 = strstr(path+8, "/"); | |
350 | if (!p1) | |
351 | return NULL; | |
352 | return p1+1; | |
353 | } | |
354 | ||
355 | static bool is_child_cgroup(const char *contr, const char *dir, const char *f) | |
356 | { | |
357 | nih_local char **list = NULL; | |
358 | int i; | |
359 | ||
360 | if (!f) | |
361 | return false; | |
362 | if (*f == '/') | |
363 | f++; | |
364 | ||
365 | if (!cgm_list_children(contr, dir, &list)) | |
366 | return false; | |
367 | for (i = 0; list[i]; i++) { | |
368 | if (strcmp(list[i], f) == 0) | |
369 | return true; | |
370 | } | |
371 | ||
372 | return false; | |
373 | } | |
374 | ||
375 | static struct cgm_keys *get_cgroup_key(const char *contr, const char *dir, const char *f) | |
376 | { | |
377 | nih_local struct cgm_keys **list = NULL; | |
378 | struct cgm_keys *k; | |
379 | int i; | |
380 | ||
381 | if (!f) | |
382 | return NULL; | |
383 | if (*f == '/') | |
384 | f++; | |
385 | if (!cgm_list_keys(contr, dir, &list)) | |
386 | return NULL; | |
387 | for (i = 0; list[i]; i++) { | |
388 | if (strcmp(list[i]->name, f) == 0) { | |
389 | k = NIH_MUST( nih_alloc(NULL, (sizeof(*k))) ); | |
390 | k->name = NIH_MUST( nih_strdup(k, list[i]->name) ); | |
391 | k->uid = list[i]->uid; | |
392 | k->gid = list[i]->gid; | |
393 | k->mode = list[i]->mode; | |
394 | return k; | |
395 | } | |
396 | } | |
397 | ||
398 | return NULL; | |
399 | } | |
400 | ||
401 | static void get_cgdir_and_path(const char *cg, char **dir, char **file) | |
402 | { | |
403 | char *p; | |
404 | ||
405 | *dir = NIH_MUST( nih_strdup(NULL, cg) ); | |
406 | *file = strrchr(cg, '/'); | |
407 | if (!*file) { | |
408 | *file = NULL; | |
409 | return; | |
410 | } | |
411 | p = strrchr(*dir, '/'); | |
412 | *p = '\0'; | |
413 | } | |
414 | ||
415 | static size_t get_file_size(const char *contrl, const char *cg, const char *f) | |
416 | { | |
417 | nih_local char *data = NULL; | |
418 | size_t s; | |
419 | if (!cgm_get_value(contrl, cg, f, &data)) | |
420 | return -EINVAL; | |
421 | s = strlen(data); | |
422 | return s; | |
423 | } | |
424 | ||
425 | /* | |
426 | * FUSE ops for /cgroup | |
427 | */ | |
428 | ||
429 | static int cg_getattr(const char *path, struct stat *sb) | |
430 | { | |
431 | struct timespec now; | |
432 | struct fuse_context *fc = fuse_get_context(); | |
433 | nih_local char * cgdir = NULL; | |
434 | char *fpath = NULL, *path1, *path2; | |
435 | nih_local struct cgm_keys *k = NULL; | |
436 | const char *cgroup; | |
437 | nih_local char *controller = NULL; | |
438 | ||
439 | ||
440 | if (!fc) | |
441 | return -EIO; | |
442 | ||
443 | memset(sb, 0, sizeof(struct stat)); | |
444 | ||
445 | if (clock_gettime(CLOCK_REALTIME, &now) < 0) | |
446 | return -EINVAL; | |
447 | ||
448 | sb->st_uid = sb->st_gid = 0; | |
449 | sb->st_atim = sb->st_mtim = sb->st_ctim = now; | |
450 | sb->st_size = 0; | |
451 | ||
452 | if (strcmp(path, "/cgroup") == 0) { | |
453 | sb->st_mode = S_IFDIR | 00755; | |
454 | sb->st_nlink = 2; | |
455 | return 0; | |
456 | } | |
457 | ||
458 | controller = pick_controller_from_path(fc, path); | |
459 | if (!controller) | |
460 | return -EIO; | |
461 | cgroup = find_cgroup_in_path(path); | |
462 | if (!cgroup) { | |
463 | /* this is just /cgroup/controller, return it as a dir */ | |
464 | sb->st_mode = S_IFDIR | 00755; | |
465 | sb->st_nlink = 2; | |
466 | return 0; | |
467 | } | |
468 | ||
469 | get_cgdir_and_path(cgroup, &cgdir, &fpath); | |
470 | ||
471 | if (!fpath) { | |
472 | path1 = "/"; | |
473 | path2 = cgdir; | |
474 | } else { | |
475 | path1 = cgdir; | |
476 | path2 = fpath; | |
477 | } | |
478 | ||
479 | /* check that cgcopy is either a child cgroup of cgdir, or listed in its keys. | |
480 | * Then check that caller's cgroup is under path if fpath is a child | |
481 | * cgroup, or cgdir if fpath is a file */ | |
482 | ||
483 | if (is_child_cgroup(controller, path1, path2)) { | |
484 | if (!caller_is_in_ancestor(fc->pid, controller, cgroup, NULL)) { | |
485 | /* this is just /cgroup/controller, return it as a dir */ | |
486 | sb->st_mode = S_IFDIR | 00555; | |
487 | sb->st_nlink = 2; | |
488 | return 0; | |
489 | } | |
490 | if (!fc_may_access(fc, controller, cgroup, NULL, O_RDONLY)) | |
491 | return -EACCES; | |
492 | ||
493 | // get uid, gid, from '/tasks' file and make up a mode | |
494 | // That is a hack, until cgmanager gains a GetCgroupPerms fn. | |
495 | sb->st_mode = S_IFDIR | 00755; | |
496 | k = get_cgroup_key(controller, cgroup, "tasks"); | |
497 | if (!k) { | |
498 | sb->st_uid = sb->st_gid = 0; | |
499 | } else { | |
500 | sb->st_uid = k->uid; | |
501 | sb->st_gid = k->gid; | |
502 | } | |
503 | sb->st_nlink = 2; | |
504 | return 0; | |
505 | } | |
506 | ||
507 | if ((k = get_cgroup_key(controller, path1, path2)) != NULL) { | |
508 | if (!caller_is_in_ancestor(fc->pid, controller, path1, NULL)) | |
509 | return -ENOENT; | |
510 | if (!fc_may_access(fc, controller, path1, path2, O_RDONLY)) | |
511 | return -EACCES; | |
512 | ||
513 | sb->st_mode = S_IFREG | k->mode; | |
514 | sb->st_nlink = 1; | |
515 | sb->st_uid = k->uid; | |
516 | sb->st_gid = k->gid; | |
517 | sb->st_size = get_file_size(controller, path1, path2); | |
518 | return 0; | |
519 | } | |
520 | ||
521 | return -ENOENT; | |
522 | } | |
523 | ||
524 | /* | |
525 | * TODO - cache these results in a table for use in opendir, free | |
526 | * in releasedir | |
527 | */ | |
528 | static int cg_opendir(const char *path, struct fuse_file_info *fi) | |
529 | { | |
530 | struct fuse_context *fc = fuse_get_context(); | |
531 | nih_local struct cgm_keys **list = NULL; | |
532 | const char *cgroup; | |
533 | nih_local char *controller = NULL; | |
534 | nih_local char *nextcg = NULL; | |
535 | ||
536 | if (!fc) | |
537 | return -EIO; | |
538 | ||
539 | if (strcmp(path, "/cgroup") == 0) | |
540 | return 0; | |
541 | ||
542 | // return list of keys for the controller, and list of child cgroups | |
543 | controller = pick_controller_from_path(fc, path); | |
544 | if (!controller) | |
545 | return -EIO; | |
546 | ||
547 | cgroup = find_cgroup_in_path(path); | |
548 | if (!cgroup) { | |
549 | /* this is just /cgroup/controller, return its contents */ | |
550 | cgroup = "/"; | |
551 | } | |
552 | ||
553 | if (!fc_may_access(fc, controller, cgroup, NULL, O_RDONLY)) | |
554 | return -EACCES; | |
555 | return 0; | |
556 | } | |
557 | ||
558 | static int cg_readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset, | |
559 | struct fuse_file_info *fi) | |
560 | { | |
561 | struct fuse_context *fc = fuse_get_context(); | |
562 | ||
563 | if (!fc) | |
564 | return -EIO; | |
565 | ||
566 | if (strcmp(path, "/cgroup") == 0) { | |
567 | // get list of controllers | |
568 | char **list = LXCFS_DATA ? LXCFS_DATA->subsystems : NULL; | |
569 | int i; | |
570 | ||
571 | if (!list) | |
572 | return -EIO; | |
573 | ||
574 | for (i = 0; list[i]; i++) { | |
575 | if (filler(buf, list[i], NULL, 0) != 0) { | |
576 | return -EIO; | |
577 | } | |
578 | } | |
579 | return 0; | |
580 | } | |
581 | ||
582 | // return list of keys for the controller, and list of child cgroups | |
583 | nih_local struct cgm_keys **list = NULL; | |
584 | const char *cgroup; | |
585 | nih_local char *controller = NULL; | |
586 | int i; | |
587 | nih_local char *nextcg = NULL; | |
588 | ||
589 | controller = pick_controller_from_path(fc, path); | |
590 | if (!controller) | |
591 | return -EIO; | |
592 | ||
593 | cgroup = find_cgroup_in_path(path); | |
594 | if (!cgroup) { | |
595 | /* this is just /cgroup/controller, return its contents */ | |
596 | cgroup = "/"; | |
597 | } | |
598 | ||
599 | if (!fc_may_access(fc, controller, cgroup, NULL, O_RDONLY)) | |
600 | return -EACCES; | |
601 | ||
602 | if (!cgm_list_keys(controller, cgroup, &list)) | |
603 | // not a valid cgroup | |
604 | return -EINVAL; | |
605 | ||
606 | if (!caller_is_in_ancestor(fc->pid, controller, cgroup, &nextcg)) { | |
607 | if (nextcg) { | |
608 | int ret; | |
609 | ret = filler(buf, nextcg, NULL, 0); | |
610 | if (ret != 0) | |
611 | return -EIO; | |
612 | } | |
613 | return 0; | |
614 | } | |
615 | ||
616 | for (i = 0; list[i]; i++) { | |
617 | if (filler(buf, list[i]->name, NULL, 0) != 0) { | |
618 | return -EIO; | |
619 | } | |
620 | } | |
621 | ||
622 | // now get the list of child cgroups | |
623 | nih_local char **clist; | |
624 | ||
625 | if (!cgm_list_children(controller, cgroup, &clist)) | |
626 | return 0; | |
627 | for (i = 0; clist[i]; i++) { | |
628 | if (filler(buf, clist[i], NULL, 0) != 0) { | |
629 | return -EIO; | |
630 | } | |
631 | } | |
632 | return 0; | |
633 | } | |
634 | ||
635 | static int cg_releasedir(const char *path, struct fuse_file_info *fi) | |
636 | { | |
637 | return 0; | |
638 | } | |
639 | ||
640 | /* | |
641 | * TODO - cache info here for read/write, release in cg_release. | |
642 | */ | |
643 | static int cg_open(const char *path, struct fuse_file_info *fi) | |
644 | { | |
645 | nih_local char *controller = NULL; | |
646 | const char *cgroup; | |
647 | char *fpath = NULL, *path1, *path2; | |
648 | nih_local char * cgdir = NULL; | |
649 | nih_local struct cgm_keys *k = NULL; | |
650 | struct fuse_context *fc = fuse_get_context(); | |
651 | ||
652 | if (!fc) | |
653 | return -EIO; | |
654 | ||
655 | controller = pick_controller_from_path(fc, path); | |
656 | if (!controller) | |
657 | return -EIO; | |
658 | cgroup = find_cgroup_in_path(path); | |
659 | if (!cgroup) | |
660 | return -EINVAL; | |
661 | ||
662 | get_cgdir_and_path(cgroup, &cgdir, &fpath); | |
663 | if (!fpath) { | |
664 | path1 = "/"; | |
665 | path2 = cgdir; | |
666 | } else { | |
667 | path1 = cgdir; | |
668 | path2 = fpath; | |
669 | } | |
670 | ||
671 | if ((k = get_cgroup_key(controller, path1, path2)) != NULL) { | |
672 | if (!fc_may_access(fc, controller, path1, path2, fi->flags)) | |
673 | // should never get here | |
674 | return -EACCES; | |
675 | ||
676 | return 0; | |
677 | } | |
678 | ||
679 | return -EINVAL; | |
680 | } | |
681 | ||
682 | static int msgrecv(int sockfd, void *buf, size_t len) | |
683 | { | |
684 | struct timeval tv; | |
685 | fd_set rfds; | |
686 | ||
687 | FD_ZERO(&rfds); | |
688 | FD_SET(sockfd, &rfds); | |
689 | tv.tv_sec = 2; | |
690 | tv.tv_usec = 0; | |
691 | ||
692 | if (select(sockfd+1, &rfds, NULL, NULL, &tv) < 0) | |
693 | return -1; | |
694 | return recv(sockfd, buf, len, MSG_DONTWAIT); | |
695 | } | |
696 | ||
697 | #define SEND_CREDS_OK 0 | |
698 | #define SEND_CREDS_NOTSK 1 | |
699 | #define SEND_CREDS_FAIL 2 | |
700 | static int send_creds(int sock, struct ucred *cred, char v, bool pingfirst) | |
701 | { | |
702 | struct msghdr msg = { 0 }; | |
703 | struct iovec iov; | |
704 | struct cmsghdr *cmsg; | |
705 | char cmsgbuf[CMSG_SPACE(sizeof(*cred))]; | |
706 | char buf[1]; | |
707 | buf[0] = 'p'; | |
708 | ||
709 | if (pingfirst) { | |
710 | if (msgrecv(sock, buf, 1) != 1) { | |
711 | printf("%s: Error getting reply from server over socketpair", | |
712 | __func__); | |
713 | return SEND_CREDS_FAIL; | |
714 | } | |
715 | } | |
716 | ||
717 | msg.msg_control = cmsgbuf; | |
718 | msg.msg_controllen = sizeof(cmsgbuf); | |
719 | ||
720 | cmsg = CMSG_FIRSTHDR(&msg); | |
721 | cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred)); | |
722 | cmsg->cmsg_level = SOL_SOCKET; | |
723 | cmsg->cmsg_type = SCM_CREDENTIALS; | |
724 | memcpy(CMSG_DATA(cmsg), cred, sizeof(*cred)); | |
725 | ||
726 | msg.msg_name = NULL; | |
727 | msg.msg_namelen = 0; | |
728 | ||
729 | buf[0] = v; | |
730 | iov.iov_base = buf; | |
731 | iov.iov_len = sizeof(buf); | |
732 | msg.msg_iov = &iov; | |
733 | msg.msg_iovlen = 1; | |
734 | ||
735 | if (sendmsg(sock, &msg, 0) < 0) { | |
736 | printf("%s: failed at sendmsg: %s", __func__, | |
737 | strerror(errno)); | |
738 | if (errno == 3) | |
739 | return SEND_CREDS_NOTSK; | |
740 | return SEND_CREDS_FAIL; | |
741 | } | |
742 | ||
743 | return SEND_CREDS_OK; | |
744 | } | |
745 | ||
746 | static bool recv_creds(int sock, struct ucred *cred, char *v) | |
747 | { | |
748 | struct msghdr msg = { 0 }; | |
749 | struct iovec iov; | |
750 | struct cmsghdr *cmsg; | |
751 | char cmsgbuf[CMSG_SPACE(sizeof(*cred))]; | |
752 | char buf[1]; | |
753 | int ret; | |
754 | int optval = 1; | |
755 | ||
756 | *v = '1'; | |
757 | ||
758 | cred->pid = -1; | |
759 | cred->uid = -1; | |
760 | cred->gid = -1; | |
761 | ||
762 | if (setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &optval, sizeof(optval)) == -1) { | |
763 | printf("Failed to set passcred: %s", strerror(errno)); | |
764 | return false; | |
765 | } | |
766 | buf[0] = '1'; | |
767 | if (write(sock, buf, 1) != 1) { | |
768 | printf("Failed to start write on scm fd: %s", strerror(errno)); | |
769 | return false; | |
770 | } | |
771 | ||
772 | msg.msg_name = NULL; | |
773 | msg.msg_namelen = 0; | |
774 | msg.msg_control = cmsgbuf; | |
775 | msg.msg_controllen = sizeof(cmsgbuf); | |
776 | ||
777 | iov.iov_base = buf; | |
778 | iov.iov_len = sizeof(buf); | |
779 | msg.msg_iov = &iov; | |
780 | msg.msg_iovlen = 1; | |
781 | ||
782 | // retry logic is not ideal, especially as we are not | |
783 | // threaded. Sleep at most 1 second waiting for the client | |
784 | // to send us the scm_cred | |
785 | ret = recvmsg(sock, &msg, 0); | |
786 | if (ret < 0) { | |
787 | printf("Failed to receive scm_cred: %s", | |
788 | strerror(errno)); | |
789 | return false; | |
790 | } | |
791 | ||
792 | cmsg = CMSG_FIRSTHDR(&msg); | |
793 | ||
794 | if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)) && | |
795 | cmsg->cmsg_level == SOL_SOCKET && | |
796 | cmsg->cmsg_type == SCM_CREDENTIALS) { | |
797 | memcpy(cred, CMSG_DATA(cmsg), sizeof(*cred)); | |
798 | } | |
799 | *v = buf[0]; | |
800 | ||
801 | return true; | |
802 | } | |
803 | ||
804 | ||
805 | /* | |
806 | * pid_to_ns - reads pids from a ucred over a socket, then writes the | |
807 | * int value back over the socket. This shifts the pid from the | |
808 | * sender's pidns into tpid's pidns. | |
809 | */ | |
810 | static void pid_to_ns(int sock, pid_t tpid) | |
811 | { | |
812 | char v = '0'; | |
813 | struct ucred cred; | |
814 | ||
815 | while (recv_creds(sock, &cred, &v)) { | |
816 | if (v == '1') | |
817 | exit(0); | |
818 | if (write(sock, &cred.pid, sizeof(pid_t)) != sizeof(pid_t)) | |
819 | exit(1); | |
820 | } | |
821 | exit(0); | |
822 | } | |
823 | ||
824 | /* | |
825 | * pid_to_ns_wrapper: when you setns into a pidns, you yourself remain | |
826 | * in your old pidns. Only children which you fork will be in the target | |
827 | * pidns. So the pid_to_ns_wrapper does the setns, then forks a child to | |
828 | * actually convert pids | |
829 | */ | |
830 | static void pid_to_ns_wrapper(int sock, pid_t tpid) | |
831 | { | |
832 | int newnsfd = -1; | |
833 | char fnam[100]; | |
834 | pid_t cpid; | |
835 | ||
836 | sprintf(fnam, "/proc/%d/ns/pid", tpid); | |
837 | newnsfd = open(fnam, O_RDONLY); | |
838 | if (newnsfd < 0) | |
839 | exit(1); | |
840 | if (setns(newnsfd, 0) < 0) | |
841 | exit(1); | |
842 | close(newnsfd); | |
843 | ||
844 | cpid = fork(); | |
845 | ||
846 | if (cpid < 0) | |
847 | exit(1); | |
848 | if (!cpid) | |
849 | pid_to_ns(sock, tpid); | |
850 | if (!wait_for_pid(cpid)) | |
851 | exit(1); | |
852 | exit(0); | |
853 | } | |
854 | ||
855 | /* | |
856 | * To read cgroup files with a particular pid, we will setns into the child | |
857 | * pidns, open a pipe, fork a child - which will be the first to really be in | |
858 | * the child ns - which does the cgm_get_value and writes the data to the pipe. | |
859 | */ | |
860 | static bool do_read_pids(pid_t tpid, const char *contrl, const char *cg, const char *file, char **d) | |
861 | { | |
862 | int sock[2] = {-1, -1}; | |
863 | nih_local char *tmpdata = NULL; | |
864 | int ret; | |
865 | pid_t qpid, cpid = -1; | |
866 | bool answer = false; | |
867 | char v = '0'; | |
868 | struct ucred cred; | |
869 | struct timeval tv; | |
870 | fd_set s; | |
871 | ||
872 | if (!cgm_get_value(contrl, cg, file, &tmpdata)) | |
873 | return false; | |
874 | ||
875 | /* | |
876 | * Now we read the pids from returned data one by one, pass | |
877 | * them into a child in the target namespace, read back the | |
878 | * translated pids, and put them into our to-return data | |
879 | */ | |
880 | ||
881 | if (socketpair(AF_UNIX, SOCK_DGRAM, 0, sock) < 0) { | |
882 | perror("socketpair"); | |
883 | exit(1); | |
884 | } | |
885 | ||
886 | cpid = fork(); | |
887 | if (cpid == -1) | |
888 | goto out; | |
889 | ||
890 | if (!cpid) // child | |
891 | pid_to_ns_wrapper(sock[1], tpid); | |
892 | ||
893 | char *ptr = tmpdata; | |
894 | cred.uid = 0; | |
895 | cred.gid = 0; | |
896 | while (sscanf(ptr, "%d\n", &qpid) == 1) { | |
897 | cred.pid = qpid; | |
898 | ret = send_creds(sock[0], &cred, v, true); | |
899 | ||
900 | if (ret == SEND_CREDS_NOTSK) | |
901 | goto next; | |
902 | if (ret == SEND_CREDS_FAIL) | |
903 | goto out; | |
904 | ||
905 | // read converted results | |
906 | FD_ZERO(&s); | |
907 | FD_SET(sock[0], &s); | |
908 | tv.tv_sec = 1; | |
909 | tv.tv_usec = 0; | |
910 | ret = select(sock[0]+1, &s, NULL, NULL, &tv); | |
911 | if (ret <= 0) { | |
912 | kill(cpid, SIGTERM); | |
913 | goto out; | |
914 | } | |
915 | if (read(sock[0], &qpid, sizeof(qpid)) != sizeof(qpid)) { | |
916 | kill(cpid, SIGTERM); | |
917 | perror("read"); | |
918 | goto out; | |
919 | } | |
920 | NIH_MUST( nih_strcat_sprintf(d, NULL, "%d\n", qpid) ); | |
921 | next: | |
922 | ptr = strchr(ptr, '\n'); | |
923 | if (!ptr) | |
924 | break; | |
925 | ptr++; | |
926 | } | |
927 | ||
928 | cred.pid = getpid(); | |
929 | v = '1'; | |
930 | if (send_creds(sock[0], &cred, v, true) != SEND_CREDS_OK) { | |
931 | // failed to ask child to exit | |
932 | kill(cpid, SIGTERM); | |
933 | goto out; | |
934 | } | |
935 | ||
936 | answer = true; | |
937 | ||
938 | out: | |
939 | if (cpid != -1) | |
940 | wait_for_pid(cpid); | |
941 | if (sock[0] != -1) { | |
942 | close(sock[0]); | |
943 | close(sock[1]); | |
944 | } | |
945 | return answer; | |
946 | } | |
947 | ||
948 | static int cg_read(const char *path, char *buf, size_t size, off_t offset, | |
949 | struct fuse_file_info *fi) | |
950 | { | |
951 | nih_local char *controller = NULL; | |
952 | const char *cgroup; | |
953 | char *fpath = NULL, *path1, *path2; | |
954 | struct fuse_context *fc = fuse_get_context(); | |
955 | nih_local char * cgdir = NULL; | |
956 | nih_local struct cgm_keys *k = NULL; | |
957 | ||
958 | if (offset) | |
959 | return -EIO; | |
960 | ||
961 | if (!fc) | |
962 | return -EIO; | |
963 | ||
964 | controller = pick_controller_from_path(fc, path); | |
965 | if (!controller) | |
966 | return -EINVAL; | |
967 | cgroup = find_cgroup_in_path(path); | |
968 | if (!cgroup) | |
969 | return -EINVAL; | |
970 | ||
971 | get_cgdir_and_path(cgroup, &cgdir, &fpath); | |
972 | if (!fpath) { | |
973 | path1 = "/"; | |
974 | path2 = cgdir; | |
975 | } else { | |
976 | path1 = cgdir; | |
977 | path2 = fpath; | |
978 | } | |
979 | ||
980 | if ((k = get_cgroup_key(controller, path1, path2)) != NULL) { | |
981 | nih_local char *data = NULL; | |
982 | int s; | |
983 | bool r; | |
984 | ||
985 | if (!fc_may_access(fc, controller, path1, path2, O_RDONLY)) | |
986 | // should never get here | |
987 | return -EACCES; | |
988 | ||
989 | if (strcmp(path2, "tasks") == 0 || | |
990 | strcmp(path2, "/tasks") == 0 || | |
991 | strcmp(path2, "/cgroup.procs") == 0 || | |
992 | strcmp(path2, "cgroup.procs") == 0) | |
993 | // special case - we have to translate the pids | |
994 | r = do_read_pids(fc->pid, controller, path1, path2, &data); | |
995 | else | |
996 | r = cgm_get_value(controller, path1, path2, &data); | |
997 | ||
998 | if (!r) | |
999 | return -EINVAL; | |
1000 | ||
1001 | if (!data) | |
1002 | return 0; | |
1003 | s = strlen(data); | |
1004 | if (s > size) | |
1005 | s = size; | |
1006 | memcpy(buf, data, s); | |
1007 | ||
1008 | return s; | |
1009 | } | |
1010 | ||
1011 | return -EINVAL; | |
1012 | } | |
1013 | ||
1014 | static void pid_from_ns(int sock, pid_t tpid) | |
1015 | { | |
1016 | pid_t vpid; | |
1017 | struct ucred cred; | |
1018 | char v; | |
1019 | ||
1020 | cred.uid = 0; | |
1021 | cred.gid = 0; | |
1022 | while (read(sock, &vpid, sizeof(pid_t)) == sizeof(pid_t)) { | |
1023 | if (vpid == -1) // done | |
1024 | break; | |
1025 | v = '0'; | |
1026 | cred.pid = vpid; | |
1027 | if (send_creds(sock, &cred, v, true) != SEND_CREDS_OK) { | |
1028 | v = '1'; | |
1029 | cred.pid = getpid(); | |
1030 | if (send_creds(sock, &cred, v, false) != SEND_CREDS_OK) | |
1031 | exit(1); | |
1032 | } | |
1033 | } | |
1034 | exit(0); | |
1035 | } | |
1036 | ||
1037 | static void pid_from_ns_wrapper(int sock, pid_t tpid) | |
1038 | { | |
1039 | int newnsfd = -1; | |
1040 | char fnam[100]; | |
1041 | pid_t cpid; | |
1042 | ||
1043 | sprintf(fnam, "/proc/%d/ns/pid", tpid); | |
1044 | newnsfd = open(fnam, O_RDONLY); | |
1045 | if (newnsfd < 0) | |
1046 | exit(1); | |
1047 | if (setns(newnsfd, 0) < 0) | |
1048 | exit(1); | |
1049 | close(newnsfd); | |
1050 | ||
1051 | cpid = fork(); | |
1052 | ||
1053 | if (cpid < 0) | |
1054 | exit(1); | |
1055 | if (!cpid) | |
1056 | pid_from_ns(sock, tpid); | |
1057 | if (!wait_for_pid(cpid)) | |
1058 | exit(1); | |
1059 | exit(0); | |
1060 | } | |
1061 | ||
1062 | static bool do_write_pids(pid_t tpid, const char *contrl, const char *cg, const char *file, const char *buf) | |
1063 | { | |
1064 | int sock[2] = {-1, -1}; | |
1065 | pid_t qpid, cpid = -1; | |
1066 | bool answer = false, fail = false; | |
1067 | ||
1068 | /* | |
1069 | * write the pids to a socket, have helper in writer's pidns | |
1070 | * call movepid for us | |
1071 | */ | |
1072 | if (socketpair(AF_UNIX, SOCK_DGRAM, 0, sock) < 0) { | |
1073 | perror("socketpair"); | |
1074 | exit(1); | |
1075 | } | |
1076 | ||
1077 | cpid = fork(); | |
1078 | if (cpid == -1) | |
1079 | goto out; | |
1080 | ||
1081 | if (!cpid) // child | |
1082 | pid_from_ns_wrapper(sock[1], tpid); | |
1083 | ||
1084 | const char *ptr = buf; | |
1085 | while (sscanf(ptr, "%d", &qpid) == 1) { | |
1086 | struct ucred cred; | |
1087 | char v; | |
1088 | ||
1089 | if (write(sock[0], &qpid, sizeof(qpid)) != sizeof(qpid)) { | |
1090 | kill(cpid, SIGTERM); | |
1091 | perror("write"); | |
1092 | goto out; | |
1093 | } | |
1094 | ||
1095 | if (recv_creds(sock[0], &cred, &v)) { | |
1096 | if (v == '0') { | |
1097 | if (!cgm_move_pid(contrl, cg, cred.pid)) | |
1098 | fail = true; | |
1099 | } | |
1100 | } | |
1101 | ||
1102 | ptr = strchr(ptr, '\n'); | |
1103 | if (!ptr) | |
1104 | break; | |
1105 | ptr++; | |
1106 | } | |
1107 | ||
1108 | /* All good, write the value */ | |
1109 | qpid = -1; | |
1110 | if (write(sock[0], &qpid ,sizeof(qpid)) != sizeof(qpid)) | |
1111 | printf("Warning: failed to ask child to exit\n"); | |
1112 | ||
1113 | if (!fail) | |
1114 | answer = true; | |
1115 | ||
1116 | out: | |
1117 | if (cpid != -1) | |
1118 | wait_for_pid(cpid); | |
1119 | if (sock[0] != -1) { | |
1120 | close(sock[0]); | |
1121 | close(sock[1]); | |
1122 | } | |
1123 | return answer; | |
1124 | } | |
1125 | ||
1126 | int cg_write(const char *path, const char *buf, size_t size, off_t offset, | |
1127 | struct fuse_file_info *fi) | |
1128 | { | |
1129 | nih_local char *controller = NULL; | |
1130 | const char *cgroup; | |
1131 | char *fpath = NULL, *path1, *path2; | |
1132 | struct fuse_context *fc = fuse_get_context(); | |
1133 | nih_local char * cgdir = NULL; | |
1134 | nih_local struct cgm_keys *k = NULL; | |
1135 | ||
1136 | if (offset) | |
1137 | return -EINVAL; | |
1138 | ||
1139 | if (!fc) | |
1140 | return -EIO; | |
1141 | ||
1142 | controller = pick_controller_from_path(fc, path); | |
1143 | if (!controller) | |
1144 | return -EINVAL; | |
1145 | cgroup = find_cgroup_in_path(path); | |
1146 | if (!cgroup) | |
1147 | return -EINVAL; | |
1148 | ||
1149 | get_cgdir_and_path(cgroup, &cgdir, &fpath); | |
1150 | if (!fpath) { | |
1151 | path1 = "/"; | |
1152 | path2 = cgdir; | |
1153 | } else { | |
1154 | path1 = cgdir; | |
1155 | path2 = fpath; | |
1156 | } | |
1157 | ||
1158 | if ((k = get_cgroup_key(controller, path1, path2)) != NULL) { | |
1159 | bool r; | |
1160 | ||
1161 | if (!fc_may_access(fc, controller, path1, path2, O_WRONLY)) | |
1162 | return -EACCES; | |
1163 | ||
1164 | if (strcmp(path2, "tasks") == 0 || | |
1165 | strcmp(path2, "/tasks") == 0 || | |
1166 | strcmp(path2, "/cgroup.procs") == 0 || | |
1167 | strcmp(path2, "cgroup.procs") == 0) | |
1168 | // special case - we have to translate the pids | |
1169 | r = do_write_pids(fc->pid, controller, path1, path2, buf); | |
1170 | else | |
1171 | r = cgm_set_value(controller, path1, path2, buf); | |
1172 | ||
1173 | if (!r) | |
1174 | return -EINVAL; | |
1175 | ||
1176 | return size; | |
1177 | } | |
1178 | ||
1179 | return -EINVAL; | |
1180 | } | |
1181 | ||
1182 | int cg_chown(const char *path, uid_t uid, gid_t gid) | |
1183 | { | |
1184 | struct fuse_context *fc = fuse_get_context(); | |
1185 | nih_local char * cgdir = NULL; | |
1186 | char *fpath = NULL, *path1, *path2; | |
1187 | nih_local struct cgm_keys *k = NULL; | |
1188 | const char *cgroup; | |
1189 | nih_local char *controller = NULL; | |
1190 | ||
1191 | ||
1192 | if (!fc) | |
1193 | return -EIO; | |
1194 | ||
1195 | if (strcmp(path, "/cgroup") == 0) | |
1196 | return -EINVAL; | |
1197 | ||
1198 | controller = pick_controller_from_path(fc, path); | |
1199 | if (!controller) | |
1200 | return -EINVAL; | |
1201 | cgroup = find_cgroup_in_path(path); | |
1202 | if (!cgroup) | |
1203 | /* this is just /cgroup/controller */ | |
1204 | return -EINVAL; | |
1205 | ||
1206 | get_cgdir_and_path(cgroup, &cgdir, &fpath); | |
1207 | ||
1208 | if (!fpath) { | |
1209 | path1 = "/"; | |
1210 | path2 = cgdir; | |
1211 | } else { | |
1212 | path1 = cgdir; | |
1213 | path2 = fpath; | |
1214 | } | |
1215 | ||
1216 | if (is_child_cgroup(controller, path1, path2)) { | |
1217 | // get uid, gid, from '/tasks' file and make up a mode | |
1218 | // That is a hack, until cgmanager gains a GetCgroupPerms fn. | |
1219 | k = get_cgroup_key(controller, cgroup, "tasks"); | |
1220 | ||
1221 | } else | |
1222 | k = get_cgroup_key(controller, path1, path2); | |
1223 | ||
1224 | if (!k) | |
1225 | return -EINVAL; | |
1226 | ||
1227 | /* | |
1228 | * This being a fuse request, the uid and gid must be valid | |
1229 | * in the caller's namespace. So we can just check to make | |
1230 | * sure that the caller is root in his uid, and privileged | |
1231 | * over the file's current owner. | |
1232 | */ | |
1233 | if (!is_privileged_over(fc->pid, fc->uid, k->uid, NS_ROOT_REQD)) | |
1234 | return -EACCES; | |
1235 | ||
1236 | if (!cgm_chown_file(controller, cgroup, uid, gid)) | |
1237 | return -EINVAL; | |
1238 | return 0; | |
1239 | } | |
1240 | ||
1241 | int cg_chmod(const char *path, mode_t mode) | |
1242 | { | |
1243 | struct fuse_context *fc = fuse_get_context(); | |
1244 | nih_local char * cgdir = NULL; | |
1245 | char *fpath = NULL, *path1, *path2; | |
1246 | nih_local struct cgm_keys *k = NULL; | |
1247 | const char *cgroup; | |
1248 | nih_local char *controller = NULL; | |
1249 | ||
1250 | if (!fc) | |
1251 | return -EIO; | |
1252 | ||
1253 | if (strcmp(path, "/cgroup") == 0) | |
1254 | return -EINVAL; | |
1255 | ||
1256 | controller = pick_controller_from_path(fc, path); | |
1257 | if (!controller) | |
1258 | return -EINVAL; | |
1259 | cgroup = find_cgroup_in_path(path); | |
1260 | if (!cgroup) | |
1261 | /* this is just /cgroup/controller */ | |
1262 | return -EINVAL; | |
1263 | ||
1264 | get_cgdir_and_path(cgroup, &cgdir, &fpath); | |
1265 | ||
1266 | if (!fpath) { | |
1267 | path1 = "/"; | |
1268 | path2 = cgdir; | |
1269 | } else { | |
1270 | path1 = cgdir; | |
1271 | path2 = fpath; | |
1272 | } | |
1273 | ||
1274 | if (is_child_cgroup(controller, path1, path2)) { | |
1275 | // get uid, gid, from '/tasks' file and make up a mode | |
1276 | // That is a hack, until cgmanager gains a GetCgroupPerms fn. | |
1277 | k = get_cgroup_key(controller, cgroup, "tasks"); | |
1278 | ||
1279 | } else | |
1280 | k = get_cgroup_key(controller, path1, path2); | |
1281 | ||
1282 | if (!k) | |
1283 | return -EINVAL; | |
1284 | ||
1285 | /* | |
1286 | * This being a fuse request, the uid and gid must be valid | |
1287 | * in the caller's namespace. So we can just check to make | |
1288 | * sure that the caller is root in his uid, and privileged | |
1289 | * over the file's current owner. | |
1290 | */ | |
1291 | if (!is_privileged_over(fc->pid, fc->uid, k->uid, NS_ROOT_OPT)) | |
1292 | return -EPERM; | |
1293 | ||
1294 | if (!cgm_chmod_file(controller, cgroup, mode)) | |
1295 | return -EINVAL; | |
1296 | return 0; | |
1297 | } | |
1298 | ||
1299 | int cg_mkdir(const char *path, mode_t mode) | |
1300 | { | |
1301 | struct fuse_context *fc = fuse_get_context(); | |
1302 | nih_local struct cgm_keys **list = NULL; | |
1303 | char *fpath = NULL, *path1; | |
1304 | nih_local char * cgdir = NULL; | |
1305 | const char *cgroup; | |
1306 | nih_local char *controller = NULL; | |
1307 | ||
1308 | if (!fc) | |
1309 | return -EIO; | |
1310 | ||
1311 | ||
1312 | controller = pick_controller_from_path(fc, path); | |
1313 | if (!controller) | |
1314 | return -EINVAL; | |
1315 | ||
1316 | cgroup = find_cgroup_in_path(path); | |
1317 | if (!cgroup) | |
1318 | return -EINVAL; | |
1319 | ||
1320 | get_cgdir_and_path(cgroup, &cgdir, &fpath); | |
1321 | if (!fpath) | |
1322 | path1 = "/"; | |
1323 | else | |
1324 | path1 = cgdir; | |
1325 | ||
1326 | if (!fc_may_access(fc, controller, path1, NULL, O_RDWR)) | |
1327 | return -EACCES; | |
1328 | ||
1329 | ||
1330 | if (!cgm_create(controller, cgroup, fc->uid, fc->gid)) | |
1331 | return -EINVAL; | |
1332 | ||
1333 | return 0; | |
1334 | } | |
1335 | ||
1336 | static int cg_rmdir(const char *path) | |
1337 | { | |
1338 | struct fuse_context *fc = fuse_get_context(); | |
1339 | nih_local struct cgm_keys **list = NULL; | |
1340 | char *fpath = NULL; | |
1341 | nih_local char * cgdir = NULL; | |
1342 | const char *cgroup; | |
1343 | nih_local char *controller = NULL; | |
1344 | ||
1345 | if (!fc) | |
1346 | return -EIO; | |
1347 | ||
1348 | ||
1349 | controller = pick_controller_from_path(fc, path); | |
1350 | if (!controller) | |
1351 | return -EINVAL; | |
1352 | ||
1353 | cgroup = find_cgroup_in_path(path); | |
1354 | if (!cgroup) | |
1355 | return -EINVAL; | |
1356 | ||
1357 | get_cgdir_and_path(cgroup, &cgdir, &fpath); | |
1358 | if (!fpath) | |
1359 | return -EINVAL; | |
1360 | ||
1361 | if (!fc_may_access(fc, controller, cgdir, NULL, O_WRONLY)) | |
1362 | return -EACCES; | |
1363 | ||
1364 | if (!cgm_remove(controller, cgroup)) | |
1365 | return -EINVAL; | |
1366 | ||
1367 | return 0; | |
1368 | } | |
1369 | ||
1370 | static bool startswith(const char *line, const char *pref) | |
1371 | { | |
1372 | if (strncmp(line, pref, strlen(pref)) == 0) | |
1373 | return true; | |
1374 | return false; | |
1375 | } | |
1376 | ||
1377 | static void get_mem_cached(char *memstat, unsigned long *v) | |
1378 | { | |
1379 | char *eol; | |
1380 | ||
1381 | *v = 0; | |
1382 | while (*memstat) { | |
1383 | if (startswith(memstat, "total_cache")) { | |
1384 | sscanf(memstat + 11, "%lu", v); | |
1385 | *v /= 1024; | |
1386 | return; | |
1387 | } | |
1388 | eol = strchr(memstat, '\n'); | |
1389 | if (!eol) | |
1390 | return; | |
1391 | memstat = eol+1; | |
1392 | } | |
1393 | } | |
1394 | ||
1395 | static char *get_pid_cgroup(pid_t pid, const char *contrl) | |
1396 | { | |
1397 | nih_local char *fnam = NULL; | |
1398 | FILE *f; | |
1399 | char *answer = NULL; | |
1400 | char *line = NULL; | |
1401 | size_t len = 0; | |
1402 | ||
1403 | fnam = NIH_MUST( nih_sprintf(NULL, "/proc/%d/cgroup", pid) ); | |
1404 | if (!(f = fopen(fnam, "r"))) | |
1405 | return false; | |
1406 | ||
1407 | while (getline(&line, &len, f) != -1) { | |
1408 | char *c1, *c2; | |
1409 | if (!line[0]) | |
1410 | continue; | |
1411 | c1 = strchr(line, ':'); | |
1412 | if (!c1) | |
1413 | goto out; | |
1414 | c1++; | |
1415 | c2 = strchr(c1, ':'); | |
1416 | if (!c2) | |
1417 | goto out; | |
1418 | *c2 = '\0'; | |
1419 | if (strcmp(c1, contrl) != 0) | |
1420 | continue; | |
1421 | c2++; | |
1422 | stripnewline(c2); | |
1423 | answer = NIH_MUST( nih_strdup(NULL, c2) ); | |
1424 | goto out; | |
1425 | } | |
1426 | ||
1427 | out: | |
1428 | fclose(f); | |
1429 | free(line); | |
1430 | return answer; | |
1431 | } | |
1432 | ||
1433 | /* | |
1434 | * FUSE ops for /proc | |
1435 | */ | |
1436 | ||
1437 | static int proc_meminfo_read(char *buf, size_t size, off_t offset, | |
1438 | struct fuse_file_info *fi) | |
1439 | { | |
1440 | struct fuse_context *fc = fuse_get_context(); | |
1441 | nih_local char *cg = get_pid_cgroup(fc->pid, "memory"); | |
1442 | nih_local char *memlimit_str = NULL, *memusage_str = NULL, *memstat_str = NULL; | |
1443 | unsigned long memlimit = 0, memusage = 0, cached = 0, hosttotal = 0; | |
1444 | char *line = NULL; | |
1445 | size_t linelen = 0, total_len = 0; | |
1446 | FILE *f; | |
1447 | ||
1448 | if (offset) | |
1449 | return -EINVAL; | |
1450 | ||
1451 | if (!cg) | |
1452 | return 0; | |
1453 | ||
1454 | if (!cgm_get_value("memory", cg, "memory.limit_in_bytes", &memlimit_str)) | |
1455 | return 0; | |
1456 | if (!cgm_get_value("memory", cg, "memory.usage_in_bytes", &memusage_str)) | |
1457 | return 0; | |
1458 | if (!cgm_get_value("memory", cg, "memory.stat", &memstat_str)) | |
1459 | return 0; | |
1460 | memlimit = strtoul(memlimit_str, NULL, 10); | |
1461 | memusage = strtoul(memusage_str, NULL, 10); | |
1462 | memlimit /= 1024; | |
1463 | memusage /= 1024; | |
1464 | get_mem_cached(memstat_str, &cached); | |
1465 | ||
1466 | f = fopen("/proc/meminfo", "r"); | |
1467 | if (!f) | |
1468 | return 0; | |
1469 | ||
1470 | while (getline(&line, &linelen, f) != -1) { | |
1471 | size_t l; | |
1472 | char *printme, lbuf[100]; | |
1473 | ||
1474 | memset(lbuf, 0, 100); | |
1475 | if (startswith(line, "MemTotal:")) { | |
1476 | sscanf(line+14, "%lu", &hosttotal); | |
1477 | if (hosttotal < memlimit) | |
1478 | memlimit = hosttotal; | |
1479 | snprintf(lbuf, 100, "MemTotal: %8lu kB\n", memlimit); | |
1480 | printme = lbuf; | |
1481 | } else if (startswith(line, "MemFree:")) { | |
1482 | snprintf(lbuf, 100, "MemFree: %8lu kB\n", memlimit - memusage); | |
1483 | printme = lbuf; | |
1484 | } else if (startswith(line, "MemAvailable:")) { | |
1485 | snprintf(lbuf, 100, "MemAvailable: %8lu kB\n", memlimit - memusage); | |
1486 | printme = lbuf; | |
1487 | } else if (startswith(line, "Buffers:")) { | |
1488 | snprintf(lbuf, 100, "Buffers: %8lu kB\n", 0UL); | |
1489 | printme = lbuf; | |
1490 | } else if (startswith(line, "Cached:")) { | |
1491 | snprintf(lbuf, 100, "Cached: %8lu kB\n", cached); | |
1492 | printme = lbuf; | |
1493 | } else if (startswith(line, "SwapCached:")) { | |
1494 | snprintf(lbuf, 100, "SwapCached: %8lu kB\n", 0UL); | |
1495 | printme = lbuf; | |
1496 | } else | |
1497 | printme = line; | |
1498 | l = snprintf(buf, size, "%s", printme); | |
1499 | buf += l; | |
1500 | size -= l; | |
1501 | total_len += l; | |
1502 | } | |
1503 | ||
1504 | return total_len; | |
1505 | } | |
1506 | ||
1507 | /* | |
1508 | * Read the cpuset.cpus for cg | |
1509 | * Return the answer in a nih_alloced string | |
1510 | */ | |
1511 | static char *get_cpuset(const char *cg) | |
1512 | { | |
1513 | char *answer; | |
1514 | ||
1515 | if (!cgm_get_value("cpuset", cg, "cpuset.cpus", &answer)) | |
1516 | return NULL; | |
1517 | return answer; | |
1518 | } | |
1519 | ||
1520 | /* | |
1521 | * Helper functions for cpuset_in-set | |
1522 | */ | |
1523 | char *cpuset_nexttok(const char *c) | |
1524 | { | |
1525 | char *r = strchr(c+1, ','); | |
1526 | if (r) | |
1527 | return r+1; | |
1528 | return NULL; | |
1529 | } | |
1530 | ||
1531 | int cpuset_getrange(const char *c, int *a, int *b) | |
1532 | { | |
1533 | int ret; | |
1534 | ||
1535 | ret = sscanf(c, "%d-%d", a, b); | |
1536 | return ret; | |
1537 | } | |
1538 | ||
1539 | /* | |
1540 | * cpusets are in format "1,2-3,4" | |
1541 | * iow, comma-delimited ranges | |
1542 | */ | |
1543 | static bool cpu_in_cpuset(int cpu, const char *cpuset) | |
1544 | { | |
1545 | const char *c; | |
1546 | ||
1547 | for (c = cpuset; c; c = cpuset_nexttok(c)) { | |
1548 | int a, b, ret; | |
1549 | ||
1550 | ret = cpuset_getrange(c, &a, &b); | |
1551 | if (ret == 1 && cpu == a) | |
1552 | return true; | |
1553 | if (ret != 2) // bad cpuset! | |
1554 | return false; | |
1555 | if (cpu >= a && cpu <= b) | |
1556 | return true; | |
1557 | } | |
1558 | ||
1559 | return false; | |
1560 | } | |
1561 | ||
1562 | static bool cpuline_in_cpuset(const char *line, const char *cpuset) | |
1563 | { | |
1564 | int cpu; | |
1565 | ||
1566 | if (sscanf(line, "processor : %d", &cpu) != 1) | |
1567 | return false; | |
1568 | return cpu_in_cpuset(cpu, cpuset); | |
1569 | } | |
1570 | ||
1571 | /* | |
1572 | * check whether this is a '^processor" line in /proc/cpuinfo | |
1573 | */ | |
1574 | static bool is_processor_line(const char *line) | |
1575 | { | |
1576 | int cpu; | |
1577 | ||
1578 | if (sscanf(line, "processor : %d", &cpu) == 1) | |
1579 | return true; | |
1580 | return false; | |
1581 | } | |
1582 | ||
1583 | static int proc_cpuinfo_read(char *buf, size_t size, off_t offset, | |
1584 | struct fuse_file_info *fi) | |
1585 | { | |
1586 | struct fuse_context *fc = fuse_get_context(); | |
1587 | nih_local char *cg = get_pid_cgroup(fc->pid, "cpuset"); | |
1588 | nih_local char *cpuset = NULL; | |
1589 | char *line = NULL; | |
1590 | size_t linelen = 0, total_len = 0; | |
1591 | bool am_printing = false; | |
1592 | int curcpu = -1; | |
1593 | FILE *f; | |
1594 | ||
1595 | if (offset) | |
1596 | return -EINVAL; | |
1597 | ||
1598 | if (!cg) | |
1599 | return 0; | |
1600 | ||
1601 | cpuset = get_cpuset(cg); | |
1602 | if (!cpuset) | |
1603 | return 0; | |
1604 | ||
1605 | f = fopen("/proc/cpuinfo", "r"); | |
1606 | if (!f) | |
1607 | return 0; | |
1608 | ||
1609 | while (getline(&line, &linelen, f) != -1) { | |
1610 | size_t l; | |
1611 | if (is_processor_line(line)) { | |
1612 | am_printing = cpuline_in_cpuset(line, cpuset); | |
1613 | if (am_printing) { | |
1614 | curcpu ++; | |
1615 | l = snprintf(buf, size, "processor : %d\n", curcpu); | |
1616 | buf += l; | |
1617 | size -= l; | |
1618 | total_len += l; | |
1619 | } | |
1620 | continue; | |
1621 | } | |
1622 | if (am_printing) { | |
1623 | l = snprintf(buf, size, "%s", line); | |
1624 | buf += l; | |
1625 | size -= l; | |
1626 | total_len += l; | |
1627 | } | |
1628 | } | |
1629 | ||
1630 | return total_len; | |
1631 | } | |
1632 | ||
1633 | static int proc_stat_read(char *buf, size_t size, off_t offset, | |
1634 | struct fuse_file_info *fi) | |
1635 | { | |
1636 | struct fuse_context *fc = fuse_get_context(); | |
1637 | nih_local char *cg = get_pid_cgroup(fc->pid, "cpuset"); | |
1638 | nih_local char *cpuset = NULL; | |
1639 | char *line = NULL; | |
1640 | size_t linelen = 0, total_len = 0; | |
1641 | int curcpu = 0; | |
1642 | FILE *f; | |
1643 | ||
1644 | if (offset) | |
1645 | return -EINVAL; | |
1646 | ||
1647 | if (!cg) | |
1648 | return 0; | |
1649 | ||
1650 | cpuset = get_cpuset(cg); | |
1651 | if (!cpuset) | |
1652 | return 0; | |
1653 | ||
1654 | f = fopen("/proc/stat", "r"); | |
1655 | if (!f) | |
1656 | return 0; | |
1657 | ||
1658 | while (getline(&line, &linelen, f) != -1) { | |
1659 | size_t l; | |
1660 | int cpu; | |
1661 | char *c; | |
1662 | ||
1663 | if (sscanf(line, "cpu%d", &cpu) != 1) { | |
1664 | /* not a ^cpu line, just print it */ | |
1665 | l = snprintf(buf, size, "%s", line); | |
1666 | buf += l; | |
1667 | size -= l; | |
1668 | total_len += l; | |
1669 | continue; | |
1670 | } | |
1671 | if (!cpu_in_cpuset(cpu, cpuset)) | |
1672 | continue; | |
1673 | curcpu ++; | |
1674 | ||
1675 | c = strchr(line, ' '); | |
1676 | if (!c) | |
1677 | continue; | |
1678 | l = snprintf(buf, size, "cpu%d %s", curcpu, c); | |
1679 | buf += l; | |
1680 | size -= l; | |
1681 | total_len += l; | |
1682 | } | |
1683 | ||
1684 | return total_len; | |
1685 | } | |
1686 | ||
1687 | /* | |
1688 | * How to guess what to present for uptime? | |
1689 | * One thing we could do would be to take the date on the caller's | |
1690 | * memory.usage_in_bytes file, which should equal the time of creation | |
1691 | * of his cgroup. However, a task could be in a sub-cgroup of the | |
1692 | * container. The same problem exists if we try to look at the ages | |
1693 | * of processes in the caller's cgroup. | |
1694 | * | |
1695 | * So we'll fork a task that will enter the caller's pidns, mount a | |
1696 | * fresh procfs, get the age of /proc/1, and pass that back over a pipe. | |
1697 | * | |
1698 | * For the second uptime #, we'll do as Stéphane had done, just copy | |
1699 | * the number from /proc/uptime. Not sure how to best emulate 'idle' | |
1700 | * time. Maybe someone can come up with a good algorithm and submit a | |
1701 | * patch. Maybe something based on cpushare info? | |
1702 | */ | |
1703 | ||
1704 | /* return age of the reaper for $pid, taken from ctime of its procdir */ | |
1705 | static long int get_pid1_time(pid_t pid) | |
1706 | { | |
1707 | char fnam[100]; | |
1708 | int fd; | |
1709 | struct stat sb; | |
1710 | int ret; | |
1711 | pid_t npid; | |
1712 | ||
1713 | if (unshare(CLONE_NEWNS)) | |
1714 | return 0; | |
1715 | ||
1716 | sprintf(fnam, "/proc/%d/ns/pid", pid); | |
1717 | fd = open(fnam, O_RDONLY); | |
1718 | if (fd < 0) { | |
1719 | perror("get_pid1_time open of ns/pid"); | |
1720 | return 0; | |
1721 | } | |
1722 | if (setns(fd, 0)) { | |
1723 | perror("get_pid1_time setns 1"); | |
1724 | close(fd); | |
1725 | return 0; | |
1726 | } | |
1727 | close(fd); | |
1728 | npid = fork(); | |
1729 | if (npid < 0) | |
1730 | return 0; | |
1731 | ||
1732 | if (npid) { | |
1733 | // child will do the writing for us | |
1734 | wait_for_pid(npid); | |
1735 | exit(0); | |
1736 | } | |
1737 | ||
1738 | umount2("/proc", MNT_DETACH); | |
1739 | ||
1740 | if (mount("proc", "/proc", "proc", 0, NULL)) { | |
1741 | perror("get_pid1_time mount"); | |
1742 | return 0; | |
1743 | } | |
1744 | ret = lstat("/proc/1", &sb); | |
1745 | if (ret) { | |
1746 | perror("get_pid1_time lstat"); | |
1747 | return 0; | |
1748 | } | |
1749 | return time(NULL) - sb.st_ctime; | |
1750 | } | |
1751 | ||
1752 | static long int getreaperage(pid_t qpid) | |
1753 | { | |
1754 | int pid, mypipe[2], ret; | |
1755 | struct timeval tv; | |
1756 | fd_set s; | |
1757 | long int mtime, answer = 0; | |
1758 | ||
1759 | if (pipe(mypipe)) { | |
1760 | return 0; | |
1761 | } | |
1762 | ||
1763 | pid = fork(); | |
1764 | ||
1765 | if (!pid) { // child | |
1766 | mtime = get_pid1_time(qpid); | |
1767 | if (write(mypipe[1], &mtime, sizeof(mtime)) != sizeof(mtime)) | |
1768 | fprintf(stderr, "Warning: bad write from getreaperage\n"); | |
1769 | exit(0); | |
1770 | } | |
1771 | ||
1772 | close(mypipe[1]); | |
1773 | FD_ZERO(&s); | |
1774 | FD_SET(mypipe[0], &s); | |
1775 | tv.tv_sec = 1; | |
1776 | tv.tv_usec = 0; | |
1777 | ret = select(mypipe[0]+1, &s, NULL, NULL, &tv); | |
1778 | if (ret == -1) { | |
1779 | perror("select"); | |
1780 | goto out; | |
1781 | } | |
1782 | if (!ret) { | |
1783 | printf("timed out\n"); | |
1784 | goto out; | |
1785 | } | |
1786 | if (read(mypipe[0], &mtime, sizeof(mtime)) != sizeof(mtime)) { | |
1787 | perror("read"); | |
1788 | goto out; | |
1789 | } | |
1790 | answer = mtime; | |
1791 | ||
1792 | out: | |
1793 | wait_for_pid(pid); | |
1794 | close(mypipe[0]); | |
1795 | return answer; | |
1796 | } | |
1797 | ||
1798 | static long int getprocidle(void) | |
1799 | { | |
1800 | FILE *f = fopen("/proc/uptime", "r"); | |
1801 | long int age, idle; | |
1802 | if (!f) | |
1803 | return 0; | |
1804 | if (fscanf(f, "%ld %ld", &age, &idle) != 2) | |
1805 | return 0; | |
1806 | return idle; | |
1807 | } | |
1808 | ||
1809 | /* | |
1810 | * We read /proc/uptime and reuse its second field. | |
1811 | * For the first field, we use the mtime for the reaper for | |
1812 | * the calling pid as returned by getreaperage | |
1813 | */ | |
1814 | static int proc_uptime_read(char *buf, size_t size, off_t offset, | |
1815 | struct fuse_file_info *fi) | |
1816 | { | |
1817 | struct fuse_context *fc = fuse_get_context(); | |
1818 | long int reaperage = getreaperage(fc->pid);; | |
1819 | long int idletime = getprocidle(); | |
1820 | ||
1821 | if (offset) | |
1822 | return -EINVAL; | |
1823 | return snprintf(buf, size, "%ld %ld\n", reaperage, idletime); | |
1824 | } | |
1825 | ||
1826 | static off_t get_procfile_size(const char *which) | |
1827 | { | |
1828 | FILE *f = fopen(which, "r"); | |
1829 | char *line = NULL; | |
1830 | size_t len = 0; | |
1831 | ssize_t sz, answer = 0; | |
1832 | if (!f) | |
1833 | return 0; | |
1834 | ||
1835 | while ((sz = getline(&line, &len, f)) != -1) | |
1836 | answer += sz; | |
1837 | fclose (f); | |
1838 | ||
1839 | return answer; | |
1840 | } | |
1841 | ||
1842 | static int proc_getattr(const char *path, struct stat *sb) | |
1843 | { | |
1844 | struct timespec now; | |
1845 | ||
1846 | memset(sb, 0, sizeof(struct stat)); | |
1847 | if (clock_gettime(CLOCK_REALTIME, &now) < 0) | |
1848 | return -EINVAL; | |
1849 | sb->st_uid = sb->st_gid = 0; | |
1850 | sb->st_atim = sb->st_mtim = sb->st_ctim = now; | |
1851 | if (strcmp(path, "/proc") == 0) { | |
1852 | sb->st_mode = S_IFDIR | 00555; | |
1853 | sb->st_nlink = 2; | |
1854 | return 0; | |
1855 | } | |
1856 | if (strcmp(path, "/proc/meminfo") == 0 || | |
1857 | strcmp(path, "/proc/cpuinfo") == 0 || | |
1858 | strcmp(path, "/proc/uptime") == 0 || | |
1859 | strcmp(path, "/proc/stat") == 0) { | |
1860 | ||
1861 | sb->st_size = get_procfile_size(path); | |
1862 | sb->st_mode = S_IFREG | 00444; | |
1863 | sb->st_nlink = 1; | |
1864 | return 0; | |
1865 | } | |
1866 | ||
1867 | return -ENOENT; | |
1868 | } | |
1869 | ||
1870 | static int proc_readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset, | |
1871 | struct fuse_file_info *fi) | |
1872 | { | |
1873 | if (filler(buf, "cpuinfo", NULL, 0) != 0 || | |
1874 | filler(buf, "meminfo", NULL, 0) != 0 || | |
1875 | filler(buf, "stat", NULL, 0) != 0 || | |
1876 | filler(buf, "uptime", NULL, 0) != 0) | |
1877 | return -EINVAL; | |
1878 | return 0; | |
1879 | } | |
1880 | ||
1881 | static int proc_open(const char *path, struct fuse_file_info *fi) | |
1882 | { | |
1883 | if (strcmp(path, "/proc/meminfo") == 0 || | |
1884 | strcmp(path, "/proc/cpuinfo") == 0 || | |
1885 | strcmp(path, "/proc/uptime") == 0 || | |
1886 | strcmp(path, "/proc/stat") == 0) | |
1887 | return 0; | |
1888 | return -ENOENT; | |
1889 | } | |
1890 | ||
1891 | static int proc_read(const char *path, char *buf, size_t size, off_t offset, | |
1892 | struct fuse_file_info *fi) | |
1893 | { | |
1894 | if (strcmp(path, "/proc/meminfo") == 0) | |
1895 | return proc_meminfo_read(buf, size, offset, fi); | |
1896 | if (strcmp(path, "/proc/cpuinfo") == 0) | |
1897 | return proc_cpuinfo_read(buf, size, offset, fi); | |
1898 | if (strcmp(path, "/proc/uptime") == 0) | |
1899 | return proc_uptime_read(buf, size, offset, fi); | |
1900 | if (strcmp(path, "/proc/stat") == 0) | |
1901 | return proc_stat_read(buf, size, offset, fi); | |
1902 | return -EINVAL; | |
1903 | } | |
1904 | ||
1905 | /* | |
1906 | * FUSE ops for / | |
1907 | * these just delegate to the /proc and /cgroup ops as | |
1908 | * needed | |
1909 | */ | |
1910 | ||
1911 | static int lxcfs_getattr(const char *path, struct stat *sb) | |
1912 | { | |
1913 | if (strcmp(path, "/") == 0) { | |
1914 | sb->st_mode = S_IFDIR | 00755; | |
1915 | sb->st_nlink = 2; | |
1916 | return 0; | |
1917 | } | |
1918 | if (strncmp(path, "/cgroup", 7) == 0) { | |
1919 | return cg_getattr(path, sb); | |
1920 | } | |
1921 | if (strncmp(path, "/proc", 5) == 0) { | |
1922 | return proc_getattr(path, sb); | |
1923 | } | |
1924 | return -EINVAL; | |
1925 | } | |
1926 | ||
1927 | static int lxcfs_opendir(const char *path, struct fuse_file_info *fi) | |
1928 | { | |
1929 | if (strcmp(path, "/") == 0) | |
1930 | return 0; | |
1931 | ||
1932 | if (strncmp(path, "/cgroup", 7) == 0) { | |
1933 | return cg_opendir(path, fi); | |
1934 | } | |
1935 | if (strcmp(path, "/proc") == 0) | |
1936 | return 0; | |
1937 | return -ENOENT; | |
1938 | } | |
1939 | ||
1940 | static int lxcfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset, | |
1941 | struct fuse_file_info *fi) | |
1942 | { | |
1943 | if (strcmp(path, "/") == 0) { | |
1944 | if (filler(buf, "proc", NULL, 0) != 0 || | |
1945 | filler(buf, "cgroup", NULL, 0) != 0) | |
1946 | return -EINVAL; | |
1947 | return 0; | |
1948 | } | |
1949 | if (strncmp(path, "/cgroup", 7) == 0) | |
1950 | return cg_readdir(path, buf, filler, offset, fi); | |
1951 | if (strcmp(path, "/proc") == 0) | |
1952 | return proc_readdir(path, buf, filler, offset, fi); | |
1953 | return -EINVAL; | |
1954 | } | |
1955 | ||
1956 | static int lxcfs_releasedir(const char *path, struct fuse_file_info *fi) | |
1957 | { | |
1958 | if (strcmp(path, "/") == 0) | |
1959 | return 0; | |
1960 | if (strncmp(path, "/cgroup", 7) == 0) { | |
1961 | return cg_releasedir(path, fi); | |
1962 | } | |
1963 | if (strcmp(path, "/proc") == 0) | |
1964 | return 0; | |
1965 | return -EINVAL; | |
1966 | } | |
1967 | ||
1968 | static int lxcfs_open(const char *path, struct fuse_file_info *fi) | |
1969 | { | |
1970 | if (strncmp(path, "/cgroup", 7) == 0) | |
1971 | return cg_open(path, fi); | |
1972 | if (strncmp(path, "/proc", 5) == 0) | |
1973 | return proc_open(path, fi); | |
1974 | ||
1975 | return -EINVAL; | |
1976 | } | |
1977 | ||
1978 | static int lxcfs_read(const char *path, char *buf, size_t size, off_t offset, | |
1979 | struct fuse_file_info *fi) | |
1980 | { | |
1981 | if (strncmp(path, "/cgroup", 7) == 0) | |
1982 | return cg_read(path, buf, size, offset, fi); | |
1983 | if (strncmp(path, "/proc", 5) == 0) | |
1984 | return proc_read(path, buf, size, offset, fi); | |
1985 | ||
1986 | return -EINVAL; | |
1987 | } | |
1988 | ||
1989 | int lxcfs_write(const char *path, const char *buf, size_t size, off_t offset, | |
1990 | struct fuse_file_info *fi) | |
1991 | { | |
1992 | if (strncmp(path, "/cgroup", 7) == 0) { | |
1993 | return cg_write(path, buf, size, offset, fi); | |
1994 | } | |
1995 | ||
1996 | return -EINVAL; | |
1997 | } | |
1998 | ||
1999 | static int lxcfs_flush(const char *path, struct fuse_file_info *fi) | |
2000 | { | |
2001 | return 0; | |
2002 | } | |
2003 | ||
2004 | static int lxcfs_release(const char *path, struct fuse_file_info *fi) | |
2005 | { | |
2006 | return 0; | |
2007 | } | |
2008 | ||
2009 | static int lxcfs_fsync(const char *path, int datasync, struct fuse_file_info *fi) | |
2010 | { | |
2011 | return 0; | |
2012 | } | |
2013 | ||
2014 | int lxcfs_mkdir(const char *path, mode_t mode) | |
2015 | { | |
2016 | if (strncmp(path, "/cgroup", 7) == 0) | |
2017 | return cg_mkdir(path, mode); | |
2018 | ||
2019 | return -EINVAL; | |
2020 | } | |
2021 | ||
2022 | int lxcfs_chown(const char *path, uid_t uid, gid_t gid) | |
2023 | { | |
2024 | if (strncmp(path, "/cgroup", 7) == 0) | |
2025 | return cg_chown(path, uid, gid); | |
2026 | ||
2027 | return -EINVAL; | |
2028 | } | |
2029 | ||
2030 | /* | |
2031 | * cat first does a truncate before doing ops->write. This doesn't | |
2032 | * really make sense for cgroups. So just return 0 always but do | |
2033 | * nothing. | |
2034 | */ | |
2035 | int lxcfs_truncate(const char *path, off_t newsize) | |
2036 | { | |
2037 | if (strncmp(path, "/cgroup", 7) == 0) | |
2038 | return 0; | |
2039 | return -EINVAL; | |
2040 | } | |
2041 | ||
2042 | int lxcfs_rmdir(const char *path) | |
2043 | { | |
2044 | if (strncmp(path, "/cgroup", 7) == 0) | |
2045 | return cg_rmdir(path); | |
2046 | return -EINVAL; | |
2047 | } | |
2048 | ||
2049 | int lxcfs_chmod(const char *path, mode_t mode) | |
2050 | { | |
2051 | if (strncmp(path, "/cgroup", 7) == 0) | |
2052 | return cg_chmod(path, mode); | |
2053 | return -EINVAL; | |
2054 | } | |
2055 | ||
2056 | const struct fuse_operations lxcfs_ops = { | |
2057 | .getattr = lxcfs_getattr, | |
2058 | .readlink = NULL, | |
2059 | .getdir = NULL, | |
2060 | .mknod = NULL, | |
2061 | .mkdir = lxcfs_mkdir, | |
2062 | .unlink = NULL, | |
2063 | .rmdir = lxcfs_rmdir, | |
2064 | .symlink = NULL, | |
2065 | .rename = NULL, | |
2066 | .link = NULL, | |
2067 | .chmod = lxcfs_chmod, | |
2068 | .chown = lxcfs_chown, | |
2069 | .truncate = lxcfs_truncate, | |
2070 | .utime = NULL, | |
2071 | ||
2072 | .open = lxcfs_open, | |
2073 | .read = lxcfs_read, | |
2074 | .release = lxcfs_release, | |
2075 | .write = lxcfs_write, | |
2076 | ||
2077 | .statfs = NULL, | |
2078 | .flush = lxcfs_flush, | |
2079 | .fsync = lxcfs_fsync, | |
2080 | ||
2081 | .setxattr = NULL, | |
2082 | .getxattr = NULL, | |
2083 | .listxattr = NULL, | |
2084 | .removexattr = NULL, | |
2085 | ||
2086 | .opendir = lxcfs_opendir, | |
2087 | .readdir = lxcfs_readdir, | |
2088 | .releasedir = lxcfs_releasedir, | |
2089 | ||
2090 | .fsyncdir = NULL, | |
2091 | .init = NULL, | |
2092 | .destroy = NULL, | |
2093 | .access = NULL, | |
2094 | .create = NULL, | |
2095 | .ftruncate = NULL, | |
2096 | .fgetattr = NULL, | |
2097 | }; | |
2098 | ||
2099 | static void usage(const char *me) | |
2100 | { | |
2101 | fprintf(stderr, "Usage:\n"); | |
2102 | fprintf(stderr, "\n"); | |
2103 | fprintf(stderr, "%s [FUSE and mount options] mountpoint\n", me); | |
2104 | exit(1); | |
2105 | } | |
2106 | ||
2107 | static bool is_help(char *w) | |
2108 | { | |
2109 | if (strcmp(w, "-h") == 0 || | |
2110 | strcmp(w, "--help") == 0 || | |
2111 | strcmp(w, "-help") == 0 || | |
2112 | strcmp(w, "help") == 0) | |
2113 | return true; | |
2114 | return false; | |
2115 | } | |
2116 | ||
2117 | int main(int argc, char *argv[]) | |
2118 | { | |
2119 | int ret; | |
2120 | struct lxcfs_state *d; | |
2121 | ||
2122 | if (argc < 2 || is_help(argv[1])) | |
2123 | usage(argv[0]); | |
2124 | ||
2125 | d = malloc(sizeof(*d)); | |
2126 | if (!d) | |
2127 | return -1; | |
2128 | ||
2129 | if (!cgm_escape_cgroup()) | |
2130 | fprintf(stderr, "WARNING: failed to escape to root cgroup\n"); | |
2131 | ||
2132 | if (!cgm_get_controllers(&d->subsystems)) | |
2133 | return -1; | |
2134 | ||
2135 | ret = fuse_main(argc, argv, &lxcfs_ops, d); | |
2136 | ||
2137 | return ret; | |
2138 | } |