3 * Copyright © 2014-2016 Canonical, Inc
4 * Author: Serge Hallyn <serge.hallyn@ubuntu.com>
6 * See COPYING file for details.
9 #define FUSE_USE_VERSION 26
25 #include <linux/sched.h>
26 #include <sys/epoll.h>
28 #include <sys/mount.h>
29 #include <sys/param.h>
30 #include <sys/socket.h>
31 #include <sys/syscall.h>
34 #include "config.h" // for VERSION
36 /* Define pivot_root() if missing from the C library */
37 #ifndef HAVE_PIVOT_ROOT
38 static int pivot_root(const char * new_root
, const char * put_old
)
40 #ifdef __NR_pivot_root
41 return syscall(__NR_pivot_root
, new_root
, put_old
);
48 extern int pivot_root(const char * new_root
, const char * put_old
);
52 #define lxcfs_debug(format, ...) \
54 fprintf(stderr, "%s: %d: %s: " format, __FILE__, __LINE__, \
55 __func__, __VA_ARGS__); \
58 #define lxcfs_debug(format, ...)
64 LXC_TYPE_PROC_MEMINFO
,
65 LXC_TYPE_PROC_CPUINFO
,
68 LXC_TYPE_PROC_DISKSTATS
,
77 char *buf
; // unused as of yet
79 int size
; //actual data size
83 /* reserve buffer size, for cpuall in /proc/stat */
84 #define BUF_RESERVE_SIZE 256
87 * A table caching which pid is init for a pid namespace.
88 * When looking up which pid is init for $qpid, we first
89 * 1. Stat /proc/$qpid/ns/pid.
90 * 2. Check whether the ino_t is in our store.
91 * a. if not, fork a child in qpid's ns to send us
92 * ucred.pid = 1, and read the initpid. Cache
93 * initpid and creation time for /proc/initpid
94 * in a new store entry.
95 * b. if so, verify that /proc/initpid still matches
96 * what we have saved. If not, clear the store
97 * entry and go back to a. If so, return the
100 struct pidns_init_store
{
101 ino_t ino
; // inode number for /proc/$pid/ns/pid
102 pid_t initpid
; // the pid of nit in that ns
103 long int ctime
; // the time at which /proc/$initpid was created
104 struct pidns_init_store
*next
;
108 /* lol - look at how they are allocated in the kernel */
109 #define PIDNS_HASH_SIZE 4096
110 #define HASH(x) ((x) % PIDNS_HASH_SIZE)
112 static struct pidns_init_store
*pidns_hash_table
[PIDNS_HASH_SIZE
];
113 static pthread_mutex_t pidns_store_mutex
= PTHREAD_MUTEX_INITIALIZER
;
114 static void lock_mutex(pthread_mutex_t
*l
)
118 if ((ret
= pthread_mutex_lock(l
)) != 0) {
119 fprintf(stderr
, "pthread_mutex_lock returned:%d %s\n", ret
, strerror(ret
));
124 /* READ-ONLY after __constructor__ collect_and_mount_subsystems() has run.
125 * Number of hierarchies mounted. */
126 static int num_hierarchies
;
128 /* READ-ONLY after __constructor__ collect_and_mount_subsystems() has run.
129 * Hierachies mounted {cpuset, blkio, ...}:
130 * Initialized via __constructor__ collect_and_mount_subsystems(). */
131 static char **hierarchies
;
133 /* READ-ONLY after __constructor__ collect_and_mount_subsystems() has run.
134 * Open file descriptors:
135 * @fd_hierarchies[i] refers to cgroup @hierarchies[i]. They are mounted in a
136 * private mount namespace.
137 * Initialized via __constructor__ collect_and_mount_subsystems().
138 * @fd_hierarchies[i] can be used to perform file operations on the cgroup
139 * mounts and respective files in the private namespace even when located in
140 * another namespace using the *at() family of functions
141 * {openat(), fchownat(), ...}. */
142 static int *fd_hierarchies
;
144 static void unlock_mutex(pthread_mutex_t
*l
)
148 if ((ret
= pthread_mutex_unlock(l
)) != 0) {
149 fprintf(stderr
, "pthread_mutex_unlock returned:%d %s\n", ret
, strerror(ret
));
154 static void store_lock(void)
156 lock_mutex(&pidns_store_mutex
);
159 static void store_unlock(void)
161 unlock_mutex(&pidns_store_mutex
);
164 /* Must be called under store_lock */
165 static bool initpid_still_valid(struct pidns_init_store
*e
, struct stat
*nsfdsb
)
170 snprintf(fnam
, 100, "/proc/%d", e
->initpid
);
171 if (stat(fnam
, &initsb
) < 0)
174 lxcfs_debug("Comparing ctime %ld == %ld for pid %d.\n", e
->ctime
,
175 initsb
.st_ctime
, e
->initpid
);
177 if (e
->ctime
!= initsb
.st_ctime
)
182 /* Must be called under store_lock */
183 static void remove_initpid(struct pidns_init_store
*e
)
185 struct pidns_init_store
*tmp
;
188 lxcfs_debug("Remove_initpid: removing entry for %d.\n", e
->initpid
);
191 if (pidns_hash_table
[h
] == e
) {
192 pidns_hash_table
[h
] = e
->next
;
197 tmp
= pidns_hash_table
[h
];
199 if (tmp
->next
== e
) {
209 /* Must be called under store_lock */
210 static void prune_initpid_store(void)
212 static long int last_prune
= 0;
213 struct pidns_init_store
*e
, *prev
, *delme
;
214 long int now
, threshold
;
218 last_prune
= time(NULL
);
222 if (now
< last_prune
+ PURGE_SECS
)
225 lxcfs_debug("%s\n", "Pruning.");
228 threshold
= now
- 2 * PURGE_SECS
;
230 for (i
= 0; i
< PIDNS_HASH_SIZE
; i
++) {
231 for (prev
= NULL
, e
= pidns_hash_table
[i
]; e
; ) {
232 if (e
->lastcheck
< threshold
) {
234 lxcfs_debug("Removing cached entry for %d.\n", e
->initpid
);
238 prev
->next
= e
->next
;
240 pidns_hash_table
[i
] = e
->next
;
251 /* Must be called under store_lock */
252 static void save_initpid(struct stat
*sb
, pid_t pid
)
254 struct pidns_init_store
*e
;
259 lxcfs_debug("Save_initpid: adding entry for %d.\n", pid
);
261 snprintf(fpath
, 100, "/proc/%d", pid
);
262 if (stat(fpath
, &procsb
) < 0)
265 e
= malloc(sizeof(*e
));
269 e
->ctime
= procsb
.st_ctime
;
271 e
->next
= pidns_hash_table
[h
];
272 e
->lastcheck
= time(NULL
);
273 pidns_hash_table
[h
] = e
;
277 * Given the stat(2) info for a nsfd pid inode, lookup the init_pid_store
278 * entry for the inode number and creation time. Verify that the init pid
279 * is still valid. If not, remove it. Return the entry if valid, NULL
281 * Must be called under store_lock
283 static struct pidns_init_store
*lookup_verify_initpid(struct stat
*sb
)
285 int h
= HASH(sb
->st_ino
);
286 struct pidns_init_store
*e
= pidns_hash_table
[h
];
289 if (e
->ino
== sb
->st_ino
) {
290 if (initpid_still_valid(e
, sb
)) {
291 e
->lastcheck
= time(NULL
);
303 static int is_dir(const char *path
, int fd
)
306 int ret
= fstatat(fd
, path
, &statbuf
, fd
);
307 if (ret
== 0 && S_ISDIR(statbuf
.st_mode
))
312 static char *must_copy_string(const char *str
)
324 static inline void drop_trailing_newlines(char *s
)
328 for (l
=strlen(s
); l
>0 && s
[l
-1] == '\n'; l
--)
332 #define BATCH_SIZE 50
333 static void dorealloc(char **mem
, size_t oldlen
, size_t newlen
)
335 int newbatches
= (newlen
/ BATCH_SIZE
) + 1;
336 int oldbatches
= (oldlen
/ BATCH_SIZE
) + 1;
338 if (!*mem
|| newbatches
> oldbatches
) {
341 tmp
= realloc(*mem
, newbatches
* BATCH_SIZE
);
346 static void append_line(char **contents
, size_t *len
, char *line
, ssize_t linelen
)
348 size_t newlen
= *len
+ linelen
;
349 dorealloc(contents
, *len
, newlen
+ 1);
350 memcpy(*contents
+ *len
, line
, linelen
+1);
354 static char *slurp_file(const char *from
, int fd
)
357 char *contents
= NULL
;
358 FILE *f
= fdopen(fd
, "r");
359 size_t len
= 0, fulllen
= 0;
365 while ((linelen
= getline(&line
, &len
, f
)) != -1) {
366 append_line(&contents
, &fulllen
, line
, linelen
);
371 drop_trailing_newlines(contents
);
376 static bool write_string(const char *fnam
, const char *string
, int fd
)
381 if (!(f
= fdopen(fd
, "w")))
383 len
= strlen(string
);
384 ret
= fwrite(string
, 1, len
, f
);
386 fprintf(stderr
, "Error writing to file: %s\n", strerror(errno
));
391 fprintf(stderr
, "Error writing to file: %s\n", strerror(errno
));
404 static bool store_hierarchy(char *stridx
, char *h
)
406 if (num_hierarchies
% ALLOC_NUM
== 0) {
407 size_t n
= (num_hierarchies
/ ALLOC_NUM
) + 1;
409 char **tmp
= realloc(hierarchies
, n
* sizeof(char *));
411 fprintf(stderr
, "Out of memory\n");
417 hierarchies
[num_hierarchies
++] = must_copy_string(h
);
421 static void print_subsystems(void)
425 fprintf(stderr
, "hierarchies:\n");
426 for (i
= 0; i
< num_hierarchies
; i
++) {
428 fprintf(stderr
, " %d: %s\n", i
, hierarchies
[i
]);
432 static bool in_comma_list(const char *needle
, const char *haystack
)
434 const char *s
= haystack
, *e
;
435 size_t nlen
= strlen(needle
);
437 while (*s
&& (e
= strchr(s
, ','))) {
442 if (strncmp(needle
, s
, nlen
) == 0)
446 if (strcmp(needle
, s
) == 0)
451 /* do we need to do any massaging here? I'm not sure... */
452 /* Return the mounted controller and store the corresponding open file descriptor
453 * referring to the controller mountpoint in the private lxcfs namespace in
456 static char *find_mounted_controller(const char *controller
, int *cfd
)
460 for (i
= 0; i
< num_hierarchies
; i
++) {
463 if (strcmp(hierarchies
[i
], controller
) == 0) {
464 *cfd
= fd_hierarchies
[i
];
465 return hierarchies
[i
];
467 if (in_comma_list(controller
, hierarchies
[i
])) {
468 *cfd
= fd_hierarchies
[i
];
469 return hierarchies
[i
];
476 bool cgfs_set_value(const char *controller
, const char *cgroup
, const char *file
,
483 tmpc
= find_mounted_controller(controller
, &cfd
);
487 /* Make sure we pass a relative path to *at() family of functions.
488 * . + /cgroup + / + file + \0
490 len
= strlen(cgroup
) + strlen(file
) + 3;
492 ret
= snprintf(fnam
, len
, "%s%s/%s", *cgroup
== '/' ? "." : "", cgroup
, file
);
493 if (ret
< 0 || (size_t)ret
>= len
)
496 fd
= openat(cfd
, fnam
, O_WRONLY
);
500 return write_string(fnam
, value
, fd
);
503 // Chown all the files in the cgroup directory. We do this when we create
504 // a cgroup on behalf of a user.
505 static void chown_all_cgroup_files(const char *dirname
, uid_t uid
, gid_t gid
, int fd
)
507 struct dirent
*direntp
;
508 char path
[MAXPATHLEN
];
513 len
= strlen(dirname
);
514 if (len
>= MAXPATHLEN
) {
515 fprintf(stderr
, "chown_all_cgroup_files: pathname too long: %s\n", dirname
);
519 fd1
= openat(fd
, dirname
, O_DIRECTORY
);
525 fprintf(stderr
, "chown_all_cgroup_files: failed to open %s\n", dirname
);
529 while ((direntp
= readdir(d
))) {
530 if (!strcmp(direntp
->d_name
, ".") || !strcmp(direntp
->d_name
, ".."))
532 ret
= snprintf(path
, MAXPATHLEN
, "%s/%s", dirname
, direntp
->d_name
);
533 if (ret
< 0 || ret
>= MAXPATHLEN
) {
534 fprintf(stderr
, "chown_all_cgroup_files: pathname too long under %s\n", dirname
);
537 if (fchownat(fd
, path
, uid
, gid
, 0) < 0)
538 fprintf(stderr
, "Failed to chown file %s to %u:%u", path
, uid
, gid
);
543 int cgfs_create(const char *controller
, const char *cg
, uid_t uid
, gid_t gid
)
549 tmpc
= find_mounted_controller(controller
, &cfd
);
553 /* Make sure we pass a relative path to *at() family of functions.
556 len
= strlen(cg
) + 2;
557 dirnam
= alloca(len
);
558 snprintf(dirnam
, len
, "%s%s", *cg
== '/' ? "." : "", cg
);
560 if (mkdirat(cfd
, dirnam
, 0755) < 0)
563 if (uid
== 0 && gid
== 0)
566 if (fchownat(cfd
, dirnam
, uid
, gid
, 0) < 0)
569 chown_all_cgroup_files(dirnam
, uid
, gid
, cfd
);
574 static bool recursive_rmdir(const char *dirname
, int fd
, const int cfd
)
576 struct dirent
*direntp
;
579 char pathname
[MAXPATHLEN
];
582 dupfd
= dup(fd
); // fdopendir() does bad things once it uses an fd.
586 dir
= fdopendir(dupfd
);
588 lxcfs_debug("Failed to open %s: %s.\n", dirname
, strerror(errno
));
593 while ((direntp
= readdir(dir
))) {
597 if (!strcmp(direntp
->d_name
, ".") ||
598 !strcmp(direntp
->d_name
, ".."))
601 rc
= snprintf(pathname
, MAXPATHLEN
, "%s/%s", dirname
, direntp
->d_name
);
602 if (rc
< 0 || rc
>= MAXPATHLEN
) {
603 fprintf(stderr
, "pathname too long\n");
607 rc
= fstatat(cfd
, pathname
, &mystat
, AT_SYMLINK_NOFOLLOW
);
609 lxcfs_debug("Failed to stat %s: %s.\n", pathname
, strerror(errno
));
612 if (S_ISDIR(mystat
.st_mode
))
613 if (!recursive_rmdir(pathname
, fd
, cfd
))
614 lxcfs_debug("Error removing %s.\n", pathname
);
618 if (closedir(dir
) < 0) {
619 fprintf(stderr
, "%s: failed to close directory %s: %s\n", __func__
, dirname
, strerror(errno
));
623 if (unlinkat(cfd
, dirname
, AT_REMOVEDIR
) < 0) {
624 lxcfs_debug("Failed to delete %s: %s.\n", dirname
, strerror(errno
));
633 bool cgfs_remove(const char *controller
, const char *cg
)
640 tmpc
= find_mounted_controller(controller
, &cfd
);
644 /* Make sure we pass a relative path to *at() family of functions.
647 len
= strlen(cg
) + 2;
648 dirnam
= alloca(len
);
649 snprintf(dirnam
, len
, "%s%s", *cg
== '/' ? "." : "", cg
);
651 fd
= openat(cfd
, dirnam
, O_DIRECTORY
);
655 bret
= recursive_rmdir(dirnam
, fd
, cfd
);
660 bool cgfs_chmod_file(const char *controller
, const char *file
, mode_t mode
)
664 char *pathname
, *tmpc
;
666 tmpc
= find_mounted_controller(controller
, &cfd
);
670 /* Make sure we pass a relative path to *at() family of functions.
673 len
= strlen(file
) + 2;
674 pathname
= alloca(len
);
675 snprintf(pathname
, len
, "%s%s", *file
== '/' ? "." : "", file
);
676 if (fchmodat(cfd
, pathname
, mode
, 0) < 0)
681 static int chown_tasks_files(const char *dirname
, uid_t uid
, gid_t gid
, int fd
)
686 len
= strlen(dirname
) + strlen("/cgroup.procs") + 1;
688 snprintf(fname
, len
, "%s/tasks", dirname
);
689 if (fchownat(fd
, fname
, uid
, gid
, 0) != 0)
691 snprintf(fname
, len
, "%s/cgroup.procs", dirname
);
692 if (fchownat(fd
, fname
, uid
, gid
, 0) != 0)
697 int cgfs_chown_file(const char *controller
, const char *file
, uid_t uid
, gid_t gid
)
701 char *pathname
, *tmpc
;
703 tmpc
= find_mounted_controller(controller
, &cfd
);
707 /* Make sure we pass a relative path to *at() family of functions.
710 len
= strlen(file
) + 2;
711 pathname
= alloca(len
);
712 snprintf(pathname
, len
, "%s%s", *file
== '/' ? "." : "", file
);
713 if (fchownat(cfd
, pathname
, uid
, gid
, 0) < 0)
716 if (is_dir(pathname
, cfd
))
717 // like cgmanager did, we want to chown the tasks file as well
718 return chown_tasks_files(pathname
, uid
, gid
, cfd
);
723 FILE *open_pids_file(const char *controller
, const char *cgroup
)
727 char *pathname
, *tmpc
;
729 tmpc
= find_mounted_controller(controller
, &cfd
);
733 /* Make sure we pass a relative path to *at() family of functions.
734 * . + /cgroup + / "cgroup.procs" + \0
736 len
= strlen(cgroup
) + strlen("cgroup.procs") + 3;
737 pathname
= alloca(len
);
738 snprintf(pathname
, len
, "%s%s/cgroup.procs", *cgroup
== '/' ? "." : "", cgroup
);
740 fd
= openat(cfd
, pathname
, O_WRONLY
);
744 return fdopen(fd
, "w");
747 static bool cgfs_iterate_cgroup(const char *controller
, const char *cgroup
, bool directories
,
748 void ***list
, size_t typesize
,
749 void* (*iterator
)(const char*, const char*, const char*))
754 char pathname
[MAXPATHLEN
];
755 size_t sz
= 0, asz
= 0;
756 struct dirent
*dirent
;
759 tmpc
= find_mounted_controller(controller
, &cfd
);
764 /* Make sure we pass a relative path to *at() family of functions. */
765 len
= strlen(cgroup
) + 1 /* . */ + 1 /* \0 */;
767 ret
= snprintf(cg
, len
, "%s%s", *cgroup
== '/' ? "." : "", cgroup
);
768 if (ret
< 0 || (size_t)ret
>= len
) {
769 fprintf(stderr
, "%s: pathname too long under %s\n", __func__
, cgroup
);
773 fd
= openat(cfd
, cg
, O_DIRECTORY
);
781 while ((dirent
= readdir(dir
))) {
784 if (!strcmp(dirent
->d_name
, ".") ||
785 !strcmp(dirent
->d_name
, ".."))
788 ret
= snprintf(pathname
, MAXPATHLEN
, "%s/%s", cg
, dirent
->d_name
);
789 if (ret
< 0 || ret
>= MAXPATHLEN
) {
790 fprintf(stderr
, "%s: pathname too long under %s\n", __func__
, cg
);
794 ret
= fstatat(cfd
, pathname
, &mystat
, AT_SYMLINK_NOFOLLOW
);
796 fprintf(stderr
, "%s: failed to stat %s: %s\n", __func__
, pathname
, strerror(errno
));
799 if ((!directories
&& !S_ISREG(mystat
.st_mode
)) ||
800 (directories
&& !S_ISDIR(mystat
.st_mode
)))
807 tmp
= realloc(*list
, asz
* typesize
);
811 (*list
)[sz
] = (*iterator
)(controller
, cg
, dirent
->d_name
);
812 (*list
)[sz
+1] = NULL
;
815 if (closedir(dir
) < 0) {
816 fprintf(stderr
, "%s: failed closedir for %s: %s\n", __func__
, cgroup
, strerror(errno
));
822 static void *make_children_list_entry(const char *controller
, const char *cgroup
, const char *dir_entry
)
826 dup
= strdup(dir_entry
);
831 bool cgfs_list_children(const char *controller
, const char *cgroup
, char ***list
)
833 return cgfs_iterate_cgroup(controller
, cgroup
, true, (void***)list
, sizeof(*list
), &make_children_list_entry
);
836 void free_key(struct cgfs_files
*k
)
844 void free_keys(struct cgfs_files
**keys
)
850 for (i
= 0; keys
[i
]; i
++) {
856 bool cgfs_get_value(const char *controller
, const char *cgroup
, const char *file
, char **value
)
862 tmpc
= find_mounted_controller(controller
, &cfd
);
866 /* Make sure we pass a relative path to *at() family of functions.
867 * . + /cgroup + / + file + \0
869 len
= strlen(cgroup
) + strlen(file
) + 3;
871 ret
= snprintf(fnam
, len
, "%s%s/%s", *cgroup
== '/' ? "." : "", cgroup
, file
);
872 if (ret
< 0 || (size_t)ret
>= len
)
875 fd
= openat(cfd
, fnam
, O_RDONLY
);
879 *value
= slurp_file(fnam
, fd
);
880 return *value
!= NULL
;
883 struct cgfs_files
*cgfs_get_key(const char *controller
, const char *cgroup
, const char *file
)
889 struct cgfs_files
*newkey
;
891 tmpc
= find_mounted_controller(controller
, &cfd
);
895 if (file
&& *file
== '/')
898 if (file
&& strchr(file
, '/'))
901 /* Make sure we pass a relative path to *at() family of functions.
902 * . + /cgroup + / + file + \0
904 len
= strlen(cgroup
) + 3;
906 len
+= strlen(file
) + 1;
908 snprintf(fnam
, len
, "%s%s%s%s", *cgroup
== '/' ? "." : "", cgroup
,
909 file
? "/" : "", file
? file
: "");
911 ret
= fstatat(cfd
, fnam
, &sb
, 0);
916 newkey
= malloc(sizeof(struct cgfs_files
));
919 newkey
->name
= must_copy_string(file
);
920 else if (strrchr(cgroup
, '/'))
921 newkey
->name
= must_copy_string(strrchr(cgroup
, '/'));
923 newkey
->name
= must_copy_string(cgroup
);
924 newkey
->uid
= sb
.st_uid
;
925 newkey
->gid
= sb
.st_gid
;
926 newkey
->mode
= sb
.st_mode
;
931 static void *make_key_list_entry(const char *controller
, const char *cgroup
, const char *dir_entry
)
933 struct cgfs_files
*entry
= cgfs_get_key(controller
, cgroup
, dir_entry
);
935 fprintf(stderr
, "%s: Error getting files under %s:%s\n",
936 __func__
, controller
, cgroup
);
941 bool cgfs_list_keys(const char *controller
, const char *cgroup
, struct cgfs_files
***keys
)
943 return cgfs_iterate_cgroup(controller
, cgroup
, false, (void***)keys
, sizeof(*keys
), &make_key_list_entry
);
946 bool is_child_cgroup(const char *controller
, const char *cgroup
, const char *f
)
954 tmpc
= find_mounted_controller(controller
, &cfd
);
958 /* Make sure we pass a relative path to *at() family of functions.
959 * . + /cgroup + / + f + \0
961 len
= strlen(cgroup
) + strlen(f
) + 3;
963 ret
= snprintf(fnam
, len
, "%s%s/%s", *cgroup
== '/' ? "." : "", cgroup
, f
);
964 if (ret
< 0 || (size_t)ret
>= len
)
967 ret
= fstatat(cfd
, fnam
, &sb
, 0);
968 if (ret
< 0 || !S_ISDIR(sb
.st_mode
))
974 #define SEND_CREDS_OK 0
975 #define SEND_CREDS_NOTSK 1
976 #define SEND_CREDS_FAIL 2
977 static bool recv_creds(int sock
, struct ucred
*cred
, char *v
);
978 static int wait_for_pid(pid_t pid
);
979 static int send_creds(int sock
, struct ucred
*cred
, char v
, bool pingfirst
);
980 static int send_creds_clone_wrapper(void *arg
);
983 * clone a task which switches to @task's namespace and writes '1'.
984 * over a unix sock so we can read the task's reaper's pid in our
987 * Note: glibc's fork() does not respect pidns, which can lead to failed
988 * assertions inside glibc (and thus failed forks) if the child's pid in
989 * the pidns and the parent pid outside are identical. Using clone prevents
992 static void write_task_init_pid_exit(int sock
, pid_t target
)
997 size_t stack_size
= sysconf(_SC_PAGESIZE
);
998 void *stack
= alloca(stack_size
);
1000 ret
= snprintf(fnam
, sizeof(fnam
), "/proc/%d/ns/pid", (int)target
);
1001 if (ret
< 0 || ret
>= sizeof(fnam
))
1004 fd
= open(fnam
, O_RDONLY
);
1006 perror("write_task_init_pid_exit open of ns/pid");
1010 perror("write_task_init_pid_exit setns 1");
1014 pid
= clone(send_creds_clone_wrapper
, stack
+ stack_size
, SIGCHLD
, &sock
);
1018 if (!wait_for_pid(pid
))
1024 static int send_creds_clone_wrapper(void *arg
) {
1027 int sock
= *(int *)arg
;
1029 /* we are the child */
1034 if (send_creds(sock
, &cred
, v
, true) != SEND_CREDS_OK
)
1039 static pid_t
get_init_pid_for_task(pid_t task
)
1047 if (socketpair(AF_UNIX
, SOCK_DGRAM
, 0, sock
) < 0) {
1048 perror("socketpair");
1057 write_task_init_pid_exit(sock
[0], task
);
1061 if (!recv_creds(sock
[1], &cred
, &v
))
1073 static pid_t
lookup_initpid_in_store(pid_t qpid
)
1077 struct pidns_init_store
*e
;
1080 snprintf(fnam
, 100, "/proc/%d/ns/pid", qpid
);
1082 if (stat(fnam
, &sb
) < 0)
1084 e
= lookup_verify_initpid(&sb
);
1086 answer
= e
->initpid
;
1089 answer
= get_init_pid_for_task(qpid
);
1091 save_initpid(&sb
, answer
);
1094 /* we prune at end in case we are returning
1095 * the value we were about to return */
1096 prune_initpid_store();
1101 static int wait_for_pid(pid_t pid
)
1109 ret
= waitpid(pid
, &status
, 0);
1117 if (!WIFEXITED(status
) || WEXITSTATUS(status
) != 0)
1124 * append pid to *src.
1125 * src: a pointer to a char* in which ot append the pid.
1126 * sz: the number of characters printed so far, minus trailing \0.
1127 * asz: the allocated size so far
1128 * pid: the pid to append
1130 static void must_strcat_pid(char **src
, size_t *sz
, size_t *asz
, pid_t pid
)
1134 int tmplen
= sprintf(tmp
, "%d\n", (int)pid
);
1136 if (!*src
|| tmplen
+ *sz
+ 1 >= *asz
) {
1139 tmp
= realloc(*src
, *asz
+ BUF_RESERVE_SIZE
);
1142 *asz
+= BUF_RESERVE_SIZE
;
1144 memcpy((*src
) +*sz
, tmp
, tmplen
+1); /* include the \0 */
1149 * Given a open file * to /proc/pid/{u,g}id_map, and an id
1150 * valid in the caller's namespace, return the id mapped into
1152 * Returns the mapped id, or -1 on error.
1155 convert_id_to_ns(FILE *idfile
, unsigned int in_id
)
1157 unsigned int nsuid
, // base id for a range in the idfile's namespace
1158 hostuid
, // base id for a range in the caller's namespace
1159 count
; // number of ids in this range
1163 fseek(idfile
, 0L, SEEK_SET
);
1164 while (fgets(line
, 400, idfile
)) {
1165 ret
= sscanf(line
, "%u %u %u\n", &nsuid
, &hostuid
, &count
);
1168 if (hostuid
+ count
< hostuid
|| nsuid
+ count
< nsuid
) {
1170 * uids wrapped around - unexpected as this is a procfile,
1173 fprintf(stderr
, "pid wrapparound at entry %u %u %u in %s\n",
1174 nsuid
, hostuid
, count
, line
);
1177 if (hostuid
<= in_id
&& hostuid
+count
> in_id
) {
1179 * now since hostuid <= in_id < hostuid+count, and
1180 * hostuid+count and nsuid+count do not wrap around,
1181 * we know that nsuid+(in_id-hostuid) which must be
1182 * less that nsuid+(count) must not wrap around
1184 return (in_id
- hostuid
) + nsuid
;
1193 * for is_privileged_over,
1194 * specify whether we require the calling uid to be root in his
1197 #define NS_ROOT_REQD true
1198 #define NS_ROOT_OPT false
1202 static bool is_privileged_over(pid_t pid
, uid_t uid
, uid_t victim
, bool req_ns_root
)
1204 char fpath
[PROCLEN
];
1206 bool answer
= false;
1209 if (victim
== -1 || uid
== -1)
1213 * If the request is one not requiring root in the namespace,
1214 * then having the same uid suffices. (i.e. uid 1000 has write
1215 * access to files owned by uid 1000
1217 if (!req_ns_root
&& uid
== victim
)
1220 ret
= snprintf(fpath
, PROCLEN
, "/proc/%d/uid_map", pid
);
1221 if (ret
< 0 || ret
>= PROCLEN
)
1223 FILE *f
= fopen(fpath
, "r");
1227 /* if caller's not root in his namespace, reject */
1228 nsuid
= convert_id_to_ns(f
, uid
);
1233 * If victim is not mapped into caller's ns, reject.
1234 * XXX I'm not sure this check is needed given that fuse
1235 * will be sending requests where the vfs has converted
1237 nsuid
= convert_id_to_ns(f
, victim
);
1248 static bool perms_include(int fmode
, mode_t req_mode
)
1252 switch (req_mode
& O_ACCMODE
) {
1260 r
= S_IROTH
| S_IWOTH
;
1265 return ((fmode
& r
) == r
);
1271 * querycg is /a/b/c/d/e
1274 static char *get_next_cgroup_dir(const char *taskcg
, const char *querycg
)
1278 if (strlen(taskcg
) <= strlen(querycg
)) {
1279 fprintf(stderr
, "%s: I was fed bad input\n", __func__
);
1283 if ((strcmp(querycg
, "/") == 0) || (strcmp(querycg
, "./") == 0))
1284 start
= strdup(taskcg
+ 1);
1286 start
= strdup(taskcg
+ strlen(querycg
) + 1);
1289 end
= strchr(start
, '/');
1295 static void stripnewline(char *x
)
1297 size_t l
= strlen(x
);
1298 if (l
&& x
[l
-1] == '\n')
1302 static char *get_pid_cgroup(pid_t pid
, const char *contrl
)
1307 char *answer
= NULL
;
1311 const char *h
= find_mounted_controller(contrl
, &cfd
);
1315 ret
= snprintf(fnam
, PROCLEN
, "/proc/%d/cgroup", pid
);
1316 if (ret
< 0 || ret
>= PROCLEN
)
1318 if (!(f
= fopen(fnam
, "r")))
1321 while (getline(&line
, &len
, f
) != -1) {
1325 c1
= strchr(line
, ':');
1329 c2
= strchr(c1
, ':');
1333 if (strcmp(c1
, h
) != 0)
1338 answer
= strdup(c2
);
1350 * check whether a fuse context may access a cgroup dir or file
1352 * If file is not null, it is a cgroup file to check under cg.
1353 * If file is null, then we are checking perms on cg itself.
1355 * For files we can check the mode of the list_keys result.
1356 * For cgroups, we must make assumptions based on the files under the
1357 * cgroup, because cgmanager doesn't tell us ownership/perms of cgroups
1360 static bool fc_may_access(struct fuse_context
*fc
, const char *contrl
, const char *cg
, const char *file
, mode_t mode
)
1362 struct cgfs_files
*k
= NULL
;
1365 k
= cgfs_get_key(contrl
, cg
, file
);
1369 if (is_privileged_over(fc
->pid
, fc
->uid
, k
->uid
, NS_ROOT_OPT
)) {
1370 if (perms_include(k
->mode
>> 6, mode
)) {
1375 if (fc
->gid
== k
->gid
) {
1376 if (perms_include(k
->mode
>> 3, mode
)) {
1381 ret
= perms_include(k
->mode
, mode
);
1388 #define INITSCOPE "/init.scope"
1389 static void prune_init_slice(char *cg
)
1392 size_t cg_len
= strlen(cg
), initscope_len
= strlen(INITSCOPE
);
1394 if (cg_len
< initscope_len
)
1397 point
= cg
+ cg_len
- initscope_len
;
1398 if (strcmp(point
, INITSCOPE
) == 0) {
1407 * If pid is in /a/b/c/d, he may only act on things under cg=/a/b/c/d.
1408 * If pid is in /a, he may act on /a/b, but not on /b.
1409 * if the answer is false and nextcg is not NULL, then *nextcg will point
1410 * to a string containing the next cgroup directory under cg, which must be
1411 * freed by the caller.
1413 static bool caller_is_in_ancestor(pid_t pid
, const char *contrl
, const char *cg
, char **nextcg
)
1415 bool answer
= false;
1416 char *c2
= get_pid_cgroup(pid
, contrl
);
1421 prune_init_slice(c2
);
1424 * callers pass in '/' or './' (openat()) for root cgroup, otherwise
1425 * they pass in a cgroup without leading '/'
1427 * The original line here was:
1428 * linecmp = *cg == '/' ? c2 : c2+1;
1429 * TODO: I'm not sure why you'd want to increment when *cg != '/'?
1430 * Serge, do you know?
1432 if (*cg
== '/' || !strncmp(cg
, "./", 2))
1436 if (strncmp(linecmp
, cg
, strlen(linecmp
)) != 0) {
1438 *nextcg
= get_next_cgroup_dir(linecmp
, cg
);
1450 * If pid is in /a/b/c, he may see that /a exists, but not /b or /a/c.
1452 static bool caller_may_see_dir(pid_t pid
, const char *contrl
, const char *cg
)
1454 bool answer
= false;
1456 size_t target_len
, task_len
;
1458 if (strcmp(cg
, "/") == 0 || strcmp(cg
, "./") == 0)
1461 c2
= get_pid_cgroup(pid
, contrl
);
1464 prune_init_slice(c2
);
1467 target_len
= strlen(cg
);
1468 task_len
= strlen(task_cg
);
1469 if (task_len
== 0) {
1470 /* Task is in the root cg, it can see everything. This case is
1471 * not handled by the strmcps below, since they test for the
1472 * last /, but that is the first / that we've chopped off
1478 if (strcmp(cg
, task_cg
) == 0) {
1482 if (target_len
< task_len
) {
1483 /* looking up a parent dir */
1484 if (strncmp(task_cg
, cg
, target_len
) == 0 && task_cg
[target_len
] == '/')
1488 if (target_len
> task_len
) {
1489 /* looking up a child dir */
1490 if (strncmp(task_cg
, cg
, task_len
) == 0 && cg
[task_len
] == '/')
1501 * given /cgroup/freezer/a/b, return "freezer".
1502 * the returned char* should NOT be freed.
1504 static char *pick_controller_from_path(struct fuse_context
*fc
, const char *path
)
1507 char *contr
, *slash
;
1509 if (strlen(path
) < 9)
1511 if (*(path
+7) != '/')
1514 contr
= strdupa(p1
);
1517 slash
= strstr(contr
, "/");
1522 for (i
= 0; i
< num_hierarchies
; i
++) {
1523 if (hierarchies
[i
] && strcmp(hierarchies
[i
], contr
) == 0)
1524 return hierarchies
[i
];
1530 * Find the start of cgroup in /cgroup/controller/the/cgroup/path
1531 * Note that the returned value may include files (keynames) etc
1533 static const char *find_cgroup_in_path(const char *path
)
1537 if (strlen(path
) < 9)
1539 p1
= strstr(path
+8, "/");
1546 * split the last path element from the path in @cg.
1547 * @dir is newly allocated and should be freed, @last not
1549 static void get_cgdir_and_path(const char *cg
, char **dir
, char **last
)
1556 *last
= strrchr(cg
, '/');
1561 p
= strrchr(*dir
, '/');
1566 * FUSE ops for /cgroup
1569 int cg_getattr(const char *path
, struct stat
*sb
)
1571 struct timespec now
;
1572 struct fuse_context
*fc
= fuse_get_context();
1573 char * cgdir
= NULL
;
1574 char *last
= NULL
, *path1
, *path2
;
1575 struct cgfs_files
*k
= NULL
;
1577 const char *controller
= NULL
;
1584 memset(sb
, 0, sizeof(struct stat
));
1586 if (clock_gettime(CLOCK_REALTIME
, &now
) < 0)
1589 sb
->st_uid
= sb
->st_gid
= 0;
1590 sb
->st_atim
= sb
->st_mtim
= sb
->st_ctim
= now
;
1593 if (strcmp(path
, "/cgroup") == 0) {
1594 sb
->st_mode
= S_IFDIR
| 00755;
1599 controller
= pick_controller_from_path(fc
, path
);
1602 cgroup
= find_cgroup_in_path(path
);
1604 /* this is just /cgroup/controller, return it as a dir */
1605 sb
->st_mode
= S_IFDIR
| 00755;
1610 get_cgdir_and_path(cgroup
, &cgdir
, &last
);
1620 pid_t initpid
= lookup_initpid_in_store(fc
->pid
);
1623 /* check that cgcopy is either a child cgroup of cgdir, or listed in its keys.
1624 * Then check that caller's cgroup is under path if last is a child
1625 * cgroup, or cgdir if last is a file */
1627 if (is_child_cgroup(controller
, path1
, path2
)) {
1628 if (!caller_may_see_dir(initpid
, controller
, cgroup
)) {
1632 if (!caller_is_in_ancestor(initpid
, controller
, cgroup
, NULL
)) {
1633 /* this is just /cgroup/controller, return it as a dir */
1634 sb
->st_mode
= S_IFDIR
| 00555;
1639 if (!fc_may_access(fc
, controller
, cgroup
, NULL
, O_RDONLY
)) {
1644 // get uid, gid, from '/tasks' file and make up a mode
1645 // That is a hack, until cgmanager gains a GetCgroupPerms fn.
1646 sb
->st_mode
= S_IFDIR
| 00755;
1647 k
= cgfs_get_key(controller
, cgroup
, NULL
);
1649 sb
->st_uid
= sb
->st_gid
= 0;
1651 sb
->st_uid
= k
->uid
;
1652 sb
->st_gid
= k
->gid
;
1660 if ((k
= cgfs_get_key(controller
, path1
, path2
)) != NULL
) {
1661 sb
->st_mode
= S_IFREG
| k
->mode
;
1663 sb
->st_uid
= k
->uid
;
1664 sb
->st_gid
= k
->gid
;
1667 if (!caller_is_in_ancestor(initpid
, controller
, path1
, NULL
)) {
1671 if (!fc_may_access(fc
, controller
, path1
, path2
, O_RDONLY
)) {
1684 int cg_opendir(const char *path
, struct fuse_file_info
*fi
)
1686 struct fuse_context
*fc
= fuse_get_context();
1688 struct file_info
*dir_info
;
1689 char *controller
= NULL
;
1694 if (strcmp(path
, "/cgroup") == 0) {
1698 // return list of keys for the controller, and list of child cgroups
1699 controller
= pick_controller_from_path(fc
, path
);
1703 cgroup
= find_cgroup_in_path(path
);
1705 /* this is just /cgroup/controller, return its contents */
1710 pid_t initpid
= lookup_initpid_in_store(fc
->pid
);
1714 if (!caller_may_see_dir(initpid
, controller
, cgroup
))
1716 if (!fc_may_access(fc
, controller
, cgroup
, NULL
, O_RDONLY
))
1720 /* we'll free this at cg_releasedir */
1721 dir_info
= malloc(sizeof(*dir_info
));
1724 dir_info
->controller
= must_copy_string(controller
);
1725 dir_info
->cgroup
= must_copy_string(cgroup
);
1726 dir_info
->type
= LXC_TYPE_CGDIR
;
1727 dir_info
->buf
= NULL
;
1728 dir_info
->file
= NULL
;
1729 dir_info
->buflen
= 0;
1731 fi
->fh
= (unsigned long)dir_info
;
1735 int cg_readdir(const char *path
, void *buf
, fuse_fill_dir_t filler
, off_t offset
,
1736 struct fuse_file_info
*fi
)
1738 struct file_info
*d
= (struct file_info
*)fi
->fh
;
1739 struct cgfs_files
**list
= NULL
;
1741 char *nextcg
= NULL
;
1742 struct fuse_context
*fc
= fuse_get_context();
1743 char **clist
= NULL
;
1745 if (filler(buf
, ".", NULL
, 0) != 0 || filler(buf
, "..", NULL
, 0) != 0)
1748 if (d
->type
!= LXC_TYPE_CGDIR
) {
1749 fprintf(stderr
, "Internal error: file cache info used in readdir\n");
1752 if (!d
->cgroup
&& !d
->controller
) {
1753 // ls /var/lib/lxcfs/cgroup - just show list of controllers
1756 for (i
= 0; i
< num_hierarchies
; i
++) {
1757 if (hierarchies
[i
] && filler(buf
, hierarchies
[i
], NULL
, 0) != 0) {
1764 if (!cgfs_list_keys(d
->controller
, d
->cgroup
, &list
)) {
1765 // not a valid cgroup
1770 pid_t initpid
= lookup_initpid_in_store(fc
->pid
);
1773 if (!caller_is_in_ancestor(initpid
, d
->controller
, d
->cgroup
, &nextcg
)) {
1775 ret
= filler(buf
, nextcg
, NULL
, 0);
1786 for (i
= 0; list
[i
]; i
++) {
1787 if (filler(buf
, list
[i
]->name
, NULL
, 0) != 0) {
1793 // now get the list of child cgroups
1795 if (!cgfs_list_children(d
->controller
, d
->cgroup
, &clist
)) {
1800 for (i
= 0; clist
[i
]; i
++) {
1801 if (filler(buf
, clist
[i
], NULL
, 0) != 0) {
1812 for (i
= 0; clist
[i
]; i
++)
1819 static void do_release_file_info(struct fuse_file_info
*fi
)
1821 struct file_info
*f
= (struct file_info
*)fi
->fh
;
1828 free(f
->controller
);
1829 f
->controller
= NULL
;
1839 int cg_releasedir(const char *path
, struct fuse_file_info
*fi
)
1841 do_release_file_info(fi
);
1845 int cg_open(const char *path
, struct fuse_file_info
*fi
)
1848 char *last
= NULL
, *path1
, *path2
, * cgdir
= NULL
, *controller
;
1849 struct cgfs_files
*k
= NULL
;
1850 struct file_info
*file_info
;
1851 struct fuse_context
*fc
= fuse_get_context();
1857 controller
= pick_controller_from_path(fc
, path
);
1860 cgroup
= find_cgroup_in_path(path
);
1864 get_cgdir_and_path(cgroup
, &cgdir
, &last
);
1873 k
= cgfs_get_key(controller
, path1
, path2
);
1880 pid_t initpid
= lookup_initpid_in_store(fc
->pid
);
1883 if (!caller_may_see_dir(initpid
, controller
, path1
)) {
1887 if (!fc_may_access(fc
, controller
, path1
, path2
, fi
->flags
)) {
1892 /* we'll free this at cg_release */
1893 file_info
= malloc(sizeof(*file_info
));
1898 file_info
->controller
= must_copy_string(controller
);
1899 file_info
->cgroup
= must_copy_string(path1
);
1900 file_info
->file
= must_copy_string(path2
);
1901 file_info
->type
= LXC_TYPE_CGFILE
;
1902 file_info
->buf
= NULL
;
1903 file_info
->buflen
= 0;
1905 fi
->fh
= (unsigned long)file_info
;
1913 int cg_access(const char *path
, int mode
)
1917 char *path1
, *path2
, *controller
;
1918 char *last
= NULL
, *cgdir
= NULL
;
1919 struct cgfs_files
*k
= NULL
;
1920 struct fuse_context
*fc
= fuse_get_context();
1922 if (strcmp(path
, "/cgroup") == 0) {
1923 if ((mode
& W_OK
) == 0)
1931 controller
= pick_controller_from_path(fc
, path
);
1934 cgroup
= find_cgroup_in_path(path
);
1936 // access("/sys/fs/cgroup/systemd", mode) - rx allowed, w not
1937 if ((mode
& W_OK
) == 0)
1942 get_cgdir_and_path(cgroup
, &cgdir
, &last
);
1951 k
= cgfs_get_key(controller
, path1
, path2
);
1953 if ((mode
& W_OK
) == 0)
1961 pid_t initpid
= lookup_initpid_in_store(fc
->pid
);
1964 if (!caller_may_see_dir(initpid
, controller
, path1
)) {
1968 if (!fc_may_access(fc
, controller
, path1
, path2
, mode
)) {
1980 int cg_release(const char *path
, struct fuse_file_info
*fi
)
1982 do_release_file_info(fi
);
1986 #define POLLIN_SET ( EPOLLIN | EPOLLHUP | EPOLLRDHUP )
1988 static bool wait_for_sock(int sock
, int timeout
)
1990 struct epoll_event ev
;
1991 int epfd
, ret
, now
, starttime
, deltatime
, saved_errno
;
1993 if ((starttime
= time(NULL
)) < 0)
1996 if ((epfd
= epoll_create(1)) < 0) {
1997 fprintf(stderr
, "Failed to create epoll socket: %m\n");
2001 ev
.events
= POLLIN_SET
;
2003 if (epoll_ctl(epfd
, EPOLL_CTL_ADD
, sock
, &ev
) < 0) {
2004 fprintf(stderr
, "Failed adding socket to epoll: %m\n");
2010 if ((now
= time(NULL
)) < 0) {
2015 deltatime
= (starttime
+ timeout
) - now
;
2016 if (deltatime
< 0) { // timeout
2021 ret
= epoll_wait(epfd
, &ev
, 1, 1000*deltatime
+ 1);
2022 if (ret
< 0 && errno
== EINTR
)
2024 saved_errno
= errno
;
2028 errno
= saved_errno
;
2034 static int msgrecv(int sockfd
, void *buf
, size_t len
)
2036 if (!wait_for_sock(sockfd
, 2))
2038 return recv(sockfd
, buf
, len
, MSG_DONTWAIT
);
2041 static int send_creds(int sock
, struct ucred
*cred
, char v
, bool pingfirst
)
2043 struct msghdr msg
= { 0 };
2045 struct cmsghdr
*cmsg
;
2046 char cmsgbuf
[CMSG_SPACE(sizeof(*cred
))];
2051 if (msgrecv(sock
, buf
, 1) != 1) {
2052 fprintf(stderr
, "%s: Error getting reply from server over socketpair\n",
2054 return SEND_CREDS_FAIL
;
2058 msg
.msg_control
= cmsgbuf
;
2059 msg
.msg_controllen
= sizeof(cmsgbuf
);
2061 cmsg
= CMSG_FIRSTHDR(&msg
);
2062 cmsg
->cmsg_len
= CMSG_LEN(sizeof(struct ucred
));
2063 cmsg
->cmsg_level
= SOL_SOCKET
;
2064 cmsg
->cmsg_type
= SCM_CREDENTIALS
;
2065 memcpy(CMSG_DATA(cmsg
), cred
, sizeof(*cred
));
2067 msg
.msg_name
= NULL
;
2068 msg
.msg_namelen
= 0;
2072 iov
.iov_len
= sizeof(buf
);
2076 if (sendmsg(sock
, &msg
, 0) < 0) {
2077 fprintf(stderr
, "%s: failed at sendmsg: %s\n", __func__
,
2080 return SEND_CREDS_NOTSK
;
2081 return SEND_CREDS_FAIL
;
2084 return SEND_CREDS_OK
;
2087 static bool recv_creds(int sock
, struct ucred
*cred
, char *v
)
2089 struct msghdr msg
= { 0 };
2091 struct cmsghdr
*cmsg
;
2092 char cmsgbuf
[CMSG_SPACE(sizeof(*cred
))];
2103 if (setsockopt(sock
, SOL_SOCKET
, SO_PASSCRED
, &optval
, sizeof(optval
)) == -1) {
2104 fprintf(stderr
, "Failed to set passcred: %s\n", strerror(errno
));
2108 if (write(sock
, buf
, 1) != 1) {
2109 fprintf(stderr
, "Failed to start write on scm fd: %s\n", strerror(errno
));
2113 msg
.msg_name
= NULL
;
2114 msg
.msg_namelen
= 0;
2115 msg
.msg_control
= cmsgbuf
;
2116 msg
.msg_controllen
= sizeof(cmsgbuf
);
2119 iov
.iov_len
= sizeof(buf
);
2123 if (!wait_for_sock(sock
, 2)) {
2124 fprintf(stderr
, "Timed out waiting for scm_cred: %s\n",
2128 ret
= recvmsg(sock
, &msg
, MSG_DONTWAIT
);
2130 fprintf(stderr
, "Failed to receive scm_cred: %s\n",
2135 cmsg
= CMSG_FIRSTHDR(&msg
);
2137 if (cmsg
&& cmsg
->cmsg_len
== CMSG_LEN(sizeof(struct ucred
)) &&
2138 cmsg
->cmsg_level
== SOL_SOCKET
&&
2139 cmsg
->cmsg_type
== SCM_CREDENTIALS
) {
2140 memcpy(cred
, CMSG_DATA(cmsg
), sizeof(*cred
));
2147 struct pid_ns_clone_args
{
2151 int (*wrapped
) (int, pid_t
); // pid_from_ns or pid_to_ns
2155 * pid_ns_clone_wrapper - wraps pid_to_ns or pid_from_ns for usage
2156 * with clone(). This simply writes '1' as ACK back to the parent
2157 * before calling the actual wrapped function.
2159 static int pid_ns_clone_wrapper(void *arg
) {
2160 struct pid_ns_clone_args
* args
= (struct pid_ns_clone_args
*) arg
;
2163 close(args
->cpipe
[0]);
2164 if (write(args
->cpipe
[1], &b
, sizeof(char)) < 0) {
2165 fprintf(stderr
, "%s (child): error on write: %s\n",
2166 __func__
, strerror(errno
));
2168 close(args
->cpipe
[1]);
2169 return args
->wrapped(args
->sock
, args
->tpid
);
2173 * pid_to_ns - reads pids from a ucred over a socket, then writes the
2174 * int value back over the socket. This shifts the pid from the
2175 * sender's pidns into tpid's pidns.
2177 static int pid_to_ns(int sock
, pid_t tpid
)
2182 while (recv_creds(sock
, &cred
, &v
)) {
2185 if (write(sock
, &cred
.pid
, sizeof(pid_t
)) != sizeof(pid_t
))
2193 * pid_to_ns_wrapper: when you setns into a pidns, you yourself remain
2194 * in your old pidns. Only children which you clone will be in the target
2195 * pidns. So the pid_to_ns_wrapper does the setns, then clones a child to
2196 * actually convert pids.
2198 * Note: glibc's fork() does not respect pidns, which can lead to failed
2199 * assertions inside glibc (and thus failed forks) if the child's pid in
2200 * the pidns and the parent pid outside are identical. Using clone prevents
2203 static void pid_to_ns_wrapper(int sock
, pid_t tpid
)
2205 int newnsfd
= -1, ret
, cpipe
[2];
2210 ret
= snprintf(fnam
, sizeof(fnam
), "/proc/%d/ns/pid", tpid
);
2211 if (ret
< 0 || ret
>= sizeof(fnam
))
2213 newnsfd
= open(fnam
, O_RDONLY
);
2216 if (setns(newnsfd
, 0) < 0)
2220 if (pipe(cpipe
) < 0)
2223 struct pid_ns_clone_args args
= {
2227 .wrapped
= &pid_to_ns
2229 size_t stack_size
= sysconf(_SC_PAGESIZE
);
2230 void *stack
= alloca(stack_size
);
2232 cpid
= clone(pid_ns_clone_wrapper
, stack
+ stack_size
, SIGCHLD
, &args
);
2236 // give the child 1 second to be done forking and
2238 if (!wait_for_sock(cpipe
[0], 1))
2240 ret
= read(cpipe
[0], &v
, 1);
2241 if (ret
!= sizeof(char) || v
!= '1')
2244 if (!wait_for_pid(cpid
))
2250 * To read cgroup files with a particular pid, we will setns into the child
2251 * pidns, open a pipe, fork a child - which will be the first to really be in
2252 * the child ns - which does the cgfs_get_value and writes the data to the pipe.
2254 bool do_read_pids(pid_t tpid
, const char *contrl
, const char *cg
, const char *file
, char **d
)
2256 int sock
[2] = {-1, -1};
2257 char *tmpdata
= NULL
;
2259 pid_t qpid
, cpid
= -1;
2260 bool answer
= false;
2263 size_t sz
= 0, asz
= 0;
2265 if (!cgfs_get_value(contrl
, cg
, file
, &tmpdata
))
2269 * Now we read the pids from returned data one by one, pass
2270 * them into a child in the target namespace, read back the
2271 * translated pids, and put them into our to-return data
2274 if (socketpair(AF_UNIX
, SOCK_DGRAM
, 0, sock
) < 0) {
2275 perror("socketpair");
2284 if (!cpid
) // child - exits when done
2285 pid_to_ns_wrapper(sock
[1], tpid
);
2287 char *ptr
= tmpdata
;
2290 while (sscanf(ptr
, "%d\n", &qpid
) == 1) {
2292 ret
= send_creds(sock
[0], &cred
, v
, true);
2294 if (ret
== SEND_CREDS_NOTSK
)
2296 if (ret
== SEND_CREDS_FAIL
)
2299 // read converted results
2300 if (!wait_for_sock(sock
[0], 2)) {
2301 fprintf(stderr
, "%s: timed out waiting for pid from child: %s\n",
2302 __func__
, strerror(errno
));
2305 if (read(sock
[0], &qpid
, sizeof(qpid
)) != sizeof(qpid
)) {
2306 fprintf(stderr
, "%s: error reading pid from child: %s\n",
2307 __func__
, strerror(errno
));
2310 must_strcat_pid(d
, &sz
, &asz
, qpid
);
2312 ptr
= strchr(ptr
, '\n');
2318 cred
.pid
= getpid();
2320 if (send_creds(sock
[0], &cred
, v
, true) != SEND_CREDS_OK
) {
2321 // failed to ask child to exit
2322 fprintf(stderr
, "%s: failed to ask child to exit: %s\n",
2323 __func__
, strerror(errno
));
2333 if (sock
[0] != -1) {
2340 int cg_read(const char *path
, char *buf
, size_t size
, off_t offset
,
2341 struct fuse_file_info
*fi
)
2343 struct fuse_context
*fc
= fuse_get_context();
2344 struct file_info
*f
= (struct file_info
*)fi
->fh
;
2345 struct cgfs_files
*k
= NULL
;
2350 if (f
->type
!= LXC_TYPE_CGFILE
) {
2351 fprintf(stderr
, "Internal error: directory cache info used in cg_read\n");
2364 if ((k
= cgfs_get_key(f
->controller
, f
->cgroup
, f
->file
)) == NULL
) {
2370 if (!fc_may_access(fc
, f
->controller
, f
->cgroup
, f
->file
, O_RDONLY
)) {
2375 if (strcmp(f
->file
, "tasks") == 0 ||
2376 strcmp(f
->file
, "/tasks") == 0 ||
2377 strcmp(f
->file
, "/cgroup.procs") == 0 ||
2378 strcmp(f
->file
, "cgroup.procs") == 0)
2379 // special case - we have to translate the pids
2380 r
= do_read_pids(fc
->pid
, f
->controller
, f
->cgroup
, f
->file
, &data
);
2382 r
= cgfs_get_value(f
->controller
, f
->cgroup
, f
->file
, &data
);
2396 memcpy(buf
, data
, s
);
2397 if (s
> 0 && s
< size
&& data
[s
-1] != '\n')
2407 static int pid_from_ns(int sock
, pid_t tpid
)
2417 if (!wait_for_sock(sock
, 2)) {
2418 fprintf(stderr
, "%s: timeout reading from parent\n", __func__
);
2421 if ((ret
= read(sock
, &vpid
, sizeof(pid_t
))) != sizeof(pid_t
)) {
2422 fprintf(stderr
, "%s: bad read from parent: %s\n",
2423 __func__
, strerror(errno
));
2426 if (vpid
== -1) // done
2430 if (send_creds(sock
, &cred
, v
, true) != SEND_CREDS_OK
) {
2432 cred
.pid
= getpid();
2433 if (send_creds(sock
, &cred
, v
, false) != SEND_CREDS_OK
)
2440 static void pid_from_ns_wrapper(int sock
, pid_t tpid
)
2442 int newnsfd
= -1, ret
, cpipe
[2];
2447 ret
= snprintf(fnam
, sizeof(fnam
), "/proc/%d/ns/pid", tpid
);
2448 if (ret
< 0 || ret
>= sizeof(fnam
))
2450 newnsfd
= open(fnam
, O_RDONLY
);
2453 if (setns(newnsfd
, 0) < 0)
2457 if (pipe(cpipe
) < 0)
2460 struct pid_ns_clone_args args
= {
2464 .wrapped
= &pid_from_ns
2466 size_t stack_size
= sysconf(_SC_PAGESIZE
);
2467 void *stack
= alloca(stack_size
);
2469 cpid
= clone(pid_ns_clone_wrapper
, stack
+ stack_size
, SIGCHLD
, &args
);
2473 // give the child 1 second to be done forking and
2475 if (!wait_for_sock(cpipe
[0], 1))
2477 ret
= read(cpipe
[0], &v
, 1);
2478 if (ret
!= sizeof(char) || v
!= '1')
2481 if (!wait_for_pid(cpid
))
2487 * Given host @uid, return the uid to which it maps in
2488 * @pid's user namespace, or -1 if none.
2490 bool hostuid_to_ns(uid_t uid
, pid_t pid
, uid_t
*answer
)
2495 sprintf(line
, "/proc/%d/uid_map", pid
);
2496 if ((f
= fopen(line
, "r")) == NULL
) {
2500 *answer
= convert_id_to_ns(f
, uid
);
2509 * get_pid_creds: get the real uid and gid of @pid from
2511 * (XXX should we use euid here?)
2513 void get_pid_creds(pid_t pid
, uid_t
*uid
, gid_t
*gid
)
2522 sprintf(line
, "/proc/%d/status", pid
);
2523 if ((f
= fopen(line
, "r")) == NULL
) {
2524 fprintf(stderr
, "Error opening %s: %s\n", line
, strerror(errno
));
2527 while (fgets(line
, 400, f
)) {
2528 if (strncmp(line
, "Uid:", 4) == 0) {
2529 if (sscanf(line
+4, "%u", &u
) != 1) {
2530 fprintf(stderr
, "bad uid line for pid %u\n", pid
);
2535 } else if (strncmp(line
, "Gid:", 4) == 0) {
2536 if (sscanf(line
+4, "%u", &g
) != 1) {
2537 fprintf(stderr
, "bad gid line for pid %u\n", pid
);
2548 * May the requestor @r move victim @v to a new cgroup?
2549 * This is allowed if
2550 * . they are the same task
2551 * . they are ownedy by the same uid
2552 * . @r is root on the host, or
2553 * . @v's uid is mapped into @r's where @r is root.
2555 bool may_move_pid(pid_t r
, uid_t r_uid
, pid_t v
)
2557 uid_t v_uid
, tmpuid
;
2564 get_pid_creds(v
, &v_uid
, &v_gid
);
2567 if (hostuid_to_ns(r_uid
, r
, &tmpuid
) && tmpuid
== 0
2568 && hostuid_to_ns(v_uid
, r
, &tmpuid
))
2573 static bool do_write_pids(pid_t tpid
, uid_t tuid
, const char *contrl
, const char *cg
,
2574 const char *file
, const char *buf
)
2576 int sock
[2] = {-1, -1};
2577 pid_t qpid
, cpid
= -1;
2578 FILE *pids_file
= NULL
;
2579 bool answer
= false, fail
= false;
2581 pids_file
= open_pids_file(contrl
, cg
);
2586 * write the pids to a socket, have helper in writer's pidns
2587 * call movepid for us
2589 if (socketpair(AF_UNIX
, SOCK_DGRAM
, 0, sock
) < 0) {
2590 perror("socketpair");
2598 if (!cpid
) { // child
2600 pid_from_ns_wrapper(sock
[1], tpid
);
2603 const char *ptr
= buf
;
2604 while (sscanf(ptr
, "%d", &qpid
) == 1) {
2608 if (write(sock
[0], &qpid
, sizeof(qpid
)) != sizeof(qpid
)) {
2609 fprintf(stderr
, "%s: error writing pid to child: %s\n",
2610 __func__
, strerror(errno
));
2614 if (recv_creds(sock
[0], &cred
, &v
)) {
2616 if (!may_move_pid(tpid
, tuid
, cred
.pid
)) {
2620 if (fprintf(pids_file
, "%d", (int) cred
.pid
) < 0)
2625 ptr
= strchr(ptr
, '\n');
2631 /* All good, write the value */
2633 if (write(sock
[0], &qpid
,sizeof(qpid
)) != sizeof(qpid
))
2634 fprintf(stderr
, "Warning: failed to ask child to exit\n");
2642 if (sock
[0] != -1) {
2647 if (fclose(pids_file
) != 0)
2653 int cg_write(const char *path
, const char *buf
, size_t size
, off_t offset
,
2654 struct fuse_file_info
*fi
)
2656 struct fuse_context
*fc
= fuse_get_context();
2657 char *localbuf
= NULL
;
2658 struct cgfs_files
*k
= NULL
;
2659 struct file_info
*f
= (struct file_info
*)fi
->fh
;
2662 if (f
->type
!= LXC_TYPE_CGFILE
) {
2663 fprintf(stderr
, "Internal error: directory cache info used in cg_write\n");
2673 localbuf
= alloca(size
+1);
2674 localbuf
[size
] = '\0';
2675 memcpy(localbuf
, buf
, size
);
2677 if ((k
= cgfs_get_key(f
->controller
, f
->cgroup
, f
->file
)) == NULL
) {
2682 if (!fc_may_access(fc
, f
->controller
, f
->cgroup
, f
->file
, O_WRONLY
)) {
2687 if (strcmp(f
->file
, "tasks") == 0 ||
2688 strcmp(f
->file
, "/tasks") == 0 ||
2689 strcmp(f
->file
, "/cgroup.procs") == 0 ||
2690 strcmp(f
->file
, "cgroup.procs") == 0)
2691 // special case - we have to translate the pids
2692 r
= do_write_pids(fc
->pid
, fc
->uid
, f
->controller
, f
->cgroup
, f
->file
, localbuf
);
2694 r
= cgfs_set_value(f
->controller
, f
->cgroup
, f
->file
, localbuf
);
2704 int cg_chown(const char *path
, uid_t uid
, gid_t gid
)
2706 struct fuse_context
*fc
= fuse_get_context();
2707 char *cgdir
= NULL
, *last
= NULL
, *path1
, *path2
, *controller
;
2708 struct cgfs_files
*k
= NULL
;
2715 if (strcmp(path
, "/cgroup") == 0)
2718 controller
= pick_controller_from_path(fc
, path
);
2721 cgroup
= find_cgroup_in_path(path
);
2723 /* this is just /cgroup/controller */
2726 get_cgdir_and_path(cgroup
, &cgdir
, &last
);
2736 if (is_child_cgroup(controller
, path1
, path2
)) {
2737 // get uid, gid, from '/tasks' file and make up a mode
2738 // That is a hack, until cgmanager gains a GetCgroupPerms fn.
2739 k
= cgfs_get_key(controller
, cgroup
, "tasks");
2742 k
= cgfs_get_key(controller
, path1
, path2
);
2750 * This being a fuse request, the uid and gid must be valid
2751 * in the caller's namespace. So we can just check to make
2752 * sure that the caller is root in his uid, and privileged
2753 * over the file's current owner.
2755 if (!is_privileged_over(fc
->pid
, fc
->uid
, k
->uid
, NS_ROOT_REQD
)) {
2760 ret
= cgfs_chown_file(controller
, cgroup
, uid
, gid
);
2769 int cg_chmod(const char *path
, mode_t mode
)
2771 struct fuse_context
*fc
= fuse_get_context();
2772 char * cgdir
= NULL
, *last
= NULL
, *path1
, *path2
, *controller
;
2773 struct cgfs_files
*k
= NULL
;
2780 if (strcmp(path
, "/cgroup") == 0)
2783 controller
= pick_controller_from_path(fc
, path
);
2786 cgroup
= find_cgroup_in_path(path
);
2788 /* this is just /cgroup/controller */
2791 get_cgdir_and_path(cgroup
, &cgdir
, &last
);
2801 if (is_child_cgroup(controller
, path1
, path2
)) {
2802 // get uid, gid, from '/tasks' file and make up a mode
2803 // That is a hack, until cgmanager gains a GetCgroupPerms fn.
2804 k
= cgfs_get_key(controller
, cgroup
, "tasks");
2807 k
= cgfs_get_key(controller
, path1
, path2
);
2815 * This being a fuse request, the uid and gid must be valid
2816 * in the caller's namespace. So we can just check to make
2817 * sure that the caller is root in his uid, and privileged
2818 * over the file's current owner.
2820 if (!is_privileged_over(fc
->pid
, fc
->uid
, k
->uid
, NS_ROOT_OPT
)) {
2825 if (!cgfs_chmod_file(controller
, cgroup
, mode
)) {
2837 int cg_mkdir(const char *path
, mode_t mode
)
2839 struct fuse_context
*fc
= fuse_get_context();
2840 char *last
= NULL
, *path1
, *cgdir
= NULL
, *controller
, *next
= NULL
;
2848 controller
= pick_controller_from_path(fc
, path
);
2852 cgroup
= find_cgroup_in_path(path
);
2856 get_cgdir_and_path(cgroup
, &cgdir
, &last
);
2862 pid_t initpid
= lookup_initpid_in_store(fc
->pid
);
2865 if (!caller_is_in_ancestor(initpid
, controller
, path1
, &next
)) {
2868 else if (last
&& strcmp(next
, last
) == 0)
2875 if (!fc_may_access(fc
, controller
, path1
, NULL
, O_RDWR
)) {
2879 if (!caller_is_in_ancestor(initpid
, controller
, path1
, NULL
)) {
2884 ret
= cgfs_create(controller
, cgroup
, fc
->uid
, fc
->gid
);
2892 int cg_rmdir(const char *path
)
2894 struct fuse_context
*fc
= fuse_get_context();
2895 char *last
= NULL
, *cgdir
= NULL
, *controller
, *next
= NULL
;
2902 controller
= pick_controller_from_path(fc
, path
);
2906 cgroup
= find_cgroup_in_path(path
);
2910 get_cgdir_and_path(cgroup
, &cgdir
, &last
);
2916 pid_t initpid
= lookup_initpid_in_store(fc
->pid
);
2919 if (!caller_is_in_ancestor(initpid
, controller
, cgroup
, &next
)) {
2920 if (!last
|| strcmp(next
, last
) == 0)
2927 if (!fc_may_access(fc
, controller
, cgdir
, NULL
, O_WRONLY
)) {
2931 if (!caller_is_in_ancestor(initpid
, controller
, cgroup
, NULL
)) {
2936 if (!cgfs_remove(controller
, cgroup
)) {
2949 static bool startswith(const char *line
, const char *pref
)
2951 if (strncmp(line
, pref
, strlen(pref
)) == 0)
2956 static void parse_memstat(char *memstat
, unsigned long *cached
,
2957 unsigned long *active_anon
, unsigned long *inactive_anon
,
2958 unsigned long *active_file
, unsigned long *inactive_file
,
2959 unsigned long *unevictable
)
2964 if (startswith(memstat
, "cache")) {
2965 sscanf(memstat
+ 11, "%lu", cached
);
2967 } else if (startswith(memstat
, "active_anon")) {
2968 sscanf(memstat
+ 11, "%lu", active_anon
);
2969 *active_anon
/= 1024;
2970 } else if (startswith(memstat
, "inactive_anon")) {
2971 sscanf(memstat
+ 11, "%lu", inactive_anon
);
2972 *inactive_anon
/= 1024;
2973 } else if (startswith(memstat
, "active_file")) {
2974 sscanf(memstat
+ 11, "%lu", active_file
);
2975 *active_file
/= 1024;
2976 } else if (startswith(memstat
, "inactive_file")) {
2977 sscanf(memstat
+ 11, "%lu", inactive_file
);
2978 *inactive_file
/= 1024;
2979 } else if (startswith(memstat
, "unevictable")) {
2980 sscanf(memstat
+ 11, "%lu", unevictable
);
2981 *unevictable
/= 1024;
2983 eol
= strchr(memstat
, '\n');
2990 static void get_blkio_io_value(char *str
, unsigned major
, unsigned minor
, char *iotype
, unsigned long *v
)
2996 snprintf(key
, 32, "%u:%u %s", major
, minor
, iotype
);
2998 size_t len
= strlen(key
);
3002 if (startswith(str
, key
)) {
3003 sscanf(str
+ len
, "%lu", v
);
3006 eol
= strchr(str
, '\n');
3013 static int read_file(const char *path
, char *buf
, size_t size
,
3014 struct file_info
*d
)
3016 size_t linelen
= 0, total_len
= 0, rv
= 0;
3018 char *cache
= d
->buf
;
3019 size_t cache_size
= d
->buflen
;
3020 FILE *f
= fopen(path
, "r");
3024 while (getline(&line
, &linelen
, f
) != -1) {
3025 ssize_t l
= snprintf(cache
, cache_size
, "%s", line
);
3027 perror("Error writing to cache");
3031 if (l
>= cache_size
) {
3032 fprintf(stderr
, "Internal error: truncated write to cache\n");
3041 d
->size
= total_len
;
3042 if (total_len
> size
)
3045 /* read from off 0 */
3046 memcpy(buf
, d
->buf
, total_len
);
3055 * FUSE ops for /proc
3058 static unsigned long get_memlimit(const char *cgroup
)
3060 char *memlimit_str
= NULL
;
3061 unsigned long memlimit
= -1;
3063 if (cgfs_get_value("memory", cgroup
, "memory.limit_in_bytes", &memlimit_str
))
3064 memlimit
= strtoul(memlimit_str
, NULL
, 10);
3071 static unsigned long get_min_memlimit(const char *cgroup
)
3073 char *copy
= strdupa(cgroup
);
3074 unsigned long memlimit
= 0, retlimit
;
3076 retlimit
= get_memlimit(copy
);
3078 while (strcmp(copy
, "/") != 0) {
3079 copy
= dirname(copy
);
3080 memlimit
= get_memlimit(copy
);
3081 if (memlimit
!= -1 && memlimit
< retlimit
)
3082 retlimit
= memlimit
;
3088 static int proc_meminfo_read(char *buf
, size_t size
, off_t offset
,
3089 struct fuse_file_info
*fi
)
3091 struct fuse_context
*fc
= fuse_get_context();
3092 struct file_info
*d
= (struct file_info
*)fi
->fh
;
3094 char *memusage_str
= NULL
, *memstat_str
= NULL
,
3095 *memswlimit_str
= NULL
, *memswusage_str
= NULL
,
3096 *memswlimit_default_str
= NULL
, *memswusage_default_str
= NULL
;
3097 unsigned long memlimit
= 0, memusage
= 0, memswlimit
= 0, memswusage
= 0,
3098 cached
= 0, hosttotal
= 0, active_anon
= 0, inactive_anon
= 0,
3099 active_file
= 0, inactive_file
= 0, unevictable
= 0;
3101 size_t linelen
= 0, total_len
= 0, rv
= 0;
3102 char *cache
= d
->buf
;
3103 size_t cache_size
= d
->buflen
;
3107 if (offset
> d
->size
)
3111 int left
= d
->size
- offset
;
3112 total_len
= left
> size
? size
: left
;
3113 memcpy(buf
, cache
+ offset
, total_len
);
3117 pid_t initpid
= lookup_initpid_in_store(fc
->pid
);
3120 cg
= get_pid_cgroup(initpid
, "memory");
3122 return read_file("/proc/meminfo", buf
, size
, d
);
3123 prune_init_slice(cg
);
3125 memlimit
= get_min_memlimit(cg
);
3126 if (!cgfs_get_value("memory", cg
, "memory.usage_in_bytes", &memusage_str
))
3128 if (!cgfs_get_value("memory", cg
, "memory.stat", &memstat_str
))
3131 // Following values are allowed to fail, because swapaccount might be turned
3132 // off for current kernel
3133 if(cgfs_get_value("memory", cg
, "memory.memsw.limit_in_bytes", &memswlimit_str
) &&
3134 cgfs_get_value("memory", cg
, "memory.memsw.usage_in_bytes", &memswusage_str
))
3136 /* If swapaccounting is turned on, then default value is assumed to be that of cgroup / */
3137 if (!cgfs_get_value("memory", "/", "memory.memsw.limit_in_bytes", &memswlimit_default_str
))
3139 if (!cgfs_get_value("memory", "/", "memory.memsw.usage_in_bytes", &memswusage_default_str
))
3142 memswlimit
= strtoul(memswlimit_str
, NULL
, 10);
3143 memswusage
= strtoul(memswusage_str
, NULL
, 10);
3145 if (!strcmp(memswlimit_str
, memswlimit_default_str
))
3147 if (!strcmp(memswusage_str
, memswusage_default_str
))
3150 memswlimit
= memswlimit
/ 1024;
3151 memswusage
= memswusage
/ 1024;
3154 memusage
= strtoul(memusage_str
, NULL
, 10);
3158 parse_memstat(memstat_str
, &cached
, &active_anon
,
3159 &inactive_anon
, &active_file
, &inactive_file
,
3162 f
= fopen("/proc/meminfo", "r");
3166 while (getline(&line
, &linelen
, f
) != -1) {
3168 char *printme
, lbuf
[100];
3170 memset(lbuf
, 0, 100);
3171 if (startswith(line
, "MemTotal:")) {
3172 sscanf(line
+14, "%lu", &hosttotal
);
3173 if (hosttotal
< memlimit
)
3174 memlimit
= hosttotal
;
3175 snprintf(lbuf
, 100, "MemTotal: %8lu kB\n", memlimit
);
3177 } else if (startswith(line
, "MemFree:")) {
3178 snprintf(lbuf
, 100, "MemFree: %8lu kB\n", memlimit
- memusage
);
3180 } else if (startswith(line
, "MemAvailable:")) {
3181 snprintf(lbuf
, 100, "MemAvailable: %8lu kB\n", memlimit
- memusage
);
3183 } else if (startswith(line
, "SwapTotal:") && memswlimit
> 0) {
3184 snprintf(lbuf
, 100, "SwapTotal: %8lu kB\n", memswlimit
- memlimit
);
3186 } else if (startswith(line
, "SwapFree:") && memswlimit
> 0 && memswusage
> 0) {
3187 unsigned long swaptotal
= memswlimit
- memlimit
,
3188 swapusage
= memswusage
- memusage
,
3189 swapfree
= swapusage
< swaptotal
? swaptotal
- swapusage
: 0;
3190 snprintf(lbuf
, 100, "SwapFree: %8lu kB\n", swapfree
);
3192 } else if (startswith(line
, "Slab:")) {
3193 snprintf(lbuf
, 100, "Slab: %8lu kB\n", 0UL);
3195 } else if (startswith(line
, "Buffers:")) {
3196 snprintf(lbuf
, 100, "Buffers: %8lu kB\n", 0UL);
3198 } else if (startswith(line
, "Cached:")) {
3199 snprintf(lbuf
, 100, "Cached: %8lu kB\n", cached
);
3201 } else if (startswith(line
, "SwapCached:")) {
3202 snprintf(lbuf
, 100, "SwapCached: %8lu kB\n", 0UL);
3204 } else if (startswith(line
, "Active")) {
3205 snprintf(lbuf
, 100, "Active: %8lu kB\n",
3206 active_anon
+ active_file
);
3208 } else if (startswith(line
, "Inactive")) {
3209 snprintf(lbuf
, 100, "Inactive: %8lu kB\n",
3210 inactive_anon
+ inactive_file
);
3212 } else if (startswith(line
, "Active(anon)")) {
3213 snprintf(lbuf
, 100, "Active(anon): %8lu kB\n", active_anon
);
3215 } else if (startswith(line
, "Inactive(anon)")) {
3216 snprintf(lbuf
, 100, "Inactive(anon): %8lu kB\n", inactive_anon
);
3218 } else if (startswith(line
, "Active(file)")) {
3219 snprintf(lbuf
, 100, "Active(file): %8lu kB\n", active_file
);
3221 } else if (startswith(line
, "Inactive(file)")) {
3222 snprintf(lbuf
, 100, "Inactive(file): %8lu kB\n", inactive_file
);
3224 } else if (startswith(line
, "Unevictable")) {
3225 snprintf(lbuf
, 100, "Unevictable: %8lu kB\n", unevictable
);
3227 } else if (startswith(line
, "SReclaimable")) {
3228 snprintf(lbuf
, 100, "SReclaimable: %8lu kB\n", 0UL);
3230 } else if (startswith(line
, "SUnreclaim")) {
3231 snprintf(lbuf
, 100, "SUnreclaim: %8lu kB\n", 0UL);
3236 l
= snprintf(cache
, cache_size
, "%s", printme
);
3238 perror("Error writing to cache");
3243 if (l
>= cache_size
) {
3244 fprintf(stderr
, "Internal error: truncated write to cache\n");
3255 d
->size
= total_len
;
3256 if (total_len
> size
) total_len
= size
;
3257 memcpy(buf
, d
->buf
, total_len
);
3266 free(memswlimit_str
);
3267 free(memswusage_str
);
3269 free(memswlimit_default_str
);
3270 free(memswusage_default_str
);
3275 * Read the cpuset.cpus for cg
3276 * Return the answer in a newly allocated string which must be freed
3278 static char *get_cpuset(const char *cg
)
3282 if (!cgfs_get_value("cpuset", cg
, "cpuset.cpus", &answer
))
3287 bool cpu_in_cpuset(int cpu
, const char *cpuset
);
3289 static bool cpuline_in_cpuset(const char *line
, const char *cpuset
)
3293 if (sscanf(line
, "processor : %d", &cpu
) != 1)
3295 return cpu_in_cpuset(cpu
, cpuset
);
3299 * check whether this is a '^processor" line in /proc/cpuinfo
3301 static bool is_processor_line(const char *line
)
3305 if (sscanf(line
, "processor : %d", &cpu
) == 1)
3310 static int proc_cpuinfo_read(char *buf
, size_t size
, off_t offset
,
3311 struct fuse_file_info
*fi
)
3313 struct fuse_context
*fc
= fuse_get_context();
3314 struct file_info
*d
= (struct file_info
*)fi
->fh
;
3316 char *cpuset
= NULL
;
3318 size_t linelen
= 0, total_len
= 0, rv
= 0;
3319 bool am_printing
= false, firstline
= true, is_s390x
= false;
3320 int curcpu
= -1, cpu
;
3321 char *cache
= d
->buf
;
3322 size_t cache_size
= d
->buflen
;
3326 if (offset
> d
->size
)
3330 int left
= d
->size
- offset
;
3331 total_len
= left
> size
? size
: left
;
3332 memcpy(buf
, cache
+ offset
, total_len
);
3336 pid_t initpid
= lookup_initpid_in_store(fc
->pid
);
3339 cg
= get_pid_cgroup(initpid
, "cpuset");
3341 return read_file("proc/cpuinfo", buf
, size
, d
);
3342 prune_init_slice(cg
);
3344 cpuset
= get_cpuset(cg
);
3348 f
= fopen("/proc/cpuinfo", "r");
3352 while (getline(&line
, &linelen
, f
) != -1) {
3356 if (strstr(line
, "IBM/S390") != NULL
) {
3362 if (strncmp(line
, "# processors:", 12) == 0)
3364 if (is_processor_line(line
)) {
3365 am_printing
= cpuline_in_cpuset(line
, cpuset
);
3368 l
= snprintf(cache
, cache_size
, "processor : %d\n", curcpu
);
3370 perror("Error writing to cache");
3374 if (l
>= cache_size
) {
3375 fprintf(stderr
, "Internal error: truncated write to cache\n");
3384 } else if (is_s390x
&& sscanf(line
, "processor %d:", &cpu
) == 1) {
3386 if (!cpu_in_cpuset(cpu
, cpuset
))
3389 p
= strchr(line
, ':');
3393 l
= snprintf(cache
, cache_size
, "processor %d:%s", curcpu
, p
);
3395 perror("Error writing to cache");
3399 if (l
>= cache_size
) {
3400 fprintf(stderr
, "Internal error: truncated write to cache\n");
3411 l
= snprintf(cache
, cache_size
, "%s", line
);
3413 perror("Error writing to cache");
3417 if (l
>= cache_size
) {
3418 fprintf(stderr
, "Internal error: truncated write to cache\n");
3429 char *origcache
= d
->buf
;
3432 d
->buf
= malloc(d
->buflen
);
3435 cache_size
= d
->buflen
;
3437 l
= snprintf(cache
, cache_size
, "vendor_id : IBM/S390\n");
3438 if (l
< 0 || l
>= cache_size
) {
3445 l
= snprintf(cache
, cache_size
, "# processors : %d\n", curcpu
+ 1);
3446 if (l
< 0 || l
>= cache_size
) {
3453 l
= snprintf(cache
, cache_size
, "%s", origcache
);
3455 if (l
< 0 || l
>= cache_size
)
3461 d
->size
= total_len
;
3462 if (total_len
> size
) total_len
= size
;
3464 /* read from off 0 */
3465 memcpy(buf
, d
->buf
, total_len
);
3476 static int proc_stat_read(char *buf
, size_t size
, off_t offset
,
3477 struct fuse_file_info
*fi
)
3479 struct fuse_context
*fc
= fuse_get_context();
3480 struct file_info
*d
= (struct file_info
*)fi
->fh
;
3482 char *cpuset
= NULL
;
3484 size_t linelen
= 0, total_len
= 0, rv
= 0;
3485 int curcpu
= -1; /* cpu numbering starts at 0 */
3486 unsigned long user
= 0, nice
= 0, system
= 0, idle
= 0, iowait
= 0, irq
= 0, softirq
= 0, steal
= 0, guest
= 0;
3487 unsigned long user_sum
= 0, nice_sum
= 0, system_sum
= 0, idle_sum
= 0, iowait_sum
= 0,
3488 irq_sum
= 0, softirq_sum
= 0, steal_sum
= 0, guest_sum
= 0;
3489 #define CPUALL_MAX_SIZE BUF_RESERVE_SIZE
3490 char cpuall
[CPUALL_MAX_SIZE
];
3491 /* reserve for cpu all */
3492 char *cache
= d
->buf
+ CPUALL_MAX_SIZE
;
3493 size_t cache_size
= d
->buflen
- CPUALL_MAX_SIZE
;
3497 if (offset
> d
->size
)
3501 int left
= d
->size
- offset
;
3502 total_len
= left
> size
? size
: left
;
3503 memcpy(buf
, d
->buf
+ offset
, total_len
);
3507 pid_t initpid
= lookup_initpid_in_store(fc
->pid
);
3510 cg
= get_pid_cgroup(initpid
, "cpuset");
3512 return read_file("/proc/stat", buf
, size
, d
);
3513 prune_init_slice(cg
);
3515 cpuset
= get_cpuset(cg
);
3519 f
= fopen("/proc/stat", "r");
3524 if (getline(&line
, &linelen
, f
) < 0) {
3525 fprintf(stderr
, "proc_stat_read read first line failed\n");
3529 while (getline(&line
, &linelen
, f
) != -1) {
3532 char cpu_char
[10]; /* That's a lot of cores */
3535 if (strlen(line
) == 0)
3537 if (sscanf(line
, "cpu%9[^ ]", cpu_char
) != 1) {
3538 /* not a ^cpuN line containing a number N, just print it */
3539 l
= snprintf(cache
, cache_size
, "%s", line
);
3541 perror("Error writing to cache");
3545 if (l
>= cache_size
) {
3546 fprintf(stderr
, "Internal error: truncated write to cache\n");
3556 if (sscanf(cpu_char
, "%d", &cpu
) != 1)
3558 if (!cpu_in_cpuset(cpu
, cpuset
))
3562 c
= strchr(line
, ' ');
3565 l
= snprintf(cache
, cache_size
, "cpu%d%s", curcpu
, c
);
3567 perror("Error writing to cache");
3572 if (l
>= cache_size
) {
3573 fprintf(stderr
, "Internal error: truncated write to cache\n");
3582 if (sscanf(line
, "%*s %lu %lu %lu %lu %lu %lu %lu %lu %lu", &user
, &nice
, &system
, &idle
, &iowait
, &irq
,
3583 &softirq
, &steal
, &guest
) != 9)
3587 system_sum
+= system
;
3589 iowait_sum
+= iowait
;
3591 softirq_sum
+= softirq
;
3598 int cpuall_len
= snprintf(cpuall
, CPUALL_MAX_SIZE
, "%s %lu %lu %lu %lu %lu %lu %lu %lu %lu\n",
3599 "cpu ", user_sum
, nice_sum
, system_sum
, idle_sum
, iowait_sum
, irq_sum
, softirq_sum
, steal_sum
, guest_sum
);
3600 if (cpuall_len
> 0 && cpuall_len
< CPUALL_MAX_SIZE
){
3601 memcpy(cache
, cpuall
, cpuall_len
);
3602 cache
+= cpuall_len
;
3604 /* shouldn't happen */
3605 fprintf(stderr
, "proc_stat_read copy cpuall failed, cpuall_len=%d\n", cpuall_len
);
3609 memmove(cache
, d
->buf
+ CPUALL_MAX_SIZE
, total_len
);
3610 total_len
+= cpuall_len
;
3612 d
->size
= total_len
;
3613 if (total_len
> size
) total_len
= size
;
3615 memcpy(buf
, d
->buf
, total_len
);
3627 static long int getreaperage(pid_t pid
)
3634 qpid
= lookup_initpid_in_store(pid
);
3638 ret
= snprintf(fnam
, 100, "/proc/%d", qpid
);
3639 if (ret
< 0 || ret
>= 100)
3642 if (lstat(fnam
, &sb
) < 0)
3645 return time(NULL
) - sb
.st_ctime
;
3648 static unsigned long get_reaper_busy(pid_t task
)
3650 pid_t initpid
= lookup_initpid_in_store(task
);
3651 char *cgroup
= NULL
, *usage_str
= NULL
;
3652 unsigned long usage
= 0;
3657 cgroup
= get_pid_cgroup(initpid
, "cpuacct");
3660 prune_init_slice(cgroup
);
3661 if (!cgfs_get_value("cpuacct", cgroup
, "cpuacct.usage", &usage_str
))
3663 usage
= strtoul(usage_str
, NULL
, 10);
3664 usage
/= 1000000000;
3677 fd
= creat("/tmp/lxcfs-iwashere", 0644);
3684 * We read /proc/uptime and reuse its second field.
3685 * For the first field, we use the mtime for the reaper for
3686 * the calling pid as returned by getreaperage
3688 static int proc_uptime_read(char *buf
, size_t size
, off_t offset
,
3689 struct fuse_file_info
*fi
)
3691 struct fuse_context
*fc
= fuse_get_context();
3692 struct file_info
*d
= (struct file_info
*)fi
->fh
;
3693 long int reaperage
= getreaperage(fc
->pid
);
3694 unsigned long int busytime
= get_reaper_busy(fc
->pid
), idletime
;
3695 char *cache
= d
->buf
;
3696 ssize_t total_len
= 0;
3703 if (offset
> d
->size
)
3707 int left
= d
->size
- offset
;
3708 total_len
= left
> size
? size
: left
;
3709 memcpy(buf
, cache
+ offset
, total_len
);
3713 idletime
= reaperage
- busytime
;
3714 if (idletime
> reaperage
)
3715 idletime
= reaperage
;
3717 total_len
= snprintf(d
->buf
, d
->size
, "%ld.0 %lu.0\n", reaperage
, idletime
);
3719 perror("Error writing to cache");
3723 d
->size
= (int)total_len
;
3726 if (total_len
> size
) total_len
= size
;
3728 memcpy(buf
, d
->buf
, total_len
);
3732 static int proc_diskstats_read(char *buf
, size_t size
, off_t offset
,
3733 struct fuse_file_info
*fi
)
3736 struct fuse_context
*fc
= fuse_get_context();
3737 struct file_info
*d
= (struct file_info
*)fi
->fh
;
3739 char *io_serviced_str
= NULL
, *io_merged_str
= NULL
, *io_service_bytes_str
= NULL
,
3740 *io_wait_time_str
= NULL
, *io_service_time_str
= NULL
;
3741 unsigned long read
= 0, write
= 0;
3742 unsigned long read_merged
= 0, write_merged
= 0;
3743 unsigned long read_sectors
= 0, write_sectors
= 0;
3744 unsigned long read_ticks
= 0, write_ticks
= 0;
3745 unsigned long ios_pgr
= 0, tot_ticks
= 0, rq_ticks
= 0;
3746 unsigned long rd_svctm
= 0, wr_svctm
= 0, rd_wait
= 0, wr_wait
= 0;
3747 char *cache
= d
->buf
;
3748 size_t cache_size
= d
->buflen
;
3750 size_t linelen
= 0, total_len
= 0, rv
= 0;
3751 unsigned int major
= 0, minor
= 0;
3756 if (offset
> d
->size
)
3760 int left
= d
->size
- offset
;
3761 total_len
= left
> size
? size
: left
;
3762 memcpy(buf
, cache
+ offset
, total_len
);
3766 pid_t initpid
= lookup_initpid_in_store(fc
->pid
);
3769 cg
= get_pid_cgroup(initpid
, "blkio");
3771 return read_file("/proc/diskstats", buf
, size
, d
);
3772 prune_init_slice(cg
);
3774 if (!cgfs_get_value("blkio", cg
, "blkio.io_serviced_recursive", &io_serviced_str
))
3776 if (!cgfs_get_value("blkio", cg
, "blkio.io_merged_recursive", &io_merged_str
))
3778 if (!cgfs_get_value("blkio", cg
, "blkio.io_service_bytes_recursive", &io_service_bytes_str
))
3780 if (!cgfs_get_value("blkio", cg
, "blkio.io_wait_time_recursive", &io_wait_time_str
))
3782 if (!cgfs_get_value("blkio", cg
, "blkio.io_service_time_recursive", &io_service_time_str
))
3786 f
= fopen("/proc/diskstats", "r");
3790 while (getline(&line
, &linelen
, f
) != -1) {
3794 i
= sscanf(line
, "%u %u %71s", &major
, &minor
, dev_name
);
3798 get_blkio_io_value(io_serviced_str
, major
, minor
, "Read", &read
);
3799 get_blkio_io_value(io_serviced_str
, major
, minor
, "Write", &write
);
3800 get_blkio_io_value(io_merged_str
, major
, minor
, "Read", &read_merged
);
3801 get_blkio_io_value(io_merged_str
, major
, minor
, "Write", &write_merged
);
3802 get_blkio_io_value(io_service_bytes_str
, major
, minor
, "Read", &read_sectors
);
3803 read_sectors
= read_sectors
/512;
3804 get_blkio_io_value(io_service_bytes_str
, major
, minor
, "Write", &write_sectors
);
3805 write_sectors
= write_sectors
/512;
3807 get_blkio_io_value(io_service_time_str
, major
, minor
, "Read", &rd_svctm
);
3808 rd_svctm
= rd_svctm
/1000000;
3809 get_blkio_io_value(io_wait_time_str
, major
, minor
, "Read", &rd_wait
);
3810 rd_wait
= rd_wait
/1000000;
3811 read_ticks
= rd_svctm
+ rd_wait
;
3813 get_blkio_io_value(io_service_time_str
, major
, minor
, "Write", &wr_svctm
);
3814 wr_svctm
= wr_svctm
/1000000;
3815 get_blkio_io_value(io_wait_time_str
, major
, minor
, "Write", &wr_wait
);
3816 wr_wait
= wr_wait
/1000000;
3817 write_ticks
= wr_svctm
+ wr_wait
;
3819 get_blkio_io_value(io_service_time_str
, major
, minor
, "Total", &tot_ticks
);
3820 tot_ticks
= tot_ticks
/1000000;
3822 memset(lbuf
, 0, 256);
3823 if (read
|| write
|| read_merged
|| write_merged
|| read_sectors
|| write_sectors
|| read_ticks
|| write_ticks
)
3824 snprintf(lbuf
, 256, "%u %u %s %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu\n",
3825 major
, minor
, dev_name
, read
, read_merged
, read_sectors
, read_ticks
,
3826 write
, write_merged
, write_sectors
, write_ticks
, ios_pgr
, tot_ticks
, rq_ticks
);
3830 l
= snprintf(cache
, cache_size
, "%s", lbuf
);
3832 perror("Error writing to fuse buf");
3836 if (l
>= cache_size
) {
3837 fprintf(stderr
, "Internal error: truncated write to cache\n");
3847 d
->size
= total_len
;
3848 if (total_len
> size
) total_len
= size
;
3849 memcpy(buf
, d
->buf
, total_len
);
3857 free(io_serviced_str
);
3858 free(io_merged_str
);
3859 free(io_service_bytes_str
);
3860 free(io_wait_time_str
);
3861 free(io_service_time_str
);
3865 static int proc_swaps_read(char *buf
, size_t size
, off_t offset
,
3866 struct fuse_file_info
*fi
)
3868 struct fuse_context
*fc
= fuse_get_context();
3869 struct file_info
*d
= (struct file_info
*)fi
->fh
;
3871 char *memswlimit_str
= NULL
, *memlimit_str
= NULL
, *memusage_str
= NULL
, *memswusage_str
= NULL
,
3872 *memswlimit_default_str
= NULL
, *memswusage_default_str
= NULL
;
3873 unsigned long memswlimit
= 0, memlimit
= 0, memusage
= 0, memswusage
= 0, swap_total
= 0, swap_free
= 0;
3874 ssize_t total_len
= 0, rv
= 0;
3876 char *cache
= d
->buf
;
3879 if (offset
> d
->size
)
3883 int left
= d
->size
- offset
;
3884 total_len
= left
> size
? size
: left
;
3885 memcpy(buf
, cache
+ offset
, total_len
);
3889 pid_t initpid
= lookup_initpid_in_store(fc
->pid
);
3892 cg
= get_pid_cgroup(initpid
, "memory");
3894 return read_file("/proc/swaps", buf
, size
, d
);
3895 prune_init_slice(cg
);
3897 if (!cgfs_get_value("memory", cg
, "memory.limit_in_bytes", &memlimit_str
))
3900 if (!cgfs_get_value("memory", cg
, "memory.usage_in_bytes", &memusage_str
))
3903 memlimit
= strtoul(memlimit_str
, NULL
, 10);
3904 memusage
= strtoul(memusage_str
, NULL
, 10);
3906 if (cgfs_get_value("memory", cg
, "memory.memsw.usage_in_bytes", &memswusage_str
) &&
3907 cgfs_get_value("memory", cg
, "memory.memsw.limit_in_bytes", &memswlimit_str
)) {
3909 /* If swap accounting is turned on, then default value is assumed to be that of cgroup / */
3910 if (!cgfs_get_value("memory", "/", "memory.memsw.limit_in_bytes", &memswlimit_default_str
))
3912 if (!cgfs_get_value("memory", "/", "memory.memsw.usage_in_bytes", &memswusage_default_str
))
3915 memswlimit
= strtoul(memswlimit_str
, NULL
, 10);
3916 memswusage
= strtoul(memswusage_str
, NULL
, 10);
3918 if (!strcmp(memswlimit_str
, memswlimit_default_str
))
3920 if (!strcmp(memswusage_str
, memswusage_default_str
))
3923 swap_total
= (memswlimit
- memlimit
) / 1024;
3924 swap_free
= (memswusage
- memusage
) / 1024;
3927 total_len
= snprintf(d
->buf
, d
->size
, "Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n");
3929 /* When no mem + swap limit is specified or swapaccount=0*/
3933 FILE *f
= fopen("/proc/meminfo", "r");
3938 while (getline(&line
, &linelen
, f
) != -1) {
3939 if (startswith(line
, "SwapTotal:")) {
3940 sscanf(line
, "SwapTotal: %8lu kB", &swap_total
);
3941 } else if (startswith(line
, "SwapFree:")) {
3942 sscanf(line
, "SwapFree: %8lu kB", &swap_free
);
3950 if (swap_total
> 0) {
3951 l
= snprintf(d
->buf
+ total_len
, d
->size
- total_len
,
3952 "none%*svirtual\t\t%lu\t%lu\t0\n", 36, " ",
3953 swap_total
, swap_free
);
3957 if (total_len
< 0 || l
< 0) {
3958 perror("Error writing to cache");
3964 d
->size
= (int)total_len
;
3966 if (total_len
> size
) total_len
= size
;
3967 memcpy(buf
, d
->buf
, total_len
);
3972 free(memswlimit_str
);
3975 free(memswusage_str
);
3976 free(memswusage_default_str
);
3977 free(memswlimit_default_str
);
3981 static off_t
get_procfile_size(const char *which
)
3983 FILE *f
= fopen(which
, "r");
3986 ssize_t sz
, answer
= 0;
3990 while ((sz
= getline(&line
, &len
, f
)) != -1)
3998 int proc_getattr(const char *path
, struct stat
*sb
)
4000 struct timespec now
;
4002 memset(sb
, 0, sizeof(struct stat
));
4003 if (clock_gettime(CLOCK_REALTIME
, &now
) < 0)
4005 sb
->st_uid
= sb
->st_gid
= 0;
4006 sb
->st_atim
= sb
->st_mtim
= sb
->st_ctim
= now
;
4007 if (strcmp(path
, "/proc") == 0) {
4008 sb
->st_mode
= S_IFDIR
| 00555;
4012 if (strcmp(path
, "/proc/meminfo") == 0 ||
4013 strcmp(path
, "/proc/cpuinfo") == 0 ||
4014 strcmp(path
, "/proc/uptime") == 0 ||
4015 strcmp(path
, "/proc/stat") == 0 ||
4016 strcmp(path
, "/proc/diskstats") == 0 ||
4017 strcmp(path
, "/proc/swaps") == 0) {
4019 sb
->st_mode
= S_IFREG
| 00444;
4027 int proc_readdir(const char *path
, void *buf
, fuse_fill_dir_t filler
, off_t offset
,
4028 struct fuse_file_info
*fi
)
4030 if (filler(buf
, ".", NULL
, 0) != 0 ||
4031 filler(buf
, "..", NULL
, 0) != 0 ||
4032 filler(buf
, "cpuinfo", NULL
, 0) != 0 ||
4033 filler(buf
, "meminfo", NULL
, 0) != 0 ||
4034 filler(buf
, "stat", NULL
, 0) != 0 ||
4035 filler(buf
, "uptime", NULL
, 0) != 0 ||
4036 filler(buf
, "diskstats", NULL
, 0) != 0 ||
4037 filler(buf
, "swaps", NULL
, 0) != 0)
4042 int proc_open(const char *path
, struct fuse_file_info
*fi
)
4045 struct file_info
*info
;
4047 if (strcmp(path
, "/proc/meminfo") == 0)
4048 type
= LXC_TYPE_PROC_MEMINFO
;
4049 else if (strcmp(path
, "/proc/cpuinfo") == 0)
4050 type
= LXC_TYPE_PROC_CPUINFO
;
4051 else if (strcmp(path
, "/proc/uptime") == 0)
4052 type
= LXC_TYPE_PROC_UPTIME
;
4053 else if (strcmp(path
, "/proc/stat") == 0)
4054 type
= LXC_TYPE_PROC_STAT
;
4055 else if (strcmp(path
, "/proc/diskstats") == 0)
4056 type
= LXC_TYPE_PROC_DISKSTATS
;
4057 else if (strcmp(path
, "/proc/swaps") == 0)
4058 type
= LXC_TYPE_PROC_SWAPS
;
4062 info
= malloc(sizeof(*info
));
4066 memset(info
, 0, sizeof(*info
));
4069 info
->buflen
= get_procfile_size(path
) + BUF_RESERVE_SIZE
;
4071 info
->buf
= malloc(info
->buflen
);
4072 } while (!info
->buf
);
4073 memset(info
->buf
, 0, info
->buflen
);
4074 /* set actual size to buffer size */
4075 info
->size
= info
->buflen
;
4077 fi
->fh
= (unsigned long)info
;
4081 int proc_access(const char *path
, int mask
)
4083 if (strcmp(path
, "/proc") == 0 && access(path
, R_OK
) == 0)
4086 /* these are all read-only */
4087 if ((mask
& ~R_OK
) != 0)
4092 int proc_release(const char *path
, struct fuse_file_info
*fi
)
4094 do_release_file_info(fi
);
4098 int proc_read(const char *path
, char *buf
, size_t size
, off_t offset
,
4099 struct fuse_file_info
*fi
)
4101 struct file_info
*f
= (struct file_info
*) fi
->fh
;
4104 case LXC_TYPE_PROC_MEMINFO
:
4105 return proc_meminfo_read(buf
, size
, offset
, fi
);
4106 case LXC_TYPE_PROC_CPUINFO
:
4107 return proc_cpuinfo_read(buf
, size
, offset
, fi
);
4108 case LXC_TYPE_PROC_UPTIME
:
4109 return proc_uptime_read(buf
, size
, offset
, fi
);
4110 case LXC_TYPE_PROC_STAT
:
4111 return proc_stat_read(buf
, size
, offset
, fi
);
4112 case LXC_TYPE_PROC_DISKSTATS
:
4113 return proc_diskstats_read(buf
, size
, offset
, fi
);
4114 case LXC_TYPE_PROC_SWAPS
:
4115 return proc_swaps_read(buf
, size
, offset
, fi
);
4122 * Functions needed to setup cgroups in the __constructor__.
4125 static bool mkdir_p(const char *dir
, mode_t mode
)
4127 const char *tmp
= dir
;
4128 const char *orig
= dir
;
4132 dir
= tmp
+ strspn(tmp
, "/");
4133 tmp
= dir
+ strcspn(dir
, "/");
4134 makeme
= strndup(orig
, dir
- orig
);
4137 if (mkdir(makeme
, mode
) && errno
!= EEXIST
) {
4138 fprintf(stderr
, "failed to create directory '%s': %s",
4139 makeme
, strerror(errno
));
4144 } while(tmp
!= dir
);
4149 static bool umount_if_mounted(void)
4151 if (umount2(BASEDIR
, MNT_DETACH
) < 0 && errno
!= EINVAL
) {
4152 fprintf(stderr
, "failed to unmount %s: %s.\n", BASEDIR
, strerror(errno
));
4158 static int pivot_enter(void)
4160 int ret
= -1, oldroot
= -1, newroot
= -1;
4162 oldroot
= open("/", O_DIRECTORY
| O_RDONLY
);
4164 fprintf(stderr
, "%s: Failed to open old root for fchdir.\n", __func__
);
4168 newroot
= open(ROOTDIR
, O_DIRECTORY
| O_RDONLY
);
4170 fprintf(stderr
, "%s: Failed to open new root for fchdir.\n", __func__
);
4174 /* change into new root fs */
4175 if (fchdir(newroot
) < 0) {
4176 fprintf(stderr
, "%s: Failed to change directory to new rootfs: %s.\n", __func__
, ROOTDIR
);
4180 /* pivot_root into our new root fs */
4181 if (pivot_root(".", ".") < 0) {
4182 fprintf(stderr
, "%s: pivot_root() syscall failed: %s.\n", __func__
, strerror(errno
));
4187 * At this point the old-root is mounted on top of our new-root.
4188 * To unmounted it we must not be chdir'd into it, so escape back
4191 if (fchdir(oldroot
) < 0) {
4192 fprintf(stderr
, "%s: Failed to enter old root.\n", __func__
);
4195 if (umount2(".", MNT_DETACH
) < 0) {
4196 fprintf(stderr
, "%s: Failed to detach old root.\n", __func__
);
4200 if (fchdir(newroot
) < 0) {
4201 fprintf(stderr
, "%s: Failed to re-enter new root.\n", __func__
);
4215 /* Prepare our new clean root. */
4216 static int pivot_prepare(void)
4218 if (mkdir(ROOTDIR
, 0700) < 0 && errno
!= EEXIST
) {
4219 fprintf(stderr
, "%s: Failed to create directory for new root.\n", __func__
);
4223 if (mount("/", ROOTDIR
, NULL
, MS_BIND
, 0) < 0) {
4224 fprintf(stderr
, "%s: Failed to bind-mount / for new root: %s.\n", __func__
, strerror(errno
));
4228 if (mount(RUNTIME_PATH
, ROOTDIR RUNTIME_PATH
, NULL
, MS_BIND
, 0) < 0) {
4229 fprintf(stderr
, "%s: Failed to bind-mount /run into new root: %s.\n", __func__
, strerror(errno
));
4233 if (mount(BASEDIR
, ROOTDIR BASEDIR
, NULL
, MS_REC
| MS_MOVE
, 0) < 0) {
4234 printf("%s: failed to move " BASEDIR
" into new root: %s.\n", __func__
, strerror(errno
));
4241 static bool pivot_new_root(void)
4243 /* Prepare new root. */
4244 if (pivot_prepare() < 0)
4247 /* Pivot into new root. */
4248 if (pivot_enter() < 0)
4254 static bool setup_cgfs_dir(void)
4256 if (!mkdir_p(BASEDIR
, 0700)) {
4257 fprintf(stderr
, "Failed to create lxcfs cgroup mountpoint.\n");
4261 if (!umount_if_mounted()) {
4262 fprintf(stderr
, "Failed to clean up old lxcfs cgroup mountpoint.\n");
4266 if (unshare(CLONE_NEWNS
) < 0) {
4267 fprintf(stderr
, "%s: Failed to unshare mount namespace: %s.\n", __func__
, strerror(errno
));
4271 if (mount(NULL
, "/", NULL
, MS_REC
| MS_PRIVATE
, 0) < 0) {
4272 fprintf(stderr
, "%s: Failed to remount / private: %s.\n", __func__
, strerror(errno
));
4276 if (mount("tmpfs", BASEDIR
, "tmpfs", 0, "size=100000,mode=700") < 0) {
4277 fprintf(stderr
, "Failed to mount tmpfs over lxcfs cgroup mountpoint.\n");
4284 static bool do_mount_cgroups(void)
4290 for (i
= 0; i
< num_hierarchies
; i
++) {
4291 char *controller
= hierarchies
[i
];
4292 clen
= strlen(controller
);
4293 len
= strlen(BASEDIR
) + clen
+ 2;
4294 target
= malloc(len
);
4297 ret
= snprintf(target
, len
, "%s/%s", BASEDIR
, controller
);
4298 if (ret
< 0 || ret
>= len
) {
4302 if (mkdir(target
, 0755) < 0 && errno
!= EEXIST
) {
4306 if (mount(controller
, target
, "cgroup", 0, controller
) < 0) {
4307 fprintf(stderr
, "Failed mounting cgroup %s\n", controller
);
4312 fd_hierarchies
[i
] = open(target
, O_DIRECTORY
);
4313 if (fd_hierarchies
[i
] < 0) {
4322 static bool cgfs_setup_controllers(void)
4324 if (!setup_cgfs_dir())
4327 if (!do_mount_cgroups()) {
4328 fprintf(stderr
, "Failed to set up private lxcfs cgroup mounts.\n");
4332 if (!pivot_new_root())
4338 static int preserve_ns(int pid
)
4341 size_t len
= 5 /* /proc */ + 21 /* /int_as_str */ + 7 /* /ns/mnt */ + 1 /* \0 */;
4344 ret
= snprintf(path
, len
, "/proc/%d/ns/mnt", pid
);
4345 if (ret
< 0 || (size_t)ret
>= len
)
4348 return open(path
, O_RDONLY
| O_CLOEXEC
);
4351 static void __attribute__((constructor
)) collect_and_mount_subsystems(void)
4356 int i
, init_ns
= -1;
4358 if ((f
= fopen("/proc/self/cgroup", "r")) == NULL
) {
4359 fprintf(stderr
, "Error opening /proc/self/cgroup: %s\n", strerror(errno
));
4362 while (getline(&line
, &len
, f
) != -1) {
4365 p
= strchr(line
, ':');
4370 p2
= strrchr(p
, ':');
4375 /* With cgroupv2 /proc/self/cgroup can contain entries of the
4376 * form: 0::/ This will cause lxcfs to fail the cgroup mounts
4377 * because it parses out the empty string "" and later on passes
4378 * it to mount(). Let's skip such entries.
4383 if (!store_hierarchy(line
, p
))
4387 /* Preserve initial namespace. */
4388 init_ns
= preserve_ns(getpid());
4392 fd_hierarchies
= malloc(sizeof(int *) * num_hierarchies
);
4393 if (!fd_hierarchies
)
4396 for (i
= 0; i
< num_hierarchies
; i
++)
4397 fd_hierarchies
[i
] = -1;
4399 /* This function calls unshare(CLONE_NEWNS) our initial mount namespace
4400 * to privately mount lxcfs cgroups. */
4401 if (!cgfs_setup_controllers())
4404 if (setns(init_ns
, 0) < 0)
4416 static void __attribute__((destructor
)) free_subsystems(void)
4420 for (i
= 0; i
< num_hierarchies
; i
++) {
4422 free(hierarchies
[i
]);
4423 if (fd_hierarchies
&& fd_hierarchies
[i
] >= 0)
4424 close(fd_hierarchies
[i
]);
4427 free(fd_hierarchies
);