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0ad19a3f | 1 | /* |
2 | * lxc: linux Container library | |
3 | * | |
4 | * (C) Copyright IBM Corp. 2007, 2008 | |
5 | * | |
6 | * Authors: | |
9afe19d6 | 7 | * Daniel Lezcano <daniel.lezcano at free.fr> |
0ad19a3f | 8 | * |
9 | * This library is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU Lesser General Public | |
11 | * License as published by the Free Software Foundation; either | |
12 | * version 2.1 of the License, or (at your option) any later version. | |
13 | * | |
14 | * This library is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * Lesser General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU Lesser General Public | |
20 | * License along with this library; if not, write to the Free Software | |
250b1eec | 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
0ad19a3f | 22 | */ |
f1a4a029 ÇO |
23 | #ifndef __LXC_UTILS_H |
24 | #define __LXC_UTILS_H | |
0ad19a3f | 25 | |
c6868a1f CB |
26 | /* Properly support loop devices on 32bit systems. */ |
27 | #define _FILE_OFFSET_BITS 64 | |
28 | ||
a1e5280d CB |
29 | #include "config.h" |
30 | ||
6a44839f | 31 | #include <errno.h> |
61a1d519 | 32 | #include <stdarg.h> |
d0386d66 | 33 | #include <stdio.h> |
502657d5 | 34 | #include <stdbool.h> |
c6868a1f CB |
35 | #include <unistd.h> |
36 | #include <linux/loop.h> | |
29a11a7f | 37 | #include <linux/magic.h> |
ec346ea1 | 38 | #include <sys/syscall.h> |
c797a220 | 39 | #include <sys/types.h> |
a035c53a | 40 | #include <sys/vfs.h> |
f2363e38 | 41 | |
f749d524 CB |
42 | #ifdef HAVE_LINUX_MEMFD_H |
43 | #include <linux/memfd.h> | |
44 | #endif | |
45 | ||
4295c5de | 46 | #include "initutils.h" |
c797a220 | 47 | |
a394f952 CB |
48 | /* Define __S_ISTYPE if missing from the C library. */ |
49 | #ifndef __S_ISTYPE | |
50 | #define __S_ISTYPE(mode, mask) (((mode)&S_IFMT) == (mask)) | |
51 | #endif | |
52 | ||
478fb51d CB |
53 | #if HAVE_LIBCAP |
54 | #ifndef CAP_SETFCAP | |
55 | #define CAP_SETFCAP 31 | |
56 | #endif | |
57 | ||
58 | #ifndef CAP_MAC_OVERRIDE | |
59 | #define CAP_MAC_OVERRIDE 32 | |
60 | #endif | |
61 | ||
62 | #ifndef CAP_MAC_ADMIN | |
63 | #define CAP_MAC_ADMIN 33 | |
64 | #endif | |
65 | #endif | |
66 | ||
67 | #ifndef PR_CAPBSET_DROP | |
68 | #define PR_CAPBSET_DROP 24 | |
69 | #endif | |
70 | ||
71 | #ifndef LO_FLAGS_AUTOCLEAR | |
72 | #define LO_FLAGS_AUTOCLEAR 4 | |
73 | #endif | |
74 | ||
75 | #ifndef CAP_SETUID | |
76 | #define CAP_SETUID 7 | |
77 | #endif | |
78 | ||
79 | #ifndef CAP_SETGID | |
80 | #define CAP_SETGID 6 | |
81 | #endif | |
82 | ||
83 | /* needed for cgroup automount checks, regardless of whether we | |
84 | * have included linux/capability.h or not */ | |
85 | #ifndef CAP_SYS_ADMIN | |
86 | #define CAP_SYS_ADMIN 21 | |
87 | #endif | |
88 | ||
b07511df CB |
89 | /* Useful macros */ |
90 | /* Maximum number for 64 bit integer is a string with 21 digits: 2^64 - 1 = 21 */ | |
eab15c1e CB |
91 | #define LXC_NUMSTRLEN64 21 |
92 | #define LXC_LINELEN 4096 | |
4bc3b759 | 93 | #define LXC_IDMAPLEN 4096 |
b07511df | 94 | |
60bf62d4 | 95 | /* returns 1 on success, 0 if there were any failures */ |
18aa217b | 96 | extern int lxc_rmdir_onedev(char *path, const char *exclude); |
7c11d57a | 97 | extern int get_u16(unsigned short *val, const char *arg, int base); |
1b09f2c0 | 98 | extern int mkdir_p(const char *dir, mode_t mode); |
fd8c2777 | 99 | extern char *get_rundir(void); |
9e60f51d | 100 | |
6a44839f DE |
101 | /* Define getline() if missing from the C library */ |
102 | #ifndef HAVE_GETLINE | |
103 | #ifdef HAVE_FGETLN | |
104 | #include <../include/getline.h> | |
105 | #endif | |
106 | #endif | |
107 | ||
108 | /* Define setns() if missing from the C library */ | |
109 | #ifndef HAVE_SETNS | |
110 | static inline int setns(int fd, int nstype) | |
111 | { | |
112 | #ifdef __NR_setns | |
113 | return syscall(__NR_setns, fd, nstype); | |
a1258e6d | 114 | #elif defined(__NR_set_ns) |
92e23841 | 115 | return syscall(__NR_set_ns, fd, nstype); |
6a44839f DE |
116 | #else |
117 | errno = ENOSYS; | |
118 | return -1; | |
119 | #endif | |
120 | } | |
121 | #endif | |
122 | ||
123 | /* Define unshare() if missing from the C library */ | |
124 | #ifndef HAVE_UNSHARE | |
125 | static inline int unshare(int flags) | |
126 | { | |
127 | #ifdef __NR_unshare | |
128 | return syscall(__NR_unshare, flags); | |
129 | #else | |
130 | errno = ENOSYS; | |
131 | return -1; | |
132 | #endif | |
133 | } | |
134 | #else | |
1a0e70ac | 135 | extern int unshare(int); |
6a44839f DE |
136 | #endif |
137 | ||
b5159817 DE |
138 | /* Define signalfd() if missing from the C library */ |
139 | #ifdef HAVE_SYS_SIGNALFD_H | |
140 | # include <sys/signalfd.h> | |
141 | #else | |
142 | /* assume kernel headers are too old */ | |
143 | #include <stdint.h> | |
144 | struct signalfd_siginfo | |
145 | { | |
146 | uint32_t ssi_signo; | |
147 | int32_t ssi_errno; | |
148 | int32_t ssi_code; | |
149 | uint32_t ssi_pid; | |
150 | uint32_t ssi_uid; | |
151 | int32_t ssi_fd; | |
152 | uint32_t ssi_tid; | |
153 | uint32_t ssi_band; | |
154 | uint32_t ssi_overrun; | |
155 | uint32_t ssi_trapno; | |
156 | int32_t ssi_status; | |
157 | int32_t ssi_int; | |
158 | uint64_t ssi_ptr; | |
159 | uint64_t ssi_utime; | |
160 | uint64_t ssi_stime; | |
161 | uint64_t ssi_addr; | |
162 | uint8_t __pad[48]; | |
163 | }; | |
164 | ||
165 | # ifndef __NR_signalfd4 | |
166 | /* assume kernel headers are too old */ | |
167 | # if __i386__ | |
168 | # define __NR_signalfd4 327 | |
169 | # elif __x86_64__ | |
170 | # define __NR_signalfd4 289 | |
171 | # elif __powerpc__ | |
172 | # define __NR_signalfd4 313 | |
173 | # elif __s390x__ | |
174 | # define __NR_signalfd4 322 | |
180edd67 SG |
175 | # elif __arm__ |
176 | # define __NR_signalfd4 355 | |
f53b5916 JC |
177 | # elif __mips__ && _MIPS_SIM == _ABIO32 |
178 | # define __NR_signalfd4 4324 | |
179 | # elif __mips__ && _MIPS_SIM == _ABI64 | |
180 | # define __NR_signalfd4 5283 | |
181 | # elif __mips__ && _MIPS_SIM == _ABIN32 | |
182 | # define __NR_signalfd4 6287 | |
b5159817 DE |
183 | # endif |
184 | #endif | |
185 | ||
186 | # ifndef __NR_signalfd | |
187 | /* assume kernel headers are too old */ | |
188 | # if __i386__ | |
189 | # define __NR_signalfd 321 | |
190 | # elif __x86_64__ | |
191 | # define __NR_signalfd 282 | |
192 | # elif __powerpc__ | |
193 | # define __NR_signalfd 305 | |
194 | # elif __s390x__ | |
195 | # define __NR_signalfd 316 | |
180edd67 SG |
196 | # elif __arm__ |
197 | # define __NR_signalfd 349 | |
f53b5916 JC |
198 | # elif __mips__ && _MIPS_SIM == _ABIO32 |
199 | # define __NR_signalfd 4317 | |
200 | # elif __mips__ && _MIPS_SIM == _ABI64 | |
201 | # define __NR_signalfd 5276 | |
202 | # elif __mips__ && _MIPS_SIM == _ABIN32 | |
203 | # define __NR_signalfd 6280 | |
b5159817 DE |
204 | # endif |
205 | #endif | |
206 | ||
207 | static inline int signalfd(int fd, const sigset_t *mask, int flags) | |
208 | { | |
209 | int retval; | |
210 | ||
211 | retval = syscall (__NR_signalfd4, fd, mask, _NSIG / 8, flags); | |
212 | if (errno == ENOSYS && flags == 0) | |
213 | retval = syscall (__NR_signalfd, fd, mask, _NSIG / 8); | |
214 | return retval; | |
215 | } | |
216 | #endif | |
217 | ||
c6868a1f CB |
218 | /* loop devices */ |
219 | #ifndef LO_FLAGS_AUTOCLEAR | |
220 | #define LO_FLAGS_AUTOCLEAR 4 | |
221 | #endif | |
222 | ||
223 | #ifndef LOOP_CTL_GET_FREE | |
224 | #define LOOP_CTL_GET_FREE 0x4C82 | |
225 | #endif | |
226 | ||
f749d524 CB |
227 | /* memfd_create() */ |
228 | #ifndef MFD_CLOEXEC | |
229 | #define MFD_CLOEXEC 0x0001U | |
230 | #endif | |
231 | ||
232 | #ifndef MFD_ALLOW_SEALING | |
233 | #define MFD_ALLOW_SEALING 0x0002U | |
234 | #endif | |
235 | ||
236 | #ifndef HAVE_MEMFD_CREATE | |
237 | static inline int memfd_create(const char *name, unsigned int flags) { | |
238 | #ifndef __NR_memfd_create | |
239 | #if defined __i386__ | |
240 | #define __NR_memfd_create 356 | |
241 | #elif defined __x86_64__ | |
242 | #define __NR_memfd_create 319 | |
243 | #elif defined __arm__ | |
244 | #define __NR_memfd_create 385 | |
245 | #elif defined __aarch64__ | |
246 | #define __NR_memfd_create 279 | |
247 | #elif defined __s390__ | |
248 | #define __NR_memfd_create 350 | |
249 | #elif defined __powerpc__ | |
250 | #define __NR_memfd_create 360 | |
251 | #elif defined __sparc__ | |
252 | #define __NR_memfd_create 348 | |
253 | #elif defined __blackfin__ | |
254 | #define __NR_memfd_create 390 | |
255 | #elif defined __ia64__ | |
256 | #define __NR_memfd_create 1340 | |
257 | #elif defined _MIPS_SIM | |
258 | #if _MIPS_SIM == _MIPS_SIM_ABI32 | |
259 | #define __NR_memfd_create 4354 | |
260 | #endif | |
261 | #if _MIPS_SIM == _MIPS_SIM_NABI32 | |
262 | #define __NR_memfd_create 6318 | |
263 | #endif | |
264 | #if _MIPS_SIM == _MIPS_SIM_ABI64 | |
265 | #define __NR_memfd_create 5314 | |
266 | #endif | |
267 | #endif | |
268 | #endif | |
269 | #ifdef __NR_memfd_create | |
270 | return syscall(__NR_memfd_create, name, flags); | |
271 | #else | |
272 | errno = ENOSYS; | |
273 | return -1; | |
274 | #endif | |
275 | } | |
276 | #else | |
277 | extern int memfd_create(const char *name, unsigned int flags); | |
278 | #endif | |
279 | ||
b499121f CB |
280 | static inline int lxc_set_cloexec(int fd) |
281 | { | |
282 | return fcntl(fd, F_SETFD, FD_CLOEXEC); | |
283 | } | |
284 | ||
ebec9176 AM |
285 | /* Struct to carry child pid from lxc_popen() to lxc_pclose(). |
286 | * Not an opaque struct to allow direct access to the underlying FILE * | |
287 | * (i.e., struct lxc_popen_FILE *file; fgets(buf, sizeof(buf), file->f)) | |
288 | * without additional wrappers. | |
289 | */ | |
290 | struct lxc_popen_FILE { | |
8bd8018e | 291 | int pipe; |
ebec9176 AM |
292 | FILE *f; |
293 | pid_t child_pid; | |
294 | }; | |
295 | ||
296 | /* popen(command, "re") replacement that restores default signal mask | |
297 | * via sigprocmask(2) (unblocks all signals) after fork(2) but prior to calling exec(3). | |
298 | * In short, popen(command, "re") does pipe() + fork() + exec() | |
299 | * while lxc_popen(command) does pipe() + fork() + sigprocmask() + exec(). | |
ebec9176 AM |
300 | * Returns pointer to struct lxc_popen_FILE, that should be freed with lxc_pclose(). |
301 | * On error returns NULL. | |
302 | */ | |
303 | extern struct lxc_popen_FILE *lxc_popen(const char *command); | |
304 | ||
305 | /* pclose() replacement to be used on struct lxc_popen_FILE *, | |
306 | * returned by lxc_popen(). | |
307 | * Waits for associated process to terminate, returns its exit status and | |
308 | * frees resources, pointed to by struct lxc_popen_FILE *. | |
ebec9176 AM |
309 | */ |
310 | extern int lxc_pclose(struct lxc_popen_FILE *fp); | |
311 | ||
e51d4895 DE |
312 | /** |
313 | * BUILD_BUG_ON - break compile if a condition is true. | |
314 | * @condition: the condition which the compiler should know is false. | |
315 | * | |
316 | * If you have some code which relies on certain constants being equal, or | |
317 | * other compile-time-evaluated condition, you should use BUILD_BUG_ON to | |
318 | * detect if someone changes it. | |
319 | * | |
320 | * The implementation uses gcc's reluctance to create a negative array, but | |
321 | * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments | |
322 | * to inline functions). So as a fallback we use the optimizer; if it can't | |
323 | * prove the condition is false, it will cause a link error on the undefined | |
324 | * "__build_bug_on_failed". This error message can be harder to track down | |
325 | * though, hence the two different methods. | |
326 | */ | |
327 | #ifndef __OPTIMIZE__ | |
328 | #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) | |
329 | #else | |
330 | extern int __build_bug_on_failed; | |
331 | #define BUILD_BUG_ON(condition) \ | |
332 | do { \ | |
333 | ((void)sizeof(char[1 - 2*!!(condition)])); \ | |
334 | if (condition) __build_bug_on_failed = 1; \ | |
335 | } while(0) | |
336 | #endif | |
337 | ||
9be53773 SH |
338 | /* |
339 | * wait on a child we forked | |
340 | */ | |
341 | extern int wait_for_pid(pid_t pid); | |
c797a220 | 342 | extern int lxc_wait_for_pid_status(pid_t pid); |
9be53773 | 343 | |
92f023dc | 344 | /* send and receive buffers completely */ |
650468bb CS |
345 | extern ssize_t lxc_write_nointr(int fd, const void* buf, size_t count); |
346 | extern ssize_t lxc_read_nointr(int fd, void* buf, size_t count); | |
1a0e70ac CB |
347 | extern ssize_t lxc_read_nointr_expect(int fd, void *buf, size_t count, |
348 | const void *expected_buf); | |
3ce74686 SH |
349 | #if HAVE_LIBGNUTLS |
350 | #define SHA_DIGEST_LENGTH 20 | |
351 | extern int sha1sum_file(char *fnam, unsigned char *md_value); | |
352 | #endif | |
92f023dc | 353 | |
0e95426b | 354 | /* read and write whole files */ |
1a0e70ac CB |
355 | extern int lxc_write_to_file(const char *filename, const void *buf, |
356 | size_t count, bool add_newline); | |
0e95426b | 357 | extern int lxc_read_from_file(const char *filename, void* buf, size_t count); |
0e95426b | 358 | |
61a1d519 CS |
359 | /* convert variadic argument lists to arrays (for execl type argument lists) */ |
360 | extern char** lxc_va_arg_list_to_argv(va_list ap, size_t skip, int do_strdup); | |
361 | extern const char** lxc_va_arg_list_to_argv_const(va_list ap, size_t skip); | |
362 | ||
1a0e70ac CB |
363 | /* Some simple string functions; if they return pointers, they are allocated |
364 | * buffers. | |
365 | */ | |
366 | extern char *lxc_string_replace(const char *needle, const char *replacement, | |
367 | const char *haystack); | |
502657d5 | 368 | extern bool lxc_string_in_array(const char *needle, const char **haystack); |
1a0e70ac CB |
369 | extern char *lxc_string_join(const char *sep, const char **parts, |
370 | bool use_as_prefix); | |
502657d5 CS |
371 | /* Normalize and split path: Leading and trailing / are removed, multiple |
372 | * / are compactified, .. and . are resolved (.. on the top level is considered | |
373 | * identical to .). | |
374 | * Examples: | |
375 | * / -> { NULL } | |
376 | * foo/../bar -> { bar, NULL } | |
377 | * ../../ -> { NULL } | |
378 | * ./bar/baz/.. -> { bar, NULL } | |
379 | * foo//bar -> { foo, bar, NULL } | |
380 | */ | |
381 | extern char **lxc_normalize_path(const char *path); | |
aeb3682f | 382 | /* remove multiple slashes from the path, e.g. ///foo//bar -> /foo/bar */ |
eda0afd4 | 383 | extern char *lxc_deslashify(const char *path); |
24b51482 | 384 | extern char *lxc_append_paths(const char *first, const char *second); |
502657d5 CS |
385 | /* Note: the following two functions use strtok(), so they will never |
386 | * consider an empty element, even if two delimiters are next to | |
387 | * each other. | |
388 | */ | |
1a0e70ac CB |
389 | extern bool lxc_string_in_list(const char *needle, const char *haystack, |
390 | char sep); | |
502657d5 CS |
391 | extern char **lxc_string_split(const char *string, char sep); |
392 | extern char **lxc_string_split_and_trim(const char *string, char sep); | |
3dca1af0 | 393 | extern char **lxc_string_split_quoted(char *string); |
000dfda7 CB |
394 | /* Append string to NULL-terminated string array. */ |
395 | extern int lxc_append_string(char ***list, char *entry); | |
502657d5 CS |
396 | |
397 | /* some simple array manipulation utilities */ | |
398 | typedef void (*lxc_free_fn)(void *); | |
399 | typedef void *(*lxc_dup_fn)(void *); | |
1a0e70ac CB |
400 | extern int lxc_grow_array(void ***array, size_t *capacity, size_t new_size, |
401 | size_t capacity_increment); | |
502657d5 CS |
402 | extern void lxc_free_array(void **array, lxc_free_fn element_free_fn); |
403 | extern size_t lxc_array_len(void **array); | |
502657d5 | 404 | |
799f29ab | 405 | extern void **lxc_append_null_to_array(void **array, size_t count); |
1adbd020 | 406 | |
a1e5280d | 407 | /* mmap() wrapper. lxc_strmmap() will take care to \0-terminate files so that |
1adbd020 | 408 | * normal string-handling functions can be used on the buffer. */ |
25086a5f CB |
409 | extern void *lxc_strmmap(void *addr, size_t length, int prot, int flags, int fd, |
410 | off_t offset); | |
a1e5280d | 411 | /* munmap() wrapper. Use it to free memory mmap()ed with lxc_strmmap(). */ |
25086a5f | 412 | extern int lxc_strmunmap(void *addr, size_t length); |
1adbd020 | 413 | |
1a0e70ac | 414 | /* initialize rand with urandom */ |
508c263e | 415 | extern int randseed(bool); |
052616eb | 416 | |
1354955b SH |
417 | inline static bool am_unpriv(void) { |
418 | return geteuid() != 0; | |
419 | } | |
5d897655 SH |
420 | |
421 | /* | |
422 | * parse /proc/self/uid_map to find what @orig maps to | |
423 | */ | |
424 | extern uid_t get_ns_uid(uid_t orig); | |
c476bdce SH |
425 | |
426 | extern bool dir_exists(const char *path); | |
93c379f0 ÇO |
427 | |
428 | #define FNV1A_64_INIT ((uint64_t)0xcbf29ce484222325ULL) | |
1a0e70ac CB |
429 | extern uint64_t fnv_64a_buf(void *buf, size_t len, uint64_t hval); |
430 | ||
431 | extern int detect_shared_rootfs(void); | |
432 | extern bool detect_ramfs_rootfs(void); | |
433 | extern char *on_path(const char *cmd, const char *rootfs); | |
434 | extern bool file_exists(const char *f); | |
435 | extern bool cgns_supported(void); | |
436 | extern char *choose_init(const char *rootfs); | |
437 | extern int print_to_file(const char *file, const char *content); | |
438 | extern bool switch_to_ns(pid_t pid, const char *ns); | |
439 | extern int is_dir(const char *path); | |
440 | extern char *get_template_path(const char *t); | |
1a0e70ac CB |
441 | extern int safe_mount(const char *src, const char *dest, const char *fstype, |
442 | unsigned long flags, const void *data, | |
443 | const char *rootfs); | |
444 | extern int lxc_mount_proc_if_needed(const char *rootfs); | |
445 | extern int open_devnull(void); | |
446 | extern int set_stdfds(int fd); | |
447 | extern int null_stdfds(void); | |
448 | extern int lxc_count_file_lines(const char *fn); | |
449 | extern int lxc_preserve_ns(const int pid, const char *ns); | |
330ae3d3 CB |
450 | |
451 | /* Check whether a signal is blocked by a process. */ | |
1a0e70ac | 452 | extern bool task_blocking_signal(pid_t pid, int signal); |
6bc2eafe CB |
453 | |
454 | /* Helper functions to parse numbers. */ | |
1a0e70ac CB |
455 | extern int lxc_safe_uint(const char *numstr, unsigned int *converted); |
456 | extern int lxc_safe_int(const char *numstr, int *converted); | |
457 | extern int lxc_safe_long(const char *numstr, long int *converted); | |
b037bc67 | 458 | extern int lxc_safe_long_long(const char *numstr, long long int *converted); |
1a0e70ac | 459 | extern int lxc_safe_ulong(const char *numstr, unsigned long *converted); |
e3db0162 CB |
460 | /* Handles B, kb, MB, GB. Detects overflows and reports -ERANGE. */ |
461 | extern int parse_byte_size_string(const char *s, int64_t *converted); | |
6bc2eafe | 462 | |
dbaf55a3 | 463 | /* Switch to a new uid and gid. */ |
1a0e70ac CB |
464 | extern int lxc_switch_uid_gid(uid_t uid, gid_t gid); |
465 | extern int lxc_setgroups(int size, gid_t list[]); | |
dbaf55a3 | 466 | |
c6868a1f | 467 | /* Find an unused loop device and associate it with source. */ |
1a0e70ac | 468 | extern int lxc_prepare_loop_dev(const char *source, char *loop_dev, int flags); |
c6868a1f | 469 | |
74251e49 CB |
470 | /* Clear all mounts on a given node. |
471 | * >= 0 successfully cleared. The number returned is the number of umounts | |
472 | * performed. | |
473 | * < 0 error umounting. Return -errno. | |
474 | */ | |
1a0e70ac | 475 | extern int lxc_unstack_mountpoint(const char *path, bool lazy); |
74251e49 | 476 | |
ea3a694f CB |
477 | /* |
478 | * run_command runs a command and collect it's std{err,out} output in buf. | |
479 | * | |
480 | * @param[out] buf The buffer where the commands std{err,out] output will be | |
481 | * read into. If no output was produced, buf will be memset | |
482 | * to 0. | |
483 | * @param[in] buf_size The size of buf. This function will reserve one byte for | |
484 | * \0-termination. | |
485 | * @param[in] child_fn The function to be run in the child process. This | |
486 | * function must exec. | |
487 | * @param[in] args Arguments to be passed to child_fn. | |
488 | */ | |
1a0e70ac CB |
489 | extern int run_command(char *buf, size_t buf_size, int (*child_fn)(void *), |
490 | void *args); | |
ea3a694f | 491 | |
04ad7ffe CB |
492 | /* Concatenate all passed-in strings into one path. Do not fail. If any piece |
493 | * is not prefixed with '/', add a '/'. | |
494 | */ | |
1a0e70ac | 495 | extern char *must_make_path(const char *first, ...) __attribute__((sentinel)); |
04ad7ffe CB |
496 | |
497 | /* return copy of string @entry; do not fail. */ | |
1a0e70ac | 498 | extern char *must_copy_string(const char *entry); |
04ad7ffe CB |
499 | |
500 | /* Re-alllocate a pointer, do not fail */ | |
1a0e70ac | 501 | extern void *must_realloc(void *orig, size_t sz); |
04ad7ffe | 502 | |
a035c53a CB |
503 | /* __typeof__ should be safe to use with all compilers. */ |
504 | typedef __typeof__(((struct statfs *)NULL)->f_type) fs_type_magic; | |
1a0e70ac CB |
505 | extern bool has_fs_type(const char *path, fs_type_magic magic_val); |
506 | extern bool is_fs_type(const struct statfs *fs, fs_type_magic magic_val); | |
d75c14e2 | 507 | extern bool lxc_nic_exists(char *nic); |
127c6e70 | 508 | extern int lxc_make_tmpfile(char *template, bool rm); |
e4636123 | 509 | extern uint64_t lxc_getpagesize(void); |
a035c53a | 510 | |
6222c3f4 CB |
511 | /* If n is not a power of 2 this function will return the next power of 2 |
512 | * greater than that number. Note that this function always returns the *next* | |
513 | * power of 2 *greater* that number not the *nearest*. For example, passing 1025 | |
514 | * as argument this function will return 2048 although the closest power of 2 | |
515 | * would be 1024. | |
516 | * If the caller passes in 0 they will receive 0 in return since this is invalid | |
517 | * input and 0 is not a power of 2. | |
518 | */ | |
519 | extern uint64_t lxc_find_next_power2(uint64_t n); | |
520 | ||
5b72de5f | 521 | #endif /* __LXC_UTILS_H */ |