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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 | ||
6a44839f | 29 | #include <errno.h> |
c6868a1f | 30 | #include <linux/loop.h> |
5038d11a | 31 | #include <linux/types.h> |
d38dd64a CB |
32 | #include <stdarg.h> |
33 | #include <stdbool.h> | |
34 | #include <stdio.h> | |
ec346ea1 | 35 | #include <sys/syscall.h> |
c797a220 | 36 | #include <sys/types.h> |
a035c53a | 37 | #include <sys/vfs.h> |
d38dd64a | 38 | #include <unistd.h> |
f749d524 | 39 | |
37ef15bb | 40 | #include "file_utils.h" |
4295c5de | 41 | #include "initutils.h" |
279c45ee | 42 | #include "macro.h" |
d7b58715 | 43 | #include "raw_syscalls.h" |
37ef15bb | 44 | #include "string_utils.h" |
b07511df | 45 | |
60bf62d4 | 46 | /* returns 1 on success, 0 if there were any failures */ |
41dc7155 | 47 | extern int lxc_rmdir_onedev(const char *path, const char *exclude); |
7c11d57a | 48 | extern int get_u16(unsigned short *val, const char *arg, int base); |
1b09f2c0 | 49 | extern int mkdir_p(const char *dir, mode_t mode); |
fd8c2777 | 50 | extern char *get_rundir(void); |
9e60f51d | 51 | |
6a44839f DE |
52 | /* Define getline() if missing from the C library */ |
53 | #ifndef HAVE_GETLINE | |
54 | #ifdef HAVE_FGETLN | |
55 | #include <../include/getline.h> | |
56 | #endif | |
57 | #endif | |
58 | ||
b499121f CB |
59 | static inline int lxc_set_cloexec(int fd) |
60 | { | |
61 | return fcntl(fd, F_SETFD, FD_CLOEXEC); | |
62 | } | |
63 | ||
ebec9176 AM |
64 | /* Struct to carry child pid from lxc_popen() to lxc_pclose(). |
65 | * Not an opaque struct to allow direct access to the underlying FILE * | |
66 | * (i.e., struct lxc_popen_FILE *file; fgets(buf, sizeof(buf), file->f)) | |
67 | * without additional wrappers. | |
68 | */ | |
69 | struct lxc_popen_FILE { | |
8bd8018e | 70 | int pipe; |
ebec9176 AM |
71 | FILE *f; |
72 | pid_t child_pid; | |
73 | }; | |
74 | ||
75 | /* popen(command, "re") replacement that restores default signal mask | |
76 | * via sigprocmask(2) (unblocks all signals) after fork(2) but prior to calling exec(3). | |
77 | * In short, popen(command, "re") does pipe() + fork() + exec() | |
78 | * while lxc_popen(command) does pipe() + fork() + sigprocmask() + exec(). | |
ebec9176 AM |
79 | * Returns pointer to struct lxc_popen_FILE, that should be freed with lxc_pclose(). |
80 | * On error returns NULL. | |
81 | */ | |
82 | extern struct lxc_popen_FILE *lxc_popen(const char *command); | |
83 | ||
84 | /* pclose() replacement to be used on struct lxc_popen_FILE *, | |
85 | * returned by lxc_popen(). | |
86 | * Waits for associated process to terminate, returns its exit status and | |
87 | * frees resources, pointed to by struct lxc_popen_FILE *. | |
ebec9176 AM |
88 | */ |
89 | extern int lxc_pclose(struct lxc_popen_FILE *fp); | |
90 | ||
9be53773 SH |
91 | /* |
92 | * wait on a child we forked | |
93 | */ | |
94 | extern int wait_for_pid(pid_t pid); | |
c797a220 | 95 | extern int lxc_wait_for_pid_status(pid_t pid); |
9be53773 | 96 | |
3ce74686 SH |
97 | #if HAVE_LIBGNUTLS |
98 | #define SHA_DIGEST_LENGTH 20 | |
99 | extern int sha1sum_file(char *fnam, unsigned char *md_value); | |
100 | #endif | |
92f023dc | 101 | |
1a0e70ac | 102 | /* initialize rand with urandom */ |
508c263e | 103 | extern int randseed(bool); |
052616eb | 104 | |
477aa378 SH |
105 | /* are we unprivileged with respect to our namespaces */ |
106 | inline static bool am_guest_unpriv(void) { | |
107 | return geteuid() != 0; | |
108 | } | |
109 | ||
110 | /* are we unprivileged with respect to init_user_ns */ | |
5384e99d | 111 | inline static bool am_host_unpriv(void) |
4692c01a TA |
112 | { |
113 | FILE *f; | |
114 | uid_t user, host, count; | |
115 | int ret; | |
116 | ||
117 | if (geteuid() != 0) | |
118 | return true; | |
119 | ||
120 | /* Now: are we in a user namespace? Because then we're also | |
121 | * unprivileged. | |
122 | */ | |
123 | f = fopen("/proc/self/uid_map", "r"); | |
124 | if (!f) { | |
125 | return false; | |
126 | } | |
127 | ||
128 | ret = fscanf(f, "%u %u %u", &user, &host, &count); | |
129 | fclose(f); | |
130 | if (ret != 3) { | |
131 | return false; | |
132 | } | |
133 | ||
134 | if (user != 0 || host != 0 || count != UINT32_MAX) | |
135 | return true; | |
136 | return false; | |
1354955b | 137 | } |
5d897655 SH |
138 | |
139 | /* | |
140 | * parse /proc/self/uid_map to find what @orig maps to | |
141 | */ | |
142 | extern uid_t get_ns_uid(uid_t orig); | |
b962868f CB |
143 | /* |
144 | * parse /proc/self/gid_map to find what @orig maps to | |
145 | */ | |
146 | extern gid_t get_ns_gid(gid_t orig); | |
c476bdce SH |
147 | |
148 | extern bool dir_exists(const char *path); | |
93c379f0 ÇO |
149 | |
150 | #define FNV1A_64_INIT ((uint64_t)0xcbf29ce484222325ULL) | |
1a0e70ac CB |
151 | extern uint64_t fnv_64a_buf(void *buf, size_t len, uint64_t hval); |
152 | ||
f6310f18 | 153 | extern bool is_shared_mountpoint(const char *path); |
1a0e70ac CB |
154 | extern int detect_shared_rootfs(void); |
155 | extern bool detect_ramfs_rootfs(void); | |
156 | extern char *on_path(const char *cmd, const char *rootfs); | |
1a0e70ac CB |
157 | extern bool cgns_supported(void); |
158 | extern char *choose_init(const char *rootfs); | |
1a0e70ac | 159 | extern bool switch_to_ns(pid_t pid, const char *ns); |
1a0e70ac | 160 | extern char *get_template_path(const char *t); |
1a0e70ac CB |
161 | extern int safe_mount(const char *src, const char *dest, const char *fstype, |
162 | unsigned long flags, const void *data, | |
163 | const char *rootfs); | |
164 | extern int lxc_mount_proc_if_needed(const char *rootfs); | |
165 | extern int open_devnull(void); | |
166 | extern int set_stdfds(int fd); | |
167 | extern int null_stdfds(void); | |
1a0e70ac | 168 | extern int lxc_preserve_ns(const int pid, const char *ns); |
330ae3d3 CB |
169 | |
170 | /* Check whether a signal is blocked by a process. */ | |
573ad77f | 171 | extern bool task_blocks_signal(pid_t pid, int signal); |
6bc2eafe | 172 | |
db2d1af1 CB |
173 | /* Switch to a new uid and gid. |
174 | * If LXC_INVALID_{G,U}ID is passed then the set{g,u}id() will not be called. | |
175 | */ | |
464c4611 | 176 | extern bool lxc_switch_uid_gid(uid_t uid, gid_t gid); |
8af07f82 | 177 | extern bool lxc_setgroups(int size, gid_t list[]); |
dbaf55a3 | 178 | |
c6868a1f | 179 | /* Find an unused loop device and associate it with source. */ |
1a0e70ac | 180 | extern int lxc_prepare_loop_dev(const char *source, char *loop_dev, int flags); |
c6868a1f | 181 | |
74251e49 CB |
182 | /* Clear all mounts on a given node. |
183 | * >= 0 successfully cleared. The number returned is the number of umounts | |
184 | * performed. | |
185 | * < 0 error umounting. Return -errno. | |
186 | */ | |
1a0e70ac | 187 | extern int lxc_unstack_mountpoint(const char *path, bool lazy); |
74251e49 | 188 | |
ea3a694f CB |
189 | /* |
190 | * run_command runs a command and collect it's std{err,out} output in buf. | |
191 | * | |
192 | * @param[out] buf The buffer where the commands std{err,out] output will be | |
193 | * read into. If no output was produced, buf will be memset | |
194 | * to 0. | |
195 | * @param[in] buf_size The size of buf. This function will reserve one byte for | |
196 | * \0-termination. | |
197 | * @param[in] child_fn The function to be run in the child process. This | |
198 | * function must exec. | |
199 | * @param[in] args Arguments to be passed to child_fn. | |
200 | */ | |
1a0e70ac CB |
201 | extern int run_command(char *buf, size_t buf_size, int (*child_fn)(void *), |
202 | void *args); | |
ea3a694f | 203 | |
04ad7ffe CB |
204 | /* Concatenate all passed-in strings into one path. Do not fail. If any piece |
205 | * is not prefixed with '/', add a '/'. | |
206 | */ | |
eb5c2e6a | 207 | __attribute__((sentinel)) extern char *must_concat(const char *first, ...); |
0c3deb94 CB |
208 | __attribute__((sentinel)) extern char *must_make_path(const char *first, ...); |
209 | __attribute__((sentinel)) extern char *must_append_path(char *first, ...); | |
04ad7ffe CB |
210 | |
211 | /* return copy of string @entry; do not fail. */ | |
1a0e70ac | 212 | extern char *must_copy_string(const char *entry); |
04ad7ffe CB |
213 | |
214 | /* Re-alllocate a pointer, do not fail */ | |
1a0e70ac | 215 | extern void *must_realloc(void *orig, size_t sz); |
04ad7ffe | 216 | |
d75c14e2 | 217 | extern bool lxc_nic_exists(char *nic); |
0059379f CB |
218 | |
219 | static inline uint64_t lxc_getpagesize(void) | |
220 | { | |
221 | int64_t pgsz; | |
222 | ||
223 | pgsz = sysconf(_SC_PAGESIZE); | |
224 | if (pgsz <= 0) | |
225 | pgsz = 1 << 12; | |
226 | ||
227 | return pgsz; | |
228 | } | |
a035c53a | 229 | |
6222c3f4 CB |
230 | /* If n is not a power of 2 this function will return the next power of 2 |
231 | * greater than that number. Note that this function always returns the *next* | |
232 | * power of 2 *greater* that number not the *nearest*. For example, passing 1025 | |
233 | * as argument this function will return 2048 although the closest power of 2 | |
234 | * would be 1024. | |
235 | * If the caller passes in 0 they will receive 0 in return since this is invalid | |
236 | * input and 0 is not a power of 2. | |
237 | */ | |
238 | extern uint64_t lxc_find_next_power2(uint64_t n); | |
239 | ||
1fd0f41e | 240 | /* Set a signal the child process will receive after the parent has died. */ |
c7f493ae | 241 | extern int lxc_set_death_signal(int signal, pid_t parent); |
a9d4ebc1 | 242 | extern int fd_cloexec(int fd, bool cloexec); |
d7ab0375 | 243 | extern int recursive_destroy(char *dirname); |
b25291da | 244 | extern int lxc_setup_keyring(void); |
1fd0f41e | 245 | |
5b72de5f | 246 | #endif /* __LXC_UTILS_H */ |