#include <stdbool.h>
#include <unistd.h>
#include <linux/loop.h>
-#include <linux/magic.h>
+#include <linux/types.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/vfs.h>
-#include "initutils.h"
-
-/* Define __S_ISTYPE if missing from the C library. */
-#ifndef __S_ISTYPE
-#define __S_ISTYPE(mode, mask) (((mode)&S_IFMT) == (mask))
+#ifdef HAVE_LINUX_MEMFD_H
+#include <linux/memfd.h>
#endif
-/* Useful macros */
-/* Maximum number for 64 bit integer is a string with 21 digits: 2^64 - 1 = 21 */
-#define LXC_NUMSTRLEN64 21
-#define LXC_LINELEN 4096
-#define LXC_IDMAPLEN 4096
+#include "file_utils.h"
+#include "initutils.h"
+#include "macro.h"
+#include "string_utils.h"
/* returns 1 on success, 0 if there were any failures */
-extern int lxc_rmdir_onedev(char *path, const char *exclude);
+extern int lxc_rmdir_onedev(const char *path, const char *exclude);
extern int get_u16(unsigned short *val, const char *arg, int base);
extern int mkdir_p(const char *dir, mode_t mode);
extern char *get_rundir(void);
#endif
#endif
+#if !defined(__NR_setns) && !defined(__NR_set_ns)
+ #if defined(__x86_64__)
+ #define __NR_setns 308
+ #elif defined(__i386__)
+ #define __NR_setns 346
+ #elif defined(__arm__)
+ #define __NR_setns 375
+ #elif defined(__aarch64__)
+ #define __NR_setns 375
+ #elif defined(__powerpc__)
+ #define __NR_setns 350
+ #elif defined(__s390__)
+ #define __NR_setns 339
+ #endif
+#endif
+
/* Define setns() if missing from the C library */
#ifndef HAVE_SETNS
static inline int setns(int fd, int nstype)
}
#endif
+/* Define sethostname() if missing from the C library */
+#ifndef HAVE_SETHOSTNAME
+static inline int sethostname(const char *name, size_t len)
+{
+#ifdef __NR_sethostname
+return syscall(__NR_sethostname, name, len);
+#else
+errno = ENOSYS;
+return -1;
+#endif
+}
+#endif
+
/* Define unshare() if missing from the C library */
#ifndef HAVE_UNSHARE
static inline int unshare(int flags)
}
#endif
-/* loop devices */
-#ifndef LO_FLAGS_AUTOCLEAR
-#define LO_FLAGS_AUTOCLEAR 4
+#ifndef HAVE_MEMFD_CREATE
+static inline int memfd_create(const char *name, unsigned int flags) {
+ #ifndef __NR_memfd_create
+ #if defined __i386__
+ #define __NR_memfd_create 356
+ #elif defined __x86_64__
+ #define __NR_memfd_create 319
+ #elif defined __arm__
+ #define __NR_memfd_create 385
+ #elif defined __aarch64__
+ #define __NR_memfd_create 279
+ #elif defined __s390__
+ #define __NR_memfd_create 350
+ #elif defined __powerpc__
+ #define __NR_memfd_create 360
+ #elif defined __sparc__
+ #define __NR_memfd_create 348
+ #elif defined __blackfin__
+ #define __NR_memfd_create 390
+ #elif defined __ia64__
+ #define __NR_memfd_create 1340
+ #elif defined _MIPS_SIM
+ #if _MIPS_SIM == _MIPS_SIM_ABI32
+ #define __NR_memfd_create 4354
+ #endif
+ #if _MIPS_SIM == _MIPS_SIM_NABI32
+ #define __NR_memfd_create 6318
+ #endif
+ #if _MIPS_SIM == _MIPS_SIM_ABI64
+ #define __NR_memfd_create 5314
+ #endif
+ #endif
+ #endif
+ #ifdef __NR_memfd_create
+ return syscall(__NR_memfd_create, name, flags);
+ #else
+ errno = ENOSYS;
+ return -1;
+ #endif
+}
+#else
+extern int memfd_create(const char *name, unsigned int flags);
#endif
-#ifndef LOOP_CTL_GET_FREE
-#define LOOP_CTL_GET_FREE 0x4C82
-#endif
+static inline int lxc_set_cloexec(int fd)
+{
+ return fcntl(fd, F_SETFD, FD_CLOEXEC);
+}
/* Struct to carry child pid from lxc_popen() to lxc_pclose().
* Not an opaque struct to allow direct access to the underlying FILE *
*/
extern int lxc_pclose(struct lxc_popen_FILE *fp);
-/**
- * BUILD_BUG_ON - break compile if a condition is true.
- * @condition: the condition which the compiler should know is false.
- *
- * If you have some code which relies on certain constants being equal, or
- * other compile-time-evaluated condition, you should use BUILD_BUG_ON to
- * detect if someone changes it.
- *
- * The implementation uses gcc's reluctance to create a negative array, but
- * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments
- * to inline functions). So as a fallback we use the optimizer; if it can't
- * prove the condition is false, it will cause a link error on the undefined
- * "__build_bug_on_failed". This error message can be harder to track down
- * though, hence the two different methods.
- */
-#ifndef __OPTIMIZE__
-#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
-#else
-extern int __build_bug_on_failed;
-#define BUILD_BUG_ON(condition) \
- do { \
- ((void)sizeof(char[1 - 2*!!(condition)])); \
- if (condition) __build_bug_on_failed = 1; \
- } while(0)
-#endif
-
/*
* wait on a child we forked
*/
extern int wait_for_pid(pid_t pid);
extern int lxc_wait_for_pid_status(pid_t pid);
-/* send and receive buffers completely */
-extern ssize_t lxc_write_nointr(int fd, const void* buf, size_t count);
-extern ssize_t lxc_read_nointr(int fd, void* buf, size_t count);
-extern ssize_t lxc_read_nointr_expect(int fd, void *buf, size_t count,
- const void *expected_buf);
#if HAVE_LIBGNUTLS
#define SHA_DIGEST_LENGTH 20
extern int sha1sum_file(char *fnam, unsigned char *md_value);
#endif
-/* read and write whole files */
-extern int lxc_write_to_file(const char *filename, const void *buf,
- size_t count, bool add_newline);
-extern int lxc_read_from_file(const char *filename, void* buf, size_t count);
-
-/* convert variadic argument lists to arrays (for execl type argument lists) */
-extern char** lxc_va_arg_list_to_argv(va_list ap, size_t skip, int do_strdup);
-extern const char** lxc_va_arg_list_to_argv_const(va_list ap, size_t skip);
-
-/* Some simple string functions; if they return pointers, they are allocated
- * buffers.
- */
-extern char *lxc_string_replace(const char *needle, const char *replacement,
- const char *haystack);
-extern bool lxc_string_in_array(const char *needle, const char **haystack);
-extern char *lxc_string_join(const char *sep, const char **parts,
- bool use_as_prefix);
-/* Normalize and split path: Leading and trailing / are removed, multiple
- * / are compactified, .. and . are resolved (.. on the top level is considered
- * identical to .).
- * Examples:
- * / -> { NULL }
- * foo/../bar -> { bar, NULL }
- * ../../ -> { NULL }
- * ./bar/baz/.. -> { bar, NULL }
- * foo//bar -> { foo, bar, NULL }
- */
-extern char **lxc_normalize_path(const char *path);
-/* remove multiple slashes from the path, e.g. ///foo//bar -> /foo/bar */
-extern char *lxc_deslashify(const char *path);
-extern char *lxc_append_paths(const char *first, const char *second);
-/* Note: the following two functions use strtok(), so they will never
- * consider an empty element, even if two delimiters are next to
- * each other.
- */
-extern bool lxc_string_in_list(const char *needle, const char *haystack,
- char sep);
-extern char **lxc_string_split(const char *string, char sep);
-extern char **lxc_string_split_and_trim(const char *string, char sep);
-/* Append string to NULL-terminated string array. */
-extern int lxc_append_string(char ***list, char *entry);
-
-/* some simple array manipulation utilities */
-typedef void (*lxc_free_fn)(void *);
-typedef void *(*lxc_dup_fn)(void *);
-extern int lxc_grow_array(void ***array, size_t *capacity, size_t new_size,
- size_t capacity_increment);
-extern void lxc_free_array(void **array, lxc_free_fn element_free_fn);
-extern size_t lxc_array_len(void **array);
-
-extern void **lxc_append_null_to_array(void **array, size_t count);
-
-/* mmap() wrapper. lxc_strmmap() will take care to \0-terminate files so that
- * normal string-handling functions can be used on the buffer. */
-extern void *lxc_strmmap(void *addr, size_t length, int prot, int flags, int fd,
- off_t offset);
-/* munmap() wrapper. Use it to free memory mmap()ed with lxc_strmmap(). */
-extern int lxc_strmunmap(void *addr, size_t length);
-
/* initialize rand with urandom */
extern int randseed(bool);
-inline static bool am_unpriv(void) {
+/* are we unprivileged with respect to our namespaces */
+inline static bool am_guest_unpriv(void) {
return geteuid() != 0;
}
+/* are we unprivileged with respect to init_user_ns */
+inline static bool am_host_unpriv(void)
+{
+ FILE *f;
+ uid_t user, host, count;
+ int ret;
+
+ if (geteuid() != 0)
+ return true;
+
+ /* Now: are we in a user namespace? Because then we're also
+ * unprivileged.
+ */
+ f = fopen("/proc/self/uid_map", "r");
+ if (!f) {
+ return false;
+ }
+
+ ret = fscanf(f, "%u %u %u", &user, &host, &count);
+ fclose(f);
+ if (ret != 3) {
+ return false;
+ }
+
+ if (user != 0 || host != 0 || count != UINT32_MAX)
+ return true;
+ return false;
+}
+
/*
* parse /proc/self/uid_map to find what @orig maps to
*/
extern uid_t get_ns_uid(uid_t orig);
+/*
+ * parse /proc/self/gid_map to find what @orig maps to
+ */
+extern gid_t get_ns_gid(gid_t orig);
extern bool dir_exists(const char *path);
#define FNV1A_64_INIT ((uint64_t)0xcbf29ce484222325ULL)
extern uint64_t fnv_64a_buf(void *buf, size_t len, uint64_t hval);
+extern bool is_shared_mountpoint(const char *path);
extern int detect_shared_rootfs(void);
extern bool detect_ramfs_rootfs(void);
extern char *on_path(const char *cmd, const char *rootfs);
-extern bool file_exists(const char *f);
extern bool cgns_supported(void);
extern char *choose_init(const char *rootfs);
-extern int print_to_file(const char *file, const char *content);
extern bool switch_to_ns(pid_t pid, const char *ns);
-extern int is_dir(const char *path);
extern char *get_template_path(const char *t);
-extern int setproctitle(char *title);
extern int safe_mount(const char *src, const char *dest, const char *fstype,
unsigned long flags, const void *data,
const char *rootfs);
extern int open_devnull(void);
extern int set_stdfds(int fd);
extern int null_stdfds(void);
-extern int lxc_count_file_lines(const char *fn);
extern int lxc_preserve_ns(const int pid, const char *ns);
/* Check whether a signal is blocked by a process. */
-extern bool task_blocking_signal(pid_t pid, int signal);
+extern bool task_blocks_signal(pid_t pid, int signal);
-/* Helper functions to parse numbers. */
-extern int lxc_safe_uint(const char *numstr, unsigned int *converted);
-extern int lxc_safe_int(const char *numstr, int *converted);
-extern int lxc_safe_long(const char *numstr, long int *converted);
-extern int lxc_safe_ulong(const char *numstr, unsigned long *converted);
-
-/* Switch to a new uid and gid. */
+/* Switch to a new uid and gid.
+ * If LXC_INVALID_{G,U}ID is passed then the set{g,u}id() will not be called.
+ */
extern int lxc_switch_uid_gid(uid_t uid, gid_t gid);
-extern int lxc_setgroups(int size, gid_t list[]);
+extern bool lxc_setgroups(int size, gid_t list[]);
/* Find an unused loop device and associate it with source. */
extern int lxc_prepare_loop_dev(const char *source, char *loop_dev, int flags);
/* Concatenate all passed-in strings into one path. Do not fail. If any piece
* is not prefixed with '/', add a '/'.
*/
-extern char *must_make_path(const char *first, ...) __attribute__((sentinel));
+__attribute__((sentinel)) extern char *must_concat(const char *first, ...);
+__attribute__((sentinel)) extern char *must_make_path(const char *first, ...);
+__attribute__((sentinel)) extern char *must_append_path(char *first, ...);
/* return copy of string @entry; do not fail. */
extern char *must_copy_string(const char *entry);
/* Re-alllocate a pointer, do not fail */
extern void *must_realloc(void *orig, size_t sz);
-/* __typeof__ should be safe to use with all compilers. */
-typedef __typeof__(((struct statfs *)NULL)->f_type) fs_type_magic;
-extern bool has_fs_type(const char *path, fs_type_magic magic_val);
-extern bool is_fs_type(const struct statfs *fs, fs_type_magic magic_val);
extern bool lxc_nic_exists(char *nic);
+static inline uint64_t lxc_getpagesize(void)
+{
+ int64_t pgsz;
+
+ pgsz = sysconf(_SC_PAGESIZE);
+ if (pgsz <= 0)
+ pgsz = 1 << 12;
+
+ return pgsz;
+}
+
+/* If n is not a power of 2 this function will return the next power of 2
+ * greater than that number. Note that this function always returns the *next*
+ * power of 2 *greater* that number not the *nearest*. For example, passing 1025
+ * as argument this function will return 2048 although the closest power of 2
+ * would be 1024.
+ * If the caller passes in 0 they will receive 0 in return since this is invalid
+ * input and 0 is not a power of 2.
+ */
+extern uint64_t lxc_find_next_power2(uint64_t n);
+
+static inline pid_t lxc_raw_gettid(void)
+{
+#ifdef SYS_gettid
+ return syscall(SYS_gettid);
+#else
+ return lxc_raw_getpid();
+#endif
+}
+
+/* Set a signal the child process will receive after the parent has died. */
+extern int lxc_set_death_signal(int signal);
+extern int fd_cloexec(int fd, bool cloexec);
+extern int recursive_destroy(char *dirname);
+
#endif /* __LXC_UTILS_H */