| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| #pragma once |
| |
| #include <inttypes.h> |
| #include <stdbool.h> |
| #include <sys/types.h> |
| |
| #include "stdio-util.h" |
| |
| int parse_devnum(const char *s, dev_t *ret); |
| |
| /* glibc and the Linux kernel have different ideas about the major/minor size. These calls will check whether the |
| * specified major is valid by the Linux kernel's standards, not by glibc's. Linux has 20bits of minor, and 12 bits of |
| * major space. See MINORBITS in linux/kdev_t.h in the kernel sources. (If you wonder why we define _y here, instead of |
| * comparing directly >= 0: it's to trick out -Wtype-limits, which would otherwise complain if the type is unsigned, as |
| * such a test would be pointless in such a case.) */ |
| |
| #define DEVICE_MAJOR_VALID(x) \ |
| ({ \ |
| typeof(x) _x = (x), _y = 0; \ |
| _x >= _y && _x < (UINT32_C(1) << 12); \ |
| \ |
| }) |
| |
| #define DEVICE_MINOR_VALID(x) \ |
| ({ \ |
| typeof(x) _x = (x), _y = 0; \ |
| _x >= _y && _x < (UINT32_C(1) << 20); \ |
| }) |
| |
| int device_path_make_major_minor(mode_t mode, dev_t devnum, char **ret); |
| int device_path_make_inaccessible(mode_t mode, char **ret); |
| int device_path_make_canonical(mode_t mode, dev_t devnum, char **ret); |
| int device_path_parse_major_minor(const char *path, mode_t *ret_mode, dev_t *ret_devnum); |
| |
| static inline bool devnum_set_and_equal(dev_t a, dev_t b) { |
| /* Returns true if a and b definitely refer to the same device. If either is zero, this means "don't |
| * know" and we'll return false */ |
| return a == b && a != 0; |
| } |
| |
| /* Maximum string length for a major:minor string. (Note that DECIMAL_STR_MAX includes space for a trailing NUL) */ |
| #define DEVNUM_STR_MAX (DECIMAL_STR_MAX(dev_t)-1+1+DECIMAL_STR_MAX(dev_t)) |
| |
| #define DEVNUM_FORMAT_STR "%u:%u" |
| #define DEVNUM_FORMAT_VAL(d) major(d), minor(d) |
| |
| static inline char *format_devnum(dev_t d, char buf[static DEVNUM_STR_MAX]) { |
| return ASSERT_PTR(snprintf_ok(buf, DEVNUM_STR_MAX, DEVNUM_FORMAT_STR, DEVNUM_FORMAT_VAL(d))); |
| } |
| |
| #define FORMAT_DEVNUM(d) format_devnum((d), (char[DEVNUM_STR_MAX]) {}) |