15263807472

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <fcntl.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <time.h>
#include <unistd.h>

#include "alloc-util.h"
#include "chattr-util.h"
#include "efivars.h"
#include "fd-util.h"
#include "io-util.h"
#include "log.h"
#include "memory-util.h"
#include "string-util.h"
#include "time-util.h"
#include "utf8.h"
#include "virt.h"

#if ENABLE_EFI

/* Reads from efivarfs sometimes fail with EINTR. Retry that many times. */
#define EFI_N_RETRIES_NO_DELAY 20
#define EFI_N_RETRIES_TOTAL 25
#define EFI_RETRY_DELAY (50 * USEC_PER_MSEC)

int efi_get_variable(
                const char *variable,
                uint32_t *ret_attribute,
                void **ret_value,
                size_t *ret_size) {

        _cleanup_close_ int fd = -EBADF;
        _cleanup_free_ void *buf = NULL;
        struct stat st;
        usec_t begin = 0; /* Unnecessary initialization to appease gcc */
        uint32_t a;
        ssize_t n;

        assert(variable);

        const char *p = strjoina("/sys/firmware/efi/efivars/", variable);

        if (!ret_value && !ret_size && !ret_attribute) {
                /* If caller is not interested in anything, just check if the variable exists and is
                 * readable. */
                if (access(p, R_OK) < 0)
                        return -errno;

                return 0;
        }

        if (DEBUG_LOGGING) {
                log_debug("Reading EFI variable %s.", p);
                begin = now(CLOCK_MONOTONIC);
        }

        fd = open(p, O_RDONLY|O_NOCTTY|O_CLOEXEC);
        if (fd < 0)
                return log_debug_errno(errno, "open(\"%s\") failed: %m", p);

        if (fstat(fd, &st) < 0)
                return log_debug_errno(errno, "fstat(\"%s\") failed: %m", p);
        if (st.st_size < 4)
                return log_debug_errno(SYNTHETIC_ERRNO(ENODATA), "EFI variable %s is shorter than 4 bytes, refusing.", p);
        if (st.st_size > 4*1024*1024 + 4)
                return log_debug_errno(SYNTHETIC_ERRNO(E2BIG), "EFI variable %s is ridiculously large, refusing.", p);

        if (ret_value || ret_attribute) {
                /* The kernel ratelimits reads from the efivarfs because EFI is inefficient, and we'll
                 * occasionally fail with EINTR here. A slowdown is better than a failure for us, so
                 * retry a few times and eventually fail with -EBUSY.
                 *
                 * See https://github.com/torvalds/linux/blob/master/fs/efivarfs/file.c#L75
                 * and
                 * https://github.com/torvalds/linux/commit/bef3efbeb897b56867e271cdbc5f8adaacaeb9cd.
                 */
                for (unsigned try = 0;; try++) {
                        n = read(fd, &a, sizeof(a));
                        if (n >= 0)
                                break;
                        log_debug_errno(errno, "Reading from \"%s\" failed: %m", p);
                        if (errno != EINTR)
                                return -errno;
                        if (try >= EFI_N_RETRIES_TOTAL)
                                return -EBUSY;

                        if (try >= EFI_N_RETRIES_NO_DELAY)
                                (void) usleep_safe(EFI_RETRY_DELAY);
                }

                /* Unfortunately kernel reports EOF if there's an inconsistency between efivarfs var list
                 * and what's actually stored in firmware, c.f. #34304. A zero size env var is not allowed in
                 * efi and hence the variable doesn't really exist in the backing store as long as it is zero
                 * sized, and the kernel calls this "uncommitted". Hence we translate EOF back to ENOENT here,
                 * as with kernel behavior before
                 * https://github.com/torvalds/linux/commit/3fab70c165795431f00ddf9be8b84ddd07bd1f8f
                 *
                 * If the kernel changes behaviour (to flush dentries on resume), we can drop
                 * this at some point in the future. But note that the commit is 11
                 * years old at this point so we'll need to deal with the current behaviour for
                 * a long time.
                 */
                if (n == 0)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOENT),
                                               "EFI variable %s is uncommitted", p);

                if (n != sizeof(a))
                        return log_debug_errno(SYNTHETIC_ERRNO(EIO),
                                               "Read %zi bytes from EFI variable %s, expected %zu.",  n, p, sizeof(a));
        }

        if (ret_value) {
                buf = malloc(st.st_size - 4 + 3);
                if (!buf)
                        return -ENOMEM;

                n = read(fd, buf, (size_t) st.st_size - 4);
                if (n < 0)
                        return log_debug_errno(errno, "Failed to read value of EFI variable %s: %m", p);
                assert(n <= st.st_size - 4);

                /* Always NUL-terminate (3 bytes, to properly protect UTF-16, even if truncated in the middle
                 * of a character) */
                ((char*) buf)[n] = 0;
                ((char*) buf)[n + 1] = 0;
                ((char*) buf)[n + 2] = 0;
        } else
                /* Assume that the reported size is accurate */
                n = st.st_size - 4;

        if (DEBUG_LOGGING) {
                usec_t end = now(CLOCK_MONOTONIC);
                if (end > begin + EFI_RETRY_DELAY)
                        log_debug("Detected slow EFI variable read access on %s: %s",
                                  variable, FORMAT_TIMESPAN(end - begin, 1));
        }

        /* Note that efivarfs interestingly doesn't require ftruncate() to update an existing EFI variable
         * with a smaller value. */

        if (ret_attribute)
                *ret_attribute = a;

        if (ret_value)
                *ret_value = TAKE_PTR(buf);

        if (ret_size)
                *ret_size = n;

        return 0;
}

int efi_get_variable_string(const char *variable, char **ret) {
        _cleanup_free_ void *s = NULL;
        size_t ss = 0;
        char *x;
        int r;

        assert(variable);

        r = efi_get_variable(variable, NULL, &s, &ss);
        if (r < 0)
                return r;

        x = utf16_to_utf8(s, ss);
        if (!x)
                return -ENOMEM;

        if (ret)
                *ret = x;

        return 0;
}

int efi_get_variable_path(const char *variable, char **ret) {
        int r;

        assert(variable);

        r = efi_get_variable_string(variable, ret);
        if (r < 0)
                return r;

        if (ret)
                efi_tilt_backslashes(*ret);

        return r;
}

static int efi_verify_variable(const char *variable, uint32_t attr, const void *value, size_t size) {
        _cleanup_free_ void *buf = NULL;
        size_t n;
        uint32_t a;
        int r;

        assert(variable);
        assert(value || size == 0);

        r = efi_get_variable(variable, &a, &buf, &n);
        if (r < 0)
                return r;

        return a == attr && memcmp_nn(buf, n, value, size) == 0;
}

int efi_set_variable(const char *variable, const void *value, size_t size) {
        static const uint32_t attr = EFI_VARIABLE_NON_VOLATILE|EFI_VARIABLE_BOOTSERVICE_ACCESS|EFI_VARIABLE_RUNTIME_ACCESS;

        struct var {
                uint32_t attr;
                char buf[];
        } _packed_ * _cleanup_free_ buf = NULL;
        _cleanup_close_ int fd = -EBADF;
        bool saved_flags_valid = false;
        unsigned saved_flags;
        int r;

        assert(variable);
        assert(value || size == 0);

        /* size 0 means removal, empty variable would not be enough for that */
        if (size > 0 && efi_verify_variable(variable, attr, value, size) > 0) {
                log_debug("Variable '%s' is already in wanted state, skipping write.", variable);
                return 0;
        }

        const char *p = strjoina("/sys/firmware/efi/efivars/", variable);

        /* Newer efivarfs protects variables that are not in an allow list with FS_IMMUTABLE_FL by default,
         * to protect them for accidental removal and modification. We are not changing these variables
         * accidentally however, hence let's unset the bit first. */

        r = chattr_full(AT_FDCWD, p,
                        /* value = */ 0,
                        /* mask = */ FS_IMMUTABLE_FL,
                        /* ret_previous = */ &saved_flags,
                        /* ret_final = */ NULL,
                        /* flags = */ 0);
        if (r < 0 && r != -ENOENT)
                log_debug_errno(r, "Failed to drop FS_IMMUTABLE_FL flag from '%s', ignoring: %m", p);

        saved_flags_valid = r >= 0;

        if (size == 0) {
                if (unlink(p) < 0) {
                        r = -errno;
                        goto finish;
                }

                return 0;
        }

        fd = open(p, O_WRONLY|O_CREAT|O_NOCTTY|O_CLOEXEC, 0644);
        if (fd < 0) {
                r = -errno;
                goto finish;
        }

        buf = malloc(sizeof(uint32_t) + size);
        if (!buf) {
                r = -ENOMEM;
                goto finish;
        }

        buf->attr = attr;
        memcpy(buf->buf, value, size);

        r = loop_write(fd, buf, sizeof(uint32_t) + size);
        if (r < 0)
                goto finish;

        /* For some reason efivarfs doesn't update mtime automatically. Let's do it manually then. This is
         * useful for processes that cache EFI variables to detect when changes occurred. */
        if (futimens(fd, /* times = */ NULL) < 0)
                log_debug_errno(errno, "Failed to update mtime/atime on %s, ignoring: %m", p);

        r = 0;

finish:
        if (saved_flags_valid) {
                int q;

                /* Restore the original flags field, just in case */
                if (fd < 0)
                        q = chattr_path(p, saved_flags, FS_IMMUTABLE_FL);
                else
                        q = chattr_fd(fd, saved_flags, FS_IMMUTABLE_FL);
                if (q < 0)
                        log_debug_errno(q, "Failed to restore FS_IMMUTABLE_FL on '%s', ignoring: %m", p);
        }

        return r;
}

int efi_set_variable_string(const char *variable, const char *value) {
        _cleanup_free_ char16_t *u16 = NULL;

        u16 = utf8_to_utf16(value, SIZE_MAX);
        if (!u16)
                return -ENOMEM;

        return efi_set_variable(variable, u16, (char16_strlen(u16) + 1) * sizeof(char16_t));
}

bool is_efi_boot(void) {
        static int cache = -1;

        if (cache < 0) {
                if (detect_container() > 0)
                        cache = false;
                else {
                        cache = access("/sys/firmware/efi/", F_OK) >= 0;
                        if (!cache && errno != ENOENT)
                                log_debug_errno(errno, "Unable to test whether /sys/firmware/efi/ exists, assuming EFI not available: %m");
                }
        }

        return cache;
}

static int read_flag(const char *variable) {
        _cleanup_free_ void *v = NULL;
        uint8_t b;
        size_t s;
        int r;

        if (!is_efi_boot()) /* If this is not an EFI boot, assume the queried flags are zero */
                return 0;

        r = efi_get_variable(variable, NULL, &v, &s);
        if (r < 0)
                return r;

        if (s != 1)
                return -EINVAL;

        b = *(uint8_t *)v;
        return !!b;
}

bool is_efi_secure_boot(void) {
        static int cache = -1;
        int r;

        if (cache < 0) {
                r = read_flag(EFI_GLOBAL_VARIABLE_STR("SecureBoot"));
                if (r == -ENOENT)
                        cache = false;
                else if (r < 0)
                        log_debug_errno(r, "Error reading SecureBoot EFI variable, assuming not in SecureBoot mode: %m");
                else
                        cache = r;
        }

        return cache > 0;
}

SecureBootMode efi_get_secure_boot_mode(void) {
        static SecureBootMode cache = _SECURE_BOOT_INVALID;

        if (cache != _SECURE_BOOT_INVALID)
                return cache;

        int secure = read_flag(EFI_GLOBAL_VARIABLE_STR("SecureBoot"));
        if (secure < 0) {
                if (secure != -ENOENT)
                        log_debug_errno(secure, "Error reading SecureBoot EFI variable, assuming not in SecureBoot mode: %m");

                return (cache = SECURE_BOOT_UNSUPPORTED);
        }

        /* We can assume false for all these if they are abscent (AuditMode and
         * DeployedMode may not exist on older firmware). */
        int audit    = read_flag(EFI_GLOBAL_VARIABLE_STR("AuditMode"));
        int deployed = read_flag(EFI_GLOBAL_VARIABLE_STR("DeployedMode"));
        int setup    = read_flag(EFI_GLOBAL_VARIABLE_STR("SetupMode"));
        log_debug("Secure boot variables: SecureBoot=%d AuditMode=%d DeployedMode=%d SetupMode=%d",
                  secure, audit, deployed, setup);

        return (cache = decode_secure_boot_mode(secure, audit > 0, deployed > 0, setup > 0));
}
#endif

char *efi_tilt_backslashes(char *s) {
        return string_replace_char(s, '\\', '/');
}

1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3	#include <fcntl.h>
4	#include <stdlib.h>
5	#include <sys/stat.h>
6	#include <time.h>
7	#include <unistd.h>
8
9	#include "alloc-util.h"
10	#include "chattr-util.h"
11	#include "efivars.h"
12	#include "fd-util.h"
13	#include "io-util.h"
14	#include "log.h"
15	#include "memory-util.h"
16	#include "string-util.h"
17	#include "time-util.h"
18	#include "utf8.h"
19	#include "virt.h"
20
21	#if ENABLE_EFI
22
23	/* Reads from efivarfs sometimes fail with EINTR. Retry that many times. */
24	#define EFI_N_RETRIES_NO_DELAY 20
25	#define EFI_N_RETRIES_TOTAL 25
26	#define EFI_RETRY_DELAY (50 * USEC_PER_MSEC)
27
28	int efi_get_variable(	306✔
29	const char *variable,
30	uint32_t *ret_attribute,
31	void **ret_value,
32	size_t *ret_size) {
33
34	_cleanup_close_ int fd = -EBADF;	306✔
35	_cleanup_free_ void *buf = NULL;	306✔
36	struct stat st;	306✔
37	usec_t begin = 0; /* Unnecessary initialization to appease gcc */	306✔
38	uint32_t a;	306✔
39	ssize_t n;	306✔
40
41	assert(variable);	306✔
42
43	const char *p = strjoina("/sys/firmware/efi/efivars/", variable);	1,530✔
44
45	if (!ret_value && !ret_size && !ret_attribute) {	306✔
46	/* If caller is not interested in anything, just check if the variable exists and is
47	* readable. */
UNCOV 48	if (access(p, R_OK) < 0)	×
UNCOV 49	return -errno;	×
50
51	return 0;
52	}
53
54	if (DEBUG_LOGGING) {	306✔
55	log_debug("Reading EFI variable %s.", p);	306✔
56	begin = now(CLOCK_MONOTONIC);	306✔
57	}
58
59	fd = open(p, O_RDONLY\|O_NOCTTY\|O_CLOEXEC);	306✔
60	if (fd < 0)	306✔
61	return log_debug_errno(errno, "open(\"%s\") failed: %m", p);	100✔
62
63	if (fstat(fd, &st) < 0)	206✔
UNCOV 64	return log_debug_errno(errno, "fstat(\"%s\") failed: %m", p);	×
65	if (st.st_size < 4)	206✔
UNCOV 66	return log_debug_errno(SYNTHETIC_ERRNO(ENODATA), "EFI variable %s is shorter than 4 bytes, refusing.", p);	×
67	if (st.st_size > 410241024 + 4)	206✔
UNCOV 68	return log_debug_errno(SYNTHETIC_ERRNO(E2BIG), "EFI variable %s is ridiculously large, refusing.", p);	×
69
70	if (ret_value \|\| ret_attribute) {	206✔
71	/* The kernel ratelimits reads from the efivarfs because EFI is inefficient, and we'll
72	* occasionally fail with EINTR here. A slowdown is better than a failure for us, so
73	* retry a few times and eventually fail with -EBUSY.
74	*
75	* See https://github.com/torvalds/linux/blob/master/fs/efivarfs/file.c#L75
76	* and
77	* https://github.com/torvalds/linux/commit/bef3efbeb897b56867e271cdbc5f8adaacaeb9cd.
78	*/
UNCOV 79	for (unsigned try = 0;; try++) {	×
80	n = read(fd, &a, sizeof(a));	203✔
81	if (n >= 0)	203✔
82	break;
UNCOV 83	log_debug_errno(errno, "Reading from \"%s\" failed: %m", p);	×
UNCOV 84	if (errno != EINTR)	×
UNCOV 85	return -errno;	×
86	if (try >= EFI_N_RETRIES_TOTAL)	×
87	return -EBUSY;
88
UNCOV 89	if (try >= EFI_N_RETRIES_NO_DELAY)	×
90	(void) usleep_safe(EFI_RETRY_DELAY);	×
91	}
92
93	/* Unfortunately kernel reports EOF if there's an inconsistency between efivarfs var list
94	* and what's actually stored in firmware, c.f. #34304. A zero size env var is not allowed in
95	* efi and hence the variable doesn't really exist in the backing store as long as it is zero
96	* sized, and the kernel calls this "uncommitted". Hence we translate EOF back to ENOENT here,
97	* as with kernel behavior before
98	* https://github.com/torvalds/linux/commit/3fab70c165795431f00ddf9be8b84ddd07bd1f8f
99	*
100	* If the kernel changes behaviour (to flush dentries on resume), we can drop
101	* this at some point in the future. But note that the commit is 11
102	* years old at this point so we'll need to deal with the current behaviour for
103	* a long time.
104	*/
105	if (n == 0)	203✔
UNCOV 106	return log_debug_errno(SYNTHETIC_ERRNO(ENOENT),	×
107	"EFI variable %s is uncommitted", p);
108
109	if (n != sizeof(a))	203✔
UNCOV 110	return log_debug_errno(SYNTHETIC_ERRNO(EIO),	×
111	"Read %zi bytes from EFI variable %s, expected %zu.", n, p, sizeof(a));
112	}
113
114	if (ret_value) {	203✔
115	buf = malloc(st.st_size - 4 + 3);	203✔
116	if (!buf)	203✔
117	return -ENOMEM;
118
119	n = read(fd, buf, (size_t) st.st_size - 4);	203✔
120	if (n < 0)	203✔
UNCOV 121	return log_debug_errno(errno, "Failed to read value of EFI variable %s: %m", p);	×
122	assert(n <= st.st_size - 4);	203✔
123
124	/* Always NUL-terminate (3 bytes, to properly protect UTF-16, even if truncated in the middle
125	* of a character) */
126	((char*) buf)[n] = 0;	203✔
127	((char*) buf)[n + 1] = 0;	203✔
128	((char*) buf)[n + 2] = 0;	203✔
129	} else
130	/* Assume that the reported size is accurate */
131	n = st.st_size - 4;	3✔
132
133	if (DEBUG_LOGGING) {	206✔
134	usec_t end = now(CLOCK_MONOTONIC);	206✔
135	if (end > begin + EFI_RETRY_DELAY)	206✔
UNCOV 136	log_debug("Detected slow EFI variable read access on %s: %s",	×
137	variable, FORMAT_TIMESPAN(end - begin, 1));
138	}
139
140	/* Note that efivarfs interestingly doesn't require ftruncate() to update an existing EFI variable
141	* with a smaller value. */
142
143	if (ret_attribute)	206✔
144	*ret_attribute = a;	2✔
145
146	if (ret_value)	206✔
147	*ret_value = TAKE_PTR(buf);	203✔
148
149	if (ret_size)	206✔
150	*ret_size = n;	206✔
151
152	return 0;
153	}
154
155	int efi_get_variable_string(const char variable, char *ret) {	229✔
156	_cleanup_free_ void *s = NULL;	229✔
157	size_t ss = 0;	229✔
158	char *x;	229✔
159	int r;	229✔
160
161	assert(variable);	229✔
162
163	r = efi_get_variable(variable, NULL, &s, &ss);	229✔
164	if (r < 0)	229✔
165	return r;
166
167	x = utf16_to_utf8(s, ss);	147✔
168	if (!x)	147✔
169	return -ENOMEM;
170
171	if (ret)	147✔
172	*ret = x;	147✔
173
174	return 0;
175	}
176
177	int efi_get_variable_path(const char variable, char *ret) {	18✔
178	int r;	18✔
179
180	assert(variable);	18✔
181
182	r = efi_get_variable_string(variable, ret);	18✔
183	if (r < 0)	18✔
184	return r;
185
186	if (ret)	18✔
187	efi_tilt_backslashes(*ret);	18✔
188
189	return r;
190	}
191
192	static int efi_verify_variable(const char variable, uint32_t attr, const void value, size_t size) {	9✔
193	_cleanup_free_ void *buf = NULL;	9✔
194	size_t n;	9✔
195	uint32_t a;	9✔
196	int r;	9✔
197
198	assert(variable);	9✔
199	assert(value \|\| size == 0);	9✔
200
201	r = efi_get_variable(variable, &a, &buf, &n);	9✔
202	if (r < 0)	9✔
203	return r;
204
205	return a == attr && memcmp_nn(buf, n, value, size) == 0;	2✔
206	}
207
208	int efi_set_variable(const char variable, const void value, size_t size) {	9✔
209	static const uint32_t attr = EFI_VARIABLE_NON_VOLATILE\|EFI_VARIABLE_BOOTSERVICE_ACCESS\|EFI_VARIABLE_RUNTIME_ACCESS;	9✔
210
211	struct var {	9✔
212	uint32_t attr;
213	char buf[];
214	} _packed_ * _cleanup_free_ buf = NULL;	9✔
215	_cleanup_close_ int fd = -EBADF;	9✔
216	bool saved_flags_valid = false;	9✔
217	unsigned saved_flags;	9✔
218	int r;	9✔
219
220	assert(variable);	9✔
221	assert(value \|\| size == 0);	9✔
222
223	/* size 0 means removal, empty variable would not be enough for that */
224	if (size > 0 && efi_verify_variable(variable, attr, value, size) > 0) {	9✔
UNCOV 225	log_debug("Variable '%s' is already in wanted state, skipping write.", variable);	×
UNCOV 226	return 0;	×
227	}
228
229	const char *p = strjoina("/sys/firmware/efi/efivars/", variable);	45✔
230
231	/* Newer efivarfs protects variables that are not in an allow list with FS_IMMUTABLE_FL by default,
232	* to protect them for accidental removal and modification. We are not changing these variables
233	* accidentally however, hence let's unset the bit first. */
234
235	r = chattr_full(AT_FDCWD, p,	9✔
236	/* value = */ 0,
237	/* mask = */ FS_IMMUTABLE_FL,
238	/* ret_previous = */ &saved_flags,
239	/* ret_final = */ NULL,
240	/* flags = */ 0);
241	if (r < 0 && r != -ENOENT)	9✔
UNCOV 242	log_debug_errno(r, "Failed to drop FS_IMMUTABLE_FL flag from '%s', ignoring: %m", p);	×
243
244	saved_flags_valid = r >= 0;	9✔
245
246	if (size == 0) {	9✔
UNCOV 247	if (unlink(p) < 0) {	×
UNCOV 248	r = -errno;	×
249	goto finish;	×
250	}
251
252	return 0;
253	}
254
255	fd = open(p, O_WRONLY\|O_CREAT\|O_NOCTTY\|O_CLOEXEC, 0644);	9✔
256	if (fd < 0) {	9✔
UNCOV 257	r = -errno;	×
UNCOV 258	goto finish;	×
259	}
260
261	buf = malloc(sizeof(uint32_t) + size);	9✔
262	if (!buf) {	9✔
UNCOV 263	r = -ENOMEM;	×
264	goto finish;	×
265	}
266
267	buf->attr = attr;	9✔
268	memcpy(buf->buf, value, size);	9✔
269
270	r = loop_write(fd, buf, sizeof(uint32_t) + size);	9✔
271	if (r < 0)	9✔
UNCOV 272	goto finish;	×
273
274	/* For some reason efivarfs doesn't update mtime automatically. Let's do it manually then. This is
275	* useful for processes that cache EFI variables to detect when changes occurred. */
276	if (futimens(fd, /* times = */ NULL) < 0)	9✔
277	log_debug_errno(errno, "Failed to update mtime/atime on %s, ignoring: %m", p);	7✔
278
279	r = 0;
280
281	finish:	9✔
282	if (saved_flags_valid) {	9✔
283	int q;	2✔
284
285	/* Restore the original flags field, just in case */
286	if (fd < 0)	2✔
UNCOV 287	q = chattr_path(p, saved_flags, FS_IMMUTABLE_FL);	×
288	else
289	q = chattr_fd(fd, saved_flags, FS_IMMUTABLE_FL);	2✔
290	if (q < 0)	2✔
291	log_debug_errno(q, "Failed to restore FS_IMMUTABLE_FL on '%s', ignoring: %m", p);	9✔
292	}
293
294	return r;
295	}
296
UNCOV 297	int efi_set_variable_string(const char variable, const char value) {	×
UNCOV 298	_cleanup_free_ char16_t *u16 = NULL;	×
299
UNCOV 300	u16 = utf8_to_utf16(value, SIZE_MAX);	×
UNCOV 301	if (!u16)	×
302	return -ENOMEM;
303
304	return efi_set_variable(variable, u16, (char16_strlen(u16) + 1) * sizeof(char16_t));	×
305	}
306
307	bool is_efi_boot(void) {	571✔
308	static int cache = -1;	571✔
309
310	if (cache < 0) {	571✔
311	if (detect_container() > 0)	346✔
312	cache = false;	63✔
313	else {
314	cache = access("/sys/firmware/efi/", F_OK) >= 0;	283✔
315	if (!cache && errno != ENOENT)	283✔
UNCOV 316	log_debug_errno(errno, "Unable to test whether /sys/firmware/efi/ exists, assuming EFI not available: %m");	×
317	}
318	}
319
320	return cache;	571✔
321	}
322
323	static int read_flag(const char *variable) {	9✔
324	_cleanup_free_ void *v = NULL;	9✔
325	uint8_t b;	9✔
326	size_t s;	9✔
327	int r;	9✔
328
329	if (!is_efi_boot()) /* If this is not an EFI boot, assume the queried flags are zero */	9✔
330	return 0;
331
332	r = efi_get_variable(variable, NULL, &v, &s);	7✔
333	if (r < 0)	7✔
334	return r;
335
UNCOV 336	if (s != 1)	×
337	return -EINVAL;
338
UNCOV 339	b = (uint8_t )v;	×
UNCOV 340	return !!b;	×
341	}
342
343	bool is_efi_secure_boot(void) {	5✔
344	static int cache = -1;	5✔
345	int r;	5✔
346
347	if (cache < 0) {	5✔
348	r = read_flag(EFI_GLOBAL_VARIABLE_STR("SecureBoot"));	3✔
349	if (r == -ENOENT)	3✔
350	cache = false;	1✔
351	else if (r < 0)	2✔
UNCOV 352	log_debug_errno(r, "Error reading SecureBoot EFI variable, assuming not in SecureBoot mode: %m");	×
353	else
354	cache = r;	2✔
355	}
356
357	return cache > 0;	5✔
358	}
359
360	SecureBootMode efi_get_secure_boot_mode(void) {	6✔
361	static SecureBootMode cache = _SECURE_BOOT_INVALID;	6✔
362
363	if (cache != _SECURE_BOOT_INVALID)	6✔
364	return cache;
365
366	int secure = read_flag(EFI_GLOBAL_VARIABLE_STR("SecureBoot"));	6✔
367	if (secure < 0) {	6✔
368	if (secure != -ENOENT)	6✔
UNCOV 369	log_debug_errno(secure, "Error reading SecureBoot EFI variable, assuming not in SecureBoot mode: %m");	×
370
371	return (cache = SECURE_BOOT_UNSUPPORTED);	6✔
372	}
373
374	/* We can assume false for all these if they are abscent (AuditMode and
375	* DeployedMode may not exist on older firmware). */
376	int audit = read_flag(EFI_GLOBAL_VARIABLE_STR("AuditMode"));	×
UNCOV 377	int deployed = read_flag(EFI_GLOBAL_VARIABLE_STR("DeployedMode"));	×
UNCOV 378	int setup = read_flag(EFI_GLOBAL_VARIABLE_STR("SetupMode"));	×
UNCOV 379	log_debug("Secure boot variables: SecureBoot=%d AuditMode=%d DeployedMode=%d SetupMode=%d",	×
380	secure, audit, deployed, setup);
381
UNCOV 382	return (cache = decode_secure_boot_mode(secure, audit > 0, deployed > 0, setup > 0));	×
383	}
384	#endif
385
386	char efi_tilt_backslashes(char s) {	18✔
387	return string_replace_char(s, '\\', '/');	18✔
388	}

systemd / systemd / 15263807472

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