Commit | Line | Data |
---|---|---|
ed8b0de5 | 1 | #include <errno.h> |
455ce1c7 JK |
2 | #include <stdio.h> |
3 | #include <stdint.h> | |
4 | #include <stdlib.h> | |
5 | #include <unistd.h> | |
ed8b0de5 | 6 | #include <sys/ioctl.h> |
455ce1c7 JK |
7 | #include <sys/types.h> |
8 | #include <sys/stat.h> | |
9 | #include <fcntl.h> | |
ed8b0de5 PJ |
10 | #include <linux/fs.h> |
11 | ||
12 | static int set_immutable(const char *path, int immutable) | |
13 | { | |
14 | unsigned int flags; | |
15 | int fd; | |
16 | int rc; | |
17 | int error; | |
18 | ||
19 | fd = open(path, O_RDONLY); | |
20 | if (fd < 0) | |
21 | return fd; | |
22 | ||
23 | rc = ioctl(fd, FS_IOC_GETFLAGS, &flags); | |
24 | if (rc < 0) { | |
25 | error = errno; | |
26 | close(fd); | |
27 | errno = error; | |
28 | return rc; | |
29 | } | |
30 | ||
31 | if (immutable) | |
32 | flags |= FS_IMMUTABLE_FL; | |
33 | else | |
34 | flags &= ~FS_IMMUTABLE_FL; | |
35 | ||
36 | rc = ioctl(fd, FS_IOC_SETFLAGS, &flags); | |
37 | error = errno; | |
38 | close(fd); | |
39 | errno = error; | |
40 | return rc; | |
41 | } | |
42 | ||
43 | static int get_immutable(const char *path) | |
44 | { | |
45 | unsigned int flags; | |
46 | int fd; | |
47 | int rc; | |
48 | int error; | |
49 | ||
50 | fd = open(path, O_RDONLY); | |
51 | if (fd < 0) | |
52 | return fd; | |
53 | ||
54 | rc = ioctl(fd, FS_IOC_GETFLAGS, &flags); | |
55 | if (rc < 0) { | |
56 | error = errno; | |
57 | close(fd); | |
58 | errno = error; | |
59 | return rc; | |
60 | } | |
61 | close(fd); | |
62 | if (flags & FS_IMMUTABLE_FL) | |
63 | return 1; | |
64 | return 0; | |
65 | } | |
455ce1c7 JK |
66 | |
67 | int main(int argc, char **argv) | |
68 | { | |
69 | const char *path; | |
70 | char buf[5]; | |
71 | int fd, rc; | |
72 | ||
73 | if (argc < 2) { | |
74 | fprintf(stderr, "usage: %s <path>\n", argv[0]); | |
75 | return EXIT_FAILURE; | |
76 | } | |
77 | ||
78 | path = argv[1]; | |
79 | ||
80 | /* attributes: EFI_VARIABLE_NON_VOLATILE | | |
81 | * EFI_VARIABLE_BOOTSERVICE_ACCESS | | |
82 | * EFI_VARIABLE_RUNTIME_ACCESS | |
83 | */ | |
84 | *(uint32_t *)buf = 0x7; | |
85 | buf[4] = 0; | |
86 | ||
87 | /* create a test variable */ | |
ed8b0de5 | 88 | fd = open(path, O_WRONLY | O_CREAT, 0600); |
455ce1c7 JK |
89 | if (fd < 0) { |
90 | perror("open(O_WRONLY)"); | |
91 | return EXIT_FAILURE; | |
92 | } | |
93 | ||
94 | rc = write(fd, buf, sizeof(buf)); | |
95 | if (rc != sizeof(buf)) { | |
96 | perror("write"); | |
97 | return EXIT_FAILURE; | |
98 | } | |
99 | ||
100 | close(fd); | |
101 | ||
ed8b0de5 PJ |
102 | rc = get_immutable(path); |
103 | if (rc < 0) { | |
104 | perror("ioctl(FS_IOC_GETFLAGS)"); | |
105 | return EXIT_FAILURE; | |
106 | } else if (rc) { | |
107 | rc = set_immutable(path, 0); | |
108 | if (rc < 0) { | |
109 | perror("ioctl(FS_IOC_SETFLAGS)"); | |
110 | return EXIT_FAILURE; | |
111 | } | |
112 | } | |
113 | ||
455ce1c7 JK |
114 | fd = open(path, O_RDONLY); |
115 | if (fd < 0) { | |
116 | perror("open"); | |
117 | return EXIT_FAILURE; | |
118 | } | |
119 | ||
120 | if (unlink(path) < 0) { | |
121 | perror("unlink"); | |
122 | return EXIT_FAILURE; | |
123 | } | |
124 | ||
125 | rc = read(fd, buf, sizeof(buf)); | |
126 | if (rc > 0) { | |
127 | fprintf(stderr, "reading from an unlinked variable " | |
128 | "shouldn't be possible\n"); | |
129 | return EXIT_FAILURE; | |
130 | } | |
131 | ||
132 | return EXIT_SUCCESS; | |
133 | } |