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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
ddeb4241 | 2 | |
11c3a366 | 3 | #include <errno.h> |
ddeb4241 | 4 | #include <fcntl.h> |
11c3a366 TA |
5 | #include <sys/stat.h> |
6 | #include <unistd.h> | |
349cc4a5 | 7 | #if HAVE_LINUX_MEMFD_H |
07630cea | 8 | #include <linux/memfd.h> |
27c64db6 | 9 | #endif |
07630cea LP |
10 | #include <stdio.h> |
11 | #include <sys/mman.h> | |
12 | #include <sys/prctl.h> | |
27c64db6 | 13 | |
b5efdb8a | 14 | #include "alloc-util.h" |
3ffd4af2 | 15 | #include "fd-util.h" |
93cc7779 | 16 | #include "macro.h" |
3ffd4af2 | 17 | #include "memfd-util.h" |
07630cea LP |
18 | #include "missing.h" |
19 | #include "string-util.h" | |
20 | #include "utf8.h" | |
ddeb4241 | 21 | |
4531a9bc | 22 | int memfd_new(const char *name) { |
7f96b1d8 | 23 | _cleanup_free_ char *g = NULL; |
4531a9bc | 24 | int fd; |
ddeb4241 | 25 | |
5755381f | 26 | if (!name) { |
7f96b1d8 LP |
27 | char pr[17] = {}; |
28 | ||
29 | /* If no name is specified we generate one. We include | |
30 | * a hint indicating our library implementation, and | |
31 | * add the thread name to it */ | |
32 | ||
33 | assert_se(prctl(PR_GET_NAME, (unsigned long) pr) >= 0); | |
34 | ||
35 | if (isempty(pr)) | |
36 | name = "sd"; | |
37 | else { | |
5755381f LP |
38 | _cleanup_free_ char *e = NULL; |
39 | ||
40 | e = utf8_escape_invalid(pr); | |
41 | if (!e) | |
42 | return -ENOMEM; | |
43 | ||
44 | g = strappend("sd-", e); | |
7f96b1d8 LP |
45 | if (!g) |
46 | return -ENOMEM; | |
47 | ||
48 | name = g; | |
49 | } | |
50 | } | |
51 | ||
45071fca | 52 | fd = memfd_create(name, MFD_ALLOW_SEALING | MFD_CLOEXEC); |
4531a9bc | 53 | if (fd < 0) |
a6082d77 | 54 | return -errno; |
ddeb4241 | 55 | |
4531a9bc | 56 | return fd; |
ddeb4241 LP |
57 | } |
58 | ||
fac9c0d5 | 59 | int memfd_map(int fd, uint64_t offset, size_t size, void **p) { |
ddeb4241 LP |
60 | void *q; |
61 | int sealed; | |
62 | ||
4531a9bc LP |
63 | assert(fd >= 0); |
64 | assert(size > 0); | |
65 | assert(p); | |
ddeb4241 | 66 | |
fac9c0d5 | 67 | sealed = memfd_get_sealed(fd); |
ddeb4241 LP |
68 | if (sealed < 0) |
69 | return sealed; | |
70 | ||
23972f42 | 71 | if (sealed) |
fac9c0d5 | 72 | q = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, offset); |
23972f42 | 73 | else |
fac9c0d5 | 74 | q = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, offset); |
23972f42 | 75 | |
ddeb4241 LP |
76 | if (q == MAP_FAILED) |
77 | return -errno; | |
78 | ||
79 | *p = q; | |
80 | return 0; | |
81 | } | |
82 | ||
fac9c0d5 | 83 | int memfd_set_sealed(int fd) { |
ddeb4241 LP |
84 | int r; |
85 | ||
4531a9bc | 86 | assert(fd >= 0); |
ddeb4241 | 87 | |
db74cc0d | 88 | r = fcntl(fd, F_ADD_SEALS, F_SEAL_SHRINK | F_SEAL_GROW | F_SEAL_WRITE | F_SEAL_SEAL); |
ddeb4241 LP |
89 | if (r < 0) |
90 | return -errno; | |
91 | ||
92 | return 0; | |
93 | } | |
94 | ||
fac9c0d5 | 95 | int memfd_get_sealed(int fd) { |
a6082d77 | 96 | int r; |
ddeb4241 | 97 | |
4531a9bc | 98 | assert(fd >= 0); |
ddeb4241 | 99 | |
fac9c0d5 | 100 | r = fcntl(fd, F_GET_SEALS); |
ddeb4241 LP |
101 | if (r < 0) |
102 | return -errno; | |
103 | ||
db74cc0d | 104 | return r == (F_SEAL_SHRINK | F_SEAL_GROW | F_SEAL_WRITE | F_SEAL_SEAL); |
ddeb4241 LP |
105 | } |
106 | ||
fac9c0d5 | 107 | int memfd_get_size(int fd, uint64_t *sz) { |
a6082d77 | 108 | struct stat stat; |
4531a9bc | 109 | int r; |
ddeb4241 | 110 | |
4531a9bc LP |
111 | assert(fd >= 0); |
112 | assert(sz); | |
ddeb4241 | 113 | |
fac9c0d5 | 114 | r = fstat(fd, &stat); |
ddeb4241 LP |
115 | if (r < 0) |
116 | return -errno; | |
117 | ||
a6082d77 | 118 | *sz = stat.st_size; |
5755381f | 119 | return 0; |
ddeb4241 LP |
120 | } |
121 | ||
fac9c0d5 | 122 | int memfd_set_size(int fd, uint64_t sz) { |
ddeb4241 LP |
123 | int r; |
124 | ||
4531a9bc | 125 | assert(fd >= 0); |
ddeb4241 | 126 | |
fac9c0d5 | 127 | r = ftruncate(fd, sz); |
ddeb4241 LP |
128 | if (r < 0) |
129 | return -errno; | |
130 | ||
5755381f | 131 | return 0; |
ddeb4241 | 132 | } |
453a0c29 | 133 | |
4531a9bc LP |
134 | int memfd_new_and_map(const char *name, size_t sz, void **p) { |
135 | _cleanup_close_ int fd = -1; | |
453a0c29 LP |
136 | int r; |
137 | ||
4531a9bc LP |
138 | assert(sz > 0); |
139 | assert(p); | |
140 | ||
141 | fd = memfd_new(name); | |
142 | if (fd < 0) | |
143 | return fd; | |
453a0c29 | 144 | |
4531a9bc | 145 | r = memfd_set_size(fd, sz); |
8a02deca | 146 | if (r < 0) |
453a0c29 | 147 | return r; |
453a0c29 | 148 | |
4531a9bc | 149 | r = memfd_map(fd, 0, sz, p); |
8a02deca | 150 | if (r < 0) |
453a0c29 | 151 | return r; |
453a0c29 | 152 | |
c10d6bdb | 153 | return TAKE_FD(fd); |
453a0c29 | 154 | } |