]>
Commit | Line | Data |
---|---|---|
db9ecf05 | 1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
3577de7a KS |
2 | |
3 | #include <errno.h> | |
a8fbdf54 TA |
4 | #include <fcntl.h> |
5 | #include <stdbool.h> | |
3577de7a | 6 | #include <stdlib.h> |
07630cea | 7 | #include <sys/stat.h> |
a8fbdf54 | 8 | #include <syslog.h> |
3577de7a KS |
9 | #include <unistd.h> |
10 | ||
b5efdb8a | 11 | #include "alloc-util.h" |
a965a319 | 12 | #include "architecture.h" |
affb60b1 LP |
13 | #include "base-filesystem.h" |
14 | #include "fd-util.h" | |
3577de7a KS |
15 | #include "log.h" |
16 | #include "macro.h" | |
d8b4d14d | 17 | #include "nulstr-util.h" |
65290fbf | 18 | #include "path-util.h" |
07630cea | 19 | #include "string-util.h" |
affb60b1 | 20 | #include "umask-util.h" |
ee104e11 | 21 | #include "user-util.h" |
3577de7a KS |
22 | |
23 | typedef struct BaseFilesystem { | |
04ba1bb0 | 24 | const char *dir; /* directory or symlink to create */ |
3577de7a | 25 | mode_t mode; |
04ba1bb0 | 26 | const char *target; /* if non-NULL create as symlink to this target */ |
a6f44d61 | 27 | const char *exists; /* conditionalize this entry on existence of this file */ |
6404ecc8 | 28 | bool ignore_failure; |
3577de7a KS |
29 | } BaseFilesystem; |
30 | ||
31 | static const BaseFilesystem table[] = { | |
30d7c9c4 HH |
32 | { "bin", 0, "usr/bin\0", NULL }, |
33 | { "lib", 0, "usr/lib\0", NULL }, | |
6404ecc8 | 34 | { "root", 0755, NULL, NULL, true }, |
30d7c9c4 | 35 | { "sbin", 0, "usr/sbin\0", NULL }, |
03cfe0d5 LP |
36 | { "usr", 0755, NULL, NULL }, |
37 | { "var", 0755, NULL, NULL }, | |
38 | { "etc", 0755, NULL, NULL }, | |
10404d52 DH |
39 | { "proc", 0755, NULL, NULL, true }, |
40 | { "sys", 0755, NULL, NULL, true }, | |
41 | { "dev", 0755, NULL, NULL, true }, | |
6f32005f | 42 | |
04ba1bb0 LP |
43 | /* Various architecture ABIs define the path to the dynamic loader via the /lib64/ subdirectory of |
44 | * the root directory. When booting from an otherwise empty root file system (where only /usr/ has | |
45 | * been mounted into) it is thus necessary to create a symlink pointing to the right subdirectory of | |
46 | * /usr/ first — otherwise we couldn't invoke any dynamic binary. Let's detect this case here, and | |
47 | * create the symlink as needed should it be missing. We prefer doing this consistently with Debian's | |
48 | * multiarch logic, but support Fedora-style multilib too.*/ | |
6f32005f | 49 | #if defined(__aarch64__) |
dcc87c68 ZJS |
50 | /* aarch64 ELF ABI actually says dynamic loader is in /lib/, but Fedora puts it in /lib64/ anyway and |
51 | * just symlinks /lib/ld-linux-aarch64.so.1 to ../lib64/ld-linux-aarch64.so.1. For this to work | |
52 | * correctly, /lib64/ must be symlinked to /usr/lib64/. */ | |
a965a319 | 53 | { "lib64", 0, "usr/lib/"LIB_ARCH_TUPLE"\0" |
dcc87c68 ZJS |
54 | "usr/lib64\0", "ld-linux-aarch64.so.1" }, |
55 | # define KNOW_LIB64_DIRS 1 | |
6f32005f ZJS |
56 | #elif defined(__alpha__) |
57 | #elif defined(__arc__) || defined(__tilegx__) | |
58 | #elif defined(__arm__) | |
2db409ce ZJS |
59 | /* No /lib64 on arm. The linker is /lib/ld-linux-armhf.so.3. */ |
60 | # define KNOW_LIB64_DIRS 1 | |
6f32005f | 61 | #elif defined(__i386__) || defined(__x86_64__) |
a965a319 | 62 | { "lib64", 0, "usr/lib/"LIB_ARCH_TUPLE"\0" |
30d7c9c4 | 63 | "usr/lib64\0", "ld-linux-x86-64.so.2" }, |
6f32005f ZJS |
64 | # define KNOW_LIB64_DIRS 1 |
65 | #elif defined(__ia64__) | |
66 | #elif defined(__m68k__) | |
996eaea5 ZJS |
67 | /* No link needed. */ |
68 | # define KNOW_LIB64_DIRS 1 | |
6f32005f ZJS |
69 | #elif defined(_MIPS_SIM) |
70 | # if _MIPS_SIM == _MIPS_SIM_ABI32 | |
71 | # elif _MIPS_SIM == _MIPS_SIM_NABI32 | |
72 | # elif _MIPS_SIM == _MIPS_SIM_ABI64 | |
73 | # else | |
74 | # error "Unknown MIPS ABI" | |
75 | # endif | |
76 | #elif defined(__powerpc__) | |
e98157b9 | 77 | # if defined(__PPC64__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ |
a965a319 | 78 | { "lib64", 0, "usr/lib/"LIB_ARCH_TUPLE"\0" |
e98157b9 ZJS |
79 | "usr/lib64\0", "ld64.so.2" }, |
80 | # define KNOW_LIB64_DIRS 1 | |
81 | # elif defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ | |
82 | /* powerpc64-linux-gnu */ | |
83 | # else | |
84 | /* powerpc-linux-gnu */ | |
85 | # endif | |
6f32005f ZJS |
86 | #elif defined(__riscv) |
87 | # if __riscv_xlen == 32 | |
88 | # elif __riscv_xlen == 64 | |
761e9382 | 89 | /* Same situation as for aarch64 */ |
a965a319 | 90 | { "lib64", 0, "usr/lib/"LIB_ARCH_TUPLE"\0" |
761e9382 ZJS |
91 | "usr/lib64\0", "ld-linux-riscv64-lp64d.so.1" }, |
92 | # define KNOW_LIB64_DIRS 1 | |
6f32005f ZJS |
93 | # else |
94 | # error "Unknown RISC-V ABI" | |
95 | # endif | |
96 | #elif defined(__s390__) | |
fe037986 | 97 | /* s390-linux-gnu */ |
6f32005f | 98 | #elif defined(__s390x__) |
a965a319 | 99 | { "lib64", 0, "usr/lib/"LIB_ARCH_TUPLE"\0" |
fe037986 ZJS |
100 | "usr/lib64", "ld-lsb-s390x.so.3" }, |
101 | # define KNOW_LIB64_DIRS 1 | |
6f32005f | 102 | #elif defined(__sparc__) |
e1ae9755 | 103 | #endif |
6f32005f | 104 | /* gcc doesn't allow pragma to be used within constructs, hence log about this separately below */ |
3577de7a KS |
105 | }; |
106 | ||
6f32005f ZJS |
107 | #ifndef KNOW_LIB64_DIRS |
108 | # pragma message "Please add an entry above specifying whether your architecture uses /lib64/, /lib32/, or no such links." | |
04ba1bb0 LP |
109 | #endif |
110 | ||
03cfe0d5 | 111 | int base_filesystem_create(const char *root, uid_t uid, gid_t gid) { |
3577de7a | 112 | _cleanup_close_ int fd = -1; |
8a383bf2 | 113 | int r; |
3577de7a KS |
114 | |
115 | fd = open(root, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW); | |
4a62c710 MS |
116 | if (fd < 0) |
117 | return log_error_errno(errno, "Failed to open root file system: %m"); | |
3577de7a | 118 | |
9b4aba10 | 119 | for (size_t i = 0; i < ELEMENTSOF(table); i++) { |
6f4f8056 HH |
120 | if (faccessat(fd, table[i].dir, F_OK, AT_SYMLINK_NOFOLLOW) >= 0) |
121 | continue; | |
122 | ||
3577de7a | 123 | if (table[i].target) { |
6dc2852c | 124 | const char *target = NULL, *s; |
e1ae9755 KS |
125 | |
126 | /* check if one of the targets exists */ | |
127 | NULSTR_FOREACH(s, table[i].target) { | |
128 | if (faccessat(fd, s, F_OK, AT_SYMLINK_NOFOLLOW) < 0) | |
129 | continue; | |
130 | ||
3fd165e5 KS |
131 | /* check if a specific file exists at the target path */ |
132 | if (table[i].exists) { | |
133 | _cleanup_free_ char *p = NULL; | |
134 | ||
65290fbf | 135 | p = path_join(s, table[i].exists); |
3fd165e5 KS |
136 | if (!p) |
137 | return log_oom(); | |
138 | ||
139 | if (faccessat(fd, p, F_OK, AT_SYMLINK_NOFOLLOW) < 0) | |
140 | continue; | |
141 | } | |
142 | ||
e1ae9755 KS |
143 | target = s; |
144 | break; | |
145 | } | |
146 | ||
147 | if (!target) | |
3577de7a KS |
148 | continue; |
149 | ||
8258578f LP |
150 | if (symlinkat(target, fd, table[i].dir) < 0) { |
151 | log_full_errno(IN_SET(errno, EEXIST, EROFS) || table[i].ignore_failure ? LOG_DEBUG : LOG_ERR, errno, | |
152 | "Failed to create symlink at %s/%s: %m", root, table[i].dir); | |
153 | ||
154 | if (IN_SET(errno, EEXIST, EROFS) || table[i].ignore_failure) | |
155 | continue; | |
156 | ||
157 | return -errno; | |
158 | } | |
03cfe0d5 | 159 | |
9b4aba10 | 160 | if (uid_is_valid(uid) || gid_is_valid(gid)) |
03cfe0d5 LP |
161 | if (fchownat(fd, table[i].dir, uid, gid, AT_SYMLINK_NOFOLLOW) < 0) |
162 | return log_error_errno(errno, "Failed to chown symlink at %s/%s: %m", root, table[i].dir); | |
03cfe0d5 | 163 | |
3577de7a KS |
164 | continue; |
165 | } | |
166 | ||
167 | RUN_WITH_UMASK(0000) | |
168 | r = mkdirat(fd, table[i].dir, table[i].mode); | |
8258578f LP |
169 | if (r < 0) { |
170 | log_full_errno(IN_SET(errno, EEXIST, EROFS) || table[i].ignore_failure ? LOG_DEBUG : LOG_ERR, errno, | |
6404ecc8 LP |
171 | "Failed to create directory at %s/%s: %m", root, table[i].dir); |
172 | ||
8258578f LP |
173 | if (IN_SET(errno, EEXIST, EROFS) || table[i].ignore_failure) |
174 | continue; | |
d1d59eeb | 175 | |
8258578f | 176 | return -errno; |
6404ecc8 | 177 | } |
03cfe0d5 | 178 | |
9b4aba10 | 179 | if (uid != UID_INVALID || gid != UID_INVALID) |
03cfe0d5 LP |
180 | if (fchownat(fd, table[i].dir, uid, gid, AT_SYMLINK_NOFOLLOW) < 0) |
181 | return log_error_errno(errno, "Failed to chown directory at %s/%s: %m", root, table[i].dir); | |
3577de7a KS |
182 | } |
183 | ||
184 | return 0; | |
185 | } |