2 eac9287d 2023-06-24 op * Copyright (c) 2021, 2023 Omar Polo <op@omarpolo.com>
3 4d9d3093 2023-08-23 op * Copyright (c) 2022 Claudio Jeker <claudio@openbsd.org>
5 e29dbd72 2021-01-23 op * Permission to use, copy, modify, and distribute this software for any
6 e29dbd72 2021-01-23 op * purpose with or without fee is hereby granted, provided that the above
7 e29dbd72 2021-01-23 op * copyright notice and this permission notice appear in all copies.
9 e29dbd72 2021-01-23 op * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 e29dbd72 2021-01-23 op * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 e29dbd72 2021-01-23 op * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 e29dbd72 2021-01-23 op * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 e29dbd72 2021-01-23 op * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 e29dbd72 2021-01-23 op * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 e29dbd72 2021-01-23 op * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 dafb57b8 2021-01-15 op #include "gmid.h"
19 eae52ad4 2023-06-06 op #include "log.h"
21 0b62f484 2023-05-08 op #if defined(__OpenBSD__)
23 71b7eb2f 2021-01-17 op #include <unistd.h>
26 c26f2460 2023-06-08 op sandbox_main_process(void)
28 226f13ec 2023-07-24 op if (pledge("stdio rpath wpath cpath inet dns sendfd", NULL) == -1)
29 c26f2460 2023-06-08 op fatal("pledge");
33 1e0b9745 2023-05-08 op sandbox_server_process(void)
35 c5ded53a 2023-06-23 op if (pledge("stdio rpath inet unix dns recvfd", NULL) == -1)
36 8e56d6ad 2021-02-11 op fatal("pledge");
40 86693a33 2023-06-11 op sandbox_crypto_process(void)
42 86693a33 2023-06-11 op if (pledge("stdio recvfd", NULL) == -1)
43 86693a33 2023-06-11 op fatal("pledge");
47 62e001b0 2021-03-20 op sandbox_logger_process(void)
49 e952c505 2021-06-15 op if (pledge("stdio recvfd", NULL) == -1)
50 2dd5994a 2023-06-06 op fatal("pledge");
53 4d9d3093 2023-08-23 op #elif HAVE_LANDLOCK
55 4d9d3093 2023-08-23 op #include <linux/landlock.h>
57 4d9d3093 2023-08-23 op #include <sys/prctl.h>
58 4d9d3093 2023-08-23 op #include <sys/syscall.h>
59 4d9d3093 2023-08-23 op #include <sys/types.h>
61 4d9d3093 2023-08-23 op #include <errno.h>
64 4d9d3093 2023-08-23 op * What's the deal with landlock? While distro with linux >= 5.13
65 4d9d3093 2023-08-23 op * have the struct declarations, libc wrappers are missing. The
66 4d9d3093 2023-08-23 op * sample landlock code provided by the authors includes these "shims"
67 4d9d3093 2023-08-23 op * in their example for the landlock API until libc provides them.
70 4d9d3093 2023-08-23 op #ifndef landlock_create_ruleset
71 4d9d3093 2023-08-23 op static inline int
72 4d9d3093 2023-08-23 op landlock_create_ruleset(const struct landlock_ruleset_attr *attr, size_t size,
75 4d9d3093 2023-08-23 op return syscall(__NR_landlock_create_ruleset, attr, size, flags);
79 4d9d3093 2023-08-23 op #ifndef landlock_add_rule
80 4d9d3093 2023-08-23 op static inline int
81 4d9d3093 2023-08-23 op landlock_add_rule(int ruleset_fd, enum landlock_rule_type type,
82 4d9d3093 2023-08-23 op const void *attr, __u32 flags)
84 4d9d3093 2023-08-23 op return syscall(__NR_landlock_add_rule, ruleset_fd, type, attr, flags);
88 4d9d3093 2023-08-23 op #ifndef landlock_restrict_self
89 4d9d3093 2023-08-23 op static inline int
90 4d9d3093 2023-08-23 op landlock_restrict_self(int ruleset_fd, __u32 flags)
92 4d9d3093 2023-08-23 op return syscall(__NR_landlock_restrict_self, ruleset_fd, flags);
97 4d9d3093 2023-08-23 op * Maybe we should ship with a full copy of the linux headers because
98 4d9d3093 2023-08-23 op * you never know...
101 4d9d3093 2023-08-23 op #ifndef LANDLOCK_ACCESS_FS_REFER
102 4d9d3093 2023-08-23 op #define LANDLOCK_ACCESS_FS_REFER (1ULL << 13)
105 4d9d3093 2023-08-23 op #ifndef LANDLOCK_ACCESS_FS_TRUNCATE
106 4d9d3093 2023-08-23 op #define LANDLOCK_ACCESS_FS_TRUNCATE (1ULL << 14)
109 4d9d3093 2023-08-23 op static int landlock_state;
110 4d9d3093 2023-08-23 op static int landlock_fd;
113 4d9d3093 2023-08-23 op * Initialize landlock, which is stupidly complicated.
116 4d9d3093 2023-08-23 op landlock_init(void)
118 4d9d3093 2023-08-23 op struct landlock_ruleset_attr rattr = {
120 4d9d3093 2023-08-23 op * List all capabilities currently defined by landlock.
121 4d9d3093 2023-08-23 op * Failure in doing so will implicitly allow those actions
122 4d9d3093 2023-08-23 op * (i.e. omitting READ_FILE will allow to read _any_ file.)
124 4d9d3093 2023-08-23 op .handled_access_fs =
125 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_EXECUTE |
126 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_READ_FILE |
127 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_READ_DIR |
128 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_WRITE_FILE |
129 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_REMOVE_DIR |
130 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_REMOVE_FILE |
131 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_MAKE_CHAR |
132 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_MAKE_DIR |
133 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_MAKE_REG |
134 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_MAKE_SOCK |
135 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_MAKE_FIFO |
136 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_MAKE_BLOCK |
137 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_MAKE_SYM |
138 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_REFER |
139 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_TRUNCATE,
141 4d9d3093 2023-08-23 op int fd, abi, saved_errno;
143 4d9d3093 2023-08-23 op if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) == -1)
146 4d9d3093 2023-08-23 op abi = landlock_create_ruleset(NULL, 0, LANDLOCK_CREATE_RULESET_VERSION);
147 4d9d3093 2023-08-23 op if (abi == -1)
150 4d9d3093 2023-08-23 op rattr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_REFER;
152 4d9d3093 2023-08-23 op rattr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_TRUNCATE;
154 4d9d3093 2023-08-23 op landlock_state = 1;
155 4d9d3093 2023-08-23 op return landlock_create_ruleset(&rattr, sizeof(rattr), 0);
159 4d9d3093 2023-08-23 op landlock_lock(void)
161 4d9d3093 2023-08-23 op int saved_errno;
163 4d9d3093 2023-08-23 op if (landlock_restrict_self(landlock_fd, 0)) {
164 4d9d3093 2023-08-23 op saved_errno = errno;
165 4d9d3093 2023-08-23 op close(landlock_fd);
166 4d9d3093 2023-08-23 op errno = saved_errno;
167 4d9d3093 2023-08-23 op landlock_state = -1;
171 4d9d3093 2023-08-23 op landlock_state = 2;
172 4d9d3093 2023-08-23 op close(landlock_fd);
177 4d9d3093 2023-08-23 op landlock_unveil(const char *path, const char *permissions)
179 4d9d3093 2023-08-23 op struct landlock_path_beneath_attr lpba;
180 4d9d3093 2023-08-23 op int fd, saved_errno;
182 4d9d3093 2023-08-23 op if (landlock_state == 0) {
183 4d9d3093 2023-08-23 op if ((landlock_fd = landlock_init()) == -1) {
184 4d9d3093 2023-08-23 op landlock_state = -1;
185 4d9d3093 2023-08-23 op /* this kernel doesn't have landlock built in */
186 4d9d3093 2023-08-23 op if (errno == ENOSYS || errno == EOPNOTSUPP)
192 4d9d3093 2023-08-23 op /* no landlock available */
193 4d9d3093 2023-08-23 op if (landlock_state == -1)
196 4d9d3093 2023-08-23 op if (path == NULL && permissions == NULL)
197 4d9d3093 2023-08-23 op return landlock_lock();
199 4d9d3093 2023-08-23 op if (path == NULL || permissions == NULL || landlock_state != 1) {
200 4d9d3093 2023-08-23 op errno = EINVAL;
204 4d9d3093 2023-08-23 op if (!strcmp(permissions, "r")) {
205 4d9d3093 2023-08-23 op fd = open(path, O_PATH | O_CLOEXEC);
206 4d9d3093 2023-08-23 op if (fd == -1)
208 4d9d3093 2023-08-23 op lpba = (struct landlock_path_beneath_attr){
209 4d9d3093 2023-08-23 op .allowed_access =
210 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_READ_FILE |
211 4d9d3093 2023-08-23 op LANDLOCK_ACCESS_FS_READ_DIR,
212 4d9d3093 2023-08-23 op .parent_fd = fd,
214 4d9d3093 2023-08-23 op if (landlock_add_rule(landlock_fd, LANDLOCK_RULE_PATH_BENEATH,
215 4d9d3093 2023-08-23 op &lpba, 0) == -1) {
216 4d9d3093 2023-08-23 op saved_errno = errno;
218 4d9d3093 2023-08-23 op errno = saved_errno;
228 4d9d3093 2023-08-23 op sandbox_main_process(void)
234 4d9d3093 2023-08-23 op sandbox_server_process(void)
236 4d9d3093 2023-08-23 op if (landlock_unveil("/", "r") == -1)
237 4d9d3093 2023-08-23 op fatal("landlock_unveil(/)");
239 4d9d3093 2023-08-23 op if (landlock_unveil(NULL, NULL) == -1)
240 4d9d3093 2023-08-23 op fatal("landlock_unveil(NULL, NULL)");
244 4d9d3093 2023-08-23 op sandbox_crypto_process(void)
246 4d9d3093 2023-08-23 op /* contrary to unveil(2), this removes all fs access. */
247 4d9d3093 2023-08-23 op if (landlock_unveil(NULL, NULL) == -1)
248 4d9d3093 2023-08-23 op fatal("landlock_unveil(NULL, NULL)");
252 4d9d3093 2023-08-23 op sandbox_logger_process(void)
254 4d9d3093 2023-08-23 op /* contrary to unveil(2), this removes all fs access. */
255 4d9d3093 2023-08-23 op if (landlock_unveil(NULL, NULL) == -1)
256 4d9d3093 2023-08-23 op fatal("landlock_unveil(NULL, NULL)");
262 fc440833 2023-06-08 op sandbox_main_process(void)
268 1e0b9745 2023-05-08 op sandbox_server_process(void)
274 86693a33 2023-06-11 op sandbox_crypto_process(void)
280 62e001b0 2021-03-20 op sandbox_logger_process(void)