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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 13:00:47 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 13:00:47 +0000 |
commit | 2cb7e0aaedad73b076ea18c6900b0e86c5760d79 (patch) | |
tree | da68ca54bb79f4080079bf0828acda937593a4e1 /src/basic/smack-util.c | |
parent | Initial commit. (diff) | |
download | systemd-2cb7e0aaedad73b076ea18c6900b0e86c5760d79.tar.xz systemd-2cb7e0aaedad73b076ea18c6900b0e86c5760d79.zip |
Adding upstream version 247.3.upstream/247.3upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/basic/smack-util.c')
-rw-r--r-- | src/basic/smack-util.c | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/src/basic/smack-util.c b/src/basic/smack-util.c new file mode 100644 index 0000000..3362ee3 --- /dev/null +++ b/src/basic/smack-util.c @@ -0,0 +1,288 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/*** + Copyright © 2013 Intel Corporation + + Author: Auke Kok <auke-jan.h.kok@intel.com> +***/ + +#include <errno.h> +#include <fcntl.h> +#include <sys/stat.h> +#include <sys/xattr.h> +#include <unistd.h> + +#include "alloc-util.h" +#include "fd-util.h" +#include "fileio.h" +#include "log.h" +#include "macro.h" +#include "path-util.h" +#include "process-util.h" +#include "smack-util.h" +#include "stdio-util.h" +#include "string-table.h" +#include "xattr-util.h" + +#if ENABLE_SMACK +bool mac_smack_use(void) { + static int cached_use = -1; + + if (cached_use < 0) + cached_use = access("/sys/fs/smackfs/", F_OK) >= 0; + + return cached_use; +} + +static const char* const smack_attr_table[_SMACK_ATTR_MAX] = { + [SMACK_ATTR_ACCESS] = "security.SMACK64", + [SMACK_ATTR_EXEC] = "security.SMACK64EXEC", + [SMACK_ATTR_MMAP] = "security.SMACK64MMAP", + [SMACK_ATTR_TRANSMUTE] = "security.SMACK64TRANSMUTE", + [SMACK_ATTR_IPIN] = "security.SMACK64IPIN", + [SMACK_ATTR_IPOUT] = "security.SMACK64IPOUT", +}; + +DEFINE_STRING_TABLE_LOOKUP(smack_attr, SmackAttr); + +int mac_smack_read(const char *path, SmackAttr attr, char **label) { + assert(path); + assert(attr >= 0 && attr < _SMACK_ATTR_MAX); + assert(label); + + if (!mac_smack_use()) + return 0; + + return getxattr_malloc(path, smack_attr_to_string(attr), label, true); +} + +int mac_smack_read_fd(int fd, SmackAttr attr, char **label) { + assert(fd >= 0); + assert(attr >= 0 && attr < _SMACK_ATTR_MAX); + assert(label); + + if (!mac_smack_use()) + return 0; + + return fgetxattr_malloc(fd, smack_attr_to_string(attr), label); +} + +int mac_smack_apply(const char *path, SmackAttr attr, const char *label) { + int r; + + assert(path); + assert(attr >= 0 && attr < _SMACK_ATTR_MAX); + + if (!mac_smack_use()) + return 0; + + if (label) + r = lsetxattr(path, smack_attr_to_string(attr), label, strlen(label), 0); + else + r = lremovexattr(path, smack_attr_to_string(attr)); + if (r < 0) + return -errno; + + return 0; +} + +int mac_smack_apply_fd(int fd, SmackAttr attr, const char *label) { + int r; + + assert(fd >= 0); + assert(attr >= 0 && attr < _SMACK_ATTR_MAX); + + if (!mac_smack_use()) + return 0; + + if (label) + r = fsetxattr(fd, smack_attr_to_string(attr), label, strlen(label), 0); + else + r = fremovexattr(fd, smack_attr_to_string(attr)); + if (r < 0) + return -errno; + + return 0; +} + +int mac_smack_apply_pid(pid_t pid, const char *label) { + const char *p; + int r; + + assert(label); + + if (!mac_smack_use()) + return 0; + + p = procfs_file_alloca(pid, "attr/current"); + r = write_string_file(p, label, WRITE_STRING_FILE_DISABLE_BUFFER); + if (r < 0) + return r; + + return r; +} + +static int smack_fix_fd(int fd , const char *abspath, LabelFixFlags flags) { + char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)]; + const char *label; + struct stat st; + int r; + + /* The caller should have done the sanity checks. */ + assert(abspath); + assert(path_is_absolute(abspath)); + + /* Path must be in /dev. */ + if (!path_startswith(abspath, "/dev")) + return 0; + + if (fstat(fd, &st) < 0) + return -errno; + + /* + * Label directories and character devices "*". + * Label symlinks "_". + * Don't change anything else. + */ + + if (S_ISDIR(st.st_mode)) + label = SMACK_STAR_LABEL; + else if (S_ISLNK(st.st_mode)) + label = SMACK_FLOOR_LABEL; + else if (S_ISCHR(st.st_mode)) + label = SMACK_STAR_LABEL; + else + return 0; + + xsprintf(procfs_path, "/proc/self/fd/%i", fd); + if (setxattr(procfs_path, "security.SMACK64", label, strlen(label), 0) < 0) { + _cleanup_free_ char *old_label = NULL; + + r = -errno; + + /* If the FS doesn't support labels, then exit without warning */ + if (r == -EOPNOTSUPP) + return 0; + + /* It the FS is read-only and we were told to ignore failures caused by that, suppress error */ + if (r == -EROFS && (flags & LABEL_IGNORE_EROFS)) + return 0; + + /* If the old label is identical to the new one, suppress any kind of error */ + if (getxattr_malloc(procfs_path, "security.SMACK64", &old_label, false) >= 0 && + streq(old_label, label)) + return 0; + + return log_debug_errno(r, "Unable to fix SMACK label of %s: %m", abspath); + } + + return 0; +} + +int mac_smack_fix_at(int dirfd, const char *path, LabelFixFlags flags) { + _cleanup_free_ char *p = NULL; + _cleanup_close_ int fd = -1; + int r; + + assert(path); + + if (!mac_smack_use()) + return 0; + + fd = openat(dirfd, path, O_NOFOLLOW|O_CLOEXEC|O_PATH); + if (fd < 0) { + if ((flags & LABEL_IGNORE_ENOENT) && errno == ENOENT) + return 0; + + return -errno; + } + + if (!path_is_absolute(path)) { + r = fd_get_path(fd, &p); + if (r < 0) + return r; + path = p; + } + + return smack_fix_fd(fd, path, flags); +} + +int mac_smack_fix_container(const char *path, const char *inside_path, LabelFixFlags flags) { + _cleanup_free_ char *abspath = NULL; + _cleanup_close_ int fd = -1; + int r; + + assert(path); + + if (!mac_smack_use()) + return 0; + + r = path_make_absolute_cwd(path, &abspath); + if (r < 0) + return r; + + fd = open(abspath, O_NOFOLLOW|O_CLOEXEC|O_PATH); + if (fd < 0) { + if ((flags & LABEL_IGNORE_ENOENT) && errno == ENOENT) + return 0; + + return -errno; + } + + return smack_fix_fd(fd, inside_path, flags); +} + +int mac_smack_copy(const char *dest, const char *src) { + int r; + _cleanup_free_ char *label = NULL; + + assert(dest); + assert(src); + + r = mac_smack_read(src, SMACK_ATTR_ACCESS, &label); + if (r < 0) + return r; + + r = mac_smack_apply(dest, SMACK_ATTR_ACCESS, label); + if (r < 0) + return r; + + return r; +} + +#else +bool mac_smack_use(void) { + return false; +} + +int mac_smack_read(const char *path, SmackAttr attr, char **label) { + return -EOPNOTSUPP; +} + +int mac_smack_read_fd(int fd, SmackAttr attr, char **label) { + return -EOPNOTSUPP; +} + +int mac_smack_apply(const char *path, SmackAttr attr, const char *label) { + return 0; +} + +int mac_smack_apply_fd(int fd, SmackAttr attr, const char *label) { + return 0; +} + +int mac_smack_apply_pid(pid_t pid, const char *label) { + return 0; +} + +int mac_smack_fix_container(const char *path, const char *inside_path, LabelFixFlags flags) { + return 0; +} + +int mac_smack_fix_at(int dirfd, const char *path, LabelFixFlags flags) { + return 0; +} + +int mac_smack_copy(const char *dest, const char *src) { + return 0; +} +#endif |