/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2013 Intel Corporation Author: Auke Kok <auke-jan.h.kok@intel.com> systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <sys/xattr.h> #include "util.h" #include "process-util.h" #include "path-util.h" #include "fileio.h" #include "smack-util.h" #define SMACK_FLOOR_LABEL "_" #define SMACK_STAR_LABEL "*" #ifdef HAVE_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 = 0; assert(label); if (!mac_smack_use()) return 0; p = procfs_file_alloca(pid, "attr/current"); r = write_string_file(p, label, 0); if (r < 0) return r; return r; } int mac_smack_fix(const char *path, bool ignore_enoent, bool ignore_erofs) { struct stat st; int r = 0; assert(path); if (!mac_smack_use()) return 0; /* * Path must be in /dev and must exist */ if (!path_startswith(path, "/dev")) return 0; r = lstat(path, &st); if (r >= 0) { const char *label; /* * 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; r = lsetxattr(path, "security.SMACK64", label, strlen(label), 0); /* If the FS doesn't support labels, then exit without warning */ if (r < 0 && errno == EOPNOTSUPP) return 0; } if (r < 0) { /* Ignore ENOENT in some cases */ if (ignore_enoent && errno == ENOENT) return 0; if (ignore_erofs && errno == EROFS) return 0; r = log_debug_errno(errno, "Unable to fix SMACK label of %s: %m", path); } 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(const char *path, bool ignore_enoent, bool ignore_erofs) { return 0; } #endif