/*-*- 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 "path-util.h" #include "fileio.h" #include "smack-util.h" #define SMACK_FLOOR_LABEL "_" #define SMACK_STAR_LABEL "*" bool mac_smack_use(void) { #ifdef HAVE_SMACK static int cached_use = -1; if (cached_use < 0) cached_use = access("/sys/fs/smackfs/", F_OK) >= 0; return cached_use; #else return false; #endif } int mac_smack_apply(const char *path, const char *label) { int r = 0; assert(path); #ifdef HAVE_SMACK if (!mac_smack_use()) return 0; if (label) r = lsetxattr(path, "security.SMACK64", label, strlen(label), 0); else r = lremovexattr(path, "security.SMACK64"); if (r < 0) return -errno; #endif return r; } int mac_smack_apply_fd(int fd, const char *label) { int r = 0; assert(fd >= 0); #ifdef HAVE_SMACK if (!mac_smack_use()) return 0; if (label) r = fsetxattr(fd, "security.SMACK64", label, strlen(label), 0); else r = fremovexattr(fd, "security.SMACK64"); if (r < 0) return -errno; #endif return r; } int mac_smack_apply_ip_out_fd(int fd, const char *label) { int r = 0; assert(fd >= 0); #ifdef HAVE_SMACK if (!mac_smack_use()) return 0; if (label) r = fsetxattr(fd, "security.SMACK64IPOUT", label, strlen(label), 0); else r = fremovexattr(fd, "security.SMACK64IPOUT"); if (r < 0) return -errno; #endif return r; } int mac_smack_apply_ip_in_fd(int fd, const char *label) { int r = 0; assert(fd >= 0); #ifdef HAVE_SMACK if (!mac_smack_use()) return 0; if (label) r = fsetxattr(fd, "security.SMACK64IPIN", label, strlen(label), 0); else r = fremovexattr(fd, "security.SMACK64IPIN"); if (r < 0) return -errno; #endif return r; } int mac_smack_apply_pid(pid_t pid, const char *label) { int r = 0; const char *p; assert(label); #ifdef HAVE_SMACK if (!mac_smack_use()) return 0; p = procfs_file_alloca(pid, "attr/current"); r = write_string_file(p, label); if (r < 0) return r; #endif return r; } int mac_smack_fix(const char *path, bool ignore_enoent, bool ignore_erofs) { int r = 0; #ifdef HAVE_SMACK struct stat st; 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 == ENOTSUP) return 0; } if (r < 0) { /* Ignore ENOENT in some cases */ if (ignore_enoent && errno == ENOENT) return 0; if (ignore_erofs && errno == EROFS) return 0; log_debug("Unable to fix SMACK label of %s: %m", path); r = -errno; } #endif return r; }