/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2014 Kay Sievers 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 <errno.h> #include <sys/stat.h> #include <stdlib.h> #include <unistd.h> #include "base-filesystem.h" #include "log.h" #include "macro.h" #include "util.h" typedef struct BaseFilesystem { const char *dir; mode_t mode; const char *target; const char *exists; } BaseFilesystem; static const BaseFilesystem table[] = { { "bin", 0, "usr/bin\0", NULL }, { "lib", 0, "usr/lib\0", NULL }, { "root", 0755, NULL, NULL }, { "sbin", 0, "usr/sbin\0", NULL }, { "usr", 0755, NULL, NULL }, { "var", 0755, NULL, NULL }, { "etc", 0755, NULL, NULL }, #if defined(__i386__) || defined(__x86_64__) { "lib64", 0, "usr/lib/x86_64-linux-gnu\0" "usr/lib64\0", "ld-linux-x86-64.so.2" }, #endif }; int base_filesystem_create(const char *root, uid_t uid, gid_t gid) { _cleanup_close_ int fd = -1; unsigned i; int r = 0; fd = open(root, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW); if (fd < 0) return log_error_errno(errno, "Failed to open root file system: %m"); for (i = 0; i < ELEMENTSOF(table); i ++) { if (faccessat(fd, table[i].dir, F_OK, AT_SYMLINK_NOFOLLOW) >= 0) continue; if (table[i].target) { const char *target = NULL, *s; /* check if one of the targets exists */ NULSTR_FOREACH(s, table[i].target) { if (faccessat(fd, s, F_OK, AT_SYMLINK_NOFOLLOW) < 0) continue; /* check if a specific file exists at the target path */ if (table[i].exists) { _cleanup_free_ char *p = NULL; p = strjoin(s, "/", table[i].exists, NULL); if (!p) return log_oom(); if (faccessat(fd, p, F_OK, AT_SYMLINK_NOFOLLOW) < 0) continue; } target = s; break; } if (!target) continue; r = symlinkat(target, fd, table[i].dir); if (r < 0 && errno != EEXIST) return log_error_errno(errno, "Failed to create symlink at %s/%s: %m", root, table[i].dir); if (uid != UID_INVALID || gid != UID_INVALID) { if (fchownat(fd, table[i].dir, uid, gid, AT_SYMLINK_NOFOLLOW) < 0) return log_error_errno(errno, "Failed to chown symlink at %s/%s: %m", root, table[i].dir); } continue; } RUN_WITH_UMASK(0000) r = mkdirat(fd, table[i].dir, table[i].mode); if (r < 0 && errno != EEXIST) return log_error_errno(errno, "Failed to create directory at %s/%s: %m", root, table[i].dir); if (uid != UID_INVALID || gid != UID_INVALID) { if (fchownat(fd, table[i].dir, uid, gid, AT_SYMLINK_NOFOLLOW) < 0) return log_error_errno(errno, "Failed to chown directory at %s/%s: %m", root, table[i].dir); } } return 0; }