125 lines
4.8 KiB
C
125 lines
4.8 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
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#include <errno.h>
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#include <fcntl.h>
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#include <stdbool.h>
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#include <stdlib.h>
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#include <sys/stat.h>
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#include <syslog.h>
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#include <unistd.h>
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#include "alloc-util.h"
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#include "base-filesystem.h"
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#include "fd-util.h"
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#include "log.h"
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#include "macro.h"
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#include "nulstr-util.h"
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#include "path-util.h"
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#include "string-util.h"
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#include "umask-util.h"
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#include "user-util.h"
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typedef struct BaseFilesystem {
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const char *dir;
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mode_t mode;
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const char *target;
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const char *exists;
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bool ignore_failure;
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} BaseFilesystem;
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static const BaseFilesystem table[] = {
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{ "bin", 0, "usr/bin\0", NULL },
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{ "lib", 0, "usr/lib\0", NULL },
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{ "root", 0755, NULL, NULL, true },
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{ "sbin", 0, "usr/sbin\0", NULL },
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{ "usr", 0755, NULL, NULL },
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{ "var", 0755, NULL, NULL },
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{ "etc", 0755, NULL, NULL },
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{ "proc", 0755, NULL, NULL, true },
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{ "sys", 0755, NULL, NULL, true },
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{ "dev", 0755, NULL, NULL, true },
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#if defined(__i386__) || defined(__x86_64__)
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{ "lib64", 0, "usr/lib/x86_64-linux-gnu\0"
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"usr/lib64\0", "ld-linux-x86-64.so.2" },
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#endif
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};
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int base_filesystem_create(const char *root, uid_t uid, gid_t gid) {
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_cleanup_close_ int fd = -1;
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size_t i;
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int r;
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fd = open(root, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW);
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if (fd < 0)
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return log_error_errno(errno, "Failed to open root file system: %m");
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for (i = 0; i < ELEMENTSOF(table); i ++) {
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if (faccessat(fd, table[i].dir, F_OK, AT_SYMLINK_NOFOLLOW) >= 0)
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continue;
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if (table[i].target) {
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const char *target = NULL, *s;
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/* check if one of the targets exists */
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NULSTR_FOREACH(s, table[i].target) {
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if (faccessat(fd, s, F_OK, AT_SYMLINK_NOFOLLOW) < 0)
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continue;
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/* check if a specific file exists at the target path */
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if (table[i].exists) {
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_cleanup_free_ char *p = NULL;
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p = path_join(s, table[i].exists);
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if (!p)
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return log_oom();
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if (faccessat(fd, p, F_OK, AT_SYMLINK_NOFOLLOW) < 0)
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continue;
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}
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target = s;
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break;
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}
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if (!target)
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continue;
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if (symlinkat(target, fd, table[i].dir) < 0) {
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log_full_errno(IN_SET(errno, EEXIST, EROFS) || table[i].ignore_failure ? LOG_DEBUG : LOG_ERR, errno,
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"Failed to create symlink at %s/%s: %m", root, table[i].dir);
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if (IN_SET(errno, EEXIST, EROFS) || table[i].ignore_failure)
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continue;
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return -errno;
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}
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if (uid_is_valid(uid) || gid_is_valid(gid)) {
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if (fchownat(fd, table[i].dir, uid, gid, AT_SYMLINK_NOFOLLOW) < 0)
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return log_error_errno(errno, "Failed to chown symlink at %s/%s: %m", root, table[i].dir);
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}
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continue;
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}
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RUN_WITH_UMASK(0000)
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r = mkdirat(fd, table[i].dir, table[i].mode);
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if (r < 0) {
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log_full_errno(IN_SET(errno, EEXIST, EROFS) || table[i].ignore_failure ? LOG_DEBUG : LOG_ERR, errno,
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"Failed to create directory at %s/%s: %m", root, table[i].dir);
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if (IN_SET(errno, EEXIST, EROFS) || table[i].ignore_failure)
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continue;
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return -errno;
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}
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if (uid != UID_INVALID || gid != UID_INVALID) {
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if (fchownat(fd, table[i].dir, uid, gid, AT_SYMLINK_NOFOLLOW) < 0)
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return log_error_errno(errno, "Failed to chown directory at %s/%s: %m", root, table[i].dir);
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}
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}
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return 0;
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}
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