/* SPDX-License-Identifier: LGPL-2.1+ */ #include #include #include #include #include "alloc-util.h" #include "btrfs-util.h" #include "capability-util.h" #include "dirent-util.h" #include "fd-util.h" #include "fileio.h" #include "fs-util.h" #include "import-common.h" #include "os-util.h" #include "process-util.h" #include "signal-util.h" #include "util.h" int import_make_read_only_fd(int fd) { int r; assert(fd >= 0); /* First, let's make this a read-only subvolume if it refers * to a subvolume */ r = btrfs_subvol_set_read_only_fd(fd, true); if (IN_SET(r, -ENOTTY, -ENOTDIR, -EINVAL)) { struct stat st; /* This doesn't refer to a subvolume, or the file * system isn't even btrfs. In that, case fall back to * chmod()ing */ r = fstat(fd, &st); if (r < 0) return log_error_errno(errno, "Failed to stat temporary image: %m"); /* Drop "w" flag */ if (fchmod(fd, st.st_mode & 07555) < 0) return log_error_errno(errno, "Failed to chmod() final image: %m"); return 0; } else if (r < 0) return log_error_errno(r, "Failed to make subvolume read-only: %m"); return 0; } int import_make_read_only(const char *path) { _cleanup_close_ int fd = 1; fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC); if (fd < 0) return log_error_errno(errno, "Failed to open %s: %m", path); return import_make_read_only_fd(fd); } int import_fork_tar_x(const char *path, pid_t *ret) { _cleanup_close_pair_ int pipefd[2] = { -1, -1 }; pid_t pid; int r; assert(path); assert(ret); if (pipe2(pipefd, O_CLOEXEC) < 0) return log_error_errno(errno, "Failed to create pipe for tar: %m"); r = safe_fork("(tar)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &pid); if (r < 0) return r; if (r == 0) { uint64_t retain = (1ULL << CAP_CHOWN) | (1ULL << CAP_FOWNER) | (1ULL << CAP_FSETID) | (1ULL << CAP_MKNOD) | (1ULL << CAP_SETFCAP) | (1ULL << CAP_DAC_OVERRIDE); /* Child */ pipefd[1] = safe_close(pipefd[1]); r = rearrange_stdio(pipefd[0], -1, STDERR_FILENO); if (r < 0) { log_error_errno(r, "Failed to rearrange stdin/stdout: %m"); _exit(EXIT_FAILURE); } if (unshare(CLONE_NEWNET) < 0) log_error_errno(errno, "Failed to lock tar into network namespace, ignoring: %m"); r = capability_bounding_set_drop(retain, true); if (r < 0) log_error_errno(r, "Failed to drop capabilities, ignoring: %m"); execlp("tar", "tar", "--numeric-owner", "-C", path, "-px", "--xattrs", "--xattrs-include=*", NULL); log_error_errno(errno, "Failed to execute tar: %m"); _exit(EXIT_FAILURE); } *ret = pid; return TAKE_FD(pipefd[1]); } int import_fork_tar_c(const char *path, pid_t *ret) { _cleanup_close_pair_ int pipefd[2] = { -1, -1 }; pid_t pid; int r; assert(path); assert(ret); if (pipe2(pipefd, O_CLOEXEC) < 0) return log_error_errno(errno, "Failed to create pipe for tar: %m"); r = safe_fork("(tar)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &pid); if (r < 0) return r; if (r == 0) { uint64_t retain = (1ULL << CAP_DAC_OVERRIDE); /* Child */ pipefd[0] = safe_close(pipefd[0]); r = rearrange_stdio(-1, pipefd[1], STDERR_FILENO); if (r < 0) { log_error_errno(r, "Failed to rearrange stdin/stdout: %m"); _exit(EXIT_FAILURE); } if (unshare(CLONE_NEWNET) < 0) log_error_errno(errno, "Failed to lock tar into network namespace, ignoring: %m"); r = capability_bounding_set_drop(retain, true); if (r < 0) log_error_errno(r, "Failed to drop capabilities, ignoring: %m"); execlp("tar", "tar", "-C", path, "-c", "--xattrs", "--xattrs-include=*", ".", NULL); log_error_errno(errno, "Failed to execute tar: %m"); _exit(EXIT_FAILURE); } *ret = pid; return TAKE_FD(pipefd[0]); } int import_mangle_os_tree(const char *path) { _cleanup_closedir_ DIR *d = NULL, *cd = NULL; _cleanup_free_ char *child = NULL, *t = NULL; const char *joined; struct dirent *de; int r; assert(path); /* Some tarballs contain a single top-level directory that contains the actual OS directory tree. Try to * recognize this, and move the tree one level up. */ r = path_is_os_tree(path); if (r < 0) return log_error_errno(r, "Failed to determine whether '%s' is an OS tree: %m", path); if (r > 0) { log_debug("Directory tree '%s' is a valid OS tree.", path); return 0; } log_debug("Directory tree '%s' is not recognizable as OS tree, checking whether to rearrange it.", path); d = opendir(path); if (!d) return log_error_errno(r, "Failed to open directory '%s': %m", path); errno = 0; de = readdir_no_dot(d); if (!de) { if (errno != 0) return log_error_errno(errno, "Failed to iterate through directory '%s': %m", path); log_debug("Directory '%s' is empty, leaving it as it is.", path); return 0; } child = strdup(de->d_name); if (!child) return log_oom(); errno = 0; de = readdir_no_dot(d); if (de) { if (errno != 0) return log_error_errno(errno, "Failed to iterate through directory '%s': %m", path); log_debug("Directory '%s' does not look like a directory tree, and has multiple children, leaving as it is.", path); return 0; } joined = strjoina(path, "/", child); r = path_is_os_tree(joined); if (r == -ENOTDIR) { log_debug("Directory '%s' does not look like a directory tree, and contains a single regular file only, leaving as it is.", path); return 0; } if (r < 0) return log_error_errno(r, "Failed to determine whether '%s' is an OS tree: %m", joined); if (r == 0) { log_debug("Neither '%s' nor '%s' is a valid OS tree, leaving them as they are.", path, joined); return 0; } /* Nice, we have checked now: * * 1. The top-level directory does not qualify as OS tree * 1. The top-level directory only contains one item * 2. That item is a directory * 3. And that directory qualifies as OS tree * * Let's now rearrange things, moving everything in the inner directory one level up */ cd = xopendirat(dirfd(d), child, O_NOFOLLOW); if (!cd) return log_error_errno(errno, "Can't open directory '%s': %m", joined); log_info("Rearranging '%s', moving OS tree one directory up.", joined); /* Let's rename the child to an unguessable name so that we can be sure all files contained in it can be * safely moved up and won't collide with the name. */ r = tempfn_random(child, NULL, &t); if (r < 0) return log_oom(); r = rename_noreplace(dirfd(d), child, dirfd(d), t); if (r < 0) return log_error_errno(r, "Unable to rename '%s' to '%s/%s': %m", joined, path, t); FOREACH_DIRENT_ALL(de, cd, return log_error_errno(errno, "Failed to iterate through directory '%s': %m", joined)) { if (dot_or_dot_dot(de->d_name)) continue; r = rename_noreplace(dirfd(cd), de->d_name, dirfd(d), de->d_name); if (r < 0) return log_error_errno(r, "Unable to move '%s/%s/%s' to '%s/%s': %m", path, t, de->d_name, path, de->d_name); } if (unlinkat(dirfd(d), t, AT_REMOVEDIR) < 0) return log_error_errno(errno, "Failed to remove temporary directory '%s/%s': %m", path, t); log_info("Successfully rearranged OS tree."); return 0; }