diff options
Diffstat (limited to 'src/home/homework-cifs.c')
| -rw-r--r-- | src/home/homework-cifs.c | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/src/home/homework-cifs.c b/src/home/homework-cifs.c new file mode 100644 index 0000000..19f1cd5 --- /dev/null +++ b/src/home/homework-cifs.c @@ -0,0 +1,254 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <sys/mount.h> +#if WANT_LINUX_FS_H +#include <linux/fs.h> +#endif + +#include "dirent-util.h" +#include "fd-util.h" +#include "fileio.h" +#include "format-util.h" +#include "fs-util.h" +#include "homework-cifs.h" +#include "homework-mount.h" +#include "mkdir.h" +#include "mount-util.h" +#include "process-util.h" +#include "stat-util.h" +#include "strv.h" +#include "tmpfile-util.h" + +int home_setup_cifs( + UserRecord *h, + HomeSetupFlags flags, + HomeSetup *setup) { + + _cleanup_free_ char *chost = NULL, *cservice = NULL, *cdir = NULL, *chost_and_service = NULL, *j = NULL; + int r; + + assert(h); + assert(user_record_storage(h) == USER_CIFS); + assert(setup); + assert(!setup->undo_mount); + assert(setup->root_fd < 0); + + if (FLAGS_SET(flags, HOME_SETUP_ALREADY_ACTIVATED)) { + setup->root_fd = open(user_record_home_directory(h), O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); + if (setup->root_fd < 0) + return log_error_errno(errno, "Failed to open home directory: %m"); + + return 0; + } + + if (!h->cifs_service) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "User record lacks CIFS service, refusing."); + + r = parse_cifs_service(h->cifs_service, &chost, &cservice, &cdir); + if (r < 0) + return log_error_errno(r, "Failed parse CIFS service specification: %m"); + + /* Just the host and service part, without the directory */ + chost_and_service = strjoin("//", chost, "/", cservice); + if (!chost_and_service) + return log_oom(); + + r = home_unshare_and_mkdir(); + if (r < 0) + return r; + + STRV_FOREACH(pw, h->password) { + _cleanup_(unlink_and_freep) char *p = NULL; + _cleanup_free_ char *options = NULL; + _cleanup_fclose_ FILE *f = NULL; + pid_t mount_pid; + int exit_status; + + r = fopen_temporary_child(NULL, &f, &p); + if (r < 0) + return log_error_errno(r, "Failed to create temporary credentials file: %m"); + + fprintf(f, + "username=%s\n" + "password=%s\n", + user_record_cifs_user_name(h), + *pw); + + if (h->cifs_domain) + fprintf(f, "domain=%s\n", h->cifs_domain); + + r = fflush_and_check(f); + if (r < 0) + return log_error_errno(r, "Failed to write temporary credentials file: %m"); + + f = safe_fclose(f); + + if (asprintf(&options, "credentials=%s,uid=" UID_FMT ",forceuid,gid=" GID_FMT ",forcegid,file_mode=0%3o,dir_mode=0%3o", + p, h->uid, user_record_gid(h), user_record_access_mode(h), user_record_access_mode(h)) < 0) + return log_oom(); + + if (h->cifs_extra_mount_options) + if (!strextend_with_separator(&options, ",", h->cifs_extra_mount_options)) + return log_oom(); + + r = safe_fork("(mount)", FORK_RESET_SIGNALS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG_SIGTERM|FORK_LOG|FORK_STDOUT_TO_STDERR, &mount_pid); + if (r < 0) + return r; + if (r == 0) { + /* Child */ + execl("/bin/mount", "/bin/mount", "-n", "-t", "cifs", + chost_and_service, HOME_RUNTIME_WORK_DIR, + "-o", options, NULL); + + log_error_errno(errno, "Failed to execute mount: %m"); + _exit(EXIT_FAILURE); + } + + exit_status = wait_for_terminate_and_check("mount", mount_pid, WAIT_LOG_ABNORMAL|WAIT_LOG_NON_ZERO_EXIT_STATUS); + if (exit_status < 0) + return exit_status; + if (exit_status == EXIT_SUCCESS) { + setup->undo_mount = true; + break; + } + + if (pw[1]) + log_info("CIFS mount failed with password #%zu, trying next password.", (size_t) (pw - h->password) + 1); + } + + if (!setup->undo_mount) + return log_error_errno(SYNTHETIC_ERRNO(ENOKEY), + "Failed to mount home directory, supplied password(s) possibly wrong."); + + /* Adjust MS_SUID and similar flags */ + r = mount_nofollow_verbose(LOG_ERR, NULL, HOME_RUNTIME_WORK_DIR, NULL, MS_BIND|MS_REMOUNT|user_record_mount_flags(h), NULL); + if (r < 0) + return r; + + if (cdir) { + j = path_join(HOME_RUNTIME_WORK_DIR, cdir); + if (!j) + return log_oom(); + + if (FLAGS_SET(flags, HOME_SETUP_CIFS_MKDIR)) { + setup->root_fd = open_mkdir_at(AT_FDCWD, j, O_CLOEXEC, 0700); + if (setup->root_fd < 0) + return log_error_errno(setup->root_fd, "Failed to create CIFS subdirectory: %m"); + } + } + + if (setup->root_fd < 0) { + setup->root_fd = open(j ?: HOME_RUNTIME_WORK_DIR, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); + if (setup->root_fd < 0) + return log_error_errno(errno, "Failed to open home directory: %m"); + } + + setup->mount_suffix = TAKE_PTR(cdir); + return 0; +} + +int home_activate_cifs( + UserRecord *h, + HomeSetupFlags flags, + HomeSetup *setup, + PasswordCache *cache, + UserRecord **ret_home) { + + _cleanup_(user_record_unrefp) UserRecord *new_home = NULL, *header_home = NULL; + const char *hdo, *hd; + int r; + + assert(h); + assert(user_record_storage(h) == USER_CIFS); + assert(setup); + assert(ret_home); + + assert_se(hdo = user_record_home_directory(h)); + hd = strdupa_safe(hdo); /* copy the string out, since it might change later in the home record object */ + + r = home_setup(h, 0, setup, cache, &header_home); + if (r < 0) + return r; + + r = home_refresh(h, flags, setup, header_home, cache, NULL, &new_home); + if (r < 0) + return r; + + setup->root_fd = safe_close(setup->root_fd); + + r = home_move_mount(setup->mount_suffix, hd); + if (r < 0) + return r; + + setup->undo_mount = false; + setup->do_drop_caches = false; + + log_info("Everything completed."); + + *ret_home = TAKE_PTR(new_home); + return 1; +} + +int home_create_cifs(UserRecord *h, HomeSetup *setup, UserRecord **ret_home) { + _cleanup_(user_record_unrefp) UserRecord *new_home = NULL; + int r; + + assert(h); + assert(user_record_storage(h) == USER_CIFS); + assert(setup); + assert(ret_home); + + if (!h->cifs_service) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "User record lacks CIFS service, refusing."); + + if (access("/sbin/mount.cifs", F_OK) < 0) { + if (errno == ENOENT) + return log_error_errno(SYNTHETIC_ERRNO(ENOLINK), "/sbin/mount.cifs is missing."); + + return log_error_errno(errno, "Unable to detect whether /sbin/mount.cifs exists: %m"); + } + + r = home_setup_cifs(h, HOME_SETUP_CIFS_MKDIR, setup); + if (r < 0) + return r; + + r = dir_is_empty_at(setup->root_fd, NULL, /* ignore_hidden_or_backup= */ false); + if (r < 0) + return log_error_errno(r, "Failed to detect if CIFS directory is empty: %m"); + if (r == 0) + return log_error_errno(SYNTHETIC_ERRNO(ENOTEMPTY), "Selected CIFS directory not empty, refusing."); + + r = home_populate(h, setup->root_fd); + if (r < 0) + return r; + + r = home_sync_and_statfs(setup->root_fd, NULL); + if (r < 0) + return r; + + r = user_record_clone(h, USER_RECORD_LOAD_MASK_SECRET|USER_RECORD_PERMISSIVE, &new_home); + if (r < 0) + return log_error_errno(r, "Failed to clone record: %m"); + + r = user_record_add_binding( + new_home, + USER_CIFS, + NULL, + SD_ID128_NULL, + SD_ID128_NULL, + SD_ID128_NULL, + NULL, + NULL, + UINT64_MAX, + NULL, + NULL, + h->uid, + (gid_t) h->uid); + if (r < 0) + return log_error_errno(r, "Failed to add binding to record: %m"); + + log_info("Everything completed."); + + *ret_home = TAKE_PTR(new_home); + return 0; +} |