/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include "alloc-util.h" #include "creds-util.h" #include "errno-util.h" #include "fd-util.h" #include "fileio.h" #include "generator.h" #include "initrd-util.h" #include "log.h" #include "mkdir-label.h" #include "parse-util.h" #include "path-util.h" #include "proc-cmdline.h" #include "process-util.h" #include "strv.h" #include "terminal-util.h" #include "unit-name.h" #include "virt.h" static const char *arg_dest = NULL; static bool arg_enabled = true; static int add_symlink(const char *fservice, const char *tservice) { const char *from, *to; assert(fservice); assert(tservice); from = strjoina(SYSTEM_DATA_UNIT_DIR "/", fservice); to = strjoina(arg_dest, "/getty.target.wants/", tservice); (void) mkdir_parents_label(to, 0755); if (symlink(from, to) < 0) { /* In case console=hvc0 is passed this will very likely result in EEXIST */ if (errno == EEXIST) return 0; return log_error_errno(errno, "Failed to create symlink %s: %m", to); } return 0; } static int add_serial_getty(const char *tty) { _cleanup_free_ char *n = NULL; int r; assert(tty); log_debug("Automatically adding serial getty for /dev/%s.", tty); r = unit_name_from_path_instance("serial-getty", tty, ".service", &n); if (r < 0) return log_error_errno(r, "Failed to generate service name: %m"); return add_symlink("serial-getty@.service", n); } static int add_container_getty(const char *tty) { _cleanup_free_ char *n = NULL; int r; assert(tty); log_debug("Automatically adding container getty for /dev/pts/%s.", tty); r = unit_name_from_path_instance("container-getty", tty, ".service", &n); if (r < 0) return log_error_errno(r, "Failed to generate service name: %m"); return add_symlink("container-getty@.service", n); } static int verify_tty(const char *name) { _cleanup_close_ int fd = -EBADF; const char *p; /* Some TTYs are weird and have been enumerated but don't work * when you try to use them, such as classic ttyS0 and * friends. Let's check that and open the device and run * isatty() on it. */ p = strjoina("/dev/", name); /* O_NONBLOCK is essential here, to make sure we don't wait * for DCD */ fd = open(p, O_RDWR|O_NONBLOCK|O_NOCTTY|O_CLOEXEC|O_NOFOLLOW); if (fd < 0) return -errno; errno = 0; if (isatty(fd) <= 0) return errno_or_else(EIO); return 0; } static int run_container(void) { _cleanup_free_ char *container_ttys = NULL; int r; log_debug("Automatically adding console shell."); r = add_symlink("console-getty.service", "console-getty.service"); if (r < 0) return r; /* When $container_ttys is set for PID 1, spawn gettys on all ptys named therein. * Note that despite the variable name we only support ptys here. */ (void) getenv_for_pid(1, "container_ttys", &container_ttys); for (const char *p = container_ttys;;) { _cleanup_free_ char *word = NULL; r = extract_first_word(&p, &word, NULL, 0); if (r < 0) return log_error_errno(r, "Failed to parse $container_ttys: %m"); if (r == 0) return 0; const char *tty = word; /* First strip off /dev/ if it is specified */ tty = path_startswith(tty, "/dev/") ?: tty; /* Then, make sure it's actually a pty */ tty = path_startswith(tty, "pts/"); if (!tty) continue; r = add_container_getty(tty); if (r < 0) return r; } } static int add_credential_gettys(void) { static const struct { const char *credential_name; int (*func)(const char *tty); } table[] = { { "getty.ttys.serial", add_serial_getty }, { "getty.ttys.container", add_container_getty }, }; int r; FOREACH_ARRAY(t, table, ELEMENTSOF(table)) { _cleanup_free_ char *b = NULL; size_t sz = 0; r = read_credential_with_decryption(t->credential_name, (void*) &b, &sz); if (r < 0) return r; if (r == 0) continue; _cleanup_fclose_ FILE *f = NULL; f = fmemopen_unlocked(b, sz, "r"); if (!f) return log_oom(); for (;;) { _cleanup_free_ char *tty = NULL; r = read_stripped_line(f, PATH_MAX, &tty); if (r == 0) break; if (r < 0) { log_error_errno(r, "Failed to parse credential %s: %m", t->credential_name); break; } if (startswith(tty, "#")) continue; r = t->func(tty); if (r < 0) return r; } } return 0; } static int parse_proc_cmdline_item(const char *key, const char *value, void *data) { int r; assert(key); if (proc_cmdline_key_streq(key, "systemd.getty_auto")) { r = value ? parse_boolean(value) : 1; if (r < 0) log_warning_errno(r, "Failed to parse getty_auto switch \"%s\", ignoring: %m", value); else arg_enabled = r; } return 0; } static int run(const char *dest, const char *dest_early, const char *dest_late) { _cleanup_free_ char *getty_auto = NULL; int r; assert_se(arg_dest = dest); if (in_initrd()) { log_debug("Skipping generator, running in the initrd."); return EXIT_SUCCESS; } r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0); if (r < 0) log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m"); r = getenv_for_pid(1, "SYSTEMD_GETTY_AUTO", &getty_auto); if (r < 0) log_warning_errno(r, "Failed to parse $SYSTEMD_GETTY_AUTO environment variable, ignoring: %m"); else if (r > 0) { r = parse_boolean(getty_auto); if (r < 0) log_warning_errno(r, "Failed to parse $SYSTEMD_GETTY_AUTO value \"%s\", ignoring: %m", getty_auto); else arg_enabled = r; } if (!arg_enabled) { log_debug("Disabled, exiting."); return 0; } r = add_credential_gettys(); if (r < 0) return r; if (detect_container() > 0) /* Add console shell and look at $container_ttys, but don't do add any * further magic if we are in a container. */ return run_container(); /* Automatically add in a serial getty on all active kernel consoles */ _cleanup_free_ char *active = NULL; (void) read_one_line_file("/sys/class/tty/console/active", &active); for (const char *p = active;;) { _cleanup_free_ char *tty = NULL; r = extract_first_word(&p, &tty, NULL, 0); if (r < 0) return log_error_errno(r, "Failed to parse /sys/class/tty/console/active: %m"); if (r == 0) break; /* We assume that gettys on virtual terminals are started via manual configuration and do * this magic only for non-VC terminals. */ if (isempty(tty) || tty_is_vc(tty)) continue; if (verify_tty(tty) < 0) continue; r = add_serial_getty(tty); if (r < 0) return r; } /* Automatically add in a serial getty on the first virtualizer console */ FOREACH_STRING(j, "hvc0", "xvc0", "hvsi0", "sclp_line0", "ttysclp0", "3270!tty1") { _cleanup_free_ char *p = NULL; p = path_join("/sys/class/tty", j); if (!p) return log_oom(); if (access(p, F_OK) < 0) continue; r = add_serial_getty(j); if (r < 0) return r; } return 0; } DEFINE_MAIN_GENERATOR_FUNCTION(run);