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-rw-r--r--src/getty-generator/getty-generator.c298
-rw-r--r--src/getty-generator/meson.build8
2 files changed, 306 insertions, 0 deletions
diff --git a/src/getty-generator/getty-generator.c b/src/getty-generator/getty-generator.c
new file mode 100644
index 0000000..7486118
--- /dev/null
+++ b/src/getty-generator/getty-generator.c
@@ -0,0 +1,298 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#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);
diff --git a/src/getty-generator/meson.build b/src/getty-generator/meson.build
new file mode 100644
index 0000000..44eeb86
--- /dev/null
+++ b/src/getty-generator/meson.build
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+executables += [
+ generator_template + {
+ 'name' : 'systemd-getty-generator',
+ 'sources' : files('getty-generator.c'),
+ },
+]
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-14 14:39:10 +0000