Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 298 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);