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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:35:18 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:35:18 +0000 |
commit | b750101eb236130cf056c675997decbac904cc49 (patch) | |
tree | a5df1a06754bdd014cb975c051c83b01c9a97532 /src/getty-generator/getty-generator.c | |
parent | Initial commit. (diff) | |
download | systemd-upstream.tar.xz systemd-upstream.zip |
Adding upstream version 252.22.upstream/252.22upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/getty-generator/getty-generator.c | 242 |
1 files changed, 242 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..4e8162a --- /dev/null +++ b/src/getty-generator/getty-generator.c @@ -0,0 +1,242 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <fcntl.h> +#include <unistd.h> + +#include "alloc-util.h" +#include "errno-util.h" +#include "fd-util.h" +#include "fileio.h" +#include "generator.h" +#include "log.h" +#include "mkdir-label.h" +#include "parse-util.h" +#include "path-util.h" +#include "process-util.h" +#include "proc-cmdline.h" +#include "strv.h" +#include "terminal-util.h" +#include "unit-name.h" +#include "util.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) { + char *from, *to; + int r; + + 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); + + r = symlink(from, to); + if (r < 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 = -1; + 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 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); + + 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; + } + + 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 -ENOMEM; + if (access(p, F_OK) < 0) + continue; + + r = add_serial_getty(j); + if (r < 0) + return r; + } + + return 0; +} + +DEFINE_MAIN_GENERATOR_FUNCTION(run); |