diff options
Diffstat (limited to 'src/debug-generator')
| -rw-r--r-- | src/debug-generator/debug-generator.c | 178 | ||||
| -rw-r--r-- | src/debug-generator/meson.build | 8 |
2 files changed, 186 insertions, 0 deletions
diff --git a/src/debug-generator/debug-generator.c b/src/debug-generator/debug-generator.c new file mode 100644 index 0000000..8a474c5 --- /dev/null +++ b/src/debug-generator/debug-generator.c @@ -0,0 +1,178 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <unistd.h> + +#include "alloc-util.h" +#include "dropin.h" +#include "generator.h" +#include "initrd-util.h" +#include "mkdir-label.h" +#include "parse-util.h" +#include "path-util.h" +#include "proc-cmdline.h" +#include "special.h" +#include "string-util.h" +#include "strv.h" +#include "unit-file.h" +#include "unit-name.h" + +static const char *arg_dest = NULL; +static char *arg_default_unit = NULL; +static char **arg_mask = NULL; +static char **arg_wants = NULL; +static char *arg_debug_shell = NULL; + +STATIC_DESTRUCTOR_REGISTER(arg_default_unit, freep); +STATIC_DESTRUCTOR_REGISTER(arg_mask, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_wants, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_debug_shell, freep); + +static int parse_proc_cmdline_item(const char *key, const char *value, void *data) { + int r; + + assert(key); + + if (streq(key, "systemd.mask")) { + char *n; + + if (proc_cmdline_value_missing(key, value)) + return 0; + + r = unit_name_mangle(value, UNIT_NAME_MANGLE_WARN, &n); + if (r < 0) + return log_error_errno(r, "Failed to glob unit name: %m"); + + r = strv_consume(&arg_mask, n); + if (r < 0) + return log_oom(); + + } else if (streq(key, "systemd.wants")) { + char *n; + + if (proc_cmdline_value_missing(key, value)) + return 0; + + r = unit_name_mangle(value, UNIT_NAME_MANGLE_WARN, &n); + if (r < 0) + return log_error_errno(r, "Failed to glob unit name: %m"); + + r = strv_consume(&arg_wants, n); + if (r < 0) + return log_oom(); + + } else if (proc_cmdline_key_streq(key, "systemd.debug_shell")) { + const char *t = NULL; + + r = value ? parse_boolean(value) : 1; + if (r < 0) + t = skip_dev_prefix(value); + else if (r > 0) + t = skip_dev_prefix(DEBUGTTY); + + return free_and_strdup_warn(&arg_debug_shell, t); + + } else if (streq(key, "systemd.unit")) { + + if (proc_cmdline_value_missing(key, value)) + return 0; + + return free_and_strdup_warn(&arg_default_unit, value); + + } else if (!value) { + const char *target; + + target = runlevel_to_target(key); + if (target) + return free_and_strdup_warn(&arg_default_unit, target); + } + + return 0; +} + +static int generate_mask_symlinks(void) { + int r = 0; + + STRV_FOREACH(u, arg_mask) { + _cleanup_free_ char *p = NULL; + + p = path_join(empty_to_root(arg_dest), *u); + if (!p) + return log_oom(); + + if (symlink("/dev/null", p) < 0) + r = log_error_errno(errno, + "Failed to create mask symlink %s: %m", + p); + } + + return r; +} + +static int generate_wants_symlinks(void) { + int r = 0; + + STRV_FOREACH(u, arg_wants) { + _cleanup_free_ char *f = NULL; + const char *target; + + /* This should match what do_queue_default_job() in core/main.c does. */ + if (arg_default_unit) + target = arg_default_unit; + else if (in_initrd()) + target = SPECIAL_INITRD_TARGET; + else + target = SPECIAL_DEFAULT_TARGET; + + f = path_join(SYSTEM_DATA_UNIT_DIR, *u); + if (!f) + return log_oom(); + + r = generator_add_symlink(arg_dest, target, "wants", f); + if (r < 0) + return r; + } + + return r; +} + +static void install_debug_shell_dropin(const char *dir) { + int r; + + if (streq(arg_debug_shell, skip_dev_prefix(DEBUGTTY))) + return; + + r = write_drop_in_format(dir, "debug-shell.service", 50, "tty", + "[Unit]\n" + "Description=Early root shell on /dev/%s FOR DEBUGGING ONLY\n" + "ConditionPathExists=\n" + "[Service]\n" + "TTYPath=/dev/%s", + arg_debug_shell, arg_debug_shell); + if (r < 0) + log_warning_errno(r, "Failed to write drop-in for debug-shell.service, ignoring: %m"); +} + +static int run(const char *dest, const char *dest_early, const char *dest_late) { + int r, q; + + assert_se(arg_dest = dest_early); + + r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, PROC_CMDLINE_RD_STRICT | PROC_CMDLINE_STRIP_RD_PREFIX); + if (r < 0) + log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m"); + + if (arg_debug_shell) { + r = strv_extend(&arg_wants, "debug-shell.service"); + if (r < 0) + return log_oom(); + + install_debug_shell_dropin(arg_dest); + } + + r = generate_mask_symlinks(); + q = generate_wants_symlinks(); + + return r < 0 ? r : q; +} + +DEFINE_MAIN_GENERATOR_FUNCTION(run); diff --git a/src/debug-generator/meson.build b/src/debug-generator/meson.build new file mode 100644 index 0000000..33cb344 --- /dev/null +++ b/src/debug-generator/meson.build @@ -0,0 +1,8 @@ +# SPDX-License-Identifier: LGPL-2.1-or-later + +executables += [ + generator_template + { + 'name' : 'systemd-debug-generator', + 'sources' : files('debug-generator.c'), + }, +] |