1 files changed, 165 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..fa4ca57
--- /dev/null
+++ b/src/debug-generator/debug-generator.c
@@ -0,0 +1,165 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "alloc-util.h"
+#include "generator.h"
+#include "mkdir.h"
+#include "parse-util.h"
+#include "proc-cmdline.h"
+#include "special.h"
+#include "string-util.h"
+#include "strv.h"
+#include "unit-name.h"
+#include "util.h"
+
+static const char *arg_dest = NULL;
+static char *arg_default_unit = NULL;
+static char **arg_mask = NULL;
+static char **arg_wants = NULL;
+static bool arg_debug_shell = false;
+
+STATIC_DESTRUCTOR_REGISTER(arg_default_unit, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_mask, strv_freep);
+STATIC_DESTRUCTOR_REGISTER(arg_wants, strv_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")) {
+
+                if (value) {
+                        r = parse_boolean(value);
+                        if (r < 0)
+                                log_error("Failed to parse systemd.debug_shell= argument '%s', ignoring.", value);
+                        else
+                                arg_debug_shell = r;
+                } else
+                        arg_debug_shell = true;
+
+        } else if (streq(key, "systemd.unit")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = free_and_strdup(&arg_default_unit, value);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to set default unit %s: %m", value);
+
+        } else if (!value) {
+                const char *target;
+
+                target = runlevel_to_target(key);
+                if (target) {
+                        r = free_and_strdup(&arg_default_unit, target);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to set default unit %s: %m", target);
+                }
+        }
+
+        return 0;
+}
+
+static int generate_mask_symlinks(void) {
+        char **u;
+        int r = 0;
+
+        if (strv_isempty(arg_mask))
+                return 0;
+
+        STRV_FOREACH(u, arg_mask) {
+                _cleanup_free_ char *p = NULL;
+
+                p = strjoin(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) {
+        char **u;
+        int r = 0;
+
+        if (strv_isempty(arg_wants))
+                return 0;
+
+        STRV_FOREACH(u, arg_wants) {
+                _cleanup_free_ char *p = NULL, *f = NULL;
+                const char *target = arg_default_unit ?: SPECIAL_DEFAULT_TARGET;
+
+                p = strjoin(arg_dest, "/", target, ".wants/", *u);
+                if (!p)
+                        return log_oom();
+
+                f = strappend(SYSTEM_DATA_UNIT_PATH "/", *u);
+                if (!f)
+                        return log_oom();
+
+                mkdir_parents_label(p, 0755);
+
+                if (symlink(f, p) < 0)
+                        r = log_error_errno(errno,
+                                            "Failed to create wants symlink %s: %m",
+                                            p);
+        }
+
+        return r;
+}
+
+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();
+        }
+
+        r = generate_mask_symlinks();
+        q = generate_wants_symlinks();
+
+        return r < 0 ? r : q;
+}
+
+DEFINE_MAIN_GENERATOR_FUNCTION(run);