udev: fix several option parsing edge cases (#42997)

Boundary tests were conducted on the udev subsystem, and some issues
were identified and resolved.

src/udev/test-udev-manager.c

@@ -2,6 +2,7 @@
 
 #include "alloc-util.h"
 #include "tests.h"
+#include "udev-config.h"
 #include "udev-manager.h"
 
 TEST(devpath_conflict) {
@@ -35,4 +36,16 @@ TEST(worker_free_detaches_event) {
         ASSERT_NULL(event->worker);
 }
 
+TEST(manager_load_merges_children_max) {
+        _cleanup_(manager_freep) Manager *manager = ASSERT_PTR(manager_new());
+        char *argv[] = {
+                (char*) "systemd-udevd",
+                (char*) "--children-max=1",
+                NULL,
+        };
+
+        ASSERT_OK_POSITIVE(manager_load(manager, ELEMENTSOF(argv) - 1, argv));
+        ASSERT_EQ(manager->config.children_max, 1U);
+}
+
 DEFINE_TEST_MAIN(LOG_DEBUG);

src/udev/udev-builtin-input_id.c

@@ -118,7 +118,7 @@ static void get_cap_mask(
 
                 val = bitmask_size / sizeof (unsigned long);
                 /* skip trailing zeros */
-                while (bitmask[val-1] == 0 && val > 0)
+                while (val > 0 && bitmask[val-1] == 0)
                         --val;
 
                 /* IN_SET() cannot be used in assert_cc(). */

src/udev/udev-config.c

@@ -281,6 +281,7 @@ static void manager_merge_config(Manager *manager) {
 
         manager_merge_config_log_level(manager);
         MERGE_NON_NEGATIVE(resolve_name_timing, RESOLVE_NAME_EARLY);
+        MERGE_NON_ZERO(children_max, 0);
         MERGE_NON_ZERO(exec_delay_usec, 0);
         MERGE_NON_ZERO(timeout_usec, DEFAULT_WORKER_TIMEOUT_USEC);
         MERGE_NON_ZERO(timeout_signal, SIGKILL);

src/udev/udevadm-info.c

@@ -530,7 +530,7 @@ static int setup_matches(sd_device_enumerator *e) {
         STRV_FOREACH(a, arg_attr_match) {
                 _cleanup_free_ char *k = NULL, *v = NULL;
 
-                r = parse_key_value_argument(*a, /* require_value= */ true, &k, &v);
+                r = parse_key_value_argument(*a, /* require_value= */ false, &k, &v);
                 if (r < 0)
                         return r;
 
@@ -542,7 +542,7 @@ static int setup_matches(sd_device_enumerator *e) {
         STRV_FOREACH(a, arg_attr_nomatch) {
                 _cleanup_free_ char *k = NULL, *v = NULL;
 
-                r = parse_key_value_argument(*a, /* require_value= */ true, &k, &v);
+                r = parse_key_value_argument(*a, /* require_value= */ false, &k, &v);
                 if (r < 0)
                         return r;
 
@@ -1118,10 +1118,6 @@ static int parse_argv(int argc, char *argv[]) {
 
                 OPTION_LONG("attr-match", "FILE[=VALUE]",
                             "Query devices that match an attribute"):
-                        if (!strchr(opts.arg, '='))
-                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                                "Expected <ATTR>=<value> instead of '%s'", opts.arg);
-
                         r = strv_extend(&arg_attr_match, opts.arg);
                         if (r < 0)
                                 return log_oom();
@@ -1129,10 +1125,6 @@ static int parse_argv(int argc, char *argv[]) {
 
                 OPTION_LONG("attr-nomatch", "FILE[=VALUE]",
                             "Query devices that do not match an attribute"):
-                        if (!strchr(opts.arg, '='))
-                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                                "Expected <ATTR>=<value> instead of '%s'", opts.arg);
-
                         r = strv_extend(&arg_attr_nomatch, opts.arg);
                         if (r < 0)
                                 return log_oom();

src/udev/udevadm-settle.c

@@ -88,6 +88,10 @@ static int parse_argv(int argc, char *argv[]) {
                                               opts.opt->short_code);
                 }
 
+        if (option_parser_get_n_args(&opts) > 0)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "This subprogram takes no positional arguments.");
+
         return 1;
 }
 

src/udev/udevadm-trigger.c

@@ -469,7 +469,7 @@ static int parse_argv(int argc, char *argv[]) {
                         if (opts.arg) {
                                 r = parse_sec(opts.arg, &arg_ping_timeout_usec);
                                 if (r < 0)
-                                        log_error_errno(r, "Failed to parse timeout value '%s', ignoring: %m", opts.arg);
+                                        return log_error_errno(r, "Failed to parse timeout value '%s': %m", opts.arg);
                         }
                         break;
 

src/udev/udevadm-wait.c

@@ -32,6 +32,7 @@ typedef enum WaitUntil {
 
 static WaitUntil arg_wait_until = WAIT_UNTIL_INITIALIZED;
 static usec_t arg_timeout_usec = USEC_INFINITY;
+static bool arg_removed = false;
 static bool arg_settle = false;
 static char **arg_devices = NULL;
 
@@ -350,7 +351,7 @@ static int parse_argv(int argc, char *argv[]) {
                         break;
 
                 OPTION_LONG("removed", NULL, "Wait for devices being removed"):
-                        arg_wait_until = WAIT_UNTIL_REMOVED;
+                        arg_removed = true;
                         break;
 
                 OPTION_LONG("settle", NULL, "Also wait for all queued events being processed"):
@@ -358,6 +359,9 @@ static int parse_argv(int argc, char *argv[]) {
                         break;
                 }
 
+        if (arg_removed)
+                arg_wait_until = WAIT_UNTIL_REMOVED;
+
         char **args = option_parser_get_args(&opts);
         if (strv_isempty(args))
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),