From 3c1844015ff471ca28b7359624323948cc1303f5 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 15 Oct 2024 13:40:24 +0200
Subject: [PATCH] sd-varlink: add new sd_varlink_error_is_invalid_parameter()
 helper

(cherry picked from commit 12641ecd67875b7bf18db06c0afa40c37d804750)

Related: RHEL-55266
---
 src/shared/varlink.c    | 20 +++++++++++++++
 src/shared/varlink.h    |  2 ++
 src/test/test-varlink.c | 56 ++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 77 insertions(+), 1 deletion(-)

diff --git a/src/shared/varlink.c b/src/shared/varlink.c
index 49593aa05a..0f5db09cea 100644
--- a/src/shared/varlink.c
+++ b/src/shared/varlink.c
@@ -2687,3 +2687,23 @@ int varlink_server_deserialize_one(VarlinkServer *s, const char *value, FDSet *f
         LIST_PREPEND(sockets, s->sockets, TAKE_PTR(ss));
         return 0;
 }
+
+int varlink_error_is_invalid_parameter(const char *error, JsonVariant *parameter, const char *name) {
+
+        /* Returns true if the specified error result is an invalid parameter error for the parameter 'name' */
+
+        if (!streq_ptr(error, VARLINK_ERROR_INVALID_PARAMETER))
+                return false;
+
+        if (!name)
+                return true;
+
+        if (!json_variant_is_object(parameter))
+                return false;
+
+        JsonVariant *e = json_variant_by_key(parameter, "parameter");
+        if (!e || !json_variant_is_string(e))
+                return false;
+
+        return streq(json_variant_string(e), name);
+}
diff --git a/src/shared/varlink.h b/src/shared/varlink.h
index e51ccd9107..a4170737db 100644
--- a/src/shared/varlink.h
+++ b/src/shared/varlink.h
@@ -161,6 +161,8 @@ unsigned varlink_server_current_connections(VarlinkServer *s);
 
 int varlink_server_set_description(VarlinkServer *s, const char *description);
 
+int varlink_error_is_invalid_parameter(const char *error, JsonVariant *parameter, const char *name);
+
 DEFINE_TRIVIAL_CLEANUP_FUNC(Varlink *, varlink_unref);
 DEFINE_TRIVIAL_CLEANUP_FUNC(Varlink *, varlink_close_unref);
 DEFINE_TRIVIAL_CLEANUP_FUNC(Varlink *, varlink_flush_close_unref);
diff --git a/src/test/test-varlink.c b/src/test/test-varlink.c
index 634baf1ae8..13f772cf4e 100644
--- a/src/test/test-varlink.c
+++ b/src/test/test-varlink.c
@@ -10,6 +10,7 @@
 #include "json.h"
 #include "rm-rf.h"
 #include "strv.h"
+#include "tests.h"
 #include "tmpfile-util.h"
 #include "user-util.h"
 #include "varlink.h"
@@ -184,7 +185,7 @@ static int block_fd_handler(sd_event_source *s, int fd, uint32_t revents, void *
         return 0;
 }
 
-int main(int argc, char *argv[]) {
+TEST(chat) {
         _cleanup_(sd_event_source_unrefp) sd_event_source *block_event = NULL;
         _cleanup_(varlink_server_unrefp) VarlinkServer *s = NULL;
         _cleanup_(varlink_flush_close_unrefp) Varlink *c = NULL;
@@ -234,6 +235,59 @@ int main(int argc, char *argv[]) {
         assert_se(sd_event_loop(e) >= 0);
 
         assert_se(pthread_join(t, NULL) == 0);
+}
+
+static int method_invalid(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) {
+        int r;
+
+        JsonDispatch table[] = {
+                { "iexist", JSON_VARIANT_STRING, json_dispatch_const_string, 0, JSON_MANDATORY },
+                {}
+        };
+
+        const char *p = NULL;
+
+        r = varlink_dispatch(link, parameters, table, &p);
+        if (r != 0)
+                return r;
 
+        assert_not_reached();
+}
+
+static int reply_invalid(Varlink *link, JsonVariant *parameters, const char *error_id, VarlinkReplyFlags flags, void *userdata) {
+        assert(varlink_error_is_invalid_parameter(error_id, parameters, "idontexist"));
+        assert(sd_event_exit(varlink_get_event(link), EXIT_SUCCESS) >= 0);
         return 0;
 }
+
+TEST(invalid_parameter) {
+        _cleanup_(sd_event_unrefp) sd_event *e = NULL;
+        assert_se(sd_event_default(&e) >= 0);
+
+        _cleanup_(varlink_server_unrefp) VarlinkServer *s = NULL;
+        assert_se(varlink_server_new(&s, 0) >= 0);
+
+        assert_se(varlink_server_attach_event(s, e, 0) >= 0);
+
+        assert_se(varlink_server_bind_method(s, "foo.mytest.Invalid", method_invalid) >= 0);
+
+        int connfd[2];
+        assert_se(socketpair(AF_UNIX, SOCK_STREAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, connfd) >= 0);
+        assert_se(varlink_server_add_connection(s, connfd[0], /* ret= */ NULL) >= 0);
+
+        _cleanup_(varlink_unrefp) Varlink *c = NULL;
+        assert_se(varlink_connect_fd(&c, connfd[1]) >= 0);
+
+        assert_se(varlink_attach_event(c, e, 0) >= 0);
+
+        assert_se(varlink_bind_reply(c, reply_invalid) >= 0);
+
+        assert_se(varlink_invokeb(c, "foo.mytest.Invalid", JSON_BUILD_OBJECT(
+                                      JSON_BUILD_PAIR_STRING("iexist", "foo"),
+                                      JSON_BUILD_PAIR_STRING("idontexist", "bar"))) >= 0);
+
+
+        assert_se(sd_event_loop(e) >= 0);
+}
+
+DEFINE_TEST_MAIN(LOG_DEBUG);