resolved: minor clean-ups for resolved-bus.c

1 files changed, 29 insertions, 11 deletions

diff --git a/src/resolve/resolved-bus.c b/src/resolve/resolved-bus.c
index 4a36c554a9..97cc125232 100644
--- a/src/resolve/resolved-bus.c
+++ b/src/resolve/resolved-bus.c
@@ -59,6 +59,9 @@ static int dns_query_bus_track(DnsQuery *q, sd_bus_message *m) {
 
 static int reply_query_state(DnsQuery *q) {
 
+        assert(q);
+        assert(q->bus_request);
+
         switch (q->state) {
 
         case DNS_TRANSACTION_NO_SERVERS:
@@ -172,6 +175,7 @@ static void bus_method_resolve_hostname_complete(DnsQuery *q) {
         _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *canonical = NULL;
         _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
         _cleanup_free_ char *normalized = NULL;
+        DnsQuestion *question;
         DnsResourceRecord *rr;
         unsigned added = 0;
         int ifindex, r;
@@ -201,10 +205,9 @@ static void bus_method_resolve_hostname_complete(DnsQuery *q) {
         if (r < 0)
                 goto finish;
 
-        DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, q->answer) {
-                DnsQuestion *question;
+        question = dns_query_question_for_protocol(q, q->answer_protocol);
 
-                question = dns_query_question_for_protocol(q, q->answer_protocol);
+        DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, q->answer) {
 
                 r = dns_question_matches_rr(question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain));
                 if (r < 0)
@@ -231,14 +234,14 @@ static void bus_method_resolve_hostname_complete(DnsQuery *q) {
         if (r < 0)
                 goto finish;
 
-        /* The key names are not necessarily normalized, make sure that they are when we return them to our bus
-         * clients. */
+        /* The key names are not necessarily normalized, make sure that they are when we return them to our
+         * bus clients. */
+        assert(canonical);
         r = dns_name_normalize(dns_resource_key_name(canonical->key), 0, &normalized);
         if (r < 0)
                 goto finish;
 
         /* Return the precise spelling and uppercasing and CNAME target reported by the server */
-        assert(canonical);
         r = sd_bus_message_append(
                         reply, "st",
                         normalized,
@@ -257,9 +260,23 @@ finish:
         dns_query_free(q);
 }
 
-static int check_ifindex_flags(int ifindex, uint64_t *flags, uint64_t ok, sd_bus_error *error) {
+static int validate_and_mangle_ifindex_and_flags(int ifindex, uint64_t *flags, uint64_t ok, sd_bus_error *error) {
         assert(flags);
 
+        /* Checks that the client supplied interface index and flags parameter actually are valid and make
+         * sense in our method call context. Specifically:
+         *
+         * 1. Checks that the interface index is either 0 (meaning *all* interfaces) or positive
+         *
+         * 2. Only the protocols flags and the NO_CNAME flag are set, at most. Plus additional flags specific
+         *    to our method, passed in the "ok" parameter.
+         *
+         * 3. If zero protocol flags are specified it is automatically turned into *all* protocols. This way
+         *    clients can simply pass 0 as flags and all will work as it should. They can also use this so
+         *    that clients don't have to know all the protocols resolved implements, but can just specify 0
+         *    to mean "all supported protocols".
+         */
+
         if (ifindex < 0)
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid interface index");
 
@@ -357,7 +374,7 @@ static int bus_method_resolve_hostname(sd_bus_message *message, void *userdata,
         if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC))
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family);
 
-        r = check_ifindex_flags(ifindex, &flags, SD_RESOLVED_NO_SEARCH, error);
+        r = validate_and_mangle_ifindex_and_flags(ifindex, &flags, SD_RESOLVED_NO_SEARCH, error);
         if (r < 0)
                 return r;
 
@@ -510,7 +527,7 @@ static int bus_method_resolve_address(sd_bus_message *message, void *userdata, s
         if (r < 0)
                 return r;
 
-        r = check_ifindex_flags(ifindex, &flags, 0, error);
+        r = validate_and_mangle_ifindex_and_flags(ifindex, &flags, 0, error);
         if (r < 0)
                 return r;
 
@@ -675,7 +692,7 @@ static int bus_method_resolve_record(sd_bus_message *message, void *userdata, sd
         if (dns_type_is_obsolete(type))
                 return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Specified DNS resource record type %" PRIu16 " is obsolete.", type);
 
-        r = check_ifindex_flags(ifindex, &flags, 0, error);
+        r = validate_and_mangle_ifindex_and_flags(ifindex, &flags, 0, error);
         if (r < 0)
                 return r;
 
@@ -945,6 +962,7 @@ static void resolve_service_all_complete(DnsQuery *q) {
                 goto finish;
 
         question = dns_query_question_for_protocol(q, q->answer_protocol);
+
         DNS_ANSWER_FOREACH(rr, q->answer) {
                 r = dns_question_matches_rr(question, rr, NULL);
                 if (r < 0)
@@ -1209,7 +1227,7 @@ static int bus_method_resolve_service(sd_bus_message *message, void *userdata, s
         if (name && !type)
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Service name cannot be specified without service type.");
 
-        r = check_ifindex_flags(ifindex, &flags, SD_RESOLVED_NO_TXT|SD_RESOLVED_NO_ADDRESS, error);
+        r = validate_and_mangle_ifindex_and_flags(ifindex, &flags, SD_RESOLVED_NO_TXT|SD_RESOLVED_NO_ADDRESS, error);
         if (r < 0)
                 return r;