diff --git a/src/resolve/resolved-bus.c b/src/resolve/resolved-bus.c index 834ae837de..251e7a50a4 100644 --- a/src/resolve/resolved-bus.c +++ b/src/resolve/resolved-bus.c @@ -281,6 +281,7 @@ static int bus_method_resolve_hostname(sd_bus_message *message, void *userdata, q->request = sd_bus_message_ref(message); q->request_family = family; q->complete = bus_method_resolve_hostname_complete; + q->suppress_unroutable_family = family == AF_UNSPEC; r = dns_query_bus_track(q, message); if (r < 0) diff --git a/src/resolve/resolved-dns-query.c b/src/resolve/resolved-dns-query.c index a00851658e..06d30d7863 100644 --- a/src/resolve/resolved-dns-query.c +++ b/src/resolve/resolved-dns-query.c @@ -21,6 +21,7 @@ #include "alloc-util.h" #include "dns-domain.h" +#include "dns-type.h" #include "hostname-util.h" #include "local-addresses.h" #include "resolved-dns-query.h" @@ -161,6 +162,7 @@ static int dns_query_candidate_go(DnsQueryCandidate *c) { DnsTransaction *t; Iterator i; int r; + unsigned n = 0; assert(c); @@ -172,8 +174,14 @@ static int dns_query_candidate_go(DnsQueryCandidate *c) { r = dns_transaction_go(t); if (r < 0) return r; + + n++; } + /* If there was nothing to start, then let's proceed immediately */ + if (n == 0) + dns_query_candidate_notify(c); + return 0; } @@ -222,6 +230,31 @@ static DnsTransactionState dns_query_candidate_state(DnsQueryCandidate *c) { return state; } +static bool dns_query_candidate_is_routable(DnsQueryCandidate *c, uint16_t type) { + int family; + + assert(c); + + /* Checks whether the specified RR type matches an address family that is routable on the link(s) the scope of + * this candidate belongs to. Specifically, whether there's a routable IPv4 address on it if we query an A RR, + * or a routable IPv6 address if we query an AAAA RR. */ + + if (!c->query->suppress_unroutable_family) + return true; + + if (c->scope->protocol != DNS_PROTOCOL_DNS) + return true; + + family = dns_type_to_af(type); + if (family < 0) + return true; + + if (c->scope->link) + return link_relevant(c->scope->link, family, false); + else + return manager_routable(c->scope->manager, family); +} + static int dns_query_candidate_setup_transactions(DnsQueryCandidate *c) { DnsQuestion *question; DnsResourceKey *key; @@ -236,14 +269,24 @@ static int dns_query_candidate_setup_transactions(DnsQueryCandidate *c) { /* Create one transaction per question key */ DNS_QUESTION_FOREACH(key, question) { _cleanup_(dns_resource_key_unrefp) DnsResourceKey *new_key = NULL; + DnsResourceKey *qkey; + + if (!dns_query_candidate_is_routable(c, key->type)) + continue; if (c->search_domain) { r = dns_resource_key_new_append_suffix(&new_key, key, c->search_domain->name); if (r < 0) goto fail; - } - r = dns_query_candidate_add_transaction(c, new_key ?: key); + qkey = new_key; + } else + qkey = key; + + if (!dns_scope_good_key(c->scope, qkey)) + continue; + + r = dns_query_candidate_add_transaction(c, qkey); if (r < 0) goto fail; diff --git a/src/resolve/resolved-dns-query.h b/src/resolve/resolved-dns-query.h index c7e4ce9a00..75c2c14c1f 100644 --- a/src/resolve/resolved-dns-query.h +++ b/src/resolve/resolved-dns-query.h @@ -69,6 +69,10 @@ struct DnsQuery { uint64_t flags; int ifindex; + /* If true, A or AAAA RR lookups will be suppressed on links with no routable address of the matching address + * family */ + bool suppress_unroutable_family; + DnsTransactionState state; unsigned n_cname_redirects; diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c index ac4887abea..03239794ee 100644 --- a/src/resolve/resolved-dns-scope.c +++ b/src/resolve/resolved-dns-scope.c @@ -490,7 +490,9 @@ DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, co } } -int dns_scope_good_key(DnsScope *s, DnsResourceKey *key) { +bool dns_scope_good_key(DnsScope *s, const DnsResourceKey *key) { + int key_family; + assert(s); assert(key); @@ -498,6 +500,9 @@ int dns_scope_good_key(DnsScope *s, DnsResourceKey *key) { * this scope. Note that this call assumes as fully qualified * name, i.e. the search suffixes already appended. */ + if (key->class != DNS_CLASS_IN) + return false; + if (s->protocol == DNS_PROTOCOL_DNS) { /* On classic DNS, looking up non-address RRs is always @@ -519,13 +524,11 @@ int dns_scope_good_key(DnsScope *s, DnsResourceKey *key) { /* On mDNS and LLMNR, send A and AAAA queries only on the * respective scopes */ - if (s->family == AF_INET && key->class == DNS_CLASS_IN && key->type == DNS_TYPE_AAAA) - return false; + key_family = dns_type_to_af(key->type); + if (key_family < 0) + return true; - if (s->family == AF_INET6 && key->class == DNS_CLASS_IN && key->type == DNS_TYPE_A) - return false; - - return true; + return key_family == s->family; } static int dns_scope_multicast_membership(DnsScope *s, bool b, struct in_addr in, struct in6_addr in6) { @@ -1017,9 +1020,6 @@ bool dns_scope_name_needs_search_domain(DnsScope *s, const char *name) { } bool dns_scope_network_good(DnsScope *s) { - Iterator i; - Link *l; - /* Checks whether the network is in good state for lookups on this scope. For mDNS/LLMNR/Classic DNS scopes * bound to links this is easy, as they don't even exist if the link isn't in a suitable state. For the global * DNS scope we check whether there are any links that are up and have an address. */ @@ -1027,10 +1027,5 @@ bool dns_scope_network_good(DnsScope *s) { if (s->link) return true; - HASHMAP_FOREACH(l, s->manager->links, i) { - if (link_relevant(l, AF_UNSPEC, false)) - return true; - } - - return false; + return manager_routable(s->manager, AF_UNSPEC); } diff --git a/src/resolve/resolved-dns-scope.h b/src/resolve/resolved-dns-scope.h index f9b63d56d9..05b8d66de0 100644 --- a/src/resolve/resolved-dns-scope.h +++ b/src/resolve/resolved-dns-scope.h @@ -87,7 +87,7 @@ int dns_scope_socket_tcp(DnsScope *s, int family, const union in_addr_union *add int dns_scope_socket_udp(DnsScope *s, DnsServer *server, uint16_t port); DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain); -int dns_scope_good_key(DnsScope *s, DnsResourceKey *key); +bool dns_scope_good_key(DnsScope *s, const DnsResourceKey *key); DnsServer *dns_scope_get_dns_server(DnsScope *s); void dns_scope_next_dns_server(DnsScope *s); diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c index 637b99aaa5..501f13063e 100644 --- a/src/resolve/resolved-dns-transaction.c +++ b/src/resolve/resolved-dns-transaction.c @@ -1411,12 +1411,6 @@ static int dns_transaction_make_packet(DnsTransaction *t) { if (r < 0) return r; - r = dns_scope_good_key(t->scope, t->key); - if (r < 0) - return r; - if (r == 0) - return -EDOM; - r = dns_packet_append_key(p, t->key, NULL); if (r < 0) return r; @@ -1498,13 +1492,6 @@ int dns_transaction_go(DnsTransaction *t) { /* Otherwise, we need to ask the network */ r = dns_transaction_make_packet(t); - if (r == -EDOM) { - /* Not the right request to make on this network? - * (i.e. an A request made on IPv6 or an AAAA request - * made on IPv4, on LLMNR or mDNS.) */ - dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); - return 0; - } if (r < 0) return r; diff --git a/src/resolve/resolved-link.c b/src/resolve/resolved-link.c index 37dd4a6e78..7412e64622 100644 --- a/src/resolve/resolved-link.c +++ b/src/resolve/resolved-link.c @@ -515,14 +515,17 @@ int link_update_monitor(Link *l) { return 0; } -bool link_relevant(Link *l, int family, bool multicast) { +bool link_relevant(Link *l, int family, bool local_multicast) { _cleanup_free_ char *state = NULL; LinkAddress *a; assert(l); - /* A link is relevant for multicast traffic if it isn't a loopback or pointopoint device, has a link beat, can - * do multicast and has at least one relevant IP address */ + /* A link is relevant for local multicast traffic if it isn't a loopback or pointopoint device, has a link + * beat, can do multicast and has at least one link-local (or better) IP address. + * + * A link is relevant for non-multicast traffic if it isn't a loopback device, has a link beat, and has at + * least one routable address.*/ if (l->flags & (IFF_LOOPBACK|IFF_DORMANT)) return false; @@ -530,7 +533,7 @@ bool link_relevant(Link *l, int family, bool multicast) { if ((l->flags & (IFF_UP|IFF_LOWER_UP)) != (IFF_UP|IFF_LOWER_UP)) return false; - if (multicast) { + if (local_multicast) { if (l->flags & IFF_POINTOPOINT) return false; @@ -548,7 +551,7 @@ bool link_relevant(Link *l, int family, bool multicast) { return false; LIST_FOREACH(addresses, a, l->addresses) - if ((family == AF_UNSPEC || a->family == family) && link_address_relevant(a)) + if ((family == AF_UNSPEC || a->family == family) && link_address_relevant(a, local_multicast)) return true; return false; @@ -692,7 +695,7 @@ void link_address_add_rrs(LinkAddress *a, bool force_remove) { if (a->family == AF_INET) { if (!force_remove && - link_address_relevant(a) && + link_address_relevant(a, true) && a->link->llmnr_ipv4_scope && a->link->llmnr_support == RESOLVE_SUPPORT_YES && a->link->manager->llmnr_support == RESOLVE_SUPPORT_YES) { @@ -749,7 +752,7 @@ void link_address_add_rrs(LinkAddress *a, bool force_remove) { if (a->family == AF_INET6) { if (!force_remove && - link_address_relevant(a) && + link_address_relevant(a, true) && a->link->llmnr_ipv6_scope && a->link->llmnr_support == RESOLVE_SUPPORT_YES && a->link->manager->llmnr_support == RESOLVE_SUPPORT_YES) { @@ -826,13 +829,13 @@ int link_address_update_rtnl(LinkAddress *a, sd_netlink_message *m) { return 0; } -bool link_address_relevant(LinkAddress *a) { +bool link_address_relevant(LinkAddress *a, bool local_multicast) { assert(a); if (a->flags & (IFA_F_DEPRECATED|IFA_F_TENTATIVE)) return false; - if (IN_SET(a->scope, RT_SCOPE_HOST, RT_SCOPE_NOWHERE)) + if (a->scope >= (local_multicast ? RT_SCOPE_HOST : RT_SCOPE_LINK)) return false; return true; diff --git a/src/resolve/resolved-link.h b/src/resolve/resolved-link.h index 3b6aafb8f0..29e7b72247 100644 --- a/src/resolve/resolved-link.h +++ b/src/resolve/resolved-link.h @@ -89,7 +89,7 @@ int link_new(Manager *m, Link **ret, int ifindex); Link *link_free(Link *l); int link_update_rtnl(Link *l, sd_netlink_message *m); int link_update_monitor(Link *l); -bool link_relevant(Link *l, int family, bool multicast); +bool link_relevant(Link *l, int family, bool local_multicast); LinkAddress* link_find_address(Link *l, int family, const union in_addr_union *in_addr); void link_add_rrs(Link *l, bool force_remove); @@ -107,7 +107,7 @@ bool link_dnssec_supported(Link *l); int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr_union *in_addr); LinkAddress *link_address_free(LinkAddress *a); int link_address_update_rtnl(LinkAddress *a, sd_netlink_message *m); -bool link_address_relevant(LinkAddress *l); +bool link_address_relevant(LinkAddress *l, bool local_multicast); void link_address_add_rrs(LinkAddress *a, bool force_remove); DEFINE_TRIVIAL_CLEANUP_FUNC(Link*, link_free); diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c index fbd188c2ac..f1dbda1a6a 100644 --- a/src/resolve/resolved-manager.c +++ b/src/resolve/resolved-manager.c @@ -1226,3 +1226,18 @@ void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResource m->n_dnssec_verdict[verdict]++; } + +bool manager_routable(Manager *m, int family) { + Iterator i; + Link *l; + + assert(m); + + /* Returns true if the host has at least one interface with a routable address of the specified type */ + + HASHMAP_FOREACH(l, m->links, i) + if (link_relevant(l, family, false)) + return true; + + return false; +} diff --git a/src/resolve/resolved-manager.h b/src/resolve/resolved-manager.h index 1af49c8fb9..e2c539d3d2 100644 --- a/src/resolve/resolved-manager.h +++ b/src/resolve/resolved-manager.h @@ -169,3 +169,5 @@ DnssecMode manager_get_dnssec_mode(Manager *m); bool manager_dnssec_supported(Manager *m); void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key); + +bool manager_routable(Manager *m, int family);