resolved: populate mDNS scopes' zones with RRs for the host

Signed-off-by: Dmitry Rozhkov <dmitry.rozhkov@linux.intel.com>

5 files changed, 134 insertions, 0 deletions

diff --git a/src/resolve/resolved-dns-zone.h b/src/resolve/resolved-dns-zone.h
index a41df37e6b..545ec958fb 100644
--- a/src/resolve/resolved-dns-zone.h
+++ b/src/resolve/resolved-dns-zone.h
@@ -37,6 +37,9 @@ typedef enum DnsZoneItemState DnsZoneItemState;
 /* RFC 4795 Section 2.8. suggests a TTL of 30s by default */
 #define LLMNR_DEFAULT_TTL (30)
 
+/* RFC 6762 Section 10. suggests a TTL of 120s by default */
+#define MDNS_DEFAULT_TTL (120)
+
 enum DnsZoneItemState {
         DNS_ZONE_ITEM_PROBING,
         DNS_ZONE_ITEM_ESTABLISHED,
diff --git a/src/resolve/resolved-link.c b/src/resolve/resolved-link.c
index 4e38e88815..4d7447b507 100644
--- a/src/resolve/resolved-link.c
+++ b/src/resolve/resolved-link.c
@@ -692,10 +692,26 @@ LinkAddress *link_address_free(LinkAddress *a) {
                         else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope)
                                 dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr);
                 }
+
+                if (a->mdns_address_rr) {
+                        if (a->family == AF_INET && a->link->mdns_ipv4_scope)
+                                dns_zone_remove_rr(&a->link->mdns_ipv4_scope->zone, a->mdns_address_rr);
+                        else if (a->family == AF_INET6 && a->link->mdns_ipv6_scope)
+                                dns_zone_remove_rr(&a->link->mdns_ipv6_scope->zone, a->mdns_address_rr);
+                }
+
+                if (a->mdns_ptr_rr) {
+                        if (a->family == AF_INET && a->link->mdns_ipv4_scope)
+                                dns_zone_remove_rr(&a->link->mdns_ipv4_scope->zone, a->mdns_ptr_rr);
+                        else if (a->family == AF_INET6 && a->link->mdns_ipv6_scope)
+                                dns_zone_remove_rr(&a->link->mdns_ipv6_scope->zone, a->mdns_ptr_rr);
+                }
         }
 
         dns_resource_record_unref(a->llmnr_address_rr);
         dns_resource_record_unref(a->llmnr_ptr_rr);
+        dns_resource_record_unref(a->mdns_address_rr);
+        dns_resource_record_unref(a->mdns_ptr_rr);
 
         return mfree(a);
 }
@@ -760,6 +776,59 @@ void link_address_add_rrs(LinkAddress *a, bool force_remove) {
                                 a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr);
                         }
                 }
+
+                if (!force_remove &&
+                    link_address_relevant(a, true) &&
+                    a->link->mdns_ipv4_scope &&
+                    a->link->mdns_support == RESOLVE_SUPPORT_YES &&
+                    a->link->manager->mdns_support == RESOLVE_SUPPORT_YES) {
+                        if (!a->link->manager->mdns_host_ipv4_key) {
+                                a->link->manager->mdns_host_ipv4_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, a->link->manager->mdns_hostname);
+                                if (!a->link->manager->mdns_host_ipv4_key) {
+                                        r = -ENOMEM;
+                                        goto fail;
+                                }
+                        }
+
+                        if (!a->mdns_address_rr) {
+                                a->mdns_address_rr = dns_resource_record_new(a->link->manager->mdns_host_ipv4_key);
+                                if (!a->mdns_address_rr) {
+                                        r = -ENOMEM;
+                                        goto fail;
+                                }
+
+                                a->mdns_address_rr->a.in_addr = a->in_addr.in;
+                                a->mdns_address_rr->ttl = MDNS_DEFAULT_TTL;
+                        }
+
+                        if (!a->mdns_ptr_rr) {
+                                r = dns_resource_record_new_reverse(&a->mdns_ptr_rr, a->family, &a->in_addr, a->link->manager->mdns_hostname);
+                                if (r < 0)
+                                        goto fail;
+
+                                a->mdns_ptr_rr->ttl = MDNS_DEFAULT_TTL;
+                        }
+
+                        r = dns_zone_put(&a->link->mdns_ipv4_scope->zone, a->link->mdns_ipv4_scope, a->mdns_address_rr, true);
+                        if (r < 0)
+                                log_warning_errno(r, "Failed to add A record to MDNS zone: %m");
+
+                        r = dns_zone_put(&a->link->mdns_ipv4_scope->zone, a->link->mdns_ipv4_scope, a->mdns_ptr_rr, false);
+                        if (r < 0)
+                                log_warning_errno(r, "Failed to add IPv4 PTR record to MDNS zone: %m");
+                } else {
+                        if (a->mdns_address_rr) {
+                                if (a->link->mdns_ipv4_scope)
+                                        dns_zone_remove_rr(&a->link->mdns_ipv4_scope->zone, a->mdns_address_rr);
+                                a->mdns_address_rr = dns_resource_record_unref(a->mdns_address_rr);
+                        }
+
+                        if (a->mdns_ptr_rr) {
+                                if (a->link->mdns_ipv4_scope)
+                                        dns_zone_remove_rr(&a->link->mdns_ipv4_scope->zone, a->mdns_ptr_rr);
+                                a->mdns_ptr_rr = dns_resource_record_unref(a->mdns_ptr_rr);
+                        }
+                }
         }
 
         if (a->family == AF_INET6) {
@@ -817,6 +886,60 @@ void link_address_add_rrs(LinkAddress *a, bool force_remove) {
                                 a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr);
                         }
                 }
+
+                if (!force_remove &&
+                    link_address_relevant(a, true) &&
+                    a->link->mdns_ipv6_scope &&
+                    a->link->mdns_support == RESOLVE_SUPPORT_YES &&
+                    a->link->manager->mdns_support == RESOLVE_SUPPORT_YES) {
+
+                        if (!a->link->manager->mdns_host_ipv6_key) {
+                                a->link->manager->mdns_host_ipv6_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, a->link->manager->mdns_hostname);
+                                if (!a->link->manager->mdns_host_ipv6_key) {
+                                        r = -ENOMEM;
+                                        goto fail;
+                                }
+                        }
+
+                        if (!a->mdns_address_rr) {
+                                a->mdns_address_rr = dns_resource_record_new(a->link->manager->mdns_host_ipv6_key);
+                                if (!a->mdns_address_rr) {
+                                        r = -ENOMEM;
+                                        goto fail;
+                                }
+
+                                a->mdns_address_rr->aaaa.in6_addr = a->in_addr.in6;
+                                a->mdns_address_rr->ttl = MDNS_DEFAULT_TTL;
+                        }
+
+                        if (!a->mdns_ptr_rr) {
+                                r = dns_resource_record_new_reverse(&a->mdns_ptr_rr, a->family, &a->in_addr, a->link->manager->mdns_hostname);
+                                if (r < 0)
+                                        goto fail;
+
+                                a->mdns_ptr_rr->ttl = MDNS_DEFAULT_TTL;
+                        }
+
+                        r = dns_zone_put(&a->link->mdns_ipv6_scope->zone, a->link->mdns_ipv6_scope, a->mdns_address_rr, true);
+                        if (r < 0)
+                                log_warning_errno(r, "Failed to add AAAA record to MDNS zone: %m");
+
+                        r = dns_zone_put(&a->link->mdns_ipv6_scope->zone, a->link->mdns_ipv6_scope, a->mdns_ptr_rr, false);
+                        if (r < 0)
+                                log_warning_errno(r, "Failed to add IPv6 PTR record to MDNS zone: %m");
+                } else {
+                        if (a->mdns_address_rr) {
+                                if (a->link->mdns_ipv6_scope)
+                                        dns_zone_remove_rr(&a->link->mdns_ipv6_scope->zone, a->mdns_address_rr);
+                                a->mdns_address_rr = dns_resource_record_unref(a->mdns_address_rr);
+                        }
+
+                        if (a->mdns_ptr_rr) {
+                                if (a->link->mdns_ipv6_scope)
+                                        dns_zone_remove_rr(&a->link->mdns_ipv6_scope->zone, a->mdns_ptr_rr);
+                                a->mdns_ptr_rr = dns_resource_record_unref(a->mdns_ptr_rr);
+                        }
+                }
         }
 
         return;
diff --git a/src/resolve/resolved-link.h b/src/resolve/resolved-link.h
index c9b2a58c34..1e9be8ae84 100644
--- a/src/resolve/resolved-link.h
+++ b/src/resolve/resolved-link.h
@@ -47,6 +47,8 @@ struct LinkAddress {
 
         DnsResourceRecord *llmnr_address_rr;
         DnsResourceRecord *llmnr_ptr_rr;
+        DnsResourceRecord *mdns_address_rr;
+        DnsResourceRecord *mdns_ptr_rr;
 
         LIST_FIELDS(LinkAddress, addresses);
 };
diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c
index 0954641c20..97c1c2389d 100644
--- a/src/resolve/resolved-manager.c
+++ b/src/resolve/resolved-manager.c
@@ -621,6 +621,8 @@ Manager *manager_free(Manager *m) {
 
         dns_resource_key_unref(m->llmnr_host_ipv4_key);
         dns_resource_key_unref(m->llmnr_host_ipv6_key);
+        dns_resource_key_unref(m->mdns_host_ipv4_key);
+        dns_resource_key_unref(m->mdns_host_ipv6_key);
 
         sd_event_source_unref(m->hostname_event_source);
         safe_close(m->hostname_fd);
@@ -1007,6 +1009,8 @@ void manager_refresh_rrs(Manager *m) {
 
         m->llmnr_host_ipv4_key = dns_resource_key_unref(m->llmnr_host_ipv4_key);
         m->llmnr_host_ipv6_key = dns_resource_key_unref(m->llmnr_host_ipv6_key);
+        m->mdns_host_ipv4_key = dns_resource_key_unref(m->mdns_host_ipv4_key);
+        m->mdns_host_ipv6_key = dns_resource_key_unref(m->mdns_host_ipv6_key);
 
         HASHMAP_FOREACH(l, m->links, i) {
                 link_add_rrs(l, true);
diff --git a/src/resolve/resolved-manager.h b/src/resolve/resolved-manager.h
index 6b2208ed94..0b52ca594a 100644
--- a/src/resolve/resolved-manager.h
+++ b/src/resolve/resolved-manager.h
@@ -113,6 +113,8 @@ struct Manager {
         char *mdns_hostname;
         DnsResourceKey *llmnr_host_ipv4_key;
         DnsResourceKey *llmnr_host_ipv6_key;
+        DnsResourceKey *mdns_host_ipv4_key;
+        DnsResourceKey *mdns_host_ipv6_key;
 
         /* Watch the system hostname */
         int hostname_fd;