resolved: rework synthesizing logic

With this change we'll now also generate synthesized RRs for the local
LLMNR hostname (first label of system hostname), the local mDNS hostname
(first label of system hostname suffixed with .local), the "gateway"
hostname and all the reverse PTRs. This hence takes over part of what
nss-myhostname already implemented.

Local hostnames resolve to the set of local IP addresses. Since the
addresses are possibly on different interfaces it is necessary to change
the internal DnsAnswer object to track per-RR interface indexes, and to
change the bus API to always return the interface per-address rather than
per-reply. This change also patches  the existing clients for resolved
accordingly (nss-resolve + systemd-resolve-host).

This also changes the routing logic for queries slightly: we now ensure
that the local hostname is never resolved via LLMNR, thus making it
trustable on the local system.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/resolve/resolved-dns-rr.h b/src/resolve/resolved-dns-rr.h
index 0f40f3ceef..8986a298af 100644
--- a/src/resolve/resolved-dns-rr.h
+++ b/src/resolve/resolved-dns-rr.h
@@ -191,6 +191,7 @@ DnsResourceRecord* dns_resource_record_new_full(uint16_t class, uint16_t type, c
 DnsResourceRecord* dns_resource_record_ref(DnsResourceRecord *rr);
 DnsResourceRecord* dns_resource_record_unref(DnsResourceRecord *rr);
 int dns_resource_record_new_reverse(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *name);
+int dns_resource_record_new_address(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *name);
 int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecord *b);
 int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret);
 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceRecord*, dns_resource_record_unref);