1 files changed, 12 insertions, 2 deletions
diff --git a/src/resolve/resolved-dns-packet.h b/src/resolve/resolved-dns-packet.h
index d4c6b3c9cb..b873c0f745 100644
--- a/src/resolve/resolved-dns-packet.h
+++ b/src/resolve/resolved-dns-packet.h
@@ -73,7 +73,7 @@ struct DnsPacketHeader {
 struct DnsPacket {
         int n_ref;
         DnsProtocol protocol;
-        size_t size, allocated, rindex;
+        size_t size, allocated, rindex, max_size;
         void *_data; /* don't access directly, use DNS_PACKET_DATA()! */
         Hashmap *names; /* For name compression */
         size_t opt_start, opt_size;
@@ -187,7 +187,7 @@ static inline unsigned DNS_PACKET_RRCOUNT(DnsPacket *p) {
                 (unsigned) DNS_PACKET_ARCOUNT(p);
 }
 
-int dns_packet_new(DnsPacket **p, DnsProtocol protocol, size_t min_alloc_dsize);
+int dns_packet_new(DnsPacket **p, DnsProtocol protocol, size_t min_alloc_dsize, size_t max_size);
 int dns_packet_new_query(DnsPacket **p, DnsProtocol protocol, size_t min_alloc_dsize, bool dnssec_checking_disabled);
 
 void dns_packet_set_flags(DnsPacket *p, bool dnssec_checking_disabled, bool truncated);
@@ -303,3 +303,13 @@ static inline uint64_t SD_RESOLVED_FLAGS_MAKE(DnsProtocol protocol, int family,
                 return f;
         }
 }
+
+static inline size_t dns_packet_size_max(DnsPacket *p) {
+        assert(p);
+
+        /* Why not insist on a fully initialized max_size during DnsPacket construction? Well, this way it's easy to
+         * allocate a transient, throw-away DnsPacket on the stack by simple zero initialization, without having to
+         * deal with explicit field initialization. */
+
+        return p->max_size != 0 ? p->max_size : DNS_PACKET_SIZE_MAX;
+}