+
+int dns_resource_record_new_reverse(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *hostname) {
+ _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
+ _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
+ _cleanup_free_ char *ptr = NULL;
+ int r;
+
+ assert(ret);
+ assert(address);
+ assert(hostname);
+
+ r = dns_name_reverse(family, address, &ptr);
+ if (r < 0)
+ return r;
+
+ key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, ptr);
+ if (!key)
+ return -ENOMEM;
+
+ ptr = NULL;
+
+ rr = dns_resource_record_new(key);
+ if (!rr)
+ return -ENOMEM;
+
+ rr->ptr.name = strdup(hostname);
+ if (!rr->ptr.name)
+ return -ENOMEM;
+
+ *ret = rr;
+ rr = NULL;
+
+ return 0;
+}
+
+int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecord *b) {
+ int r;
+
+ assert(a);
+ assert(b);
+
+ r = dns_resource_key_equal(a->key, b->key);
+ if (r <= 0)
+ return r;
+
+ if (IN_SET(a->key->type, DNS_TYPE_PTR, DNS_TYPE_NS, DNS_TYPE_CNAME))
+ return dns_name_equal(a->ptr.name, b->ptr.name);
+ else if (a->key->type == DNS_TYPE_HINFO)
+ return strcasecmp(a->hinfo.cpu, b->hinfo.cpu) == 0 &&
+ strcasecmp(a->hinfo.os, b->hinfo.os) == 0;
+ else if (a->key->type == DNS_TYPE_A)
+ return memcmp(&a->a.in_addr, &b->a.in_addr, sizeof(struct in_addr)) == 0;
+ else if (a->key->type == DNS_TYPE_AAAA)
+ return memcmp(&a->aaaa.in6_addr, &b->aaaa.in6_addr, sizeof(struct in6_addr)) == 0;
+ else if (a->key->type == DNS_TYPE_SOA) {
+ r = dns_name_equal(a->soa.mname, b->soa.mname);
+ if (r <= 0)
+ return r;
+ r = dns_name_equal(a->soa.rname, b->soa.rname);
+ if (r <= 0)
+ return r;
+
+ return a->soa.serial == b->soa.serial &&
+ a->soa.refresh == b->soa.refresh &&
+ a->soa.retry == b->soa.retry &&
+ a->soa.expire == b->soa.expire &&
+ a->soa.minimum == b->soa.minimum;
+ } else
+ return a->generic.size == b->generic.size &&
+ memcmp(a->generic.data, b->generic.data, a->generic.size) == 0;
+}
+
+const char *dns_class_to_string(uint16_t class) {
+
+ switch (class) {
+
+ case DNS_CLASS_IN:
+ return "IN";
+
+ case DNS_CLASS_ANY:
+ return "ANY";
+ }
+
+ return NULL;
+}
+
+const char *dns_type_to_string(uint16_t type) {
+
+ switch (type) {
+
+ case DNS_TYPE_A:
+ return "A";
+
+ case DNS_TYPE_NS:
+ return "NS";
+
+ case DNS_TYPE_CNAME:
+ return "CNAME";
+
+ case DNS_TYPE_SOA:
+ return "SOA";
+
+ case DNS_TYPE_PTR:
+ return "PTR";
+
+ case DNS_TYPE_HINFO:
+ return "HINFO";
+
+ case DNS_TYPE_MX:
+ return "MX";
+
+ case DNS_TYPE_TXT:
+ return "TXT";
+
+ case DNS_TYPE_AAAA:
+ return "AAAA";
+
+ case DNS_TYPE_SRV:
+ return "SRV";
+
+ case DNS_TYPE_SSHFP:
+ return "SSHFP";
+
+ case DNS_TYPE_DNAME:
+ return "DNAME";
+
+ case DNS_TYPE_ANY:
+ return "ANY";
+
+ case DNS_TYPE_OPT:
+ return "OPT";
+
+ case DNS_TYPE_TKEY:
+ return "TKEY";
+
+ case DNS_TYPE_TSIG:
+ return "TSIG";
+
+ case DNS_TYPE_IXFR:
+ return "IXFR";
+
+ case DNS_TYPE_AXFR:
+ return "AXFR";
+ }
+
+ return NULL;
+}