1 files changed, 10 insertions, 21 deletions

diff --git a/src/resolve/resolved-dns-rr.c b/src/resolve/resolved-dns-rr.c
index 4e2dd46155..d0a86ef206 100644
--- a/src/resolve/resolved-dns-rr.c
+++ b/src/resolve/resolved-dns-rr.c
@@ -324,31 +324,22 @@ const struct hash_ops dns_resource_key_hash_ops = {
         .compare = dns_resource_key_compare_func
 };
 
-int dns_resource_key_to_string(const DnsResourceKey *key, char **ret) {
-        char cbuf[strlen("CLASS") + DECIMAL_STR_MAX(uint16_t)], tbuf[strlen("TYPE") + DECIMAL_STR_MAX(uint16_t)];
+char* dns_resource_key_to_string(const DnsResourceKey *key, char *buf, size_t buf_size) {
         const char *c, *t;
-        char *s;
+        char *ans = buf;
 
         /* If we cannot convert the CLASS/TYPE into a known string,
            use the format recommended by RFC 3597, Section 5. */
 
         c = dns_class_to_string(key->class);
-        if (!c) {
-                sprintf(cbuf, "CLASS%u", key->class);
-                c = cbuf;
-        }
-
         t = dns_type_to_string(key->type);
-        if (!t){
-                sprintf(tbuf, "TYPE%u", key->type);
-                t = tbuf;
-        }
 
-        if (asprintf(&s, "%s %s %-5s", dns_resource_key_name(key), c, t) < 0)
-                return -ENOMEM;
+        snprintf(buf, buf_size, "%s %s%s%.0u %s%s%.0u",
+                 dns_resource_key_name(key),
+                 c ?: "", c ? "" : "CLASS", c ? 0 : key->class,
+                 t ?: "", t ? "" : "TYPE", t ? 0 : key->class);
 
-        *ret = s;
-        return 0;
+        return ans;
 }
 
 bool dns_resource_key_reduce(DnsResourceKey **a, DnsResourceKey **b) {
@@ -846,8 +837,8 @@ static char *format_txt(DnsTxtItem *first) {
 }
 
 const char *dns_resource_record_to_string(DnsResourceRecord *rr) {
-        _cleanup_free_ char *k = NULL, *t = NULL;
-        char *s;
+        _cleanup_free_ char *t = NULL;
+        char *s, k[DNS_RESOURCE_KEY_STRING_MAX];
         int r;
 
         assert(rr);
@@ -855,9 +846,7 @@ const char *dns_resource_record_to_string(DnsResourceRecord *rr) {
         if (rr->to_string)
                 return rr->to_string;
 
-        r = dns_resource_key_to_string(rr->key, &k);
-        if (r < 0)
-                return NULL;
+        dns_resource_key_to_string(rr->key, k, sizeof(k));
 
         switch (rr->unparseable ? _DNS_TYPE_INVALID : rr->key->type) {