Use provided buffer in dns_resource_key_to_string

When the buffer is allocated on the stack we do not have to check for
failure everywhere. This is especially useful in debug statements, because
we can put dns_resource_key_to_string() call in the debug statement, and
we do not need a seperate if (log_level >= LOG_DEBUG) for the conversion.

dns_resource_key_to_string() is changed not to provide any whitespace
padding. Most callers were stripping the whitespace with strstrip(),
and it did not look to well anyway. systemd-resolve output is not column
aligned anymore.

The result of the conversion is not stored in DnsTransaction object
anymore. It is used only for debugging, so it seems fine to generate it
when needed.

Various debug statements are extended to provide more information.

1 files changed, 6 insertions, 1 deletions

diff --git a/src/resolve/resolved-dns-rr.h b/src/resolve/resolved-dns-rr.h
index 6feefdfe62..646e34598d 100644
--- a/src/resolve/resolved-dns-rr.h
+++ b/src/resolve/resolved-dns-rr.h
@@ -294,7 +294,12 @@ int dns_resource_key_equal(const DnsResourceKey *a, const DnsResourceKey *b);
 int dns_resource_key_match_rr(const DnsResourceKey *key, DnsResourceRecord *rr, const char *search_domain);
 int dns_resource_key_match_cname_or_dname(const DnsResourceKey *key, const DnsResourceKey *cname, const char *search_domain);
 int dns_resource_key_match_soa(const DnsResourceKey *key, const DnsResourceKey *soa);
-int dns_resource_key_to_string(const DnsResourceKey *key, char **ret);
+
+/* _DNS_{CLASS,TYPE}_STRING_MAX include one byte for NUL, which we use for space instead below.
+ * DNS_HOSTNAME_MAX does not include the NUL byte, so we need to add 1. */
+#define DNS_RESOURCE_KEY_STRING_MAX (_DNS_CLASS_STRING_MAX + _DNS_TYPE_STRING_MAX + DNS_HOSTNAME_MAX + 1)
+
+char* dns_resource_key_to_string(const DnsResourceKey *key, char *buf, size_t buf_size);
 ssize_t dns_resource_record_payload(DnsResourceRecord *rr, void **out);
 
 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceKey*, dns_resource_key_unref);