[knot-dns-users] [PATCH] kdig: Record the dnstap SocketProtocol correctly when retrying over TCP

Previously, kdig's write_dnstap() function passed net->srv->ai_protocol as dt_message_fill()'s 'protocol' parameter, but net->srv->ai_protocol is not actually guaranteed to be the socket protocol used for the query/response. When kdig's process_query_packet() retries over TCP, it only sets net->socktype to SOCK_STREAM in an already initialized net_t and calls itself. The addrinfo's in the net_t aren't updated, so they have the original values from the first invocation of process_query_packet(), i.e., the lookup that occurred over UDP. However, net->socktype is actually what controls whether TCP or UDP is ultimately used in net_connect(). Instead of passing net->srv->ai_protocol to dt_message_fill(), map net->socktype to an IPPROTO_* value. (Which is what kdig does elsewhere via get_sockname(), which is why the formatted output written to stdout at the same time, e.g. "127.0.0.1@53(TCP)" doesn't have a similiar bug.) --- src/utils/kdig/kdig_exec.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/src/utils/kdig/kdig_exec.c b/src/utils/kdig/kdig_exec.c index b91a958..1f6a64d 100644 --- a/src/utils/kdig/kdig_exec.c +++ b/src/utils/kdig/kdig_exec.c @@ -44,6 +44,7 @@ static int write_dnstap(dt_writer_t *writer, Dnstap__Message msg; Dnstap__Message__Type msg_type; int ret; + int protocol = 0; if (writer == NULL) { return KNOT_EOK; @@ -54,8 +55,14 @@ static int write_dnstap(dt_writer_t *writer, msg_type = is_response ? DNSTAP__MESSAGE__TYPE__TOOL_RESPONSE : DNSTAP__MESSAGE__TYPE__TOOL_QUERY; + if (net->socktype == SOCK_DGRAM) { + protocol = IPPROTO_UDP; + } else if (net->socktype == SOCK_STREAM) { + protocol = IPPROTO_TCP; + } + ret = dt_message_fill(&msg, msg_type, net->local_info->ai_addr, - net->srv->ai_addr, net->srv->ai_protocol, + net->srv->ai_addr, protocol, wire, wire_len, qtime, rtime); if (ret != KNOT_EOK) { return ret; -- 2.1.4