s4-dns: Make dns_server_process_query async

Signed-off-by: Kai Blin <kai@samba.org>

diff --git a/source4/dns_server/dns_query.c b/source4/dns_server/dns_query.c
index fe4e13119f836e092403479eaaa1ab8846ae0da7..65f770cacdc8819a0e3539cfe59d12ed275f6cca 100644 (file)
--- a/source4/dns_server/dns_query.c
+++ b/source4/dns_server/dns_query.c
@@ -311,59 +311,142 @@ static WERROR handle_question(struct dns_server *dns,
 
 }
 
-WERROR dns_server_process_query(struct dns_server *dns,
-                               struct dns_request_state *state,
-                               TALLOC_CTX *mem_ctx,
-                               struct dns_name_packet *in,
-                               struct dns_res_rec **answers,    uint16_t *ancount,
-                               struct dns_res_rec **nsrecs,     uint16_t *nscount,
-                               struct dns_res_rec **additional, uint16_t *arcount)
+struct dns_server_process_query_state {
+       struct dns_res_rec *answers;
+       uint16_t ancount;
+       struct dns_res_rec *nsrecs;
+       uint16_t nscount;
+       struct dns_res_rec *additional;
+       uint16_t arcount;
+};
+
+static void dns_server_process_query_got_response(struct tevent_req *subreq);
+
+static struct tevent_req *dns_server_process_query_send(
+       TALLOC_CTX *mem_ctx, struct tevent_context *ev,
+       struct dns_server *dns, struct dns_request_state *req_state,
+       const struct dns_name_packet *in)
 {
-       uint16_t num_answers=0, num_nsrecs=0, num_additional=0;
-       struct dns_res_rec *ans=NULL, *ns=NULL, *adds=NULL;
-       WERROR werror;
+       struct tevent_req *req, *subreq;
+       struct dns_server_process_query_state *state;
 
+       req = tevent_req_create(mem_ctx, &state,
+                               struct dns_server_process_query_state);
+       if (req == NULL) {
+               return NULL;
+       }
        if (in->qdcount != 1) {
-               return DNS_ERR(FORMAT_ERROR);
+               tevent_req_werror(req, DNS_ERR(FORMAT_ERROR));
+               return tevent_req_post(req, ev);
        }
 
        /* Windows returns NOT_IMPLEMENTED on this as well */
        if (in->questions[0].question_class == DNS_QCLASS_NONE) {
-               return DNS_ERR(NOT_IMPLEMENTED);
+               tevent_req_werror(req, DNS_ERR(NOT_IMPLEMENTED));
+               return tevent_req_post(req, ev);
        }
 
        if (dns_authorative_for_zone(dns, in->questions[0].name)) {
-               state->flags |= DNS_FLAG_AUTHORITATIVE;
-               werror = handle_question(dns, mem_ctx, &in->questions[0],
-                                        &ans, &num_answers);
-       } else {
-               if (state->flags & DNS_FLAG_RECURSION_DESIRED &&
-                   state->flags & DNS_FLAG_RECURSION_AVAIL) {
-                       DEBUG(2, ("Not authoritative for '%s', forwarding\n",
-                                 in->questions[0].name));
-                       werror = ask_forwarder(dns, mem_ctx, &in->questions[0],
-                                              &ans, &num_answers,
-                                              &ns, &num_nsrecs,
-                                              &adds, &num_additional);
-               } else {
-                       werror = DNS_ERR(NAME_ERROR);
+               WERROR err;
+
+               req_state->flags |= DNS_FLAG_AUTHORITATIVE;
+               err = handle_question(dns, state, &in->questions[0],
+                                     &state->answers, &state->ancount);
+               if (tevent_req_werror(req, err)) {
+                       return tevent_req_post(req, ev);
                }
+               tevent_req_done(req);
+               return tevent_req_post(req, ev);
        }
-       W_ERROR_NOT_OK_GOTO(werror, query_failed);
 
-       *answers = ans;
-       *ancount = num_answers;
+       if ((req_state->flags & DNS_FLAG_RECURSION_DESIRED) &&
+           (req_state->flags & DNS_FLAG_RECURSION_AVAIL)) {
+               DEBUG(2, ("Not authoritative for '%s', forwarding\n",
+                         in->questions[0].name));
+
+               subreq = ask_forwarder_send(
+                       state, ev, lpcfg_dns_forwarder(dns->task->lp_ctx),
+                       &in->questions[0]);
+               if (tevent_req_nomem(subreq, req)) {
+                       return tevent_req_post(req, ev);
+               }
+               tevent_req_set_callback(
+                       subreq, dns_server_process_query_got_response, req);
+               return req;
+       }
+
+       tevent_req_werror(req, DNS_ERR(NAME_ERROR));
+       return tevent_req_post(req, ev);
+}
 
-       /*FIXME: Do something for these */
-       *nsrecs  = ns;
-       *nscount = num_nsrecs;
+static void dns_server_process_query_got_response(struct tevent_req *subreq)
+{
+       struct tevent_req *req = tevent_req_callback_data(
+               subreq, struct tevent_req);
+       struct dns_server_process_query_state *state = tevent_req_data(
+               req, struct dns_server_process_query_state);
+       WERROR err;
+
+       err = ask_forwarder_recv(subreq, state,
+                                &state->answers, &state->ancount,
+                                &state->nsrecs, &state->nscount,
+                                &state->additional, &state->arcount);
+       TALLOC_FREE(subreq);
+       if (tevent_req_werror(req, err)) {
+               return;
+       }
+       tevent_req_done(req);
+}
 
-       *additional = adds;
-       *arcount    = num_additional;
+static WERROR dns_server_process_query_recv(
+       struct tevent_req *req, TALLOC_CTX *mem_ctx,
+       struct dns_res_rec **answers,    uint16_t *ancount,
+       struct dns_res_rec **nsrecs,     uint16_t *nscount,
+       struct dns_res_rec **additional, uint16_t *arcount)
+{
+       struct dns_server_process_query_state *state = tevent_req_data(
+               req, struct dns_server_process_query_state);
+       WERROR err;
 
+       if (tevent_req_is_werror(req, &err)) {
+               return err;
+       }
+       *answers = talloc_move(mem_ctx, &state->answers);
+       *ancount = state->ancount;
+       *nsrecs = talloc_move(mem_ctx, &state->nsrecs);
+       *nscount = state->nscount;
+       *additional = talloc_move(mem_ctx, &state->additional);
+       *arcount = state->arcount;
        return WERR_OK;
+}
 
-query_failed:
-       /*FIXME: add our SOA record to nsrecs */
-       return werror;
+WERROR dns_server_process_query(struct dns_server *dns,
+                               struct dns_request_state *state,
+                               TALLOC_CTX *mem_ctx,
+                               struct dns_name_packet *in,
+                               struct dns_res_rec **answers,    uint16_t *ancount,
+                               struct dns_res_rec **nsrecs,     uint16_t *nscount,
+                               struct dns_res_rec **additional, uint16_t *arcount)
+{
+       struct tevent_context *ev;
+       struct tevent_req *req;
+       WERROR err = WERR_NOMEM;
+
+       ev = tevent_context_init(talloc_tos());
+       if (ev == NULL) {
+               goto fail;
+       }
+       req = dns_server_process_query_send(ev, ev, dns, state, in);
+       if (req == NULL) {
+               goto fail;
+       }
+       if (!tevent_req_poll_werror(req, ev, &err)) {
+               goto fail;
+       }
+       err = dns_server_process_query_recv(req, mem_ctx, answers, ancount,
+                                           nsrecs, nscount,
+                                           additional, arcount);
+fail:
+       TALLOC_FREE(ev);
+       return err;
 }