dns_server: Simplify talloc handling

By making sure that the answers are always allocated, we don't have
to pass an explicit mem_ctx anymore

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Kai Blin <kai@samba.org>

diff --git a/source4/dns_server/dns_query.c b/source4/dns_server/dns_query.c
index fb29e8fca68b6586c26aa3d58d92b6a5585e05bf..98b4e6269a70015a5794643a2f7225145b9515cf 100644 (file)
--- a/source4/dns_server/dns_query.c
+++ b/source4/dns_server/dns_query.c
@@ -40,7 +40,7 @@
 #undef DBGC_CLASS
 #define DBGC_CLASS DBGC_DNS
 
-static WERROR add_response_rr(TALLOC_CTX *mem_ctx, const char *name,
+static WERROR add_response_rr(const char *name,
                              const struct dnsp_DnssrvRpcRecord *rec,
                              struct dns_res_rec **answers, uint16_t *ancount)
 {
@@ -53,7 +53,10 @@ static WERROR add_response_rr(TALLOC_CTX *mem_ctx, const char *name,
                return WERR_BUFFER_OVERFLOW;
        }
 
-       ans = talloc_realloc(mem_ctx, ans, struct dns_res_rec, ai+1);
+       /*
+        * "ans" is always non-NULL and thus its own talloc context
+        */
+       ans = talloc_realloc(ans, ans, struct dns_res_rec, ai+1);
        if (ans == NULL) {
                return WERR_NOMEM;
        }
@@ -292,7 +295,7 @@ static WERROR add_zone_authority_record(struct dns_server *dns,
 
        for (ri = 0; ri < rec_count; ri++) {
                if (recs[ri].wType == DNS_TYPE_SOA) {
-                       werror = add_response_rr(mem_ctx, zone, &recs[ri],
+                       werror = add_response_rr(zone, &recs[ri],
                                                 &ns, &ni);
                        if (!W_ERROR_IS_OK(werror)) {
                                return werror;
@@ -347,8 +350,8 @@ static WERROR handle_question(struct dns_server *dns,
                        }
 
                        /* First put in the CNAME record */
-                       werror = add_response_rr(mem_ctx, question->name,
-                                                &recs[ri], &ans, &ai);
+                       werror = add_response_rr(question->name, &recs[ri],
+                                                &ans, &ai);
                        if (!W_ERROR_IS_OK(werror)) {
                                TALLOC_FREE(new_q);
                                return werror;
@@ -379,7 +382,7 @@ static WERROR handle_question(struct dns_server *dns,
                        werror_return = WERR_OK;
                        continue;
                }
-               werror = add_response_rr(mem_ctx, question->name, &recs[ri],
+               werror = add_response_rr(question->name, &recs[ri],
                                         &ans, &ai);
                if (!W_ERROR_IS_OK(werror)) {
                        return werror;
@@ -668,6 +671,21 @@ struct tevent_req *dns_server_process_query_send(
                WERROR err;
 
                req_state->flags |= DNS_FLAG_AUTHORITATIVE;
+
+               /*
+                * Initialize the response arrays, so that we can use
+                * them as their own talloc contexts when doing the
+                * realloc
+                */
+               state->answers = talloc_array(state, struct dns_res_rec, 0);
+               if (tevent_req_nomem(state->answers, req)) {
+                       return tevent_req_post(req, ev);
+               }
+               state->nsrecs = talloc_array(state, struct dns_res_rec, 0);
+               if (tevent_req_nomem(state->nsrecs, req)) {
+                       return tevent_req_post(req, ev);
+               }
+
                err = handle_question(dns, state, &in->questions[0],
                                      &state->answers, &state->ancount,
                                      &state->nsrecs, &state->nscount);