lib: new state 'YIELD', layers can interrupt processing with it

this is useful when you need to issue several subrequests before
continuing with the current query, resuming is not supported yet, so it
will requery after the subrequests complete

diff --git a/daemon/lua/kres.lua b/daemon/lua/kres.lua
index 225341059d8c44ec3e993f13b373425d4461aeda..5441a49fbe64bda171bac5b82f47e6307e1151b1 100644 (file)
--- a/daemon/lua/kres.lua
+++ b/daemon/lua/kres.lua
@@ -165,7 +165,7 @@ struct kr_query {
        uint16_t type;
        uint16_t class;
        uint16_t id;
-       uint16_t flags;
+       uint32_t flags;
        unsigned secret;
        uint8_t _stub[]; /* Do not touch */
 };
@@ -353,7 +353,7 @@ local kres = {
        section = ffi.new('struct pkt_section'),
        rcode = ffi.new('struct pkt_rcode'),
        query = ffi.new('struct query_flag'),
-       NOOP = 0, CONSUME = 1, PRODUCE = 2, DONE = 4, FAIL = 8,
+       NOOP = 0, YIELD = 0, CONSUME = 1, PRODUCE = 2, DONE = 4, FAIL = 8,
        -- Metatypes
        pkt_t = function (udata) return ffi.cast('knot_pkt_t *', udata) end,
        request_t = function (udata) return ffi.cast('struct kr_request *', udata) end,

diff --git a/lib/layer.h b/lib/layer.h
index 827118dfe58241080020f140be4cc5c72c285f5b..2ad9a71da6f6a2150e762254be7bec0c5115383d 100644 (file)
--- a/lib/layer.h
+++ b/lib/layer.h
@@ -29,4 +29,7 @@
     } while (0)
 #else
  #define QRDEBUG(query, cls, fmt, ...)
-#endif
\ No newline at end of file
+#endif
+
+/* Repurpose layer states. */
+#define KNOT_STATE_YIELD KNOT_STATE_NOOP
\ No newline at end of file

diff --git a/lib/layer/iterate.c b/lib/layer/iterate.c
index 2518e249fae7b52b1c3343fe7a6820a290760ad3..df74229d8c613f746ff0c8205576c6ec69367eef 100644 (file)
--- a/lib/layer/iterate.c
+++ b/lib/layer/iterate.c
@@ -333,13 +333,12 @@ static int process_authority(knot_pkt_t *pkt, struct kr_request *req)
                        }
                        qry->zone_cut.name = knot_dname_copy(signer, &req->pool);
                } /* else zone cut matches, but DS/DNSKEY doesn't => refetch. */
-               knot_wire_set_tc(pkt->wire);
-               result = KNOT_STATE_NOOP;
+               result = KNOT_STATE_YIELD;
        }
 
        /* CONSUME => Unhelpful referral.
         * DONE    => Zone cut updated.
-        * NOOP    => Ignore this answer. */
+        * YIELD   => Bail out. */
        return result;
 }
 
@@ -449,7 +448,6 @@ static int resolve_error(knot_pkt_t *pkt, struct kr_request *req)
 
 /* State-less single resolution iteration step, not needed. */
 static int reset(knot_layer_t *ctx)  { return KNOT_STATE_PRODUCE; }
-static int finish(knot_layer_t *ctx) { return KNOT_STATE_NOOP; }
 
 /* Set resolution context and parameters. */
 static int begin(knot_layer_t *ctx, void *module_param)
@@ -581,9 +579,6 @@ static int resolve(knot_layer_t *ctx, knot_pkt_t *pkt)
        case KNOT_STATE_DONE: /* Referral */
                DEBUG_MSG("<= referral response, follow\n");
                break;
-       case KNOT_STATE_NOOP: /* Deferred, bail out. */
-               state = KNOT_STATE_CONSUME;
-               break;
        default:
                break;
        }
@@ -597,7 +592,6 @@ const knot_layer_api_t *iterate_layer(struct kr_module *module)
        static const knot_layer_api_t _layer = {
                .begin = &begin,
                .reset = &reset,
-               .finish = &finish,
                .consume = &resolve,
                .produce = &prepare_query
        };

diff --git a/lib/resolve.c b/lib/resolve.c
index b2e3e0a1f14b4075e18aa11c3b390e6060653120..c4e7ec89844929c9d2c177337e77418c6b80ddaf 100644 (file)
--- a/lib/resolve.c
+++ b/lib/resolve.c
@@ -33,10 +33,12 @@
     (req)->current_query = (qry); \
        for (unsigned i = 0; i < (req)->ctx->modules->len; ++i) { \
                struct kr_module *mod = (req)->ctx->modules->at[i]; \
-               if (mod->layer ) { \
+               if (mod->layer) { \
                        struct knot_layer layer = {.state = (req)->state, .api = mod->layer(mod), .data = (req)}; \
                        if (layer.api && layer.api->func) { \
                                (req)->state = layer.api->func(&layer, ##__VA_ARGS__); \
+                               if ((req)->state == KNOT_STATE_YIELD) \
+                                       break; \
                        } \
                } \
        } /* Invalidate current query. */ \
@@ -324,6 +326,7 @@ int kr_resolve_consume(struct kr_request *request, const struct sockaddr *src, k
                if (qname_raw && qry->secret != 0) {
                        randomized_qname_case(qname_raw, qry->secret);
                }
+               request->state = KNOT_STATE_CONSUME;
                ITERATE_LAYERS(request, qry, consume, packet);
        }
 
@@ -485,6 +488,7 @@ int kr_resolve_produce(struct kr_request *request, struct sockaddr **dst, int *t
 
        /* Resolve current query and produce dependent or finish */
        struct kr_query *qry = TAIL(rplan->pending);
+       request->state = KNOT_STATE_PRODUCE;
        ITERATE_LAYERS(request, qry, produce, packet);
        if (request->state != KNOT_STATE_FAIL && knot_wire_get_qr(packet->wire)) {
                /* Produced an answer, consume it. */