modules/hints: proof of concept static hints

modules/hints/hints.c

@@ -14,11 +14,42 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <libknot/packet/pkt.h>
+#include <libknot/descriptor.h>
+#include <libknot/internal/lists.h>
+#include <libknot/internal/mempool.h>
+#include <libknot/rrtype/aaaa.h>
+
+#include "lib/layer/iterate.h"
+#include "lib/utils.h"
+#include "lib/defines.h"
 #include "lib/module.h"
 #include "lib/layer.h"
 
+#define DEFAULT_FILE "/etc/hosts"
 #define DEBUG_MSG(fmt...) QRDEBUG(NULL, "hint",  fmt)
 
+/* TODO: this is an experimental (slow) proof-of-concept,
+ *       this will be rewritten with namedb API
+ */ 
+
+typedef int (*rr_callback_t)(const knot_rrset_t *, unsigned, struct kr_layer_param *);
+
+struct hint_map
+{
+	list_t list;
+	mm_ctx_t pool;
+};
+
+struct hint_pair
+{
+	node_t n;
+	knot_dname_t *name;
+	char *addr;
+};
+
+static struct hint_map *g_map = NULL;
+
 static int begin(knot_layer_t *ctx, void *module_param)
 {
 	ctx->data = module_param;
@@ -27,9 +58,94 @@ static int begin(knot_layer_t *ctx, void *module_param)
 
 static int query(knot_layer_t *ctx, knot_pkt_t *pkt)
 {
+	assert(pkt && ctx);
+	struct kr_layer_param *param = ctx->data;
+	struct kr_query *cur = kr_rplan_current(param->rplan);
+	if (cur == NULL) {
+		return ctx->state;
+	}
+
+	const knot_dname_t *qname = knot_pkt_qname(pkt);
+	uint16_t qtype = knot_pkt_qtype(pkt);
+	if (qtype != KNOT_RRTYPE_A && qtype != KNOT_RRTYPE_AAAA) {
+		return ctx->state;
+	}
+
+	/* Check if updating parent zone cut. */
+	rr_callback_t callback = &rr_update_parent;
+	if (cur->parent == NULL) {
+		callback = &rr_update_answer;
+	}
+
+	struct hint_pair *pair = NULL;
+	WALK_LIST(pair, g_map->list) {
+		DEBUG_MSG("scanning '%s'\n", knot_dname_to_str_alloc(pair->name));
+		if (knot_dname_is_equal(qname, pair->name)) {
+			DEBUG_MSG("found hint '%s'\n", pair->addr);
+			int addr_type = strchr(pair->addr, ':') ? AF_INET6 : AF_INET;
+			if ((addr_type == AF_INET) != (qtype == KNOT_RRTYPE_A)) {
+				continue;
+			}
+			knot_rrset_t rr;
+			knot_rrset_init(&rr, pair->name, qtype, KNOT_CLASS_IN);
+			struct sockaddr_storage addr;
+			sockaddr_set(&addr, addr_type, pair->addr, 0); 
+			size_t addr_len = 0;
+			uint8_t *raw_addr = sockaddr_raw(&addr, &addr_len);
+			knot_rrset_add_rdata(&rr, raw_addr, addr_len, 0, &param->answer->mm);
+			callback(&rr, 0, param);
+			kr_rplan_pop(param->rplan, cur);
+			return KNOT_NS_PROC_DONE;
+		}
+	}
+
 	return ctx->state;
 }
 
+static int load_map(struct hint_map *map, FILE *fp)
+{
+	knot_dname_t name_buf[KNOT_DNAME_MAXLEN];
+	size_t line_len = 0;
+	auto_free char *line = NULL;
+	init_list(&map->list);
+
+	while(getline(&line, &line_len, fp) > 0) {
+		char *saveptr = NULL;
+		char *tok = strtok_r(line, " \t\r", &saveptr);
+		if (tok == NULL || strchr(tok, '#') || strlen(tok) == 0) {
+			continue;
+		}
+		char *name_tok = strtok_r(NULL, " \t\n", &saveptr);
+		while (name_tok != NULL) {
+			struct hint_pair *pair = mm_alloc(&map->pool, sizeof(struct hint_pair));
+			if (pair == NULL) {
+				return kr_error(ENOMEM);
+			}
+			pair->name = knot_dname_from_str(name_buf, name_tok, sizeof(name_buf));
+			if (pair->name == NULL) {
+				continue;
+			}
+
+			pair->name = knot_dname_copy(pair->name, &map->pool);
+			if (pair->name == NULL) {
+				return kr_error(ENOMEM);
+			}
+			pair->addr = mm_alloc(&map->pool, strlen(tok) + 1);
+			if (pair->addr == NULL) {
+				return kr_error(ENOMEM);
+			}
+			
+			strcpy(pair->addr, tok);
+			add_tail(&map->list, &pair->n);
+			name_tok = strtok_r(NULL, " \t\n", &saveptr);
+		}
+	}
+
+	DEBUG_MSG("loaded %zu hints\n", list_size(&map->list));
+
+	return kr_ok();
+}
+
 /*
  * Module implementation.
  */
@@ -45,12 +161,31 @@ const knot_layer_api_t *hints_layer(void)
 
 int hints_init(struct kr_module *module)
 {
-	return 0;
+	auto_fclose FILE *fp = fopen(DEFAULT_FILE, "r");
+	if (fp == NULL) {
+		DEBUG_MSG("reading %s failed", DEFAULT_FILE);
+		return kr_error(errno);
+	}
+
+	mm_ctx_t pool;
+	mm_ctx_mempool(&pool, MM_DEFAULT_BLKSIZE);
+	struct hint_map *map = mm_alloc(&pool, sizeof(struct hint_map));
+	map->pool = pool;
+	module->data = map;
+
+	g_map = map;
+
+	return load_map(map, fp);
 }
 
 int hints_deinit(struct kr_module *module)
 {
-	return 0;
+	struct hint_map *map = module->data;
+	if (map) {
+		mp_delete(map->pool.ctx);
+	}
+
+	return kr_ok();
 }
 
 KR_MODULE_EXPORT(hints);

tests/tests.mk

@@ -40,18 +40,18 @@ _test_integration_DEPEND := libmock_calls
 $(eval $(call make_shared,_test_integration,tests))
 
 # Preload mock library
-insert_libs := tests/libmock_calls$(LIBEXT):modules/hints/hints$(LIBEXT)
+preload_PATH := tests
 ifeq ($(PLATFORM),Darwin)
-	preload_libs := @DYLD_FORCE_FLAT_NAMESPACE=1 DYLD_INSERT_LIBRARIES="$(insert_libs)"
+	preload_LIBS := @DYLD_FORCE_FLAT_NAMESPACE=1 DYLD_LIBRARY_PATH="$(preload_PATH):${DYLD_LIBRARY_PATH}"
 else
-	preload_libs := @LD_PRELOAD="$(subst :, ,$(insert_libs))"
+	preload_LIBS := @LD_LIBRARY_PATH="$(preload_PATH):${LD_LIBRARY_PATH}"
 endif
 
 # Targets
 .PHONY: check-integration check-unit tests tests-clean
 check-integration: libmock_calls _test_integration
-	$(call preload_libs) tests/test_integration.py tests/testdata
+	$(call preload_LIBS) tests/test_integration.py tests/testdata
 check-unit: $(tests_BIN)
 	tests/runtests -b tests $^	
 tests: check-unit check-integration
-tests-clean: $(foreach test,$(tests_BIN),$(test)-clean) libmock_calls-clean _test_integration-clean
\ No newline at end of file
+tests-clean: $(foreach test,$(tests_BIN),$(test)-clean) libmock_calls-clean _test_integration-clean