extend DLZ interface and example with ECS support

Apparently we forgot about DLZ when updating DNS_CLIENTINFO_VERSION
constant for ECS, which is at value "3" since ECS was introduced.

The code in example drivers and tests now hardcodes version numbers
2 (without ECS) and 3 (with ECS) depending on what a given code path
requires.

bin/tests/system/dlzexternal/driver/driver.c

@@ -480,8 +480,7 @@ dlz_lookup(const char *zone, const char *name, void *dbdata,
 	 * If the DLZ only operates on 'live' data, then version
 	 * wouldn't necessarily be needed.
 	 */
-	if (clientinfo != NULL && clientinfo->version >= DNS_CLIENTINFO_VERSION)
+	if (clientinfo != NULL && clientinfo->version >= 2) {
-	{
 		dbversion = clientinfo->dbversion;
 		if (dbversion != NULL && *(bool *)dbversion) {
 			loginfo("dlz_example: lookup against live transaction");

contrib/dlz/example/dlz_example.c

@@ -428,8 +428,7 @@ dlz_lookup(const char *zone, const char *name, void *dbdata,
 	 * If the DLZ only operates on 'live' data, then version
 	 * wouldn't necessarily be needed.
 	 */
-	if (clientinfo != NULL && clientinfo->version >= DNS_CLIENTINFO_VERSION)
+	if (clientinfo != NULL && clientinfo->version >= 2) {
-	{
 		dbversion = clientinfo->dbversion;
 		if (dbversion != NULL && *(bool *)dbversion) {
 			state->log(ISC_LOG_INFO, "dlz_example: lookup against "
@@ -439,6 +438,7 @@ dlz_lookup(const char *zone, const char *name, void *dbdata,
 	}
 
 	if (strcmp(name, "source-addr") == 0) {
+		char ecsbuf[100] = "not supported";
 		strcpy(buf, "unknown");
 		if (methods != NULL && methods->sourceip != NULL &&
 		    (methods->version - methods->age <=
@@ -448,12 +448,25 @@ dlz_lookup(const char *zone, const char *name, void *dbdata,
 			methods->sourceip(clientinfo, &src);
 			fmt_address(src, buf, sizeof(buf));
 		}
+		if (clientinfo != NULL && clientinfo->version >= 3) {
+			if (clientinfo->ecs.addr.family != AF_UNSPEC) {
+				dns_ecs_format(&clientinfo->ecs, ecsbuf,
+					       sizeof(ecsbuf));
+			} else {
+				strcpy(ecsbuf, "not present");
+			}
+		}
+		i = strlen(buf);
+		snprintf(buf + i, sizeof(buf) - i - 1, " ECS %s", ecsbuf);
 
 		state->log(ISC_LOG_INFO,
 			   "dlz_example: lookup connection from: %s", buf);
 
 		found = true;
 		result = state->putrr(lookup, "TXT", 0, buf);
+		/* We could also generate a CNAME RR:
+		snprintf(buf, sizeof(buf), "%s.redirect.example.", ecsbuf);
+		result = state->putrr(lookup, "CNAME", 0, buf); */
 		if (result != ISC_R_SUCCESS) {
 			return (result);
 		}

contrib/dlz/modules/include/dlz_minimal.h

@@ -28,6 +28,8 @@
 #include <inttypes.h>
 #include <stdbool.h>
 
+#include <dns/ecs.h>
+
 #include <arpa/inet.h>
 #include <net/if.h>
 #include <netinet/in.h>
@@ -35,7 +37,6 @@
 #include <sys/types.h>
 #include <sys/un.h>
 
-typedef unsigned int isc_result_t;
 typedef uint32_t dns_ttl_t;
 
 /*
@@ -88,8 +89,6 @@ typedef uint32_t     dns_ttl_t;
 /* opaque structures */
 typedef void *dns_sdlzlookup_t;
 typedef void *dns_sdlzallnodes_t;
-typedef void *dns_view_t;
-typedef void *dns_dlzdb_t;
 
 #if DLZ_DLOPEN_VERSION > 1
 /*
@@ -107,11 +106,12 @@ typedef struct isc_sockaddr {
 	void	     *link;
 } isc_sockaddr_t;
 
-#define DNS_CLIENTINFO_VERSION 2
+#define DNS_CLIENTINFO_VERSION 3
 typedef struct dns_clientinfo {
 	uint16_t  version;
 	void     *data;
 	void     *dbversion;
+	dns_ecs_t ecs;
 } dns_clientinfo_t;
 
 typedef isc_result_t (*dns_clientinfo_sourceip_t)(dns_clientinfo_t *client,

contrib/dlz/modules/mysqldyn/dlz_mysqldyn_mod.c

@@ -1128,8 +1128,7 @@ dlz_lookup(const char *zone, const char *name, void *dbdata,
 	}
 
 	/* Are we okay to try to find the txn version?  */
-	if (clientinfo != NULL && clientinfo->version >= DNS_CLIENTINFO_VERSION)
+	if (clientinfo != NULL && clientinfo->version >= 2) {
-	{
 		txn = (mysql_transaction_t *)clientinfo->dbversion;
 		if (txn != NULL && validate_txn(state, txn) == ISC_R_SUCCESS) {
 			dbi = txn->dbi;