Merge branch 'master' into hackathon/get-root-zone-with-etag

Co-authored-by: Wouter Wijngaards <wcawijngaards@users.noreply.github.com>

services/authzone.c

@@ -5238,7 +5238,7 @@ apply_axfr(struct auth_xfer* xfr, struct auth_zone* z,
 /** apply HTTP to zone in memory. z is locked. false on failure(mallocfail) */
 static int
 apply_http(struct auth_xfer* xfr, struct auth_zone* z,
-	struct sldns_buffer* scratch_buffer)
+	struct sldns_buffer* scratch_buffer, char* etag)
 {
 	/* parse data in chunks */
 	/* parse RR's and read into memory. ignore $INCLUDE from the
@@ -5334,7 +5334,11 @@ apply_http(struct auth_xfer* xfr, struct auth_zone* z,
 			pstate.lineno,
 			sldns_buffer_begin(scratch_buffer));
 		return 0;
-	}
+  }
+	if (etag) {
+		verbose(VERB_OPS, "etag %s stored", etag);
+		strcpy(z->etag, etag);
+  }
 	return 1;
 }
 
@@ -5492,7 +5496,7 @@ static int xfr_process_reacquire_locks(struct auth_xfer* xfr,
  * return false if it did not work */
 static int
 xfr_process_chunk_list(struct auth_xfer* xfr, struct module_env* env,
-	int* ixfr_fail)
+	int* ixfr_fail, char *etag)
 {
 	struct auth_zone* z;
 	int zonemd_in_progress;
@@ -5508,7 +5512,7 @@ xfr_process_chunk_list(struct auth_xfer* xfr, struct module_env* env,
 
 	/* apply data */
 	if(xfr->task_transfer->master->http) {
-		if(!apply_http(xfr, z, env->scratch_buffer)) {
+		if(!apply_http(xfr, z, env->scratch_buffer, etag)) {
 			auth_zone_clear_data(z);
 			lock_rw_unlock(&z->lock);
 			verbose(VERB_ALGO, "http from %s: could not store data",
@@ -5788,6 +5792,21 @@ xfr_transfer_init_fetch(struct auth_xfer* xfr, struct module_env* env)
 	xfr->task_transfer->start_time = *env->now_tv;
 
 	if(master->http) {
+		char etag[128], *etag_str = NULL;
+		struct auth_zone* z;
+		/* Obtain locks and structures. */
+		lock_basic_unlock(&xfr->lock);
+		if(!xfr_process_reacquire_locks(xfr, env, &z)) {
+			/* The zone is gone, ignore xfr transfer. */
+			return 1; /* Stop processing this xfr. */
+		}
+		/* Holding xfr and z locks. */
+
+		if(z && z->etag[0] && strlen(z->etag) < sizeof(etag)) {
+			strlcpy(etag, z->etag, sizeof(etag));
+			etag_str = etag;
+		}
+		lock_rw_unlock(&z->lock);
 		/* perform http fetch */
 		/* store http port number into sockaddr,
 		 * unless someone used unbound's host@port notation */
@@ -5797,7 +5816,7 @@ xfr_transfer_init_fetch(struct auth_xfer* xfr, struct module_env* env)
 		xfr->task_transfer->cp = outnet_comm_point_for_http(
 			env->outnet, auth_xfer_transfer_http_callback, xfr,
 			&addr, addrlen, -1, master->ssl, master->host,
-			master->file, env->cfg);
+			master->file, env->cfg, etag_str);
 		if(!xfr->task_transfer->cp) {
 			char zname[LDNS_MAX_DOMAINLEN], as[256];
 			dname_str(xfr->name, zname);
@@ -6389,10 +6408,10 @@ xfer_link_data(sldns_buffer* pkt, struct auth_xfer* xfr)
 /** task transfer.  the list of data is complete. process it and if failed
  * move to next master, if succeeded, end the task transfer */
 static void
-process_list_end_transfer(struct auth_xfer* xfr, struct module_env* env)
+process_list_end_transfer(struct auth_xfer* xfr, struct module_env* env, char* etag)
 {
 	int ixfr_fail = 0;
-	if(xfr_process_chunk_list(xfr, env, &ixfr_fail)) {
+	if(xfr_process_chunk_list(xfr, env, &ixfr_fail, etag)) {
 		/* it worked! */
 		auth_chunks_delete(xfr->task_transfer);
 
@@ -6564,9 +6583,15 @@ auth_xfer_transfer_tcp_callback(struct comm_point* c, void* arg, int err,
 	}
 	/* if the transfer is done now, disconnect and process the list */
 	if(transferdone) {
-		comm_point_delete(xfr->task_transfer->cp);
+		/* Convey etag (captured on the comm_point) to auth zone,
+		 * if there was any */
+		struct comm_point *cp;
+		cp = xfr->task_transfer->cp;
 		xfr->task_transfer->cp = NULL;
-		process_list_end_transfer(xfr, env);
+		process_list_end_transfer(xfr, env,
+			(  xfr->task_transfer->master->http && cp->etag[0]
+			?  cp->etag : NULL));
+		comm_point_delete(cp);
 		return 0;
 	}
 
@@ -6648,11 +6673,17 @@ auth_xfer_transfer_http_callback(struct comm_point* c, void* arg, int err,
 	}
 	/* if the transfer is done now, disconnect and process the list */
 	if(err == NETEVENT_DONE) {
+		/* Convey etag (captured on the comm_point) to auth zone,
+		 * if there was any */
+		struct comm_point *cp;
 		if(repinfo) repinfo->c = NULL; /* signal cp deleted to
 				the routine calling this callback */
-		comm_point_delete(xfr->task_transfer->cp);
+		cp = xfr->task_transfer->cp;
 		xfr->task_transfer->cp = NULL;
-		process_list_end_transfer(xfr, env);
+		process_list_end_transfer(xfr, env,
+			(  xfr->task_transfer->master->http && cp->etag[0]
+			?  cp->etag : NULL));
+		comm_point_delete(cp);
 		return 0;
 	}
 

services/authzone.h

@@ -125,6 +125,8 @@ struct auth_zone {
 	int zone_expired;
 	/** zone is a slave zone (it has masters) */
 	int zone_is_slave;
+	/** store etag */
+	char etag[128];
 	/** for downstream: this zone answers queries towards the downstream
 	 * clients */
 	int for_downstream;

services/outside_network.c

@@ -3900,11 +3900,15 @@ setup_http_user_agent(sldns_buffer* buf, struct config_file* cfg)
 /** setup http request headers in buffer for sending query to destination */
 static int
 setup_http_request(sldns_buffer* buf, char* host, char* path,
-	struct config_file* cfg)
+	struct config_file* cfg, const char* etag)
 {
 	sldns_buffer_clear(buf);
 	sldns_buffer_printf(buf, "GET /%s HTTP/1.1\r\n", path);
 	sldns_buffer_printf(buf, "Host: %s\r\n", host);
+	if (etag) {
+		verbose(VERB_OPS, "sending along ETag %s in http request", etag);
+		sldns_buffer_printf(buf, "If-None-Match: %s\r\n", etag);
+	}
 	setup_http_user_agent(buf, cfg);
 	/* We do not really do multiple queries per connection,
 	 * but this header setting is also not needed.
@@ -3921,7 +3925,7 @@ struct comm_point*
 outnet_comm_point_for_http(struct outside_network* outnet,
 	comm_point_callback_type* cb, void* cb_arg,
 	struct sockaddr_storage* to_addr, socklen_t to_addrlen, int timeout,
-	int ssl, char* host, char* path, struct config_file* cfg)
+	int ssl, char* host, char* path, struct config_file* cfg, char* etag)
 {
 	/* cp calls cb with err=NETEVENT_DONE when transfer is done */
 	struct comm_point* cp;
@@ -3959,7 +3963,7 @@ outnet_comm_point_for_http(struct outside_network* outnet,
 	comm_point_start_listening(cp, fd, timeout);
 
 	/* setup http request in cp->buffer */
-	if(!setup_http_request(cp->buffer, host, path, cfg)) {
+	if(!setup_http_request(cp->buffer, host, path, cfg, etag)) {
 		log_err("error setting up http request");
 		comm_point_delete(cp);
 		return NULL;

services/outside_network.h

@@ -854,7 +854,7 @@ struct comm_point* outnet_comm_point_for_tcp(struct outside_network* outnet,
 struct comm_point* outnet_comm_point_for_http(struct outside_network* outnet,
 	comm_point_callback_type* cb, void* cb_arg,
 	struct sockaddr_storage* to_addr, socklen_t to_addrlen, int timeout,
-	int ssl, char* host, char* path, struct config_file* cfg);
+	int ssl, char* host, char* path, struct config_file* cfg, char* etag);
 
 /** connect tcp connection to addr, 0 on failure */
 int outnet_tcp_connect(int s, struct sockaddr_storage* addr, socklen_t addrlen);

util/netevent.c

@@ -5037,6 +5037,10 @@ http_process_initial_header(struct comm_point* c)
 	} else if(strncasecmp(line, "Transfer-Encoding: chunked", 19+7) == 0) {
 		c->tcp_byte_count = 0;
 		c->http_is_chunked = 1;
+	} else if(strncasecmp(line, "ETag: ", 6) == 0) {
+		if (strlen(line + 6) < sizeof(c->etag)) {
+			strcpy(c->etag, line + 6);
+		}
 	} else if(line[0] == 0) {
 		/* end of initial headers */
 		c->http_in_headers = 0;
@@ -6581,6 +6585,7 @@ comm_point_create_http_out(struct comm_base *base, size_t bufsize,
 	c->http_in_chunk_headers = 0;
 	c->http_is_chunked = 0;
 	c->http_temp = temp;
+	c->etag[0] = 0;
 #ifdef USE_MSG_FASTOPEN
 	c->tcp_do_fastopen = 1;
 #endif

util/netevent.h

@@ -286,6 +286,8 @@ struct comm_point {
 	struct sldns_buffer* http_temp;
 	/** http stored content in buffer */
 	size_t http_stored;
+	/** http Entity-Tag */
+	char etag[128];
 	/* -------- HTTP/2 ------- */
 	/** http2 session */
 	struct http2_session* h2_session;