Reimplement the max-transfer-time-out and max-transfer-idle-out

While refactoring the libns to use the new network manager, the
max-transfer-*-out options were not implemented and they were turned
non-operational.

Reimplement the max-transfer-idle-out functionality using the write
timer and max-transfer-time-out using the new isc_nm_timer API.

lib/ns/xfrout.c

@@ -16,6 +16,7 @@
 
 #include <isc/formatcheck.h>
 #include <isc/mem.h>
+#include <isc/netmgr.h>
 #include <isc/print.h>
 #include <isc/result.h>
 #include <isc/stats.h>
@@ -668,6 +669,12 @@ typedef struct {
 	const char *mnemonic;	/* Style of transfer */
 	uint32_t end_serial;	/* Serial number after XFR is done */
 	struct xfr_stats stats; /*%< Transfer statistics */
+
+	/* Timeouts */
+	uint64_t maxtime; /*%< Maximum XFR timeout (in ms) */
+	isc_nm_timer_t *maxtime_timer;
+
+	uint64_t idletime; /*%< XFR idle timeout (in ms) */
 } xfrout_ctx_t;
 
 static void
@@ -695,6 +702,9 @@ xfrout_maybe_destroy(xfrout_ctx_t *xfr);
 static void
 xfrout_ctx_destroy(xfrout_ctx_t **xfrp);
 
+static void
+xfrout_client_timeout(void *arg, isc_result_t result);
+
 static void
 xfrout_log1(ns_client_t *client, dns_name_t *zonename, dns_rdataclass_t rdclass,
 	    int level, const char *fmt, ...) ISC_FORMAT_PRINTF(5, 6);
@@ -1143,6 +1153,14 @@ have_stream:
 		}
 	}
 
+	/* Start the timers */
+	if (xfr->maxtime > 0) {
+		xfrout_log(xfr, ISC_LOG_ERROR,
+			   "starting maxtime timer %" PRIu64 " ms",
+			   xfr->maxtime);
+		isc_nm_timer_start(xfr->maxtime_timer, xfr->maxtime);
+	}
+
 	/*
 	 * Hand the context over to sendstream().  Set xfr to NULL;
 	 * sendstream() is responsible for either passing the
@@ -1202,64 +1220,52 @@ xfrout_ctx_create(isc_mem_t *mctx, ns_client_t *client, unsigned int id,
 		  bool verified_tsig, unsigned int maxtime,
 		  unsigned int idletime, bool many_answers,
 		  xfrout_ctx_t **xfrp) {
-	xfrout_ctx_t *xfr;
+	xfrout_ctx_t *xfr = NULL;
-	unsigned int len;
+	unsigned int len = NS_CLIENT_TCP_BUFFER_SIZE;
-	void *mem;
+	void *mem = NULL;
 
 	REQUIRE(xfrp != NULL && *xfrp == NULL);
 
-	UNUSED(maxtime);
-	UNUSED(idletime);
-
 	xfr = isc_mem_get(mctx, sizeof(*xfr));
-	xfr->mctx = NULL;
+	*xfr = (xfrout_ctx_t){
+		.client = client,
+		.id = id,
+		.qname = qname,
+		.qtype = qtype,
+		.qclass = qclass,
+		.maxtime = maxtime * 1000,   /* in milliseconds */
+		.idletime = idletime * 1000, /* In milliseconds */
+		.tsigkey = tsigkey,
+		.lasttsig = lasttsig,
+		.verified_tsig = verified_tsig,
+		.many_answers = many_answers,
+	};
+
 	isc_mem_attach(mctx, &xfr->mctx);
-	xfr->client = client;
+
-	xfr->id = id;
-	xfr->qname = qname;
-	xfr->qtype = qtype;
-	xfr->qclass = qclass;
-	xfr->zone = NULL;
-	xfr->db = NULL;
-	xfr->ver = NULL;
 	if (zone != NULL) { /* zone will be NULL if it's DLZ */
 		dns_zone_attach(zone, &xfr->zone);
 	}
 	dns_db_attach(db, &xfr->db);
 	dns_db_attachversion(db, ver, &xfr->ver);
-	xfr->question_added = false;
-	xfr->end_of_stream = false;
-	xfr->tsigkey = tsigkey;
-	xfr->lasttsig = lasttsig;
-	xfr->verified_tsig = verified_tsig;
-	xfr->many_answers = many_answers;
-	xfr->sends = 0;
-	xfr->shuttingdown = false;
-	xfr->poll = false;
-	xfr->mnemonic = NULL;
-	xfr->buf.base = NULL;
-	xfr->buf.length = 0;
-	xfr->txmem = NULL;
-	xfr->txmemlen = 0;
-	xfr->stream = NULL;
-	xfr->quota = NULL;
 
-	xfr->stats.nmsg = 0;
-	xfr->stats.nrecs = 0;
-	xfr->stats.nbytes = 0;
 	isc_time_now(&xfr->stats.start);
 
+	isc_nm_timer_create(xfr->client->handle, xfrout_client_timeout, xfr,
+			    &xfr->maxtime_timer);
+
 	/*
 	 * Allocate a temporary buffer for the uncompressed response
-	 * message data.  The size should be no more than 65535 bytes
+	 * message data.  The buffer size must be 65535 bytes
-	 * so that the compressed data will fit in a TCP message,
+	 * (NS_CLIENT_TCP_BUFFER_SIZE): small enough that compressed
-	 * and no less than 65535 bytes so that an almost maximum-sized
+	 * data will fit in a single TCP message, and big enough to
-	 * RR will fit.  Note that although 65535-byte RRs are allowed
+	 * hold a maximum-sized RR.
-	 * in principle, they cannot be zone-transferred (at least not
+	 *
-	 * if uncompressible), because the message and RR headers would
+	 * Note that although 65535-byte RRs are allowed in principle, they
-	 * push the size of the TCP message over the 65536 byte limit.
+	 * cannot be zone-transferred (at least not if uncompressible),
+	 * because the message and RR headers would push the size of the
+	 * TCP message over the 65536 byte limit.
 	 */
-	len = 65535;
 	mem = isc_mem_get(mctx, len);
 	isc_buffer_init(&xfr->buf, mem, len);
 
@@ -1267,7 +1273,6 @@ xfrout_ctx_create(isc_mem_t *mctx, ns_client_t *client, unsigned int id,
 	 * Allocate another temporary buffer for the compressed
 	 * response message.
 	 */
-	len = NS_CLIENT_TCP_BUFFER_SIZE;
 	mem = isc_mem_get(mctx, len);
 	isc_buffer_init(&xfr->txbuf, (char *)mem, len);
 	xfr->txmem = mem;
@@ -1557,6 +1562,10 @@ sendstream(xfrout_ctx_t *xfr) {
 
 		isc_nmhandle_attach(xfr->client->handle,
 				    &xfr->client->sendhandle);
+		if (xfr->idletime > 0) {
+			isc_nmhandle_setwritetimeout(xfr->client->sendhandle,
+						     xfr->idletime);
+		}
 		isc_nm_send(xfr->client->sendhandle, &used, xfrout_senddone,
 			    xfr);
 		xfr->sends++;
@@ -1622,6 +1631,9 @@ xfrout_ctx_destroy(xfrout_ctx_t **xfrp) {
 
 	INSIST(xfr->sends == 0);
 
+	isc_nm_timer_stop(xfr->maxtime_timer);
+	isc_nm_timer_detach(&xfr->maxtime_timer);
+
 	if (xfr->stream != NULL) {
 		xfr->stream->methods->destroy(&xfr->stream);
 	}
@@ -1726,6 +1738,15 @@ xfrout_maybe_destroy(xfrout_ctx_t *xfr) {
 	xfrout_ctx_destroy(&xfr);
 }
 
+static void
+xfrout_client_timeout(void *arg, isc_result_t result) {
+	xfrout_ctx_t *xfr = (xfrout_ctx_t *)arg;
+
+	xfr->shuttingdown = true;
+	xfrout_log(xfr, ISC_LOG_ERROR, "%s: %s", "aborted",
+		   isc_result_totext(result));
+}
+
 /*
  * Log outgoing zone transfer messages in a format like
  * <client>: transfer of <zone>: <message>