Move dig(1) and needed DNS libraries into it's own source directory in

usr.bin/dig.

From the beginning when we started to remove unneeded nameserver code,
it was our goal to extract dig functionality from the bind sources,
for everyone's benefit as this is easier to reason about.

In total we removed about 2/3 or over 300.000 lines of code.

We kept the lib/ subdirectory layout but moved the content of bin/ to
the top from the old bind source directory.

Previous sources and history can be found in the src/usr.sbin/bind
Attic.

With & OK deraadt
Proposed directory layout sounds good to sthen

16 files changed, 4803 insertions, 0 deletions

diff --git a/usr.bin/dig/lib/isc/unix/Makefile.inc b/usr.bin/dig/lib/isc/unix/Makefile.inc
new file mode 100644
index 00000000000..217d1c15a7d
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/Makefile.inc
@@ -0,0 +1,6 @@
+#	$OpenBSD: Makefile.inc,v 1.1 2020/02/07 09:58:54 florian Exp $
+
+.PATH: ${.CURDIR}/lib/isc/unix
+
+SRCS+=	app.c errno.c errno2result.c socket.c stdio.c net.c stdtime.c
+SRCS+=	strerror.c time.c
diff --git a/usr.bin/dig/lib/isc/unix/app.c b/usr.bin/dig/lib/isc/unix/app.c
new file mode 100644
index 00000000000..555a81340e8
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/app.c
@@ -0,0 +1,583 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*! \file */
+
+
+
+#include <sys/param.h>	/* Openserver 5.0.6A and FD_SETSIZE */
+#include <sys/types.h>
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/time.h>
+
+#include <isc/app.h>
+#include <isc/boolean.h>
+
+
+#include <isc/msgs.h>
+#include <isc/event.h>
+
+#include <isc/strerror.h>
+#include <string.h>
+#include <isc/task.h>
+#include <isc/time.h>
+#include <isc/util.h>
+
+/*%
+ * For BIND9 internal applications built with threads, we use a single app
+ * context and let multiple worker, I/O, timer threads do actual jobs.
+ * For other cases (including BIND9 built without threads) an app context acts
+ * as an event loop dispatching various events.
+ */
+#include "../timer_p.h"
+#include "../task_p.h"
+#include "socket_p.h"
+
+/*%
+ * The following are intended for internal use (indicated by "isc__"
+ * prefix) but are not declared as static, allowing direct access from
+ * unit tests etc.
+ */
+isc_result_t isc__app_start(void);
+isc_result_t isc__app_ctxstart(isc_appctx_t *ctx);
+isc_result_t isc__app_onrun(isc_task_t *task,
+			    isc_taskaction_t action, void *arg);
+isc_result_t isc__app_ctxrun(isc_appctx_t *ctx);
+isc_result_t isc__app_run(void);
+isc_result_t isc__app_ctxshutdown(isc_appctx_t *ctx);
+isc_result_t isc__app_shutdown(void);
+isc_result_t isc__app_reload(void);
+isc_result_t isc__app_ctxsuspend(isc_appctx_t *ctx);
+void isc__app_ctxfinish(isc_appctx_t *ctx);
+void isc__app_finish(void);
+void isc__app_block(void);
+void isc__app_unblock(void);
+isc_result_t isc__appctx_create(isc_appctx_t **ctxp);
+void isc__appctx_destroy(isc_appctx_t **ctxp);
+void isc__appctx_settaskmgr(isc_appctx_t *ctx, isc_taskmgr_t *taskmgr);
+void isc__appctx_setsocketmgr(isc_appctx_t *ctx, isc_socketmgr_t *socketmgr);
+void isc__appctx_settimermgr(isc_appctx_t *ctx, isc_timermgr_t *timermgr);
+isc_result_t isc__app_ctxonrun(isc_appctx_t *ctx,
+			       isc_task_t *task, isc_taskaction_t action,
+			       void *arg);
+
+/*
+ * The application context of this module.  This implementation actually
+ * doesn't use it. (This may change in the future).
+ */
+#define APPCTX_MAGIC		ISC_MAGIC('A', 'p', 'c', 'x')
+#define VALID_APPCTX(c)		ISC_MAGIC_VALID(c, APPCTX_MAGIC)
+
+typedef struct isc__appctx {
+	isc_appctx_t		common;
+	isc_eventlist_t		on_run;
+	isc_boolean_t		shutdown_requested;
+	isc_boolean_t		running;
+
+	/*!
+	 * We assume that 'want_shutdown' can be read and written atomically.
+	 */
+	isc_boolean_t		want_shutdown;
+	/*
+	 * We assume that 'want_reload' can be read and written atomically.
+	 */
+	isc_boolean_t		want_reload;
+
+	isc_boolean_t		blocked;
+
+	isc_taskmgr_t		*taskmgr;
+	isc_socketmgr_t		*socketmgr;
+	isc_timermgr_t		*timermgr;
+} isc__appctx_t;
+
+static isc__appctx_t isc_g_appctx;
+
+static struct {
+	isc_appmethods_t methods;
+
+	/*%
+	 * The following are defined just for avoiding unused static functions.
+	 */
+	void *run, *shutdown, *start, *reload, *finish, *block, *unblock;
+} appmethods = {
+	{
+		isc__appctx_destroy,
+		isc__app_ctxstart,
+		isc__app_ctxrun,
+		isc__app_ctxsuspend,
+		isc__app_ctxshutdown,
+		isc__app_ctxfinish,
+		isc__appctx_settaskmgr,
+		isc__appctx_setsocketmgr,
+		isc__appctx_settimermgr,
+		isc__app_ctxonrun
+	},
+	(void *)isc__app_run,
+	(void *)isc__app_shutdown,
+	(void *)isc__app_start,
+	(void *)isc__app_reload,
+	(void *)isc__app_finish,
+	(void *)isc__app_block,
+	(void *)isc__app_unblock
+};
+
+static void
+reload_action(int arg) {
+	UNUSED(arg);
+	isc_g_appctx.want_reload = ISC_TRUE;
+}
+
+static isc_result_t
+handle_signal(int sig, void (*handler)(int)) {
+	struct sigaction sa;
+	char strbuf[ISC_STRERRORSIZE];
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_handler = handler;
+
+	if (sigfillset(&sa.sa_mask) != 0 ||
+	    sigaction(sig, &sa, NULL) < 0) {
+		isc__strerror(errno, strbuf, sizeof(strbuf));
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "handle_signal() %d setup: %s", sig, strbuf);
+		return (ISC_R_UNEXPECTED);
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc__app_ctxstart(isc_appctx_t *ctx0) {
+	isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
+	isc_result_t result;
+	int presult;
+	sigset_t sset;
+	char strbuf[ISC_STRERRORSIZE];
+
+	REQUIRE(VALID_APPCTX(ctx));
+
+	/*
+	 * Start an ISC library application.
+	 */
+
+	ISC_LIST_INIT(ctx->on_run);
+
+	ctx->shutdown_requested = ISC_FALSE;
+	ctx->running = ISC_FALSE;
+	ctx->want_shutdown = ISC_FALSE;
+	ctx->want_reload = ISC_FALSE;
+	ctx->blocked = ISC_FALSE;
+
+	/*
+	 * Always ignore SIGPIPE.
+	 */
+	result = handle_signal(SIGPIPE, SIG_IGN);
+	if (result != ISC_R_SUCCESS)
+		goto cleanup;
+
+	/*
+	 * On Solaris 2, delivery of a signal whose action is SIG_IGN
+	 * will not cause sigwait() to return. We may have inherited
+	 * unexpected actions for SIGHUP, SIGINT, and SIGTERM from our parent
+	 * process (e.g, Solaris cron).  Set an action of SIG_DFL to make
+	 * sure sigwait() works as expected.  Only do this for SIGTERM and
+	 * SIGINT if we don't have sigwait(), since a different handler is
+	 * installed above.
+	 */
+	result = handle_signal(SIGHUP, SIG_DFL);
+	if (result != ISC_R_SUCCESS)
+		goto cleanup;
+
+	result = handle_signal(SIGTERM, SIG_DFL);
+	if (result != ISC_R_SUCCESS)
+		goto cleanup;
+	result = handle_signal(SIGINT, SIG_DFL);
+	if (result != ISC_R_SUCCESS)
+		goto cleanup;
+
+	/*
+	 * Unblock SIGHUP, SIGINT, SIGTERM.
+	 *
+	 * If we're not using threads, we need to make sure that SIGHUP,
+	 * SIGINT and SIGTERM are not inherited as blocked from the parent
+	 * process.
+	 */
+	if (sigemptyset(&sset) != 0 ||
+	    sigaddset(&sset, SIGHUP) != 0 ||
+	    sigaddset(&sset, SIGINT) != 0 ||
+	    sigaddset(&sset, SIGTERM) != 0) {
+		isc__strerror(errno, strbuf, sizeof(strbuf));
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "isc_app_start() sigsetops: %s", strbuf);
+		result = ISC_R_UNEXPECTED;
+		goto cleanup;
+	}
+	presult = sigprocmask(SIG_UNBLOCK, &sset, NULL);
+	if (presult != 0) {
+		isc__strerror(errno, strbuf, sizeof(strbuf));
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "isc_app_start() sigprocmask: %s", strbuf);
+		result = ISC_R_UNEXPECTED;
+		goto cleanup;
+	}
+
+	return (ISC_R_SUCCESS);
+
+ cleanup:
+	return (result);
+}
+
+isc_result_t
+isc__app_start(void) {
+	isc_g_appctx.common.impmagic = APPCTX_MAGIC;
+	isc_g_appctx.common.magic = ISCAPI_APPCTX_MAGIC;
+	isc_g_appctx.common.methods = &appmethods.methods;
+	/* The remaining members will be initialized in ctxstart() */
+
+	return (isc__app_ctxstart((isc_appctx_t *)&isc_g_appctx));
+}
+
+isc_result_t
+isc__app_onrun(isc_task_t *task, isc_taskaction_t action,
+	      void *arg)
+{
+	return (isc__app_ctxonrun((isc_appctx_t *)&isc_g_appctx,
+				  task, action, arg));
+}
+
+isc_result_t
+isc__app_ctxonrun(isc_appctx_t *ctx0, isc_task_t *task,
+		  isc_taskaction_t action, void *arg)
+{
+	isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
+	isc_event_t *event;
+	isc_task_t *cloned_task = NULL;
+	isc_result_t result;
+
+	if (ctx->running) {
+		result = ISC_R_ALREADYRUNNING;
+		goto unlock;
+	}
+
+	/*
+	 * Note that we store the task to which we're going to send the event
+	 * in the event's "sender" field.
+	 */
+	isc_task_attach(task, &cloned_task);
+	event = isc_event_allocate(cloned_task, ISC_APPEVENT_SHUTDOWN,
+				   action, arg, sizeof(*event));
+	if (event == NULL) {
+		isc_task_detach(&cloned_task);
+		result = ISC_R_NOMEMORY;
+		goto unlock;
+	}
+
+	ISC_LIST_APPEND(ctx->on_run, event, ev_link);
+
+	result = ISC_R_SUCCESS;
+
+ unlock:
+	return (result);
+}
+
+/*!
+ * Event loop for nonthreaded programs.
+ */
+static isc_result_t
+evloop(isc__appctx_t *ctx) {
+	isc_result_t result;
+
+	while (!ctx->want_shutdown) {
+		int n;
+		isc_time_t when, now;
+		struct timeval tv, *tvp;
+		isc_socketwait_t *swait;
+		isc_boolean_t readytasks;
+		isc_boolean_t call_timer_dispatch = ISC_FALSE;
+
+		/*
+		 * Check the reload (or suspend) case first for exiting the
+		 * loop as fast as possible in case:
+		 *   - the direct call to isc__taskmgr_dispatch() in
+		 *     isc__app_ctxrun() completes all the tasks so far,
+		 *   - there is thus currently no active task, and
+		 *   - there is a timer event
+		 */
+		if (ctx->want_reload) {
+			ctx->want_reload = ISC_FALSE;
+			return (ISC_R_RELOAD);
+		}
+
+		readytasks = isc__taskmgr_ready(ctx->taskmgr);
+		if (readytasks) {
+			tv.tv_sec = 0;
+			tv.tv_usec = 0;
+			tvp = &tv;
+			call_timer_dispatch = ISC_TRUE;
+		} else {
+			result = isc__timermgr_nextevent(ctx->timermgr, &when);
+			if (result != ISC_R_SUCCESS)
+				tvp = NULL;
+			else {
+				uint64_t us;
+
+				TIME_NOW(&now);
+				us = isc_time_microdiff(&when, &now);
+				if (us == 0)
+					call_timer_dispatch = ISC_TRUE;
+				tv.tv_sec = us / 1000000;
+				tv.tv_usec = us % 1000000;
+				tvp = &tv;
+			}
+		}
+
+		swait = NULL;
+		n = isc__socketmgr_waitevents(ctx->socketmgr, tvp, &swait);
+
+		if (n == 0 || call_timer_dispatch) {
+			/*
+			 * We call isc__timermgr_dispatch() only when
+			 * necessary, in order to reduce overhead.  If the
+			 * select() call indicates a timeout, we need the
+			 * dispatch.  Even if not, if we set the 0-timeout
+			 * for the select() call, we need to check the timer
+			 * events.  In the 'readytasks' case, there may be no
+			 * timeout event actually, but there is no other way
+			 * to reduce the overhead.
+			 * Note that we do not have to worry about the case
+			 * where a new timer is inserted during the select()
+			 * call, since this loop only runs in the non-thread
+			 * mode.
+			 */
+			isc__timermgr_dispatch(ctx->timermgr);
+		}
+		if (n > 0)
+			(void)isc__socketmgr_dispatch(ctx->socketmgr, swait);
+		(void)isc__taskmgr_dispatch(ctx->taskmgr);
+	}
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc__app_ctxrun(isc_appctx_t *ctx0) {
+	isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
+	int result;
+	isc_event_t *event, *next_event;
+	isc_task_t *task;
+
+	REQUIRE(VALID_APPCTX(ctx));
+
+	if (!ctx->running) {
+		ctx->running = ISC_TRUE;
+
+		/*
+		 * Post any on-run events (in FIFO order).
+		 */
+		for (event = ISC_LIST_HEAD(ctx->on_run);
+		     event != NULL;
+		     event = next_event) {
+			next_event = ISC_LIST_NEXT(event, ev_link);
+			ISC_LIST_UNLINK(ctx->on_run, event, ev_link);
+			task = event->ev_sender;
+			event->ev_sender = NULL;
+			isc_task_sendanddetach(&task, &event);
+		}
+
+	}
+
+	if (ctx == &isc_g_appctx) {
+		result = handle_signal(SIGHUP, reload_action);
+		if (result != ISC_R_SUCCESS)
+			return (ISC_R_SUCCESS);
+	}
+
+	(void) isc__taskmgr_dispatch(ctx->taskmgr);
+	result = evloop(ctx);
+	return (result);
+}
+
+isc_result_t
+isc__app_run(void) {
+	return (isc__app_ctxrun((isc_appctx_t *)&isc_g_appctx));
+}
+
+isc_result_t
+isc__app_ctxshutdown(isc_appctx_t *ctx0) {
+	isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
+	isc_boolean_t want_kill = ISC_TRUE;
+
+	REQUIRE(VALID_APPCTX(ctx));
+
+	REQUIRE(ctx->running);
+
+	if (ctx->shutdown_requested)
+		want_kill = ISC_FALSE;
+	else
+		ctx->shutdown_requested = ISC_TRUE;
+
+	if (want_kill) {
+		if (ctx != &isc_g_appctx)
+			/* BIND9 internal, but using multiple contexts */
+			ctx->want_shutdown = ISC_TRUE;
+		else {
+			ctx->want_shutdown = ISC_TRUE;
+		}
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc__app_shutdown(void) {
+	return (isc__app_ctxshutdown((isc_appctx_t *)&isc_g_appctx));
+}
+
+isc_result_t
+isc__app_ctxsuspend(isc_appctx_t *ctx0) {
+	isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
+	isc_boolean_t want_kill = ISC_TRUE;
+
+	REQUIRE(VALID_APPCTX(ctx));
+
+	REQUIRE(ctx->running);
+
+	/*
+	 * Don't send the reload signal if we're shutting down.
+	 */
+	if (ctx->shutdown_requested)
+		want_kill = ISC_FALSE;
+
+	if (want_kill) {
+		if (ctx != &isc_g_appctx)
+			/* BIND9 internal, but using multiple contexts */
+			ctx->want_reload = ISC_TRUE;
+		else {
+			ctx->want_reload = ISC_TRUE;
+		}
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc__app_reload(void) {
+	return (isc__app_ctxsuspend((isc_appctx_t *)&isc_g_appctx));
+}
+
+void
+isc__app_ctxfinish(isc_appctx_t *ctx0) {
+	isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
+
+	REQUIRE(VALID_APPCTX(ctx));
+}
+
+void
+isc__app_finish(void) {
+	isc__app_ctxfinish((isc_appctx_t *)&isc_g_appctx);
+}
+
+void
+isc__app_block(void) {
+	REQUIRE(isc_g_appctx.running);
+	REQUIRE(!isc_g_appctx.blocked);
+
+	isc_g_appctx.blocked = ISC_TRUE;
+}
+
+void
+isc__app_unblock(void) {
+
+	REQUIRE(isc_g_appctx.running);
+	REQUIRE(isc_g_appctx.blocked);
+
+	isc_g_appctx.blocked = ISC_FALSE;
+
+}
+
+isc_result_t
+isc__appctx_create(isc_appctx_t **ctxp) {
+	isc__appctx_t *ctx;
+
+	REQUIRE(ctxp != NULL && *ctxp == NULL);
+
+	ctx = malloc(sizeof(*ctx));
+	if (ctx == NULL)
+		return (ISC_R_NOMEMORY);
+
+	ctx->common.impmagic = APPCTX_MAGIC;
+	ctx->common.magic = ISCAPI_APPCTX_MAGIC;
+	ctx->common.methods = &appmethods.methods;
+
+	ctx->taskmgr = NULL;
+	ctx->socketmgr = NULL;
+	ctx->timermgr = NULL;
+
+	*ctxp = (isc_appctx_t *)ctx;
+
+	return (ISC_R_SUCCESS);
+}
+
+void
+isc__appctx_destroy(isc_appctx_t **ctxp) {
+	isc__appctx_t *ctx;
+
+	REQUIRE(ctxp != NULL);
+	ctx = (isc__appctx_t *)*ctxp;
+	REQUIRE(VALID_APPCTX(ctx));
+
+	free(ctx);
+
+	*ctxp = NULL;
+}
+
+void
+isc__appctx_settaskmgr(isc_appctx_t *ctx0, isc_taskmgr_t *taskmgr) {
+	isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
+
+	REQUIRE(VALID_APPCTX(ctx));
+
+	ctx->taskmgr = taskmgr;
+}
+
+void
+isc__appctx_setsocketmgr(isc_appctx_t *ctx0, isc_socketmgr_t *socketmgr) {
+	isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
+
+	REQUIRE(VALID_APPCTX(ctx));
+
+	ctx->socketmgr = socketmgr;
+}
+
+void
+isc__appctx_settimermgr(isc_appctx_t *ctx0, isc_timermgr_t *timermgr) {
+	isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
+
+	REQUIRE(VALID_APPCTX(ctx));
+
+	ctx->timermgr = timermgr;
+}
+
+isc_result_t
+isc__app_register(void) {
+	return (isc_app_register(isc__appctx_create));
+}
+
+#include "../app_api.c"
diff --git a/usr.bin/dig/lib/isc/unix/errno.c b/usr.bin/dig/lib/isc/unix/errno.c
new file mode 100644
index 00000000000..6117fa70b40
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/errno.c
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*! \file */
+
+
+
+#include <isc/errno.h>
+#include <isc/util.h>
+
+#include "errno2result.h"
+
+isc_result_t
+isc_errno_toresult(int err) {
+	return (isc___errno2result(err, ISC_FALSE, 0, 0));
+}
diff --git a/usr.bin/dig/lib/isc/unix/errno2result.c b/usr.bin/dig/lib/isc/unix/errno2result.c
new file mode 100644
index 00000000000..4430910a346
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/errno2result.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: errno2result.c,v 1.1 2020/02/07 09:58:54 florian Exp $ */
+
+/*! \file */
+
+
+
+#include <isc/result.h>
+#include <isc/strerror.h>
+#include <isc/util.h>
+
+#include "errno2result.h"
+
+/*%
+ * Convert a POSIX errno value into an isc_result_t.  The
+ * list of supported errno values is not complete; new users
+ * of this function should add any expected errors that are
+ * not already there.
+ */
+isc_result_t
+isc___errno2result(int posixerrno, isc_boolean_t dolog,
+		   const char *file, unsigned int line)
+{
+	char strbuf[ISC_STRERRORSIZE];
+
+	switch (posixerrno) {
+	case ENOTDIR:
+	case ELOOP:
+	case EINVAL:		/* XXX sometimes this is not for files */
+	case ENAMETOOLONG:
+	case EBADF:
+		return (ISC_R_INVALIDFILE);
+	case ENOENT:
+		return (ISC_R_FILENOTFOUND);
+	case EACCES:
+	case EPERM:
+		return (ISC_R_NOPERM);
+	case EEXIST:
+		return (ISC_R_FILEEXISTS);
+	case EIO:
+		return (ISC_R_IOERROR);
+	case ENOMEM:
+		return (ISC_R_NOMEMORY);
+	case ENFILE:
+	case EMFILE:
+		return (ISC_R_TOOMANYOPENFILES);
+#ifdef EOVERFLOW
+	case EOVERFLOW:
+		return (ISC_R_RANGE);
+#endif
+	case EPIPE:
+#ifdef ECONNRESET
+	case ECONNRESET:
+#endif
+#ifdef ECONNABORTED
+	case ECONNABORTED:
+#endif
+		return (ISC_R_CONNECTIONRESET);
+#ifdef ENOTCONN
+	case ENOTCONN:
+		return (ISC_R_NOTCONNECTED);
+#endif
+#ifdef ETIMEDOUT
+	case ETIMEDOUT:
+		return (ISC_R_TIMEDOUT);
+#endif
+#ifdef ENOBUFS
+	case ENOBUFS:
+		return (ISC_R_NORESOURCES);
+#endif
+#ifdef EAFNOSUPPORT
+	case EAFNOSUPPORT:
+		return (ISC_R_FAMILYNOSUPPORT);
+#endif
+#ifdef ENETDOWN
+	case ENETDOWN:
+		return (ISC_R_NETDOWN);
+#endif
+#ifdef EHOSTDOWN
+	case EHOSTDOWN:
+		return (ISC_R_HOSTDOWN);
+#endif
+#ifdef ENETUNREACH
+	case ENETUNREACH:
+		return (ISC_R_NETUNREACH);
+#endif
+#ifdef EHOSTUNREACH
+	case EHOSTUNREACH:
+		return (ISC_R_HOSTUNREACH);
+#endif
+#ifdef EADDRINUSE
+	case EADDRINUSE:
+		return (ISC_R_ADDRINUSE);
+#endif
+	case EADDRNOTAVAIL:
+		return (ISC_R_ADDRNOTAVAIL);
+	case ECONNREFUSED:
+		return (ISC_R_CONNREFUSED);
+	default:
+		if (dolog) {
+			isc__strerror(posixerrno, strbuf, sizeof(strbuf));
+			UNEXPECTED_ERROR(file, line, "unable to convert errno "
+					 "to isc_result: %d: %s",
+					 posixerrno, strbuf);
+		}
+		/*
+		 * XXXDCL would be nice if perhaps this function could
+		 * return the system's error string, so the caller
+		 * might have something more descriptive than "unexpected
+		 * error" to log with.
+		 */
+		return (ISC_R_UNEXPECTED);
+	}
+}
diff --git a/usr.bin/dig/lib/isc/unix/errno2result.h b/usr.bin/dig/lib/isc/unix/errno2result.h
new file mode 100644
index 00000000000..9c9c00daca8
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/errno2result.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef UNIX_ERRNO2RESULT_H
+#define UNIX_ERRNO2RESULT_H 1
+
+/*! \file */
+
+/* XXXDCL this should be moved to lib/isc/include/isc/errno2result.h. */
+
+#include <errno.h>		/* Provides errno. */
+
+#include <isc/lang.h>
+#include <isc/types.h>
+
+ISC_LANG_BEGINDECLS
+
+#define isc__errno2result(x) isc___errno2result(x, ISC_TRUE, __FILE__, __LINE__)
+
+isc_result_t
+isc___errno2result(int posixerrno, isc_boolean_t dolog,
+		   const char *file, unsigned int line);
+
+ISC_LANG_ENDDECLS
+
+#endif /* UNIX_ERRNO2RESULT_H */
diff --git a/usr.bin/dig/lib/isc/unix/include/isc/net.h b/usr.bin/dig/lib/isc/unix/include/isc/net.h
new file mode 100644
index 00000000000..b8e1d8c6478
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/include/isc/net.h
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: net.h,v 1.1 2020/02/07 09:58:54 florian Exp $ */
+
+#ifndef ISC_NET_H
+#define ISC_NET_H 1
+
+/*****
+ ***** Module Info
+ *****/
+
+/*! \file
+ * \brief
+ * Basic Networking Types
+ *
+ * This module is responsible for defining the following basic networking
+ * types:
+ *
+ *\li		struct in_addr
+ *\li		struct in6_addr
+ *\li		struct in6_pktinfo
+ *\li		struct sockaddr
+ *\li		struct sockaddr_in
+ *\li		struct sockaddr_in6
+ *\li		struct sockaddr_storage
+ *\li		in_port_t
+ *
+ * It ensures that the AF_ and PF_ macros are defined.
+ *
+ * It declares ntoh[sl]() and hton[sl]().
+ *
+ * It declares inet_aton(), inet_ntop(), and inet_pton().
+ *
+ * It ensures that #INADDR_LOOPBACK, #INADDR_ANY, #IN6ADDR_ANY_INIT,
+ * IN6ADDR_V4MAPPED_INIT, in6addr_any, and in6addr_loopback are available.
+ *
+ * It ensures that IN_MULTICAST() is available to check for multicast
+ * addresses.
+ *
+ * MP:
+ *\li	No impact.
+ *
+ * Reliability:
+ *\li	No anticipated impact.
+ *
+ * Resources:
+ *\li	N/A.
+ *
+ * Security:
+ *\li	No anticipated impact.
+ *
+ * Standards:
+ *\li	BSD Socket API
+ *\li	RFC2553
+ */
+
+/***
+ *** Imports.
+ ***/
+
+
+#include <sys/types.h>
+#include <sys/socket.h>		/* Contractual promise. */
+
+#include <net/if.h>
+
+#include <netinet/in.h>		/* Contractual promise. */
+#include <arpa/inet.h>		/* Contractual promise. */
+
+#include <isc/lang.h>
+#include <isc/types.h>
+
+#ifndef IN6_IS_ADDR_SITELOCAL
+/*% is IPv6 address sitelocal? */
+#define IN6_IS_ADDR_SITELOCAL(a) \
+	(((a)->s6_addr[0] == 0xfe) && (((a)->s6_addr[1] & 0xc0) == 0xc0))
+#endif
+
+
+#ifndef IN6_IS_ADDR_LOOPBACK
+/*% is IPv6 address loopback? */
+#define IN6_IS_ADDR_LOOPBACK(x) \
+	(memcmp((x)->s6_addr, in6addr_loopback.s6_addr, 16) == 0)
+#endif
+
+/*% IP address. */
+#define ISC__IPADDR(x)	((uint32_t)htonl((uint32_t)(x)))
+
+/*% Is IP address multicast? */
+#define ISC_IPADDR_ISMULTICAST(i) \
+		(((uint32_t)(i) & ISC__IPADDR(0xf0000000)) \
+		 == ISC__IPADDR(0xe0000000))
+
+#define ISC_IPADDR_ISEXPERIMENTAL(i) \
+		(((uint32_t)(i) & ISC__IPADDR(0xf0000000)) \
+		 == ISC__IPADDR(0xf0000000))
+
+/***
+ *** Functions.
+ ***/
+
+ISC_LANG_BEGINDECLS
+
+void
+isc_net_disableipv4(void);
+
+void
+isc_net_disableipv6(void);
+
+#define ISC_NET_DSCPRECVV4	0x01	/* Can receive sent DSCP value IPv4 */
+#define ISC_NET_DSCPRECVV6	0x02	/* Can receive sent DSCP value IPv6 */
+#define ISC_NET_DSCPSETV4	0x04	/* Can set DSCP on socket IPv4 */
+#define ISC_NET_DSCPSETV6	0x08	/* Can set DSCP on socket IPv6 */
+#define ISC_NET_DSCPPKTV4	0x10	/* Can set DSCP on per packet IPv4 */
+#define ISC_NET_DSCPPKTV6	0x20	/* Can set DSCP on per packet IPv6 */
+#define ISC_NET_DSCPALL		0x3f	/* All valid flags */
+
+unsigned int
+isc_net_probedscp(void);
+/*%<
+ * Probe the level of DSCP support.
+ */
+
+int
+isc_net_aton(const char *cp, struct in_addr *addr);
+#undef inet_aton
+#define inet_aton isc_net_aton
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISC_NET_H */
diff --git a/usr.bin/dig/lib/isc/unix/include/isc/stdtime.h b/usr.bin/dig/lib/isc/unix/include/isc/stdtime.h
new file mode 100644
index 00000000000..15c2107c7dc
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/include/isc/stdtime.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: stdtime.h,v 1.1 2020/02/07 09:58:54 florian Exp $ */
+
+#ifndef ISC_STDTIME_H
+#define ISC_STDTIME_H 1
+
+/*! \file */
+
+#include <isc/lang.h>
+
+
+/*%
+ * It's public information that 'isc_stdtime_t' is an unsigned integral type.
+ * Applications that want maximum portability should not assume anything
+ * about its size.
+ */
+typedef uint32_t isc_stdtime_t;
+
+/* but this flag helps... */
+#define STDTIME_ON_32BITS	1
+
+/*
+ * isc_stdtime32_t is a 32-bit version of isc_stdtime_t.  A variable of this
+ * type should only be used as an opaque integer (e.g.,) to compare two
+ * time values.
+ */
+typedef uint32_t isc_stdtime32_t;
+
+ISC_LANG_BEGINDECLS
+/* */
+void
+isc_stdtime_get(isc_stdtime_t *t);
+/*%<
+ * Set 't' to the number of seconds since 00:00:00 UTC, January 1, 1970.
+ *
+ * Requires:
+ *
+ *\li	't' is a valid pointer.
+ */
+
+#define isc_stdtime_convert32(t, t32p) (*(t32p) = t)
+/*
+ * Convert the standard time to its 32-bit version.
+ */
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISC_STDTIME_H */
diff --git a/usr.bin/dig/lib/isc/unix/include/isc/strerror.h b/usr.bin/dig/lib/isc/unix/include/isc/strerror.h
new file mode 100644
index 00000000000..4d7f7184f43
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/include/isc/strerror.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: strerror.h,v 1.1 2020/02/07 09:58:54 florian Exp $ */
+
+#ifndef ISC_STRERROR_H
+#define ISC_STRERROR_H
+
+/*! \file */
+
+#include <sys/types.h>
+
+#include <isc/lang.h>
+
+ISC_LANG_BEGINDECLS
+
+/*% String Error Size */
+#define ISC_STRERRORSIZE 128
+
+/*%
+ * Provide a thread safe wrapper to strerror().
+ *
+ * Requires:
+ * 	'buf' to be non NULL.
+ */
+void
+isc__strerror(int num, char *buf, size_t bufsize);
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISC_STRERROR_H */
diff --git a/usr.bin/dig/lib/isc/unix/include/isc/time.h b/usr.bin/dig/lib/isc/unix/include/isc/time.h
new file mode 100644
index 00000000000..20012137fa2
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/include/isc/time.h
@@ -0,0 +1,340 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: time.h,v 1.1 2020/02/07 09:58:54 florian Exp $ */
+
+#ifndef ISC_TIME_H
+#define ISC_TIME_H 1
+
+/*! \file */
+
+#include <isc/lang.h>
+#include <isc/types.h>
+
+/***
+ *** Intervals
+ ***/
+
+/*!
+ *  \brief
+ * The contents of this structure are private, and MUST NOT be accessed
+ * directly by callers.
+ *
+ * The contents are exposed only to allow callers to avoid dynamic allocation.
+ */
+struct interval {
+	unsigned int seconds;
+	unsigned int nanoseconds;
+};
+
+extern const interval_t * const interval_zero;
+
+/*
+ * ISC_FORMATHTTPTIMESTAMP_SIZE needs to be 30 in C locale and potentially
+ * more for other locales to handle longer national abbreviations when
+ * expanding strftime's %a and %b.
+ */
+#define ISC_FORMATHTTPTIMESTAMP_SIZE 50
+
+ISC_LANG_BEGINDECLS
+
+void
+interval_set(interval_t *i,
+		 unsigned int seconds, unsigned int nanoseconds);
+/*%<
+ * Set 'i' to a value representing an interval of 'seconds' seconds and
+ * 'nanoseconds' nanoseconds, suitable for use in isc_time_add() and
+ * isc_time_subtract().
+ *
+ * Requires:
+ *
+ *\li	't' is a valid pointer.
+ *\li	nanoseconds < 1000000000.
+ */
+
+isc_boolean_t
+interval_iszero(const interval_t *i);
+/*%<
+ * Returns ISC_TRUE iff. 'i' is the zero interval.
+ *
+ * Requires:
+ *
+ *\li	'i' is a valid pointer.
+ */
+
+/***
+ *** Absolute Times
+ ***/
+
+/*%
+ * The contents of this structure are private, and MUST NOT be accessed
+ * directly by callers.
+ *
+ * The contents are exposed only to allow callers to avoid dynamic allocation.
+ */
+
+struct isc_time {
+	unsigned int	seconds;
+	unsigned int	nanoseconds;
+};
+
+extern const isc_time_t * const isc_time_epoch;
+
+void
+isc_time_set(isc_time_t *t, unsigned int seconds, unsigned int nanoseconds);
+/*%<
+ * Set 't' to a value which represents the given number of seconds and
+ * nanoseconds since 00:00:00 January 1, 1970, UTC.
+ *
+ * Notes:
+ *\li	The Unix version of this call is equivalent to:
+ *\code
+ *	isc_time_settoepoch(t);
+ *	interval_set(i, seconds, nanoseconds);
+ *	isc_time_add(t, i, t);
+ *\endcode
+ *
+ * Requires:
+ *\li	't' is a valid pointer.
+ *\li	nanoseconds < 1000000000.
+ */
+
+void
+isc_time_settoepoch(isc_time_t *t);
+/*%<
+ * Set 't' to the time of the epoch.
+ *
+ * Notes:
+ *\li	The date of the epoch is platform-dependent.
+ *
+ * Requires:
+ *
+ *\li	't' is a valid pointer.
+ */
+
+isc_boolean_t
+isc_time_isepoch(const isc_time_t *t);
+/*%<
+ * Returns ISC_TRUE iff. 't' is the epoch ("time zero").
+ *
+ * Requires:
+ *
+ *\li	't' is a valid pointer.
+ */
+
+isc_result_t
+isc_time_now(isc_time_t *t);
+/*%<
+ * Set 't' to the current absolute time.
+ *
+ * Requires:
+ *
+ *\li	't' is a valid pointer.
+ *
+ * Returns:
+ *
+ *\li	Success
+ *\li	Unexpected error
+ *		Getting the time from the system failed.
+ *\li	Out of range
+ *		The time from the system is too large to be represented
+ *		in the current definition of isc_time_t.
+ */
+
+isc_result_t
+isc_time_nowplusinterval(isc_time_t *t, const interval_t *i);
+/*%<
+ * Set *t to the current absolute time + i.
+ *
+ * Note:
+ *\li	This call is equivalent to:
+ *
+ *\code
+ *		isc_time_now(t);
+ *		isc_time_add(t, i, t);
+ *\endcode
+ *
+ * Requires:
+ *
+ *\li	't' and 'i' are valid pointers.
+ *
+ * Returns:
+ *
+ *\li	Success
+ *\li	Unexpected error
+ *		Getting the time from the system failed.
+ *\li	Out of range
+ *		The interval added to the time from the system is too large to
+ *		be represented in the current definition of isc_time_t.
+ */
+
+int
+isc_time_compare(const isc_time_t *t1, const isc_time_t *t2);
+/*%<
+ * Compare the times referenced by 't1' and 't2'
+ *
+ * Requires:
+ *
+ *\li	't1' and 't2' are valid pointers.
+ *
+ * Returns:
+ *
+ *\li	-1		t1 < t2		(comparing times, not pointers)
+ *\li	0		t1 = t2
+ *\li	1		t1 > t2
+ */
+
+isc_result_t
+isc_time_add(const isc_time_t *t, const interval_t *i, isc_time_t *result);
+/*%<
+ * Add 'i' to 't', storing the result in 'result'.
+ *
+ * Requires:
+ *
+ *\li	't', 'i', and 'result' are valid pointers.
+ *
+ * Returns:
+ *\li	Success
+ *\li	Out of range
+ * 		The interval added to the time is too large to
+ *		be represented in the current definition of isc_time_t.
+ */
+
+isc_result_t
+isc_time_subtract(const isc_time_t *t, const interval_t *i,
+		  isc_time_t *result);
+/*%<
+ * Subtract 'i' from 't', storing the result in 'result'.
+ *
+ * Requires:
+ *
+ *\li	't', 'i', and 'result' are valid pointers.
+ *
+ * Returns:
+ *\li	Success
+ *\li	Out of range
+ *		The interval is larger than the time since the epoch.
+ */
+
+uint64_t
+isc_time_microdiff(const isc_time_t *t1, const isc_time_t *t2);
+/*%<
+ * Find the difference in microseconds between time t1 and time t2.
+ * t2 is the subtrahend of t1; ie, difference = t1 - t2.
+ *
+ * Requires:
+ *
+ *\li	't1' and 't2' are valid pointers.
+ *
+ * Returns:
+ *\li	The difference of t1 - t2, or 0 if t1 <= t2.
+ */
+
+uint32_t
+isc_time_seconds(const isc_time_t *t);
+/*%<
+ * Return the number of seconds since the epoch stored in a time structure.
+ *
+ * Requires:
+ *
+ *\li	't' is a valid pointer.
+ */
+
+isc_result_t
+isc_time_secondsastimet(const isc_time_t *t, time_t *secondsp);
+/*%<
+ * Ensure the number of seconds in an isc_time_t is representable by a time_t.
+ *
+ * Notes:
+ *\li	The number of seconds stored in an isc_time_t might be larger
+ *	than the number of seconds a time_t is able to handle.  Since
+ *	time_t is mostly opaque according to the ANSI/ISO standard
+ *	(essentially, all you can be sure of is that it is an arithmetic type,
+ *	not even necessarily integral), it can be tricky to ensure that
+ *	the isc_time_t is in the range a time_t can handle.  Use this
+ *	function in place of isc_time_seconds() any time you need to set a
+ *	time_t from an isc_time_t.
+ *
+ * Requires:
+ *\li	't' is a valid pointer.
+ *
+ * Returns:
+ *\li	Success
+ *\li	Out of range
+ */
+
+uint32_t
+isc_time_nanoseconds(const isc_time_t *t);
+/*%<
+ * Return the number of nanoseconds stored in a time structure.
+ *
+ * Notes:
+ *\li	This is the number of nanoseconds in excess of the number
+ *	of seconds since the epoch; it will always be less than one
+ *	full second.
+ *
+ * Requires:
+ *\li	't' is a valid pointer.
+ *
+ * Ensures:
+ *\li	The returned value is less than 1*10^9.
+ */
+
+void
+isc_time_formattimestamp(const isc_time_t *t, char *buf, unsigned int len);
+/*%<
+ * Format the time 't' into the buffer 'buf' of length 'len',
+ * using a format like "30-Aug-2000 04:06:47.997" and the local time zone.
+ * If the text does not fit in the buffer, the result is indeterminate,
+ * but is always guaranteed to be null terminated.
+ *
+ *  Requires:
+ *\li      'len' > 0
+ *\li      'buf' points to an array of at least len chars
+ *
+ */
+
+void
+isc_time_formathttptimestamp(const isc_time_t *t, char *buf, unsigned int len);
+/*%<
+ * Format the time 't' into the buffer 'buf' of length 'len',
+ * using a format like "Mon, 30 Aug 2000 04:06:47 GMT"
+ * If the text does not fit in the buffer, the result is indeterminate,
+ * but is always guaranteed to be null terminated.
+ *
+ *  Requires:
+ *\li      'len' > 0
+ *\li      'buf' points to an array of at least len chars
+ *
+ */
+
+void
+isc_time_formatISO8601(const isc_time_t *t, char *buf, unsigned int len);
+/*%<
+ * Format the time 't' into the buffer 'buf' of length 'len',
+ * using the ISO8601 format: "yyyy-mm-ddThh:mm:ssZ"
+ * If the text does not fit in the buffer, the result is indeterminate,
+ * but is always guaranteed to be null terminated.
+ *
+ *  Requires:
+ *\li      'len' > 0
+ *\li      'buf' points to an array of at least len chars
+ *
+ */
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISC_TIME_H */
diff --git a/usr.bin/dig/lib/isc/unix/net.c b/usr.bin/dig/lib/isc/unix/net.c
new file mode 100644
index 00000000000..cd37a756ffa
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/net.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: net.c,v 1.1 2020/02/07 09:58:54 florian Exp $ */
+
+#include <isc/net.h>
+#include <isc/result.h>
+
+static isc_result_t	ipv4_result = ISC_R_SUCCESS;
+static isc_result_t	ipv6_result = ISC_R_SUCCESS;
+static unsigned int	dscp_result =
+		ISC_NET_DSCPSETV4 | ISC_NET_DSCPRECVV4 | ISC_NET_DSCPPKTV4 |
+		ISC_NET_DSCPSETV6 | ISC_NET_DSCPRECVV6 | ISC_NET_DSCPPKTV6;
+
+unsigned int
+isc_net_probedscp(void) {
+	return (dscp_result);
+}
+
+void
+isc_net_disableipv4(void) {
+	if (ipv4_result == ISC_R_SUCCESS)
+		ipv4_result = ISC_R_DISABLED;
+}
+
+void
+isc_net_disableipv6(void) {
+	if (ipv6_result == ISC_R_SUCCESS)
+		ipv6_result = ISC_R_DISABLED;
+}
diff --git a/usr.bin/dig/lib/isc/unix/socket.c b/usr.bin/dig/lib/isc/unix/socket.c
new file mode 100644
index 00000000000..a115ed1492f
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/socket.c
@@ -0,0 +1,2753 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*! \file */
+
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/event.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/uio.h>
+#include <sys/un.h>
+
+#include <netinet/tcp.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <inttypes.h> /* uintptr_t */
+
+#include <isc/buffer.h>
+#include <isc/bufferlist.h>
+#include <isc/formatcheck.h>
+#include <isc/list.h>
+#include <isc/log.h>
+#include <isc/msgs.h>
+#include <isc/net.h>
+#include <isc/region.h>
+#include <isc/socket.h>
+#include <isc/strerror.h>
+#include <isc/task.h>
+#include <isc/util.h>
+
+#include "errno2result.h"
+
+#include "socket_p.h"
+#include "../task_p.h"
+
+struct isc_socketwait {
+	fd_set *readset;
+	fd_set *writeset;
+	int nfds;
+	int maxfd;
+};
+
+/*
+ * Set by the -T dscp option on the command line. If set to a value
+ * other than -1, we check to make sure DSCP values match it, and
+ * assert if not.
+ */
+int isc_dscp_check_value = -1;
+
+/*%
+ * Size of per-FD lock buckets.
+ */
+#define FDLOCK_COUNT		1
+#define FDLOCK_ID(fd)		0
+
+/*%
+ * Some systems define the socket length argument as an int, some as size_t,
+ * some as socklen_t.  This is here so it can be easily changed if needed.
+ */
+
+/*%
+ * Define what the possible "soft" errors can be.  These are non-fatal returns
+ * of various network related functions, like recv() and so on.
+ *
+ * For some reason, BSDI (and perhaps others) will sometimes return <0
+ * from recv() but will have errno==0.  This is broken, but we have to
+ * work around it here.
+ */
+#define SOFT_ERROR(e)	((e) == EAGAIN || \
+			 (e) == EWOULDBLOCK || \
+			 (e) == EINTR || \
+			 (e) == 0)
+
+#define DLVL(x) ISC_LOGCATEGORY_GENERAL, ISC_LOGMODULE_SOCKET, ISC_LOG_DEBUG(x)
+
+/*!<
+ * DLVL(90)  --  Function entry/exit and other tracing.
+ * DLVL(70)  --  Socket "correctness" -- including returning of events, etc.
+ * DLVL(60)  --  Socket data send/receive
+ * DLVL(50)  --  Event tracing, including receiving/sending completion events.
+ * DLVL(20)  --  Socket creation/destruction.
+ */
+#define TRACE_LEVEL		90
+#define CORRECTNESS_LEVEL	70
+#define IOEVENT_LEVEL		60
+#define EVENT_LEVEL		50
+#define CREATION_LEVEL		20
+
+#define TRACE		DLVL(TRACE_LEVEL)
+#define CORRECTNESS	DLVL(CORRECTNESS_LEVEL)
+#define IOEVENT		DLVL(IOEVENT_LEVEL)
+#define EVENT		DLVL(EVENT_LEVEL)
+#define CREATION	DLVL(CREATION_LEVEL)
+
+typedef isc_event_t intev_t;
+
+#define SOCKET_MAGIC		ISC_MAGIC('I', 'O', 'i', 'o')
+#define VALID_SOCKET(s)		ISC_MAGIC_VALID(s, SOCKET_MAGIC)
+
+/*!
+ * IPv6 control information.  If the socket is an IPv6 socket we want
+ * to collect the destination address and interface so the client can
+ * set them on outgoing packets.
+ */
+
+/*%
+ * NetBSD and FreeBSD can timestamp packets.  XXXMLG Should we have
+ * a setsockopt() like interface to request timestamps, and if the OS
+ * doesn't do it for us, call gettimeofday() on every UDP receive?
+ */
+
+/*%
+ * The size to raise the receive buffer to (from BIND 8).
+ */
+#define RCVBUFSIZE (32*1024)
+
+/*%
+ * Instead of calculating the cmsgbuf lengths every time we take
+ * a rule of thumb approach - sizes are taken from x86_64 linux,
+ * multiplied by 2, everything should fit. Those sizes are not
+ * large enough to cause any concern.
+ */
+#define CMSG_SP_IN6PKT 40
+
+#define CMSG_SP_TIMESTAMP 32
+
+#define CMSG_SP_TCTOS 24
+
+#define CMSG_SP_INT 24
+
+#define RECVCMSGBUFLEN (2*(CMSG_SP_IN6PKT + CMSG_SP_TIMESTAMP + CMSG_SP_TCTOS)+1)
+#define SENDCMSGBUFLEN (2*(CMSG_SP_IN6PKT + CMSG_SP_INT + CMSG_SP_TCTOS)+1)
+
+/*%
+ * The number of times a send operation is repeated if the result is EINTR.
+ */
+#define NRETRIES 10
+
+typedef struct isc__socket isc__socket_t;
+typedef struct isc__socketmgr isc__socketmgr_t;
+
+#define NEWCONNSOCK(ev) ((isc__socket_t *)(ev)->newsocket)
+
+struct isc__socket {
+	/* Not locked. */
+	isc_socket_t		common;
+	isc__socketmgr_t	*manager;
+	isc_sockettype_t	type;
+
+	/* Locked by socket lock. */
+	ISC_LINK(isc__socket_t)	link;
+	unsigned int		references;
+	int			fd;
+	int			pf;
+
+	ISC_LIST(isc_socketevent_t)		send_list;
+	ISC_LIST(isc_socketevent_t)		recv_list;
+	isc_socket_connev_t		       *connect_ev;
+
+	/*
+	 * Internal events.  Posted when a descriptor is readable or
+	 * writable.  These are statically allocated and never freed.
+	 * They will be set to non-purgable before use.
+	 */
+	intev_t			readable_ev;
+	intev_t			writable_ev;
+
+	isc_sockaddr_t		peer_address;       /* remote address */
+
+	unsigned int		pending_recv : 1,
+				pending_send : 1,
+				connected : 1,
+				connecting : 1,     /* connect pending */
+				bound : 1,          /* bound to local addr */
+				active : 1,         /* currently active */
+				pktdscp : 1;	    /* per packet dscp */
+	unsigned int		dscp;
+};
+
+#define SOCKET_MANAGER_MAGIC	ISC_MAGIC('I', 'O', 'm', 'g')
+#define VALID_MANAGER(m)	ISC_MAGIC_VALID(m, SOCKET_MANAGER_MAGIC)
+
+struct isc__socketmgr {
+	/* Not locked. */
+	isc_socketmgr_t		common;
+	int			fd_bufsize;
+	unsigned int		maxsocks;
+
+	isc__socket_t	       **fds;
+	int			*fdstate;
+
+	/* Locked by manager lock. */
+	ISC_LIST(isc__socket_t)	socklist;
+	fd_set			*read_fds;
+	fd_set			*read_fds_copy;
+	fd_set			*write_fds;
+	fd_set			*write_fds_copy;
+	int			maxfd;
+	unsigned int		refs;
+};
+
+static isc__socketmgr_t *socketmgr = NULL;
+
+#define CLOSED			0	/* this one must be zero */
+#define MANAGED			1
+#define CLOSE_PENDING		2
+
+/*
+ * send() and recv() iovec counts
+ */
+#define MAXSCATTERGATHER_SEND	(ISC_SOCKET_MAXSCATTERGATHER)
+#define MAXSCATTERGATHER_RECV	(ISC_SOCKET_MAXSCATTERGATHER)
+
+static isc_result_t socket_create(isc_socketmgr_t *manager0, int pf,
+				  isc_sockettype_t type,
+				  isc_socket_t **socketp);
+static void send_recvdone_event(isc__socket_t *, isc_socketevent_t **);
+static void send_senddone_event(isc__socket_t *, isc_socketevent_t **);
+static void free_socket(isc__socket_t **);
+static isc_result_t allocate_socket(isc__socketmgr_t *, isc_sockettype_t,
+				    isc__socket_t **);
+static void destroy(isc__socket_t **);
+static void internal_connect(isc_task_t *, isc_event_t *);
+static void internal_recv(isc_task_t *, isc_event_t *);
+static void internal_send(isc_task_t *, isc_event_t *);
+static void process_cmsg(isc__socket_t *, struct msghdr *, isc_socketevent_t *);
+static void build_msghdr_send(isc__socket_t *, char *, isc_socketevent_t *,
+			      struct msghdr *, struct iovec *, size_t *);
+static void build_msghdr_recv(isc__socket_t *, char *, isc_socketevent_t *,
+			      struct msghdr *, struct iovec *, size_t *);
+
+/*%
+ * The following are intended for internal use (indicated by "isc__"
+ * prefix) but are not declared as static, allowing direct access from
+ * unit tests etc.
+ */
+
+isc_result_t
+isc__socket_create(isc_socketmgr_t *manager, int pf, isc_sockettype_t type,
+		   isc_socket_t **socketp);
+void
+isc__socket_attach(isc_socket_t *sock, isc_socket_t **socketp);
+void
+isc__socket_detach(isc_socket_t **socketp);
+isc_result_t
+isc__socket_recvv(isc_socket_t *sock, isc_bufferlist_t *buflist,
+		 unsigned int minimum, isc_task_t *task,
+		  isc_taskaction_t action, void *arg);
+isc_result_t
+isc__socket_sendv(isc_socket_t *sock, isc_bufferlist_t *buflist,
+		  isc_task_t *task, isc_taskaction_t action, void *arg);
+isc_result_t
+isc__socket_sendtov2(isc_socket_t *sock, isc_bufferlist_t *buflist,
+		     isc_task_t *task, isc_taskaction_t action, void *arg,
+		     isc_sockaddr_t *address, struct in6_pktinfo *pktinfo,
+		     unsigned int flags);
+isc_result_t
+isc__socket_bind(isc_socket_t *sock, isc_sockaddr_t *sockaddr,
+		 unsigned int options);
+isc_result_t
+isc__socket_connect(isc_socket_t *sock, isc_sockaddr_t *addr,
+		    isc_task_t *task, isc_taskaction_t action,
+		    void *arg);
+void
+isc__socket_cancel(isc_socket_t *sock, isc_task_t *task, unsigned int how);
+
+isc_result_t
+isc__socketmgr_create(isc_socketmgr_t **managerp);
+isc_result_t
+isc__socketmgr_create2(isc_socketmgr_t **managerp,
+		       unsigned int maxsocks);
+isc_result_t
+isc_socketmgr_getmaxsockets(isc_socketmgr_t *manager0, unsigned int *nsockp);
+void
+isc__socketmgr_destroy(isc_socketmgr_t **managerp);
+
+static struct {
+	isc_socketmethods_t methods;
+
+	/*%
+	 * The following are defined just for avoiding unused static functions.
+	 */
+	void *recvv, *sendv;
+} socketmethods = {
+	{
+		isc__socket_attach,
+		isc__socket_detach,
+		isc__socket_bind,
+		isc__socket_connect,
+		isc__socket_cancel,
+	},
+	(void *)isc__socket_recvv,
+	(void *)isc__socket_sendv,
+};
+
+static isc_socketmgrmethods_t socketmgrmethods = {
+	isc__socketmgr_destroy,
+	isc__socket_create
+};
+
+#define SELECT_POKE_SHUTDOWN		(-1)
+#define SELECT_POKE_NOTHING		(-2)
+#define SELECT_POKE_READ		(-3)
+#define SELECT_POKE_ACCEPT		(-3) /*%< Same as _READ */
+#define SELECT_POKE_WRITE		(-4)
+#define SELECT_POKE_CONNECT		(-4) /*%< Same as _WRITE */
+#define SELECT_POKE_CLOSE		(-5)
+
+#define SOCK_DEAD(s)			((s)->references == 0)
+
+/*%
+ * Shortcut index arrays to get access to statistics counters.
+ */
+enum {
+	STATID_OPEN = 0,
+	STATID_OPENFAIL = 1,
+	STATID_CLOSE = 2,
+	STATID_BINDFAIL = 3,
+	STATID_CONNECTFAIL = 4,
+	STATID_CONNECT = 5,
+	STATID_ACCEPTFAIL = 6,
+	STATID_ACCEPT = 7,
+	STATID_SENDFAIL = 8,
+	STATID_RECVFAIL = 9,
+	STATID_ACTIVE = 10
+};
+
+
+static void
+socket_log(isc__socket_t *sock, isc_sockaddr_t *address,
+	   isc_logcategory_t *category, isc_logmodule_t *module, int level,
+	   const char *fmt, ...) ISC_FORMAT_PRINTF(6, 7);
+static void
+socket_log(isc__socket_t *sock, isc_sockaddr_t *address,
+	   isc_logcategory_t *category, isc_logmodule_t *module, int level,
+	   const char *fmt, ...)
+{
+	char msgbuf[2048];
+	char peerbuf[ISC_SOCKADDR_FORMATSIZE];
+	va_list ap;
+
+	if (! isc_log_wouldlog(isc_lctx, level))
+		return;
+
+	va_start(ap, fmt);
+	vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap);
+	va_end(ap);
+
+	if (address == NULL) {
+		isc_log_write(isc_lctx, category, module, level,
+			       "socket %p: %s", sock, msgbuf);
+	} else {
+		isc_sockaddr_format(address, peerbuf, sizeof(peerbuf));
+		isc_log_write(isc_lctx, category, module, level,
+			       "socket %p %s: %s", sock, peerbuf, msgbuf);
+	}
+}
+
+static inline isc_result_t
+watch_fd(isc__socketmgr_t *manager, int fd, int msg) {
+	isc_result_t result = ISC_R_SUCCESS;
+
+	if (msg == SELECT_POKE_READ)
+		FD_SET(fd, manager->read_fds);
+	if (msg == SELECT_POKE_WRITE)
+		FD_SET(fd, manager->write_fds);
+
+	return (result);
+}
+
+static inline isc_result_t
+unwatch_fd(isc__socketmgr_t *manager, int fd, int msg) {
+	isc_result_t result = ISC_R_SUCCESS;
+
+	if (msg == SELECT_POKE_READ)
+		FD_CLR(fd, manager->read_fds);
+	else if (msg == SELECT_POKE_WRITE)
+		FD_CLR(fd, manager->write_fds);
+
+	return (result);
+}
+
+static void
+wakeup_socket(isc__socketmgr_t *manager, int fd, int msg) {
+	isc_result_t result;
+
+	/*
+	 * This is a wakeup on a socket.  If the socket is not in the
+	 * process of being closed, start watching it for either reads
+	 * or writes.
+	 */
+
+	INSIST(fd >= 0 && fd < (int)manager->maxsocks);
+
+	if (msg == SELECT_POKE_CLOSE) {
+		/* No one should be updating fdstate, so no need to lock it */
+		INSIST(manager->fdstate[fd] == CLOSE_PENDING);
+		manager->fdstate[fd] = CLOSED;
+		(void)unwatch_fd(manager, fd, SELECT_POKE_READ);
+		(void)unwatch_fd(manager, fd, SELECT_POKE_WRITE);
+		(void)close(fd);
+		return;
+	}
+
+	if (manager->fdstate[fd] == CLOSE_PENDING) {
+
+		/*
+		 * We accept (and ignore) any error from unwatch_fd() as we are
+		 * closing the socket, hoping it doesn't leave dangling state in
+		 * the kernel.
+		 */
+		(void)unwatch_fd(manager, fd, SELECT_POKE_READ);
+		(void)unwatch_fd(manager, fd, SELECT_POKE_WRITE);
+		return;
+	}
+	if (manager->fdstate[fd] != MANAGED) {
+		return;
+	}
+
+	/*
+	 * Set requested bit.
+	 */
+	result = watch_fd(manager, fd, msg);
+	if (result != ISC_R_SUCCESS) {
+		/*
+		 * XXXJT: what should we do?  Ignoring the failure of watching
+		 * a socket will make the application dysfunctional, but there
+		 * seems to be no reasonable recovery process.
+		 */
+		isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
+			      ISC_LOGMODULE_SOCKET, ISC_LOG_ERROR,
+			      "failed to start watching FD (%d): %s",
+			      fd, isc_result_totext(result));
+	}
+}
+
+/*
+ * Update the state of the socketmgr when something changes.
+ */
+static void
+select_poke(isc__socketmgr_t *manager, int fd, int msg) {
+	if (msg == SELECT_POKE_SHUTDOWN)
+		return;
+	else if (fd >= 0)
+		wakeup_socket(manager, fd, msg);
+	return;
+}
+
+/*
+ * Make a fd non-blocking.
+ */
+static isc_result_t
+make_nonblock(int fd) {
+	int ret;
+	char strbuf[ISC_STRERRORSIZE];
+	int flags;
+
+	flags = fcntl(fd, F_GETFL, 0);
+	flags |= O_NONBLOCK;
+	ret = fcntl(fd, F_SETFL, flags);
+
+	if (ret == -1) {
+		isc__strerror(errno, strbuf, sizeof(strbuf));
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "fcntl(%d, F_SETFL, %d): %s", fd, flags,
+				 strbuf);
+
+		return (ISC_R_UNEXPECTED);
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+/*
+ * Not all OSes support advanced CMSG macros: CMSG_LEN and CMSG_SPACE.
+ * In order to ensure as much portability as possible, we provide wrapper
+ * functions of these macros.
+ * Note that cmsg_space() could run slow on OSes that do not have
+ * CMSG_SPACE.
+ */
+static inline socklen_t
+cmsg_len(socklen_t len) {
+	return (CMSG_LEN(len));
+}
+
+static inline socklen_t
+cmsg_space(socklen_t len) {
+	return (CMSG_SPACE(len));
+}
+
+/*
+ * Process control messages received on a socket.
+ */
+static void
+process_cmsg(isc__socket_t *sock, struct msghdr *msg, isc_socketevent_t *dev) {
+	struct cmsghdr *cmsgp;
+	struct in6_pktinfo *pktinfop;
+	void *timevalp;
+
+	/*
+	 * sock is used only when ISC_NET_BSD44MSGHDR and USE_CMSG are defined.
+	 * msg and dev are used only when ISC_NET_BSD44MSGHDR is defined.
+	 * They are all here, outside of the CPP tests, because it is
+	 * more consistent with the usual ISC coding style.
+	 */
+	UNUSED(sock);
+	UNUSED(msg);
+	UNUSED(dev);
+
+	if ((msg->msg_flags & MSG_TRUNC) == MSG_TRUNC)
+		dev->attributes |= ISC_SOCKEVENTATTR_TRUNC;
+
+	if ((msg->msg_flags & MSG_CTRUNC) == MSG_CTRUNC)
+		dev->attributes |= ISC_SOCKEVENTATTR_CTRUNC;
+
+	if (msg->msg_controllen == 0U || msg->msg_control == NULL)
+		return;
+
+	timevalp = NULL;
+	pktinfop = NULL;
+
+	cmsgp = CMSG_FIRSTHDR(msg);
+	while (cmsgp != NULL) {
+		socket_log(sock, NULL, TRACE,
+			   "processing cmsg %p", cmsgp);
+
+		if (cmsgp->cmsg_level == IPPROTO_IPV6
+		    && cmsgp->cmsg_type == IPV6_PKTINFO) {
+
+			pktinfop = (struct in6_pktinfo *)CMSG_DATA(cmsgp);
+			memmove(&dev->pktinfo, pktinfop,
+				sizeof(struct in6_pktinfo));
+			dev->attributes |= ISC_SOCKEVENTATTR_PKTINFO;
+			socket_log(sock, NULL, TRACE,
+				   "interface received on ifindex %u",
+				   dev->pktinfo.ipi6_ifindex);
+			if (IN6_IS_ADDR_MULTICAST(&pktinfop->ipi6_addr))
+				dev->attributes |= ISC_SOCKEVENTATTR_MULTICAST;
+			goto next;
+		}
+
+		if (cmsgp->cmsg_level == SOL_SOCKET
+		    && cmsgp->cmsg_type == SCM_TIMESTAMP) {
+			struct timeval tv;
+			timevalp = CMSG_DATA(cmsgp);
+			memmove(&tv, timevalp, sizeof(tv));
+			dev->timestamp.seconds = tv.tv_sec;
+			dev->timestamp.nanoseconds = tv.tv_usec * 1000;
+			dev->attributes |= ISC_SOCKEVENTATTR_TIMESTAMP;
+			goto next;
+		}
+
+		if (cmsgp->cmsg_level == IPPROTO_IPV6
+		    && cmsgp->cmsg_type == IPV6_TCLASS) {
+			dev->dscp = *(int *)CMSG_DATA(cmsgp);
+			dev->dscp >>= 2;
+			dev->attributes |= ISC_SOCKEVENTATTR_DSCP;
+			goto next;
+		}
+
+		if (cmsgp->cmsg_level == IPPROTO_IP
+		    && (cmsgp->cmsg_type == IP_TOS)) {
+			dev->dscp = (int) *(unsigned char *)CMSG_DATA(cmsgp);
+			dev->dscp >>= 2;
+			dev->attributes |= ISC_SOCKEVENTATTR_DSCP;
+			goto next;
+		}
+	next:
+		cmsgp = CMSG_NXTHDR(msg, cmsgp);
+	}
+
+}
+
+/*
+ * Construct an iov array and attach it to the msghdr passed in.  This is
+ * the SEND constructor, which will use the used region of the buffer
+ * (if using a buffer list) or will use the internal region (if a single
+ * buffer I/O is requested).
+ *
+ * Nothing can be NULL, and the done event must list at least one buffer
+ * on the buffer linked list for this function to be meaningful.
+ *
+ * If write_countp != NULL, *write_countp will hold the number of bytes
+ * this transaction can send.
+ */
+static void
+build_msghdr_send(isc__socket_t *sock, char* cmsgbuf, isc_socketevent_t *dev,
+		  struct msghdr *msg, struct iovec *iov, size_t *write_countp)
+{
+	unsigned int iovcount;
+	isc_buffer_t *buffer;
+	isc_region_t used;
+	size_t write_count;
+	size_t skip_count;
+	struct cmsghdr *cmsgp;
+
+	memset(msg, 0, sizeof(*msg));
+
+	if (!sock->connected) {
+		msg->msg_name = (void *)&dev->address.type.sa;
+		msg->msg_namelen = dev->address.length;
+	} else {
+		msg->msg_name = NULL;
+		msg->msg_namelen = 0;
+	}
+
+	buffer = ISC_LIST_HEAD(dev->bufferlist);
+	write_count = 0;
+	iovcount = 0;
+
+	/*
+	 * Single buffer I/O?  Skip what we've done so far in this region.
+	 */
+	if (buffer == NULL) {
+		write_count = dev->region.length - dev->n;
+		iov[0].iov_base = (void *)(dev->region.base + dev->n);
+		iov[0].iov_len = write_count;
+		iovcount = 1;
+
+		goto config;
+	}
+
+	/*
+	 * Multibuffer I/O.
+	 * Skip the data in the buffer list that we have already written.
+	 */
+	skip_count = dev->n;
+	while (buffer != NULL) {
+		REQUIRE(ISC_BUFFER_VALID(buffer));
+		if (skip_count < isc_buffer_usedlength(buffer))
+			break;
+		skip_count -= isc_buffer_usedlength(buffer);
+		buffer = ISC_LIST_NEXT(buffer, link);
+	}
+
+	while (buffer != NULL) {
+		INSIST(iovcount < MAXSCATTERGATHER_SEND);
+
+		isc_buffer_usedregion(buffer, &used);
+
+		if (used.length > 0) {
+			iov[iovcount].iov_base = (void *)(used.base
+							  + skip_count);
+			iov[iovcount].iov_len = used.length - skip_count;
+			write_count += (used.length - skip_count);
+			skip_count = 0;
+			iovcount++;
+		}
+		buffer = ISC_LIST_NEXT(buffer, link);
+	}
+
+	INSIST(skip_count == 0U);
+
+ config:
+	msg->msg_iov = iov;
+	msg->msg_iovlen = iovcount;
+
+	msg->msg_control = NULL;
+	msg->msg_controllen = 0;
+	msg->msg_flags = 0;
+
+	if ((sock->type == isc_sockettype_udp) &&
+	    ((dev->attributes & ISC_SOCKEVENTATTR_PKTINFO) != 0))
+	{
+		struct in6_pktinfo *pktinfop;
+
+		socket_log(sock, NULL, TRACE,
+			   "sendto pktinfo data, ifindex %u",
+			   dev->pktinfo.ipi6_ifindex);
+
+		msg->msg_control = (void *)cmsgbuf;
+		msg->msg_controllen = cmsg_space(sizeof(struct in6_pktinfo));
+		INSIST(msg->msg_controllen <= SENDCMSGBUFLEN);
+
+		cmsgp = (struct cmsghdr *)cmsgbuf;
+		cmsgp->cmsg_level = IPPROTO_IPV6;
+		cmsgp->cmsg_type = IPV6_PKTINFO;
+		cmsgp->cmsg_len = cmsg_len(sizeof(struct in6_pktinfo));
+		pktinfop = (struct in6_pktinfo *)CMSG_DATA(cmsgp);
+		memmove(pktinfop, &dev->pktinfo, sizeof(struct in6_pktinfo));
+	}
+
+	if ((sock->type == isc_sockettype_udp) &&
+	    ((dev->attributes & ISC_SOCKEVENTATTR_USEMINMTU) != 0))
+	{
+		int use_min_mtu = 1;	/* -1, 0, 1 */
+
+		cmsgp = (struct cmsghdr *)(cmsgbuf +
+					   msg->msg_controllen);
+
+		msg->msg_control = (void *)cmsgbuf;
+		msg->msg_controllen += cmsg_space(sizeof(use_min_mtu));
+		INSIST(msg->msg_controllen <= SENDCMSGBUFLEN);
+
+		cmsgp->cmsg_level = IPPROTO_IPV6;
+		cmsgp->cmsg_type = IPV6_USE_MIN_MTU;
+		cmsgp->cmsg_len = cmsg_len(sizeof(use_min_mtu));
+		memmove(CMSG_DATA(cmsgp), &use_min_mtu, sizeof(use_min_mtu));
+	}
+
+	if (isc_dscp_check_value > -1) {
+		if (sock->type == isc_sockettype_udp)
+			INSIST((int)dev->dscp == isc_dscp_check_value);
+		else if (sock->type == isc_sockettype_tcp)
+			INSIST((int)sock->dscp == isc_dscp_check_value);
+	}
+
+	if ((sock->type == isc_sockettype_udp) &&
+	    ((dev->attributes & ISC_SOCKEVENTATTR_DSCP) != 0))
+	{
+		int dscp = (dev->dscp << 2) & 0xff;
+
+		INSIST(dev->dscp < 0x40);
+
+		if (sock->pf == AF_INET && sock->pktdscp) {
+			cmsgp = (struct cmsghdr *)(cmsgbuf +
+						   msg->msg_controllen);
+			msg->msg_control = (void *)cmsgbuf;
+			msg->msg_controllen += cmsg_space(sizeof(dscp));
+			INSIST(msg->msg_controllen <= SENDCMSGBUFLEN);
+
+			cmsgp->cmsg_level = IPPROTO_IP;
+			cmsgp->cmsg_type = IP_TOS;
+			cmsgp->cmsg_len = cmsg_len(sizeof(char));
+			*(unsigned char*)CMSG_DATA(cmsgp) = dscp;
+		} else if (sock->pf == AF_INET && sock->dscp != dev->dscp) {
+			if (setsockopt(sock->fd, IPPROTO_IP, IP_TOS,
+			       (void *)&dscp, sizeof(int)) < 0)
+			{
+				char strbuf[ISC_STRERRORSIZE];
+				isc__strerror(errno, strbuf, sizeof(strbuf));
+				UNEXPECTED_ERROR(__FILE__, __LINE__,
+						 "setsockopt(%d, IP_TOS, %.02x)"
+						 " %s: %s",
+						 sock->fd, dscp >> 2,
+						 "failed", strbuf);
+			} else
+				sock->dscp = dscp;
+		}
+
+		if (sock->pf == AF_INET6 && sock->pktdscp) {
+			cmsgp = (struct cmsghdr *)(cmsgbuf +
+						   msg->msg_controllen);
+			msg->msg_control = (void *)cmsgbuf;
+			msg->msg_controllen += cmsg_space(sizeof(dscp));
+			INSIST(msg->msg_controllen <= SENDCMSGBUFLEN);
+
+			cmsgp->cmsg_level = IPPROTO_IPV6;
+			cmsgp->cmsg_type = IPV6_TCLASS;
+			cmsgp->cmsg_len = cmsg_len(sizeof(dscp));
+			memmove(CMSG_DATA(cmsgp), &dscp, sizeof(dscp));
+		} else if (sock->pf == AF_INET6 && sock->dscp != dev->dscp) {
+			if (setsockopt(sock->fd, IPPROTO_IPV6, IPV6_TCLASS,
+				       (void *)&dscp, sizeof(int)) < 0) {
+				char strbuf[ISC_STRERRORSIZE];
+				isc__strerror(errno, strbuf, sizeof(strbuf));
+				UNEXPECTED_ERROR(__FILE__, __LINE__,
+						 "setsockopt(%d, IPV6_TCLASS, "
+						 "%.02x) %s: %s",
+						 sock->fd, dscp >> 2,
+						 "failed", strbuf);
+			} else
+				sock->dscp = dscp;
+		}
+
+		if (msg->msg_controllen != 0 &&
+		    msg->msg_controllen < SENDCMSGBUFLEN)
+		{
+			memset(cmsgbuf + msg->msg_controllen, 0,
+			       SENDCMSGBUFLEN - msg->msg_controllen);
+		}
+	}
+
+	if (write_countp != NULL)
+		*write_countp = write_count;
+}
+
+/*
+ * Construct an iov array and attach it to the msghdr passed in.  This is
+ * the RECV constructor, which will use the available region of the buffer
+ * (if using a buffer list) or will use the internal region (if a single
+ * buffer I/O is requested).
+ *
+ * Nothing can be NULL, and the done event must list at least one buffer
+ * on the buffer linked list for this function to be meaningful.
+ *
+ * If read_countp != NULL, *read_countp will hold the number of bytes
+ * this transaction can receive.
+ */
+static void
+build_msghdr_recv(isc__socket_t *sock, char *cmsgbuf, isc_socketevent_t *dev,
+		  struct msghdr *msg, struct iovec *iov, size_t *read_countp)
+{
+	unsigned int iovcount;
+	isc_buffer_t *buffer;
+	isc_region_t available;
+	size_t read_count;
+
+	memset(msg, 0, sizeof(struct msghdr));
+
+	if (sock->type == isc_sockettype_udp) {
+		memset(&dev->address, 0, sizeof(dev->address));
+		msg->msg_name = (void *)&dev->address.type.sa;
+		msg->msg_namelen = sizeof(dev->address.type);
+	} else { /* TCP */
+		msg->msg_name = NULL;
+		msg->msg_namelen = 0;
+		dev->address = sock->peer_address;
+	}
+
+	buffer = ISC_LIST_HEAD(dev->bufferlist);
+	read_count = 0;
+
+	/*
+	 * Single buffer I/O?  Skip what we've done so far in this region.
+	 */
+	if (buffer == NULL) {
+		read_count = dev->region.length - dev->n;
+		iov[0].iov_base = (void *)(dev->region.base + dev->n);
+		iov[0].iov_len = read_count;
+		iovcount = 1;
+
+		goto config;
+	}
+
+	/*
+	 * Multibuffer I/O.
+	 * Skip empty buffers.
+	 */
+	while (buffer != NULL) {
+		REQUIRE(ISC_BUFFER_VALID(buffer));
+		if (isc_buffer_availablelength(buffer) != 0)
+			break;
+		buffer = ISC_LIST_NEXT(buffer, link);
+	}
+
+	iovcount = 0;
+	while (buffer != NULL) {
+		INSIST(iovcount < MAXSCATTERGATHER_RECV);
+
+		isc_buffer_availableregion(buffer, &available);
+
+		if (available.length > 0) {
+			iov[iovcount].iov_base = (void *)(available.base);
+			iov[iovcount].iov_len = available.length;
+			read_count += available.length;
+			iovcount++;
+		}
+		buffer = ISC_LIST_NEXT(buffer, link);
+	}
+
+ config:
+
+	/*
+	 * If needed, set up to receive that one extra byte.
+	 */
+	msg->msg_iov = iov;
+	msg->msg_iovlen = iovcount;
+
+	msg->msg_control = cmsgbuf;
+	msg->msg_controllen = RECVCMSGBUFLEN;
+	msg->msg_flags = 0;
+
+	if (read_countp != NULL)
+		*read_countp = read_count;
+}
+
+static void
+set_dev_address(isc_sockaddr_t *address, isc__socket_t *sock,
+		isc_socketevent_t *dev)
+{
+	if (sock->type == isc_sockettype_udp) {
+		if (address != NULL)
+			dev->address = *address;
+		else
+			dev->address = sock->peer_address;
+	} else if (sock->type == isc_sockettype_tcp) {
+		INSIST(address == NULL);
+		dev->address = sock->peer_address;
+	}
+}
+
+static void
+destroy_socketevent(isc_event_t *event) {
+	isc_socketevent_t *ev = (isc_socketevent_t *)event;
+
+	INSIST(ISC_LIST_EMPTY(ev->bufferlist));
+
+	(ev->destroy)(event);
+}
+
+static isc_socketevent_t *
+allocate_socketevent(void *sender,
+		     isc_eventtype_t eventtype, isc_taskaction_t action,
+		     void *arg)
+{
+	isc_socketevent_t *ev;
+
+	ev = (isc_socketevent_t *)isc_event_allocate(sender,
+						     eventtype, action, arg,
+						     sizeof(*ev));
+
+	if (ev == NULL)
+		return (NULL);
+
+	ev->result = ISC_R_UNSET;
+	ISC_LINK_INIT(ev, ev_link);
+	ISC_LIST_INIT(ev->bufferlist);
+	ev->region.base = NULL;
+	ev->n = 0;
+	ev->offset = 0;
+	ev->attributes = 0;
+	ev->destroy = ev->ev_destroy;
+	ev->ev_destroy = destroy_socketevent;
+	ev->dscp = 0;
+
+	return (ev);
+}
+
+#define DOIO_SUCCESS		0	/* i/o ok, event sent */
+#define DOIO_SOFT		1	/* i/o ok, soft error, no event sent */
+#define DOIO_HARD		2	/* i/o error, event sent */
+#define DOIO_EOF		3	/* EOF, no event sent */
+
+static int
+doio_recv(isc__socket_t *sock, isc_socketevent_t *dev) {
+	int cc;
+	struct iovec iov[MAXSCATTERGATHER_RECV];
+	size_t read_count;
+	size_t actual_count;
+	struct msghdr msghdr;
+	isc_buffer_t *buffer;
+	int recv_errno;
+	char strbuf[ISC_STRERRORSIZE];
+	char cmsgbuf[RECVCMSGBUFLEN] = {0};
+
+	build_msghdr_recv(sock, cmsgbuf, dev, &msghdr, iov, &read_count);
+
+	cc = recvmsg(sock->fd, &msghdr, 0);
+	recv_errno = errno;
+
+	if (cc < 0) {
+		if (SOFT_ERROR(recv_errno))
+			return (DOIO_SOFT);
+
+		if (isc_log_wouldlog(isc_lctx, IOEVENT_LEVEL)) {
+			isc__strerror(recv_errno, strbuf, sizeof(strbuf));
+			socket_log(sock, NULL, IOEVENT,
+				  "doio_recv: recvmsg(%d) %d bytes, err %d/%s",
+				   sock->fd, cc, recv_errno, strbuf);
+		}
+
+#define SOFT_OR_HARD(_system, _isc) \
+	if (recv_errno == _system) { \
+		if (sock->connected) { \
+			dev->result = _isc; \
+			return (DOIO_HARD); \
+		} \
+		return (DOIO_SOFT); \
+	}
+#define ALWAYS_HARD(_system, _isc) \
+	if (recv_errno == _system) { \
+		dev->result = _isc; \
+		return (DOIO_HARD); \
+	}
+
+		SOFT_OR_HARD(ECONNREFUSED, ISC_R_CONNREFUSED);
+		SOFT_OR_HARD(ENETUNREACH, ISC_R_NETUNREACH);
+		SOFT_OR_HARD(EHOSTUNREACH, ISC_R_HOSTUNREACH);
+		SOFT_OR_HARD(EHOSTDOWN, ISC_R_HOSTDOWN);
+		/* HPUX 11.11 can return EADDRNOTAVAIL. */
+		SOFT_OR_HARD(EADDRNOTAVAIL, ISC_R_ADDRNOTAVAIL);
+		ALWAYS_HARD(ENOBUFS, ISC_R_NORESOURCES);
+		/* Should never get this one but it was seen. */
+#ifdef ENOPROTOOPT
+		SOFT_OR_HARD(ENOPROTOOPT, ISC_R_HOSTUNREACH);
+#endif
+		/*
+		 * HPUX returns EPROTO and EINVAL on receiving some ICMP/ICMPv6
+		 * errors.
+		 */
+#ifdef EPROTO
+		SOFT_OR_HARD(EPROTO, ISC_R_HOSTUNREACH);
+#endif
+		SOFT_OR_HARD(EINVAL, ISC_R_HOSTUNREACH);
+
+#undef SOFT_OR_HARD
+#undef ALWAYS_HARD
+
+		dev->result = isc__errno2result(recv_errno);
+		return (DOIO_HARD);
+	}
+
+	/*
+	 * On TCP and UNIX sockets, zero length reads indicate EOF,
+	 * while on UDP sockets, zero length reads are perfectly valid,
+	 * although strange.
+	 */
+	switch (sock->type) {
+	case isc_sockettype_tcp:
+		if (cc == 0)
+			return (DOIO_EOF);
+		break;
+	case isc_sockettype_udp:
+		break;
+	default:
+		INSIST(0);
+	}
+
+	if (sock->type == isc_sockettype_udp) {
+		dev->address.length = msghdr.msg_namelen;
+		if (isc_sockaddr_getport(&dev->address) == 0) {
+			if (isc_log_wouldlog(isc_lctx, IOEVENT_LEVEL)) {
+				socket_log(sock, &dev->address, IOEVENT,
+					   "dropping source port zero packet");
+			}
+			return (DOIO_SOFT);
+		}
+	}
+
+	socket_log(sock, &dev->address, IOEVENT,
+		   "packet received correctly");
+
+	/*
+	 * Overflow bit detection.  If we received MORE bytes than we should,
+	 * this indicates an overflow situation.  Set the flag in the
+	 * dev entry and adjust how much we read by one.
+	 */
+	/*
+	 * If there are control messages attached, run through them and pull
+	 * out the interesting bits.
+	 */
+	process_cmsg(sock, &msghdr, dev);
+
+	/*
+	 * update the buffers (if any) and the i/o count
+	 */
+	dev->n += cc;
+	actual_count = cc;
+	buffer = ISC_LIST_HEAD(dev->bufferlist);
+	while (buffer != NULL && actual_count > 0U) {
+		REQUIRE(ISC_BUFFER_VALID(buffer));
+		if (isc_buffer_availablelength(buffer) <= actual_count) {
+			actual_count -= isc_buffer_availablelength(buffer);
+			isc_buffer_add(buffer,
+				       isc_buffer_availablelength(buffer));
+		} else {
+			isc_buffer_add(buffer, actual_count);
+			actual_count = 0;
+			POST(actual_count);
+			break;
+		}
+		buffer = ISC_LIST_NEXT(buffer, link);
+		if (buffer == NULL) {
+			INSIST(actual_count == 0U);
+		}
+	}
+
+	/*
+	 * If we read less than we expected, update counters,
+	 * and let the upper layer poke the descriptor.
+	 */
+	if (((size_t)cc != read_count) && (dev->n < dev->minimum))
+		return (DOIO_SOFT);
+
+	/*
+	 * Full reads are posted, or partials if partials are ok.
+	 */
+	dev->result = ISC_R_SUCCESS;
+	return (DOIO_SUCCESS);
+}
+
+/*
+ * Returns:
+ *	DOIO_SUCCESS	The operation succeeded.  dev->result contains
+ *			ISC_R_SUCCESS.
+ *
+ *	DOIO_HARD	A hard or unexpected I/O error was encountered.
+ *			dev->result contains the appropriate error.
+ *
+ *	DOIO_SOFT	A soft I/O error was encountered.  No senddone
+ *			event was sent.  The operation should be retried.
+ *
+ *	No other return values are possible.
+ */
+static int
+doio_send(isc__socket_t *sock, isc_socketevent_t *dev) {
+	int cc;
+	struct iovec iov[MAXSCATTERGATHER_SEND];
+	size_t write_count;
+	struct msghdr msghdr;
+	char addrbuf[ISC_SOCKADDR_FORMATSIZE];
+	int attempts = 0;
+	int send_errno;
+	char strbuf[ISC_STRERRORSIZE];
+	char cmsgbuf[SENDCMSGBUFLEN] = {0};
+
+	build_msghdr_send(sock, cmsgbuf, dev, &msghdr, iov, &write_count);
+
+ resend:
+	cc = sendmsg(sock->fd, &msghdr, 0);
+	send_errno = errno;
+
+	/*
+	 * Check for error or block condition.
+	 */
+	if (cc < 0) {
+		if (send_errno == EINTR && ++attempts < NRETRIES)
+			goto resend;
+
+		if (SOFT_ERROR(send_errno)) {
+			if (errno == EWOULDBLOCK || errno == EAGAIN)
+				dev->result = ISC_R_WOULDBLOCK;
+			return (DOIO_SOFT);
+		}
+
+#define SOFT_OR_HARD(_system, _isc) \
+	if (send_errno == _system) { \
+		if (sock->connected) { \
+			dev->result = _isc; \
+			return (DOIO_HARD); \
+		} \
+		return (DOIO_SOFT); \
+	}
+#define ALWAYS_HARD(_system, _isc) \
+	if (send_errno == _system) { \
+		dev->result = _isc; \
+		return (DOIO_HARD); \
+	}
+
+		SOFT_OR_HARD(ECONNREFUSED, ISC_R_CONNREFUSED);
+		ALWAYS_HARD(EACCES, ISC_R_NOPERM);
+		ALWAYS_HARD(EAFNOSUPPORT, ISC_R_ADDRNOTAVAIL);
+		ALWAYS_HARD(EADDRNOTAVAIL, ISC_R_ADDRNOTAVAIL);
+		ALWAYS_HARD(EHOSTUNREACH, ISC_R_HOSTUNREACH);
+#ifdef EHOSTDOWN
+		ALWAYS_HARD(EHOSTDOWN, ISC_R_HOSTUNREACH);
+#endif
+		ALWAYS_HARD(ENETUNREACH, ISC_R_NETUNREACH);
+		ALWAYS_HARD(ENOBUFS, ISC_R_NORESOURCES);
+		ALWAYS_HARD(EPERM, ISC_R_HOSTUNREACH);
+		ALWAYS_HARD(EPIPE, ISC_R_NOTCONNECTED);
+		ALWAYS_HARD(ECONNRESET, ISC_R_CONNECTIONRESET);
+
+#undef SOFT_OR_HARD
+#undef ALWAYS_HARD
+
+		/*
+		 * The other error types depend on whether or not the
+		 * socket is UDP or TCP.  If it is UDP, some errors
+		 * that we expect to be fatal under TCP are merely
+		 * annoying, and are really soft errors.
+		 *
+		 * However, these soft errors are still returned as
+		 * a status.
+		 */
+		isc_sockaddr_format(&dev->address, addrbuf, sizeof(addrbuf));
+		isc__strerror(send_errno, strbuf, sizeof(strbuf));
+		UNEXPECTED_ERROR(__FILE__, __LINE__, "internal_send: %s: %s",
+				 addrbuf, strbuf);
+		dev->result = isc__errno2result(send_errno);
+		return (DOIO_HARD);
+	}
+
+	if (cc == 0) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "doio_send: send() %s 0", "returned");
+	}
+
+	/*
+	 * If we write less than we expected, update counters, poke.
+	 */
+	dev->n += cc;
+	if ((size_t)cc != write_count)
+		return (DOIO_SOFT);
+
+	/*
+	 * Exactly what we wanted to write.  We're done with this
+	 * entry.  Post its completion event.
+	 */
+	dev->result = ISC_R_SUCCESS;
+	return (DOIO_SUCCESS);
+}
+
+/*
+ * Kill.
+ *
+ * Caller must ensure that the socket is not locked and no external
+ * references exist.
+ */
+static void
+socketclose(isc__socketmgr_t *manager, isc__socket_t *sock, int fd) {
+	/*
+	 * No one has this socket open, so the watcher doesn't have to be
+	 * poked, and the socket doesn't have to be locked.
+	 */
+	manager->fds[fd] = NULL;
+	manager->fdstate[fd] = CLOSE_PENDING;
+	select_poke(manager, fd, SELECT_POKE_CLOSE);
+
+	if (sock->active == 1) {
+		sock->active = 0;
+	}
+
+	/*
+	 * update manager->maxfd here (XXX: this should be implemented more
+	 * efficiently)
+	 */
+	if (manager->maxfd == fd) {
+		int i;
+
+		manager->maxfd = 0;
+		for (i = fd - 1; i >= 0; i--) {
+			if (manager->fdstate[i] == MANAGED) {
+				manager->maxfd = i;
+				break;
+			}
+		}
+	}
+
+}
+
+static void
+destroy(isc__socket_t **sockp) {
+	int fd;
+	isc__socket_t *sock = *sockp;
+	isc__socketmgr_t *manager = sock->manager;
+
+	socket_log(sock, NULL, CREATION, "destroying");
+
+	INSIST(ISC_LIST_EMPTY(sock->recv_list));
+	INSIST(ISC_LIST_EMPTY(sock->send_list));
+	INSIST(sock->connect_ev == NULL);
+	INSIST(sock->fd >= -1 && sock->fd < (int)manager->maxsocks);
+
+	if (sock->fd >= 0) {
+		fd = sock->fd;
+		sock->fd = -1;
+		socketclose(manager, sock, fd);
+	}
+
+	ISC_LIST_UNLINK(manager->socklist, sock, link);
+
+	/* can't unlock manager as its memory context is still used */
+	free_socket(sockp);
+}
+
+static isc_result_t
+allocate_socket(isc__socketmgr_t *manager, isc_sockettype_t type,
+		isc__socket_t **socketp)
+{
+	isc__socket_t *sock;
+
+	sock = malloc(sizeof(*sock));
+
+	if (sock == NULL)
+		return (ISC_R_NOMEMORY);
+
+	sock->common.magic = 0;
+	sock->common.impmagic = 0;
+	sock->references = 0;
+
+	sock->manager = manager;
+	sock->type = type;
+	sock->fd = -1;
+	sock->dscp = 0;		/* TOS/TCLASS is zero until set. */
+	sock->active = 0;
+
+	ISC_LINK_INIT(sock, link);
+
+	/*
+	 * Set up list of readers and writers to be initially empty.
+	 */
+	ISC_LIST_INIT(sock->recv_list);
+	ISC_LIST_INIT(sock->send_list);
+	sock->connect_ev = NULL;
+	sock->pending_recv = 0;
+	sock->pending_send = 0;
+	sock->connected = 0;
+	sock->connecting = 0;
+	sock->bound = 0;
+	sock->pktdscp = 0;
+
+	/*
+	 * Initialize readable and writable events.
+	 */
+	ISC_EVENT_INIT(&sock->readable_ev, sizeof(intev_t),
+		       ISC_EVENTATTR_NOPURGE, NULL, ISC_SOCKEVENT_INTR,
+		       NULL, sock, sock, NULL);
+	ISC_EVENT_INIT(&sock->writable_ev, sizeof(intev_t),
+		       ISC_EVENTATTR_NOPURGE, NULL, ISC_SOCKEVENT_INTW,
+		       NULL, sock, sock, NULL);
+
+	sock->common.magic = ISCAPI_SOCKET_MAGIC;
+	sock->common.impmagic = SOCKET_MAGIC;
+	*socketp = sock;
+
+	return (ISC_R_SUCCESS);
+}
+
+/*
+ * This event requires that the various lists be empty, that the reference
+ * count be 1, and that the magic number is valid.  The other socket bits,
+ * like the lock, must be initialized as well.  The fd associated must be
+ * marked as closed, by setting it to -1 on close, or this routine will
+ * also close the socket.
+ */
+static void
+free_socket(isc__socket_t **socketp) {
+	isc__socket_t *sock = *socketp;
+
+	INSIST(VALID_SOCKET(sock));
+	INSIST(sock->references == 0);
+	INSIST(!sock->connecting);
+	INSIST(!sock->pending_recv);
+	INSIST(!sock->pending_send);
+	INSIST(ISC_LIST_EMPTY(sock->recv_list));
+	INSIST(ISC_LIST_EMPTY(sock->send_list));
+	INSIST(!ISC_LINK_LINKED(sock, link));
+
+	sock->common.magic = 0;
+	sock->common.impmagic = 0;
+
+	free(sock);
+
+	*socketp = NULL;
+}
+
+static void
+use_min_mtu(isc__socket_t *sock) {
+	/* use minimum MTU */
+	if (sock->pf == AF_INET6) {
+		int on = 1;
+		(void)setsockopt(sock->fd, IPPROTO_IPV6, IPV6_USE_MIN_MTU,
+				(void *)&on, sizeof(on));
+	}
+}
+
+static void
+set_tcp_maxseg(isc__socket_t *sock, int size) {
+	if (sock->type == isc_sockettype_tcp)
+		(void)setsockopt(sock->fd, IPPROTO_TCP, TCP_MAXSEG,
+				(void *)&size, sizeof(size));
+}
+
+static isc_result_t
+opensocket(isc__socket_t *sock)
+{
+	isc_result_t result;
+	char strbuf[ISC_STRERRORSIZE];
+	const char *err = "socket";
+	int on = 1;
+
+	switch (sock->type) {
+	case isc_sockettype_udp:
+		sock->fd = socket(sock->pf, SOCK_DGRAM, IPPROTO_UDP);
+		break;
+	case isc_sockettype_tcp:
+		sock->fd = socket(sock->pf, SOCK_STREAM, IPPROTO_TCP);
+		break;
+	}
+
+	if (sock->fd < 0) {
+		switch (errno) {
+		case EMFILE:
+		case ENFILE:
+			isc__strerror(errno, strbuf, sizeof(strbuf));
+			isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
+				       ISC_LOGMODULE_SOCKET, ISC_LOG_ERROR,
+				       "%s: %s", err, strbuf);
+			/* fallthrough */
+		case ENOBUFS:
+			return (ISC_R_NORESOURCES);
+
+		case EPROTONOSUPPORT:
+		case EPFNOSUPPORT:
+		case EAFNOSUPPORT:
+		/*
+		 * Linux 2.2 (and maybe others) return EINVAL instead of
+		 * EAFNOSUPPORT.
+		 */
+		case EINVAL:
+			return (ISC_R_FAMILYNOSUPPORT);
+
+		default:
+			isc__strerror(errno, strbuf, sizeof(strbuf));
+			UNEXPECTED_ERROR(__FILE__, __LINE__,
+					 "%s() %s: %s", err, "failed",
+					 strbuf);
+			return (ISC_R_UNEXPECTED);
+		}
+	}
+
+	result = make_nonblock(sock->fd);
+	if (result != ISC_R_SUCCESS) {
+		(void)close(sock->fd);
+		return (result);
+	}
+
+	/*
+	 * Use minimum mtu if possible.
+	 */
+	if (sock->type == isc_sockettype_tcp && sock->pf == AF_INET6) {
+		use_min_mtu(sock);
+		set_tcp_maxseg(sock, 1280 - 20 - 40); /* 1280 - TCP - IPV6 */
+	}
+
+	if (sock->type == isc_sockettype_udp) {
+
+		if (setsockopt(sock->fd, SOL_SOCKET, SO_TIMESTAMP,
+			       (void *)&on, sizeof(on)) < 0
+		    && errno != ENOPROTOOPT) {
+			isc__strerror(errno, strbuf, sizeof(strbuf));
+			UNEXPECTED_ERROR(__FILE__, __LINE__,
+					 "setsockopt(%d, SO_TIMESTAMP) %s: %s",
+					 sock->fd, "failed", strbuf);
+			/* Press on... */
+		}
+
+		/* RFC 3542 */
+		if ((sock->pf == AF_INET6)
+		    && (setsockopt(sock->fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
+				   (void *)&on, sizeof(on)) < 0)) {
+			isc__strerror(errno, strbuf, sizeof(strbuf));
+			UNEXPECTED_ERROR(__FILE__, __LINE__,
+					 "setsockopt(%d, IPV6_RECVPKTINFO) "
+					 "%s: %s", sock->fd, "failed",
+					 strbuf);
+		}
+	}
+
+	if (sock->active == 0) {
+		sock->active = 1;
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+/*
+ * Create a 'type' socket managed
+ * by 'manager'.  Events will be posted to 'task' and when dispatched
+ * 'action' will be called with 'arg' as the arg value.  The new
+ * socket is returned in 'socketp'.
+ */
+static isc_result_t
+socket_create(isc_socketmgr_t *manager0, int pf, isc_sockettype_t type,
+	      isc_socket_t **socketp)
+{
+	isc__socket_t *sock = NULL;
+	isc__socketmgr_t *manager = (isc__socketmgr_t *)manager0;
+	isc_result_t result;
+	int lockid;
+
+	REQUIRE(VALID_MANAGER(manager));
+	REQUIRE(socketp != NULL && *socketp == NULL);
+
+	result = allocate_socket(manager, type, &sock);
+	if (result != ISC_R_SUCCESS)
+		return (result);
+
+	switch (sock->type) {
+	case isc_sockettype_udp:
+#define DCSPPKT(pf) ((pf == AF_INET) ? ISC_NET_DSCPPKTV4 : ISC_NET_DSCPPKTV6)
+		sock->pktdscp = (isc_net_probedscp() & DCSPPKT(pf)) != 0;
+		break;
+	case isc_sockettype_tcp:
+		break;
+	default:
+		INSIST(0);
+	}
+
+	sock->pf = pf;
+
+	result = opensocket(sock);
+	if (result != ISC_R_SUCCESS) {
+		free_socket(&sock);
+		return (result);
+	}
+
+	sock->common.methods = (isc_socketmethods_t *)&socketmethods;
+	sock->references = 1;
+	*socketp = (isc_socket_t *)sock;
+
+	/*
+	 * Note we don't have to lock the socket like we normally would because
+	 * there are no external references to it yet.
+	 */
+
+	lockid = FDLOCK_ID(sock->fd);
+	manager->fds[sock->fd] = sock;
+	manager->fdstate[sock->fd] = MANAGED;
+
+	ISC_LIST_APPEND(manager->socklist, sock, link);
+	if (manager->maxfd < sock->fd)
+		manager->maxfd = sock->fd;
+
+	socket_log(sock, NULL, CREATION, "created");
+
+	return (ISC_R_SUCCESS);
+}
+
+/*%
+ * Create a new 'type' socket managed by 'manager'.  Events
+ * will be posted to 'task' and when dispatched 'action' will be
+ * called with 'arg' as the arg value.  The new socket is returned
+ * in 'socketp'.
+ */
+isc_result_t
+isc__socket_create(isc_socketmgr_t *manager0, int pf, isc_sockettype_t type,
+		   isc_socket_t **socketp)
+{
+	return (socket_create(manager0, pf, type, socketp));
+}
+
+/*
+ * Attach to a socket.  Caller must explicitly detach when it is done.
+ */
+void
+isc__socket_attach(isc_socket_t *sock0, isc_socket_t **socketp) {
+	isc__socket_t *sock = (isc__socket_t *)sock0;
+
+	REQUIRE(VALID_SOCKET(sock));
+	REQUIRE(socketp != NULL && *socketp == NULL);
+
+	sock->references++;
+
+	*socketp = (isc_socket_t *)sock;
+}
+
+/*
+ * Dereference a socket.  If this is the last reference to it, clean things
+ * up by destroying the socket.
+ */
+void
+isc__socket_detach(isc_socket_t **socketp) {
+	isc__socket_t *sock;
+	isc_boolean_t kill_socket = ISC_FALSE;
+
+	REQUIRE(socketp != NULL);
+	sock = (isc__socket_t *)*socketp;
+	REQUIRE(VALID_SOCKET(sock));
+
+	REQUIRE(sock->references > 0);
+	sock->references--;
+	if (sock->references == 0)
+		kill_socket = ISC_TRUE;
+
+	if (kill_socket)
+		destroy(&sock);
+
+	*socketp = NULL;
+}
+
+/*
+ * I/O is possible on a given socket.  Schedule an event to this task that
+ * will call an internal function to do the I/O.  This will charge the
+ * task with the I/O operation and let our select loop handler get back
+ * to doing something real as fast as possible.
+ *
+ * The socket and manager must be locked before calling this function.
+ */
+static void
+dispatch_recv(isc__socket_t *sock) {
+	intev_t *iev;
+	isc_socketevent_t *ev;
+	isc_task_t *sender;
+
+	INSIST(!sock->pending_recv);
+
+	ev = ISC_LIST_HEAD(sock->recv_list);
+	if (ev == NULL)
+		return;
+	socket_log(sock, NULL, EVENT, NULL, 0, 0,
+		   "dispatch_recv:  event %p -> task %p",
+		   ev, ev->ev_sender);
+	sender = ev->ev_sender;
+
+	sock->pending_recv = 1;
+	iev = &sock->readable_ev;
+
+	sock->references++;
+	iev->ev_sender = sock;
+	iev->ev_action = internal_recv;
+	iev->ev_arg = sock;
+
+	isc_task_send(sender, (isc_event_t **)&iev);
+}
+
+static void
+dispatch_send(isc__socket_t *sock) {
+	intev_t *iev;
+	isc_socketevent_t *ev;
+	isc_task_t *sender;
+
+	INSIST(!sock->pending_send);
+
+	ev = ISC_LIST_HEAD(sock->send_list);
+	if (ev == NULL)
+		return;
+	socket_log(sock, NULL, EVENT, NULL, 0, 0,
+		   "dispatch_send:  event %p -> task %p",
+		   ev, ev->ev_sender);
+	sender = ev->ev_sender;
+
+	sock->pending_send = 1;
+	iev = &sock->writable_ev;
+
+	sock->references++;
+	iev->ev_sender = sock;
+	iev->ev_action = internal_send;
+	iev->ev_arg = sock;
+
+	isc_task_send(sender, (isc_event_t **)&iev);
+}
+
+static void
+dispatch_connect(isc__socket_t *sock) {
+	intev_t *iev;
+	isc_socket_connev_t *ev;
+
+	iev = &sock->writable_ev;
+
+	ev = sock->connect_ev;
+	INSIST(ev != NULL); /* XXX */
+
+	INSIST(sock->connecting);
+
+	sock->references++;  /* keep socket around for this internal event */
+	iev->ev_sender = sock;
+	iev->ev_action = internal_connect;
+	iev->ev_arg = sock;
+
+	isc_task_send(ev->ev_sender, (isc_event_t **)&iev);
+}
+
+/*
+ * Dequeue an item off the given socket's read queue, set the result code
+ * in the done event to the one provided, and send it to the task it was
+ * destined for.
+ *
+ * If the event to be sent is on a list, remove it before sending.  If
+ * asked to, send and detach from the socket as well.
+ *
+ * Caller must have the socket locked if the event is attached to the socket.
+ */
+static void
+send_recvdone_event(isc__socket_t *sock, isc_socketevent_t **dev) {
+	isc_task_t *task;
+
+	task = (*dev)->ev_sender;
+
+	(*dev)->ev_sender = sock;
+
+	if (ISC_LINK_LINKED(*dev, ev_link))
+		ISC_LIST_DEQUEUE(sock->recv_list, *dev, ev_link);
+
+	if (((*dev)->attributes & ISC_SOCKEVENTATTR_ATTACHED)
+	    == ISC_SOCKEVENTATTR_ATTACHED)
+		isc_task_sendanddetach(&task, (isc_event_t **)dev);
+	else
+		isc_task_send(task, (isc_event_t **)dev);
+}
+
+/*
+ * See comments for send_recvdone_event() above.
+ *
+ * Caller must have the socket locked if the event is attached to the socket.
+ */
+static void
+send_senddone_event(isc__socket_t *sock, isc_socketevent_t **dev) {
+	isc_task_t *task;
+
+	INSIST(dev != NULL && *dev != NULL);
+
+	task = (*dev)->ev_sender;
+	(*dev)->ev_sender = sock;
+
+	if (ISC_LINK_LINKED(*dev, ev_link))
+		ISC_LIST_DEQUEUE(sock->send_list, *dev, ev_link);
+
+	if (((*dev)->attributes & ISC_SOCKEVENTATTR_ATTACHED)
+	    == ISC_SOCKEVENTATTR_ATTACHED)
+		isc_task_sendanddetach(&task, (isc_event_t **)dev);
+	else
+		isc_task_send(task, (isc_event_t **)dev);
+}
+
+static void
+internal_recv(isc_task_t *me, isc_event_t *ev) {
+	isc_socketevent_t *dev;
+	isc__socket_t *sock;
+
+	INSIST(ev->ev_type == ISC_SOCKEVENT_INTR);
+
+	sock = ev->ev_sender;
+	INSIST(VALID_SOCKET(sock));
+
+	socket_log(sock, NULL, IOEVENT,
+		   "internal_recv: task %p got event %p", me, ev);
+
+	INSIST(sock->pending_recv == 1);
+	sock->pending_recv = 0;
+
+	INSIST(sock->references > 0);
+	sock->references--;  /* the internal event is done with this socket */
+	if (sock->references == 0) {
+		destroy(&sock);
+		return;
+	}
+
+	/*
+	 * Try to do as much I/O as possible on this socket.  There are no
+	 * limits here, currently.
+	 */
+	dev = ISC_LIST_HEAD(sock->recv_list);
+	while (dev != NULL) {
+		switch (doio_recv(sock, dev)) {
+		case DOIO_SOFT:
+			goto poke;
+
+		case DOIO_EOF:
+			/*
+			 * read of 0 means the remote end was closed.
+			 * Run through the event queue and dispatch all
+			 * the events with an EOF result code.
+			 */
+			do {
+				dev->result = ISC_R_EOF;
+				send_recvdone_event(sock, &dev);
+				dev = ISC_LIST_HEAD(sock->recv_list);
+			} while (dev != NULL);
+			goto poke;
+
+		case DOIO_SUCCESS:
+		case DOIO_HARD:
+			send_recvdone_event(sock, &dev);
+			break;
+		}
+
+		dev = ISC_LIST_HEAD(sock->recv_list);
+	}
+
+ poke:
+	if (!ISC_LIST_EMPTY(sock->recv_list))
+		select_poke(sock->manager, sock->fd, SELECT_POKE_READ);
+}
+
+static void
+internal_send(isc_task_t *me, isc_event_t *ev) {
+	isc_socketevent_t *dev;
+	isc__socket_t *sock;
+
+	INSIST(ev->ev_type == ISC_SOCKEVENT_INTW);
+
+	/*
+	 * Find out what socket this is and lock it.
+	 */
+	sock = (isc__socket_t *)ev->ev_sender;
+	INSIST(VALID_SOCKET(sock));
+	socket_log(sock, NULL, IOEVENT,
+		   "internal_send: task %p got event %p", me, ev);
+
+	INSIST(sock->pending_send == 1);
+	sock->pending_send = 0;
+
+	INSIST(sock->references > 0);
+	sock->references--;  /* the internal event is done with this socket */
+	if (sock->references == 0) {
+		destroy(&sock);
+		return;
+	}
+
+	/*
+	 * Try to do as much I/O as possible on this socket.  There are no
+	 * limits here, currently.
+	 */
+	dev = ISC_LIST_HEAD(sock->send_list);
+	while (dev != NULL) {
+		switch (doio_send(sock, dev)) {
+		case DOIO_SOFT:
+			goto poke;
+
+		case DOIO_HARD:
+		case DOIO_SUCCESS:
+			send_senddone_event(sock, &dev);
+			break;
+		}
+
+		dev = ISC_LIST_HEAD(sock->send_list);
+	}
+
+ poke:
+	if (!ISC_LIST_EMPTY(sock->send_list))
+		select_poke(sock->manager, sock->fd, SELECT_POKE_WRITE);
+}
+
+/*
+ * Process read/writes on each fd here.  Avoid locking
+ * and unlocking twice if both reads and writes are possible.
+ */
+static void
+process_fd(isc__socketmgr_t *manager, int fd, isc_boolean_t readable,
+	   isc_boolean_t writeable)
+{
+	isc__socket_t *sock;
+	isc_boolean_t unwatch_read = ISC_FALSE, unwatch_write = ISC_FALSE;
+
+	/*
+	 * If the socket is going to be closed, don't do more I/O.
+	 */
+	if (manager->fdstate[fd] == CLOSE_PENDING) {
+		(void)unwatch_fd(manager, fd, SELECT_POKE_READ);
+		(void)unwatch_fd(manager, fd, SELECT_POKE_WRITE);
+		return;
+	}
+
+	sock = manager->fds[fd];
+	if (readable) {
+		if (sock == NULL) {
+			unwatch_read = ISC_TRUE;
+			goto check_write;
+		}
+		if (!SOCK_DEAD(sock)) {
+			dispatch_recv(sock);
+		}
+		unwatch_read = ISC_TRUE;
+	}
+check_write:
+	if (writeable) {
+		if (sock == NULL) {
+			unwatch_write = ISC_TRUE;
+			goto unlock_fd;
+		}
+		if (!SOCK_DEAD(sock)) {
+			if (sock->connecting)
+				dispatch_connect(sock);
+			else
+				dispatch_send(sock);
+		}
+		unwatch_write = ISC_TRUE;
+	}
+
+ unlock_fd:
+	if (unwatch_read)
+		(void)unwatch_fd(manager, fd, SELECT_POKE_READ);
+	if (unwatch_write)
+		(void)unwatch_fd(manager, fd, SELECT_POKE_WRITE);
+
+}
+
+static void
+process_fds(isc__socketmgr_t *manager, int maxfd, fd_set *readfds,
+	    fd_set *writefds)
+{
+	int i;
+
+	REQUIRE(maxfd <= (int)manager->maxsocks);
+
+	for (i = 0; i < maxfd; i++) {
+		process_fd(manager, i, FD_ISSET(i, readfds),
+			   FD_ISSET(i, writefds));
+	}
+}
+
+/*
+ * Create a new socket manager.
+ */
+
+static isc_result_t
+setup_watcher(isc__socketmgr_t *manager) {
+	isc_result_t result;
+
+	UNUSED(result);
+
+	manager->fd_bufsize = sizeof(fd_set);
+
+	manager->read_fds = NULL;
+	manager->read_fds_copy = NULL;
+	manager->write_fds = NULL;
+	manager->write_fds_copy = NULL;
+
+	manager->read_fds = malloc(manager->fd_bufsize);
+	if (manager->read_fds != NULL)
+		manager->read_fds_copy = malloc(manager->fd_bufsize);
+	if (manager->read_fds_copy != NULL)
+		manager->write_fds = malloc(manager->fd_bufsize);
+	if (manager->write_fds != NULL) {
+		manager->write_fds_copy = malloc(manager->fd_bufsize);
+	}
+	if (manager->write_fds_copy == NULL) {
+		if (manager->write_fds != NULL) {
+			free(manager->write_fds);
+		}
+		if (manager->read_fds_copy != NULL) {
+			free(manager->read_fds_copy);
+		}
+		if (manager->read_fds != NULL) {
+			free(manager->read_fds);
+		}
+		return (ISC_R_NOMEMORY);
+	}
+	memset(manager->read_fds, 0, manager->fd_bufsize);
+	memset(manager->write_fds, 0, manager->fd_bufsize);
+
+	manager->maxfd = 0;
+
+	return (ISC_R_SUCCESS);
+}
+
+static void
+cleanup_watcher(isc__socketmgr_t *manager) {
+
+	if (manager->read_fds != NULL)
+		free(manager->read_fds);
+	if (manager->read_fds_copy != NULL)
+		free(manager->read_fds_copy);
+	if (manager->write_fds != NULL)
+		free(manager->write_fds);
+	if (manager->write_fds_copy != NULL)
+		free(manager->write_fds_copy);
+}
+
+isc_result_t
+isc__socketmgr_create(isc_socketmgr_t **managerp) {
+	return (isc__socketmgr_create2(managerp, 0));
+}
+
+isc_result_t
+isc__socketmgr_create2(isc_socketmgr_t **managerp,
+		       unsigned int maxsocks)
+{
+	isc__socketmgr_t *manager;
+	isc_result_t result;
+
+	REQUIRE(managerp != NULL && *managerp == NULL);
+
+	if (socketmgr != NULL) {
+		/* Don't allow maxsocks to be updated */
+		if (maxsocks > 0 && socketmgr->maxsocks != maxsocks)
+			return (ISC_R_EXISTS);
+
+		socketmgr->refs++;
+		*managerp = (isc_socketmgr_t *)socketmgr;
+		return (ISC_R_SUCCESS);
+	}
+
+	if (maxsocks == 0)
+		maxsocks = FD_SETSIZE;
+
+	manager = malloc(sizeof(*manager));
+	if (manager == NULL)
+		return (ISC_R_NOMEMORY);
+
+	/* zero-clear so that necessary cleanup on failure will be easy */
+	memset(manager, 0, sizeof(*manager));
+	manager->maxsocks = maxsocks;
+	manager->fds = malloc(manager->maxsocks * sizeof(isc__socket_t *));
+	if (manager->fds == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto free_manager;
+	}
+	manager->fdstate = malloc(manager->maxsocks * sizeof(int));
+	if (manager->fdstate == NULL) {
+		result = ISC_R_NOMEMORY;
+		goto free_manager;
+	}
+
+	manager->common.methods = &socketmgrmethods;
+	manager->common.magic = ISCAPI_SOCKETMGR_MAGIC;
+	manager->common.impmagic = SOCKET_MANAGER_MAGIC;
+	memset(manager->fds, 0, manager->maxsocks * sizeof(isc_socket_t *));
+	ISC_LIST_INIT(manager->socklist);
+
+	manager->refs = 1;
+
+	/*
+	 * Set up initial state for the select loop
+	 */
+	result = setup_watcher(manager);
+	if (result != ISC_R_SUCCESS)
+		goto cleanup;
+
+	memset(manager->fdstate, 0, manager->maxsocks * sizeof(int));
+
+	socketmgr = manager;
+	*managerp = (isc_socketmgr_t *)manager;
+
+	return (ISC_R_SUCCESS);
+
+cleanup:
+
+free_manager:
+	if (manager->fdstate != NULL) {
+		free(manager->fdstate);
+	}
+	if (manager->fds != NULL) {
+		free(manager->fds);
+	}
+	free(manager);
+
+	return (result);
+}
+
+void
+isc__socketmgr_destroy(isc_socketmgr_t **managerp) {
+	isc__socketmgr_t *manager;
+	int i;
+
+	/*
+	 * Destroy a socket manager.
+	 */
+
+	REQUIRE(managerp != NULL);
+	manager = (isc__socketmgr_t *)*managerp;
+	REQUIRE(VALID_MANAGER(manager));
+
+	manager->refs--;
+	if (manager->refs > 0) {
+		*managerp = NULL;
+		return;
+	}
+	socketmgr = NULL;
+
+	/*
+	 * Wait for all sockets to be destroyed.
+	 */
+	while (!ISC_LIST_EMPTY(manager->socklist)) {
+		isc__taskmgr_dispatch(NULL);
+	}
+
+	/*
+	 * Here, poke our select/poll thread.  Do this by closing the write
+	 * half of the pipe, which will send EOF to the read half.
+	 * This is currently a no-op in the non-threaded case.
+	 */
+	select_poke(manager, 0, SELECT_POKE_SHUTDOWN);
+
+	/*
+	 * Clean up.
+	 */
+	cleanup_watcher(manager);
+
+	for (i = 0; i < (int)manager->maxsocks; i++)
+		if (manager->fdstate[i] == CLOSE_PENDING) /* no need to lock */
+			(void)close(i);
+
+	free(manager->fds);
+	free(manager->fdstate);
+
+	manager->common.magic = 0;
+	manager->common.impmagic = 0;
+	free(manager);
+
+	*managerp = NULL;
+
+	socketmgr = NULL;
+}
+
+static isc_result_t
+socket_recv(isc__socket_t *sock, isc_socketevent_t *dev, isc_task_t *task,
+	    unsigned int flags)
+{
+	int io_state;
+	isc_task_t *ntask = NULL;
+	isc_result_t result = ISC_R_SUCCESS;
+
+	dev->ev_sender = task;
+
+	if (sock->type == isc_sockettype_udp) {
+		io_state = doio_recv(sock, dev);
+	} else {
+		if (ISC_LIST_EMPTY(sock->recv_list))
+			io_state = doio_recv(sock, dev);
+		else
+			io_state = DOIO_SOFT;
+	}
+
+	switch (io_state) {
+	case DOIO_SOFT:
+		/*
+		 * We couldn't read all or part of the request right now, so
+		 * queue it.
+		 *
+		 * Attach to socket and to task
+		 */
+		isc_task_attach(task, &ntask);
+		dev->attributes |= ISC_SOCKEVENTATTR_ATTACHED;
+
+		/*
+		 * Enqueue the request.  If the socket was previously not being
+		 * watched, poke the watcher to start paying attention to it.
+		 */
+		if (ISC_LIST_EMPTY(sock->recv_list) && !sock->pending_recv)
+			select_poke(sock->manager, sock->fd, SELECT_POKE_READ);
+		ISC_LIST_ENQUEUE(sock->recv_list, dev, ev_link);
+
+		socket_log(sock, NULL, EVENT, NULL, 0, 0,
+			   "socket_recv: event %p -> task %p",
+			   dev, ntask);
+
+		if ((flags & ISC_SOCKFLAG_IMMEDIATE) != 0)
+			result = ISC_R_INPROGRESS;
+		break;
+
+	case DOIO_EOF:
+		dev->result = ISC_R_EOF;
+		/* fallthrough */
+
+	case DOIO_HARD:
+	case DOIO_SUCCESS:
+		if ((flags & ISC_SOCKFLAG_IMMEDIATE) == 0)
+			send_recvdone_event(sock, &dev);
+		break;
+	}
+
+	return (result);
+}
+
+isc_result_t
+isc__socket_recvv(isc_socket_t *sock0, isc_bufferlist_t *buflist,
+		  unsigned int minimum, isc_task_t *task,
+		  isc_taskaction_t action, void *arg)
+{
+	isc__socket_t *sock = (isc__socket_t *)sock0;
+	isc_socketevent_t *dev;
+	isc__socketmgr_t *manager;
+	unsigned int iocount;
+	isc_buffer_t *buffer;
+
+	REQUIRE(VALID_SOCKET(sock));
+	REQUIRE(buflist != NULL);
+	REQUIRE(!ISC_LIST_EMPTY(*buflist));
+	REQUIRE(task != NULL);
+	REQUIRE(action != NULL);
+
+	manager = sock->manager;
+	REQUIRE(VALID_MANAGER(manager));
+
+	iocount = isc_bufferlist_availablecount(buflist);
+	REQUIRE(iocount > 0);
+
+	INSIST(sock->bound);
+
+	dev = allocate_socketevent(sock,
+				   ISC_SOCKEVENT_RECVDONE, action, arg);
+	if (dev == NULL)
+		return (ISC_R_NOMEMORY);
+
+	/*
+	 * UDP sockets are always partial read
+	 */
+	if (sock->type == isc_sockettype_udp)
+		dev->minimum = 1;
+	else {
+		if (minimum == 0)
+			dev->minimum = iocount;
+		else
+			dev->minimum = minimum;
+	}
+
+	/*
+	 * Move each buffer from the passed in list to our internal one.
+	 */
+	buffer = ISC_LIST_HEAD(*buflist);
+	while (buffer != NULL) {
+		ISC_LIST_DEQUEUE(*buflist, buffer, link);
+		ISC_LIST_ENQUEUE(dev->bufferlist, buffer, link);
+		buffer = ISC_LIST_HEAD(*buflist);
+	}
+
+	return (socket_recv(sock, dev, task, 0));
+}
+
+static isc_result_t
+socket_send(isc__socket_t *sock, isc_socketevent_t *dev, isc_task_t *task,
+	    isc_sockaddr_t *address, struct in6_pktinfo *pktinfo,
+	    unsigned int flags)
+{
+	int io_state;
+	isc_task_t *ntask = NULL;
+	isc_result_t result = ISC_R_SUCCESS;
+
+	dev->ev_sender = task;
+
+	set_dev_address(address, sock, dev);
+	if (pktinfo != NULL) {
+		dev->attributes |= ISC_SOCKEVENTATTR_PKTINFO;
+		dev->pktinfo = *pktinfo;
+
+		if (!isc_sockaddr_issitelocal(&dev->address) &&
+		    !isc_sockaddr_islinklocal(&dev->address)) {
+			socket_log(sock, NULL, TRACE,
+				   "pktinfo structure provided, ifindex %u "
+				   "(set to 0)", pktinfo->ipi6_ifindex);
+
+			/*
+			 * Set the pktinfo index to 0 here, to let the
+			 * kernel decide what interface it should send on.
+			 */
+			dev->pktinfo.ipi6_ifindex = 0;
+		}
+	}
+
+	if (sock->type == isc_sockettype_udp)
+		io_state = doio_send(sock, dev);
+	else {
+		if (ISC_LIST_EMPTY(sock->send_list))
+			io_state = doio_send(sock, dev);
+		else
+			io_state = DOIO_SOFT;
+	}
+
+	switch (io_state) {
+	case DOIO_SOFT:
+		/*
+		 * We couldn't send all or part of the request right now, so
+		 * queue it unless ISC_SOCKFLAG_NORETRY is set.
+		 */
+		if ((flags & ISC_SOCKFLAG_NORETRY) == 0) {
+			isc_task_attach(task, &ntask);
+			dev->attributes |= ISC_SOCKEVENTATTR_ATTACHED;
+
+			/*
+			 * Enqueue the request.  If the socket was previously
+			 * not being watched, poke the watcher to start
+			 * paying attention to it.
+			 */
+			if (ISC_LIST_EMPTY(sock->send_list) &&
+			    !sock->pending_send)
+				select_poke(sock->manager, sock->fd,
+					    SELECT_POKE_WRITE);
+			ISC_LIST_ENQUEUE(sock->send_list, dev, ev_link);
+
+			socket_log(sock, NULL, EVENT, NULL, 0, 0,
+				   "socket_send: event %p -> task %p",
+				   dev, ntask);
+
+			if ((flags & ISC_SOCKFLAG_IMMEDIATE) != 0)
+				result = ISC_R_INPROGRESS;
+			break;
+		}
+
+		/* FALLTHROUGH */
+
+	case DOIO_HARD:
+	case DOIO_SUCCESS:
+		if ((flags & ISC_SOCKFLAG_IMMEDIATE) == 0)
+			send_senddone_event(sock, &dev);
+		break;
+	}
+
+	return (result);
+}
+
+isc_result_t
+isc__socket_sendv(isc_socket_t *sock, isc_bufferlist_t *buflist,
+		  isc_task_t *task, isc_taskaction_t action, void *arg)
+{
+	return (isc__socket_sendtov2(sock, buflist, task, action, arg, NULL,
+				     NULL, 0));
+}
+
+isc_result_t
+isc__socket_sendtov2(isc_socket_t *sock0, isc_bufferlist_t *buflist,
+		     isc_task_t *task, isc_taskaction_t action, void *arg,
+		     isc_sockaddr_t *address, struct in6_pktinfo *pktinfo,
+		     unsigned int flags)
+{
+	isc__socket_t *sock = (isc__socket_t *)sock0;
+	isc_socketevent_t *dev;
+	isc__socketmgr_t *manager;
+	unsigned int iocount;
+	isc_buffer_t *buffer;
+
+	REQUIRE(VALID_SOCKET(sock));
+	REQUIRE(buflist != NULL);
+	REQUIRE(!ISC_LIST_EMPTY(*buflist));
+	REQUIRE(task != NULL);
+	REQUIRE(action != NULL);
+
+	manager = sock->manager;
+	REQUIRE(VALID_MANAGER(manager));
+
+	iocount = isc_bufferlist_usedcount(buflist);
+	REQUIRE(iocount > 0);
+
+	dev = allocate_socketevent(sock,
+				   ISC_SOCKEVENT_SENDDONE, action, arg);
+	if (dev == NULL)
+		return (ISC_R_NOMEMORY);
+
+	/*
+	 * Move each buffer from the passed in list to our internal one.
+	 */
+	buffer = ISC_LIST_HEAD(*buflist);
+	while (buffer != NULL) {
+		ISC_LIST_DEQUEUE(*buflist, buffer, link);
+		ISC_LIST_ENQUEUE(dev->bufferlist, buffer, link);
+		buffer = ISC_LIST_HEAD(*buflist);
+	}
+
+	return (socket_send(sock, dev, task, address, pktinfo, flags));
+}
+
+isc_result_t
+isc__socket_bind(isc_socket_t *sock0, isc_sockaddr_t *sockaddr,
+		 unsigned int options) {
+	isc__socket_t *sock = (isc__socket_t *)sock0;
+	char strbuf[ISC_STRERRORSIZE];
+	int on = 1;
+
+	REQUIRE(VALID_SOCKET(sock));
+
+	INSIST(!sock->bound);
+
+	if (sock->pf != sockaddr->type.sa.sa_family) {
+		return (ISC_R_FAMILYMISMATCH);
+	}
+
+	/*
+	 * Only set SO_REUSEADDR when we want a specific port.
+	 */
+	if ((options & ISC_SOCKET_REUSEADDRESS) != 0 &&
+	    isc_sockaddr_getport(sockaddr) != (in_port_t)0 &&
+	    setsockopt(sock->fd, SOL_SOCKET, SO_REUSEADDR, (void *)&on,
+		       sizeof(on)) < 0) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "setsockopt(%d) %s", sock->fd, "failed");
+		/* Press on... */
+	}
+	if (bind(sock->fd, &sockaddr->type.sa, sockaddr->length) < 0) {
+		switch (errno) {
+		case EACCES:
+			return (ISC_R_NOPERM);
+		case EADDRNOTAVAIL:
+			return (ISC_R_ADDRNOTAVAIL);
+		case EADDRINUSE:
+			return (ISC_R_ADDRINUSE);
+		case EINVAL:
+			return (ISC_R_BOUND);
+		default:
+			isc__strerror(errno, strbuf, sizeof(strbuf));
+			UNEXPECTED_ERROR(__FILE__, __LINE__, "bind: %s",
+					 strbuf);
+			return (ISC_R_UNEXPECTED);
+		}
+	}
+
+	socket_log(sock, sockaddr, TRACE, "bound");
+	sock->bound = 1;
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc__socket_connect(isc_socket_t *sock0, isc_sockaddr_t *addr,
+		   isc_task_t *task, isc_taskaction_t action, void *arg)
+{
+	isc__socket_t *sock = (isc__socket_t *)sock0;
+	isc_socket_connev_t *dev;
+	isc_task_t *ntask = NULL;
+	isc__socketmgr_t *manager;
+	int cc;
+	char strbuf[ISC_STRERRORSIZE];
+	char addrbuf[ISC_SOCKADDR_FORMATSIZE];
+
+	REQUIRE(VALID_SOCKET(sock));
+	REQUIRE(addr != NULL);
+	REQUIRE(task != NULL);
+	REQUIRE(action != NULL);
+
+	manager = sock->manager;
+	REQUIRE(VALID_MANAGER(manager));
+	REQUIRE(addr != NULL);
+
+	if (isc_sockaddr_ismulticast(addr))
+		return (ISC_R_MULTICAST);
+
+	REQUIRE(!sock->connecting);
+
+	dev = (isc_socket_connev_t *)isc_event_allocate(sock,
+							ISC_SOCKEVENT_CONNECT,
+							action,	arg,
+							sizeof(*dev));
+	if (dev == NULL) {
+		return (ISC_R_NOMEMORY);
+	}
+	ISC_LINK_INIT(dev, ev_link);
+
+	/*
+	 * Try to do the connect right away, as there can be only one
+	 * outstanding, and it might happen to complete.
+	 */
+	sock->peer_address = *addr;
+	cc = connect(sock->fd, &addr->type.sa, addr->length);
+	if (cc < 0) {
+		/*
+		 * HP-UX "fails" to connect a UDP socket and sets errno to
+		 * EINPROGRESS if it's non-blocking.  We'd rather regard this as
+		 * a success and let the user detect it if it's really an error
+		 * at the time of sending a packet on the socket.
+		 */
+		if (sock->type == isc_sockettype_udp && errno == EINPROGRESS) {
+			cc = 0;
+			goto success;
+		}
+		if (SOFT_ERROR(errno) || errno == EINPROGRESS)
+			goto queue;
+
+		switch (errno) {
+#define ERROR_MATCH(a, b) case a: dev->result = b; goto err_exit;
+			ERROR_MATCH(EACCES, ISC_R_NOPERM);
+			ERROR_MATCH(EADDRNOTAVAIL, ISC_R_ADDRNOTAVAIL);
+			ERROR_MATCH(EAFNOSUPPORT, ISC_R_ADDRNOTAVAIL);
+			ERROR_MATCH(ECONNREFUSED, ISC_R_CONNREFUSED);
+			ERROR_MATCH(EHOSTUNREACH, ISC_R_HOSTUNREACH);
+#ifdef EHOSTDOWN
+			ERROR_MATCH(EHOSTDOWN, ISC_R_HOSTUNREACH);
+#endif
+			ERROR_MATCH(ENETUNREACH, ISC_R_NETUNREACH);
+			ERROR_MATCH(ENOBUFS, ISC_R_NORESOURCES);
+			ERROR_MATCH(EPERM, ISC_R_HOSTUNREACH);
+			ERROR_MATCH(EPIPE, ISC_R_NOTCONNECTED);
+			ERROR_MATCH(ECONNRESET, ISC_R_CONNECTIONRESET);
+#undef ERROR_MATCH
+		}
+
+		sock->connected = 0;
+
+		isc__strerror(errno, strbuf, sizeof(strbuf));
+		isc_sockaddr_format(addr, addrbuf, sizeof(addrbuf));
+		UNEXPECTED_ERROR(__FILE__, __LINE__, "connect(%s) %d/%s",
+				 addrbuf, errno, strbuf);
+
+		isc_event_free(ISC_EVENT_PTR(&dev));
+		return (ISC_R_UNEXPECTED);
+
+	err_exit:
+		sock->connected = 0;
+		isc_task_send(task, ISC_EVENT_PTR(&dev));
+
+		return (ISC_R_SUCCESS);
+	}
+
+	/*
+	 * If connect completed, fire off the done event.
+	 */
+ success:
+	if (cc == 0) {
+		sock->connected = 1;
+		sock->bound = 1;
+		dev->result = ISC_R_SUCCESS;
+		isc_task_send(task, ISC_EVENT_PTR(&dev));
+
+		return (ISC_R_SUCCESS);
+	}
+
+ queue:
+
+	/*
+	 * Attach to task.
+	 */
+	isc_task_attach(task, &ntask);
+
+	sock->connecting = 1;
+
+	dev->ev_sender = ntask;
+
+	/*
+	 * Poke watcher here.  We still have the socket locked, so there
+	 * is no race condition.  We will keep the lock for such a short
+	 * bit of time waking it up now or later won't matter all that much.
+	 */
+	if (sock->connect_ev == NULL)
+		select_poke(manager, sock->fd, SELECT_POKE_CONNECT);
+
+	sock->connect_ev = dev;
+
+	return (ISC_R_SUCCESS);
+}
+
+/*
+ * Called when a socket with a pending connect() finishes.
+ */
+static void
+internal_connect(isc_task_t *me, isc_event_t *ev) {
+	isc__socket_t *sock;
+	isc_socket_connev_t *dev;
+	isc_task_t *task;
+	int cc;
+	socklen_t optlen;
+	char strbuf[ISC_STRERRORSIZE];
+	char peerbuf[ISC_SOCKADDR_FORMATSIZE];
+
+	UNUSED(me);
+	INSIST(ev->ev_type == ISC_SOCKEVENT_INTW);
+
+	sock = ev->ev_sender;
+	INSIST(VALID_SOCKET(sock));
+
+	/*
+	 * When the internal event was sent the reference count was bumped
+	 * to keep the socket around for us.  Decrement the count here.
+	 */
+	INSIST(sock->references > 0);
+	sock->references--;
+	if (sock->references == 0) {
+		destroy(&sock);
+		return;
+	}
+
+	/*
+	 * Has this event been canceled?
+	 */
+	dev = sock->connect_ev;
+	if (dev == NULL) {
+		INSIST(!sock->connecting);
+		return;
+	}
+
+	INSIST(sock->connecting);
+	sock->connecting = 0;
+
+	/*
+	 * Get any possible error status here.
+	 */
+	optlen = sizeof(cc);
+	if (getsockopt(sock->fd, SOL_SOCKET, SO_ERROR,
+		       (void *)&cc, (void *)&optlen) < 0)
+		cc = errno;
+	else
+		errno = cc;
+
+	if (errno != 0) {
+		/*
+		 * If the error is EAGAIN, just re-select on this
+		 * fd and pretend nothing strange happened.
+		 */
+		if (SOFT_ERROR(errno) || errno == EINPROGRESS) {
+			sock->connecting = 1;
+			select_poke(sock->manager, sock->fd,
+				    SELECT_POKE_CONNECT);
+			return;
+		}
+
+
+		/*
+		 * Translate other errors into ISC_R_* flavors.
+		 */
+		switch (errno) {
+#define ERROR_MATCH(a, b) case a: dev->result = b; break;
+			ERROR_MATCH(EACCES, ISC_R_NOPERM);
+			ERROR_MATCH(EADDRNOTAVAIL, ISC_R_ADDRNOTAVAIL);
+			ERROR_MATCH(EAFNOSUPPORT, ISC_R_ADDRNOTAVAIL);
+			ERROR_MATCH(ECONNREFUSED, ISC_R_CONNREFUSED);
+			ERROR_MATCH(EHOSTUNREACH, ISC_R_HOSTUNREACH);
+#ifdef EHOSTDOWN
+			ERROR_MATCH(EHOSTDOWN, ISC_R_HOSTUNREACH);
+#endif
+			ERROR_MATCH(ENETUNREACH, ISC_R_NETUNREACH);
+			ERROR_MATCH(ENOBUFS, ISC_R_NORESOURCES);
+			ERROR_MATCH(EPERM, ISC_R_HOSTUNREACH);
+			ERROR_MATCH(EPIPE, ISC_R_NOTCONNECTED);
+			ERROR_MATCH(ETIMEDOUT, ISC_R_TIMEDOUT);
+			ERROR_MATCH(ECONNRESET, ISC_R_CONNECTIONRESET);
+#undef ERROR_MATCH
+		default:
+			dev->result = ISC_R_UNEXPECTED;
+			isc_sockaddr_format(&sock->peer_address, peerbuf,
+					    sizeof(peerbuf));
+			isc__strerror(errno, strbuf, sizeof(strbuf));
+			UNEXPECTED_ERROR(__FILE__, __LINE__,
+					 "internal_connect: connect(%s) %s",
+					 peerbuf, strbuf);
+		}
+	} else {
+		dev->result = ISC_R_SUCCESS;
+		sock->connected = 1;
+		sock->bound = 1;
+	}
+
+	sock->connect_ev = NULL;
+
+	task = dev->ev_sender;
+	dev->ev_sender = sock;
+	isc_task_sendanddetach(&task, ISC_EVENT_PTR(&dev));
+}
+
+/*
+ * Run through the list of events on this socket, and cancel the ones
+ * queued for task "task" of type "how".  "how" is a bitmask.
+ */
+void
+isc__socket_cancel(isc_socket_t *sock0, isc_task_t *task, unsigned int how) {
+	isc__socket_t *sock = (isc__socket_t *)sock0;
+
+	REQUIRE(VALID_SOCKET(sock));
+
+	/*
+	 * Quick exit if there is nothing to do.  Don't even bother locking
+	 * in this case.
+	 */
+	if (how == 0)
+		return;
+
+	/*
+	 * All of these do the same thing, more or less.
+	 * Each will:
+	 *	o If the internal event is marked as "posted" try to
+	 *	  remove it from the task's queue.  If this fails, mark it
+	 *	  as canceled instead, and let the task clean it up later.
+	 *	o For each I/O request for that task of that type, post
+	 *	  its done event with status of "ISC_R_CANCELED".
+	 *	o Reset any state needed.
+	 */
+	if (((how & ISC_SOCKCANCEL_RECV) == ISC_SOCKCANCEL_RECV)
+	    && !ISC_LIST_EMPTY(sock->recv_list)) {
+		isc_socketevent_t      *dev;
+		isc_socketevent_t      *next;
+		isc_task_t	       *current_task;
+
+		dev = ISC_LIST_HEAD(sock->recv_list);
+
+		while (dev != NULL) {
+			current_task = dev->ev_sender;
+			next = ISC_LIST_NEXT(dev, ev_link);
+
+			if ((task == NULL) || (task == current_task)) {
+				dev->result = ISC_R_CANCELED;
+				send_recvdone_event(sock, &dev);
+			}
+			dev = next;
+		}
+	}
+
+	if (((how & ISC_SOCKCANCEL_SEND) == ISC_SOCKCANCEL_SEND)
+	    && !ISC_LIST_EMPTY(sock->send_list)) {
+		isc_socketevent_t      *dev;
+		isc_socketevent_t      *next;
+		isc_task_t	       *current_task;
+
+		dev = ISC_LIST_HEAD(sock->send_list);
+
+		while (dev != NULL) {
+			current_task = dev->ev_sender;
+			next = ISC_LIST_NEXT(dev, ev_link);
+
+			if ((task == NULL) || (task == current_task)) {
+				dev->result = ISC_R_CANCELED;
+				send_senddone_event(sock, &dev);
+			}
+			dev = next;
+		}
+	}
+
+	/*
+	 * Connecting is not a list.
+	 */
+	if (((how & ISC_SOCKCANCEL_CONNECT) == ISC_SOCKCANCEL_CONNECT)
+	    && sock->connect_ev != NULL) {
+		isc_socket_connev_t    *dev;
+		isc_task_t	       *current_task;
+
+		INSIST(sock->connecting);
+		sock->connecting = 0;
+
+		dev = sock->connect_ev;
+		current_task = dev->ev_sender;
+
+		if ((task == NULL) || (task == current_task)) {
+			sock->connect_ev = NULL;
+
+			dev->result = ISC_R_CANCELED;
+			dev->ev_sender = sock;
+			isc_task_sendanddetach(&current_task,
+					       ISC_EVENT_PTR(&dev));
+		}
+	}
+
+}
+
+/*
+ * In our assumed scenario, we can simply use a single static object.
+ * XXX: this is not true if the application uses multiple threads with
+ *      'multi-context' mode.  Fixing this is a future TODO item.
+ */
+static isc_socketwait_t swait_private;
+
+int
+isc__socketmgr_waitevents(isc_socketmgr_t *manager0, struct timeval *tvp,
+			  isc_socketwait_t **swaitp)
+{
+	isc__socketmgr_t *manager = (isc__socketmgr_t *)manager0;
+	int n;
+
+	REQUIRE(swaitp != NULL && *swaitp == NULL);
+
+	if (manager == NULL)
+		manager = socketmgr;
+	if (manager == NULL)
+		return (0);
+
+	memmove(manager->read_fds_copy, manager->read_fds, manager->fd_bufsize);
+	memmove(manager->write_fds_copy, manager->write_fds,
+		manager->fd_bufsize);
+
+	swait_private.readset = manager->read_fds_copy;
+	swait_private.writeset = manager->write_fds_copy;
+	swait_private.maxfd = manager->maxfd + 1;
+
+	n = select(swait_private.maxfd, swait_private.readset,
+		   swait_private.writeset, NULL, tvp);
+
+	*swaitp = &swait_private;
+	return (n);
+}
+
+isc_result_t
+isc__socketmgr_dispatch(isc_socketmgr_t *manager0, isc_socketwait_t *swait) {
+	isc__socketmgr_t *manager = (isc__socketmgr_t *)manager0;
+
+	REQUIRE(swait == &swait_private);
+
+	if (manager == NULL)
+		manager = socketmgr;
+	if (manager == NULL)
+		return (ISC_R_NOTFOUND);
+
+	process_fds(manager, swait->maxfd, swait->readset, swait->writeset);
+	return (ISC_R_SUCCESS);
+}
+
+#include "../socket_api.c"
diff --git a/usr.bin/dig/lib/isc/unix/socket_p.h b/usr.bin/dig/lib/isc/unix/socket_p.h
new file mode 100644
index 00000000000..ec3a83042a5
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/socket_p.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: socket_p.h,v 1.1 2020/02/07 09:58:54 florian Exp $ */
+
+#ifndef ISC_SOCKET_P_H
+#define ISC_SOCKET_P_H
+
+/*! \file */
+
+#include <sys/select.h>
+
+typedef struct isc_socketwait isc_socketwait_t;
+int isc__socketmgr_waitevents(isc_socketmgr_t *, struct timeval *,
+			      isc_socketwait_t **);
+isc_result_t isc__socketmgr_dispatch(isc_socketmgr_t *, isc_socketwait_t *);
+#endif /* ISC_SOCKET_P_H */
diff --git a/usr.bin/dig/lib/isc/unix/stdio.c b/usr.bin/dig/lib/isc/unix/stdio.c
new file mode 100644
index 00000000000..f5cd6fd456f
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/stdio.c
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: stdio.c,v 1.1 2020/02/07 09:58:54 florian Exp $ */
+
+
+
+#include <errno.h>
+#include <unistd.h>
+
+#include <isc/stdio.h>
+#include <isc/util.h>
+
+#include "errno2result.h"
+
+isc_result_t
+isc_stdio_open(const char *filename, const char *mode, FILE **fp) {
+	FILE *f;
+
+	f = fopen(filename, mode);
+	if (f == NULL)
+		return (isc__errno2result(errno));
+	*fp = f;
+	return (ISC_R_SUCCESS);
+}
diff --git a/usr.bin/dig/lib/isc/unix/stdtime.c b/usr.bin/dig/lib/isc/unix/stdtime.c
new file mode 100644
index 00000000000..bc43cf1aa48
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/stdtime.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: stdtime.c,v 1.1 2020/02/07 09:58:54 florian Exp $ */
+
+/*! \file */
+
+
+
+#include <stddef.h>	/* NULL */
+#include <stdlib.h>	/* NULL */
+#include <syslog.h>
+
+#include <sys/time.h>
+
+#include <isc/stdtime.h>
+#include <isc/util.h>
+
+#ifndef ISC_FIX_TV_USEC
+#define ISC_FIX_TV_USEC 1
+#endif
+
+#define US_PER_S 1000000
+
+#if ISC_FIX_TV_USEC
+static inline void
+fix_tv_usec(struct timeval *tv) {
+	isc_boolean_t fixed = ISC_FALSE;
+
+	if (tv->tv_usec < 0) {
+		fixed = ISC_TRUE;
+		do {
+			tv->tv_sec -= 1;
+			tv->tv_usec += US_PER_S;
+		} while (tv->tv_usec < 0);
+	} else if (tv->tv_usec >= US_PER_S) {
+		fixed = ISC_TRUE;
+		do {
+			tv->tv_sec += 1;
+			tv->tv_usec -= US_PER_S;
+		} while (tv->tv_usec >=US_PER_S);
+	}
+	/*
+	 * Call syslog directly as we are called from the logging functions.
+	 */
+	if (fixed)
+		(void)syslog(LOG_ERR, "gettimeofday returned bad tv_usec: corrected");
+}
+#endif
+
+void
+isc_stdtime_get(isc_stdtime_t *t) {
+	struct timeval tv;
+
+	/*
+	 * Set 't' to the number of seconds since 00:00:00 UTC, January 1,
+	 * 1970.
+	 */
+
+	REQUIRE(t != NULL);
+
+	RUNTIME_CHECK(gettimeofday(&tv, NULL) != -1);
+
+#if ISC_FIX_TV_USEC
+	fix_tv_usec(&tv);
+	INSIST(tv.tv_usec >= 0);
+#else
+	INSIST(tv.tv_usec >= 0 && tv.tv_usec < US_PER_S);
+#endif
+
+	*t = (unsigned int)tv.tv_sec;
+}
diff --git a/usr.bin/dig/lib/isc/unix/strerror.c b/usr.bin/dig/lib/isc/unix/strerror.c
new file mode 100644
index 00000000000..a476ad0c989
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/strerror.c
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: strerror.c,v 1.1 2020/02/07 09:58:54 florian Exp $ */
+
+/*! \file */
+
+
+
+#include <stdio.h>
+#include <string.h>
+
+#include <isc/strerror.h>
+#include <isc/util.h>
+
+void
+isc__strerror(int num, char *buf, size_t size) {
+	char *msg;
+	unsigned int unum = (unsigned int)num;
+
+	REQUIRE(buf != NULL);
+
+	msg = strerror(num);
+	if (msg != NULL)
+		snprintf(buf, size, "%s", msg);
+	else
+		snprintf(buf, size, "Unknown error: %u", unum);
+}
diff --git a/usr.bin/dig/lib/isc/unix/time.c b/usr.bin/dig/lib/isc/unix/time.c
new file mode 100644
index 00000000000..85ca1977243
--- /dev/null
+++ b/usr.bin/dig/lib/isc/unix/time.c
@@ -0,0 +1,435 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: time.c,v 1.1 2020/02/07 09:58:54 florian Exp $ */
+
+/*! \file */
+
+
+
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <syslog.h>
+#include <time.h>
+
+#include <sys/time.h>	/* Required for struct timeval on some platforms. */
+
+#include <isc/log.h>
+
+
+#include <isc/strerror.h>
+#include <string.h>
+#include <isc/time.h>
+
+#include <isc/util.h>
+
+#define NS_PER_S	1000000000	/*%< Nanoseconds per second. */
+#define NS_PER_US	1000		/*%< Nanoseconds per microsecond. */
+#define US_PER_S	1000000		/*%< Microseconds per second. */
+
+/*
+ * All of the INSIST()s checks of nanoseconds < NS_PER_S are for
+ * consistency checking of the type. In lieu of magic numbers, it
+ * is the best we've got.  The check is only performed on functions which
+ * need an initialized type.
+ */
+
+#ifndef ISC_FIX_TV_USEC
+#define ISC_FIX_TV_USEC 1
+#endif
+
+/*%
+ *** Intervals
+ ***/
+
+static const interval_t zero_interval = { 0, 0 };
+const interval_t * const interval_zero = &zero_interval;
+
+#if ISC_FIX_TV_USEC
+static inline void
+fix_tv_usec(struct timeval *tv) {
+	isc_boolean_t fixed = ISC_FALSE;
+
+	if (tv->tv_usec < 0) {
+		fixed = ISC_TRUE;
+		do {
+			tv->tv_sec -= 1;
+			tv->tv_usec += US_PER_S;
+		} while (tv->tv_usec < 0);
+	} else if (tv->tv_usec >= US_PER_S) {
+		fixed = ISC_TRUE;
+		do {
+			tv->tv_sec += 1;
+			tv->tv_usec -= US_PER_S;
+		} while (tv->tv_usec >=US_PER_S);
+	}
+	/*
+	 * Call syslog directly as was are called from the logging functions.
+	 */
+	if (fixed)
+		(void)syslog(LOG_ERR, "gettimeofday returned bad tv_usec: corrected");
+}
+#endif
+
+void
+interval_set(interval_t *i,
+		 unsigned int seconds, unsigned int nanoseconds)
+{
+	REQUIRE(i != NULL);
+	REQUIRE(nanoseconds < NS_PER_S);
+
+	i->seconds = seconds;
+	i->nanoseconds = nanoseconds;
+}
+
+isc_boolean_t
+interval_iszero(const interval_t *i) {
+	REQUIRE(i != NULL);
+	INSIST(i->nanoseconds < NS_PER_S);
+
+	if (i->seconds == 0 && i->nanoseconds == 0)
+		return (ISC_TRUE);
+
+	return (ISC_FALSE);
+}
+
+
+/***
+ *** Absolute Times
+ ***/
+
+static const isc_time_t epoch = { 0, 0 };
+const isc_time_t * const isc_time_epoch = &epoch;
+
+void
+isc_time_set(isc_time_t *t, unsigned int seconds, unsigned int nanoseconds) {
+	REQUIRE(t != NULL);
+	REQUIRE(nanoseconds < NS_PER_S);
+
+	t->seconds = seconds;
+	t->nanoseconds = nanoseconds;
+}
+
+void
+isc_time_settoepoch(isc_time_t *t) {
+	REQUIRE(t != NULL);
+
+	t->seconds = 0;
+	t->nanoseconds = 0;
+}
+
+isc_boolean_t
+isc_time_isepoch(const isc_time_t *t) {
+	REQUIRE(t != NULL);
+	INSIST(t->nanoseconds < NS_PER_S);
+
+	if (t->seconds == 0 && t->nanoseconds == 0)
+		return (ISC_TRUE);
+
+	return (ISC_FALSE);
+}
+
+
+isc_result_t
+isc_time_now(isc_time_t *t) {
+	struct timeval tv;
+	char strbuf[ISC_STRERRORSIZE];
+
+	REQUIRE(t != NULL);
+
+	if (gettimeofday(&tv, NULL) == -1) {
+		isc__strerror(errno, strbuf, sizeof(strbuf));
+		UNEXPECTED_ERROR(__FILE__, __LINE__, "%s", strbuf);
+		return (ISC_R_UNEXPECTED);
+	}
+
+	/*
+	 * Does POSIX guarantee the signedness of tv_sec and tv_usec?  If not,
+	 * then this test will generate warnings for platforms on which it is
+	 * unsigned.  In any event, the chances of any of these problems
+	 * happening are pretty much zero, but since the libisc library ensures
+	 * certain things to be true ...
+	 */
+#if ISC_FIX_TV_USEC
+	fix_tv_usec(&tv);
+	if (tv.tv_sec < 0)
+		return (ISC_R_UNEXPECTED);
+#else
+	if (tv.tv_sec < 0 || tv.tv_usec < 0 || tv.tv_usec >= US_PER_S)
+		return (ISC_R_UNEXPECTED);
+#endif
+
+	/*
+	 * Ensure the tv_sec value fits in t->seconds.
+	 */
+	if (sizeof(tv.tv_sec) > sizeof(t->seconds) &&
+	    ((tv.tv_sec | (unsigned int)-1) ^ (unsigned int)-1) != 0U)
+		return (ISC_R_RANGE);
+
+	t->seconds = tv.tv_sec;
+	t->nanoseconds = tv.tv_usec * NS_PER_US;
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_time_nowplusinterval(isc_time_t *t, const interval_t *i) {
+	struct timeval tv;
+	char strbuf[ISC_STRERRORSIZE];
+
+	REQUIRE(t != NULL);
+	REQUIRE(i != NULL);
+	INSIST(i->nanoseconds < NS_PER_S);
+
+	if (gettimeofday(&tv, NULL) == -1) {
+		isc__strerror(errno, strbuf, sizeof(strbuf));
+		UNEXPECTED_ERROR(__FILE__, __LINE__, "%s", strbuf);
+		return (ISC_R_UNEXPECTED);
+	}
+
+	/*
+	 * Does POSIX guarantee the signedness of tv_sec and tv_usec?  If not,
+	 * then this test will generate warnings for platforms on which it is
+	 * unsigned.  In any event, the chances of any of these problems
+	 * happening are pretty much zero, but since the libisc library ensures
+	 * certain things to be true ...
+	 */
+#if ISC_FIX_TV_USEC
+	fix_tv_usec(&tv);
+	if (tv.tv_sec < 0)
+		return (ISC_R_UNEXPECTED);
+#else
+	if (tv.tv_sec < 0 || tv.tv_usec < 0 || tv.tv_usec >= US_PER_S)
+		return (ISC_R_UNEXPECTED);
+#endif
+
+	/*
+	 * Ensure the resulting seconds value fits in the size of an
+	 * unsigned int.  (It is written this way as a slight optimization;
+	 * note that even if both values == INT_MAX, then when added
+	 * and getting another 1 added below the result is UINT_MAX.)
+	 */
+	if ((tv.tv_sec > INT_MAX || i->seconds > INT_MAX) &&
+	    ((long long)tv.tv_sec + i->seconds > UINT_MAX))
+		return (ISC_R_RANGE);
+
+	t->seconds = tv.tv_sec + i->seconds;
+	t->nanoseconds = tv.tv_usec * NS_PER_US + i->nanoseconds;
+	if (t->nanoseconds >= NS_PER_S) {
+		t->seconds++;
+		t->nanoseconds -= NS_PER_S;
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+int
+isc_time_compare(const isc_time_t *t1, const isc_time_t *t2) {
+	REQUIRE(t1 != NULL && t2 != NULL);
+	INSIST(t1->nanoseconds < NS_PER_S && t2->nanoseconds < NS_PER_S);
+
+	if (t1->seconds < t2->seconds)
+		return (-1);
+	if (t1->seconds > t2->seconds)
+		return (1);
+	if (t1->nanoseconds < t2->nanoseconds)
+		return (-1);
+	if (t1->nanoseconds > t2->nanoseconds)
+		return (1);
+	return (0);
+}
+
+isc_result_t
+isc_time_add(const isc_time_t *t, const interval_t *i, isc_time_t *result)
+{
+	REQUIRE(t != NULL && i != NULL && result != NULL);
+	INSIST(t->nanoseconds < NS_PER_S && i->nanoseconds < NS_PER_S);
+
+	/*
+	 * Ensure the resulting seconds value fits in the size of an
+	 * unsigned int.  (It is written this way as a slight optimization;
+	 * note that even if both values == INT_MAX, then when added
+	 * and getting another 1 added below the result is UINT_MAX.)
+	 */
+	if ((t->seconds > INT_MAX || i->seconds > INT_MAX) &&
+	    ((long long)t->seconds + i->seconds > UINT_MAX))
+		return (ISC_R_RANGE);
+
+	result->seconds = t->seconds + i->seconds;
+	result->nanoseconds = t->nanoseconds + i->nanoseconds;
+	if (result->nanoseconds >= NS_PER_S) {
+		result->seconds++;
+		result->nanoseconds -= NS_PER_S;
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_time_subtract(const isc_time_t *t, const interval_t *i,
+		  isc_time_t *result)
+{
+	REQUIRE(t != NULL && i != NULL && result != NULL);
+	INSIST(t->nanoseconds < NS_PER_S && i->nanoseconds < NS_PER_S);
+
+	if ((unsigned int)t->seconds < i->seconds ||
+	    ((unsigned int)t->seconds == i->seconds &&
+	     t->nanoseconds < i->nanoseconds))
+	    return (ISC_R_RANGE);
+
+	result->seconds = t->seconds - i->seconds;
+	if (t->nanoseconds >= i->nanoseconds)
+		result->nanoseconds = t->nanoseconds - i->nanoseconds;
+	else {
+		result->nanoseconds = NS_PER_S - i->nanoseconds +
+			t->nanoseconds;
+		result->seconds--;
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+uint64_t
+isc_time_microdiff(const isc_time_t *t1, const isc_time_t *t2) {
+	uint64_t i1, i2, i3;
+
+	REQUIRE(t1 != NULL && t2 != NULL);
+	INSIST(t1->nanoseconds < NS_PER_S && t2->nanoseconds < NS_PER_S);
+
+	i1 = (uint64_t)t1->seconds * NS_PER_S + t1->nanoseconds;
+	i2 = (uint64_t)t2->seconds * NS_PER_S + t2->nanoseconds;
+
+	if (i1 <= i2)
+		return (0);
+
+	i3 = i1 - i2;
+
+	/*
+	 * Convert to microseconds.
+	 */
+	i3 /= NS_PER_US;
+
+	return (i3);
+}
+
+uint32_t
+isc_time_seconds(const isc_time_t *t) {
+	REQUIRE(t != NULL);
+	INSIST(t->nanoseconds < NS_PER_S);
+
+	return ((uint32_t)t->seconds);
+}
+
+isc_result_t
+isc_time_secondsastimet(const isc_time_t *t, time_t *secondsp) {
+	time_t seconds;
+
+	REQUIRE(t != NULL);
+	INSIST(t->nanoseconds < NS_PER_S);
+
+	/*
+	 * Ensure that the number of seconds represented by t->seconds
+	 * can be represented by a time_t.  Since t->seconds is an unsigned
+	 * int and since time_t is mostly opaque, this is trickier than
+	 * it seems.  (This standardized opaqueness of time_t is *very*
+	 * frustrating; time_t is not even limited to being an integral
+	 * type.)
+	 *
+	 * The mission, then, is to avoid generating any kind of warning
+	 * about "signed versus unsigned" while trying to determine if the
+	 * the unsigned int t->seconds is out range for tv_sec, which is
+	 * pretty much only true if time_t is a signed integer of the same
+	 * size as the return value of isc_time_seconds.
+	 *
+	 * If the paradox in the if clause below is true, t->seconds is out
+	 * of range for time_t.
+	 */
+	seconds = (time_t)t->seconds;
+
+	INSIST(sizeof(unsigned int) == sizeof(uint32_t));
+	INSIST(sizeof(time_t) >= sizeof(uint32_t));
+
+	if (t->seconds > (~0U>>1) && seconds <= (time_t)(~0U>>1))
+		return (ISC_R_RANGE);
+
+	*secondsp = seconds;
+
+	return (ISC_R_SUCCESS);
+}
+
+uint32_t
+isc_time_nanoseconds(const isc_time_t *t) {
+	REQUIRE(t != NULL);
+
+	ENSURE(t->nanoseconds < NS_PER_S);
+
+	return ((uint32_t)t->nanoseconds);
+}
+
+void
+isc_time_formattimestamp(const isc_time_t *t, char *buf, unsigned int len) {
+	time_t now;
+	unsigned int flen;
+
+	REQUIRE(t != NULL);
+	INSIST(t->nanoseconds < NS_PER_S);
+	REQUIRE(buf != NULL);
+	REQUIRE(len > 0);
+
+	now = (time_t) t->seconds;
+	flen = strftime(buf, len, "%d-%b-%Y %X", localtime(&now));
+	INSIST(flen < len);
+	if (flen != 0) {
+		snprintf(buf + flen, len - flen,
+			 ".%03u", t->nanoseconds / 1000000);
+	} else {
+		strlcpy(buf, "99-Bad-9999 99:99:99.999", len);
+	}
+}
+
+void
+isc_time_formathttptimestamp(const isc_time_t *t, char *buf, unsigned int len) {
+	time_t now;
+	unsigned int flen;
+
+	REQUIRE(t != NULL);
+	INSIST(t->nanoseconds < NS_PER_S);
+	REQUIRE(buf != NULL);
+	REQUIRE(len > 0);
+
+	/*
+	 * 5 spaces, 1 comma, 3 GMT, 2 %d, 4 %Y, 8 %H:%M:%S, 3+ %a, 3+ %b (29+)
+	 */
+	now = (time_t)t->seconds;
+	flen = strftime(buf, len, "%a, %d %b %Y %H:%M:%S GMT", gmtime(&now));
+	INSIST(flen < len);
+}
+
+void
+isc_time_formatISO8601(const isc_time_t *t, char *buf, unsigned int len) {
+	time_t now;
+	unsigned int flen;
+
+	REQUIRE(t != NULL);
+	INSIST(t->nanoseconds < NS_PER_S);
+	REQUIRE(buf != NULL);
+	REQUIRE(len > 0);
+
+	now = (time_t)t->seconds;
+	flen = strftime(buf, len, "%Y-%m-%dT%H:%M:%SZ", gmtime(&now));
+	INSIST(flen < len);
+}