diff --git a/MANIFEST b/MANIFEST
index 742f86647..2248ad338 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -147,6 +147,7 @@ include/gettext.h
 include/lbuf.h
 include/list.h
 include/missing.h
+include/queue.h
 include/secure_path.h
 include/sudo_conf.h
 include/sudo_debug.h
diff --git a/common/Makefile.in b/common/Makefile.in
index 5d58dce45..f9e33b41c 100644
--- a/common/Makefile.in
+++ b/common/Makefile.in
@@ -170,22 +170,22 @@ atoid.lo: $(srcdir)/atoid.c $(top_builddir)/config.h \
 	$(LIBTOOL) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/atoid.c
 conf_test.lo: $(srcdir)/regress/sudo_conf/conf_test.c $(top_builddir)/config.h \
               $(top_srcdir)/compat/stdbool.h $(incdir)/missing.h \
-              $(incdir)/sudo_conf.h $(incdir)/list.h
+              $(incdir)/sudo_conf.h $(incdir)/queue.h
 	$(LIBTOOL) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/regress/sudo_conf/conf_test.c
 event.lo: $(srcdir)/event.c $(top_builddir)/config.h \
           $(top_srcdir)/compat/stdbool.h $(incdir)/missing.h $(incdir)/alloc.h \
-          $(incdir)/fatal.h $(incdir)/list.h $(incdir)/sudo_debug.h \
-          $(incdir)/sudo_event.h
+          $(incdir)/fatal.h $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+          $(incdir)/queue.h
 	$(LIBTOOL) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/event.c
 event_poll.lo: $(srcdir)/event_poll.c $(top_builddir)/config.h \
                $(top_srcdir)/compat/stdbool.h $(incdir)/missing.h \
-               $(incdir)/alloc.h $(incdir)/fatal.h $(incdir)/list.h \
-               $(incdir)/sudo_debug.h $(incdir)/sudo_event.h
+               $(incdir)/alloc.h $(incdir)/fatal.h $(incdir)/sudo_debug.h \
+               $(incdir)/sudo_event.h $(incdir)/queue.h
 	$(LIBTOOL) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/event_poll.c
 event_select.lo: $(srcdir)/event_select.c $(top_builddir)/config.h \
                  $(top_srcdir)/compat/stdbool.h $(incdir)/missing.h \
-                 $(incdir)/alloc.h $(incdir)/fatal.h $(incdir)/list.h \
-                 $(incdir)/sudo_debug.h $(incdir)/sudo_event.h
+                 $(incdir)/alloc.h $(incdir)/fatal.h $(incdir)/sudo_debug.h \
+                 $(incdir)/sudo_event.h $(incdir)/queue.h
 	$(LIBTOOL) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/event_select.c
 fatal.lo: $(srcdir)/fatal.c $(top_builddir)/config.h \
           $(top_srcdir)/compat/stdbool.h $(incdir)/missing.h $(incdir)/alloc.h \
@@ -224,7 +224,7 @@ sudo_conf.lo: $(srcdir)/sudo_conf.c $(top_builddir)/config.h \
               $(top_srcdir)/compat/stdbool.h $(incdir)/missing.h \
               $(incdir)/alloc.h $(incdir)/fatal.h $(incdir)/fileops.h \
               $(top_builddir)/pathnames.h $(incdir)/sudo_plugin.h \
-              $(incdir)/sudo_conf.h $(incdir)/list.h $(incdir)/sudo_debug.h \
+              $(incdir)/sudo_conf.h $(incdir)/queue.h $(incdir)/sudo_debug.h \
               $(incdir)/secure_path.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/sudo_conf.c
 sudo_debug.lo: $(srcdir)/sudo_debug.c $(top_builddir)/config.h \
diff --git a/common/event.c b/common/event.c
index 5067bd41d..4c6ad02c1 100644
--- a/common/event.c
+++ b/common/event.c
@@ -45,7 +45,6 @@
 #include "missing.h"
 #include "alloc.h"
 #include "fatal.h"
-#include "list.h"
 #include "sudo_debug.h"
 #include "sudo_event.h"
 
@@ -58,6 +57,7 @@ sudo_ev_base_alloc(void)
     debug_decl(sudo_ev_base_alloc, SUDO_DEBUG_EVENT)
 
     base = ecalloc(1, sizeof(*base));
+    TAILQ_INIT(&base->events);
     if (sudo_ev_base_alloc_impl(base) != 0) {
 	efree(base);
 	base = NULL;
@@ -110,9 +110,9 @@ sudo_ev_add(struct sudo_event_base *base, struct sudo_event *ev, bool tohead)
 	    debug_return_int(-1);
 	ev->base = base;
 	if (tohead) {
-	    tq_insert_head(base, ev);
+	    TAILQ_INSERT_HEAD(&base->events, ev, entries);
 	} else {
-	    tq_insert_tail(base, ev);
+	    TAILQ_INSERT_TAIL(&base->events, ev, entries);
 	}
     }
     /* Clear pending delete so adding from callback works properly. */
@@ -149,17 +149,15 @@ sudo_ev_del(struct sudo_event_base *base, struct sudo_event *ev)
 	debug_return_int(-1);
 
     /* Unlink from list. */
-    tq_remove(base, ev);
+    TAILQ_REMOVE(&base->events, ev, entries);
 
     /* If we removed the pending event, replace it with the next one. */
     if (base->pending == ev)
-	base->pending = ev->next;
+	base->pending = TAILQ_NEXT(ev, entries);
 
     /* Mark event unused. */
     ev->pfd_idx = -1;
     ev->base = NULL;
-    ev->prev = NULL;
-    ev->next = NULL;
 
     debug_return_int(0);
 }
diff --git a/common/event_poll.c b/common/event_poll.c
index 19993fef2..4f153b5a0 100644
--- a/common/event_poll.c
+++ b/common/event_poll.c
@@ -46,7 +46,6 @@
 #include "missing.h"
 #include "alloc.h"
 #include "fatal.h"
-#include "list.h"
 #include "sudo_debug.h"
 #include "sudo_event.h"
 
@@ -154,8 +153,7 @@ rescan:
 	    break;
 	default:
 	    /* Service each event that fired. */
-	    for (ev = tq_first(base); ev != NULL; ev = base->pending) {
-		base->pending = list_next(ev);
+	    TAILQ_FOREACH_SAFE(ev, &base->events, entries, base->pending) {
 		if (ev->pfd_idx != -1 && base->pfds[ev->pfd_idx].revents) {
 		    int what = 0;
 		    if (base->pfds[ev->pfd_idx].revents & (POLLIN|POLLHUP|POLLNVAL|POLLERR))
diff --git a/common/event_select.c b/common/event_select.c
index 23e9e6a96..c7e7a3980 100644
--- a/common/event_select.c
+++ b/common/event_select.c
@@ -51,7 +51,6 @@
 #include "missing.h"
 #include "alloc.h"
 #include "fatal.h"
-#include "list.h"
 #include "sudo_debug.h"
 #include "sudo_event.h"
 
@@ -133,7 +132,7 @@ rescan:
 	/* For select we need to redo readfds and writefds each time. */
 	memset(base->readfds, 0, howmany(base->maxfd + 1, NFDBITS) * sizeof(fd_mask));
 	memset(base->writefds, 0, howmany(base->maxfd + 1, NFDBITS) * sizeof(fd_mask));
-	tq_foreach_fwd(base, ev) {
+	TAILQ_FOREACH(ev, &base->events, entries) {
 	    if (ISSET(ev->events, SUDO_EV_READ)) {
 		sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: added fd %d to readfs",
 		    __func__, ev->fd);
@@ -164,7 +163,7 @@ rescan:
 	    break;
 	default:
 	    /* Service each event that fired. */
-	    for (ev = tq_first(base); ev != NULL; ev = base->pending) {
+	    TAILQ_FOREACH_SAFE(ev, &base->events, entries, base->pending) {
 		int what = 0;
 		base->pending = list_next(ev);
 		if (FD_ISSET(ev->fd, base->readfds))
diff --git a/common/list.c b/common/list.c
index 86aeffeb4..dce6489ab 100644
--- a/common/list.c
+++ b/common/list.c
@@ -129,42 +129,6 @@ tq_append(void *vh, void *vl)
     h->last = tail;
 }
 
-/*
- * Insert a single item at the head of the queue.
- */
-void
-tq_insert_head(void *vh, void *vl)
-{
-    struct list_head_proto *h = (struct list_head_proto *)vh;
-    struct list_proto *l = (struct list_proto *)vl;
-
-    l->prev = NULL;
-    l->next = h->first;
-    if (tq_empty(h))
-	h->last = l;
-    else
-	h->first->prev = l;
-    h->first = l;
-}
-
-/*
- * Insert a single item at the tail of the queue.
- */
-void
-tq_insert_tail(void *vh, void *vl)
-{
-    struct list_head_proto *h = (struct list_head_proto *)vh;
-    struct list_proto *l = (struct list_proto *)vl;
-
-    l->prev = h->last;
-    l->next = NULL;
-    if (tq_empty(h))
-	h->first = l;
-    else
-	h->last->next = l;
-    h->last = l;
-}
-
 /*
  * Remove element from the tail_queue
  */
@@ -182,7 +146,7 @@ tq_remove(void *vh, void *vl)
 	/* At least two elements in the list. */
 	if (h->first == l) {
 	    h->first = l->next;
-	    h->first->prev = h->first; /* XXX - do we rely on this behavior? */
+	    h->first->prev = h->first;
 	} else if (h->last == l) {
 	    h->last = l->prev;
 	    h->last->next = NULL;
diff --git a/common/regress/sudo_conf/conf_test.c b/common/regress/sudo_conf/conf_test.c
index 8f1fbf318..63852e84b 100644
--- a/common/regress/sudo_conf/conf_test.c
+++ b/common/regress/sudo_conf/conf_test.c
@@ -86,7 +86,7 @@ sudo_conf_dump(void)
     if (sudo_conf_noexec_path() != NULL)
 	printf("Path noexec %s\n", sudo_conf_noexec_path());
 #endif
-    tq_foreach_fwd(plugins, info) {
+    TAILQ_FOREACH(info, plugins, entries) {
 	printf("Plugin %s %s", info->symbol_name, info->path);
 	if (info->options) {
 	    char * const * op;
diff --git a/common/sudo_conf.c b/common/sudo_conf.c
index ce7131f5f..b415f0deb 100644
--- a/common/sudo_conf.c
+++ b/common/sudo_conf.c
@@ -110,13 +110,14 @@ static struct sudo_conf_data {
     int group_source;
     int max_groups;
     const char *debug_flags;
-    struct sudo_conf_paths paths[5];
     struct plugin_info_list plugins;
+    struct sudo_conf_paths paths[5];
 } sudo_conf_data = {
     true,
     GROUP_SOURCE_ADAPTIVE,
     -1,
     NULL,
+    TAILQ_HEAD_INITIALIZER(sudo_conf_data.plugins),
     {
 #define SUDO_CONF_ASKPASS_IDX	0
 	{ "askpass", sizeof("askpass") - 1, _PATH_SUDO_ASKPASS },
@@ -302,10 +303,8 @@ set_plugin(const char *entry, const char *conf_file)
     info->symbol_name = estrndup(name, namelen);
     info->path = estrndup(path, pathlen);
     info->options = options;
-    info->prev = info;
-    /* info->next = NULL; */
     info->lineno = conf_lineno;
-    tq_append(&sudo_conf_data.plugins, info);
+    TAILQ_INSERT_TAIL(&sudo_conf_data.plugins, info, entries);
 }
 
 const char *
diff --git a/doc/LICENSE b/doc/LICENSE
index 6bb71c8f3..fe9df7920 100644
--- a/doc/LICENSE
+++ b/doc/LICENSE
@@ -41,7 +41,8 @@ The file redblack.c bears the following license:
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-The files getcwd.c, glob.c, glob.h and snprintf.c bear the following license:
+The files getcwd.c, glob.c, glob.h, snprintf.c and queue.h bear the
+following license:
 
    Copyright (c) 1989, 1990, 1991, 1993
         The Regents of the University of California.  All rights reserved.
diff --git a/include/list.h b/include/list.h
index 30072501a..1055e227a 100644
--- a/include/list.h
+++ b/include/list.h
@@ -69,8 +69,6 @@ struct n##_list {					\
  */
 void *tq_pop(void *);
 void tq_append(void *, void *);
-void tq_insert_head(void *, void *);
-void tq_insert_tail(void *, void *);
 void tq_remove(void *, void *);
 void list_append(void *, void *);
 void list2tq(void *, void *);
diff --git a/include/missing.h b/include/missing.h
index b0bcc6b05..5421025b7 100644
--- a/include/missing.h
+++ b/include/missing.h
@@ -73,6 +73,14 @@
 # endif
 #endif
 
+/*
+ * Given the pointer x to the member m of the struct s, return
+ * a pointer to the containing structure.
+ */
+#ifndef __containerof
+# define __containerof(x, s, m)	((s *)((char *)(x) - offsetof(s, m)))
+#endif
+
 #ifndef __dso_public
 # ifdef HAVE_DSO_VISIBILITY
 #  if defined(__GNUC__)
diff --git a/include/queue.h b/include/queue.h
new file mode 100644
index 000000000..de4ef162a
--- /dev/null
+++ b/include/queue.h
@@ -0,0 +1,715 @@
+/*
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)queue.h	8.5 (Berkeley) 8/20/94
+ * $FreeBSD: head/sys/sys/queue.h 251887 2013-06-18 02:57:56Z lstewart $
+ */
+
+#ifndef _SUDO_QUEUE_H_
+#define	_SUDO_QUEUE_H_
+
+/*
+ * This file defines four types of data structures: singly-linked lists,
+ * singly-linked tail queues, lists and tail queues.
+ *
+ * A singly-linked list is headed by a single forward pointer. The elements
+ * are singly linked for minimum space and pointer manipulation overhead at
+ * the expense of O(n) removal for arbitrary elements. New elements can be
+ * added to the list after an existing element or at the head of the list.
+ * Elements being removed from the head of the list should use the explicit
+ * macro for this purpose for optimum efficiency. A singly-linked list may
+ * only be traversed in the forward direction.  Singly-linked lists are ideal
+ * for applications with large datasets and few or no removals or for
+ * implementing a LIFO queue.
+ *
+ * A singly-linked tail queue is headed by a pair of pointers, one to the
+ * head of the list and the other to the tail of the list. The elements are
+ * singly linked for minimum space and pointer manipulation overhead at the
+ * expense of O(n) removal for arbitrary elements. New elements can be added
+ * to the list after an existing element, at the head of the list, or at the
+ * end of the list. Elements being removed from the head of the tail queue
+ * should use the explicit macro for this purpose for optimum efficiency.
+ * A singly-linked tail queue may only be traversed in the forward direction.
+ * Singly-linked tail queues are ideal for applications with large datasets
+ * and few or no removals or for implementing a FIFO queue.
+ *
+ * A list is headed by a single forward pointer (or an array of forward
+ * pointers for a hash table header). The elements are doubly linked
+ * so that an arbitrary element can be removed without a need to
+ * traverse the list. New elements can be added to the list before
+ * or after an existing element or at the head of the list. A list
+ * may be traversed in either direction.
+ *
+ * A tail queue is headed by a pair of pointers, one to the head of the
+ * list and the other to the tail of the list. The elements are doubly
+ * linked so that an arbitrary element can be removed without a need to
+ * traverse the list. New elements can be added to the list before or
+ * after an existing element, at the head of the list, or at the end of
+ * the list. A tail queue may be traversed in either direction.
+ *
+ * For details on the use of these macros, see the queue(3) manual page.
+ *
+ *
+ *				SLIST	LIST	STAILQ	TAILQ
+ * _HEAD			+	+	+	+
+ * _HEAD_INITIALIZER		+	+	+	+
+ * _ENTRY			+	+	+	+
+ * _INIT			+	+	+	+
+ * _EMPTY			+	+	+	+
+ * _FIRST			+	+	+	+
+ * _NEXT			+	+	+	+
+ * _PREV			-	+	-	+
+ * _LAST			-	-	+	+
+ * _FOREACH			+	+	+	+
+ * _FOREACH_FROM		+	+	+	+
+ * _FOREACH_SAFE		+	+	+	+
+ * _FOREACH_FROM_SAFE		+	+	+	+
+ * _FOREACH_REVERSE		-	-	-	+
+ * _FOREACH_REVERSE_FROM	-	-	-	+
+ * _FOREACH_REVERSE_SAFE	-	-	-	+
+ * _FOREACH_REVERSE_FROM_SAFE	-	-	-	+
+ * _INSERT_HEAD			+	+	+	+
+ * _INSERT_BEFORE		-	+	-	+
+ * _INSERT_AFTER		+	+	+	+
+ * _INSERT_TAIL			-	-	+	+
+ * _CONCAT			-	-	+	+
+ * _REMOVE_AFTER		+	-	+	-
+ * _REMOVE_HEAD			+	-	+	-
+ * _REMOVE			+	+	+	+
+ * _SWAP			+	+	+	+
+ *
+ */
+#ifdef QUEUE_MACRO_DEBUG
+/* Store the last 2 places the queue element or head was altered */
+struct qm_trace {
+	unsigned long	 lastline;
+	unsigned long	 prevline;
+	const char	*lastfile;
+	const char	*prevfile;
+};
+
+#undef TRACEBUF
+#define	TRACEBUF	struct qm_trace trace;
+#undef TRACEBUF_INITIALIZER
+#define	TRACEBUF_INITIALIZER	{ __FILE__, __LINE__, NULL, 0 } ,
+#undef TRASHIT
+#define	TRASHIT(x)	do {(x) = (void *)-1;} while (0)
+#undef QMD_SAVELINK
+#define	QMD_SAVELINK(name, link)	void **name = (void *)&(link)
+
+#undef QMD_TRACE_HEAD
+#define	QMD_TRACE_HEAD(head) do {					\
+	(head)->trace.prevline = (head)->trace.lastline;		\
+	(head)->trace.prevfile = (head)->trace.lastfile;		\
+	(head)->trace.lastline = __LINE__;				\
+	(head)->trace.lastfile = __FILE__;				\
+} while (0)
+
+#undef QMD_TRACE_ELEM
+#define	QMD_TRACE_ELEM(elem) do {					\
+	(elem)->trace.prevline = (elem)->trace.lastline;		\
+	(elem)->trace.prevfile = (elem)->trace.lastfile;		\
+	(elem)->trace.lastline = __LINE__;				\
+	(elem)->trace.lastfile = __FILE__;				\
+} while (0)
+
+#else
+#undef QMD_TRACE_ELEM
+#define	QMD_TRACE_ELEM(elem)
+#undef QMD_TRACE_HEAD
+#define	QMD_TRACE_HEAD(head)
+#undef QMD_SAVELINK
+#define	QMD_SAVELINK(name, link)
+#undef TRACEBUF
+#define	TRACEBUF
+#undef TRACEBUF_INITIALIZER
+#define	TRACEBUF_INITIALIZER
+#undef TRASHIT
+#define	TRASHIT(x)
+#endif	/* QUEUE_MACRO_DEBUG */
+
+/*
+ * Singly-linked List declarations.
+ */
+#undef SLIST_HEAD
+#define	SLIST_HEAD(name, type)						\
+struct name {								\
+	struct type *slh_first;	/* first element */			\
+}
+
+#undef SLIST_HEAD_INITIALIZER
+#define	SLIST_HEAD_INITIALIZER(head)					\
+	{ NULL }
+
+#undef SLIST_ENTRY
+#define	SLIST_ENTRY(type)						\
+struct {								\
+	struct type *sle_next;	/* next element */			\
+}
+
+/*
+ * Singly-linked List functions.
+ */
+#undef SLIST_EMPTY
+#define	SLIST_EMPTY(head)	((head)->slh_first == NULL)
+
+#undef SLIST_FIRST
+#define	SLIST_FIRST(head)	((head)->slh_first)
+
+#undef SLIST_FOREACH
+#define	SLIST_FOREACH(var, head, field)					\
+	for ((var) = SLIST_FIRST((head));				\
+	    (var);							\
+	    (var) = SLIST_NEXT((var), field))
+
+#undef SLIST_FOREACH_FROM
+#define	SLIST_FOREACH_FROM(var, head, field)				\
+	for ((var) = ((var) ? (var) : SLIST_FIRST((head)));		\
+	    (var);							\
+	    (var) = SLIST_NEXT((var), field))
+
+#undef SLIST_FOREACH_SAFE
+#define	SLIST_FOREACH_SAFE(var, head, field, tvar)			\
+	for ((var) = SLIST_FIRST((head));				\
+	    (var) && ((tvar) = SLIST_NEXT((var), field), 1);		\
+	    (var) = (tvar))
+
+#undef SLIST_FOREACH_FROM_SAFE
+#define	SLIST_FOREACH_FROM_SAFE(var, head, field, tvar)			\
+	for ((var) = ((var) ? (var) : SLIST_FIRST((head)));		\
+	    (var) && ((tvar) = SLIST_NEXT((var), field), 1);		\
+	    (var) = (tvar))
+
+#undef SLIST_FOREACH_PREVPTR
+#define	SLIST_FOREACH_PREVPTR(var, varp, head, field)			\
+	for ((varp) = &SLIST_FIRST((head));				\
+	    ((var) = *(varp)) != NULL;					\
+	    (varp) = &SLIST_NEXT((var), field))
+
+#undef SLIST_INIT
+#define	SLIST_INIT(head) do {						\
+	SLIST_FIRST((head)) = NULL;					\
+} while (0)
+
+#undef SLIST_INSERT_AFTER
+#define	SLIST_INSERT_AFTER(slistelm, elm, field) do {			\
+	SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field);	\
+	SLIST_NEXT((slistelm), field) = (elm);				\
+} while (0)
+
+#undef SLIST_INSERT_HEAD
+#define	SLIST_INSERT_HEAD(head, elm, field) do {			\
+	SLIST_NEXT((elm), field) = SLIST_FIRST((head));			\
+	SLIST_FIRST((head)) = (elm);					\
+} while (0)
+
+#undef SLIST_NEXT
+#define	SLIST_NEXT(elm, field)	((elm)->field.sle_next)
+
+#undef SLIST_REMOVE
+#define	SLIST_REMOVE(head, elm, type, field) do {			\
+	QMD_SAVELINK(oldnext, (elm)->field.sle_next);			\
+	if (SLIST_FIRST((head)) == (elm)) {				\
+		SLIST_REMOVE_HEAD((head), field);			\
+	}								\
+	else {								\
+		struct type *curelm = SLIST_FIRST((head));		\
+		while (SLIST_NEXT(curelm, field) != (elm))		\
+			curelm = SLIST_NEXT(curelm, field);		\
+		SLIST_REMOVE_AFTER(curelm, field);			\
+	}								\
+	TRASHIT(*oldnext);						\
+} while (0)
+
+#undef SLIST_REMOVE_AFTER
+#define SLIST_REMOVE_AFTER(elm, field) do {				\
+	SLIST_NEXT(elm, field) =					\
+	    SLIST_NEXT(SLIST_NEXT(elm, field), field);			\
+} while (0)
+
+#undef SLIST_REMOVE_HEAD
+#define	SLIST_REMOVE_HEAD(head, field) do {				\
+	SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field);	\
+} while (0)
+
+#undef SLIST_SWAP
+#define SLIST_SWAP(head1, head2, type) do {				\
+	struct type *swap_first = SLIST_FIRST(head1);			\
+	SLIST_FIRST(head1) = SLIST_FIRST(head2);			\
+	SLIST_FIRST(head2) = swap_first;				\
+} while (0)
+
+/*
+ * Singly-linked Tail queue declarations.
+ */
+#undef STAILQ_HEAD
+#define	STAILQ_HEAD(name, type)						\
+struct name {								\
+	struct type *stqh_first;/* first element */			\
+	struct type **stqh_last;/* addr of last next element */		\
+}
+
+#undef STAILQ_HEAD_INITIALIZER
+#define	STAILQ_HEAD_INITIALIZER(head)					\
+	{ NULL, &(head).stqh_first }
+
+#undef STAILQ_ENTRY
+#define	STAILQ_ENTRY(type)						\
+struct {								\
+	struct type *stqe_next;	/* next element */			\
+}
+
+/*
+ * Singly-linked Tail queue functions.
+ */
+#undef STAILQ_CONCAT
+#define	STAILQ_CONCAT(head1, head2) do {				\
+	if (!STAILQ_EMPTY((head2))) {					\
+		*(head1)->stqh_last = (head2)->stqh_first;		\
+		(head1)->stqh_last = (head2)->stqh_last;		\
+		STAILQ_INIT((head2));					\
+	}								\
+} while (0)
+
+#undef STAILQ_EMPTY
+#define	STAILQ_EMPTY(head)	((head)->stqh_first == NULL)
+
+#undef STAILQ_FIRST
+#define	STAILQ_FIRST(head)	((head)->stqh_first)
+
+#undef STAILQ_FOREACH
+#define	STAILQ_FOREACH(var, head, field)				\
+	for ((var) = STAILQ_FIRST((head));				\
+	   (var);							\
+	   (var) = STAILQ_NEXT((var), field))
+
+#undef STAILQ_FOREACH_FROM
+#define	STAILQ_FOREACH_FROM(var, head, field)				\
+	for ((var) = ((var) ? (var) : STAILQ_FIRST((head)));		\
+	   (var);							\
+	   (var) = STAILQ_NEXT((var), field))
+
+#undef STAILQ_FOREACH_SAFE
+#define	STAILQ_FOREACH_SAFE(var, head, field, tvar)			\
+	for ((var) = STAILQ_FIRST((head));				\
+	    (var) && ((tvar) = STAILQ_NEXT((var), field), 1);		\
+	    (var) = (tvar))
+
+#undef STAILQ_FOREACH_FROM_SAFE
+#define	STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar)		\
+	for ((var) = ((var) ? (var) : STAILQ_FIRST((head)));		\
+	    (var) && ((tvar) = STAILQ_NEXT((var), field), 1);		\
+	    (var) = (tvar))
+
+#undef STAILQ_INIT
+#define	STAILQ_INIT(head) do {						\
+	STAILQ_FIRST((head)) = NULL;					\
+	(head)->stqh_last = &STAILQ_FIRST((head));			\
+} while (0)
+
+#undef STAILQ_INSERT_AFTER
+#define	STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {		\
+	if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
+		(head)->stqh_last = &STAILQ_NEXT((elm), field);		\
+	STAILQ_NEXT((tqelm), field) = (elm);				\
+} while (0)
+
+#undef STAILQ_INSERT_HEAD
+#define	STAILQ_INSERT_HEAD(head, elm, field) do {			\
+	if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL)	\
+		(head)->stqh_last = &STAILQ_NEXT((elm), field);		\
+	STAILQ_FIRST((head)) = (elm);					\
+} while (0)
+
+#undef STAILQ_INSERT_TAIL
+#define	STAILQ_INSERT_TAIL(head, elm, field) do {			\
+	STAILQ_NEXT((elm), field) = NULL;				\
+	*(head)->stqh_last = (elm);					\
+	(head)->stqh_last = &STAILQ_NEXT((elm), field);			\
+} while (0)
+
+#undef STAILQ_LAST
+#define	STAILQ_LAST(head, type, field)					\
+	(STAILQ_EMPTY((head)) ? NULL :					\
+	    __containerof((head)->stqh_last, struct type, field.stqe_next))
+
+#undef STAILQ_NEXT
+#define	STAILQ_NEXT(elm, field)	((elm)->field.stqe_next)
+
+#undef STAILQ_REMOVE
+#define	STAILQ_REMOVE(head, elm, type, field) do {			\
+	QMD_SAVELINK(oldnext, (elm)->field.stqe_next);			\
+	if (STAILQ_FIRST((head)) == (elm)) {				\
+		STAILQ_REMOVE_HEAD((head), field);			\
+	}								\
+	else {								\
+		struct type *curelm = STAILQ_FIRST((head));		\
+		while (STAILQ_NEXT(curelm, field) != (elm))		\
+			curelm = STAILQ_NEXT(curelm, field);		\
+		STAILQ_REMOVE_AFTER(head, curelm, field);		\
+	}								\
+	TRASHIT(*oldnext);						\
+} while (0)
+
+#undef STAILQ_REMOVE_AFTER
+#define STAILQ_REMOVE_AFTER(head, elm, field) do {			\
+	if ((STAILQ_NEXT(elm, field) =					\
+	     STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL)	\
+		(head)->stqh_last = &STAILQ_NEXT((elm), field);		\
+} while (0)
+
+#undef STAILQ_REMOVE_HEAD
+#define	STAILQ_REMOVE_HEAD(head, field) do {				\
+	if ((STAILQ_FIRST((head)) =					\
+	     STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL)		\
+		(head)->stqh_last = &STAILQ_FIRST((head));		\
+} while (0)
+
+#undef STAILQ_SWAP
+#define STAILQ_SWAP(head1, head2, type) do {				\
+	struct type *swap_first = STAILQ_FIRST(head1);			\
+	struct type **swap_last = (head1)->stqh_last;			\
+	STAILQ_FIRST(head1) = STAILQ_FIRST(head2);			\
+	(head1)->stqh_last = (head2)->stqh_last;			\
+	STAILQ_FIRST(head2) = swap_first;				\
+	(head2)->stqh_last = swap_last;					\
+	if (STAILQ_EMPTY(head1))					\
+		(head1)->stqh_last = &STAILQ_FIRST(head1);		\
+	if (STAILQ_EMPTY(head2))					\
+		(head2)->stqh_last = &STAILQ_FIRST(head2);		\
+} while (0)
+
+
+/*
+ * List declarations.
+ */
+#undef LIST_HEAD
+#define	LIST_HEAD(name, type)						\
+struct name {								\
+	struct type *lh_first;	/* first element */			\
+}
+
+#undef LIST_HEAD_INITIALIZER
+#define	LIST_HEAD_INITIALIZER(head)					\
+	{ NULL }
+
+#undef LIST_ENTRY
+#define	LIST_ENTRY(type)						\
+struct {								\
+	struct type *le_next;	/* next element */			\
+	struct type **le_prev;	/* address of previous next element */	\
+}
+
+/*
+ * List functions.
+ */
+#undef LIST_EMPTY
+#define	LIST_EMPTY(head)	((head)->lh_first == NULL)
+
+#undef LIST_FIRST
+#define	LIST_FIRST(head)	((head)->lh_first)
+
+#undef LIST_FOREACH
+#define	LIST_FOREACH(var, head, field)					\
+	for ((var) = LIST_FIRST((head));				\
+	    (var);							\
+	    (var) = LIST_NEXT((var), field))
+
+#undef LIST_FOREACH_FROM
+#define	LIST_FOREACH_FROM(var, head, field)				\
+	for ((var) = ((var) ? (var) : LIST_FIRST((head)));		\
+	    (var);							\
+	    (var) = LIST_NEXT((var), field))
+
+#undef LIST_FOREACH_SAFE
+#define	LIST_FOREACH_SAFE(var, head, field, tvar)			\
+	for ((var) = LIST_FIRST((head));				\
+	    (var) && ((tvar) = LIST_NEXT((var), field), 1);		\
+	    (var) = (tvar))
+
+#undef LIST_FOREACH_FROM_SAFE
+#define	LIST_FOREACH_FROM_SAFE(var, head, field, tvar)			\
+	for ((var) = ((var) ? (var) : LIST_FIRST((head)));		\
+	    (var) && ((tvar) = LIST_NEXT((var), field), 1);		\
+	    (var) = (tvar))
+
+#undef LIST_INIT
+#define	LIST_INIT(head) do {						\
+	LIST_FIRST((head)) = NULL;					\
+} while (0)
+
+#undef LIST_INSERT_AFTER
+#define	LIST_INSERT_AFTER(listelm, elm, field) do {			\
+	if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
+		LIST_NEXT((listelm), field)->field.le_prev =		\
+		    &LIST_NEXT((elm), field);				\
+	LIST_NEXT((listelm), field) = (elm);				\
+	(elm)->field.le_prev = &LIST_NEXT((listelm), field);		\
+} while (0)
+
+#undef LIST_INSERT_BEFORE
+#define	LIST_INSERT_BEFORE(listelm, elm, field) do {			\
+	(elm)->field.le_prev = (listelm)->field.le_prev;		\
+	LIST_NEXT((elm), field) = (listelm);				\
+	*(listelm)->field.le_prev = (elm);				\
+	(listelm)->field.le_prev = &LIST_NEXT((elm), field);		\
+} while (0)
+
+#undef LIST_INSERT_HEAD
+#define	LIST_INSERT_HEAD(head, elm, field) do {				\
+	if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL)	\
+		LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
+	LIST_FIRST((head)) = (elm);					\
+	(elm)->field.le_prev = &LIST_FIRST((head));			\
+} while (0)
+
+#undef LIST_NEXT
+#define	LIST_NEXT(elm, field)	((elm)->field.le_next)
+
+#undef LIST_PREV
+#define	LIST_PREV(elm, head, type, field)				\
+	((elm)->field.le_prev == &LIST_FIRST((head)) ? NULL :		\
+	    __containerof((elm)->field.le_prev, struct type, field.le_next))
+
+#undef LIST_REMOVE
+#define	LIST_REMOVE(elm, field) do {					\
+	QMD_SAVELINK(oldnext, (elm)->field.le_next);			\
+	QMD_SAVELINK(oldprev, (elm)->field.le_prev);			\
+	if (LIST_NEXT((elm), field) != NULL)				\
+		LIST_NEXT((elm), field)->field.le_prev = 		\
+		    (elm)->field.le_prev;				\
+	*(elm)->field.le_prev = LIST_NEXT((elm), field);		\
+	TRASHIT(*oldnext);						\
+	TRASHIT(*oldprev);						\
+} while (0)
+
+#undef LIST_SWAP
+#define LIST_SWAP(head1, head2, type, field) do {			\
+	struct type *swap_tmp = LIST_FIRST((head1));			\
+	LIST_FIRST((head1)) = LIST_FIRST((head2));			\
+	LIST_FIRST((head2)) = swap_tmp;					\
+	if ((swap_tmp = LIST_FIRST((head1))) != NULL)			\
+		swap_tmp->field.le_prev = &LIST_FIRST((head1));		\
+	if ((swap_tmp = LIST_FIRST((head2))) != NULL)			\
+		swap_tmp->field.le_prev = &LIST_FIRST((head2));		\
+} while (0)
+
+/*
+ * Tail queue declarations.
+ */
+#undef TAILQ_HEAD
+#define	TAILQ_HEAD(name, type)						\
+struct name {								\
+	struct type *tqh_first;	/* first element */			\
+	struct type **tqh_last;	/* addr of last next element */		\
+	TRACEBUF							\
+}
+
+#undef TAILQ_HEAD_INITIALIZER
+#define	TAILQ_HEAD_INITIALIZER(head)					\
+	{ NULL, &(head).tqh_first, TRACEBUF_INITIALIZER }
+
+#undef TAILQ_ENTRY
+#define	TAILQ_ENTRY(type)						\
+struct {								\
+	struct type *tqe_next;	/* next element */			\
+	struct type **tqe_prev;	/* address of previous next element */	\
+	TRACEBUF							\
+}
+
+/*
+ * Tail queue functions.
+ */
+#undef TAILQ_CONCAT
+#define	TAILQ_CONCAT(head1, head2, field) do {				\
+	if (!TAILQ_EMPTY(head2)) {					\
+		*(head1)->tqh_last = (head2)->tqh_first;		\
+		(head2)->tqh_first->field.tqe_prev = (head1)->tqh_last;	\
+		(head1)->tqh_last = (head2)->tqh_last;			\
+		TAILQ_INIT((head2));					\
+		QMD_TRACE_HEAD(head1);					\
+		QMD_TRACE_HEAD(head2);					\
+	}								\
+} while (0)
+
+#undef TAILQ_EMPTY
+#define	TAILQ_EMPTY(head)	((head)->tqh_first == NULL)
+
+#undef TAILQ_FIRST
+#define	TAILQ_FIRST(head)	((head)->tqh_first)
+
+#undef TAILQ_FOREACH
+#define	TAILQ_FOREACH(var, head, field)					\
+	for ((var) = TAILQ_FIRST((head));				\
+	    (var);							\
+	    (var) = TAILQ_NEXT((var), field))
+
+#undef TAILQ_FOREACH_FROM
+#define	TAILQ_FOREACH_FROM(var, head, field)				\
+	for ((var) = ((var) ? (var) : TAILQ_FIRST((head)));		\
+	    (var);							\
+	    (var) = TAILQ_NEXT((var), field))
+
+#undef TAILQ_FOREACH_SAFE
+#define	TAILQ_FOREACH_SAFE(var, head, field, tvar)			\
+	for ((var) = TAILQ_FIRST((head));				\
+	    (var) && ((tvar) = TAILQ_NEXT((var), field), 1);		\
+	    (var) = (tvar))
+
+#undef TAILQ_FOREACH_FROM_SAFE
+#define	TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar)			\
+	for ((var) = ((var) ? (var) : TAILQ_FIRST((head)));		\
+	    (var) && ((tvar) = TAILQ_NEXT((var), field), 1);		\
+	    (var) = (tvar))
+
+#undef TAILQ_FOREACH_REVERSE
+#define	TAILQ_FOREACH_REVERSE(var, head, headname, field)		\
+	for ((var) = TAILQ_LAST((head), headname);			\
+	    (var);							\
+	    (var) = TAILQ_PREV((var), headname, field))
+
+#undef TAILQ_FOREACH_REVERSE_FROM
+#define	TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field)		\
+	for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname));	\
+	    (var);							\
+	    (var) = TAILQ_PREV((var), headname, field))
+
+#undef TAILQ_FOREACH_REVERSE_SAFE
+#define	TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar)	\
+	for ((var) = TAILQ_LAST((head), headname);			\
+	    (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1);	\
+	    (var) = (tvar))
+
+#undef TAILQ_FOREACH_REVERSE_FROM_SAFE
+#define	TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar) \
+	for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname));	\
+	    (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1);	\
+	    (var) = (tvar))
+
+#undef TAILQ_INIT
+#define	TAILQ_INIT(head) do {						\
+	TAILQ_FIRST((head)) = NULL;					\
+	(head)->tqh_last = &TAILQ_FIRST((head));			\
+	QMD_TRACE_HEAD(head);						\
+} while (0)
+
+#undef TAILQ_INSERT_AFTER
+#define	TAILQ_INSERT_AFTER(head, listelm, elm, field) do {		\
+	if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
+		TAILQ_NEXT((elm), field)->field.tqe_prev = 		\
+		    &TAILQ_NEXT((elm), field);				\
+	else {								\
+		(head)->tqh_last = &TAILQ_NEXT((elm), field);		\
+		QMD_TRACE_HEAD(head);					\
+	}								\
+	TAILQ_NEXT((listelm), field) = (elm);				\
+	(elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field);		\
+	QMD_TRACE_ELEM(&(elm)->field);					\
+	QMD_TRACE_ELEM(&listelm->field);				\
+} while (0)
+
+#undef TAILQ_INSERT_BEFORE
+#define	TAILQ_INSERT_BEFORE(listelm, elm, field) do {			\
+	(elm)->field.tqe_prev = (listelm)->field.tqe_prev;		\
+	TAILQ_NEXT((elm), field) = (listelm);				\
+	*(listelm)->field.tqe_prev = (elm);				\
+	(listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field);		\
+	QMD_TRACE_ELEM(&(elm)->field);					\
+	QMD_TRACE_ELEM(&listelm->field);				\
+} while (0)
+
+#undef TAILQ_INSERT_HEAD
+#define	TAILQ_INSERT_HEAD(head, elm, field) do {			\
+	if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL)	\
+		TAILQ_FIRST((head))->field.tqe_prev =			\
+		    &TAILQ_NEXT((elm), field);				\
+	else								\
+		(head)->tqh_last = &TAILQ_NEXT((elm), field);		\
+	TAILQ_FIRST((head)) = (elm);					\
+	(elm)->field.tqe_prev = &TAILQ_FIRST((head));			\
+	QMD_TRACE_HEAD(head);						\
+	QMD_TRACE_ELEM(&(elm)->field);					\
+} while (0)
+
+#undef TAILQ_INSERT_TAIL
+#define	TAILQ_INSERT_TAIL(head, elm, field) do {			\
+	TAILQ_NEXT((elm), field) = NULL;				\
+	(elm)->field.tqe_prev = (head)->tqh_last;			\
+	*(head)->tqh_last = (elm);					\
+	(head)->tqh_last = &TAILQ_NEXT((elm), field);			\
+	QMD_TRACE_HEAD(head);						\
+	QMD_TRACE_ELEM(&(elm)->field);					\
+} while (0)
+
+#undef TAILQ_LAST
+#define	TAILQ_LAST(head, headname)					\
+	(*(((struct headname *)((head)->tqh_last))->tqh_last))
+
+#undef TAILQ_NEXT
+#define	TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
+
+#undef TAILQ_PREV
+#define	TAILQ_PREV(elm, headname, field)				\
+	(*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
+
+#undef TAILQ_REMOVE
+#define	TAILQ_REMOVE(head, elm, field) do {				\
+	QMD_SAVELINK(oldnext, (elm)->field.tqe_next);			\
+	QMD_SAVELINK(oldprev, (elm)->field.tqe_prev);			\
+	if ((TAILQ_NEXT((elm), field)) != NULL)				\
+		TAILQ_NEXT((elm), field)->field.tqe_prev = 		\
+		    (elm)->field.tqe_prev;				\
+	else {								\
+		(head)->tqh_last = (elm)->field.tqe_prev;		\
+		QMD_TRACE_HEAD(head);					\
+	}								\
+	*(elm)->field.tqe_prev = TAILQ_NEXT((elm), field);		\
+	TRASHIT(*oldnext);						\
+	TRASHIT(*oldprev);						\
+	QMD_TRACE_ELEM(&(elm)->field);					\
+} while (0)
+
+#undef TAILQ_SWAP
+#define TAILQ_SWAP(head1, head2, type, field) do {			\
+	struct type *swap_first = (head1)->tqh_first;			\
+	struct type **swap_last = (head1)->tqh_last;			\
+	(head1)->tqh_first = (head2)->tqh_first;			\
+	(head1)->tqh_last = (head2)->tqh_last;				\
+	(head2)->tqh_first = swap_first;				\
+	(head2)->tqh_last = swap_last;					\
+	if ((swap_first = (head1)->tqh_first) != NULL)			\
+		swap_first->field.tqe_prev = &(head1)->tqh_first;	\
+	else								\
+		(head1)->tqh_last = &(head1)->tqh_first;		\
+	if ((swap_first = (head2)->tqh_first) != NULL)			\
+		swap_first->field.tqe_prev = &(head2)->tqh_first;	\
+	else								\
+		(head2)->tqh_last = &(head2)->tqh_first;		\
+} while (0)
+
+#endif /* !_SUDO_QUEUE_H_ */
diff --git a/include/sudo_conf.h b/include/sudo_conf.h
index 2c86b8e95..27a096d06 100644
--- a/include/sudo_conf.h
+++ b/include/sudo_conf.h
@@ -17,21 +17,20 @@
 #ifndef _SUDO_CONF_H
 #define _SUDO_CONF_H
 
-#include "list.h"
+#include "queue.h"
 
 #define GROUP_SOURCE_ADAPTIVE	0
 #define GROUP_SOURCE_STATIC	1
 #define GROUP_SOURCE_DYNAMIC	2
 
 struct plugin_info {
-    struct plugin_info *prev; /* required */
-    struct plugin_info *next; /* required */
+    TAILQ_ENTRY(plugin_info) entries;
     const char *path;
     const char *symbol_name;
     char * const * options;
     int lineno;
 };
-TQ_DECLARE(plugin_info)
+TAILQ_HEAD(plugin_info_list, plugin_info);
 
 /* Read main sudo.conf file. */
 void sudo_conf_read(const char *);
diff --git a/include/sudo_event.h b/include/sudo_event.h
index 5b697e71c..bc1150b85 100644
--- a/include/sudo_event.h
+++ b/include/sudo_event.h
@@ -17,6 +17,8 @@
 #ifndef _SUDO_EVENT_H
 #define _SUDO_EVENT_H
 
+#include "queue.h"
+
 /* Event types */
 #define SUDO_EV_READ	0x01		/* fire when readable */
 #define SUDO_EV_WRITE	0x02		/* fire when writable */
@@ -39,8 +41,7 @@ typedef void (*sudo_ev_callback_t)(int fd, int what, void *closure);
 
 /* Member of struct sudo_event_base. */
 struct sudo_event {
-    struct sudo_event *prev;	/* must be first element in struct */
-    struct sudo_event *next;	/* must be second element in struct */
+    TAILQ_ENTRY(sudo_event) entries;
     struct sudo_event_base *base; /* base this event belongs to */
     int fd;			/* fd we are interested in */
     short events;		/* SUDO_EV_* flags */
@@ -49,11 +50,12 @@ struct sudo_event {
     void *closure;		/* user-provided data pointer */
 };
 
-/* Tail queue of events. */
+TAILQ_HEAD(sudo_event_list, sudo_event);
+
 struct sudo_event_base {
-    struct sudo_event *first;	/* must be first element in struct */
-    struct sudo_event *last;	/* must be second element in struct */
-    struct sudo_event *pending;	/* next event to be run in the event loop */
+    struct sudo_event_list events; /* tail queue of events */
+    /* XXX - also list of active events and timed events */
+    struct sudo_event *pending;	/* next event to be run in the event loop XXX */
 #ifdef HAVE_POLL
     struct pollfd *pfds;	/* array of struct pollfd */
     int pfd_max;		/* size of the pfds array */
diff --git a/plugins/sudoers/Makefile.in b/plugins/sudoers/Makefile.in
index 930bdd597..8a9e868bc 100644
--- a/plugins/sudoers/Makefile.in
+++ b/plugins/sudoers/Makefile.in
@@ -432,14 +432,14 @@ cleandir: realclean
 afs.lo: $(authdir)/afs.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
         $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
         $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-        $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+        $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
         $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
         $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(authdir)/afs.c
 aix_auth.lo: $(authdir)/aix_auth.c $(top_builddir)/config.h \
              $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
              $(top_builddir)/pathnames.h $(incdir)/missing.h $(incdir)/fatal.h \
-             $(incdir)/alloc.h $(incdir)/list.h $(incdir)/fileops.h \
+             $(incdir)/alloc.h $(incdir)/queue.h $(incdir)/fileops.h \
              $(srcdir)/defaults.h $(devdir)/def_data.h $(srcdir)/logging.h \
              $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h \
              $(incdir)/sudo_debug.h $(incdir)/gettext.h
@@ -447,10 +447,11 @@ aix_auth.lo: $(authdir)/aix_auth.c $(top_builddir)/config.h \
 alias.lo: $(srcdir)/alias.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
           $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
           $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-          $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+          $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
           $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
           $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-          $(srcdir)/parse.h $(srcdir)/redblack.h $(devdir)/gram.h
+          $(srcdir)/parse.h $(incdir)/list.h $(srcdir)/redblack.h \
+          $(devdir)/gram.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/alias.c
 audit.lo: $(srcdir)/audit.c $(top_builddir)/config.h \
           $(top_srcdir)/compat/stdbool.h $(incdir)/missing.h \
@@ -467,7 +468,7 @@ boottime.lo: $(srcdir)/boottime.c $(top_builddir)/config.h $(incdir)/missing.h \
 bsdauth.lo: $(authdir)/bsdauth.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
             $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
             $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-            $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+            $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
             $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
             $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(authdir)/bsdauth.c
@@ -478,7 +479,7 @@ bsm_audit.lo: $(srcdir)/bsm_audit.c $(top_builddir)/config.h \
 check.lo: $(srcdir)/check.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
           $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
           $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-          $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+          $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
           $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
           $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
           $(srcdir)/check.h
@@ -486,11 +487,11 @@ check.lo: $(srcdir)/check.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
 check_addr.o: $(srcdir)/regress/parser/check_addr.c $(top_builddir)/config.h \
               $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
               $(top_builddir)/pathnames.h $(incdir)/missing.h \
-              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/list.h \
+              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/queue.h \
               $(incdir)/fileops.h $(srcdir)/defaults.h $(devdir)/def_data.h \
               $(srcdir)/logging.h $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h \
               $(incdir)/sudo_debug.h $(incdir)/gettext.h $(srcdir)/parse.h \
-              $(srcdir)/interfaces.h
+              $(incdir)/list.h $(srcdir)/interfaces.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/regress/parser/check_addr.c
 check_base64.o: $(srcdir)/regress/parser/check_base64.c \
                 $(top_builddir)/config.h $(incdir)/missing.h
@@ -500,14 +501,14 @@ check_digest.o: $(srcdir)/regress/parser/check_digest.c \
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/regress/parser/check_digest.c
 check_fill.o: $(srcdir)/regress/parser/check_fill.c $(top_builddir)/config.h \
               $(top_srcdir)/compat/stdbool.h $(incdir)/missing.h \
-              $(incdir)/list.h $(srcdir)/parse.h $(srcdir)/toke.h \
-              $(incdir)/sudo_plugin.h $(devdir)/gram.h
+              $(incdir)/list.h $(srcdir)/parse.h $(incdir)/list.h \
+              $(srcdir)/toke.h $(incdir)/sudo_plugin.h $(devdir)/gram.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/regress/parser/check_fill.c
 check_iolog_path.o: $(srcdir)/regress/iolog_path/check_iolog_path.c \
                     $(top_builddir)/config.h $(srcdir)/sudoers.h \
                     $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
                     $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-                    $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+                    $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
                     $(devdir)/def_data.h $(srcdir)/logging.h \
                     $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h \
                     $(incdir)/sudo_debug.h $(incdir)/gettext.h \
@@ -523,30 +524,30 @@ check_wrap.o: $(srcdir)/regress/logging/check_wrap.c $(top_builddir)/config.h \
 dce.lo: $(authdir)/dce.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
         $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
         $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-        $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+        $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
         $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
         $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(authdir)/dce.c
 defaults.lo: $(srcdir)/defaults.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
              $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
              $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-             $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+             $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
              $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
              $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h \
-             $(incdir)/gettext.h $(srcdir)/parse.h $(devdir)/gram.h \
-             $(devdir)/def_data.c
+             $(incdir)/gettext.h $(srcdir)/parse.h $(incdir)/list.h \
+             $(devdir)/gram.h $(devdir)/def_data.c
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/defaults.c
 env.lo: $(srcdir)/env.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
         $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
         $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-        $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+        $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
         $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
         $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/env.c
 find_path.lo: $(srcdir)/find_path.c $(top_builddir)/config.h \
               $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
               $(top_builddir)/pathnames.h $(incdir)/missing.h \
-              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/list.h \
+              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/queue.h \
               $(incdir)/fileops.h $(srcdir)/defaults.h $(devdir)/def_data.h \
               $(srcdir)/logging.h $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h \
               $(incdir)/sudo_debug.h $(incdir)/gettext.h
@@ -555,7 +556,7 @@ find_path.o: find_path.lo
 fwtk.lo: $(authdir)/fwtk.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
          $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
          $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-         $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+         $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
          $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
          $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(authdir)/fwtk.c
@@ -565,7 +566,7 @@ getdate.o: $(devdir)/getdate.c $(top_builddir)/config.h \
 getspwuid.lo: $(srcdir)/getspwuid.c $(top_builddir)/config.h \
               $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
               $(top_builddir)/pathnames.h $(incdir)/missing.h \
-              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/list.h \
+              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/queue.h \
               $(incdir)/fileops.h $(srcdir)/defaults.h $(devdir)/def_data.h \
               $(srcdir)/logging.h $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h \
               $(incdir)/sudo_debug.h $(incdir)/gettext.h
@@ -573,7 +574,7 @@ getspwuid.lo: $(srcdir)/getspwuid.c $(top_builddir)/config.h \
 goodpath.lo: $(srcdir)/goodpath.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
              $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
              $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-             $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+             $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
              $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
              $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/goodpath.c
@@ -581,16 +582,16 @@ goodpath.o: goodpath.lo
 gram.lo: $(devdir)/gram.c $(top_builddir)/config.h $(top_builddir)/config.h \
          $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
          $(top_builddir)/pathnames.h $(incdir)/missing.h $(incdir)/fatal.h \
-         $(incdir)/alloc.h $(incdir)/list.h $(incdir)/fileops.h \
+         $(incdir)/alloc.h $(incdir)/queue.h $(incdir)/fileops.h \
          $(srcdir)/defaults.h $(devdir)/def_data.h $(srcdir)/logging.h \
          $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h \
-         $(incdir)/gettext.h $(srcdir)/parse.h $(srcdir)/toke.h
+         $(incdir)/gettext.h $(srcdir)/parse.h $(incdir)/list.h $(srcdir)/toke.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(devdir)/gram.c
 group_plugin.lo: $(srcdir)/group_plugin.c $(top_builddir)/config.h \
                  $(top_srcdir)/compat/dlfcn.h $(srcdir)/sudoers.h \
                  $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
                  $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-                 $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+                 $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
                  $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
                  $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h \
                  $(incdir)/gettext.h
@@ -603,7 +604,7 @@ hexchar.o: hexchar.lo
 interfaces.lo: $(srcdir)/interfaces.c $(top_builddir)/config.h \
                $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
                $(top_builddir)/pathnames.h $(incdir)/missing.h \
-               $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/list.h \
+               $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/queue.h \
                $(incdir)/fileops.h $(srcdir)/defaults.h $(devdir)/def_data.h \
                $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
                $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h \
@@ -613,7 +614,7 @@ interfaces.o: interfaces.lo
 iolog.lo: $(srcdir)/iolog.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
           $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
           $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-          $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+          $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
           $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
           $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
           $(srcdir)/iolog.h
@@ -621,7 +622,7 @@ iolog.lo: $(srcdir)/iolog.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
 iolog_path.lo: $(srcdir)/iolog_path.c $(top_builddir)/config.h \
                $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
                $(top_builddir)/pathnames.h $(incdir)/missing.h \
-               $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/list.h \
+               $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/queue.h \
                $(incdir)/fileops.h $(srcdir)/defaults.h $(devdir)/def_data.h \
                $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
                $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h \
@@ -631,7 +632,7 @@ iolog_path.o: iolog_path.lo
 kerb5.lo: $(authdir)/kerb5.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
           $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
           $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-          $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+          $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
           $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
           $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(authdir)/kerb5.c
@@ -639,10 +640,10 @@ ldap.lo: $(srcdir)/ldap.c $(top_builddir)/config.h \
          $(top_srcdir)/compat/dlfcn.h $(srcdir)/sudoers.h \
          $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
          $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-         $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+         $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
          $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
          $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-         $(srcdir)/parse.h $(incdir)/lbuf.h
+         $(srcdir)/parse.h $(incdir)/list.h $(incdir)/lbuf.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/ldap.c
 linux_audit.lo: $(srcdir)/linux_audit.c $(top_builddir)/config.h \
                 $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
@@ -658,14 +659,14 @@ locale.o: locale.lo
 logging.lo: $(srcdir)/logging.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
             $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
             $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-            $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+            $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
             $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
             $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/logging.c
 logwrap.lo: $(srcdir)/logwrap.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
             $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
             $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-            $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+            $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
             $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
             $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/logwrap.c
@@ -674,16 +675,16 @@ match.lo: $(srcdir)/match.c $(top_builddir)/config.h \
           $(top_srcdir)/compat/fnmatch.h $(top_srcdir)/compat/glob.h \
           $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
           $(top_builddir)/pathnames.h $(incdir)/missing.h $(incdir)/fatal.h \
-          $(incdir)/alloc.h $(incdir)/list.h $(incdir)/fileops.h \
+          $(incdir)/alloc.h $(incdir)/queue.h $(incdir)/fileops.h \
           $(srcdir)/defaults.h $(devdir)/def_data.h $(srcdir)/logging.h \
           $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h \
-          $(incdir)/gettext.h $(srcdir)/parse.h $(srcdir)/sha2.h \
-          $(devdir)/gram.h
+          $(incdir)/gettext.h $(srcdir)/parse.h $(incdir)/list.h \
+          $(srcdir)/sha2.h $(devdir)/gram.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/match.c
 match_addr.lo: $(srcdir)/match_addr.c $(top_builddir)/config.h \
                $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
                $(top_builddir)/pathnames.h $(incdir)/missing.h \
-               $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/list.h \
+               $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/queue.h \
                $(incdir)/fileops.h $(srcdir)/defaults.h $(devdir)/def_data.h \
                $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
                $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h \
@@ -697,29 +698,29 @@ net_ifs.o: $(top_srcdir)/src/net_ifs.c $(top_builddir)/config.h \
 pam.lo: $(authdir)/pam.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
         $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
         $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-        $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+        $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
         $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
         $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(authdir)/pam.c
 parse.lo: $(srcdir)/parse.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
           $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
           $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-          $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+          $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
           $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
           $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-          $(srcdir)/parse.h $(incdir)/lbuf.h $(devdir)/gram.h
+          $(srcdir)/parse.h $(incdir)/list.h $(incdir)/lbuf.h $(devdir)/gram.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/parse.c
 passwd.lo: $(authdir)/passwd.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
            $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
            $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-           $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+           $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
            $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
            $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(authdir)/passwd.c
 policy.lo: $(srcdir)/policy.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
            $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
            $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-           $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+           $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
            $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
            $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
            $(srcdir)/sudoers_version.h $(srcdir)/interfaces.h
@@ -727,14 +728,14 @@ policy.lo: $(srcdir)/policy.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
 prompt.lo: $(srcdir)/prompt.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
            $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
            $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-           $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+           $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
            $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
            $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/prompt.c
 pwutil.lo: $(srcdir)/pwutil.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
            $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
            $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-           $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+           $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
            $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
            $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
            $(srcdir)/redblack.h $(srcdir)/pwutil.h
@@ -743,7 +744,7 @@ pwutil.o: pwutil.lo
 pwutil_impl.lo: $(srcdir)/pwutil_impl.c $(top_builddir)/config.h \
                 $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
                 $(top_builddir)/pathnames.h $(incdir)/missing.h \
-                $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/list.h \
+                $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/queue.h \
                 $(incdir)/fileops.h $(srcdir)/defaults.h $(devdir)/def_data.h \
                 $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
                 $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h \
@@ -757,14 +758,14 @@ redblack.o: redblack.lo
 rfc1938.lo: $(authdir)/rfc1938.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
             $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
             $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-            $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+            $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
             $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
             $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(authdir)/rfc1938.c
 secureware.lo: $(authdir)/secureware.c $(top_builddir)/config.h \
                $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
                $(top_builddir)/pathnames.h $(incdir)/missing.h \
-               $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/list.h \
+               $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/queue.h \
                $(incdir)/fileops.h $(srcdir)/defaults.h $(devdir)/def_data.h \
                $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
                $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h \
@@ -773,7 +774,7 @@ secureware.lo: $(authdir)/secureware.c $(top_builddir)/config.h \
 securid5.lo: $(authdir)/securid5.c $(top_builddir)/config.h \
              $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
              $(top_builddir)/pathnames.h $(incdir)/missing.h $(incdir)/fatal.h \
-             $(incdir)/alloc.h $(incdir)/list.h $(incdir)/fileops.h \
+             $(incdir)/alloc.h $(incdir)/queue.h $(incdir)/fileops.h \
              $(srcdir)/defaults.h $(devdir)/def_data.h $(srcdir)/logging.h \
              $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h \
              $(incdir)/sudo_debug.h $(incdir)/gettext.h
@@ -781,7 +782,7 @@ securid5.lo: $(authdir)/securid5.c $(top_builddir)/config.h \
 set_perms.lo: $(srcdir)/set_perms.c $(top_builddir)/config.h \
               $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
               $(top_builddir)/pathnames.h $(incdir)/missing.h \
-              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/list.h \
+              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/queue.h \
               $(incdir)/fileops.h $(srcdir)/defaults.h $(devdir)/def_data.h \
               $(srcdir)/logging.h $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h \
               $(incdir)/sudo_debug.h $(incdir)/gettext.h
@@ -793,7 +794,7 @@ sha2.o: sha2.lo
 sia.lo: $(authdir)/sia.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
         $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
         $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-        $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+        $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
         $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
         $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(authdir)/sia.c
@@ -801,15 +802,16 @@ sssd.lo: $(srcdir)/sssd.c $(top_builddir)/config.h \
          $(top_srcdir)/compat/dlfcn.h $(srcdir)/sudoers.h \
          $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
          $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-         $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+         $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
          $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
          $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-         $(srcdir)/parse.h $(incdir)/lbuf.h $(incdir)/sudo_debug.h
+         $(srcdir)/parse.h $(incdir)/list.h $(incdir)/lbuf.h \
+         $(incdir)/sudo_debug.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/sssd.c
 sudo_auth.lo: $(authdir)/sudo_auth.c $(top_builddir)/config.h \
               $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
               $(top_builddir)/pathnames.h $(incdir)/missing.h \
-              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/list.h \
+              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/queue.h \
               $(incdir)/fileops.h $(srcdir)/defaults.h $(devdir)/def_data.h \
               $(srcdir)/logging.h $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h \
               $(incdir)/sudo_debug.h $(incdir)/gettext.h $(srcdir)/insults.h \
@@ -819,7 +821,7 @@ sudo_auth.lo: $(authdir)/sudo_auth.c $(top_builddir)/config.h \
 sudo_nss.lo: $(srcdir)/sudo_nss.c $(top_builddir)/config.h $(srcdir)/sudoers.h \
              $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
              $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-             $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+             $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
              $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
              $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h \
              $(incdir)/gettext.h $(incdir)/lbuf.h
@@ -828,7 +830,7 @@ sudoers.lo: $(srcdir)/sudoers.c $(top_builddir)/config.h \
             $(top_srcdir)/compat/getaddrinfo.h $(top_builddir)/config.h \
             $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
             $(top_builddir)/pathnames.h $(incdir)/missing.h $(incdir)/fatal.h \
-            $(incdir)/alloc.h $(incdir)/list.h $(incdir)/fileops.h \
+            $(incdir)/alloc.h $(incdir)/queue.h $(incdir)/fileops.h \
             $(srcdir)/defaults.h $(devdir)/def_data.h $(srcdir)/logging.h \
             $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h \
             $(incdir)/sudo_debug.h $(incdir)/gettext.h \
@@ -839,7 +841,7 @@ sudoreplay.o: $(srcdir)/sudoreplay.c $(top_builddir)/config.h \
               $(top_srcdir)/compat/getopt.h $(top_builddir)/pathnames.h \
               $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
               $(incdir)/gettext.h $(srcdir)/logging.h $(srcdir)/iolog.h \
-              $(incdir)/sudo_plugin.h $(incdir)/sudo_conf.h $(incdir)/list.h \
+              $(incdir)/sudo_plugin.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
               $(incdir)/sudo_debug.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/sudoreplay.c
 testsudoers.o: $(srcdir)/testsudoers.c $(top_builddir)/config.h \
@@ -847,17 +849,17 @@ testsudoers.o: $(srcdir)/testsudoers.c $(top_builddir)/config.h \
                $(top_builddir)/config.h $(srcdir)/sudoers.h \
                $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
                $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-               $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+               $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
                $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
                $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h \
                $(incdir)/gettext.h $(srcdir)/interfaces.h $(srcdir)/parse.h \
-               $(incdir)/sudo_conf.h $(incdir)/list.h $(incdir)/secure_path.h \
-               $(devdir)/gram.h
+               $(incdir)/list.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+               $(incdir)/secure_path.h $(devdir)/gram.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/testsudoers.c
 timestamp.lo: $(srcdir)/timestamp.c $(top_builddir)/config.h \
               $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
               $(top_builddir)/pathnames.h $(incdir)/missing.h \
-              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/list.h \
+              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/queue.h \
               $(incdir)/fileops.h $(srcdir)/defaults.h $(devdir)/def_data.h \
               $(srcdir)/logging.h $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h \
               $(incdir)/sudo_debug.h $(incdir)/gettext.h $(srcdir)/check.h
@@ -867,28 +869,28 @@ timestr.lo: $(srcdir)/timestr.c $(top_builddir)/config.h $(incdir)/missing.h
 toke.lo: $(devdir)/toke.c $(top_builddir)/config.h $(top_builddir)/config.h \
          $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
          $(top_builddir)/pathnames.h $(incdir)/missing.h $(incdir)/fatal.h \
-         $(incdir)/alloc.h $(incdir)/list.h $(incdir)/fileops.h \
+         $(incdir)/alloc.h $(incdir)/queue.h $(incdir)/fileops.h \
          $(srcdir)/defaults.h $(devdir)/def_data.h $(srcdir)/logging.h \
          $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h \
-         $(incdir)/gettext.h $(srcdir)/parse.h $(srcdir)/toke.h \
-         $(devdir)/gram.h $(incdir)/lbuf.h $(srcdir)/sha2.h \
+         $(incdir)/gettext.h $(srcdir)/parse.h $(incdir)/list.h \
+         $(srcdir)/toke.h $(devdir)/gram.h $(incdir)/lbuf.h $(srcdir)/sha2.h \
          $(incdir)/secure_path.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(devdir)/toke.c
 toke_util.lo: $(srcdir)/toke_util.c $(top_builddir)/config.h \
               $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
               $(top_builddir)/pathnames.h $(incdir)/missing.h \
-              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/list.h \
+              $(incdir)/fatal.h $(incdir)/alloc.h $(incdir)/queue.h \
               $(incdir)/fileops.h $(srcdir)/defaults.h $(devdir)/def_data.h \
               $(srcdir)/logging.h $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h \
               $(incdir)/sudo_debug.h $(incdir)/gettext.h $(srcdir)/parse.h \
-              $(srcdir)/toke.h $(devdir)/gram.h
+              $(incdir)/list.h $(srcdir)/toke.h $(devdir)/gram.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/toke_util.c
 toke_util.o: toke_util.lo
 tsgetgrpw.o: $(srcdir)/tsgetgrpw.c $(top_builddir)/config.h \
              $(srcdir)/tsgetgrpw.h $(top_builddir)/config.h \
              $(srcdir)/sudoers.h $(top_srcdir)/compat/stdbool.h \
              $(top_builddir)/pathnames.h $(incdir)/missing.h $(incdir)/fatal.h \
-             $(incdir)/alloc.h $(incdir)/list.h $(incdir)/fileops.h \
+             $(incdir)/alloc.h $(incdir)/queue.h $(incdir)/fileops.h \
              $(srcdir)/defaults.h $(devdir)/def_data.h $(srcdir)/logging.h \
              $(srcdir)/sudo_nss.h $(incdir)/sudo_plugin.h \
              $(incdir)/sudo_debug.h $(incdir)/gettext.h
@@ -897,10 +899,10 @@ visudo.o: $(srcdir)/visudo.c $(top_builddir)/config.h \
           $(top_srcdir)/compat/getopt.h $(srcdir)/sudoers.h \
           $(top_srcdir)/compat/stdbool.h $(top_builddir)/pathnames.h \
           $(incdir)/missing.h $(incdir)/fatal.h $(incdir)/alloc.h \
-          $(incdir)/list.h $(incdir)/fileops.h $(srcdir)/defaults.h \
+          $(incdir)/queue.h $(incdir)/fileops.h $(srcdir)/defaults.h \
           $(devdir)/def_data.h $(srcdir)/logging.h $(srcdir)/sudo_nss.h \
           $(incdir)/sudo_plugin.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-          $(srcdir)/parse.h $(srcdir)/redblack.h $(incdir)/gettext.h \
-          $(srcdir)/sudoers_version.h $(incdir)/sudo_conf.h $(incdir)/list.h \
-          $(devdir)/gram.h
+          $(srcdir)/parse.h $(incdir)/list.h $(srcdir)/redblack.h \
+          $(incdir)/queue.h $(incdir)/gettext.h $(srcdir)/sudoers_version.h \
+          $(incdir)/sudo_conf.h $(incdir)/queue.h $(devdir)/gram.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/visudo.c
diff --git a/plugins/sudoers/ldap.c b/plugins/sudoers/ldap.c
index e7f621ba7..cb7be8cb6 100644
--- a/plugins/sudoers/ldap.c
+++ b/plugins/sudoers/ldap.c
@@ -371,8 +371,7 @@ struct sudo_ldap_handle {
 };
 
 struct sudo_nss sudo_nss_ldap = {
-    &sudo_nss_ldap,
-    NULL,
+    { NULL, NULL },
     sudo_ldap_open,
     sudo_ldap_close,
     sudo_ldap_parse,
diff --git a/plugins/sudoers/parse.c b/plugins/sudoers/parse.c
index f99f2d514..f91e41308 100644
--- a/plugins/sudoers/parse.c
+++ b/plugins/sudoers/parse.c
@@ -51,8 +51,7 @@
 
 /* sudoers nsswitch routines */
 struct sudo_nss sudo_nss_file = {
-    &sudo_nss_file,
-    NULL,
+    { NULL, NULL },
     sudo_file_open,
     sudo_file_close,
     sudo_file_parse,
diff --git a/plugins/sudoers/parse.h b/plugins/sudoers/parse.h
index a892e97b3..b396da52d 100644
--- a/plugins/sudoers/parse.h
+++ b/plugins/sudoers/parse.h
@@ -18,6 +18,8 @@
 #ifndef _SUDOERS_PARSE_H
 #define _SUDOERS_PARSE_H
 
+#include "list.h"	/* XXX */
+
 #undef UNSPEC
 #define UNSPEC	-1
 #undef DENY
diff --git a/plugins/sudoers/sssd.c b/plugins/sudoers/sssd.c
index ca3a48296..9d57a519f 100644
--- a/plugins/sudoers/sssd.c
+++ b/plugins/sudoers/sssd.c
@@ -226,8 +226,7 @@ sudo_sss_filter_result(struct sudo_sss_handle *handle,
 }
 
 struct sudo_nss sudo_nss_sss = {
-    &sudo_nss_sss,
-    NULL,
+    { NULL, NULL },
     sudo_sss_open,
     sudo_sss_close,
     sudo_sss_parse,
diff --git a/plugins/sudoers/sudo_nss.c b/plugins/sudoers/sudo_nss.c
index fd09dc626..26c5874f8 100644
--- a/plugins/sudoers/sudo_nss.c
+++ b/plugins/sudoers/sudo_nss.c
@@ -69,7 +69,7 @@ sudo_read_nss(void)
     bool saw_files = false;
     bool saw_ldap = false;
     bool got_match = false;
-    static struct sudo_nss_list snl;
+    static struct sudo_nss_list snl = TAILQ_HEAD_INITIALIZER(snl);
     debug_decl(sudo_read_nss, SUDO_DEBUG_NSS)
 
     if ((fp = fopen(_PATH_NSSWITCH_CONF, "r")) == NULL)
@@ -87,25 +87,25 @@ sudo_read_nss(void)
 	/* Parse line */
 	for ((cp = strtok(line + 8, " \t")); cp != NULL; (cp = strtok(NULL, " \t"))) {
 	    if (strcasecmp(cp, "files") == 0 && !saw_files) {
-		tq_append(&snl, &sudo_nss_file);
+		TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries);
 		got_match = true;
 #ifdef HAVE_LDAP
 	    } else if (strcasecmp(cp, "ldap") == 0 && !saw_ldap) {
-		tq_append(&snl, &sudo_nss_ldap);
+		TAILQ_INSERT_TAIL(&snl, &sudo_nss_ldap, entries);
 		got_match = true;
 #endif
 #ifdef HAVE_SSSD
 	    } else if (strcasecmp(cp, "sss") == 0 && !saw_sss) {
-		tq_append(&snl, &sudo_nss_sss);
+		TAILQ_INSERT_TAIL(&snl, &sudo_nss_sss, entries);
 		got_match = true;
 #endif
 	    } else if (strcasecmp(cp, "[NOTFOUND=return]") == 0 && got_match) {
 		/* NOTFOUND affects the most recent entry */
-		tq_last(&snl)->ret_if_notfound = true;
+		TAILQ_LAST(&snl, sudo_nss_list)->ret_if_notfound = true;
 		got_match = false;
 	    } else if (strcasecmp(cp, "[SUCCESS=return]") == 0 && got_match) {
 		/* SUCCESS affects the most recent entry */
-		tq_last(&snl)->ret_if_found = true;
+		TAILQ_LAST(&snl, sudo_nss_list)->ret_if_found = true;
 		got_match = false;
 	    } else
 		got_match = false;
@@ -118,8 +118,8 @@ sudo_read_nss(void)
 
 nomatch:
     /* Default to files only if no matches */
-    if (tq_empty(&snl))
-	tq_append(&snl, &sudo_nss_file);
+    if (TAILQ_EMPTY(&snl))
+	TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries);
 
     debug_return_ptr(&snl);
 }
@@ -144,7 +144,7 @@ sudo_read_nss(void)
     bool saw_files = false;
     bool saw_ldap = false;
     bool got_match = false;
-    static struct sudo_nss_list snl;
+    static struct sudo_nss_list snl = TAILQ_HEAD_INITIALIZER(snl);
     debug_decl(sudo_read_nss, SUDO_DEBUG_NSS)
 
     if ((fp = fopen(_PATH_NETSVC_CONF, "r")) == NULL)
@@ -172,20 +172,20 @@ sudo_read_nss(void)
 
 	    if (!saw_files && strncasecmp(cp, "files", 5) == 0 &&
 		(isspace((unsigned char)cp[5]) || cp[5] == '\0')) {
-		tq_append(&snl, &sudo_nss_file);
+		TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries);
 		got_match = true;
 		ep = &cp[5];
 #ifdef HAVE_LDAP
 	    } else if (!saw_ldap && strncasecmp(cp, "ldap", 4) == 0 &&
 		(isspace((unsigned char)cp[4]) || cp[4] == '\0')) {
-		tq_append(&snl, &sudo_nss_ldap);
+		TAILQ_INSERT_TAIL(&snl, &sudo_nss_ldap, entries);
 		got_match = true;
 		ep = &cp[4];
 #endif
 #ifdef HAVE_SSSD
 	    } else if (!saw_sss && strncasecmp(cp, "sss", 3) == 0 &&
 		(isspace((unsigned char)cp[3]) || cp[3] == '\0')) {
-		tq_append(&snl, &sudo_nss_sss);
+		TAILQ_INSERT_TAIL(&snl, &sudo_nss_sss, entries);
 		got_match = true;
 		ep = &cp[3];
 #endif
@@ -200,7 +200,7 @@ sudo_read_nss(void)
 		    cp++;
 		if (strncasecmp(cp, "auth", 4) == 0 &&
 		    (isspace((unsigned char)cp[4]) || cp[4] == '\0')) {
-		    tq_last(&snl)->ret_if_found = true;
+		    TAILQ_LAST(&snl, sudo_nss_list)->ret_if_found = true;
 		}
 	    }
 	}
@@ -211,8 +211,8 @@ sudo_read_nss(void)
 
 nomatch:
     /* Default to files only if no matches */
-    if (tq_empty(&snl))
-	tq_append(&snl, &sudo_nss_file);
+    if (TAILQ_EMPTY(&snl))
+	TAILQ_INSERT_TAIL(&snl, &sudo_nss_files, entries);
 
     debug_return_ptr(&snl);
 }
@@ -225,16 +225,16 @@ nomatch:
 struct sudo_nss_list *
 sudo_read_nss(void)
 {
-    static struct sudo_nss_list snl;
+    static struct sudo_nss_list snl = TAILQ_HEAD_INITIALIZER(snl);
     debug_decl(sudo_read_nss, SUDO_DEBUG_NSS)
 
 #  ifdef HAVE_SSSD
-    tq_append(&snl, &sudo_nss_sss);
+    TAILQ_INSERT_TAIL(&snl, &sudo_nss_sss, entries);
 #  endif
 #  ifdef HAVE_LDAP
-    tq_append(&snl, &sudo_nss_ldap);
+    TAILQ_INSERT_TAIL(&snl, &sudo_nss_ldap, entries);
 #  endif
-    tq_append(&snl, &sudo_nss_file);
+    TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries);
 
     debug_return_ptr(&snl);
 }
@@ -283,7 +283,7 @@ display_privs(struct sudo_nss_list *snl, struct passwd *pw)
     lbuf_append(&defs, _("Matching Defaults entries for %s on %s:\n"),
 	pw->pw_name, user_srunhost);
     count = 0;
-    tq_foreach_fwd(snl, nss) {
+    TAILQ_FOREACH(nss, snl, entries) {
 	count += nss->display_defaults(nss, pw, &defs);
     }
     if (count)
@@ -296,7 +296,7 @@ display_privs(struct sudo_nss_list *snl, struct passwd *pw)
     lbuf_append(&defs, _("Runas and Command-specific defaults for %s:\n"),
 	pw->pw_name);
     count = 0;
-    tq_foreach_fwd(snl, nss) {
+    TAILQ_FOREACH(nss, snl, entries) {
 	count += nss->display_bound_defaults(nss, pw, &defs);
     }
     if (count)
@@ -309,7 +309,7 @@ display_privs(struct sudo_nss_list *snl, struct passwd *pw)
 	_("User %s may run the following commands on %s:\n"),
 	pw->pw_name, user_srunhost);
     count = 0;
-    tq_foreach_fwd(snl, nss) {
+    TAILQ_FOREACH(nss, snl, entries) {
 	count += nss->display_privs(nss, pw, &privs);
     }
     if (count == 0) {
@@ -338,7 +338,7 @@ display_cmnd(struct sudo_nss_list *snl, struct passwd *pw)
     struct sudo_nss *nss;
     debug_decl(display_cmnd, SUDO_DEBUG_NSS)
 
-    tq_foreach_fwd(snl, nss) {
+    TAILQ_FOREACH(nss, snl, entries) {
 	if (nss->display_cmnd(nss, pw) == 0)
 	    debug_return_bool(true);
     }
diff --git a/plugins/sudoers/sudo_nss.h b/plugins/sudoers/sudo_nss.h
index 3e74f3ab8..40c3fa009 100644
--- a/plugins/sudoers/sudo_nss.h
+++ b/plugins/sudoers/sudo_nss.h
@@ -21,8 +21,7 @@ struct lbuf;
 struct passwd;
 
 struct sudo_nss {
-    struct sudo_nss *prev;
-    struct sudo_nss *next;
+    TAILQ_ENTRY(sudo_nss) entries;
     int (*open)(struct sudo_nss *nss);
     int (*close)(struct sudo_nss *nss);
     int (*parse)(struct sudo_nss *nss);
@@ -37,7 +36,7 @@ struct sudo_nss {
     short ret_if_notfound;
 };
 
-TQ_DECLARE(sudo_nss)
+TAILQ_HEAD(sudo_nss_list, sudo_nss);
 
 struct sudo_nss_list *sudo_read_nss(void);
 
diff --git a/plugins/sudoers/sudoers.c b/plugins/sudoers/sudoers.c
index 94a62d2b0..71525244c 100644
--- a/plugins/sudoers/sudoers.c
+++ b/plugins/sudoers/sudoers.c
@@ -150,14 +150,13 @@ sudoers_policy_init(void *info, char * const envp[])
     set_perms(PERM_ROOT);
 
     /* Open and parse sudoers, set global defaults */
-    for (nss = snl->first; nss != NULL; nss = nss_next) {
-        nss_next = nss->next;
+    TAILQ_FOREACH_SAFE(nss, snl, entries, nss_next) {
         if (nss->open(nss) == 0 && nss->parse(nss) == 0) {
             sources++;
             if (nss->setdefs(nss) != 0)
                 log_warning(NO_STDERR, N_("problem with defaults entries"));
         } else {
-            tq_remove(snl, nss);
+	    TAILQ_REMOVE(snl, nss, entries);
         }
     }
     if (sources == 0) {
@@ -273,7 +272,7 @@ sudoers_policy_main(int argc, char * const argv[], int pwflag, char *env_add[],
      */
     sudoers_setlocale(SUDOERS_LOCALE_SUDOERS, &oldlocale);
     validated = FLAG_NO_USER | FLAG_NO_HOST;
-    tq_foreach_fwd(snl, nss) {
+    TAILQ_FOREACH(nss, snl, entries) {
 	validated = nss->lookup(nss, validated, pwflag);
 
 	if (ISSET(validated, VALIDATE_OK)) {
@@ -413,7 +412,7 @@ sudoers_policy_main(int argc, char * const argv[], int pwflag, char *env_add[],
 	display_privs(snl, list_pw ? list_pw : sudo_user.pw); /* XXX - return val */
 
     /* Cleanup sudoers sources */
-    tq_foreach_fwd(snl, nss) {
+    TAILQ_FOREACH(nss, snl, entries) {
 	nss->close(nss);
     }
     if (def_group_plugin)
@@ -902,8 +901,9 @@ sudoers_cleanup(void)
     debug_decl(sudoers_cleanup, SUDO_DEBUG_PLUGIN)
 
     if (snl != NULL) {
-	tq_foreach_fwd(snl, nss)
+	TAILQ_FOREACH(nss, snl, entries) {
 	    nss->close(nss);
+	}
     }
     if (def_group_plugin)
 	group_plugin_unload();
diff --git a/plugins/sudoers/sudoers.h b/plugins/sudoers/sudoers.h
index 8118ea460..81a1bcfad 100644
--- a/plugins/sudoers/sudoers.h
+++ b/plugins/sudoers/sudoers.h
@@ -33,7 +33,7 @@
 #include "missing.h"
 #include "fatal.h"
 #include "alloc.h"
-#include "list.h"
+#include "queue.h"
 #include "fileops.h"
 #include "defaults.h"
 #include "logging.h"
diff --git a/plugins/sudoers/visudo.c b/plugins/sudoers/visudo.c
index 4d788e7a6..79418de27 100644
--- a/plugins/sudoers/visudo.c
+++ b/plugins/sudoers/visudo.c
@@ -79,20 +79,21 @@
 #include "sudoers.h"
 #include "parse.h"
 #include "redblack.h"
+#include "queue.h"
 #include "gettext.h"
 #include "sudoers_version.h"
 #include "sudo_conf.h"
 #include <gram.h>
 
 struct sudoersfile {
-    struct sudoersfile *prev, *next;
+    TAILQ_ENTRY(sudoersfile) entries;
     char *path;
     char *tpath;
     int fd;
     int modified;
     int doedit;
 };
-TQ_DECLARE(sudoersfile)
+TAILQ_HEAD(sudoersfile_list, sudoersfile);
 
 /*
  * Function prototypes
@@ -131,7 +132,7 @@ extern bool parse_error;
  */
 struct sudo_user sudo_user;
 struct passwd *list_pw;
-static struct sudoersfile_list sudoerslist;
+static struct sudoersfile_list sudoerslist = TAILQ_HEAD_INITIALIZER(sudoerslist);
 static struct rbtree *alias_freelist;
 static bool checkonly;
 static const char short_opts[] =  "cf:hqsV";
@@ -250,10 +251,10 @@ main(int argc, char *argv[])
     setup_signals();
 
     /* Edit the sudoers file(s) */
-    tq_foreach_fwd(&sudoerslist, sp) {
+    TAILQ_FOREACH(sp, &sudoerslist, entries) {
 	if (!sp->doedit)
 	    continue;
-	if (sp != tq_first(&sudoerslist)) {
+	if (sp != TAILQ_FIRST(&sudoerslist)) {
 	    printf(_("press return to edit %s: "), sp->path);
 	    while ((ch = getchar()) != EOF && ch != '\n')
 		    continue;
@@ -266,7 +267,7 @@ main(int argc, char *argv[])
      * and install the edited files as needed.
      */
     if (reparse_sudoers(editor, args, strict, quiet)) {
-	tq_foreach_fwd(&sudoerslist, sp) {
+	TAILQ_FOREACH(sp, &sudoerslist, entries) {
 	    (void) install_sudoers(sp, oldperms);
 	}
     }
@@ -482,8 +483,8 @@ reparse_sudoers(char *editor, char *args, bool strict, bool quiet)
     /*
      * Parse the edited sudoers files and do sanity checking
      */
-    while ((sp = tq_first(&sudoerslist)) != NULL) {
-	last = tq_last(&sudoerslist);
+    while ((sp = TAILQ_FIRST(&sudoerslist)) != NULL) {
+	last = TAILQ_LAST(&sudoerslist, sudoersfile_list);
 	fp = fopen(sp->tpath, "r+");
 	if (fp == NULL)
 	    fatalx(_("unable to re-open temporary file (%s), %s unchanged."),
@@ -524,7 +525,7 @@ reparse_sudoers(char *editor, char *args, bool strict, bool quiet)
 	    case 'e':
 	    default:
 		/* Edit file with the parse error */
-		tq_foreach_fwd(&sudoerslist, sp) {
+		TAILQ_FOREACH(sp, &sudoerslist, entries) {
 		    if (errorfile == NULL || strcmp(sp->path, errorfile) == 0) {
 			edit_sudoers(sp, editor, args, errorlineno);
 			if (errorfile != NULL)
@@ -540,7 +541,7 @@ reparse_sudoers(char *editor, char *args, bool strict, bool quiet)
 	}
 
 	/* If any new #include directives were added, edit them too. */
-	for (sp = last->next; sp != NULL; sp = sp->next) {
+	for (sp = TAILQ_NEXT(last, entries); sp != NULL; sp = TAILQ_NEXT(sp, entries)) {
 	    printf(_("press return to edit %s: "), sp->path);
 	    while ((ch = getchar()) != EOF && ch != '\n')
 		    continue;
@@ -858,7 +859,7 @@ check_syntax(char *sudoers_path, bool quiet, bool strict, bool oldperms)
 	} else {
 	    ok = false;
 	}
-	tq_foreach_fwd(&sudoerslist, sp) {
+	TAILQ_FOREACH(sp, &sudoerslist, entries) {
 	    if (oldperms || check_owner(sp->path, quiet)) {
 		if (!quiet)
 		    (void) printf(_("%s: parsed OK\n"), sp->path);
@@ -890,7 +891,7 @@ open_sudoers(const char *path, bool doedit, bool *keepopen)
 	open_flags = O_RDWR | O_CREAT;
 
     /* Check for existing entry */
-    tq_foreach_fwd(&sudoerslist, entry) {
+    TAILQ_FOREACH(entry, &sudoerslist, entries) {
 	if (strcmp(path, entry->path) == 0)
 	    break;
     }
@@ -898,8 +899,6 @@ open_sudoers(const char *path, bool doedit, bool *keepopen)
 	entry = ecalloc(1, sizeof(*entry));
 	entry->path = estrdup(path);
 	/* entry->modified = 0; */
-	entry->prev = entry;
-	/* entry->next = NULL; */
 	entry->fd = open(entry->path, open_flags, SUDOERS_MODE);
 	/* entry->tpath = NULL; */
 	entry->doedit = doedit;
@@ -912,7 +911,7 @@ open_sudoers(const char *path, bool doedit, bool *keepopen)
 	    fatalx(_("%s busy, try again later"), entry->path);
 	if ((fp = fdopen(entry->fd, "r")) == NULL)
 	    fatal("%s", entry->path);
-	tq_append(&sudoerslist, entry);
+	TAILQ_INSERT_TAIL(&sudoerslist, entry, entries);
     } else {
 	/* Already exists, open .tmp version if there is one. */
 	if (entry->tpath != NULL) {
@@ -1271,7 +1270,7 @@ visudo_cleanup(void)
 {
     struct sudoersfile *sp;
 
-    tq_foreach_fwd(&sudoerslist, sp) {
+    TAILQ_FOREACH(sp, &sudoerslist, entries) {
 	if (sp->tpath != NULL)
 	    (void) unlink(sp->tpath);
     }
@@ -1288,7 +1287,7 @@ quit(int signo)
     struct sudoersfile *sp;
     struct iovec iov[4];
 
-    tq_foreach_fwd(&sudoerslist, sp) {
+    TAILQ_FOREACH(sp, &sudoerslist, entries) {
 	if (sp->tpath != NULL)
 	    (void) unlink(sp->tpath);
     }
diff --git a/src/Makefile.in b/src/Makefile.in
index 275bb3416..9a3f93e2a 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -186,63 +186,61 @@ conversation.o: $(srcdir)/conversation.c $(top_builddir)/config.h \
                 $(srcdir)/sudo.h $(top_builddir)/pathnames.h \
                 $(top_srcdir)/compat/stdbool.h $(incdir)/missing.h \
                 $(incdir)/alloc.h $(incdir)/fatal.h $(incdir)/fileops.h \
-                $(incdir)/list.h $(incdir)/sudo_conf.h $(incdir)/list.h \
-                $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-                $(incdir)/sudo_plugin.h $(srcdir)/sudo_plugin_int.h
+                $(incdir)/sudo_conf.h $(incdir)/queue.h $(incdir)/sudo_debug.h \
+                $(incdir)/gettext.h $(incdir)/sudo_plugin.h \
+                $(srcdir)/sudo_plugin_int.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/conversation.c
 env_hooks.o: $(srcdir)/env_hooks.c $(top_builddir)/config.h \
              $(top_srcdir)/compat/dlfcn.h $(srcdir)/sudo.h \
              $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
              $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-             $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-             $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-             $(incdir)/sudo_plugin.h
+             $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+             $(incdir)/sudo_debug.h $(incdir)/gettext.h $(incdir)/sudo_plugin.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/env_hooks.c
 exec.o: $(srcdir)/exec.c $(top_builddir)/config.h $(srcdir)/sudo.h \
         $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
         $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-        $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-        $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-        $(srcdir)/sudo_exec.h $(incdir)/sudo_plugin.h \
+        $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+        $(incdir)/sudo_debug.h $(incdir)/gettext.h $(srcdir)/sudo_exec.h \
+        $(incdir)/sudo_event.h $(incdir)/queue.h $(incdir)/sudo_plugin.h \
         $(srcdir)/sudo_plugin_int.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/exec.c
 exec_common.o: $(srcdir)/exec_common.c $(top_builddir)/config.h \
                $(srcdir)/sudo.h $(top_builddir)/pathnames.h \
                $(top_srcdir)/compat/stdbool.h $(incdir)/missing.h \
                $(incdir)/alloc.h $(incdir)/fatal.h $(incdir)/fileops.h \
-               $(incdir)/list.h $(incdir)/sudo_conf.h $(incdir)/list.h \
-               $(incdir)/sudo_debug.h $(incdir)/gettext.h $(srcdir)/sudo_exec.h
+               $(incdir)/sudo_conf.h $(incdir)/queue.h $(incdir)/sudo_debug.h \
+               $(incdir)/gettext.h $(srcdir)/sudo_exec.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/exec_common.c
 exec_pty.o: $(srcdir)/exec_pty.c $(top_builddir)/config.h $(srcdir)/sudo.h \
             $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
             $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-            $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-            $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-            $(srcdir)/sudo_exec.h $(incdir)/sudo_plugin.h \
+            $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+            $(incdir)/sudo_debug.h $(incdir)/gettext.h $(incdir)/sudo_event.h \
+            $(incdir)/queue.h $(srcdir)/sudo_exec.h $(incdir)/sudo_plugin.h \
             $(srcdir)/sudo_plugin_int.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/exec_pty.c
 get_pty.o: $(srcdir)/get_pty.c $(top_builddir)/config.h $(srcdir)/sudo.h \
            $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
            $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-           $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-           $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
+           $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+           $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/get_pty.c
 hooks.o: $(srcdir)/hooks.c $(top_builddir)/config.h $(srcdir)/sudo.h \
          $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
          $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-         $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-         $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-         $(incdir)/sudo_plugin.h $(srcdir)/sudo_plugin_int.h \
-         $(incdir)/sudo_debug.h
+         $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+         $(incdir)/sudo_debug.h $(incdir)/gettext.h $(incdir)/sudo_plugin.h \
+         $(srcdir)/sudo_plugin_int.h $(incdir)/sudo_debug.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/hooks.c
 load_plugins.o: $(srcdir)/load_plugins.c $(top_builddir)/config.h \
                 $(top_srcdir)/compat/dlfcn.h $(srcdir)/sudo.h \
                 $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
                 $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-                $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-                $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
+                $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+                $(incdir)/sudo_debug.h $(incdir)/gettext.h \
                 $(incdir)/sudo_plugin.h $(srcdir)/sudo_plugin_int.h \
-                $(incdir)/sudo_conf.h $(incdir)/list.h $(incdir)/sudo_debug.h
+                $(incdir)/sudo_conf.h $(incdir)/queue.h $(incdir)/sudo_debug.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/load_plugins.c
 locale_stub.o: $(srcdir)/locale_stub.c $(top_builddir)/config.h \
                $(incdir)/missing.h $(incdir)/fatal.h
@@ -254,56 +252,54 @@ net_ifs.o: $(srcdir)/net_ifs.c $(top_builddir)/config.h $(incdir)/missing.h \
 openbsd.o: $(srcdir)/openbsd.c $(top_builddir)/config.h $(srcdir)/sudo.h \
            $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
            $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-           $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-           $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
+           $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+           $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/openbsd.c
 parse_args.o: $(srcdir)/parse_args.c $(top_builddir)/config.h \
               $(top_srcdir)/compat/getopt.h ./sudo_usage.h $(srcdir)/sudo.h \
               $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
               $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-              $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-              $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-              $(incdir)/lbuf.h
+              $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+              $(incdir)/sudo_debug.h $(incdir)/gettext.h $(incdir)/lbuf.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/parse_args.c
 preload.o: $(srcdir)/preload.c $(top_builddir)/config.h $(incdir)/sudo_plugin.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/preload.c
 selinux.o: $(srcdir)/selinux.c $(top_builddir)/config.h $(srcdir)/sudo.h \
            $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
            $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-           $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-           $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-           $(srcdir)/sudo_exec.h
+           $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+           $(incdir)/sudo_debug.h $(incdir)/gettext.h $(srcdir)/sudo_exec.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/selinux.c
 sesh.o: $(srcdir)/sesh.c $(top_builddir)/config.h \
         $(top_srcdir)/compat/stdbool.h $(incdir)/missing.h $(incdir)/alloc.h \
         $(incdir)/fatal.h $(incdir)/gettext.h $(incdir)/sudo_conf.h \
-        $(incdir)/list.h $(incdir)/sudo_debug.h $(srcdir)/sudo_exec.h \
+        $(incdir)/queue.h $(incdir)/sudo_debug.h $(srcdir)/sudo_exec.h \
         $(incdir)/sudo_plugin.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/sesh.c
 signal.o: $(srcdir)/signal.c $(top_builddir)/config.h $(srcdir)/sudo.h \
           $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
           $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-          $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-          $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
+          $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+          $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/signal.c
 solaris.o: $(srcdir)/solaris.c $(top_builddir)/config.h $(srcdir)/sudo.h \
            $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
            $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-           $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-           $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
+           $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+           $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/solaris.c
 sudo.o: $(srcdir)/sudo.c $(top_builddir)/config.h ./sudo_usage.h \
         $(srcdir)/sudo.h $(top_builddir)/pathnames.h \
         $(top_srcdir)/compat/stdbool.h $(incdir)/missing.h $(incdir)/alloc.h \
-        $(incdir)/fatal.h $(incdir)/fileops.h $(incdir)/list.h \
-        $(incdir)/sudo_conf.h $(incdir)/list.h $(incdir)/sudo_debug.h \
-        $(incdir)/gettext.h $(incdir)/sudo_plugin.h $(srcdir)/sudo_plugin_int.h
+        $(incdir)/fatal.h $(incdir)/fileops.h $(incdir)/sudo_conf.h \
+        $(incdir)/queue.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
+        $(incdir)/sudo_plugin.h $(srcdir)/sudo_plugin_int.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/sudo.c
 sudo_edit.o: $(srcdir)/sudo_edit.c $(top_builddir)/config.h $(srcdir)/sudo.h \
              $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
              $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-             $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-             $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
+             $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+             $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/sudo_edit.c
 sudo_noexec.lo: $(srcdir)/sudo_noexec.c $(top_builddir)/config.h \
                 $(incdir)/missing.h
@@ -311,20 +307,18 @@ sudo_noexec.lo: $(srcdir)/sudo_noexec.c $(top_builddir)/config.h \
 tgetpass.o: $(srcdir)/tgetpass.c $(top_builddir)/config.h $(srcdir)/sudo.h \
             $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
             $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-            $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-            $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-            $(incdir)/sudo_plugin.h
+            $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+            $(incdir)/sudo_debug.h $(incdir)/gettext.h $(incdir)/sudo_plugin.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/tgetpass.c
 ttyname.o: $(srcdir)/ttyname.c $(top_builddir)/config.h $(srcdir)/sudo.h \
            $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
            $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-           $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-           $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h
+           $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+           $(incdir)/sudo_debug.h $(incdir)/gettext.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/ttyname.c
 utmp.o: $(srcdir)/utmp.c $(top_builddir)/config.h $(srcdir)/sudo.h \
         $(top_builddir)/pathnames.h $(top_srcdir)/compat/stdbool.h \
         $(incdir)/missing.h $(incdir)/alloc.h $(incdir)/fatal.h \
-        $(incdir)/fileops.h $(incdir)/list.h $(incdir)/sudo_conf.h \
-        $(incdir)/list.h $(incdir)/sudo_debug.h $(incdir)/gettext.h \
-        $(srcdir)/sudo_exec.h
+        $(incdir)/fileops.h $(incdir)/sudo_conf.h $(incdir)/queue.h \
+        $(incdir)/sudo_debug.h $(incdir)/gettext.h $(srcdir)/sudo_exec.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/utmp.c
diff --git a/src/exec.c b/src/exec.c
index ecc699fcf..8c6b4678f 100644
--- a/src/exec.c
+++ b/src/exec.c
@@ -65,14 +65,13 @@ struct exec_closure {
 
 /* We keep a tailq of signals to forward to child. */
 struct sigforward {
-    struct sigforward *prev, *next;
+    TAILQ_ENTRY(sigforward) entries;
     int signo;
 };
-static struct {
-    struct sigforward *first, *last;
-    struct sudo_event *event;
-} sigfwd_list;
+TAILQ_HEAD(sigfwd_list, sigforward);
+static struct sigfwd_list sigfwd_list = TAILQ_HEAD_INITIALIZER(sigfwd_list);
 static struct sudo_event *signal_event;
+static struct sudo_event *sigfwd_event;
 static struct sudo_event *backchannel_event;
 static pid_t ppgrp = -1;
 
@@ -318,9 +317,9 @@ exec_event_setup(int backchannel, struct exec_closure *ec)
 	fatal(_("unable to add event to queue"));
 
     /* The signal forwarding event gets added on demand. */
-    sigfwd_list.event = sudo_ev_alloc(backchannel,
+    sigfwd_event = sudo_ev_alloc(backchannel,
 	SUDO_EV_WRITE, forward_signals, NULL);
-    if (sigfwd_list.event == NULL)
+    if (sigfwd_event == NULL)
 	fatal(NULL);
 
     sudo_debug_printf(SUDO_DEBUG_INFO, "signal pipe fd %d\n", signal_pipe[0]);
@@ -373,7 +372,7 @@ sudo_execute(struct command_details *details, struct command_status *cstat)
      * need to allocate a pty.  It is OK to set log_io in the pty-only case
      * as the io plugin tailqueue will be empty and no I/O logging will occur.
      */
-    if (!tq_empty(&io_plugins) || ISSET(details->flags, CD_USE_PTY)) {
+    if (!TAILQ_EMPTY(&io_plugins) || ISSET(details->flags, CD_USE_PTY)) {
 	log_io = true;
 	if (ISSET(details->flags, CD_SET_UTMP))
 	    utmp_user = details->utmp_user ? details->utmp_user : user_details.username;
@@ -494,12 +493,12 @@ sudo_execute(struct command_details *details, struct command_status *cstat)
 #endif
 
     /* Free things up. */
-    while (!tq_empty(&sigfwd_list)) {
-	struct sigforward *sigfwd = tq_first(&sigfwd_list);
-	tq_remove(&sigfwd_list, sigfwd);
+    while (!TAILQ_EMPTY(&sigfwd_list)) {
+	struct sigforward *sigfwd = TAILQ_FIRST(&sigfwd_list);
+	TAILQ_REMOVE(&sigfwd_list, sigfwd, entries);
 	efree(sigfwd);
     }
-    sudo_ev_free(sigfwd_list.event);
+    sudo_ev_free(sigfwd_event);
     sudo_ev_free(signal_event);
     sudo_ev_free(backchannel_event);
     sudo_ev_base_free(evbase);
@@ -782,8 +781,8 @@ forward_signals(int sock, int what, void *v)
     ssize_t nsent;
     debug_decl(forward_signals, SUDO_DEBUG_EXEC)
 
-    while (!tq_empty(&sigfwd_list)) {
-	sigfwd = tq_first(&sigfwd_list);
+    while (!TAILQ_EMPTY(&sigfwd_list)) {
+	sigfwd = TAILQ_FIRST(&sigfwd_list);
 	if (sigfwd->signo == SIGCONT_FG)
 	    strlcpy(signame, "CONT_FG", sizeof(signame));
 	else if (sigfwd->signo == SIGCONT_BG)
@@ -797,16 +796,16 @@ forward_signals(int sock, int what, void *v)
 	do {
 	    nsent = send(sock, &cstat, sizeof(cstat), 0);
 	} while (nsent == -1 && errno == EINTR);
-	tq_remove(&sigfwd_list, sigfwd);
+	TAILQ_REMOVE(&sigfwd_list, sigfwd, entries);
 	efree(sigfwd);
 	if (nsent != sizeof(cstat)) {
 	    if (errno == EPIPE) {
 		sudo_debug_printf(SUDO_DEBUG_ERROR,
 		    "broken pipe writing to child over backchannel");
 		/* Other end of socket gone, empty out sigfwd_list. */
-		while (!tq_empty(&sigfwd_list)) {
-		    sigfwd = tq_first(&sigfwd_list);
-		    tq_remove(&sigfwd_list, sigfwd);
+		while (!TAILQ_EMPTY(&sigfwd_list)) {
+		    sigfwd = TAILQ_FIRST(&sigfwd_list);
+		    TAILQ_REMOVE(&sigfwd_list, sigfwd, entries);
 		    efree(sigfwd);
 		}
 		/* XXX - child (monitor) is dead, we should exit too? */
@@ -835,12 +834,10 @@ schedule_signal(struct sudo_event_base *evbase, int signo)
     sudo_debug_printf(SUDO_DEBUG_DIAG, "scheduled SIG%s for child", signame);
 
     sigfwd = ecalloc(1, sizeof(*sigfwd));
-    sigfwd->prev = sigfwd;
-    /* sigfwd->next = NULL; */
     sigfwd->signo = signo;
-    tq_append(&sigfwd_list, sigfwd);
+    TAILQ_INSERT_TAIL(&sigfwd_list, sigfwd, entries);
 
-    if (sudo_ev_add(evbase, sigfwd_list.event, true) == -1)
+    if (sudo_ev_add(evbase, sigfwd_event, true) == -1)
 	fatal(_("unable to add event to queue"));
 
     debug_return;
diff --git a/src/exec_pty.c b/src/exec_pty.c
index f6fd62378..a4a635e3f 100644
--- a/src/exec_pty.c
+++ b/src/exec_pty.c
@@ -117,7 +117,7 @@ pty_cleanup(void)
 {
     debug_decl(cleanup, SUDO_DEBUG_EXEC);
 
-    if (!tq_empty(&io_plugins) && io_fds[SFD_USERTTY] != -1) {
+    if (!TAILQ_EMPTY(&io_plugins) && io_fds[SFD_USERTTY] != -1) {
 	check_foreground();
 	if (foreground)
 	    term_restore(io_fds[SFD_USERTTY], 0);
@@ -202,7 +202,7 @@ log_ttyin(const char *buf, unsigned int n)
     debug_decl(log_ttyin, SUDO_DEBUG_EXEC);
 
     sigprocmask(SIG_BLOCK, &ttyblock, &omask);
-    tq_foreach_fwd(&io_plugins, plugin) {
+    TAILQ_FOREACH(plugin, &io_plugins, entries) {
 	if (plugin->u.io->log_ttyin) {
 	    if (!plugin->u.io->log_ttyin(buf, n)) {
 	    	rval = false;
@@ -225,7 +225,7 @@ log_stdin(const char *buf, unsigned int n)
     debug_decl(log_stdin, SUDO_DEBUG_EXEC);
 
     sigprocmask(SIG_BLOCK, &ttyblock, &omask);
-    tq_foreach_fwd(&io_plugins, plugin) {
+    TAILQ_FOREACH(plugin, &io_plugins, entries) {
 	if (plugin->u.io->log_stdin) {
 	    if (!plugin->u.io->log_stdin(buf, n)) {
 	    	rval = false;
@@ -248,7 +248,7 @@ log_ttyout(const char *buf, unsigned int n)
     debug_decl(log_ttyout, SUDO_DEBUG_EXEC);
 
     sigprocmask(SIG_BLOCK, &ttyblock, &omask);
-    tq_foreach_fwd(&io_plugins, plugin) {
+    TAILQ_FOREACH(plugin, &io_plugins, entries) {
 	if (plugin->u.io->log_ttyout) {
 	    if (!plugin->u.io->log_ttyout(buf, n)) {
 	    	rval = false;
@@ -271,7 +271,7 @@ log_stdout(const char *buf, unsigned int n)
     debug_decl(log_stdout, SUDO_DEBUG_EXEC);
 
     sigprocmask(SIG_BLOCK, &ttyblock, &omask);
-    tq_foreach_fwd(&io_plugins, plugin) {
+    TAILQ_FOREACH(plugin, &io_plugins, entries) {
 	if (plugin->u.io->log_stdout) {
 	    if (!plugin->u.io->log_stdout(buf, n)) {
 	    	rval = false;
@@ -294,7 +294,7 @@ log_stderr(const char *buf, unsigned int n)
     debug_decl(log_stderr, SUDO_DEBUG_EXEC);
 
     sigprocmask(SIG_BLOCK, &ttyblock, &omask);
-    tq_foreach_fwd(&io_plugins, plugin) {
+    TAILQ_FOREACH(plugin, &io_plugins, entries) {
 	if (plugin->u.io->log_stderr) {
 	    if (!plugin->u.io->log_stderr(buf, n)) {
 	    	rval = false;
diff --git a/src/load_plugins.c b/src/load_plugins.c
index 1817d0efd..c84dacbf1 100644
--- a/src/load_plugins.c
+++ b/src/load_plugins.c
@@ -231,7 +231,7 @@ sudo_load_plugin(struct plugin_container *policy_plugin,
 	}
     } else if (plugin->type == SUDO_IO_PLUGIN) {
 	/* Check for duplicate entries. */
-	tq_foreach_fwd(io_plugins, container) {
+	TAILQ_FOREACH(container, io_plugins, entries) {
 	    if (strcmp(container->name, info->symbol_name) == 0) {
 		warningx(_("ignoring duplicate I/O plugin `%s' in %s, line %d"),
 		    info->symbol_name, _PATH_SUDO_CONF, info->lineno);
@@ -242,13 +242,11 @@ sudo_load_plugin(struct plugin_container *policy_plugin,
 	}
 	if (handle != NULL) {
 	    container = ecalloc(1, sizeof(*container));
-	    container->prev = container;
-	    /* container->next = NULL; */
 	    container->handle = handle;
 	    container->name = info->symbol_name;
 	    container->options = info->options;
 	    container->u.generic = plugin;
-	    tq_append(io_plugins, container);
+	    TAILQ_INSERT_TAIL(io_plugins, container, entries);
 	}
     }
 
@@ -272,7 +270,7 @@ sudo_load_plugins(struct plugin_container *policy_plugin,
 
     /* Walk the plugin list from sudo.conf, if any. */
     plugins = sudo_conf_plugins();
-    tq_foreach_fwd(plugins, info) {
+    TAILQ_FOREACH(info, plugins, entries) {
 	rval = sudo_load_plugin(policy_plugin, io_plugins, info);
 	if (!rval)
 	    goto done;
@@ -288,21 +286,17 @@ sudo_load_plugins(struct plugin_container *policy_plugin,
 	info->symbol_name = "sudoers_policy";
 	info->path = SUDOERS_PLUGIN;
 	/* info->options = NULL; */
-	info->prev = info;
-	/* info->next = NULL; */
 	rval = sudo_load_plugin(policy_plugin, io_plugins, info);
 	efree(info);
 	if (!rval)
 	    goto done;
 
 	/* Default I/O plugin */
-	if (tq_empty(io_plugins)) {
+	if (TAILQ_EMPTY(io_plugins)) {
 	    info = ecalloc(1, sizeof(*info));
 	    info->symbol_name = "sudoers_io";
 	    info->path = SUDOERS_PLUGIN;
 	    /* info->options = NULL; */
-	    info->prev = info;
-	    /* info->next = NULL; */
 	    rval = sudo_load_plugin(policy_plugin, io_plugins, info);
 	    efree(info);
 	    if (!rval)
@@ -321,7 +315,7 @@ sudo_load_plugins(struct plugin_container *policy_plugin,
 	if (policy_plugin->u.policy->register_hooks != NULL)
 	    policy_plugin->u.policy->register_hooks(SUDO_HOOK_VERSION, register_hook);
     }
-    tq_foreach_fwd(io_plugins, container) {
+    TAILQ_FOREACH(container, io_plugins, entries) {
 	if (container->u.io->version >= SUDO_API_MKVERSION(1, 2)) {
 	    if (container->u.io->register_hooks != NULL)
 		container->u.io->register_hooks(SUDO_HOOK_VERSION, register_hook);
diff --git a/src/sudo.c b/src/sudo.c
index 15190d260..a3a36ba20 100644
--- a/src/sudo.c
+++ b/src/sudo.c
@@ -92,7 +92,7 @@
  * Local variables
  */
 struct plugin_container policy_plugin;
-struct plugin_container_list io_plugins;
+struct plugin_container_list io_plugins = TAILQ_HEAD_INITIALIZER(io_plugins);
 struct user_details user_details;
 const char *list_user; /* extern for parse_args.c */
 static struct command_details command_details;
@@ -216,7 +216,7 @@ main(int argc, char *argv[], char *envp[])
     switch (sudo_mode & MODE_MASK) {
 	case MODE_VERSION:
 	    policy_show_version(&policy_plugin, !user_details.uid);
-	    tq_foreach_fwd(&io_plugins, plugin) {
+	    TAILQ_FOREACH(plugin, &io_plugins, entries) {
 		ok = iolog_open(plugin, settings, user_info, NULL,
 		    nargc, nargv, envp);
 		if (ok != -1)
@@ -250,8 +250,7 @@ main(int argc, char *argv[], char *envp[])
 		exit(1); /* plugin printed error message */
 	    }
 	    /* Open I/O plugins once policy plugin succeeds. */
-	    for (plugin = io_plugins.first; plugin != NULL; plugin = next) {
-		next = plugin->next;
+	    TAILQ_FOREACH_SAFE(plugin, &io_plugins, entries, next) {
 		ok = iolog_open(plugin, settings, user_info,
 		    command_info, nargc, nargv, envp);
 		switch (ok) {
@@ -1051,7 +1050,7 @@ run_command(struct command_details *details)
 	sudo_debug_printf(SUDO_DEBUG_DEBUG,
 	    "calling policy close with errno %d", cstat.val);
 	policy_close(&policy_plugin, 0, cstat.val);
-	tq_foreach_fwd(&io_plugins, plugin) {
+	TAILQ_FOREACH(plugin, &io_plugins, entries) {
 	    sudo_debug_printf(SUDO_DEBUG_DEBUG,
 		"calling I/O close with errno %d", cstat.val);
 	    iolog_close(plugin, 0, cstat.val);
@@ -1063,7 +1062,7 @@ run_command(struct command_details *details)
 	sudo_debug_printf(SUDO_DEBUG_DEBUG,
 	    "calling policy close with wait status %d", cstat.val);
 	policy_close(&policy_plugin, cstat.val, 0);
-	tq_foreach_fwd(&io_plugins, plugin) {
+	TAILQ_FOREACH(plugin, &io_plugins, entries) {
 	    sudo_debug_printf(SUDO_DEBUG_DEBUG,
 		"calling I/O close with wait status %d", cstat.val);
 	    iolog_close(plugin, cstat.val, 0);
@@ -1262,7 +1261,7 @@ iolog_unlink(struct plugin_container *plugin)
 		deregister_hook);
     }
     /* Remove from io_plugins list and free. */
-    tq_remove(&io_plugins, plugin);
+    TAILQ_REMOVE(&io_plugins, plugin, entries);
     efree(plugin);
 
     debug_return;
diff --git a/src/sudo.h b/src/sudo.h
index 7576d5ae4..9758c40c9 100644
--- a/src/sudo.h
+++ b/src/sudo.h
@@ -34,7 +34,6 @@
 #include "alloc.h"
 #include "fatal.h"
 #include "fileops.h"
-#include "list.h"
 #include "sudo_conf.h"
 #include "sudo_debug.h"
 #include "gettext.h"
diff --git a/src/sudo_plugin_int.h b/src/sudo_plugin_int.h
index 898ae4f49..a1d3e9baa 100644
--- a/src/sudo_plugin_int.h
+++ b/src/sudo_plugin_int.h
@@ -81,8 +81,7 @@ struct io_plugin_1_1 {
  * Sudo plugin internals.
  */
 struct plugin_container {
-    struct plugin_container *prev; /* required */
-    struct plugin_container *next; /* required */
+    TAILQ_ENTRY(plugin_container) entries;
     const char *name;
     char * const *options;
     void *handle;
@@ -95,7 +94,7 @@ struct plugin_container {
 	struct io_plugin_1_1 *io_1_1;
     } u;
 };
-TQ_DECLARE(plugin_container)
+TAILQ_HEAD(plugin_container_list, plugin_container);
 
 extern struct plugin_container policy_plugin;
 extern struct plugin_container_list io_plugins;