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index 658b602ba3f740d4a2672f6c633dc0e36ac9e746..11e28b4c912554caf2c9cae8adebb407a46ce0fb 100644 (file)
-/*-
- * 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.
- * 4. 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
- * $FreeBSD$
- */
-
-#ifndef _SYS_QUEUE_H_
-#define        _SYS_QUEUE_H_
-
 /*
- * This file defines four types of data structures: singly-linked lists,
- * singly-linked tail queues, lists and tail queues.
+ * lists and queues implementations
  *
- * 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.
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
  *
- * 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.
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
  *
- * 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 only be traversed in the forward 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_SAFE               +       +       +       +
- * _FOREACH_REVERSE            -       -       -       +
- * _FOREACH_REVERSE_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 {
-       char *lastfile;
-       int lastline;
-       char *prevfile;
-       int prevline;
-};
-
-#define        TRACEBUF        struct qm_trace trace;
-#define        TRASHIT(x)      do {(x) = (void *)-1;} while (0)
-#define        QMD_SAVELINK(name, link)        void **name = (void *)&(link)
-
-#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)
-
-#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
-#define        QMD_TRACE_ELEM(elem)
-#define        QMD_TRACE_HEAD(head)
-#define        QMD_SAVELINK(name, link)
-#define        TRACEBUF
-#define        TRASHIT(x)
-#endif /* QUEUE_MACRO_DEBUG */
-
-/*
- * Singly-linked List declarations.
- */
-#define SLIST_HEAD(name, type)                                                 \
-       struct name {                                                          \
-               struct type *slh_first; /* first element */                    \
-       }
-
-#define SLIST_HEAD_INITIALIZER(head)                                           \
-       {                                                                      \
-               NULL                                                           \
-       }
-
-#define SLIST_ENTRY(type)                                                      \
-       struct {                                                               \
-               struct type *sle_next; /* next element */                      \
-       }
-
-/*
- * Singly-linked List functions.
- */
-#define        SLIST_EMPTY(head)       ((head)->slh_first == NULL)
-
-#define        SLIST_FIRST(head)       ((head)->slh_first)
-
-#define SLIST_FOREACH(var, head, field)                                        \
-       for ((var) = SLIST_FIRST((head)); (var);                               \
-            (var) = SLIST_NEXT((var), field))
-
-#define SLIST_FOREACH_SAFE(var, head, field, tvar)                             \
-       for ((var) = SLIST_FIRST((head));                                      \
-            (var) && ((tvar) = SLIST_NEXT((var), field), 1); (var) = (tvar))
-
-#define SLIST_FOREACH_PREVPTR(var, varp, head, field)                          \
-       for ((varp) = &SLIST_FIRST((head)); ((var) = *(varp)) != NULL;         \
-            (varp) = &SLIST_NEXT((var), field))
-
-#define SLIST_INIT(head)                                                       \
-       do {                                                                   \
-               SLIST_FIRST((head)) = NULL;                                    \
-       } while (0)
-
-#define SLIST_INSERT_AFTER(slistelm, elm, field)                               \
-       do {                                                                   \
-               SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field);      \
-               SLIST_NEXT((slistelm), field) = (elm);                         \
-       } while (0)
-
-#define SLIST_INSERT_HEAD(head, elm, field)                                    \
-       do {                                                                   \
-               SLIST_NEXT((elm), field) = SLIST_FIRST((head));                \
-               SLIST_FIRST((head)) = (elm);                                   \
-       } while (0)
-
-#define        SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
-
-#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)
-
-#define SLIST_REMOVE_AFTER(elm, field)                                         \
-       do {                                                                   \
-               SLIST_NEXT(elm, field) =                                       \
-                       SLIST_NEXT(SLIST_NEXT(elm, field), field);             \
-       } while (0)
-
-#define SLIST_REMOVE_HEAD(head, field)                                         \
-       do {                                                                   \
-               SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field);  \
-       } while (0)
-
-#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.
- */
-#define STAILQ_HEAD(name, type)                                                \
-       struct name {                                                          \
-               struct type *stqh_first; /* first element */                   \
-               struct type **stqh_last; /* addr of last next element */       \
-       }
-
-#define STAILQ_HEAD_INITIALIZER(head)                                          \
-       {                                                                      \
-               NULL, &(head).stqh_first                                       \
-       }
-
-#define STAILQ_ENTRY(type)                                                     \
-       struct {                                                               \
-               struct type *stqe_next; /* next element */                     \
-       }
-
-/*
- * Singly-linked Tail queue functions.
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
-#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)
-
-#define        STAILQ_EMPTY(head)      ((head)->stqh_first == NULL)
-
-#define        STAILQ_FIRST(head)      ((head)->stqh_first)
-
-#define STAILQ_FOREACH(var, head, field)                                       \
-       for ((var) = STAILQ_FIRST((head)); (var);                              \
-            (var) = STAILQ_NEXT((var), field))
-
-
-#define STAILQ_FOREACH_SAFE(var, head, field, tvar)                            \
-       for ((var) = STAILQ_FIRST((head));                                     \
-            (var) && ((tvar) = STAILQ_NEXT((var), field), 1); (var) = (tvar))
-
-#define STAILQ_INIT(head)                                                      \
-       do {                                                                   \
-               STAILQ_FIRST((head)) = NULL;                                   \
-               (head)->stqh_last = &STAILQ_FIRST((head));                     \
-       } while (0)
-
-#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)
-
-#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)
-
-#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)
 
+#ifndef _FRR_QUEUE_H
+#define _FRR_QUEUE_H
+
+#if defined(__OpenBSD__) && !defined(STAILQ_HEAD)
+#include "openbsd-queue.h"
+
+/* Try to map FreeBSD implementation to OpenBSD one. */
+#define STAILQ_HEAD(name, type)                                SIMPLEQ_HEAD(name, type)
+#define STAILQ_HEAD_INITIALIZER(head)                  SIMPLEQ_HEAD_INITIALIZER(head)
+#define STAILQ_ENTRY(entry)                            SIMPLEQ_ENTRY(entry)
+
+#define STAILQ_CONCAT(head1, head2)                    SIMPLEQ_CONCAT(head1, head2)
+#define STAILQ_EMPTY(head)                             SIMPLEQ_EMPTY(head)
+#define STAILQ_FIRST(head)                             SIMPLEQ_FIRST(head)
+#define STAILQ_FOREACH(var, head, field)               SIMPLEQ_FOREACH(var, head, field)
+#define STAILQ_FOREACH_SAFE(var, head, field, tvar)    SIMPLEQ_FOREACH_SAFE(var, head, field, tvar)
+#define STAILQ_INIT(head)                              SIMPLEQ_INIT(head)
+#define STAILQ_INSERT_AFTER(head, tqelm, elm, field)   SIMPLEQ_INSERT_AFTER(head, tqelm, elm, field)
+#define STAILQ_INSERT_HEAD(head, elm, field)           SIMPLEQ_INSERT_HEAD(head, elm, field)
+#define STAILQ_INSERT_TAIL(head, elm, field)           SIMPLEQ_INSERT_TAIL(head, elm, field)
 #define STAILQ_LAST(head, type, field)                                         \
-       (STAILQ_EMPTY((head))                                                  \
+       (SIMPLEQ_EMPTY((head))                                                 \
                 ? NULL                                                        \
-                : ((struct type *)(void *)((char *)((head)->stqh_last)        \
-                                           - __offsetof(struct type,          \
-                                                        field))))
-
-#define        STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
-
+                : ((struct type *)(void *)((char *)((head)->sqh_last)         \
+                                           - offsetof(struct type, field))))
+#define STAILQ_NEXT(elm, field)                                SIMPLEQ_NEXT(elm, field)
 #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);                     \
+               if (SIMPLEQ_FIRST((head)) == (elm)) {                          \
+                       SIMPLEQ_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);              \
+                       struct type *curelm = SIMPLEQ_FIRST((head));           \
+                       while (SIMPLEQ_NEXT(curelm, field) != (elm))           \
+                               curelm = SIMPLEQ_NEXT(curelm, field);          \
+                       SIMPLEQ_REMOVE_AFTER(head, curelm, field);             \
                }                                                              \
-               TRASHIT(*oldnext);                                             \
-       } while (0)
-
-#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)
-
-#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)
-
+#define STAILQ_REMOVE_AFTER(head, elm, field)          SIMPLEQ_REMOVE_AFTER(head, elm, field)
+#define STAILQ_REMOVE_HEAD(head, field)                        SIMPLEQ_REMOVE_HEAD(head, field)
 #define STAILQ_SWAP(head1, head2, type)                                        \
        do {                                                                   \
                struct type *swap_first = STAILQ_FIRST(head1);                 \
-               struct type **swap_last = (head1)->stqh_last;                  \
+               struct type **swap_last = (head1)->sqh_last;                   \
                STAILQ_FIRST(head1) = STAILQ_FIRST(head2);                     \
-               (head1)->stqh_last = (head2)->stqh_last;                       \
+               (head1)->sqh_last = (head2)->sqh_last;                         \
                STAILQ_FIRST(head2) = swap_first;                              \
-               (head2)->stqh_last = swap_last;                                \
+               (head2)->sqh_last = swap_last;                                 \
                if (STAILQ_EMPTY(head1))                                       \
-                       (head1)->stqh_last = &STAILQ_FIRST(head1);             \
+                       (head1)->sqh_last = &STAILQ_FIRST(head1);              \
                if (STAILQ_EMPTY(head2))                                       \
-                       (head2)->stqh_last = &STAILQ_FIRST(head2);             \
-       } while (0)
-
-
-/*
- * List declarations.
- */
-#define LIST_HEAD(name, type)                                                  \
-       struct name {                                                          \
-               struct type *lh_first; /* first element */                     \
-       }
-
-#define LIST_HEAD_INITIALIZER(head)                                            \
-       {                                                                      \
-               NULL                                                           \
-       }
-
-#define LIST_ENTRY(type)                                                       \
-       struct {                                                               \
-               struct type *le_next;  /* next element */                      \
-               struct type **le_prev; /* address of previous next element */  \
-       }
-
-/*
- * List functions.
- */
-
-#if (defined(_KERNEL) && defined(INVARIANTS))
-#define QMD_LIST_CHECK_HEAD(head, field)                                       \
-       do {                                                                   \
-               if (LIST_FIRST((head)) != NULL                                 \
-                   && LIST_FIRST((head))->field.le_prev                       \
-                              != &LIST_FIRST((head)))                         \
-                       panic("Bad list head %p first->prev != head", (head)); \
-       } while (0)
-
-#define QMD_LIST_CHECK_NEXT(elm, field)                                        \
-       do {                                                                   \
-               if (LIST_NEXT((elm), field) != NULL                            \
-                   && LIST_NEXT((elm), field)->field.le_prev                  \
-                              != &((elm)->field.le_next))                     \
-                       panic("Bad link elm %p next->prev != elm", (elm));     \
-       } while (0)
-
-#define QMD_LIST_CHECK_PREV(elm, field)                                        \
-       do {                                                                   \
-               if (*(elm)->field.le_prev != (elm))                            \
-                       panic("Bad link elm %p prev->next != elm", (elm));     \
-       } while (0)
-#else
-#define        QMD_LIST_CHECK_HEAD(head, field)
-#define        QMD_LIST_CHECK_NEXT(elm, field)
-#define        QMD_LIST_CHECK_PREV(elm, field)
-#endif /* (_KERNEL && INVARIANTS) */
-
-#define        LIST_EMPTY(head)        ((head)->lh_first == NULL)
-
-#define        LIST_FIRST(head)        ((head)->lh_first)
-
-#define LIST_FOREACH(var, head, field)                                         \
-       for ((var) = LIST_FIRST((head)); (var); (var) = LIST_NEXT((var), field))
-
-#define LIST_FOREACH_SAFE(var, head, field, tvar)                              \
-       for ((var) = LIST_FIRST((head));                                       \
-            (var) && ((tvar) = LIST_NEXT((var), field), 1); (var) = (tvar))
-
-#define LIST_INIT(head)                                                        \
-       do {                                                                   \
-               LIST_FIRST((head)) = NULL;                                     \
-       } while (0)
-
-#define LIST_INSERT_AFTER(listelm, elm, field)                                 \
-       do {                                                                   \
-               QMD_LIST_CHECK_NEXT(listelm, field);                           \
-               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)
-
-#define LIST_INSERT_BEFORE(listelm, elm, field)                                \
-       do {                                                                   \
-               QMD_LIST_CHECK_PREV(listelm, field);                           \
-               (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)
-
-#define LIST_INSERT_HEAD(head, elm, field)                                     \
-       do {                                                                   \
-               QMD_LIST_CHECK_HEAD((head), field);                            \
-               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)
-
-#define        LIST_NEXT(elm, field)   ((elm)->field.le_next)
-
-#define LIST_REMOVE(elm, field)                                                \
-       do {                                                                   \
-               QMD_SAVELINK(oldnext, (elm)->field.le_next);                   \
-               QMD_SAVELINK(oldprev, (elm)->field.le_prev);                   \
-               QMD_LIST_CHECK_NEXT(elm, field);                               \
-               QMD_LIST_CHECK_PREV(elm, field);                               \
-               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)
-
-#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.
- */
-#define TAILQ_HEAD(name, type)                                                 \
-       struct name {                                                          \
-               struct type *tqh_first; /* first element */                    \
-               struct type **tqh_last; /* addr of last next element */        \
-               TRACEBUF                                                       \
-       }
-
-#define TAILQ_HEAD_INITIALIZER(head)                                           \
-       {                                                                      \
-               NULL, &(head).tqh_first                                        \
-       }
-
-#define TAILQ_ENTRY(type)                                                      \
-       struct {                                                               \
-               struct type *tqe_next;  /* next element */                     \
-               struct type **tqe_prev; /* address of previous next element */ \
-               TRACEBUF                                                       \
-       }
-
-/*
- * Tail queue functions.
- */
-#if (defined(_KERNEL) && defined(INVARIANTS))
-#define QMD_TAILQ_CHECK_HEAD(head, field)                                      \
-       do {                                                                   \
-               if (!TAILQ_EMPTY(head)                                         \
-                   && TAILQ_FIRST((head))->field.tqe_prev                     \
-                              != &TAILQ_FIRST((head)))                        \
-                       panic("Bad tailq head %p first->prev != head",         \
-                             (head));                                         \
-       } while (0)
-
-#define QMD_TAILQ_CHECK_TAIL(head, field)                                      \
-       do {                                                                   \
-               if (*(head)->tqh_last != NULL)                                 \
-                       panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \
-       } while (0)
-
-#define QMD_TAILQ_CHECK_NEXT(elm, field)                                       \
-       do {                                                                   \
-               if (TAILQ_NEXT((elm), field) != NULL                           \
-                   && TAILQ_NEXT((elm), field)->field.tqe_prev                \
-                              != &((elm)->field.tqe_next))                    \
-                       panic("Bad link elm %p next->prev != elm", (elm));     \
-       } while (0)
-
-#define QMD_TAILQ_CHECK_PREV(elm, field)                                       \
-       do {                                                                   \
-               if (*(elm)->field.tqe_prev != (elm))                           \
-                       panic("Bad link elm %p prev->next != elm", (elm));     \
+                       (head2)->sqh_last = &STAILQ_FIRST(head2);              \
        } while (0)
 #else
-#define        QMD_TAILQ_CHECK_HEAD(head, field)
-#define        QMD_TAILQ_CHECK_TAIL(head, headname)
-#define        QMD_TAILQ_CHECK_NEXT(elm, field)
-#define        QMD_TAILQ_CHECK_PREV(elm, field)
-#endif /* (_KERNEL && INVARIANTS) */
-
-#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)
-
-#define        TAILQ_EMPTY(head)       ((head)->tqh_first == NULL)
-
-#define        TAILQ_FIRST(head)       ((head)->tqh_first)
-
-#define TAILQ_FOREACH(var, head, field)                                        \
-       for ((var) = TAILQ_FIRST((head)); (var);                               \
-            (var) = TAILQ_NEXT((var), field))
-
-#define TAILQ_FOREACH_SAFE(var, head, field, tvar)                             \
-       for ((var) = TAILQ_FIRST((head));                                      \
-            (var) && ((tvar) = TAILQ_NEXT((var), field), 1); (var) = (tvar))
-
-#define TAILQ_FOREACH_REVERSE(var, head, headname, field)                      \
-       for ((var) = TAILQ_LAST((head), headname); (var);                      \
-            (var) = TAILQ_PREV((var), headname, field))
-
-#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))
-
-#define TAILQ_INIT(head)                                                       \
-       do {                                                                   \
-               TAILQ_FIRST((head)) = NULL;                                    \
-               (head)->tqh_last = &TAILQ_FIRST((head));                       \
-               QMD_TRACE_HEAD(head);                                          \
-       } while (0)
-
-#define TAILQ_INSERT_AFTER(head, listelm, elm, field)                          \
-       do {                                                                   \
-               QMD_TAILQ_CHECK_NEXT(listelm, field);                          \
-               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)
-
-#define TAILQ_INSERT_BEFORE(listelm, elm, field)                               \
-       do {                                                                   \
-               QMD_TAILQ_CHECK_PREV(listelm, field);                          \
-               (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)
-
-#define TAILQ_INSERT_HEAD(head, elm, field)                                    \
-       do {                                                                   \
-               QMD_TAILQ_CHECK_HEAD(head, field);                             \
-               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)
-
-#define TAILQ_INSERT_TAIL(head, elm, field)                                    \
-       do {                                                                   \
-               QMD_TAILQ_CHECK_TAIL(head, field);                             \
-               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)
-
-#define TAILQ_LAST(head, headname)                                             \
-       (*(((struct headname *)((head)->tqh_last))->tqh_last))
-
-#define        TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
-
-#define TAILQ_PREV(elm, headname, field)                                       \
-       (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
-
-#define TAILQ_REMOVE(head, elm, field)                                         \
-       do {                                                                   \
-               QMD_SAVELINK(oldnext, (elm)->field.tqe_next);                  \
-               QMD_SAVELINK(oldprev, (elm)->field.tqe_prev);                  \
-               QMD_TAILQ_CHECK_NEXT(elm, field);                              \
-               QMD_TAILQ_CHECK_PREV(elm, field);                              \
-               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)
-
-#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;      \
+#include "freebsd-queue.h"
+#endif /* defined(__OpenBSD__) && !defined(STAILQ_HEAD) */
+
+#ifndef TAILQ_POP_FIRST
+#define TAILQ_POP_FIRST(head, field)                                           \
+       ({  typeof((head)->tqh_first) _elm = TAILQ_FIRST(head);                \
+           if (_elm) {                                                        \
+               if ((TAILQ_NEXT((_elm), field)) != NULL)                       \
+                       TAILQ_NEXT((_elm), field)->field.tqe_prev =            \
+                               &TAILQ_FIRST(head);                            \
                else                                                           \
-                       (head2)->tqh_last = &(head2)->tqh_first;               \
-       } while (0)
+                       (head)->tqh_last = &TAILQ_FIRST(head);                 \
+               TAILQ_FIRST(head) = TAILQ_NEXT((_elm), field);                 \
+       }; _elm; })
+#endif
 
-#endif /* !_SYS_QUEUE_H_ */
+#endif /* _FRR_QUEUE_H */