blkcg: misc preparations for unified hierarchy interface
[linux-2.6/btrfs-unstable.git] / net / tipc / msg.h
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1 /*
2 * net/tipc/msg.h: Include file for TIPC message header routines
4 * Copyright (c) 2000-2007, 2014-2015 Ericsson AB
5 * Copyright (c) 2005-2008, 2010-2011, Wind River Systems
6 * All rights reserved.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the names of the copyright holders nor the names of its
17 * contributors may be used to endorse or promote products derived from
18 * this software without specific prior written permission.
20 * Alternatively, this software may be distributed under the terms of the
21 * GNU General Public License ("GPL") version 2 as published by the Free
22 * Software Foundation.
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
37 #ifndef _TIPC_MSG_H
38 #define _TIPC_MSG_H
40 #include <linux/tipc.h>
43 * Constants and routines used to read and write TIPC payload message headers
45 * Note: Some items are also used with TIPC internal message headers
47 #define TIPC_VERSION 2
48 struct plist;
51 * Payload message users are defined in TIPC's public API:
52 * - TIPC_LOW_IMPORTANCE
53 * - TIPC_MEDIUM_IMPORTANCE
54 * - TIPC_HIGH_IMPORTANCE
55 * - TIPC_CRITICAL_IMPORTANCE
57 #define TIPC_SYSTEM_IMPORTANCE 4
61 * Payload message types
63 #define TIPC_CONN_MSG 0
64 #define TIPC_MCAST_MSG 1
65 #define TIPC_NAMED_MSG 2
66 #define TIPC_DIRECT_MSG 3
69 * Internal message users
71 #define BCAST_PROTOCOL 5
72 #define MSG_BUNDLER 6
73 #define LINK_PROTOCOL 7
74 #define CONN_MANAGER 8
75 #define TUNNEL_PROTOCOL 10
76 #define NAME_DISTRIBUTOR 11
77 #define MSG_FRAGMENTER 12
78 #define LINK_CONFIG 13
79 #define SOCK_WAKEUP 14 /* pseudo user */
82 * Message header sizes
84 #define SHORT_H_SIZE 24 /* In-cluster basic payload message */
85 #define BASIC_H_SIZE 32 /* Basic payload message */
86 #define NAMED_H_SIZE 40 /* Named payload message */
87 #define MCAST_H_SIZE 44 /* Multicast payload message */
88 #define INT_H_SIZE 40 /* Internal messages */
89 #define MIN_H_SIZE 24 /* Smallest legal TIPC header size */
90 #define MAX_H_SIZE 60 /* Largest possible TIPC header size */
92 #define MAX_MSG_SIZE (MAX_H_SIZE + TIPC_MAX_USER_MSG_SIZE)
94 #define TIPC_MEDIA_INFO_OFFSET 5
96 /**
97 * TIPC message buffer code
99 * TIPC message buffer headroom reserves space for the worst-case
100 * link-level device header (in case the message is sent off-node).
102 * Note: Headroom should be a multiple of 4 to ensure the TIPC header fields
103 * are word aligned for quicker access
105 #define BUF_HEADROOM (LL_MAX_HEADER + 48)
107 struct tipc_skb_cb {
108 void *handle;
109 struct sk_buff *tail;
110 bool validated;
111 bool wakeup_pending;
112 bool bundling;
113 u16 chain_sz;
114 u16 chain_imp;
117 #define TIPC_SKB_CB(__skb) ((struct tipc_skb_cb *)&((__skb)->cb[0]))
119 struct tipc_msg {
120 __be32 hdr[15];
123 static inline struct tipc_msg *buf_msg(struct sk_buff *skb)
125 return (struct tipc_msg *)skb->data;
128 static inline u32 msg_word(struct tipc_msg *m, u32 pos)
130 return ntohl(m->hdr[pos]);
133 static inline void msg_set_word(struct tipc_msg *m, u32 w, u32 val)
135 m->hdr[w] = htonl(val);
138 static inline u32 msg_bits(struct tipc_msg *m, u32 w, u32 pos, u32 mask)
140 return (msg_word(m, w) >> pos) & mask;
143 static inline void msg_set_bits(struct tipc_msg *m, u32 w,
144 u32 pos, u32 mask, u32 val)
146 val = (val & mask) << pos;
147 mask = mask << pos;
148 m->hdr[w] &= ~htonl(mask);
149 m->hdr[w] |= htonl(val);
152 static inline void msg_swap_words(struct tipc_msg *msg, u32 a, u32 b)
154 u32 temp = msg->hdr[a];
156 msg->hdr[a] = msg->hdr[b];
157 msg->hdr[b] = temp;
161 * Word 0
163 static inline u32 msg_version(struct tipc_msg *m)
165 return msg_bits(m, 0, 29, 7);
168 static inline void msg_set_version(struct tipc_msg *m)
170 msg_set_bits(m, 0, 29, 7, TIPC_VERSION);
173 static inline u32 msg_user(struct tipc_msg *m)
175 return msg_bits(m, 0, 25, 0xf);
178 static inline u32 msg_isdata(struct tipc_msg *m)
180 return msg_user(m) <= TIPC_CRITICAL_IMPORTANCE;
183 static inline void msg_set_user(struct tipc_msg *m, u32 n)
185 msg_set_bits(m, 0, 25, 0xf, n);
188 static inline u32 msg_hdr_sz(struct tipc_msg *m)
190 return msg_bits(m, 0, 21, 0xf) << 2;
193 static inline void msg_set_hdr_sz(struct tipc_msg *m, u32 n)
195 msg_set_bits(m, 0, 21, 0xf, n>>2);
198 static inline u32 msg_size(struct tipc_msg *m)
200 return msg_bits(m, 0, 0, 0x1ffff);
203 static inline u32 msg_data_sz(struct tipc_msg *m)
205 return msg_size(m) - msg_hdr_sz(m);
208 static inline int msg_non_seq(struct tipc_msg *m)
210 return msg_bits(m, 0, 20, 1);
213 static inline void msg_set_non_seq(struct tipc_msg *m, u32 n)
215 msg_set_bits(m, 0, 20, 1, n);
218 static inline int msg_dest_droppable(struct tipc_msg *m)
220 return msg_bits(m, 0, 19, 1);
223 static inline void msg_set_dest_droppable(struct tipc_msg *m, u32 d)
225 msg_set_bits(m, 0, 19, 1, d);
228 static inline int msg_src_droppable(struct tipc_msg *m)
230 return msg_bits(m, 0, 18, 1);
233 static inline void msg_set_src_droppable(struct tipc_msg *m, u32 d)
235 msg_set_bits(m, 0, 18, 1, d);
238 static inline void msg_set_size(struct tipc_msg *m, u32 sz)
240 m->hdr[0] = htonl((msg_word(m, 0) & ~0x1ffff) | sz);
243 static inline unchar *msg_data(struct tipc_msg *m)
245 return ((unchar *)m) + msg_hdr_sz(m);
248 static inline struct tipc_msg *msg_get_wrapped(struct tipc_msg *m)
250 return (struct tipc_msg *)msg_data(m);
254 * Word 1
256 static inline u32 msg_type(struct tipc_msg *m)
258 return msg_bits(m, 1, 29, 0x7);
261 static inline void msg_set_type(struct tipc_msg *m, u32 n)
263 msg_set_bits(m, 1, 29, 0x7, n);
266 static inline u32 msg_named(struct tipc_msg *m)
268 return msg_type(m) == TIPC_NAMED_MSG;
271 static inline u32 msg_mcast(struct tipc_msg *m)
273 return msg_type(m) == TIPC_MCAST_MSG;
276 static inline u32 msg_connected(struct tipc_msg *m)
278 return msg_type(m) == TIPC_CONN_MSG;
281 static inline u32 msg_errcode(struct tipc_msg *m)
283 return msg_bits(m, 1, 25, 0xf);
286 static inline void msg_set_errcode(struct tipc_msg *m, u32 err)
288 msg_set_bits(m, 1, 25, 0xf, err);
291 static inline u32 msg_reroute_cnt(struct tipc_msg *m)
293 return msg_bits(m, 1, 21, 0xf);
296 static inline void msg_incr_reroute_cnt(struct tipc_msg *m)
298 msg_set_bits(m, 1, 21, 0xf, msg_reroute_cnt(m) + 1);
301 static inline void msg_reset_reroute_cnt(struct tipc_msg *m)
303 msg_set_bits(m, 1, 21, 0xf, 0);
306 static inline u32 msg_lookup_scope(struct tipc_msg *m)
308 return msg_bits(m, 1, 19, 0x3);
311 static inline void msg_set_lookup_scope(struct tipc_msg *m, u32 n)
313 msg_set_bits(m, 1, 19, 0x3, n);
316 static inline u16 msg_bcast_ack(struct tipc_msg *m)
318 return msg_bits(m, 1, 0, 0xffff);
321 static inline void msg_set_bcast_ack(struct tipc_msg *m, u16 n)
323 msg_set_bits(m, 1, 0, 0xffff, n);
328 * Word 2
330 static inline u16 msg_ack(struct tipc_msg *m)
332 return msg_bits(m, 2, 16, 0xffff);
335 static inline void msg_set_ack(struct tipc_msg *m, u16 n)
337 msg_set_bits(m, 2, 16, 0xffff, n);
340 static inline u16 msg_seqno(struct tipc_msg *m)
342 return msg_bits(m, 2, 0, 0xffff);
345 static inline void msg_set_seqno(struct tipc_msg *m, u16 n)
347 msg_set_bits(m, 2, 0, 0xffff, n);
351 * Words 3-10
353 static inline u32 msg_importance(struct tipc_msg *m)
355 int usr = msg_user(m);
357 if (likely((usr <= TIPC_CRITICAL_IMPORTANCE) && !msg_errcode(m)))
358 return usr;
359 if ((usr == MSG_FRAGMENTER) || (usr == MSG_BUNDLER))
360 return msg_bits(m, 5, 13, 0x7);
361 return TIPC_SYSTEM_IMPORTANCE;
364 static inline void msg_set_importance(struct tipc_msg *m, u32 i)
366 int usr = msg_user(m);
368 if (likely((usr == MSG_FRAGMENTER) || (usr == MSG_BUNDLER)))
369 msg_set_bits(m, 5, 13, 0x7, i);
370 else if (i < TIPC_SYSTEM_IMPORTANCE)
371 msg_set_user(m, i);
372 else
373 pr_warn("Trying to set illegal importance in message\n");
376 static inline u32 msg_prevnode(struct tipc_msg *m)
378 return msg_word(m, 3);
381 static inline void msg_set_prevnode(struct tipc_msg *m, u32 a)
383 msg_set_word(m, 3, a);
386 static inline u32 msg_origport(struct tipc_msg *m)
388 if (msg_user(m) == MSG_FRAGMENTER)
389 m = msg_get_wrapped(m);
390 return msg_word(m, 4);
393 static inline void msg_set_origport(struct tipc_msg *m, u32 p)
395 msg_set_word(m, 4, p);
398 static inline u32 msg_destport(struct tipc_msg *m)
400 return msg_word(m, 5);
403 static inline void msg_set_destport(struct tipc_msg *m, u32 p)
405 msg_set_word(m, 5, p);
408 static inline u32 msg_mc_netid(struct tipc_msg *m)
410 return msg_word(m, 5);
413 static inline void msg_set_mc_netid(struct tipc_msg *m, u32 p)
415 msg_set_word(m, 5, p);
418 static inline int msg_short(struct tipc_msg *m)
420 return msg_hdr_sz(m) == SHORT_H_SIZE;
423 static inline u32 msg_orignode(struct tipc_msg *m)
425 if (likely(msg_short(m)))
426 return msg_prevnode(m);
427 return msg_word(m, 6);
430 static inline void msg_set_orignode(struct tipc_msg *m, u32 a)
432 msg_set_word(m, 6, a);
435 static inline u32 msg_destnode(struct tipc_msg *m)
437 return msg_word(m, 7);
440 static inline void msg_set_destnode(struct tipc_msg *m, u32 a)
442 msg_set_word(m, 7, a);
445 static inline u32 msg_nametype(struct tipc_msg *m)
447 return msg_word(m, 8);
450 static inline void msg_set_nametype(struct tipc_msg *m, u32 n)
452 msg_set_word(m, 8, n);
455 static inline u32 msg_nameinst(struct tipc_msg *m)
457 return msg_word(m, 9);
460 static inline u32 msg_namelower(struct tipc_msg *m)
462 return msg_nameinst(m);
465 static inline void msg_set_namelower(struct tipc_msg *m, u32 n)
467 msg_set_word(m, 9, n);
470 static inline void msg_set_nameinst(struct tipc_msg *m, u32 n)
472 msg_set_namelower(m, n);
475 static inline u32 msg_nameupper(struct tipc_msg *m)
477 return msg_word(m, 10);
480 static inline void msg_set_nameupper(struct tipc_msg *m, u32 n)
482 msg_set_word(m, 10, n);
486 * Constants and routines used to read and write TIPC internal message headers
490 * Connection management protocol message types
492 #define CONN_PROBE 0
493 #define CONN_PROBE_REPLY 1
494 #define CONN_ACK 2
497 * Name distributor message types
499 #define PUBLICATION 0
500 #define WITHDRAWAL 1
503 * Segmentation message types
505 #define FIRST_FRAGMENT 0
506 #define FRAGMENT 1
507 #define LAST_FRAGMENT 2
510 * Link management protocol message types
512 #define STATE_MSG 0
513 #define RESET_MSG 1
514 #define ACTIVATE_MSG 2
517 * Changeover tunnel message types
519 #define SYNCH_MSG 0
520 #define FAILOVER_MSG 1
523 * Config protocol message types
525 #define DSC_REQ_MSG 0
526 #define DSC_RESP_MSG 1
529 * Word 1
531 static inline u32 msg_seq_gap(struct tipc_msg *m)
533 return msg_bits(m, 1, 16, 0x1fff);
536 static inline void msg_set_seq_gap(struct tipc_msg *m, u32 n)
538 msg_set_bits(m, 1, 16, 0x1fff, n);
541 static inline u32 msg_node_sig(struct tipc_msg *m)
543 return msg_bits(m, 1, 0, 0xffff);
546 static inline void msg_set_node_sig(struct tipc_msg *m, u32 n)
548 msg_set_bits(m, 1, 0, 0xffff, n);
551 static inline u32 msg_node_capabilities(struct tipc_msg *m)
553 return msg_bits(m, 1, 15, 0x1fff);
556 static inline void msg_set_node_capabilities(struct tipc_msg *m, u32 n)
558 msg_set_bits(m, 1, 15, 0x1fff, n);
561 static inline bool msg_dup(struct tipc_msg *m)
563 if (likely(msg_user(m) != TUNNEL_PROTOCOL))
564 return false;
565 if (msg_type(m) != SYNCH_MSG)
566 return false;
567 return true;
571 * Word 2
573 static inline u32 msg_dest_domain(struct tipc_msg *m)
575 return msg_word(m, 2);
578 static inline void msg_set_dest_domain(struct tipc_msg *m, u32 n)
580 msg_set_word(m, 2, n);
583 static inline u32 msg_bcgap_after(struct tipc_msg *m)
585 return msg_bits(m, 2, 16, 0xffff);
588 static inline void msg_set_bcgap_after(struct tipc_msg *m, u32 n)
590 msg_set_bits(m, 2, 16, 0xffff, n);
593 static inline u32 msg_bcgap_to(struct tipc_msg *m)
595 return msg_bits(m, 2, 0, 0xffff);
598 static inline void msg_set_bcgap_to(struct tipc_msg *m, u32 n)
600 msg_set_bits(m, 2, 0, 0xffff, n);
605 * Word 4
607 static inline u32 msg_last_bcast(struct tipc_msg *m)
609 return msg_bits(m, 4, 16, 0xffff);
612 static inline void msg_set_last_bcast(struct tipc_msg *m, u32 n)
614 msg_set_bits(m, 4, 16, 0xffff, n);
617 static inline void msg_set_fragm_no(struct tipc_msg *m, u32 n)
619 msg_set_bits(m, 4, 16, 0xffff, n);
623 static inline u32 msg_next_sent(struct tipc_msg *m)
625 return msg_bits(m, 4, 0, 0xffff);
628 static inline void msg_set_next_sent(struct tipc_msg *m, u32 n)
630 msg_set_bits(m, 4, 0, 0xffff, n);
633 static inline void msg_set_long_msgno(struct tipc_msg *m, u32 n)
635 msg_set_bits(m, 4, 0, 0xffff, n);
638 static inline u32 msg_bc_netid(struct tipc_msg *m)
640 return msg_word(m, 4);
643 static inline void msg_set_bc_netid(struct tipc_msg *m, u32 id)
645 msg_set_word(m, 4, id);
648 static inline u32 msg_link_selector(struct tipc_msg *m)
650 return msg_bits(m, 4, 0, 1);
653 static inline void msg_set_link_selector(struct tipc_msg *m, u32 n)
655 msg_set_bits(m, 4, 0, 1, n);
659 * Word 5
661 static inline u32 msg_session(struct tipc_msg *m)
663 return msg_bits(m, 5, 16, 0xffff);
666 static inline void msg_set_session(struct tipc_msg *m, u32 n)
668 msg_set_bits(m, 5, 16, 0xffff, n);
671 static inline u32 msg_probe(struct tipc_msg *m)
673 return msg_bits(m, 5, 0, 1);
676 static inline void msg_set_probe(struct tipc_msg *m, u32 val)
678 msg_set_bits(m, 5, 0, 1, val);
681 static inline char msg_net_plane(struct tipc_msg *m)
683 return msg_bits(m, 5, 1, 7) + 'A';
686 static inline void msg_set_net_plane(struct tipc_msg *m, char n)
688 msg_set_bits(m, 5, 1, 7, (n - 'A'));
691 static inline u32 msg_linkprio(struct tipc_msg *m)
693 return msg_bits(m, 5, 4, 0x1f);
696 static inline void msg_set_linkprio(struct tipc_msg *m, u32 n)
698 msg_set_bits(m, 5, 4, 0x1f, n);
701 static inline u32 msg_bearer_id(struct tipc_msg *m)
703 return msg_bits(m, 5, 9, 0x7);
706 static inline void msg_set_bearer_id(struct tipc_msg *m, u32 n)
708 msg_set_bits(m, 5, 9, 0x7, n);
711 static inline u32 msg_redundant_link(struct tipc_msg *m)
713 return msg_bits(m, 5, 12, 0x1);
716 static inline void msg_set_redundant_link(struct tipc_msg *m, u32 r)
718 msg_set_bits(m, 5, 12, 0x1, r);
721 static inline char *msg_media_addr(struct tipc_msg *m)
723 return (char *)&m->hdr[TIPC_MEDIA_INFO_OFFSET];
727 * Word 9
729 static inline u32 msg_msgcnt(struct tipc_msg *m)
731 return msg_bits(m, 9, 16, 0xffff);
734 static inline void msg_set_msgcnt(struct tipc_msg *m, u32 n)
736 msg_set_bits(m, 9, 16, 0xffff, n);
739 static inline u32 msg_bcast_tag(struct tipc_msg *m)
741 return msg_bits(m, 9, 16, 0xffff);
744 static inline void msg_set_bcast_tag(struct tipc_msg *m, u32 n)
746 msg_set_bits(m, 9, 16, 0xffff, n);
749 static inline u32 msg_max_pkt(struct tipc_msg *m)
751 return msg_bits(m, 9, 16, 0xffff) * 4;
754 static inline void msg_set_max_pkt(struct tipc_msg *m, u32 n)
756 msg_set_bits(m, 9, 16, 0xffff, (n / 4));
759 static inline u32 msg_link_tolerance(struct tipc_msg *m)
761 return msg_bits(m, 9, 0, 0xffff);
764 static inline void msg_set_link_tolerance(struct tipc_msg *m, u32 n)
766 msg_set_bits(m, 9, 0, 0xffff, n);
769 struct sk_buff *tipc_buf_acquire(u32 size);
770 bool tipc_msg_validate(struct sk_buff *skb);
771 bool tipc_msg_reverse(u32 own_addr, struct sk_buff *buf, u32 *dnode,
772 int err);
773 void tipc_msg_init(u32 own_addr, struct tipc_msg *m, u32 user, u32 type,
774 u32 hsize, u32 destnode);
775 struct sk_buff *tipc_msg_create(uint user, uint type, uint hdr_sz,
776 uint data_sz, u32 dnode, u32 onode,
777 u32 dport, u32 oport, int errcode);
778 int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf);
779 bool tipc_msg_bundle(struct sk_buff *skb, struct tipc_msg *msg, u32 mtu);
780 bool tipc_msg_make_bundle(struct sk_buff **skb, struct tipc_msg *msg,
781 u32 mtu, u32 dnode);
782 bool tipc_msg_extract(struct sk_buff *skb, struct sk_buff **iskb, int *pos);
783 int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
784 int offset, int dsz, int mtu, struct sk_buff_head *list);
785 bool tipc_msg_lookup_dest(struct net *net, struct sk_buff *skb, u32 *dnode,
786 int *err);
787 struct sk_buff *tipc_msg_reassemble(struct sk_buff_head *list);
789 static inline u16 buf_seqno(struct sk_buff *skb)
791 return msg_seqno(buf_msg(skb));
794 /* tipc_skb_peek(): peek and reserve first buffer in list
795 * @list: list to be peeked in
796 * Returns pointer to first buffer in list, if any
798 static inline struct sk_buff *tipc_skb_peek(struct sk_buff_head *list,
799 spinlock_t *lock)
801 struct sk_buff *skb;
803 spin_lock_bh(lock);
804 skb = skb_peek(list);
805 if (skb)
806 skb_get(skb);
807 spin_unlock_bh(lock);
808 return skb;
811 /* tipc_skb_peek_port(): find a destination port, ignoring all destinations
812 * up to and including 'filter'.
813 * Note: ignoring previously tried destinations minimizes the risk of
814 * contention on the socket lock
815 * @list: list to be peeked in
816 * @filter: last destination to be ignored from search
817 * Returns a destination port number, of applicable.
819 static inline u32 tipc_skb_peek_port(struct sk_buff_head *list, u32 filter)
821 struct sk_buff *skb;
822 u32 dport = 0;
823 bool ignore = true;
825 spin_lock_bh(&list->lock);
826 skb_queue_walk(list, skb) {
827 dport = msg_destport(buf_msg(skb));
828 if (!filter || skb_queue_is_last(list, skb))
829 break;
830 if (dport == filter)
831 ignore = false;
832 else if (!ignore)
833 break;
835 spin_unlock_bh(&list->lock);
836 return dport;
839 /* tipc_skb_dequeue(): unlink first buffer with dest 'dport' from list
840 * @list: list to be unlinked from
841 * @dport: selection criteria for buffer to unlink
843 static inline struct sk_buff *tipc_skb_dequeue(struct sk_buff_head *list,
844 u32 dport)
846 struct sk_buff *_skb, *tmp, *skb = NULL;
848 spin_lock_bh(&list->lock);
849 skb_queue_walk_safe(list, _skb, tmp) {
850 if (msg_destport(buf_msg(_skb)) == dport) {
851 __skb_unlink(_skb, list);
852 skb = _skb;
853 break;
856 spin_unlock_bh(&list->lock);
857 return skb;
860 /* tipc_skb_queue_tail(): add buffer to tail of list;
861 * @list: list to be appended to
862 * @skb: buffer to append. Always appended
863 * @dport: the destination port of the buffer
864 * returns true if dport differs from previous destination
866 static inline bool tipc_skb_queue_tail(struct sk_buff_head *list,
867 struct sk_buff *skb, u32 dport)
869 struct sk_buff *_skb = NULL;
870 bool rv = false;
872 spin_lock_bh(&list->lock);
873 _skb = skb_peek_tail(list);
874 if (!_skb || (msg_destport(buf_msg(_skb)) != dport) ||
875 (skb_queue_len(list) > 32))
876 rv = true;
877 __skb_queue_tail(list, skb);
878 spin_unlock_bh(&list->lock);
879 return rv;
882 #endif