2 * net/tipc/msg.c: TIPC message header routines
4 * Copyright (c) 2000-2006, 2014-2015, Ericsson AB
5 * Copyright (c) 2005, 2010-2011, Wind River Systems
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
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31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
41 #include "name_table.h"
44 #define MAX_FORWARD_SIZE 1024
45 #ifdef CONFIG_TIPC_CRYPTO
46 #define BUF_HEADROOM ALIGN(((LL_MAX_HEADER + 48) + EHDR_MAX_SIZE), 16)
47 #define BUF_TAILROOM (TIPC_AES_GCM_TAG_SIZE)
49 #define BUF_HEADROOM (LL_MAX_HEADER + 48)
50 #define BUF_TAILROOM 16
53 static unsigned int align(unsigned int i)
59 * tipc_buf_acquire - creates a TIPC message buffer
60 * @size: message size (including TIPC header)
62 * Returns a new buffer with data pointers set to the specified size.
64 * NOTE: Headroom is reserved to allow prepending of a data link header.
65 * There may also be unrequested tailroom present at the buffer's end.
67 struct sk_buff *tipc_buf_acquire(u32 size, gfp_t gfp)
70 #ifdef CONFIG_TIPC_CRYPTO
71 unsigned int buf_size = (BUF_HEADROOM + size + BUF_TAILROOM + 3) & ~3u;
73 unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u;
76 skb = alloc_skb_fclone(buf_size, gfp);
78 skb_reserve(skb, BUF_HEADROOM);
85 void tipc_msg_init(u32 own_node, struct tipc_msg *m, u32 user, u32 type,
90 msg_set_user(m, user);
91 msg_set_hdr_sz(m, hsize);
92 msg_set_size(m, hsize);
93 msg_set_prevnode(m, own_node);
94 msg_set_type(m, type);
95 if (hsize > SHORT_H_SIZE) {
96 msg_set_orignode(m, own_node);
97 msg_set_destnode(m, dnode);
101 struct sk_buff *tipc_msg_create(uint user, uint type,
102 uint hdr_sz, uint data_sz, u32 dnode,
103 u32 onode, u32 dport, u32 oport, int errcode)
105 struct tipc_msg *msg;
108 buf = tipc_buf_acquire(hdr_sz + data_sz, GFP_ATOMIC);
113 tipc_msg_init(onode, msg, user, type, hdr_sz, dnode);
114 msg_set_size(msg, hdr_sz + data_sz);
115 msg_set_origport(msg, oport);
116 msg_set_destport(msg, dport);
117 msg_set_errcode(msg, errcode);
118 if (hdr_sz > SHORT_H_SIZE) {
119 msg_set_orignode(msg, onode);
120 msg_set_destnode(msg, dnode);
125 /* tipc_buf_append(): Append a buffer to the fragment list of another buffer
126 * @*headbuf: in: NULL for first frag, otherwise value returned from prev call
127 * out: set when successful non-complete reassembly, otherwise NULL
128 * @*buf: in: the buffer to append. Always defined
129 * out: head buf after successful complete reassembly, otherwise NULL
130 * Returns 1 when reassembly complete, otherwise 0
132 int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
134 struct sk_buff *head = *headbuf;
135 struct sk_buff *frag = *buf;
136 struct sk_buff *tail = NULL;
137 struct tipc_msg *msg;
146 fragid = msg_type(msg);
148 skb_pull(frag, msg_hdr_sz(msg));
150 if (fragid == FIRST_FRAGMENT) {
153 if (unlikely(skb_unclone(frag, GFP_ATOMIC)))
155 head = *headbuf = frag;
157 TIPC_SKB_CB(head)->tail = NULL;
158 if (skb_is_nonlinear(head)) {
159 skb_walk_frags(head, tail) {
160 TIPC_SKB_CB(head)->tail = tail;
163 skb_frag_list_init(head);
171 if (skb_try_coalesce(head, frag, &headstolen, &delta)) {
172 kfree_skb_partial(frag, headstolen);
174 tail = TIPC_SKB_CB(head)->tail;
175 if (!skb_has_frag_list(head))
176 skb_shinfo(head)->frag_list = frag;
179 head->truesize += frag->truesize;
180 head->data_len += frag->len;
181 head->len += frag->len;
182 TIPC_SKB_CB(head)->tail = frag;
185 if (fragid == LAST_FRAGMENT) {
186 TIPC_SKB_CB(head)->validated = 0;
187 if (unlikely(!tipc_msg_validate(&head)))
190 TIPC_SKB_CB(head)->tail = NULL;
199 *buf = *headbuf = NULL;
204 * tipc_msg_append(): Append data to tail of an existing buffer queue
205 * @hdr: header to be used
206 * @m: the data to be appended
207 * @mss: max allowable size of buffer
208 * @dlen: size of data to be appended
209 * @txq: queue to appand to
210 * Returns the number og 1k blocks appended or errno value
212 int tipc_msg_append(struct tipc_msg *_hdr, struct msghdr *m, int dlen,
213 int mss, struct sk_buff_head *txq)
215 struct sk_buff *skb, *prev;
216 int accounted, total, curr;
217 int mlen, cpy, rem = dlen;
218 struct tipc_msg *hdr;
220 skb = skb_peek_tail(txq);
221 accounted = skb ? msg_blocks(buf_msg(skb)) : 0;
225 if (!skb || skb->len >= mss) {
227 skb = tipc_buf_acquire(mss, GFP_KERNEL);
231 skb_trim(skb, MIN_H_SIZE);
233 skb_copy_to_linear_data(skb, _hdr, MIN_H_SIZE);
234 msg_set_hdr_sz(hdr, MIN_H_SIZE);
235 msg_set_size(hdr, MIN_H_SIZE);
236 __skb_queue_tail(txq, skb);
239 msg_set_ack_required(buf_msg(prev), 0);
240 msg_set_ack_required(hdr, 1);
243 curr = msg_blocks(hdr);
244 mlen = msg_size(hdr);
245 cpy = min_t(int, rem, mss - mlen);
246 if (cpy != copy_from_iter(skb->data + mlen, cpy, &m->msg_iter))
248 msg_set_size(hdr, mlen + cpy);
251 total += msg_blocks(hdr) - curr;
253 return total - accounted;
256 /* tipc_msg_validate - validate basic format of received message
258 * This routine ensures a TIPC message has an acceptable header, and at least
259 * as much data as the header indicates it should. The routine also ensures
260 * that the entire message header is stored in the main fragment of the message
261 * buffer, to simplify future access to message header fields.
263 * Note: Having extra info present in the message header or data areas is OK.
264 * TIPC will ignore the excess, under the assumption that it is optional info
265 * introduced by a later release of the protocol.
267 bool tipc_msg_validate(struct sk_buff **_skb)
269 struct sk_buff *skb = *_skb;
270 struct tipc_msg *hdr;
273 /* Ensure that flow control ratio condition is satisfied */
274 if (unlikely(skb->truesize / buf_roundup_len(skb) >= 4)) {
275 skb = skb_copy_expand(skb, BUF_HEADROOM, 0, GFP_ATOMIC);
282 if (unlikely(TIPC_SKB_CB(skb)->validated))
285 if (unlikely(!pskb_may_pull(skb, MIN_H_SIZE)))
288 hsz = msg_hdr_sz(buf_msg(skb));
289 if (unlikely(hsz < MIN_H_SIZE) || (hsz > MAX_H_SIZE))
291 if (unlikely(!pskb_may_pull(skb, hsz)))
295 if (unlikely(msg_version(hdr) != TIPC_VERSION))
299 if (unlikely(msz < hsz))
301 if (unlikely((msz - hsz) > TIPC_MAX_USER_MSG_SIZE))
303 if (unlikely(skb->len < msz))
306 TIPC_SKB_CB(skb)->validated = 1;
311 * tipc_msg_fragment - build a fragment skb list for TIPC message
313 * @skb: TIPC message skb
314 * @hdr: internal msg header to be put on the top of the fragments
315 * @pktmax: max size of a fragment incl. the header
316 * @frags: returned fragment skb list
318 * Returns 0 if the fragmentation is successful, otherwise: -EINVAL
321 int tipc_msg_fragment(struct sk_buff *skb, const struct tipc_msg *hdr,
322 int pktmax, struct sk_buff_head *frags)
324 int pktno, nof_fragms, dsz, dmax, eat;
325 struct tipc_msg *_hdr;
326 struct sk_buff *_skb;
329 /* Non-linear buffer? */
330 if (skb_linearize(skb))
333 data = (u8 *)skb->data;
334 dsz = msg_size(buf_msg(skb));
335 dmax = pktmax - INT_H_SIZE;
336 if (dsz <= dmax || !dmax)
339 nof_fragms = dsz / dmax + 1;
340 for (pktno = 1; pktno <= nof_fragms; pktno++) {
341 if (pktno < nof_fragms)
345 /* Allocate a new fragment */
346 _skb = tipc_buf_acquire(INT_H_SIZE + eat, GFP_ATOMIC);
350 __skb_queue_tail(frags, _skb);
351 /* Copy header & data to the fragment */
352 skb_copy_to_linear_data(_skb, hdr, INT_H_SIZE);
353 skb_copy_to_linear_data_offset(_skb, INT_H_SIZE, data, eat);
355 /* Update the fragment's header */
356 _hdr = buf_msg(_skb);
357 msg_set_fragm_no(_hdr, pktno);
358 msg_set_nof_fragms(_hdr, nof_fragms);
359 msg_set_size(_hdr, INT_H_SIZE + eat);
364 __skb_queue_purge(frags);
365 __skb_queue_head_init(frags);
370 * tipc_msg_build - create buffer chain containing specified header and data
371 * @mhdr: Message header, to be prepended to data
373 * @dsz: Total length of user data
374 * @pktmax: Max packet size that can be used
375 * @list: Buffer or chain of buffers to be returned to caller
377 * Note that the recursive call we are making here is safe, since it can
378 * logically go only one further level down.
380 * Returns message data size or errno: -ENOMEM, -EFAULT
382 int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, int offset,
383 int dsz, int pktmax, struct sk_buff_head *list)
385 int mhsz = msg_hdr_sz(mhdr);
386 struct tipc_msg pkthdr;
387 int msz = mhsz + dsz;
396 msg_set_size(mhdr, msz);
398 /* No fragmentation needed? */
399 if (likely(msz <= pktmax)) {
400 skb = tipc_buf_acquire(msz, GFP_KERNEL);
402 /* Fall back to smaller MTU if node local message */
403 if (unlikely(!skb)) {
404 if (pktmax != MAX_MSG_SIZE)
406 rc = tipc_msg_build(mhdr, m, offset, dsz, FB_MTU, list);
409 if (tipc_msg_assemble(list))
414 __skb_queue_tail(list, skb);
415 skb_copy_to_linear_data(skb, mhdr, mhsz);
416 pktpos = skb->data + mhsz;
417 if (copy_from_iter_full(pktpos, dsz, &m->msg_iter))
423 /* Prepare reusable fragment header */
424 tipc_msg_init(msg_prevnode(mhdr), &pkthdr, MSG_FRAGMENTER,
425 FIRST_FRAGMENT, INT_H_SIZE, msg_destnode(mhdr));
426 msg_set_size(&pkthdr, pktmax);
427 msg_set_fragm_no(&pkthdr, pktno);
428 msg_set_importance(&pkthdr, msg_importance(mhdr));
430 /* Prepare first fragment */
431 skb = tipc_buf_acquire(pktmax, GFP_KERNEL);
435 __skb_queue_tail(list, skb);
437 skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
438 pktpos += INT_H_SIZE;
439 pktrem -= INT_H_SIZE;
440 skb_copy_to_linear_data_offset(skb, INT_H_SIZE, mhdr, mhsz);
448 if (!copy_from_iter_full(pktpos, pktrem, &m->msg_iter)) {
457 /* Prepare new fragment: */
458 if (drem < (pktmax - INT_H_SIZE))
459 pktsz = drem + INT_H_SIZE;
462 skb = tipc_buf_acquire(pktsz, GFP_KERNEL);
468 __skb_queue_tail(list, skb);
469 msg_set_type(&pkthdr, FRAGMENT);
470 msg_set_size(&pkthdr, pktsz);
471 msg_set_fragm_no(&pkthdr, ++pktno);
472 skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
473 pktpos = skb->data + INT_H_SIZE;
474 pktrem = pktsz - INT_H_SIZE;
477 msg_set_type(buf_msg(skb), LAST_FRAGMENT);
480 __skb_queue_purge(list);
481 __skb_queue_head_init(list);
486 * tipc_msg_bundle - Append contents of a buffer to tail of an existing one
487 * @bskb: the bundle buffer to append to
488 * @msg: message to be appended
489 * @max: max allowable size for the bundle buffer
491 * Returns "true" if bundling has been performed, otherwise "false"
493 static bool tipc_msg_bundle(struct sk_buff *bskb, struct tipc_msg *msg,
496 struct tipc_msg *bmsg = buf_msg(bskb);
497 u32 msz, bsz, offset, pad;
500 bsz = msg_size(bmsg);
504 if (unlikely(skb_tailroom(bskb) < (pad + msz)))
506 if (unlikely(max < (offset + msz)))
509 skb_put(bskb, pad + msz);
510 skb_copy_to_linear_data_offset(bskb, offset, msg, msz);
511 msg_set_size(bmsg, offset + msz);
512 msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
517 * tipc_msg_try_bundle - Try to bundle a new message to the last one
518 * @tskb: the last/target message to which the new one will be appended
519 * @skb: the new message skb pointer
520 * @mss: max message size (header inclusive)
521 * @dnode: destination node for the message
522 * @new_bundle: if this call made a new bundle or not
524 * Return: "true" if the new message skb is potential for bundling this time or
525 * later, in the case a bundling has been done this time, the skb is consumed
526 * (the skb pointer = NULL).
527 * Otherwise, "false" if the skb cannot be bundled at all.
529 bool tipc_msg_try_bundle(struct sk_buff *tskb, struct sk_buff **skb, u32 mss,
530 u32 dnode, bool *new_bundle)
532 struct tipc_msg *msg, *inner, *outer;
535 /* First, check if the new buffer is suitable for bundling */
537 if (msg_user(msg) == MSG_FRAGMENTER)
539 if (msg_user(msg) == TUNNEL_PROTOCOL)
541 if (msg_user(msg) == BCAST_PROTOCOL)
543 if (mss <= INT_H_SIZE + msg_size(msg))
546 /* Ok, but the last/target buffer can be empty? */
550 /* Is it a bundle already? Try to bundle the new message to it */
551 if (msg_user(buf_msg(tskb)) == MSG_BUNDLER) {
556 /* Make a new bundle of the two messages if possible */
557 tsz = msg_size(buf_msg(tskb));
558 if (unlikely(mss < align(INT_H_SIZE + tsz) + msg_size(msg)))
560 if (unlikely(pskb_expand_head(tskb, INT_H_SIZE, mss - tsz - INT_H_SIZE,
563 inner = buf_msg(tskb);
564 skb_push(tskb, INT_H_SIZE);
565 outer = buf_msg(tskb);
566 tipc_msg_init(msg_prevnode(inner), outer, MSG_BUNDLER, 0, INT_H_SIZE,
568 msg_set_importance(outer, msg_importance(inner));
569 msg_set_size(outer, INT_H_SIZE + tsz);
570 msg_set_msgcnt(outer, 1);
574 if (likely(tipc_msg_bundle(tskb, msg, mss))) {
582 * tipc_msg_extract(): extract bundled inner packet from buffer
583 * @skb: buffer to be extracted from.
584 * @iskb: extracted inner buffer, to be returned
585 * @pos: position in outer message of msg to be extracted.
586 * Returns position of next msg
587 * Consumes outer buffer when last packet extracted
588 * Returns true when when there is an extracted buffer, otherwise false
590 bool tipc_msg_extract(struct sk_buff *skb, struct sk_buff **iskb, int *pos)
592 struct tipc_msg *hdr, *ihdr;
596 if (unlikely(skb_linearize(skb)))
600 if (unlikely(*pos > (msg_data_sz(hdr) - MIN_H_SIZE)))
603 ihdr = (struct tipc_msg *)(msg_data(hdr) + *pos);
604 imsz = msg_size(ihdr);
606 if ((*pos + imsz) > msg_data_sz(hdr))
609 *iskb = tipc_buf_acquire(imsz, GFP_ATOMIC);
613 skb_copy_to_linear_data(*iskb, ihdr, imsz);
614 if (unlikely(!tipc_msg_validate(iskb)))
627 * tipc_msg_reverse(): swap source and destination addresses and add error code
628 * @own_node: originating node id for reversed message
629 * @skb: buffer containing message to be reversed; will be consumed
630 * @err: error code to be set in message, if any
631 * Replaces consumed buffer with new one when successful
632 * Returns true if success, otherwise false
634 bool tipc_msg_reverse(u32 own_node, struct sk_buff **skb, int err)
636 struct sk_buff *_skb = *skb;
637 struct tipc_msg *_hdr, *hdr;
640 if (skb_linearize(_skb))
642 _hdr = buf_msg(_skb);
643 dlen = min_t(uint, msg_data_sz(_hdr), MAX_FORWARD_SIZE);
644 hlen = msg_hdr_sz(_hdr);
646 if (msg_dest_droppable(_hdr))
648 if (msg_errcode(_hdr))
651 /* Never return SHORT header */
652 if (hlen == SHORT_H_SIZE)
655 /* Don't return data along with SYN+, - sender has a clone */
656 if (msg_is_syn(_hdr) && err == TIPC_ERR_OVERLOAD)
659 /* Allocate new buffer to return */
660 *skb = tipc_buf_acquire(hlen + dlen, GFP_ATOMIC);
663 memcpy((*skb)->data, _skb->data, msg_hdr_sz(_hdr));
664 memcpy((*skb)->data + hlen, msg_data(_hdr), dlen);
666 /* Build reverse header in new buffer */
668 msg_set_hdr_sz(hdr, hlen);
669 msg_set_errcode(hdr, err);
670 msg_set_non_seq(hdr, 0);
671 msg_set_origport(hdr, msg_destport(_hdr));
672 msg_set_destport(hdr, msg_origport(_hdr));
673 msg_set_destnode(hdr, msg_prevnode(_hdr));
674 msg_set_prevnode(hdr, own_node);
675 msg_set_orignode(hdr, own_node);
676 msg_set_size(hdr, hlen + dlen);
686 bool tipc_msg_skb_clone(struct sk_buff_head *msg, struct sk_buff_head *cpy)
688 struct sk_buff *skb, *_skb;
690 skb_queue_walk(msg, skb) {
691 _skb = skb_clone(skb, GFP_ATOMIC);
693 __skb_queue_purge(cpy);
694 pr_err_ratelimited("Failed to clone buffer chain\n");
697 __skb_queue_tail(cpy, _skb);
703 * tipc_msg_lookup_dest(): try to find new destination for named message
704 * @skb: the buffer containing the message.
705 * @err: error code to be used by caller if lookup fails
706 * Does not consume buffer
707 * Returns true if a destination is found, false otherwise
709 bool tipc_msg_lookup_dest(struct net *net, struct sk_buff *skb, int *err)
711 struct tipc_msg *msg = buf_msg(skb);
713 u32 onode = tipc_own_addr(net);
715 if (!msg_isdata(msg))
719 if (msg_errcode(msg))
721 *err = TIPC_ERR_NO_NAME;
722 if (skb_linearize(skb))
725 if (msg_reroute_cnt(msg))
727 dnode = tipc_scope2node(net, msg_lookup_scope(msg));
728 dport = tipc_nametbl_translate(net, msg_nametype(msg),
729 msg_nameinst(msg), &dnode);
732 msg_incr_reroute_cnt(msg);
734 msg_set_prevnode(msg, onode);
735 msg_set_destnode(msg, dnode);
736 msg_set_destport(msg, dport);
739 if (!skb_cloned(skb))
745 /* tipc_msg_assemble() - assemble chain of fragments into one message
747 bool tipc_msg_assemble(struct sk_buff_head *list)
749 struct sk_buff *skb, *tmp = NULL;
751 if (skb_queue_len(list) == 1)
754 while ((skb = __skb_dequeue(list))) {
756 if (tipc_buf_append(&tmp, &skb)) {
757 __skb_queue_tail(list, skb);
763 __skb_queue_purge(list);
764 __skb_queue_head_init(list);
765 pr_warn("Failed do assemble buffer\n");
769 /* tipc_msg_reassemble() - clone a buffer chain of fragments and
770 * reassemble the clones into one message
772 bool tipc_msg_reassemble(struct sk_buff_head *list, struct sk_buff_head *rcvq)
774 struct sk_buff *skb, *_skb;
775 struct sk_buff *frag = NULL;
776 struct sk_buff *head = NULL;
779 /* Copy header if single buffer */
780 if (skb_queue_len(list) == 1) {
781 skb = skb_peek(list);
782 hdr_len = skb_headroom(skb) + msg_hdr_sz(buf_msg(skb));
783 _skb = __pskb_copy(skb, hdr_len, GFP_ATOMIC);
786 __skb_queue_tail(rcvq, _skb);
790 /* Clone all fragments and reassemble */
791 skb_queue_walk(list, skb) {
792 frag = skb_clone(skb, GFP_ATOMIC);
796 if (tipc_buf_append(&head, &frag))
801 __skb_queue_tail(rcvq, frag);
804 pr_warn("Failed do clone local mcast rcv buffer\n");
809 bool tipc_msg_pskb_copy(u32 dst, struct sk_buff_head *msg,
810 struct sk_buff_head *cpy)
812 struct sk_buff *skb, *_skb;
814 skb_queue_walk(msg, skb) {
815 _skb = pskb_copy(skb, GFP_ATOMIC);
817 __skb_queue_purge(cpy);
820 msg_set_destnode(buf_msg(_skb), dst);
821 __skb_queue_tail(cpy, _skb);
826 /* tipc_skb_queue_sorted(); sort pkt into list according to sequence number
827 * @list: list to be appended to
828 * @seqno: sequence number of buffer to add
829 * @skb: buffer to add
831 void __tipc_skb_queue_sorted(struct sk_buff_head *list, u16 seqno,
834 struct sk_buff *_skb, *tmp;
836 if (skb_queue_empty(list) || less(seqno, buf_seqno(skb_peek(list)))) {
837 __skb_queue_head(list, skb);
841 if (more(seqno, buf_seqno(skb_peek_tail(list)))) {
842 __skb_queue_tail(list, skb);
846 skb_queue_walk_safe(list, _skb, tmp) {
847 if (more(seqno, buf_seqno(_skb)))
849 if (seqno == buf_seqno(_skb))
851 __skb_queue_before(list, _skb, skb);
857 void tipc_skb_reject(struct net *net, int err, struct sk_buff *skb,
858 struct sk_buff_head *xmitq)
860 if (tipc_msg_reverse(tipc_own_addr(net), &skb, err))
861 __skb_queue_tail(xmitq, skb);