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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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)
61 * @gfp: memory allocation flags
63 * Return: a new buffer with data pointers set to the specified size.
66 * Headroom is reserved to allow prepending of a data link header.
67 * There may also be unrequested tailroom present at the buffer's end.
69 struct sk_buff *tipc_buf_acquire(u32 size, gfp_t gfp)
72 #ifdef CONFIG_TIPC_CRYPTO
73 unsigned int buf_size = (BUF_HEADROOM + size + BUF_TAILROOM + 3) & ~3u;
75 unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u;
78 skb = alloc_skb_fclone(buf_size, gfp);
80 skb_reserve(skb, BUF_HEADROOM);
87 void tipc_msg_init(u32 own_node, struct tipc_msg *m, u32 user, u32 type,
92 msg_set_user(m, user);
93 msg_set_hdr_sz(m, hsize);
94 msg_set_size(m, hsize);
95 msg_set_prevnode(m, own_node);
96 msg_set_type(m, type);
97 if (hsize > SHORT_H_SIZE) {
98 msg_set_orignode(m, own_node);
99 msg_set_destnode(m, dnode);
103 struct sk_buff *tipc_msg_create(uint user, uint type,
104 uint hdr_sz, uint data_sz, u32 dnode,
105 u32 onode, u32 dport, u32 oport, int errcode)
107 struct tipc_msg *msg;
110 buf = tipc_buf_acquire(hdr_sz + data_sz, GFP_ATOMIC);
115 tipc_msg_init(onode, msg, user, type, hdr_sz, dnode);
116 msg_set_size(msg, hdr_sz + data_sz);
117 msg_set_origport(msg, oport);
118 msg_set_destport(msg, dport);
119 msg_set_errcode(msg, errcode);
123 /* tipc_buf_append(): Append a buffer to the fragment list of another buffer
124 * @*headbuf: in: NULL for first frag, otherwise value returned from prev call
125 * out: set when successful non-complete reassembly, otherwise NULL
126 * @*buf: in: the buffer to append. Always defined
127 * out: head buf after successful complete reassembly, otherwise NULL
128 * Returns 1 when reassembly complete, otherwise 0
130 int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
132 struct sk_buff *head = *headbuf;
133 struct sk_buff *frag = *buf;
134 struct sk_buff *tail = NULL;
135 struct tipc_msg *msg;
144 fragid = msg_type(msg);
146 skb_pull(frag, msg_hdr_sz(msg));
148 if (fragid == FIRST_FRAGMENT) {
152 if (skb_has_frag_list(frag) && __skb_linearize(frag))
154 frag = skb_unshare(frag, GFP_ATOMIC);
157 head = *headbuf = frag;
158 TIPC_SKB_CB(head)->tail = NULL;
165 if (skb_try_coalesce(head, frag, &headstolen, &delta)) {
166 kfree_skb_partial(frag, headstolen);
168 tail = TIPC_SKB_CB(head)->tail;
169 if (!skb_has_frag_list(head))
170 skb_shinfo(head)->frag_list = frag;
173 head->truesize += frag->truesize;
174 head->data_len += frag->len;
175 head->len += frag->len;
176 TIPC_SKB_CB(head)->tail = frag;
179 if (fragid == LAST_FRAGMENT) {
180 TIPC_SKB_CB(head)->validated = 0;
181 if (unlikely(!tipc_msg_validate(&head)))
184 TIPC_SKB_CB(head)->tail = NULL;
193 *buf = *headbuf = NULL;
198 * tipc_msg_append(): Append data to tail of an existing buffer queue
199 * @_hdr: header to be used
200 * @m: the data to be appended
201 * @mss: max allowable size of buffer
202 * @dlen: size of data to be appended
203 * @txq: queue to append to
205 * Return: the number of 1k blocks appended or errno value
207 int tipc_msg_append(struct tipc_msg *_hdr, struct msghdr *m, int dlen,
208 int mss, struct sk_buff_head *txq)
211 int accounted, total, curr;
212 int mlen, cpy, rem = dlen;
213 struct tipc_msg *hdr;
215 skb = skb_peek_tail(txq);
216 accounted = skb ? msg_blocks(buf_msg(skb)) : 0;
220 if (!skb || skb->len >= mss) {
221 skb = tipc_buf_acquire(mss, GFP_KERNEL);
225 skb_trim(skb, MIN_H_SIZE);
227 skb_copy_to_linear_data(skb, _hdr, MIN_H_SIZE);
228 msg_set_hdr_sz(hdr, MIN_H_SIZE);
229 msg_set_size(hdr, MIN_H_SIZE);
230 __skb_queue_tail(txq, skb);
234 curr = msg_blocks(hdr);
235 mlen = msg_size(hdr);
236 cpy = min_t(size_t, rem, mss - mlen);
237 if (cpy != copy_from_iter(skb->data + mlen, cpy, &m->msg_iter))
239 msg_set_size(hdr, mlen + cpy);
242 total += msg_blocks(hdr) - curr;
244 return total - accounted;
247 /* tipc_msg_validate - validate basic format of received message
249 * This routine ensures a TIPC message has an acceptable header, and at least
250 * as much data as the header indicates it should. The routine also ensures
251 * that the entire message header is stored in the main fragment of the message
252 * buffer, to simplify future access to message header fields.
254 * Note: Having extra info present in the message header or data areas is OK.
255 * TIPC will ignore the excess, under the assumption that it is optional info
256 * introduced by a later release of the protocol.
258 bool tipc_msg_validate(struct sk_buff **_skb)
260 struct sk_buff *skb = *_skb;
261 struct tipc_msg *hdr;
264 /* Ensure that flow control ratio condition is satisfied */
265 if (unlikely(skb->truesize / buf_roundup_len(skb) >= 4)) {
266 skb = skb_copy_expand(skb, BUF_HEADROOM, 0, GFP_ATOMIC);
273 if (unlikely(TIPC_SKB_CB(skb)->validated))
276 if (unlikely(!pskb_may_pull(skb, MIN_H_SIZE)))
279 hsz = msg_hdr_sz(buf_msg(skb));
280 if (unlikely(hsz < MIN_H_SIZE) || (hsz > MAX_H_SIZE))
282 if (unlikely(!pskb_may_pull(skb, hsz)))
286 if (unlikely(msg_version(hdr) != TIPC_VERSION))
290 if (unlikely(msz < hsz))
292 if (unlikely((msz - hsz) > TIPC_MAX_USER_MSG_SIZE))
294 if (unlikely(skb->len < msz))
297 TIPC_SKB_CB(skb)->validated = 1;
302 * tipc_msg_fragment - build a fragment skb list for TIPC message
304 * @skb: TIPC message skb
305 * @hdr: internal msg header to be put on the top of the fragments
306 * @pktmax: max size of a fragment incl. the header
307 * @frags: returned fragment skb list
309 * Return: 0 if the fragmentation is successful, otherwise: -EINVAL
312 int tipc_msg_fragment(struct sk_buff *skb, const struct tipc_msg *hdr,
313 int pktmax, struct sk_buff_head *frags)
315 int pktno, nof_fragms, dsz, dmax, eat;
316 struct tipc_msg *_hdr;
317 struct sk_buff *_skb;
320 /* Non-linear buffer? */
321 if (skb_linearize(skb))
324 data = (u8 *)skb->data;
325 dsz = msg_size(buf_msg(skb));
326 dmax = pktmax - INT_H_SIZE;
327 if (dsz <= dmax || !dmax)
330 nof_fragms = dsz / dmax + 1;
331 for (pktno = 1; pktno <= nof_fragms; pktno++) {
332 if (pktno < nof_fragms)
336 /* Allocate a new fragment */
337 _skb = tipc_buf_acquire(INT_H_SIZE + eat, GFP_ATOMIC);
341 __skb_queue_tail(frags, _skb);
342 /* Copy header & data to the fragment */
343 skb_copy_to_linear_data(_skb, hdr, INT_H_SIZE);
344 skb_copy_to_linear_data_offset(_skb, INT_H_SIZE, data, eat);
346 /* Update the fragment's header */
347 _hdr = buf_msg(_skb);
348 msg_set_fragm_no(_hdr, pktno);
349 msg_set_nof_fragms(_hdr, nof_fragms);
350 msg_set_size(_hdr, INT_H_SIZE + eat);
355 __skb_queue_purge(frags);
356 __skb_queue_head_init(frags);
361 * tipc_msg_build - create buffer chain containing specified header and data
362 * @mhdr: Message header, to be prepended to data
364 * @offset: buffer offset for fragmented messages (FIXME)
365 * @dsz: Total length of user data
366 * @pktmax: Max packet size that can be used
367 * @list: Buffer or chain of buffers to be returned to caller
369 * Note that the recursive call we are making here is safe, since it can
370 * logically go only one further level down.
372 * Return: message data size or errno: -ENOMEM, -EFAULT
374 int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, int offset,
375 int dsz, int pktmax, struct sk_buff_head *list)
377 int mhsz = msg_hdr_sz(mhdr);
378 struct tipc_msg pkthdr;
379 int msz = mhsz + dsz;
388 msg_set_size(mhdr, msz);
390 /* No fragmentation needed? */
391 if (likely(msz <= pktmax)) {
392 skb = tipc_buf_acquire(msz, GFP_KERNEL);
394 /* Fall back to smaller MTU if node local message */
395 if (unlikely(!skb)) {
396 if (pktmax != MAX_MSG_SIZE)
398 rc = tipc_msg_build(mhdr, m, offset, dsz, FB_MTU, list);
401 if (tipc_msg_assemble(list))
406 __skb_queue_tail(list, skb);
407 skb_copy_to_linear_data(skb, mhdr, mhsz);
408 pktpos = skb->data + mhsz;
409 if (copy_from_iter_full(pktpos, dsz, &m->msg_iter))
415 /* Prepare reusable fragment header */
416 tipc_msg_init(msg_prevnode(mhdr), &pkthdr, MSG_FRAGMENTER,
417 FIRST_FRAGMENT, INT_H_SIZE, msg_destnode(mhdr));
418 msg_set_size(&pkthdr, pktmax);
419 msg_set_fragm_no(&pkthdr, pktno);
420 msg_set_importance(&pkthdr, msg_importance(mhdr));
422 /* Prepare first fragment */
423 skb = tipc_buf_acquire(pktmax, GFP_KERNEL);
427 __skb_queue_tail(list, skb);
429 skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
430 pktpos += INT_H_SIZE;
431 pktrem -= INT_H_SIZE;
432 skb_copy_to_linear_data_offset(skb, INT_H_SIZE, mhdr, mhsz);
440 if (!copy_from_iter_full(pktpos, pktrem, &m->msg_iter)) {
449 /* Prepare new fragment: */
450 if (drem < (pktmax - INT_H_SIZE))
451 pktsz = drem + INT_H_SIZE;
454 skb = tipc_buf_acquire(pktsz, GFP_KERNEL);
460 __skb_queue_tail(list, skb);
461 msg_set_type(&pkthdr, FRAGMENT);
462 msg_set_size(&pkthdr, pktsz);
463 msg_set_fragm_no(&pkthdr, ++pktno);
464 skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
465 pktpos = skb->data + INT_H_SIZE;
466 pktrem = pktsz - INT_H_SIZE;
469 msg_set_type(buf_msg(skb), LAST_FRAGMENT);
472 __skb_queue_purge(list);
473 __skb_queue_head_init(list);
478 * tipc_msg_bundle - Append contents of a buffer to tail of an existing one
479 * @bskb: the bundle buffer to append to
480 * @msg: message to be appended
481 * @max: max allowable size for the bundle buffer
483 * Return: "true" if bundling has been performed, otherwise "false"
485 static bool tipc_msg_bundle(struct sk_buff *bskb, struct tipc_msg *msg,
488 struct tipc_msg *bmsg = buf_msg(bskb);
489 u32 msz, bsz, offset, pad;
492 bsz = msg_size(bmsg);
496 if (unlikely(skb_tailroom(bskb) < (pad + msz)))
498 if (unlikely(max < (offset + msz)))
501 skb_put(bskb, pad + msz);
502 skb_copy_to_linear_data_offset(bskb, offset, msg, msz);
503 msg_set_size(bmsg, offset + msz);
504 msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
509 * tipc_msg_try_bundle - Try to bundle a new message to the last one
510 * @tskb: the last/target message to which the new one will be appended
511 * @skb: the new message skb pointer
512 * @mss: max message size (header inclusive)
513 * @dnode: destination node for the message
514 * @new_bundle: if this call made a new bundle or not
516 * Return: "true" if the new message skb is potential for bundling this time or
517 * later, in the case a bundling has been done this time, the skb is consumed
518 * (the skb pointer = NULL).
519 * Otherwise, "false" if the skb cannot be bundled at all.
521 bool tipc_msg_try_bundle(struct sk_buff *tskb, struct sk_buff **skb, u32 mss,
522 u32 dnode, bool *new_bundle)
524 struct tipc_msg *msg, *inner, *outer;
527 /* First, check if the new buffer is suitable for bundling */
529 if (msg_user(msg) == MSG_FRAGMENTER)
531 if (msg_user(msg) == TUNNEL_PROTOCOL)
533 if (msg_user(msg) == BCAST_PROTOCOL)
535 if (mss <= INT_H_SIZE + msg_size(msg))
538 /* Ok, but the last/target buffer can be empty? */
542 /* Is it a bundle already? Try to bundle the new message to it */
543 if (msg_user(buf_msg(tskb)) == MSG_BUNDLER) {
548 /* Make a new bundle of the two messages if possible */
549 tsz = msg_size(buf_msg(tskb));
550 if (unlikely(mss < align(INT_H_SIZE + tsz) + msg_size(msg)))
552 if (unlikely(pskb_expand_head(tskb, INT_H_SIZE, mss - tsz - INT_H_SIZE,
555 inner = buf_msg(tskb);
556 skb_push(tskb, INT_H_SIZE);
557 outer = buf_msg(tskb);
558 tipc_msg_init(msg_prevnode(inner), outer, MSG_BUNDLER, 0, INT_H_SIZE,
560 msg_set_importance(outer, msg_importance(inner));
561 msg_set_size(outer, INT_H_SIZE + tsz);
562 msg_set_msgcnt(outer, 1);
566 if (likely(tipc_msg_bundle(tskb, msg, mss))) {
574 * tipc_msg_extract(): extract bundled inner packet from buffer
575 * @skb: buffer to be extracted from.
576 * @iskb: extracted inner buffer, to be returned
577 * @pos: position in outer message of msg to be extracted.
578 * Returns position of next msg.
579 * Consumes outer buffer when last packet extracted
580 * Return: true when there is an extracted buffer, otherwise false
582 bool tipc_msg_extract(struct sk_buff *skb, struct sk_buff **iskb, int *pos)
584 struct tipc_msg *hdr, *ihdr;
588 if (unlikely(skb_linearize(skb)))
592 if (unlikely(*pos > (msg_data_sz(hdr) - MIN_H_SIZE)))
595 ihdr = (struct tipc_msg *)(msg_data(hdr) + *pos);
596 imsz = msg_size(ihdr);
598 if ((*pos + imsz) > msg_data_sz(hdr))
601 *iskb = tipc_buf_acquire(imsz, GFP_ATOMIC);
605 skb_copy_to_linear_data(*iskb, ihdr, imsz);
606 if (unlikely(!tipc_msg_validate(iskb)))
619 * tipc_msg_reverse(): swap source and destination addresses and add error code
620 * @own_node: originating node id for reversed message
621 * @skb: buffer containing message to be reversed; will be consumed
622 * @err: error code to be set in message, if any
623 * Replaces consumed buffer with new one when successful
624 * Return: true if success, otherwise false
626 bool tipc_msg_reverse(u32 own_node, struct sk_buff **skb, int err)
628 struct sk_buff *_skb = *skb;
629 struct tipc_msg *_hdr, *hdr;
632 if (skb_linearize(_skb))
634 _hdr = buf_msg(_skb);
635 dlen = min_t(uint, msg_data_sz(_hdr), MAX_FORWARD_SIZE);
636 hlen = msg_hdr_sz(_hdr);
638 if (msg_dest_droppable(_hdr))
640 if (msg_errcode(_hdr))
643 /* Never return SHORT header */
644 if (hlen == SHORT_H_SIZE)
647 /* Don't return data along with SYN+, - sender has a clone */
648 if (msg_is_syn(_hdr) && err == TIPC_ERR_OVERLOAD)
651 /* Allocate new buffer to return */
652 *skb = tipc_buf_acquire(hlen + dlen, GFP_ATOMIC);
655 memcpy((*skb)->data, _skb->data, msg_hdr_sz(_hdr));
656 memcpy((*skb)->data + hlen, msg_data(_hdr), dlen);
658 /* Build reverse header in new buffer */
660 msg_set_hdr_sz(hdr, hlen);
661 msg_set_errcode(hdr, err);
662 msg_set_non_seq(hdr, 0);
663 msg_set_origport(hdr, msg_destport(_hdr));
664 msg_set_destport(hdr, msg_origport(_hdr));
665 msg_set_destnode(hdr, msg_prevnode(_hdr));
666 msg_set_prevnode(hdr, own_node);
667 msg_set_orignode(hdr, own_node);
668 msg_set_size(hdr, hlen + dlen);
678 bool tipc_msg_skb_clone(struct sk_buff_head *msg, struct sk_buff_head *cpy)
680 struct sk_buff *skb, *_skb;
682 skb_queue_walk(msg, skb) {
683 _skb = skb_clone(skb, GFP_ATOMIC);
685 __skb_queue_purge(cpy);
686 pr_err_ratelimited("Failed to clone buffer chain\n");
689 __skb_queue_tail(cpy, _skb);
695 * tipc_msg_lookup_dest(): try to find new destination for named message
696 * @net: pointer to associated network namespace
697 * @skb: the buffer containing the message.
698 * @err: error code to be used by caller if lookup fails
699 * Does not consume buffer
700 * Return: true if a destination is found, false otherwise
702 bool tipc_msg_lookup_dest(struct net *net, struct sk_buff *skb, int *err)
704 struct tipc_msg *msg = buf_msg(skb);
705 u32 scope = msg_lookup_scope(msg);
706 u32 self = tipc_own_addr(net);
707 u32 inst = msg_nameinst(msg);
708 struct tipc_socket_addr sk;
709 struct tipc_uaddr ua;
711 if (!msg_isdata(msg))
715 if (msg_errcode(msg))
717 *err = TIPC_ERR_NO_NAME;
718 if (skb_linearize(skb))
721 if (msg_reroute_cnt(msg))
723 tipc_uaddr(&ua, TIPC_SERVICE_RANGE, scope,
724 msg_nametype(msg), inst, inst);
725 sk.node = tipc_scope2node(net, scope);
726 if (!tipc_nametbl_lookup_anycast(net, &ua, &sk))
728 msg_incr_reroute_cnt(msg);
730 msg_set_prevnode(msg, self);
731 msg_set_destnode(msg, sk.node);
732 msg_set_destport(msg, sk.ref);
738 /* tipc_msg_assemble() - assemble chain of fragments into one message
740 bool tipc_msg_assemble(struct sk_buff_head *list)
742 struct sk_buff *skb, *tmp = NULL;
744 if (skb_queue_len(list) == 1)
747 while ((skb = __skb_dequeue(list))) {
749 if (tipc_buf_append(&tmp, &skb)) {
750 __skb_queue_tail(list, skb);
756 __skb_queue_purge(list);
757 __skb_queue_head_init(list);
758 pr_warn("Failed do assemble buffer\n");
762 /* tipc_msg_reassemble() - clone a buffer chain of fragments and
763 * reassemble the clones into one message
765 bool tipc_msg_reassemble(struct sk_buff_head *list, struct sk_buff_head *rcvq)
767 struct sk_buff *skb, *_skb;
768 struct sk_buff *frag = NULL;
769 struct sk_buff *head = NULL;
772 /* Copy header if single buffer */
773 if (skb_queue_len(list) == 1) {
774 skb = skb_peek(list);
775 hdr_len = skb_headroom(skb) + msg_hdr_sz(buf_msg(skb));
776 _skb = __pskb_copy(skb, hdr_len, GFP_ATOMIC);
779 __skb_queue_tail(rcvq, _skb);
783 /* Clone all fragments and reassemble */
784 skb_queue_walk(list, skb) {
785 frag = skb_clone(skb, GFP_ATOMIC);
789 if (tipc_buf_append(&head, &frag))
794 __skb_queue_tail(rcvq, frag);
797 pr_warn("Failed do clone local mcast rcv buffer\n");
802 bool tipc_msg_pskb_copy(u32 dst, struct sk_buff_head *msg,
803 struct sk_buff_head *cpy)
805 struct sk_buff *skb, *_skb;
807 skb_queue_walk(msg, skb) {
808 _skb = pskb_copy(skb, GFP_ATOMIC);
810 __skb_queue_purge(cpy);
813 msg_set_destnode(buf_msg(_skb), dst);
814 __skb_queue_tail(cpy, _skb);
819 /* tipc_skb_queue_sorted(); sort pkt into list according to sequence number
820 * @list: list to be appended to
821 * @seqno: sequence number of buffer to add
822 * @skb: buffer to add
824 bool __tipc_skb_queue_sorted(struct sk_buff_head *list, u16 seqno,
827 struct sk_buff *_skb, *tmp;
829 if (skb_queue_empty(list) || less(seqno, buf_seqno(skb_peek(list)))) {
830 __skb_queue_head(list, skb);
834 if (more(seqno, buf_seqno(skb_peek_tail(list)))) {
835 __skb_queue_tail(list, skb);
839 skb_queue_walk_safe(list, _skb, tmp) {
840 if (more(seqno, buf_seqno(_skb)))
842 if (seqno == buf_seqno(_skb))
844 __skb_queue_before(list, _skb, skb);
851 void tipc_skb_reject(struct net *net, int err, struct sk_buff *skb,
852 struct sk_buff_head *xmitq)
854 if (tipc_msg_reverse(tipc_own_addr(net), &skb, err))
855 __skb_queue_tail(xmitq, skb);