2 * net/tipc/msg.c: TIPC message header routines
4 * Copyright (c) 2000-2006, 2014, Ericsson AB
5 * Copyright (c) 2005, 2010-2011, Wind River Systems
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21 * GNU General Public License ("GPL") version 2 as published by the Free
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41 #include "name_table.h"
43 #define MAX_FORWARD_SIZE 1024
45 static unsigned int align(unsigned int i)
51 * tipc_buf_acquire - creates a TIPC message buffer
52 * @size: message size (including TIPC header)
54 * Returns a new buffer with data pointers set to the specified size.
56 * NOTE: Headroom is reserved to allow prepending of a data link header.
57 * There may also be unrequested tailroom present at the buffer's end.
59 struct sk_buff *tipc_buf_acquire(u32 size)
62 unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u;
64 skb = alloc_skb_fclone(buf_size, GFP_ATOMIC);
66 skb_reserve(skb, BUF_HEADROOM);
73 void tipc_msg_init(struct tipc_msg *m, u32 user, u32 type, u32 hsize,
78 msg_set_user(m, user);
79 msg_set_hdr_sz(m, hsize);
80 msg_set_size(m, hsize);
81 msg_set_prevnode(m, tipc_own_addr);
82 msg_set_type(m, type);
83 if (hsize > SHORT_H_SIZE) {
84 msg_set_orignode(m, tipc_own_addr);
85 msg_set_destnode(m, destnode);
89 struct sk_buff *tipc_msg_create(uint user, uint type, uint hdr_sz,
90 uint data_sz, u32 dnode, u32 onode,
91 u32 dport, u32 oport, int errcode)
96 buf = tipc_buf_acquire(hdr_sz + data_sz);
101 tipc_msg_init(msg, user, type, hdr_sz, dnode);
102 msg_set_size(msg, hdr_sz + data_sz);
103 msg_set_prevnode(msg, onode);
104 msg_set_origport(msg, oport);
105 msg_set_destport(msg, dport);
106 msg_set_errcode(msg, errcode);
107 if (hdr_sz > SHORT_H_SIZE) {
108 msg_set_orignode(msg, onode);
109 msg_set_destnode(msg, dnode);
114 /* tipc_buf_append(): Append a buffer to the fragment list of another buffer
115 * @*headbuf: in: NULL for first frag, otherwise value returned from prev call
116 * out: set when successful non-complete reassembly, otherwise NULL
117 * @*buf: in: the buffer to append. Always defined
118 * out: head buf after successful complete reassembly, otherwise NULL
119 * Returns 1 when reassembly complete, otherwise 0
121 int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
123 struct sk_buff *head = *headbuf;
124 struct sk_buff *frag = *buf;
125 struct sk_buff *tail;
126 struct tipc_msg *msg;
135 fragid = msg_type(msg);
137 skb_pull(frag, msg_hdr_sz(msg));
139 if (fragid == FIRST_FRAGMENT) {
142 if (unlikely(skb_unclone(frag, GFP_ATOMIC)))
144 head = *headbuf = frag;
145 skb_frag_list_init(head);
146 TIPC_SKB_CB(head)->tail = NULL;
154 if (skb_try_coalesce(head, frag, &headstolen, &delta)) {
155 kfree_skb_partial(frag, headstolen);
157 tail = TIPC_SKB_CB(head)->tail;
158 if (!skb_has_frag_list(head))
159 skb_shinfo(head)->frag_list = frag;
162 head->truesize += frag->truesize;
163 head->data_len += frag->len;
164 head->len += frag->len;
165 TIPC_SKB_CB(head)->tail = frag;
168 if (fragid == LAST_FRAGMENT) {
170 TIPC_SKB_CB(head)->tail = NULL;
178 pr_warn_ratelimited("Unable to build fragment list\n");
181 *buf = *headbuf = NULL;
187 * tipc_msg_build - create buffer chain containing specified header and data
188 * @mhdr: Message header, to be prepended to data
190 * @offset: Posision in iov to start copying from
191 * @dsz: Total length of user data
192 * @pktmax: Max packet size that can be used
193 * @list: Buffer or chain of buffers to be returned to caller
195 * Returns message data size or errno: -ENOMEM, -EFAULT
197 int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, int offset,
198 int dsz, int pktmax, struct sk_buff_head *list)
200 int mhsz = msg_hdr_sz(mhdr);
201 int msz = mhsz + dsz;
206 struct tipc_msg pkthdr;
211 msg_set_size(mhdr, msz);
213 /* No fragmentation needed? */
214 if (likely(msz <= pktmax)) {
215 skb = tipc_buf_acquire(msz);
219 __skb_queue_tail(list, skb);
220 skb_copy_to_linear_data(skb, mhdr, mhsz);
221 pktpos = skb->data + mhsz;
222 if (!dsz || !memcpy_fromiovecend(pktpos, m->msg_iter.iov, offset,
229 /* Prepare reusable fragment header */
230 tipc_msg_init(&pkthdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
231 INT_H_SIZE, msg_destnode(mhdr));
232 msg_set_size(&pkthdr, pktmax);
233 msg_set_fragm_no(&pkthdr, pktno);
235 /* Prepare first fragment */
236 skb = tipc_buf_acquire(pktmax);
240 __skb_queue_tail(list, skb);
242 skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
243 pktpos += INT_H_SIZE;
244 pktrem -= INT_H_SIZE;
245 skb_copy_to_linear_data_offset(skb, INT_H_SIZE, mhdr, mhsz);
253 if (memcpy_fromiovecend(pktpos, m->msg_iter.iov, offset, pktrem)) {
263 /* Prepare new fragment: */
264 if (drem < (pktmax - INT_H_SIZE))
265 pktsz = drem + INT_H_SIZE;
268 skb = tipc_buf_acquire(pktsz);
274 __skb_queue_tail(list, skb);
275 msg_set_type(&pkthdr, FRAGMENT);
276 msg_set_size(&pkthdr, pktsz);
277 msg_set_fragm_no(&pkthdr, ++pktno);
278 skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
279 pktpos = skb->data + INT_H_SIZE;
280 pktrem = pktsz - INT_H_SIZE;
283 msg_set_type(buf_msg(skb), LAST_FRAGMENT);
286 __skb_queue_purge(list);
287 __skb_queue_head_init(list);
292 * tipc_msg_bundle(): Append contents of a buffer to tail of an existing one
293 * @list: the buffer chain of the existing buffer ("bundle")
294 * @skb: buffer to be appended
295 * @mtu: max allowable size for the bundle buffer
296 * Consumes buffer if successful
297 * Returns true if bundling could be performed, otherwise false
299 bool tipc_msg_bundle(struct sk_buff_head *list, struct sk_buff *skb, u32 mtu)
301 struct sk_buff *bskb = skb_peek_tail(list);
302 struct tipc_msg *bmsg = buf_msg(bskb);
303 struct tipc_msg *msg = buf_msg(skb);
304 unsigned int bsz = msg_size(bmsg);
305 unsigned int msz = msg_size(msg);
306 u32 start = align(bsz);
307 u32 max = mtu - INT_H_SIZE;
308 u32 pad = start - bsz;
310 if (likely(msg_user(msg) == MSG_FRAGMENTER))
312 if (unlikely(msg_user(msg) == CHANGEOVER_PROTOCOL))
314 if (unlikely(msg_user(msg) == BCAST_PROTOCOL))
316 if (likely(msg_user(bmsg) != MSG_BUNDLER))
318 if (likely(!TIPC_SKB_CB(bskb)->bundling))
320 if (unlikely(skb_tailroom(bskb) < (pad + msz)))
322 if (unlikely(max < (start + msz)))
325 skb_put(bskb, pad + msz);
326 skb_copy_to_linear_data_offset(bskb, start, skb->data, msz);
327 msg_set_size(bmsg, start + msz);
328 msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
334 * tipc_msg_make_bundle(): Create bundle buf and append message to its tail
335 * @list: the buffer chain
336 * @skb: buffer to be appended and replaced
337 * @mtu: max allowable size for the bundle buffer, inclusive header
338 * @dnode: destination node for message. (Not always present in header)
339 * Replaces buffer if successful
340 * Returns true if success, otherwise false
342 bool tipc_msg_make_bundle(struct sk_buff_head *list, struct sk_buff *skb,
345 struct sk_buff *bskb;
346 struct tipc_msg *bmsg;
347 struct tipc_msg *msg = buf_msg(skb);
348 u32 msz = msg_size(msg);
349 u32 max = mtu - INT_H_SIZE;
351 if (msg_user(msg) == MSG_FRAGMENTER)
353 if (msg_user(msg) == CHANGEOVER_PROTOCOL)
355 if (msg_user(msg) == BCAST_PROTOCOL)
360 bskb = tipc_buf_acquire(max);
364 skb_trim(bskb, INT_H_SIZE);
365 bmsg = buf_msg(bskb);
366 tipc_msg_init(bmsg, MSG_BUNDLER, 0, INT_H_SIZE, dnode);
367 msg_set_seqno(bmsg, msg_seqno(msg));
368 msg_set_ack(bmsg, msg_ack(msg));
369 msg_set_bcast_ack(bmsg, msg_bcast_ack(msg));
370 TIPC_SKB_CB(bskb)->bundling = true;
371 __skb_queue_tail(list, bskb);
372 return tipc_msg_bundle(list, skb, mtu);
376 * tipc_msg_reverse(): swap source and destination addresses and add error code
377 * @buf: buffer containing message to be reversed
378 * @dnode: return value: node where to send message after reversal
379 * @err: error code to be set in message
380 * Consumes buffer if failure
381 * Returns true if success, otherwise false
383 bool tipc_msg_reverse(struct sk_buff *buf, u32 *dnode, int err)
385 struct tipc_msg *msg = buf_msg(buf);
386 uint imp = msg_importance(msg);
387 struct tipc_msg ohdr;
388 uint rdsz = min_t(uint, msg_data_sz(msg), MAX_FORWARD_SIZE);
390 if (skb_linearize(buf))
392 if (msg_dest_droppable(msg))
394 if (msg_errcode(msg))
397 memcpy(&ohdr, msg, msg_hdr_sz(msg));
398 imp = min_t(uint, imp + 1, TIPC_CRITICAL_IMPORTANCE);
400 msg_set_importance(msg, imp);
401 msg_set_errcode(msg, err);
402 msg_set_origport(msg, msg_destport(&ohdr));
403 msg_set_destport(msg, msg_origport(&ohdr));
404 msg_set_prevnode(msg, tipc_own_addr);
405 if (!msg_short(msg)) {
406 msg_set_orignode(msg, msg_destnode(&ohdr));
407 msg_set_destnode(msg, msg_orignode(&ohdr));
409 msg_set_size(msg, msg_hdr_sz(msg) + rdsz);
410 skb_trim(buf, msg_size(msg));
412 *dnode = msg_orignode(&ohdr);
420 * tipc_msg_eval: determine fate of message that found no destination
421 * @buf: the buffer containing the message.
422 * @dnode: return value: next-hop node, if message to be forwarded
423 * @err: error code to use, if message to be rejected
425 * Does not consume buffer
426 * Returns 0 (TIPC_OK) if message ok and we can try again, -TIPC error
427 * code if message to be rejected
429 int tipc_msg_eval(struct net *net, struct sk_buff *buf, u32 *dnode)
431 struct tipc_msg *msg = buf_msg(buf);
434 if (msg_type(msg) != TIPC_NAMED_MSG)
435 return -TIPC_ERR_NO_PORT;
436 if (skb_linearize(buf))
437 return -TIPC_ERR_NO_NAME;
438 if (msg_data_sz(msg) > MAX_FORWARD_SIZE)
439 return -TIPC_ERR_NO_NAME;
440 if (msg_reroute_cnt(msg) > 0)
441 return -TIPC_ERR_NO_NAME;
443 *dnode = addr_domain(msg_lookup_scope(msg));
444 dport = tipc_nametbl_translate(net, msg_nametype(msg),
448 return -TIPC_ERR_NO_NAME;
449 msg_incr_reroute_cnt(msg);
450 msg_set_destnode(msg, *dnode);
451 msg_set_destport(msg, dport);
455 /* tipc_msg_reassemble() - clone a buffer chain of fragments and
456 * reassemble the clones into one message
458 struct sk_buff *tipc_msg_reassemble(struct sk_buff_head *list)
461 struct sk_buff *frag = NULL;
462 struct sk_buff *head = NULL;
465 /* Copy header if single buffer */
466 if (skb_queue_len(list) == 1) {
467 skb = skb_peek(list);
468 hdr_sz = skb_headroom(skb) + msg_hdr_sz(buf_msg(skb));
469 return __pskb_copy(skb, hdr_sz, GFP_ATOMIC);
472 /* Clone all fragments and reassemble */
473 skb_queue_walk(list, skb) {
474 frag = skb_clone(skb, GFP_ATOMIC);
478 if (tipc_buf_append(&head, &frag))
485 pr_warn("Failed do clone local mcast rcv buffer\n");