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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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.
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40 #include "name_table.h"
42 #define MAX_FORWARD_SIZE 1024
44 static unsigned int align(unsigned int i)
49 void tipc_msg_init(struct tipc_msg *m, u32 user, u32 type, u32 hsize,
54 msg_set_user(m, user);
55 msg_set_hdr_sz(m, hsize);
56 msg_set_size(m, hsize);
57 msg_set_prevnode(m, tipc_own_addr);
58 msg_set_type(m, type);
59 if (hsize > SHORT_H_SIZE) {
60 msg_set_orignode(m, tipc_own_addr);
61 msg_set_destnode(m, destnode);
65 struct sk_buff *tipc_msg_create(uint user, uint type, uint hdr_sz,
66 uint data_sz, u32 dnode, u32 onode,
67 u32 dport, u32 oport, int errcode)
72 buf = tipc_buf_acquire(hdr_sz + data_sz);
77 tipc_msg_init(msg, user, type, hdr_sz, dnode);
78 msg_set_size(msg, hdr_sz + data_sz);
79 msg_set_prevnode(msg, onode);
80 msg_set_origport(msg, oport);
81 msg_set_destport(msg, dport);
82 msg_set_errcode(msg, errcode);
83 if (hdr_sz > SHORT_H_SIZE) {
84 msg_set_orignode(msg, onode);
85 msg_set_destnode(msg, dnode);
90 /* tipc_buf_append(): Append a buffer to the fragment list of another buffer
91 * @*headbuf: in: NULL for first frag, otherwise value returned from prev call
92 * out: set when successful non-complete reassembly, otherwise NULL
93 * @*buf: in: the buffer to append. Always defined
94 * out: head buf after sucessful complete reassembly, otherwise NULL
95 * Returns 1 when reassembly complete, otherwise 0
97 int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
99 struct sk_buff *head = *headbuf;
100 struct sk_buff *frag = *buf;
101 struct sk_buff *tail;
102 struct tipc_msg *msg;
111 fragid = msg_type(msg);
113 skb_pull(frag, msg_hdr_sz(msg));
115 if (fragid == FIRST_FRAGMENT) {
118 if (unlikely(skb_unclone(frag, GFP_ATOMIC)))
120 head = *headbuf = frag;
121 skb_frag_list_init(head);
122 TIPC_SKB_CB(head)->tail = NULL;
130 if (skb_try_coalesce(head, frag, &headstolen, &delta)) {
131 kfree_skb_partial(frag, headstolen);
133 tail = TIPC_SKB_CB(head)->tail;
134 if (!skb_has_frag_list(head))
135 skb_shinfo(head)->frag_list = frag;
138 head->truesize += frag->truesize;
139 head->data_len += frag->len;
140 head->len += frag->len;
141 TIPC_SKB_CB(head)->tail = frag;
144 if (fragid == LAST_FRAGMENT) {
146 TIPC_SKB_CB(head)->tail = NULL;
154 pr_warn_ratelimited("Unable to build fragment list\n");
157 *buf = *headbuf = NULL;
163 * tipc_msg_build - create buffer chain containing specified header and data
164 * @mhdr: Message header, to be prepended to data
166 * @offset: Posision in iov to start copying from
167 * @dsz: Total length of user data
168 * @pktmax: Max packet size that can be used
169 * @chain: Buffer or chain of buffers to be returned to caller
170 * Returns message data size or errno: -ENOMEM, -EFAULT
172 int tipc_msg_build(struct tipc_msg *mhdr, struct iovec const *iov,
173 int offset, int dsz, int pktmax , struct sk_buff **chain)
175 int mhsz = msg_hdr_sz(mhdr);
176 int msz = mhsz + dsz;
181 struct tipc_msg pkthdr;
182 struct sk_buff *buf, *prev;
186 msg_set_size(mhdr, msz);
188 /* No fragmentation needed? */
189 if (likely(msz <= pktmax)) {
190 buf = tipc_buf_acquire(msz);
194 skb_copy_to_linear_data(buf, mhdr, mhsz);
195 pktpos = buf->data + mhsz;
196 TIPC_SKB_CB(buf)->chain_sz = 1;
197 if (!dsz || !memcpy_fromiovecend(pktpos, iov, offset, dsz))
203 /* Prepare reusable fragment header */
204 tipc_msg_init(&pkthdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
205 INT_H_SIZE, msg_destnode(mhdr));
206 msg_set_size(&pkthdr, pktmax);
207 msg_set_fragm_no(&pkthdr, pktno);
209 /* Prepare first fragment */
210 *chain = buf = tipc_buf_acquire(pktmax);
215 skb_copy_to_linear_data(buf, &pkthdr, INT_H_SIZE);
216 pktpos += INT_H_SIZE;
217 pktrem -= INT_H_SIZE;
218 skb_copy_to_linear_data_offset(buf, INT_H_SIZE, mhdr, mhsz);
226 if (memcpy_fromiovecend(pktpos, iov, offset, pktrem)) {
236 /* Prepare new fragment: */
237 if (drem < (pktmax - INT_H_SIZE))
238 pktsz = drem + INT_H_SIZE;
242 buf = tipc_buf_acquire(pktsz);
249 msg_set_type(&pkthdr, FRAGMENT);
250 msg_set_size(&pkthdr, pktsz);
251 msg_set_fragm_no(&pkthdr, ++pktno);
252 skb_copy_to_linear_data(buf, &pkthdr, INT_H_SIZE);
253 pktpos = buf->data + INT_H_SIZE;
254 pktrem = pktsz - INT_H_SIZE;
257 TIPC_SKB_CB(*chain)->chain_sz = chain_sz;
258 msg_set_type(buf_msg(buf), LAST_FRAGMENT);
261 kfree_skb_list(*chain);
267 * tipc_msg_bundle(): Append contents of a buffer to tail of an existing one
268 * @bbuf: the existing buffer ("bundle")
269 * @buf: buffer to be appended
270 * @mtu: max allowable size for the bundle buffer
271 * Consumes buffer if successful
272 * Returns true if bundling could be performed, otherwise false
274 bool tipc_msg_bundle(struct sk_buff *bbuf, struct sk_buff *buf, u32 mtu)
276 struct tipc_msg *bmsg = buf_msg(bbuf);
277 struct tipc_msg *msg = buf_msg(buf);
278 unsigned int bsz = msg_size(bmsg);
279 unsigned int msz = msg_size(msg);
280 u32 start = align(bsz);
281 u32 max = mtu - INT_H_SIZE;
282 u32 pad = start - bsz;
284 if (likely(msg_user(msg) == MSG_FRAGMENTER))
286 if (unlikely(msg_user(msg) == CHANGEOVER_PROTOCOL))
288 if (unlikely(msg_user(msg) == BCAST_PROTOCOL))
290 if (likely(msg_user(bmsg) != MSG_BUNDLER))
292 if (likely(msg_type(bmsg) != BUNDLE_OPEN))
294 if (unlikely(skb_tailroom(bbuf) < (pad + msz)))
296 if (unlikely(max < (start + msz)))
299 skb_put(bbuf, pad + msz);
300 skb_copy_to_linear_data_offset(bbuf, start, buf->data, msz);
301 msg_set_size(bmsg, start + msz);
302 msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
303 bbuf->next = buf->next;
309 * tipc_msg_make_bundle(): Create bundle buf and append message to its tail
310 * @buf: buffer to be appended and replaced
311 * @mtu: max allowable size for the bundle buffer, inclusive header
312 * @dnode: destination node for message. (Not always present in header)
313 * Replaces buffer if successful
314 * Returns true if sucess, otherwise false
316 bool tipc_msg_make_bundle(struct sk_buff **buf, u32 mtu, u32 dnode)
318 struct sk_buff *bbuf;
319 struct tipc_msg *bmsg;
320 struct tipc_msg *msg = buf_msg(*buf);
321 u32 msz = msg_size(msg);
322 u32 max = mtu - INT_H_SIZE;
324 if (msg_user(msg) == MSG_FRAGMENTER)
326 if (msg_user(msg) == CHANGEOVER_PROTOCOL)
328 if (msg_user(msg) == BCAST_PROTOCOL)
333 bbuf = tipc_buf_acquire(max);
337 skb_trim(bbuf, INT_H_SIZE);
338 bmsg = buf_msg(bbuf);
339 tipc_msg_init(bmsg, MSG_BUNDLER, BUNDLE_OPEN, INT_H_SIZE, dnode);
340 msg_set_seqno(bmsg, msg_seqno(msg));
341 msg_set_ack(bmsg, msg_ack(msg));
342 msg_set_bcast_ack(bmsg, msg_bcast_ack(msg));
343 bbuf->next = (*buf)->next;
344 tipc_msg_bundle(bbuf, *buf, mtu);
350 * tipc_msg_reverse(): swap source and destination addresses and add error code
351 * @buf: buffer containing message to be reversed
352 * @dnode: return value: node where to send message after reversal
353 * @err: error code to be set in message
354 * Consumes buffer if failure
355 * Returns true if success, otherwise false
357 bool tipc_msg_reverse(struct sk_buff *buf, u32 *dnode, int err)
359 struct tipc_msg *msg = buf_msg(buf);
360 uint imp = msg_importance(msg);
361 struct tipc_msg ohdr;
362 uint rdsz = min_t(uint, msg_data_sz(msg), MAX_FORWARD_SIZE);
364 if (skb_linearize(buf))
366 if (msg_dest_droppable(msg))
368 if (msg_errcode(msg))
371 memcpy(&ohdr, msg, msg_hdr_sz(msg));
372 imp = min_t(uint, imp + 1, TIPC_CRITICAL_IMPORTANCE);
374 msg_set_importance(msg, imp);
375 msg_set_errcode(msg, err);
376 msg_set_origport(msg, msg_destport(&ohdr));
377 msg_set_destport(msg, msg_origport(&ohdr));
378 msg_set_prevnode(msg, tipc_own_addr);
379 if (!msg_short(msg)) {
380 msg_set_orignode(msg, msg_destnode(&ohdr));
381 msg_set_destnode(msg, msg_orignode(&ohdr));
383 msg_set_size(msg, msg_hdr_sz(msg) + rdsz);
384 skb_trim(buf, msg_size(msg));
386 *dnode = msg_orignode(&ohdr);
394 * tipc_msg_eval: determine fate of message that found no destination
395 * @buf: the buffer containing the message.
396 * @dnode: return value: next-hop node, if message to be forwarded
397 * @err: error code to use, if message to be rejected
399 * Does not consume buffer
400 * Returns 0 (TIPC_OK) if message ok and we can try again, -TIPC error
401 * code if message to be rejected
403 int tipc_msg_eval(struct sk_buff *buf, u32 *dnode)
405 struct tipc_msg *msg = buf_msg(buf);
408 if (msg_type(msg) != TIPC_NAMED_MSG)
409 return -TIPC_ERR_NO_PORT;
410 if (skb_linearize(buf))
411 return -TIPC_ERR_NO_NAME;
412 if (msg_data_sz(msg) > MAX_FORWARD_SIZE)
413 return -TIPC_ERR_NO_NAME;
414 if (msg_reroute_cnt(msg) > 0)
415 return -TIPC_ERR_NO_NAME;
417 *dnode = addr_domain(msg_lookup_scope(msg));
418 dport = tipc_nametbl_translate(msg_nametype(msg),
422 return -TIPC_ERR_NO_NAME;
423 msg_incr_reroute_cnt(msg);
424 msg_set_destnode(msg, *dnode);
425 msg_set_destport(msg, dport);
429 /* tipc_msg_reassemble() - clone a buffer chain of fragments and
430 * reassemble the clones into one message
432 struct sk_buff *tipc_msg_reassemble(struct sk_buff *chain)
434 struct sk_buff *buf = chain;
435 struct sk_buff *frag = buf;
436 struct sk_buff *head = NULL;
439 /* Copy header if single buffer */
441 hdr_sz = skb_headroom(buf) + msg_hdr_sz(buf_msg(buf));
442 return __pskb_copy(buf, hdr_sz, GFP_ATOMIC);
445 /* Clone all fragments and reassemble */
447 frag = skb_clone(buf, GFP_ATOMIC);
451 if (tipc_buf_append(&head, &frag))
459 pr_warn("Failed do clone local mcast rcv buffer\n");