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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9 * modification, are permitted provided that the following conditions are met:
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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 msg_set_orignode(m, tipc_own_addr);
60 msg_set_destnode(m, destnode);
64 * tipc_msg_build - create message using specified header and data
66 * Note: Caller must not hold any locks in case copy_from_user() is interrupted!
68 * Returns message data size or errno
70 int tipc_msg_build(struct tipc_msg *hdr, struct iovec const *msg_sect,
71 unsigned int len, int max_size, struct sk_buff **buf)
77 hsz = msg_hdr_sz(hdr);
79 msg_set_size(hdr, sz);
80 if (unlikely(sz > max_size)) {
85 *buf = tipc_buf_acquire(sz);
88 skb_copy_to_linear_data(*buf, hdr, hsz);
89 to = (*buf)->data + hsz;
90 if (len && memcpy_fromiovecend(to, msg_sect, 0, dsz)) {
98 /* tipc_buf_append(): Append a buffer to the fragment list of another buffer
99 * @*headbuf: in: NULL for first frag, otherwise value returned from prev call
100 * out: set when successful non-complete reassembly, otherwise NULL
101 * @*buf: in: the buffer to append. Always defined
102 * out: head buf after sucessful complete reassembly, otherwise NULL
103 * Returns 1 when reassembly complete, otherwise 0
105 int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
107 struct sk_buff *head = *headbuf;
108 struct sk_buff *frag = *buf;
109 struct sk_buff *tail;
110 struct tipc_msg *msg = buf_msg(frag);
111 u32 fragid = msg_type(msg);
115 skb_pull(frag, msg_hdr_sz(msg));
117 if (fragid == FIRST_FRAGMENT) {
118 if (head || skb_unclone(frag, GFP_ATOMIC))
120 head = *headbuf = frag;
121 skb_frag_list_init(head);
127 tail = TIPC_SKB_CB(head)->tail;
128 if (skb_try_coalesce(head, frag, &headstolen, &delta)) {
129 kfree_skb_partial(frag, headstolen);
131 if (!skb_has_frag_list(head))
132 skb_shinfo(head)->frag_list = frag;
135 head->truesize += frag->truesize;
136 head->data_len += frag->len;
137 head->len += frag->len;
138 TIPC_SKB_CB(head)->tail = frag;
140 if (fragid == LAST_FRAGMENT) {
142 TIPC_SKB_CB(head)->tail = NULL;
149 pr_warn_ratelimited("Unable to build fragment list\n");
152 *buf = *headbuf = NULL;
158 * tipc_msg_build2 - create buffer chain containing specified header and data
159 * @mhdr: Message header, to be prepended to data
161 * @offset: Posision in iov to start copying from
162 * @dsz: Total length of user data
163 * @pktmax: Max packet size that can be used
164 * @chain: Buffer or chain of buffers to be returned to caller
165 * Returns message data size or errno: -ENOMEM, -EFAULT
167 int tipc_msg_build2(struct tipc_msg *mhdr, struct iovec const *iov,
168 int offset, int dsz, int pktmax , struct sk_buff **chain)
170 int mhsz = msg_hdr_sz(mhdr);
171 int msz = mhsz + dsz;
176 struct tipc_msg pkthdr;
177 struct sk_buff *buf, *prev;
181 msg_set_size(mhdr, msz);
183 /* No fragmentation needed? */
184 if (likely(msz <= pktmax)) {
185 buf = tipc_buf_acquire(msz);
189 skb_copy_to_linear_data(buf, mhdr, mhsz);
190 pktpos = buf->data + mhsz;
191 if (!dsz || !memcpy_fromiovecend(pktpos, iov, offset, dsz))
197 /* Prepare reusable fragment header */
198 tipc_msg_init(&pkthdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
199 INT_H_SIZE, msg_destnode(mhdr));
200 msg_set_size(&pkthdr, pktmax);
201 msg_set_fragm_no(&pkthdr, pktno);
203 /* Prepare first fragment */
204 *chain = buf = tipc_buf_acquire(pktmax);
208 skb_copy_to_linear_data(buf, &pkthdr, INT_H_SIZE);
209 pktpos += INT_H_SIZE;
210 pktrem -= INT_H_SIZE;
211 skb_copy_to_linear_data_offset(buf, INT_H_SIZE, mhdr, mhsz);
219 if (memcpy_fromiovecend(pktpos, iov, offset, pktrem)) {
229 /* Prepare new fragment: */
230 if (drem < (pktmax - INT_H_SIZE))
231 pktsz = drem + INT_H_SIZE;
235 buf = tipc_buf_acquire(pktsz);
241 msg_set_type(&pkthdr, FRAGMENT);
242 msg_set_size(&pkthdr, pktsz);
243 msg_set_fragm_no(&pkthdr, ++pktno);
244 skb_copy_to_linear_data(buf, &pkthdr, INT_H_SIZE);
245 pktpos = buf->data + INT_H_SIZE;
246 pktrem = pktsz - INT_H_SIZE;
250 msg_set_type(buf_msg(buf), LAST_FRAGMENT);
253 kfree_skb_list(*chain);
259 * tipc_msg_bundle(): Append contents of a buffer to tail of an existing one
260 * @bbuf: the existing buffer ("bundle")
261 * @buf: buffer to be appended
262 * @mtu: max allowable size for the bundle buffer
263 * Consumes buffer if successful
264 * Returns true if bundling could be performed, otherwise false
266 bool tipc_msg_bundle(struct sk_buff *bbuf, struct sk_buff *buf, u32 mtu)
268 struct tipc_msg *bmsg = buf_msg(bbuf);
269 struct tipc_msg *msg = buf_msg(buf);
270 unsigned int bsz = msg_size(bmsg);
271 unsigned int msz = msg_size(msg);
272 u32 start = align(bsz);
273 u32 max = mtu - INT_H_SIZE;
274 u32 pad = start - bsz;
276 if (likely(msg_user(msg) == MSG_FRAGMENTER))
278 if (unlikely(msg_user(msg) == CHANGEOVER_PROTOCOL))
280 if (unlikely(msg_user(msg) == BCAST_PROTOCOL))
282 if (likely(msg_user(bmsg) != MSG_BUNDLER))
284 if (likely(msg_type(bmsg) != BUNDLE_OPEN))
286 if (unlikely(skb_tailroom(bbuf) < (pad + msz)))
288 if (unlikely(max < (start + msz)))
291 skb_put(bbuf, pad + msz);
292 skb_copy_to_linear_data_offset(bbuf, start, buf->data, msz);
293 msg_set_size(bmsg, start + msz);
294 msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
295 bbuf->next = buf->next;
301 * tipc_msg_make_bundle(): Create bundle buf and append message to its tail
302 * @buf: buffer to be appended and replaced
303 * @mtu: max allowable size for the bundle buffer, inclusive header
304 * @dnode: destination node for message. (Not always present in header)
305 * Replaces buffer if successful
306 * Returns true if sucess, otherwise false
308 bool tipc_msg_make_bundle(struct sk_buff **buf, u32 mtu, u32 dnode)
310 struct sk_buff *bbuf;
311 struct tipc_msg *bmsg;
312 struct tipc_msg *msg = buf_msg(*buf);
313 u32 msz = msg_size(msg);
314 u32 max = mtu - INT_H_SIZE;
316 if (msg_user(msg) == MSG_FRAGMENTER)
318 if (msg_user(msg) == CHANGEOVER_PROTOCOL)
320 if (msg_user(msg) == BCAST_PROTOCOL)
325 bbuf = tipc_buf_acquire(max);
329 skb_trim(bbuf, INT_H_SIZE);
330 bmsg = buf_msg(bbuf);
331 tipc_msg_init(bmsg, MSG_BUNDLER, BUNDLE_OPEN, INT_H_SIZE, dnode);
332 msg_set_seqno(bmsg, msg_seqno(msg));
333 msg_set_ack(bmsg, msg_ack(msg));
334 msg_set_bcast_ack(bmsg, msg_bcast_ack(msg));
335 bbuf->next = (*buf)->next;
336 tipc_msg_bundle(bbuf, *buf, mtu);
342 * tipc_msg_reverse(): swap source and destination addresses and add error code
343 * @buf: buffer containing message to be reversed
344 * @dnode: return value: node where to send message after reversal
345 * @err: error code to be set in message
346 * Consumes buffer if failure
347 * Returns true if success, otherwise false
349 bool tipc_msg_reverse(struct sk_buff *buf, u32 *dnode, int err)
351 struct tipc_msg *msg = buf_msg(buf);
352 uint imp = msg_importance(msg);
353 struct tipc_msg ohdr;
354 uint rdsz = min_t(uint, msg_data_sz(msg), MAX_FORWARD_SIZE);
356 if (skb_linearize(buf))
358 if (msg_dest_droppable(msg))
360 if (msg_errcode(msg))
363 memcpy(&ohdr, msg, msg_hdr_sz(msg));
364 imp = min_t(uint, imp + 1, TIPC_CRITICAL_IMPORTANCE);
366 msg_set_importance(msg, imp);
367 msg_set_errcode(msg, err);
368 msg_set_origport(msg, msg_destport(&ohdr));
369 msg_set_destport(msg, msg_origport(&ohdr));
370 msg_set_prevnode(msg, tipc_own_addr);
371 if (!msg_short(msg)) {
372 msg_set_orignode(msg, msg_destnode(&ohdr));
373 msg_set_destnode(msg, msg_orignode(&ohdr));
375 msg_set_size(msg, msg_hdr_sz(msg) + rdsz);
376 skb_trim(buf, msg_size(msg));
378 *dnode = msg_orignode(&ohdr);
386 * tipc_msg_eval: determine fate of message that found no destination
387 * @buf: the buffer containing the message.
388 * @dnode: return value: next-hop node, if message to be forwarded
389 * @err: error code to use, if message to be rejected
391 * Does not consume buffer
392 * Returns 0 (TIPC_OK) if message ok and we can try again, -TIPC error
393 * code if message to be rejected
395 int tipc_msg_eval(struct sk_buff *buf, u32 *dnode)
397 struct tipc_msg *msg = buf_msg(buf);
400 if (msg_type(msg) != TIPC_NAMED_MSG)
401 return -TIPC_ERR_NO_PORT;
402 if (skb_linearize(buf))
403 return -TIPC_ERR_NO_NAME;
404 if (msg_data_sz(msg) > MAX_FORWARD_SIZE)
405 return -TIPC_ERR_NO_NAME;
406 if (msg_reroute_cnt(msg) > 0)
407 return -TIPC_ERR_NO_NAME;
409 *dnode = addr_domain(msg_lookup_scope(msg));
410 dport = tipc_nametbl_translate(msg_nametype(msg),
414 return -TIPC_ERR_NO_NAME;
415 msg_incr_reroute_cnt(msg);
416 msg_set_destnode(msg, *dnode);
417 msg_set_destport(msg, dport);