xref: /openbmc/linux/net/tipc/msg.c (revision 84764a41)
1 /*
2  * net/tipc/msg.c: TIPC message header routines
3  *
4  * Copyright (c) 2000-2006, Ericsson AB
5  * Copyright (c) 2005, 2010-2011, Wind River Systems
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are met:
10  *
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.
19  *
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.
23  *
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
27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34  * POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 #include "core.h"
38 #include "msg.h"
39 
40 u32 tipc_msg_tot_importance(struct tipc_msg *m)
41 {
42 	if (likely(msg_isdata(m))) {
43 		if (likely(msg_orignode(m) == tipc_own_addr))
44 			return msg_importance(m);
45 		return msg_importance(m) + 4;
46 	}
47 	if ((msg_user(m) == MSG_FRAGMENTER)  &&
48 	    (msg_type(m) == FIRST_FRAGMENT))
49 		return msg_importance(msg_get_wrapped(m));
50 	return msg_importance(m);
51 }
52 
53 
54 void tipc_msg_init(struct tipc_msg *m, u32 user, u32 type,
55 			    u32 hsize, u32 destnode)
56 {
57 	memset(m, 0, hsize);
58 	msg_set_version(m);
59 	msg_set_user(m, user);
60 	msg_set_hdr_sz(m, hsize);
61 	msg_set_size(m, hsize);
62 	msg_set_prevnode(m, tipc_own_addr);
63 	msg_set_type(m, type);
64 	msg_set_orignode(m, tipc_own_addr);
65 	msg_set_destnode(m, destnode);
66 }
67 
68 /**
69  * tipc_msg_build - create message using specified header and data
70  *
71  * Note: Caller must not hold any locks in case copy_from_user() is interrupted!
72  *
73  * Returns message data size or errno
74  */
75 int tipc_msg_build(struct tipc_msg *hdr, struct iovec const *msg_sect,
76 		   u32 num_sect, unsigned int total_len,
77 			    int max_size, int usrmem, struct sk_buff **buf)
78 {
79 	int dsz, sz, hsz, pos, res, cnt;
80 
81 	dsz = total_len;
82 	pos = hsz = msg_hdr_sz(hdr);
83 	sz = hsz + dsz;
84 	msg_set_size(hdr, sz);
85 	if (unlikely(sz > max_size)) {
86 		*buf = NULL;
87 		return dsz;
88 	}
89 
90 	*buf = tipc_buf_acquire(sz);
91 	if (!(*buf))
92 		return -ENOMEM;
93 	skb_copy_to_linear_data(*buf, hdr, hsz);
94 	for (res = 1, cnt = 0; res && (cnt < num_sect); cnt++) {
95 		if (likely(usrmem))
96 			res = !copy_from_user((*buf)->data + pos,
97 					      msg_sect[cnt].iov_base,
98 					      msg_sect[cnt].iov_len);
99 		else
100 			skb_copy_to_linear_data_offset(*buf, pos,
101 						       msg_sect[cnt].iov_base,
102 						       msg_sect[cnt].iov_len);
103 		pos += msg_sect[cnt].iov_len;
104 	}
105 	if (likely(res))
106 		return dsz;
107 
108 	kfree_skb(*buf);
109 	*buf = NULL;
110 	return -EFAULT;
111 }
112