net/tipc/msg.c

   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 }