LXR linux/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
  40u32 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
  54void 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 */
  75int 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