linux/net/tipc/msg.c

155 lines
4.6 KiB
C

/*
* net/tipc/msg.c: TIPC message header routines
*
* Copyright (c) 2000-2006, 2014, Ericsson AB
* Copyright (c) 2005, 2010-2011, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "core.h"
#include "msg.h"
u32 tipc_msg_tot_importance(struct tipc_msg *m)
{
if (likely(msg_isdata(m))) {
if (likely(msg_orignode(m) == tipc_own_addr))
return msg_importance(m);
return msg_importance(m) + 4;
}
if ((msg_user(m) == MSG_FRAGMENTER) &&
(msg_type(m) == FIRST_FRAGMENT))
return msg_importance(msg_get_wrapped(m));
return msg_importance(m);
}
void tipc_msg_init(struct tipc_msg *m, u32 user, u32 type, u32 hsize,
u32 destnode)
{
memset(m, 0, hsize);
msg_set_version(m);
msg_set_user(m, user);
msg_set_hdr_sz(m, hsize);
msg_set_size(m, hsize);
msg_set_prevnode(m, tipc_own_addr);
msg_set_type(m, type);
msg_set_orignode(m, tipc_own_addr);
msg_set_destnode(m, destnode);
}
/**
* tipc_msg_build - create message using specified header and data
*
* Note: Caller must not hold any locks in case copy_from_user() is interrupted!
*
* Returns message data size or errno
*/
int tipc_msg_build(struct tipc_msg *hdr, struct iovec const *msg_sect,
unsigned int len, int max_size, struct sk_buff **buf)
{
int dsz, sz, hsz;
unsigned char *to;
dsz = len;
hsz = msg_hdr_sz(hdr);
sz = hsz + dsz;
msg_set_size(hdr, sz);
if (unlikely(sz > max_size)) {
*buf = NULL;
return dsz;
}
*buf = tipc_buf_acquire(sz);
if (!(*buf))
return -ENOMEM;
skb_copy_to_linear_data(*buf, hdr, hsz);
to = (*buf)->data + hsz;
if (len && memcpy_fromiovecend(to, msg_sect, 0, dsz)) {
kfree_skb(*buf);
*buf = NULL;
return -EFAULT;
}
return dsz;
}
/* tipc_buf_append(): Append a buffer to the fragment list of another buffer
* Let first buffer become head buffer
* Returns 1 and sets *buf to headbuf if chain is complete, otherwise 0
* Leaves headbuf pointer at NULL if failure
*/
int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
{
struct sk_buff *head = *headbuf;
struct sk_buff *frag = *buf;
struct sk_buff *tail;
struct tipc_msg *msg = buf_msg(frag);
u32 fragid = msg_type(msg);
bool headstolen;
int delta;
skb_pull(frag, msg_hdr_sz(msg));
if (fragid == FIRST_FRAGMENT) {
if (head || skb_unclone(frag, GFP_ATOMIC))
goto out_free;
head = *headbuf = frag;
skb_frag_list_init(head);
return 0;
}
if (!head)
goto out_free;
tail = TIPC_SKB_CB(head)->tail;
if (skb_try_coalesce(head, frag, &headstolen, &delta)) {
kfree_skb_partial(frag, headstolen);
} else {
if (!skb_has_frag_list(head))
skb_shinfo(head)->frag_list = frag;
else
tail->next = frag;
head->truesize += frag->truesize;
head->data_len += frag->len;
head->len += frag->len;
TIPC_SKB_CB(head)->tail = frag;
}
if (fragid == LAST_FRAGMENT) {
*buf = head;
TIPC_SKB_CB(head)->tail = NULL;
*headbuf = NULL;
return 1;
}
*buf = NULL;
return 0;
out_free:
pr_warn_ratelimited("Unable to build fragment list\n");
kfree_skb(*buf);
return 0;
}