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/*
* 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"
static unsigned int align(unsigned int i)
{
return (i + 3) & ~3u;
}
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;
}
/**
* tipc_msg_bundle(): Append contents of a buffer to tail of an existing one
* @bbuf: the existing buffer ("bundle")
* @buf: buffer to be appended
* @mtu: max allowable size for the bundle buffer
* Consumes buffer if successful
* Returns true if bundling could be performed, otherwise false
*/
bool tipc_msg_bundle(struct sk_buff *bbuf, struct sk_buff *buf, u32 mtu)
{
struct tipc_msg *bmsg = buf_msg(bbuf);
struct tipc_msg *msg = buf_msg(buf);
unsigned int bsz = msg_size(bmsg);
unsigned int msz = msg_size(msg);
u32 start = align(bsz);
u32 max = mtu - INT_H_SIZE;
u32 pad = start - bsz;
if (likely(msg_user(msg) == MSG_FRAGMENTER))
return false;
if (unlikely(msg_user(msg) == CHANGEOVER_PROTOCOL))
return false;
if (unlikely(msg_user(msg) == BCAST_PROTOCOL))
return false;
if (likely(msg_user(bmsg) != MSG_BUNDLER))
return false;
if (likely(msg_type(bmsg) != BUNDLE_OPEN))
return false;
if (unlikely(skb_tailroom(bbuf) < (pad + msz)))
return false;
if (unlikely(max < (start + msz)))
return false;
skb_put(bbuf, pad + msz);
skb_copy_to_linear_data_offset(bbuf, start, buf->data, msz);
msg_set_size(bmsg, start + msz);
msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
bbuf->next = buf->next;
kfree_skb(buf);
return true;
}
/**
* tipc_msg_make_bundle(): Create bundle buf and append message to its tail
* @buf: buffer to be appended and replaced
* @mtu: max allowable size for the bundle buffer, inclusive header
* @dnode: destination node for message. (Not always present in header)
* Replaces buffer if successful
* Returns true if sucess, otherwise false
*/
bool tipc_msg_make_bundle(struct sk_buff **buf, u32 mtu, u32 dnode)
{
struct sk_buff *bbuf;
struct tipc_msg *bmsg;
struct tipc_msg *msg = buf_msg(*buf);
u32 msz = msg_size(msg);
u32 max = mtu - INT_H_SIZE;
if (msg_user(msg) == MSG_FRAGMENTER)
return false;
if (msg_user(msg) == CHANGEOVER_PROTOCOL)
return false;
if (msg_user(msg) == BCAST_PROTOCOL)
return false;
if (msz > (max / 2))
return false;
bbuf = tipc_buf_acquire(max);
if (!bbuf)
return false;
skb_trim(bbuf, INT_H_SIZE);
bmsg = buf_msg(bbuf);
tipc_msg_init(bmsg, MSG_BUNDLER, BUNDLE_OPEN, INT_H_SIZE, dnode);
msg_set_seqno(bmsg, msg_seqno(msg));
msg_set_ack(bmsg, msg_ack(msg));
msg_set_bcast_ack(bmsg, msg_bcast_ack(msg));
bbuf->next = (*buf)->next;
tipc_msg_bundle(bbuf, *buf, mtu);
*buf = bbuf;
return true;
}
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