linux/net/tipc/msg.c
Tuong Lien e95584a889 tipc: fix unlimited bundling of small messages
We have identified a problem with the "oversubscription" policy in the
link transmission code.

When small messages are transmitted, and the sending link has reached
the transmit window limit, those messages will be bundled and put into
the link backlog queue. However, bundles of data messages are counted
at the 'CRITICAL' level, so that the counter for that level, instead of
the counter for the real, bundled message's level is the one being
increased.
Subsequent, to-be-bundled data messages at non-CRITICAL levels continue
to be tested against the unchanged counter for their own level, while
contributing to an unrestrained increase at the CRITICAL backlog level.

This leaves a gap in congestion control algorithm for small messages
that can result in starvation for other users or a "real" CRITICAL
user. Even that eventually can lead to buffer exhaustion & link reset.

We fix this by keeping a 'target_bskb' buffer pointer at each levels,
then when bundling, we only bundle messages at the same importance
level only. This way, we know exactly how many slots a certain level
have occupied in the queue, so can manage level congestion accurately.

By bundling messages at the same level, we even have more benefits. Let
consider this:
- One socket sends 64-byte messages at the 'CRITICAL' level;
- Another sends 4096-byte messages at the 'LOW' level;

When a 64-byte message comes and is bundled the first time, we put the
overhead of message bundle to it (+ 40-byte header, data copy, etc.)
for later use, but the next message can be a 4096-byte one that cannot
be bundled to the previous one. This means the last bundle carries only
one payload message which is totally inefficient, as for the receiver
also! Later on, another 64-byte message comes, now we make a new bundle
and the same story repeats...

With the new bundling algorithm, this will not happen, the 64-byte
messages will be bundled together even when the 4096-byte message(s)
comes in between. However, if the 4096-byte messages are sent at the
same level i.e. 'CRITICAL', the bundling algorithm will again cause the
same overhead.

Also, the same will happen even with only one socket sending small
messages at a rate close to the link transmit's one, so that, when one
message is bundled, it's transmitted shortly. Then, another message
comes, a new bundle is created and so on...

We will solve this issue radically by another patch.

Fixes: 365ad353c2 ("tipc: reduce risk of user starvation during link congestion")
Reported-by: Hoang Le <hoang.h.le@dektech.com.au>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-02 11:02:05 -04:00

792 lines
21 KiB
C

/*
* net/tipc/msg.c: TIPC message header routines
*
* Copyright (c) 2000-2006, 2014-2015, 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 <net/sock.h>
#include "core.h"
#include "msg.h"
#include "addr.h"
#include "name_table.h"
#define MAX_FORWARD_SIZE 1024
#define BUF_HEADROOM (LL_MAX_HEADER + 48)
#define BUF_TAILROOM 16
static unsigned int align(unsigned int i)
{
return (i + 3) & ~3u;
}
/**
* tipc_buf_acquire - creates a TIPC message buffer
* @size: message size (including TIPC header)
*
* Returns a new buffer with data pointers set to the specified size.
*
* NOTE: Headroom is reserved to allow prepending of a data link header.
* There may also be unrequested tailroom present at the buffer's end.
*/
struct sk_buff *tipc_buf_acquire(u32 size, gfp_t gfp)
{
struct sk_buff *skb;
unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u;
skb = alloc_skb_fclone(buf_size, gfp);
if (skb) {
skb_reserve(skb, BUF_HEADROOM);
skb_put(skb, size);
skb->next = NULL;
}
return skb;
}
void tipc_msg_init(u32 own_node, struct tipc_msg *m, u32 user, u32 type,
u32 hsize, u32 dnode)
{
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, own_node);
msg_set_type(m, type);
if (hsize > SHORT_H_SIZE) {
msg_set_orignode(m, own_node);
msg_set_destnode(m, dnode);
}
}
struct sk_buff *tipc_msg_create(uint user, uint type,
uint hdr_sz, uint data_sz, u32 dnode,
u32 onode, u32 dport, u32 oport, int errcode)
{
struct tipc_msg *msg;
struct sk_buff *buf;
buf = tipc_buf_acquire(hdr_sz + data_sz, GFP_ATOMIC);
if (unlikely(!buf))
return NULL;
msg = buf_msg(buf);
tipc_msg_init(onode, msg, user, type, hdr_sz, dnode);
msg_set_size(msg, hdr_sz + data_sz);
msg_set_origport(msg, oport);
msg_set_destport(msg, dport);
msg_set_errcode(msg, errcode);
if (hdr_sz > SHORT_H_SIZE) {
msg_set_orignode(msg, onode);
msg_set_destnode(msg, dnode);
}
return buf;
}
/* tipc_buf_append(): Append a buffer to the fragment list of another buffer
* @*headbuf: in: NULL for first frag, otherwise value returned from prev call
* out: set when successful non-complete reassembly, otherwise NULL
* @*buf: in: the buffer to append. Always defined
* out: head buf after successful complete reassembly, otherwise NULL
* Returns 1 when reassembly complete, otherwise 0
*/
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 = NULL;
struct tipc_msg *msg;
u32 fragid;
int delta;
bool headstolen;
if (!frag)
goto err;
msg = buf_msg(frag);
fragid = msg_type(msg);
frag->next = NULL;
skb_pull(frag, msg_hdr_sz(msg));
if (fragid == FIRST_FRAGMENT) {
if (unlikely(head))
goto err;
if (unlikely(skb_unclone(frag, GFP_ATOMIC)))
goto err;
head = *headbuf = frag;
*buf = NULL;
TIPC_SKB_CB(head)->tail = NULL;
if (skb_is_nonlinear(head)) {
skb_walk_frags(head, tail) {
TIPC_SKB_CB(head)->tail = tail;
}
} else {
skb_frag_list_init(head);
}
return 0;
}
if (!head)
goto err;
if (skb_try_coalesce(head, frag, &headstolen, &delta)) {
kfree_skb_partial(frag, headstolen);
} else {
tail = TIPC_SKB_CB(head)->tail;
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) {
TIPC_SKB_CB(head)->validated = false;
if (unlikely(!tipc_msg_validate(&head)))
goto err;
*buf = head;
TIPC_SKB_CB(head)->tail = NULL;
*headbuf = NULL;
return 1;
}
*buf = NULL;
return 0;
err:
kfree_skb(*buf);
kfree_skb(*headbuf);
*buf = *headbuf = NULL;
return 0;
}
/* tipc_msg_validate - validate basic format of received message
*
* This routine ensures a TIPC message has an acceptable header, and at least
* as much data as the header indicates it should. The routine also ensures
* that the entire message header is stored in the main fragment of the message
* buffer, to simplify future access to message header fields.
*
* Note: Having extra info present in the message header or data areas is OK.
* TIPC will ignore the excess, under the assumption that it is optional info
* introduced by a later release of the protocol.
*/
bool tipc_msg_validate(struct sk_buff **_skb)
{
struct sk_buff *skb = *_skb;
struct tipc_msg *hdr;
int msz, hsz;
/* Ensure that flow control ratio condition is satisfied */
if (unlikely(skb->truesize / buf_roundup_len(skb) >= 4)) {
skb = skb_copy_expand(skb, BUF_HEADROOM, 0, GFP_ATOMIC);
if (!skb)
return false;
kfree_skb(*_skb);
*_skb = skb;
}
if (unlikely(TIPC_SKB_CB(skb)->validated))
return true;
if (unlikely(!pskb_may_pull(skb, MIN_H_SIZE)))
return false;
hsz = msg_hdr_sz(buf_msg(skb));
if (unlikely(hsz < MIN_H_SIZE) || (hsz > MAX_H_SIZE))
return false;
if (unlikely(!pskb_may_pull(skb, hsz)))
return false;
hdr = buf_msg(skb);
if (unlikely(msg_version(hdr) != TIPC_VERSION))
return false;
msz = msg_size(hdr);
if (unlikely(msz < hsz))
return false;
if (unlikely((msz - hsz) > TIPC_MAX_USER_MSG_SIZE))
return false;
if (unlikely(skb->len < msz))
return false;
TIPC_SKB_CB(skb)->validated = true;
return true;
}
/**
* tipc_msg_fragment - build a fragment skb list for TIPC message
*
* @skb: TIPC message skb
* @hdr: internal msg header to be put on the top of the fragments
* @pktmax: max size of a fragment incl. the header
* @frags: returned fragment skb list
*
* Returns 0 if the fragmentation is successful, otherwise: -EINVAL
* or -ENOMEM
*/
int tipc_msg_fragment(struct sk_buff *skb, const struct tipc_msg *hdr,
int pktmax, struct sk_buff_head *frags)
{
int pktno, nof_fragms, dsz, dmax, eat;
struct tipc_msg *_hdr;
struct sk_buff *_skb;
u8 *data;
/* Non-linear buffer? */
if (skb_linearize(skb))
return -ENOMEM;
data = (u8 *)skb->data;
dsz = msg_size(buf_msg(skb));
dmax = pktmax - INT_H_SIZE;
if (dsz <= dmax || !dmax)
return -EINVAL;
nof_fragms = dsz / dmax + 1;
for (pktno = 1; pktno <= nof_fragms; pktno++) {
if (pktno < nof_fragms)
eat = dmax;
else
eat = dsz % dmax;
/* Allocate a new fragment */
_skb = tipc_buf_acquire(INT_H_SIZE + eat, GFP_ATOMIC);
if (!_skb)
goto error;
skb_orphan(_skb);
__skb_queue_tail(frags, _skb);
/* Copy header & data to the fragment */
skb_copy_to_linear_data(_skb, hdr, INT_H_SIZE);
skb_copy_to_linear_data_offset(_skb, INT_H_SIZE, data, eat);
data += eat;
/* Update the fragment's header */
_hdr = buf_msg(_skb);
msg_set_fragm_no(_hdr, pktno);
msg_set_nof_fragms(_hdr, nof_fragms);
msg_set_size(_hdr, INT_H_SIZE + eat);
}
return 0;
error:
__skb_queue_purge(frags);
__skb_queue_head_init(frags);
return -ENOMEM;
}
/**
* tipc_msg_build - create buffer chain containing specified header and data
* @mhdr: Message header, to be prepended to data
* @m: User message
* @dsz: Total length of user data
* @pktmax: Max packet size that can be used
* @list: Buffer or chain of buffers to be returned to caller
*
* Note that the recursive call we are making here is safe, since it can
* logically go only one further level down.
*
* Returns message data size or errno: -ENOMEM, -EFAULT
*/
int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, int offset,
int dsz, int pktmax, struct sk_buff_head *list)
{
int mhsz = msg_hdr_sz(mhdr);
struct tipc_msg pkthdr;
int msz = mhsz + dsz;
int pktrem = pktmax;
struct sk_buff *skb;
int drem = dsz;
int pktno = 1;
char *pktpos;
int pktsz;
int rc;
msg_set_size(mhdr, msz);
/* No fragmentation needed? */
if (likely(msz <= pktmax)) {
skb = tipc_buf_acquire(msz, GFP_KERNEL);
/* Fall back to smaller MTU if node local message */
if (unlikely(!skb)) {
if (pktmax != MAX_MSG_SIZE)
return -ENOMEM;
rc = tipc_msg_build(mhdr, m, offset, dsz, FB_MTU, list);
if (rc != dsz)
return rc;
if (tipc_msg_assemble(list))
return dsz;
return -ENOMEM;
}
skb_orphan(skb);
__skb_queue_tail(list, skb);
skb_copy_to_linear_data(skb, mhdr, mhsz);
pktpos = skb->data + mhsz;
if (copy_from_iter_full(pktpos, dsz, &m->msg_iter))
return dsz;
rc = -EFAULT;
goto error;
}
/* Prepare reusable fragment header */
tipc_msg_init(msg_prevnode(mhdr), &pkthdr, MSG_FRAGMENTER,
FIRST_FRAGMENT, INT_H_SIZE, msg_destnode(mhdr));
msg_set_size(&pkthdr, pktmax);
msg_set_fragm_no(&pkthdr, pktno);
msg_set_importance(&pkthdr, msg_importance(mhdr));
/* Prepare first fragment */
skb = tipc_buf_acquire(pktmax, GFP_KERNEL);
if (!skb)
return -ENOMEM;
skb_orphan(skb);
__skb_queue_tail(list, skb);
pktpos = skb->data;
skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
pktpos += INT_H_SIZE;
pktrem -= INT_H_SIZE;
skb_copy_to_linear_data_offset(skb, INT_H_SIZE, mhdr, mhsz);
pktpos += mhsz;
pktrem -= mhsz;
do {
if (drem < pktrem)
pktrem = drem;
if (!copy_from_iter_full(pktpos, pktrem, &m->msg_iter)) {
rc = -EFAULT;
goto error;
}
drem -= pktrem;
if (!drem)
break;
/* Prepare new fragment: */
if (drem < (pktmax - INT_H_SIZE))
pktsz = drem + INT_H_SIZE;
else
pktsz = pktmax;
skb = tipc_buf_acquire(pktsz, GFP_KERNEL);
if (!skb) {
rc = -ENOMEM;
goto error;
}
skb_orphan(skb);
__skb_queue_tail(list, skb);
msg_set_type(&pkthdr, FRAGMENT);
msg_set_size(&pkthdr, pktsz);
msg_set_fragm_no(&pkthdr, ++pktno);
skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
pktpos = skb->data + INT_H_SIZE;
pktrem = pktsz - INT_H_SIZE;
} while (1);
msg_set_type(buf_msg(skb), LAST_FRAGMENT);
return dsz;
error:
__skb_queue_purge(list);
__skb_queue_head_init(list);
return rc;
}
/**
* tipc_msg_bundle(): Append contents of a buffer to tail of an existing one
* @skb: the buffer to append to ("bundle")
* @msg: message 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 *skb, struct tipc_msg *msg, u32 mtu)
{
struct tipc_msg *bmsg;
unsigned int bsz;
unsigned int msz = msg_size(msg);
u32 start, pad;
u32 max = mtu - INT_H_SIZE;
if (likely(msg_user(msg) == MSG_FRAGMENTER))
return false;
if (!skb)
return false;
bmsg = buf_msg(skb);
bsz = msg_size(bmsg);
start = align(bsz);
pad = start - bsz;
if (unlikely(msg_user(msg) == TUNNEL_PROTOCOL))
return false;
if (unlikely(msg_user(msg) == BCAST_PROTOCOL))
return false;
if (unlikely(msg_user(bmsg) != MSG_BUNDLER))
return false;
if (unlikely(skb_tailroom(skb) < (pad + msz)))
return false;
if (unlikely(max < (start + msz)))
return false;
if ((msg_importance(msg) < TIPC_SYSTEM_IMPORTANCE) &&
(msg_importance(bmsg) == TIPC_SYSTEM_IMPORTANCE))
return false;
skb_put(skb, pad + msz);
skb_copy_to_linear_data_offset(skb, start, msg, msz);
msg_set_size(bmsg, start + msz);
msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
return true;
}
/**
* tipc_msg_extract(): extract bundled inner packet from buffer
* @skb: buffer to be extracted from.
* @iskb: extracted inner buffer, to be returned
* @pos: position in outer message of msg to be extracted.
* Returns position of next msg
* Consumes outer buffer when last packet extracted
* Returns true when when there is an extracted buffer, otherwise false
*/
bool tipc_msg_extract(struct sk_buff *skb, struct sk_buff **iskb, int *pos)
{
struct tipc_msg *hdr, *ihdr;
int imsz;
*iskb = NULL;
if (unlikely(skb_linearize(skb)))
goto none;
hdr = buf_msg(skb);
if (unlikely(*pos > (msg_data_sz(hdr) - MIN_H_SIZE)))
goto none;
ihdr = (struct tipc_msg *)(msg_data(hdr) + *pos);
imsz = msg_size(ihdr);
if ((*pos + imsz) > msg_data_sz(hdr))
goto none;
*iskb = tipc_buf_acquire(imsz, GFP_ATOMIC);
if (!*iskb)
goto none;
skb_copy_to_linear_data(*iskb, ihdr, imsz);
if (unlikely(!tipc_msg_validate(iskb)))
goto none;
*pos += align(imsz);
return true;
none:
kfree_skb(skb);
kfree_skb(*iskb);
*iskb = NULL;
return false;
}
/**
* tipc_msg_make_bundle(): Create bundle buf and append message to its tail
* @list: the buffer chain, where head is the buffer to replace/append
* @skb: buffer to be created, appended to and returned in case of success
* @msg: message to be appended
* @mtu: max allowable size for the bundle buffer, inclusive header
* @dnode: destination node for message. (Not always present in header)
* Returns true if success, otherwise false
*/
bool tipc_msg_make_bundle(struct sk_buff **skb, struct tipc_msg *msg,
u32 mtu, u32 dnode)
{
struct sk_buff *_skb;
struct tipc_msg *bmsg;
u32 msz = msg_size(msg);
u32 max = mtu - INT_H_SIZE;
if (msg_user(msg) == MSG_FRAGMENTER)
return false;
if (msg_user(msg) == TUNNEL_PROTOCOL)
return false;
if (msg_user(msg) == BCAST_PROTOCOL)
return false;
if (msz > (max / 2))
return false;
_skb = tipc_buf_acquire(max, GFP_ATOMIC);
if (!_skb)
return false;
skb_trim(_skb, INT_H_SIZE);
bmsg = buf_msg(_skb);
tipc_msg_init(msg_prevnode(msg), bmsg, MSG_BUNDLER, 0,
INT_H_SIZE, dnode);
msg_set_importance(bmsg, msg_importance(msg));
msg_set_seqno(bmsg, msg_seqno(msg));
msg_set_ack(bmsg, msg_ack(msg));
msg_set_bcast_ack(bmsg, msg_bcast_ack(msg));
tipc_msg_bundle(_skb, msg, mtu);
*skb = _skb;
return true;
}
/**
* tipc_msg_reverse(): swap source and destination addresses and add error code
* @own_node: originating node id for reversed message
* @skb: buffer containing message to be reversed; will be consumed
* @err: error code to be set in message, if any
* Replaces consumed buffer with new one when successful
* Returns true if success, otherwise false
*/
bool tipc_msg_reverse(u32 own_node, struct sk_buff **skb, int err)
{
struct sk_buff *_skb = *skb;
struct tipc_msg *_hdr, *hdr;
int hlen, dlen;
if (skb_linearize(_skb))
goto exit;
_hdr = buf_msg(_skb);
dlen = min_t(uint, msg_data_sz(_hdr), MAX_FORWARD_SIZE);
hlen = msg_hdr_sz(_hdr);
if (msg_dest_droppable(_hdr))
goto exit;
if (msg_errcode(_hdr))
goto exit;
/* Never return SHORT header */
if (hlen == SHORT_H_SIZE)
hlen = BASIC_H_SIZE;
/* Don't return data along with SYN+, - sender has a clone */
if (msg_is_syn(_hdr) && err == TIPC_ERR_OVERLOAD)
dlen = 0;
/* Allocate new buffer to return */
*skb = tipc_buf_acquire(hlen + dlen, GFP_ATOMIC);
if (!*skb)
goto exit;
memcpy((*skb)->data, _skb->data, msg_hdr_sz(_hdr));
memcpy((*skb)->data + hlen, msg_data(_hdr), dlen);
/* Build reverse header in new buffer */
hdr = buf_msg(*skb);
msg_set_hdr_sz(hdr, hlen);
msg_set_errcode(hdr, err);
msg_set_non_seq(hdr, 0);
msg_set_origport(hdr, msg_destport(_hdr));
msg_set_destport(hdr, msg_origport(_hdr));
msg_set_destnode(hdr, msg_prevnode(_hdr));
msg_set_prevnode(hdr, own_node);
msg_set_orignode(hdr, own_node);
msg_set_size(hdr, hlen + dlen);
skb_orphan(_skb);
kfree_skb(_skb);
return true;
exit:
kfree_skb(_skb);
*skb = NULL;
return false;
}
bool tipc_msg_skb_clone(struct sk_buff_head *msg, struct sk_buff_head *cpy)
{
struct sk_buff *skb, *_skb;
skb_queue_walk(msg, skb) {
_skb = skb_clone(skb, GFP_ATOMIC);
if (!_skb) {
__skb_queue_purge(cpy);
pr_err_ratelimited("Failed to clone buffer chain\n");
return false;
}
__skb_queue_tail(cpy, _skb);
}
return true;
}
/**
* tipc_msg_lookup_dest(): try to find new destination for named message
* @skb: the buffer containing the message.
* @err: error code to be used by caller if lookup fails
* Does not consume buffer
* Returns true if a destination is found, false otherwise
*/
bool tipc_msg_lookup_dest(struct net *net, struct sk_buff *skb, int *err)
{
struct tipc_msg *msg = buf_msg(skb);
u32 dport, dnode;
u32 onode = tipc_own_addr(net);
if (!msg_isdata(msg))
return false;
if (!msg_named(msg))
return false;
if (msg_errcode(msg))
return false;
*err = TIPC_ERR_NO_NAME;
if (skb_linearize(skb))
return false;
msg = buf_msg(skb);
if (msg_reroute_cnt(msg))
return false;
dnode = tipc_scope2node(net, msg_lookup_scope(msg));
dport = tipc_nametbl_translate(net, msg_nametype(msg),
msg_nameinst(msg), &dnode);
if (!dport)
return false;
msg_incr_reroute_cnt(msg);
if (dnode != onode)
msg_set_prevnode(msg, onode);
msg_set_destnode(msg, dnode);
msg_set_destport(msg, dport);
*err = TIPC_OK;
if (!skb_cloned(skb))
return true;
return true;
}
/* tipc_msg_assemble() - assemble chain of fragments into one message
*/
bool tipc_msg_assemble(struct sk_buff_head *list)
{
struct sk_buff *skb, *tmp = NULL;
if (skb_queue_len(list) == 1)
return true;
while ((skb = __skb_dequeue(list))) {
skb->next = NULL;
if (tipc_buf_append(&tmp, &skb)) {
__skb_queue_tail(list, skb);
return true;
}
if (!tmp)
break;
}
__skb_queue_purge(list);
__skb_queue_head_init(list);
pr_warn("Failed do assemble buffer\n");
return false;
}
/* tipc_msg_reassemble() - clone a buffer chain of fragments and
* reassemble the clones into one message
*/
bool tipc_msg_reassemble(struct sk_buff_head *list, struct sk_buff_head *rcvq)
{
struct sk_buff *skb, *_skb;
struct sk_buff *frag = NULL;
struct sk_buff *head = NULL;
int hdr_len;
/* Copy header if single buffer */
if (skb_queue_len(list) == 1) {
skb = skb_peek(list);
hdr_len = skb_headroom(skb) + msg_hdr_sz(buf_msg(skb));
_skb = __pskb_copy(skb, hdr_len, GFP_ATOMIC);
if (!_skb)
return false;
__skb_queue_tail(rcvq, _skb);
return true;
}
/* Clone all fragments and reassemble */
skb_queue_walk(list, skb) {
frag = skb_clone(skb, GFP_ATOMIC);
if (!frag)
goto error;
frag->next = NULL;
if (tipc_buf_append(&head, &frag))
break;
if (!head)
goto error;
}
__skb_queue_tail(rcvq, frag);
return true;
error:
pr_warn("Failed do clone local mcast rcv buffer\n");
kfree_skb(head);
return false;
}
bool tipc_msg_pskb_copy(u32 dst, struct sk_buff_head *msg,
struct sk_buff_head *cpy)
{
struct sk_buff *skb, *_skb;
skb_queue_walk(msg, skb) {
_skb = pskb_copy(skb, GFP_ATOMIC);
if (!_skb) {
__skb_queue_purge(cpy);
return false;
}
msg_set_destnode(buf_msg(_skb), dst);
__skb_queue_tail(cpy, _skb);
}
return true;
}
/* tipc_skb_queue_sorted(); sort pkt into list according to sequence number
* @list: list to be appended to
* @seqno: sequence number of buffer to add
* @skb: buffer to add
*/
void __tipc_skb_queue_sorted(struct sk_buff_head *list, u16 seqno,
struct sk_buff *skb)
{
struct sk_buff *_skb, *tmp;
if (skb_queue_empty(list) || less(seqno, buf_seqno(skb_peek(list)))) {
__skb_queue_head(list, skb);
return;
}
if (more(seqno, buf_seqno(skb_peek_tail(list)))) {
__skb_queue_tail(list, skb);
return;
}
skb_queue_walk_safe(list, _skb, tmp) {
if (more(seqno, buf_seqno(_skb)))
continue;
if (seqno == buf_seqno(_skb))
break;
__skb_queue_before(list, _skb, skb);
return;
}
kfree_skb(skb);
}
void tipc_skb_reject(struct net *net, int err, struct sk_buff *skb,
struct sk_buff_head *xmitq)
{
if (tipc_msg_reverse(tipc_own_addr(net), &skb, err))
__skb_queue_tail(xmitq, skb);
}