linux/net/tipc/msg.c
Xin Long b7df21cf1b tipc: skb_linearize the head skb when reassembling msgs
It's not a good idea to append the frag skb to a skb's frag_list if
the frag_list already has skbs from elsewhere, such as this skb was
created by pskb_copy() where the frag_list was cloned (all the skbs
in it were skb_get'ed) and shared by multiple skbs.

However, the new appended frag skb should have been only seen by the
current skb. Otherwise, it will cause use after free crashes as this
appended frag skb are seen by multiple skbs but it only got skb_get
called once.

The same thing happens with a skb updated by pskb_may_pull() with a
skb_cloned skb. Li Shuang has reported quite a few crashes caused
by this when doing testing over macvlan devices:

  [] kernel BUG at net/core/skbuff.c:1970!
  [] Call Trace:
  []  skb_clone+0x4d/0xb0
  []  macvlan_broadcast+0xd8/0x160 [macvlan]
  []  macvlan_process_broadcast+0x148/0x150 [macvlan]
  []  process_one_work+0x1a7/0x360
  []  worker_thread+0x30/0x390

  [] kernel BUG at mm/usercopy.c:102!
  [] Call Trace:
  []  __check_heap_object+0xd3/0x100
  []  __check_object_size+0xff/0x16b
  []  simple_copy_to_iter+0x1c/0x30
  []  __skb_datagram_iter+0x7d/0x310
  []  __skb_datagram_iter+0x2a5/0x310
  []  skb_copy_datagram_iter+0x3b/0x90
  []  tipc_recvmsg+0x14a/0x3a0 [tipc]
  []  ____sys_recvmsg+0x91/0x150
  []  ___sys_recvmsg+0x7b/0xc0

  [] kernel BUG at mm/slub.c:305!
  [] Call Trace:
  []  <IRQ>
  []  kmem_cache_free+0x3ff/0x400
  []  __netif_receive_skb_core+0x12c/0xc40
  []  ? kmem_cache_alloc+0x12e/0x270
  []  netif_receive_skb_internal+0x3d/0xb0
  []  ? get_rx_page_info+0x8e/0xa0 [be2net]
  []  be_poll+0x6ef/0xd00 [be2net]
  []  ? irq_exit+0x4f/0x100
  []  net_rx_action+0x149/0x3b0

  ...

This patch is to fix it by linearizing the head skb if it has frag_list
set in tipc_buf_append(). Note that we choose to do this before calling
skb_unshare(), as __skb_linearize() will avoid skb_copy(). Also, we can
not just drop the frag_list either as the early time.

Fixes: 45c8b7b175 ("tipc: allow non-linear first fragment buffer")
Reported-by: Li Shuang <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-05-17 13:42:17 -07:00

857 lines
22 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"
#include "crypto.h"
#define MAX_FORWARD_SIZE 1024
#ifdef CONFIG_TIPC_CRYPTO
#define BUF_HEADROOM ALIGN(((LL_MAX_HEADER + 48) + EHDR_MAX_SIZE), 16)
#define BUF_TAILROOM (TIPC_AES_GCM_TAG_SIZE)
#else
#define BUF_HEADROOM (LL_MAX_HEADER + 48)
#define BUF_TAILROOM 16
#endif
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)
* @gfp: memory allocation flags
*
* Return: 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;
#ifdef CONFIG_TIPC_CRYPTO
unsigned int buf_size = (BUF_HEADROOM + size + BUF_TAILROOM + 3) & ~3u;
#else
unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u;
#endif
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);
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;
*buf = NULL;
if (skb_has_frag_list(frag) && __skb_linearize(frag))
goto err;
frag = skb_unshare(frag, GFP_ATOMIC);
if (unlikely(!frag))
goto err;
head = *headbuf = frag;
TIPC_SKB_CB(head)->tail = NULL;
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 = 0;
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_append(): Append data to tail of an existing buffer queue
* @_hdr: header to be used
* @m: the data to be appended
* @mss: max allowable size of buffer
* @dlen: size of data to be appended
* @txq: queue to append to
*
* Return: the number of 1k blocks appended or errno value
*/
int tipc_msg_append(struct tipc_msg *_hdr, struct msghdr *m, int dlen,
int mss, struct sk_buff_head *txq)
{
struct sk_buff *skb;
int accounted, total, curr;
int mlen, cpy, rem = dlen;
struct tipc_msg *hdr;
skb = skb_peek_tail(txq);
accounted = skb ? msg_blocks(buf_msg(skb)) : 0;
total = accounted;
do {
if (!skb || skb->len >= mss) {
skb = tipc_buf_acquire(mss, GFP_KERNEL);
if (unlikely(!skb))
return -ENOMEM;
skb_orphan(skb);
skb_trim(skb, MIN_H_SIZE);
hdr = buf_msg(skb);
skb_copy_to_linear_data(skb, _hdr, MIN_H_SIZE);
msg_set_hdr_sz(hdr, MIN_H_SIZE);
msg_set_size(hdr, MIN_H_SIZE);
__skb_queue_tail(txq, skb);
total += 1;
}
hdr = buf_msg(skb);
curr = msg_blocks(hdr);
mlen = msg_size(hdr);
cpy = min_t(size_t, rem, mss - mlen);
if (cpy != copy_from_iter(skb->data + mlen, cpy, &m->msg_iter))
return -EFAULT;
msg_set_size(hdr, mlen + cpy);
skb_put(skb, cpy);
rem -= cpy;
total += msg_blocks(hdr) - curr;
} while (rem > 0);
return total - accounted;
}
/* 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 = 1;
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
*
* Return: 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
* @offset: buffer offset for fragmented messages (FIXME)
* @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.
*
* Return: 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
* @bskb: the bundle buffer to append to
* @msg: message to be appended
* @max: max allowable size for the bundle buffer
*
* Return: "true" if bundling has been performed, otherwise "false"
*/
static bool tipc_msg_bundle(struct sk_buff *bskb, struct tipc_msg *msg,
u32 max)
{
struct tipc_msg *bmsg = buf_msg(bskb);
u32 msz, bsz, offset, pad;
msz = msg_size(msg);
bsz = msg_size(bmsg);
offset = align(bsz);
pad = offset - bsz;
if (unlikely(skb_tailroom(bskb) < (pad + msz)))
return false;
if (unlikely(max < (offset + msz)))
return false;
skb_put(bskb, pad + msz);
skb_copy_to_linear_data_offset(bskb, offset, msg, msz);
msg_set_size(bmsg, offset + msz);
msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
return true;
}
/**
* tipc_msg_try_bundle - Try to bundle a new message to the last one
* @tskb: the last/target message to which the new one will be appended
* @skb: the new message skb pointer
* @mss: max message size (header inclusive)
* @dnode: destination node for the message
* @new_bundle: if this call made a new bundle or not
*
* Return: "true" if the new message skb is potential for bundling this time or
* later, in the case a bundling has been done this time, the skb is consumed
* (the skb pointer = NULL).
* Otherwise, "false" if the skb cannot be bundled at all.
*/
bool tipc_msg_try_bundle(struct sk_buff *tskb, struct sk_buff **skb, u32 mss,
u32 dnode, bool *new_bundle)
{
struct tipc_msg *msg, *inner, *outer;
u32 tsz;
/* First, check if the new buffer is suitable for bundling */
msg = buf_msg(*skb);
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 (mss <= INT_H_SIZE + msg_size(msg))
return false;
/* Ok, but the last/target buffer can be empty? */
if (unlikely(!tskb))
return true;
/* Is it a bundle already? Try to bundle the new message to it */
if (msg_user(buf_msg(tskb)) == MSG_BUNDLER) {
*new_bundle = false;
goto bundle;
}
/* Make a new bundle of the two messages if possible */
tsz = msg_size(buf_msg(tskb));
if (unlikely(mss < align(INT_H_SIZE + tsz) + msg_size(msg)))
return true;
if (unlikely(pskb_expand_head(tskb, INT_H_SIZE, mss - tsz - INT_H_SIZE,
GFP_ATOMIC)))
return true;
inner = buf_msg(tskb);
skb_push(tskb, INT_H_SIZE);
outer = buf_msg(tskb);
tipc_msg_init(msg_prevnode(inner), outer, MSG_BUNDLER, 0, INT_H_SIZE,
dnode);
msg_set_importance(outer, msg_importance(inner));
msg_set_size(outer, INT_H_SIZE + tsz);
msg_set_msgcnt(outer, 1);
*new_bundle = true;
bundle:
if (likely(tipc_msg_bundle(tskb, msg, mss))) {
consume_skb(*skb);
*skb = NULL;
}
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
* Return: true 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_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
* Return: 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
* @net: pointer to associated network namespace
* @skb: the buffer containing the message.
* @err: error code to be used by caller if lookup fails
* Does not consume buffer
* Return: 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 scope = msg_lookup_scope(msg);
u32 self = tipc_own_addr(net);
u32 inst = msg_nameinst(msg);
struct tipc_socket_addr sk;
struct tipc_uaddr ua;
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;
tipc_uaddr(&ua, TIPC_SERVICE_RANGE, scope,
msg_nametype(msg), inst, inst);
sk.node = tipc_scope2node(net, scope);
if (!tipc_nametbl_lookup_anycast(net, &ua, &sk))
return false;
msg_incr_reroute_cnt(msg);
if (sk.node != self)
msg_set_prevnode(msg, self);
msg_set_destnode(msg, sk.node);
msg_set_destport(msg, sk.ref);
*err = TIPC_OK;
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
*/
bool __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 true;
}
if (more(seqno, buf_seqno(skb_peek_tail(list)))) {
__skb_queue_tail(list, skb);
return true;
}
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 true;
}
kfree_skb(skb);
return false;
}
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);
}