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-rw-r--r--net/tipc/msg.c851
1 files changed, 851 insertions, 0 deletions
diff --git a/net/tipc/msg.c b/net/tipc/msg.c
new file mode 100644
index 000000000..5c9fd4791
--- /dev/null
+++ b/net/tipc/msg.c
@@ -0,0 +1,851 @@
+/*
+ * 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 BUF_ALIGN(x) ALIGN(x, 4)
+#define MAX_FORWARD_SIZE 1024
+#ifdef CONFIG_TIPC_CRYPTO
+#define BUF_HEADROOM ALIGN(((LL_MAX_HEADER + 48) + EHDR_MAX_SIZE), 16)
+#define BUF_OVERHEAD (BUF_HEADROOM + TIPC_AES_GCM_TAG_SIZE)
+#else
+#define BUF_HEADROOM (LL_MAX_HEADER + 48)
+#define BUF_OVERHEAD BUF_HEADROOM
+#endif
+
+const int one_page_mtu = PAGE_SIZE - SKB_DATA_ALIGN(BUF_OVERHEAD) -
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
+/**
+ * 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;
+
+ skb = alloc_skb_fclone(BUF_OVERHEAD + 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,
+ one_page_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 = BUF_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 < BUF_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 += BUF_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);
+}