Initial import

1 files changed, 574 insertions, 0 deletions

diff --git a/net/tipc/msg.c b/net/tipc/msg.c
new file mode 100644
index 000000000..c3e96e815
--- /dev/null
+++ b/net/tipc/msg.c
@@ -0,0 +1,574 @@
+/*
+ * 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
+
+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)
+{
+	struct sk_buff *skb;
+	unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u;
+
+	skb = alloc_skb_fclone(buf_size, GFP_ATOMIC);
+	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);
+	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;
+	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;
+		skb_frag_list_init(head);
+		TIPC_SKB_CB(head)->tail = NULL;
+		*buf = 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 = 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:
+	pr_warn_ratelimited("Unable to build fragment list\n");
+	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 tipc_msg *msg;
+	int msz, hsz;
+
+	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;
+
+	msg = buf_msg(skb);
+	if (unlikely(msg_version(msg) != TIPC_VERSION))
+		return false;
+
+	msz = msg_size(msg);
+	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_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
+ *
+ * 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);
+	int msz = mhsz + dsz;
+	int pktno = 1;
+	int pktsz;
+	int pktrem = pktmax;
+	int drem = dsz;
+	struct tipc_msg pkthdr;
+	struct sk_buff *skb;
+	char *pktpos;
+	int rc;
+
+	msg_set_size(mhdr, msz);
+
+	/* No fragmentation needed? */
+	if (likely(msz <= pktmax)) {
+		skb = tipc_buf_acquire(msz);
+		if (unlikely(!skb))
+			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(pktpos, dsz, &m->msg_iter) == dsz)
+			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);
+	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(pktpos, pktrem, &m->msg_iter) != pktrem) {
+			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);
+		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 buffer to append to ("bundle")
+ * @skb:  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 *bskb, struct sk_buff *skb, u32 mtu)
+{
+	struct tipc_msg *bmsg;
+	struct tipc_msg *msg = buf_msg(skb);
+	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 (!bskb)
+		return false;
+	bmsg = buf_msg(bskb);
+	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 (likely(msg_user(bmsg) != MSG_BUNDLER))
+		return false;
+	if (unlikely(skb_tailroom(bskb) < (pad + msz)))
+		return false;
+	if (unlikely(max < (start + msz)))
+		return false;
+
+	skb_put(bskb, pad + msz);
+	skb_copy_to_linear_data_offset(bskb, start, skb->data, msz);
+	msg_set_size(bmsg, start + msz);
+	msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
+	kfree_skb(skb);
+	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 *msg;
+	int imsz, offset;
+
+	*iskb = NULL;
+	if (unlikely(skb_linearize(skb)))
+		goto none;
+
+	msg = buf_msg(skb);
+	offset = msg_hdr_sz(msg) + *pos;
+	if (unlikely(offset > (msg_size(msg) - MIN_H_SIZE)))
+		goto none;
+
+	*iskb = skb_clone(skb, GFP_ATOMIC);
+	if (unlikely(!*iskb))
+		goto none;
+	skb_pull(*iskb, offset);
+	imsz = msg_size(buf_msg(*iskb));
+	skb_trim(*iskb, 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
+ * @skb: 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 success, otherwise false
+ */
+bool tipc_msg_make_bundle(struct sk_buff **skb, u32 mtu, u32 dnode)
+{
+	struct sk_buff *bskb;
+	struct tipc_msg *bmsg;
+	struct tipc_msg *msg = buf_msg(*skb);
+	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;
+
+	bskb = tipc_buf_acquire(max);
+	if (!bskb)
+		return false;
+
+	skb_trim(bskb, INT_H_SIZE);
+	bmsg = buf_msg(bskb);
+	tipc_msg_init(msg_prevnode(msg), bmsg, MSG_BUNDLER, 0,
+		      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));
+	tipc_msg_bundle(bskb, *skb, mtu);
+	*skb = bskb;
+	return true;
+}
+
+/**
+ * tipc_msg_reverse(): swap source and destination addresses and add error code
+ * @buf:  buffer containing message to be reversed
+ * @dnode: return value: node where to send message after reversal
+ * @err:  error code to be set in message
+ * Consumes buffer if failure
+ * Returns true if success, otherwise false
+ */
+bool tipc_msg_reverse(u32 own_addr,  struct sk_buff *buf, u32 *dnode,
+		      int err)
+{
+	struct tipc_msg *msg = buf_msg(buf);
+	struct tipc_msg ohdr;
+	uint rdsz = min_t(uint, msg_data_sz(msg), MAX_FORWARD_SIZE);
+
+	if (skb_linearize(buf))
+		goto exit;
+	msg = buf_msg(buf);
+	if (msg_dest_droppable(msg))
+		goto exit;
+	if (msg_errcode(msg))
+		goto exit;
+	memcpy(&ohdr, msg, msg_hdr_sz(msg));
+	msg_set_errcode(msg, err);
+	msg_set_origport(msg, msg_destport(&ohdr));
+	msg_set_destport(msg, msg_origport(&ohdr));
+	msg_set_prevnode(msg, own_addr);
+	if (!msg_short(msg)) {
+		msg_set_orignode(msg, msg_destnode(&ohdr));
+		msg_set_destnode(msg, msg_orignode(&ohdr));
+	}
+	msg_set_size(msg, msg_hdr_sz(msg) + rdsz);
+	skb_trim(buf, msg_size(msg));
+	skb_orphan(buf);
+	*dnode = msg_orignode(&ohdr);
+	return true;
+exit:
+	kfree_skb(buf);
+	*dnode = 0;
+	return false;
+}
+
+/**
+ * tipc_msg_lookup_dest(): try to find new destination for named message
+ * @skb: the buffer containing the message.
+ * @dnode: return value: next-hop node, if destination found
+ * @err: return value: error code to use, if message to be rejected
+ * 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,
+			  u32 *dnode, int *err)
+{
+	struct tipc_msg *msg = buf_msg(skb);
+	u32 dport;
+	u32 own_addr = 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;
+	if (msg_reroute_cnt(msg))
+		return false;
+	*dnode = addr_domain(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 != own_addr)
+		msg_set_prevnode(msg, own_addr);
+	msg_set_destnode(msg, *dnode);
+	msg_set_destport(msg, dport);
+	*err = TIPC_OK;
+	return true;
+}
+
+/* tipc_msg_reassemble() - clone a buffer chain of fragments and
+ *                         reassemble the clones into one message
+ */
+struct sk_buff *tipc_msg_reassemble(struct sk_buff_head *list)
+{
+	struct sk_buff *skb;
+	struct sk_buff *frag = NULL;
+	struct sk_buff *head = NULL;
+	int hdr_sz;
+
+	/* Copy header if single buffer */
+	if (skb_queue_len(list) == 1) {
+		skb = skb_peek(list);
+		hdr_sz = skb_headroom(skb) + msg_hdr_sz(buf_msg(skb));
+		return __pskb_copy(skb, hdr_sz, GFP_ATOMIC);
+	}
+
+	/* 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;
+	}
+	return frag;
+error:
+	pr_warn("Failed do clone local mcast rcv buffer\n");
+	kfree_skb(head);
+	return NULL;
+}