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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /net/tipc/msg.c
Initial import
Diffstat (limited to 'net/tipc/msg.c')
-rw-r--r--net/tipc/msg.c574
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;
+}