diff options
Diffstat (limited to 'net/tipc/msg.c')
| -rw-r--r-- | net/tipc/msg.c | 574 |
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; +} |