diff options
Diffstat (limited to 'net/tipc/msg.c')
| -rw-r--r-- | net/tipc/msg.c | 710 |
1 files changed, 710 insertions, 0 deletions
diff --git a/net/tipc/msg.c b/net/tipc/msg.c new file mode 100644 index 000000000..0ac270444 --- /dev/null +++ b/net/tipc/msg.c @@ -0,0 +1,710 @@ +/* + * 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 +#define BUF_HEADROOM (LL_MAX_HEADER + 48) +#define BUF_TAILROOM 16 + +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, gfp_t gfp) +{ + struct sk_buff *skb; + unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u; + + 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); + 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 = 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 = 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: + 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 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 = 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 + * + * Note that the recursive call we are making here is safe, since it can + * logically go only one further level down. + * + * 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); + 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 + * @skb: the buffer to append to ("bundle") + * @msg: message 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 *skb, struct tipc_msg *msg, u32 mtu) +{ + struct tipc_msg *bmsg; + 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 (!skb) + return false; + bmsg = buf_msg(skb); + 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 (unlikely(msg_user(bmsg) != MSG_BUNDLER)) + return false; + if (unlikely(skb_tailroom(skb) < (pad + msz))) + return false; + if (unlikely(max < (start + msz))) + return false; + if ((msg_importance(msg) < TIPC_SYSTEM_IMPORTANCE) && + (msg_importance(bmsg) == TIPC_SYSTEM_IMPORTANCE)) + return false; + + skb_put(skb, pad + msz); + skb_copy_to_linear_data_offset(skb, start, msg, msz); + msg_set_size(bmsg, start + msz); + msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1); + 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 *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_make_bundle(): Create bundle buf and append message to its tail + * @list: the buffer chain, where head is the buffer to replace/append + * @skb: buffer to be created, appended to and returned in case of success + * @msg: message to be appended + * @mtu: max allowable size for the bundle buffer, inclusive header + * @dnode: destination node for message. (Not always present in header) + * Returns true if success, otherwise false + */ +bool tipc_msg_make_bundle(struct sk_buff **skb, struct tipc_msg *msg, + u32 mtu, u32 dnode) +{ + struct sk_buff *_skb; + struct tipc_msg *bmsg; + 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; + + _skb = tipc_buf_acquire(max, GFP_ATOMIC); + if (!_skb) + return false; + + skb_trim(_skb, INT_H_SIZE); + bmsg = buf_msg(_skb); + tipc_msg_init(msg_prevnode(msg), bmsg, MSG_BUNDLER, 0, + INT_H_SIZE, dnode); + msg_set_importance(bmsg, msg_importance(msg)); + 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(_skb, msg, mtu); + *skb = _skb; + return true; +} + +/** + * 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; may be replaced. + * @err: error code to be set in message, if any + * Consumes buffer at failure + * Returns 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; + struct tipc_msg ohdr; + int dlen; + + if (skb_linearize(_skb)) + goto exit; + hdr = buf_msg(_skb); + dlen = min_t(uint, msg_data_sz(hdr), MAX_FORWARD_SIZE); + if (msg_dest_droppable(hdr)) + goto exit; + if (msg_errcode(hdr)) + goto exit; + + /* Take a copy of original header before altering message */ + memcpy(&ohdr, hdr, msg_hdr_sz(hdr)); + + /* Never return SHORT header; expand by replacing buffer if necessary */ + if (msg_short(hdr)) { + *skb = tipc_buf_acquire(BASIC_H_SIZE + dlen, GFP_ATOMIC); + if (!*skb) + goto exit; + memcpy((*skb)->data + BASIC_H_SIZE, msg_data(hdr), dlen); + kfree_skb(_skb); + _skb = *skb; + hdr = buf_msg(_skb); + memcpy(hdr, &ohdr, BASIC_H_SIZE); + msg_set_hdr_sz(hdr, BASIC_H_SIZE); + } + + /* Now reverse the concerned fields */ + msg_set_errcode(hdr, err); + msg_set_non_seq(hdr, 0); + msg_set_origport(hdr, msg_destport(&ohdr)); + msg_set_destport(hdr, msg_origport(&ohdr)); + msg_set_destnode(hdr, msg_prevnode(&ohdr)); + msg_set_prevnode(hdr, own_node); + msg_set_orignode(hdr, own_node); + msg_set_size(hdr, msg_hdr_sz(hdr) + dlen); + skb_trim(_skb, msg_size(hdr)); + skb_orphan(_skb); + return true; +exit: + kfree_skb(_skb); + *skb = NULL; + return false; +} + +/** + * tipc_msg_lookup_dest(): try to find new destination for named message + * @skb: the buffer containing the message. + * @err: error code to be used by caller if lookup fails + * 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, int *err) +{ + struct tipc_msg *msg = buf_msg(skb); + u32 dport, dnode; + u32 onode = 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; + msg = buf_msg(skb); + if (msg_reroute_cnt(msg)) + return false; + dnode = tipc_scope2node(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 != onode) + msg_set_prevnode(msg, onode); + msg_set_destnode(msg, dnode); + msg_set_destport(msg, dport); + *err = TIPC_OK; + + if (!skb_cloned(skb)) + return true; + + 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 + */ +void __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; + } + + if (more(seqno, buf_seqno(skb_peek_tail(list)))) { + __skb_queue_tail(list, skb); + return; + } + + 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; + } + kfree_skb(skb); +} + +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); +} |