diff options
| -rw-r--r-- | net/tipc/msg.c | 58 |
1 files changed, 28 insertions, 30 deletions
diff --git a/net/tipc/msg.c b/net/tipc/msg.c index b61891054709..00fbb5c4b2ef 100644 --- a/net/tipc/msg.c +++ b/net/tipc/msg.c @@ -499,54 +499,52 @@ bool tipc_msg_make_bundle(struct sk_buff **skb, struct tipc_msg *msg, /** * 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. + * @skb: buffer containing message to be reversed; will be consumed * @err: error code to be set in message, if any - * Consumes buffer at failure + * Replaces consumed buffer with new one when successful * 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; + 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); - if (msg_dest_droppable(hdr)) + _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)) + 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); - } + /* Never return SHORT header */ + if (hlen == SHORT_H_SIZE) + hlen = BASIC_H_SIZE; - /* Now reverse the concerned fields */ + /* 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(&ohdr)); - msg_set_destport(hdr, msg_origport(&ohdr)); - msg_set_destnode(hdr, msg_prevnode(&ohdr)); + 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, msg_hdr_sz(hdr) + dlen); - skb_trim(_skb, msg_size(hdr)); + msg_set_size(hdr, hlen + dlen); skb_orphan(_skb); + kfree_skb(_skb); return true; exit: kfree_skb(_skb); |