diff options
Diffstat (limited to 'net/tipc/msg.c')
| -rw-r--r-- | net/tipc/msg.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/net/tipc/msg.c b/net/tipc/msg.c index 922d262e153f..973795a1a968 100644 --- a/net/tipc/msg.c +++ b/net/tipc/msg.c @@ -190,6 +190,59 @@ err: return 0; } +/** + * tipc_msg_append(): Append data to tail of an existing buffer queue + * @hdr: header to be used + * @m: the data to be appended + * @mss: max allowable size of buffer + * @dlen: size of data to be appended + * @txq: queue to appand to + * Returns the number og 1k blocks appended or errno value + */ +int tipc_msg_append(struct tipc_msg *_hdr, struct msghdr *m, int dlen, + int mss, struct sk_buff_head *txq) +{ + struct sk_buff *skb, *prev; + int accounted, total, curr; + int mlen, cpy, rem = dlen; + struct tipc_msg *hdr; + + skb = skb_peek_tail(txq); + accounted = skb ? msg_blocks(buf_msg(skb)) : 0; + total = accounted; + + while (rem) { + if (!skb || skb->len >= mss) { + prev = skb; + skb = tipc_buf_acquire(mss, GFP_KERNEL); + if (unlikely(!skb)) + return -ENOMEM; + skb_orphan(skb); + skb_trim(skb, MIN_H_SIZE); + hdr = buf_msg(skb); + skb_copy_to_linear_data(skb, _hdr, MIN_H_SIZE); + msg_set_hdr_sz(hdr, MIN_H_SIZE); + msg_set_size(hdr, MIN_H_SIZE); + __skb_queue_tail(txq, skb); + total += 1; + if (prev) + msg_set_ack_required(buf_msg(prev), 0); + msg_set_ack_required(hdr, 1); + } + hdr = buf_msg(skb); + curr = msg_blocks(hdr); + mlen = msg_size(hdr); + cpy = min_t(int, rem, mss - mlen); + if (cpy != copy_from_iter(skb->data + mlen, cpy, &m->msg_iter)) + return -EFAULT; + msg_set_size(hdr, mlen + cpy); + skb_put(skb, cpy); + rem -= cpy; + total += msg_blocks(hdr) - curr; + } + return total - accounted; +} + /* tipc_msg_validate - validate basic format of received message * * This routine ensures a TIPC message has an acceptable header, and at least |