summaryrefslogtreecommitdiff
path: root/net/tipc/msg.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/tipc/msg.c')
-rw-r--r--net/tipc/msg.c53
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