+/* Get the sndbuf space available at the time on the association. */
+static inline int sctp_wspace(struct sctp_association *asoc)
+{
+ struct sock *sk = asoc->base.sk;
+ int amt = 0;
+
+ amt = sk->sk_sndbuf - asoc->sndbuf_used;
+ if (amt < 0)
+ amt = 0;
+ return amt;
+}
+
+/* Increment the used sndbuf space count of the corresponding association by
+ * the size of the outgoing data chunk.
+ * Also, set the skb destructor for sndbuf accounting later.
+ *
+ * Since it is always 1-1 between chunk and skb, and also a new skb is always
+ * allocated for chunk bundling in sctp_packet_transmit(), we can use the
+ * destructor in the data chunk skb for the purpose of the sndbuf space
+ * tracking.
+ */
+static inline void sctp_set_owner_w(struct sctp_chunk *chunk)
+{
+ struct sctp_association *asoc = chunk->asoc;
+ struct sock *sk = asoc->base.sk;
+
+ /* The sndbuf space is tracked per association. */
+ sctp_association_hold(asoc);
+
+ chunk->skb->destructor = sctp_wfree;
+ /* Save the chunk pointer in skb for sctp_wfree to use later. */
+ *((struct sctp_chunk **)(chunk->skb->cb)) = chunk;
+
+ asoc->sndbuf_used += SCTP_DATA_SNDSIZE(chunk);
+ sk->sk_wmem_queued += SCTP_DATA_SNDSIZE(chunk);
+}
+
+/* Verify that this is a valid address. */
+static inline int sctp_verify_addr(struct sock *sk, union sctp_addr *addr,
+ int len)
+{
+ struct sctp_af *af;
+
+ /* Verify basic sockaddr. */
+ af = sctp_sockaddr_af(sctp_sk(sk), addr, len);
+ if (!af)
+ return -EINVAL;
+
+ /* Is this a valid SCTP address? */
+ if (!af->addr_valid(addr, sctp_sk(sk)))
+ return -EINVAL;
+
+ if (!sctp_sk(sk)->pf->send_verify(sctp_sk(sk), (addr)))
+ return -EINVAL;
+
+ return 0;
+}
+