return t->dst;
}
+/* Calculate max payload size given a MTU, or the total overhead if
+ * given MTU is zero
+ */
+static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp,
+ __u32 mtu, __u32 extra)
+{
+ __u32 overhead = sizeof(struct sctphdr) + extra;
+
+ if (sp)
+ overhead += sp->pf->af->net_header_len;
+ else
+ overhead += sizeof(struct ipv6hdr);
+
+ if (WARN_ON_ONCE(mtu && mtu <= overhead))
+ mtu = overhead;
+
+ return mtu ? mtu - overhead : overhead;
+}
+
static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
{
__u32 pmtu = max_t(size_t, SCTP_TRUNC4(dst_mtu(t->dst)),
{
struct sctp_transport *tp = packet->transport;
struct sctp_association *asoc = tp->asoc;
+ struct sctp_sock *sp = NULL;
struct sock *sk;
- size_t overhead = sizeof(struct ipv6hdr) + sizeof(struct sctphdr);
pr_debug("%s: packet:%p vtag:0x%x\n", __func__, packet, vtag);
packet->vtag = vtag;
/* set packet max_size with pathmtu, then calculate overhead */
packet->max_size = tp->pathmtu;
+
if (asoc) {
- struct sctp_sock *sp = sctp_sk(asoc->base.sk);
- struct sctp_af *af = sp->pf->af;
-
- overhead = af->net_header_len +
- af->ip_options_len(asoc->base.sk);
- overhead += sizeof(struct sctphdr);
- packet->overhead = overhead;
- packet->size = overhead;
- } else {
- packet->overhead = overhead;
- packet->size = overhead;
- return;
+ sk = asoc->base.sk;
+ sp = sctp_sk(sk);
}
+ packet->overhead = sctp_mtu_payload(sp, 0, 0);
+ packet->size = packet->overhead;
+
+ if (!asoc)
+ return;
/* update dst or transport pathmtu if in need */
- sk = asoc->base.sk;
if (!sctp_transport_dst_check(tp)) {
- sctp_transport_route(tp, NULL, sctp_sk(sk));
+ sctp_transport_route(tp, NULL, sp);
if (asoc->param_flags & SPP_PMTUD_ENABLE)
sctp_assoc_sync_pmtu(asoc);
} else if (!sctp_transport_pmtu_check(tp)) {
if (val) {
int min_len, max_len;
- min_len = SCTP_DEFAULT_MINSEGMENT - af->net_header_len;
- min_len -= af->ip_options_len(sk);
- min_len -= sizeof(struct sctphdr) +
- sizeof(struct sctp_data_chunk);
-
+ min_len = sctp_mtu_payload(sp, SCTP_DEFAULT_MINSEGMENT,
+ sizeof(struct sctp_data_chunk));
max_len = SCTP_MAX_CHUNK_LEN - sizeof(struct sctp_data_chunk);
if (val < min_len || val > max_len)