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| author |   Xin Long <lucien.xin@gmail.com> | 2021-10-28 05:36:03 -0400 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2021-10-29 12:21:23 +0100 |
| commit | cc4665ca646c96181a7c00198aa72c59e0c576e8 (patch) | |
| tree | 7d29f94ee37490e26afb25665c942fe7e3ce2d1f /include/net/sctp | |
| parent | sctp: reset probe_timer in sctp_transport_pl_update (diff) | |
| download | linux-dev-cc4665ca646c96181a7c00198aa72c59e0c576e8.tar.xz linux-dev-cc4665ca646c96181a7c00198aa72c59e0c576e8.zip | |
sctp: subtract sctphdr len in sctp_transport_pl_hlen
sctp_transport_pl_hlen() is called to calculate the outer header length
for PL. However, as the Figure in rfc8899#section-4.4:
Any additional
headers .--- MPS -----.
| | |
v v v
+------------------------------+
| IP | ** | PL | protocol data |
+------------------------------+
<----- PLPMTU ----->
<---------- PMTU -------------->
Outer header are IP + Any additional headers, which doesn't include
Packetization Layer itself header, namely sctphdr, whereas sctphdr
is counted by __sctp_mtu_payload().
The incorrect calculation caused the link pathmtu to be set larger
than expected by t->pl.pmtu + sctp_transport_pl_hlen(). This patch
is to fix it by subtracting sctphdr len in sctp_transport_pl_hlen().
Fixes: d9e2e410ae30 ("sctp: add the constants/variables and states and some APIs for transport")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/sctp')
| -rw-r--r-- | include/net/sctp/sctp.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index bc00410223b0..189fdb9db162 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -626,7 +626,8 @@ static inline __u32 sctp_min_frag_point(struct sctp_sock *sp, __u16 datasize) static inline int sctp_transport_pl_hlen(struct sctp_transport *t) { - return __sctp_mtu_payload(sctp_sk(t->asoc->base.sk), t, 0, 0); + return __sctp_mtu_payload(sctp_sk(t->asoc->base.sk), t, 0, 0) - + sizeof(struct sctphdr); } static inline void sctp_transport_pl_reset(struct sctp_transport *t) |