SCTP: Fix to encode PROTOCOL VIOLATION error cause correctly

PROTOCOL VIOLATION error cause in ABORT is bad encode when make abort
chunk. When SCTP encode ABORT chunk with PROTOCOL VIOLATION error cause,
it just add the error messages to PROTOCOL VIOLATION error cause, the
rest four bytes(struct sctp_paramhdr) is just add to the chunk, not
change the length of error cause. This cause the ABORT chunk to be a bad
format. The chunk is like this:

ABORT chunk
  Chunk type: ABORT (6)
  Chunk flags: 0x00
  Chunk length: 72 (*1)
  Protocol violation cause
    Cause code: Protocol violation (0x000d)
    Cause length: 62 (*2)
    Cause information: 5468652063756D756C61746976652074736E2061636B2062...
    Cause padding: 0000
[Needless] 00030010
Chunk Length(*1) = 72 but Cause length(*2) only 62, not include the
extend 4 bytes.
((72 - sizeof(chunk_hdr)) = 68) != (62 +3) / 4 * 4

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

2 files changed, 2 insertions, 1 deletions

diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h
index 73cb9943c8a8..991c85bb9e36 100644
--- a/include/net/sctp/sm.h
+++ b/include/net/sctp/sm.h
@@ -214,7 +214,7 @@ struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
                                           const struct sctp_chunk *);
 struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *,
                                           const struct sctp_chunk *);
-void sctp_init_cause(struct sctp_chunk *, __be16 cause, const void *, size_t);
+void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t);
 struct sctp_chunk *sctp_make_abort(const struct sctp_association *,
                               const struct sctp_chunk *,
                               const size_t hint);
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index ee4559b11302..c0d5848c33dc 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -726,6 +726,7 @@ int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
                           struct iovec *data);
 void sctp_chunk_free(struct sctp_chunk *);
 void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
+void  *sctp_addto_param(struct sctp_chunk *, int len, const void *data);
 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
                                  const struct sctp_association *,
                                  struct sock *);