Subject: Re: [PATCHv3 net-next 2/7] sctp: add support for generating stream reconf ssn reset request chunk

From: Marcelo Ricardo Leitner <[email-masked]>
Date: Sun, 15 Jan 2017 13:51:51 -0200

On Sat, Jan 14, 2017 at 03:15:36AM +0800, Xin Long wrote:
> This patch is to add asoc strreset_outseq and strreset_inseq for
> saving the reconf request sequence, initialize them when create
> assoc and process init, and also to define Incoming and Outgoing
> SSN Reset Request Parameter described in rfc6525 section 4.1 and
> 4.2, As they can be in one same chunk as section rfc6525 3.1-3
> describes, it makes them in one function.
> 
> Signed-off-by: Xin Long <[email-masked]>
> ---
>  include/linux/sctp.h       | 26 ++++++++++++++
>  include/net/sctp/sm.h      |  5 ++-
>  include/net/sctp/structs.h |  3 ++
>  net/sctp/associola.c       |  1 +
>  net/sctp/sm_make_chunk.c   | 88 ++++++++++++++++++++++++++++++++++++++++++++++
>  5 files changed, 122 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/sctp.h b/include/linux/sctp.h
> index cdc3b05..d5da19c 100644
> --- a/include/linux/sctp.h
> +++ b/include/linux/sctp.h
> @@ -200,6 +200,13 @@ typedef enum {
>  	SCTP_PARAM_SUCCESS_REPORT	= cpu_to_be16(0xc005),
>  	SCTP_PARAM_ADAPTATION_LAYER_IND = cpu_to_be16(0xc006),
>  
> +	/* RE-CONFIG. Section 4 */
> +	SCTP_PARAM_RESET_OUT_REQUEST		= cpu_to_be16(0x000d),
> +	SCTP_PARAM_RESET_IN_REQUEST		= cpu_to_be16(0x000e),
> +	SCTP_PARAM_RESET_TSN_REQUEST		= cpu_to_be16(0x000f),
> +	SCTP_PARAM_RESET_RESPONSE		= cpu_to_be16(0x0010),
> +	SCTP_PARAM_RESET_ADD_OUT_STREAMS	= cpu_to_be16(0x0011),
> +	SCTP_PARAM_RESET_ADD_IN_STREAMS		= cpu_to_be16(0x0012),
>  } sctp_param_t; /* enum */
>  
>  
> @@ -716,4 +723,23 @@ struct sctp_reconf_chunk {
>  	__u8 params[0];
>  } __packed;
>  
> +struct sctp_strreset_req {
> +	sctp_paramhdr_t param_hdr;
> +	__u32 request_seq;
> +} __packed;
> +
> +struct sctp_strreset_outreq {
> +	sctp_paramhdr_t param_hdr;
> +	__u32 request_seq;

This should be:
+	struct sctp_strreset_req strreset_req;
Use the definition you created above for the encapsulation and make the
embedding evident.
Like it's done for sctp_chunkhdr_t.

> +	__u32 response_seq;
> +	__u32 send_reset_at_tsn;
> +	__u16 list_of_streams[0];
> +} __packed;
> +
> +struct sctp_strreset_inreq {
> +	sctp_paramhdr_t param_hdr;
> +	__u32 request_seq;

Same here.

> +	__u16 list_of_streams[0];
> +} __packed;
> +
>  #endif /* __LINUX_SCTP_H__ */
> diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h
> index ca6c971..3462cb0 100644
> --- a/include/net/sctp/sm.h
> +++ b/include/net/sctp/sm.h
> @@ -259,7 +259,10 @@ struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
>  				    __u32 new_cum_tsn, size_t nstreams,
>  				    struct sctp_fwdtsn_skip *skiplist);
>  struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc);
> -
> +struct sctp_chunk *sctp_make_strreset_req(
> +				const struct sctp_association *asoc,
> +				__u16 stream_num, __u16 *stream_list,
> +				bool out, bool in);
>  void sctp_chunk_assign_tsn(struct sctp_chunk *);
>  void sctp_chunk_assign_ssn(struct sctp_chunk *);
>  
> diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
> index 4741ec2..3dc983e 100644
> --- a/include/net/sctp/structs.h
> +++ b/include/net/sctp/structs.h
> @@ -1865,6 +1865,9 @@ struct sctp_association {
>  	     temp:1,		/* Is it a temporary association? */
>  	     prsctp_enable:1;
>  
> +	__u32 strreset_outseq; /* Update after receiving response */
> +	__u32 strreset_inseq; /* Update after receiving request */
> +
>  	struct sctp_priv_assoc_stats stats;
>  
>  	int sent_cnt_removable;
> diff --git a/net/sctp/associola.c b/net/sctp/associola.c
> index 36294f7..42ece6f 100644
> --- a/net/sctp/associola.c
> +++ b/net/sctp/associola.c
> @@ -207,6 +207,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
>  	 * association to the same value as the initial TSN.
>  	 */
>  	asoc->addip_serial = asoc->c.initial_tsn;
> +	asoc->strreset_outseq = asoc->c.initial_tsn;
>  
>  	INIT_LIST_HEAD(&asoc->addip_chunk_list);
>  	INIT_LIST_HEAD(&asoc->asconf_ack_list);
> diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
> index fd58097..172385c 100644
> --- a/net/sctp/sm_make_chunk.c
> +++ b/net/sctp/sm_make_chunk.c
> @@ -1844,6 +1844,7 @@ struct sctp_association *sctp_unpack_cookie(
>  	retval->next_tsn = retval->c.initial_tsn;
>  	retval->ctsn_ack_point = retval->next_tsn - 1;
>  	retval->addip_serial = retval->c.initial_tsn;
> +	retval->strreset_outseq = retval->c.initial_tsn;
>  	retval->adv_peer_ack_point = retval->ctsn_ack_point;
>  	retval->peer.prsctp_capable = retval->c.prsctp_capable;
>  	retval->peer.adaptation_ind = retval->c.adaptation_ind;
> @@ -2387,6 +2388,8 @@ int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
>  	asoc->peer.i.initial_tsn =
>  		ntohl(peer_init->init_hdr.initial_tsn);
>  
> +	asoc->strreset_inseq = asoc->peer.i.initial_tsn;
> +
>  	/* Apply the upper bounds for output streams based on peer's
>  	 * number of inbound streams.
>  	 */
> @@ -3559,3 +3562,88 @@ static struct sctp_chunk *sctp_make_reconf(
>  
>  	return retval;
>  }
> +
> +/* RE-CONFIG 4.1 (STREAM OUT RESET)
> + *   0                   1                   2                   3
> + *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + *  |     Parameter Type = 13       | Parameter Length = 16 + 2 * N |
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + *  |           Re-configuration Request Sequence Number            |
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + *  |           Re-configuration Response Sequence Number           |
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + *  |                Sender's Last Assigned TSN                     |
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + *  /                            ......                             /
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + *
> + * RE-CONFIG 4.2 (STREAM IN RESET)
> + *   0                   1                   2                   3
> + *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + *  |     Parameter Type = 14       |  Parameter Length = 8 + 2 * N |
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + *  |          Re-configuration Request Sequence Number             |
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + *  /                            ......                             /
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
> + *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + */
> +struct sctp_chunk *sctp_make_strreset_req(
> +				const struct sctp_association *asoc,
> +				__u16 stream_num, __u16 *stream_list,
> +				bool out, bool in)
> +{
> +	struct sctp_strreset_outreq outreq;
> +	__u16 stream_len = stream_num * 2;
> +	struct sctp_strreset_inreq inreq;
> +	struct sctp_chunk *retval;
> +	__u16 outlen, inlen, i;
> +
> +	outlen = (sizeof(outreq) + stream_len) * out;
> +	inlen = (sizeof(inreq) + stream_len) * in;
> +
> +	retval = sctp_make_reconf(asoc, outlen + inlen);
> +	if (!retval)
> +		return NULL;
> +
> +	for (i = 0; i < stream_num; i++)
> +		stream_list[i] = htons(stream_list[i]);
> +
> +	if (outlen) {
> +		outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST;
> +		outreq.param_hdr.length = htons(outlen);
> +		outreq.request_seq = htonl(asoc->strreset_outseq);
> +		outreq.response_seq = htonl(asoc->strreset_inseq - 1);
> +		outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1);
> +
> +		sctp_addto_chunk(retval, sizeof(outreq), &outreq);
> +
> +		if (stream_len)
> +			sctp_addto_chunk(retval, stream_len, stream_list);
> +	}
> +
> +	if (inlen) {
> +		inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST;
> +		inreq.param_hdr.length = htons(inlen);
> +		inreq.request_seq = htonl(asoc->strreset_outseq + out);
> +
> +		sctp_addto_chunk(retval, sizeof(inreq), &inreq);
> +
> +		if (stream_len)
> +			sctp_addto_chunk(retval, stream_len, stream_list);
> +	}
> +
> +	for (i = 0; i < stream_num; i++)
> +		stream_list[i] = ntohs(stream_list[i]);
> +
> +	return retval;
> +}
> -- 
> 2.1.0
> 
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