Re: [PATCHv3 net-next 2/4] sctp: implement sender-side procedures for SSN/TSN Reset Request Parameter

[Marcelo Ricardo Leitner]

On Fri, Jan 20, 2017 at 01:19:12AM +0800, Xin Long wrote:
> This patch is to implement Sender-Side Procedures for the SSN/TSN
> Reset Request Parameter descibed in rfc6525 section 5.1.4.
> 
> It is also to add sockopt SCTP_RESET_ASSOC in rfc6525 section 6.3.3
> for users.
> 
> Signed-off-by: Xin Long 
> ---
>  include/net/sctp/sctp.h   |  1 +
>  include/uapi/linux/sctp.h |  1 +
>  net/sctp/socket.c | 29 +
>  net/sctp/stream.c | 33 +
>  4 files changed, 64 insertions(+)
> 
> diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
> index 3cfd365b..b93820f 100644
> --- a/include/net/sctp/sctp.h
> +++ b/include/net/sctp/sctp.h
> @@ -198,6 +198,7 @@ int sctp_offload_init(void);
>   */
>  int sctp_send_reset_streams(struct sctp_association *asoc,
>   struct sctp_reset_streams *params);
> +int sctp_send_reset_assoc(struct sctp_association *asoc);
>  
>  /*
>   * Module global variables
> diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
> index 03c27ce..c0bd8c3 100644
> --- a/include/uapi/linux/sctp.h
> +++ b/include/uapi/linux/sctp.h
> @@ -117,6 +117,7 @@ typedef __s32 sctp_assoc_t;
>  #define SCTP_PR_ASSOC_STATUS 115
>  #define SCTP_ENABLE_STREAM_RESET 118
>  #define SCTP_RESET_STREAMS   119
> +#define SCTP_RESET_ASSOC 120
>  
>  /* PR-SCTP policies */
>  #define SCTP_PR_SCTP_NONE0x
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index bee4dd3..2c5c9ca 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -3812,6 +3812,32 @@ static int sctp_setsockopt_reset_streams(struct sock 
> *sk,
>   return retval;
>  }
>  
> +static int sctp_setsockopt_reset_assoc(struct sock *sk,
> +char __user *optval,
> +unsigned int optlen)
> +{
> + struct sctp_association *asoc;
> + sctp_assoc_t associd;
> + int retval = -EINVAL;
> +
> + if (optlen != sizeof(associd))
> + goto out;
> +
> + if (copy_from_user(, optval, optlen)) {
> + retval = -EFAULT;
> + goto out;
> + }
> +
> + asoc = sctp_id2assoc(sk, associd);
> + if (!asoc)
> + goto out;
> +
> + retval = sctp_send_reset_assoc(asoc);
> +
> +out:
> + return retval;
> +}
> +
>  /* API 6.2 setsockopt(), getsockopt()
>   *
>   * Applications use setsockopt() and getsockopt() to set or retrieve
> @@ -3984,6 +4010,9 @@ static int sctp_setsockopt(struct sock *sk, int level, 
> int optname,
>   case SCTP_RESET_STREAMS:
>   retval = sctp_setsockopt_reset_streams(sk, optval, optlen);
>   break;
> + case SCTP_RESET_ASSOC:
> + retval = sctp_setsockopt_reset_assoc(sk, optval, optlen);
> + break;
>   default:
>   retval = -ENOPROTOOPT;
>   break;
> diff --git a/net/sctp/stream.c b/net/sctp/stream.c
> index 13d5e07..b368191 100644
> --- a/net/sctp/stream.c
> +++ b/net/sctp/stream.c
> @@ -162,3 +162,36 @@ int sctp_send_reset_streams(struct sctp_association 
> *asoc,
>  out:
>   return retval;
>  }
> +
> +int sctp_send_reset_assoc(struct sctp_association *asoc)
> +{
> + struct sctp_chunk *chunk = NULL;
> + int retval;
> + __u16 i;
> +
> + if (!asoc->peer.reconf_capable ||
> + !(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
> + return -ENOPROTOOPT;
> +
> + if (asoc->strreset_outstanding)
> + return -EINPROGRESS;
> +
> + chunk = sctp_make_strreset_tsnreq(asoc);
> + if (!chunk)
> + return -ENOMEM;
> +

Please add a comment here explaining that the for below is to block
further xmit of data until this request is completed.

> + for (i = 0; i < asoc->stream->outcnt; i++)
> + asoc->stream->out[i].state = SCTP_STREAM_CLOSED;
> +
> + asoc->strreset_outstanding = 1;
> + asoc->strreset_chunk = chunk;
> + sctp_chunk_hold(asoc->strreset_chunk);
> +
> + retval = sctp_send_reconf(asoc, chunk);
> + if (retval) {
> + sctp_chunk_put(asoc->strreset_chunk);
> + asoc->strreset_chunk = NULL;

If this happens, the asoc will get stuck, as strreset_outstanding is
marked as 1, all streams are closed and no packet was even queued
(I'm assuming so as you're dropping the reference on it).


> + }
> +
> + return retval;
> +}
> -- 
> 2.1.0
> 
> --
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> 

[PATCHv3 net-next 2/4] sctp: implement sender-side procedures for SSN/TSN Reset Request Parameter

[Xin Long]

This patch is to implement Sender-Side Procedures for the SSN/TSN
Reset Request Parameter descibed in rfc6525 section 5.1.4.

It is also to add sockopt SCTP_RESET_ASSOC in rfc6525 section 6.3.3
for users.

Signed-off-by: Xin Long 
---
 include/net/sctp/sctp.h   |  1 +
 include/uapi/linux/sctp.h |  1 +
 net/sctp/socket.c | 29 +
 net/sctp/stream.c | 33 +
 4 files changed, 64 insertions(+)

diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index 3cfd365b..b93820f 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -198,6 +198,7 @@ int sctp_offload_init(void);
  */
 int sctp_send_reset_streams(struct sctp_association *asoc,
struct sctp_reset_streams *params);
+int sctp_send_reset_assoc(struct sctp_association *asoc);
 
 /*
  * Module global variables
diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
index 03c27ce..c0bd8c3 100644
--- a/include/uapi/linux/sctp.h
+++ b/include/uapi/linux/sctp.h
@@ -117,6 +117,7 @@ typedef __s32 sctp_assoc_t;
 #define SCTP_PR_ASSOC_STATUS   115
 #define SCTP_ENABLE_STREAM_RESET   118
 #define SCTP_RESET_STREAMS 119
+#define SCTP_RESET_ASSOC   120
 
 /* PR-SCTP policies */
 #define SCTP_PR_SCTP_NONE  0x
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index bee4dd3..2c5c9ca 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3812,6 +3812,32 @@ static int sctp_setsockopt_reset_streams(struct sock *sk,
return retval;
 }
 
+static int sctp_setsockopt_reset_assoc(struct sock *sk,
+  char __user *optval,
+  unsigned int optlen)
+{
+   struct sctp_association *asoc;
+   sctp_assoc_t associd;
+   int retval = -EINVAL;
+
+   if (optlen != sizeof(associd))
+   goto out;
+
+   if (copy_from_user(, optval, optlen)) {
+   retval = -EFAULT;
+   goto out;
+   }
+
+   asoc = sctp_id2assoc(sk, associd);
+   if (!asoc)
+   goto out;
+
+   retval = sctp_send_reset_assoc(asoc);
+
+out:
+   return retval;
+}
+
 /* API 6.2 setsockopt(), getsockopt()
  *
  * Applications use setsockopt() and getsockopt() to set or retrieve
@@ -3984,6 +4010,9 @@ static int sctp_setsockopt(struct sock *sk, int level, 
int optname,
case SCTP_RESET_STREAMS:
retval = sctp_setsockopt_reset_streams(sk, optval, optlen);
break;
+   case SCTP_RESET_ASSOC:
+   retval = sctp_setsockopt_reset_assoc(sk, optval, optlen);
+   break;
default:
retval = -ENOPROTOOPT;
break;
diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index 13d5e07..b368191 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -162,3 +162,36 @@ int sctp_send_reset_streams(struct sctp_association *asoc,
 out:
return retval;
 }
+
+int sctp_send_reset_assoc(struct sctp_association *asoc)
+{
+   struct sctp_chunk *chunk = NULL;
+   int retval;
+   __u16 i;
+
+   if (!asoc->peer.reconf_capable ||
+   !(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
+   return -ENOPROTOOPT;
+
+   if (asoc->strreset_outstanding)
+   return -EINPROGRESS;
+
+   chunk = sctp_make_strreset_tsnreq(asoc);
+   if (!chunk)
+   return -ENOMEM;
+
+   for (i = 0; i < asoc->stream->outcnt; i++)
+   asoc->stream->out[i].state = SCTP_STREAM_CLOSED;
+
+   asoc->strreset_outstanding = 1;
+   asoc->strreset_chunk = chunk;
+   sctp_chunk_hold(asoc->strreset_chunk);
+
+   retval = sctp_send_reconf(asoc, chunk);
+   if (retval) {
+   sctp_chunk_put(asoc->strreset_chunk);
+   asoc->strreset_chunk = NULL;
+   }
+
+   return retval;
+}
-- 
2.1.0