[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 <lucien....@gmail.com>
---
 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      0x0000
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(&associd, 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