[PATCHv2 net-next 7/7] sctp: add get and set sockopt for reconf_enable

[Xin Long]

This patchset is to add SCTP_RECONFIG_SUPPORTED sockopt, it would
set and get asoc reconf_enable value when asoc_id is set, or it
would set and get ep reconf_enalbe value if asoc_id is 0.

It is also to add sysctl interface for users to set the default
value for reconf_enable.

After this patch, stream reconf will work.

Signed-off-by: Xin Long <lucien....@gmail.com>
---
 include/uapi/linux/sctp.h |  1 +
 net/sctp/socket.c         | 81 +++++++++++++++++++++++++++++++++++++++++++++++
 net/sctp/sysctl.c         |  7 ++++
 3 files changed, 89 insertions(+)

diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
index fd652e6..7212870 100644
--- a/include/uapi/linux/sctp.h
+++ b/include/uapi/linux/sctp.h
@@ -115,6 +115,7 @@ typedef __s32 sctp_assoc_t;
 #define SCTP_PR_SUPPORTED      113
 #define SCTP_DEFAULT_PRINFO    114
 #define SCTP_PR_ASSOC_STATUS   115
+#define SCTP_RECONFIG_SUPPORTED        117
 #define SCTP_ENABLE_STREAM_RESET       118
 #define SCTP_RESET_STREAMS     119
 #define SCTP_RESET_ASSOC       120
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 6f0a9be..24e28cf 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3758,6 +3758,39 @@ static int sctp_setsockopt_default_prinfo(struct sock 
*sk,
        return retval;
 }
 
+static int sctp_setsockopt_reconfig_supported(struct sock *sk,
+                                             char __user *optval,
+                                             unsigned int optlen)
+{
+       struct sctp_assoc_value params;
+       struct sctp_association *asoc;
+       int retval = -EINVAL;
+
+       if (optlen != sizeof(params))
+               goto out;
+
+       if (copy_from_user(&params, optval, optlen)) {
+               retval = -EFAULT;
+               goto out;
+       }
+
+       asoc = sctp_id2assoc(sk, params.assoc_id);
+       if (asoc) {
+               asoc->reconf_enable = !!params.assoc_value;
+       } else if (!params.assoc_id) {
+               struct sctp_sock *sp = sctp_sk(sk);
+
+               sp->ep->reconf_enable = !!params.assoc_value;
+       } else {
+               goto out;
+       }
+
+       retval = 0;
+
+out:
+       return retval;
+}
+
 static int sctp_setsockopt_enable_strreset(struct sock *sk,
                                           char __user *optval,
                                           unsigned int optlen)
@@ -4038,6 +4071,9 @@ static int sctp_setsockopt(struct sock *sk, int level, 
int optname,
        case SCTP_DEFAULT_PRINFO:
                retval = sctp_setsockopt_default_prinfo(sk, optval, optlen);
                break;
+       case SCTP_RECONFIG_SUPPORTED:
+               retval = sctp_setsockopt_reconfig_supported(sk, optval, optlen);
+               break;
        case SCTP_ENABLE_STREAM_RESET:
                retval = sctp_setsockopt_enable_strreset(sk, optval, optlen);
                break;
@@ -6540,6 +6576,47 @@ static int sctp_getsockopt_pr_assocstatus(struct sock 
*sk, int len,
        return retval;
 }
 
+static int sctp_getsockopt_reconfig_supported(struct sock *sk, int len,
+                                             char __user *optval,
+                                             int __user *optlen)
+{
+       struct sctp_assoc_value params;
+       struct sctp_association *asoc;
+       int retval = -EFAULT;
+
+       if (len < sizeof(params)) {
+               retval = -EINVAL;
+               goto out;
+       }
+
+       len = sizeof(params);
+       if (copy_from_user(&params, optval, len))
+               goto out;
+
+       asoc = sctp_id2assoc(sk, params.assoc_id);
+       if (asoc) {
+               params.assoc_value = asoc->reconf_enable;
+       } else if (!params.assoc_id) {
+               struct sctp_sock *sp = sctp_sk(sk);
+
+               params.assoc_value = sp->ep->reconf_enable;
+       } else {
+               retval = -EINVAL;
+               goto out;
+       }
+
+       if (put_user(len, optlen))
+               goto out;
+
+       if (copy_to_user(optval, &params, len))
+               goto out;
+
+       retval = 0;
+
+out:
+       return retval;
+}
+
 static int sctp_getsockopt_enable_strreset(struct sock *sk, int len,
                                           char __user *optval,
                                           int __user *optlen)
@@ -6748,6 +6825,10 @@ static int sctp_getsockopt(struct sock *sk, int level, 
int optname,
                retval = sctp_getsockopt_pr_assocstatus(sk, len, optval,
                                                        optlen);
                break;
+       case SCTP_RECONFIG_SUPPORTED:
+               retval = sctp_getsockopt_reconfig_supported(sk, len, optval,
+                                                           optlen);
+               break;
        case SCTP_ENABLE_STREAM_RESET:
                retval = sctp_getsockopt_enable_strreset(sk, len, optval,
                                                         optlen);
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index daf8554..0e732f6 100644
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -275,6 +275,13 @@ static struct ctl_table sctp_net_table[] = {
                .proc_handler   = proc_dointvec,
        },
        {
+               .procname       = "reconf_enable",
+               .data           = &init_net.sctp.reconf_enable,
+               .maxlen         = sizeof(int),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec,
+       },
+       {
                .procname       = "auth_enable",
                .data           = &init_net.sctp.auth_enable,
                .maxlen         = sizeof(int),
-- 
2.1.0