[SCTP]: Add support for SCTP_DELAYED_ACK_TIME socket option.

Signed-off-by: Frank Filz <ffilz@us.ibm.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 198 insertions, 0 deletions

diff --git a/include/net/sctp/user.h b/include/net/sctp/user.h
index b9052864fa5a..8a6bef6f91eb 100644
--- a/include/net/sctp/user.h
+++ b/include/net/sctp/user.h
@@ -93,6 +93,8 @@ enum sctp_optname {
 #define SCTP_STATUS SCTP_STATUS
         SCTP_GET_PEER_ADDR_INFO,
 #define SCTP_GET_PEER_ADDR_INFO SCTP_GET_PEER_ADDR_INFO
+        SCTP_DELAYED_ACK_TIME,
+#define SCTP_DELAYED_ACK_TIME SCTP_DELAYED_ACK_TIME
 
         /* Internal Socket Options. Some of the sctp library functions are 
          * implemented using these socket options.
@@ -526,6 +528,18 @@ struct sctp_paddrparams {
         __u32                   spp_flags;
 } __attribute__((packed, aligned(4)));
 
+/* 7.1.24. Delayed Ack Timer (SCTP_DELAYED_ACK_TIME)
+ *
+ *   This options will get or set the delayed ack timer.  The time is set
+ *   in milliseconds.  If the assoc_id is 0, then this sets or gets the
+ *   endpoints default delayed ack timer value.  If the assoc_id field is
+ *   non-zero, then the set or get effects the specified association.
+ */
+struct sctp_assoc_value {
+    sctp_assoc_t            assoc_id;
+    uint32_t                assoc_value;
+};
+
 /*
  * 7.2.2 Peer Address Information
  *
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index adb5ee62c2a6..fc04d185fa33 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -2214,6 +2214,109 @@ static int sctp_setsockopt_peer_addr_params(struct sock *sk,
         return 0;
 }
 
+/* 7.1.24. Delayed Ack Timer (SCTP_DELAYED_ACK_TIME)
+ *
+ *   This options will get or set the delayed ack timer.  The time is set
+ *   in milliseconds.  If the assoc_id is 0, then this sets or gets the
+ *   endpoints default delayed ack timer value.  If the assoc_id field is
+ *   non-zero, then the set or get effects the specified association.
+ *
+ *   struct sctp_assoc_value {
+ *       sctp_assoc_t            assoc_id;
+ *       uint32_t                assoc_value;
+ *   };
+ *
+ *     assoc_id    - This parameter, indicates which association the
+ *                   user is preforming an action upon. Note that if
+ *                   this field's value is zero then the endpoints
+ *                   default value is changed (effecting future
+ *                   associations only).
+ *
+ *     assoc_value - This parameter contains the number of milliseconds
+ *                   that the user is requesting the delayed ACK timer
+ *                   be set to. Note that this value is defined in
+ *                   the standard to be between 200 and 500 milliseconds.
+ *
+ *                   Note: a value of zero will leave the value alone,
+ *                   but disable SACK delay. A non-zero value will also
+ *                   enable SACK delay.
+ */
+
+static int sctp_setsockopt_delayed_ack_time(struct sock *sk,
+                                            char __user *optval, int optlen)
+{
+        struct sctp_assoc_value  params;
+        struct sctp_transport   *trans = NULL;
+        struct sctp_association *asoc = NULL;
+        struct sctp_sock        *sp = sctp_sk(sk);
+
+        if (optlen != sizeof(struct sctp_assoc_value))
+                return - EINVAL;
+
+        if (copy_from_user(&params, optval, optlen))
+                return -EFAULT;
+
+        /* Validate value parameter. */
+        if (params.assoc_value > 500)
+                return -EINVAL;
+
+        /* Get association, if assoc_id != 0 and the socket is a one
+         * to many style socket, and an association was not found, then
+         * the id was invalid.
+         */
+        asoc = sctp_id2assoc(sk, params.assoc_id);
+        if (!asoc && params.assoc_id && sctp_style(sk, UDP))
+                return -EINVAL;
+
+        if (params.assoc_value) {
+                if (asoc) {
+                        asoc->sackdelay =
+                                msecs_to_jiffies(params.assoc_value);
+                        asoc->param_flags = 
+                                (asoc->param_flags & ~SPP_SACKDELAY) |
+                                SPP_SACKDELAY_ENABLE;
+                } else {
+                        sp->sackdelay = params.assoc_value;
+                        sp->param_flags = 
+                                (sp->param_flags & ~SPP_SACKDELAY) |
+                                SPP_SACKDELAY_ENABLE;
+                }
+        } else {
+                if (asoc) {
+                        asoc->param_flags = 
+                                (asoc->param_flags & ~SPP_SACKDELAY) |
+                                SPP_SACKDELAY_DISABLE;
+                } else {
+                        sp->param_flags = 
+                                (sp->param_flags & ~SPP_SACKDELAY) |
+                                SPP_SACKDELAY_DISABLE;
+                }
+        }
+
+        /* If change is for association, also apply to each transport. */
+        if (asoc) {
+                struct list_head *pos;
+
+                list_for_each(pos, &asoc->peer.transport_addr_list) {
+                        trans = list_entry(pos, struct sctp_transport,
+                                           transports);
+                        if (params.assoc_value) {
+                                trans->sackdelay =
+                                        msecs_to_jiffies(params.assoc_value);
+                                trans->param_flags = 
+                                        (trans->param_flags & ~SPP_SACKDELAY) |
+                                        SPP_SACKDELAY_ENABLE;
+                        } else {
+                                trans->param_flags = 
+                                        (trans->param_flags & ~SPP_SACKDELAY) |
+                                        SPP_SACKDELAY_DISABLE;
+                        }
+                }
+        }
+ 
+        return 0;
+}
+
 /* 7.1.3 Initialization Parameters (SCTP_INITMSG)
  *
  * Applications can specify protocol parameters for the default association
@@ -2660,6 +2763,10 @@ SCTP_STATIC int sctp_setsockopt(struct sock *sk, int level, int optname,
                 retval = sctp_setsockopt_peer_addr_params(sk, optval, optlen);
                 break;
 
+        case SCTP_DELAYED_ACK_TIME:
+                retval = sctp_setsockopt_delayed_ack_time(sk, optval, optlen);
+                break;
+
         case SCTP_INITMSG:
                 retval = sctp_setsockopt_initmsg(sk, optval, optlen);
                 break;
@@ -3417,6 +3524,79 @@ static int sctp_getsockopt_peer_addr_params(struct sock *sk, int len,
         return 0;
 }
 
+/* 7.1.24. Delayed Ack Timer (SCTP_DELAYED_ACK_TIME)
+ *
+ *   This options will get or set the delayed ack timer.  The time is set
+ *   in milliseconds.  If the assoc_id is 0, then this sets or gets the
+ *   endpoints default delayed ack timer value.  If the assoc_id field is
+ *   non-zero, then the set or get effects the specified association.
+ *
+ *   struct sctp_assoc_value {
+ *       sctp_assoc_t            assoc_id;
+ *       uint32_t                assoc_value;
+ *   };
+ *
+ *     assoc_id    - This parameter, indicates which association the
+ *                   user is preforming an action upon. Note that if
+ *                   this field's value is zero then the endpoints
+ *                   default value is changed (effecting future
+ *                   associations only).
+ *
+ *     assoc_value - This parameter contains the number of milliseconds
+ *                   that the user is requesting the delayed ACK timer
+ *                   be set to. Note that this value is defined in
+ *                   the standard to be between 200 and 500 milliseconds.
+ *
+ *                   Note: a value of zero will leave the value alone,
+ *                   but disable SACK delay. A non-zero value will also
+ *                   enable SACK delay.
+ */
+static int sctp_getsockopt_delayed_ack_time(struct sock *sk, int len,
+                                            char __user *optval,
+                                            int __user *optlen)
+{
+        struct sctp_assoc_value  params;
+        struct sctp_association *asoc = NULL;
+        struct sctp_sock        *sp = sctp_sk(sk);
+
+        if (len != sizeof(struct sctp_assoc_value))
+                return - EINVAL;
+
+        if (copy_from_user(&params, optval, len))
+                return -EFAULT;
+
+        /* Get association, if assoc_id != 0 and the socket is a one
+         * to many style socket, and an association was not found, then
+         * the id was invalid.
+         */
+        asoc = sctp_id2assoc(sk, params.assoc_id);
+        if (!asoc && params.assoc_id && sctp_style(sk, UDP))
+                return -EINVAL;
+
+        if (asoc) {
+                /* Fetch association values. */
+                if (asoc->param_flags & SPP_SACKDELAY_ENABLE)
+                        params.assoc_value = jiffies_to_msecs(
+                                asoc->sackdelay);
+                else
+                        params.assoc_value = 0;
+        } else {
+                /* Fetch socket values. */
+                if (sp->param_flags & SPP_SACKDELAY_ENABLE)
+                        params.assoc_value  = sp->sackdelay;
+                else
+                        params.assoc_value  = 0;
+        }
+
+        if (copy_to_user(optval, &params, len))
+                return -EFAULT;
+
+        if (put_user(len, optlen))
+                return -EFAULT;
+
+        return 0;
+}
+
 /* 7.1.3 Initialization Parameters (SCTP_INITMSG)
  *
  * Applications can specify protocol parameters for the default association
@@ -4274,6 +4454,10 @@ SCTP_STATIC int sctp_getsockopt(struct sock *sk, int level, int optname,
                 retval = sctp_getsockopt_peer_addr_params(sk, len, optval,
                                                           optlen);
                 break;
+        case SCTP_DELAYED_ACK_TIME:
+                retval = sctp_getsockopt_delayed_ack_time(sk, len, optval,
+                                                          optlen);
+                break;
         case SCTP_INITMSG:
                 retval = sctp_getsockopt_initmsg(sk, len, optval, optlen);
                 break;