[DCCP]: Introduce DCCP_SOCKOPT_PACKET_SIZE

So that applications can set dccp_sock->dccps_pkt_size, that in turn
is used in the CCID3 half connection init routines to set
ccid3hc[tr]x_s and use it in its rate calculations.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 59 insertions, 12 deletions

diff --git a/include/linux/dccp.h b/include/linux/dccp.h
index 9e3a1370b906..007c290f74d4 100644
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -186,6 +186,9 @@ enum {
         DCCPF_MAX_CCID_SPECIFIC = 255,
 };
 
+/* DCCP socket options */
+#define DCCP_SOCKOPT_PACKET_SIZE        1
+
 #ifdef __KERNEL__
 
 #include <linux/in.h>
@@ -396,7 +399,7 @@ enum dccp_role {
  * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
  * @dccps_ext_header_len - network protocol overhead (IP/IPv6 options)
  * @dccps_pmtu_cookie - Last pmtu seen by socket
- * @dccps_avg_packet_size - FIXME: has to be set by the app thru some setsockopt or ioctl, CCID3 uses it
+ * @dccps_packet_size - Set thru setsockopt
  * @dccps_role - Role of this sock, one of %dccp_role
  * @dccps_ndp_count - number of Non Data Packets since last data packet
  * @dccps_hc_rx_ackpkts - receiver half connection acked packets
@@ -417,7 +420,7 @@ struct dccp_sock {
         unsigned long                   dccps_service;
         struct timeval                  dccps_timestamp_time;
         __u32                           dccps_timestamp_echo;
-        __u32                           dccps_avg_packet_size;
+        __u32                           dccps_packet_size;
         unsigned long                   dccps_ndp_count;
         __u16                           dccps_ext_header_len;
         __u32                           dccps_pmtu_cookie;
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 4ff6ede0f07d..e22b0eefdbf9 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -672,9 +672,9 @@ static int ccid3_hc_tx_init(struct sock *sk)
 
         memset(hctx, 0, sizeof(*hctx));
 
-        if (dp->dccps_avg_packet_size >= TFRC_MIN_PACKET_SIZE &&
-            dp->dccps_avg_packet_size <= TFRC_MAX_PACKET_SIZE)
-                hctx->ccid3hctx_s = (u16)dp->dccps_avg_packet_size;
+        if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
+            dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
+                hctx->ccid3hctx_s = dp->dccps_packet_size;
         else
                 hctx->ccid3hctx_s = TFRC_STD_PACKET_SIZE;
 
@@ -1058,9 +1058,9 @@ static int ccid3_hc_rx_init(struct sock *sk)
 
         memset(hcrx, 0, sizeof(*hcrx));
 
-        if (dp->dccps_avg_packet_size >= TFRC_MIN_PACKET_SIZE &&
-            dp->dccps_avg_packet_size <= TFRC_MAX_PACKET_SIZE)
-                hcrx->ccid3hcrx_s = (u16)dp->dccps_avg_packet_size;
+        if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
+            dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
+                hcrx->ccid3hcrx_s = dp->dccps_packet_size;
         else
                 hcrx->ccid3hcrx_s = TFRC_STD_PACKET_SIZE;
 
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index f4da6561e40c..18a0e69c9dc7 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -205,23 +205,67 @@ int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 int dccp_setsockopt(struct sock *sk, int level, int optname,
                     char __user *optval, int optlen)
 {
-        dccp_pr_debug("entry\n");
+        struct dccp_sock *dp;
+        int err;
+        int val;
 
         if (level != SOL_DCCP)
                 return ip_setsockopt(sk, level, optname, optval, optlen);
 
-        return -EOPNOTSUPP;
+        if (optlen < sizeof(int))
+                return -EINVAL;
+
+        if (get_user(val, (int __user *)optval))
+                return -EFAULT;
+
+        lock_sock(sk);
+
+        dp = dccp_sk(sk);
+        err = 0;
+
+        switch (optname) {
+        case DCCP_SOCKOPT_PACKET_SIZE:
+                dp->dccps_packet_size = val;
+                break;
+        default:
+                err = -ENOPROTOOPT;
+                break;
+        }
+        
+        release_sock(sk);
+        return err;
 }
 
 int dccp_getsockopt(struct sock *sk, int level, int optname,
                     char __user *optval, int __user *optlen)
 {
-        dccp_pr_debug("entry\n");
+        struct dccp_sock *dp;
+        int val, len;
 
         if (level != SOL_DCCP)
                 return ip_getsockopt(sk, level, optname, optval, optlen);
 
-        return -EOPNOTSUPP;
+        if (get_user(len, optlen))
+                return -EFAULT;
+
+        len = min_t(unsigned int, len, sizeof(int));
+        if (len < 0)
+                return -EINVAL;
+
+        dp = dccp_sk(sk);
+
+        switch (optname) {
+        case DCCP_SOCKOPT_PACKET_SIZE:
+                val = dp->dccps_packet_size;
+                break;
+        default:
+                return -ENOPROTOOPT;
+        }
+
+        if (put_user(len, optlen) || copy_to_user(optval, &val, len))
+                return -EFAULT;
+
+        return 0;
 }
 
 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,