[DECNET]: add memory buffer settings

The patch (originally from Steve) simply adds memory buffer settings to 
DECnet similar to those in TCP.

Signed-off-by: Patrick Caulfield <patrick@tykepenguin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 62 insertions, 3 deletions

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 6bc03c911a83..4be34ef8c2f7 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -670,6 +670,9 @@ enum {
         NET_DECNET_DST_GC_INTERVAL = 9,
         NET_DECNET_CONF = 10,
         NET_DECNET_NO_FC_MAX_CWND = 11,
+        NET_DECNET_MEM = 12,
+        NET_DECNET_RMEM = 13,
+        NET_DECNET_WMEM = 14,
         NET_DECNET_DEBUG_LEVEL = 255
 };
 
diff --git a/include/net/dn.h b/include/net/dn.h
index c1dbbd222793..a4b6168e1e25 100644
--- a/include/net/dn.h
+++ b/include/net/dn.h
@@ -234,4 +234,8 @@ extern int decnet_di_count;
 extern int decnet_dr_count;
 extern int decnet_no_fc_max_cwnd;
 
+extern int sysctl_decnet_mem[3];
+extern int sysctl_decnet_wmem[3];
+extern int sysctl_decnet_rmem[3];
+
 #endif /* _NET_DN_H */
diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c
index f89e55f814d9..d402e9020c68 100644
--- a/net/decnet/af_decnet.c
+++ b/net/decnet/af_decnet.c
@@ -153,6 +153,7 @@ static struct proto_ops dn_proto_ops;
 static DEFINE_RWLOCK(dn_hash_lock);
 static struct hlist_head dn_sk_hash[DN_SK_HASH_SIZE];
 static struct hlist_head dn_wild_sk;
+static atomic_t decnet_memory_allocated;
 
 static int __dn_setsockopt(struct socket *sock, int level, int optname, char __user *optval, int optlen, int flags);
 static int __dn_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen, int flags);
@@ -446,10 +447,26 @@ static void dn_destruct(struct sock *sk)
         dst_release(xchg(&sk->sk_dst_cache, NULL));
 }
 
+static int dn_memory_pressure;
+
+static void dn_enter_memory_pressure(void)
+{
+        if (!dn_memory_pressure) {
+                dn_memory_pressure = 1;
+        }
+}
+
 static struct proto dn_proto = {
-        .name     = "DECNET",
-        .owner    = THIS_MODULE,
-        .obj_size = sizeof(struct dn_sock),
+        .name                   = "NSP",
+        .owner                  = THIS_MODULE,
+        .enter_memory_pressure  = dn_enter_memory_pressure,
+        .memory_pressure        = &dn_memory_pressure,
+        .memory_allocated       = &decnet_memory_allocated,
+        .sysctl_mem             = sysctl_decnet_mem,
+        .sysctl_wmem            = sysctl_decnet_wmem,
+        .sysctl_rmem            = sysctl_decnet_rmem,
+        .max_header             = DN_MAX_NSP_DATA_HEADER + 64,
+        .obj_size               = sizeof(struct dn_sock),
 };
 
 static struct sock *dn_alloc_sock(struct socket *sock, gfp_t gfp)
@@ -470,6 +487,8 @@ static struct sock *dn_alloc_sock(struct socket *sock, gfp_t gfp)
         sk->sk_family      = PF_DECnet;
         sk->sk_protocol    = 0;
         sk->sk_allocation  = gfp;
+        sk->sk_sndbuf      = sysctl_decnet_wmem[1];
+        sk->sk_rcvbuf      = sysctl_decnet_rmem[1];
 
         /* Initialization of DECnet Session Control Port                */
         scp = DN_SK(sk);
diff --git a/net/decnet/sysctl_net_decnet.c b/net/decnet/sysctl_net_decnet.c
index 02bca49cb508..0e9d2c571165 100644
--- a/net/decnet/sysctl_net_decnet.c
+++ b/net/decnet/sysctl_net_decnet.c
@@ -10,6 +10,7 @@
  *
  * Changes:
  * Steve Whitehouse - C99 changes and default device handling
+ * Steve Whitehouse - Memory buffer settings, like the tcp ones
  *
  */
 #include <linux/config.h>
@@ -37,6 +38,11 @@ int decnet_dr_count = 3;
 int decnet_log_martians = 1;
 int decnet_no_fc_max_cwnd = NSP_MIN_WINDOW;
 
+/* Reasonable defaults, I hope, based on tcp's defaults */
+int sysctl_decnet_mem[3] = { 768 << 3, 1024 << 3, 1536 << 3 };
+int sysctl_decnet_wmem[3] = { 4 * 1024, 16 * 1024, 128 * 1024 };
+int sysctl_decnet_rmem[3] = { 4 * 1024, 87380, 87380 * 2 };
+
 #ifdef CONFIG_SYSCTL
 extern int decnet_dst_gc_interval;
 static int min_decnet_time_wait[] = { 5 };
@@ -428,6 +434,33 @@ static ctl_table dn_table[] = {
                 .extra1 = &min_decnet_no_fc_max_cwnd,
                 .extra2 = &max_decnet_no_fc_max_cwnd
         },
+       {
+                .ctl_name = NET_DECNET_MEM,
+                .procname = "decnet_mem",
+                .data = &sysctl_decnet_mem,
+                .maxlen = sizeof(sysctl_decnet_mem),
+                .mode = 0644,
+                .proc_handler = &proc_dointvec,
+                .strategy = &sysctl_intvec,
+        },
+        {
+                .ctl_name = NET_DECNET_RMEM,
+                .procname = "decnet_rmem",
+                .data = &sysctl_decnet_rmem,
+                .maxlen = sizeof(sysctl_decnet_rmem),
+                .mode = 0644,
+                .proc_handler = &proc_dointvec,
+                .strategy = &sysctl_intvec,
+        },
+        {
+                .ctl_name = NET_DECNET_WMEM,
+                .procname = "decnet_wmem",
+                .data = &sysctl_decnet_wmem,
+                .maxlen = sizeof(sysctl_decnet_wmem),
+                .mode = 0644,
+                .proc_handler = &proc_dointvec,
+                .strategy = &sysctl_intvec,
+        },
         {
                 .ctl_name = NET_DECNET_DEBUG_LEVEL,
                 .procname = "debug",