[NETROM]: Implement G8PZT Circuit reset for NET/ROM

NET/ROM is lacking a connection reset like TCP's RST flag which at times
may result in a connecting having to slowly timing out instead of just being
reset.  An earlier attempt to reset the connection by sending a
NR_CONNACK | NR_CHOKE_FLAG transport was inacceptable as it did result in
crashes of BPQ systems.  An alternative approach of introducing a new
transport type 7 (NR_RESET) has be implemented several years ago in
Paula Jayne Dowie G8PZT's Xrouter.

Implement NR_RESET for Linux's NET/ROM but like any messing with the state
engine consider this experimental for now and thus control it by a sysctl
(net.netrom.reset) which for the time being defaults to off.

Signed-off-by: Ralf Baechle DL5RB <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 0 deletions

diff --git a/net/netrom/sysctl_net_netrom.c b/net/netrom/sysctl_net_netrom.c
index c9ed50382ea7..6bb8dda849dc 100644
--- a/net/netrom/sysctl_net_netrom.c
+++ b/net/netrom/sysctl_net_netrom.c
@@ -30,6 +30,7 @@ static int min_idle[]    = {0 * HZ};
 static int max_idle[]    = {65535 * HZ};
 static int min_route[]   = {0}, max_route[]   = {1};
 static int min_fails[]   = {1}, max_fails[]   = {10};
+static int min_reset[]   = {0}, max_reset[]   = {1};
 
 static struct ctl_table_header *nr_table_header;
 
@@ -155,6 +156,17 @@ static ctl_table nr_table[] = {
                 .extra1         = &min_fails,
                 .extra2         = &max_fails
         },
+        {
+                .ctl_name       = NET_NETROM_RESET,
+                .procname       = "reset",
+                .data           = &sysctl_netrom_reset_circuit,
+                .maxlen         = sizeof(int),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec_minmax,
+                .strategy       = &sysctl_intvec,
+                .extra1         = &min_reset,
+                .extra2         = &max_reset
+        },
         { .ctl_name = 0 }
 };