[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>
diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c
index 02b1ab5..8c3d3a7 100644
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -56,6 +56,7 @@
int sysctl_netrom_transport_no_activity_timeout = NR_DEFAULT_IDLE;
int sysctl_netrom_routing_control = NR_DEFAULT_ROUTING;
int sysctl_netrom_link_fails_count = NR_DEFAULT_FAILS;
+int sysctl_netrom_reset_circuit = NR_DEFAULT_RESET;
static unsigned short circuit = 0x101;
@@ -908,17 +909,17 @@
if (frametype != NR_CONNREQ) {
/*
* Here it would be nice to be able to send a reset but
- * NET/ROM doesn't have one. The following hack would
- * have been a way to extend the protocol but apparently
- * it kills BPQ boxes... :-(
+ * NET/ROM doesn't have one. We've tried to extend the protocol
+ * by sending NR_CONNACK | NR_CHOKE_FLAGS replies but that
+ * apparently kills BPQ boxes... :-(
+ * So now we try to follow the established behaviour of
+ * G8PZT's Xrouter which is sending packets with command type 7
+ * as an extension of the protocol.
*/
-#if 0
- /*
- * Never reply to a CONNACK/CHOKE.
- */
- if (frametype != NR_CONNACK || flags != NR_CHOKE_FLAG)
- nr_transmit_refusal(skb, 1);
-#endif
+ if (sysctl_netrom_reset_circuit &&
+ (frametype != NR_RESET || flags != 0))
+ nr_transmit_reset(skb, 1);
+
return 0;
}