[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/include/net/netrom.h b/include/net/netrom.h
index 45f2c76..ad05d7a 100644
--- a/include/net/netrom.h
+++ b/include/net/netrom.h
@@ -22,6 +22,7 @@
#define NR_DISCACK 0x04
#define NR_INFO 0x05
#define NR_INFOACK 0x06
+#define NR_RESET 0x07
#define NR_CHOKE_FLAG 0x80
#define NR_NAK_FLAG 0x40
@@ -51,6 +52,7 @@
#define NR_DEFAULT_TTL 16 /* Default Time To Live - 16 */
#define NR_DEFAULT_ROUTING 1 /* Is routing enabled ? */
#define NR_DEFAULT_FAILS 2 /* Link fails until route fails */
+#define NR_DEFAULT_RESET 0 /* Sent / accept reset cmds? */
#define NR_MODULUS 256
#define NR_MAX_WINDOW_SIZE 127 /* Maximum Window Allowable - 127 */
@@ -176,6 +178,8 @@
extern int sysctl_netrom_transport_no_activity_timeout;
extern int sysctl_netrom_routing_control;
extern int sysctl_netrom_link_fails_count;
+extern int sysctl_netrom_reset_circuit;
+
extern int nr_rx_frame(struct sk_buff *, struct net_device *);
extern void nr_destroy_socket(struct sock *);
@@ -218,7 +222,28 @@
extern int nr_validate_nr(struct sock *, unsigned short);
extern int nr_in_rx_window(struct sock *, unsigned short);
extern void nr_write_internal(struct sock *, int);
-extern void nr_transmit_refusal(struct sk_buff *, int);
+
+extern void __nr_transmit_reply(struct sk_buff *skb, int mine,
+ unsigned char cmdflags);
+
+/*
+ * This routine is called when a Connect Acknowledge with the Choke Flag
+ * set is needed to refuse a connection.
+ */
+#define nr_transmit_refusal(skb, mine) \
+do { \
+ __nr_transmit_reply((skb), (mine), NR_CONNACK | NR_CHOKE_FLAG); \
+} while (0)
+
+/*
+ * This routine is called when we don't have a circuit matching an incoming
+ * NET/ROM packet. This is an G8PZT Xrouter extension.
+ */
+#define nr_transmit_reset(skb, mine) \
+do { \
+ __nr_transmit_reply((skb), (mine), NR_RESET); \
+} while (0)
+
extern void nr_disconnect(struct sock *, int);
/* nr_timer.c */