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authorRalf Baechle <ralf@linux-mips.org>2005-09-12 14:27:37 -0700
committerDavid S. Miller <davem@davemloft.net>2005-09-12 14:27:37 -0700
commite21ce8c7c013fb223a002c70bb0a547de6c26c12 (patch)
tree767b9aae7bdd50cdf867f3cdc1a3e214692146e1
parentd2ce4bc340946d5b78484d638ac10df958c4c3bf (diff)
downloadlinux-linaro-e21ce8c7c013fb223a002c70bb0a547de6c26c12.tar.gz
[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>
-rw-r--r--include/linux/sysctl.h3
-rw-r--r--include/net/netrom.h27
-rw-r--r--net/netrom/af_netrom.c21
-rw-r--r--net/netrom/nr_in.c15
-rw-r--r--net/netrom/nr_subr.c7
-rw-r--r--net/netrom/sysctl_net_netrom.c12
6 files changed, 69 insertions, 16 deletions
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 532a6c5c24e..3a29a9f9b45 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -544,7 +544,8 @@ enum {
NET_NETROM_TRANSPORT_REQUESTED_WINDOW_SIZE=8,
NET_NETROM_TRANSPORT_NO_ACTIVITY_TIMEOUT=9,
NET_NETROM_ROUTING_CONTROL=10,
- NET_NETROM_LINK_FAILS_COUNT=11
+ NET_NETROM_LINK_FAILS_COUNT=11,
+ NET_NETROM_RESET=12
};
/* /proc/sys/net/ax25 */
diff --git a/include/net/netrom.h b/include/net/netrom.h
index 45f2c7616d8..ad05d7a3c55 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 @@ enum {
#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_requested_window_size;
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 void nr_requeue_frames(struct sock *);
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 */
diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c
index 02b1ab52dbb..8c3d3a78481 100644
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -56,6 +56,7 @@ int sysctl_netrom_transport_requested_window_size = NR_DEFAULT_WINDOW;
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 @@ int nr_rx_frame(struct sk_buff *skb, struct net_device *dev)
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;
}
diff --git a/net/netrom/nr_in.c b/net/netrom/nr_in.c
index 64b81a79690..004e8599b8f 100644
--- a/net/netrom/nr_in.c
+++ b/net/netrom/nr_in.c
@@ -98,6 +98,11 @@ static int nr_state1_machine(struct sock *sk, struct sk_buff *skb,
nr_disconnect(sk, ECONNREFUSED);
break;
+ case NR_RESET:
+ if (sysctl_netrom_reset_circuit);
+ nr_disconnect(sk, ECONNRESET);
+ break;
+
default:
break;
}
@@ -124,6 +129,11 @@ static int nr_state2_machine(struct sock *sk, struct sk_buff *skb,
nr_disconnect(sk, 0);
break;
+ case NR_RESET:
+ if (sysctl_netrom_reset_circuit);
+ nr_disconnect(sk, ECONNRESET);
+ break;
+
default:
break;
}
@@ -254,6 +264,11 @@ static int nr_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype
}
break;
+ case NR_RESET:
+ if (sysctl_netrom_reset_circuit);
+ nr_disconnect(sk, ECONNRESET);
+ break;
+
default:
break;
}
diff --git a/net/netrom/nr_subr.c b/net/netrom/nr_subr.c
index 587bed2674b..bcb9946b4f5 100644
--- a/net/netrom/nr_subr.c
+++ b/net/netrom/nr_subr.c
@@ -210,10 +210,9 @@ void nr_write_internal(struct sock *sk, int frametype)
}
/*
- * This routine is called when a Connect Acknowledge with the Choke Flag
- * set is needed to refuse a connection.
+ * This routine is called to send an error reply.
*/
-void nr_transmit_refusal(struct sk_buff *skb, int mine)
+void __nr_transmit_reply(struct sk_buff *skb, int mine, unsigned char cmdflags)
{
struct sk_buff *skbn;
unsigned char *dptr;
@@ -254,7 +253,7 @@ void nr_transmit_refusal(struct sk_buff *skb, int mine)
*dptr++ = 0;
}
- *dptr++ = NR_CONNACK | NR_CHOKE_FLAG;
+ *dptr++ = cmdflags;
*dptr++ = 0;
if (!nr_route_frame(skbn, NULL))
diff --git a/net/netrom/sysctl_net_netrom.c b/net/netrom/sysctl_net_netrom.c
index c9ed50382ea..6bb8dda849d 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 }
};