提交 e21ce8c7 编写于 作者: R Ralf Baechle 提交者: David S. Miller

[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: NRalf Baechle DL5RB <ralf@linux-mips.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
上级 d2ce4bc3
...@@ -544,7 +544,8 @@ enum { ...@@ -544,7 +544,8 @@ enum {
NET_NETROM_TRANSPORT_REQUESTED_WINDOW_SIZE=8, NET_NETROM_TRANSPORT_REQUESTED_WINDOW_SIZE=8,
NET_NETROM_TRANSPORT_NO_ACTIVITY_TIMEOUT=9, NET_NETROM_TRANSPORT_NO_ACTIVITY_TIMEOUT=9,
NET_NETROM_ROUTING_CONTROL=10, 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 */ /* /proc/sys/net/ax25 */
......
...@@ -22,6 +22,7 @@ ...@@ -22,6 +22,7 @@
#define NR_DISCACK 0x04 #define NR_DISCACK 0x04
#define NR_INFO 0x05 #define NR_INFO 0x05
#define NR_INFOACK 0x06 #define NR_INFOACK 0x06
#define NR_RESET 0x07
#define NR_CHOKE_FLAG 0x80 #define NR_CHOKE_FLAG 0x80
#define NR_NAK_FLAG 0x40 #define NR_NAK_FLAG 0x40
...@@ -51,6 +52,7 @@ enum { ...@@ -51,6 +52,7 @@ enum {
#define NR_DEFAULT_TTL 16 /* Default Time To Live - 16 */ #define NR_DEFAULT_TTL 16 /* Default Time To Live - 16 */
#define NR_DEFAULT_ROUTING 1 /* Is routing enabled ? */ #define NR_DEFAULT_ROUTING 1 /* Is routing enabled ? */
#define NR_DEFAULT_FAILS 2 /* Link fails until route fails */ #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_MODULUS 256
#define NR_MAX_WINDOW_SIZE 127 /* Maximum Window Allowable - 127 */ #define NR_MAX_WINDOW_SIZE 127 /* Maximum Window Allowable - 127 */
...@@ -176,6 +178,8 @@ extern int sysctl_netrom_transport_requested_window_size; ...@@ -176,6 +178,8 @@ extern int sysctl_netrom_transport_requested_window_size;
extern int sysctl_netrom_transport_no_activity_timeout; extern int sysctl_netrom_transport_no_activity_timeout;
extern int sysctl_netrom_routing_control; extern int sysctl_netrom_routing_control;
extern int sysctl_netrom_link_fails_count; 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 int nr_rx_frame(struct sk_buff *, struct net_device *);
extern void nr_destroy_socket(struct sock *); extern void nr_destroy_socket(struct sock *);
...@@ -218,7 +222,28 @@ extern void nr_requeue_frames(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_validate_nr(struct sock *, unsigned short);
extern int nr_in_rx_window(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_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); extern void nr_disconnect(struct sock *, int);
/* nr_timer.c */ /* nr_timer.c */
......
...@@ -56,6 +56,7 @@ int sysctl_netrom_transport_requested_window_size = NR_DEFAULT_WINDOW; ...@@ -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_transport_no_activity_timeout = NR_DEFAULT_IDLE;
int sysctl_netrom_routing_control = NR_DEFAULT_ROUTING; int sysctl_netrom_routing_control = NR_DEFAULT_ROUTING;
int sysctl_netrom_link_fails_count = NR_DEFAULT_FAILS; int sysctl_netrom_link_fails_count = NR_DEFAULT_FAILS;
int sysctl_netrom_reset_circuit = NR_DEFAULT_RESET;
static unsigned short circuit = 0x101; static unsigned short circuit = 0x101;
...@@ -908,17 +909,17 @@ int nr_rx_frame(struct sk_buff *skb, struct net_device *dev) ...@@ -908,17 +909,17 @@ int nr_rx_frame(struct sk_buff *skb, struct net_device *dev)
if (frametype != NR_CONNREQ) { if (frametype != NR_CONNREQ) {
/* /*
* Here it would be nice to be able to send a reset but * Here it would be nice to be able to send a reset but
* NET/ROM doesn't have one. The following hack would * NET/ROM doesn't have one. We've tried to extend the protocol
* have been a way to extend the protocol but apparently * by sending NR_CONNACK | NR_CHOKE_FLAGS replies but that
* it kills BPQ boxes... :-( * 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 if (sysctl_netrom_reset_circuit &&
/* (frametype != NR_RESET || flags != 0))
* Never reply to a CONNACK/CHOKE. nr_transmit_reset(skb, 1);
*/
if (frametype != NR_CONNACK || flags != NR_CHOKE_FLAG)
nr_transmit_refusal(skb, 1);
#endif
return 0; return 0;
} }
......
...@@ -98,6 +98,11 @@ static int nr_state1_machine(struct sock *sk, struct sk_buff *skb, ...@@ -98,6 +98,11 @@ static int nr_state1_machine(struct sock *sk, struct sk_buff *skb,
nr_disconnect(sk, ECONNREFUSED); nr_disconnect(sk, ECONNREFUSED);
break; break;
case NR_RESET:
if (sysctl_netrom_reset_circuit);
nr_disconnect(sk, ECONNRESET);
break;
default: default:
break; break;
} }
...@@ -124,6 +129,11 @@ static int nr_state2_machine(struct sock *sk, struct sk_buff *skb, ...@@ -124,6 +129,11 @@ static int nr_state2_machine(struct sock *sk, struct sk_buff *skb,
nr_disconnect(sk, 0); nr_disconnect(sk, 0);
break; break;
case NR_RESET:
if (sysctl_netrom_reset_circuit);
nr_disconnect(sk, ECONNRESET);
break;
default: default:
break; break;
} }
...@@ -254,6 +264,11 @@ static int nr_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype ...@@ -254,6 +264,11 @@ static int nr_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype
} }
break; break;
case NR_RESET:
if (sysctl_netrom_reset_circuit);
nr_disconnect(sk, ECONNRESET);
break;
default: default:
break; break;
} }
......
...@@ -210,10 +210,9 @@ void nr_write_internal(struct sock *sk, int frametype) ...@@ -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 * This routine is called to send an error reply.
* set is needed to refuse a connection.
*/ */
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; struct sk_buff *skbn;
unsigned char *dptr; unsigned char *dptr;
...@@ -254,7 +253,7 @@ void nr_transmit_refusal(struct sk_buff *skb, int mine) ...@@ -254,7 +253,7 @@ void nr_transmit_refusal(struct sk_buff *skb, int mine)
*dptr++ = 0; *dptr++ = 0;
} }
*dptr++ = NR_CONNACK | NR_CHOKE_FLAG; *dptr++ = cmdflags;
*dptr++ = 0; *dptr++ = 0;
if (!nr_route_frame(skbn, NULL)) if (!nr_route_frame(skbn, NULL))
......
...@@ -30,6 +30,7 @@ static int min_idle[] = {0 * HZ}; ...@@ -30,6 +30,7 @@ static int min_idle[] = {0 * HZ};
static int max_idle[] = {65535 * HZ}; static int max_idle[] = {65535 * HZ};
static int min_route[] = {0}, max_route[] = {1}; static int min_route[] = {0}, max_route[] = {1};
static int min_fails[] = {1}, max_fails[] = {10}; static int min_fails[] = {1}, max_fails[] = {10};
static int min_reset[] = {0}, max_reset[] = {1};
static struct ctl_table_header *nr_table_header; static struct ctl_table_header *nr_table_header;
...@@ -155,6 +156,17 @@ static ctl_table nr_table[] = { ...@@ -155,6 +156,17 @@ static ctl_table nr_table[] = {
.extra1 = &min_fails, .extra1 = &min_fails,
.extra2 = &max_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 } { .ctl_name = 0 }
}; };
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册