isdn_concap.c revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 
1/* $Id: isdn_concap.c,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $
2 *
3 * Linux ISDN subsystem, protocol encapsulation
4 *
5 * This software may be used and distributed according to the terms
6 * of the GNU General Public License, incorporated herein by reference.
7 *
8 */
9
10/* Stuff to support the concap_proto by isdn4linux. isdn4linux - specific
11 * stuff goes here. Stuff that depends only on the concap protocol goes to
12 * another -- protocol specific -- source file.
13 *
14 */
15
16
17#include <linux/isdn.h>
18#include "isdn_x25iface.h"
19#include "isdn_net.h"
20#include <linux/concap.h>
21#include "isdn_concap.h"
22
23
24/* The following set of device service operations are for encapsulation
25   protocols that require for reliable datalink semantics. That means:
26
27   - before any data is to be submitted the connection must explicitly
28     be set up.
29   - after the successful set up of the connection is signalled the
30     connection is considered to be reliably up.
31
32   Auto-dialing ist not compatible with this requirements. Thus, auto-dialing
33   is completely bypassed.
34
35   It might be possible to implement a (non standardized) datalink protocol
36   that provides a reliable data link service while using some auto dialing
37   mechanism. Such a protocol would need an auxiliary channel (i.e. user-user-
38   signaling on the D-channel) while the B-channel is down.
39   */
40
41
42int isdn_concap_dl_data_req(struct concap_proto *concap, struct sk_buff *skb)
43{
44	struct net_device *ndev = concap -> net_dev;
45	isdn_net_dev *nd = ((isdn_net_local *) ndev->priv)->netdev;
46	isdn_net_local *lp = isdn_net_get_locked_lp(nd);
47
48	IX25DEBUG( "isdn_concap_dl_data_req: %s \n", concap->net_dev->name);
49	if (!lp) {
50		IX25DEBUG( "isdn_concap_dl_data_req: %s : isdn_net_send_skb returned %d\n", concap -> net_dev -> name, 1);
51		return 1;
52	}
53	lp->huptimer = 0;
54	isdn_net_writebuf_skb(lp, skb);
55	spin_unlock_bh(&lp->xmit_lock);
56	IX25DEBUG( "isdn_concap_dl_data_req: %s : isdn_net_send_skb returned %d\n", concap -> net_dev -> name, 0);
57	return 0;
58}
59
60
61int isdn_concap_dl_connect_req(struct concap_proto *concap)
62{
63	struct net_device *ndev = concap -> net_dev;
64	isdn_net_local *lp = (isdn_net_local *) ndev->priv;
65	int ret;
66	IX25DEBUG( "isdn_concap_dl_connect_req: %s \n", ndev -> name);
67
68	/* dial ... */
69	ret = isdn_net_dial_req( lp );
70	if ( ret ) IX25DEBUG("dialing failed\n");
71	return ret;
72}
73
74int isdn_concap_dl_disconn_req(struct concap_proto *concap)
75{
76	IX25DEBUG( "isdn_concap_dl_disconn_req: %s \n", concap -> net_dev -> name);
77
78	isdn_net_hangup( concap -> net_dev );
79	return 0;
80}
81
82struct concap_device_ops isdn_concap_reliable_dl_dops = {
83	&isdn_concap_dl_data_req,
84	&isdn_concap_dl_connect_req,
85	&isdn_concap_dl_disconn_req
86};
87
88struct concap_device_ops isdn_concap_demand_dial_dops = {
89	NULL, /* set this first entry to something like &isdn_net_start_xmit,
90		 but the entry part of the current isdn_net_start_xmit must be
91		 separated first. */
92	/* no connection control for demand dial semantics */
93	NULL,
94	NULL,
95};
96
97/* The following should better go into a dedicated source file such that
98   this sourcefile does not need to include any protocol specific header
99   files. For now:
100   */
101struct concap_proto * isdn_concap_new( int encap )
102{
103	switch ( encap ) {
104	case ISDN_NET_ENCAP_X25IFACE:
105		return isdn_x25iface_proto_new();
106	}
107	return NULL;
108}
109