summaryrefslogtreecommitdiffstats
path: root/net/atm/signaling.c
blob: 6ff803154c046d6e174713951962331e1fef7548 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
/* net/atm/signaling.c - ATM signaling */

/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */


#include <linux/errno.h>	/* error codes */
#include <linux/kernel.h>	/* printk */
#include <linux/skbuff.h>
#include <linux/wait.h>
#include <linux/sched.h>	/* jiffies and HZ */
#include <linux/atm.h>		/* ATM stuff */
#include <linux/atmsap.h>
#include <linux/atmsvc.h>
#include <linux/atmdev.h>
#include <linux/bitops.h>

#include "resources.h"
#include "signaling.h"


#undef WAIT_FOR_DEMON		/* #define this if system calls on SVC sockets
				   should block until the demon runs.
				   Danger: may cause nasty hangs if the demon
				   crashes. */

#if 0
#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
#else
#define DPRINTK(format,args...)
#endif


struct atm_vcc *sigd = NULL;
#ifdef WAIT_FOR_DEMON
static DECLARE_WAIT_QUEUE_HEAD(sigd_sleep);
#endif


static void sigd_put_skb(struct sk_buff *skb)
{
#ifdef WAIT_FOR_DEMON
	static unsigned long silence;
	DECLARE_WAITQUEUE(wait,current);

	add_wait_queue(&sigd_sleep,&wait);
	while (!sigd) {
		set_current_state(TASK_UNINTERRUPTIBLE);
		if (time_after(jiffies, silence) || silence == 0) {
			printk(KERN_INFO "atmsvc: waiting for signaling demon "
			    "...\n");
			silence = (jiffies+30*HZ)|1;
		}
		schedule();
	}
	current->state = TASK_RUNNING;
	remove_wait_queue(&sigd_sleep,&wait);
#else
	if (!sigd) {
		printk(KERN_WARNING "atmsvc: no signaling demon\n");
		kfree_skb(skb);
		return;
	}
#endif
	atm_force_charge(sigd,skb->truesize);
	skb_queue_tail(&sk_atm(sigd)->sk_receive_queue,skb);
	sk_atm(sigd)->sk_data_ready(sk_atm(sigd), skb->len);
}


static void modify_qos(struct atm_vcc *vcc,struct atmsvc_msg *msg)
{
	struct sk_buff *skb;

	if (test_bit(ATM_VF_RELEASED,&vcc->flags) ||
	    !test_bit(ATM_VF_READY,&vcc->flags))
		return;
	msg->type = as_error;
	if (!vcc->dev->ops->change_qos) msg->reply = -EOPNOTSUPP;
	else {
		/* should lock VCC */
		msg->reply = vcc->dev->ops->change_qos(vcc,&msg->qos,
		    msg->reply);
		if (!msg->reply) msg->type = as_okay;
	}
	/*
	 * Should probably just turn around the old skb. But the, the buffer
	 * space accounting needs to follow the change too. Maybe later.
	 */
	while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))
		schedule();
	*(struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg)) = *msg;
	sigd_put_skb(skb);
}


static int sigd_send(struct atm_vcc *vcc,struct sk_buff *skb)
{
	struct atmsvc_msg *msg;
	struct atm_vcc *session_vcc;
	struct sock *sk;

	msg = (struct atmsvc_msg *) skb->data;
	atomic_sub(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
	DPRINTK("sigd_send %d (0x%lx)\n",(int) msg->type,
	  (unsigned long) msg->vcc);
	vcc = *(struct atm_vcc **) &msg->vcc;
	sk = sk_atm(vcc);

	switch (msg->type) {
		case as_okay:
			sk->sk_err = -msg->reply;
			clear_bit(ATM_VF_WAITING, &vcc->flags);
			if (!*vcc->local.sas_addr.prv &&
			    !*vcc->local.sas_addr.pub) {
				vcc->local.sas_family = AF_ATMSVC;
				memcpy(vcc->local.sas_addr.prv,
				    msg->local.sas_addr.prv,ATM_ESA_LEN);
				memcpy(vcc->local.sas_addr.pub,
				    msg->local.sas_addr.pub,ATM_E164_LEN+1);
			}
			session_vcc = vcc->session ? vcc->session : vcc;
			if (session_vcc->vpi || session_vcc->vci) break;
			session_vcc->itf = msg->pvc.sap_addr.itf;
			session_vcc->vpi = msg->pvc.sap_addr.vpi;
			session_vcc->vci = msg->pvc.sap_addr.vci;
			if (session_vcc->vpi || session_vcc->vci)
				session_vcc->qos = msg->qos;
			break;
		case as_error:
			clear_bit(ATM_VF_REGIS,&vcc->flags);
			clear_bit(ATM_VF_READY,&vcc->flags);
			sk->sk_err = -msg->reply;
			clear_bit(ATM_VF_WAITING, &vcc->flags);
			break;
		case as_indicate:
			vcc = *(struct atm_vcc **) &msg->listen_vcc;
			DPRINTK("as_indicate!!!\n");
			lock_sock(sk);
			if (sk_acceptq_is_full(sk)) {
				sigd_enq(NULL,as_reject,vcc,NULL,NULL);
				dev_kfree_skb(skb);
				goto as_indicate_complete;
			}
			sk->sk_ack_backlog++;
			skb_queue_tail(&sk->sk_receive_queue, skb);
			DPRINTK("waking sk->sk_sleep 0x%p\n", sk->sk_sleep);
			sk->sk_state_change(sk);
as_indicate_complete:
			release_sock(sk);
			return 0;
		case as_close:
			set_bit(ATM_VF_RELEASED,&vcc->flags);
			vcc_release_async(vcc, msg->reply);
			goto out;
		case as_modify:
			modify_qos(vcc,msg);
			break;
		case as_addparty:
		case as_dropparty:
			sk->sk_err_soft = msg->reply;	/* < 0 failure, otherwise ep_ref */
			clear_bit(ATM_VF_WAITING, &vcc->flags);
			break;
		default:
			printk(KERN_ALERT "sigd_send: bad message type %d\n",
			    (int) msg->type);
			return -EINVAL;
	}
	sk->sk_state_change(sk);
out:
	dev_kfree_skb(skb);
	return 0;
}


void sigd_enq2(struct atm_vcc *vcc,enum atmsvc_msg_type type,
    struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
    const struct sockaddr_atmsvc *svc,const struct atm_qos *qos,int reply)
{
	struct sk_buff *skb;
	struct atmsvc_msg *msg;
	static unsigned session = 0;

	DPRINTK("sigd_enq %d (0x%p)\n",(int) type,vcc);
	while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))
		schedule();
	msg = (struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg));
	memset(msg,0,sizeof(*msg));
	msg->type = type;
	*(struct atm_vcc **) &msg->vcc = vcc;
	*(struct atm_vcc **) &msg->listen_vcc = listen_vcc;
	msg->reply = reply;
	if (qos) msg->qos = *qos;
	if (vcc) msg->sap = vcc->sap;
	if (svc) msg->svc = *svc;
	if (vcc) msg->local = vcc->local;
	if (pvc) msg->pvc = *pvc;
	if (vcc) {
		if (type == as_connect && test_bit(ATM_VF_SESSION, &vcc->flags))
			msg->session = ++session;
			/* every new pmp connect gets the next session number */
	}
	sigd_put_skb(skb);
	if (vcc) set_bit(ATM_VF_REGIS,&vcc->flags);
}


void sigd_enq(struct atm_vcc *vcc,enum atmsvc_msg_type type,
    struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
    const struct sockaddr_atmsvc *svc)
{
	sigd_enq2(vcc,type,listen_vcc,pvc,svc,vcc ? &vcc->qos : NULL,0);
	/* other ISP applications may use "reply" */
}


static void purge_vcc(struct atm_vcc *vcc)
{
	if (sk_atm(vcc)->sk_family == PF_ATMSVC &&
	    !test_bit(ATM_VF_META,&vcc->flags)) {
		set_bit(ATM_VF_RELEASED,&vcc->flags);
		vcc_release_async(vcc, -EUNATCH);
	}
}


static void sigd_close(struct atm_vcc *vcc)
{
	struct hlist_node *node;
	struct sock *s;
	int i;

	DPRINTK("sigd_close\n");
	sigd = NULL;
	if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
		printk(KERN_ERR "sigd_close: closing with requests pending\n");
	skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);

	read_lock(&vcc_sklist_lock);
	for(i = 0; i < VCC_HTABLE_SIZE; ++i) {
		struct hlist_head *head = &vcc_hash[i];

		sk_for_each(s, node, head) {
			struct atm_vcc *vcc = atm_sk(s);

			if (vcc->dev)
				purge_vcc(vcc);
		}
	}
	read_unlock(&vcc_sklist_lock);
}


static struct atmdev_ops sigd_dev_ops = {
	.close = sigd_close,
	.send =	sigd_send
};


static struct atm_dev sigd_dev = {
	.ops =		&sigd_dev_ops,
	.type =		"sig",
	.number =	999,
	.lock =		SPIN_LOCK_UNLOCKED
};


int sigd_attach(struct atm_vcc *vcc)
{
	if (sigd) return -EADDRINUSE;
	DPRINTK("sigd_attach\n");
	sigd = vcc;
	vcc->dev = &sigd_dev;
	vcc_insert_socket(sk_atm(vcc));
	set_bit(ATM_VF_META,&vcc->flags);
	set_bit(ATM_VF_READY,&vcc->flags);
#ifdef WAIT_FOR_DEMON
	wake_up(&sigd_sleep);
#endif
	return 0;
}