xref: /openbmc/linux/net/atm/signaling.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
1 /* net/atm/signaling.c - ATM signaling */
2 
3 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
4 
5 
6 #include <linux/errno.h>	/* error codes */
7 #include <linux/kernel.h>	/* printk */
8 #include <linux/skbuff.h>
9 #include <linux/wait.h>
10 #include <linux/sched.h>	/* jiffies and HZ */
11 #include <linux/atm.h>		/* ATM stuff */
12 #include <linux/atmsap.h>
13 #include <linux/atmsvc.h>
14 #include <linux/atmdev.h>
15 #include <linux/bitops.h>
16 
17 #include "resources.h"
18 #include "signaling.h"
19 
20 
21 #undef WAIT_FOR_DEMON		/* #define this if system calls on SVC sockets
22 				   should block until the demon runs.
23 				   Danger: may cause nasty hangs if the demon
24 				   crashes. */
25 
26 #if 0
27 #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
28 #else
29 #define DPRINTK(format,args...)
30 #endif
31 
32 
33 struct atm_vcc *sigd = NULL;
34 #ifdef WAIT_FOR_DEMON
35 static DECLARE_WAIT_QUEUE_HEAD(sigd_sleep);
36 #endif
37 
38 
39 static void sigd_put_skb(struct sk_buff *skb)
40 {
41 #ifdef WAIT_FOR_DEMON
42 	static unsigned long silence;
43 	DECLARE_WAITQUEUE(wait,current);
44 
45 	add_wait_queue(&sigd_sleep,&wait);
46 	while (!sigd) {
47 		set_current_state(TASK_UNINTERRUPTIBLE);
48 		if (time_after(jiffies, silence) || silence == 0) {
49 			printk(KERN_INFO "atmsvc: waiting for signaling demon "
50 			    "...\n");
51 			silence = (jiffies+30*HZ)|1;
52 		}
53 		schedule();
54 	}
55 	current->state = TASK_RUNNING;
56 	remove_wait_queue(&sigd_sleep,&wait);
57 #else
58 	if (!sigd) {
59 		printk(KERN_WARNING "atmsvc: no signaling demon\n");
60 		kfree_skb(skb);
61 		return;
62 	}
63 #endif
64 	atm_force_charge(sigd,skb->truesize);
65 	skb_queue_tail(&sk_atm(sigd)->sk_receive_queue,skb);
66 	sk_atm(sigd)->sk_data_ready(sk_atm(sigd), skb->len);
67 }
68 
69 
70 static void modify_qos(struct atm_vcc *vcc,struct atmsvc_msg *msg)
71 {
72 	struct sk_buff *skb;
73 
74 	if (test_bit(ATM_VF_RELEASED,&vcc->flags) ||
75 	    !test_bit(ATM_VF_READY,&vcc->flags))
76 		return;
77 	msg->type = as_error;
78 	if (!vcc->dev->ops->change_qos) msg->reply = -EOPNOTSUPP;
79 	else {
80 		/* should lock VCC */
81 		msg->reply = vcc->dev->ops->change_qos(vcc,&msg->qos,
82 		    msg->reply);
83 		if (!msg->reply) msg->type = as_okay;
84 	}
85 	/*
86 	 * Should probably just turn around the old skb. But the, the buffer
87 	 * space accounting needs to follow the change too. Maybe later.
88 	 */
89 	while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))
90 		schedule();
91 	*(struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg)) = *msg;
92 	sigd_put_skb(skb);
93 }
94 
95 
96 static int sigd_send(struct atm_vcc *vcc,struct sk_buff *skb)
97 {
98 	struct atmsvc_msg *msg;
99 	struct atm_vcc *session_vcc;
100 	struct sock *sk;
101 
102 	msg = (struct atmsvc_msg *) skb->data;
103 	atomic_sub(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
104 	DPRINTK("sigd_send %d (0x%lx)\n",(int) msg->type,
105 	  (unsigned long) msg->vcc);
106 	vcc = *(struct atm_vcc **) &msg->vcc;
107 	sk = sk_atm(vcc);
108 
109 	switch (msg->type) {
110 		case as_okay:
111 			sk->sk_err = -msg->reply;
112 			clear_bit(ATM_VF_WAITING, &vcc->flags);
113 			if (!*vcc->local.sas_addr.prv &&
114 			    !*vcc->local.sas_addr.pub) {
115 				vcc->local.sas_family = AF_ATMSVC;
116 				memcpy(vcc->local.sas_addr.prv,
117 				    msg->local.sas_addr.prv,ATM_ESA_LEN);
118 				memcpy(vcc->local.sas_addr.pub,
119 				    msg->local.sas_addr.pub,ATM_E164_LEN+1);
120 			}
121 			session_vcc = vcc->session ? vcc->session : vcc;
122 			if (session_vcc->vpi || session_vcc->vci) break;
123 			session_vcc->itf = msg->pvc.sap_addr.itf;
124 			session_vcc->vpi = msg->pvc.sap_addr.vpi;
125 			session_vcc->vci = msg->pvc.sap_addr.vci;
126 			if (session_vcc->vpi || session_vcc->vci)
127 				session_vcc->qos = msg->qos;
128 			break;
129 		case as_error:
130 			clear_bit(ATM_VF_REGIS,&vcc->flags);
131 			clear_bit(ATM_VF_READY,&vcc->flags);
132 			sk->sk_err = -msg->reply;
133 			clear_bit(ATM_VF_WAITING, &vcc->flags);
134 			break;
135 		case as_indicate:
136 			vcc = *(struct atm_vcc **) &msg->listen_vcc;
137 			sk = sk_atm(vcc);
138 			DPRINTK("as_indicate!!!\n");
139 			lock_sock(sk);
140 			if (sk_acceptq_is_full(sk)) {
141 				sigd_enq(NULL,as_reject,vcc,NULL,NULL);
142 				dev_kfree_skb(skb);
143 				goto as_indicate_complete;
144 			}
145 			sk->sk_ack_backlog++;
146 			skb_queue_tail(&sk->sk_receive_queue, skb);
147 			DPRINTK("waking sk->sk_sleep 0x%p\n", sk->sk_sleep);
148 			sk->sk_state_change(sk);
149 as_indicate_complete:
150 			release_sock(sk);
151 			return 0;
152 		case as_close:
153 			set_bit(ATM_VF_RELEASED,&vcc->flags);
154 			vcc_release_async(vcc, msg->reply);
155 			goto out;
156 		case as_modify:
157 			modify_qos(vcc,msg);
158 			break;
159 		case as_addparty:
160 		case as_dropparty:
161 			sk->sk_err_soft = msg->reply;	/* < 0 failure, otherwise ep_ref */
162 			clear_bit(ATM_VF_WAITING, &vcc->flags);
163 			break;
164 		default:
165 			printk(KERN_ALERT "sigd_send: bad message type %d\n",
166 			    (int) msg->type);
167 			return -EINVAL;
168 	}
169 	sk->sk_state_change(sk);
170 out:
171 	dev_kfree_skb(skb);
172 	return 0;
173 }
174 
175 
176 void sigd_enq2(struct atm_vcc *vcc,enum atmsvc_msg_type type,
177     struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
178     const struct sockaddr_atmsvc *svc,const struct atm_qos *qos,int reply)
179 {
180 	struct sk_buff *skb;
181 	struct atmsvc_msg *msg;
182 	static unsigned session = 0;
183 
184 	DPRINTK("sigd_enq %d (0x%p)\n",(int) type,vcc);
185 	while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))
186 		schedule();
187 	msg = (struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg));
188 	memset(msg,0,sizeof(*msg));
189 	msg->type = type;
190 	*(struct atm_vcc **) &msg->vcc = vcc;
191 	*(struct atm_vcc **) &msg->listen_vcc = listen_vcc;
192 	msg->reply = reply;
193 	if (qos) msg->qos = *qos;
194 	if (vcc) msg->sap = vcc->sap;
195 	if (svc) msg->svc = *svc;
196 	if (vcc) msg->local = vcc->local;
197 	if (pvc) msg->pvc = *pvc;
198 	if (vcc) {
199 		if (type == as_connect && test_bit(ATM_VF_SESSION, &vcc->flags))
200 			msg->session = ++session;
201 			/* every new pmp connect gets the next session number */
202 	}
203 	sigd_put_skb(skb);
204 	if (vcc) set_bit(ATM_VF_REGIS,&vcc->flags);
205 }
206 
207 
208 void sigd_enq(struct atm_vcc *vcc,enum atmsvc_msg_type type,
209     struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
210     const struct sockaddr_atmsvc *svc)
211 {
212 	sigd_enq2(vcc,type,listen_vcc,pvc,svc,vcc ? &vcc->qos : NULL,0);
213 	/* other ISP applications may use "reply" */
214 }
215 
216 
217 static void purge_vcc(struct atm_vcc *vcc)
218 {
219 	if (sk_atm(vcc)->sk_family == PF_ATMSVC &&
220 	    !test_bit(ATM_VF_META, &vcc->flags)) {
221 		set_bit(ATM_VF_RELEASED, &vcc->flags);
222 		clear_bit(ATM_VF_REGIS, &vcc->flags);
223 		vcc_release_async(vcc, -EUNATCH);
224 	}
225 }
226 
227 
228 static void sigd_close(struct atm_vcc *vcc)
229 {
230 	struct hlist_node *node;
231 	struct sock *s;
232 	int i;
233 
234 	DPRINTK("sigd_close\n");
235 	sigd = NULL;
236 	if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
237 		printk(KERN_ERR "sigd_close: closing with requests pending\n");
238 	skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
239 
240 	read_lock(&vcc_sklist_lock);
241 	for(i = 0; i < VCC_HTABLE_SIZE; ++i) {
242 		struct hlist_head *head = &vcc_hash[i];
243 
244 		sk_for_each(s, node, head) {
245 			struct atm_vcc *vcc = atm_sk(s);
246 
247 			purge_vcc(vcc);
248 		}
249 	}
250 	read_unlock(&vcc_sklist_lock);
251 }
252 
253 
254 static struct atmdev_ops sigd_dev_ops = {
255 	.close = sigd_close,
256 	.send =	sigd_send
257 };
258 
259 
260 static struct atm_dev sigd_dev = {
261 	.ops =		&sigd_dev_ops,
262 	.type =		"sig",
263 	.number =	999,
264 	.lock =		SPIN_LOCK_UNLOCKED
265 };
266 
267 
268 int sigd_attach(struct atm_vcc *vcc)
269 {
270 	if (sigd) return -EADDRINUSE;
271 	DPRINTK("sigd_attach\n");
272 	sigd = vcc;
273 	vcc->dev = &sigd_dev;
274 	vcc_insert_socket(sk_atm(vcc));
275 	set_bit(ATM_VF_META,&vcc->flags);
276 	set_bit(ATM_VF_READY,&vcc->flags);
277 #ifdef WAIT_FOR_DEMON
278 	wake_up(&sigd_sleep);
279 #endif
280 	return 0;
281 }
282