File: /usr/src/linux/net/atm/signaling.c
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 static DECLARE_WAIT_QUEUE_HEAD(sigd_sleep);
35
36 extern spinlock_t atm_dev_lock;
37
38 static void sigd_put_skb(struct sk_buff *skb)
39 {
40 #ifdef WAIT_FOR_DEMON
41 static unsigned long silence = 0;
42 DECLARE_WAITQUEUE(wait,current);
43
44 add_wait_queue(&sigd_sleep,&wait);
45 while (!sigd) {
46 set_current_state(TASK_UNINTERRUPTIBLE);
47 if (time_after(jiffies, silence) || silence == 0) {
48 printk(KERN_INFO "atmsvc: waiting for signaling demon "
49 "...\n");
50 silence = (jiffies+30*HZ)|1;
51 }
52 schedule();
53 }
54 current->state = TASK_RUNNING;
55 remove_wait_queue(&sigd_sleep,&wait);
56 #else
57 if (!sigd) {
58 printk(KERN_WARNING "atmsvc: no signaling demon\n");
59 kfree_skb(skb);
60 return;
61 }
62 #endif
63 atm_force_charge(sigd,skb->truesize);
64 skb_queue_tail(&sigd->recvq,skb);
65 wake_up(&sigd->sleep);
66 }
67
68
69 static void modify_qos(struct atm_vcc *vcc,struct atmsvc_msg *msg)
70 {
71 struct sk_buff *skb;
72
73 if (test_bit(ATM_VF_RELEASED,&vcc->flags) ||
74 !test_bit(ATM_VF_READY,&vcc->flags))
75 return;
76 msg->type = as_error;
77 if (!vcc->dev->ops->change_qos) msg->reply = -EOPNOTSUPP;
78 else {
79 /* should lock VCC */
80 msg->reply = vcc->dev->ops->change_qos(vcc,&msg->qos,
81 msg->reply);
82 if (!msg->reply) msg->type = as_okay;
83 }
84 /*
85 * Should probably just turn around the old skb. But the, the buffer
86 * space accounting needs to follow the change too. Maybe later.
87 */
88 while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))
89 schedule();
90 *(struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg)) = *msg;
91 sigd_put_skb(skb);
92 }
93
94
95 static int sigd_send(struct atm_vcc *vcc,struct sk_buff *skb)
96 {
97 struct atmsvc_msg *msg;
98 struct atm_vcc *session_vcc;
99
100 msg = (struct atmsvc_msg *) skb->data;
101 atomic_sub(skb->truesize+ATM_PDU_OVHD,&vcc->tx_inuse);
102 DPRINTK("sigd_send %d (0x%lx)\n",(int) msg->type,
103 (unsigned long) msg->vcc);
104 vcc = *(struct atm_vcc **) &msg->vcc;
105 switch (msg->type) {
106 case as_okay:
107 vcc->reply = msg->reply;
108 if (!*vcc->local.sas_addr.prv &&
109 !*vcc->local.sas_addr.pub) {
110 vcc->local.sas_family = AF_ATMSVC;
111 memcpy(vcc->local.sas_addr.prv,
112 msg->local.sas_addr.prv,ATM_ESA_LEN);
113 memcpy(vcc->local.sas_addr.pub,
114 msg->local.sas_addr.pub,ATM_E164_LEN+1);
115 }
116 session_vcc = vcc->session ? vcc->session : vcc;
117 if (session_vcc->vpi || session_vcc->vci) break;
118 session_vcc->itf = msg->pvc.sap_addr.itf;
119 session_vcc->vpi = msg->pvc.sap_addr.vpi;
120 session_vcc->vci = msg->pvc.sap_addr.vci;
121 if (session_vcc->vpi || session_vcc->vci)
122 session_vcc->qos = msg->qos;
123 break;
124 case as_error:
125 clear_bit(ATM_VF_REGIS,&vcc->flags);
126 clear_bit(ATM_VF_READY,&vcc->flags);
127 vcc->reply = msg->reply;
128 break;
129 case as_indicate:
130 vcc = *(struct atm_vcc **) &msg->listen_vcc;
131 DPRINTK("as_indicate!!!\n");
132 if (!vcc->backlog_quota) {
133 sigd_enq(0,as_reject,vcc,NULL,NULL);
134 return 0;
135 }
136 vcc->backlog_quota--;
137 skb_queue_tail(&vcc->listenq,skb);
138 if (vcc->callback) {
139 DPRINTK("waking vcc->sleep 0x%p\n",
140 &vcc->sleep);
141 vcc->callback(vcc);
142 }
143 return 0;
144 case as_close:
145 set_bit(ATM_VF_RELEASED,&vcc->flags);
146 clear_bit(ATM_VF_READY,&vcc->flags);
147 vcc->reply = msg->reply;
148 break;
149 case as_modify:
150 modify_qos(vcc,msg);
151 break;
152 default:
153 printk(KERN_ALERT "sigd_send: bad message type %d\n",
154 (int) msg->type);
155 return -EINVAL;
156 }
157 if (vcc->callback) vcc->callback(vcc);
158 dev_kfree_skb(skb);
159 return 0;
160 }
161
162
163 void sigd_enq2(struct atm_vcc *vcc,enum atmsvc_msg_type type,
164 struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
165 const struct sockaddr_atmsvc *svc,const struct atm_qos *qos,int reply)
166 {
167 struct sk_buff *skb;
168 struct atmsvc_msg *msg;
169
170 DPRINTK("sigd_enq %d (0x%p)\n",(int) type,vcc);
171 while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))
172 schedule();
173 msg = (struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg));
174 memset(msg,0,sizeof(*msg));
175 msg->type = type;
176 *(struct atm_vcc **) &msg->vcc = vcc;
177 *(struct atm_vcc **) &msg->listen_vcc = listen_vcc;
178 msg->reply = reply;
179 if (qos) msg->qos = *qos;
180 if (vcc) msg->sap = vcc->sap;
181 if (svc) msg->svc = *svc;
182 if (vcc) msg->local = vcc->local;
183 if (pvc) msg->pvc = *pvc;
184 sigd_put_skb(skb);
185 if (vcc) set_bit(ATM_VF_REGIS,&vcc->flags);
186 }
187
188
189 void sigd_enq(struct atm_vcc *vcc,enum atmsvc_msg_type type,
190 struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
191 const struct sockaddr_atmsvc *svc)
192 {
193 sigd_enq2(vcc,type,listen_vcc,pvc,svc,vcc ? &vcc->qos : NULL,0);
194 /* other ISP applications may use "reply" */
195 }
196
197
198 static void purge_vccs(struct atm_vcc *vcc)
199 {
200 while (vcc) {
201 if (vcc->family == PF_ATMSVC &&
202 !test_bit(ATM_VF_META,&vcc->flags)) {
203 set_bit(ATM_VF_RELEASED,&vcc->flags);
204 vcc->reply = -EUNATCH;
205 wake_up(&vcc->sleep);
206 }
207 vcc = vcc->next;
208 }
209 }
210
211
212 static void sigd_close(struct atm_vcc *vcc)
213 {
214 struct atm_dev *dev;
215
216 DPRINTK("sigd_close\n");
217 sigd = NULL;
218 if (skb_peek(&vcc->recvq))
219 printk(KERN_ERR "sigd_close: closing with requests pending\n");
220 skb_queue_purge(&vcc->recvq);
221 purge_vccs(nodev_vccs);
222
223 spin_lock (&atm_dev_lock);
224 for (dev = atm_devs; dev; dev = dev->next) purge_vccs(dev->vccs);
225 spin_unlock (&atm_dev_lock);
226 }
227
228
229 static struct atmdev_ops sigd_dev_ops = {
230 close: sigd_close,
231 send: sigd_send
232 };
233
234
235 static struct atm_dev sigd_dev = {
236 &sigd_dev_ops,
237 NULL, /* no PHY */
238 "sig", /* type */
239 999, /* dummy device number */
240 NULL,NULL, /* pretend not to have any VCCs */
241 NULL,NULL, /* no data */
242 { 0 }, /* no flags */
243 NULL, /* no local address */
244 { 0 } /* no ESI, no statistics */
245 };
246
247
248 int sigd_attach(struct atm_vcc *vcc)
249 {
250 if (sigd) return -EADDRINUSE;
251 DPRINTK("sigd_attach\n");
252 sigd = vcc;
253 bind_vcc(vcc,&sigd_dev);
254 set_bit(ATM_VF_META,&vcc->flags);
255 set_bit(ATM_VF_READY,&vcc->flags);
256 wake_up(&sigd_sleep);
257 return 0;
258 }
259