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
sigd_put_skb(struct sk_buff * skb)37 static void sigd_put_skb(struct sk_buff *skb)
38 {
39 #ifdef WAIT_FOR_DEMON
40 static unsigned long silence = 0;
41 DECLARE_WAITQUEUE(wait,current);
42
43 add_wait_queue(&sigd_sleep,&wait);
44 while (!sigd) {
45 set_current_state(TASK_UNINTERRUPTIBLE);
46 if (time_after(jiffies, silence) || silence == 0) {
47 printk(KERN_INFO "atmsvc: waiting for signaling demon "
48 "...\n");
49 silence = (jiffies+30*HZ)|1;
50 }
51 schedule();
52 }
53 current->state = TASK_RUNNING;
54 remove_wait_queue(&sigd_sleep,&wait);
55 #else
56 if (!sigd) {
57 printk(KERN_WARNING "atmsvc: no signaling demon\n");
58 kfree_skb(skb);
59 return;
60 }
61 #endif
62 atm_force_charge(sigd,skb->truesize);
63 skb_queue_tail(&sigd->sk->receive_queue,skb);
64 wake_up(&sigd->sleep);
65 }
66
67
modify_qos(struct atm_vcc * vcc,struct atmsvc_msg * msg)68 static void modify_qos(struct atm_vcc *vcc,struct atmsvc_msg *msg)
69 {
70 struct sk_buff *skb;
71
72 if (test_bit(ATM_VF_RELEASED,&vcc->flags) ||
73 !test_bit(ATM_VF_READY,&vcc->flags))
74 return;
75 msg->type = as_error;
76 if (!vcc->dev->ops->change_qos) msg->reply = -EOPNOTSUPP;
77 else {
78 /* should lock VCC */
79 msg->reply = vcc->dev->ops->change_qos(vcc,&msg->qos,
80 msg->reply);
81 if (!msg->reply) msg->type = as_okay;
82 }
83 /*
84 * Should probably just turn around the old skb. But the, the buffer
85 * space accounting needs to follow the change too. Maybe later.
86 */
87 while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))
88 schedule();
89 *(struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg)) = *msg;
90 sigd_put_skb(skb);
91 }
92
93
sigd_send(struct atm_vcc * vcc,struct sk_buff * skb)94 static int sigd_send(struct atm_vcc *vcc,struct sk_buff *skb)
95 {
96 struct atmsvc_msg *msg;
97 struct atm_vcc *session_vcc;
98
99 msg = (struct atmsvc_msg *) skb->data;
100 atomic_sub(skb->truesize, &vcc->sk->wmem_alloc);
101 DPRINTK("sigd_send %d (0x%lx)\n",(int) msg->type,
102 (unsigned long) msg->vcc);
103 vcc = *(struct atm_vcc **) &msg->vcc;
104 switch (msg->type) {
105 case as_okay:
106 vcc->reply = msg->reply;
107 if (!*vcc->local.sas_addr.prv &&
108 !*vcc->local.sas_addr.pub) {
109 vcc->local.sas_family = AF_ATMSVC;
110 memcpy(vcc->local.sas_addr.prv,
111 msg->local.sas_addr.prv,ATM_ESA_LEN);
112 memcpy(vcc->local.sas_addr.pub,
113 msg->local.sas_addr.pub,ATM_E164_LEN+1);
114 }
115 session_vcc = vcc->session ? vcc->session : vcc;
116 if (session_vcc->vpi || session_vcc->vci) break;
117 session_vcc->itf = msg->pvc.sap_addr.itf;
118 session_vcc->vpi = msg->pvc.sap_addr.vpi;
119 session_vcc->vci = msg->pvc.sap_addr.vci;
120 if (session_vcc->vpi || session_vcc->vci)
121 session_vcc->qos = msg->qos;
122 break;
123 case as_error:
124 clear_bit(ATM_VF_REGIS,&vcc->flags);
125 clear_bit(ATM_VF_READY,&vcc->flags);
126 vcc->reply = msg->reply;
127 vcc->sk->err = -msg->reply;
128 break;
129 case as_indicate:
130 vcc = *(struct atm_vcc **) &msg->listen_vcc;
131 DPRINTK("as_indicate!!!\n");
132 lock_sock(vcc->sk);
133 if (vcc->sk->ack_backlog == vcc->sk->max_ack_backlog) {
134 sigd_enq(0,as_reject,vcc,NULL,NULL);
135 goto as_indicate_complete;
136 }
137 vcc->sk->ack_backlog++;
138 skb_queue_tail(&vcc->sk->receive_queue,skb);
139 if (vcc->callback) {
140 DPRINTK("waking vcc->sleep 0x%p\n",
141 &vcc->sleep);
142 vcc->callback(vcc);
143 }
144 as_indicate_complete:
145 release_sock(vcc->sk);
146 return 0;
147 case as_close:
148 set_bit(ATM_VF_RELEASED,&vcc->flags);
149 clear_bit(ATM_VF_READY,&vcc->flags);
150 vcc->reply = msg->reply;
151 vcc->sk->err = -msg->reply;
152 break;
153 case as_modify:
154 modify_qos(vcc,msg);
155 break;
156 default:
157 printk(KERN_ALERT "sigd_send: bad message type %d\n",
158 (int) msg->type);
159 return -EINVAL;
160 }
161 if (vcc->callback) vcc->callback(vcc);
162 dev_kfree_skb(skb);
163 return 0;
164 }
165
166
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)167 void sigd_enq2(struct atm_vcc *vcc,enum atmsvc_msg_type type,
168 struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
169 const struct sockaddr_atmsvc *svc,const struct atm_qos *qos,int reply)
170 {
171 struct sk_buff *skb;
172 struct atmsvc_msg *msg;
173
174 DPRINTK("sigd_enq %d (0x%p)\n",(int) type,vcc);
175 while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))
176 schedule();
177 msg = (struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg));
178 memset(msg,0,sizeof(*msg));
179 msg->type = type;
180 *(struct atm_vcc **) &msg->vcc = vcc;
181 *(struct atm_vcc **) &msg->listen_vcc = listen_vcc;
182 msg->reply = reply;
183 if (qos) msg->qos = *qos;
184 if (vcc) msg->sap = vcc->sap;
185 if (svc) msg->svc = *svc;
186 if (vcc) msg->local = vcc->local;
187 if (pvc) msg->pvc = *pvc;
188 sigd_put_skb(skb);
189 if (vcc) set_bit(ATM_VF_REGIS,&vcc->flags);
190 }
191
192
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)193 void sigd_enq(struct atm_vcc *vcc,enum atmsvc_msg_type type,
194 struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
195 const struct sockaddr_atmsvc *svc)
196 {
197 sigd_enq2(vcc,type,listen_vcc,pvc,svc,vcc ? &vcc->qos : NULL,0);
198 /* other ISP applications may use "reply" */
199 }
200
201
purge_vcc(struct atm_vcc * vcc)202 static void purge_vcc(struct atm_vcc *vcc)
203 {
204 if (vcc->sk->family == PF_ATMSVC &&
205 !test_bit(ATM_VF_META, &vcc->flags)) {
206 set_bit(ATM_VF_RELEASED, &vcc->flags);
207 vcc->reply = -EUNATCH;
208 vcc->sk->err = EUNATCH;
209 wake_up(&vcc->sleep);
210 }
211 }
212
213
sigd_close(struct atm_vcc * vcc)214 static void sigd_close(struct atm_vcc *vcc)
215 {
216 struct sock *s;
217
218 DPRINTK("sigd_close\n");
219 sigd = NULL;
220 if (skb_peek(&vcc->sk->receive_queue))
221 printk(KERN_ERR "sigd_close: closing with requests pending\n");
222 skb_queue_purge(&vcc->sk->receive_queue);
223
224 read_lock(&vcc_sklist_lock);
225 for(s = vcc_sklist; s; s = s->next) {
226 struct atm_vcc *vcc = s->protinfo.af_atm;
227
228 if (vcc->dev)
229 purge_vcc(vcc);
230 }
231 read_unlock(&vcc_sklist_lock);
232 }
233
234
235 static struct atmdev_ops sigd_dev_ops = {
236 .close = sigd_close,
237 .send = sigd_send
238 };
239
240
241 static struct atm_dev sigd_dev = {
242 .ops = &sigd_dev_ops,
243 .type = "sig",
244 .number = 999,
245 .lock = SPIN_LOCK_UNLOCKED
246 };
247
248
sigd_attach(struct atm_vcc * vcc)249 int sigd_attach(struct atm_vcc *vcc)
250 {
251 if (sigd) return -EADDRINUSE;
252 DPRINTK("sigd_attach\n");
253 sigd = vcc;
254 vcc->dev = &sigd_dev;
255 vcc_insert_socket(vcc->sk);
256 set_bit(ATM_VF_META,&vcc->flags);
257 set_bit(ATM_VF_READY,&vcc->flags);
258 wake_up(&sigd_sleep);
259 return 0;
260 }
261