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