1 /* net/atm/signaling.c - ATM signaling */
2
3 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
4
5 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
6
7 #include <linux/errno.h> /* error codes */
8 #include <linux/kernel.h> /* printk */
9 #include <linux/skbuff.h>
10 #include <linux/wait.h>
11 #include <linux/sched.h> /* jiffies and HZ */
12 #include <linux/atm.h> /* ATM stuff */
13 #include <linux/atmsap.h>
14 #include <linux/atmsvc.h>
15 #include <linux/atmdev.h>
16 #include <linux/bitops.h>
17 #include <linux/slab.h>
18
19 #include "resources.h"
20 #include "signaling.h"
21
22 #undef WAIT_FOR_DEMON /* #define this if system calls on SVC sockets
23 should block until the demon runs.
24 Danger: may cause nasty hangs if the demon
25 crashes. */
26
27 struct atm_vcc *sigd = NULL;
28 #ifdef WAIT_FOR_DEMON
29 static DECLARE_WAIT_QUEUE_HEAD(sigd_sleep);
30 #endif
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 daemon...\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 daemon\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
modify_qos(struct atm_vcc * vcc,struct atmsvc_msg * msg)57 static void modify_qos(struct atm_vcc *vcc, struct atmsvc_msg *msg)
58 {
59 struct sk_buff *skb;
60
61 if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
62 !test_bit(ATM_VF_READY, &vcc->flags))
63 return;
64 msg->type = as_error;
65 if (!vcc->dev->ops->change_qos)
66 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)
72 msg->type = as_okay;
73 }
74 /*
75 * Should probably just turn around the old skb. But the, the buffer
76 * space accounting needs to follow the change too. Maybe later.
77 */
78 while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL)))
79 schedule();
80 *(struct atmsvc_msg *)skb_put(skb, sizeof(struct atmsvc_msg)) = *msg;
81 sigd_put_skb(skb);
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("%d (0x%lx)\n", (int)msg->type, (unsigned long)vcc);
94 sk = sk_atm(vcc);
95
96 switch (msg->type) {
97 case as_okay:
98 sk->sk_err = -msg->reply;
99 clear_bit(ATM_VF_WAITING, &vcc->flags);
100 if (!*vcc->local.sas_addr.prv && !*vcc->local.sas_addr.pub) {
101 vcc->local.sas_family = AF_ATMSVC;
102 memcpy(vcc->local.sas_addr.prv,
103 msg->local.sas_addr.prv, ATM_ESA_LEN);
104 memcpy(vcc->local.sas_addr.pub,
105 msg->local.sas_addr.pub, ATM_E164_LEN + 1);
106 }
107 session_vcc = vcc->session ? vcc->session : vcc;
108 if (session_vcc->vpi || session_vcc->vci)
109 break;
110 session_vcc->itf = msg->pvc.sap_addr.itf;
111 session_vcc->vpi = msg->pvc.sap_addr.vpi;
112 session_vcc->vci = msg->pvc.sap_addr.vci;
113 if (session_vcc->vpi || session_vcc->vci)
114 session_vcc->qos = msg->qos;
115 break;
116 case as_error:
117 clear_bit(ATM_VF_REGIS, &vcc->flags);
118 clear_bit(ATM_VF_READY, &vcc->flags);
119 sk->sk_err = -msg->reply;
120 clear_bit(ATM_VF_WAITING, &vcc->flags);
121 break;
122 case as_indicate:
123 vcc = *(struct atm_vcc **)&msg->listen_vcc;
124 sk = sk_atm(vcc);
125 pr_debug("as_indicate!!!\n");
126 lock_sock(sk);
127 if (sk_acceptq_is_full(sk)) {
128 sigd_enq(NULL, as_reject, vcc, NULL, NULL);
129 dev_kfree_skb(skb);
130 goto as_indicate_complete;
131 }
132 sk->sk_ack_backlog++;
133 skb_queue_tail(&sk->sk_receive_queue, skb);
134 pr_debug("waking sk_sleep(sk) 0x%p\n", sk_sleep(sk));
135 sk->sk_state_change(sk);
136 as_indicate_complete:
137 release_sock(sk);
138 return 0;
139 case as_close:
140 set_bit(ATM_VF_RELEASED, &vcc->flags);
141 vcc_release_async(vcc, msg->reply);
142 goto out;
143 case as_modify:
144 modify_qos(vcc, msg);
145 break;
146 case as_addparty:
147 case as_dropparty:
148 sk->sk_err_soft = msg->reply;
149 /* < 0 failure, otherwise ep_ref */
150 clear_bit(ATM_VF_WAITING, &vcc->flags);
151 break;
152 default:
153 pr_alert("bad message type %d\n", (int)msg->type);
154 return -EINVAL;
155 }
156 sk->sk_state_change(sk);
157 out:
158 dev_kfree_skb(skb);
159 return 0;
160 }
161
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)162 void sigd_enq2(struct atm_vcc *vcc, enum atmsvc_msg_type type,
163 struct atm_vcc *listen_vcc, const struct sockaddr_atmpvc *pvc,
164 const struct sockaddr_atmsvc *svc, const struct atm_qos *qos,
165 int reply)
166 {
167 struct sk_buff *skb;
168 struct atmsvc_msg *msg;
169 static unsigned session = 0;
170
171 pr_debug("%d (0x%p)\n", (int)type, vcc);
172 while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL)))
173 schedule();
174 msg = (struct atmsvc_msg *)skb_put(skb, sizeof(struct atmsvc_msg));
175 memset(msg, 0, sizeof(*msg));
176 msg->type = type;
177 *(struct atm_vcc **) &msg->vcc = vcc;
178 *(struct atm_vcc **) &msg->listen_vcc = listen_vcc;
179 msg->reply = reply;
180 if (qos)
181 msg->qos = *qos;
182 if (vcc)
183 msg->sap = vcc->sap;
184 if (svc)
185 msg->svc = *svc;
186 if (vcc)
187 msg->local = vcc->local;
188 if (pvc)
189 msg->pvc = *pvc;
190 if (vcc) {
191 if (type == as_connect && test_bit(ATM_VF_SESSION, &vcc->flags))
192 msg->session = ++session;
193 /* every new pmp connect gets the next session number */
194 }
195 sigd_put_skb(skb);
196 if (vcc)
197 set_bit(ATM_VF_REGIS, &vcc->flags);
198 }
199
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)200 void sigd_enq(struct atm_vcc *vcc, enum atmsvc_msg_type type,
201 struct atm_vcc *listen_vcc, const struct sockaddr_atmpvc *pvc,
202 const struct sockaddr_atmsvc *svc)
203 {
204 sigd_enq2(vcc, type, listen_vcc, pvc, svc, vcc ? &vcc->qos : NULL, 0);
205 /* other ISP applications may use "reply" */
206 }
207
purge_vcc(struct atm_vcc * vcc)208 static void purge_vcc(struct atm_vcc *vcc)
209 {
210 if (sk_atm(vcc)->sk_family == PF_ATMSVC &&
211 !test_bit(ATM_VF_META, &vcc->flags)) {
212 set_bit(ATM_VF_RELEASED, &vcc->flags);
213 clear_bit(ATM_VF_REGIS, &vcc->flags);
214 vcc_release_async(vcc, -EUNATCH);
215 }
216 }
217
sigd_close(struct atm_vcc * vcc)218 static void sigd_close(struct atm_vcc *vcc)
219 {
220 struct hlist_node *node;
221 struct sock *s;
222 int i;
223
224 pr_debug("\n");
225 sigd = NULL;
226 if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
227 pr_err("closing with requests pending\n");
228 skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
229
230 read_lock(&vcc_sklist_lock);
231 for (i = 0; i < VCC_HTABLE_SIZE; ++i) {
232 struct hlist_head *head = &vcc_hash[i];
233
234 sk_for_each(s, node, head) {
235 vcc = atm_sk(s);
236
237 purge_vcc(vcc);
238 }
239 }
240 read_unlock(&vcc_sklist_lock);
241 }
242
243 static struct atmdev_ops sigd_dev_ops = {
244 .close = sigd_close,
245 .send = sigd_send
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
sigd_attach(struct atm_vcc * vcc)255 int sigd_attach(struct atm_vcc *vcc)
256 {
257 if (sigd)
258 return -EADDRINUSE;
259 pr_debug("\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