mqprio: Avoid panic if no options are provided
[linux-2.6.git] / net / atm / signaling.c
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
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
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
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
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
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
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
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
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 }