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 #ifdef WAIT_FOR_DEMON
  35 static DECLARE_WAIT_QUEUE_HEAD(sigd_sleep);
  36 #endif
  37
  38
  39 static void sigd_put_skb(struct sk_buff *skb)
  40 {
  41 #ifdef WAIT_FOR_DEMON
  42         DECLARE_WAITQUEUE(wait,current);
  43
  44         add_wait_queue(&sigd_sleep,&wait);
  45         while (!sigd) {
  46                 set_current_state(TASK_UNINTERRUPTIBLE);
  47                 DPRINTK("atmsvc: waiting for signaling demon...\n");
  48                 schedule();
  49         }
  50         current->state = TASK_RUNNING;
  51         remove_wait_queue(&sigd_sleep,&wait);
  52 #else
  53         if (!sigd) {
  54                 DPRINTK("atmsvc: no signaling demon\n");
  55                 kfree_skb(skb);
  56                 return;
  57         }
  58 #endif
  59         atm_force_charge(sigd,skb->truesize);
  60         skb_queue_tail(&sk_atm(sigd)->sk_receive_queue,skb);
  61         sk_atm(sigd)->sk_data_ready(sk_atm(sigd), skb->len);
  62 }
  63
  64
  65 static void modify_qos(struct atm_vcc *vcc,struct atmsvc_msg *msg)
  66 {
  67         struct sk_buff *skb;
  68
  69         if (test_bit(ATM_VF_RELEASED,&vcc->flags) ||
  70             !test_bit(ATM_VF_READY,&vcc->flags))
  71                 return;
  72         msg->type = as_error;
  73         if (!vcc->dev->ops->change_qos) msg->reply = -EOPNOTSUPP;
  74         else {
  75                 /* should lock VCC */
  76                 msg->reply = vcc->dev->ops->change_qos(vcc,&msg->qos,
  77                     msg->reply);
  78                 if (!msg->reply) msg->type = as_okay;
  79         }
  80         /*
  81          * Should probably just turn around the old skb. But the, the buffer
  82          * space accounting needs to follow the change too. Maybe later.
  83          */
  84         while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))
  85                 schedule();
  86         *(struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg)) = *msg;
  87         sigd_put_skb(skb);
  88 }
  89
  90
  91 static int sigd_send(struct atm_vcc *vcc,struct sk_buff *skb)
  92 {
  93         struct atmsvc_msg *msg;
  94         struct atm_vcc *session_vcc;
  95         struct sock *sk;
  96
  97         msg = (struct atmsvc_msg *) skb->data;
  98         atomic_sub(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
  99         DPRINTK("sigd_send %d (0x%lx)\n",(int) msg->type,
 100           (unsigned long) msg->vcc);
 101         vcc = *(struct atm_vcc **) &msg->vcc;
 102         sk = sk_atm(vcc);
 103
 104         switch (msg->type) {
 105                 case as_okay:
 106                         sk->sk_err = -msg->reply;
 107                         clear_bit(ATM_VF_WAITING, &vcc->flags);
 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                         sk->sk_err = -msg->reply;
 128                         clear_bit(ATM_VF_WAITING, &vcc->flags);
 129                         break;
 130                 case as_indicate:
 131                         vcc = *(struct atm_vcc **) &msg->listen_vcc;
 132                         sk = sk_atm(vcc);
 133                         DPRINTK("as_indicate!!!\n");
 134                         lock_sock(sk);
 135                         if (sk_acceptq_is_full(sk)) {
 136                                 sigd_enq(NULL,as_reject,vcc,NULL,NULL);
 137                                 dev_kfree_skb(skb);
 138                                 goto as_indicate_complete;
 139                         }
 140                         sk->sk_ack_backlog++;
 141                         skb_queue_tail(&sk->sk_receive_queue, skb);
 142                         DPRINTK("waking sk->sk_sleep 0x%p\n", sk->sk_sleep);
 143                         sk->sk_state_change(sk);
 144 as_indicate_complete:
 145                         release_sock(sk);
 146                         return 0;
 147                 case as_close:
 148                         set_bit(ATM_VF_RELEASED,&vcc->flags);
 149                         vcc_release_async(vcc, msg->reply);
 150                         goto out;
 151                 case as_modify:
 152                         modify_qos(vcc,msg);
 153                         break;
 154                 case as_addparty:
 155                 case as_dropparty:
 156                         sk->sk_err_soft = msg->reply;   /* < 0 failure, otherwise ep_ref */
 157                         clear_bit(ATM_VF_WAITING, &vcc->flags);
 158                         break;
 159                 default:
 160                         printk(KERN_ALERT "sigd_send: bad message type %d\n",
 161                             (int) msg->type);
 162                         return -EINVAL;
 163         }
 164         sk->sk_state_change(sk);
 165 out:
 166         dev_kfree_skb(skb);
 167         return 0;
 168 }
 169
 170
 171 void sigd_enq2(struct atm_vcc *vcc,enum atmsvc_msg_type type,
 172     struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
 173     const struct sockaddr_atmsvc *svc,const struct atm_qos *qos,int reply)
 174 {
 175         struct sk_buff *skb;
 176         struct atmsvc_msg *msg;
 177         static unsigned session = 0;
 178
 179         DPRINTK("sigd_enq %d (0x%p)\n",(int) type,vcc);
 180         while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))
 181                 schedule();
 182         msg = (struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg));
 183         memset(msg,0,sizeof(*msg));
 184         msg->type = type;
 185         *(struct atm_vcc **) &msg->vcc = vcc;
 186         *(struct atm_vcc **) &msg->listen_vcc = listen_vcc;
 187         msg->reply = reply;
 188         if (qos) msg->qos = *qos;
 189         if (vcc) msg->sap = vcc->sap;
 190         if (svc) msg->svc = *svc;
 191         if (vcc) msg->local = vcc->local;
 192         if (pvc) msg->pvc = *pvc;
 193         if (vcc) {
 194                 if (type == as_connect && test_bit(ATM_VF_SESSION, &vcc->flags))
 195                         msg->session = ++session;
 196                         /* every new pmp connect gets the next session number */
 197         }
 198         sigd_put_skb(skb);
 199         if (vcc) set_bit(ATM_VF_REGIS,&vcc->flags);
 200 }
 201
 202
 203 void sigd_enq(struct atm_vcc *vcc,enum atmsvc_msg_type type,
 204     struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
 205     const struct sockaddr_atmsvc *svc)
 206 {
 207         sigd_enq2(vcc,type,listen_vcc,pvc,svc,vcc ? &vcc->qos : NULL,0);
 208         /* other ISP applications may use "reply" */
 209 }
 210
 211
 212 static void purge_vcc(struct atm_vcc *vcc)
 213 {
 214         if (sk_atm(vcc)->sk_family == PF_ATMSVC &&
 215             !test_bit(ATM_VF_META, &vcc->flags)) {
 216                 set_bit(ATM_VF_RELEASED, &vcc->flags);
 217                 clear_bit(ATM_VF_REGIS, &vcc->flags);
 218                 vcc_release_async(vcc, -EUNATCH);
 219         }
 220 }
 221
 222
 223 static void sigd_close(struct atm_vcc *vcc)
 224 {
 225         struct hlist_node *node;
 226         struct sock *s;
 227         int i;
 228
 229         DPRINTK("sigd_close\n");
 230         sigd = NULL;
 231         if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
 232                 printk(KERN_ERR "sigd_close: closing with requests pending\n");
 233         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 234
 235         read_lock(&vcc_sklist_lock);
 236         for(i = 0; i < VCC_HTABLE_SIZE; ++i) {
 237                 struct hlist_head *head = &vcc_hash[i];
 238
 239                 sk_for_each(s, node, head) {
 240                         struct atm_vcc *vcc = atm_sk(s);
 241
 242                         purge_vcc(vcc);
 243                 }
 244         }
 245         read_unlock(&vcc_sklist_lock);
 246 }
 247
 248
 249 static struct atmdev_ops sigd_dev_ops = {
 250         .close = sigd_close,
 251         .send = sigd_send
 252 };
 253
 254
 255 static struct atm_dev sigd_dev = {
 256         .ops =          &sigd_dev_ops,
 257         .type =         "sig",
 258         .number =       999,
 259         .lock =         SPIN_LOCK_UNLOCKED
 260 };
 261
 262
 263 int sigd_attach(struct atm_vcc *vcc)
 264 {
 265         if (sigd) return -EADDRINUSE;
 266         DPRINTK("sigd_attach\n");
 267         sigd = vcc;
 268         vcc->dev = &sigd_dev;
 269         vcc_insert_socket(sk_atm(vcc));
 270         set_bit(ATM_VF_META,&vcc->flags);
 271         set_bit(ATM_VF_READY,&vcc->flags);
 272 #ifdef WAIT_FOR_DEMON
 273         wake_up(&sigd_sleep);
 274 #endif
 275         return 0;
 276 }