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 static DECLARE_WAIT_QUEUE_HEAD(sigd_sleep);
  35
  36
  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
  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
  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
 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
 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
 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
 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
 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 }