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