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(&sk_atm(sigd)->sk_receive_queue,skb);
  66         sk_atm(sigd)->sk_data_ready(sk_atm(sigd), 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         struct sock *sk;
 101
 102         msg = (struct atmsvc_msg *) skb->data;
 103         atomic_sub(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
 104         DPRINTK("sigd_send %d (0x%lx)\n",(int) msg->type,
 105           (unsigned long) msg->vcc);
 106         vcc = *(struct atm_vcc **) &msg->vcc;
 107         sk = sk_atm(vcc);
 108
 109         switch (msg->type) {
 110                 case as_okay:
 111                         sk->sk_err = -msg->reply;
 112                         clear_bit(ATM_VF_WAITING, &vcc->flags);
 113                         if (!*vcc->local.sas_addr.prv &&
 114                             !*vcc->local.sas_addr.pub) {
 115                                 vcc->local.sas_family = AF_ATMSVC;
 116                                 memcpy(vcc->local.sas_addr.prv,
 117                                     msg->local.sas_addr.prv,ATM_ESA_LEN);
 118                                 memcpy(vcc->local.sas_addr.pub,
 119                                     msg->local.sas_addr.pub,ATM_E164_LEN+1);
 120                         }
 121                         session_vcc = vcc->session ? vcc->session : vcc;
 122                         if (session_vcc->vpi || session_vcc->vci) break;
 123                         session_vcc->itf = msg->pvc.sap_addr.itf;
 124                         session_vcc->vpi = msg->pvc.sap_addr.vpi;
 125                         session_vcc->vci = msg->pvc.sap_addr.vci;
 126                         if (session_vcc->vpi || session_vcc->vci)
 127                                 session_vcc->qos = msg->qos;
 128                         break;
 129                 case as_error:
 130                         clear_bit(ATM_VF_REGIS,&vcc->flags);
 131                         clear_bit(ATM_VF_READY,&vcc->flags);
 132                         sk->sk_err = -msg->reply;
 133                         clear_bit(ATM_VF_WAITING, &vcc->flags);
 134                         break;
 135                 case as_indicate:
 136                         vcc = *(struct atm_vcc **) &msg->listen_vcc;
 137                         sk = sk_atm(vcc);
 138                         DPRINTK("as_indicate!!!\n");
 139                         lock_sock(sk);
 140                         if (sk_acceptq_is_full(sk)) {
 141                                 sigd_enq(NULL,as_reject,vcc,NULL,NULL);
 142                                 dev_kfree_skb(skb);
 143                                 goto as_indicate_complete;
 144                         }
 145                         sk->sk_ack_backlog++;
 146                         skb_queue_tail(&sk->sk_receive_queue, skb);
 147                         DPRINTK("waking sk->sk_sleep 0x%p\n", sk->sk_sleep);
 148                         sk->sk_state_change(sk);
 149 as_indicate_complete:
 150                         release_sock(sk);
 151                         return 0;
 152                 case as_close:
 153                         set_bit(ATM_VF_RELEASED,&vcc->flags);
 154                         vcc_release_async(vcc, msg->reply);
 155                         goto out;
 156                 case as_modify:
 157                         modify_qos(vcc,msg);
 158                         break;
 159                 case as_addparty:
 160                 case as_dropparty:
 161                         sk->sk_err_soft = msg->reply;   /* < 0 failure, otherwise ep_ref */
 162                         clear_bit(ATM_VF_WAITING, &vcc->flags);
 163                         break;
 164                 default:
 165                         printk(KERN_ALERT "sigd_send: bad message type %d\n",
 166                             (int) msg->type);
 167                         return -EINVAL;
 168         }
 169         sk->sk_state_change(sk);
 170 out:
 171         dev_kfree_skb(skb);
 172         return 0;
 173 }
 174
 175
 176 void sigd_enq2(struct atm_vcc *vcc,enum atmsvc_msg_type type,
 177     struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
 178     const struct sockaddr_atmsvc *svc,const struct atm_qos *qos,int reply)
 179 {
 180         struct sk_buff *skb;
 181         struct atmsvc_msg *msg;
 182         static unsigned session = 0;
 183
 184         DPRINTK("sigd_enq %d (0x%p)\n",(int) type,vcc);
 185         while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))
 186                 schedule();
 187         msg = (struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg));
 188         memset(msg,0,sizeof(*msg));
 189         msg->type = type;
 190         *(struct atm_vcc **) &msg->vcc = vcc;
 191         *(struct atm_vcc **) &msg->listen_vcc = listen_vcc;
 192         msg->reply = reply;
 193         if (qos) msg->qos = *qos;
 194         if (vcc) msg->sap = vcc->sap;
 195         if (svc) msg->svc = *svc;
 196         if (vcc) msg->local = vcc->local;
 197         if (pvc) msg->pvc = *pvc;
 198         if (vcc) {
 199                 if (type == as_connect && test_bit(ATM_VF_SESSION, &vcc->flags))
 200                         msg->session = ++session;
 201                         /* every new pmp connect gets the next session number */
 202         }
 203         sigd_put_skb(skb);
 204         if (vcc) set_bit(ATM_VF_REGIS,&vcc->flags);
 205 }
 206
 207
 208 void sigd_enq(struct atm_vcc *vcc,enum atmsvc_msg_type type,
 209     struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
 210     const struct sockaddr_atmsvc *svc)
 211 {
 212         sigd_enq2(vcc,type,listen_vcc,pvc,svc,vcc ? &vcc->qos : NULL,0);
 213         /* other ISP applications may use "reply" */
 214 }
 215
 216
 217 static void purge_vcc(struct atm_vcc *vcc)
 218 {
 219         if (sk_atm(vcc)->sk_family == PF_ATMSVC &&
 220             !test_bit(ATM_VF_META, &vcc->flags)) {
 221                 set_bit(ATM_VF_RELEASED, &vcc->flags);
 222                 clear_bit(ATM_VF_REGIS, &vcc->flags);
 223                 vcc_release_async(vcc, -EUNATCH);
 224         }
 225 }
 226
 227
 228 static void sigd_close(struct atm_vcc *vcc)
 229 {
 230         struct hlist_node *node;
 231         struct sock *s;
 232         int i;
 233
 234         DPRINTK("sigd_close\n");
 235         sigd = NULL;
 236         if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
 237                 printk(KERN_ERR "sigd_close: closing with requests pending\n");
 238         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 239
 240         read_lock(&vcc_sklist_lock);
 241         for(i = 0; i < VCC_HTABLE_SIZE; ++i) {
 242                 struct hlist_head *head = &vcc_hash[i];
 243
 244                 sk_for_each(s, node, head) {
 245                         struct atm_vcc *vcc = atm_sk(s);
 246
 247                         purge_vcc(vcc);
 248                 }
 249         }
 250         read_unlock(&vcc_sklist_lock);
 251 }
 252
 253
 254 static struct atmdev_ops sigd_dev_ops = {
 255         .close = sigd_close,
 256         .send = sigd_send
 257 };
 258
 259
 260 static struct atm_dev sigd_dev = {
 261         .ops =          &sigd_dev_ops,
 262         .type =         "sig",
 263         .number =       999,
 264         .lock =         SPIN_LOCK_UNLOCKED
 265 };
 266
 267
 268 int sigd_attach(struct atm_vcc *vcc)
 269 {
 270         if (sigd) return -EADDRINUSE;
 271         DPRINTK("sigd_attach\n");
 272         sigd = vcc;
 273         vcc->dev = &sigd_dev;
 274         vcc_insert_socket(sk_atm(vcc));
 275         set_bit(ATM_VF_META,&vcc->flags);
 276         set_bit(ATM_VF_READY,&vcc->flags);
 277 #ifdef WAIT_FOR_DEMON
 278         wake_up(&sigd_sleep);
 279 #endif
 280         return 0;
 281 }