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 struct atm_vcc *sigd = NULL;
  27 #ifdef WAIT_FOR_DEMON
  28 static DECLARE_WAIT_QUEUE_HEAD(sigd_sleep);
  29 #endif
  30
  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 demon...\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 demon\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
  58 static void modify_qos(struct atm_vcc *vcc,struct atmsvc_msg *msg)
  59 {
  60         struct sk_buff *skb;
  61
  62         if (test_bit(ATM_VF_RELEASED,&vcc->flags) ||
  63             !test_bit(ATM_VF_READY,&vcc->flags))
  64                 return;
  65         msg->type = as_error;
  66         if (!vcc->dev->ops->change_qos) 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) msg->type = as_okay;
  72         }
  73         /*
  74          * Should probably just turn around the old skb. But the, the buffer
  75          * space accounting needs to follow the change too. Maybe later.
  76          */
  77         while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))
  78                 schedule();
  79         *(struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg)) = *msg;
  80         sigd_put_skb(skb);
  81 }
  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("sigd_send %d (0x%lx)\n",(int) msg->type,
  94           (unsigned long) vcc);
  95         sk = sk_atm(vcc);
  96
  97         switch (msg->type) {
  98                 case as_okay:
  99                         sk->sk_err = -msg->reply;
 100                         clear_bit(ATM_VF_WAITING, &vcc->flags);
 101                         if (!*vcc->local.sas_addr.prv &&
 102                             !*vcc->local.sas_addr.pub) {
 103                                 vcc->local.sas_family = AF_ATMSVC;
 104                                 memcpy(vcc->local.sas_addr.prv,
 105                                     msg->local.sas_addr.prv,ATM_ESA_LEN);
 106                                 memcpy(vcc->local.sas_addr.pub,
 107                                     msg->local.sas_addr.pub,ATM_E164_LEN+1);
 108                         }
 109                         session_vcc = vcc->session ? vcc->session : vcc;
 110                         if (session_vcc->vpi || session_vcc->vci) break;
 111                         session_vcc->itf = msg->pvc.sap_addr.itf;
 112                         session_vcc->vpi = msg->pvc.sap_addr.vpi;
 113                         session_vcc->vci = msg->pvc.sap_addr.vci;
 114                         if (session_vcc->vpi || session_vcc->vci)
 115                                 session_vcc->qos = msg->qos;
 116                         break;
 117                 case as_error:
 118                         clear_bit(ATM_VF_REGIS,&vcc->flags);
 119                         clear_bit(ATM_VF_READY,&vcc->flags);
 120                         sk->sk_err = -msg->reply;
 121                         clear_bit(ATM_VF_WAITING, &vcc->flags);
 122                         break;
 123                 case as_indicate:
 124                         vcc = *(struct atm_vcc **) &msg->listen_vcc;
 125                         sk = sk_atm(vcc);
 126                         pr_debug("as_indicate!!!\n");
 127                         lock_sock(sk);
 128                         if (sk_acceptq_is_full(sk)) {
 129                                 sigd_enq(NULL,as_reject,vcc,NULL,NULL);
 130                                 dev_kfree_skb(skb);
 131                                 goto as_indicate_complete;
 132                         }
 133                         sk->sk_ack_backlog++;
 134                         skb_queue_tail(&sk->sk_receive_queue, skb);
 135                         pr_debug("waking sk->sk_sleep 0x%p\n", sk->sk_sleep);
 136                         sk->sk_state_change(sk);
 137 as_indicate_complete:
 138                         release_sock(sk);
 139                         return 0;
 140                 case as_close:
 141                         set_bit(ATM_VF_RELEASED,&vcc->flags);
 142                         vcc_release_async(vcc, msg->reply);
 143                         goto out;
 144                 case as_modify:
 145                         modify_qos(vcc,msg);
 146                         break;
 147                 case as_addparty:
 148                 case as_dropparty:
 149                         sk->sk_err_soft = msg->reply;   /* < 0 failure, otherwise ep_ref */
 150                         clear_bit(ATM_VF_WAITING, &vcc->flags);
 151                         break;
 152                 default:
 153                         printk(KERN_ALERT "sigd_send: bad message type %d\n",
 154                             (int) msg->type);
 155                         return -EINVAL;
 156         }
 157         sk->sk_state_change(sk);
 158 out:
 159         dev_kfree_skb(skb);
 160         return 0;
 161 }
 162
 163
 164 void sigd_enq2(struct atm_vcc *vcc,enum atmsvc_msg_type type,
 165     struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
 166     const struct sockaddr_atmsvc *svc,const struct atm_qos *qos,int reply)
 167 {
 168         struct sk_buff *skb;
 169         struct atmsvc_msg *msg;
 170         static unsigned session = 0;
 171
 172         pr_debug("sigd_enq %d (0x%p)\n",(int) type,vcc);
 173         while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))
 174                 schedule();
 175         msg = (struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg));
 176         memset(msg,0,sizeof(*msg));
 177         msg->type = type;
 178         *(struct atm_vcc **) &msg->vcc = vcc;
 179         *(struct atm_vcc **) &msg->listen_vcc = listen_vcc;
 180         msg->reply = reply;
 181         if (qos) msg->qos = *qos;
 182         if (vcc) msg->sap = vcc->sap;
 183         if (svc) msg->svc = *svc;
 184         if (vcc) msg->local = vcc->local;
 185         if (pvc) msg->pvc = *pvc;
 186         if (vcc) {
 187                 if (type == as_connect && test_bit(ATM_VF_SESSION, &vcc->flags))
 188                         msg->session = ++session;
 189                         /* every new pmp connect gets the next session number */
 190         }
 191         sigd_put_skb(skb);
 192         if (vcc) set_bit(ATM_VF_REGIS,&vcc->flags);
 193 }
 194
 195
 196 void sigd_enq(struct atm_vcc *vcc,enum atmsvc_msg_type type,
 197     struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,
 198     const struct sockaddr_atmsvc *svc)
 199 {
 200         sigd_enq2(vcc,type,listen_vcc,pvc,svc,vcc ? &vcc->qos : NULL,0);
 201         /* other ISP applications may use "reply" */
 202 }
 203
 204
 205 static void purge_vcc(struct atm_vcc *vcc)
 206 {
 207         if (sk_atm(vcc)->sk_family == PF_ATMSVC &&
 208             !test_bit(ATM_VF_META, &vcc->flags)) {
 209                 set_bit(ATM_VF_RELEASED, &vcc->flags);
 210                 clear_bit(ATM_VF_REGIS, &vcc->flags);
 211                 vcc_release_async(vcc, -EUNATCH);
 212         }
 213 }
 214
 215
 216 static void sigd_close(struct atm_vcc *vcc)
 217 {
 218         struct hlist_node *node;
 219         struct sock *s;
 220         int i;
 221
 222         pr_debug("sigd_close\n");
 223         sigd = NULL;
 224         if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
 225                 printk(KERN_ERR "sigd_close: closing with requests pending\n");
 226         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 227
 228         read_lock(&vcc_sklist_lock);
 229         for(i = 0; i < VCC_HTABLE_SIZE; ++i) {
 230                 struct hlist_head *head = &vcc_hash[i];
 231
 232                 sk_for_each(s, node, head) {
 233                         vcc = atm_sk(s);
 234
 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(sigd_dev.lock)
 253 };
 254
 255
 256 int sigd_attach(struct atm_vcc *vcc)
 257 {
 258         if (sigd) return -EADDRINUSE;
 259         pr_debug("sigd_attach\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 }