LXR linux-old/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
  33struct atm_vcc *sigd = NULL;
  34static DECLARE_WAIT_QUEUE_HEAD(sigd_sleep);
  35
  36
  37static 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
  68static 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
  94static 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                        }
 144as_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
 167void 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
 193void 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
 202static 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
 214static 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
 235static struct atmdev_ops sigd_dev_ops = {
 236        .close =        sigd_close,
 237        .send =         sigd_send
 238};
 239
 240
 241static struct atm_dev sigd_dev = {
 242        .ops =          &sigd_dev_ops,
 243        .type =         "sig",
 244        .number =       999,
 245        .lock =         SPIN_LOCK_UNLOCKED
 246};
 247
 248
 249int 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}
 261