linux/net/atm/signaling.c
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   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
  26struct atm_vcc *sigd = NULL;
  27#ifdef WAIT_FOR_DEMON
  28static DECLARE_WAIT_QUEUE_HEAD(sigd_sleep);
  29#endif
  30
  31
  32static 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
  58static 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
  84static 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);
 137as_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);
 158out:
 159        dev_kfree_skb(skb);
 160        return 0;
 161}
 162
 163
 164void 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
 196void 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
 205static 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
 216static 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
 242static struct atmdev_ops sigd_dev_ops = {
 243        .close = sigd_close,
 244        .send = sigd_send
 245};
 246
 247
 248static 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
 256int 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}
 270