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/* net/atm/signaling.c - ATM signaling */

/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */

#include <linux/errno.h>        /* error codes */

#include <linux/kernel.h>       /* printk */

#include <linux/skbuff.h>

#include <linux/wait.h>

#include <linux/sched.h>        /* jiffies and HZ */

#include <linux/atm.h>          /* ATM stuff */

#include <linux/atmsap.h>

#include <linux/atmsvc.h>

#include <linux/atmdev.h>

#include <linux/bitops.h>

#include "resources.h"

#include "signaling.h"

#undef WAIT_FOR_DEMON           /* #define this if system calls on SVC sockets

                                   should block until the demon runs.

                                   Danger: may cause nasty hangs if the demon

                                   crashes. */

#if 0

#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)

#else

#define DPRINTK(format,args...)

#endif

struct atm_vcc *sigd = NULL;

static DECLARE_WAIT_QUEUE_HEAD(sigd_sleep);

static void sigd_put_skb(struct sk_buff *skb)

{

#ifdef WAIT_FOR_DEMON

        static unsigned long silence = 0;

        DECLARE_WAITQUEUE(wait,current);

        add_wait_queue(&sigd_sleep,&wait);

        while (!sigd) {

                set_current_state(TASK_UNINTERRUPTIBLE);

                if (time_after(jiffies, silence) || silence == 0) {

                        printk(KERN_INFO "atmsvc: waiting for signaling demon "

                            "...\n");

                        silence = (jiffies+30*HZ)|1;

                }

                schedule();

        }

        current->state = TASK_RUNNING;

        remove_wait_queue(&sigd_sleep,&wait);

#else

        if (!sigd) {

                printk(KERN_WARNING "atmsvc: no signaling demon\n");

                kfree_skb(skb);

                return;

        }

#endif

        atm_force_charge(sigd,skb->truesize);

        skb_queue_tail(&sigd->sk->receive_queue,skb);

        wake_up(&sigd->sleep);

}

static void modify_qos(struct atm_vcc *vcc,struct atmsvc_msg *msg)

{

        struct sk_buff *skb;

        if (test_bit(ATM_VF_RELEASED,&vcc->flags) ||

            !test_bit(ATM_VF_READY,&vcc->flags))

                return;

        msg->type = as_error;

        if (!vcc->dev->ops->change_qos) msg->reply = -EOPNOTSUPP;

        else {

                /* should lock VCC */

                msg->reply = vcc->dev->ops->change_qos(vcc,&msg->qos,

                    msg->reply);

                if (!msg->reply) msg->type = as_okay;

        }

        /*

         * Should probably just turn around the old skb. But the, the buffer

         * space accounting needs to follow the change too. Maybe later.

         */

        while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))

                schedule();

        *(struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg)) = *msg;

        sigd_put_skb(skb);

}

static int sigd_send(struct atm_vcc *vcc,struct sk_buff *skb)

{

        struct atmsvc_msg *msg;

        struct atm_vcc *session_vcc;

        msg = (struct atmsvc_msg *) skb->data;

        atomic_sub(skb->truesize, &vcc->sk->wmem_alloc);

        DPRINTK("sigd_send %d (0x%lx)\n",(int) msg->type,

          (unsigned long) msg->vcc);

        vcc = *(struct atm_vcc **) &msg->vcc;

        switch (msg->type) {

                case as_okay:

                        vcc->reply = msg->reply;

                        if (!*vcc->local.sas_addr.prv &&

                            !*vcc->local.sas_addr.pub) {

                                vcc->local.sas_family = AF_ATMSVC;

                                memcpy(vcc->local.sas_addr.prv,

                                    msg->local.sas_addr.prv,ATM_ESA_LEN);

                                memcpy(vcc->local.sas_addr.pub,

                                    msg->local.sas_addr.pub,ATM_E164_LEN+1);

                        }

                        session_vcc = vcc->session ? vcc->session : vcc;

                        if (session_vcc->vpi || session_vcc->vci) break;

                        session_vcc->itf = msg->pvc.sap_addr.itf;

                        session_vcc->vpi = msg->pvc.sap_addr.vpi;

                        session_vcc->vci = msg->pvc.sap_addr.vci;

                        if (session_vcc->vpi || session_vcc->vci)

                                session_vcc->qos = msg->qos;

                        break;

                case as_error:

                        clear_bit(ATM_VF_REGIS,&vcc->flags);

                        clear_bit(ATM_VF_READY,&vcc->flags);

                        vcc->reply = msg->reply;

                        vcc->sk->err = -msg->reply;

                        break;

                case as_indicate:

                        vcc = *(struct atm_vcc **) &msg->listen_vcc;

                        DPRINTK("as_indicate!!!\n");

                        lock_sock(vcc->sk);

                        if (vcc->sk->ack_backlog == vcc->sk->max_ack_backlog) {

                                sigd_enq(0,as_reject,vcc,NULL,NULL);

                                goto as_indicate_complete;

                        }

                        vcc->sk->ack_backlog++;

                        skb_queue_tail(&vcc->sk->receive_queue,skb);

                        if (vcc->callback) {

                                DPRINTK("waking vcc->sleep 0x%p\n",

                                    &vcc->sleep);

                                vcc->callback(vcc);

                        }

as_indicate_complete:

                        release_sock(vcc->sk);

                        return 0;

                case as_close:

                        set_bit(ATM_VF_RELEASED,&vcc->flags);

                        clear_bit(ATM_VF_READY,&vcc->flags);

                        vcc->reply = msg->reply;

                        vcc->sk->err = -msg->reply;

                        break;

                case as_modify:

                        modify_qos(vcc,msg);

                        break;

                default:

                        printk(KERN_ALERT "sigd_send: bad message type %d\n",

                            (int) msg->type);

                        return -EINVAL;

        }

        if (vcc->callback) vcc->callback(vcc);

        dev_kfree_skb(skb);

        return 0;

}

void sigd_enq2(struct atm_vcc *vcc,enum atmsvc_msg_type type,

    struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,

    const struct sockaddr_atmsvc *svc,const struct atm_qos *qos,int reply)

{

        struct sk_buff *skb;

        struct atmsvc_msg *msg;

        DPRINTK("sigd_enq %d (0x%p)\n",(int) type,vcc);

        while (!(skb = alloc_skb(sizeof(struct atmsvc_msg),GFP_KERNEL)))

                schedule();

        msg = (struct atmsvc_msg *) skb_put(skb,sizeof(struct atmsvc_msg));

        memset(msg,0,sizeof(*msg));

        msg->type = type;

        *(struct atm_vcc **) &msg->vcc = vcc;

        *(struct atm_vcc **) &msg->listen_vcc = listen_vcc;

        msg->reply = reply;

        if (qos) msg->qos = *qos;

        if (vcc) msg->sap = vcc->sap;

        if (svc) msg->svc = *svc;

        if (vcc) msg->local = vcc->local;

        if (pvc) msg->pvc = *pvc;

        sigd_put_skb(skb);

        if (vcc) set_bit(ATM_VF_REGIS,&vcc->flags);

}

void sigd_enq(struct atm_vcc *vcc,enum atmsvc_msg_type type,

    struct atm_vcc *listen_vcc,const struct sockaddr_atmpvc *pvc,

    const struct sockaddr_atmsvc *svc)

{

        sigd_enq2(vcc,type,listen_vcc,pvc,svc,vcc ? &vcc->qos : NULL,0);

        /* other ISP applications may use "reply" */

}

static void purge_vcc(struct atm_vcc *vcc)

{

        if (vcc->sk->family == PF_ATMSVC &&

            !test_bit(ATM_VF_META, &vcc->flags)) {

                set_bit(ATM_VF_RELEASED, &vcc->flags);

                vcc->reply = -EUNATCH;

                vcc->sk->err = EUNATCH;

                wake_up(&vcc->sleep);

        }

}

static void sigd_close(struct atm_vcc *vcc)

{

        struct sock *s;

        DPRINTK("sigd_close\n");

        sigd = NULL;

        if (skb_peek(&vcc->sk->receive_queue))

                printk(KERN_ERR "sigd_close: closing with requests pending\n");

        skb_queue_purge(&vcc->sk->receive_queue);

        read_lock(&vcc_sklist_lock);

        for(s = vcc_sklist; s; s = s->next) {

                struct atm_vcc *vcc = s->protinfo.af_atm;

                if (vcc->dev)

                        purge_vcc(vcc);

        }

        read_unlock(&vcc_sklist_lock);

}

static struct atmdev_ops sigd_dev_ops = {

        .close =        sigd_close,

        .send =         sigd_send

};

static struct atm_dev sigd_dev = {

        .ops =          &sigd_dev_ops,

        .type =         "sig",

        .number =       999,

        .lock =         SPIN_LOCK_UNLOCKED

};

int sigd_attach(struct atm_vcc *vcc)

{

        if (sigd) return -EADDRINUSE;

        DPRINTK("sigd_attach\n");

        sigd = vcc;

        vcc->dev = &sigd_dev;

        vcc_insert_socket(vcc->sk);

        set_bit(ATM_VF_META,&vcc->flags);

        set_bit(ATM_VF_READY,&vcc->flags);

        wake_up(&sigd_sleep);

        return 0;

}