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root/net/atm/signaling.c

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DEFINITIONS

This source file includes following definitions.
  1. sigd_put_skb
  2. modify_qos
  3. sigd_send
  4. sigd_enq2
  5. sigd_enq
  6. purge_vcc
  7. sigd_close
  8. sigd_attach

/* 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. */

struct atm_vcc *sigd = NULL;
#ifdef WAIT_FOR_DEMON
static DECLARE_WAIT_QUEUE_HEAD(sigd_sleep);
#endif


static void sigd_put_skb(struct sk_buff *skb)
{
#ifdef WAIT_FOR_DEMON
        DECLARE_WAITQUEUE(wait,current);

        add_wait_queue(&sigd_sleep,&wait);
        while (!sigd) {
                set_current_state(TASK_UNINTERRUPTIBLE);
                pr_debug("atmsvc: waiting for signaling demon...\n");
                schedule();
        }
        current->state = TASK_RUNNING;
        remove_wait_queue(&sigd_sleep,&wait);
#else
        if (!sigd) {
                pr_debug("atmsvc: no signaling demon\n");
                kfree_skb(skb);
                return;
        }
#endif
        atm_force_charge(sigd,skb->truesize);
        skb_queue_tail(&sk_atm(sigd)->sk_receive_queue,skb);
        sk_atm(sigd)->sk_data_ready(sk_atm(sigd), skb->len);
}


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;
        struct sock *sk;

        msg = (struct atmsvc_msg *) skb->data;
        atomic_sub(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
        vcc = *(struct atm_vcc **) &msg->vcc;
        pr_debug("sigd_send %d (0x%lx)\n",(int) msg->type,
          (unsigned long) vcc);
        sk = sk_atm(vcc);

        switch (msg->type) {
                case as_okay:
                        sk->sk_err = -msg->reply;
                        clear_bit(ATM_VF_WAITING, &vcc->flags);
                        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);
                        sk->sk_err = -msg->reply;
                        clear_bit(ATM_VF_WAITING, &vcc->flags);
                        break;
                case as_indicate:
                        vcc = *(struct atm_vcc **) &msg->listen_vcc;
                        sk = sk_atm(vcc);
                        pr_debug("as_indicate!!!\n");
                        lock_sock(sk);
                        if (sk_acceptq_is_full(sk)) {
                                sigd_enq(NULL,as_reject,vcc,NULL,NULL);
                                dev_kfree_skb(skb);
                                goto as_indicate_complete;
                        }
                        sk->sk_ack_backlog++;
                        skb_queue_tail(&sk->sk_receive_queue, skb);
                        pr_debug("waking sk->sk_sleep 0x%p\n", sk->sk_sleep);
                        sk->sk_state_change(sk);
as_indicate_complete:
                        release_sock(sk);
                        return 0;
                case as_close:
                        set_bit(ATM_VF_RELEASED,&vcc->flags);
                        vcc_release_async(vcc, msg->reply);
                        goto out;
                case as_modify:
                        modify_qos(vcc,msg);
                        break;
                case as_addparty:
                case as_dropparty:
                        sk->sk_err_soft = msg->reply;   /* < 0 failure, otherwise ep_ref */
                        clear_bit(ATM_VF_WAITING, &vcc->flags);
                        break;
                default:
                        printk(KERN_ALERT "sigd_send: bad message type %d\n",
                            (int) msg->type);
                        return -EINVAL;
        }
        sk->sk_state_change(sk);
out:
        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;
        static unsigned session = 0;

        pr_debug("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;
        if (vcc) {
                if (type == as_connect && test_bit(ATM_VF_SESSION, &vcc->flags))
                        msg->session = ++session;
                        /* every new pmp connect gets the next session number */
        }
        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 (sk_atm(vcc)->sk_family == PF_ATMSVC &&
            !test_bit(ATM_VF_META, &vcc->flags)) {
                set_bit(ATM_VF_RELEASED, &vcc->flags);
                clear_bit(ATM_VF_REGIS, &vcc->flags);
                vcc_release_async(vcc, -EUNATCH);
        }
}


static void sigd_close(struct atm_vcc *vcc)
{
        struct hlist_node *node;
        struct sock *s;
        int i;

        pr_debug("sigd_close\n");
        sigd = NULL;
        if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
                printk(KERN_ERR "sigd_close: closing with requests pending\n");
        skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);

        read_lock(&vcc_sklist_lock);
        for(i = 0; i < VCC_HTABLE_SIZE; ++i) {
                struct hlist_head *head = &vcc_hash[i];

                sk_for_each(s, node, head) {
                        vcc = atm_sk(s);

                        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(sigd_dev.lock)
};


int sigd_attach(struct atm_vcc *vcc)
{
        if (sigd) return -EADDRINUSE;
        pr_debug("sigd_attach\n");
        sigd = vcc;
        vcc->dev = &sigd_dev;
        vcc_insert_socket(sk_atm(vcc));
        set_bit(ATM_VF_META,&vcc->flags);
        set_bit(ATM_VF_READY,&vcc->flags);
#ifdef WAIT_FOR_DEMON
        wake_up(&sigd_sleep);
#endif
        return 0;
}

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