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![Rikard Falkeborn](/assets/img/avatar_default.png)
The only usage of atmtcp_v_dev_ops is to pass its address to atm_dev_register() which takes a pointer to const, and comparing its address to another address, which does not modify it. Make it const to allow the compiler to put it in read-only memory. Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
499 lines
12 KiB
C
499 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* drivers/atm/atmtcp.c - ATM over TCP "device" driver */
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/* Written 1997-2000 by Werner Almesberger, EPFL LRC/ICA */
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#include <linux/module.h>
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#include <linux/wait.h>
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#include <linux/atmdev.h>
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#include <linux/atm_tcp.h>
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#include <linux/bitops.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <linux/atomic.h>
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extern int atm_init_aal5(struct atm_vcc *vcc); /* "raw" AAL5 transport */
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#define PRIV(dev) ((struct atmtcp_dev_data *) ((dev)->dev_data))
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struct atmtcp_dev_data {
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struct atm_vcc *vcc; /* control VCC; NULL if detached */
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int persist; /* non-zero if persistent */
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};
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#define DEV_LABEL "atmtcp"
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#define MAX_VPI_BITS 8 /* simplifies life */
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#define MAX_VCI_BITS 16
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/*
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* Hairy code ahead: the control VCC may be closed while we're still
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* waiting for an answer, so we need to re-validate out_vcc every once
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* in a while.
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*/
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static int atmtcp_send_control(struct atm_vcc *vcc,int type,
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const struct atmtcp_control *msg,int flag)
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{
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DECLARE_WAITQUEUE(wait,current);
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struct atm_vcc *out_vcc;
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struct sk_buff *skb;
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struct atmtcp_control *new_msg;
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int old_test;
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int error = 0;
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out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
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if (!out_vcc) return -EUNATCH;
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skb = alloc_skb(sizeof(*msg),GFP_KERNEL);
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if (!skb) return -ENOMEM;
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mb();
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out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
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if (!out_vcc) {
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dev_kfree_skb(skb);
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return -EUNATCH;
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}
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atm_force_charge(out_vcc,skb->truesize);
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new_msg = skb_put(skb, sizeof(*new_msg));
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*new_msg = *msg;
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new_msg->hdr.length = ATMTCP_HDR_MAGIC;
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new_msg->type = type;
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memset(&new_msg->vcc,0,sizeof(atm_kptr_t));
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*(struct atm_vcc **) &new_msg->vcc = vcc;
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old_test = test_bit(flag,&vcc->flags);
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out_vcc->push(out_vcc,skb);
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add_wait_queue(sk_sleep(sk_atm(vcc)), &wait);
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while (test_bit(flag,&vcc->flags) == old_test) {
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mb();
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out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
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if (!out_vcc) {
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error = -EUNATCH;
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break;
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}
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set_current_state(TASK_UNINTERRUPTIBLE);
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schedule();
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}
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set_current_state(TASK_RUNNING);
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remove_wait_queue(sk_sleep(sk_atm(vcc)), &wait);
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return error;
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}
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static int atmtcp_recv_control(const struct atmtcp_control *msg)
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{
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struct atm_vcc *vcc = *(struct atm_vcc **) &msg->vcc;
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vcc->vpi = msg->addr.sap_addr.vpi;
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vcc->vci = msg->addr.sap_addr.vci;
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vcc->qos = msg->qos;
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sk_atm(vcc)->sk_err = -msg->result;
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switch (msg->type) {
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case ATMTCP_CTRL_OPEN:
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change_bit(ATM_VF_READY,&vcc->flags);
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break;
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case ATMTCP_CTRL_CLOSE:
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change_bit(ATM_VF_ADDR,&vcc->flags);
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break;
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default:
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printk(KERN_ERR "atmtcp_recv_control: unknown type %d\n",
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msg->type);
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return -EINVAL;
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}
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wake_up(sk_sleep(sk_atm(vcc)));
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return 0;
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}
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static void atmtcp_v_dev_close(struct atm_dev *dev)
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{
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/* Nothing.... Isn't this simple :-) -- REW */
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}
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static int atmtcp_v_open(struct atm_vcc *vcc)
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{
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struct atmtcp_control msg;
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int error;
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short vpi = vcc->vpi;
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int vci = vcc->vci;
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memset(&msg,0,sizeof(msg));
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msg.addr.sap_family = AF_ATMPVC;
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msg.hdr.vpi = htons(vpi);
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msg.addr.sap_addr.vpi = vpi;
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msg.hdr.vci = htons(vci);
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msg.addr.sap_addr.vci = vci;
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if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) return 0;
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msg.type = ATMTCP_CTRL_OPEN;
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msg.qos = vcc->qos;
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set_bit(ATM_VF_ADDR,&vcc->flags);
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clear_bit(ATM_VF_READY,&vcc->flags); /* just in case ... */
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error = atmtcp_send_control(vcc,ATMTCP_CTRL_OPEN,&msg,ATM_VF_READY);
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if (error) return error;
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return -sk_atm(vcc)->sk_err;
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}
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static void atmtcp_v_close(struct atm_vcc *vcc)
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{
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struct atmtcp_control msg;
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memset(&msg,0,sizeof(msg));
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msg.addr.sap_family = AF_ATMPVC;
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msg.addr.sap_addr.vpi = vcc->vpi;
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msg.addr.sap_addr.vci = vcc->vci;
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clear_bit(ATM_VF_READY,&vcc->flags);
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(void) atmtcp_send_control(vcc,ATMTCP_CTRL_CLOSE,&msg,ATM_VF_ADDR);
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}
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static int atmtcp_v_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg)
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{
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struct atm_cirange ci;
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struct atm_vcc *vcc;
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struct sock *s;
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int i;
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if (cmd != ATM_SETCIRANGE) return -ENOIOCTLCMD;
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if (copy_from_user(&ci, arg,sizeof(ci))) return -EFAULT;
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if (ci.vpi_bits == ATM_CI_MAX) ci.vpi_bits = MAX_VPI_BITS;
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if (ci.vci_bits == ATM_CI_MAX) ci.vci_bits = MAX_VCI_BITS;
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if (ci.vpi_bits > MAX_VPI_BITS || ci.vpi_bits < 0 ||
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ci.vci_bits > MAX_VCI_BITS || ci.vci_bits < 0) return -EINVAL;
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read_lock(&vcc_sklist_lock);
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for(i = 0; i < VCC_HTABLE_SIZE; ++i) {
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struct hlist_head *head = &vcc_hash[i];
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sk_for_each(s, head) {
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vcc = atm_sk(s);
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if (vcc->dev != dev)
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continue;
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if ((vcc->vpi >> ci.vpi_bits) ||
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(vcc->vci >> ci.vci_bits)) {
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read_unlock(&vcc_sklist_lock);
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return -EBUSY;
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}
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}
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}
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read_unlock(&vcc_sklist_lock);
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dev->ci_range = ci;
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return 0;
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}
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static int atmtcp_v_send(struct atm_vcc *vcc,struct sk_buff *skb)
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{
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struct atmtcp_dev_data *dev_data;
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struct atm_vcc *out_vcc=NULL; /* Initializer quietens GCC warning */
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struct sk_buff *new_skb;
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struct atmtcp_hdr *hdr;
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int size;
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if (vcc->qos.txtp.traffic_class == ATM_NONE) {
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if (vcc->pop) vcc->pop(vcc,skb);
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else dev_kfree_skb(skb);
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return -EINVAL;
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}
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dev_data = PRIV(vcc->dev);
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if (dev_data) out_vcc = dev_data->vcc;
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if (!dev_data || !out_vcc) {
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if (vcc->pop) vcc->pop(vcc,skb);
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else dev_kfree_skb(skb);
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if (dev_data) return 0;
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atomic_inc(&vcc->stats->tx_err);
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return -ENOLINK;
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}
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size = skb->len+sizeof(struct atmtcp_hdr);
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new_skb = atm_alloc_charge(out_vcc,size,GFP_ATOMIC);
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if (!new_skb) {
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if (vcc->pop) vcc->pop(vcc,skb);
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else dev_kfree_skb(skb);
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atomic_inc(&vcc->stats->tx_err);
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return -ENOBUFS;
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}
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hdr = skb_put(new_skb, sizeof(struct atmtcp_hdr));
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hdr->vpi = htons(vcc->vpi);
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hdr->vci = htons(vcc->vci);
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hdr->length = htonl(skb->len);
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skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
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if (vcc->pop) vcc->pop(vcc,skb);
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else dev_kfree_skb(skb);
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out_vcc->push(out_vcc,new_skb);
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atomic_inc(&vcc->stats->tx);
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atomic_inc(&out_vcc->stats->rx);
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return 0;
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}
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static int atmtcp_v_proc(struct atm_dev *dev,loff_t *pos,char *page)
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{
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struct atmtcp_dev_data *dev_data = PRIV(dev);
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if (*pos) return 0;
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if (!dev_data->persist) return sprintf(page,"ephemeral\n");
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return sprintf(page,"persistent, %sconnected\n",
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dev_data->vcc ? "" : "dis");
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}
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static void atmtcp_c_close(struct atm_vcc *vcc)
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{
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struct atm_dev *atmtcp_dev;
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struct atmtcp_dev_data *dev_data;
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atmtcp_dev = (struct atm_dev *) vcc->dev_data;
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dev_data = PRIV(atmtcp_dev);
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dev_data->vcc = NULL;
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if (dev_data->persist) return;
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atmtcp_dev->dev_data = NULL;
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kfree(dev_data);
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atm_dev_deregister(atmtcp_dev);
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vcc->dev_data = NULL;
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module_put(THIS_MODULE);
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}
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static struct atm_vcc *find_vcc(struct atm_dev *dev, short vpi, int vci)
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{
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struct hlist_head *head;
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struct atm_vcc *vcc;
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struct sock *s;
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head = &vcc_hash[vci & (VCC_HTABLE_SIZE -1)];
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sk_for_each(s, head) {
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vcc = atm_sk(s);
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if (vcc->dev == dev &&
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vcc->vci == vci && vcc->vpi == vpi &&
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vcc->qos.rxtp.traffic_class != ATM_NONE) {
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return vcc;
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}
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}
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return NULL;
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}
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static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb)
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{
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struct atm_dev *dev;
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struct atmtcp_hdr *hdr;
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struct atm_vcc *out_vcc;
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struct sk_buff *new_skb;
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int result = 0;
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if (!skb->len) return 0;
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dev = vcc->dev_data;
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hdr = (struct atmtcp_hdr *) skb->data;
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if (hdr->length == ATMTCP_HDR_MAGIC) {
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result = atmtcp_recv_control(
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(struct atmtcp_control *) skb->data);
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goto done;
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}
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read_lock(&vcc_sklist_lock);
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out_vcc = find_vcc(dev, ntohs(hdr->vpi), ntohs(hdr->vci));
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read_unlock(&vcc_sklist_lock);
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if (!out_vcc) {
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result = -EUNATCH;
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atomic_inc(&vcc->stats->tx_err);
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goto done;
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}
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skb_pull(skb,sizeof(struct atmtcp_hdr));
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new_skb = atm_alloc_charge(out_vcc,skb->len,GFP_KERNEL);
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if (!new_skb) {
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result = -ENOBUFS;
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goto done;
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}
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__net_timestamp(new_skb);
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skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
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out_vcc->push(out_vcc,new_skb);
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atomic_inc(&vcc->stats->tx);
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atomic_inc(&out_vcc->stats->rx);
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done:
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if (vcc->pop) vcc->pop(vcc,skb);
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else dev_kfree_skb(skb);
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return result;
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}
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/*
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* Device operations for the virtual ATM devices created by ATMTCP.
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*/
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static const struct atmdev_ops atmtcp_v_dev_ops = {
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.dev_close = atmtcp_v_dev_close,
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.open = atmtcp_v_open,
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.close = atmtcp_v_close,
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.ioctl = atmtcp_v_ioctl,
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.send = atmtcp_v_send,
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.proc_read = atmtcp_v_proc,
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.owner = THIS_MODULE
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};
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/*
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* Device operations for the ATMTCP control device.
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*/
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static const struct atmdev_ops atmtcp_c_dev_ops = {
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.close = atmtcp_c_close,
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.send = atmtcp_c_send
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};
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static struct atm_dev atmtcp_control_dev = {
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.ops = &atmtcp_c_dev_ops,
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.type = "atmtcp",
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.number = 999,
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.lock = __SPIN_LOCK_UNLOCKED(atmtcp_control_dev.lock)
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};
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static int atmtcp_create(int itf,int persist,struct atm_dev **result)
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{
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struct atmtcp_dev_data *dev_data;
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struct atm_dev *dev;
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dev_data = kmalloc(sizeof(*dev_data),GFP_KERNEL);
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if (!dev_data)
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return -ENOMEM;
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dev = atm_dev_register(DEV_LABEL,NULL,&atmtcp_v_dev_ops,itf,NULL);
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if (!dev) {
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kfree(dev_data);
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return itf == -1 ? -ENOMEM : -EBUSY;
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}
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dev->ci_range.vpi_bits = MAX_VPI_BITS;
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dev->ci_range.vci_bits = MAX_VCI_BITS;
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dev->dev_data = dev_data;
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PRIV(dev)->vcc = NULL;
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PRIV(dev)->persist = persist;
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if (result) *result = dev;
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return 0;
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}
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static int atmtcp_attach(struct atm_vcc *vcc,int itf)
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{
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struct atm_dev *dev;
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dev = NULL;
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if (itf != -1) dev = atm_dev_lookup(itf);
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if (dev) {
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if (dev->ops != &atmtcp_v_dev_ops) {
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atm_dev_put(dev);
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return -EMEDIUMTYPE;
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}
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if (PRIV(dev)->vcc) {
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atm_dev_put(dev);
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return -EBUSY;
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}
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}
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else {
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int error;
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error = atmtcp_create(itf,0,&dev);
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if (error) return error;
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}
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PRIV(dev)->vcc = vcc;
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vcc->dev = &atmtcp_control_dev;
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vcc_insert_socket(sk_atm(vcc));
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set_bit(ATM_VF_META,&vcc->flags);
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set_bit(ATM_VF_READY,&vcc->flags);
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vcc->dev_data = dev;
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(void) atm_init_aal5(vcc); /* @@@ losing AAL in transit ... */
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vcc->stats = &atmtcp_control_dev.stats.aal5;
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return dev->number;
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}
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static int atmtcp_create_persistent(int itf)
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{
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return atmtcp_create(itf,1,NULL);
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}
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static int atmtcp_remove_persistent(int itf)
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{
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struct atm_dev *dev;
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struct atmtcp_dev_data *dev_data;
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dev = atm_dev_lookup(itf);
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if (!dev) return -ENODEV;
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if (dev->ops != &atmtcp_v_dev_ops) {
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atm_dev_put(dev);
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return -EMEDIUMTYPE;
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}
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dev_data = PRIV(dev);
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if (!dev_data->persist) {
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atm_dev_put(dev);
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return 0;
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}
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dev_data->persist = 0;
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if (PRIV(dev)->vcc) {
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atm_dev_put(dev);
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return 0;
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}
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kfree(dev_data);
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atm_dev_put(dev);
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atm_dev_deregister(dev);
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return 0;
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}
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static int atmtcp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
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{
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int err = 0;
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struct atm_vcc *vcc = ATM_SD(sock);
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if (cmd != SIOCSIFATMTCP && cmd != ATMTCP_CREATE && cmd != ATMTCP_REMOVE)
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return -ENOIOCTLCMD;
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if (!capable(CAP_NET_ADMIN))
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return -EPERM;
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switch (cmd) {
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case SIOCSIFATMTCP:
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err = atmtcp_attach(vcc, (int) arg);
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if (err >= 0) {
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sock->state = SS_CONNECTED;
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__module_get(THIS_MODULE);
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}
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break;
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case ATMTCP_CREATE:
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err = atmtcp_create_persistent((int) arg);
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break;
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case ATMTCP_REMOVE:
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err = atmtcp_remove_persistent((int) arg);
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break;
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}
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return err;
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}
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static struct atm_ioctl atmtcp_ioctl_ops = {
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.owner = THIS_MODULE,
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.ioctl = atmtcp_ioctl,
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|
};
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|
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static __init int atmtcp_init(void)
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|
{
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|
register_atm_ioctl(&atmtcp_ioctl_ops);
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|
return 0;
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|
}
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|
|
|
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static void __exit atmtcp_exit(void)
|
|
{
|
|
deregister_atm_ioctl(&atmtcp_ioctl_ops);
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|
}
|
|
|
|
MODULE_LICENSE("GPL");
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|
module_init(atmtcp_init);
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|
module_exit(atmtcp_exit);
|