// SPDX-License-Identifier: GPL-2.0
/* net/atm/raw.c - Raw AAL0 and AAL5 transports */

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

#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__

#include <linux/module.h>
#include <linux/atmdev.h>
#include <linux/capability.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/mm.h>
#include <linux/slab.h>

#include "common.h"
#include "protocols.h"

/*
 * SKB == NULL indicates that the link is being closed
 */

static void atm_push_raw(struct atm_vcc *vcc, struct sk_buff *skb)
{
        if (skb) {
                struct sock *sk = sk_atm(vcc);

                skb_queue_tail(&sk->sk_receive_queue, skb);
                sk->sk_data_ready(sk);
        }
}

static void atm_pop_raw(struct atm_vcc *vcc, struct sk_buff *skb)
{
        struct sock *sk = sk_atm(vcc);

        pr_debug("(%d) %d -= %d\n",
                 vcc->vci, sk_wmem_alloc_get(sk), ATM_SKB(skb)->acct_truesize);
        atm_return_tx(vcc, skb);
        dev_kfree_skb_any(skb);
        sk->sk_write_space(sk);
}

static int atm_send_aal0(struct atm_vcc *vcc, struct sk_buff *skb)
{
        /*
         * Note that if vpi/vci are _ANY or _UNSPEC the below will
         * still work
         */
        if (!capable(CAP_NET_ADMIN) &&
            (((u32 *)skb->data)[0] & (ATM_HDR_VPI_MASK | ATM_HDR_VCI_MASK)) !=
            ((vcc->vpi << ATM_HDR_VPI_SHIFT) |
             (vcc->vci << ATM_HDR_VCI_SHIFT))) {
                kfree_skb(skb);
                return -EADDRNOTAVAIL;
        }
        if (vcc->dev->ops->send_bh)
                return vcc->dev->ops->send_bh(vcc, skb);
        return vcc->dev->ops->send(vcc, skb);
}

int atm_init_aal0(struct atm_vcc *vcc)
{
        vcc->push = atm_push_raw;
        vcc->pop = atm_pop_raw;
        vcc->push_oam = NULL;
        vcc->send = atm_send_aal0;
        return 0;
}

int atm_init_aal34(struct atm_vcc *vcc)
{
        vcc->push = atm_push_raw;
        vcc->pop = atm_pop_raw;
        vcc->push_oam = NULL;
        if (vcc->dev->ops->send_bh)
                vcc->send = vcc->dev->ops->send_bh;
        else
                vcc->send = vcc->dev->ops->send;
        return 0;
}

int atm_init_aal5(struct atm_vcc *vcc)
{
        vcc->push = atm_push_raw;
        vcc->pop = atm_pop_raw;
        vcc->push_oam = NULL;
        if (vcc->dev->ops->send_bh)
                vcc->send = vcc->dev->ops->send_bh;
        else
                vcc->send = vcc->dev->ops->send;
        return 0;
}
EXPORT_SYMBOL(atm_init_aal5);