net/atm/raw.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* net/atm/raw.c - Raw AAL0 and AAL5 transports */
   3
   4 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
   5
   6 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
   7
   8 #include <linux/module.h>
   9 #include <linux/atmdev.h>
  10 #include <linux/capability.h>
  11 #include <linux/kernel.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/mm.h>
  14 #include <linux/slab.h>
  15
  16 #include "common.h"
  17 #include "protocols.h"
  18
  19 /*
  20  * SKB == NULL indicates that the link is being closed
  21  */
  22
  23 static void atm_push_raw(struct atm_vcc *vcc, struct sk_buff *skb)
  24 {
  25         if (skb) {
  26                 struct sock *sk = sk_atm(vcc);
  27
  28                 skb_queue_tail(&sk->sk_receive_queue, skb);
  29                 sk->sk_data_ready(sk);
  30         }
  31 }
  32
  33 static void atm_pop_raw(struct atm_vcc *vcc, struct sk_buff *skb)
  34 {
  35         struct sock *sk = sk_atm(vcc);
  36
  37         pr_debug("(%d) %d -= %d\n",
  38                  vcc->vci, sk_wmem_alloc_get(sk), skb->truesize);
  39         WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
  40         dev_kfree_skb_any(skb);
  41         sk->sk_write_space(sk);
  42 }
  43
  44 static int atm_send_aal0(struct atm_vcc *vcc, struct sk_buff *skb)
  45 {
  46         /*
  47          * Note that if vpi/vci are _ANY or _UNSPEC the below will
  48          * still work
  49          */
  50         if (!capable(CAP_NET_ADMIN) &&
  51             (((u32 *)skb->data)[0] & (ATM_HDR_VPI_MASK | ATM_HDR_VCI_MASK)) !=
  52             ((vcc->vpi << ATM_HDR_VPI_SHIFT) |
  53              (vcc->vci << ATM_HDR_VCI_SHIFT))) {
  54                 kfree_skb(skb);
  55                 return -EADDRNOTAVAIL;
  56         }
  57         return vcc->dev->ops->send(vcc, skb);
  58 }
  59
  60 int atm_init_aal0(struct atm_vcc *vcc)
  61 {
  62         vcc->push = atm_push_raw;
  63         vcc->pop = atm_pop_raw;
  64         vcc->push_oam = NULL;
  65         vcc->send = atm_send_aal0;
  66         return 0;
  67 }
  68
  69 int atm_init_aal34(struct atm_vcc *vcc)
  70 {
  71         vcc->push = atm_push_raw;
  72         vcc->pop = atm_pop_raw;
  73         vcc->push_oam = NULL;
  74         vcc->send = vcc->dev->ops->send;
  75         return 0;
  76 }
  77
  78 int atm_init_aal5(struct atm_vcc *vcc)
  79 {
  80         vcc->push = atm_push_raw;
  81         vcc->pop = atm_pop_raw;
  82         vcc->push_oam = NULL;
  83         vcc->send = vcc->dev->ops->send;
  84         return 0;
  85 }
  86 EXPORT_SYMBOL(atm_init_aal5);