xref: /openbmc/linux/net/atm/raw.c (revision faa16bc4)
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);
87