summaryrefslogtreecommitdiff
path: root/net/rose/rose_loopback.c
blob: 11c45c8c6c1641781dd733e93e5453c2be75340b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *
 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
 */
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/socket.h>
#include <linux/timer.h>
#include <net/ax25.h>
#include <linux/skbuff.h>
#include <net/rose.h>
#include <linux/init.h>

static struct sk_buff_head loopback_queue;
#define ROSE_LOOPBACK_LIMIT 1000
static struct timer_list loopback_timer;

static void rose_set_loopback_timer(void);
static void rose_loopback_timer(struct timer_list *unused);

void rose_loopback_init(void)
{
	skb_queue_head_init(&loopback_queue);

	timer_setup(&loopback_timer, rose_loopback_timer, 0);
}

static int rose_loopback_running(void)
{
	return timer_pending(&loopback_timer);
}

int rose_loopback_queue(struct sk_buff *skb, struct rose_neigh *neigh)
{
	struct sk_buff *skbn = NULL;

	if (skb_queue_len(&loopback_queue) < ROSE_LOOPBACK_LIMIT)
		skbn = skb_clone(skb, GFP_ATOMIC);

	if (skbn) {
		consume_skb(skb);
		skb_queue_tail(&loopback_queue, skbn);

		if (!rose_loopback_running())
			rose_set_loopback_timer();
	} else {
		kfree_skb(skb);
	}

	return 1;
}

static void rose_set_loopback_timer(void)
{
	mod_timer(&loopback_timer, jiffies + 10);
}

static void rose_loopback_timer(struct timer_list *unused)
{
	struct sk_buff *skb;
	struct net_device *dev;
	rose_address *dest;
	struct sock *sk;
	unsigned short frametype;
	unsigned int lci_i, lci_o;
	int count;

	for (count = 0; count < ROSE_LOOPBACK_LIMIT; count++) {
		skb = skb_dequeue(&loopback_queue);
		if (!skb)
			return;
		if (skb->len < ROSE_MIN_LEN) {
			kfree_skb(skb);
			continue;
		}
		lci_i     = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
		frametype = skb->data[2];
		if (frametype == ROSE_CALL_REQUEST &&
		    (skb->len <= ROSE_CALL_REQ_FACILITIES_OFF ||
		     skb->data[ROSE_CALL_REQ_ADDR_LEN_OFF] !=
		     ROSE_CALL_REQ_ADDR_LEN_VAL)) {
			kfree_skb(skb);
			continue;
		}
		dest      = (rose_address *)(skb->data + ROSE_CALL_REQ_DEST_ADDR_OFF);
		lci_o     = ROSE_DEFAULT_MAXVC + 1 - lci_i;

		skb_reset_transport_header(skb);

		sk = rose_find_socket(lci_o, rose_loopback_neigh);
		if (sk) {
			if (rose_process_rx_frame(sk, skb) == 0)
				kfree_skb(skb);
			continue;
		}

		if (frametype == ROSE_CALL_REQUEST) {
			if (!rose_loopback_neigh->dev) {
				kfree_skb(skb);
				continue;
			}

			dev = rose_dev_get(dest);
			if (!dev) {
				kfree_skb(skb);
				continue;
			}

			if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0) {
				dev_put(dev);
				kfree_skb(skb);
			}
		} else {
			kfree_skb(skb);
		}
	}
	if (!skb_queue_empty(&loopback_queue))
		mod_timer(&loopback_timer, jiffies + 1);
}

void __exit rose_loopback_clear(void)
{
	struct sk_buff *skb;

	del_timer(&loopback_timer);

	while ((skb = skb_dequeue(&loopback_queue)) != NULL) {
		skb->sk = NULL;
		kfree_skb(skb);
	}
}