xref: /openbmc/linux/net/rose/rose_loopback.c (revision be709d48)
1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License as published by
4  * the Free Software Foundation; either version 2 of the License, or
5  * (at your option) any later version.
6  *
7  * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
8  */
9 #include <linux/types.h>
10 #include <linux/slab.h>
11 #include <linux/socket.h>
12 #include <linux/timer.h>
13 #include <net/ax25.h>
14 #include <linux/skbuff.h>
15 #include <net/rose.h>
16 #include <linux/init.h>
17 
18 static struct sk_buff_head loopback_queue;
19 static struct timer_list loopback_timer;
20 
21 static void rose_set_loopback_timer(void);
22 static void rose_loopback_timer(struct timer_list *unused);
23 
24 void rose_loopback_init(void)
25 {
26 	skb_queue_head_init(&loopback_queue);
27 
28 	timer_setup(&loopback_timer, rose_loopback_timer, 0);
29 }
30 
31 static int rose_loopback_running(void)
32 {
33 	return timer_pending(&loopback_timer);
34 }
35 
36 int rose_loopback_queue(struct sk_buff *skb, struct rose_neigh *neigh)
37 {
38 	struct sk_buff *skbn;
39 
40 	skbn = skb_clone(skb, GFP_ATOMIC);
41 
42 	kfree_skb(skb);
43 
44 	if (skbn != NULL) {
45 		skb_queue_tail(&loopback_queue, skbn);
46 
47 		if (!rose_loopback_running())
48 			rose_set_loopback_timer();
49 	}
50 
51 	return 1;
52 }
53 
54 
55 static void rose_set_loopback_timer(void)
56 {
57 	del_timer(&loopback_timer);
58 
59 	loopback_timer.expires  = jiffies + 10;
60 	add_timer(&loopback_timer);
61 }
62 
63 static void rose_loopback_timer(struct timer_list *unused)
64 {
65 	struct sk_buff *skb;
66 	struct net_device *dev;
67 	rose_address *dest;
68 	struct sock *sk;
69 	unsigned short frametype;
70 	unsigned int lci_i, lci_o;
71 
72 	while ((skb = skb_dequeue(&loopback_queue)) != NULL) {
73 		if (skb->len < ROSE_MIN_LEN) {
74 			kfree_skb(skb);
75 			continue;
76 		}
77 		lci_i     = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
78 		frametype = skb->data[2];
79 		if (frametype == ROSE_CALL_REQUEST &&
80 		    (skb->len <= ROSE_CALL_REQ_FACILITIES_OFF ||
81 		     skb->data[ROSE_CALL_REQ_ADDR_LEN_OFF] !=
82 		     ROSE_CALL_REQ_ADDR_LEN_VAL)) {
83 			kfree_skb(skb);
84 			continue;
85 		}
86 		dest      = (rose_address *)(skb->data + ROSE_CALL_REQ_DEST_ADDR_OFF);
87 		lci_o     = ROSE_DEFAULT_MAXVC + 1 - lci_i;
88 
89 		skb_reset_transport_header(skb);
90 
91 		sk = rose_find_socket(lci_o, rose_loopback_neigh);
92 		if (sk) {
93 			if (rose_process_rx_frame(sk, skb) == 0)
94 				kfree_skb(skb);
95 			continue;
96 		}
97 
98 		if (frametype == ROSE_CALL_REQUEST) {
99 			if ((dev = rose_dev_get(dest)) != NULL) {
100 				if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0)
101 					kfree_skb(skb);
102 			} else {
103 				kfree_skb(skb);
104 			}
105 		} else {
106 			kfree_skb(skb);
107 		}
108 	}
109 }
110 
111 void __exit rose_loopback_clear(void)
112 {
113 	struct sk_buff *skb;
114 
115 	del_timer(&loopback_timer);
116 
117 	while ((skb = skb_dequeue(&loopback_queue)) != NULL) {
118 		skb->sk = NULL;
119 		kfree_skb(skb);
120 	}
121 }
122