1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * |
4 | * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) |
5 | */ |
6 | #include <linux/types.h> |
7 | #include <linux/slab.h> |
8 | #include <linux/socket.h> |
9 | #include <linux/timer.h> |
10 | #include <net/ax25.h> |
11 | #include <linux/skbuff.h> |
12 | #include <net/rose.h> |
13 | #include <linux/init.h> |
14 | |
15 | static struct sk_buff_head loopback_queue; |
16 | #define ROSE_LOOPBACK_LIMIT 1000 |
17 | static struct timer_list loopback_timer; |
18 | |
19 | static void rose_set_loopback_timer(void); |
20 | static void rose_loopback_timer(struct timer_list *unused); |
21 | |
22 | void rose_loopback_init(void) |
23 | { |
24 | skb_queue_head_init(list: &loopback_queue); |
25 | |
26 | timer_setup(&loopback_timer, rose_loopback_timer, 0); |
27 | } |
28 | |
29 | static int rose_loopback_running(void) |
30 | { |
31 | return timer_pending(timer: &loopback_timer); |
32 | } |
33 | |
34 | int rose_loopback_queue(struct sk_buff *skb, struct rose_neigh *neigh) |
35 | { |
36 | struct sk_buff *skbn = NULL; |
37 | |
38 | if (skb_queue_len(list_: &loopback_queue) < ROSE_LOOPBACK_LIMIT) |
39 | skbn = skb_clone(skb, GFP_ATOMIC); |
40 | |
41 | if (skbn) { |
42 | consume_skb(skb); |
43 | skb_queue_tail(list: &loopback_queue, newsk: skbn); |
44 | |
45 | if (!rose_loopback_running()) |
46 | rose_set_loopback_timer(); |
47 | } else { |
48 | kfree_skb(skb); |
49 | } |
50 | |
51 | return 1; |
52 | } |
53 | |
54 | static void rose_set_loopback_timer(void) |
55 | { |
56 | mod_timer(timer: &loopback_timer, expires: jiffies + 10); |
57 | } |
58 | |
59 | static void rose_loopback_timer(struct timer_list *unused) |
60 | { |
61 | struct sk_buff *skb; |
62 | struct net_device *dev; |
63 | rose_address *dest; |
64 | struct sock *sk; |
65 | unsigned short frametype; |
66 | unsigned int lci_i, lci_o; |
67 | int count; |
68 | |
69 | for (count = 0; count < ROSE_LOOPBACK_LIMIT; count++) { |
70 | skb = skb_dequeue(list: &loopback_queue); |
71 | if (!skb) |
72 | return; |
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 (!rose_loopback_neigh->dev && |
100 | !rose_loopback_neigh->loopback) { |
101 | kfree_skb(skb); |
102 | continue; |
103 | } |
104 | |
105 | dev = rose_dev_get(dest); |
106 | if (!dev) { |
107 | kfree_skb(skb); |
108 | continue; |
109 | } |
110 | |
111 | if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0) { |
112 | dev_put(dev); |
113 | kfree_skb(skb); |
114 | } |
115 | } else { |
116 | kfree_skb(skb); |
117 | } |
118 | } |
119 | if (!skb_queue_empty(list: &loopback_queue)) |
120 | mod_timer(timer: &loopback_timer, expires: jiffies + 1); |
121 | } |
122 | |
123 | void __exit rose_loopback_clear(void) |
124 | { |
125 | struct sk_buff *skb; |
126 | |
127 | del_timer(timer: &loopback_timer); |
128 | |
129 | while ((skb = skb_dequeue(list: &loopback_queue)) != NULL) { |
130 | skb->sk = NULL; |
131 | kfree_skb(skb); |
132 | } |
133 | } |
134 | |