1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun #include <linux/types.h>
7*4882a593Smuzhiyun #include <linux/slab.h>
8*4882a593Smuzhiyun #include <linux/socket.h>
9*4882a593Smuzhiyun #include <linux/timer.h>
10*4882a593Smuzhiyun #include <net/ax25.h>
11*4882a593Smuzhiyun #include <linux/skbuff.h>
12*4882a593Smuzhiyun #include <net/rose.h>
13*4882a593Smuzhiyun #include <linux/init.h>
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun static struct sk_buff_head loopback_queue;
16*4882a593Smuzhiyun #define ROSE_LOOPBACK_LIMIT 1000
17*4882a593Smuzhiyun static struct timer_list loopback_timer;
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun static void rose_set_loopback_timer(void);
20*4882a593Smuzhiyun static void rose_loopback_timer(struct timer_list *unused);
21*4882a593Smuzhiyun
rose_loopback_init(void)22*4882a593Smuzhiyun void rose_loopback_init(void)
23*4882a593Smuzhiyun {
24*4882a593Smuzhiyun skb_queue_head_init(&loopback_queue);
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun timer_setup(&loopback_timer, rose_loopback_timer, 0);
27*4882a593Smuzhiyun }
28*4882a593Smuzhiyun
rose_loopback_running(void)29*4882a593Smuzhiyun static int rose_loopback_running(void)
30*4882a593Smuzhiyun {
31*4882a593Smuzhiyun return timer_pending(&loopback_timer);
32*4882a593Smuzhiyun }
33*4882a593Smuzhiyun
rose_loopback_queue(struct sk_buff * skb,struct rose_neigh * neigh)34*4882a593Smuzhiyun int rose_loopback_queue(struct sk_buff *skb, struct rose_neigh *neigh)
35*4882a593Smuzhiyun {
36*4882a593Smuzhiyun struct sk_buff *skbn = NULL;
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun if (skb_queue_len(&loopback_queue) < ROSE_LOOPBACK_LIMIT)
39*4882a593Smuzhiyun skbn = skb_clone(skb, GFP_ATOMIC);
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun if (skbn) {
42*4882a593Smuzhiyun consume_skb(skb);
43*4882a593Smuzhiyun skb_queue_tail(&loopback_queue, skbn);
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun if (!rose_loopback_running())
46*4882a593Smuzhiyun rose_set_loopback_timer();
47*4882a593Smuzhiyun } else {
48*4882a593Smuzhiyun kfree_skb(skb);
49*4882a593Smuzhiyun }
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun return 1;
52*4882a593Smuzhiyun }
53*4882a593Smuzhiyun
rose_set_loopback_timer(void)54*4882a593Smuzhiyun static void rose_set_loopback_timer(void)
55*4882a593Smuzhiyun {
56*4882a593Smuzhiyun mod_timer(&loopback_timer, jiffies + 10);
57*4882a593Smuzhiyun }
58*4882a593Smuzhiyun
rose_loopback_timer(struct timer_list * unused)59*4882a593Smuzhiyun static void rose_loopback_timer(struct timer_list *unused)
60*4882a593Smuzhiyun {
61*4882a593Smuzhiyun struct sk_buff *skb;
62*4882a593Smuzhiyun struct net_device *dev;
63*4882a593Smuzhiyun rose_address *dest;
64*4882a593Smuzhiyun struct sock *sk;
65*4882a593Smuzhiyun unsigned short frametype;
66*4882a593Smuzhiyun unsigned int lci_i, lci_o;
67*4882a593Smuzhiyun int count;
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun for (count = 0; count < ROSE_LOOPBACK_LIMIT; count++) {
70*4882a593Smuzhiyun skb = skb_dequeue(&loopback_queue);
71*4882a593Smuzhiyun if (!skb)
72*4882a593Smuzhiyun return;
73*4882a593Smuzhiyun if (skb->len < ROSE_MIN_LEN) {
74*4882a593Smuzhiyun kfree_skb(skb);
75*4882a593Smuzhiyun continue;
76*4882a593Smuzhiyun }
77*4882a593Smuzhiyun lci_i = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
78*4882a593Smuzhiyun frametype = skb->data[2];
79*4882a593Smuzhiyun if (frametype == ROSE_CALL_REQUEST &&
80*4882a593Smuzhiyun (skb->len <= ROSE_CALL_REQ_FACILITIES_OFF ||
81*4882a593Smuzhiyun skb->data[ROSE_CALL_REQ_ADDR_LEN_OFF] !=
82*4882a593Smuzhiyun ROSE_CALL_REQ_ADDR_LEN_VAL)) {
83*4882a593Smuzhiyun kfree_skb(skb);
84*4882a593Smuzhiyun continue;
85*4882a593Smuzhiyun }
86*4882a593Smuzhiyun dest = (rose_address *)(skb->data + ROSE_CALL_REQ_DEST_ADDR_OFF);
87*4882a593Smuzhiyun lci_o = ROSE_DEFAULT_MAXVC + 1 - lci_i;
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun skb_reset_transport_header(skb);
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun sk = rose_find_socket(lci_o, rose_loopback_neigh);
92*4882a593Smuzhiyun if (sk) {
93*4882a593Smuzhiyun if (rose_process_rx_frame(sk, skb) == 0)
94*4882a593Smuzhiyun kfree_skb(skb);
95*4882a593Smuzhiyun continue;
96*4882a593Smuzhiyun }
97*4882a593Smuzhiyun
98*4882a593Smuzhiyun if (frametype == ROSE_CALL_REQUEST) {
99*4882a593Smuzhiyun if (!rose_loopback_neigh->dev &&
100*4882a593Smuzhiyun !rose_loopback_neigh->loopback) {
101*4882a593Smuzhiyun kfree_skb(skb);
102*4882a593Smuzhiyun continue;
103*4882a593Smuzhiyun }
104*4882a593Smuzhiyun
105*4882a593Smuzhiyun dev = rose_dev_get(dest);
106*4882a593Smuzhiyun if (!dev) {
107*4882a593Smuzhiyun kfree_skb(skb);
108*4882a593Smuzhiyun continue;
109*4882a593Smuzhiyun }
110*4882a593Smuzhiyun
111*4882a593Smuzhiyun if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0) {
112*4882a593Smuzhiyun dev_put(dev);
113*4882a593Smuzhiyun kfree_skb(skb);
114*4882a593Smuzhiyun }
115*4882a593Smuzhiyun } else {
116*4882a593Smuzhiyun kfree_skb(skb);
117*4882a593Smuzhiyun }
118*4882a593Smuzhiyun }
119*4882a593Smuzhiyun if (!skb_queue_empty(&loopback_queue))
120*4882a593Smuzhiyun mod_timer(&loopback_timer, jiffies + 1);
121*4882a593Smuzhiyun }
122*4882a593Smuzhiyun
rose_loopback_clear(void)123*4882a593Smuzhiyun void __exit rose_loopback_clear(void)
124*4882a593Smuzhiyun {
125*4882a593Smuzhiyun struct sk_buff *skb;
126*4882a593Smuzhiyun
127*4882a593Smuzhiyun del_timer(&loopback_timer);
128*4882a593Smuzhiyun
129*4882a593Smuzhiyun while ((skb = skb_dequeue(&loopback_queue)) != NULL) {
130*4882a593Smuzhiyun skb->sk = NULL;
131*4882a593Smuzhiyun kfree_skb(skb);
132*4882a593Smuzhiyun }
133*4882a593Smuzhiyun }
134