1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * 4 * Copyright Tomi Manninen OH2BNS (oh2bns@sral.fi) 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/netrom.h> 13 #include <linux/init.h> 14 15 static void nr_loopback_timer(struct timer_list *); 16 17 static struct sk_buff_head loopback_queue; 18 static DEFINE_TIMER(loopback_timer, nr_loopback_timer); 19 20 void __init nr_loopback_init(void) 21 { 22 skb_queue_head_init(&loopback_queue); 23 } 24 25 static inline int nr_loopback_running(void) 26 { 27 return timer_pending(&loopback_timer); 28 } 29 30 int nr_loopback_queue(struct sk_buff *skb) 31 { 32 struct sk_buff *skbn; 33 34 if ((skbn = alloc_skb(skb->len, GFP_ATOMIC)) != NULL) { 35 skb_copy_from_linear_data(skb, skb_put(skbn, skb->len), skb->len); 36 skb_reset_transport_header(skbn); 37 38 skb_queue_tail(&loopback_queue, skbn); 39 40 if (!nr_loopback_running()) 41 mod_timer(&loopback_timer, jiffies + 10); 42 } 43 44 kfree_skb(skb); 45 return 1; 46 } 47 48 static void nr_loopback_timer(struct timer_list *unused) 49 { 50 struct sk_buff *skb; 51 ax25_address *nr_dest; 52 struct net_device *dev; 53 54 if ((skb = skb_dequeue(&loopback_queue)) != NULL) { 55 nr_dest = (ax25_address *)(skb->data + 7); 56 57 dev = nr_dev_get(nr_dest); 58 59 if (dev == NULL || nr_rx_frame(skb, dev) == 0) 60 kfree_skb(skb); 61 62 if (dev != NULL) 63 dev_put(dev); 64 65 if (!skb_queue_empty(&loopback_queue) && !nr_loopback_running()) 66 mod_timer(&loopback_timer, jiffies + 10); 67 } 68 } 69 70 void nr_loopback_clear(void) 71 { 72 del_timer_sync(&loopback_timer); 73 skb_queue_purge(&loopback_queue); 74 } 75