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 #define ROSE_LOOPBACK_LIMIT 1000 20 static struct timer_list loopback_timer; 21 22 static void rose_set_loopback_timer(void); 23 static void rose_loopback_timer(struct timer_list *unused); 24 25 void rose_loopback_init(void) 26 { 27 skb_queue_head_init(&loopback_queue); 28 29 timer_setup(&loopback_timer, rose_loopback_timer, 0); 30 } 31 32 static int rose_loopback_running(void) 33 { 34 return timer_pending(&loopback_timer); 35 } 36 37 int rose_loopback_queue(struct sk_buff *skb, struct rose_neigh *neigh) 38 { 39 struct sk_buff *skbn = NULL; 40 41 if (skb_queue_len(&loopback_queue) < ROSE_LOOPBACK_LIMIT) 42 skbn = skb_clone(skb, GFP_ATOMIC); 43 44 if (skbn) { 45 consume_skb(skb); 46 skb_queue_tail(&loopback_queue, skbn); 47 48 if (!rose_loopback_running()) 49 rose_set_loopback_timer(); 50 } else { 51 kfree_skb(skb); 52 } 53 54 return 1; 55 } 56 57 static void rose_set_loopback_timer(void) 58 { 59 mod_timer(&loopback_timer, jiffies + 10); 60 } 61 62 static void rose_loopback_timer(struct timer_list *unused) 63 { 64 struct sk_buff *skb; 65 struct net_device *dev; 66 rose_address *dest; 67 struct sock *sk; 68 unsigned short frametype; 69 unsigned int lci_i, lci_o; 70 int count; 71 72 for (count = 0; count < ROSE_LOOPBACK_LIMIT; count++) { 73 skb = skb_dequeue(&loopback_queue); 74 if (!skb) 75 return; 76 if (skb->len < ROSE_MIN_LEN) { 77 kfree_skb(skb); 78 continue; 79 } 80 lci_i = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF); 81 frametype = skb->data[2]; 82 if (frametype == ROSE_CALL_REQUEST && 83 (skb->len <= ROSE_CALL_REQ_FACILITIES_OFF || 84 skb->data[ROSE_CALL_REQ_ADDR_LEN_OFF] != 85 ROSE_CALL_REQ_ADDR_LEN_VAL)) { 86 kfree_skb(skb); 87 continue; 88 } 89 dest = (rose_address *)(skb->data + ROSE_CALL_REQ_DEST_ADDR_OFF); 90 lci_o = ROSE_DEFAULT_MAXVC + 1 - lci_i; 91 92 skb_reset_transport_header(skb); 93 94 sk = rose_find_socket(lci_o, rose_loopback_neigh); 95 if (sk) { 96 if (rose_process_rx_frame(sk, skb) == 0) 97 kfree_skb(skb); 98 continue; 99 } 100 101 if (frametype == ROSE_CALL_REQUEST) { 102 if ((dev = rose_dev_get(dest)) != NULL) { 103 if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0) 104 kfree_skb(skb); 105 } else { 106 kfree_skb(skb); 107 } 108 } else { 109 kfree_skb(skb); 110 } 111 } 112 if (!skb_queue_empty(&loopback_queue)) 113 mod_timer(&loopback_timer, jiffies + 1); 114 } 115 116 void __exit rose_loopback_clear(void) 117 { 118 struct sk_buff *skb; 119 120 del_timer(&loopback_timer); 121 122 while ((skb = skb_dequeue(&loopback_queue)) != NULL) { 123 skb->sk = NULL; 124 kfree_skb(skb); 125 } 126 } 127