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/errno.h> 7 #include <linux/types.h> 8 #include <linux/socket.h> 9 #include <linux/slab.h> 10 #include <linux/in.h> 11 #include <linux/kernel.h> 12 #include <linux/timer.h> 13 #include <linux/string.h> 14 #include <linux/sockios.h> 15 #include <linux/net.h> 16 #include <linux/spinlock.h> 17 #include <net/ax25.h> 18 #include <linux/inet.h> 19 #include <linux/netdevice.h> 20 #include <linux/if_arp.h> 21 #include <linux/skbuff.h> 22 #include <net/sock.h> 23 #include <linux/uaccess.h> 24 #include <linux/fcntl.h> 25 #include <linux/list.h> 26 #include <linux/mm.h> 27 #include <linux/interrupt.h> 28 #include <linux/init.h> 29 30 static LIST_HEAD(ax25_dev_list); 31 DEFINE_SPINLOCK(ax25_dev_lock); 32 33 ax25_dev *ax25_addr_ax25dev(ax25_address *addr) 34 { 35 ax25_dev *ax25_dev, *res = NULL; 36 37 spin_lock_bh(&ax25_dev_lock); 38 list_for_each_entry(ax25_dev, &ax25_dev_list, list) 39 if (ax25cmp(addr, (const ax25_address *)ax25_dev->dev->dev_addr) == 0) { 40 res = ax25_dev; 41 ax25_dev_hold(ax25_dev); 42 break; 43 } 44 spin_unlock_bh(&ax25_dev_lock); 45 46 return res; 47 } 48 49 /* 50 * This is called when an interface is brought up. These are 51 * reasonable defaults. 52 */ 53 void ax25_dev_device_up(struct net_device *dev) 54 { 55 ax25_dev *ax25_dev; 56 57 ax25_dev = kzalloc_obj(*ax25_dev, GFP_KERNEL); 58 if (!ax25_dev) { 59 printk(KERN_ERR "AX.25: ax25_dev_device_up - out of memory\n"); 60 return; 61 } 62 63 refcount_set(&ax25_dev->refcount, 1); 64 ax25_dev->dev = dev; 65 netdev_hold(dev, &ax25_dev->dev_tracker, GFP_KERNEL); 66 ax25_dev->forward = NULL; 67 ax25_dev->device_up = true; 68 69 ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE; 70 ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE; 71 ax25_dev->values[AX25_VALUES_BACKOFF] = AX25_DEF_BACKOFF; 72 ax25_dev->values[AX25_VALUES_CONMODE] = AX25_DEF_CONMODE; 73 ax25_dev->values[AX25_VALUES_WINDOW] = AX25_DEF_WINDOW; 74 ax25_dev->values[AX25_VALUES_EWINDOW] = AX25_DEF_EWINDOW; 75 ax25_dev->values[AX25_VALUES_T1] = AX25_DEF_T1; 76 ax25_dev->values[AX25_VALUES_T2] = AX25_DEF_T2; 77 ax25_dev->values[AX25_VALUES_T3] = AX25_DEF_T3; 78 ax25_dev->values[AX25_VALUES_IDLE] = AX25_DEF_IDLE; 79 ax25_dev->values[AX25_VALUES_N2] = AX25_DEF_N2; 80 ax25_dev->values[AX25_VALUES_PACLEN] = AX25_DEF_PACLEN; 81 ax25_dev->values[AX25_VALUES_PROTOCOL] = AX25_DEF_PROTOCOL; 82 83 #ifdef CONFIG_AX25_DAMA_SLAVE 84 ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT; 85 86 ax25_ds_setup_timer(ax25_dev); 87 #endif 88 89 spin_lock_bh(&ax25_dev_lock); 90 list_add(&ax25_dev->list, &ax25_dev_list); 91 rcu_assign_pointer(dev->ax25_ptr, ax25_dev); 92 spin_unlock_bh(&ax25_dev_lock); 93 94 ax25_register_dev_sysctl(ax25_dev); 95 } 96 97 void ax25_dev_device_down(struct net_device *dev) 98 { 99 ax25_dev *s, *ax25_dev; 100 101 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) 102 return; 103 104 ax25_unregister_dev_sysctl(ax25_dev); 105 106 spin_lock_bh(&ax25_dev_lock); 107 108 #ifdef CONFIG_AX25_DAMA_SLAVE 109 timer_shutdown_sync(&ax25_dev->dama.slave_timer); 110 #endif 111 112 /* 113 * Remove any packet forwarding that points to this device. 114 */ 115 list_for_each_entry(s, &ax25_dev_list, list) 116 if (s->forward == dev) 117 s->forward = NULL; 118 119 list_for_each_entry(s, &ax25_dev_list, list) { 120 if (s == ax25_dev) { 121 list_del(&s->list); 122 break; 123 } 124 } 125 126 RCU_INIT_POINTER(dev->ax25_ptr, NULL); 127 spin_unlock_bh(&ax25_dev_lock); 128 netdev_put(dev, &ax25_dev->dev_tracker); 129 ax25_dev_put(ax25_dev); 130 } 131 132 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd) 133 { 134 ax25_dev *ax25_dev, *fwd_dev; 135 136 if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL) 137 return -EINVAL; 138 139 switch (cmd) { 140 case SIOCAX25ADDFWD: 141 fwd_dev = ax25_addr_ax25dev(&fwd->port_to); 142 if (!fwd_dev) { 143 ax25_dev_put(ax25_dev); 144 return -EINVAL; 145 } 146 if (ax25_dev->forward) { 147 ax25_dev_put(fwd_dev); 148 ax25_dev_put(ax25_dev); 149 return -EINVAL; 150 } 151 ax25_dev->forward = fwd_dev->dev; 152 ax25_dev_put(fwd_dev); 153 ax25_dev_put(ax25_dev); 154 break; 155 156 case SIOCAX25DELFWD: 157 if (!ax25_dev->forward) { 158 ax25_dev_put(ax25_dev); 159 return -EINVAL; 160 } 161 ax25_dev->forward = NULL; 162 ax25_dev_put(ax25_dev); 163 break; 164 165 default: 166 ax25_dev_put(ax25_dev); 167 return -EINVAL; 168 } 169 170 return 0; 171 } 172 173 struct net_device *ax25_fwd_dev(struct net_device *dev) 174 { 175 ax25_dev *ax25_dev; 176 177 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) 178 return dev; 179 180 if (ax25_dev->forward == NULL) 181 return dev; 182 183 return ax25_dev->forward; 184 } 185 186 /* 187 * Free all memory associated with device structures. 188 */ 189 void __exit ax25_dev_free(void) 190 { 191 ax25_dev *s, *n; 192 193 spin_lock_bh(&ax25_dev_lock); 194 list_for_each_entry_safe(s, n, &ax25_dev_list, list) { 195 netdev_put(s->dev, &s->dev_tracker); 196 list_del(&s->list); 197 ax25_dev_put(s); 198 } 199 spin_unlock_bh(&ax25_dev_lock); 200 } 201