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/errno.h> 10 #include <linux/types.h> 11 #include <linux/socket.h> 12 #include <linux/in.h> 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/spinlock.h> 16 #include <linux/timer.h> 17 #include <linux/string.h> 18 #include <linux/sockios.h> 19 #include <linux/net.h> 20 #include <net/ax25.h> 21 #include <linux/inet.h> 22 #include <linux/netdevice.h> 23 #include <linux/skbuff.h> 24 #include <net/sock.h> 25 #include <asm/uaccess.h> 26 #include <asm/system.h> 27 #include <linux/fcntl.h> 28 #include <linux/mm.h> 29 #include <linux/interrupt.h> 30 31 static struct ax25_protocol *protocol_list; 32 static DEFINE_RWLOCK(protocol_list_lock); 33 34 static HLIST_HEAD(ax25_linkfail_list); 35 static DEFINE_SPINLOCK(linkfail_lock); 36 37 static struct listen_struct { 38 struct listen_struct *next; 39 ax25_address callsign; 40 struct net_device *dev; 41 } *listen_list = NULL; 42 static DEFINE_SPINLOCK(listen_lock); 43 44 /* 45 * Do not register the internal protocols AX25_P_TEXT, AX25_P_SEGMENT, 46 * AX25_P_IP or AX25_P_ARP ... 47 */ 48 void ax25_register_pid(struct ax25_protocol *ap) 49 { 50 write_lock_bh(&protocol_list_lock); 51 ap->next = protocol_list; 52 protocol_list = ap; 53 write_unlock_bh(&protocol_list_lock); 54 } 55 56 EXPORT_SYMBOL_GPL(ax25_register_pid); 57 58 void ax25_protocol_release(unsigned int pid) 59 { 60 struct ax25_protocol *s, *protocol; 61 62 write_lock_bh(&protocol_list_lock); 63 protocol = protocol_list; 64 if (protocol == NULL) { 65 write_unlock_bh(&protocol_list_lock); 66 return; 67 } 68 69 if (protocol->pid == pid) { 70 protocol_list = protocol->next; 71 write_unlock_bh(&protocol_list_lock); 72 return; 73 } 74 75 while (protocol != NULL && protocol->next != NULL) { 76 if (protocol->next->pid == pid) { 77 s = protocol->next; 78 protocol->next = protocol->next->next; 79 write_unlock_bh(&protocol_list_lock); 80 return; 81 } 82 83 protocol = protocol->next; 84 } 85 write_unlock_bh(&protocol_list_lock); 86 } 87 88 EXPORT_SYMBOL(ax25_protocol_release); 89 90 void ax25_linkfail_register(struct ax25_linkfail *lf) 91 { 92 spin_lock_bh(&linkfail_lock); 93 hlist_add_head(&lf->lf_node, &ax25_linkfail_list); 94 spin_unlock_bh(&linkfail_lock); 95 } 96 97 EXPORT_SYMBOL(ax25_linkfail_register); 98 99 void ax25_linkfail_release(struct ax25_linkfail *lf) 100 { 101 spin_lock_bh(&linkfail_lock); 102 hlist_del_init(&lf->lf_node); 103 spin_unlock_bh(&linkfail_lock); 104 } 105 106 EXPORT_SYMBOL(ax25_linkfail_release); 107 108 int ax25_listen_register(ax25_address *callsign, struct net_device *dev) 109 { 110 struct listen_struct *listen; 111 112 if (ax25_listen_mine(callsign, dev)) 113 return 0; 114 115 if ((listen = kmalloc(sizeof(*listen), GFP_ATOMIC)) == NULL) 116 return -ENOMEM; 117 118 listen->callsign = *callsign; 119 listen->dev = dev; 120 121 spin_lock_bh(&listen_lock); 122 listen->next = listen_list; 123 listen_list = listen; 124 spin_unlock_bh(&listen_lock); 125 126 return 0; 127 } 128 129 EXPORT_SYMBOL(ax25_listen_register); 130 131 void ax25_listen_release(ax25_address *callsign, struct net_device *dev) 132 { 133 struct listen_struct *s, *listen; 134 135 spin_lock_bh(&listen_lock); 136 listen = listen_list; 137 if (listen == NULL) { 138 spin_unlock_bh(&listen_lock); 139 return; 140 } 141 142 if (ax25cmp(&listen->callsign, callsign) == 0 && listen->dev == dev) { 143 listen_list = listen->next; 144 spin_unlock_bh(&listen_lock); 145 kfree(listen); 146 return; 147 } 148 149 while (listen != NULL && listen->next != NULL) { 150 if (ax25cmp(&listen->next->callsign, callsign) == 0 && listen->next->dev == dev) { 151 s = listen->next; 152 listen->next = listen->next->next; 153 spin_unlock_bh(&listen_lock); 154 kfree(s); 155 return; 156 } 157 158 listen = listen->next; 159 } 160 spin_unlock_bh(&listen_lock); 161 } 162 163 EXPORT_SYMBOL(ax25_listen_release); 164 165 int (*ax25_protocol_function(unsigned int pid))(struct sk_buff *, ax25_cb *) 166 { 167 int (*res)(struct sk_buff *, ax25_cb *) = NULL; 168 struct ax25_protocol *protocol; 169 170 read_lock(&protocol_list_lock); 171 for (protocol = protocol_list; protocol != NULL; protocol = protocol->next) 172 if (protocol->pid == pid) { 173 res = protocol->func; 174 break; 175 } 176 read_unlock(&protocol_list_lock); 177 178 return res; 179 } 180 181 int ax25_listen_mine(ax25_address *callsign, struct net_device *dev) 182 { 183 struct listen_struct *listen; 184 185 spin_lock_bh(&listen_lock); 186 for (listen = listen_list; listen != NULL; listen = listen->next) 187 if (ax25cmp(&listen->callsign, callsign) == 0 && 188 (listen->dev == dev || listen->dev == NULL)) { 189 spin_unlock_bh(&listen_lock); 190 return 1; 191 } 192 spin_unlock_bh(&listen_lock); 193 194 return 0; 195 } 196 197 void ax25_link_failed(ax25_cb *ax25, int reason) 198 { 199 struct ax25_linkfail *lf; 200 struct hlist_node *node; 201 202 spin_lock_bh(&linkfail_lock); 203 hlist_for_each_entry(lf, node, &ax25_linkfail_list, lf_node) 204 lf->func(ax25, reason); 205 spin_unlock_bh(&linkfail_lock); 206 } 207 208 int ax25_protocol_is_registered(unsigned int pid) 209 { 210 struct ax25_protocol *protocol; 211 int res = 0; 212 213 read_lock_bh(&protocol_list_lock); 214 for (protocol = protocol_list; protocol != NULL; protocol = protocol->next) 215 if (protocol->pid == pid) { 216 res = 1; 217 break; 218 } 219 read_unlock_bh(&protocol_list_lock); 220 221 return res; 222 } 223