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 goto out; 66 67 if (protocol->pid == pid) { 68 protocol_list = protocol->next; 69 goto out; 70 } 71 72 while (protocol != NULL && protocol->next != NULL) { 73 if (protocol->next->pid == pid) { 74 s = protocol->next; 75 protocol->next = protocol->next->next; 76 goto out; 77 } 78 79 protocol = protocol->next; 80 } 81 out: 82 write_unlock_bh(&protocol_list_lock); 83 } 84 85 EXPORT_SYMBOL(ax25_protocol_release); 86 87 void ax25_linkfail_register(struct ax25_linkfail *lf) 88 { 89 spin_lock_bh(&linkfail_lock); 90 hlist_add_head(&lf->lf_node, &ax25_linkfail_list); 91 spin_unlock_bh(&linkfail_lock); 92 } 93 94 EXPORT_SYMBOL(ax25_linkfail_register); 95 96 void ax25_linkfail_release(struct ax25_linkfail *lf) 97 { 98 spin_lock_bh(&linkfail_lock); 99 hlist_del_init(&lf->lf_node); 100 spin_unlock_bh(&linkfail_lock); 101 } 102 103 EXPORT_SYMBOL(ax25_linkfail_release); 104 105 int ax25_listen_register(ax25_address *callsign, struct net_device *dev) 106 { 107 struct listen_struct *listen; 108 109 if (ax25_listen_mine(callsign, dev)) 110 return 0; 111 112 if ((listen = kmalloc(sizeof(*listen), GFP_ATOMIC)) == NULL) 113 return -ENOMEM; 114 115 listen->callsign = *callsign; 116 listen->dev = dev; 117 118 spin_lock_bh(&listen_lock); 119 listen->next = listen_list; 120 listen_list = listen; 121 spin_unlock_bh(&listen_lock); 122 123 return 0; 124 } 125 126 EXPORT_SYMBOL(ax25_listen_register); 127 128 void ax25_listen_release(ax25_address *callsign, struct net_device *dev) 129 { 130 struct listen_struct *s, *listen; 131 132 spin_lock_bh(&listen_lock); 133 listen = listen_list; 134 if (listen == NULL) { 135 spin_unlock_bh(&listen_lock); 136 return; 137 } 138 139 if (ax25cmp(&listen->callsign, callsign) == 0 && listen->dev == dev) { 140 listen_list = listen->next; 141 spin_unlock_bh(&listen_lock); 142 kfree(listen); 143 return; 144 } 145 146 while (listen != NULL && listen->next != NULL) { 147 if (ax25cmp(&listen->next->callsign, callsign) == 0 && listen->next->dev == dev) { 148 s = listen->next; 149 listen->next = listen->next->next; 150 spin_unlock_bh(&listen_lock); 151 kfree(s); 152 return; 153 } 154 155 listen = listen->next; 156 } 157 spin_unlock_bh(&listen_lock); 158 } 159 160 EXPORT_SYMBOL(ax25_listen_release); 161 162 int (*ax25_protocol_function(unsigned int pid))(struct sk_buff *, ax25_cb *) 163 { 164 int (*res)(struct sk_buff *, ax25_cb *) = NULL; 165 struct ax25_protocol *protocol; 166 167 read_lock(&protocol_list_lock); 168 for (protocol = protocol_list; protocol != NULL; protocol = protocol->next) 169 if (protocol->pid == pid) { 170 res = protocol->func; 171 break; 172 } 173 read_unlock(&protocol_list_lock); 174 175 return res; 176 } 177 178 int ax25_listen_mine(ax25_address *callsign, struct net_device *dev) 179 { 180 struct listen_struct *listen; 181 182 spin_lock_bh(&listen_lock); 183 for (listen = listen_list; listen != NULL; listen = listen->next) 184 if (ax25cmp(&listen->callsign, callsign) == 0 && 185 (listen->dev == dev || listen->dev == NULL)) { 186 spin_unlock_bh(&listen_lock); 187 return 1; 188 } 189 spin_unlock_bh(&listen_lock); 190 191 return 0; 192 } 193 194 void ax25_link_failed(ax25_cb *ax25, int reason) 195 { 196 struct ax25_linkfail *lf; 197 struct hlist_node *node; 198 199 spin_lock_bh(&linkfail_lock); 200 hlist_for_each_entry(lf, node, &ax25_linkfail_list, lf_node) 201 lf->func(ax25, reason); 202 spin_unlock_bh(&linkfail_lock); 203 } 204 205 int ax25_protocol_is_registered(unsigned int pid) 206 { 207 struct ax25_protocol *protocol; 208 int res = 0; 209 210 read_lock_bh(&protocol_list_lock); 211 for (protocol = protocol_list; protocol != NULL; protocol = protocol->next) 212 if (protocol->pid == pid) { 213 res = 1; 214 break; 215 } 216 read_unlock_bh(&protocol_list_lock); 217 218 return res; 219 } 220