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