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