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