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/jiffies.h> 15 #include <linux/timer.h> 16 #include <linux/string.h> 17 #include <linux/sockios.h> 18 #include <linux/net.h> 19 #include <net/ax25.h> 20 #include <linux/inet.h> 21 #include <linux/netdevice.h> 22 #include <linux/skbuff.h> 23 #include <net/sock.h> 24 #include <asm/system.h> 25 #include <linux/fcntl.h> 26 #include <linux/mm.h> 27 #include <linux/interrupt.h> 28 #include <linux/netfilter.h> 29 #include <net/rose.h> 30 31 static void rose_ftimer_expiry(unsigned long); 32 static void rose_t0timer_expiry(unsigned long); 33 34 static void rose_transmit_restart_confirmation(struct rose_neigh *neigh); 35 static void rose_transmit_restart_request(struct rose_neigh *neigh); 36 37 void rose_start_ftimer(struct rose_neigh *neigh) 38 { 39 del_timer(&neigh->ftimer); 40 41 neigh->ftimer.data = (unsigned long)neigh; 42 neigh->ftimer.function = &rose_ftimer_expiry; 43 neigh->ftimer.expires = 44 jiffies + msecs_to_jiffies(sysctl_rose_link_fail_timeout); 45 46 add_timer(&neigh->ftimer); 47 } 48 49 static void rose_start_t0timer(struct rose_neigh *neigh) 50 { 51 del_timer(&neigh->t0timer); 52 53 neigh->t0timer.data = (unsigned long)neigh; 54 neigh->t0timer.function = &rose_t0timer_expiry; 55 neigh->t0timer.expires = 56 jiffies + msecs_to_jiffies(sysctl_rose_restart_request_timeout); 57 58 add_timer(&neigh->t0timer); 59 } 60 61 void rose_stop_ftimer(struct rose_neigh *neigh) 62 { 63 del_timer(&neigh->ftimer); 64 } 65 66 void rose_stop_t0timer(struct rose_neigh *neigh) 67 { 68 del_timer(&neigh->t0timer); 69 } 70 71 int rose_ftimer_running(struct rose_neigh *neigh) 72 { 73 return timer_pending(&neigh->ftimer); 74 } 75 76 static int rose_t0timer_running(struct rose_neigh *neigh) 77 { 78 return timer_pending(&neigh->t0timer); 79 } 80 81 static void rose_ftimer_expiry(unsigned long param) 82 { 83 } 84 85 static void rose_t0timer_expiry(unsigned long param) 86 { 87 struct rose_neigh *neigh = (struct rose_neigh *)param; 88 89 rose_transmit_restart_request(neigh); 90 91 neigh->dce_mode = 0; 92 93 rose_start_t0timer(neigh); 94 } 95 96 /* 97 * Interface to ax25_send_frame. Changes my level 2 callsign depending 98 * on whether we have a global ROSE callsign or use the default port 99 * callsign. 100 */ 101 static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh) 102 { 103 ax25_address *rose_call; 104 105 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0) 106 rose_call = (ax25_address *)neigh->dev->dev_addr; 107 else 108 rose_call = &rose_callsign; 109 110 neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev); 111 112 return (neigh->ax25 != NULL); 113 } 114 115 /* 116 * Interface to ax25_link_up. Changes my level 2 callsign depending 117 * on whether we have a global ROSE callsign or use the default port 118 * callsign. 119 */ 120 static int rose_link_up(struct rose_neigh *neigh) 121 { 122 ax25_address *rose_call; 123 124 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0) 125 rose_call = (ax25_address *)neigh->dev->dev_addr; 126 else 127 rose_call = &rose_callsign; 128 129 neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev); 130 131 return (neigh->ax25 != NULL); 132 } 133 134 /* 135 * This handles all restart and diagnostic frames. 136 */ 137 void rose_link_rx_restart(struct sk_buff *skb, struct rose_neigh *neigh, unsigned short frametype) 138 { 139 struct sk_buff *skbn; 140 141 switch (frametype) { 142 case ROSE_RESTART_REQUEST: 143 rose_stop_t0timer(neigh); 144 neigh->restarted = 1; 145 neigh->dce_mode = (skb->data[3] == ROSE_DTE_ORIGINATED); 146 rose_transmit_restart_confirmation(neigh); 147 break; 148 149 case ROSE_RESTART_CONFIRMATION: 150 rose_stop_t0timer(neigh); 151 neigh->restarted = 1; 152 break; 153 154 case ROSE_DIAGNOSTIC: 155 printk(KERN_WARNING "ROSE: received diagnostic #%d - %02X %02X %02X\n", skb->data[3], skb->data[4], skb->data[5], skb->data[6]); 156 break; 157 158 default: 159 printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n", frametype); 160 break; 161 } 162 163 if (neigh->restarted) { 164 while ((skbn = skb_dequeue(&neigh->queue)) != NULL) 165 if (!rose_send_frame(skbn, neigh)) 166 kfree_skb(skbn); 167 } 168 } 169 170 /* 171 * This routine is called when a Restart Request is needed 172 */ 173 static void rose_transmit_restart_request(struct rose_neigh *neigh) 174 { 175 struct sk_buff *skb; 176 unsigned char *dptr; 177 int len; 178 179 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3; 180 181 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) 182 return; 183 184 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); 185 186 dptr = skb_put(skb, ROSE_MIN_LEN + 3); 187 188 *dptr++ = AX25_P_ROSE; 189 *dptr++ = ROSE_GFI; 190 *dptr++ = 0x00; 191 *dptr++ = ROSE_RESTART_REQUEST; 192 *dptr++ = ROSE_DTE_ORIGINATED; 193 *dptr++ = 0; 194 195 if (!rose_send_frame(skb, neigh)) 196 kfree_skb(skb); 197 } 198 199 /* 200 * This routine is called when a Restart Confirmation is needed 201 */ 202 static void rose_transmit_restart_confirmation(struct rose_neigh *neigh) 203 { 204 struct sk_buff *skb; 205 unsigned char *dptr; 206 int len; 207 208 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1; 209 210 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) 211 return; 212 213 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); 214 215 dptr = skb_put(skb, ROSE_MIN_LEN + 1); 216 217 *dptr++ = AX25_P_ROSE; 218 *dptr++ = ROSE_GFI; 219 *dptr++ = 0x00; 220 *dptr++ = ROSE_RESTART_CONFIRMATION; 221 222 if (!rose_send_frame(skb, neigh)) 223 kfree_skb(skb); 224 } 225 226 /* 227 * This routine is called when a Clear Request is needed outside of the context 228 * of a connected socket. 229 */ 230 void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic) 231 { 232 struct sk_buff *skb; 233 unsigned char *dptr; 234 int len; 235 236 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3; 237 238 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) 239 return; 240 241 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); 242 243 dptr = skb_put(skb, ROSE_MIN_LEN + 3); 244 245 *dptr++ = AX25_P_ROSE; 246 *dptr++ = ((lci >> 8) & 0x0F) | ROSE_GFI; 247 *dptr++ = ((lci >> 0) & 0xFF); 248 *dptr++ = ROSE_CLEAR_REQUEST; 249 *dptr++ = cause; 250 *dptr++ = diagnostic; 251 252 if (!rose_send_frame(skb, neigh)) 253 kfree_skb(skb); 254 } 255 256 void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh) 257 { 258 unsigned char *dptr; 259 260 #if 0 261 if (call_fw_firewall(PF_ROSE, skb->dev, skb->data, NULL, &skb) != FW_ACCEPT) { 262 kfree_skb(skb); 263 return; 264 } 265 #endif 266 267 if (neigh->loopback) { 268 rose_loopback_queue(skb, neigh); 269 return; 270 } 271 272 if (!rose_link_up(neigh)) 273 neigh->restarted = 0; 274 275 dptr = skb_push(skb, 1); 276 *dptr++ = AX25_P_ROSE; 277 278 if (neigh->restarted) { 279 if (!rose_send_frame(skb, neigh)) 280 kfree_skb(skb); 281 } else { 282 skb_queue_tail(&neigh->queue, skb); 283 284 if (!rose_t0timer_running(neigh)) { 285 rose_transmit_restart_request(neigh); 286 neigh->dce_mode = 0; 287 rose_start_t0timer(neigh); 288 } 289 } 290 } 291