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 <linux/slab.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 <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 ax25_cb *ax25s; 105 106 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0) 107 rose_call = (ax25_address *)neigh->dev->dev_addr; 108 else 109 rose_call = &rose_callsign; 110 111 ax25s = neigh->ax25; 112 neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev); 113 if (ax25s) 114 ax25_cb_put(ax25s); 115 116 return neigh->ax25 != NULL; 117 } 118 119 /* 120 * Interface to ax25_link_up. Changes my level 2 callsign depending 121 * on whether we have a global ROSE callsign or use the default port 122 * callsign. 123 */ 124 static int rose_link_up(struct rose_neigh *neigh) 125 { 126 ax25_address *rose_call; 127 ax25_cb *ax25s; 128 129 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0) 130 rose_call = (ax25_address *)neigh->dev->dev_addr; 131 else 132 rose_call = &rose_callsign; 133 134 ax25s = neigh->ax25; 135 neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev); 136 if (ax25s) 137 ax25_cb_put(ax25s); 138 139 return neigh->ax25 != NULL; 140 } 141 142 /* 143 * This handles all restart and diagnostic frames. 144 */ 145 void rose_link_rx_restart(struct sk_buff *skb, struct rose_neigh *neigh, unsigned short frametype) 146 { 147 struct sk_buff *skbn; 148 149 switch (frametype) { 150 case ROSE_RESTART_REQUEST: 151 rose_stop_t0timer(neigh); 152 neigh->restarted = 1; 153 neigh->dce_mode = (skb->data[3] == ROSE_DTE_ORIGINATED); 154 rose_transmit_restart_confirmation(neigh); 155 break; 156 157 case ROSE_RESTART_CONFIRMATION: 158 rose_stop_t0timer(neigh); 159 neigh->restarted = 1; 160 break; 161 162 case ROSE_DIAGNOSTIC: 163 pr_warn("ROSE: received diagnostic #%d - %3ph\n", skb->data[3], 164 skb->data + 4); 165 break; 166 167 default: 168 printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n", frametype); 169 break; 170 } 171 172 if (neigh->restarted) { 173 while ((skbn = skb_dequeue(&neigh->queue)) != NULL) 174 if (!rose_send_frame(skbn, neigh)) 175 kfree_skb(skbn); 176 } 177 } 178 179 /* 180 * This routine is called when a Restart Request is needed 181 */ 182 static void rose_transmit_restart_request(struct rose_neigh *neigh) 183 { 184 struct sk_buff *skb; 185 unsigned char *dptr; 186 int len; 187 188 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3; 189 190 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) 191 return; 192 193 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); 194 195 dptr = skb_put(skb, ROSE_MIN_LEN + 3); 196 197 *dptr++ = AX25_P_ROSE; 198 *dptr++ = ROSE_GFI; 199 *dptr++ = 0x00; 200 *dptr++ = ROSE_RESTART_REQUEST; 201 *dptr++ = ROSE_DTE_ORIGINATED; 202 *dptr++ = 0; 203 204 if (!rose_send_frame(skb, neigh)) 205 kfree_skb(skb); 206 } 207 208 /* 209 * This routine is called when a Restart Confirmation is needed 210 */ 211 static void rose_transmit_restart_confirmation(struct rose_neigh *neigh) 212 { 213 struct sk_buff *skb; 214 unsigned char *dptr; 215 int len; 216 217 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1; 218 219 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) 220 return; 221 222 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); 223 224 dptr = skb_put(skb, ROSE_MIN_LEN + 1); 225 226 *dptr++ = AX25_P_ROSE; 227 *dptr++ = ROSE_GFI; 228 *dptr++ = 0x00; 229 *dptr++ = ROSE_RESTART_CONFIRMATION; 230 231 if (!rose_send_frame(skb, neigh)) 232 kfree_skb(skb); 233 } 234 235 /* 236 * This routine is called when a Clear Request is needed outside of the context 237 * of a connected socket. 238 */ 239 void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic) 240 { 241 struct sk_buff *skb; 242 unsigned char *dptr; 243 int len; 244 245 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3; 246 247 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) 248 return; 249 250 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); 251 252 dptr = skb_put(skb, ROSE_MIN_LEN + 3); 253 254 *dptr++ = AX25_P_ROSE; 255 *dptr++ = ((lci >> 8) & 0x0F) | ROSE_GFI; 256 *dptr++ = ((lci >> 0) & 0xFF); 257 *dptr++ = ROSE_CLEAR_REQUEST; 258 *dptr++ = cause; 259 *dptr++ = diagnostic; 260 261 if (!rose_send_frame(skb, neigh)) 262 kfree_skb(skb); 263 } 264 265 void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh) 266 { 267 unsigned char *dptr; 268 269 if (neigh->loopback) { 270 rose_loopback_queue(skb, neigh); 271 return; 272 } 273 274 if (!rose_link_up(neigh)) 275 neigh->restarted = 0; 276 277 dptr = skb_push(skb, 1); 278 *dptr++ = AX25_P_ROSE; 279 280 if (neigh->restarted) { 281 if (!rose_send_frame(skb, neigh)) 282 kfree_skb(skb); 283 } else { 284 skb_queue_tail(&neigh->queue, skb); 285 286 if (!rose_t0timer_running(neigh)) { 287 rose_transmit_restart_request(neigh); 288 neigh->dce_mode = 0; 289 rose_start_t0timer(neigh); 290 } 291 } 292 } 293