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/jiffies.h> 12 #include <linux/timer.h> 13 #include <linux/string.h> 14 #include <linux/sockios.h> 15 #include <linux/net.h> 16 #include <linux/slab.h> 17 #include <net/ax25.h> 18 #include <linux/inet.h> 19 #include <linux/netdevice.h> 20 #include <linux/skbuff.h> 21 #include <net/sock.h> 22 #include <linux/fcntl.h> 23 #include <linux/mm.h> 24 #include <linux/interrupt.h> 25 #include <net/rose.h> 26 27 static void rose_ftimer_expiry(struct timer_list *); 28 static void rose_t0timer_expiry(struct timer_list *); 29 30 static void rose_transmit_restart_confirmation(struct rose_neigh *neigh); 31 static void rose_transmit_restart_request(struct rose_neigh *neigh); 32 33 void rose_start_ftimer(struct rose_neigh *neigh) 34 { 35 del_timer(&neigh->ftimer); 36 37 neigh->ftimer.function = rose_ftimer_expiry; 38 neigh->ftimer.expires = 39 jiffies + msecs_to_jiffies(sysctl_rose_link_fail_timeout); 40 41 add_timer(&neigh->ftimer); 42 } 43 44 static void rose_start_t0timer(struct rose_neigh *neigh) 45 { 46 del_timer(&neigh->t0timer); 47 48 neigh->t0timer.function = rose_t0timer_expiry; 49 neigh->t0timer.expires = 50 jiffies + msecs_to_jiffies(sysctl_rose_restart_request_timeout); 51 52 add_timer(&neigh->t0timer); 53 } 54 55 void rose_stop_ftimer(struct rose_neigh *neigh) 56 { 57 del_timer(&neigh->ftimer); 58 } 59 60 void rose_stop_t0timer(struct rose_neigh *neigh) 61 { 62 del_timer(&neigh->t0timer); 63 } 64 65 int rose_ftimer_running(struct rose_neigh *neigh) 66 { 67 return timer_pending(&neigh->ftimer); 68 } 69 70 static int rose_t0timer_running(struct rose_neigh *neigh) 71 { 72 return timer_pending(&neigh->t0timer); 73 } 74 75 static void rose_ftimer_expiry(struct timer_list *t) 76 { 77 } 78 79 static void rose_t0timer_expiry(struct timer_list *t) 80 { 81 struct rose_neigh *neigh = from_timer(neigh, t, t0timer); 82 83 rose_transmit_restart_request(neigh); 84 85 neigh->dce_mode = 0; 86 87 rose_start_t0timer(neigh); 88 } 89 90 /* 91 * Interface to ax25_send_frame. Changes my level 2 callsign depending 92 * on whether we have a global ROSE callsign or use the default port 93 * callsign. 94 */ 95 static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh) 96 { 97 ax25_address *rose_call; 98 ax25_cb *ax25s; 99 100 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0) 101 rose_call = (ax25_address *)neigh->dev->dev_addr; 102 else 103 rose_call = &rose_callsign; 104 105 ax25s = neigh->ax25; 106 neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev); 107 if (ax25s) 108 ax25_cb_put(ax25s); 109 110 return neigh->ax25 != NULL; 111 } 112 113 /* 114 * Interface to ax25_link_up. Changes my level 2 callsign depending 115 * on whether we have a global ROSE callsign or use the default port 116 * callsign. 117 */ 118 static int rose_link_up(struct rose_neigh *neigh) 119 { 120 ax25_address *rose_call; 121 ax25_cb *ax25s; 122 123 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0) 124 rose_call = (ax25_address *)neigh->dev->dev_addr; 125 else 126 rose_call = &rose_callsign; 127 128 ax25s = neigh->ax25; 129 neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev); 130 if (ax25s) 131 ax25_cb_put(ax25s); 132 133 return neigh->ax25 != NULL; 134 } 135 136 /* 137 * This handles all restart and diagnostic frames. 138 */ 139 void rose_link_rx_restart(struct sk_buff *skb, struct rose_neigh *neigh, unsigned short frametype) 140 { 141 struct sk_buff *skbn; 142 143 switch (frametype) { 144 case ROSE_RESTART_REQUEST: 145 rose_stop_t0timer(neigh); 146 neigh->restarted = 1; 147 neigh->dce_mode = (skb->data[3] == ROSE_DTE_ORIGINATED); 148 rose_transmit_restart_confirmation(neigh); 149 break; 150 151 case ROSE_RESTART_CONFIRMATION: 152 rose_stop_t0timer(neigh); 153 neigh->restarted = 1; 154 break; 155 156 case ROSE_DIAGNOSTIC: 157 pr_warn("ROSE: received diagnostic #%d - %3ph\n", skb->data[3], 158 skb->data + 4); 159 break; 160 161 default: 162 printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n", frametype); 163 break; 164 } 165 166 if (neigh->restarted) { 167 while ((skbn = skb_dequeue(&neigh->queue)) != NULL) 168 if (!rose_send_frame(skbn, neigh)) 169 kfree_skb(skbn); 170 } 171 } 172 173 /* 174 * This routine is called when a Restart Request is needed 175 */ 176 static void rose_transmit_restart_request(struct rose_neigh *neigh) 177 { 178 struct sk_buff *skb; 179 unsigned char *dptr; 180 int len; 181 182 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3; 183 184 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) 185 return; 186 187 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); 188 189 dptr = skb_put(skb, ROSE_MIN_LEN + 3); 190 191 *dptr++ = AX25_P_ROSE; 192 *dptr++ = ROSE_GFI; 193 *dptr++ = 0x00; 194 *dptr++ = ROSE_RESTART_REQUEST; 195 *dptr++ = ROSE_DTE_ORIGINATED; 196 *dptr++ = 0; 197 198 if (!rose_send_frame(skb, neigh)) 199 kfree_skb(skb); 200 } 201 202 /* 203 * This routine is called when a Restart Confirmation is needed 204 */ 205 static void rose_transmit_restart_confirmation(struct rose_neigh *neigh) 206 { 207 struct sk_buff *skb; 208 unsigned char *dptr; 209 int len; 210 211 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1; 212 213 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) 214 return; 215 216 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); 217 218 dptr = skb_put(skb, ROSE_MIN_LEN + 1); 219 220 *dptr++ = AX25_P_ROSE; 221 *dptr++ = ROSE_GFI; 222 *dptr++ = 0x00; 223 *dptr++ = ROSE_RESTART_CONFIRMATION; 224 225 if (!rose_send_frame(skb, neigh)) 226 kfree_skb(skb); 227 } 228 229 /* 230 * This routine is called when a Clear Request is needed outside of the context 231 * of a connected socket. 232 */ 233 void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic) 234 { 235 struct sk_buff *skb; 236 unsigned char *dptr; 237 int len; 238 239 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3; 240 241 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) 242 return; 243 244 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); 245 246 dptr = skb_put(skb, ROSE_MIN_LEN + 3); 247 248 *dptr++ = AX25_P_ROSE; 249 *dptr++ = ((lci >> 8) & 0x0F) | ROSE_GFI; 250 *dptr++ = ((lci >> 0) & 0xFF); 251 *dptr++ = ROSE_CLEAR_REQUEST; 252 *dptr++ = cause; 253 *dptr++ = diagnostic; 254 255 if (!rose_send_frame(skb, neigh)) 256 kfree_skb(skb); 257 } 258 259 void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh) 260 { 261 unsigned char *dptr; 262 263 if (neigh->loopback) { 264 rose_loopback_queue(skb, neigh); 265 return; 266 } 267 268 if (!rose_link_up(neigh)) 269 neigh->restarted = 0; 270 271 dptr = skb_push(skb, 1); 272 *dptr++ = AX25_P_ROSE; 273 274 if (neigh->restarted) { 275 if (!rose_send_frame(skb, neigh)) 276 kfree_skb(skb); 277 } else { 278 skb_queue_tail(&neigh->queue, skb); 279 280 if (!rose_t0timer_running(neigh)) { 281 rose_transmit_restart_request(neigh); 282 neigh->dce_mode = 0; 283 rose_start_t0timer(neigh); 284 } 285 } 286 } 287