Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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/config.h> |
| 10 | #include <linux/errno.h> |
| 11 | #include <linux/types.h> |
| 12 | #include <linux/socket.h> |
| 13 | #include <linux/in.h> |
| 14 | #include <linux/kernel.h> |
| 15 | #include <linux/sched.h> |
| 16 | #include <linux/timer.h> |
| 17 | #include <linux/string.h> |
| 18 | #include <linux/sockios.h> |
| 19 | #include <linux/net.h> |
| 20 | #include <net/ax25.h> |
| 21 | #include <linux/inet.h> |
| 22 | #include <linux/netdevice.h> |
| 23 | #include <linux/if_arp.h> |
| 24 | #include <linux/skbuff.h> |
| 25 | #include <net/sock.h> |
| 26 | #include <asm/uaccess.h> |
| 27 | #include <asm/system.h> |
| 28 | #include <linux/fcntl.h> |
| 29 | #include <linux/termios.h> /* For TIOCINQ/OUTQ */ |
| 30 | #include <linux/mm.h> |
| 31 | #include <linux/interrupt.h> |
| 32 | #include <linux/notifier.h> |
| 33 | #include <linux/proc_fs.h> |
| 34 | #include <linux/stat.h> |
| 35 | #include <linux/netfilter.h> |
| 36 | #include <linux/sysctl.h> |
| 37 | #include <net/ip.h> |
| 38 | #include <net/arp.h> |
| 39 | |
| 40 | /* |
| 41 | * IP over AX.25 encapsulation. |
| 42 | */ |
| 43 | |
| 44 | /* |
| 45 | * Shove an AX.25 UI header on an IP packet and handle ARP |
| 46 | */ |
| 47 | |
| 48 | #ifdef CONFIG_INET |
| 49 | |
| 50 | int ax25_encapsulate(struct sk_buff *skb, struct net_device *dev, unsigned short type, void *daddr, void *saddr, unsigned len) |
| 51 | { |
| 52 | unsigned char *buff; |
| 53 | |
| 54 | /* they sometimes come back to us... */ |
| 55 | if (type == ETH_P_AX25) |
| 56 | return 0; |
| 57 | |
| 58 | /* header is an AX.25 UI frame from us to them */ |
| 59 | buff = skb_push(skb, AX25_HEADER_LEN); |
| 60 | *buff++ = 0x00; /* KISS DATA */ |
| 61 | |
| 62 | if (daddr != NULL) |
| 63 | memcpy(buff, daddr, dev->addr_len); /* Address specified */ |
| 64 | |
| 65 | buff[6] &= ~AX25_CBIT; |
| 66 | buff[6] &= ~AX25_EBIT; |
| 67 | buff[6] |= AX25_SSSID_SPARE; |
| 68 | buff += AX25_ADDR_LEN; |
| 69 | |
| 70 | if (saddr != NULL) |
| 71 | memcpy(buff, saddr, dev->addr_len); |
| 72 | else |
| 73 | memcpy(buff, dev->dev_addr, dev->addr_len); |
| 74 | |
| 75 | buff[6] &= ~AX25_CBIT; |
| 76 | buff[6] |= AX25_EBIT; |
| 77 | buff[6] |= AX25_SSSID_SPARE; |
| 78 | buff += AX25_ADDR_LEN; |
| 79 | |
| 80 | *buff++ = AX25_UI; /* UI */ |
| 81 | |
| 82 | /* Append a suitable AX.25 PID */ |
| 83 | switch (type) { |
| 84 | case ETH_P_IP: |
| 85 | *buff++ = AX25_P_IP; |
| 86 | break; |
| 87 | case ETH_P_ARP: |
| 88 | *buff++ = AX25_P_ARP; |
| 89 | break; |
| 90 | default: |
| 91 | printk(KERN_ERR "AX.25: ax25_encapsulate - wrong protocol type 0x%2.2x\n", type); |
| 92 | *buff++ = 0; |
| 93 | break; |
| 94 | } |
| 95 | |
| 96 | if (daddr != NULL) |
| 97 | return AX25_HEADER_LEN; |
| 98 | |
| 99 | return -AX25_HEADER_LEN; /* Unfinished header */ |
| 100 | } |
| 101 | |
| 102 | int ax25_rebuild_header(struct sk_buff *skb) |
| 103 | { |
| 104 | struct sk_buff *ourskb; |
| 105 | unsigned char *bp = skb->data; |
| 106 | struct net_device *dev; |
| 107 | ax25_address *src, *dst; |
| 108 | ax25_dev *ax25_dev; |
| 109 | ax25_route _route, *route = &_route; |
| 110 | ax25_cb *ax25; |
| 111 | |
| 112 | dst = (ax25_address *)(bp + 1); |
| 113 | src = (ax25_address *)(bp + 8); |
| 114 | |
| 115 | if (arp_find(bp + 1, skb)) |
| 116 | return 1; |
| 117 | |
| 118 | route = ax25_rt_find_route(route, dst, NULL); |
| 119 | dev = route->dev; |
| 120 | |
| 121 | if (dev == NULL) |
| 122 | dev = skb->dev; |
| 123 | |
| 124 | if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) { |
| 125 | goto put; |
| 126 | } |
| 127 | |
| 128 | if (bp[16] == AX25_P_IP) { |
| 129 | if (route->ip_mode == 'V' || (route->ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) { |
| 130 | /* |
| 131 | * We copy the buffer and release the original thereby |
| 132 | * keeping it straight |
| 133 | * |
| 134 | * Note: we report 1 back so the caller will |
| 135 | * not feed the frame direct to the physical device |
| 136 | * We don't want that to happen. (It won't be upset |
| 137 | * as we have pulled the frame from the queue by |
| 138 | * freeing it). |
| 139 | * |
| 140 | * NB: TCP modifies buffers that are still |
| 141 | * on a device queue, thus we use skb_copy() |
| 142 | * instead of using skb_clone() unless this |
| 143 | * gets fixed. |
| 144 | */ |
| 145 | |
| 146 | ax25_address src_c; |
| 147 | ax25_address dst_c; |
| 148 | |
| 149 | if ((ourskb = skb_copy(skb, GFP_ATOMIC)) == NULL) { |
| 150 | kfree_skb(skb); |
| 151 | goto put; |
| 152 | } |
| 153 | |
| 154 | if (skb->sk != NULL) |
| 155 | skb_set_owner_w(ourskb, skb->sk); |
| 156 | |
| 157 | kfree_skb(skb); |
| 158 | /* dl9sau: bugfix |
| 159 | * after kfree_skb(), dst and src which were pointer |
| 160 | * to bp which is part of skb->data would not be valid |
| 161 | * anymore hope that after skb_pull(ourskb, ..) our |
| 162 | * dsc_c and src_c will not become invalid |
| 163 | */ |
| 164 | bp = ourskb->data; |
| 165 | dst_c = *(ax25_address *)(bp + 1); |
| 166 | src_c = *(ax25_address *)(bp + 8); |
| 167 | |
| 168 | skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */ |
| 169 | ourskb->nh.raw = ourskb->data; |
| 170 | |
| 171 | ax25=ax25_send_frame( |
| 172 | ourskb, |
| 173 | ax25_dev->values[AX25_VALUES_PACLEN], |
| 174 | &src_c, |
| 175 | &dst_c, route->digipeat, dev); |
| 176 | if (ax25) { |
| 177 | ax25_cb_put(ax25); |
| 178 | } |
| 179 | goto put; |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | bp[7] &= ~AX25_CBIT; |
| 184 | bp[7] &= ~AX25_EBIT; |
| 185 | bp[7] |= AX25_SSSID_SPARE; |
| 186 | |
| 187 | bp[14] &= ~AX25_CBIT; |
| 188 | bp[14] |= AX25_EBIT; |
| 189 | bp[14] |= AX25_SSSID_SPARE; |
| 190 | |
| 191 | skb_pull(skb, AX25_KISS_HEADER_LEN); |
| 192 | |
| 193 | if (route->digipeat != NULL) { |
| 194 | if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL) { |
| 195 | kfree_skb(skb); |
| 196 | goto put; |
| 197 | } |
| 198 | |
| 199 | skb = ourskb; |
| 200 | } |
| 201 | |
| 202 | skb->dev = dev; |
| 203 | |
| 204 | ax25_queue_xmit(skb); |
| 205 | |
| 206 | put: |
| 207 | ax25_put_route(route); |
| 208 | |
| 209 | return 1; |
| 210 | } |
| 211 | |
| 212 | #else /* INET */ |
| 213 | |
| 214 | int ax25_encapsulate(struct sk_buff *skb, struct net_device *dev, unsigned short type, void *daddr, void *saddr, unsigned len) |
| 215 | { |
| 216 | return -AX25_HEADER_LEN; |
| 217 | } |
| 218 | |
| 219 | int ax25_rebuild_header(struct sk_buff *skb) |
| 220 | { |
| 221 | return 1; |
| 222 | } |
| 223 | |
| 224 | #endif |
| 225 | |