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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 | /* * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) */ #include <linux/config.h> #include <linux/errno.h> #include <linux/types.h> #include <linux/socket.h> #include <linux/in.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/timer.h> #include <linux/string.h> #include <linux/sockios.h> #include <linux/net.h> #include <net/ax25.h> #include <linux/inet.h> #include <linux/netdevice.h> #include <linux/if_arp.h> #include <linux/skbuff.h> #include <net/sock.h> #include <asm/uaccess.h> #include <asm/system.h> #include <linux/fcntl.h> #include <linux/termios.h> /* For TIOCINQ/OUTQ */ #include <linux/mm.h> #include <linux/interrupt.h> #include <linux/notifier.h> #include <linux/proc_fs.h> #include <linux/stat.h> #include <linux/netfilter.h> #include <linux/sysctl.h> #include <net/ip.h> #include <net/arp.h> /* * IP over AX.25 encapsulation. */ /* * Shove an AX.25 UI header on an IP packet and handle ARP */ #ifdef CONFIG_INET int ax25_encapsulate(struct sk_buff *skb, struct net_device *dev, unsigned short type, void *daddr, void *saddr, unsigned len) { unsigned char *buff; /* they sometimes come back to us... */ if (type == ETH_P_AX25) return 0; /* header is an AX.25 UI frame from us to them */ buff = skb_push(skb, AX25_HEADER_LEN); *buff++ = 0x00; /* KISS DATA */ if (daddr != NULL) memcpy(buff, daddr, dev->addr_len); /* Address specified */ buff[6] &= ~AX25_CBIT; buff[6] &= ~AX25_EBIT; buff[6] |= AX25_SSSID_SPARE; buff += AX25_ADDR_LEN; if (saddr != NULL) memcpy(buff, saddr, dev->addr_len); else memcpy(buff, dev->dev_addr, dev->addr_len); buff[6] &= ~AX25_CBIT; buff[6] |= AX25_EBIT; buff[6] |= AX25_SSSID_SPARE; buff += AX25_ADDR_LEN; *buff++ = AX25_UI; /* UI */ /* Append a suitable AX.25 PID */ switch (type) { case ETH_P_IP: *buff++ = AX25_P_IP; break; case ETH_P_ARP: *buff++ = AX25_P_ARP; break; default: printk(KERN_ERR "AX.25: ax25_encapsulate - wrong protocol type 0x%2.2x\n", type); *buff++ = 0; break; } if (daddr != NULL) return AX25_HEADER_LEN; return -AX25_HEADER_LEN; /* Unfinished header */ } int ax25_rebuild_header(struct sk_buff *skb) { struct sk_buff *ourskb; unsigned char *bp = skb->data; struct net_device *dev; ax25_address *src, *dst; ax25_dev *ax25_dev; ax25_route _route, *route = &_route; dst = (ax25_address *)(bp + 1); src = (ax25_address *)(bp + 8); if (arp_find(bp + 1, skb)) return 1; route = ax25_rt_find_route(route, dst, NULL); dev = route->dev; if (dev == NULL) dev = skb->dev; if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) { goto put; } if (bp[16] == AX25_P_IP) { if (route->ip_mode == 'V' || (route->ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) { /* * We copy the buffer and release the original thereby * keeping it straight * * Note: we report 1 back so the caller will * not feed the frame direct to the physical device * We don't want that to happen. (It won't be upset * as we have pulled the frame from the queue by * freeing it). * * NB: TCP modifies buffers that are still * on a device queue, thus we use skb_copy() * instead of using skb_clone() unless this * gets fixed. */ ax25_address src_c; ax25_address dst_c; if ((ourskb = skb_copy(skb, GFP_ATOMIC)) == NULL) { kfree_skb(skb); goto put; } if (skb->sk != NULL) skb_set_owner_w(ourskb, skb->sk); kfree_skb(skb); src_c = *src; dst_c = *dst; skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */ ourskb->nh.raw = ourskb->data; ax25_send_frame(ourskb, ax25_dev->values[AX25_VALUES_PACLEN], &src_c, &dst_c, route->digipeat, dev); goto put; } } bp[7] &= ~AX25_CBIT; bp[7] &= ~AX25_EBIT; bp[7] |= AX25_SSSID_SPARE; bp[14] &= ~AX25_CBIT; bp[14] |= AX25_EBIT; bp[14] |= AX25_SSSID_SPARE; skb_pull(skb, AX25_KISS_HEADER_LEN); if (route->digipeat != NULL) { if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL) { kfree_skb(skb); goto put; } skb = ourskb; } skb->dev = dev; ax25_queue_xmit(skb); put: ax25_put_route(route); return 1; } #else /* INET */ int ax25_encapsulate(struct sk_buff *skb, struct net_device *dev, unsigned short type, void *daddr, void *saddr, unsigned len) { return -AX25_HEADER_LEN; } int ax25_rebuild_header(struct sk_buff *skb) { return 1; } #endif |