/* * 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/errno.h> #include <linux/types.h> #include <linux/socket.h> #include <linux/in.h> #include <linux/kernel.h> #include <linux/module.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_hard_header(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_hard_header - 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; ax25_route *route; struct net_device *dev = NULL; ax25_address *src, *dst; ax25_digi *digipeat = NULL; ax25_dev *ax25_dev; ax25_cb *ax25; char ip_mode = ' '; dst = (ax25_address *)(bp + 1); src = (ax25_address *)(bp + 8); if (arp_find(bp + 1, skb)) return 1; route = ax25_get_route(dst, NULL); if (route) { digipeat = route->digipeat; dev = route->dev; ip_mode = route->ip_mode; }; if (dev == NULL) dev = skb->dev; if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) { goto put; } if (bp[16] == AX25_P_IP) { if (ip_mode == 'V' || (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); /* dl9sau: bugfix * after kfree_skb(), dst and src which were pointer * to bp which is part of skb->data would not be valid * anymore hope that after skb_pull(ourskb, ..) our * dsc_c and src_c will not become invalid */ bp = ourskb->data; dst_c = *(ax25_address *)(bp + 1); src_c = *(ax25_address *)(bp + 8); skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */ ourskb->nh.raw = ourskb->data; ax25=ax25_send_frame( ourskb, ax25_dev->values[AX25_VALUES_PACLEN], &src_c, &dst_c, digipeat, dev); if (ax25) { ax25_cb_put(ax25); } 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 (digipeat != NULL) { if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL) { kfree_skb(skb); goto put; } skb = ourskb; } ax25_queue_xmit(skb, dev); put: if (route) ax25_put_route(route); return 1; } #else /* INET */ int ax25_hard_header(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 EXPORT_SYMBOL(ax25_hard_header); EXPORT_SYMBOL(ax25_rebuild_header);