--- /dev/null
+/*
+ * 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/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/slab.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 <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
+
+static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
+ unsigned short type, const void *daddr,
+ const void *saddr, unsigned int 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 */
+}
+
+netdev_tx_t ax25_ip_xmit(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);
+
+ 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) {
+ kfree_skb(skb);
+ 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 */
+ skb_reset_network_header(ourskb);
+
+ 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 NETDEV_TX_OK;
+}
+
+#else /* INET */
+
+static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
+ unsigned short type, const void *daddr,
+ const void *saddr, unsigned int len)
+{
+ return -AX25_HEADER_LEN;
+}
+
+netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
+{
+ kfree_skb(skb);
+ return NETDEV_TX_OK;
+}
+#endif
+
+const struct header_ops ax25_header_ops = {
+ .create = ax25_hard_header,
+};
+
+EXPORT_SYMBOL(ax25_header_ops);
+EXPORT_SYMBOL(ax25_ip_xmit);
+
Code Review / kvmfornfv.git / blobdiff