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246 lines
5.3 KiB
246 lines
5.3 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* |
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* Copyright (C) Jonathan Naylor G4KLX ([email protected]) |
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*/ |
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#include <linux/errno.h> |
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#include <linux/types.h> |
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#include <linux/socket.h> |
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#include <linux/in.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/timer.h> |
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#include <linux/string.h> |
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#include <linux/sockios.h> |
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#include <linux/net.h> |
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#include <linux/slab.h> |
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#include <net/ax25.h> |
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#include <linux/inet.h> |
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#include <linux/netdevice.h> |
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#include <linux/if_arp.h> |
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#include <linux/skbuff.h> |
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#include <net/sock.h> |
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#include <linux/uaccess.h> |
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#include <linux/fcntl.h> |
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#include <linux/termios.h> /* For TIOCINQ/OUTQ */ |
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#include <linux/mm.h> |
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#include <linux/interrupt.h> |
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#include <linux/notifier.h> |
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#include <linux/proc_fs.h> |
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#include <linux/stat.h> |
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#include <linux/sysctl.h> |
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#include <net/ip.h> |
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#include <net/arp.h> |
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/* |
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* IP over AX.25 encapsulation. |
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*/ |
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/* |
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* Shove an AX.25 UI header on an IP packet and handle ARP |
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*/ |
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#ifdef CONFIG_INET |
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static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev, |
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unsigned short type, const void *daddr, |
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const void *saddr, unsigned int len) |
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{ |
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unsigned char *buff; |
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/* they sometimes come back to us... */ |
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if (type == ETH_P_AX25) |
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return 0; |
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/* header is an AX.25 UI frame from us to them */ |
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buff = skb_push(skb, AX25_HEADER_LEN); |
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*buff++ = 0x00; /* KISS DATA */ |
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if (daddr != NULL) |
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memcpy(buff, daddr, dev->addr_len); /* Address specified */ |
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buff[6] &= ~AX25_CBIT; |
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buff[6] &= ~AX25_EBIT; |
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buff[6] |= AX25_SSSID_SPARE; |
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buff += AX25_ADDR_LEN; |
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if (saddr != NULL) |
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memcpy(buff, saddr, dev->addr_len); |
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else |
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memcpy(buff, dev->dev_addr, dev->addr_len); |
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buff[6] &= ~AX25_CBIT; |
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buff[6] |= AX25_EBIT; |
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buff[6] |= AX25_SSSID_SPARE; |
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buff += AX25_ADDR_LEN; |
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*buff++ = AX25_UI; /* UI */ |
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/* Append a suitable AX.25 PID */ |
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switch (type) { |
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case ETH_P_IP: |
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*buff++ = AX25_P_IP; |
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break; |
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case ETH_P_ARP: |
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*buff++ = AX25_P_ARP; |
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break; |
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default: |
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printk(KERN_ERR "AX.25: ax25_hard_header - wrong protocol type 0x%2.2x\n", type); |
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*buff++ = 0; |
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break; |
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} |
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if (daddr != NULL) |
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return AX25_HEADER_LEN; |
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return -AX25_HEADER_LEN; /* Unfinished header */ |
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} |
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netdev_tx_t ax25_ip_xmit(struct sk_buff *skb) |
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{ |
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struct sk_buff *ourskb; |
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unsigned char *bp = skb->data; |
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ax25_route *route; |
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struct net_device *dev = NULL; |
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ax25_address *src, *dst; |
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ax25_digi *digipeat = NULL; |
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ax25_dev *ax25_dev; |
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ax25_cb *ax25; |
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char ip_mode = ' '; |
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dst = (ax25_address *)(bp + 1); |
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src = (ax25_address *)(bp + 8); |
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ax25_route_lock_use(); |
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route = ax25_get_route(dst, NULL); |
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if (route) { |
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digipeat = route->digipeat; |
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dev = route->dev; |
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ip_mode = route->ip_mode; |
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} |
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if (dev == NULL) |
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dev = skb->dev; |
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if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) { |
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kfree_skb(skb); |
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goto put; |
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} |
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if (bp[16] == AX25_P_IP) { |
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if (ip_mode == 'V' || (ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) { |
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/* |
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* We copy the buffer and release the original thereby |
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* keeping it straight |
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* |
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* Note: we report 1 back so the caller will |
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* not feed the frame direct to the physical device |
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* We don't want that to happen. (It won't be upset |
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* as we have pulled the frame from the queue by |
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* freeing it). |
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* |
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* NB: TCP modifies buffers that are still |
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* on a device queue, thus we use skb_copy() |
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* instead of using skb_clone() unless this |
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* gets fixed. |
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*/ |
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ax25_address src_c; |
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ax25_address dst_c; |
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if ((ourskb = skb_copy(skb, GFP_ATOMIC)) == NULL) { |
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kfree_skb(skb); |
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goto put; |
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} |
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if (skb->sk != NULL) |
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skb_set_owner_w(ourskb, skb->sk); |
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kfree_skb(skb); |
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/* dl9sau: bugfix |
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* after kfree_skb(), dst and src which were pointer |
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* to bp which is part of skb->data would not be valid |
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* anymore hope that after skb_pull(ourskb, ..) our |
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* dsc_c and src_c will not become invalid |
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*/ |
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bp = ourskb->data; |
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dst_c = *(ax25_address *)(bp + 1); |
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src_c = *(ax25_address *)(bp + 8); |
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skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */ |
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skb_reset_network_header(ourskb); |
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ax25=ax25_send_frame( |
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ourskb, |
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ax25_dev->values[AX25_VALUES_PACLEN], |
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&src_c, |
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&dst_c, digipeat, dev); |
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if (ax25) { |
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ax25_cb_put(ax25); |
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} |
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goto put; |
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} |
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} |
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bp[7] &= ~AX25_CBIT; |
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bp[7] &= ~AX25_EBIT; |
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bp[7] |= AX25_SSSID_SPARE; |
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bp[14] &= ~AX25_CBIT; |
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bp[14] |= AX25_EBIT; |
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bp[14] |= AX25_SSSID_SPARE; |
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skb_pull(skb, AX25_KISS_HEADER_LEN); |
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if (digipeat != NULL) { |
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if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL) |
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goto put; |
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skb = ourskb; |
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} |
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ax25_queue_xmit(skb, dev); |
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put: |
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ax25_route_lock_unuse(); |
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return NETDEV_TX_OK; |
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} |
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#else /* INET */ |
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static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev, |
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unsigned short type, const void *daddr, |
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const void *saddr, unsigned int len) |
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{ |
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return -AX25_HEADER_LEN; |
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} |
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netdev_tx_t ax25_ip_xmit(struct sk_buff *skb) |
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{ |
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kfree_skb(skb); |
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return NETDEV_TX_OK; |
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} |
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#endif |
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static bool ax25_validate_header(const char *header, unsigned int len) |
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{ |
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ax25_digi digi; |
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if (!len) |
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return false; |
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if (header[0]) |
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return true; |
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return ax25_addr_parse(header + 1, len - 1, NULL, NULL, &digi, NULL, |
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NULL); |
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} |
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const struct header_ops ax25_header_ops = { |
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.create = ax25_hard_header, |
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.validate = ax25_validate_header, |
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}; |
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EXPORT_SYMBOL(ax25_header_ops); |
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EXPORT_SYMBOL(ax25_ip_xmit);
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