158 строки
3.4 KiB
C
158 строки
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* History
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* 03-01-2007 Added forwarding for x.25 Andrew Hendry
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*/
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#define pr_fmt(fmt) "X25: " fmt
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#include <linux/if_arp.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <net/x25.h>
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LIST_HEAD(x25_forward_list);
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DEFINE_RWLOCK(x25_forward_list_lock);
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int x25_forward_call(struct x25_address *dest_addr, struct x25_neigh *from,
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struct sk_buff *skb, int lci)
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{
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struct x25_route *rt;
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struct x25_neigh *neigh_new = NULL;
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struct x25_forward *x25_frwd, *new_frwd;
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struct sk_buff *skbn;
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short same_lci = 0;
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int rc = 0;
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if ((rt = x25_get_route(dest_addr)) == NULL)
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goto out_no_route;
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if ((neigh_new = x25_get_neigh(rt->dev)) == NULL) {
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/* This shouldn't happen, if it occurs somehow
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* do something sensible
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*/
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goto out_put_route;
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}
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/* Avoid a loop. This is the normal exit path for a
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* system with only one x.25 iface and default route
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*/
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if (rt->dev == from->dev) {
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goto out_put_nb;
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}
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/* Remote end sending a call request on an already
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* established LCI? It shouldn't happen, just in case..
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*/
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read_lock_bh(&x25_forward_list_lock);
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list_for_each_entry(x25_frwd, &x25_forward_list, node) {
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if (x25_frwd->lci == lci) {
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pr_warn("call request for lci which is already registered!, transmitting but not registering new pair\n");
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same_lci = 1;
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}
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}
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read_unlock_bh(&x25_forward_list_lock);
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/* Save the forwarding details for future traffic */
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if (!same_lci){
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if ((new_frwd = kmalloc(sizeof(struct x25_forward),
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GFP_ATOMIC)) == NULL){
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rc = -ENOMEM;
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goto out_put_nb;
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}
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new_frwd->lci = lci;
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new_frwd->dev1 = rt->dev;
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new_frwd->dev2 = from->dev;
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write_lock_bh(&x25_forward_list_lock);
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list_add(&new_frwd->node, &x25_forward_list);
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write_unlock_bh(&x25_forward_list_lock);
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}
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/* Forward the call request */
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if ( (skbn = skb_clone(skb, GFP_ATOMIC)) == NULL){
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goto out_put_nb;
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}
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x25_transmit_link(skbn, neigh_new);
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rc = 1;
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out_put_nb:
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x25_neigh_put(neigh_new);
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out_put_route:
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x25_route_put(rt);
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out_no_route:
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return rc;
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}
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int x25_forward_data(int lci, struct x25_neigh *from, struct sk_buff *skb) {
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struct x25_forward *frwd;
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struct net_device *peer = NULL;
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struct x25_neigh *nb;
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struct sk_buff *skbn;
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int rc = 0;
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read_lock_bh(&x25_forward_list_lock);
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list_for_each_entry(frwd, &x25_forward_list, node) {
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if (frwd->lci == lci) {
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/* The call is established, either side can send */
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if (from->dev == frwd->dev1) {
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peer = frwd->dev2;
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} else {
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peer = frwd->dev1;
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}
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break;
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}
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}
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read_unlock_bh(&x25_forward_list_lock);
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if ( (nb = x25_get_neigh(peer)) == NULL)
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goto out;
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if ( (skbn = pskb_copy(skb, GFP_ATOMIC)) == NULL){
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goto output;
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}
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x25_transmit_link(skbn, nb);
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rc = 1;
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output:
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x25_neigh_put(nb);
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out:
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return rc;
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}
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void x25_clear_forward_by_lci(unsigned int lci)
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{
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struct x25_forward *fwd, *tmp;
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write_lock_bh(&x25_forward_list_lock);
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list_for_each_entry_safe(fwd, tmp, &x25_forward_list, node) {
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if (fwd->lci == lci) {
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list_del(&fwd->node);
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kfree(fwd);
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}
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}
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write_unlock_bh(&x25_forward_list_lock);
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}
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void x25_clear_forward_by_dev(struct net_device *dev)
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{
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struct x25_forward *fwd, *tmp;
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write_lock_bh(&x25_forward_list_lock);
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list_for_each_entry_safe(fwd, tmp, &x25_forward_list, node) {
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if ((fwd->dev1 == dev) || (fwd->dev2 == dev)){
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list_del(&fwd->node);
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kfree(fwd);
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}
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}
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write_unlock_bh(&x25_forward_list_lock);
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}
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