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ipv6: avoid high order memory allocations for /proc/net/ipv6_route
Dumping routes on a system with lots rt6_infos in the fibs causes up to 11-order allocations in seq_file (which fail). While we could switch there to vmalloc we could just implement the streaming interface for /proc/net/ipv6_route. This patch switches /proc/net/ipv6_route from single_open_net to seq_open_net. loff_t *pos tracks dst entries. Also kill never used struct rt6_proc_arg and now unused function fib6_clean_all_ro. Cc: Ben Greear <greearb@candelatech.com> Cc: Patrick McHardy <kaber@trash.net> Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Hannes Frederic Sowa
David S. Miller
parent
6229ed1f22
commit
8d2ca1d7b5
@ -280,10 +280,6 @@ struct fib6_node *fib6_locate(struct fib6_node *root,
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const struct in6_addr *daddr, int dst_len,
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const struct in6_addr *saddr, int src_len);
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void fib6_clean_all_ro(struct net *net,
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int (*func)(struct rt6_info *, void *arg),
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int prune, void *arg);
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void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
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int prune, void *arg);
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@ -299,6 +295,8 @@ void fib6_gc_cleanup(void);
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int fib6_init(void);
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int ipv6_route_open(struct inode *inode, struct file *file);
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#ifdef CONFIG_IPV6_MULTIPLE_TABLES
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int fib6_rules_init(void);
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void fib6_rules_cleanup(void);
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@ -1529,25 +1529,6 @@ static void fib6_clean_tree(struct net *net, struct fib6_node *root,
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fib6_walk(&c.w);
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}
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void fib6_clean_all_ro(struct net *net, int (*func)(struct rt6_info *, void *arg),
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int prune, void *arg)
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{
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struct fib6_table *table;
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struct hlist_head *head;
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unsigned int h;
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rcu_read_lock();
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for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
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head = &net->ipv6.fib_table_hash[h];
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hlist_for_each_entry_rcu(table, head, tb6_hlist) {
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read_lock_bh(&table->tb6_lock);
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fib6_clean_tree(net, &table->tb6_root,
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func, prune, arg);
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read_unlock_bh(&table->tb6_lock);
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}
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}
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rcu_read_unlock();
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}
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void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
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int prune, void *arg)
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{
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@ -1782,3 +1763,175 @@ void fib6_gc_cleanup(void)
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unregister_pernet_subsys(&fib6_net_ops);
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kmem_cache_destroy(fib6_node_kmem);
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}
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#ifdef CONFIG_PROC_FS
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struct ipv6_route_iter {
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struct seq_net_private p;
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struct fib6_walker_t w;
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loff_t skip;
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struct fib6_table *tbl;
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};
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static int ipv6_route_seq_show(struct seq_file *seq, void *v)
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{
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struct rt6_info *rt = v;
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struct ipv6_route_iter *iter = seq->private;
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seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen);
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#ifdef CONFIG_IPV6_SUBTREES
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seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen);
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#else
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seq_puts(seq, "00000000000000000000000000000000 00 ");
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#endif
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if (rt->rt6i_flags & RTF_GATEWAY)
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seq_printf(seq, "%pi6", &rt->rt6i_gateway);
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else
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seq_puts(seq, "00000000000000000000000000000000");
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seq_printf(seq, " %08x %08x %08x %08x %8s\n",
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rt->rt6i_metric, atomic_read(&rt->dst.__refcnt),
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rt->dst.__use, rt->rt6i_flags,
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rt->dst.dev ? rt->dst.dev->name : "");
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iter->w.leaf = NULL;
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return 0;
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}
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static int ipv6_route_yield(struct fib6_walker_t *w)
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{
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struct ipv6_route_iter *iter = w->args;
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if (!iter->skip)
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return 1;
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do {
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iter->w.leaf = iter->w.leaf->dst.rt6_next;
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iter->skip--;
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if (!iter->skip && iter->w.leaf)
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return 1;
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} while (iter->w.leaf);
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return 0;
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}
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static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter)
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{
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memset(&iter->w, 0, sizeof(iter->w));
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iter->w.func = ipv6_route_yield;
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iter->w.root = &iter->tbl->tb6_root;
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iter->w.state = FWS_INIT;
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iter->w.node = iter->w.root;
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iter->w.args = iter;
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INIT_LIST_HEAD(&iter->w.lh);
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fib6_walker_link(&iter->w);
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}
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static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
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struct net *net)
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{
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unsigned int h;
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struct hlist_node *node;
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if (tbl) {
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h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1;
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node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist));
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} else {
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h = 0;
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node = NULL;
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}
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while (!node && h < FIB6_TABLE_HASHSZ) {
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node = rcu_dereference_bh(
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hlist_first_rcu(&net->ipv6.fib_table_hash[h++]));
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}
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return hlist_entry_safe(node, struct fib6_table, tb6_hlist);
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}
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static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
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{
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int r;
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struct rt6_info *n;
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struct net *net = seq_file_net(seq);
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struct ipv6_route_iter *iter = seq->private;
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if (!v)
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goto iter_table;
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n = ((struct rt6_info *)v)->dst.rt6_next;
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if (n) {
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++*pos;
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return n;
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}
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iter_table:
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read_lock(&iter->tbl->tb6_lock);
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r = fib6_walk_continue(&iter->w);
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read_unlock(&iter->tbl->tb6_lock);
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if (r > 0) {
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if (v)
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++*pos;
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return iter->w.leaf;
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} else if (r < 0) {
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fib6_walker_unlink(&iter->w);
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return NULL;
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}
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fib6_walker_unlink(&iter->w);
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iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
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if (!iter->tbl)
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return NULL;
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ipv6_route_seq_setup_walk(iter);
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goto iter_table;
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}
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static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
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__acquires(RCU_BH)
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{
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struct net *net = seq_file_net(seq);
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struct ipv6_route_iter *iter = seq->private;
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rcu_read_lock_bh();
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iter->tbl = ipv6_route_seq_next_table(NULL, net);
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iter->skip = *pos;
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if (iter->tbl) {
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ipv6_route_seq_setup_walk(iter);
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return ipv6_route_seq_next(seq, NULL, pos);
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} else {
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return NULL;
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}
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}
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static bool ipv6_route_iter_active(struct ipv6_route_iter *iter)
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{
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struct fib6_walker_t *w = &iter->w;
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return w->node && !(w->state == FWS_U && w->node == w->root);
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}
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static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
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__releases(RCU_BH)
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{
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struct ipv6_route_iter *iter = seq->private;
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if (ipv6_route_iter_active(iter))
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fib6_walker_unlink(&iter->w);
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rcu_read_unlock_bh();
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}
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static const struct seq_operations ipv6_route_seq_ops = {
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.start = ipv6_route_seq_start,
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.next = ipv6_route_seq_next,
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.stop = ipv6_route_seq_stop,
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.show = ipv6_route_seq_show
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};
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int ipv6_route_open(struct inode *inode, struct file *file)
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{
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return seq_open_net(inode, file, &ipv6_route_seq_ops,
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sizeof(struct ipv6_route_iter));
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}
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#endif /* CONFIG_PROC_FS */
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@ -2800,56 +2800,12 @@ static int ip6_route_dev_notify(struct notifier_block *this,
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#ifdef CONFIG_PROC_FS
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struct rt6_proc_arg
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{
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char *buffer;
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int offset;
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int length;
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int skip;
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int len;
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};
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static int rt6_info_route(struct rt6_info *rt, void *p_arg)
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{
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struct seq_file *m = p_arg;
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seq_printf(m, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen);
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#ifdef CONFIG_IPV6_SUBTREES
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seq_printf(m, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen);
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#else
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seq_puts(m, "00000000000000000000000000000000 00 ");
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#endif
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if (rt->rt6i_flags & RTF_GATEWAY) {
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seq_printf(m, "%pi6", &rt->rt6i_gateway);
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} else {
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seq_puts(m, "00000000000000000000000000000000");
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}
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seq_printf(m, " %08x %08x %08x %08x %8s\n",
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rt->rt6i_metric, atomic_read(&rt->dst.__refcnt),
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rt->dst.__use, rt->rt6i_flags,
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rt->dst.dev ? rt->dst.dev->name : "");
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return 0;
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}
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static int ipv6_route_show(struct seq_file *m, void *v)
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{
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struct net *net = (struct net *)m->private;
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fib6_clean_all_ro(net, rt6_info_route, 0, m);
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return 0;
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}
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static int ipv6_route_open(struct inode *inode, struct file *file)
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{
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return single_open_net(inode, file, ipv6_route_show);
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}
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static const struct file_operations ipv6_route_proc_fops = {
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.owner = THIS_MODULE,
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.open = ipv6_route_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release_net,
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.release = seq_release_net,
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};
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static int rt6_stats_seq_show(struct seq_file *seq, void *v)
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