![Alexey Dobriyan](/assets/img/avatar_default.png)
Make per-netns a) expectation hash and b) expectations count. Expectations always belongs to netns to which it's master conntrack belong. This is natural and doesn't bloat expectation. Proc files and leaf users are stubbed to init_net, this is temporary. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Patrick McHardy <kaber@trash.net>
203 lines
5.4 KiB
C
203 lines
5.4 KiB
C
/* Helper handling for netfilter. */
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/* (C) 1999-2001 Paul `Rusty' Russell
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* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
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* (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/types.h>
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#include <linux/netfilter.h>
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/vmalloc.h>
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#include <linux/stddef.h>
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#include <linux/slab.h>
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#include <linux/random.h>
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/netdevice.h>
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#include <linux/rculist.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_l3proto.h>
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#include <net/netfilter/nf_conntrack_l4proto.h>
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#include <net/netfilter/nf_conntrack_helper.h>
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#include <net/netfilter/nf_conntrack_core.h>
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#include <net/netfilter/nf_conntrack_extend.h>
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static DEFINE_MUTEX(nf_ct_helper_mutex);
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static struct hlist_head *nf_ct_helper_hash __read_mostly;
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static unsigned int nf_ct_helper_hsize __read_mostly;
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static unsigned int nf_ct_helper_count __read_mostly;
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static int nf_ct_helper_vmalloc;
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/* Stupid hash, but collision free for the default registrations of the
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* helpers currently in the kernel. */
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static unsigned int helper_hash(const struct nf_conntrack_tuple *tuple)
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{
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return (((tuple->src.l3num << 8) | tuple->dst.protonum) ^
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(__force __u16)tuple->src.u.all) % nf_ct_helper_hsize;
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}
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struct nf_conntrack_helper *
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__nf_ct_helper_find(const struct nf_conntrack_tuple *tuple)
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{
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struct nf_conntrack_helper *helper;
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struct nf_conntrack_tuple_mask mask = { .src.u.all = htons(0xFFFF) };
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struct hlist_node *n;
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unsigned int h;
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if (!nf_ct_helper_count)
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return NULL;
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h = helper_hash(tuple);
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hlist_for_each_entry_rcu(helper, n, &nf_ct_helper_hash[h], hnode) {
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if (nf_ct_tuple_src_mask_cmp(tuple, &helper->tuple, &mask))
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return helper;
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}
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return NULL;
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}
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EXPORT_SYMBOL_GPL(__nf_ct_helper_find);
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struct nf_conntrack_helper *
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__nf_conntrack_helper_find_byname(const char *name)
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{
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struct nf_conntrack_helper *h;
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struct hlist_node *n;
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unsigned int i;
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for (i = 0; i < nf_ct_helper_hsize; i++) {
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hlist_for_each_entry_rcu(h, n, &nf_ct_helper_hash[i], hnode) {
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if (!strcmp(h->name, name))
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return h;
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}
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}
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return NULL;
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}
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EXPORT_SYMBOL_GPL(__nf_conntrack_helper_find_byname);
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struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp)
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{
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struct nf_conn_help *help;
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help = nf_ct_ext_add(ct, NF_CT_EXT_HELPER, gfp);
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if (help)
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INIT_HLIST_HEAD(&help->expectations);
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else
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pr_debug("failed to add helper extension area");
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return help;
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}
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EXPORT_SYMBOL_GPL(nf_ct_helper_ext_add);
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static inline int unhelp(struct nf_conntrack_tuple_hash *i,
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const struct nf_conntrack_helper *me)
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{
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struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i);
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struct nf_conn_help *help = nfct_help(ct);
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if (help && help->helper == me) {
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nf_conntrack_event(IPCT_HELPER, ct);
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rcu_assign_pointer(help->helper, NULL);
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}
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return 0;
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}
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int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
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{
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unsigned int h = helper_hash(&me->tuple);
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BUG_ON(me->expect_policy == NULL);
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BUG_ON(me->expect_class_max >= NF_CT_MAX_EXPECT_CLASSES);
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mutex_lock(&nf_ct_helper_mutex);
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hlist_add_head_rcu(&me->hnode, &nf_ct_helper_hash[h]);
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nf_ct_helper_count++;
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mutex_unlock(&nf_ct_helper_mutex);
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return 0;
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}
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EXPORT_SYMBOL_GPL(nf_conntrack_helper_register);
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void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me)
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{
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struct nf_conntrack_tuple_hash *h;
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struct nf_conntrack_expect *exp;
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const struct hlist_node *n, *next;
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unsigned int i;
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mutex_lock(&nf_ct_helper_mutex);
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hlist_del_rcu(&me->hnode);
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nf_ct_helper_count--;
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mutex_unlock(&nf_ct_helper_mutex);
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/* Make sure every nothing is still using the helper unless its a
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* connection in the hash.
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*/
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synchronize_rcu();
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spin_lock_bh(&nf_conntrack_lock);
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/* Get rid of expectations */
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for (i = 0; i < nf_ct_expect_hsize; i++) {
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hlist_for_each_entry_safe(exp, n, next,
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&init_net.ct.expect_hash[i], hnode) {
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struct nf_conn_help *help = nfct_help(exp->master);
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if ((help->helper == me || exp->helper == me) &&
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del_timer(&exp->timeout)) {
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nf_ct_unlink_expect(exp);
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nf_ct_expect_put(exp);
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}
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}
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}
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/* Get rid of expecteds, set helpers to NULL. */
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hlist_for_each_entry(h, n, &unconfirmed, hnode)
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unhelp(h, me);
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for (i = 0; i < nf_conntrack_htable_size; i++) {
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hlist_for_each_entry(h, n, &init_net.ct.hash[i], hnode)
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unhelp(h, me);
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}
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spin_unlock_bh(&nf_conntrack_lock);
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}
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EXPORT_SYMBOL_GPL(nf_conntrack_helper_unregister);
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static struct nf_ct_ext_type helper_extend __read_mostly = {
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.len = sizeof(struct nf_conn_help),
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.align = __alignof__(struct nf_conn_help),
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.id = NF_CT_EXT_HELPER,
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};
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int nf_conntrack_helper_init(void)
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{
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int err;
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nf_ct_helper_hsize = 1; /* gets rounded up to use one page */
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nf_ct_helper_hash = nf_ct_alloc_hashtable(&nf_ct_helper_hsize,
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&nf_ct_helper_vmalloc);
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if (!nf_ct_helper_hash)
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return -ENOMEM;
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err = nf_ct_extend_register(&helper_extend);
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if (err < 0)
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goto err1;
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return 0;
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err1:
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nf_ct_free_hashtable(nf_ct_helper_hash, nf_ct_helper_vmalloc,
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nf_ct_helper_hsize);
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return err;
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}
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void nf_conntrack_helper_fini(void)
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{
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nf_ct_extend_unregister(&helper_extend);
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nf_ct_free_hashtable(nf_ct_helper_hash, nf_ct_helper_vmalloc,
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nf_ct_helper_hsize);
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}
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