Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 1 | /* Helper handling for netfilter. */ |
| 2 | |
| 3 | /* (C) 1999-2001 Paul `Rusty' Russell |
| 4 | * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> |
| 5 | * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/types.h> |
| 13 | #include <linux/netfilter.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/skbuff.h> |
| 16 | #include <linux/vmalloc.h> |
| 17 | #include <linux/stddef.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/random.h> |
| 20 | #include <linux/err.h> |
| 21 | #include <linux/kernel.h> |
| 22 | #include <linux/netdevice.h> |
| 23 | |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 24 | #include <net/netfilter/nf_conntrack.h> |
| 25 | #include <net/netfilter/nf_conntrack_l3proto.h> |
Martin Josefsson | 605dcad | 2006-11-29 02:35:06 +0100 | [diff] [blame] | 26 | #include <net/netfilter/nf_conntrack_l4proto.h> |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 27 | #include <net/netfilter/nf_conntrack_helper.h> |
| 28 | #include <net/netfilter/nf_conntrack_core.h> |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 29 | #include <net/netfilter/nf_conntrack_extend.h> |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 30 | |
Patrick McHardy | 58a3c9b | 2008-01-31 04:36:54 -0800 | [diff] [blame] | 31 | static DEFINE_MUTEX(nf_ct_helper_mutex); |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 32 | static struct hlist_head *nf_ct_helper_hash __read_mostly; |
| 33 | static unsigned int nf_ct_helper_hsize __read_mostly; |
| 34 | static unsigned int nf_ct_helper_count __read_mostly; |
| 35 | static int nf_ct_helper_vmalloc; |
| 36 | |
| 37 | |
| 38 | /* Stupid hash, but collision free for the default registrations of the |
| 39 | * helpers currently in the kernel. */ |
| 40 | static unsigned int helper_hash(const struct nf_conntrack_tuple *tuple) |
| 41 | { |
| 42 | return (((tuple->src.l3num << 8) | tuple->dst.protonum) ^ |
Al Viro | a34c458 | 2007-07-26 17:33:19 +0100 | [diff] [blame] | 43 | (__force __u16)tuple->src.u.all) % nf_ct_helper_hsize; |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 44 | } |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 45 | |
| 46 | struct nf_conntrack_helper * |
| 47 | __nf_ct_helper_find(const struct nf_conntrack_tuple *tuple) |
| 48 | { |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 49 | struct nf_conntrack_helper *helper; |
Patrick McHardy | d4156e8 | 2007-07-07 22:31:32 -0700 | [diff] [blame] | 50 | struct nf_conntrack_tuple_mask mask = { .src.u.all = htons(0xFFFF) }; |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 51 | struct hlist_node *n; |
| 52 | unsigned int h; |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 53 | |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 54 | if (!nf_ct_helper_count) |
| 55 | return NULL; |
| 56 | |
| 57 | h = helper_hash(tuple); |
Patrick McHardy | 58a3c9b | 2008-01-31 04:36:54 -0800 | [diff] [blame] | 58 | hlist_for_each_entry_rcu(helper, n, &nf_ct_helper_hash[h], hnode) { |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 59 | if (nf_ct_tuple_src_mask_cmp(tuple, &helper->tuple, &mask)) |
| 60 | return helper; |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 61 | } |
| 62 | return NULL; |
| 63 | } |
Patrick McHardy | 58a3c9b | 2008-01-31 04:36:54 -0800 | [diff] [blame] | 64 | EXPORT_SYMBOL_GPL(__nf_ct_helper_find); |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 65 | |
| 66 | struct nf_conntrack_helper * |
| 67 | __nf_conntrack_helper_find_byname(const char *name) |
| 68 | { |
| 69 | struct nf_conntrack_helper *h; |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 70 | struct hlist_node *n; |
| 71 | unsigned int i; |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 72 | |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 73 | for (i = 0; i < nf_ct_helper_hsize; i++) { |
Patrick McHardy | 58a3c9b | 2008-01-31 04:36:54 -0800 | [diff] [blame] | 74 | hlist_for_each_entry_rcu(h, n, &nf_ct_helper_hash[i], hnode) { |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 75 | if (!strcmp(h->name, name)) |
| 76 | return h; |
| 77 | } |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 78 | } |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 79 | return NULL; |
| 80 | } |
Patrick McHardy | 13b1833 | 2006-12-02 22:11:25 -0800 | [diff] [blame] | 81 | EXPORT_SYMBOL_GPL(__nf_conntrack_helper_find_byname); |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 82 | |
Patrick McHardy | b560580 | 2007-07-07 22:35:56 -0700 | [diff] [blame] | 83 | struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp) |
| 84 | { |
| 85 | struct nf_conn_help *help; |
| 86 | |
| 87 | help = nf_ct_ext_add(ct, NF_CT_EXT_HELPER, gfp); |
| 88 | if (help) |
| 89 | INIT_HLIST_HEAD(&help->expectations); |
| 90 | else |
| 91 | pr_debug("failed to add helper extension area"); |
| 92 | return help; |
| 93 | } |
| 94 | EXPORT_SYMBOL_GPL(nf_ct_helper_ext_add); |
| 95 | |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 96 | static inline int unhelp(struct nf_conntrack_tuple_hash *i, |
| 97 | const struct nf_conntrack_helper *me) |
| 98 | { |
| 99 | struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i); |
| 100 | struct nf_conn_help *help = nfct_help(ct); |
| 101 | |
| 102 | if (help && help->helper == me) { |
| 103 | nf_conntrack_event(IPCT_HELPER, ct); |
Patrick McHarrdy | 3c158f7 | 2007-06-05 12:55:27 -0700 | [diff] [blame] | 104 | rcu_assign_pointer(help->helper, NULL); |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 105 | } |
| 106 | return 0; |
| 107 | } |
| 108 | |
| 109 | int nf_conntrack_helper_register(struct nf_conntrack_helper *me) |
| 110 | { |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 111 | unsigned int h = helper_hash(&me->tuple); |
| 112 | |
Patrick McHardy | 6002f266 | 2008-03-25 20:09:15 -0700 | [diff] [blame^] | 113 | BUG_ON(me->expect_policy == NULL); |
| 114 | BUG_ON(me->expect_class_max >= NF_CT_MAX_EXPECT_CLASSES); |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 115 | |
Patrick McHardy | 58a3c9b | 2008-01-31 04:36:54 -0800 | [diff] [blame] | 116 | mutex_lock(&nf_ct_helper_mutex); |
| 117 | hlist_add_head_rcu(&me->hnode, &nf_ct_helper_hash[h]); |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 118 | nf_ct_helper_count++; |
Patrick McHardy | 58a3c9b | 2008-01-31 04:36:54 -0800 | [diff] [blame] | 119 | mutex_unlock(&nf_ct_helper_mutex); |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 120 | |
| 121 | return 0; |
| 122 | } |
Patrick McHardy | 13b1833 | 2006-12-02 22:11:25 -0800 | [diff] [blame] | 123 | EXPORT_SYMBOL_GPL(nf_conntrack_helper_register); |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 124 | |
| 125 | void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me) |
| 126 | { |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 127 | struct nf_conntrack_tuple_hash *h; |
Patrick McHardy | 31f1587 | 2007-07-07 22:35:21 -0700 | [diff] [blame] | 128 | struct nf_conntrack_expect *exp; |
| 129 | struct hlist_node *n, *next; |
| 130 | unsigned int i; |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 131 | |
Patrick McHardy | 58a3c9b | 2008-01-31 04:36:54 -0800 | [diff] [blame] | 132 | mutex_lock(&nf_ct_helper_mutex); |
| 133 | hlist_del_rcu(&me->hnode); |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 134 | nf_ct_helper_count--; |
Patrick McHardy | 58a3c9b | 2008-01-31 04:36:54 -0800 | [diff] [blame] | 135 | mutex_unlock(&nf_ct_helper_mutex); |
| 136 | |
| 137 | /* Make sure every nothing is still using the helper unless its a |
| 138 | * connection in the hash. |
| 139 | */ |
| 140 | synchronize_rcu(); |
| 141 | |
Patrick McHardy | f8ba1af | 2008-01-31 04:38:58 -0800 | [diff] [blame] | 142 | spin_lock_bh(&nf_conntrack_lock); |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 143 | |
| 144 | /* Get rid of expectations */ |
Patrick McHardy | 31f1587 | 2007-07-07 22:35:21 -0700 | [diff] [blame] | 145 | for (i = 0; i < nf_ct_expect_hsize; i++) { |
| 146 | hlist_for_each_entry_safe(exp, n, next, |
| 147 | &nf_ct_expect_hash[i], hnode) { |
| 148 | struct nf_conn_help *help = nfct_help(exp->master); |
| 149 | if ((help->helper == me || exp->helper == me) && |
| 150 | del_timer(&exp->timeout)) { |
| 151 | nf_ct_unlink_expect(exp); |
| 152 | nf_ct_expect_put(exp); |
| 153 | } |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 154 | } |
| 155 | } |
| 156 | |
| 157 | /* Get rid of expecteds, set helpers to NULL. */ |
Patrick McHardy | f205c5e | 2007-07-07 22:28:14 -0700 | [diff] [blame] | 158 | hlist_for_each_entry(h, n, &unconfirmed, hnode) |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 159 | unhelp(h, me); |
| 160 | for (i = 0; i < nf_conntrack_htable_size; i++) { |
Patrick McHardy | f205c5e | 2007-07-07 22:28:14 -0700 | [diff] [blame] | 161 | hlist_for_each_entry(h, n, &nf_conntrack_hash[i], hnode) |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 162 | unhelp(h, me); |
| 163 | } |
Patrick McHardy | f8ba1af | 2008-01-31 04:38:58 -0800 | [diff] [blame] | 164 | spin_unlock_bh(&nf_conntrack_lock); |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 165 | } |
Patrick McHardy | 13b1833 | 2006-12-02 22:11:25 -0800 | [diff] [blame] | 166 | EXPORT_SYMBOL_GPL(nf_conntrack_helper_unregister); |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 167 | |
Patrick McHardy | 61eb310 | 2007-07-07 22:27:06 -0700 | [diff] [blame] | 168 | static struct nf_ct_ext_type helper_extend __read_mostly = { |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 169 | .len = sizeof(struct nf_conn_help), |
| 170 | .align = __alignof__(struct nf_conn_help), |
| 171 | .id = NF_CT_EXT_HELPER, |
| 172 | }; |
| 173 | |
Al Viro | 8d4bc5b | 2007-07-20 16:15:28 +0100 | [diff] [blame] | 174 | int nf_conntrack_helper_init(void) |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 175 | { |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 176 | int err; |
| 177 | |
| 178 | nf_ct_helper_hsize = 1; /* gets rounded up to use one page */ |
| 179 | nf_ct_helper_hash = nf_ct_alloc_hashtable(&nf_ct_helper_hsize, |
| 180 | &nf_ct_helper_vmalloc); |
| 181 | if (!nf_ct_helper_hash) |
| 182 | return -ENOMEM; |
| 183 | |
| 184 | err = nf_ct_extend_register(&helper_extend); |
| 185 | if (err < 0) |
| 186 | goto err1; |
| 187 | |
| 188 | return 0; |
| 189 | |
| 190 | err1: |
| 191 | nf_ct_free_hashtable(nf_ct_helper_hash, nf_ct_helper_vmalloc, |
| 192 | nf_ct_helper_hsize); |
| 193 | return err; |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 194 | } |
| 195 | |
Al Viro | 8d4bc5b | 2007-07-20 16:15:28 +0100 | [diff] [blame] | 196 | void nf_conntrack_helper_fini(void) |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 197 | { |
| 198 | nf_ct_extend_unregister(&helper_extend); |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 199 | nf_ct_free_hashtable(nf_ct_helper_hash, nf_ct_helper_vmalloc, |
| 200 | nf_ct_helper_hsize); |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 201 | } |