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> |
Patrick McHardy | f229f6c | 2013-04-06 15:24:29 +0200 | [diff] [blame] | 6 | * (C) 2006-2012 Patrick McHardy <kaber@trash.net> |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License version 2 as |
| 10 | * published by the Free Software Foundation. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/types.h> |
| 14 | #include <linux/netfilter.h> |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/skbuff.h> |
| 17 | #include <linux/vmalloc.h> |
| 18 | #include <linux/stddef.h> |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 19 | #include <linux/random.h> |
| 20 | #include <linux/err.h> |
| 21 | #include <linux/kernel.h> |
| 22 | #include <linux/netdevice.h> |
Ingo Molnar | 2ba4cc3 | 2008-05-13 15:37:05 +0200 | [diff] [blame] | 23 | #include <linux/rculist.h> |
Alexey Dobriyan | efb9a8c | 2008-11-05 03:03:18 -0800 | [diff] [blame] | 24 | #include <linux/rtnetlink.h> |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 25 | |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 26 | #include <net/netfilter/nf_conntrack.h> |
| 27 | #include <net/netfilter/nf_conntrack_l3proto.h> |
Martin Josefsson | 605dcad | 2006-11-29 02:35:06 +0100 | [diff] [blame] | 28 | #include <net/netfilter/nf_conntrack_l4proto.h> |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 29 | #include <net/netfilter/nf_conntrack_helper.h> |
| 30 | #include <net/netfilter/nf_conntrack_core.h> |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 31 | #include <net/netfilter/nf_conntrack_extend.h> |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 32 | #include <net/netfilter/nf_log.h> |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 33 | |
Patrick McHardy | 58a3c9b | 2008-01-31 04:36:54 -0800 | [diff] [blame] | 34 | static DEFINE_MUTEX(nf_ct_helper_mutex); |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 35 | struct hlist_head *nf_ct_helper_hash __read_mostly; |
| 36 | EXPORT_SYMBOL_GPL(nf_ct_helper_hash); |
| 37 | unsigned int nf_ct_helper_hsize __read_mostly; |
| 38 | EXPORT_SYMBOL_GPL(nf_ct_helper_hsize); |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 39 | static unsigned int nf_ct_helper_count __read_mostly; |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 40 | |
Pablo Neira Ayuso | 3bb398d | 2016-04-14 17:13:41 +0200 | [diff] [blame] | 41 | static bool nf_ct_auto_assign_helper __read_mostly = false; |
Eric Leblond | a900689 | 2012-04-18 11:20:41 +0200 | [diff] [blame] | 42 | module_param_named(nf_conntrack_helper, nf_ct_auto_assign_helper, bool, 0644); |
| 43 | MODULE_PARM_DESC(nf_conntrack_helper, |
Pablo Neira Ayuso | 3bb398d | 2016-04-14 17:13:41 +0200 | [diff] [blame] | 44 | "Enable automatic conntrack helper assignment (default 0)"); |
Eric Leblond | a900689 | 2012-04-18 11:20:41 +0200 | [diff] [blame] | 45 | |
| 46 | #ifdef CONFIG_SYSCTL |
| 47 | static struct ctl_table helper_sysctl_table[] = { |
| 48 | { |
| 49 | .procname = "nf_conntrack_helper", |
| 50 | .data = &init_net.ct.sysctl_auto_assign_helper, |
| 51 | .maxlen = sizeof(unsigned int), |
| 52 | .mode = 0644, |
| 53 | .proc_handler = proc_dointvec, |
| 54 | }, |
| 55 | {} |
| 56 | }; |
| 57 | |
| 58 | static int nf_conntrack_helper_init_sysctl(struct net *net) |
| 59 | { |
| 60 | struct ctl_table *table; |
| 61 | |
| 62 | table = kmemdup(helper_sysctl_table, sizeof(helper_sysctl_table), |
| 63 | GFP_KERNEL); |
| 64 | if (!table) |
| 65 | goto out; |
| 66 | |
| 67 | table[0].data = &net->ct.sysctl_auto_assign_helper; |
| 68 | |
Eric W. Biederman | 464dc80 | 2012-11-16 03:02:59 +0000 | [diff] [blame] | 69 | /* Don't export sysctls to unprivileged users */ |
| 70 | if (net->user_ns != &init_user_ns) |
| 71 | table[0].procname = NULL; |
| 72 | |
Eric Leblond | a900689 | 2012-04-18 11:20:41 +0200 | [diff] [blame] | 73 | net->ct.helper_sysctl_header = |
| 74 | register_net_sysctl(net, "net/netfilter", table); |
| 75 | |
| 76 | if (!net->ct.helper_sysctl_header) { |
| 77 | pr_err("nf_conntrack_helper: can't register to sysctl.\n"); |
| 78 | goto out_register; |
| 79 | } |
| 80 | return 0; |
| 81 | |
| 82 | out_register: |
| 83 | kfree(table); |
| 84 | out: |
| 85 | return -ENOMEM; |
| 86 | } |
| 87 | |
| 88 | static void nf_conntrack_helper_fini_sysctl(struct net *net) |
| 89 | { |
| 90 | struct ctl_table *table; |
| 91 | |
| 92 | table = net->ct.helper_sysctl_header->ctl_table_arg; |
| 93 | unregister_net_sysctl_table(net->ct.helper_sysctl_header); |
| 94 | kfree(table); |
| 95 | } |
| 96 | #else |
| 97 | static int nf_conntrack_helper_init_sysctl(struct net *net) |
| 98 | { |
| 99 | return 0; |
| 100 | } |
| 101 | |
| 102 | static void nf_conntrack_helper_fini_sysctl(struct net *net) |
| 103 | { |
| 104 | } |
| 105 | #endif /* CONFIG_SYSCTL */ |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 106 | |
| 107 | /* Stupid hash, but collision free for the default registrations of the |
| 108 | * helpers currently in the kernel. */ |
| 109 | static unsigned int helper_hash(const struct nf_conntrack_tuple *tuple) |
| 110 | { |
| 111 | return (((tuple->src.l3num << 8) | tuple->dst.protonum) ^ |
Al Viro | a34c458 | 2007-07-26 17:33:19 +0100 | [diff] [blame] | 112 | (__force __u16)tuple->src.u.all) % nf_ct_helper_hsize; |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 113 | } |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 114 | |
Pablo Neira Ayuso | 226c0c0 | 2008-11-18 11:54:05 +0100 | [diff] [blame] | 115 | static struct nf_conntrack_helper * |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 116 | __nf_ct_helper_find(const struct nf_conntrack_tuple *tuple) |
| 117 | { |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 118 | struct nf_conntrack_helper *helper; |
Patrick McHardy | d4156e8 | 2007-07-07 22:31:32 -0700 | [diff] [blame] | 119 | struct nf_conntrack_tuple_mask mask = { .src.u.all = htons(0xFFFF) }; |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 120 | unsigned int h; |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 121 | |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 122 | if (!nf_ct_helper_count) |
| 123 | return NULL; |
| 124 | |
| 125 | h = helper_hash(tuple); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 126 | hlist_for_each_entry_rcu(helper, &nf_ct_helper_hash[h], hnode) { |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 127 | if (nf_ct_tuple_src_mask_cmp(tuple, &helper->tuple, &mask)) |
| 128 | return helper; |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 129 | } |
| 130 | return NULL; |
| 131 | } |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 132 | |
| 133 | struct nf_conntrack_helper * |
Patrick McHardy | 794e687 | 2010-02-03 13:41:29 +0100 | [diff] [blame] | 134 | __nf_conntrack_helper_find(const char *name, u16 l3num, u8 protonum) |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 135 | { |
| 136 | struct nf_conntrack_helper *h; |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 137 | unsigned int i; |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 138 | |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 139 | for (i = 0; i < nf_ct_helper_hsize; i++) { |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 140 | hlist_for_each_entry_rcu(h, &nf_ct_helper_hash[i], hnode) { |
Florian Westphal | 6114cc5 | 2016-11-03 14:44:42 +0100 | [diff] [blame] | 141 | if (strcmp(h->name, name)) |
| 142 | continue; |
| 143 | |
| 144 | if (h->tuple.src.l3num != NFPROTO_UNSPEC && |
| 145 | h->tuple.src.l3num != l3num) |
| 146 | continue; |
| 147 | |
| 148 | if (h->tuple.dst.protonum == protonum) |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 149 | return h; |
| 150 | } |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 151 | } |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 152 | return NULL; |
| 153 | } |
Patrick McHardy | 794e687 | 2010-02-03 13:41:29 +0100 | [diff] [blame] | 154 | EXPORT_SYMBOL_GPL(__nf_conntrack_helper_find); |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 155 | |
Patrick McHardy | 84f3bb9 | 2010-02-03 17:17:06 +0100 | [diff] [blame] | 156 | struct nf_conntrack_helper * |
| 157 | nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum) |
| 158 | { |
| 159 | struct nf_conntrack_helper *h; |
| 160 | |
| 161 | h = __nf_conntrack_helper_find(name, l3num, protonum); |
| 162 | #ifdef CONFIG_MODULES |
| 163 | if (h == NULL) { |
| 164 | if (request_module("nfct-helper-%s", name) == 0) |
| 165 | h = __nf_conntrack_helper_find(name, l3num, protonum); |
| 166 | } |
| 167 | #endif |
| 168 | if (h != NULL && !try_module_get(h->me)) |
| 169 | h = NULL; |
| 170 | |
| 171 | return h; |
| 172 | } |
| 173 | EXPORT_SYMBOL_GPL(nf_conntrack_helper_try_module_get); |
| 174 | |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 175 | struct nf_conn_help * |
| 176 | nf_ct_helper_ext_add(struct nf_conn *ct, |
| 177 | struct nf_conntrack_helper *helper, gfp_t gfp) |
Patrick McHardy | b560580 | 2007-07-07 22:35:56 -0700 | [diff] [blame] | 178 | { |
| 179 | struct nf_conn_help *help; |
| 180 | |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 181 | help = nf_ct_ext_add_length(ct, NF_CT_EXT_HELPER, |
| 182 | helper->data_len, gfp); |
Patrick McHardy | b560580 | 2007-07-07 22:35:56 -0700 | [diff] [blame] | 183 | if (help) |
| 184 | INIT_HLIST_HEAD(&help->expectations); |
| 185 | else |
| 186 | pr_debug("failed to add helper extension area"); |
| 187 | return help; |
| 188 | } |
| 189 | EXPORT_SYMBOL_GPL(nf_ct_helper_ext_add); |
| 190 | |
Jiri Kosina | 8f9872b | 2017-02-01 21:01:54 +0100 | [diff] [blame] | 191 | static struct nf_conntrack_helper * |
| 192 | nf_ct_lookup_helper(struct nf_conn *ct, struct net *net) |
| 193 | { |
| 194 | if (!net->ct.sysctl_auto_assign_helper) { |
| 195 | if (net->ct.auto_assign_helper_warned) |
| 196 | return NULL; |
| 197 | if (!__nf_ct_helper_find(&ct->tuplehash[IP_CT_DIR_REPLY].tuple)) |
| 198 | return NULL; |
| 199 | pr_info("nf_conntrack: default automatic helper assignment " |
| 200 | "has been turned off for security reasons and CT-based " |
| 201 | " firewall rule not found. Use the iptables CT target " |
| 202 | "to attach helpers instead.\n"); |
| 203 | net->ct.auto_assign_helper_warned = 1; |
| 204 | return NULL; |
| 205 | } |
| 206 | |
| 207 | return __nf_ct_helper_find(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); |
| 208 | } |
| 209 | |
| 210 | |
Patrick McHardy | b2a15a6 | 2010-02-03 14:13:03 +0100 | [diff] [blame] | 211 | int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl, |
| 212 | gfp_t flags) |
Pablo Neira Ayuso | 226c0c0 | 2008-11-18 11:54:05 +0100 | [diff] [blame] | 213 | { |
Patrick McHardy | b2a15a6 | 2010-02-03 14:13:03 +0100 | [diff] [blame] | 214 | struct nf_conntrack_helper *helper = NULL; |
| 215 | struct nf_conn_help *help; |
Eric Leblond | a900689 | 2012-04-18 11:20:41 +0200 | [diff] [blame] | 216 | struct net *net = nf_ct_net(ct); |
Pablo Neira Ayuso | 226c0c0 | 2008-11-18 11:54:05 +0100 | [diff] [blame] | 217 | |
Pablo Neira Ayuso | 6714cf5 | 2012-05-03 02:17:45 +0000 | [diff] [blame] | 218 | /* We already got a helper explicitly attached. The function |
| 219 | * nf_conntrack_alter_reply - in case NAT is in use - asks for looking |
| 220 | * the helper up again. Since now the user is in full control of |
| 221 | * making consistent helper configurations, skip this automatic |
| 222 | * re-lookup, otherwise we'll lose the helper. |
| 223 | */ |
| 224 | if (test_bit(IPS_HELPER_BIT, &ct->status)) |
| 225 | return 0; |
| 226 | |
Patrick McHardy | b2a15a6 | 2010-02-03 14:13:03 +0100 | [diff] [blame] | 227 | if (tmpl != NULL) { |
| 228 | help = nfct_help(tmpl); |
Pablo Neira Ayuso | 6714cf5 | 2012-05-03 02:17:45 +0000 | [diff] [blame] | 229 | if (help != NULL) { |
Patrick McHardy | b2a15a6 | 2010-02-03 14:13:03 +0100 | [diff] [blame] | 230 | helper = help->helper; |
Pablo Neira Ayuso | 6714cf5 | 2012-05-03 02:17:45 +0000 | [diff] [blame] | 231 | set_bit(IPS_HELPER_BIT, &ct->status); |
| 232 | } |
Patrick McHardy | b2a15a6 | 2010-02-03 14:13:03 +0100 | [diff] [blame] | 233 | } |
| 234 | |
| 235 | help = nfct_help(ct); |
Eric Leblond | a900689 | 2012-04-18 11:20:41 +0200 | [diff] [blame] | 236 | |
Pablo Neira Ayuso | 226c0c0 | 2008-11-18 11:54:05 +0100 | [diff] [blame] | 237 | if (helper == NULL) { |
Jiri Kosina | 8f9872b | 2017-02-01 21:01:54 +0100 | [diff] [blame] | 238 | helper = nf_ct_lookup_helper(ct, net); |
| 239 | if (helper == NULL) { |
| 240 | if (help) |
| 241 | RCU_INIT_POINTER(help->helper, NULL); |
| 242 | return 0; |
| 243 | } |
Pablo Neira Ayuso | 226c0c0 | 2008-11-18 11:54:05 +0100 | [diff] [blame] | 244 | } |
| 245 | |
| 246 | if (help == NULL) { |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 247 | help = nf_ct_helper_ext_add(ct, helper, flags); |
Pablo Neira | cf71c03 | 2016-09-09 14:01:26 +0200 | [diff] [blame] | 248 | if (help == NULL) |
| 249 | return -ENOMEM; |
Pablo Neira Ayuso | 226c0c0 | 2008-11-18 11:54:05 +0100 | [diff] [blame] | 250 | } else { |
Pablo Neira Ayuso | 32f5376 | 2012-06-18 17:29:53 +0200 | [diff] [blame] | 251 | /* We only allow helper re-assignment of the same sort since |
| 252 | * we cannot reallocate the helper extension area. |
| 253 | */ |
Florian Westphal | 6e2f0aa | 2013-02-12 05:59:53 +0000 | [diff] [blame] | 254 | struct nf_conntrack_helper *tmp = rcu_dereference(help->helper); |
| 255 | |
| 256 | if (tmp && tmp->help != helper->help) { |
Pablo Neira Ayuso | 32f5376 | 2012-06-18 17:29:53 +0200 | [diff] [blame] | 257 | RCU_INIT_POINTER(help->helper, NULL); |
Pablo Neira | cf71c03 | 2016-09-09 14:01:26 +0200 | [diff] [blame] | 258 | return 0; |
Pablo Neira Ayuso | 32f5376 | 2012-06-18 17:29:53 +0200 | [diff] [blame] | 259 | } |
Pablo Neira Ayuso | 226c0c0 | 2008-11-18 11:54:05 +0100 | [diff] [blame] | 260 | } |
| 261 | |
Eric Dumazet | cf778b0 | 2012-01-12 04:41:32 +0000 | [diff] [blame] | 262 | rcu_assign_pointer(help->helper, helper); |
Pablo Neira | cf71c03 | 2016-09-09 14:01:26 +0200 | [diff] [blame] | 263 | |
| 264 | return 0; |
Pablo Neira Ayuso | 226c0c0 | 2008-11-18 11:54:05 +0100 | [diff] [blame] | 265 | } |
| 266 | EXPORT_SYMBOL_GPL(__nf_ct_try_assign_helper); |
| 267 | |
stephen hemminger | 01cfa0a | 2014-10-29 22:57:19 -0700 | [diff] [blame] | 268 | /* appropriate ct lock protecting must be taken by caller */ |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 269 | static inline int unhelp(struct nf_conntrack_tuple_hash *i, |
| 270 | const struct nf_conntrack_helper *me) |
| 271 | { |
| 272 | struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i); |
| 273 | struct nf_conn_help *help = nfct_help(ct); |
| 274 | |
Jesper Dangaard Brouer | ca7433d | 2014-03-03 14:46:01 +0100 | [diff] [blame] | 275 | if (help && rcu_dereference_raw(help->helper) == me) { |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 276 | nf_conntrack_event(IPCT_HELPER, ct); |
Stephen Hemminger | a9b3cd7 | 2011-08-01 16:19:00 +0000 | [diff] [blame] | 277 | RCU_INIT_POINTER(help->helper, NULL); |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 278 | } |
| 279 | return 0; |
| 280 | } |
| 281 | |
Pablo Neira Ayuso | 9858a3a | 2009-06-13 12:28:22 +0200 | [diff] [blame] | 282 | void nf_ct_helper_destroy(struct nf_conn *ct) |
| 283 | { |
| 284 | struct nf_conn_help *help = nfct_help(ct); |
| 285 | struct nf_conntrack_helper *helper; |
| 286 | |
| 287 | if (help) { |
| 288 | rcu_read_lock(); |
| 289 | helper = rcu_dereference(help->helper); |
| 290 | if (helper && helper->destroy) |
| 291 | helper->destroy(ct); |
| 292 | rcu_read_unlock(); |
| 293 | } |
| 294 | } |
| 295 | |
Pablo Neira Ayuso | 544d5c7 | 2012-02-05 03:44:51 +0100 | [diff] [blame] | 296 | static LIST_HEAD(nf_ct_helper_expectfn_list); |
| 297 | |
| 298 | void nf_ct_helper_expectfn_register(struct nf_ct_helper_expectfn *n) |
| 299 | { |
Jesper Dangaard Brouer | ca7433d | 2014-03-03 14:46:01 +0100 | [diff] [blame] | 300 | spin_lock_bh(&nf_conntrack_expect_lock); |
Pablo Neira Ayuso | 544d5c7 | 2012-02-05 03:44:51 +0100 | [diff] [blame] | 301 | list_add_rcu(&n->head, &nf_ct_helper_expectfn_list); |
Jesper Dangaard Brouer | ca7433d | 2014-03-03 14:46:01 +0100 | [diff] [blame] | 302 | spin_unlock_bh(&nf_conntrack_expect_lock); |
Pablo Neira Ayuso | 544d5c7 | 2012-02-05 03:44:51 +0100 | [diff] [blame] | 303 | } |
| 304 | EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_register); |
| 305 | |
| 306 | void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n) |
| 307 | { |
Jesper Dangaard Brouer | ca7433d | 2014-03-03 14:46:01 +0100 | [diff] [blame] | 308 | spin_lock_bh(&nf_conntrack_expect_lock); |
Pablo Neira Ayuso | 544d5c7 | 2012-02-05 03:44:51 +0100 | [diff] [blame] | 309 | list_del_rcu(&n->head); |
Jesper Dangaard Brouer | ca7433d | 2014-03-03 14:46:01 +0100 | [diff] [blame] | 310 | spin_unlock_bh(&nf_conntrack_expect_lock); |
Pablo Neira Ayuso | 544d5c7 | 2012-02-05 03:44:51 +0100 | [diff] [blame] | 311 | } |
| 312 | EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_unregister); |
| 313 | |
| 314 | struct nf_ct_helper_expectfn * |
| 315 | nf_ct_helper_expectfn_find_by_name(const char *name) |
| 316 | { |
| 317 | struct nf_ct_helper_expectfn *cur; |
| 318 | bool found = false; |
| 319 | |
| 320 | rcu_read_lock(); |
| 321 | list_for_each_entry_rcu(cur, &nf_ct_helper_expectfn_list, head) { |
| 322 | if (!strcmp(cur->name, name)) { |
| 323 | found = true; |
| 324 | break; |
| 325 | } |
| 326 | } |
| 327 | rcu_read_unlock(); |
| 328 | return found ? cur : NULL; |
| 329 | } |
| 330 | EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_name); |
| 331 | |
| 332 | struct nf_ct_helper_expectfn * |
| 333 | nf_ct_helper_expectfn_find_by_symbol(const void *symbol) |
| 334 | { |
| 335 | struct nf_ct_helper_expectfn *cur; |
| 336 | bool found = false; |
| 337 | |
| 338 | rcu_read_lock(); |
| 339 | list_for_each_entry_rcu(cur, &nf_ct_helper_expectfn_list, head) { |
| 340 | if (cur->expectfn == symbol) { |
| 341 | found = true; |
| 342 | break; |
| 343 | } |
| 344 | } |
| 345 | rcu_read_unlock(); |
| 346 | return found ? cur : NULL; |
| 347 | } |
| 348 | EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_symbol); |
| 349 | |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 350 | __printf(3, 4) |
| 351 | void nf_ct_helper_log(struct sk_buff *skb, const struct nf_conn *ct, |
| 352 | const char *fmt, ...) |
| 353 | { |
| 354 | const struct nf_conn_help *help; |
| 355 | const struct nf_conntrack_helper *helper; |
Joe Perches | f9caed5 | 2013-02-18 21:51:07 +0000 | [diff] [blame] | 356 | struct va_format vaf; |
| 357 | va_list args; |
| 358 | |
| 359 | va_start(args, fmt); |
| 360 | |
| 361 | vaf.fmt = fmt; |
| 362 | vaf.va = &args; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 363 | |
| 364 | /* Called from the helper function, this call never fails */ |
| 365 | help = nfct_help(ct); |
| 366 | |
Aaron Conole | e2361cb | 2016-09-21 11:35:04 -0400 | [diff] [blame] | 367 | /* rcu_read_lock()ed by nf_hook_thresh */ |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 368 | helper = rcu_dereference(help->helper); |
| 369 | |
Gao feng | 30e0c6a | 2013-03-24 23:50:40 +0000 | [diff] [blame] | 370 | nf_log_packet(nf_ct_net(ct), nf_ct_l3num(ct), 0, skb, NULL, NULL, NULL, |
Joe Perches | f9caed5 | 2013-02-18 21:51:07 +0000 | [diff] [blame] | 371 | "nf_ct_%s: dropping packet: %pV ", helper->name, &vaf); |
| 372 | |
| 373 | va_end(args); |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 374 | } |
| 375 | EXPORT_SYMBOL_GPL(nf_ct_helper_log); |
| 376 | |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 377 | int nf_conntrack_helper_register(struct nf_conntrack_helper *me) |
| 378 | { |
Pablo Neira Ayuso | 893e093 | 2016-05-24 11:23:51 +0200 | [diff] [blame] | 379 | struct nf_conntrack_tuple_mask mask = { .src.u.all = htons(0xFFFF) }; |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 380 | unsigned int h = helper_hash(&me->tuple); |
Pablo Neira Ayuso | 893e093 | 2016-05-24 11:23:51 +0200 | [diff] [blame] | 381 | struct nf_conntrack_helper *cur; |
Liping Zhang | 3a04271 | 2017-04-15 19:27:42 +0800 | [diff] [blame] | 382 | int ret = 0, i; |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 383 | |
Patrick McHardy | 6002f266 | 2008-03-25 20:09:15 -0700 | [diff] [blame] | 384 | BUG_ON(me->expect_policy == NULL); |
| 385 | BUG_ON(me->expect_class_max >= NF_CT_MAX_EXPECT_CLASSES); |
Holger Eitzenberger | af9d32a | 2009-03-25 18:44:01 +0100 | [diff] [blame] | 386 | BUG_ON(strlen(me->name) > NF_CT_HELPER_NAME_LEN - 1); |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 387 | |
Patrick McHardy | 58a3c9b | 2008-01-31 04:36:54 -0800 | [diff] [blame] | 388 | mutex_lock(&nf_ct_helper_mutex); |
Liping Zhang | 3a04271 | 2017-04-15 19:27:42 +0800 | [diff] [blame] | 389 | for (i = 0; i < nf_ct_helper_hsize; i++) { |
| 390 | hlist_for_each_entry(cur, &nf_ct_helper_hash[i], hnode) { |
| 391 | if (!strcmp(cur->name, me->name) && |
| 392 | (cur->tuple.src.l3num == NFPROTO_UNSPEC || |
| 393 | cur->tuple.src.l3num == me->tuple.src.l3num) && |
| 394 | cur->tuple.dst.protonum == me->tuple.dst.protonum) { |
| 395 | ret = -EEXIST; |
| 396 | goto out; |
| 397 | } |
| 398 | } |
| 399 | } |
| 400 | |
| 401 | /* avoid unpredictable behaviour for auto_assign_helper */ |
| 402 | if (!(me->flags & NF_CT_HELPER_F_USERSPACE)) { |
| 403 | hlist_for_each_entry(cur, &nf_ct_helper_hash[h], hnode) { |
| 404 | if (nf_ct_tuple_src_mask_cmp(&cur->tuple, &me->tuple, |
| 405 | &mask)) { |
| 406 | ret = -EEXIST; |
| 407 | goto out; |
| 408 | } |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 409 | } |
| 410 | } |
Patrick McHardy | 58a3c9b | 2008-01-31 04:36:54 -0800 | [diff] [blame] | 411 | hlist_add_head_rcu(&me->hnode, &nf_ct_helper_hash[h]); |
Patrick McHardy | b8a7fe6 | 2007-07-07 22:36:46 -0700 | [diff] [blame] | 412 | nf_ct_helper_count++; |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 413 | out: |
Patrick McHardy | 58a3c9b | 2008-01-31 04:36:54 -0800 | [diff] [blame] | 414 | mutex_unlock(&nf_ct_helper_mutex); |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 415 | return ret; |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 416 | } |
Patrick McHardy | 13b1833 | 2006-12-02 22:11:25 -0800 | [diff] [blame] | 417 | EXPORT_SYMBOL_GPL(nf_conntrack_helper_register); |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 418 | |
Alexey Dobriyan | 6804793 | 2008-10-08 11:35:06 +0200 | [diff] [blame] | 419 | static void __nf_conntrack_helper_unregister(struct nf_conntrack_helper *me, |
| 420 | struct net *net) |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 421 | { |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 422 | struct nf_conntrack_tuple_hash *h; |
Florian Westphal | 436a850 | 2016-05-15 19:50:14 +0200 | [diff] [blame] | 423 | const struct hlist_nulls_node *nn; |
| 424 | int cpu; |
| 425 | |
| 426 | /* Get rid of expecteds, set helpers to NULL. */ |
| 427 | for_each_possible_cpu(cpu) { |
| 428 | struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu); |
| 429 | |
| 430 | spin_lock_bh(&pcpu->lock); |
| 431 | hlist_nulls_for_each_entry(h, nn, &pcpu->unconfirmed, hnnode) |
| 432 | unhelp(h, me); |
| 433 | spin_unlock_bh(&pcpu->lock); |
| 434 | } |
| 435 | } |
| 436 | |
| 437 | void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me) |
| 438 | { |
| 439 | struct nf_conntrack_tuple_hash *h; |
Patrick McHardy | 31f1587 | 2007-07-07 22:35:21 -0700 | [diff] [blame] | 440 | struct nf_conntrack_expect *exp; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 441 | const struct hlist_node *next; |
Eric Dumazet | ea781f1 | 2009-03-25 21:05:46 +0100 | [diff] [blame] | 442 | const struct hlist_nulls_node *nn; |
Liping Zhang | 8786a97 | 2016-07-03 13:18:45 +0800 | [diff] [blame] | 443 | unsigned int last_hsize; |
| 444 | spinlock_t *lock; |
Florian Westphal | 436a850 | 2016-05-15 19:50:14 +0200 | [diff] [blame] | 445 | struct net *net; |
Patrick McHardy | 31f1587 | 2007-07-07 22:35:21 -0700 | [diff] [blame] | 446 | unsigned int i; |
Florian Westphal | 436a850 | 2016-05-15 19:50:14 +0200 | [diff] [blame] | 447 | |
| 448 | mutex_lock(&nf_ct_helper_mutex); |
| 449 | hlist_del_rcu(&me->hnode); |
| 450 | nf_ct_helper_count--; |
| 451 | mutex_unlock(&nf_ct_helper_mutex); |
| 452 | |
| 453 | /* Make sure every nothing is still using the helper unless its a |
| 454 | * connection in the hash. |
| 455 | */ |
| 456 | synchronize_rcu(); |
Martin Josefsson | 7e5d03b | 2006-11-29 02:34:59 +0100 | [diff] [blame] | 457 | |
Alexey Dobriyan | 6804793 | 2008-10-08 11:35:06 +0200 | [diff] [blame] | 458 | /* Get rid of expectations */ |
Jesper Dangaard Brouer | ca7433d | 2014-03-03 14:46:01 +0100 | [diff] [blame] | 459 | spin_lock_bh(&nf_conntrack_expect_lock); |
Alexey Dobriyan | 6804793 | 2008-10-08 11:35:06 +0200 | [diff] [blame] | 460 | for (i = 0; i < nf_ct_expect_hsize; i++) { |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 461 | hlist_for_each_entry_safe(exp, next, |
Florian Westphal | 0a93aae | 2016-05-06 00:51:49 +0200 | [diff] [blame] | 462 | &nf_ct_expect_hash[i], hnode) { |
Alexey Dobriyan | 6804793 | 2008-10-08 11:35:06 +0200 | [diff] [blame] | 463 | struct nf_conn_help *help = nfct_help(exp->master); |
Eric Dumazet | c5d277d | 2010-11-15 19:45:13 +0100 | [diff] [blame] | 464 | if ((rcu_dereference_protected( |
| 465 | help->helper, |
Jesper Dangaard Brouer | ca7433d | 2014-03-03 14:46:01 +0100 | [diff] [blame] | 466 | lockdep_is_held(&nf_conntrack_expect_lock) |
Eric Dumazet | c5d277d | 2010-11-15 19:45:13 +0100 | [diff] [blame] | 467 | ) == me || exp->helper == me) && |
Alexey Dobriyan | 6804793 | 2008-10-08 11:35:06 +0200 | [diff] [blame] | 468 | del_timer(&exp->timeout)) { |
| 469 | nf_ct_unlink_expect(exp); |
| 470 | nf_ct_expect_put(exp); |
| 471 | } |
| 472 | } |
| 473 | } |
Jesper Dangaard Brouer | ca7433d | 2014-03-03 14:46:01 +0100 | [diff] [blame] | 474 | spin_unlock_bh(&nf_conntrack_expect_lock); |
Alexey Dobriyan | 6804793 | 2008-10-08 11:35:06 +0200 | [diff] [blame] | 475 | |
Florian Westphal | 436a850 | 2016-05-15 19:50:14 +0200 | [diff] [blame] | 476 | rtnl_lock(); |
| 477 | for_each_net(net) |
| 478 | __nf_conntrack_helper_unregister(me, net); |
| 479 | rtnl_unlock(); |
Jesper Dangaard Brouer | b7779d0 | 2014-03-03 14:45:20 +0100 | [diff] [blame] | 480 | |
Jesper Dangaard Brouer | 93bb0ce | 2014-03-03 14:46:13 +0100 | [diff] [blame] | 481 | local_bh_disable(); |
Liping Zhang | 8786a97 | 2016-07-03 13:18:45 +0800 | [diff] [blame] | 482 | restart: |
| 483 | last_hsize = nf_conntrack_htable_size; |
| 484 | for (i = 0; i < last_hsize; i++) { |
| 485 | lock = &nf_conntrack_locks[i % CONNTRACK_LOCKS]; |
| 486 | nf_conntrack_lock(lock); |
| 487 | if (last_hsize != nf_conntrack_htable_size) { |
| 488 | spin_unlock(lock); |
| 489 | goto restart; |
Jesper Dangaard Brouer | 93bb0ce | 2014-03-03 14:46:13 +0100 | [diff] [blame] | 490 | } |
Liping Zhang | 8786a97 | 2016-07-03 13:18:45 +0800 | [diff] [blame] | 491 | hlist_nulls_for_each_entry(h, nn, &nf_conntrack_hash[i], hnnode) |
| 492 | unhelp(h, me); |
| 493 | spin_unlock(lock); |
Alexey Dobriyan | 6804793 | 2008-10-08 11:35:06 +0200 | [diff] [blame] | 494 | } |
Jesper Dangaard Brouer | 93bb0ce | 2014-03-03 14:46:13 +0100 | [diff] [blame] | 495 | local_bh_enable(); |
Alexey Dobriyan | 6804793 | 2008-10-08 11:35:06 +0200 | [diff] [blame] | 496 | } |
Patrick McHardy | 13b1833 | 2006-12-02 22:11:25 -0800 | [diff] [blame] | 497 | EXPORT_SYMBOL_GPL(nf_conntrack_helper_unregister); |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 498 | |
Gao Feng | 82de0be | 2016-07-18 11:39:23 +0800 | [diff] [blame] | 499 | void nf_ct_helper_init(struct nf_conntrack_helper *helper, |
| 500 | u16 l3num, u16 protonum, const char *name, |
| 501 | u16 default_port, u16 spec_port, u32 id, |
| 502 | const struct nf_conntrack_expect_policy *exp_pol, |
| 503 | u32 expect_class_max, u32 data_len, |
| 504 | int (*help)(struct sk_buff *skb, unsigned int protoff, |
| 505 | struct nf_conn *ct, |
| 506 | enum ip_conntrack_info ctinfo), |
| 507 | int (*from_nlattr)(struct nlattr *attr, |
| 508 | struct nf_conn *ct), |
| 509 | struct module *module) |
| 510 | { |
| 511 | helper->tuple.src.l3num = l3num; |
| 512 | helper->tuple.dst.protonum = protonum; |
| 513 | helper->tuple.src.u.all = htons(spec_port); |
| 514 | helper->expect_policy = exp_pol; |
| 515 | helper->expect_class_max = expect_class_max; |
| 516 | helper->data_len = data_len; |
| 517 | helper->help = help; |
| 518 | helper->from_nlattr = from_nlattr; |
| 519 | helper->me = module; |
| 520 | |
| 521 | if (spec_port == default_port) |
| 522 | snprintf(helper->name, sizeof(helper->name), "%s", name); |
| 523 | else |
| 524 | snprintf(helper->name, sizeof(helper->name), "%s-%u", name, id); |
| 525 | } |
| 526 | EXPORT_SYMBOL_GPL(nf_ct_helper_init); |
| 527 | |
| 528 | int nf_conntrack_helpers_register(struct nf_conntrack_helper *helper, |
| 529 | unsigned int n) |
| 530 | { |
| 531 | unsigned int i; |
| 532 | int err = 0; |
| 533 | |
| 534 | for (i = 0; i < n; i++) { |
| 535 | err = nf_conntrack_helper_register(&helper[i]); |
| 536 | if (err < 0) |
| 537 | goto err; |
| 538 | } |
| 539 | |
| 540 | return err; |
| 541 | err: |
| 542 | if (i > 0) |
| 543 | nf_conntrack_helpers_unregister(helper, i); |
| 544 | return err; |
| 545 | } |
| 546 | EXPORT_SYMBOL_GPL(nf_conntrack_helpers_register); |
| 547 | |
| 548 | void nf_conntrack_helpers_unregister(struct nf_conntrack_helper *helper, |
| 549 | unsigned int n) |
| 550 | { |
| 551 | while (n-- > 0) |
| 552 | nf_conntrack_helper_unregister(&helper[n]); |
| 553 | } |
| 554 | EXPORT_SYMBOL_GPL(nf_conntrack_helpers_unregister); |
| 555 | |
Patrick McHardy | 61eb310 | 2007-07-07 22:27:06 -0700 | [diff] [blame] | 556 | static struct nf_ct_ext_type helper_extend __read_mostly = { |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 557 | .len = sizeof(struct nf_conn_help), |
| 558 | .align = __alignof__(struct nf_conn_help), |
| 559 | .id = NF_CT_EXT_HELPER, |
| 560 | }; |
| 561 | |
Gao feng | 5e615b2 | 2013-01-21 22:10:30 +0000 | [diff] [blame] | 562 | int nf_conntrack_helper_pernet_init(struct net *net) |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 563 | { |
Eric Leblond | a900689 | 2012-04-18 11:20:41 +0200 | [diff] [blame] | 564 | net->ct.auto_assign_helper_warned = false; |
| 565 | net->ct.sysctl_auto_assign_helper = nf_ct_auto_assign_helper; |
Gao feng | 5e615b2 | 2013-01-21 22:10:30 +0000 | [diff] [blame] | 566 | return nf_conntrack_helper_init_sysctl(net); |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 567 | } |
| 568 | |
Gao feng | 5e615b2 | 2013-01-21 22:10:30 +0000 | [diff] [blame] | 569 | void nf_conntrack_helper_pernet_fini(struct net *net) |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 570 | { |
Eric Leblond | a900689 | 2012-04-18 11:20:41 +0200 | [diff] [blame] | 571 | nf_conntrack_helper_fini_sysctl(net); |
Gao feng | 5e615b2 | 2013-01-21 22:10:30 +0000 | [diff] [blame] | 572 | } |
| 573 | |
| 574 | int nf_conntrack_helper_init(void) |
| 575 | { |
| 576 | int ret; |
| 577 | nf_ct_helper_hsize = 1; /* gets rounded up to use one page */ |
| 578 | nf_ct_helper_hash = |
| 579 | nf_ct_alloc_hashtable(&nf_ct_helper_hsize, 0); |
| 580 | if (!nf_ct_helper_hash) |
| 581 | return -ENOMEM; |
| 582 | |
| 583 | ret = nf_ct_extend_register(&helper_extend); |
| 584 | if (ret < 0) { |
| 585 | pr_err("nf_ct_helper: Unable to register helper extension.\n"); |
| 586 | goto out_extend; |
Eric Leblond | a900689 | 2012-04-18 11:20:41 +0200 | [diff] [blame] | 587 | } |
Gao feng | 5e615b2 | 2013-01-21 22:10:30 +0000 | [diff] [blame] | 588 | |
| 589 | return 0; |
| 590 | out_extend: |
| 591 | nf_ct_free_hashtable(nf_ct_helper_hash, nf_ct_helper_hsize); |
| 592 | return ret; |
| 593 | } |
| 594 | |
| 595 | void nf_conntrack_helper_fini(void) |
| 596 | { |
| 597 | nf_ct_extend_unregister(&helper_extend); |
| 598 | nf_ct_free_hashtable(nf_ct_helper_hash, nf_ct_helper_hsize); |
Yasuyuki Kozakai | ceceae1 | 2007-07-07 22:23:42 -0700 | [diff] [blame] | 599 | } |