Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 1 | /* |
| 2 | * (C) 2012 Pablo Neira Ayuso <pablo@netfilter.org> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation (or any later at your option). |
| 7 | * |
| 8 | * This software has been sponsored by Vyatta Inc. <http://www.vyatta.com> |
| 9 | */ |
| 10 | #include <linux/init.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/skbuff.h> |
| 14 | #include <linux/netlink.h> |
| 15 | #include <linux/rculist.h> |
| 16 | #include <linux/slab.h> |
| 17 | #include <linux/types.h> |
| 18 | #include <linux/list.h> |
| 19 | #include <linux/errno.h> |
| 20 | #include <net/netlink.h> |
| 21 | #include <net/sock.h> |
| 22 | |
| 23 | #include <net/netfilter/nf_conntrack_helper.h> |
| 24 | #include <net/netfilter/nf_conntrack_expect.h> |
| 25 | #include <net/netfilter/nf_conntrack_ecache.h> |
| 26 | |
| 27 | #include <linux/netfilter/nfnetlink.h> |
| 28 | #include <linux/netfilter/nfnetlink_conntrack.h> |
| 29 | #include <linux/netfilter/nfnetlink_cthelper.h> |
| 30 | |
| 31 | MODULE_LICENSE("GPL"); |
| 32 | MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); |
| 33 | MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers"); |
| 34 | |
| 35 | static int |
| 36 | nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff, |
| 37 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) |
| 38 | { |
| 39 | const struct nf_conn_help *help; |
| 40 | struct nf_conntrack_helper *helper; |
| 41 | |
| 42 | help = nfct_help(ct); |
| 43 | if (help == NULL) |
| 44 | return NF_DROP; |
| 45 | |
| 46 | /* rcu_read_lock()ed by nf_hook_slow */ |
| 47 | helper = rcu_dereference(help->helper); |
| 48 | if (helper == NULL) |
| 49 | return NF_DROP; |
| 50 | |
| 51 | /* This is an user-space helper not yet configured, skip. */ |
| 52 | if ((helper->flags & |
| 53 | (NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) == |
| 54 | NF_CT_HELPER_F_USERSPACE) |
| 55 | return NF_ACCEPT; |
| 56 | |
| 57 | /* If the user-space helper is not available, don't block traffic. */ |
| 58 | return NF_QUEUE_NR(helper->queue_num) | NF_VERDICT_FLAG_QUEUE_BYPASS; |
| 59 | } |
| 60 | |
| 61 | static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = { |
| 62 | [NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, }, |
| 63 | [NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, }, |
| 64 | }; |
| 65 | |
| 66 | static int |
| 67 | nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple, |
| 68 | const struct nlattr *attr) |
| 69 | { |
Daniel Borkmann | 130ffbc | 2013-06-12 17:54:51 +0200 | [diff] [blame] | 70 | int err; |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 71 | struct nlattr *tb[NFCTH_TUPLE_MAX+1]; |
| 72 | |
Daniel Borkmann | 130ffbc | 2013-06-12 17:54:51 +0200 | [diff] [blame] | 73 | err = nla_parse_nested(tb, NFCTH_TUPLE_MAX, attr, nfnl_cthelper_tuple_pol); |
| 74 | if (err < 0) |
| 75 | return err; |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 76 | |
| 77 | if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM]) |
| 78 | return -EINVAL; |
| 79 | |
Patrick McHardy | fe31d1a | 2012-08-19 10:16:09 +0000 | [diff] [blame] | 80 | tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM])); |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 81 | tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]); |
| 82 | |
| 83 | return 0; |
| 84 | } |
| 85 | |
| 86 | static int |
| 87 | nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct) |
| 88 | { |
| 89 | const struct nf_conn_help *help = nfct_help(ct); |
| 90 | |
Pablo Neira Ayuso | 7be54ca | 2012-09-21 16:52:08 +0200 | [diff] [blame] | 91 | if (attr == NULL) |
| 92 | return -EINVAL; |
| 93 | |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 94 | if (help->helper->data_len == 0) |
| 95 | return -EINVAL; |
| 96 | |
| 97 | memcpy(&help->data, nla_data(attr), help->helper->data_len); |
| 98 | return 0; |
| 99 | } |
| 100 | |
| 101 | static int |
| 102 | nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct) |
| 103 | { |
| 104 | const struct nf_conn_help *help = nfct_help(ct); |
| 105 | |
| 106 | if (help->helper->data_len && |
| 107 | nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data)) |
| 108 | goto nla_put_failure; |
| 109 | |
| 110 | return 0; |
| 111 | |
| 112 | nla_put_failure: |
| 113 | return -ENOSPC; |
| 114 | } |
| 115 | |
| 116 | static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = { |
| 117 | [NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING, |
| 118 | .len = NF_CT_HELPER_NAME_LEN-1 }, |
| 119 | [NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, }, |
| 120 | [NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, }, |
| 121 | }; |
| 122 | |
| 123 | static int |
| 124 | nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy, |
| 125 | const struct nlattr *attr) |
| 126 | { |
Daniel Borkmann | 130ffbc | 2013-06-12 17:54:51 +0200 | [diff] [blame] | 127 | int err; |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 128 | struct nlattr *tb[NFCTH_POLICY_MAX+1]; |
| 129 | |
Daniel Borkmann | 130ffbc | 2013-06-12 17:54:51 +0200 | [diff] [blame] | 130 | err = nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, nfnl_cthelper_expect_pol); |
| 131 | if (err < 0) |
| 132 | return err; |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 133 | |
| 134 | if (!tb[NFCTH_POLICY_NAME] || |
| 135 | !tb[NFCTH_POLICY_EXPECT_MAX] || |
| 136 | !tb[NFCTH_POLICY_EXPECT_TIMEOUT]) |
| 137 | return -EINVAL; |
| 138 | |
| 139 | strncpy(expect_policy->name, |
| 140 | nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN); |
| 141 | expect_policy->max_expected = |
| 142 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); |
| 143 | expect_policy->timeout = |
| 144 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); |
| 145 | |
| 146 | return 0; |
| 147 | } |
| 148 | |
| 149 | static const struct nla_policy |
| 150 | nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = { |
| 151 | [NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, }, |
| 152 | }; |
| 153 | |
| 154 | static int |
| 155 | nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper, |
| 156 | const struct nlattr *attr) |
| 157 | { |
| 158 | int i, ret; |
| 159 | struct nf_conntrack_expect_policy *expect_policy; |
| 160 | struct nlattr *tb[NFCTH_POLICY_SET_MAX+1]; |
| 161 | |
Daniel Borkmann | 130ffbc | 2013-06-12 17:54:51 +0200 | [diff] [blame] | 162 | ret = nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr, |
| 163 | nfnl_cthelper_expect_policy_set); |
| 164 | if (ret < 0) |
| 165 | return ret; |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 166 | |
| 167 | if (!tb[NFCTH_POLICY_SET_NUM]) |
| 168 | return -EINVAL; |
| 169 | |
| 170 | helper->expect_class_max = |
| 171 | ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM])); |
| 172 | |
| 173 | if (helper->expect_class_max != 0 && |
| 174 | helper->expect_class_max > NF_CT_MAX_EXPECT_CLASSES) |
| 175 | return -EOVERFLOW; |
| 176 | |
| 177 | expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) * |
| 178 | helper->expect_class_max, GFP_KERNEL); |
| 179 | if (expect_policy == NULL) |
| 180 | return -ENOMEM; |
| 181 | |
| 182 | for (i=0; i<helper->expect_class_max; i++) { |
| 183 | if (!tb[NFCTH_POLICY_SET+i]) |
| 184 | goto err; |
| 185 | |
| 186 | ret = nfnl_cthelper_expect_policy(&expect_policy[i], |
| 187 | tb[NFCTH_POLICY_SET+i]); |
| 188 | if (ret < 0) |
| 189 | goto err; |
| 190 | } |
| 191 | helper->expect_policy = expect_policy; |
| 192 | return 0; |
| 193 | err: |
| 194 | kfree(expect_policy); |
| 195 | return -EINVAL; |
| 196 | } |
| 197 | |
| 198 | static int |
| 199 | nfnl_cthelper_create(const struct nlattr * const tb[], |
| 200 | struct nf_conntrack_tuple *tuple) |
| 201 | { |
| 202 | struct nf_conntrack_helper *helper; |
| 203 | int ret; |
| 204 | |
| 205 | if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN]) |
| 206 | return -EINVAL; |
| 207 | |
| 208 | helper = kzalloc(sizeof(struct nf_conntrack_helper), GFP_KERNEL); |
| 209 | if (helper == NULL) |
| 210 | return -ENOMEM; |
| 211 | |
| 212 | ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]); |
| 213 | if (ret < 0) |
| 214 | goto err; |
| 215 | |
| 216 | strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN); |
| 217 | helper->data_len = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN])); |
| 218 | helper->flags |= NF_CT_HELPER_F_USERSPACE; |
| 219 | memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple)); |
| 220 | |
| 221 | helper->me = THIS_MODULE; |
| 222 | helper->help = nfnl_userspace_cthelper; |
| 223 | helper->from_nlattr = nfnl_cthelper_from_nlattr; |
| 224 | helper->to_nlattr = nfnl_cthelper_to_nlattr; |
| 225 | |
| 226 | /* Default to queue number zero, this can be updated at any time. */ |
| 227 | if (tb[NFCTH_QUEUE_NUM]) |
| 228 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); |
| 229 | |
| 230 | if (tb[NFCTH_STATUS]) { |
| 231 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); |
| 232 | |
| 233 | switch(status) { |
| 234 | case NFCT_HELPER_STATUS_ENABLED: |
| 235 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; |
| 236 | break; |
| 237 | case NFCT_HELPER_STATUS_DISABLED: |
| 238 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; |
| 239 | break; |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | ret = nf_conntrack_helper_register(helper); |
| 244 | if (ret < 0) |
| 245 | goto err; |
| 246 | |
| 247 | return 0; |
| 248 | err: |
| 249 | kfree(helper); |
| 250 | return ret; |
| 251 | } |
| 252 | |
| 253 | static int |
| 254 | nfnl_cthelper_update(const struct nlattr * const tb[], |
| 255 | struct nf_conntrack_helper *helper) |
| 256 | { |
| 257 | int ret; |
| 258 | |
| 259 | if (tb[NFCTH_PRIV_DATA_LEN]) |
| 260 | return -EBUSY; |
| 261 | |
| 262 | if (tb[NFCTH_POLICY]) { |
| 263 | ret = nfnl_cthelper_parse_expect_policy(helper, |
| 264 | tb[NFCTH_POLICY]); |
| 265 | if (ret < 0) |
| 266 | return ret; |
| 267 | } |
| 268 | if (tb[NFCTH_QUEUE_NUM]) |
| 269 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); |
| 270 | |
| 271 | if (tb[NFCTH_STATUS]) { |
| 272 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); |
| 273 | |
| 274 | switch(status) { |
| 275 | case NFCT_HELPER_STATUS_ENABLED: |
| 276 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; |
| 277 | break; |
| 278 | case NFCT_HELPER_STATUS_DISABLED: |
| 279 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; |
| 280 | break; |
| 281 | } |
| 282 | } |
| 283 | return 0; |
| 284 | } |
| 285 | |
| 286 | static int |
| 287 | nfnl_cthelper_new(struct sock *nfnl, struct sk_buff *skb, |
| 288 | const struct nlmsghdr *nlh, const struct nlattr * const tb[]) |
| 289 | { |
| 290 | const char *helper_name; |
| 291 | struct nf_conntrack_helper *cur, *helper = NULL; |
| 292 | struct nf_conntrack_tuple tuple; |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 293 | int ret = 0, i; |
| 294 | |
| 295 | if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE]) |
| 296 | return -EINVAL; |
| 297 | |
| 298 | helper_name = nla_data(tb[NFCTH_NAME]); |
| 299 | |
| 300 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); |
| 301 | if (ret < 0) |
| 302 | return ret; |
| 303 | |
| 304 | rcu_read_lock(); |
| 305 | for (i = 0; i < nf_ct_helper_hsize && !helper; i++) { |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 306 | hlist_for_each_entry_rcu(cur, &nf_ct_helper_hash[i], hnode) { |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 307 | |
| 308 | /* skip non-userspace conntrack helpers. */ |
| 309 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) |
| 310 | continue; |
| 311 | |
| 312 | if (strncmp(cur->name, helper_name, |
| 313 | NF_CT_HELPER_NAME_LEN) != 0) |
| 314 | continue; |
| 315 | |
| 316 | if ((tuple.src.l3num != cur->tuple.src.l3num || |
| 317 | tuple.dst.protonum != cur->tuple.dst.protonum)) |
| 318 | continue; |
| 319 | |
| 320 | if (nlh->nlmsg_flags & NLM_F_EXCL) { |
| 321 | ret = -EEXIST; |
| 322 | goto err; |
| 323 | } |
| 324 | helper = cur; |
| 325 | break; |
| 326 | } |
| 327 | } |
| 328 | rcu_read_unlock(); |
| 329 | |
| 330 | if (helper == NULL) |
| 331 | ret = nfnl_cthelper_create(tb, &tuple); |
| 332 | else |
| 333 | ret = nfnl_cthelper_update(tb, helper); |
| 334 | |
| 335 | return ret; |
| 336 | err: |
| 337 | rcu_read_unlock(); |
| 338 | return ret; |
| 339 | } |
| 340 | |
| 341 | static int |
| 342 | nfnl_cthelper_dump_tuple(struct sk_buff *skb, |
| 343 | struct nf_conntrack_helper *helper) |
| 344 | { |
| 345 | struct nlattr *nest_parms; |
| 346 | |
| 347 | nest_parms = nla_nest_start(skb, NFCTH_TUPLE | NLA_F_NESTED); |
| 348 | if (nest_parms == NULL) |
| 349 | goto nla_put_failure; |
| 350 | |
| 351 | if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM, |
| 352 | htons(helper->tuple.src.l3num))) |
| 353 | goto nla_put_failure; |
| 354 | |
| 355 | if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum)) |
| 356 | goto nla_put_failure; |
| 357 | |
| 358 | nla_nest_end(skb, nest_parms); |
| 359 | return 0; |
| 360 | |
| 361 | nla_put_failure: |
| 362 | return -1; |
| 363 | } |
| 364 | |
| 365 | static int |
| 366 | nfnl_cthelper_dump_policy(struct sk_buff *skb, |
| 367 | struct nf_conntrack_helper *helper) |
| 368 | { |
| 369 | int i; |
| 370 | struct nlattr *nest_parms1, *nest_parms2; |
| 371 | |
| 372 | nest_parms1 = nla_nest_start(skb, NFCTH_POLICY | NLA_F_NESTED); |
| 373 | if (nest_parms1 == NULL) |
| 374 | goto nla_put_failure; |
| 375 | |
| 376 | if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM, |
| 377 | htonl(helper->expect_class_max))) |
| 378 | goto nla_put_failure; |
| 379 | |
| 380 | for (i=0; i<helper->expect_class_max; i++) { |
| 381 | nest_parms2 = nla_nest_start(skb, |
| 382 | (NFCTH_POLICY_SET+i) | NLA_F_NESTED); |
| 383 | if (nest_parms2 == NULL) |
| 384 | goto nla_put_failure; |
| 385 | |
| 386 | if (nla_put_string(skb, NFCTH_POLICY_NAME, |
| 387 | helper->expect_policy[i].name)) |
| 388 | goto nla_put_failure; |
| 389 | |
| 390 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX, |
| 391 | htonl(helper->expect_policy[i].max_expected))) |
| 392 | goto nla_put_failure; |
| 393 | |
| 394 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT, |
| 395 | htonl(helper->expect_policy[i].timeout))) |
| 396 | goto nla_put_failure; |
| 397 | |
| 398 | nla_nest_end(skb, nest_parms2); |
| 399 | } |
| 400 | nla_nest_end(skb, nest_parms1); |
| 401 | return 0; |
| 402 | |
| 403 | nla_put_failure: |
| 404 | return -1; |
| 405 | } |
| 406 | |
| 407 | static int |
Eric W. Biederman | 15e4730 | 2012-09-07 20:12:54 +0000 | [diff] [blame] | 408 | nfnl_cthelper_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 409 | int event, struct nf_conntrack_helper *helper) |
| 410 | { |
| 411 | struct nlmsghdr *nlh; |
| 412 | struct nfgenmsg *nfmsg; |
Eric W. Biederman | 15e4730 | 2012-09-07 20:12:54 +0000 | [diff] [blame] | 413 | unsigned int flags = portid ? NLM_F_MULTI : 0; |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 414 | int status; |
| 415 | |
| 416 | event |= NFNL_SUBSYS_CTHELPER << 8; |
Eric W. Biederman | 15e4730 | 2012-09-07 20:12:54 +0000 | [diff] [blame] | 417 | nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags); |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 418 | if (nlh == NULL) |
| 419 | goto nlmsg_failure; |
| 420 | |
| 421 | nfmsg = nlmsg_data(nlh); |
| 422 | nfmsg->nfgen_family = AF_UNSPEC; |
| 423 | nfmsg->version = NFNETLINK_V0; |
| 424 | nfmsg->res_id = 0; |
| 425 | |
| 426 | if (nla_put_string(skb, NFCTH_NAME, helper->name)) |
| 427 | goto nla_put_failure; |
| 428 | |
| 429 | if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num))) |
| 430 | goto nla_put_failure; |
| 431 | |
| 432 | if (nfnl_cthelper_dump_tuple(skb, helper) < 0) |
| 433 | goto nla_put_failure; |
| 434 | |
| 435 | if (nfnl_cthelper_dump_policy(skb, helper) < 0) |
| 436 | goto nla_put_failure; |
| 437 | |
| 438 | if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len))) |
| 439 | goto nla_put_failure; |
| 440 | |
| 441 | if (helper->flags & NF_CT_HELPER_F_CONFIGURED) |
| 442 | status = NFCT_HELPER_STATUS_ENABLED; |
| 443 | else |
| 444 | status = NFCT_HELPER_STATUS_DISABLED; |
| 445 | |
| 446 | if (nla_put_be32(skb, NFCTH_STATUS, htonl(status))) |
| 447 | goto nla_put_failure; |
| 448 | |
| 449 | nlmsg_end(skb, nlh); |
| 450 | return skb->len; |
| 451 | |
| 452 | nlmsg_failure: |
| 453 | nla_put_failure: |
| 454 | nlmsg_cancel(skb, nlh); |
| 455 | return -1; |
| 456 | } |
| 457 | |
| 458 | static int |
| 459 | nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb) |
| 460 | { |
| 461 | struct nf_conntrack_helper *cur, *last; |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 462 | |
| 463 | rcu_read_lock(); |
| 464 | last = (struct nf_conntrack_helper *)cb->args[1]; |
| 465 | for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) { |
| 466 | restart: |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 467 | hlist_for_each_entry_rcu(cur, |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 468 | &nf_ct_helper_hash[cb->args[0]], hnode) { |
| 469 | |
| 470 | /* skip non-userspace conntrack helpers. */ |
| 471 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) |
| 472 | continue; |
| 473 | |
| 474 | if (cb->args[1]) { |
| 475 | if (cur != last) |
| 476 | continue; |
| 477 | cb->args[1] = 0; |
| 478 | } |
| 479 | if (nfnl_cthelper_fill_info(skb, |
Eric W. Biederman | 15e4730 | 2012-09-07 20:12:54 +0000 | [diff] [blame] | 480 | NETLINK_CB(cb->skb).portid, |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 481 | cb->nlh->nlmsg_seq, |
| 482 | NFNL_MSG_TYPE(cb->nlh->nlmsg_type), |
| 483 | NFNL_MSG_CTHELPER_NEW, cur) < 0) { |
| 484 | cb->args[1] = (unsigned long)cur; |
| 485 | goto out; |
| 486 | } |
| 487 | } |
| 488 | } |
| 489 | if (cb->args[1]) { |
| 490 | cb->args[1] = 0; |
| 491 | goto restart; |
| 492 | } |
| 493 | out: |
| 494 | rcu_read_unlock(); |
| 495 | return skb->len; |
| 496 | } |
| 497 | |
| 498 | static int |
| 499 | nfnl_cthelper_get(struct sock *nfnl, struct sk_buff *skb, |
| 500 | const struct nlmsghdr *nlh, const struct nlattr * const tb[]) |
| 501 | { |
| 502 | int ret = -ENOENT, i; |
| 503 | struct nf_conntrack_helper *cur; |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 504 | struct sk_buff *skb2; |
| 505 | char *helper_name = NULL; |
| 506 | struct nf_conntrack_tuple tuple; |
| 507 | bool tuple_set = false; |
| 508 | |
| 509 | if (nlh->nlmsg_flags & NLM_F_DUMP) { |
| 510 | struct netlink_dump_control c = { |
| 511 | .dump = nfnl_cthelper_dump_table, |
| 512 | }; |
| 513 | return netlink_dump_start(nfnl, skb, nlh, &c); |
| 514 | } |
| 515 | |
| 516 | if (tb[NFCTH_NAME]) |
| 517 | helper_name = nla_data(tb[NFCTH_NAME]); |
| 518 | |
| 519 | if (tb[NFCTH_TUPLE]) { |
| 520 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); |
| 521 | if (ret < 0) |
| 522 | return ret; |
| 523 | |
| 524 | tuple_set = true; |
| 525 | } |
| 526 | |
| 527 | for (i = 0; i < nf_ct_helper_hsize; i++) { |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 528 | hlist_for_each_entry_rcu(cur, &nf_ct_helper_hash[i], hnode) { |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 529 | |
| 530 | /* skip non-userspace conntrack helpers. */ |
| 531 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) |
| 532 | continue; |
| 533 | |
| 534 | if (helper_name && strncmp(cur->name, helper_name, |
| 535 | NF_CT_HELPER_NAME_LEN) != 0) { |
| 536 | continue; |
| 537 | } |
| 538 | if (tuple_set && |
| 539 | (tuple.src.l3num != cur->tuple.src.l3num || |
| 540 | tuple.dst.protonum != cur->tuple.dst.protonum)) |
| 541 | continue; |
| 542 | |
| 543 | skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); |
| 544 | if (skb2 == NULL) { |
| 545 | ret = -ENOMEM; |
| 546 | break; |
| 547 | } |
| 548 | |
Eric W. Biederman | 15e4730 | 2012-09-07 20:12:54 +0000 | [diff] [blame] | 549 | ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).portid, |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 550 | nlh->nlmsg_seq, |
| 551 | NFNL_MSG_TYPE(nlh->nlmsg_type), |
| 552 | NFNL_MSG_CTHELPER_NEW, cur); |
| 553 | if (ret <= 0) { |
| 554 | kfree_skb(skb2); |
| 555 | break; |
| 556 | } |
| 557 | |
Eric W. Biederman | 15e4730 | 2012-09-07 20:12:54 +0000 | [diff] [blame] | 558 | ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid, |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 559 | MSG_DONTWAIT); |
| 560 | if (ret > 0) |
| 561 | ret = 0; |
| 562 | |
| 563 | /* this avoids a loop in nfnetlink. */ |
| 564 | return ret == -EAGAIN ? -ENOBUFS : ret; |
| 565 | } |
| 566 | } |
| 567 | return ret; |
| 568 | } |
| 569 | |
| 570 | static int |
| 571 | nfnl_cthelper_del(struct sock *nfnl, struct sk_buff *skb, |
| 572 | const struct nlmsghdr *nlh, const struct nlattr * const tb[]) |
| 573 | { |
| 574 | char *helper_name = NULL; |
| 575 | struct nf_conntrack_helper *cur; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 576 | struct hlist_node *tmp; |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 577 | struct nf_conntrack_tuple tuple; |
| 578 | bool tuple_set = false, found = false; |
| 579 | int i, j = 0, ret; |
| 580 | |
| 581 | if (tb[NFCTH_NAME]) |
| 582 | helper_name = nla_data(tb[NFCTH_NAME]); |
| 583 | |
| 584 | if (tb[NFCTH_TUPLE]) { |
| 585 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); |
| 586 | if (ret < 0) |
| 587 | return ret; |
| 588 | |
| 589 | tuple_set = true; |
| 590 | } |
| 591 | |
| 592 | for (i = 0; i < nf_ct_helper_hsize; i++) { |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 593 | hlist_for_each_entry_safe(cur, tmp, &nf_ct_helper_hash[i], |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 594 | hnode) { |
| 595 | /* skip non-userspace conntrack helpers. */ |
| 596 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) |
| 597 | continue; |
| 598 | |
| 599 | j++; |
| 600 | |
| 601 | if (helper_name && strncmp(cur->name, helper_name, |
| 602 | NF_CT_HELPER_NAME_LEN) != 0) { |
| 603 | continue; |
| 604 | } |
| 605 | if (tuple_set && |
| 606 | (tuple.src.l3num != cur->tuple.src.l3num || |
| 607 | tuple.dst.protonum != cur->tuple.dst.protonum)) |
| 608 | continue; |
| 609 | |
| 610 | found = true; |
| 611 | nf_conntrack_helper_unregister(cur); |
| 612 | } |
| 613 | } |
| 614 | /* Make sure we return success if we flush and there is no helpers */ |
| 615 | return (found || j == 0) ? 0 : -ENOENT; |
| 616 | } |
| 617 | |
| 618 | static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = { |
| 619 | [NFCTH_NAME] = { .type = NLA_NUL_STRING, |
| 620 | .len = NF_CT_HELPER_NAME_LEN-1 }, |
| 621 | [NFCTH_QUEUE_NUM] = { .type = NLA_U32, }, |
| 622 | }; |
| 623 | |
| 624 | static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = { |
| 625 | [NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new, |
| 626 | .attr_count = NFCTH_MAX, |
| 627 | .policy = nfnl_cthelper_policy }, |
| 628 | [NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get, |
| 629 | .attr_count = NFCTH_MAX, |
| 630 | .policy = nfnl_cthelper_policy }, |
| 631 | [NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del, |
| 632 | .attr_count = NFCTH_MAX, |
| 633 | .policy = nfnl_cthelper_policy }, |
| 634 | }; |
| 635 | |
| 636 | static const struct nfnetlink_subsystem nfnl_cthelper_subsys = { |
| 637 | .name = "cthelper", |
| 638 | .subsys_id = NFNL_SUBSYS_CTHELPER, |
| 639 | .cb_count = NFNL_MSG_CTHELPER_MAX, |
| 640 | .cb = nfnl_cthelper_cb, |
| 641 | }; |
| 642 | |
| 643 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER); |
| 644 | |
| 645 | static int __init nfnl_cthelper_init(void) |
| 646 | { |
| 647 | int ret; |
| 648 | |
| 649 | ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys); |
| 650 | if (ret < 0) { |
| 651 | pr_err("nfnl_cthelper: cannot register with nfnetlink.\n"); |
| 652 | goto err_out; |
| 653 | } |
| 654 | return 0; |
| 655 | err_out: |
| 656 | return ret; |
| 657 | } |
| 658 | |
| 659 | static void __exit nfnl_cthelper_exit(void) |
| 660 | { |
| 661 | struct nf_conntrack_helper *cur; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 662 | struct hlist_node *tmp; |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 663 | int i; |
| 664 | |
| 665 | nfnetlink_subsys_unregister(&nfnl_cthelper_subsys); |
| 666 | |
| 667 | for (i=0; i<nf_ct_helper_hsize; i++) { |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 668 | hlist_for_each_entry_safe(cur, tmp, &nf_ct_helper_hash[i], |
Pablo Neira Ayuso | 12f7a50 | 2012-05-13 21:44:54 +0200 | [diff] [blame] | 669 | hnode) { |
| 670 | /* skip non-userspace conntrack helpers. */ |
| 671 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) |
| 672 | continue; |
| 673 | |
| 674 | nf_conntrack_helper_unregister(cur); |
| 675 | } |
| 676 | } |
| 677 | } |
| 678 | |
| 679 | module_init(nfnl_cthelper_init); |
| 680 | module_exit(nfnl_cthelper_exit); |