1 /* 2 * net/sched/cls_fw.c Classifier mapping ipchains' fwmark to traffic class. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 10 * 11 * Changes: 12 * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_walk off by one 13 * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_delete killed all the filter (and kernel). 14 * Alex <alex@pilotsoft.com> : 2004xxyy: Added Action extension 15 * 16 * JHS: We should remove the CONFIG_NET_CLS_IND from here 17 * eventually when the meta match extension is made available 18 * 19 */ 20 21 #include <linux/module.h> 22 #include <linux/slab.h> 23 #include <linux/types.h> 24 #include <linux/kernel.h> 25 #include <linux/string.h> 26 #include <linux/errno.h> 27 #include <linux/skbuff.h> 28 #include <net/netlink.h> 29 #include <net/act_api.h> 30 #include <net/pkt_cls.h> 31 #include <net/sch_generic.h> 32 33 #define HTSIZE 256 34 35 struct fw_head { 36 u32 mask; 37 struct fw_filter __rcu *ht[HTSIZE]; 38 struct rcu_head rcu; 39 }; 40 41 struct fw_filter { 42 struct fw_filter __rcu *next; 43 u32 id; 44 struct tcf_result res; 45 #ifdef CONFIG_NET_CLS_IND 46 int ifindex; 47 #endif /* CONFIG_NET_CLS_IND */ 48 struct tcf_exts exts; 49 struct tcf_proto *tp; 50 union { 51 struct work_struct work; 52 struct rcu_head rcu; 53 }; 54 }; 55 56 static u32 fw_hash(u32 handle) 57 { 58 handle ^= (handle >> 16); 59 handle ^= (handle >> 8); 60 return handle % HTSIZE; 61 } 62 63 static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp, 64 struct tcf_result *res) 65 { 66 struct fw_head *head = rcu_dereference_bh(tp->root); 67 struct fw_filter *f; 68 int r; 69 u32 id = skb->mark; 70 71 if (head != NULL) { 72 id &= head->mask; 73 74 for (f = rcu_dereference_bh(head->ht[fw_hash(id)]); f; 75 f = rcu_dereference_bh(f->next)) { 76 if (f->id == id) { 77 *res = f->res; 78 #ifdef CONFIG_NET_CLS_IND 79 if (!tcf_match_indev(skb, f->ifindex)) 80 continue; 81 #endif /* CONFIG_NET_CLS_IND */ 82 r = tcf_exts_exec(skb, &f->exts, res); 83 if (r < 0) 84 continue; 85 86 return r; 87 } 88 } 89 } else { 90 struct Qdisc *q = tcf_block_q(tp->chain->block); 91 92 /* Old method: classify the packet using its skb mark. */ 93 if (id && (TC_H_MAJ(id) == 0 || 94 !(TC_H_MAJ(id ^ q->handle)))) { 95 res->classid = id; 96 res->class = 0; 97 return 0; 98 } 99 } 100 101 return -1; 102 } 103 104 static void *fw_get(struct tcf_proto *tp, u32 handle) 105 { 106 struct fw_head *head = rtnl_dereference(tp->root); 107 struct fw_filter *f; 108 109 if (head == NULL) 110 return NULL; 111 112 f = rtnl_dereference(head->ht[fw_hash(handle)]); 113 for (; f; f = rtnl_dereference(f->next)) { 114 if (f->id == handle) 115 return f; 116 } 117 return NULL; 118 } 119 120 static int fw_init(struct tcf_proto *tp) 121 { 122 /* We don't allocate fw_head here, because in the old method 123 * we don't need it at all. 124 */ 125 return 0; 126 } 127 128 static void __fw_delete_filter(struct fw_filter *f) 129 { 130 tcf_exts_destroy(&f->exts); 131 tcf_exts_put_net(&f->exts); 132 kfree(f); 133 } 134 135 static void fw_delete_filter_work(struct work_struct *work) 136 { 137 struct fw_filter *f = container_of(work, struct fw_filter, work); 138 139 rtnl_lock(); 140 __fw_delete_filter(f); 141 rtnl_unlock(); 142 } 143 144 static void fw_delete_filter(struct rcu_head *head) 145 { 146 struct fw_filter *f = container_of(head, struct fw_filter, rcu); 147 148 INIT_WORK(&f->work, fw_delete_filter_work); 149 tcf_queue_work(&f->work); 150 } 151 152 static void fw_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack) 153 { 154 struct fw_head *head = rtnl_dereference(tp->root); 155 struct fw_filter *f; 156 int h; 157 158 if (head == NULL) 159 return; 160 161 for (h = 0; h < HTSIZE; h++) { 162 while ((f = rtnl_dereference(head->ht[h])) != NULL) { 163 RCU_INIT_POINTER(head->ht[h], 164 rtnl_dereference(f->next)); 165 tcf_unbind_filter(tp, &f->res); 166 if (tcf_exts_get_net(&f->exts)) 167 call_rcu(&f->rcu, fw_delete_filter); 168 else 169 __fw_delete_filter(f); 170 } 171 } 172 kfree_rcu(head, rcu); 173 } 174 175 static int fw_delete(struct tcf_proto *tp, void *arg, bool *last, 176 struct netlink_ext_ack *extack) 177 { 178 struct fw_head *head = rtnl_dereference(tp->root); 179 struct fw_filter *f = arg; 180 struct fw_filter __rcu **fp; 181 struct fw_filter *pfp; 182 int ret = -EINVAL; 183 int h; 184 185 if (head == NULL || f == NULL) 186 goto out; 187 188 fp = &head->ht[fw_hash(f->id)]; 189 190 for (pfp = rtnl_dereference(*fp); pfp; 191 fp = &pfp->next, pfp = rtnl_dereference(*fp)) { 192 if (pfp == f) { 193 RCU_INIT_POINTER(*fp, rtnl_dereference(f->next)); 194 tcf_unbind_filter(tp, &f->res); 195 tcf_exts_get_net(&f->exts); 196 call_rcu(&f->rcu, fw_delete_filter); 197 ret = 0; 198 break; 199 } 200 } 201 202 *last = true; 203 for (h = 0; h < HTSIZE; h++) { 204 if (rcu_access_pointer(head->ht[h])) { 205 *last = false; 206 break; 207 } 208 } 209 210 out: 211 return ret; 212 } 213 214 static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = { 215 [TCA_FW_CLASSID] = { .type = NLA_U32 }, 216 [TCA_FW_INDEV] = { .type = NLA_STRING, .len = IFNAMSIZ }, 217 [TCA_FW_MASK] = { .type = NLA_U32 }, 218 }; 219 220 static int fw_set_parms(struct net *net, struct tcf_proto *tp, 221 struct fw_filter *f, struct nlattr **tb, 222 struct nlattr **tca, unsigned long base, bool ovr, 223 struct netlink_ext_ack *extack) 224 { 225 struct fw_head *head = rtnl_dereference(tp->root); 226 u32 mask; 227 int err; 228 229 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &f->exts, ovr, 230 extack); 231 if (err < 0) 232 return err; 233 234 if (tb[TCA_FW_CLASSID]) { 235 f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]); 236 tcf_bind_filter(tp, &f->res, base); 237 } 238 239 #ifdef CONFIG_NET_CLS_IND 240 if (tb[TCA_FW_INDEV]) { 241 int ret; 242 ret = tcf_change_indev(net, tb[TCA_FW_INDEV], extack); 243 if (ret < 0) 244 return ret; 245 f->ifindex = ret; 246 } 247 #endif /* CONFIG_NET_CLS_IND */ 248 249 err = -EINVAL; 250 if (tb[TCA_FW_MASK]) { 251 mask = nla_get_u32(tb[TCA_FW_MASK]); 252 if (mask != head->mask) 253 return err; 254 } else if (head->mask != 0xFFFFFFFF) 255 return err; 256 257 return 0; 258 } 259 260 static int fw_change(struct net *net, struct sk_buff *in_skb, 261 struct tcf_proto *tp, unsigned long base, 262 u32 handle, struct nlattr **tca, void **arg, 263 bool ovr, struct netlink_ext_ack *extack) 264 { 265 struct fw_head *head = rtnl_dereference(tp->root); 266 struct fw_filter *f = *arg; 267 struct nlattr *opt = tca[TCA_OPTIONS]; 268 struct nlattr *tb[TCA_FW_MAX + 1]; 269 int err; 270 271 if (!opt) 272 return handle ? -EINVAL : 0; /* Succeed if it is old method. */ 273 274 err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy, NULL); 275 if (err < 0) 276 return err; 277 278 if (f) { 279 struct fw_filter *pfp, *fnew; 280 struct fw_filter __rcu **fp; 281 282 if (f->id != handle && handle) 283 return -EINVAL; 284 285 fnew = kzalloc(sizeof(struct fw_filter), GFP_KERNEL); 286 if (!fnew) 287 return -ENOBUFS; 288 289 fnew->id = f->id; 290 fnew->res = f->res; 291 #ifdef CONFIG_NET_CLS_IND 292 fnew->ifindex = f->ifindex; 293 #endif /* CONFIG_NET_CLS_IND */ 294 fnew->tp = f->tp; 295 296 err = tcf_exts_init(&fnew->exts, TCA_FW_ACT, TCA_FW_POLICE); 297 if (err < 0) { 298 kfree(fnew); 299 return err; 300 } 301 302 err = fw_set_parms(net, tp, fnew, tb, tca, base, ovr, extack); 303 if (err < 0) { 304 tcf_exts_destroy(&fnew->exts); 305 kfree(fnew); 306 return err; 307 } 308 309 fp = &head->ht[fw_hash(fnew->id)]; 310 for (pfp = rtnl_dereference(*fp); pfp; 311 fp = &pfp->next, pfp = rtnl_dereference(*fp)) 312 if (pfp == f) 313 break; 314 315 RCU_INIT_POINTER(fnew->next, rtnl_dereference(pfp->next)); 316 rcu_assign_pointer(*fp, fnew); 317 tcf_unbind_filter(tp, &f->res); 318 tcf_exts_get_net(&f->exts); 319 call_rcu(&f->rcu, fw_delete_filter); 320 321 *arg = fnew; 322 return err; 323 } 324 325 if (!handle) 326 return -EINVAL; 327 328 if (!head) { 329 u32 mask = 0xFFFFFFFF; 330 if (tb[TCA_FW_MASK]) 331 mask = nla_get_u32(tb[TCA_FW_MASK]); 332 333 head = kzalloc(sizeof(*head), GFP_KERNEL); 334 if (!head) 335 return -ENOBUFS; 336 head->mask = mask; 337 338 rcu_assign_pointer(tp->root, head); 339 } 340 341 f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL); 342 if (f == NULL) 343 return -ENOBUFS; 344 345 err = tcf_exts_init(&f->exts, TCA_FW_ACT, TCA_FW_POLICE); 346 if (err < 0) 347 goto errout; 348 f->id = handle; 349 f->tp = tp; 350 351 err = fw_set_parms(net, tp, f, tb, tca, base, ovr, extack); 352 if (err < 0) 353 goto errout; 354 355 RCU_INIT_POINTER(f->next, head->ht[fw_hash(handle)]); 356 rcu_assign_pointer(head->ht[fw_hash(handle)], f); 357 358 *arg = f; 359 return 0; 360 361 errout: 362 tcf_exts_destroy(&f->exts); 363 kfree(f); 364 return err; 365 } 366 367 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg) 368 { 369 struct fw_head *head = rtnl_dereference(tp->root); 370 int h; 371 372 if (head == NULL) 373 arg->stop = 1; 374 375 if (arg->stop) 376 return; 377 378 for (h = 0; h < HTSIZE; h++) { 379 struct fw_filter *f; 380 381 for (f = rtnl_dereference(head->ht[h]); f; 382 f = rtnl_dereference(f->next)) { 383 if (arg->count < arg->skip) { 384 arg->count++; 385 continue; 386 } 387 if (arg->fn(tp, f, arg) < 0) { 388 arg->stop = 1; 389 return; 390 } 391 arg->count++; 392 } 393 } 394 } 395 396 static int fw_dump(struct net *net, struct tcf_proto *tp, void *fh, 397 struct sk_buff *skb, struct tcmsg *t) 398 { 399 struct fw_head *head = rtnl_dereference(tp->root); 400 struct fw_filter *f = fh; 401 struct nlattr *nest; 402 403 if (f == NULL) 404 return skb->len; 405 406 t->tcm_handle = f->id; 407 408 if (!f->res.classid && !tcf_exts_has_actions(&f->exts)) 409 return skb->len; 410 411 nest = nla_nest_start(skb, TCA_OPTIONS); 412 if (nest == NULL) 413 goto nla_put_failure; 414 415 if (f->res.classid && 416 nla_put_u32(skb, TCA_FW_CLASSID, f->res.classid)) 417 goto nla_put_failure; 418 #ifdef CONFIG_NET_CLS_IND 419 if (f->ifindex) { 420 struct net_device *dev; 421 dev = __dev_get_by_index(net, f->ifindex); 422 if (dev && nla_put_string(skb, TCA_FW_INDEV, dev->name)) 423 goto nla_put_failure; 424 } 425 #endif /* CONFIG_NET_CLS_IND */ 426 if (head->mask != 0xFFFFFFFF && 427 nla_put_u32(skb, TCA_FW_MASK, head->mask)) 428 goto nla_put_failure; 429 430 if (tcf_exts_dump(skb, &f->exts) < 0) 431 goto nla_put_failure; 432 433 nla_nest_end(skb, nest); 434 435 if (tcf_exts_dump_stats(skb, &f->exts) < 0) 436 goto nla_put_failure; 437 438 return skb->len; 439 440 nla_put_failure: 441 nla_nest_cancel(skb, nest); 442 return -1; 443 } 444 445 static void fw_bind_class(void *fh, u32 classid, unsigned long cl) 446 { 447 struct fw_filter *f = fh; 448 449 if (f && f->res.classid == classid) 450 f->res.class = cl; 451 } 452 453 static struct tcf_proto_ops cls_fw_ops __read_mostly = { 454 .kind = "fw", 455 .classify = fw_classify, 456 .init = fw_init, 457 .destroy = fw_destroy, 458 .get = fw_get, 459 .change = fw_change, 460 .delete = fw_delete, 461 .walk = fw_walk, 462 .dump = fw_dump, 463 .bind_class = fw_bind_class, 464 .owner = THIS_MODULE, 465 }; 466 467 static int __init init_fw(void) 468 { 469 return register_tcf_proto_ops(&cls_fw_ops); 470 } 471 472 static void __exit exit_fw(void) 473 { 474 unregister_tcf_proto_ops(&cls_fw_ops); 475 } 476 477 module_init(init_fw) 478 module_exit(exit_fw) 479 MODULE_LICENSE("GPL"); 480