1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * net/sched/cls_fw.c Classifier mapping ipchains' fwmark to traffic class. 4 * 5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 6 * 7 * Changes: 8 * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_walk off by one 9 * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_delete killed all the filter (and kernel). 10 * Alex <alex@pilotsoft.com> : 2004xxyy: Added Action extension 11 */ 12 13 #include <linux/module.h> 14 #include <linux/slab.h> 15 #include <linux/types.h> 16 #include <linux/kernel.h> 17 #include <linux/string.h> 18 #include <linux/errno.h> 19 #include <linux/skbuff.h> 20 #include <net/netlink.h> 21 #include <net/act_api.h> 22 #include <net/pkt_cls.h> 23 #include <net/sch_generic.h> 24 25 #define HTSIZE 256 26 27 struct fw_head { 28 u32 mask; 29 struct fw_filter __rcu *ht[HTSIZE]; 30 struct rcu_head rcu; 31 }; 32 33 struct fw_filter { 34 struct fw_filter __rcu *next; 35 u32 id; 36 struct tcf_result res; 37 int ifindex; 38 struct tcf_exts exts; 39 struct tcf_proto *tp; 40 struct rcu_work rwork; 41 }; 42 43 static u32 fw_hash(u32 handle) 44 { 45 handle ^= (handle >> 16); 46 handle ^= (handle >> 8); 47 return handle % HTSIZE; 48 } 49 50 static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp, 51 struct tcf_result *res) 52 { 53 struct fw_head *head = rcu_dereference_bh(tp->root); 54 struct fw_filter *f; 55 int r; 56 u32 id = skb->mark; 57 58 if (head != NULL) { 59 id &= head->mask; 60 61 for (f = rcu_dereference_bh(head->ht[fw_hash(id)]); f; 62 f = rcu_dereference_bh(f->next)) { 63 if (f->id == id) { 64 *res = f->res; 65 if (!tcf_match_indev(skb, f->ifindex)) 66 continue; 67 r = tcf_exts_exec(skb, &f->exts, res); 68 if (r < 0) 69 continue; 70 71 return r; 72 } 73 } 74 } else { 75 struct Qdisc *q = tcf_block_q(tp->chain->block); 76 77 /* Old method: classify the packet using its skb mark. */ 78 if (id && (TC_H_MAJ(id) == 0 || 79 !(TC_H_MAJ(id ^ q->handle)))) { 80 res->classid = id; 81 res->class = 0; 82 return 0; 83 } 84 } 85 86 return -1; 87 } 88 89 static void *fw_get(struct tcf_proto *tp, u32 handle) 90 { 91 struct fw_head *head = rtnl_dereference(tp->root); 92 struct fw_filter *f; 93 94 if (head == NULL) 95 return NULL; 96 97 f = rtnl_dereference(head->ht[fw_hash(handle)]); 98 for (; f; f = rtnl_dereference(f->next)) { 99 if (f->id == handle) 100 return f; 101 } 102 return NULL; 103 } 104 105 static int fw_init(struct tcf_proto *tp) 106 { 107 /* We don't allocate fw_head here, because in the old method 108 * we don't need it at all. 109 */ 110 return 0; 111 } 112 113 static void __fw_delete_filter(struct fw_filter *f) 114 { 115 tcf_exts_destroy(&f->exts); 116 tcf_exts_put_net(&f->exts); 117 kfree(f); 118 } 119 120 static void fw_delete_filter_work(struct work_struct *work) 121 { 122 struct fw_filter *f = container_of(to_rcu_work(work), 123 struct fw_filter, 124 rwork); 125 rtnl_lock(); 126 __fw_delete_filter(f); 127 rtnl_unlock(); 128 } 129 130 static void fw_destroy(struct tcf_proto *tp, bool rtnl_held, 131 struct netlink_ext_ack *extack) 132 { 133 struct fw_head *head = rtnl_dereference(tp->root); 134 struct fw_filter *f; 135 int h; 136 137 if (head == NULL) 138 return; 139 140 for (h = 0; h < HTSIZE; h++) { 141 while ((f = rtnl_dereference(head->ht[h])) != NULL) { 142 RCU_INIT_POINTER(head->ht[h], 143 rtnl_dereference(f->next)); 144 tcf_unbind_filter(tp, &f->res); 145 if (tcf_exts_get_net(&f->exts)) 146 tcf_queue_work(&f->rwork, fw_delete_filter_work); 147 else 148 __fw_delete_filter(f); 149 } 150 } 151 kfree_rcu(head, rcu); 152 } 153 154 static int fw_delete(struct tcf_proto *tp, void *arg, bool *last, 155 bool rtnl_held, struct netlink_ext_ack *extack) 156 { 157 struct fw_head *head = rtnl_dereference(tp->root); 158 struct fw_filter *f = arg; 159 struct fw_filter __rcu **fp; 160 struct fw_filter *pfp; 161 int ret = -EINVAL; 162 int h; 163 164 if (head == NULL || f == NULL) 165 goto out; 166 167 fp = &head->ht[fw_hash(f->id)]; 168 169 for (pfp = rtnl_dereference(*fp); pfp; 170 fp = &pfp->next, pfp = rtnl_dereference(*fp)) { 171 if (pfp == f) { 172 RCU_INIT_POINTER(*fp, rtnl_dereference(f->next)); 173 tcf_unbind_filter(tp, &f->res); 174 tcf_exts_get_net(&f->exts); 175 tcf_queue_work(&f->rwork, fw_delete_filter_work); 176 ret = 0; 177 break; 178 } 179 } 180 181 *last = true; 182 for (h = 0; h < HTSIZE; h++) { 183 if (rcu_access_pointer(head->ht[h])) { 184 *last = false; 185 break; 186 } 187 } 188 189 out: 190 return ret; 191 } 192 193 static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = { 194 [TCA_FW_CLASSID] = { .type = NLA_U32 }, 195 [TCA_FW_INDEV] = { .type = NLA_STRING, .len = IFNAMSIZ }, 196 [TCA_FW_MASK] = { .type = NLA_U32 }, 197 }; 198 199 static int fw_set_parms(struct net *net, struct tcf_proto *tp, 200 struct fw_filter *f, struct nlattr **tb, 201 struct nlattr **tca, unsigned long base, u32 flags, 202 struct netlink_ext_ack *extack) 203 { 204 struct fw_head *head = rtnl_dereference(tp->root); 205 u32 mask; 206 int err; 207 208 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &f->exts, flags, 209 extack); 210 if (err < 0) 211 return err; 212 213 if (tb[TCA_FW_CLASSID]) { 214 f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]); 215 tcf_bind_filter(tp, &f->res, base); 216 } 217 218 if (tb[TCA_FW_INDEV]) { 219 int ret; 220 ret = tcf_change_indev(net, tb[TCA_FW_INDEV], extack); 221 if (ret < 0) 222 return ret; 223 f->ifindex = ret; 224 } 225 226 err = -EINVAL; 227 if (tb[TCA_FW_MASK]) { 228 mask = nla_get_u32(tb[TCA_FW_MASK]); 229 if (mask != head->mask) 230 return err; 231 } else if (head->mask != 0xFFFFFFFF) 232 return err; 233 234 return 0; 235 } 236 237 static int fw_change(struct net *net, struct sk_buff *in_skb, 238 struct tcf_proto *tp, unsigned long base, 239 u32 handle, struct nlattr **tca, void **arg, 240 u32 flags, struct netlink_ext_ack *extack) 241 { 242 struct fw_head *head = rtnl_dereference(tp->root); 243 struct fw_filter *f = *arg; 244 struct nlattr *opt = tca[TCA_OPTIONS]; 245 struct nlattr *tb[TCA_FW_MAX + 1]; 246 int err; 247 248 if (!opt) 249 return handle ? -EINVAL : 0; /* Succeed if it is old method. */ 250 251 err = nla_parse_nested_deprecated(tb, TCA_FW_MAX, opt, fw_policy, 252 NULL); 253 if (err < 0) 254 return err; 255 256 if (f) { 257 struct fw_filter *pfp, *fnew; 258 struct fw_filter __rcu **fp; 259 260 if (f->id != handle && handle) 261 return -EINVAL; 262 263 fnew = kzalloc(sizeof(struct fw_filter), GFP_KERNEL); 264 if (!fnew) 265 return -ENOBUFS; 266 267 fnew->id = f->id; 268 fnew->res = f->res; 269 fnew->ifindex = f->ifindex; 270 fnew->tp = f->tp; 271 272 err = tcf_exts_init(&fnew->exts, net, TCA_FW_ACT, 273 TCA_FW_POLICE); 274 if (err < 0) { 275 kfree(fnew); 276 return err; 277 } 278 279 err = fw_set_parms(net, tp, fnew, tb, tca, base, flags, extack); 280 if (err < 0) { 281 tcf_exts_destroy(&fnew->exts); 282 kfree(fnew); 283 return err; 284 } 285 286 fp = &head->ht[fw_hash(fnew->id)]; 287 for (pfp = rtnl_dereference(*fp); pfp; 288 fp = &pfp->next, pfp = rtnl_dereference(*fp)) 289 if (pfp == f) 290 break; 291 292 RCU_INIT_POINTER(fnew->next, rtnl_dereference(pfp->next)); 293 rcu_assign_pointer(*fp, fnew); 294 tcf_unbind_filter(tp, &f->res); 295 tcf_exts_get_net(&f->exts); 296 tcf_queue_work(&f->rwork, fw_delete_filter_work); 297 298 *arg = fnew; 299 return err; 300 } 301 302 if (!handle) 303 return -EINVAL; 304 305 if (!head) { 306 u32 mask = 0xFFFFFFFF; 307 if (tb[TCA_FW_MASK]) 308 mask = nla_get_u32(tb[TCA_FW_MASK]); 309 310 head = kzalloc(sizeof(*head), GFP_KERNEL); 311 if (!head) 312 return -ENOBUFS; 313 head->mask = mask; 314 315 rcu_assign_pointer(tp->root, head); 316 } 317 318 f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL); 319 if (f == NULL) 320 return -ENOBUFS; 321 322 err = tcf_exts_init(&f->exts, net, TCA_FW_ACT, TCA_FW_POLICE); 323 if (err < 0) 324 goto errout; 325 f->id = handle; 326 f->tp = tp; 327 328 err = fw_set_parms(net, tp, f, tb, tca, base, flags, extack); 329 if (err < 0) 330 goto errout; 331 332 RCU_INIT_POINTER(f->next, head->ht[fw_hash(handle)]); 333 rcu_assign_pointer(head->ht[fw_hash(handle)], f); 334 335 *arg = f; 336 return 0; 337 338 errout: 339 tcf_exts_destroy(&f->exts); 340 kfree(f); 341 return err; 342 } 343 344 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg, 345 bool rtnl_held) 346 { 347 struct fw_head *head = rtnl_dereference(tp->root); 348 int h; 349 350 if (head == NULL) 351 arg->stop = 1; 352 353 if (arg->stop) 354 return; 355 356 for (h = 0; h < HTSIZE; h++) { 357 struct fw_filter *f; 358 359 for (f = rtnl_dereference(head->ht[h]); f; 360 f = rtnl_dereference(f->next)) { 361 if (arg->count < arg->skip) { 362 arg->count++; 363 continue; 364 } 365 if (arg->fn(tp, f, arg) < 0) { 366 arg->stop = 1; 367 return; 368 } 369 arg->count++; 370 } 371 } 372 } 373 374 static int fw_dump(struct net *net, struct tcf_proto *tp, void *fh, 375 struct sk_buff *skb, struct tcmsg *t, bool rtnl_held) 376 { 377 struct fw_head *head = rtnl_dereference(tp->root); 378 struct fw_filter *f = fh; 379 struct nlattr *nest; 380 381 if (f == NULL) 382 return skb->len; 383 384 t->tcm_handle = f->id; 385 386 if (!f->res.classid && !tcf_exts_has_actions(&f->exts)) 387 return skb->len; 388 389 nest = nla_nest_start_noflag(skb, TCA_OPTIONS); 390 if (nest == NULL) 391 goto nla_put_failure; 392 393 if (f->res.classid && 394 nla_put_u32(skb, TCA_FW_CLASSID, f->res.classid)) 395 goto nla_put_failure; 396 if (f->ifindex) { 397 struct net_device *dev; 398 dev = __dev_get_by_index(net, f->ifindex); 399 if (dev && nla_put_string(skb, TCA_FW_INDEV, dev->name)) 400 goto nla_put_failure; 401 } 402 if (head->mask != 0xFFFFFFFF && 403 nla_put_u32(skb, TCA_FW_MASK, head->mask)) 404 goto nla_put_failure; 405 406 if (tcf_exts_dump(skb, &f->exts) < 0) 407 goto nla_put_failure; 408 409 nla_nest_end(skb, nest); 410 411 if (tcf_exts_dump_stats(skb, &f->exts) < 0) 412 goto nla_put_failure; 413 414 return skb->len; 415 416 nla_put_failure: 417 nla_nest_cancel(skb, nest); 418 return -1; 419 } 420 421 static void fw_bind_class(void *fh, u32 classid, unsigned long cl, void *q, 422 unsigned long base) 423 { 424 struct fw_filter *f = fh; 425 426 if (f && f->res.classid == classid) { 427 if (cl) 428 __tcf_bind_filter(q, &f->res, base); 429 else 430 __tcf_unbind_filter(q, &f->res); 431 } 432 } 433 434 static struct tcf_proto_ops cls_fw_ops __read_mostly = { 435 .kind = "fw", 436 .classify = fw_classify, 437 .init = fw_init, 438 .destroy = fw_destroy, 439 .get = fw_get, 440 .change = fw_change, 441 .delete = fw_delete, 442 .walk = fw_walk, 443 .dump = fw_dump, 444 .bind_class = fw_bind_class, 445 .owner = THIS_MODULE, 446 }; 447 448 static int __init init_fw(void) 449 { 450 return register_tcf_proto_ops(&cls_fw_ops); 451 } 452 453 static void __exit exit_fw(void) 454 { 455 unregister_tcf_proto_ops(&cls_fw_ops); 456 } 457 458 module_init(init_fw) 459 module_exit(exit_fw) 460 MODULE_LICENSE("GPL"); 461