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