1 /* 2 * net/sched/cls_basic.c Basic Packet Classifier. 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: Thomas Graf <tgraf@suug.ch> 10 */ 11 12 #include <linux/module.h> 13 #include <linux/slab.h> 14 #include <linux/types.h> 15 #include <linux/kernel.h> 16 #include <linux/string.h> 17 #include <linux/errno.h> 18 #include <linux/rtnetlink.h> 19 #include <linux/skbuff.h> 20 #include <linux/idr.h> 21 #include <net/netlink.h> 22 #include <net/act_api.h> 23 #include <net/pkt_cls.h> 24 25 struct basic_head { 26 struct list_head flist; 27 struct idr handle_idr; 28 struct rcu_head rcu; 29 }; 30 31 struct basic_filter { 32 u32 handle; 33 struct tcf_exts exts; 34 struct tcf_ematch_tree ematches; 35 struct tcf_result res; 36 struct tcf_proto *tp; 37 struct list_head link; 38 union { 39 struct work_struct work; 40 struct rcu_head rcu; 41 }; 42 }; 43 44 static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp, 45 struct tcf_result *res) 46 { 47 int r; 48 struct basic_head *head = rcu_dereference_bh(tp->root); 49 struct basic_filter *f; 50 51 list_for_each_entry_rcu(f, &head->flist, link) { 52 if (!tcf_em_tree_match(skb, &f->ematches, NULL)) 53 continue; 54 *res = f->res; 55 r = tcf_exts_exec(skb, &f->exts, res); 56 if (r < 0) 57 continue; 58 return r; 59 } 60 return -1; 61 } 62 63 static void *basic_get(struct tcf_proto *tp, u32 handle) 64 { 65 struct basic_head *head = rtnl_dereference(tp->root); 66 struct basic_filter *f; 67 68 list_for_each_entry(f, &head->flist, link) { 69 if (f->handle == handle) { 70 return f; 71 } 72 } 73 74 return NULL; 75 } 76 77 static int basic_init(struct tcf_proto *tp) 78 { 79 struct basic_head *head; 80 81 head = kzalloc(sizeof(*head), GFP_KERNEL); 82 if (head == NULL) 83 return -ENOBUFS; 84 INIT_LIST_HEAD(&head->flist); 85 idr_init(&head->handle_idr); 86 rcu_assign_pointer(tp->root, head); 87 return 0; 88 } 89 90 static void __basic_delete_filter(struct basic_filter *f) 91 { 92 tcf_exts_destroy(&f->exts); 93 tcf_em_tree_destroy(&f->ematches); 94 tcf_exts_put_net(&f->exts); 95 kfree(f); 96 } 97 98 static void basic_delete_filter_work(struct work_struct *work) 99 { 100 struct basic_filter *f = container_of(work, struct basic_filter, work); 101 102 rtnl_lock(); 103 __basic_delete_filter(f); 104 rtnl_unlock(); 105 } 106 107 static void basic_delete_filter(struct rcu_head *head) 108 { 109 struct basic_filter *f = container_of(head, struct basic_filter, rcu); 110 111 INIT_WORK(&f->work, basic_delete_filter_work); 112 tcf_queue_work(&f->work); 113 } 114 115 static void basic_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack) 116 { 117 struct basic_head *head = rtnl_dereference(tp->root); 118 struct basic_filter *f, *n; 119 120 list_for_each_entry_safe(f, n, &head->flist, link) { 121 list_del_rcu(&f->link); 122 tcf_unbind_filter(tp, &f->res); 123 idr_remove_ext(&head->handle_idr, f->handle); 124 if (tcf_exts_get_net(&f->exts)) 125 call_rcu(&f->rcu, basic_delete_filter); 126 else 127 __basic_delete_filter(f); 128 } 129 idr_destroy(&head->handle_idr); 130 kfree_rcu(head, rcu); 131 } 132 133 static int basic_delete(struct tcf_proto *tp, void *arg, bool *last, 134 struct netlink_ext_ack *extack) 135 { 136 struct basic_head *head = rtnl_dereference(tp->root); 137 struct basic_filter *f = arg; 138 139 list_del_rcu(&f->link); 140 tcf_unbind_filter(tp, &f->res); 141 idr_remove_ext(&head->handle_idr, f->handle); 142 tcf_exts_get_net(&f->exts); 143 call_rcu(&f->rcu, basic_delete_filter); 144 *last = list_empty(&head->flist); 145 return 0; 146 } 147 148 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = { 149 [TCA_BASIC_CLASSID] = { .type = NLA_U32 }, 150 [TCA_BASIC_EMATCHES] = { .type = NLA_NESTED }, 151 }; 152 153 static int basic_set_parms(struct net *net, struct tcf_proto *tp, 154 struct basic_filter *f, unsigned long base, 155 struct nlattr **tb, 156 struct nlattr *est, bool ovr, 157 struct netlink_ext_ack *extack) 158 { 159 int err; 160 161 err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, extack); 162 if (err < 0) 163 return err; 164 165 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &f->ematches); 166 if (err < 0) 167 return err; 168 169 if (tb[TCA_BASIC_CLASSID]) { 170 f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]); 171 tcf_bind_filter(tp, &f->res, base); 172 } 173 174 f->tp = tp; 175 return 0; 176 } 177 178 static int basic_change(struct net *net, struct sk_buff *in_skb, 179 struct tcf_proto *tp, unsigned long base, u32 handle, 180 struct nlattr **tca, void **arg, bool ovr, 181 struct netlink_ext_ack *extack) 182 { 183 int err; 184 struct basic_head *head = rtnl_dereference(tp->root); 185 struct nlattr *tb[TCA_BASIC_MAX + 1]; 186 struct basic_filter *fold = (struct basic_filter *) *arg; 187 struct basic_filter *fnew; 188 unsigned long idr_index; 189 190 if (tca[TCA_OPTIONS] == NULL) 191 return -EINVAL; 192 193 err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS], 194 basic_policy, NULL); 195 if (err < 0) 196 return err; 197 198 if (fold != NULL) { 199 if (handle && fold->handle != handle) 200 return -EINVAL; 201 } 202 203 fnew = kzalloc(sizeof(*fnew), GFP_KERNEL); 204 if (!fnew) 205 return -ENOBUFS; 206 207 err = tcf_exts_init(&fnew->exts, TCA_BASIC_ACT, TCA_BASIC_POLICE); 208 if (err < 0) 209 goto errout; 210 211 if (handle) { 212 fnew->handle = handle; 213 if (!fold) { 214 err = idr_alloc_ext(&head->handle_idr, fnew, &idr_index, 215 handle, handle + 1, GFP_KERNEL); 216 if (err) 217 goto errout; 218 } 219 } else { 220 err = idr_alloc_ext(&head->handle_idr, fnew, &idr_index, 221 1, 0x7FFFFFFF, GFP_KERNEL); 222 if (err) 223 goto errout; 224 fnew->handle = idr_index; 225 } 226 227 err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], ovr, 228 extack); 229 if (err < 0) { 230 if (!fold) 231 idr_remove_ext(&head->handle_idr, fnew->handle); 232 goto errout; 233 } 234 235 *arg = fnew; 236 237 if (fold) { 238 idr_replace_ext(&head->handle_idr, fnew, fnew->handle); 239 list_replace_rcu(&fold->link, &fnew->link); 240 tcf_unbind_filter(tp, &fold->res); 241 tcf_exts_get_net(&fold->exts); 242 call_rcu(&fold->rcu, basic_delete_filter); 243 } else { 244 list_add_rcu(&fnew->link, &head->flist); 245 } 246 247 return 0; 248 errout: 249 tcf_exts_destroy(&fnew->exts); 250 kfree(fnew); 251 return err; 252 } 253 254 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg) 255 { 256 struct basic_head *head = rtnl_dereference(tp->root); 257 struct basic_filter *f; 258 259 list_for_each_entry(f, &head->flist, link) { 260 if (arg->count < arg->skip) 261 goto skip; 262 263 if (arg->fn(tp, f, arg) < 0) { 264 arg->stop = 1; 265 break; 266 } 267 skip: 268 arg->count++; 269 } 270 } 271 272 static void basic_bind_class(void *fh, u32 classid, unsigned long cl) 273 { 274 struct basic_filter *f = fh; 275 276 if (f && f->res.classid == classid) 277 f->res.class = cl; 278 } 279 280 static int basic_dump(struct net *net, struct tcf_proto *tp, void *fh, 281 struct sk_buff *skb, struct tcmsg *t) 282 { 283 struct basic_filter *f = fh; 284 struct nlattr *nest; 285 286 if (f == NULL) 287 return skb->len; 288 289 t->tcm_handle = f->handle; 290 291 nest = nla_nest_start(skb, TCA_OPTIONS); 292 if (nest == NULL) 293 goto nla_put_failure; 294 295 if (f->res.classid && 296 nla_put_u32(skb, TCA_BASIC_CLASSID, f->res.classid)) 297 goto nla_put_failure; 298 299 if (tcf_exts_dump(skb, &f->exts) < 0 || 300 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0) 301 goto nla_put_failure; 302 303 nla_nest_end(skb, nest); 304 305 if (tcf_exts_dump_stats(skb, &f->exts) < 0) 306 goto nla_put_failure; 307 308 return skb->len; 309 310 nla_put_failure: 311 nla_nest_cancel(skb, nest); 312 return -1; 313 } 314 315 static struct tcf_proto_ops cls_basic_ops __read_mostly = { 316 .kind = "basic", 317 .classify = basic_classify, 318 .init = basic_init, 319 .destroy = basic_destroy, 320 .get = basic_get, 321 .change = basic_change, 322 .delete = basic_delete, 323 .walk = basic_walk, 324 .dump = basic_dump, 325 .bind_class = basic_bind_class, 326 .owner = THIS_MODULE, 327 }; 328 329 static int __init init_basic(void) 330 { 331 return register_tcf_proto_ops(&cls_basic_ops); 332 } 333 334 static void __exit exit_basic(void) 335 { 336 unregister_tcf_proto_ops(&cls_basic_ops); 337 } 338 339 module_init(init_basic) 340 module_exit(exit_basic) 341 MODULE_LICENSE("GPL"); 342 343