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(&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(&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; 188 189 if (tca[TCA_OPTIONS] == NULL) 190 return -EINVAL; 191 192 err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS], 193 basic_policy, NULL); 194 if (err < 0) 195 return err; 196 197 if (fold != NULL) { 198 if (handle && fold->handle != handle) 199 return -EINVAL; 200 } 201 202 fnew = kzalloc(sizeof(*fnew), GFP_KERNEL); 203 if (!fnew) 204 return -ENOBUFS; 205 206 err = tcf_exts_init(&fnew->exts, TCA_BASIC_ACT, TCA_BASIC_POLICE); 207 if (err < 0) 208 goto errout; 209 210 if (!handle) { 211 handle = 1; 212 err = idr_alloc_u32(&head->handle_idr, fnew, &handle, 213 INT_MAX, GFP_KERNEL); 214 } else if (!fold) { 215 err = idr_alloc_u32(&head->handle_idr, fnew, &handle, 216 handle, GFP_KERNEL); 217 } 218 if (err) 219 goto errout; 220 fnew->handle = handle; 221 222 err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], ovr, 223 extack); 224 if (err < 0) { 225 if (!fold) 226 idr_remove(&head->handle_idr, fnew->handle); 227 goto errout; 228 } 229 230 *arg = fnew; 231 232 if (fold) { 233 idr_replace(&head->handle_idr, fnew, fnew->handle); 234 list_replace_rcu(&fold->link, &fnew->link); 235 tcf_unbind_filter(tp, &fold->res); 236 tcf_exts_get_net(&fold->exts); 237 call_rcu(&fold->rcu, basic_delete_filter); 238 } else { 239 list_add_rcu(&fnew->link, &head->flist); 240 } 241 242 return 0; 243 errout: 244 tcf_exts_destroy(&fnew->exts); 245 kfree(fnew); 246 return err; 247 } 248 249 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg) 250 { 251 struct basic_head *head = rtnl_dereference(tp->root); 252 struct basic_filter *f; 253 254 list_for_each_entry(f, &head->flist, link) { 255 if (arg->count < arg->skip) 256 goto skip; 257 258 if (arg->fn(tp, f, arg) < 0) { 259 arg->stop = 1; 260 break; 261 } 262 skip: 263 arg->count++; 264 } 265 } 266 267 static void basic_bind_class(void *fh, u32 classid, unsigned long cl) 268 { 269 struct basic_filter *f = fh; 270 271 if (f && f->res.classid == classid) 272 f->res.class = cl; 273 } 274 275 static int basic_dump(struct net *net, struct tcf_proto *tp, void *fh, 276 struct sk_buff *skb, struct tcmsg *t) 277 { 278 struct basic_filter *f = fh; 279 struct nlattr *nest; 280 281 if (f == NULL) 282 return skb->len; 283 284 t->tcm_handle = f->handle; 285 286 nest = nla_nest_start(skb, TCA_OPTIONS); 287 if (nest == NULL) 288 goto nla_put_failure; 289 290 if (f->res.classid && 291 nla_put_u32(skb, TCA_BASIC_CLASSID, f->res.classid)) 292 goto nla_put_failure; 293 294 if (tcf_exts_dump(skb, &f->exts) < 0 || 295 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0) 296 goto nla_put_failure; 297 298 nla_nest_end(skb, nest); 299 300 if (tcf_exts_dump_stats(skb, &f->exts) < 0) 301 goto nla_put_failure; 302 303 return skb->len; 304 305 nla_put_failure: 306 nla_nest_cancel(skb, nest); 307 return -1; 308 } 309 310 static struct tcf_proto_ops cls_basic_ops __read_mostly = { 311 .kind = "basic", 312 .classify = basic_classify, 313 .init = basic_init, 314 .destroy = basic_destroy, 315 .get = basic_get, 316 .change = basic_change, 317 .delete = basic_delete, 318 .walk = basic_walk, 319 .dump = basic_dump, 320 .bind_class = basic_bind_class, 321 .owner = THIS_MODULE, 322 }; 323 324 static int __init init_basic(void) 325 { 326 return register_tcf_proto_ops(&cls_basic_ops); 327 } 328 329 static void __exit exit_basic(void) 330 { 331 unregister_tcf_proto_ops(&cls_basic_ops); 332 } 333 334 module_init(init_basic) 335 module_exit(exit_basic) 336 MODULE_LICENSE("GPL"); 337 338