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_work(struct work_struct *work) 91 { 92 struct basic_filter *f = container_of(work, struct basic_filter, work); 93 94 rtnl_lock(); 95 tcf_exts_destroy(&f->exts); 96 tcf_em_tree_destroy(&f->ematches); 97 rtnl_unlock(); 98 99 kfree(f); 100 } 101 102 static void basic_delete_filter(struct rcu_head *head) 103 { 104 struct basic_filter *f = container_of(head, struct basic_filter, rcu); 105 106 INIT_WORK(&f->work, basic_delete_filter_work); 107 tcf_queue_work(&f->work); 108 } 109 110 static void basic_destroy(struct tcf_proto *tp) 111 { 112 struct basic_head *head = rtnl_dereference(tp->root); 113 struct basic_filter *f, *n; 114 115 list_for_each_entry_safe(f, n, &head->flist, link) { 116 list_del_rcu(&f->link); 117 tcf_unbind_filter(tp, &f->res); 118 idr_remove_ext(&head->handle_idr, f->handle); 119 call_rcu(&f->rcu, basic_delete_filter); 120 } 121 idr_destroy(&head->handle_idr); 122 kfree_rcu(head, rcu); 123 } 124 125 static int basic_delete(struct tcf_proto *tp, void *arg, bool *last) 126 { 127 struct basic_head *head = rtnl_dereference(tp->root); 128 struct basic_filter *f = arg; 129 130 list_del_rcu(&f->link); 131 tcf_unbind_filter(tp, &f->res); 132 idr_remove_ext(&head->handle_idr, f->handle); 133 call_rcu(&f->rcu, basic_delete_filter); 134 *last = list_empty(&head->flist); 135 return 0; 136 } 137 138 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = { 139 [TCA_BASIC_CLASSID] = { .type = NLA_U32 }, 140 [TCA_BASIC_EMATCHES] = { .type = NLA_NESTED }, 141 }; 142 143 static int basic_set_parms(struct net *net, struct tcf_proto *tp, 144 struct basic_filter *f, unsigned long base, 145 struct nlattr **tb, 146 struct nlattr *est, bool ovr) 147 { 148 int err; 149 150 err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr); 151 if (err < 0) 152 return err; 153 154 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &f->ematches); 155 if (err < 0) 156 return err; 157 158 if (tb[TCA_BASIC_CLASSID]) { 159 f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]); 160 tcf_bind_filter(tp, &f->res, base); 161 } 162 163 f->tp = tp; 164 return 0; 165 } 166 167 static int basic_change(struct net *net, struct sk_buff *in_skb, 168 struct tcf_proto *tp, unsigned long base, u32 handle, 169 struct nlattr **tca, void **arg, bool ovr) 170 { 171 int err; 172 struct basic_head *head = rtnl_dereference(tp->root); 173 struct nlattr *tb[TCA_BASIC_MAX + 1]; 174 struct basic_filter *fold = (struct basic_filter *) *arg; 175 struct basic_filter *fnew; 176 unsigned long idr_index; 177 178 if (tca[TCA_OPTIONS] == NULL) 179 return -EINVAL; 180 181 err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS], 182 basic_policy, NULL); 183 if (err < 0) 184 return err; 185 186 if (fold != NULL) { 187 if (handle && fold->handle != handle) 188 return -EINVAL; 189 } 190 191 fnew = kzalloc(sizeof(*fnew), GFP_KERNEL); 192 if (!fnew) 193 return -ENOBUFS; 194 195 err = tcf_exts_init(&fnew->exts, TCA_BASIC_ACT, TCA_BASIC_POLICE); 196 if (err < 0) 197 goto errout; 198 199 if (handle) { 200 fnew->handle = handle; 201 if (!fold) { 202 err = idr_alloc_ext(&head->handle_idr, fnew, &idr_index, 203 handle, handle + 1, GFP_KERNEL); 204 if (err) 205 goto errout; 206 } 207 } else { 208 err = idr_alloc_ext(&head->handle_idr, fnew, &idr_index, 209 1, 0x7FFFFFFF, GFP_KERNEL); 210 if (err) 211 goto errout; 212 fnew->handle = idr_index; 213 } 214 215 err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], ovr); 216 if (err < 0) { 217 if (!fold) 218 idr_remove_ext(&head->handle_idr, fnew->handle); 219 goto errout; 220 } 221 222 *arg = fnew; 223 224 if (fold) { 225 idr_replace_ext(&head->handle_idr, fnew, fnew->handle); 226 list_replace_rcu(&fold->link, &fnew->link); 227 tcf_unbind_filter(tp, &fold->res); 228 call_rcu(&fold->rcu, basic_delete_filter); 229 } else { 230 list_add_rcu(&fnew->link, &head->flist); 231 } 232 233 return 0; 234 errout: 235 tcf_exts_destroy(&fnew->exts); 236 kfree(fnew); 237 return err; 238 } 239 240 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg) 241 { 242 struct basic_head *head = rtnl_dereference(tp->root); 243 struct basic_filter *f; 244 245 list_for_each_entry(f, &head->flist, link) { 246 if (arg->count < arg->skip) 247 goto skip; 248 249 if (arg->fn(tp, f, arg) < 0) { 250 arg->stop = 1; 251 break; 252 } 253 skip: 254 arg->count++; 255 } 256 } 257 258 static void basic_bind_class(void *fh, u32 classid, unsigned long cl) 259 { 260 struct basic_filter *f = fh; 261 262 if (f && f->res.classid == classid) 263 f->res.class = cl; 264 } 265 266 static int basic_dump(struct net *net, struct tcf_proto *tp, void *fh, 267 struct sk_buff *skb, struct tcmsg *t) 268 { 269 struct basic_filter *f = fh; 270 struct nlattr *nest; 271 272 if (f == NULL) 273 return skb->len; 274 275 t->tcm_handle = f->handle; 276 277 nest = nla_nest_start(skb, TCA_OPTIONS); 278 if (nest == NULL) 279 goto nla_put_failure; 280 281 if (f->res.classid && 282 nla_put_u32(skb, TCA_BASIC_CLASSID, f->res.classid)) 283 goto nla_put_failure; 284 285 if (tcf_exts_dump(skb, &f->exts) < 0 || 286 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0) 287 goto nla_put_failure; 288 289 nla_nest_end(skb, nest); 290 291 if (tcf_exts_dump_stats(skb, &f->exts) < 0) 292 goto nla_put_failure; 293 294 return skb->len; 295 296 nla_put_failure: 297 nla_nest_cancel(skb, nest); 298 return -1; 299 } 300 301 static struct tcf_proto_ops cls_basic_ops __read_mostly = { 302 .kind = "basic", 303 .classify = basic_classify, 304 .init = basic_init, 305 .destroy = basic_destroy, 306 .get = basic_get, 307 .change = basic_change, 308 .delete = basic_delete, 309 .walk = basic_walk, 310 .dump = basic_dump, 311 .bind_class = basic_bind_class, 312 .owner = THIS_MODULE, 313 }; 314 315 static int __init init_basic(void) 316 { 317 return register_tcf_proto_ops(&cls_basic_ops); 318 } 319 320 static void __exit exit_basic(void) 321 { 322 unregister_tcf_proto_ops(&cls_basic_ops); 323 } 324 325 module_init(init_basic) 326 module_exit(exit_basic) 327 MODULE_LICENSE("GPL"); 328 329