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 <net/netlink.h> 21 #include <net/act_api.h> 22 #include <net/pkt_cls.h> 23 24 struct basic_head { 25 u32 hgenerator; 26 struct list_head flist; 27 struct rcu_head rcu; 28 }; 29 30 struct basic_filter { 31 u32 handle; 32 struct tcf_exts exts; 33 struct tcf_ematch_tree ematches; 34 struct tcf_result res; 35 struct tcf_proto *tp; 36 struct list_head link; 37 union { 38 struct work_struct work; 39 struct rcu_head rcu; 40 }; 41 }; 42 43 static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp, 44 struct tcf_result *res) 45 { 46 int r; 47 struct basic_head *head = rcu_dereference_bh(tp->root); 48 struct basic_filter *f; 49 50 list_for_each_entry_rcu(f, &head->flist, link) { 51 if (!tcf_em_tree_match(skb, &f->ematches, NULL)) 52 continue; 53 *res = f->res; 54 r = tcf_exts_exec(skb, &f->exts, res); 55 if (r < 0) 56 continue; 57 return r; 58 } 59 return -1; 60 } 61 62 static void *basic_get(struct tcf_proto *tp, u32 handle) 63 { 64 struct basic_head *head = rtnl_dereference(tp->root); 65 struct basic_filter *f; 66 67 list_for_each_entry(f, &head->flist, link) { 68 if (f->handle == handle) { 69 return f; 70 } 71 } 72 73 return NULL; 74 } 75 76 static int basic_init(struct tcf_proto *tp) 77 { 78 struct basic_head *head; 79 80 head = kzalloc(sizeof(*head), GFP_KERNEL); 81 if (head == NULL) 82 return -ENOBUFS; 83 INIT_LIST_HEAD(&head->flist); 84 rcu_assign_pointer(tp->root, head); 85 return 0; 86 } 87 88 static void __basic_delete_filter(struct basic_filter *f) 89 { 90 tcf_exts_destroy(&f->exts); 91 tcf_em_tree_destroy(&f->ematches); 92 tcf_exts_put_net(&f->exts); 93 kfree(f); 94 } 95 96 static void basic_delete_filter_work(struct work_struct *work) 97 { 98 struct basic_filter *f = container_of(work, struct basic_filter, work); 99 100 rtnl_lock(); 101 __basic_delete_filter(f); 102 rtnl_unlock(); 103 } 104 105 static void basic_delete_filter(struct rcu_head *head) 106 { 107 struct basic_filter *f = container_of(head, struct basic_filter, rcu); 108 109 INIT_WORK(&f->work, basic_delete_filter_work); 110 tcf_queue_work(&f->work); 111 } 112 113 static void basic_destroy(struct tcf_proto *tp) 114 { 115 struct basic_head *head = rtnl_dereference(tp->root); 116 struct basic_filter *f, *n; 117 118 list_for_each_entry_safe(f, n, &head->flist, link) { 119 list_del_rcu(&f->link); 120 tcf_unbind_filter(tp, &f->res); 121 if (tcf_exts_get_net(&f->exts)) 122 call_rcu(&f->rcu, basic_delete_filter); 123 else 124 __basic_delete_filter(f); 125 } 126 kfree_rcu(head, rcu); 127 } 128 129 static int basic_delete(struct tcf_proto *tp, void *arg, bool *last) 130 { 131 struct basic_head *head = rtnl_dereference(tp->root); 132 struct basic_filter *f = arg; 133 134 list_del_rcu(&f->link); 135 tcf_unbind_filter(tp, &f->res); 136 tcf_exts_get_net(&f->exts); 137 call_rcu(&f->rcu, basic_delete_filter); 138 *last = list_empty(&head->flist); 139 return 0; 140 } 141 142 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = { 143 [TCA_BASIC_CLASSID] = { .type = NLA_U32 }, 144 [TCA_BASIC_EMATCHES] = { .type = NLA_NESTED }, 145 }; 146 147 static int basic_set_parms(struct net *net, struct tcf_proto *tp, 148 struct basic_filter *f, unsigned long base, 149 struct nlattr **tb, 150 struct nlattr *est, bool ovr) 151 { 152 int err; 153 154 err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr); 155 if (err < 0) 156 return err; 157 158 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &f->ematches); 159 if (err < 0) 160 return err; 161 162 if (tb[TCA_BASIC_CLASSID]) { 163 f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]); 164 tcf_bind_filter(tp, &f->res, base); 165 } 166 167 f->tp = tp; 168 return 0; 169 } 170 171 static int basic_change(struct net *net, struct sk_buff *in_skb, 172 struct tcf_proto *tp, unsigned long base, u32 handle, 173 struct nlattr **tca, void **arg, bool ovr) 174 { 175 int err; 176 struct basic_head *head = rtnl_dereference(tp->root); 177 struct nlattr *tb[TCA_BASIC_MAX + 1]; 178 struct basic_filter *fold = (struct basic_filter *) *arg; 179 struct basic_filter *fnew; 180 181 if (tca[TCA_OPTIONS] == NULL) 182 return -EINVAL; 183 184 err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS], 185 basic_policy, NULL); 186 if (err < 0) 187 return err; 188 189 if (fold != NULL) { 190 if (handle && fold->handle != handle) 191 return -EINVAL; 192 } 193 194 fnew = kzalloc(sizeof(*fnew), GFP_KERNEL); 195 if (!fnew) 196 return -ENOBUFS; 197 198 err = tcf_exts_init(&fnew->exts, TCA_BASIC_ACT, TCA_BASIC_POLICE); 199 if (err < 0) 200 goto errout; 201 202 err = -EINVAL; 203 if (handle) { 204 fnew->handle = handle; 205 } else if (fold) { 206 fnew->handle = fold->handle; 207 } else { 208 unsigned int i = 0x80000000; 209 do { 210 if (++head->hgenerator == 0x7FFFFFFF) 211 head->hgenerator = 1; 212 } while (--i > 0 && basic_get(tp, head->hgenerator)); 213 214 if (i <= 0) { 215 pr_err("Insufficient number of handles\n"); 216 goto errout; 217 } 218 219 fnew->handle = head->hgenerator; 220 } 221 222 err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], ovr); 223 if (err < 0) 224 goto errout; 225 226 *arg = fnew; 227 228 if (fold) { 229 list_replace_rcu(&fold->link, &fnew->link); 230 tcf_unbind_filter(tp, &fold->res); 231 tcf_exts_get_net(&fold->exts); 232 call_rcu(&fold->rcu, basic_delete_filter); 233 } else { 234 list_add_rcu(&fnew->link, &head->flist); 235 } 236 237 return 0; 238 errout: 239 tcf_exts_destroy(&fnew->exts); 240 kfree(fnew); 241 return err; 242 } 243 244 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg) 245 { 246 struct basic_head *head = rtnl_dereference(tp->root); 247 struct basic_filter *f; 248 249 list_for_each_entry(f, &head->flist, link) { 250 if (arg->count < arg->skip) 251 goto skip; 252 253 if (arg->fn(tp, f, arg) < 0) { 254 arg->stop = 1; 255 break; 256 } 257 skip: 258 arg->count++; 259 } 260 } 261 262 static void basic_bind_class(void *fh, u32 classid, unsigned long cl) 263 { 264 struct basic_filter *f = fh; 265 266 if (f && f->res.classid == classid) 267 f->res.class = cl; 268 } 269 270 static int basic_dump(struct net *net, struct tcf_proto *tp, void *fh, 271 struct sk_buff *skb, struct tcmsg *t) 272 { 273 struct basic_filter *f = fh; 274 struct nlattr *nest; 275 276 if (f == NULL) 277 return skb->len; 278 279 t->tcm_handle = f->handle; 280 281 nest = nla_nest_start(skb, TCA_OPTIONS); 282 if (nest == NULL) 283 goto nla_put_failure; 284 285 if (f->res.classid && 286 nla_put_u32(skb, TCA_BASIC_CLASSID, f->res.classid)) 287 goto nla_put_failure; 288 289 if (tcf_exts_dump(skb, &f->exts) < 0 || 290 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0) 291 goto nla_put_failure; 292 293 nla_nest_end(skb, nest); 294 295 if (tcf_exts_dump_stats(skb, &f->exts) < 0) 296 goto nla_put_failure; 297 298 return skb->len; 299 300 nla_put_failure: 301 nla_nest_cancel(skb, nest); 302 return -1; 303 } 304 305 static struct tcf_proto_ops cls_basic_ops __read_mostly = { 306 .kind = "basic", 307 .classify = basic_classify, 308 .init = basic_init, 309 .destroy = basic_destroy, 310 .get = basic_get, 311 .change = basic_change, 312 .delete = basic_delete, 313 .walk = basic_walk, 314 .dump = basic_dump, 315 .bind_class = basic_bind_class, 316 .owner = THIS_MODULE, 317 }; 318 319 static int __init init_basic(void) 320 { 321 return register_tcf_proto_ops(&cls_basic_ops); 322 } 323 324 static void __exit exit_basic(void) 325 { 326 unregister_tcf_proto_ops(&cls_basic_ops); 327 } 328 329 module_init(init_basic) 330 module_exit(exit_basic) 331 MODULE_LICENSE("GPL"); 332 333