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