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