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