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 break; 72 } 73 } 74 75 return l; 76 } 77 78 static int basic_init(struct tcf_proto *tp) 79 { 80 struct basic_head *head; 81 82 head = kzalloc(sizeof(*head), GFP_KERNEL); 83 if (head == NULL) 84 return -ENOBUFS; 85 INIT_LIST_HEAD(&head->flist); 86 rcu_assign_pointer(tp->root, head); 87 return 0; 88 } 89 90 static void basic_delete_filter(struct rcu_head *head) 91 { 92 struct basic_filter *f = container_of(head, struct basic_filter, rcu); 93 94 tcf_exts_destroy(&f->exts); 95 tcf_em_tree_destroy(&f->ematches); 96 kfree(f); 97 } 98 99 static bool basic_destroy(struct tcf_proto *tp, bool force) 100 { 101 struct basic_head *head = rtnl_dereference(tp->root); 102 struct basic_filter *f, *n; 103 104 if (!force && !list_empty(&head->flist)) 105 return false; 106 107 list_for_each_entry_safe(f, n, &head->flist, link) { 108 list_del_rcu(&f->link); 109 tcf_unbind_filter(tp, &f->res); 110 call_rcu(&f->rcu, basic_delete_filter); 111 } 112 RCU_INIT_POINTER(tp->root, NULL); 113 kfree_rcu(head, rcu); 114 return true; 115 } 116 117 static int basic_delete(struct tcf_proto *tp, unsigned long arg) 118 { 119 struct basic_filter *f = (struct basic_filter *) arg; 120 121 list_del_rcu(&f->link); 122 tcf_unbind_filter(tp, &f->res); 123 call_rcu(&f->rcu, basic_delete_filter); 124 return 0; 125 } 126 127 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = { 128 [TCA_BASIC_CLASSID] = { .type = NLA_U32 }, 129 [TCA_BASIC_EMATCHES] = { .type = NLA_NESTED }, 130 }; 131 132 static int basic_set_parms(struct net *net, struct tcf_proto *tp, 133 struct basic_filter *f, unsigned long base, 134 struct nlattr **tb, 135 struct nlattr *est, bool ovr) 136 { 137 int err; 138 struct tcf_exts e; 139 struct tcf_ematch_tree t; 140 141 err = tcf_exts_init(&e, TCA_BASIC_ACT, TCA_BASIC_POLICE); 142 if (err < 0) 143 return err; 144 err = tcf_exts_validate(net, tp, tb, est, &e, ovr); 145 if (err < 0) 146 goto errout; 147 148 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &t); 149 if (err < 0) 150 goto errout; 151 152 if (tb[TCA_BASIC_CLASSID]) { 153 f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]); 154 tcf_bind_filter(tp, &f->res, base); 155 } 156 157 tcf_exts_change(tp, &f->exts, &e); 158 tcf_em_tree_change(tp, &f->ematches, &t); 159 f->tp = tp; 160 161 return 0; 162 errout: 163 tcf_exts_destroy(&e); 164 return err; 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, unsigned long *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; 176 177 if (tca[TCA_OPTIONS] == NULL) 178 return -EINVAL; 179 180 err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS], 181 basic_policy); 182 if (err < 0) 183 return err; 184 185 if (fold != NULL) { 186 if (handle && fold->handle != handle) 187 return -EINVAL; 188 } 189 190 fnew = kzalloc(sizeof(*fnew), GFP_KERNEL); 191 if (!fnew) 192 return -ENOBUFS; 193 194 err = tcf_exts_init(&fnew->exts, TCA_BASIC_ACT, TCA_BASIC_POLICE); 195 if (err < 0) 196 goto errout; 197 198 err = -EINVAL; 199 if (handle) { 200 fnew->handle = handle; 201 } else if (fold) { 202 fnew->handle = fold->handle; 203 } else { 204 unsigned int i = 0x80000000; 205 do { 206 if (++head->hgenerator == 0x7FFFFFFF) 207 head->hgenerator = 1; 208 } while (--i > 0 && basic_get(tp, head->hgenerator)); 209 210 if (i <= 0) { 211 pr_err("Insufficient number of handles\n"); 212 goto errout; 213 } 214 215 fnew->handle = head->hgenerator; 216 } 217 218 err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], ovr); 219 if (err < 0) 220 goto errout; 221 222 *arg = (unsigned long)fnew; 223 224 if (fold) { 225 list_replace_rcu(&fold->link, &fnew->link); 226 tcf_unbind_filter(tp, &fold->res); 227 call_rcu(&fold->rcu, basic_delete_filter); 228 } else { 229 list_add_rcu(&fnew->link, &head->flist); 230 } 231 232 return 0; 233 errout: 234 tcf_exts_destroy(&fnew->exts); 235 kfree(fnew); 236 return err; 237 } 238 239 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg) 240 { 241 struct basic_head *head = rtnl_dereference(tp->root); 242 struct basic_filter *f; 243 244 list_for_each_entry(f, &head->flist, link) { 245 if (arg->count < arg->skip) 246 goto skip; 247 248 if (arg->fn(tp, (unsigned long) f, arg) < 0) { 249 arg->stop = 1; 250 break; 251 } 252 skip: 253 arg->count++; 254 } 255 } 256 257 static int basic_dump(struct net *net, struct tcf_proto *tp, unsigned long fh, 258 struct sk_buff *skb, struct tcmsg *t) 259 { 260 struct basic_filter *f = (struct basic_filter *) fh; 261 struct nlattr *nest; 262 263 if (f == NULL) 264 return skb->len; 265 266 t->tcm_handle = f->handle; 267 268 nest = nla_nest_start(skb, TCA_OPTIONS); 269 if (nest == NULL) 270 goto nla_put_failure; 271 272 if (f->res.classid && 273 nla_put_u32(skb, TCA_BASIC_CLASSID, f->res.classid)) 274 goto nla_put_failure; 275 276 if (tcf_exts_dump(skb, &f->exts) < 0 || 277 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0) 278 goto nla_put_failure; 279 280 nla_nest_end(skb, nest); 281 282 if (tcf_exts_dump_stats(skb, &f->exts) < 0) 283 goto nla_put_failure; 284 285 return skb->len; 286 287 nla_put_failure: 288 nla_nest_cancel(skb, nest); 289 return -1; 290 } 291 292 static struct tcf_proto_ops cls_basic_ops __read_mostly = { 293 .kind = "basic", 294 .classify = basic_classify, 295 .init = basic_init, 296 .destroy = basic_destroy, 297 .get = basic_get, 298 .change = basic_change, 299 .delete = basic_delete, 300 .walk = basic_walk, 301 .dump = basic_dump, 302 .owner = THIS_MODULE, 303 }; 304 305 static int __init init_basic(void) 306 { 307 return register_tcf_proto_ops(&cls_basic_ops); 308 } 309 310 static void __exit exit_basic(void) 311 { 312 unregister_tcf_proto_ops(&cls_basic_ops); 313 } 314 315 module_init(init_basic) 316 module_exit(exit_basic) 317 MODULE_LICENSE("GPL"); 318 319