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 void basic_destroy(struct tcf_proto *tp) 100 { 101 struct basic_head *head = rtnl_dereference(tp->root); 102 struct basic_filter *f, *n; 103 104 list_for_each_entry_safe(f, n, &head->flist, link) { 105 list_del_rcu(&f->link); 106 tcf_unbind_filter(tp, &f->res); 107 call_rcu(&f->rcu, basic_delete_filter); 108 } 109 RCU_INIT_POINTER(tp->root, NULL); 110 kfree_rcu(head, rcu); 111 } 112 113 static int basic_delete(struct tcf_proto *tp, unsigned long arg) 114 { 115 struct basic_filter *f = (struct basic_filter *) arg; 116 117 list_del_rcu(&f->link); 118 tcf_unbind_filter(tp, &f->res); 119 call_rcu(&f->rcu, basic_delete_filter); 120 return 0; 121 } 122 123 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = { 124 [TCA_BASIC_CLASSID] = { .type = NLA_U32 }, 125 [TCA_BASIC_EMATCHES] = { .type = NLA_NESTED }, 126 }; 127 128 static int basic_set_parms(struct net *net, struct tcf_proto *tp, 129 struct basic_filter *f, unsigned long base, 130 struct nlattr **tb, 131 struct nlattr *est, bool ovr) 132 { 133 int err; 134 struct tcf_exts e; 135 struct tcf_ematch_tree t; 136 137 tcf_exts_init(&e, TCA_BASIC_ACT, TCA_BASIC_POLICE); 138 err = tcf_exts_validate(net, tp, tb, est, &e, ovr); 139 if (err < 0) 140 return err; 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); 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 tcf_exts_init(&fnew->exts, TCA_BASIC_ACT, TCA_BASIC_POLICE); 189 err = -EINVAL; 190 if (handle) { 191 fnew->handle = handle; 192 } else if (fold) { 193 fnew->handle = fold->handle; 194 } else { 195 unsigned int i = 0x80000000; 196 do { 197 if (++head->hgenerator == 0x7FFFFFFF) 198 head->hgenerator = 1; 199 } while (--i > 0 && basic_get(tp, head->hgenerator)); 200 201 if (i <= 0) { 202 pr_err("Insufficient number of handles\n"); 203 goto errout; 204 } 205 206 fnew->handle = head->hgenerator; 207 } 208 209 err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], ovr); 210 if (err < 0) 211 goto errout; 212 213 *arg = (unsigned long)fnew; 214 215 if (fold) { 216 list_replace_rcu(&fold->link, &fnew->link); 217 tcf_unbind_filter(tp, &fold->res); 218 call_rcu(&fold->rcu, basic_delete_filter); 219 } else { 220 list_add_rcu(&fnew->link, &head->flist); 221 } 222 223 return 0; 224 errout: 225 kfree(fnew); 226 return err; 227 } 228 229 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg) 230 { 231 struct basic_head *head = rtnl_dereference(tp->root); 232 struct basic_filter *f; 233 234 list_for_each_entry(f, &head->flist, link) { 235 if (arg->count < arg->skip) 236 goto skip; 237 238 if (arg->fn(tp, (unsigned long) f, arg) < 0) { 239 arg->stop = 1; 240 break; 241 } 242 skip: 243 arg->count++; 244 } 245 } 246 247 static int basic_dump(struct net *net, struct tcf_proto *tp, unsigned long fh, 248 struct sk_buff *skb, struct tcmsg *t) 249 { 250 struct basic_filter *f = (struct basic_filter *) fh; 251 struct nlattr *nest; 252 253 if (f == NULL) 254 return skb->len; 255 256 t->tcm_handle = f->handle; 257 258 nest = nla_nest_start(skb, TCA_OPTIONS); 259 if (nest == NULL) 260 goto nla_put_failure; 261 262 if (f->res.classid && 263 nla_put_u32(skb, TCA_BASIC_CLASSID, f->res.classid)) 264 goto nla_put_failure; 265 266 if (tcf_exts_dump(skb, &f->exts) < 0 || 267 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0) 268 goto nla_put_failure; 269 270 nla_nest_end(skb, nest); 271 272 if (tcf_exts_dump_stats(skb, &f->exts) < 0) 273 goto nla_put_failure; 274 275 return skb->len; 276 277 nla_put_failure: 278 nla_nest_cancel(skb, nest); 279 return -1; 280 } 281 282 static struct tcf_proto_ops cls_basic_ops __read_mostly = { 283 .kind = "basic", 284 .classify = basic_classify, 285 .init = basic_init, 286 .destroy = basic_destroy, 287 .get = basic_get, 288 .change = basic_change, 289 .delete = basic_delete, 290 .walk = basic_walk, 291 .dump = basic_dump, 292 .owner = THIS_MODULE, 293 }; 294 295 static int __init init_basic(void) 296 { 297 return register_tcf_proto_ops(&cls_basic_ops); 298 } 299 300 static void __exit exit_basic(void) 301 { 302 unregister_tcf_proto_ops(&cls_basic_ops); 303 } 304 305 module_init(init_basic) 306 module_exit(exit_basic) 307 MODULE_LICENSE("GPL"); 308 309