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