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 tcf_exts_init(&e, TCA_BASIC_ACT, TCA_BASIC_POLICE); 142 err = tcf_exts_validate(net, tp, tb, est, &e, ovr); 143 if (err < 0) 144 return err; 145 146 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &t); 147 if (err < 0) 148 goto errout; 149 150 if (tb[TCA_BASIC_CLASSID]) { 151 f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]); 152 tcf_bind_filter(tp, &f->res, base); 153 } 154 155 tcf_exts_change(tp, &f->exts, &e); 156 tcf_em_tree_change(tp, &f->ematches, &t); 157 f->tp = tp; 158 159 return 0; 160 errout: 161 tcf_exts_destroy(&e); 162 return err; 163 } 164 165 static int basic_change(struct net *net, struct sk_buff *in_skb, 166 struct tcf_proto *tp, unsigned long base, u32 handle, 167 struct nlattr **tca, unsigned long *arg, bool ovr) 168 { 169 int err; 170 struct basic_head *head = rtnl_dereference(tp->root); 171 struct nlattr *tb[TCA_BASIC_MAX + 1]; 172 struct basic_filter *fold = (struct basic_filter *) *arg; 173 struct basic_filter *fnew; 174 175 if (tca[TCA_OPTIONS] == NULL) 176 return -EINVAL; 177 178 err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS], 179 basic_policy); 180 if (err < 0) 181 return err; 182 183 if (fold != NULL) { 184 if (handle && fold->handle != handle) 185 return -EINVAL; 186 } 187 188 fnew = kzalloc(sizeof(*fnew), GFP_KERNEL); 189 if (!fnew) 190 return -ENOBUFS; 191 192 tcf_exts_init(&fnew->exts, TCA_BASIC_ACT, TCA_BASIC_POLICE); 193 err = -EINVAL; 194 if (handle) { 195 fnew->handle = handle; 196 } else if (fold) { 197 fnew->handle = fold->handle; 198 } else { 199 unsigned int i = 0x80000000; 200 do { 201 if (++head->hgenerator == 0x7FFFFFFF) 202 head->hgenerator = 1; 203 } while (--i > 0 && basic_get(tp, head->hgenerator)); 204 205 if (i <= 0) { 206 pr_err("Insufficient number of handles\n"); 207 goto errout; 208 } 209 210 fnew->handle = head->hgenerator; 211 } 212 213 err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], ovr); 214 if (err < 0) 215 goto errout; 216 217 *arg = (unsigned long)fnew; 218 219 if (fold) { 220 list_replace_rcu(&fold->link, &fnew->link); 221 tcf_unbind_filter(tp, &fold->res); 222 call_rcu(&fold->rcu, basic_delete_filter); 223 } else { 224 list_add_rcu(&fnew->link, &head->flist); 225 } 226 227 return 0; 228 errout: 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