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