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 <linux/idr.h> 21 #include <net/netlink.h> 22 #include <net/act_api.h> 23 #include <net/pkt_cls.h> 24 25 struct basic_head { 26 struct list_head flist; 27 struct idr handle_idr; 28 struct rcu_head rcu; 29 }; 30 31 struct basic_filter { 32 u32 handle; 33 struct tcf_exts exts; 34 struct tcf_ematch_tree ematches; 35 struct tcf_result res; 36 struct tcf_proto *tp; 37 struct list_head link; 38 struct rcu_head rcu; 39 }; 40 41 static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp, 42 struct tcf_result *res) 43 { 44 int r; 45 struct basic_head *head = rcu_dereference_bh(tp->root); 46 struct basic_filter *f; 47 48 list_for_each_entry_rcu(f, &head->flist, link) { 49 if (!tcf_em_tree_match(skb, &f->ematches, NULL)) 50 continue; 51 *res = f->res; 52 r = tcf_exts_exec(skb, &f->exts, res); 53 if (r < 0) 54 continue; 55 return r; 56 } 57 return -1; 58 } 59 60 static void *basic_get(struct tcf_proto *tp, u32 handle) 61 { 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 return f; 68 } 69 } 70 71 return NULL; 72 } 73 74 static int basic_init(struct tcf_proto *tp) 75 { 76 struct basic_head *head; 77 78 head = kzalloc(sizeof(*head), GFP_KERNEL); 79 if (head == NULL) 80 return -ENOBUFS; 81 INIT_LIST_HEAD(&head->flist); 82 idr_init(&head->handle_idr); 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 idr_remove_ext(&head->handle_idr, f->handle); 105 call_rcu(&f->rcu, basic_delete_filter); 106 } 107 idr_destroy(&head->handle_idr); 108 kfree_rcu(head, rcu); 109 } 110 111 static int basic_delete(struct tcf_proto *tp, void *arg, bool *last) 112 { 113 struct basic_head *head = rtnl_dereference(tp->root); 114 struct basic_filter *f = arg; 115 116 list_del_rcu(&f->link); 117 tcf_unbind_filter(tp, &f->res); 118 idr_remove_ext(&head->handle_idr, f->handle); 119 call_rcu(&f->rcu, basic_delete_filter); 120 *last = list_empty(&head->flist); 121 return 0; 122 } 123 124 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = { 125 [TCA_BASIC_CLASSID] = { .type = NLA_U32 }, 126 [TCA_BASIC_EMATCHES] = { .type = NLA_NESTED }, 127 }; 128 129 static int basic_set_parms(struct net *net, struct tcf_proto *tp, 130 struct basic_filter *f, unsigned long base, 131 struct nlattr **tb, 132 struct nlattr *est, bool ovr) 133 { 134 int err; 135 136 err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr); 137 if (err < 0) 138 return err; 139 140 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &f->ematches); 141 if (err < 0) 142 return err; 143 144 if (tb[TCA_BASIC_CLASSID]) { 145 f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]); 146 tcf_bind_filter(tp, &f->res, base); 147 } 148 149 f->tp = tp; 150 return 0; 151 } 152 153 static int basic_change(struct net *net, struct sk_buff *in_skb, 154 struct tcf_proto *tp, unsigned long base, u32 handle, 155 struct nlattr **tca, void **arg, bool ovr) 156 { 157 int err; 158 struct basic_head *head = rtnl_dereference(tp->root); 159 struct nlattr *tb[TCA_BASIC_MAX + 1]; 160 struct basic_filter *fold = (struct basic_filter *) *arg; 161 struct basic_filter *fnew; 162 unsigned long idr_index; 163 164 if (tca[TCA_OPTIONS] == NULL) 165 return -EINVAL; 166 167 err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS], 168 basic_policy, NULL); 169 if (err < 0) 170 return err; 171 172 if (fold != NULL) { 173 if (handle && fold->handle != handle) 174 return -EINVAL; 175 } 176 177 fnew = kzalloc(sizeof(*fnew), GFP_KERNEL); 178 if (!fnew) 179 return -ENOBUFS; 180 181 err = tcf_exts_init(&fnew->exts, TCA_BASIC_ACT, TCA_BASIC_POLICE); 182 if (err < 0) 183 goto errout; 184 185 if (handle) { 186 fnew->handle = handle; 187 if (!fold) { 188 err = idr_alloc_ext(&head->handle_idr, fnew, &idr_index, 189 handle, handle + 1, GFP_KERNEL); 190 if (err) 191 goto errout; 192 } 193 } else { 194 err = idr_alloc_ext(&head->handle_idr, fnew, &idr_index, 195 1, 0x7FFFFFFF, GFP_KERNEL); 196 if (err) 197 goto errout; 198 fnew->handle = idr_index; 199 } 200 201 err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], ovr); 202 if (err < 0) { 203 if (!fold) 204 idr_remove_ext(&head->handle_idr, fnew->handle); 205 goto errout; 206 } 207 208 *arg = fnew; 209 210 if (fold) { 211 idr_replace_ext(&head->handle_idr, fnew, fnew->handle); 212 list_replace_rcu(&fold->link, &fnew->link); 213 tcf_unbind_filter(tp, &fold->res); 214 call_rcu(&fold->rcu, basic_delete_filter); 215 } else { 216 list_add_rcu(&fnew->link, &head->flist); 217 } 218 219 return 0; 220 errout: 221 tcf_exts_destroy(&fnew->exts); 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, f, arg) < 0) { 236 arg->stop = 1; 237 break; 238 } 239 skip: 240 arg->count++; 241 } 242 } 243 244 static void basic_bind_class(void *fh, u32 classid, unsigned long cl) 245 { 246 struct basic_filter *f = fh; 247 248 if (f && f->res.classid == classid) 249 f->res.class = cl; 250 } 251 252 static int basic_dump(struct net *net, struct tcf_proto *tp, void *fh, 253 struct sk_buff *skb, struct tcmsg *t) 254 { 255 struct basic_filter *f = fh; 256 struct nlattr *nest; 257 258 if (f == NULL) 259 return skb->len; 260 261 t->tcm_handle = f->handle; 262 263 nest = nla_nest_start(skb, TCA_OPTIONS); 264 if (nest == NULL) 265 goto nla_put_failure; 266 267 if (f->res.classid && 268 nla_put_u32(skb, TCA_BASIC_CLASSID, f->res.classid)) 269 goto nla_put_failure; 270 271 if (tcf_exts_dump(skb, &f->exts) < 0 || 272 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0) 273 goto nla_put_failure; 274 275 nla_nest_end(skb, nest); 276 277 if (tcf_exts_dump_stats(skb, &f->exts) < 0) 278 goto nla_put_failure; 279 280 return skb->len; 281 282 nla_put_failure: 283 nla_nest_cancel(skb, nest); 284 return -1; 285 } 286 287 static struct tcf_proto_ops cls_basic_ops __read_mostly = { 288 .kind = "basic", 289 .classify = basic_classify, 290 .init = basic_init, 291 .destroy = basic_destroy, 292 .get = basic_get, 293 .change = basic_change, 294 .delete = basic_delete, 295 .walk = basic_walk, 296 .dump = basic_dump, 297 .bind_class = basic_bind_class, 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