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 }; 28 29 struct basic_filter { 30 u32 handle; 31 struct tcf_exts exts; 32 struct tcf_ematch_tree ematches; 33 struct tcf_result res; 34 struct list_head link; 35 }; 36 37 static const struct tcf_ext_map basic_ext_map = { 38 .action = TCA_BASIC_ACT, 39 .police = TCA_BASIC_POLICE 40 }; 41 42 static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp, 43 struct tcf_result *res) 44 { 45 int r; 46 struct basic_head *head = (struct basic_head *) tp->root; 47 struct basic_filter *f; 48 49 list_for_each_entry(f, &head->flist, link) { 50 if (!tcf_em_tree_match(skb, &f->ematches, NULL)) 51 continue; 52 *res = f->res; 53 r = tcf_exts_exec(skb, &f->exts, res); 54 if (r < 0) 55 continue; 56 return r; 57 } 58 return -1; 59 } 60 61 static unsigned long basic_get(struct tcf_proto *tp, u32 handle) 62 { 63 unsigned long l = 0UL; 64 struct basic_head *head = (struct basic_head *) tp->root; 65 struct basic_filter *f; 66 67 if (head == NULL) 68 return 0UL; 69 70 list_for_each_entry(f, &head->flist, link) 71 if (f->handle == handle) 72 l = (unsigned long) f; 73 74 return l; 75 } 76 77 static void basic_put(struct tcf_proto *tp, unsigned long f) 78 { 79 } 80 81 static int basic_init(struct tcf_proto *tp) 82 { 83 struct basic_head *head; 84 85 head = kzalloc(sizeof(*head), GFP_KERNEL); 86 if (head == NULL) 87 return -ENOBUFS; 88 INIT_LIST_HEAD(&head->flist); 89 tp->root = head; 90 return 0; 91 } 92 93 static void basic_delete_filter(struct tcf_proto *tp, struct basic_filter *f) 94 { 95 tcf_unbind_filter(tp, &f->res); 96 tcf_exts_destroy(tp, &f->exts); 97 tcf_em_tree_destroy(tp, &f->ematches); 98 kfree(f); 99 } 100 101 static void basic_destroy(struct tcf_proto *tp) 102 { 103 struct basic_head *head = tp->root; 104 struct basic_filter *f, *n; 105 106 list_for_each_entry_safe(f, n, &head->flist, link) { 107 list_del(&f->link); 108 basic_delete_filter(tp, f); 109 } 110 kfree(head); 111 } 112 113 static int basic_delete(struct tcf_proto *tp, unsigned long arg) 114 { 115 struct basic_head *head = (struct basic_head *) tp->root; 116 struct basic_filter *t, *f = (struct basic_filter *) arg; 117 118 list_for_each_entry(t, &head->flist, link) 119 if (t == f) { 120 tcf_tree_lock(tp); 121 list_del(&t->link); 122 tcf_tree_unlock(tp); 123 basic_delete_filter(tp, t); 124 return 0; 125 } 126 127 return -ENOENT; 128 } 129 130 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = { 131 [TCA_BASIC_CLASSID] = { .type = NLA_U32 }, 132 [TCA_BASIC_EMATCHES] = { .type = NLA_NESTED }, 133 }; 134 135 static int basic_set_parms(struct tcf_proto *tp, struct basic_filter *f, 136 unsigned long base, struct nlattr **tb, 137 struct nlattr *est) 138 { 139 int err = -EINVAL; 140 struct tcf_exts e; 141 struct tcf_ematch_tree t; 142 143 err = tcf_exts_validate(tp, tb, est, &e, &basic_ext_map); 144 if (err < 0) 145 return err; 146 147 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &t); 148 if (err < 0) 149 goto errout; 150 151 if (tb[TCA_BASIC_CLASSID]) { 152 f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]); 153 tcf_bind_filter(tp, &f->res, base); 154 } 155 156 tcf_exts_change(tp, &f->exts, &e); 157 tcf_em_tree_change(tp, &f->ematches, &t); 158 159 return 0; 160 errout: 161 tcf_exts_destroy(tp, &e); 162 return err; 163 } 164 165 static int basic_change(struct sk_buff *in_skb, 166 struct tcf_proto *tp, unsigned long base, u32 handle, 167 struct nlattr **tca, unsigned long *arg) 168 { 169 int err; 170 struct basic_head *head = (struct basic_head *) tp->root; 171 struct nlattr *tb[TCA_BASIC_MAX + 1]; 172 struct basic_filter *f = (struct basic_filter *) *arg; 173 174 if (tca[TCA_OPTIONS] == NULL) 175 return -EINVAL; 176 177 err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS], 178 basic_policy); 179 if (err < 0) 180 return err; 181 182 if (f != NULL) { 183 if (handle && f->handle != handle) 184 return -EINVAL; 185 return basic_set_parms(tp, f, base, tb, tca[TCA_RATE]); 186 } 187 188 err = -ENOBUFS; 189 f = kzalloc(sizeof(*f), GFP_KERNEL); 190 if (f == NULL) 191 goto errout; 192 193 err = -EINVAL; 194 if (handle) 195 f->handle = handle; 196 else { 197 unsigned int i = 0x80000000; 198 do { 199 if (++head->hgenerator == 0x7FFFFFFF) 200 head->hgenerator = 1; 201 } while (--i > 0 && basic_get(tp, head->hgenerator)); 202 203 if (i <= 0) { 204 pr_err("Insufficient number of handles\n"); 205 goto errout; 206 } 207 208 f->handle = head->hgenerator; 209 } 210 211 err = basic_set_parms(tp, f, base, tb, tca[TCA_RATE]); 212 if (err < 0) 213 goto errout; 214 215 tcf_tree_lock(tp); 216 list_add(&f->link, &head->flist); 217 tcf_tree_unlock(tp); 218 *arg = (unsigned long) f; 219 220 return 0; 221 errout: 222 if (*arg == 0UL && f) 223 kfree(f); 224 225 return err; 226 } 227 228 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg) 229 { 230 struct basic_head *head = (struct basic_head *) tp->root; 231 struct basic_filter *f; 232 233 list_for_each_entry(f, &head->flist, link) { 234 if (arg->count < arg->skip) 235 goto skip; 236 237 if (arg->fn(tp, (unsigned long) f, arg) < 0) { 238 arg->stop = 1; 239 break; 240 } 241 skip: 242 arg->count++; 243 } 244 } 245 246 static int basic_dump(struct tcf_proto *tp, unsigned long fh, 247 struct sk_buff *skb, struct tcmsg *t) 248 { 249 struct basic_filter *f = (struct basic_filter *) fh; 250 struct nlattr *nest; 251 252 if (f == NULL) 253 return skb->len; 254 255 t->tcm_handle = f->handle; 256 257 nest = nla_nest_start(skb, TCA_OPTIONS); 258 if (nest == NULL) 259 goto nla_put_failure; 260 261 if (f->res.classid && 262 nla_put_u32(skb, TCA_BASIC_CLASSID, f->res.classid)) 263 goto nla_put_failure; 264 265 if (tcf_exts_dump(skb, &f->exts, &basic_ext_map) < 0 || 266 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0) 267 goto nla_put_failure; 268 269 nla_nest_end(skb, nest); 270 271 if (tcf_exts_dump_stats(skb, &f->exts, &basic_ext_map) < 0) 272 goto nla_put_failure; 273 274 return skb->len; 275 276 nla_put_failure: 277 nla_nest_cancel(skb, nest); 278 return -1; 279 } 280 281 static struct tcf_proto_ops cls_basic_ops __read_mostly = { 282 .kind = "basic", 283 .classify = basic_classify, 284 .init = basic_init, 285 .destroy = basic_destroy, 286 .get = basic_get, 287 .put = basic_put, 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