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 { 26 u32 hgenerator; 27 struct list_head flist; 28 }; 29 30 struct basic_filter 31 { 32 u32 handle; 33 struct tcf_exts exts; 34 struct tcf_ematch_tree ematches; 35 struct tcf_result res; 36 struct list_head link; 37 }; 38 39 static const struct tcf_ext_map basic_ext_map = { 40 .action = TCA_BASIC_ACT, 41 .police = TCA_BASIC_POLICE 42 }; 43 44 static int basic_classify(struct sk_buff *skb, struct tcf_proto *tp, 45 struct tcf_result *res) 46 { 47 int r; 48 struct basic_head *head = (struct basic_head *) tp->root; 49 struct basic_filter *f; 50 51 list_for_each_entry(f, &head->flist, link) { 52 if (!tcf_em_tree_match(skb, &f->ematches, NULL)) 53 continue; 54 *res = f->res; 55 r = tcf_exts_exec(skb, &f->exts, res); 56 if (r < 0) 57 continue; 58 return r; 59 } 60 return -1; 61 } 62 63 static unsigned long basic_get(struct tcf_proto *tp, u32 handle) 64 { 65 unsigned long l = 0UL; 66 struct basic_head *head = (struct basic_head *) tp->root; 67 struct basic_filter *f; 68 69 if (head == NULL) 70 return 0UL; 71 72 list_for_each_entry(f, &head->flist, link) 73 if (f->handle == handle) 74 l = (unsigned long) f; 75 76 return l; 77 } 78 79 static void basic_put(struct tcf_proto *tp, unsigned long f) 80 { 81 } 82 83 static int basic_init(struct tcf_proto *tp) 84 { 85 struct basic_head *head; 86 87 head = kzalloc(sizeof(*head), GFP_KERNEL); 88 if (head == NULL) 89 return -ENOBUFS; 90 INIT_LIST_HEAD(&head->flist); 91 tp->root = head; 92 return 0; 93 } 94 95 static inline void basic_delete_filter(struct tcf_proto *tp, 96 struct basic_filter *f) 97 { 98 tcf_unbind_filter(tp, &f->res); 99 tcf_exts_destroy(tp, &f->exts); 100 tcf_em_tree_destroy(tp, &f->ematches); 101 kfree(f); 102 } 103 104 static void basic_destroy(struct tcf_proto *tp) 105 { 106 struct basic_head *head = tp->root; 107 struct basic_filter *f, *n; 108 109 list_for_each_entry_safe(f, n, &head->flist, link) { 110 list_del(&f->link); 111 basic_delete_filter(tp, f); 112 } 113 kfree(head); 114 } 115 116 static int basic_delete(struct tcf_proto *tp, unsigned long arg) 117 { 118 struct basic_head *head = (struct basic_head *) tp->root; 119 struct basic_filter *t, *f = (struct basic_filter *) arg; 120 121 list_for_each_entry(t, &head->flist, link) 122 if (t == f) { 123 tcf_tree_lock(tp); 124 list_del(&t->link); 125 tcf_tree_unlock(tp); 126 basic_delete_filter(tp, t); 127 return 0; 128 } 129 130 return -ENOENT; 131 } 132 133 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = { 134 [TCA_BASIC_CLASSID] = { .type = NLA_U32 }, 135 [TCA_BASIC_EMATCHES] = { .type = NLA_NESTED }, 136 }; 137 138 static inline int basic_set_parms(struct tcf_proto *tp, struct basic_filter *f, 139 unsigned long base, struct nlattr **tb, 140 struct nlattr *est) 141 { 142 int err = -EINVAL; 143 struct tcf_exts e; 144 struct tcf_ematch_tree t; 145 146 err = tcf_exts_validate(tp, tb, est, &e, &basic_ext_map); 147 if (err < 0) 148 return err; 149 150 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &t); 151 if (err < 0) 152 goto errout; 153 154 if (tb[TCA_BASIC_CLASSID]) { 155 f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]); 156 tcf_bind_filter(tp, &f->res, base); 157 } 158 159 tcf_exts_change(tp, &f->exts, &e); 160 tcf_em_tree_change(tp, &f->ematches, &t); 161 162 return 0; 163 errout: 164 tcf_exts_destroy(tp, &e); 165 return err; 166 } 167 168 static int basic_change(struct tcf_proto *tp, unsigned long base, u32 handle, 169 struct nlattr **tca, unsigned long *arg) 170 { 171 int err; 172 struct basic_head *head = (struct basic_head *) tp->root; 173 struct nlattr *tb[TCA_BASIC_MAX + 1]; 174 struct basic_filter *f = (struct basic_filter *) *arg; 175 176 if (tca[TCA_OPTIONS] == NULL) 177 return -EINVAL; 178 179 err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS], 180 basic_policy); 181 if (err < 0) 182 return err; 183 184 if (f != NULL) { 185 if (handle && f->handle != handle) 186 return -EINVAL; 187 return basic_set_parms(tp, f, base, tb, tca[TCA_RATE]); 188 } 189 190 err = -ENOBUFS; 191 f = kzalloc(sizeof(*f), GFP_KERNEL); 192 if (f == NULL) 193 goto errout; 194 195 err = -EINVAL; 196 if (handle) 197 f->handle = 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 printk(KERN_ERR "Insufficient number of handles\n"); 207 goto errout; 208 } 209 210 f->handle = head->hgenerator; 211 } 212 213 err = basic_set_parms(tp, f, base, tb, tca[TCA_RATE]); 214 if (err < 0) 215 goto errout; 216 217 tcf_tree_lock(tp); 218 list_add(&f->link, &head->flist); 219 tcf_tree_unlock(tp); 220 *arg = (unsigned long) f; 221 222 return 0; 223 errout: 224 if (*arg == 0UL && f) 225 kfree(f); 226 227 return err; 228 } 229 230 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg) 231 { 232 struct basic_head *head = (struct basic_head *) tp->root; 233 struct basic_filter *f; 234 235 list_for_each_entry(f, &head->flist, link) { 236 if (arg->count < arg->skip) 237 goto skip; 238 239 if (arg->fn(tp, (unsigned long) f, arg) < 0) { 240 arg->stop = 1; 241 break; 242 } 243 skip: 244 arg->count++; 245 } 246 } 247 248 static int basic_dump(struct tcf_proto *tp, unsigned long fh, 249 struct sk_buff *skb, struct tcmsg *t) 250 { 251 struct basic_filter *f = (struct basic_filter *) fh; 252 struct nlattr *nest; 253 254 if (f == NULL) 255 return skb->len; 256 257 t->tcm_handle = f->handle; 258 259 nest = nla_nest_start(skb, TCA_OPTIONS); 260 if (nest == NULL) 261 goto nla_put_failure; 262 263 if (f->res.classid) 264 NLA_PUT_U32(skb, TCA_BASIC_CLASSID, f->res.classid); 265 266 if (tcf_exts_dump(skb, &f->exts, &basic_ext_map) < 0 || 267 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0) 268 goto nla_put_failure; 269 270 nla_nest_end(skb, nest); 271 272 if (tcf_exts_dump_stats(skb, &f->exts, &basic_ext_map) < 0) 273 goto nla_put_failure; 274 275 return skb->len; 276 277 nla_put_failure: 278 nla_nest_cancel(skb, nest); 279 return -1; 280 } 281 282 static struct tcf_proto_ops cls_basic_ops __read_mostly = { 283 .kind = "basic", 284 .classify = basic_classify, 285 .init = basic_init, 286 .destroy = basic_destroy, 287 .get = basic_get, 288 .put = basic_put, 289 .change = basic_change, 290 .delete = basic_delete, 291 .walk = basic_walk, 292 .dump = basic_dump, 293 .owner = THIS_MODULE, 294 }; 295 296 static int __init init_basic(void) 297 { 298 return register_tcf_proto_ops(&cls_basic_ops); 299 } 300 301 static void __exit exit_basic(void) 302 { 303 unregister_tcf_proto_ops(&cls_basic_ops); 304 } 305 306 module_init(init_basic) 307 module_exit(exit_basic) 308 MODULE_LICENSE("GPL"); 309 310