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 int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp, 38 struct tcf_result *res) 39 { 40 int r; 41 struct basic_head *head = tp->root; 42 struct basic_filter *f; 43 44 list_for_each_entry(f, &head->flist, link) { 45 if (!tcf_em_tree_match(skb, &f->ematches, NULL)) 46 continue; 47 *res = f->res; 48 r = tcf_exts_exec(skb, &f->exts, res); 49 if (r < 0) 50 continue; 51 return r; 52 } 53 return -1; 54 } 55 56 static unsigned long basic_get(struct tcf_proto *tp, u32 handle) 57 { 58 unsigned long l = 0UL; 59 struct basic_head *head = tp->root; 60 struct basic_filter *f; 61 62 if (head == NULL) 63 return 0UL; 64 65 list_for_each_entry(f, &head->flist, link) 66 if (f->handle == handle) 67 l = (unsigned long) f; 68 69 return l; 70 } 71 72 static void basic_put(struct tcf_proto *tp, unsigned long f) 73 { 74 } 75 76 static int basic_init(struct tcf_proto *tp) 77 { 78 struct basic_head *head; 79 80 head = kzalloc(sizeof(*head), GFP_KERNEL); 81 if (head == NULL) 82 return -ENOBUFS; 83 INIT_LIST_HEAD(&head->flist); 84 tp->root = head; 85 return 0; 86 } 87 88 static void basic_delete_filter(struct tcf_proto *tp, struct basic_filter *f) 89 { 90 tcf_unbind_filter(tp, &f->res); 91 tcf_exts_destroy(tp, &f->exts); 92 tcf_em_tree_destroy(tp, &f->ematches); 93 kfree(f); 94 } 95 96 static void basic_destroy(struct tcf_proto *tp) 97 { 98 struct basic_head *head = tp->root; 99 struct basic_filter *f, *n; 100 101 list_for_each_entry_safe(f, n, &head->flist, link) { 102 list_del(&f->link); 103 basic_delete_filter(tp, f); 104 } 105 kfree(head); 106 } 107 108 static int basic_delete(struct tcf_proto *tp, unsigned long arg) 109 { 110 struct basic_head *head = tp->root; 111 struct basic_filter *t, *f = (struct basic_filter *) arg; 112 113 list_for_each_entry(t, &head->flist, link) 114 if (t == f) { 115 tcf_tree_lock(tp); 116 list_del(&t->link); 117 tcf_tree_unlock(tp); 118 basic_delete_filter(tp, t); 119 return 0; 120 } 121 122 return -ENOENT; 123 } 124 125 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = { 126 [TCA_BASIC_CLASSID] = { .type = NLA_U32 }, 127 [TCA_BASIC_EMATCHES] = { .type = NLA_NESTED }, 128 }; 129 130 static int basic_set_parms(struct net *net, struct tcf_proto *tp, 131 struct basic_filter *f, unsigned long base, 132 struct nlattr **tb, 133 struct nlattr *est, bool ovr) 134 { 135 int err; 136 struct tcf_exts e; 137 struct tcf_ematch_tree t; 138 139 tcf_exts_init(&e, TCA_BASIC_ACT, TCA_BASIC_POLICE); 140 err = tcf_exts_validate(net, tp, tb, est, &e, ovr); 141 if (err < 0) 142 return err; 143 144 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &t); 145 if (err < 0) 146 goto errout; 147 148 if (tb[TCA_BASIC_CLASSID]) { 149 f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]); 150 tcf_bind_filter(tp, &f->res, base); 151 } 152 153 tcf_exts_change(tp, &f->exts, &e); 154 tcf_em_tree_change(tp, &f->ematches, &t); 155 156 return 0; 157 errout: 158 tcf_exts_destroy(tp, &e); 159 return err; 160 } 161 162 static int basic_change(struct net *net, struct sk_buff *in_skb, 163 struct tcf_proto *tp, unsigned long base, u32 handle, 164 struct nlattr **tca, unsigned long *arg, bool ovr) 165 { 166 int err; 167 struct basic_head *head = tp->root; 168 struct nlattr *tb[TCA_BASIC_MAX + 1]; 169 struct basic_filter *f = (struct basic_filter *) *arg; 170 171 if (tca[TCA_OPTIONS] == NULL) 172 return -EINVAL; 173 174 err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS], 175 basic_policy); 176 if (err < 0) 177 return err; 178 179 if (f != NULL) { 180 if (handle && f->handle != handle) 181 return -EINVAL; 182 return basic_set_parms(net, tp, f, base, tb, tca[TCA_RATE], ovr); 183 } 184 185 err = -ENOBUFS; 186 f = kzalloc(sizeof(*f), GFP_KERNEL); 187 if (f == NULL) 188 goto errout; 189 190 tcf_exts_init(&f->exts, TCA_BASIC_ACT, TCA_BASIC_POLICE); 191 err = -EINVAL; 192 if (handle) 193 f->handle = handle; 194 else { 195 unsigned int i = 0x80000000; 196 do { 197 if (++head->hgenerator == 0x7FFFFFFF) 198 head->hgenerator = 1; 199 } while (--i > 0 && basic_get(tp, head->hgenerator)); 200 201 if (i <= 0) { 202 pr_err("Insufficient number of handles\n"); 203 goto errout; 204 } 205 206 f->handle = head->hgenerator; 207 } 208 209 err = basic_set_parms(net, tp, f, base, tb, tca[TCA_RATE], ovr); 210 if (err < 0) 211 goto errout; 212 213 tcf_tree_lock(tp); 214 list_add(&f->link, &head->flist); 215 tcf_tree_unlock(tp); 216 *arg = (unsigned long) f; 217 218 return 0; 219 errout: 220 if (*arg == 0UL && f) 221 kfree(f); 222 223 return err; 224 } 225 226 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg) 227 { 228 struct basic_head *head = 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 .put = basic_put, 286 .change = basic_change, 287 .delete = basic_delete, 288 .walk = basic_walk, 289 .dump = basic_dump, 290 .owner = THIS_MODULE, 291 }; 292 293 static int __init init_basic(void) 294 { 295 return register_tcf_proto_ops(&cls_basic_ops); 296 } 297 298 static void __exit exit_basic(void) 299 { 300 unregister_tcf_proto_ops(&cls_basic_ops); 301 } 302 303 module_init(init_basic) 304 module_exit(exit_basic) 305 MODULE_LICENSE("GPL"); 306 307