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/config.h> 13 #include <linux/module.h> 14 #include <linux/types.h> 15 #include <linux/kernel.h> 16 #include <linux/sched.h> 17 #include <linux/string.h> 18 #include <linux/mm.h> 19 #include <linux/errno.h> 20 #include <linux/rtnetlink.h> 21 #include <linux/skbuff.h> 22 #include <net/act_api.h> 23 #include <net/pkt_cls.h> 24 25 struct basic_head 26 { 27 u32 hgenerator; 28 struct list_head flist; 29 }; 30 31 struct basic_filter 32 { 33 u32 handle; 34 struct tcf_exts exts; 35 struct tcf_ematch_tree ematches; 36 struct tcf_result res; 37 struct list_head link; 38 }; 39 40 static struct tcf_ext_map basic_ext_map = { 41 .action = TCA_BASIC_ACT, 42 .police = TCA_BASIC_POLICE 43 }; 44 45 static int basic_classify(struct sk_buff *skb, struct tcf_proto *tp, 46 struct tcf_result *res) 47 { 48 int r; 49 struct basic_head *head = (struct basic_head *) tp->root; 50 struct basic_filter *f; 51 52 list_for_each_entry(f, &head->flist, link) { 53 if (!tcf_em_tree_match(skb, &f->ematches, NULL)) 54 continue; 55 *res = f->res; 56 r = tcf_exts_exec(skb, &f->exts, res); 57 if (r < 0) 58 continue; 59 return r; 60 } 61 return -1; 62 } 63 64 static unsigned long basic_get(struct tcf_proto *tp, u32 handle) 65 { 66 unsigned long l = 0UL; 67 struct basic_head *head = (struct basic_head *) tp->root; 68 struct basic_filter *f; 69 70 if (head == NULL) 71 return 0UL; 72 73 list_for_each_entry(f, &head->flist, link) 74 if (f->handle == handle) 75 l = (unsigned long) f; 76 77 return l; 78 } 79 80 static void basic_put(struct tcf_proto *tp, unsigned long f) 81 { 82 } 83 84 static int basic_init(struct tcf_proto *tp) 85 { 86 return 0; 87 } 88 89 static inline void basic_delete_filter(struct tcf_proto *tp, 90 struct basic_filter *f) 91 { 92 tcf_unbind_filter(tp, &f->res); 93 tcf_exts_destroy(tp, &f->exts); 94 tcf_em_tree_destroy(tp, &f->ematches); 95 kfree(f); 96 } 97 98 static void basic_destroy(struct tcf_proto *tp) 99 { 100 struct basic_head *head = (struct basic_head *) xchg(&tp->root, NULL); 101 struct basic_filter *f, *n; 102 103 list_for_each_entry_safe(f, n, &head->flist, link) { 104 list_del(&f->link); 105 basic_delete_filter(tp, f); 106 } 107 } 108 109 static int basic_delete(struct tcf_proto *tp, unsigned long arg) 110 { 111 struct basic_head *head = (struct basic_head *) tp->root; 112 struct basic_filter *t, *f = (struct basic_filter *) arg; 113 114 list_for_each_entry(t, &head->flist, link) 115 if (t == f) { 116 tcf_tree_lock(tp); 117 list_del(&t->link); 118 tcf_tree_unlock(tp); 119 basic_delete_filter(tp, t); 120 return 0; 121 } 122 123 return -ENOENT; 124 } 125 126 static inline int basic_set_parms(struct tcf_proto *tp, struct basic_filter *f, 127 unsigned long base, struct rtattr **tb, 128 struct rtattr *est) 129 { 130 int err = -EINVAL; 131 struct tcf_exts e; 132 struct tcf_ematch_tree t; 133 134 if (tb[TCA_BASIC_CLASSID-1]) 135 if (RTA_PAYLOAD(tb[TCA_BASIC_CLASSID-1]) < sizeof(u32)) 136 return err; 137 138 err = tcf_exts_validate(tp, tb, est, &e, &basic_ext_map); 139 if (err < 0) 140 return err; 141 142 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES-1], &t); 143 if (err < 0) 144 goto errout; 145 146 if (tb[TCA_BASIC_CLASSID-1]) { 147 f->res.classid = *(u32*)RTA_DATA(tb[TCA_BASIC_CLASSID-1]); 148 tcf_bind_filter(tp, &f->res, base); 149 } 150 151 tcf_exts_change(tp, &f->exts, &e); 152 tcf_em_tree_change(tp, &f->ematches, &t); 153 154 return 0; 155 errout: 156 tcf_exts_destroy(tp, &e); 157 return err; 158 } 159 160 static int basic_change(struct tcf_proto *tp, unsigned long base, u32 handle, 161 struct rtattr **tca, unsigned long *arg) 162 { 163 int err = -EINVAL; 164 struct basic_head *head = (struct basic_head *) tp->root; 165 struct rtattr *tb[TCA_BASIC_MAX]; 166 struct basic_filter *f = (struct basic_filter *) *arg; 167 168 if (tca[TCA_OPTIONS-1] == NULL) 169 return -EINVAL; 170 171 if (rtattr_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS-1]) < 0) 172 return -EINVAL; 173 174 if (f != NULL) { 175 if (handle && f->handle != handle) 176 return -EINVAL; 177 return basic_set_parms(tp, f, base, tb, tca[TCA_RATE-1]); 178 } 179 180 err = -ENOBUFS; 181 if (head == NULL) { 182 head = kmalloc(sizeof(*head), GFP_KERNEL); 183 if (head == NULL) 184 goto errout; 185 186 memset(head, 0, sizeof(*head)); 187 INIT_LIST_HEAD(&head->flist); 188 tp->root = head; 189 } 190 191 f = kmalloc(sizeof(*f), GFP_KERNEL); 192 if (f == NULL) 193 goto errout; 194 memset(f, 0, sizeof(*f)); 195 196 err = -EINVAL; 197 if (handle) 198 f->handle = handle; 199 else { 200 int i = 0x80000000; 201 do { 202 if (++head->hgenerator == 0x7FFFFFFF) 203 head->hgenerator = 1; 204 } while (--i > 0 && basic_get(tp, head->hgenerator)); 205 206 if (i <= 0) { 207 printk(KERN_ERR "Insufficient number of handles\n"); 208 goto errout; 209 } 210 211 f->handle = head->hgenerator; 212 } 213 214 err = basic_set_parms(tp, f, base, tb, tca[TCA_RATE-1]); 215 if (err < 0) 216 goto errout; 217 218 tcf_tree_lock(tp); 219 list_add(&f->link, &head->flist); 220 tcf_tree_unlock(tp); 221 *arg = (unsigned long) f; 222 223 return 0; 224 errout: 225 if (*arg == 0UL && f) 226 kfree(f); 227 228 return err; 229 } 230 231 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg) 232 { 233 struct basic_head *head = (struct basic_head *) tp->root; 234 struct basic_filter *f; 235 236 list_for_each_entry(f, &head->flist, link) { 237 if (arg->count < arg->skip) 238 goto skip; 239 240 if (arg->fn(tp, (unsigned long) f, arg) < 0) { 241 arg->stop = 1; 242 break; 243 } 244 skip: 245 arg->count++; 246 } 247 } 248 249 static int basic_dump(struct tcf_proto *tp, unsigned long fh, 250 struct sk_buff *skb, struct tcmsg *t) 251 { 252 struct basic_filter *f = (struct basic_filter *) fh; 253 unsigned char *b = skb->tail; 254 struct rtattr *rta; 255 256 if (f == NULL) 257 return skb->len; 258 259 t->tcm_handle = f->handle; 260 261 rta = (struct rtattr *) b; 262 RTA_PUT(skb, TCA_OPTIONS, 0, NULL); 263 264 if (f->res.classid) 265 RTA_PUT(skb, TCA_BASIC_CLASSID, sizeof(u32), &f->res.classid); 266 267 if (tcf_exts_dump(skb, &f->exts, &basic_ext_map) < 0 || 268 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0) 269 goto rtattr_failure; 270 271 rta->rta_len = (skb->tail - b); 272 return skb->len; 273 274 rtattr_failure: 275 skb_trim(skb, b - skb->data); 276 return -1; 277 } 278 279 static struct tcf_proto_ops cls_basic_ops = { 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