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/types.h> 14 #include <linux/kernel.h> 15 #include <linux/sched.h> 16 #include <linux/string.h> 17 #include <linux/mm.h> 18 #include <linux/errno.h> 19 #include <linux/rtnetlink.h> 20 #include <linux/skbuff.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 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 return 0; 86 } 87 88 static inline void basic_delete_filter(struct tcf_proto *tp, 89 struct basic_filter *f) 90 { 91 tcf_unbind_filter(tp, &f->res); 92 tcf_exts_destroy(tp, &f->exts); 93 tcf_em_tree_destroy(tp, &f->ematches); 94 kfree(f); 95 } 96 97 static void basic_destroy(struct tcf_proto *tp) 98 { 99 struct basic_head *head = (struct basic_head *) xchg(&tp->root, NULL); 100 struct basic_filter *f, *n; 101 102 list_for_each_entry_safe(f, n, &head->flist, link) { 103 list_del(&f->link); 104 basic_delete_filter(tp, f); 105 } 106 } 107 108 static int basic_delete(struct tcf_proto *tp, unsigned long arg) 109 { 110 struct basic_head *head = (struct basic_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 inline int basic_set_parms(struct tcf_proto *tp, struct basic_filter *f, 126 unsigned long base, struct rtattr **tb, 127 struct rtattr *est) 128 { 129 int err = -EINVAL; 130 struct tcf_exts e; 131 struct tcf_ematch_tree t; 132 133 if (tb[TCA_BASIC_CLASSID-1]) 134 if (RTA_PAYLOAD(tb[TCA_BASIC_CLASSID-1]) < sizeof(u32)) 135 return err; 136 137 err = tcf_exts_validate(tp, tb, est, &e, &basic_ext_map); 138 if (err < 0) 139 return err; 140 141 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES-1], &t); 142 if (err < 0) 143 goto errout; 144 145 if (tb[TCA_BASIC_CLASSID-1]) { 146 f->res.classid = *(u32*)RTA_DATA(tb[TCA_BASIC_CLASSID-1]); 147 tcf_bind_filter(tp, &f->res, base); 148 } 149 150 tcf_exts_change(tp, &f->exts, &e); 151 tcf_em_tree_change(tp, &f->ematches, &t); 152 153 return 0; 154 errout: 155 tcf_exts_destroy(tp, &e); 156 return err; 157 } 158 159 static int basic_change(struct tcf_proto *tp, unsigned long base, u32 handle, 160 struct rtattr **tca, unsigned long *arg) 161 { 162 int err = -EINVAL; 163 struct basic_head *head = (struct basic_head *) tp->root; 164 struct rtattr *tb[TCA_BASIC_MAX]; 165 struct basic_filter *f = (struct basic_filter *) *arg; 166 167 if (tca[TCA_OPTIONS-1] == NULL) 168 return -EINVAL; 169 170 if (rtattr_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS-1]) < 0) 171 return -EINVAL; 172 173 if (f != NULL) { 174 if (handle && f->handle != handle) 175 return -EINVAL; 176 return basic_set_parms(tp, f, base, tb, tca[TCA_RATE-1]); 177 } 178 179 err = -ENOBUFS; 180 if (head == NULL) { 181 head = kmalloc(sizeof(*head), GFP_KERNEL); 182 if (head == NULL) 183 goto errout; 184 185 memset(head, 0, sizeof(*head)); 186 INIT_LIST_HEAD(&head->flist); 187 tp->root = head; 188 } 189 190 f = kmalloc(sizeof(*f), GFP_KERNEL); 191 if (f == NULL) 192 goto errout; 193 memset(f, 0, sizeof(*f)); 194 195 err = -EINVAL; 196 if (handle) 197 f->handle = handle; 198 else { 199 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-1]); 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 unsigned char *b = skb->tail; 253 struct rtattr *rta; 254 255 if (f == NULL) 256 return skb->len; 257 258 t->tcm_handle = f->handle; 259 260 rta = (struct rtattr *) b; 261 RTA_PUT(skb, TCA_OPTIONS, 0, NULL); 262 263 if (f->res.classid) 264 RTA_PUT(skb, TCA_BASIC_CLASSID, sizeof(u32), &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 rtattr_failure; 269 270 rta->rta_len = (skb->tail - b); 271 return skb->len; 272 273 rtattr_failure: 274 skb_trim(skb, b - skb->data); 275 return -1; 276 } 277 278 static struct tcf_proto_ops cls_basic_ops = { 279 .kind = "basic", 280 .classify = basic_classify, 281 .init = basic_init, 282 .destroy = basic_destroy, 283 .get = basic_get, 284 .put = basic_put, 285 .change = basic_change, 286 .delete = basic_delete, 287 .walk = basic_walk, 288 .dump = basic_dump, 289 .owner = THIS_MODULE, 290 }; 291 292 static int __init init_basic(void) 293 { 294 return register_tcf_proto_ops(&cls_basic_ops); 295 } 296 297 static void __exit exit_basic(void) 298 { 299 unregister_tcf_proto_ops(&cls_basic_ops); 300 } 301 302 module_init(init_basic) 303 module_exit(exit_basic) 304 MODULE_LICENSE("GPL"); 305 306