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/string.h> 16 #include <linux/mm.h> 17 #include <linux/errno.h> 18 #include <linux/rtnetlink.h> 19 #include <linux/skbuff.h> 20 #include <net/act_api.h> 21 #include <net/pkt_cls.h> 22 23 struct basic_head 24 { 25 u32 hgenerator; 26 struct list_head flist; 27 }; 28 29 struct basic_filter 30 { 31 u32 handle; 32 struct tcf_exts exts; 33 struct tcf_ematch_tree ematches; 34 struct tcf_result res; 35 struct list_head link; 36 }; 37 38 static struct tcf_ext_map basic_ext_map = { 39 .action = TCA_BASIC_ACT, 40 .police = TCA_BASIC_POLICE 41 }; 42 43 static int basic_classify(struct sk_buff *skb, struct tcf_proto *tp, 44 struct tcf_result *res) 45 { 46 int r; 47 struct basic_head *head = (struct basic_head *) tp->root; 48 struct basic_filter *f; 49 50 list_for_each_entry(f, &head->flist, link) { 51 if (!tcf_em_tree_match(skb, &f->ematches, NULL)) 52 continue; 53 *res = f->res; 54 r = tcf_exts_exec(skb, &f->exts, res); 55 if (r < 0) 56 continue; 57 return r; 58 } 59 return -1; 60 } 61 62 static unsigned long basic_get(struct tcf_proto *tp, u32 handle) 63 { 64 unsigned long l = 0UL; 65 struct basic_head *head = (struct basic_head *) tp->root; 66 struct basic_filter *f; 67 68 if (head == NULL) 69 return 0UL; 70 71 list_for_each_entry(f, &head->flist, link) 72 if (f->handle == handle) 73 l = (unsigned long) f; 74 75 return l; 76 } 77 78 static void basic_put(struct tcf_proto *tp, unsigned long f) 79 { 80 } 81 82 static int basic_init(struct tcf_proto *tp) 83 { 84 return 0; 85 } 86 87 static inline void basic_delete_filter(struct tcf_proto *tp, 88 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 = (struct basic_head *) xchg(&tp->root, NULL); 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 } 106 107 static int basic_delete(struct tcf_proto *tp, unsigned long arg) 108 { 109 struct basic_head *head = (struct basic_head *) tp->root; 110 struct basic_filter *t, *f = (struct basic_filter *) arg; 111 112 list_for_each_entry(t, &head->flist, link) 113 if (t == f) { 114 tcf_tree_lock(tp); 115 list_del(&t->link); 116 tcf_tree_unlock(tp); 117 basic_delete_filter(tp, t); 118 return 0; 119 } 120 121 return -ENOENT; 122 } 123 124 static inline int basic_set_parms(struct tcf_proto *tp, struct basic_filter *f, 125 unsigned long base, struct rtattr **tb, 126 struct rtattr *est) 127 { 128 int err = -EINVAL; 129 struct tcf_exts e; 130 struct tcf_ematch_tree t; 131 132 if (tb[TCA_BASIC_CLASSID-1]) 133 if (RTA_PAYLOAD(tb[TCA_BASIC_CLASSID-1]) < sizeof(u32)) 134 return err; 135 136 err = tcf_exts_validate(tp, tb, est, &e, &basic_ext_map); 137 if (err < 0) 138 return err; 139 140 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES-1], &t); 141 if (err < 0) 142 goto errout; 143 144 if (tb[TCA_BASIC_CLASSID-1]) { 145 f->res.classid = *(u32*)RTA_DATA(tb[TCA_BASIC_CLASSID-1]); 146 tcf_bind_filter(tp, &f->res, base); 147 } 148 149 tcf_exts_change(tp, &f->exts, &e); 150 tcf_em_tree_change(tp, &f->ematches, &t); 151 152 return 0; 153 errout: 154 tcf_exts_destroy(tp, &e); 155 return err; 156 } 157 158 static int basic_change(struct tcf_proto *tp, unsigned long base, u32 handle, 159 struct rtattr **tca, unsigned long *arg) 160 { 161 int err = -EINVAL; 162 struct basic_head *head = (struct basic_head *) tp->root; 163 struct rtattr *tb[TCA_BASIC_MAX]; 164 struct basic_filter *f = (struct basic_filter *) *arg; 165 166 if (tca[TCA_OPTIONS-1] == NULL) 167 return -EINVAL; 168 169 if (rtattr_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS-1]) < 0) 170 return -EINVAL; 171 172 if (f != NULL) { 173 if (handle && f->handle != handle) 174 return -EINVAL; 175 return basic_set_parms(tp, f, base, tb, tca[TCA_RATE-1]); 176 } 177 178 err = -ENOBUFS; 179 if (head == NULL) { 180 head = kzalloc(sizeof(*head), GFP_KERNEL); 181 if (head == NULL) 182 goto errout; 183 184 INIT_LIST_HEAD(&head->flist); 185 tp->root = head; 186 } 187 188 f = kzalloc(sizeof(*f), GFP_KERNEL); 189 if (f == NULL) 190 goto errout; 191 192 err = -EINVAL; 193 if (handle) 194 f->handle = handle; 195 else { 196 unsigned int i = 0x80000000; 197 do { 198 if (++head->hgenerator == 0x7FFFFFFF) 199 head->hgenerator = 1; 200 } while (--i > 0 && basic_get(tp, head->hgenerator)); 201 202 if (i <= 0) { 203 printk(KERN_ERR "Insufficient number of handles\n"); 204 goto errout; 205 } 206 207 f->handle = head->hgenerator; 208 } 209 210 err = basic_set_parms(tp, f, base, tb, tca[TCA_RATE-1]); 211 if (err < 0) 212 goto errout; 213 214 tcf_tree_lock(tp); 215 list_add(&f->link, &head->flist); 216 tcf_tree_unlock(tp); 217 *arg = (unsigned long) f; 218 219 return 0; 220 errout: 221 if (*arg == 0UL && f) 222 kfree(f); 223 224 return err; 225 } 226 227 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg) 228 { 229 struct basic_head *head = (struct basic_head *) tp->root; 230 struct basic_filter *f; 231 232 list_for_each_entry(f, &head->flist, link) { 233 if (arg->count < arg->skip) 234 goto skip; 235 236 if (arg->fn(tp, (unsigned long) f, arg) < 0) { 237 arg->stop = 1; 238 break; 239 } 240 skip: 241 arg->count++; 242 } 243 } 244 245 static int basic_dump(struct tcf_proto *tp, unsigned long fh, 246 struct sk_buff *skb, struct tcmsg *t) 247 { 248 struct basic_filter *f = (struct basic_filter *) fh; 249 unsigned char *b = skb->tail; 250 struct rtattr *rta; 251 252 if (f == NULL) 253 return skb->len; 254 255 t->tcm_handle = f->handle; 256 257 rta = (struct rtattr *) b; 258 RTA_PUT(skb, TCA_OPTIONS, 0, NULL); 259 260 if (f->res.classid) 261 RTA_PUT(skb, TCA_BASIC_CLASSID, sizeof(u32), &f->res.classid); 262 263 if (tcf_exts_dump(skb, &f->exts, &basic_ext_map) < 0 || 264 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0) 265 goto rtattr_failure; 266 267 rta->rta_len = (skb->tail - b); 268 return skb->len; 269 270 rtattr_failure: 271 skb_trim(skb, b - skb->data); 272 return -1; 273 } 274 275 static struct tcf_proto_ops cls_basic_ops = { 276 .kind = "basic", 277 .classify = basic_classify, 278 .init = basic_init, 279 .destroy = basic_destroy, 280 .get = basic_get, 281 .put = basic_put, 282 .change = basic_change, 283 .delete = basic_delete, 284 .walk = basic_walk, 285 .dump = basic_dump, 286 .owner = THIS_MODULE, 287 }; 288 289 static int __init init_basic(void) 290 { 291 return register_tcf_proto_ops(&cls_basic_ops); 292 } 293 294 static void __exit exit_basic(void) 295 { 296 unregister_tcf_proto_ops(&cls_basic_ops); 297 } 298 299 module_init(init_basic) 300 module_exit(exit_basic) 301 MODULE_LICENSE("GPL"); 302 303