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 struct basic_head *head; 85 86 head = kzalloc(sizeof(*head), GFP_KERNEL); 87 if (head == NULL) 88 return -ENOBUFS; 89 INIT_LIST_HEAD(&head->flist); 90 tp->root = head; 91 return 0; 92 } 93 94 static inline void basic_delete_filter(struct tcf_proto *tp, 95 struct basic_filter *f) 96 { 97 tcf_unbind_filter(tp, &f->res); 98 tcf_exts_destroy(tp, &f->exts); 99 tcf_em_tree_destroy(tp, &f->ematches); 100 kfree(f); 101 } 102 103 static void basic_destroy(struct tcf_proto *tp) 104 { 105 struct basic_head *head = (struct basic_head *) xchg(&tp->root, NULL); 106 struct basic_filter *f, *n; 107 108 list_for_each_entry_safe(f, n, &head->flist, link) { 109 list_del(&f->link); 110 basic_delete_filter(tp, f); 111 } 112 kfree(head); 113 } 114 115 static int basic_delete(struct tcf_proto *tp, unsigned long arg) 116 { 117 struct basic_head *head = (struct basic_head *) tp->root; 118 struct basic_filter *t, *f = (struct basic_filter *) arg; 119 120 list_for_each_entry(t, &head->flist, link) 121 if (t == f) { 122 tcf_tree_lock(tp); 123 list_del(&t->link); 124 tcf_tree_unlock(tp); 125 basic_delete_filter(tp, t); 126 return 0; 127 } 128 129 return -ENOENT; 130 } 131 132 static inline int basic_set_parms(struct tcf_proto *tp, struct basic_filter *f, 133 unsigned long base, struct rtattr **tb, 134 struct rtattr *est) 135 { 136 int err = -EINVAL; 137 struct tcf_exts e; 138 struct tcf_ematch_tree t; 139 140 if (tb[TCA_BASIC_CLASSID-1]) 141 if (RTA_PAYLOAD(tb[TCA_BASIC_CLASSID-1]) < sizeof(u32)) 142 return err; 143 144 err = tcf_exts_validate(tp, tb, est, &e, &basic_ext_map); 145 if (err < 0) 146 return err; 147 148 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES-1], &t); 149 if (err < 0) 150 goto errout; 151 152 if (tb[TCA_BASIC_CLASSID-1]) { 153 f->res.classid = *(u32*)RTA_DATA(tb[TCA_BASIC_CLASSID-1]); 154 tcf_bind_filter(tp, &f->res, base); 155 } 156 157 tcf_exts_change(tp, &f->exts, &e); 158 tcf_em_tree_change(tp, &f->ematches, &t); 159 160 return 0; 161 errout: 162 tcf_exts_destroy(tp, &e); 163 return err; 164 } 165 166 static int basic_change(struct tcf_proto *tp, unsigned long base, u32 handle, 167 struct rtattr **tca, unsigned long *arg) 168 { 169 int err = -EINVAL; 170 struct basic_head *head = (struct basic_head *) tp->root; 171 struct rtattr *tb[TCA_BASIC_MAX]; 172 struct basic_filter *f = (struct basic_filter *) *arg; 173 174 if (tca[TCA_OPTIONS-1] == NULL) 175 return -EINVAL; 176 177 if (rtattr_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS-1]) < 0) 178 return -EINVAL; 179 180 if (f != NULL) { 181 if (handle && f->handle != handle) 182 return -EINVAL; 183 return basic_set_parms(tp, f, base, tb, tca[TCA_RATE-1]); 184 } 185 186 err = -ENOBUFS; 187 f = kzalloc(sizeof(*f), GFP_KERNEL); 188 if (f == NULL) 189 goto errout; 190 191 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 printk(KERN_ERR "Insufficient number of handles\n"); 203 goto errout; 204 } 205 206 f->handle = head->hgenerator; 207 } 208 209 err = basic_set_parms(tp, f, base, tb, tca[TCA_RATE-1]); 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 = (struct basic_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 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 unsigned char *b = skb_tail_pointer(skb); 249 struct rtattr *rta; 250 251 if (f == NULL) 252 return skb->len; 253 254 t->tcm_handle = f->handle; 255 256 rta = (struct rtattr *) b; 257 RTA_PUT(skb, TCA_OPTIONS, 0, NULL); 258 259 if (f->res.classid) 260 RTA_PUT(skb, TCA_BASIC_CLASSID, sizeof(u32), &f->res.classid); 261 262 if (tcf_exts_dump(skb, &f->exts, &basic_ext_map) < 0 || 263 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0) 264 goto rtattr_failure; 265 266 rta->rta_len = skb_tail_pointer(skb) - b; 267 return skb->len; 268 269 rtattr_failure: 270 skb_trim(skb, b - skb->data); 271 return -1; 272 } 273 274 static struct tcf_proto_ops cls_basic_ops = { 275 .kind = "basic", 276 .classify = basic_classify, 277 .init = basic_init, 278 .destroy = basic_destroy, 279 .get = basic_get, 280 .put = basic_put, 281 .change = basic_change, 282 .delete = basic_delete, 283 .walk = basic_walk, 284 .dump = basic_dump, 285 .owner = THIS_MODULE, 286 }; 287 288 static int __init init_basic(void) 289 { 290 return register_tcf_proto_ops(&cls_basic_ops); 291 } 292 293 static void __exit exit_basic(void) 294 { 295 unregister_tcf_proto_ops(&cls_basic_ops); 296 } 297 298 module_init(init_basic) 299 module_exit(exit_basic) 300 MODULE_LICENSE("GPL"); 301 302