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/netlink.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 struct basic_head *head; 86 87 head = kzalloc(sizeof(*head), GFP_KERNEL); 88 if (head == NULL) 89 return -ENOBUFS; 90 INIT_LIST_HEAD(&head->flist); 91 tp->root = head; 92 return 0; 93 } 94 95 static inline void basic_delete_filter(struct tcf_proto *tp, 96 struct basic_filter *f) 97 { 98 tcf_unbind_filter(tp, &f->res); 99 tcf_exts_destroy(tp, &f->exts); 100 tcf_em_tree_destroy(tp, &f->ematches); 101 kfree(f); 102 } 103 104 static void basic_destroy(struct tcf_proto *tp) 105 { 106 struct basic_head *head = (struct basic_head *) xchg(&tp->root, NULL); 107 struct basic_filter *f, *n; 108 109 list_for_each_entry_safe(f, n, &head->flist, link) { 110 list_del(&f->link); 111 basic_delete_filter(tp, f); 112 } 113 kfree(head); 114 } 115 116 static int basic_delete(struct tcf_proto *tp, unsigned long arg) 117 { 118 struct basic_head *head = (struct basic_head *) tp->root; 119 struct basic_filter *t, *f = (struct basic_filter *) arg; 120 121 list_for_each_entry(t, &head->flist, link) 122 if (t == f) { 123 tcf_tree_lock(tp); 124 list_del(&t->link); 125 tcf_tree_unlock(tp); 126 basic_delete_filter(tp, t); 127 return 0; 128 } 129 130 return -ENOENT; 131 } 132 133 static inline int basic_set_parms(struct tcf_proto *tp, struct basic_filter *f, 134 unsigned long base, struct rtattr **tb, 135 struct rtattr *est) 136 { 137 int err = -EINVAL; 138 struct tcf_exts e; 139 struct tcf_ematch_tree t; 140 141 if (tb[TCA_BASIC_CLASSID-1]) 142 if (RTA_PAYLOAD(tb[TCA_BASIC_CLASSID-1]) < sizeof(u32)) 143 return err; 144 145 err = tcf_exts_validate(tp, tb, est, &e, &basic_ext_map); 146 if (err < 0) 147 return err; 148 149 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES-1], &t); 150 if (err < 0) 151 goto errout; 152 153 if (tb[TCA_BASIC_CLASSID-1]) { 154 f->res.classid = *(u32*)RTA_DATA(tb[TCA_BASIC_CLASSID-1]); 155 tcf_bind_filter(tp, &f->res, base); 156 } 157 158 tcf_exts_change(tp, &f->exts, &e); 159 tcf_em_tree_change(tp, &f->ematches, &t); 160 161 return 0; 162 errout: 163 tcf_exts_destroy(tp, &e); 164 return err; 165 } 166 167 static int basic_change(struct tcf_proto *tp, unsigned long base, u32 handle, 168 struct rtattr **tca, unsigned long *arg) 169 { 170 int err = -EINVAL; 171 struct basic_head *head = (struct basic_head *) tp->root; 172 struct rtattr *tb[TCA_BASIC_MAX]; 173 struct basic_filter *f = (struct basic_filter *) *arg; 174 175 if (tca[TCA_OPTIONS-1] == NULL) 176 return -EINVAL; 177 178 if (rtattr_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS-1]) < 0) 179 return -EINVAL; 180 181 if (f != NULL) { 182 if (handle && f->handle != handle) 183 return -EINVAL; 184 return basic_set_parms(tp, f, base, tb, tca[TCA_RATE-1]); 185 } 186 187 err = -ENOBUFS; 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_pointer(skb); 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_pointer(skb) - b; 268 return skb->len; 269 270 rtattr_failure: 271 nlmsg_trim(skb, b); 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