1 /* 2 * net/sched/em_u32.c U32 Ematch 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 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 11 * 12 * Based on net/sched/cls_u32.c 13 */ 14 15 #include <linux/module.h> 16 #include <linux/types.h> 17 #include <linux/kernel.h> 18 #include <linux/skbuff.h> 19 #include <net/pkt_cls.h> 20 21 static int em_u32_match(struct sk_buff *skb, struct tcf_ematch *em, 22 struct tcf_pkt_info *info) 23 { 24 struct tc_u32_key *key = (struct tc_u32_key *) em->data; 25 unsigned char *ptr = skb->nh.raw; 26 27 if (info) { 28 if (info->ptr) 29 ptr = info->ptr; 30 ptr += (info->nexthdr & key->offmask); 31 } 32 33 ptr += key->off; 34 35 if (!tcf_valid_offset(skb, ptr, sizeof(u32))) 36 return 0; 37 38 return !(((*(u32*) ptr) ^ key->val) & key->mask); 39 } 40 41 static struct tcf_ematch_ops em_u32_ops = { 42 .kind = TCF_EM_U32, 43 .datalen = sizeof(struct tc_u32_key), 44 .match = em_u32_match, 45 .owner = THIS_MODULE, 46 .link = LIST_HEAD_INIT(em_u32_ops.link) 47 }; 48 49 static int __init init_em_u32(void) 50 { 51 return tcf_em_register(&em_u32_ops); 52 } 53 54 static void __exit exit_em_u32(void) 55 { 56 tcf_em_unregister(&em_u32_ops); 57 } 58 59 MODULE_LICENSE("GPL"); 60 61 module_init(init_em_u32); 62 module_exit(exit_em_u32); 63