81 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			81 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * net/sched/em_nbyte.c	N-Byte ematch
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 *
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 *		This program is free software; you can redistribute it and/or
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 *		modify it under the terms of the GNU General Public License
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 *		as published by the Free Software Foundation; either version
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 *		2 of the License, or (at your option) any later version.
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 *
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 * Authors:	Thomas Graf <tgraf@suug.ch>
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 */
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/skbuff.h>
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#include <linux/tc_ematch/tc_em_nbyte.h>
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#include <net/pkt_cls.h>
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struct nbyte_data
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{
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	struct tcf_em_nbyte	hdr;
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	char			pattern[0];
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};
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static int em_nbyte_change(struct tcf_proto *tp, void *data, int data_len,
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			   struct tcf_ematch *em)
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{
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	struct tcf_em_nbyte *nbyte = data;
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	if (data_len < sizeof(*nbyte) ||
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	    data_len < (sizeof(*nbyte) + nbyte->len))
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		return -EINVAL;
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	em->datalen = sizeof(*nbyte) + nbyte->len;
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	em->data = (unsigned long)kmemdup(data, em->datalen, GFP_KERNEL);
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	if (em->data == 0UL)
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		return -ENOBUFS;
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	return 0;
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}
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static int em_nbyte_match(struct sk_buff *skb, struct tcf_ematch *em,
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			  struct tcf_pkt_info *info)
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{
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	struct nbyte_data *nbyte = (struct nbyte_data *) em->data;
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	unsigned char *ptr = tcf_get_base_ptr(skb, nbyte->hdr.layer);
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	ptr += nbyte->hdr.off;
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	if (!tcf_valid_offset(skb, ptr, nbyte->hdr.len))
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		return 0;
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	return !memcmp(ptr + nbyte->hdr.off, nbyte->pattern, nbyte->hdr.len);
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}
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static struct tcf_ematch_ops em_nbyte_ops = {
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	.kind	  = TCF_EM_NBYTE,
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	.change	  = em_nbyte_change,
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	.match	  = em_nbyte_match,
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	.owner	  = THIS_MODULE,
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	.link	  = LIST_HEAD_INIT(em_nbyte_ops.link)
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};
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static int __init init_em_nbyte(void)
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{
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	return tcf_em_register(&em_nbyte_ops);
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}
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static void __exit exit_em_nbyte(void)
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{
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	tcf_em_unregister(&em_nbyte_ops);
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}
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MODULE_LICENSE("GPL");
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module_init(init_em_nbyte);
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module_exit(exit_em_nbyte);
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MODULE_ALIAS_TCF_EMATCH(TCF_EM_NBYTE);
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