projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 2e4e6a17 HW |
1 | /* Kernel module to match packet length. */ |
| 2 | /* (C) 1999-2001 James Morris <jmorros@intercode.com.au> | |
| 3 | * | |
| 4 | * This program is free software; you can redistribute it and/or modify | |
| 5 | * it under the terms of the GNU General Public License version 2 as | |
| 6 | * published by the Free Software Foundation. | |
| 7 | */ | |
| 8 | ||
| 9 | #include <linux/module.h> | |
| 10 | #include <linux/skbuff.h> | |
| 37d8dc82 | 11 | #include <linux/ipv6.h> |
| 2e4e6a17 HW |
12 | #include <net/ip.h> |
| 13 | ||
| 14 | #include <linux/netfilter/xt_length.h> | |
| 15 | #include <linux/netfilter/x_tables.h> | |
| 16 | ||
| 17 | MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>"); | |
| 2ae15b64 | 18 | MODULE_DESCRIPTION("Xtables: Packet length (Layer3,4,5) match"); |
| 2e4e6a17 HW |
19 | MODULE_LICENSE("GPL"); |
| 20 | MODULE_ALIAS("ipt_length"); | |
| 21 | MODULE_ALIAS("ip6t_length"); | |
| 22 | ||
| 1d93a9cb | 23 | static bool |
| d3c5ee6d JE |
24 | length_mt(const struct sk_buff *skb, const struct net_device *in, |
| 25 | const struct net_device *out, const struct xt_match *match, | |
| 26 | const void *matchinfo, int offset, unsigned int protoff, | |
| 27 | bool *hotdrop) | |
| 2e4e6a17 HW |
28 | { |
| 29 | const struct xt_length_info *info = matchinfo; | |
| eddc9ec5 | 30 | u_int16_t pktlen = ntohs(ip_hdr(skb)->tot_len); |
| 601e68e1 | 31 | |
| 2e4e6a17 HW |
32 | return (pktlen >= info->min && pktlen <= info->max) ^ info->invert; |
| 33 | } | |
| 34 | ||
| 1d93a9cb | 35 | static bool |
| d3c5ee6d JE |
36 | length_mt6(const struct sk_buff *skb, const struct net_device *in, |
| 37 | const struct net_device *out, const struct xt_match *match, | |
| 38 | const void *matchinfo, int offset, unsigned int protoff, | |
| 39 | bool *hotdrop) | |
| 2e4e6a17 HW |
40 | { |
| 41 | const struct xt_length_info *info = matchinfo; | |
| 7c4e36bc JE |
42 | const u_int16_t pktlen = ntohs(ipv6_hdr(skb)->payload_len) + |
| 43 | sizeof(struct ipv6hdr); | |
| 601e68e1 | 44 | |
| 2e4e6a17 HW |
45 | return (pktlen >= info->min && pktlen <= info->max) ^ info->invert; |
| 46 | } | |
| 47 | ||
| d3c5ee6d | 48 | static struct xt_match length_mt_reg[] __read_mostly = { |
| 4470bbc7 PM |
49 | { |
| 50 | .name = "length", | |
| 51 | .family = AF_INET, | |
| d3c5ee6d | 52 | .match = length_mt, |
| 4470bbc7 PM |
53 | .matchsize = sizeof(struct xt_length_info), |
| 54 | .me = THIS_MODULE, | |
| 55 | }, | |
| 56 | { | |
| 57 | .name = "length", | |
| 58 | .family = AF_INET6, | |
| d3c5ee6d | 59 | .match = length_mt6, |
| 4470bbc7 PM |
60 | .matchsize = sizeof(struct xt_length_info), |
| 61 | .me = THIS_MODULE, | |
| 62 | }, | |
| 2e4e6a17 HW |
63 | }; |
| 64 | ||
| d3c5ee6d | 65 | static int __init length_mt_init(void) |
| 2e4e6a17 | 66 | { |
| d3c5ee6d | 67 | return xt_register_matches(length_mt_reg, ARRAY_SIZE(length_mt_reg)); |
| 2e4e6a17 HW |
68 | } |
| 69 | ||
| d3c5ee6d | 70 | static void __exit length_mt_exit(void) |
| 2e4e6a17 | 71 | { |
| d3c5ee6d | 72 | xt_unregister_matches(length_mt_reg, ARRAY_SIZE(length_mt_reg)); |
| 2e4e6a17 HW |
73 | } |
| 74 | ||
| d3c5ee6d JE |
75 | module_init(length_mt_init); |
| 76 | module_exit(length_mt_exit); |