Yasuyuki Kozakai | 9ba1627 | 2006-08-22 00:29:37 -0700 | [diff] [blame] | 1 | /* IP tables module for matching the value of the IPv4/IPv6 DSCP field |
| 2 | * |
| 3 | * xt_dscp.c,v 1.3 2002/08/05 19:00:21 laforge Exp |
| 4 | * |
| 5 | * (C) 2002 by Harald Welte <laforge@netfilter.org> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/skbuff.h> |
| 14 | #include <linux/ip.h> |
| 15 | #include <linux/ipv6.h> |
| 16 | #include <net/dsfield.h> |
| 17 | |
| 18 | #include <linux/netfilter/xt_dscp.h> |
| 19 | #include <linux/netfilter/x_tables.h> |
| 20 | |
| 21 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); |
| 22 | MODULE_DESCRIPTION("x_tables DSCP matching module"); |
| 23 | MODULE_LICENSE("GPL"); |
| 24 | MODULE_ALIAS("ipt_dscp"); |
| 25 | MODULE_ALIAS("ip6t_dscp"); |
| 26 | |
| 27 | static int match(const struct sk_buff *skb, |
| 28 | const struct net_device *in, |
| 29 | const struct net_device *out, |
| 30 | const struct xt_match *match, |
| 31 | const void *matchinfo, |
| 32 | int offset, |
| 33 | unsigned int protoff, |
| 34 | int *hotdrop) |
| 35 | { |
| 36 | const struct xt_dscp_info *info = matchinfo; |
| 37 | u_int8_t dscp = ipv4_get_dsfield(skb->nh.iph) >> XT_DSCP_SHIFT; |
| 38 | |
| 39 | return (dscp == info->dscp) ^ !!info->invert; |
| 40 | } |
| 41 | |
| 42 | static int match6(const struct sk_buff *skb, |
| 43 | const struct net_device *in, |
| 44 | const struct net_device *out, |
| 45 | const struct xt_match *match, |
| 46 | const void *matchinfo, |
| 47 | int offset, |
| 48 | unsigned int protoff, |
| 49 | int *hotdrop) |
| 50 | { |
| 51 | const struct xt_dscp_info *info = matchinfo; |
| 52 | u_int8_t dscp = ipv6_get_dsfield(skb->nh.ipv6h) >> XT_DSCP_SHIFT; |
| 53 | |
| 54 | return (dscp == info->dscp) ^ !!info->invert; |
| 55 | } |
| 56 | |
| 57 | static int checkentry(const char *tablename, |
| 58 | const void *info, |
| 59 | const struct xt_match *match, |
| 60 | void *matchinfo, |
Yasuyuki Kozakai | 9ba1627 | 2006-08-22 00:29:37 -0700 | [diff] [blame] | 61 | unsigned int hook_mask) |
| 62 | { |
| 63 | const u_int8_t dscp = ((struct xt_dscp_info *)matchinfo)->dscp; |
| 64 | |
| 65 | if (dscp > XT_DSCP_MAX) { |
| 66 | printk(KERN_ERR "xt_dscp: dscp %x out of range\n", dscp); |
| 67 | return 0; |
| 68 | } |
| 69 | |
| 70 | return 1; |
| 71 | } |
| 72 | |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 73 | static struct xt_match xt_dscp_match[] = { |
| 74 | { |
| 75 | .name = "dscp", |
| 76 | .family = AF_INET, |
| 77 | .checkentry = checkentry, |
| 78 | .match = match, |
| 79 | .matchsize = sizeof(struct xt_dscp_info), |
| 80 | .me = THIS_MODULE, |
| 81 | }, |
| 82 | { |
| 83 | .name = "dscp", |
| 84 | .family = AF_INET6, |
| 85 | .checkentry = checkentry, |
| 86 | .match = match6, |
| 87 | .matchsize = sizeof(struct xt_dscp_info), |
| 88 | .me = THIS_MODULE, |
| 89 | }, |
Yasuyuki Kozakai | 9ba1627 | 2006-08-22 00:29:37 -0700 | [diff] [blame] | 90 | }; |
| 91 | |
| 92 | static int __init xt_dscp_match_init(void) |
| 93 | { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 94 | return xt_register_matches(xt_dscp_match, ARRAY_SIZE(xt_dscp_match)); |
Yasuyuki Kozakai | 9ba1627 | 2006-08-22 00:29:37 -0700 | [diff] [blame] | 95 | } |
| 96 | |
| 97 | static void __exit xt_dscp_match_fini(void) |
| 98 | { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 99 | xt_unregister_matches(xt_dscp_match, ARRAY_SIZE(xt_dscp_match)); |
Yasuyuki Kozakai | 9ba1627 | 2006-08-22 00:29:37 -0700 | [diff] [blame] | 100 | } |
| 101 | |
| 102 | module_init(xt_dscp_match_init); |
| 103 | module_exit(xt_dscp_match_fini); |