diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/ipv4/netfilter/ipt_ecn.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'net/ipv4/netfilter/ipt_ecn.c')
-rw-r--r-- | net/ipv4/netfilter/ipt_ecn.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/ipt_ecn.c b/net/ipv4/netfilter/ipt_ecn.c new file mode 100644 index 00000000000..b6f7181e89c --- /dev/null +++ b/net/ipv4/netfilter/ipt_ecn.c @@ -0,0 +1,131 @@ +/* IP tables module for matching the value of the IPv4 and TCP ECN bits + * + * ipt_ecn.c,v 1.3 2002/05/29 15:09:00 laforge Exp + * + * (C) 2002 by Harald Welte <laforge@gnumonks.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/tcp.h> + +#include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/netfilter_ipv4/ipt_ecn.h> + +MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); +MODULE_DESCRIPTION("iptables ECN matching module"); +MODULE_LICENSE("GPL"); + +static inline int match_ip(const struct sk_buff *skb, + const struct ipt_ecn_info *einfo) +{ + return ((skb->nh.iph->tos&IPT_ECN_IP_MASK) == einfo->ip_ect); +} + +static inline int match_tcp(const struct sk_buff *skb, + const struct ipt_ecn_info *einfo, + int *hotdrop) +{ + struct tcphdr _tcph, *th; + + /* In practice, TCP match does this, so can't fail. But let's + * be good citizens. + */ + th = skb_header_pointer(skb, skb->nh.iph->ihl * 4, + sizeof(_tcph), &_tcph); + if (th == NULL) { + *hotdrop = 0; + return 0; + } + + if (einfo->operation & IPT_ECN_OP_MATCH_ECE) { + if (einfo->invert & IPT_ECN_OP_MATCH_ECE) { + if (th->ece == 1) + return 0; + } else { + if (th->ece == 0) + return 0; + } + } + + if (einfo->operation & IPT_ECN_OP_MATCH_CWR) { + if (einfo->invert & IPT_ECN_OP_MATCH_CWR) { + if (th->cwr == 1) + return 0; + } else { + if (th->cwr == 0) + return 0; + } + } + + return 1; +} + +static int match(const struct sk_buff *skb, const struct net_device *in, + const struct net_device *out, const void *matchinfo, + int offset, int *hotdrop) +{ + const struct ipt_ecn_info *info = matchinfo; + + if (info->operation & IPT_ECN_OP_MATCH_IP) + if (!match_ip(skb, info)) + return 0; + + if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR)) { + if (skb->nh.iph->protocol != IPPROTO_TCP) + return 0; + if (!match_tcp(skb, info, hotdrop)) + return 0; + } + + return 1; +} + +static int checkentry(const char *tablename, const struct ipt_ip *ip, + void *matchinfo, unsigned int matchsize, + unsigned int hook_mask) +{ + const struct ipt_ecn_info *info = matchinfo; + + if (matchsize != IPT_ALIGN(sizeof(struct ipt_ecn_info))) + return 0; + + if (info->operation & IPT_ECN_OP_MATCH_MASK) + return 0; + + if (info->invert & IPT_ECN_OP_MATCH_MASK) + return 0; + + if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR) + && ip->proto != IPPROTO_TCP) { + printk(KERN_WARNING "ipt_ecn: can't match TCP bits in rule for" + " non-tcp packets\n"); + return 0; + } + + return 1; +} + +static struct ipt_match ecn_match = { + .name = "ecn", + .match = &match, + .checkentry = &checkentry, + .me = THIS_MODULE, +}; + +static int __init init(void) +{ + return ipt_register_match(&ecn_match); +} + +static void __exit fini(void) +{ + ipt_unregister_match(&ecn_match); +} + +module_init(init); +module_exit(fini); |