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path: root/net/ipv4/netfilter/ipt_TOS.c
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Diffstat (limited to 'net/ipv4/netfilter/ipt_TOS.c')
-rw-r--r--net/ipv4/netfilter/ipt_TOS.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/ipt_TOS.c b/net/ipv4/netfilter/ipt_TOS.c
new file mode 100644
index 00000000000..85c70d240f8
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_TOS.c
@@ -0,0 +1,105 @@
+/* This is a module which is used for setting the TOS field of a packet. */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.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/ip.h>
+#include <net/checksum.h>
+
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_TOS.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("iptables TOS mangling module");
+
+static unsigned int
+target(struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ unsigned int hooknum,
+ const void *targinfo,
+ void *userinfo)
+{
+ const struct ipt_tos_target_info *tosinfo = targinfo;
+
+ if (((*pskb)->nh.iph->tos & IPTOS_TOS_MASK) != tosinfo->tos) {
+ u_int16_t diffs[2];
+
+ if (!skb_ip_make_writable(pskb, sizeof(struct iphdr)))
+ return NF_DROP;
+
+ diffs[0] = htons((*pskb)->nh.iph->tos) ^ 0xFFFF;
+ (*pskb)->nh.iph->tos
+ = ((*pskb)->nh.iph->tos & IPTOS_PREC_MASK)
+ | tosinfo->tos;
+ diffs[1] = htons((*pskb)->nh.iph->tos);
+ (*pskb)->nh.iph->check
+ = csum_fold(csum_partial((char *)diffs,
+ sizeof(diffs),
+ (*pskb)->nh.iph->check
+ ^0xFFFF));
+ (*pskb)->nfcache |= NFC_ALTERED;
+ }
+ return IPT_CONTINUE;
+}
+
+static int
+checkentry(const char *tablename,
+ const struct ipt_entry *e,
+ void *targinfo,
+ unsigned int targinfosize,
+ unsigned int hook_mask)
+{
+ const u_int8_t tos = ((struct ipt_tos_target_info *)targinfo)->tos;
+
+ if (targinfosize != IPT_ALIGN(sizeof(struct ipt_tos_target_info))) {
+ printk(KERN_WARNING "TOS: targinfosize %u != %Zu\n",
+ targinfosize,
+ IPT_ALIGN(sizeof(struct ipt_tos_target_info)));
+ return 0;
+ }
+
+ if (strcmp(tablename, "mangle") != 0) {
+ printk(KERN_WARNING "TOS: can only be called from \"mangle\" table, not \"%s\"\n", tablename);
+ return 0;
+ }
+
+ if (tos != IPTOS_LOWDELAY
+ && tos != IPTOS_THROUGHPUT
+ && tos != IPTOS_RELIABILITY
+ && tos != IPTOS_MINCOST
+ && tos != IPTOS_NORMALSVC) {
+ printk(KERN_WARNING "TOS: bad tos value %#x\n", tos);
+ return 0;
+ }
+
+ return 1;
+}
+
+static struct ipt_target ipt_tos_reg = {
+ .name = "TOS",
+ .target = target,
+ .checkentry = checkentry,
+ .me = THIS_MODULE,
+};
+
+static int __init init(void)
+{
+ return ipt_register_target(&ipt_tos_reg);
+}
+
+static void __exit fini(void)
+{
+ ipt_unregister_target(&ipt_tos_reg);
+}
+
+module_init(init);
+module_exit(fini);