patch-2.3.99-pre2 linux/net/ipv4/netfilter/ipt_TOS.c

• Lines: 88
• Date: Fri Mar 17 10:56:20 2000
• Orig file: v2.3.99-pre1/linux/net/ipv4/netfilter/ipt_TOS.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.99-pre1/linux/net/ipv4/netfilter/ipt_TOS.c linux/net/ipv4/netfilter/ipt_TOS.c
@@ -0,0 +1,87 @@
+/* This is a module which is used for setting the TOS field of a packet. */
+#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>
+
+EXPORT_NO_SYMBOLS;
+
+static unsigned int
+target(struct sk_buff **pskb,
+       unsigned int hooknum,
+       const struct net_device *in,
+       const struct net_device *out,
+       const void *targinfo,
+       void *userinfo)
+{
+	struct iphdr *iph = (*pskb)->nh.iph;
+	const struct ipt_tos_target_info *tosinfo = targinfo;
+
+	if ((iph->tos & IPTOS_TOS_MASK) != tosinfo->tos) {
+		u_int8_t diffs[2];
+
+		diffs[0] = iph->tos;
+		iph->tos = (iph->tos & IPTOS_PREC_MASK) | tosinfo->tos;
+		diffs[1] = iph->tos;
+		iph->check = csum_fold(csum_partial((char *)diffs,
+		                                    sizeof(diffs),
+		                                    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
+= { { NULL, NULL }, "TOS", target, checkentry, THIS_MODULE };
+
+static int __init init(void)
+{
+    if (ipt_register_target(&ipt_tos_reg))
+	return -EINVAL;
+
+    return 0;
+}
+
+static void __exit fini(void)
+{
+    ipt_unregister_target(&ipt_tos_reg);
+}
+
+module_init(init);
+module_exit(fini);