patch-2.4.1 linux/net/ipv6/netfilter/ip6table_mangle.c

• Lines: 190
• Date: Mon Jan 22 13:30:21 2001
• Orig file: v2.4.0/linux/net/ipv6/netfilter/ip6table_mangle.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.0/linux/net/ipv6/netfilter/ip6table_mangle.c linux/net/ipv6/netfilter/ip6table_mangle.c
@@ -0,0 +1,189 @@
+/*
+ * IPv6 packet mangling table, a port of the IPv4 mangle table to IPv6
+ *
+ * Copyright (C) 2000 by Harald Welte <laforge@gnumonks.org>
+ */
+#include <linux/module.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+
+#define MANGLE_VALID_HOOKS ((1 << NF_IP6_PRE_ROUTING) | (1 << NF_IP6_LOCAL_OUT))
+
+#if 1
+#define DEBUGP(x, args...)	printk(KERN_DEBUG x, ## args)
+#else
+#define DEBUGP(x, args...)
+#endif
+
+/* Standard entry. */
+struct ip6t_standard
+{
+	struct ip6t_entry entry;
+	struct ip6t_standard_target target;
+};
+
+struct ip6t_error_target
+{
+	struct ip6t_entry_target target;
+	char errorname[IP6T_FUNCTION_MAXNAMELEN];
+};
+
+struct ip6t_error
+{
+	struct ip6t_entry entry;
+	struct ip6t_error_target target;
+};
+
+static struct
+{
+	struct ip6t_replace repl;
+	struct ip6t_standard entries[2];
+	struct ip6t_error term;
+} initial_table __initdata
+= { { "mangle", MANGLE_VALID_HOOKS, 3,
+      sizeof(struct ip6t_standard) * 2 + sizeof(struct ip6t_error),
+      { [NF_IP6_PRE_ROUTING] 0,
+	[NF_IP6_LOCAL_OUT] sizeof(struct ip6t_standard) },
+      { [NF_IP6_PRE_ROUTING] 0,
+	[NF_IP6_LOCAL_OUT] sizeof(struct ip6t_standard) },
+      0, NULL, { } },
+    {
+	    /* PRE_ROUTING */
+	    { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
+		0,
+		sizeof(struct ip6t_entry),
+		sizeof(struct ip6t_standard),
+		0, { 0, 0 }, { } },
+	      { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
+		-NF_ACCEPT - 1 } },
+	    /* LOCAL_OUT */
+	    { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
+		0,
+		sizeof(struct ip6t_entry),
+		sizeof(struct ip6t_standard),
+		0, { 0, 0 }, { } },
+	      { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
+		-NF_ACCEPT - 1 } }
+    },
+    /* ERROR */
+    { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
+	0,
+	sizeof(struct ip6t_entry),
+	sizeof(struct ip6t_error),
+	0, { 0, 0 }, { } },
+      { { { { IP6T_ALIGN(sizeof(struct ip6t_error_target)), IP6T_ERROR_TARGET } },
+	  { } },
+	"ERROR"
+      }
+    }
+};
+
+static struct ip6t_table packet_mangler
+= { { NULL, NULL }, "mangle", &initial_table.repl,
+    MANGLE_VALID_HOOKS, RW_LOCK_UNLOCKED, NULL };
+
+/* The work comes in here from netfilter.c. */
+static unsigned int
+ip6t_hook(unsigned int hook,
+	 struct sk_buff **pskb,
+	 const struct net_device *in,
+	 const struct net_device *out,
+	 int (*okfn)(struct sk_buff *))
+{
+	return ip6t_do_table(pskb, hook, in, out, &packet_mangler, NULL);
+}
+
+static unsigned int
+ip6t_local_out_hook(unsigned int hook,
+		   struct sk_buff **pskb,
+		   const struct net_device *in,
+		   const struct net_device *out,
+		   int (*okfn)(struct sk_buff *))
+{
+
+	unsigned long nfmark;
+	unsigned int ret;
+	struct in6_addr saddr, daddr;
+	u_int8_t hop_limit;
+	u_int32_t flowlabel;
+
+#if 0
+	/* root is playing with raw sockets. */
+	if ((*pskb)->len < sizeof(struct iphdr)
+	    || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) {
+		if (net_ratelimit())
+			printk("ip6t_hook: happy cracking.\n");
+		return NF_ACCEPT;
+	}
+#endif
+
+	/* save source/dest address, nfmark, hoplimit, flowlabel, priority,  */
+	memcpy(&saddr, &(*pskb)->nh.ipv6h->saddr, sizeof(saddr));
+	memcpy(&daddr, &(*pskb)->nh.ipv6h->daddr, sizeof(daddr));
+	nfmark = (*pskb)->nfmark;
+	hop_limit = (*pskb)->nh.ipv6h->hop_limit;
+
+	/* flowlabel and prio (includes version, which shouldn't change either */
+	flowlabel = (u_int32_t) (*pskb)->nh.ipv6h;
+
+	ret = ip6t_do_table(pskb, hook, in, out, &packet_mangler, NULL);
+
+	if (ret != NF_DROP && ret != NF_STOLEN 
+		&& (memcmp(&(*pskb)->nh.ipv6h->saddr, &saddr, sizeof(saddr))
+		    || memcmp(&(*pskb)->nh.ipv6h->daddr, &daddr, sizeof(daddr))
+		    || (*pskb)->nfmark != nfmark
+		    || (*pskb)->nh.ipv6h->hop_limit != hop_limit)) {
+
+		/* something which could affect routing has changed */
+
+		DEBUGP("ip6table_mangle: we'd need to re-route a packet\n");
+	}
+
+	return ret;
+}
+
+static struct nf_hook_ops ip6t_ops[]
+= { { { NULL, NULL }, ip6t_hook, PF_INET6, NF_IP6_PRE_ROUTING, NF_IP6_PRI_MANGLE },
+    { { NULL, NULL }, ip6t_local_out_hook, PF_INET6, NF_IP6_LOCAL_OUT,
+		NF_IP6_PRI_MANGLE }
+};
+
+static int __init init(void)
+{
+	int ret;
+
+	/* Register table */
+	ret = ip6t_register_table(&packet_mangler);
+	if (ret < 0)
+		return ret;
+
+	/* Register hooks */
+	ret = nf_register_hook(&ip6t_ops[0]);
+	if (ret < 0)
+		goto cleanup_table;
+
+	ret = nf_register_hook(&ip6t_ops[1]);
+	if (ret < 0)
+		goto cleanup_hook0;
+
+	return ret;
+
+ cleanup_hook0:
+	nf_unregister_hook(&ip6t_ops[0]);
+ cleanup_table:
+	ip6t_unregister_table(&packet_mangler);
+
+	return ret;
+}
+
+static void __exit fini(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < sizeof(ip6t_ops)/sizeof(struct nf_hook_ops); i++)
+		nf_unregister_hook(&ip6t_ops[i]);
+
+	ip6t_unregister_table(&packet_mangler);
+}
+
+module_init(init);
+module_exit(fini);