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path: root/net/ipv6/netfilter/ip6table_mangle.c
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Diffstat (limited to 'net/ipv6/netfilter/ip6table_mangle.c')
-rw-r--r--net/ipv6/netfilter/ip6table_mangle.c287
1 files changed, 287 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/ip6table_mangle.c b/net/ipv6/netfilter/ip6table_mangle.c
new file mode 100644
index 00000000000..85c1e6eada1
--- /dev/null
+++ b/net/ipv6/netfilter/ip6table_mangle.c
@@ -0,0 +1,287 @@
+/*
+ * IPv6 packet mangling table, a port of the IPv4 mangle table to IPv6
+ *
+ * Copyright (C) 2000-2001 by Harald Welte <laforge@gnumonks.org>
+ * Copyright (C) 2000-2004 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.
+ *
+ * Extended to all five netfilter hooks by Brad Chapman & Harald Welte
+ */
+#include <linux/module.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("ip6tables mangle table");
+
+#define MANGLE_VALID_HOOKS ((1 << NF_IP6_PRE_ROUTING) | \
+ (1 << NF_IP6_LOCAL_IN) | \
+ (1 << NF_IP6_FORWARD) | \
+ (1 << NF_IP6_LOCAL_OUT) | \
+ (1 << NF_IP6_POST_ROUTING))
+
+#if 0
+#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[5];
+ struct ip6t_error term;
+} initial_table __initdata
+= { { "mangle", MANGLE_VALID_HOOKS, 6,
+ sizeof(struct ip6t_standard) * 5 + sizeof(struct ip6t_error),
+ { [NF_IP6_PRE_ROUTING] = 0,
+ [NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
+ [NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
+ [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
+ [NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4},
+ { [NF_IP6_PRE_ROUTING] = 0,
+ [NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
+ [NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
+ [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
+ [NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4},
+ 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_IN */
+ { { { { { { 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 } },
+ /* FORWARD */
+ { { { { { { 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 } },
+ /* POST_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 } }
+ },
+ /* 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 = {
+ .name = "mangle",
+ .valid_hooks = MANGLE_VALID_HOOKS,
+ .lock = RW_LOCK_UNLOCKED,
+ .me = THIS_MODULE,
+};
+
+/* The work comes in here from netfilter.c. */
+static unsigned int
+ip6t_route_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_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[] = {
+ {
+ .hook = ip6t_route_hook,
+ .owner = THIS_MODULE,
+ .pf = PF_INET6,
+ .hooknum = NF_IP6_PRE_ROUTING,
+ .priority = NF_IP6_PRI_MANGLE,
+ },
+ {
+ .hook = ip6t_local_hook,
+ .owner = THIS_MODULE,
+ .pf = PF_INET6,
+ .hooknum = NF_IP6_LOCAL_IN,
+ .priority = NF_IP6_PRI_MANGLE,
+ },
+ {
+ .hook = ip6t_route_hook,
+ .owner = THIS_MODULE,
+ .pf = PF_INET6,
+ .hooknum = NF_IP6_FORWARD,
+ .priority = NF_IP6_PRI_MANGLE,
+ },
+ {
+ .hook = ip6t_local_hook,
+ .owner = THIS_MODULE,
+ .pf = PF_INET6,
+ .hooknum = NF_IP6_LOCAL_OUT,
+ .priority = NF_IP6_PRI_MANGLE,
+ },
+ {
+ .hook = ip6t_route_hook,
+ .owner = THIS_MODULE,
+ .pf = PF_INET6,
+ .hooknum = NF_IP6_POST_ROUTING,
+ .priority = NF_IP6_PRI_MANGLE,
+ },
+};
+
+static int __init init(void)
+{
+ int ret;
+
+ /* Register table */
+ ret = ip6t_register_table(&packet_mangler, &initial_table.repl);
+ 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;
+
+ ret = nf_register_hook(&ip6t_ops[2]);
+ if (ret < 0)
+ goto cleanup_hook1;
+
+ ret = nf_register_hook(&ip6t_ops[3]);
+ if (ret < 0)
+ goto cleanup_hook2;
+
+ ret = nf_register_hook(&ip6t_ops[4]);
+ if (ret < 0)
+ goto cleanup_hook3;
+
+ return ret;
+
+ cleanup_hook3:
+ nf_unregister_hook(&ip6t_ops[3]);
+ cleanup_hook2:
+ nf_unregister_hook(&ip6t_ops[2]);
+ cleanup_hook1:
+ nf_unregister_hook(&ip6t_ops[1]);
+ 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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-20 10:30:19 +0000