Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* This is a module which is used for setting up fake conntracks |
| 2 | * on packets so that they are not seen by the conntrack/NAT code. |
| 3 | */ |
| 4 | #include <linux/module.h> |
| 5 | #include <linux/skbuff.h> |
| 6 | |
| 7 | #include <linux/netfilter_ipv4/ip_tables.h> |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame^] | 8 | #include <net/netfilter/nf_conntrack_compat.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | |
| 10 | static unsigned int |
| 11 | target(struct sk_buff **pskb, |
| 12 | const struct net_device *in, |
| 13 | const struct net_device *out, |
| 14 | unsigned int hooknum, |
| 15 | const void *targinfo, |
| 16 | void *userinfo) |
| 17 | { |
| 18 | /* Previously seen (loopback)? Ignore. */ |
| 19 | if ((*pskb)->nfct != NULL) |
| 20 | return IPT_CONTINUE; |
| 21 | |
| 22 | /* Attach fake conntrack entry. |
| 23 | If there is a real ct entry correspondig to this packet, |
| 24 | it'll hang aroun till timing out. We don't deal with it |
| 25 | for performance reasons. JK */ |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame^] | 26 | nf_ct_untrack(*pskb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | (*pskb)->nfctinfo = IP_CT_NEW; |
| 28 | nf_conntrack_get((*pskb)->nfct); |
| 29 | |
| 30 | return IPT_CONTINUE; |
| 31 | } |
| 32 | |
| 33 | static int |
| 34 | checkentry(const char *tablename, |
| 35 | const struct ipt_entry *e, |
| 36 | void *targinfo, |
| 37 | unsigned int targinfosize, |
| 38 | unsigned int hook_mask) |
| 39 | { |
| 40 | if (targinfosize != 0) { |
| 41 | printk(KERN_WARNING "NOTRACK: targinfosize %u != 0\n", |
| 42 | targinfosize); |
| 43 | return 0; |
| 44 | } |
| 45 | |
| 46 | if (strcmp(tablename, "raw") != 0) { |
| 47 | printk(KERN_WARNING "NOTRACK: can only be called from \"raw\" table, not \"%s\"\n", tablename); |
| 48 | return 0; |
| 49 | } |
| 50 | |
| 51 | return 1; |
| 52 | } |
| 53 | |
| 54 | static struct ipt_target ipt_notrack_reg = { |
| 55 | .name = "NOTRACK", |
| 56 | .target = target, |
| 57 | .checkentry = checkentry, |
| 58 | .me = THIS_MODULE |
| 59 | }; |
| 60 | |
| 61 | static int __init init(void) |
| 62 | { |
| 63 | if (ipt_register_target(&ipt_notrack_reg)) |
| 64 | return -EINVAL; |
| 65 | |
| 66 | return 0; |
| 67 | } |
| 68 | |
| 69 | static void __exit fini(void) |
| 70 | { |
| 71 | ipt_unregister_target(&ipt_notrack_reg); |
| 72 | } |
| 73 | |
| 74 | module_init(init); |
| 75 | module_exit(fini); |
| 76 | MODULE_LICENSE("GPL"); |