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 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 7 | #include <linux/netfilter/x_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 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 10 | MODULE_LICENSE("GPL"); |
| 11 | MODULE_ALIAS("ipt_NOTRACK"); |
| 12 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | static unsigned int |
| 14 | target(struct sk_buff **pskb, |
| 15 | const struct net_device *in, |
| 16 | const struct net_device *out, |
| 17 | unsigned int hooknum, |
| 18 | const void *targinfo, |
| 19 | void *userinfo) |
| 20 | { |
| 21 | /* Previously seen (loopback)? Ignore. */ |
| 22 | if ((*pskb)->nfct != NULL) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 23 | return XT_CONTINUE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | |
| 25 | /* Attach fake conntrack entry. |
| 26 | If there is a real ct entry correspondig to this packet, |
| 27 | it'll hang aroun till timing out. We don't deal with it |
| 28 | for performance reasons. JK */ |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 29 | nf_ct_untrack(*pskb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | (*pskb)->nfctinfo = IP_CT_NEW; |
| 31 | nf_conntrack_get((*pskb)->nfct); |
| 32 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 33 | return XT_CONTINUE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | } |
| 35 | |
| 36 | static int |
| 37 | checkentry(const char *tablename, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 38 | const void *entry, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | void *targinfo, |
| 40 | unsigned int targinfosize, |
| 41 | unsigned int hook_mask) |
| 42 | { |
| 43 | if (targinfosize != 0) { |
| 44 | printk(KERN_WARNING "NOTRACK: targinfosize %u != 0\n", |
| 45 | targinfosize); |
| 46 | return 0; |
| 47 | } |
| 48 | |
| 49 | if (strcmp(tablename, "raw") != 0) { |
| 50 | printk(KERN_WARNING "NOTRACK: can only be called from \"raw\" table, not \"%s\"\n", tablename); |
| 51 | return 0; |
| 52 | } |
| 53 | |
| 54 | return 1; |
| 55 | } |
| 56 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 57 | static struct xt_target notrack_reg = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | .name = "NOTRACK", |
| 59 | .target = target, |
| 60 | .checkentry = checkentry, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 61 | .me = THIS_MODULE, |
| 62 | }; |
| 63 | static struct xt_target notrack6_reg = { |
| 64 | .name = "NOTRACK", |
| 65 | .target = target, |
| 66 | .checkentry = checkentry, |
| 67 | .me = THIS_MODULE, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | }; |
| 69 | |
| 70 | static int __init init(void) |
| 71 | { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 72 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 74 | ret = xt_register_target(AF_INET, ¬rack_reg); |
| 75 | if (ret) |
| 76 | return ret; |
| 77 | |
| 78 | ret = xt_register_target(AF_INET6, ¬rack6_reg); |
| 79 | if (ret) |
| 80 | xt_unregister_target(AF_INET, ¬rack_reg); |
| 81 | |
| 82 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | } |
| 84 | |
| 85 | static void __exit fini(void) |
| 86 | { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 87 | xt_unregister_target(AF_INET6, ¬rack6_reg); |
| 88 | xt_unregister_target(AF_INET, ¬rack_reg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | } |
| 90 | |
| 91 | module_init(init); |
| 92 | module_exit(fini); |