projects / thirdparty / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| edf0e1fb MT |
1 | /* iptables module for the packet checksum mangling |
| 2 | * | |
| 3 | * (C) 2002 by Harald Welte <laforge@netfilter.org> | |
| 4 | * (C) 2010 Red Hat, Inc. | |
| 5 | * | |
| 6 | * Author: Michael S. Tsirkin <mst@redhat.com> | |
| 7 | * | |
| 8 | * This program is free software; you can redistribute it and/or modify | |
| 9 | * it under the terms of the GNU General Public License version 2 as | |
| 10 | * published by the Free Software Foundation. | |
| 11 | */ | |
| 12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
| 13 | #include <linux/module.h> | |
| 14 | #include <linux/skbuff.h> | |
| 15 | ||
| 16 | #include <linux/netfilter/x_tables.h> | |
| 17 | #include <linux/netfilter/xt_CHECKSUM.h> | |
| 18 | ||
| 10568f6c FW |
19 | #include <linux/netfilter_ipv4/ip_tables.h> |
| 20 | #include <linux/netfilter_ipv6/ip6_tables.h> | |
| 21 | ||
| edf0e1fb MT |
22 | MODULE_LICENSE("GPL"); |
| 23 | MODULE_AUTHOR("Michael S. Tsirkin <mst@redhat.com>"); | |
| 24 | MODULE_DESCRIPTION("Xtables: checksum modification"); | |
| 25 | MODULE_ALIAS("ipt_CHECKSUM"); | |
| 26 | MODULE_ALIAS("ip6t_CHECKSUM"); | |
| 27 | ||
| 28 | static unsigned int | |
| 29 | checksum_tg(struct sk_buff *skb, const struct xt_action_param *par) | |
| 30 | { | |
| 10568f6c | 31 | if (skb->ip_summed == CHECKSUM_PARTIAL && !skb_is_gso(skb)) |
| edf0e1fb MT |
32 | skb_checksum_help(skb); |
| 33 | ||
| 34 | return XT_CONTINUE; | |
| 35 | } | |
| 36 | ||
| 37 | static int checksum_tg_check(const struct xt_tgchk_param *par) | |
| 38 | { | |
| 39 | const struct xt_CHECKSUM_info *einfo = par->targinfo; | |
| 10568f6c FW |
40 | const struct ip6t_ip6 *i6 = par->entryinfo; |
| 41 | const struct ipt_ip *i4 = par->entryinfo; | |
| edf0e1fb MT |
42 | |
| 43 | if (einfo->operation & ~XT_CHECKSUM_OP_FILL) { | |
| b2606644 FW |
44 | pr_info_ratelimited("unsupported CHECKSUM operation %x\n", |
| 45 | einfo->operation); | |
| edf0e1fb MT |
46 | return -EINVAL; |
| 47 | } | |
| 0cc9501f | 48 | if (!einfo->operation) |
| edf0e1fb | 49 | return -EINVAL; |
| 0cc9501f | 50 | |
| 10568f6c FW |
51 | switch (par->family) { |
| 52 | case NFPROTO_IPV4: | |
| 53 | if (i4->proto == IPPROTO_UDP && | |
| 54 | (i4->invflags & XT_INV_PROTO) == 0) | |
| 55 | return 0; | |
| 56 | break; | |
| 57 | case NFPROTO_IPV6: | |
| 58 | if ((i6->flags & IP6T_F_PROTO) && | |
| 59 | i6->proto == IPPROTO_UDP && | |
| 60 | (i6->invflags & XT_INV_PROTO) == 0) | |
| 61 | return 0; | |
| 62 | break; | |
| 63 | } | |
| 64 | ||
| 65 | pr_warn_once("CHECKSUM should be avoided. If really needed, restrict with \"-p udp\" and only use in OUTPUT\n"); | |
| edf0e1fb MT |
66 | return 0; |
| 67 | } | |
| 68 | ||
| 69 | static struct xt_target checksum_tg_reg __read_mostly = { | |
| 70 | .name = "CHECKSUM", | |
| 71 | .family = NFPROTO_UNSPEC, | |
| 72 | .target = checksum_tg, | |
| 73 | .targetsize = sizeof(struct xt_CHECKSUM_info), | |
| 74 | .table = "mangle", | |
| 75 | .checkentry = checksum_tg_check, | |
| 76 | .me = THIS_MODULE, | |
| 77 | }; | |
| 78 | ||
| 79 | static int __init checksum_tg_init(void) | |
| 80 | { | |
| 81 | return xt_register_target(&checksum_tg_reg); | |
| 82 | } | |
| 83 | ||
| 84 | static void __exit checksum_tg_exit(void) | |
| 85 | { | |
| 86 | xt_unregister_target(&checksum_tg_reg); | |
| 87 | } | |
| 88 | ||
| 89 | module_init(checksum_tg_init); | |
| 90 | module_exit(checksum_tg_exit); |