1 /* Shared library add-on to xtables for CHECKSUM
2 *
3 * (C) 2002 by Harald Welte <laforge@gnumonks.org>
4 * (C) 2010 by Red Hat, Inc
5 * Author: Michael S. Tsirkin <mst@redhat.com>
6 *
7 * This program is distributed under the terms of GNU GPL v2, 1991
8 *
9 * libxt_CHECKSUM.c borrowed some bits from libipt_ECN.c
10 */
11 #include <stdio.h>
12 #include <xtables.h>
13 #include <linux/netfilter/xt_CHECKSUM.h>
14
15 enum {
16 O_CHECKSUM_FILL = 0,
17 };
18
CHECKSUM_help(void)19 static void CHECKSUM_help(void)
20 {
21 printf(
22 "CHECKSUM target options\n"
23 " --checksum-fill Fill in packet checksum.\n");
24 }
25
26 static const struct xt_option_entry CHECKSUM_opts[] = {
27 {.name = "checksum-fill", .id = O_CHECKSUM_FILL,
28 .flags = XTOPT_MAND, .type = XTTYPE_NONE},
29 XTOPT_TABLEEND,
30 };
31
CHECKSUM_parse(struct xt_option_call * cb)32 static void CHECKSUM_parse(struct xt_option_call *cb)
33 {
34 struct xt_CHECKSUM_info *einfo = cb->data;
35
36 xtables_option_parse(cb);
37 einfo->operation = XT_CHECKSUM_OP_FILL;
38 }
39
CHECKSUM_print(const void * ip,const struct xt_entry_target * target,int numeric)40 static void CHECKSUM_print(const void *ip, const struct xt_entry_target *target,
41 int numeric)
42 {
43 const struct xt_CHECKSUM_info *einfo =
44 (const struct xt_CHECKSUM_info *)target->data;
45
46 printf(" CHECKSUM");
47
48 if (einfo->operation & XT_CHECKSUM_OP_FILL)
49 printf(" fill");
50 }
51
CHECKSUM_save(const void * ip,const struct xt_entry_target * target)52 static void CHECKSUM_save(const void *ip, const struct xt_entry_target *target)
53 {
54 const struct xt_CHECKSUM_info *einfo =
55 (const struct xt_CHECKSUM_info *)target->data;
56
57 if (einfo->operation & XT_CHECKSUM_OP_FILL)
58 printf(" --checksum-fill");
59 }
60
61 static struct xtables_target checksum_tg_reg = {
62 .name = "CHECKSUM",
63 .version = XTABLES_VERSION,
64 .family = NFPROTO_UNSPEC,
65 .size = XT_ALIGN(sizeof(struct xt_CHECKSUM_info)),
66 .userspacesize = XT_ALIGN(sizeof(struct xt_CHECKSUM_info)),
67 .help = CHECKSUM_help,
68 .print = CHECKSUM_print,
69 .save = CHECKSUM_save,
70 .x6_parse = CHECKSUM_parse,
71 .x6_options = CHECKSUM_opts,
72 };
73
_init(void)74 void _init(void)
75 {
76 xtables_register_target(&checksum_tg_reg);
77 }
78