1*a71a9546SAutomerger Merge Worker /* Shared library add-on to iptables for the TTL target
2*a71a9546SAutomerger Merge Worker * (C) 2000 by Harald Welte <[email protected]>
3*a71a9546SAutomerger Merge Worker *
4*a71a9546SAutomerger Merge Worker * This program is distributed under the terms of GNU GPL
5*a71a9546SAutomerger Merge Worker */
6*a71a9546SAutomerger Merge Worker #include <stdio.h>
7*a71a9546SAutomerger Merge Worker #include <xtables.h>
8*a71a9546SAutomerger Merge Worker #include <linux/netfilter_ipv4/ipt_TTL.h>
9*a71a9546SAutomerger Merge Worker
10*a71a9546SAutomerger Merge Worker enum {
11*a71a9546SAutomerger Merge Worker O_TTL_SET = 0,
12*a71a9546SAutomerger Merge Worker O_TTL_INC,
13*a71a9546SAutomerger Merge Worker O_TTL_DEC,
14*a71a9546SAutomerger Merge Worker F_TTL_SET = 1 << O_TTL_SET,
15*a71a9546SAutomerger Merge Worker F_TTL_INC = 1 << O_TTL_INC,
16*a71a9546SAutomerger Merge Worker F_TTL_DEC = 1 << O_TTL_DEC,
17*a71a9546SAutomerger Merge Worker F_ANY = F_TTL_SET | F_TTL_INC | F_TTL_DEC,
18*a71a9546SAutomerger Merge Worker };
19*a71a9546SAutomerger Merge Worker
20*a71a9546SAutomerger Merge Worker #define s struct ipt_TTL_info
21*a71a9546SAutomerger Merge Worker static const struct xt_option_entry TTL_opts[] = {
22*a71a9546SAutomerger Merge Worker {.name = "ttl-set", .type = XTTYPE_UINT8, .id = O_TTL_SET,
23*a71a9546SAutomerger Merge Worker .excl = F_ANY, .flags = XTOPT_PUT, XTOPT_POINTER(s, ttl)},
24*a71a9546SAutomerger Merge Worker {.name = "ttl-dec", .type = XTTYPE_UINT8, .id = O_TTL_DEC,
25*a71a9546SAutomerger Merge Worker .excl = F_ANY, .flags = XTOPT_PUT, XTOPT_POINTER(s, ttl),
26*a71a9546SAutomerger Merge Worker .min = 1},
27*a71a9546SAutomerger Merge Worker {.name = "ttl-inc", .type = XTTYPE_UINT8, .id = O_TTL_INC,
28*a71a9546SAutomerger Merge Worker .excl = F_ANY, .flags = XTOPT_PUT, XTOPT_POINTER(s, ttl),
29*a71a9546SAutomerger Merge Worker .min = 1},
30*a71a9546SAutomerger Merge Worker XTOPT_TABLEEND,
31*a71a9546SAutomerger Merge Worker };
32*a71a9546SAutomerger Merge Worker #undef s
33*a71a9546SAutomerger Merge Worker
TTL_help(void)34*a71a9546SAutomerger Merge Worker static void TTL_help(void)
35*a71a9546SAutomerger Merge Worker {
36*a71a9546SAutomerger Merge Worker printf(
37*a71a9546SAutomerger Merge Worker "TTL target options\n"
38*a71a9546SAutomerger Merge Worker " --ttl-set value Set TTL to <value 0-255>\n"
39*a71a9546SAutomerger Merge Worker " --ttl-dec value Decrement TTL by <value 1-255>\n"
40*a71a9546SAutomerger Merge Worker " --ttl-inc value Increment TTL by <value 1-255>\n");
41*a71a9546SAutomerger Merge Worker }
42*a71a9546SAutomerger Merge Worker
TTL_parse(struct xt_option_call * cb)43*a71a9546SAutomerger Merge Worker static void TTL_parse(struct xt_option_call *cb)
44*a71a9546SAutomerger Merge Worker {
45*a71a9546SAutomerger Merge Worker struct ipt_TTL_info *info = cb->data;
46*a71a9546SAutomerger Merge Worker
47*a71a9546SAutomerger Merge Worker xtables_option_parse(cb);
48*a71a9546SAutomerger Merge Worker switch (cb->entry->id) {
49*a71a9546SAutomerger Merge Worker case O_TTL_SET:
50*a71a9546SAutomerger Merge Worker info->mode = IPT_TTL_SET;
51*a71a9546SAutomerger Merge Worker break;
52*a71a9546SAutomerger Merge Worker case O_TTL_DEC:
53*a71a9546SAutomerger Merge Worker info->mode = IPT_TTL_DEC;
54*a71a9546SAutomerger Merge Worker break;
55*a71a9546SAutomerger Merge Worker case O_TTL_INC:
56*a71a9546SAutomerger Merge Worker info->mode = IPT_TTL_INC;
57*a71a9546SAutomerger Merge Worker break;
58*a71a9546SAutomerger Merge Worker }
59*a71a9546SAutomerger Merge Worker }
60*a71a9546SAutomerger Merge Worker
TTL_check(struct xt_fcheck_call * cb)61*a71a9546SAutomerger Merge Worker static void TTL_check(struct xt_fcheck_call *cb)
62*a71a9546SAutomerger Merge Worker {
63*a71a9546SAutomerger Merge Worker if (!(cb->xflags & F_ANY))
64*a71a9546SAutomerger Merge Worker xtables_error(PARAMETER_PROBLEM,
65*a71a9546SAutomerger Merge Worker "TTL: You must specify an action");
66*a71a9546SAutomerger Merge Worker }
67*a71a9546SAutomerger Merge Worker
TTL_save(const void * ip,const struct xt_entry_target * target)68*a71a9546SAutomerger Merge Worker static void TTL_save(const void *ip, const struct xt_entry_target *target)
69*a71a9546SAutomerger Merge Worker {
70*a71a9546SAutomerger Merge Worker const struct ipt_TTL_info *info =
71*a71a9546SAutomerger Merge Worker (struct ipt_TTL_info *) target->data;
72*a71a9546SAutomerger Merge Worker
73*a71a9546SAutomerger Merge Worker switch (info->mode) {
74*a71a9546SAutomerger Merge Worker case IPT_TTL_SET:
75*a71a9546SAutomerger Merge Worker printf(" --ttl-set");
76*a71a9546SAutomerger Merge Worker break;
77*a71a9546SAutomerger Merge Worker case IPT_TTL_DEC:
78*a71a9546SAutomerger Merge Worker printf(" --ttl-dec");
79*a71a9546SAutomerger Merge Worker break;
80*a71a9546SAutomerger Merge Worker
81*a71a9546SAutomerger Merge Worker case IPT_TTL_INC:
82*a71a9546SAutomerger Merge Worker printf(" --ttl-inc");
83*a71a9546SAutomerger Merge Worker break;
84*a71a9546SAutomerger Merge Worker }
85*a71a9546SAutomerger Merge Worker printf(" %u", info->ttl);
86*a71a9546SAutomerger Merge Worker }
87*a71a9546SAutomerger Merge Worker
TTL_print(const void * ip,const struct xt_entry_target * target,int numeric)88*a71a9546SAutomerger Merge Worker static void TTL_print(const void *ip, const struct xt_entry_target *target,
89*a71a9546SAutomerger Merge Worker int numeric)
90*a71a9546SAutomerger Merge Worker {
91*a71a9546SAutomerger Merge Worker const struct ipt_TTL_info *info =
92*a71a9546SAutomerger Merge Worker (struct ipt_TTL_info *) target->data;
93*a71a9546SAutomerger Merge Worker
94*a71a9546SAutomerger Merge Worker printf(" TTL ");
95*a71a9546SAutomerger Merge Worker switch (info->mode) {
96*a71a9546SAutomerger Merge Worker case IPT_TTL_SET:
97*a71a9546SAutomerger Merge Worker printf("set to");
98*a71a9546SAutomerger Merge Worker break;
99*a71a9546SAutomerger Merge Worker case IPT_TTL_DEC:
100*a71a9546SAutomerger Merge Worker printf("decrement by");
101*a71a9546SAutomerger Merge Worker break;
102*a71a9546SAutomerger Merge Worker case IPT_TTL_INC:
103*a71a9546SAutomerger Merge Worker printf("increment by");
104*a71a9546SAutomerger Merge Worker break;
105*a71a9546SAutomerger Merge Worker }
106*a71a9546SAutomerger Merge Worker printf(" %u", info->ttl);
107*a71a9546SAutomerger Merge Worker }
108*a71a9546SAutomerger Merge Worker
109*a71a9546SAutomerger Merge Worker static struct xtables_target ttl_tg_reg = {
110*a71a9546SAutomerger Merge Worker .name = "TTL",
111*a71a9546SAutomerger Merge Worker .version = XTABLES_VERSION,
112*a71a9546SAutomerger Merge Worker .family = NFPROTO_IPV4,
113*a71a9546SAutomerger Merge Worker .size = XT_ALIGN(sizeof(struct ipt_TTL_info)),
114*a71a9546SAutomerger Merge Worker .userspacesize = XT_ALIGN(sizeof(struct ipt_TTL_info)),
115*a71a9546SAutomerger Merge Worker .help = TTL_help,
116*a71a9546SAutomerger Merge Worker .print = TTL_print,
117*a71a9546SAutomerger Merge Worker .save = TTL_save,
118*a71a9546SAutomerger Merge Worker .x6_parse = TTL_parse,
119*a71a9546SAutomerger Merge Worker .x6_fcheck = TTL_check,
120*a71a9546SAutomerger Merge Worker .x6_options = TTL_opts,
121*a71a9546SAutomerger Merge Worker };
122*a71a9546SAutomerger Merge Worker
_init(void)123*a71a9546SAutomerger Merge Worker void _init(void)
124*a71a9546SAutomerger Merge Worker {
125*a71a9546SAutomerger Merge Worker xtables_register_target(&ttl_tg_reg);
126*a71a9546SAutomerger Merge Worker }
127