Merge commit 'origin/trunk@12184' into fedora

[iptables.git] / trunk / extensions / libipt_TTL.c

diff --git a/trunk/extensions/libipt_TTL.c b/trunk/extensions/libipt_TTL.c
new file mode 100644 (file)
index 0000000..9c22ba3
--- /dev/null
+++ b/trunk/extensions/libipt_TTL.c
@@ -0,0 +1,158 @@
+/* Shared library add-on to iptables for the TTL target
+ * (C) 2000 by Harald Welte <laforge@gnumonks.org>
+ *
+ * $Id$
+ *
+ * This program is distributed under the terms of GNU GPL
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <iptables.h>
+
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_TTL.h>
+
+#define IPT_TTL_USED   1
+
+static void TTL_help(void)
+{
+       printf(
+"TTL target options\n"
+"  --ttl-set value             Set TTL to <value 0-255>\n"
+"  --ttl-dec value             Decrement TTL by <value 1-255>\n"
+"  --ttl-inc value             Increment TTL by <value 1-255>\n");
+}
+
+static int TTL_parse(int c, char **argv, int invert, unsigned int *flags,
+                     const void *entry, struct xt_entry_target **target)
+{
+       struct ipt_TTL_info *info = (struct ipt_TTL_info *) (*target)->data;
+       unsigned int value;
+
+       if (*flags & IPT_TTL_USED) {
+               exit_error(PARAMETER_PROBLEM, 
+                               "Can't specify TTL option twice");
+       }
+
+       if (!optarg) 
+               exit_error(PARAMETER_PROBLEM, 
+                               "TTL: You must specify a value");
+
+       if (check_inverse(optarg, &invert, NULL, 0))
+               exit_error(PARAMETER_PROBLEM,
+                               "TTL: unexpected `!'");
+       
+       if (string_to_number(optarg, 0, 255, &value) == -1)
+               exit_error(PARAMETER_PROBLEM,
+                          "TTL: Expected value between 0 and 255");
+
+       switch (c) {
+
+               case '1':
+                       info->mode = IPT_TTL_SET;
+                       break;
+
+               case '2':
+                       if (value == 0) {
+                               exit_error(PARAMETER_PROBLEM,
+                                       "TTL: decreasing by 0?");
+                       }
+
+                       info->mode = IPT_TTL_DEC;
+                       break;
+
+               case '3':
+                       if (value == 0) {
+                               exit_error(PARAMETER_PROBLEM,
+                                       "TTL: increasing by 0?");
+                       }
+
+                       info->mode = IPT_TTL_INC;
+                       break;
+
+               default:
+                       return 0;
+
+       }
+       
+       info->ttl = value;
+       *flags |= IPT_TTL_USED;
+
+       return 1;
+}
+
+static void TTL_check(unsigned int flags)
+{
+       if (!(flags & IPT_TTL_USED))
+               exit_error(PARAMETER_PROBLEM,
+                               "TTL: You must specify an action");
+}
+
+static void TTL_save(const void *ip, const struct xt_entry_target *target)
+{
+       const struct ipt_TTL_info *info = 
+               (struct ipt_TTL_info *) target->data;
+
+       switch (info->mode) {
+               case IPT_TTL_SET:
+                       printf("--ttl-set ");
+                       break;
+               case IPT_TTL_DEC:
+                       printf("--ttl-dec ");
+                       break;
+
+               case IPT_TTL_INC:
+                       printf("--ttl-inc ");
+                       break;
+       }
+       printf("%u ", info->ttl);
+}
+
+static void TTL_print(const void *ip, const struct xt_entry_target *target,
+                      int numeric)
+{
+       const struct ipt_TTL_info *info =
+               (struct ipt_TTL_info *) target->data;
+
+       printf("TTL ");
+       switch (info->mode) {
+               case IPT_TTL_SET:
+                       printf("set to ");
+                       break;
+               case IPT_TTL_DEC:
+                       printf("decrement by ");
+                       break;
+               case IPT_TTL_INC:
+                       printf("increment by ");
+                       break;
+       }
+       printf("%u ", info->ttl);
+}
+
+static const struct option TTL_opts[] = {
+       { "ttl-set", 1, NULL, '1' },
+       { "ttl-dec", 1, NULL, '2' },
+       { "ttl-inc", 1, NULL, '3' },
+       { .name = NULL }
+};
+
+static struct xtables_target ttl_tg_reg = {
+       .name           = "TTL",
+       .version        = XTABLES_VERSION,
+       .family         = PF_INET,
+       .size           = XT_ALIGN(sizeof(struct ipt_TTL_info)),
+       .userspacesize  = XT_ALIGN(sizeof(struct ipt_TTL_info)),
+       .help           = TTL_help,
+       .parse          = TTL_parse,
+       .final_check    = TTL_check,
+       .print          = TTL_print,
+       .save           = TTL_save,
+       .extra_opts     = TTL_opts,
+};
+
+void _init(void)
+{
+       xtables_register_target(&ttl_tg_reg);
+}