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..25b9206
--- /dev/null
+++ b/trunk/extensions/libipt_ttl.c
@@ -0,0 +1,168 @@
+/* Shared library add-on to iptables to add TTL matching support 
+ * (C) 2000 by Harald Welte <laforge@gnumonks.org>
+ *
+ * $Id$
+ *
+ * This program is released under the terms of GNU GPL */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+#include <iptables.h>
+
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_ttl.h>
+
+static void ttl_help(void)
+{
+       printf(
+"ttl match options:\n"
+"  --ttl-eq value      Match time to live value\n"
+"  --ttl-lt value      Match TTL < value\n"
+"  --ttl-gt value      Match TTL > value\n");
+}
+
+static int ttl_parse(int c, char **argv, int invert, unsigned int *flags,
+                     const void *entry, struct xt_entry_match **match)
+{
+       struct ipt_ttl_info *info = (struct ipt_ttl_info *) (*match)->data;
+       unsigned int value;
+
+       check_inverse(optarg, &invert, &optind, 0);
+
+       switch (c) {
+               case '2':
+                       if (string_to_number(optarg, 0, 255, &value) == -1)
+                               exit_error(PARAMETER_PROBLEM,
+                                          "ttl: Expected value between 0 and 255");
+
+                       if (invert)
+                               info->mode = IPT_TTL_NE;
+                       else
+                               info->mode = IPT_TTL_EQ;
+
+                       /* is 0 allowed? */
+                       info->ttl = value;
+                       break;
+               case '3':
+                       if (string_to_number(optarg, 0, 255, &value) == -1)
+                               exit_error(PARAMETER_PROBLEM,
+                                          "ttl: Expected value between 0 and 255");
+
+                       if (invert) 
+                               exit_error(PARAMETER_PROBLEM,
+                                               "ttl: unexpected `!'");
+
+                       info->mode = IPT_TTL_LT;
+                       info->ttl = value;
+                       break;
+               case '4':
+                       if (string_to_number(optarg, 0, 255, &value) == -1)
+                               exit_error(PARAMETER_PROBLEM,
+                                          "ttl: Expected value between 0 and 255");
+
+                       if (invert)
+                               exit_error(PARAMETER_PROBLEM,
+                                               "ttl: unexpected `!'");
+
+                       info->mode = IPT_TTL_GT;
+                       info->ttl = value;
+                       break;
+               default:
+                       return 0;
+
+       }
+
+       if (*flags) 
+               exit_error(PARAMETER_PROBLEM, 
+                               "Can't specify TTL option twice");
+       *flags = 1;
+
+       return 1;
+}
+
+static void ttl_check(unsigned int flags)
+{
+       if (!flags) 
+               exit_error(PARAMETER_PROBLEM,
+                       "TTL match: You must specify one of "
+                       "`--ttl-eq', `--ttl-lt', `--ttl-gt");
+}
+
+static void ttl_print(const void *ip, const struct xt_entry_match *match,
+                      int numeric)
+{
+       const struct ipt_ttl_info *info = 
+               (struct ipt_ttl_info *) match->data;
+
+       printf("TTL match ");
+       switch (info->mode) {
+               case IPT_TTL_EQ:
+                       printf("TTL == ");
+                       break;
+               case IPT_TTL_NE:
+                       printf("TTL != ");
+                       break;
+               case IPT_TTL_LT:
+                       printf("TTL < ");
+                       break;
+               case IPT_TTL_GT:
+                       printf("TTL > ");
+                       break;
+       }
+       printf("%u ", info->ttl);
+}
+
+static void ttl_save(const void *ip, const struct xt_entry_match *match)
+{
+       const struct ipt_ttl_info *info =
+               (struct ipt_ttl_info *) match->data;
+
+       switch (info->mode) {
+               case IPT_TTL_EQ:
+                       printf("--ttl-eq ");
+                       break;
+               case IPT_TTL_NE:
+                       printf("! --ttl-eq ");
+                       break;
+               case IPT_TTL_LT:
+                       printf("--ttl-lt ");
+                       break;
+               case IPT_TTL_GT:
+                       printf("--ttl-gt ");
+                       break;
+               default:
+                       /* error */
+                       break;
+       }
+       printf("%u ", info->ttl);
+}
+
+static const struct option ttl_opts[] = {
+       { "ttl", 1, NULL, '2' },
+       { "ttl-eq", 1, NULL, '2'},
+       { "ttl-lt", 1, NULL, '3'},
+       { "ttl-gt", 1, NULL, '4'},
+       { .name = NULL }
+};
+
+static struct xtables_match ttl_mt_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_match(&ttl_mt_reg);
+}