Harald Welte's ttl stuff.

This patch adds two new modules to the netfilter CVS patch-o-matic system:

A TTL match and a TTL target for setting/incrementing/decrementing the TTL.

diff --git a/extensions/.TTL-test b/extensions/.TTL-test
new file mode 100755 (executable)
index 0000000..cdeda6f
--- /dev/null
+++ b/extensions/.TTL-test
@@ -0,0 +1,2 @@
+#! /bin/sh
+[ -f $KERNEL_DIR/include/linux/netfilter_ipv4/ipt_TTL.h ] && echo TTL

diff --git a/extensions/.ttl-test b/extensions/.ttl-test
new file mode 100755 (executable)
index 0000000..28a3cdc
--- /dev/null
+++ b/extensions/.ttl-test
@@ -0,0 +1,2 @@
+#! /bin/sh
+[ -f $KERNEL_DIR/include/linux/netfilter_ipv4/ipt_ttl.h ] && echo ttl

diff --git a/extensions/libipt_TTL.c b/extensions/libipt_TTL.c
new file mode 100644 (file)
index 0000000..c125bdf
--- /dev/null
+++ b/extensions/libipt_TTL.c
@@ -0,0 +1,163 @@
+/* Shared library add-on to iptables for the TTL target
+ * (C) 2000 by Harald Welte <laforge@gnumonks.org>
+ *
+ * Version: 1.2
+ *
+ * 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 init(struct ipt_entry_target *t, unsigned int *nfcache) 
+{
+}
+
+static void help(void) 
+{
+       printf(
+"TTL target v%s options\n"
+"  --ttl-set value             Set TTL to <value>\n"
+"  --ttl-dec value             Decrement TTL by <value>\n"
+"  --ttl-inc value             Increment TTL by <value>\n"
+, NETFILTER_VERSION);
+}
+
+static int parse(int c, char **argv, int invert, unsigned int *flags,
+               const struct ipt_entry *entry,
+               struct ipt_entry_target **target)
+{
+       struct ipt_TTL_info *info = (struct ipt_TTL_info *) (*target)->data;
+       u_int8_t 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))
+               exit_error(PARAMETER_PROBLEM,
+                               "TTL: unexpected `!'");
+       
+       value = atoi(optarg);
+
+       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 final_check(unsigned int flags)
+{
+       if (!(flags & IPT_TTL_USED))
+               exit_error(PARAMETER_PROBLEM,
+                               "TTL: You must specify an action");
+}
+
+static void save(const struct ipt_ip *ip,
+               const struct ipt_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 print(const struct ipt_ip *ip,
+               const struct ipt_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 struct option opts[] = {
+       { "ttl-set", 1, 0, '1' },
+       { "ttl-dec", 1, 0, '2' },
+       { "ttl-inc", 1, 0, '3' },
+       { 0 }
+};
+
+struct iptables_target TTL = { NULL, 
+       "TTL",
+       NETFILTER_VERSION,
+       IPT_ALIGN(sizeof(struct ipt_TTL_info)),
+       IPT_ALIGN(sizeof(struct ipt_TTL_info)),
+       &help,
+       &init,
+       &parse,
+       &final_check,
+       &print,
+       &save,
+       opts 
+};
+
+void _init(void)
+{
+       register_target(&TTL);
+}

diff --git a/extensions/libipt_ttl.c b/extensions/libipt_ttl.c
new file mode 100644 (file)
index 0000000..1acd7cf
--- /dev/null
+++ b/extensions/libipt_ttl.c
@@ -0,0 +1,111 @@
+/* Shared library add-on to iptables to add TTL matching support 
+ * (C) 2000 by Harald Welte <laforge@gnumonks.org>
+ *
+ * Version: 1.3
+ *
+ * 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 help(void) 
+{
+       printf(
+"TTL match v%s options:\n"
+"  --ttl value         Match time to live value\n", NETFILTER_VERSION);
+}
+
+static void init(struct ipt_entry_match *m, unsigned int *nfcache)
+{
+       /* caching not yet implemented */
+}
+
+static int parse(int c, char **argv, int invert, unsigned int *flags,
+               const struct ipt_entry *entry, unsigned int *nfcache,
+               struct ipt_entry_match **match)
+{
+       struct ipt_ttl_info *info = (struct ipt_ttl_info *) (*match)->data;
+       u_int8_t value;
+
+       switch (c) {
+               case '1':
+                       if (check_inverse(optarg, &invert))
+                               optind++;
+                       value = atoi(argv[optind-1]);
+
+                       /* is 0 allowed? */
+                       info->ttl = value;
+                       if (invert)
+                               info->invert = 1;
+                       break;
+               default:
+                       return 0;
+
+       }
+
+       return 1;
+}
+
+static void final_check(unsigned int flags)
+{
+       if (!flags) 
+               exit_error(PARAMETER_PROBLEM,
+                       "TTL match: You must specify `--ttl'");
+}
+
+static void print(const struct ipt_ip *ip, 
+               const struct ipt_entry_match *match,
+               int numeric)
+{
+       const struct ipt_ttl_info *info = 
+               (struct ipt_ttl_info *) match->data;
+
+       printf("TTL match ");
+       if (info->invert)
+               printf("!");
+       printf("%u ", info->ttl);
+}
+
+static void save(const struct ipt_ip *ip, 
+               const struct ipt_entry_match *match)
+{
+       const struct ipt_ttl_info *info =
+               (struct ipt_ttl_info *) match->data;
+
+       printf("--ttl ");
+       if (info->invert)
+               printf("!");
+       printf("%u ", info->ttl);
+}
+
+static struct option opts[] = {
+       { "ttl", 0, '1' },
+       { 0 }
+};
+
+struct iptables_match ttl = {
+       NULL,
+       "ttl",
+       NETFILTER_VERSION,
+       IPT_ALIGN(sizeof(struct ipt_ttl_info)),
+       IPT_ALIGN(sizeof(struct ipt_ttl_info)),
+       &help,
+       &init,
+       &parse,
+       &final_check,
+       &print,
+       &save,
+       opts
+};
+
+
+void _init(void) 
+{
+       register_match(&ttl);
+}