From: Balazs Scheidler <bazsi@xxxxxxxxxx>
This patch also adds userspace support for the --transparent mode
of matching, which the kernel already supports, but the iptables userspace
doesn't.
Signed-off-by: Balazs Scheidler <bazsi@xxxxxxxxxx>
Signed-off-by: KOVACS Krisztian <hidden@xxxxxxxxxx>
---
extensions/libxt_socket.c | 103 ++++++++++++++++++++++++++++++++---
extensions/libxt_socket.man | 6 ++
include/linux/netfilter/xt_socket.h | 12 ++++
3 files changed, 112 insertions(+), 9 deletions(-)
create mode 100644 include/linux/netfilter/xt_socket.h
diff --git a/extensions/libxt_socket.c b/extensions/libxt_socket.c
index 1490473..5705466 100644
--- a/extensions/libxt_socket.c
+++ b/extensions/libxt_socket.c
@@ -1,19 +1,106 @@
/*
* Shared library add-on to iptables to add early socket matching support.
*
- * Copyright (C) 2007 BalaBit IT Ltd.
+ * Copyright (C) 2007, 2009 BalaBit IT Ltd.
*/
+#include <stdio.h>
+#include <getopt.h>
#include <xtables.h>
+#include <linux/netfilter/xt_socket.h>
-static struct xtables_match socket_mt_reg = {
- .name = "socket",
- .version = XTABLES_VERSION,
- .family = NFPROTO_IPV4,
- .size = XT_ALIGN(0),
- .userspacesize = XT_ALIGN(0),
+static void socket_mt_help_v0(void)
+{
+ printf("socket match has no options.\n\n");
+}
+
+static void socket_mt_help_v1(void)
+{
+ printf("socket match options:\n"
+"--transparent Matches only if the socket's transparent option is set\n");
+}
+
+static const struct option socket_opts_v1[] = {
+ { "transparent", 0, NULL, '1' },
+ { }
+};
+
+static int socket_mt_parse_v0(int c, char **argv, int invert,
+ unsigned int *flags, const void *entry,
+ struct xt_entry_match **match)
+{
+ return 0;
+}
+
+static int socket_mt_parse_v1(int c, char **argv, int invert,
+ unsigned int *flags, const void *entry,
+ struct xt_entry_match **match)
+{
+ struct xt_socket_mtinfo1 *info = (void *) (*match)->data;
+
+ switch (c) {
+ case '1':
+ if (*flags)
+ xtables_error(PARAMETER_PROBLEM,
+ "Can't specify multiple --transparent");
+ info->flags |= XT_SOCKET_TRANSPARENT;
+ *flags = 1;
+ break;
+ default:
+ return 0;
+ }
+ return 1;
+}
+
+static void socket_mt_check(unsigned int flags)
+{
+}
+
+static void socket_mt_print_v1(const void *ip,
+ const struct xt_entry_match *match,
+ int numeric)
+{
+ const struct xt_socket_mtinfo1 *info = (const void *)match->data;
+ printf("socket ");
+ if (info->flags & XT_SOCKET_TRANSPARENT)
+ printf("transparent ");
+}
+
+static void socket_mt_save_v1(const void *ip,
+ const struct xt_entry_match *match)
+{
+ const struct xt_socket_mtinfo1 *info = (const void *)match->data;
+
+ if (info->flags & XT_SOCKET_TRANSPARENT)
+ printf("--transparent ");
+}
+
+static struct xtables_match socket_matches[] = {
+ {
+ .name = "socket",
+ .revision = 0,
+ .version = XTABLES_VERSION,
+ .family = NFPROTO_IPV4,
+ .parse = socket_mt_parse_v0,
+ .final_check = socket_mt_check,
+ .help = socket_mt_help_v0,
+ },
+ {
+ .name = "socket",
+ .version = XTABLES_VERSION,
+ .revision = 1,
+ .family = NFPROTO_UNSPEC,
+ .size = XT_ALIGN(sizeof(struct xt_socket_mtinfo1)),
+ .userspacesize = XT_ALIGN(sizeof(struct xt_socket_mtinfo1)),
+ .parse = socket_mt_parse_v1,
+ .print = socket_mt_print_v1,
+ .save = socket_mt_save_v1,
+ .final_check = socket_mt_check,
+ .help = socket_mt_help_v1,
+ .extra_opts = socket_opts_v1,
+ }
};
void _init(void)
{
- xtables_register_match(&socket_mt_reg);
+ xtables_register_matches(socket_matches, ARRAY_SIZE(socket_matches));
}
diff --git a/extensions/libxt_socket.man b/extensions/libxt_socket.man
index 50c8854..edc9d75 100644
--- a/extensions/libxt_socket.man
+++ b/extensions/libxt_socket.man
@@ -1,2 +1,6 @@
This matches if an open socket can be found by doing a socket lookup on the
-packet.
+packet which doesn\'t listen on the \'any\' IP address (0.0.0.0).
+.TP
+.BI "\-\-transparent"
+Enables additional check, that the actual socket's transparent socket option
+has to be set.
diff --git a/include/linux/netfilter/xt_socket.h b/include/linux/netfilter/xt_socket.h
new file mode 100644
index 0000000..6f475b8
--- /dev/null
+++ b/include/linux/netfilter/xt_socket.h
@@ -0,0 +1,12 @@
+#ifndef _XT_SOCKET_H
+#define _XT_SOCKET_H
+
+enum {
+ XT_SOCKET_TRANSPARENT = 1 << 0,
+};
+
+struct xt_socket_mtinfo1 {
+ __u8 flags;
+};
+
+#endif /* _XT_SOCKET_H */
--
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