netfilter: fix string extension for case insensitive pattern matching

The flag XT_STRING_FLAG_IGNORECASE indicates case insensitive string
matching. netfilter can find cmd.exe, Cmd.exe, cMd.exe and etc easily.

A new revision 1 was added, in the meantime invert of xt_string_info
was moved into flags as a flag. If revision is 1, The flag
XT_STRING_FLAG_INVERT indicates invert matching.

Signed-off-by: Joonwoo Park <joonwpark81@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 1 deletions

diff --git a/include/linux/netfilter/xt_string.h b/include/linux/netfilter/xt_string.h
index bb21dd1aee2d..8a6ba7bbef9f 100644
--- a/include/linux/netfilter/xt_string.h
+++ b/include/linux/netfilter/xt_string.h
@@ -4,6 +4,11 @@
 #define XT_STRING_MAX_PATTERN_SIZE 128
 #define XT_STRING_MAX_ALGO_NAME_SIZE 16
 
+enum {
+        XT_STRING_FLAG_INVERT           = 0x01,
+        XT_STRING_FLAG_IGNORECASE       = 0x02
+};
+
 struct xt_string_info
 {
         u_int16_t from_offset;
@@ -11,7 +16,15 @@ struct xt_string_info
         char      algo[XT_STRING_MAX_ALGO_NAME_SIZE];
         char      pattern[XT_STRING_MAX_PATTERN_SIZE];
         u_int8_t  patlen;
-        u_int8_t  invert;
+        union {
+                struct {
+                        u_int8_t  invert;
+                } v0;
+
+                struct {
+                        u_int8_t  flags;
+                } v1;
+        } u;
 
         /* Used internally by the kernel */
         struct ts_config __attribute__((aligned(8))) *config;