Refactor charset plugins a bit and add CP437 module.

Now all 8-bit charsets with gaps (not all symbols defined) could be produced through
one macro -- SMB_GENERATE_CHARSET_MODULE_8_BIT_GAP(CHARSETNAME) within source file
with three charset tables. Full source code for such modules can be generated by
source/script/gen-8bit-gap.sh script which was taken from GNU libc and changed slightly
to follow our data types and structure.
(This used to be commit 37042c7bc0f349370e93e4bed37d8fa371013247)

1 files changed, 87 insertions, 0 deletions

diff --git a/source3/include/charset.h b/source3/include/charset.h
index f999a9cf72..7a9b12ef55 100644
--- a/source3/include/charset.h
+++ b/source3/include/charset.h
@@ -38,3 +38,90 @@ struct charset_functions {
 	struct charset_functions *prev, *next;
 };
 
+/*
+ * This is auxiliary struct used by source/script/gen-8-bit-gap.sh script
+ * during generation of an encoding table for charset module
+ *     */
+
+struct charset_gap_table {
+  uint16 start;
+  uint16 end;
+  int32 idx;
+};
+
+/*
+ *   Define stub for charset module which implements 8-bit encoding with gaps.
+ *   Encoding tables for such module should be produced from glibc's CHARMAPs
+ *   using script source/script/gen-8bit-gap.sh
+ *   CHARSETNAME is CAPITALIZED charset name
+ *
+ *     */
+#define SMB_GENERATE_CHARSET_MODULE_8_BIT_GAP(CHARSETNAME) 					\
+static size_t CHARSETNAME ## _push(void *cd, char **inbuf, size_t *inbytesleft,			\
+			 char **outbuf, size_t *outbytesleft) 					\
+{ 												\
+	while (*inbytesleft >= 2 && *outbytesleft >= 1) { 					\
+		int i; 										\
+		int done = 0; 									\
+												\
+		uint16 ch = SVAL(*inbuf,0); 							\
+												\
+		for (i=0; from_idx[i].start != 0xffff; i++) {					\
+			if ((from_idx[i].start <= ch) && (from_idx[i].end >= ch)) {		\
+				((unsigned char*)(*outbuf))[0] = from_ucs2[from_idx[i].idx+ch];	\
+				(*inbytesleft) -= 2;						\
+				(*outbytesleft) -= 1;						\
+				(*inbuf)  += 2;							\
+				(*outbuf) += 1;							\
+				done = 1;							\
+				break;								\
+			}									\
+		}										\
+		if (!done) {									\
+			errno = EINVAL;								\
+			return -1;								\
+		}										\
+												\
+	}											\
+												\
+	if (*inbytesleft == 1) {								\
+		errno = EINVAL;									\
+		return -1;									\
+	}											\
+												\
+	if (*inbytesleft > 1) {									\
+		errno = E2BIG;									\
+		return -1;									\
+	}											\
+												\
+	return 0;										\
+}												\
+												\
+static size_t CHARSETNAME ## _pull(void *cd, char **inbuf, size_t *inbytesleft,				\
+			 char **outbuf, size_t *outbytesleft)					\
+{												\
+	while (*inbytesleft >= 1 && *outbytesleft >= 2) {					\
+		*(uint16*)(*outbuf) = to_ucs2[((unsigned char*)(*inbuf))[0]];			\
+		(*inbytesleft)  -= 1;								\
+		(*outbytesleft) -= 2;								\
+		(*inbuf)  += 1;									\
+		(*outbuf) += 2;									\
+	}											\
+												\
+	if (*inbytesleft > 0) {									\
+		errno = E2BIG;									\
+		return -1;									\
+	}											\
+												\
+	return 0;										\
+}												\
+												\
+struct charset_functions CHARSETNAME ## _functions = 						\
+		{#CHARSETNAME, CHARSETNAME ## _pull, CHARSETNAME ## _push};			\
+												\
+NTSTATUS charset_ ## CHARSETNAME ## _init(void)							\
+{												\
+	return smb_register_charset(& CHARSETNAME ## _functions);				\
+}												\
+
+