ObjFW  Diff

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <ctype.h>

#include <sys/stat.h>
#ifdef HAVE_MADVISE
# include <sys/mman.h>
#else
# define madvise(addr, len, advise)
#endif

#import "OFString.h"
#import "OFArray.h"
#import "OFDictionary.h"
#import "OFFile.h"
#import "OFURL.h"
#import "OFHTTPRequest.h"

int
of_string_check_utf8(const char *cString, size_t cStringLength, size_t *length)
{
	size_t i, tmpLength = cStringLength;
	int UTF8 = 0;

	madvise((void*)cString, cStringLength, MADV_SEQUENTIAL);

	for (i = 0; i < cStringLength; i++) {
		/* No sign of UTF-8 here */
		if (OF_LIKELY(!(cString[i] & 0x80)))
			continue;

		UTF8 = 1;

		/* We're missing a start byte here */
		if (OF_UNLIKELY(!(cString[i] & 0x40))) {
			madvise((void*)cString, cStringLength, MADV_NORMAL);
			return -1;
		}

		/* 2 byte sequences for code points 0 - 127 are forbidden */
		if (OF_UNLIKELY((cString[i] & 0x7E) == 0x40)) {
			madvise((void*)cString, cStringLength, MADV_NORMAL);
			return -1;
		}

		/* We have at minimum a 2 byte character -> check next byte */
		if (OF_UNLIKELY(cStringLength <= i + 1 ||
		    (cString[i + 1] & 0xC0) != 0x80)) {
			madvise((void*)cString, cStringLength, MADV_NORMAL);
			return -1;
		}

		/* Check if we have at minimum a 3 byte character */
		if (OF_LIKELY(!(cString[i] & 0x20))) {
			i++;
			tmpLength--;
			continue;
		}

		/* We have at minimum a 3 byte char -> check second next byte */
		if (OF_UNLIKELY(cStringLength <= i + 2 ||
		    (cString[i + 2] & 0xC0) != 0x80)) {
			madvise((void*)cString, cStringLength, MADV_NORMAL);
			return -1;
		}

		/* Check if we have a 4 byte character */
		if (OF_LIKELY(!(cString[i] & 0x10))) {
			i += 2;
			tmpLength -= 2;
			continue;
		}

		/* We have a 4 byte character -> check third next byte */
		if (OF_UNLIKELY(cStringLength <= i + 3 ||
		    (cString[i + 3] & 0xC0) != 0x80)) {
			madvise((void*)cString, cStringLength, MADV_NORMAL);
			return -1;
		}

		/*
		 * Just in case, check if there's a 5th character, which is
		 * forbidden by UTF-8
		 */
		if (OF_UNLIKELY(cString[i] & 0x08)) {
			madvise((void*)cString, cStringLength, MADV_NORMAL);
			return -1;
		}

		i += 3;
		tmpLength -= 3;
	}

	madvise((void*)cString, cStringLength, MADV_NORMAL);

	if (length != NULL)
		*length = tmpLength;

	return UTF8;
}

size_t