s3-charcnv: Move convert_string() et al to lib/util/charset

This is the first step to this being the common convert_string
implementation.

Andrew Bartlett

Signed-off-by: Andrew Tridgell <tridge@samba.org>

1 files changed, 467 insertions, 0 deletions

diff --git a/lib/util/charset/convert_string.c b/lib/util/charset/convert_string.c
new file mode 100644
index 0000000000..86bb625fe1
--- /dev/null
+++ b/lib/util/charset/convert_string.c
@@ -0,0 +1,467 @@
+/*
+   Unix SMB/CIFS implementation.
+   Character set conversion Extensions
+   Copyright (C) Igor Vergeichik <iverg@mail.ru> 2001
+   Copyright (C) Andrew Tridgell 2001
+   Copyright (C) Simo Sorce 2001
+   Copyright (C) Martin Pool 2003
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+#include "includes.h"
+
+/**
+ * @file
+ *
+ * @brief Character-set conversion routines built on our iconv.
+ *
+ * @note Samba's internal character set (at least in the 3.0 series)
+ * is always the same as the one for the Unix filesystem.  It is
+ * <b>not</b> necessarily UTF-8 and may be different on machines that
+ * need i18n filenames to be compatible with Unix software.  It does
+ * have to be a superset of ASCII.  All multibyte sequences must start
+ * with a byte with the high bit set.
+ *
+ * @sa lib/iconv.c
+ */
+
+
+/**
+ * Convert string from one encoding to another, making error checking etc
+ * Slow path version - uses (slow) iconv.
+ *
+ * @param src pointer to source string (multibyte or singlebyte)
+ * @param srclen length of the source string in bytes
+ * @param dest pointer to destination string (multibyte or singlebyte)
+ * @param destlen maximal length allowed for string
+ * @param converted size is the number of bytes occupied in the destination
+ *
+ * @returns false and sets errno on fail, true on success.
+ *
+ * Ensure the srclen contains the terminating zero.
+ *
+ **/
+
+static bool convert_string_internal(charset_t from, charset_t to,
+		      void const *src, size_t srclen,
+		      void *dest, size_t destlen, size_t *converted_size)
+{
+	size_t i_len, o_len;
+	size_t retval;
+	const char* inbuf = (const char*)src;
+	char* outbuf = (char*)dest;
+	smb_iconv_t descriptor;
+	struct smb_iconv_handle *ic;
+
+	lazy_initialize_conv();
+	ic = get_iconv_handle();
+	descriptor = get_conv_handle(ic, from, to);
+
+	if (srclen == (size_t)-1) {
+		if (from == CH_UTF16LE || from == CH_UTF16BE) {
+			srclen = (strlen_w((const smb_ucs2_t *)src)+1) * 2;
+		} else {
+			srclen = strlen((const char *)src)+1;
+		}
+	}
+
+
+	if (descriptor == (smb_iconv_t)-1 || descriptor == (smb_iconv_t)0) {
+		errno = EINVAL;
+		return false;
+	}
+
+	i_len=srclen;
+	o_len=destlen;
+
+	retval = smb_iconv(descriptor, &inbuf, &i_len, &outbuf, &o_len);
+	if (retval == (size_t)-1) {
+		return false;
+	}
+	*converted_size = destlen-o_len;
+	return true;
+}
+
+/**
+ * Convert string from one encoding to another, making error checking etc
+ * Fast path version - handles ASCII first.
+ *
+ * @param src pointer to source string (multibyte or singlebyte)
+ * @param srclen length of the source string in bytes, or -1 for nul terminated.
+ * @param dest pointer to destination string (multibyte or singlebyte)
+ * @param destlen maximal length allowed for string - *NEVER* -1.
+ * @param converted size is the number of bytes occupied in the destination
+ *
+ * @returns false and sets errno on fail, true on success.
+ *
+ * Ensure the srclen contains the terminating zero.
+ *
+ * This function has been hand-tuned to provide a fast path.
+ * Don't change unless you really know what you are doing. JRA.
+ **/
+
+bool convert_string_error(charset_t from, charset_t to,
+			    void const *src, size_t srclen,
+			    void *dest, size_t destlen,
+			    size_t *converted_size)
+{
+	/*
+	 * NB. We deliberately don't do a strlen here if srclen == -1.
+	 * This is very expensive over millions of calls and is taken
+	 * care of in the slow path in convert_string_internal. JRA.
+	 */
+
+#ifdef DEVELOPER
+	SMB_ASSERT(destlen != (size_t)-1);
+#endif
+
+	if (srclen == 0) {
+		*converted_size = 0;
+		return true;
+	}
+
+	if (from != CH_UTF16LE && from != CH_UTF16BE && to != CH_UTF16LE && to != CH_UTF16BE) {
+		const unsigned char *p = (const unsigned char *)src;
+		unsigned char *q = (unsigned char *)dest;
+		size_t slen = srclen;
+		size_t dlen = destlen;
+		unsigned char lastp = '\0';
+		size_t retval = 0;
+
+		/* If all characters are ascii, fast path here. */
+		while (slen && dlen) {
+			if ((lastp = *p) <= 0x7f) {
+				*q++ = *p++;
+				if (slen != (size_t)-1) {
+					slen--;
+				}
+				dlen--;
+				retval++;
+				if (!lastp)
+					break;
+			} else {
+#ifdef BROKEN_UNICODE_COMPOSE_CHARACTERS
+				goto general_case;
+#else
+				bool ret = convert_string_internal(from, to, p, slen, q, dlen, converted_size);
+				*converted_size += retval;
+				return ret;
+#endif
+			}
+		}
+
+		*converted_size = retval;
+
+		if (!dlen) {
+			/* Even if we fast path we should note if we ran out of room. */
+			if (((slen != (size_t)-1) && slen) ||
+					((slen == (size_t)-1) && lastp)) {
+				errno = E2BIG;
+				return false;
+			}
+		}
+		return true;
+	} else if (from == CH_UTF16LE && to != CH_UTF16LE) {
+		const unsigned char *p = (const unsigned char *)src;
+		unsigned char *q = (unsigned char *)dest;
+		size_t retval = 0;
+		size_t slen = srclen;
+		size_t dlen = destlen;
+		unsigned char lastp = '\0';
+
+		/* If all characters are ascii, fast path here. */
+		while (((slen == (size_t)-1) || (slen >= 2)) && dlen) {
+			if (((lastp = *p) <= 0x7f) && (p[1] == 0)) {
+				*q++ = *p;
+				if (slen != (size_t)-1) {
+					slen -= 2;
+				}
+				p += 2;
+				dlen--;
+				retval++;
+				if (!lastp)
+					break;
+			} else {
+#ifdef BROKEN_UNICODE_COMPOSE_CHARACTERS
+				goto general_case;
+#else
+				bool ret = convert_string_internal(from, to, p, slen, q, dlen, converted_size);
+				*converted_size += retval;
+				return ret;
+#endif
+			}
+		}
+
+		*converted_size = retval;
+
+		if (!dlen) {
+			/* Even if we fast path we should note if we ran out of room. */
+			if (((slen != (size_t)-1) && slen) ||
+					((slen == (size_t)-1) && lastp)) {
+				errno = E2BIG;
+				return false;
+			}
+		}
+		return true;
+	} else if (from != CH_UTF16LE && from != CH_UTF16BE && to == CH_UTF16LE) {
+		const unsigned char *p = (const unsigned char *)src;
+		unsigned char *q = (unsigned char *)dest;
+		size_t retval = 0;
+		size_t slen = srclen;
+		size_t dlen = destlen;
+		unsigned char lastp = '\0';
+
+		/* If all characters are ascii, fast path here. */
+		while (slen && (dlen >= 2)) {
+			if ((lastp = *p) <= 0x7F) {
+				*q++ = *p++;
+				*q++ = '\0';
+				if (slen != (size_t)-1) {
+					slen--;
+				}
+				dlen -= 2;
+				retval += 2;
+				if (!lastp)
+					break;
+			} else {
+#ifdef BROKEN_UNICODE_COMPOSE_CHARACTERS
+				goto general_case;
+#else
+				bool ret = convert_string_internal(from, to, p, slen, q, dlen, converted_size);
+				*converted_size += retval;
+				return ret;
+#endif
+			}
+		}
+
+		*converted_size = retval;
+
+		if (!dlen) {
+			/* Even if we fast path we should note if we ran out of room. */
+			if (((slen != (size_t)-1) && slen) ||
+					((slen == (size_t)-1) && lastp)) {
+				errno = E2BIG;
+				return false;
+			}
+		}
+		return true;
+	}
+
+#ifdef BROKEN_UNICODE_COMPOSE_CHARACTERS
+  general_case:
+#endif
+	return convert_string_internal(from, to, src, srclen, dest, destlen, converted_size);
+}
+
+bool convert_string(charset_t from, charset_t to,
+		      void const *src, size_t srclen,
+		      void *dest, size_t destlen,
+		      size_t *converted_size)
+{
+	bool ret = convert_string_error(from, to, src, srclen, dest, destlen, converted_size);
+
+	if(ret==false) {
+		const char *reason="unknown error";
+		switch(errno) {
+			case EINVAL:
+				reason="Incomplete multibyte sequence";
+				DEBUG(3,("convert_string_internal: Conversion error: %s(%s)\n",
+					 reason, (const char *)src));
+				break;
+			case E2BIG:
+			{
+				struct smb_iconv_handle *ic;
+				lazy_initialize_conv();
+				ic = get_iconv_handle();
+
+				reason="No more room";
+				if (from == CH_UNIX) {
+					DEBUG(3,("E2BIG: convert_string(%s,%s): srclen=%u destlen=%u - '%s'\n",
+						 charset_name(ic, from), charset_name(ic, to),
+						 (unsigned int)srclen, (unsigned int)destlen, (const char *)src));
+				} else {
+					DEBUG(3,("E2BIG: convert_string(%s,%s): srclen=%u destlen=%u\n",
+						 charset_name(ic, from), charset_name(ic, to),
+						 (unsigned int)srclen, (unsigned int)destlen));
+				}
+				break;
+			}
+			case EILSEQ:
+				reason="Illegal multibyte sequence";
+				DEBUG(3,("convert_string_internal: Conversion error: %s(%s)\n",
+					 reason, (const char *)src));
+				break;
+			default:
+				DEBUG(0,("convert_string_internal: Conversion error: %s(%s)\n",
+					 reason, (const char *)src));
+				break;
+		}
+		/* smb_panic(reason); */
+	}
+	return ret;
+}
+
+
+/**
+ * Convert between character sets, allocating a new buffer using talloc for the result.
+ *
+ * @param srclen length of source buffer.
+ * @param dest always set at least to NULL
+ * @parm converted_size set to the number of bytes occupied by the string in
+ * the destination on success.
+ * @note -1 is not accepted for srclen.
+ *
+ * @return true if new buffer was correctly allocated, and string was
+ * converted.
+ *
+ * Ensure the srclen contains the terminating zero.
+ *
+ * I hate the goto's in this function. It's embarressing.....
+ * There has to be a cleaner way to do this. JRA.
+ */
+bool convert_string_talloc(TALLOC_CTX *ctx, charset_t from, charset_t to,
+			   void const *src, size_t srclen, void *dst,
+			   size_t *converted_size)
+
+{
+	size_t i_len, o_len, destlen = (srclen * 3) / 2;
+	size_t retval;
+	const char *inbuf = (const char *)src;
+	char *outbuf = NULL, *ob = NULL;
+	smb_iconv_t descriptor;
+	void **dest = (void **)dst;
+	struct smb_iconv_handle *ic;
+
+	*dest = NULL;
+
+	if (src == NULL || srclen == (size_t)-1) {
+		errno = EINVAL;
+		return false;
+	}
+
+	if (srclen == 0) {
+		/* We really should treat this as an error, but
+		   there are too many callers that need this to
+		   return a NULL terminated string in the correct
+		   character set. */
+		if (to == CH_UTF16LE|| to == CH_UTF16BE || to == CH_UTF16MUNGED) {
+			destlen = 2;
+		} else {
+			destlen = 1;
+		}
+		ob = talloc_zero_array(ctx, char, destlen);
+		if (ob == NULL) {
+			errno = ENOMEM;
+			return false;
+		}
+		*converted_size = destlen;
+		*dest = ob;
+		return true;
+	}
+
+	lazy_initialize_conv();
+	ic = get_iconv_handle();
+	descriptor = get_conv_handle(ic, from, to);
+
+	if (descriptor == (smb_iconv_t)-1 || descriptor == (smb_iconv_t)0) {
+		DEBUG(0,("convert_string_talloc: Conversion not supported.\n"));
+		errno = EOPNOTSUPP;
+		return false;
+	}
+
+  convert:
+
+	/* +2 is for ucs2 null termination. */
+	if ((destlen*2)+2 < destlen) {
+		/* wrapped ! abort. */
+		DEBUG(0, ("convert_string_talloc: destlen wrapped !\n"));
+		TALLOC_FREE(outbuf);
+		errno = EOPNOTSUPP;
+		return false;
+	} else {
+		destlen = destlen * 2;
+	}
+
+	/* +2 is for ucs2 null termination. */
+	ob = (char *)TALLOC_REALLOC(ctx, ob, destlen + 2);
+
+	if (!ob) {
+		DEBUG(0, ("convert_string_talloc: realloc failed!\n"));
+		errno = ENOMEM;
+		return false;
+	}
+	outbuf = ob;
+	i_len = srclen;
+	o_len = destlen;
+
+	retval = smb_iconv(descriptor,
+			   &inbuf, &i_len,
+			   &outbuf, &o_len);
+	if(retval == (size_t)-1) 		{
+		const char *reason="unknown error";
+		switch(errno) {
+			case EINVAL:
+				reason="Incomplete multibyte sequence";
+				DEBUG(3,("convert_string_talloc: Conversion error: %s(%s)\n",reason,inbuf));
+				break;
+			case E2BIG:
+				goto convert;
+			case EILSEQ:
+				reason="Illegal multibyte sequence";
+				DEBUG(3,("convert_string_talloc: Conversion error: %s(%s)\n",reason,inbuf));
+				break;
+		}
+		DEBUG(0,("Conversion error: %s(%s)\n",reason,inbuf));
+		/* smb_panic(reason); */
+		TALLOC_FREE(ob);
+		return false;
+	}
+
+	destlen = destlen - o_len;
+	/* Don't shrink unless we're reclaiming a lot of
+	 * space. This is in the hot codepath and these
+	 * reallocs *cost*. JRA.
+	 */
+	if (o_len > 1024) {
+		/* We're shrinking here so we know the +2 is safe from wrap. */
+		ob = (char *)TALLOC_REALLOC(ctx,ob,destlen + 2);
+	}
+
+	if (destlen && !ob) {
+		DEBUG(0, ("convert_string_talloc: out of memory!\n"));
+		errno = ENOMEM;
+		return false;
+	}
+
+	*dest = ob;
+
+	/* Must ucs2 null terminate in the extra space we allocated. */
+	ob[destlen] = '\0';
+	ob[destlen+1] = '\0';
+
+	/* Ensure we can never return a *converted_size of zero. */
+	if (destlen == 0) {
+		/* As we're now returning false on a bad smb_iconv call,
+		   this should never happen. But be safe anyway. */
+		if (to == CH_UTF16LE|| to == CH_UTF16BE || to == CH_UTF16MUNGED) {
+			destlen = 2;
+		} else {
+			destlen = 1;
+		}
+	}
+
+	*converted_size = destlen;
+	return true;
+}