/* * fs/cifs/cifs_unicode.c * * Copyright (c) International Business Machines Corp., 2000,2009 * Modified by Steve French (sfrench@us.ibm.com) * * 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 2 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, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <linux/fs.h> #include <linux/slab.h> #include "cifs_unicode.h" #include "cifs_uniupr.h" #include "cifspdu.h" #include "cifsglob.h" #include "cifs_debug.h" /* * cifs_utf16_bytes - how long will a string be after conversion? * @utf16 - pointer to input string * @maxbytes - don't go past this many bytes of input string * @codepage - destination codepage * * Walk a utf16le string and return the number of bytes that the string will * be after being converted to the given charset, not including any null * termination required. Don't walk past maxbytes in the source buffer. */ int cifs_utf16_bytes(const __le16 *from, int maxbytes, const struct nls_table *codepage) { int i; int charlen, outlen = 0; int maxwords = maxbytes / 2; char tmp[NLS_MAX_CHARSET_SIZE]; __u16 ftmp; for (i = 0; i < maxwords; i++) { ftmp = get_unaligned_le16(&from[i]); if (ftmp == 0) break; charlen = codepage->uni2char(ftmp, tmp, NLS_MAX_CHARSET_SIZE); if (charlen > 0) outlen += charlen; else outlen++; } return outlen; } /* * cifs_mapchar - convert a host-endian char to proper char in codepage * @target - where converted character should be copied * @src_char - 2 byte host-endian source character * @cp - codepage to which character should be converted * @mapchar - should character be mapped according to mapchars mount option? * * This function handles the conversion of a single character. It is the * responsibility of the caller to ensure that the target buffer is large * enough to hold the result of the conversion (at least NLS_MAX_CHARSET_SIZE). */ static int cifs_mapchar(char *target, const __u16 src_char, const struct nls_table *cp, bool mapchar) { int len = 1; if (!mapchar) goto cp_convert; /* * BB: Cannot handle remapping UNI_SLASH until all the calls to * build_path_from_dentry are modified, as they use slash as * separator. */ switch (src_char) { case UNI_COLON: *target = ':'; break; case UNI_ASTERISK: *target = '*'; break; case UNI_QUESTION: *target = '?'; break; case UNI_PIPE: *target = '|'; break; case UNI_GRTRTHAN: *target = '>'; break; case UNI_LESSTHAN: *target = '<'; break; default: goto cp_convert; } out: return len; cp_convert: len = cp->uni2char(src_char, target, NLS_MAX_CHARSET_SIZE); if (len <= 0) { *target = '?'; len = 1; } goto out; } /* * cifs_from_utf16 - convert utf16le string to local charset * @to - destination buffer * @from - source buffer * @tolen - destination buffer size (in bytes) * @fromlen - source buffer size (in bytes) * @codepage - codepage to which characters should be converted * @mapchar - should characters be remapped according to the mapchars option? * * Convert a little-endian utf16le string (as sent by the server) to a string * in the provided codepage. The tolen and fromlen parameters are to ensure * that the code doesn't walk off of the end of the buffer (which is always * a danger if the alignment of the source buffer is off). The destination * string is always properly null terminated and fits in the destination * buffer. Returns the length of the destination string in bytes (including * null terminator). * * Note that some windows versions actually send multiword UTF-16 characters * instead of straight UTF16-2. The linux nls routines however aren't able to * deal with those characters properly. In the event that we get some of * those characters, they won't be translated properly. */ int cifs_from_utf16(char *to, const __le16 *from, int tolen, int fromlen, const struct nls_table *codepage, bool mapchar) { int i, charlen, safelen; int outlen = 0; int nullsize = nls_nullsize(codepage); int fromwords = fromlen / 2; char tmp[NLS_MAX_CHARSET_SIZE]; __u16 ftmp; /* * because the chars can be of varying widths, we need to take care * not to overflow the destination buffer when we get close to the * end of it. Until we get to this offset, we don't need to check * for overflow however. */ safelen = tolen - (NLS_MAX_CHARSET_SIZE + nullsize); for (i = 0; i < fromwords; i++) { ftmp = get_unaligned_le16(&from[i]); if (ftmp == 0) break; /* * check to see if converting this character might make the * conversion bleed into the null terminator */ if (outlen >= safelen) { charlen = cifs_mapchar(tmp, ftmp, codepage, mapchar); if ((outlen + charlen) > (tolen - nullsize)) break; } /* put converted char into 'to' buffer */ charlen = cifs_mapchar(&to[outlen], ftmp, codepage, mapchar); outlen += charlen; } /* properly null-terminate string */ for (i = 0; i < nullsize; i++) to[outlen++] = 0; return outlen; } /* * NAME: cifs_strtoUTF16() * * FUNCTION: Convert character string to unicode string * */ int cifs_strtoUTF16(__le16 *to, const char *from, int len, const struct nls_table *codepage) { int charlen; int i; wchar_t wchar_to; /* needed to quiet sparse */ /* special case for utf8 to handle no plane0 chars */ if (!strcmp(codepage->charset, "utf8")) { /* * convert utf8 -> utf16, we assume we have enough space * as caller should have assumed conversion does not overflow * in destination len is length in wchar_t units (16bits) */ i = utf8s_to_utf16s(from, len, UTF16_LITTLE_ENDIAN, (wchar_t *) to, len); /* if success terminate and exit */ if (i >= 0) goto success; /* * if fails fall back to UCS encoding as this * function should not return negative values * currently can fail only if source contains * invalid encoded characters */ } for (i = 0; len && *from; i++, from += charlen, len -= charlen) { charlen = codepage->char2uni(from, len, &wchar_to); if (charlen < 1) { cifs_dbg(VFS, "strtoUTF16: char2uni of 0x%x returned %d\n", *from, charlen); /* A question mark */ wchar_to = 0x003f; charlen = 1; } put_unaligned_le16(wchar_to, &to[i]); } success: put_unaligned_le16(0, &to[i]); return i; } /* * cifs_strndup_from_utf16 - copy a string from wire format to the local * codepage * @src - source string * @maxlen - don't walk past this many bytes in the source string * @is_unicode - is this a unicode string? * @codepage - destination codepage * * Take a string given by the server, convert it to the local codepage and * put it in a new buffer. Returns a pointer to the new string or NULL on * error. */ char * cifs_strndup_from_utf16(const char *src, const int maxlen, const bool is_unicode, const struct nls_table *codepage) { int len; char *dst; if (is_unicode) { len = cifs_utf16_bytes((__le16 *) src, maxlen, codepage); len += nls_nullsize(codepage); dst = kmalloc(len, GFP_KERNEL); if (!dst) return NULL; cifs_from_utf16(dst, (__le16 *) src, len, maxlen, codepage, false); } else { len = strnlen(src, maxlen); len++; dst = kmalloc(len, GFP_KERNEL); if (!dst) return NULL; strlcpy(dst, src, len); } return dst; } /* * Convert 16 bit Unicode pathname to wire format from string in current code * page. Conversion may involve remapping up the six characters that are * only legal in POSIX-like OS (if they are present in the string). Path * names are little endian 16 bit Unicode on the wire */ int cifsConvertToUTF16(__le16 *target, const char *source, int srclen, const struct nls_table *cp, int mapChars) { int i, charlen; int j = 0; char src_char; __le16 dst_char; wchar_t tmp; if (!mapChars) return cifs_strtoUTF16(target, source, PATH_MAX, cp); for (i = 0; i < srclen; j++) { src_char = source[i]; charlen = 1; switch (src_char) { case 0: goto ctoUTF16_out; case ':': dst_char = cpu_to_le16(UNI_COLON); break; case '*': dst_char = cpu_to_le16(UNI_ASTERISK); break; case '?': dst_char = cpu_to_le16(UNI_QUESTION); break; case '<': dst_char = cpu_to_le16(UNI_LESSTHAN); break; case '>': dst_char = cpu_to_le16(UNI_GRTRTHAN); break; case '|': dst_char = cpu_to_le16(UNI_PIPE); break; /* * FIXME: We can not handle remapping backslash (UNI_SLASH) * until all the calls to build_path_from_dentry are modified, * as they use backslash as separator. */ default: charlen = cp->char2uni(source + i, srclen - i, &tmp); dst_char = cpu_to_le16(tmp); /* * if no match, use question mark, which at least in * some cases serves as wild card */ if (charlen < 1) { dst_char = cpu_to_le16(0x003f); charlen = 1; } } /* * character may take more than one byte in the source string, * but will take exactly two bytes in the target string */ i += charlen; put_unaligned(dst_char, &target[j]); } ctoUTF16_out: put_unaligned(0, &target[j]); /* Null terminate target unicode string */ return j; } #ifdef CONFIG_CIFS_SMB2 /* * cifs_local_to_utf16_bytes - how long will a string be after conversion? * @from - pointer to input string * @maxbytes - don't go past this many bytes of input string * @codepage - source codepage * * Walk a string and return the number of bytes that the string will * be after being converted to the given charset, not including any null * termination required. Don't walk past maxbytes in the source buffer. */ static int cifs_local_to_utf16_bytes(const char *from, int len, const struct nls_table *codepage) { int charlen; int i; wchar_t wchar_to; for (i = 0; len && *from; i++, from += charlen, len -= charlen) { charlen = codepage->char2uni(from, len, &wchar_to); /* Failed conversion defaults to a question mark */ if (charlen < 1) charlen = 1; } return 2 * i; /* UTF16 characters are two bytes */ } /* * cifs_strndup_to_utf16 - copy a string to wire format from the local codepage * @src - source string * @maxlen - don't walk past this many bytes in the source string * @utf16_len - the length of the allocated string in bytes (including null) * @cp - source codepage * @remap - map special chars * * Take a string convert it from the local codepage to UTF16 and * put it in a new buffer. Returns a pointer to the new string or NULL on * error. */ __le16 * cifs_strndup_to_utf16(const char *src, const int maxlen, int *utf16_len, const struct nls_table *cp, int remap) { int len; __le16 *dst; len = cifs_local_to_utf16_bytes(src, maxlen, cp); len += 2; /* NULL */ dst = kmalloc(len, GFP_KERNEL); if (!dst) { *utf16_len = 0; return NULL; } cifsConvertToUTF16(dst, src, strlen(src), cp, remap); *utf16_len = len; return dst; } #endif /* CONFIG_CIFS_SMB2 */