From 74675a58507e769beee7d949dbed788af3c4139d Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Thu, 30 Apr 2009 10:08:18 -0400 Subject: [PATCH] NLS: update handling of Unicode This patch (as1239) updates the kernel's treatment of Unicode. The character-set conversion routines are well behind the current state of the Unicode specification: They don't recognize the existence of code points beyond plane 0 or of surrogate pairs in the UTF-16 encoding. The old wchar_t 16-bit type is retained because it's still used in lots of places. This shouldn't cause any new problems; if a conversion now results in an invalid 16-bit code then before it must have yielded an undefined code. Difficult-to-read names like "utf_mbstowcs" are replaced with more transparent names like "utf8s_to_utf16s" and the ordering of the parameters is rationalized (buffer lengths come immediate after the pointers they refer to, and the inputs precede the outputs). Fortunately the low-level conversion routines are used in only a few places; the interfaces to the higher-level uni2char and char2uni methods have been left unchanged. Signed-off-by: Alan Stern Acked-by: Clemens Ladisch Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/message.c | 10 +-- fs/befs/linuxvfs.c | 20 ++--- fs/fat/dir.c | 29 +++---- fs/fat/namei_vfat.c | 4 +- fs/isofs/joliet.c | 36 +------- fs/ncpfs/ncplib_kernel.c | 8 +- fs/nls/nls_base.c | 164 ++++++++++++++++++++++++------------- fs/nls/nls_utf8.c | 13 ++- include/linux/nls.h | 35 ++++++-- 9 files changed, 182 insertions(+), 137 deletions(-) diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index e98f928c08ea..9bd26dec7599 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -780,14 +780,13 @@ int usb_string(struct usb_device *dev, int index, char *buf, size_t size) { unsigned char *tbuf; int err; - unsigned int u; if (dev->state == USB_STATE_SUSPENDED) return -EHOSTUNREACH; if (size <= 0 || !buf || !index) return -EINVAL; buf[0] = 0; - tbuf = kmalloc(256 + 2, GFP_NOIO); + tbuf = kmalloc(256, GFP_NOIO); if (!tbuf) return -ENOMEM; @@ -814,12 +813,9 @@ int usb_string(struct usb_device *dev, int index, char *buf, size_t size) if (err < 0) goto errout; - for (u = 2; u < err; u += 2) - le16_to_cpus((u16 *)&tbuf[u]); - tbuf[u] = 0; - tbuf[u + 1] = 0; size--; /* leave room for trailing NULL char in output buffer */ - err = utf8_wcstombs(buf, (u16 *)&tbuf[2], size); + err = utf16s_to_utf8s((wchar_t *) &tbuf[2], (err - 2) / 2, + UTF16_LITTLE_ENDIAN, buf, size); buf[err] = 0; if (tbuf[1] != USB_DT_STRING) diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c index 9367b6297d84..89cd2deeb4af 100644 --- a/fs/befs/linuxvfs.c +++ b/fs/befs/linuxvfs.c @@ -513,7 +513,7 @@ befs_utf2nls(struct super_block *sb, const char *in, { struct nls_table *nls = BEFS_SB(sb)->nls; int i, o; - wchar_t uni; + unicode_t uni; int unilen, utflen; char *result; /* The utf8->nls conversion won't make the final nls string bigger @@ -539,16 +539,16 @@ befs_utf2nls(struct super_block *sb, const char *in, for (i = o = 0; i < in_len; i += utflen, o += unilen) { /* convert from UTF-8 to Unicode */ - utflen = utf8_mbtowc(&uni, &in[i], in_len - i); - if (utflen < 0) { + utflen = utf8_to_utf32(&in[i], in_len - i, &uni); + if (utflen < 0) goto conv_err; - } /* convert from Unicode to nls */ + if (uni > MAX_WCHAR_T) + goto conv_err; unilen = nls->uni2char(uni, &result[o], in_len - o); - if (unilen < 0) { + if (unilen < 0) goto conv_err; - } } result[o] = '\0'; *out_len = o; @@ -619,15 +619,13 @@ befs_nls2utf(struct super_block *sb, const char *in, /* convert from nls to unicode */ unilen = nls->char2uni(&in[i], in_len - i, &uni); - if (unilen < 0) { + if (unilen < 0) goto conv_err; - } /* convert from unicode to UTF-8 */ - utflen = utf8_wctomb(&result[o], uni, 3); - if (utflen <= 0) { + utflen = utf32_to_utf8(uni, &result[o], 3); + if (utflen <= 0) goto conv_err; - } } result[o] = '\0'; diff --git a/fs/fat/dir.c b/fs/fat/dir.c index f3500294eec5..7c14c8cbbaba 100644 --- a/fs/fat/dir.c +++ b/fs/fat/dir.c @@ -22,6 +22,19 @@ #include #include "fat.h" +/* + * Maximum buffer size of short name. + * [(MSDOS_NAME + '.') * max one char + nul] + * For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul] + */ +#define FAT_MAX_SHORT_SIZE ((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1) +/* + * Maximum buffer size of unicode chars from slots. + * [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)] + */ +#define FAT_MAX_UNI_CHARS ((MSDOS_SLOTS - 1) * 13 + 1) +#define FAT_MAX_UNI_SIZE (FAT_MAX_UNI_CHARS * sizeof(wchar_t)) + static inline loff_t fat_make_i_pos(struct super_block *sb, struct buffer_head *bh, struct msdos_dir_entry *de) @@ -171,7 +184,8 @@ static inline int fat_uni_to_x8(struct msdos_sb_info *sbi, const wchar_t *uni, unsigned char *buf, int size) { if (sbi->options.utf8) - return utf8_wcstombs(buf, uni, size); + return utf16s_to_utf8s(uni, FAT_MAX_UNI_CHARS, + UTF16_HOST_ENDIAN, buf, size); else return uni16_to_x8(buf, uni, size, sbi->options.unicode_xlate, sbi->nls_io); @@ -324,19 +338,6 @@ parse_long: return 0; } -/* - * Maximum buffer size of short name. - * [(MSDOS_NAME + '.') * max one char + nul] - * For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul] - */ -#define FAT_MAX_SHORT_SIZE ((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1) -/* - * Maximum buffer size of unicode chars from slots. - * [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)] - */ -#define FAT_MAX_UNI_CHARS ((MSDOS_SLOTS - 1) * 13 + 1) -#define FAT_MAX_UNI_SIZE (FAT_MAX_UNI_CHARS * sizeof(wchar_t)) - /* * Return values: negative -> error, 0 -> not found, positive -> found, * value is the total amount of slots, including the shortname entry. diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c index b50ecbe97f83..f92ad9995356 100644 --- a/fs/fat/namei_vfat.c +++ b/fs/fat/namei_vfat.c @@ -502,11 +502,11 @@ xlate_to_uni(const unsigned char *name, int len, unsigned char *outname, if (utf8) { int name_len = strlen(name); - *outlen = utf8_mbstowcs((wchar_t *)outname, name, PATH_MAX); + *outlen = utf8s_to_utf16s(name, PATH_MAX, (wchar_t *) outname); /* * We stripped '.'s before and set len appropriately, - * but utf8_mbstowcs doesn't care about len + * but utf8s_to_utf16s doesn't care about len */ *outlen -= (name_len - len); diff --git a/fs/isofs/joliet.c b/fs/isofs/joliet.c index 92c14b850e9c..a048de81c093 100644 --- a/fs/isofs/joliet.c +++ b/fs/isofs/joliet.c @@ -37,37 +37,6 @@ uni16_to_x8(unsigned char *ascii, __be16 *uni, int len, struct nls_table *nls) return (op - ascii); } -/* Convert big endian wide character string to utf8 */ -static int -wcsntombs_be(__u8 *s, const __u8 *pwcs, int inlen, int maxlen) -{ - const __u8 *ip; - __u8 *op; - int size; - __u16 c; - - op = s; - ip = pwcs; - while ((*ip || ip[1]) && (maxlen > 0) && (inlen > 0)) { - c = (*ip << 8) | ip[1]; - if (c > 0x7f) { - size = utf8_wctomb(op, c, maxlen); - if (size == -1) { - /* Ignore character and move on */ - maxlen--; - } else { - op += size; - maxlen -= size; - } - } else { - *op++ = (__u8) c; - } - ip += 2; - inlen--; - } - return (op - s); -} - int get_joliet_filename(struct iso_directory_record * de, unsigned char *outname, struct inode * inode) { @@ -79,8 +48,9 @@ get_joliet_filename(struct iso_directory_record * de, unsigned char *outname, st nls = ISOFS_SB(inode->i_sb)->s_nls_iocharset; if (utf8) { - len = wcsntombs_be(outname, de->name, - de->name_len[0] >> 1, PAGE_SIZE); + len = utf16s_to_utf8s((const wchar_t *) de->name, + de->name_len[0] >> 1, UTF16_BIG_ENDIAN, + outname, PAGE_SIZE); } else { len = uni16_to_x8(outname, (__be16 *) de->name, de->name_len[0] >> 1, nls); diff --git a/fs/ncpfs/ncplib_kernel.c b/fs/ncpfs/ncplib_kernel.c index 97645f112114..0ec6237a5970 100644 --- a/fs/ncpfs/ncplib_kernel.c +++ b/fs/ncpfs/ncplib_kernel.c @@ -1113,11 +1113,13 @@ ncp__io2vol(struct ncp_server *server, unsigned char *vname, unsigned int *vlen, if (NCP_IS_FLAG(server, NCP_FLAG_UTF8)) { int k; + unicode_t u; - k = utf8_mbtowc(&ec, iname, iname_end - iname); - if (k < 0) + k = utf8_to_utf32(iname, iname_end - iname, &u); + if (k < 0 || u > MAX_WCHAR_T) return -EINVAL; iname += k; + ec = u; } else { if (*iname == NCP_ESC) { int k; @@ -1214,7 +1216,7 @@ ncp__vol2io(struct ncp_server *server, unsigned char *iname, unsigned int *ilen, if (NCP_IS_FLAG(server, NCP_FLAG_UTF8)) { int k; - k = utf8_wctomb(iname, ec, iname_end - iname); + k = utf32_to_utf8(ec, iname, iname_end - iname); if (k < 0) { err = -ENAMETOOLONG; goto quit; diff --git a/fs/nls/nls_base.c b/fs/nls/nls_base.c index 750abf211e26..477d37d83b31 100644 --- a/fs/nls/nls_base.c +++ b/fs/nls/nls_base.c @@ -15,6 +15,7 @@ #include #include #include +#include static struct nls_table default_table; static struct nls_table *tables = &default_table; @@ -43,10 +44,17 @@ static const struct utf8_table utf8_table[] = {0, /* end of table */} }; -int -utf8_mbtowc(wchar_t *p, const __u8 *s, int n) +#define UNICODE_MAX 0x0010ffff +#define PLANE_SIZE 0x00010000 + +#define SURROGATE_MASK 0xfffff800 +#define SURROGATE_PAIR 0x0000d800 +#define SURROGATE_LOW 0x00000400 +#define SURROGATE_BITS 0x000003ff + +int utf8_to_utf32(const u8 *s, int len, unicode_t *pu) { - long l; + unsigned long l; int c0, c, nc; const struct utf8_table *t; @@ -57,12 +65,13 @@ utf8_mbtowc(wchar_t *p, const __u8 *s, int n) nc++; if ((c0 & t->cmask) == t->cval) { l &= t->lmask; - if (l < t->lval) + if (l < t->lval || l > UNICODE_MAX || + (l & SURROGATE_MASK) == SURROGATE_PAIR) return -1; - *p = l; + *pu = (unicode_t) l; return nc; } - if (n <= nc) + if (len <= nc) return -1; s++; c = (*s ^ 0x80) & 0xFF; @@ -72,76 +81,119 @@ utf8_mbtowc(wchar_t *p, const __u8 *s, int n) } return -1; } +EXPORT_SYMBOL(utf8_to_utf32); -int -utf8_mbstowcs(wchar_t *pwcs, const __u8 *s, int n) +int utf32_to_utf8(unicode_t u, u8 *s, int maxlen) { - __u16 *op; - const __u8 *ip; - int size; - - op = pwcs; - ip = s; - while (*ip && n > 0) { - if (*ip & 0x80) { - size = utf8_mbtowc(op, ip, n); - if (size == -1) { - /* Ignore character and move on */ - ip++; - n--; - } else { - op++; - ip += size; - n -= size; - } - } else { - *op++ = *ip++; - n--; - } - } - return (op - pwcs); -} - -int -utf8_wctomb(__u8 *s, wchar_t wc, int maxlen) -{ - long l; + unsigned long l; int c, nc; const struct utf8_table *t; - + if (!s) return 0; - - l = wc; + + l = u; + if (l > UNICODE_MAX || (l & SURROGATE_MASK) == SURROGATE_PAIR) + return -1; + nc = 0; for (t = utf8_table; t->cmask && maxlen; t++, maxlen--) { nc++; if (l <= t->lmask) { c = t->shift; - *s = t->cval | (l >> c); + *s = (u8) (t->cval | (l >> c)); while (c > 0) { c -= 6; s++; - *s = 0x80 | ((l >> c) & 0x3F); + *s = (u8) (0x80 | ((l >> c) & 0x3F)); } return nc; } } return -1; } +EXPORT_SYMBOL(utf32_to_utf8); -int -utf8_wcstombs(__u8 *s, const wchar_t *pwcs, int maxlen) +int utf8s_to_utf16s(const u8 *s, int len, wchar_t *pwcs) { - const __u16 *ip; - __u8 *op; + u16 *op; int size; + unicode_t u; + + op = pwcs; + while (*s && len > 0) { + if (*s & 0x80) { + size = utf8_to_utf32(s, len, &u); + if (size < 0) { + /* Ignore character and move on */ + size = 1; + } else if (u >= PLANE_SIZE) { + u -= PLANE_SIZE; + *op++ = (wchar_t) (SURROGATE_PAIR | + ((u >> 10) & SURROGATE_BITS)); + *op++ = (wchar_t) (SURROGATE_PAIR | + SURROGATE_LOW | + (u & SURROGATE_BITS)); + } else { + *op++ = (wchar_t) u; + } + s += size; + len -= size; + } else { + *op++ = *s++; + len--; + } + } + return op - pwcs; +} +EXPORT_SYMBOL(utf8s_to_utf16s); + +static inline unsigned long get_utf16(unsigned c, enum utf16_endian endian) +{ + switch (endian) { + default: + return c; + case UTF16_LITTLE_ENDIAN: + return __le16_to_cpu(c); + case UTF16_BIG_ENDIAN: + return __be16_to_cpu(c); + } +} + +int utf16s_to_utf8s(const wchar_t *pwcs, int len, enum utf16_endian endian, + u8 *s, int maxlen) +{ + u8 *op; + int size; + unsigned long u, v; op = s; - ip = pwcs; - while (*ip && maxlen > 0) { - if (*ip > 0x7f) { - size = utf8_wctomb(op, *ip, maxlen); + while (len > 0 && maxlen > 0) { + u = get_utf16(*pwcs, endian); + if (!u) + break; + pwcs++; + len--; + if (u > 0x7f) { + if ((u & SURROGATE_MASK) == SURROGATE_PAIR) { + if (u & SURROGATE_LOW) { + /* Ignore character and move on */ + continue; + } + if (len <= 0) + break; + v = get_utf16(*pwcs, endian); + if ((v & SURROGATE_MASK) != SURROGATE_PAIR || + !(v & SURROGATE_LOW)) { + /* Ignore character and move on */ + continue; + } + u = PLANE_SIZE + ((u & SURROGATE_BITS) << 10) + + (v & SURROGATE_BITS); + pwcs++; + len--; + } + size = utf32_to_utf8(u, op, maxlen); if (size == -1) { /* Ignore character and move on */ } else { @@ -149,13 +201,13 @@ utf8_wcstombs(__u8 *s, const wchar_t *pwcs, int maxlen) maxlen -= size; } } else { - *op++ = (__u8) *ip; + *op++ = (u8) u; maxlen--; } - ip++; } - return (op - s); + return op - s; } +EXPORT_SYMBOL(utf16s_to_utf8s); int register_nls(struct nls_table * nls) { @@ -467,9 +519,5 @@ EXPORT_SYMBOL(unregister_nls); EXPORT_SYMBOL(unload_nls); EXPORT_SYMBOL(load_nls); EXPORT_SYMBOL(load_nls_default); -EXPORT_SYMBOL(utf8_mbtowc); -EXPORT_SYMBOL(utf8_mbstowcs); -EXPORT_SYMBOL(utf8_wctomb); -EXPORT_SYMBOL(utf8_wcstombs); MODULE_LICENSE("Dual BSD/GPL"); diff --git a/fs/nls/nls_utf8.c b/fs/nls/nls_utf8.c index aa2c42fdd977..0d60a44acacd 100644 --- a/fs/nls/nls_utf8.c +++ b/fs/nls/nls_utf8.c @@ -15,7 +15,11 @@ static int uni2char(wchar_t uni, unsigned char *out, int boundlen) { int n; - if ( (n = utf8_wctomb(out, uni, boundlen)) == -1) { + if (boundlen <= 0) + return -ENAMETOOLONG; + + n = utf32_to_utf8(uni, out, boundlen); + if (n < 0) { *out = '?'; return -EINVAL; } @@ -25,11 +29,14 @@ static int uni2char(wchar_t uni, unsigned char *out, int boundlen) static int char2uni(const unsigned char *rawstring, int boundlen, wchar_t *uni) { int n; + unicode_t u; - if ( (n = utf8_mbtowc(uni, rawstring, boundlen)) == -1) { + n = utf8_to_utf32(rawstring, boundlen, &u); + if (n < 0 || u > MAX_WCHAR_T) { *uni = 0x003f; /* ? */ - n = -EINVAL; + return -EINVAL; } + *uni = (wchar_t) u; return n; } diff --git a/include/linux/nls.h b/include/linux/nls.h index 52b1a76c1b43..d47beef08dfd 100644 --- a/include/linux/nls.h +++ b/include/linux/nls.h @@ -3,8 +3,23 @@ #include -/* unicode character */ -typedef __u16 wchar_t; +/* Unicode has changed over the years. Unicode code points no longer + * fit into 16 bits; as of Unicode 5 valid code points range from 0 + * to 0x10ffff (17 planes, where each plane holds 65536 code points). + * + * The original decision to represent Unicode characters as 16-bit + * wchar_t values is now outdated. But plane 0 still includes the + * most commonly used characters, so we will retain it. The newer + * 32-bit unicode_t type can be used when it is necessary to + * represent the full Unicode character set. + */ + +/* Plane-0 Unicode character */ +typedef u16 wchar_t; +#define MAX_WCHAR_T 0xffff + +/* Arbitrary Unicode character */ +typedef u32 unicode_t; struct nls_table { const char *charset; @@ -21,6 +36,13 @@ struct nls_table { /* this value hold the maximum octet of charset */ #define NLS_MAX_CHARSET_SIZE 6 /* for UTF-8 */ +/* Byte order for UTF-16 strings */ +enum utf16_endian { + UTF16_HOST_ENDIAN, + UTF16_LITTLE_ENDIAN, + UTF16_BIG_ENDIAN +}; + /* nls.c */ extern int register_nls(struct nls_table *); extern int unregister_nls(struct nls_table *); @@ -28,10 +50,11 @@ extern struct nls_table *load_nls(char *); extern void unload_nls(struct nls_table *); extern struct nls_table *load_nls_default(void); -extern int utf8_mbtowc(wchar_t *, const __u8 *, int); -extern int utf8_mbstowcs(wchar_t *, const __u8 *, int); -extern int utf8_wctomb(__u8 *, wchar_t, int); -extern int utf8_wcstombs(__u8 *, const wchar_t *, int); +extern int utf8_to_utf32(const u8 *s, int len, unicode_t *pu); +extern int utf32_to_utf8(unicode_t u, u8 *s, int maxlen); +extern int utf8s_to_utf16s(const u8 *s, int len, wchar_t *pwcs); +extern int utf16s_to_utf8s(const wchar_t *pwcs, int len, + enum utf16_endian endian, u8 *s, int maxlen); static inline unsigned char nls_tolower(struct nls_table *t, unsigned char c) { -- 2.30.2