From 0720a06a7518c9d0c0125bd5d1f3b6264c55c3dd Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Thu, 17 Nov 2011 16:42:19 -0500 Subject: [PATCH 1/1] NLS: improve UTF8 -> UTF16 string conversion routine The utf8s_to_utf16s conversion routine needs to be improved. Unlike its utf16s_to_utf8s sibling, it doesn't accept arguments specifying the maximum length of the output buffer or the endianness of its 16-bit output. This patch (as1501) adds the two missing arguments, and adjusts the only two places in the kernel where the function is called. A follow-on patch will add a third caller that does utilize the new capabilities. The two conversion routines are still annoyingly inconsistent in the way they handle invalid byte combinations. But that's a subject for a different patch. Signed-off-by: Alan Stern CC: Clemens Ladisch Signed-off-by: Greg Kroah-Hartman --- drivers/hv/hv_kvp.c | 10 ++++++---- fs/fat/namei_vfat.c | 3 ++- fs/nls/nls_base.c | 43 +++++++++++++++++++++++++++++++++---------- include/linux/nls.h | 5 +++-- 4 files changed, 44 insertions(+), 17 deletions(-) diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c index 89f52440fcf4..0e8343f585bb 100644 --- a/drivers/hv/hv_kvp.c +++ b/drivers/hv/hv_kvp.c @@ -212,11 +212,13 @@ kvp_respond_to_host(char *key, char *value, int error) * The windows host expects the key/value pair to be encoded * in utf16. */ - keylen = utf8s_to_utf16s(key_name, strlen(key_name), - (wchar_t *)kvp_data->data.key); + keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN, + (wchar_t *) kvp_data->data.key, + HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2); kvp_data->data.key_size = 2*(keylen + 1); /* utf16 encoding */ - valuelen = utf8s_to_utf16s(value, strlen(value), - (wchar_t *)kvp_data->data.value); + valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN, + (wchar_t *) kvp_data->data.value, + HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2); kvp_data->data.value_size = 2*(valuelen + 1); /* utf16 encoding */ kvp_data->data.value_type = REG_SZ; /* all our values are strings */ diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c index a87a65663c25..c25cf151b84b 100644 --- a/fs/fat/namei_vfat.c +++ b/fs/fat/namei_vfat.c @@ -512,7 +512,8 @@ xlate_to_uni(const unsigned char *name, int len, unsigned char *outname, int charlen; if (utf8) { - *outlen = utf8s_to_utf16s(name, len, (wchar_t *)outname); + *outlen = utf8s_to_utf16s(name, len, UTF16_HOST_ENDIAN, + (wchar_t *) outname, FAT_LFN_LEN + 2); if (*outlen < 0) return *outlen; else if (*outlen > FAT_LFN_LEN) diff --git a/fs/nls/nls_base.c b/fs/nls/nls_base.c index 44a88a9fa2c8..0eb059ec6f28 100644 --- a/fs/nls/nls_base.c +++ b/fs/nls/nls_base.c @@ -114,34 +114,57 @@ int utf32_to_utf8(unicode_t u, u8 *s, int maxlen) } EXPORT_SYMBOL(utf32_to_utf8); -int utf8s_to_utf16s(const u8 *s, int len, wchar_t *pwcs) +static inline void put_utf16(wchar_t *s, unsigned c, enum utf16_endian endian) +{ + switch (endian) { + default: + *s = (wchar_t) c; + break; + case UTF16_LITTLE_ENDIAN: + *s = __cpu_to_le16(c); + break; + case UTF16_BIG_ENDIAN: + *s = __cpu_to_be16(c); + break; + } +} + +int utf8s_to_utf16s(const u8 *s, int len, enum utf16_endian endian, + wchar_t *pwcs, int maxlen) { u16 *op; int size; unicode_t u; op = pwcs; - while (*s && len > 0) { + while (len > 0 && maxlen > 0 && *s) { if (*s & 0x80) { size = utf8_to_utf32(s, len, &u); if (size < 0) return -EINVAL; + s += size; + len -= size; if (u >= PLANE_SIZE) { + if (maxlen < 2) + break; u -= PLANE_SIZE; - *op++ = (wchar_t) (SURROGATE_PAIR | - ((u >> 10) & SURROGATE_BITS)); - *op++ = (wchar_t) (SURROGATE_PAIR | + put_utf16(op++, SURROGATE_PAIR | + ((u >> 10) & SURROGATE_BITS), + endian); + put_utf16(op++, SURROGATE_PAIR | SURROGATE_LOW | - (u & SURROGATE_BITS)); + (u & SURROGATE_BITS), + endian); + maxlen -= 2; } else { - *op++ = (wchar_t) u; + put_utf16(op++, u, endian); + maxlen--; } - s += size; - len -= size; } else { - *op++ = *s++; + put_utf16(op++, *s++, endian); len--; + maxlen--; } } return op - pwcs; diff --git a/include/linux/nls.h b/include/linux/nls.h index d47beef08dfd..5dc635f8d79e 100644 --- a/include/linux/nls.h +++ b/include/linux/nls.h @@ -43,7 +43,7 @@ enum utf16_endian { UTF16_BIG_ENDIAN }; -/* nls.c */ +/* nls_base.c */ extern int register_nls(struct nls_table *); extern int unregister_nls(struct nls_table *); extern struct nls_table *load_nls(char *); @@ -52,7 +52,8 @@ extern struct nls_table *load_nls_default(void); 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 utf8s_to_utf16s(const u8 *s, int len, + enum utf16_endian endian, wchar_t *pwcs, int maxlen); extern int utf16s_to_utf8s(const wchar_t *pwcs, int len, enum utf16_endian endian, u8 *s, int maxlen); -- 2.39.2