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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400// SPDX-License-Identifier: GPL-2.0-only/* * unicode.c * * PURPOSE * Routines for converting between UTF-8 and OSTA Compressed Unicode. * Also handles filename mangling * * DESCRIPTION * OSTA Compressed Unicode is explained in the OSTA UDF specification. * http://www.osta.org/ * UTF-8 is explained in the IETF RFC XXXX. * ftp://ftp.internic.net/rfc/rfcxxxx.txt * */
#include "udfdecl.h"
#include <linux/hex.h>#include <linux/kernel.h>#include <linux/string.h> /* for memset */#include <linux/nls.h>#include <linux/crc-itu-t.h>#include <linux/slab.h>
#include "udf_sb.h"
#define PLANE_SIZE 0x10000#define UNICODE_MAX 0x10ffff#define SURROGATE_MASK 0xfffff800#define SURROGATE_PAIR 0x0000d800#define SURROGATE_LOW 0x00000400#define SURROGATE_CHAR_BITS 10#define SURROGATE_CHAR_MASK ((1 << SURROGATE_CHAR_BITS) - 1)
#define ILLEGAL_CHAR_MARK '_'#define EXT_MARK '.'#define CRC_MARK '#'#define EXT_SIZE 5/* Number of chars we need to store generated CRC to make filename unique */#define CRC_LEN 5
static unicode_t get_utf16_char(const uint8_t *str_i, int str_i_max_len, int str_i_idx, int u_ch, unicode_t *ret){ unicode_t c; int start_idx = str_i_idx;
/* Expand OSTA compressed Unicode to Unicode */ c = str_i[str_i_idx++]; if (u_ch > 1) c = (c << 8) | str_i[str_i_idx++]; if ((c & SURROGATE_MASK) == SURROGATE_PAIR) { unicode_t next;
/* Trailing surrogate char */ if (str_i_idx >= str_i_max_len) { c = UNICODE_MAX + 1; goto out; }
/* Low surrogate must follow the high one... */ if (c & SURROGATE_LOW) { c = UNICODE_MAX + 1; goto out; }
WARN_ON_ONCE(u_ch != 2); next = str_i[str_i_idx++] << 8; next |= str_i[str_i_idx++]; if ((next & SURROGATE_MASK) != SURROGATE_PAIR || !(next & SURROGATE_LOW)) { c = UNICODE_MAX + 1; goto out; }
c = PLANE_SIZE + ((c & SURROGATE_CHAR_MASK) << SURROGATE_CHAR_BITS) + (next & SURROGATE_CHAR_MASK); }out: *ret = c; return str_i_idx - start_idx;}
static int udf_name_conv_char(uint8_t *str_o, int str_o_max_len, int *str_o_idx, const uint8_t *str_i, int str_i_max_len, int *str_i_idx, int u_ch, int *needsCRC, int (*conv_f)(wchar_t, unsigned char *, int), int translate){ unicode_t c; int illChar = 0; int len, gotch = 0;
while (!gotch && *str_i_idx < str_i_max_len) { if (*str_o_idx >= str_o_max_len) { *needsCRC = 1; return gotch; }
len = get_utf16_char(str_i, str_i_max_len, *str_i_idx, u_ch, &c); /* These chars cannot be converted. Replace them. */ if (c == 0 || c > UNICODE_MAX || (conv_f && c > MAX_WCHAR_T) || (translate && c == '/')) { illChar = 1; if (!translate) gotch = 1; } else if (illChar) break; else gotch = 1; *str_i_idx += len; } if (illChar) { *needsCRC = 1; c = ILLEGAL_CHAR_MARK; gotch = 1; } if (gotch) { if (conv_f) { len = conv_f(c, &str_o[*str_o_idx], str_o_max_len - *str_o_idx); } else { len = utf32_to_utf8(c, &str_o[*str_o_idx], str_o_max_len - *str_o_idx); if (len < 0) len = -ENAMETOOLONG; } /* Valid character? */ if (len >= 0) *str_o_idx += len; else if (len == -ENAMETOOLONG) { *needsCRC = 1; gotch = 0; } else { str_o[(*str_o_idx)++] = ILLEGAL_CHAR_MARK; *needsCRC = 1; } } return gotch;}
static int udf_name_from_CS0(struct super_block *sb, uint8_t *str_o, int str_max_len, const uint8_t *ocu, int ocu_len, int translate){ uint32_t c; uint8_t cmp_id; int idx, len; int u_ch; int needsCRC = 0; int ext_i_len, ext_max_len; int str_o_len = 0; /* Length of resulting output */ int ext_o_len = 0; /* Extension output length */ int ext_crc_len = 0; /* Extension output length if used with CRC */ int i_ext = -1; /* Extension position in input buffer */ int o_crc = 0; /* Rightmost possible output pos for CRC+ext */ unsigned short valueCRC; uint8_t ext[EXT_SIZE * NLS_MAX_CHARSET_SIZE + 1]; uint8_t crc[CRC_LEN]; int (*conv_f)(wchar_t, unsigned char *, int);
if (str_max_len <= 0) return 0;
if (ocu_len == 0) { memset(str_o, 0, str_max_len); return 0; }
if (UDF_SB(sb)->s_nls_map) conv_f = UDF_SB(sb)->s_nls_map->uni2char; else conv_f = NULL;
cmp_id = ocu[0]; if (cmp_id != 8 && cmp_id != 16) { memset(str_o, 0, str_max_len); pr_err("unknown compression code (%u)\n", cmp_id); return -EINVAL; } u_ch = cmp_id >> 3;
ocu++; ocu_len--;
if (ocu_len % u_ch) { pr_err("incorrect filename length (%d)\n", ocu_len + 1); return -EINVAL; }
if (translate) { /* Look for extension */ for (idx = ocu_len - u_ch, ext_i_len = 0; (idx >= 0) && (ext_i_len < EXT_SIZE); idx -= u_ch, ext_i_len++) { c = ocu[idx]; if (u_ch > 1) c = (c << 8) | ocu[idx + 1];
if (c == EXT_MARK) { if (ext_i_len) i_ext = idx; break; } } if (i_ext >= 0) { /* Convert extension */ ext_max_len = min_t(int, sizeof(ext), str_max_len); ext[ext_o_len++] = EXT_MARK; idx = i_ext + u_ch; while (udf_name_conv_char(ext, ext_max_len, &ext_o_len, ocu, ocu_len, &idx, u_ch, &needsCRC, conv_f, translate)) { if ((ext_o_len + CRC_LEN) < str_max_len) ext_crc_len = ext_o_len; } } }
idx = 0; while (1) { if (translate && (idx == i_ext)) { if (str_o_len > (str_max_len - ext_o_len)) needsCRC = 1; break; }
if (!udf_name_conv_char(str_o, str_max_len, &str_o_len, ocu, ocu_len, &idx, u_ch, &needsCRC, conv_f, translate)) break;
if (translate && (str_o_len <= (str_max_len - ext_o_len - CRC_LEN))) o_crc = str_o_len; }
if (translate) { if (str_o_len > 0 && str_o_len <= 2 && str_o[0] == '.' && (str_o_len == 1 || str_o[1] == '.')) needsCRC = 1; if (needsCRC) { str_o_len = o_crc; valueCRC = crc_itu_t(0, ocu, ocu_len); crc[0] = CRC_MARK; crc[1] = hex_asc_upper_hi(valueCRC >> 8); crc[2] = hex_asc_upper_lo(valueCRC >> 8); crc[3] = hex_asc_upper_hi(valueCRC); crc[4] = hex_asc_upper_lo(valueCRC); len = min_t(int, CRC_LEN, str_max_len - str_o_len); memcpy(&str_o[str_o_len], crc, len); str_o_len += len; ext_o_len = ext_crc_len; } if (ext_o_len > 0) { memcpy(&str_o[str_o_len], ext, ext_o_len); str_o_len += ext_o_len; } }
return str_o_len;}
static int udf_name_to_CS0(struct super_block *sb, uint8_t *ocu, int ocu_max_len, const uint8_t *str_i, int str_len){ int i, len; unsigned int max_val; int u_len, u_ch; unicode_t uni_char; int (*conv_f)(const unsigned char *, int, wchar_t *);
if (ocu_max_len <= 0) return 0;
if (UDF_SB(sb)->s_nls_map) conv_f = UDF_SB(sb)->s_nls_map->char2uni; else conv_f = NULL;
memset(ocu, 0, ocu_max_len); ocu[0] = 8; max_val = 0xff; u_ch = 1;
try_again: u_len = 1; for (i = 0; i < str_len; i += len) { /* Name didn't fit? */ if (u_len + u_ch > ocu_max_len) return 0; if (conv_f) { wchar_t wchar;
len = conv_f(&str_i[i], str_len - i, &wchar); if (len > 0) uni_char = wchar; } else { len = utf8_to_utf32(&str_i[i], str_len - i, &uni_char); } /* Invalid character, deal with it */ if (len <= 0 || uni_char > UNICODE_MAX) { len = 1; uni_char = '?'; }
if (uni_char > max_val) { unicode_t c;
if (max_val == 0xff) { max_val = 0xffff; ocu[0] = 0x10; u_ch = 2; goto try_again; } /* * Use UTF-16 encoding for chars outside we * cannot encode directly. */ if (u_len + 2 * u_ch > ocu_max_len) return 0;
uni_char -= PLANE_SIZE; c = SURROGATE_PAIR | ((uni_char >> SURROGATE_CHAR_BITS) & SURROGATE_CHAR_MASK); ocu[u_len++] = (uint8_t)(c >> 8); ocu[u_len++] = (uint8_t)(c & 0xff); uni_char = SURROGATE_PAIR | SURROGATE_LOW | (uni_char & SURROGATE_CHAR_MASK); }
if (max_val == 0xffff) ocu[u_len++] = (uint8_t)(uni_char >> 8); ocu[u_len++] = (uint8_t)(uni_char & 0xff); }
return u_len;}
/* * Convert CS0 dstring to output charset. Warning: This function may truncate * input string if it is too long as it is used for informational strings only * and it is better to truncate the string than to refuse mounting a media. */int udf_dstrCS0toChar(struct super_block *sb, uint8_t *utf_o, int o_len, const uint8_t *ocu_i, int i_len){ int s_len = 0;
if (i_len > 0) { s_len = ocu_i[i_len - 1]; if (s_len >= i_len) { pr_warn("incorrect dstring lengths (%d/%d)," " truncating\n", s_len, i_len); s_len = i_len - 1; /* 2-byte encoding? Need to round properly... */ if (ocu_i[0] == 16) s_len -= (s_len - 1) & 2; } }
return udf_name_from_CS0(sb, utf_o, o_len, ocu_i, s_len, 0);}
int udf_get_filename(struct super_block *sb, const uint8_t *sname, int slen, uint8_t *dname, int dlen){ int ret;
if (!slen) return -EIO;
if (dlen <= 0) return 0;
ret = udf_name_from_CS0(sb, dname, dlen, sname, slen, 1); /* Zero length filename isn't valid... */ if (ret == 0) ret = -EINVAL; return ret;}
int udf_put_filename(struct super_block *sb, const uint8_t *sname, int slen, uint8_t *dname, int dlen){ return udf_name_to_CS0(sb, dname, dlen, sname, slen);}