1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * 4 * Copyright (c) International Business Machines Corp., 2000,2009 5 * Modified by Steve French (sfrench@us.ibm.com) 6 */ 7#include <linux/fs.h> 8#include <linux/slab.h> 9#include "cifs_fs_sb.h" 10#include "cifs_unicode.h" 11#include "cifspdu.h" 12#include "cifsglob.h" 13#include "cifs_debug.h" 14 15int cifs_remap(struct cifs_sb_info *cifs_sb) 16{ 17 int map_type; 18 19 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR) 20 map_type = SFM_MAP_UNI_RSVD; 21 else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR) 22 map_type = SFU_MAP_UNI_RSVD; 23 else 24 map_type = NO_MAP_UNI_RSVD; 25 26 return map_type; 27} 28 29/* Convert character using the SFU - "Services for Unix" remapping range */ 30static bool 31convert_sfu_char(const __u16 src_char, char *target) 32{ 33 /* 34 * BB: Cannot handle remapping UNI_SLASH until all the calls to 35 * build_path_from_dentry are modified, as they use slash as 36 * separator. 37 */ 38 switch (src_char) { 39 case UNI_COLON: 40 *target = ':'; 41 break; 42 case UNI_ASTERISK: 43 *target = '*'; 44 break; 45 case UNI_QUESTION: 46 *target = '?'; 47 break; 48 case UNI_PIPE: 49 *target = '|'; 50 break; 51 case UNI_GRTRTHAN: 52 *target = '>'; 53 break; 54 case UNI_LESSTHAN: 55 *target = '<'; 56 break; 57 default: 58 return false; 59 } 60 return true; 61} 62 63/* Convert character using the SFM - "Services for Mac" remapping range */ 64static bool 65convert_sfm_char(const __u16 src_char, char *target) 66{ 67 if (src_char >= 0xF001 && src_char <= 0xF01F) { 68 *target = src_char - 0xF000; 69 return true; 70 } 71 switch (src_char) { 72 case SFM_COLON: 73 *target = ':'; 74 break; 75 case SFM_DOUBLEQUOTE: 76 *target = '"'; 77 break; 78 case SFM_ASTERISK: 79 *target = '*'; 80 break; 81 case SFM_QUESTION: 82 *target = '?'; 83 break; 84 case SFM_PIPE: 85 *target = '|'; 86 break; 87 case SFM_GRTRTHAN: 88 *target = '>'; 89 break; 90 case SFM_LESSTHAN: 91 *target = '<'; 92 break; 93 case SFM_SPACE: 94 *target = ' '; 95 break; 96 case SFM_PERIOD: 97 *target = '.'; 98 break; 99 default: 100 return false; 101 } 102 return true; 103} 104 105 106/* 107 * cifs_mapchar - convert a host-endian char to proper char in codepage 108 * @target - where converted character should be copied 109 * @src_char - 2 byte host-endian source character 110 * @cp - codepage to which character should be converted 111 * @map_type - How should the 7 NTFS/SMB reserved characters be mapped to UCS2? 112 * 113 * This function handles the conversion of a single character. It is the 114 * responsibility of the caller to ensure that the target buffer is large 115 * enough to hold the result of the conversion (at least NLS_MAX_CHARSET_SIZE). 116 */ 117static int 118cifs_mapchar(char *target, const __u16 *from, const struct nls_table *cp, 119 int maptype) 120{ 121 int len = 1; 122 __u16 src_char; 123 124 src_char = *from; 125 126 if ((maptype == SFM_MAP_UNI_RSVD) && convert_sfm_char(src_char, target)) 127 return len; 128 else if ((maptype == SFU_MAP_UNI_RSVD) && 129 convert_sfu_char(src_char, target)) 130 return len; 131 132 /* if character not one of seven in special remap set */ 133 len = cp->uni2char(src_char, target, NLS_MAX_CHARSET_SIZE); 134 if (len <= 0) 135 goto surrogate_pair; 136 137 return len; 138 139surrogate_pair: 140 /* convert SURROGATE_PAIR and IVS */ 141 if (strcmp(cp->charset, "utf8")) 142 goto unknown; 143 len = utf16s_to_utf8s(from, 3, UTF16_LITTLE_ENDIAN, target, 6); 144 if (len <= 0) 145 goto unknown; 146 return len; 147 148unknown: 149 *target = '?'; 150 len = 1; 151 return len; 152} 153 154/* 155 * cifs_from_utf16 - convert utf16le string to local charset 156 * @to - destination buffer 157 * @from - source buffer 158 * @tolen - destination buffer size (in bytes) 159 * @fromlen - source buffer size (in bytes) 160 * @codepage - codepage to which characters should be converted 161 * @mapchar - should characters be remapped according to the mapchars option? 162 * 163 * Convert a little-endian utf16le string (as sent by the server) to a string 164 * in the provided codepage. The tolen and fromlen parameters are to ensure 165 * that the code doesn't walk off of the end of the buffer (which is always 166 * a danger if the alignment of the source buffer is off). The destination 167 * string is always properly null terminated and fits in the destination 168 * buffer. Returns the length of the destination string in bytes (including 169 * null terminator). 170 * 171 * Note that some windows versions actually send multiword UTF-16 characters 172 * instead of straight UTF16-2. The linux nls routines however aren't able to 173 * deal with those characters properly. In the event that we get some of 174 * those characters, they won't be translated properly. 175 */ 176int 177cifs_from_utf16(char *to, const __le16 *from, int tolen, int fromlen, 178 const struct nls_table *codepage, int map_type) 179{ 180 int i, charlen, safelen; 181 int outlen = 0; 182 int nullsize = nls_nullsize(codepage); 183 int fromwords = fromlen / 2; 184 char tmp[NLS_MAX_CHARSET_SIZE]; 185 __u16 ftmp[3]; /* ftmp[3] = 3array x 2bytes = 6bytes UTF-16 */ 186 187 /* 188 * because the chars can be of varying widths, we need to take care 189 * not to overflow the destination buffer when we get close to the 190 * end of it. Until we get to this offset, we don't need to check 191 * for overflow however. 192 */ 193 safelen = tolen - (NLS_MAX_CHARSET_SIZE + nullsize); 194 195 for (i = 0; i < fromwords; i++) { 196 ftmp[0] = get_unaligned_le16(&from[i]); 197 if (ftmp[0] == 0) 198 break; 199 if (i + 1 < fromwords) 200 ftmp[1] = get_unaligned_le16(&from[i + 1]); 201 else 202 ftmp[1] = 0; 203 if (i + 2 < fromwords) 204 ftmp[2] = get_unaligned_le16(&from[i + 2]); 205 else 206 ftmp[2] = 0; 207 208 /* 209 * check to see if converting this character might make the 210 * conversion bleed into the null terminator 211 */ 212 if (outlen >= safelen) { 213 charlen = cifs_mapchar(tmp, ftmp, codepage, map_type); 214 if ((outlen + charlen) > (tolen - nullsize)) 215 break; 216 } 217 218 /* put converted char into 'to' buffer */ 219 charlen = cifs_mapchar(&to[outlen], ftmp, codepage, map_type); 220 outlen += charlen; 221 222 /* charlen (=bytes of UTF-8 for 1 character) 223 * 4bytes UTF-8(surrogate pair) is charlen=4 224 * (4bytes UTF-16 code) 225 * 7-8bytes UTF-8(IVS) is charlen=3+4 or 4+4 226 * (2 UTF-8 pairs divided to 2 UTF-16 pairs) */ 227 if (charlen == 4) 228 i++; 229 else if (charlen >= 5) 230 /* 5-6bytes UTF-8 */ 231 i += 2; 232 } 233 234 /* properly null-terminate string */ 235 for (i = 0; i < nullsize; i++) 236 to[outlen++] = 0; 237 238 return outlen; 239} 240 241/* 242 * NAME: cifs_strtoUTF16() 243 * 244 * FUNCTION: Convert character string to unicode string 245 * 246 */ 247int 248cifs_strtoUTF16(__le16 *to, const char *from, int len, 249 const struct nls_table *codepage) 250{ 251 int charlen; 252 int i; 253 wchar_t wchar_to; /* needed to quiet sparse */ 254 255 /* special case for utf8 to handle no plane0 chars */ 256 if (!strcmp(codepage->charset, "utf8")) { 257 /* 258 * convert utf8 -> utf16, we assume we have enough space 259 * as caller should have assumed conversion does not overflow 260 * in destination len is length in wchar_t units (16bits) 261 */ 262 i = utf8s_to_utf16s(from, len, UTF16_LITTLE_ENDIAN, 263 (wchar_t *) to, len); 264 265 /* if success terminate and exit */ 266 if (i >= 0) 267 goto success; 268 /* 269 * if fails fall back to UCS encoding as this 270 * function should not return negative values 271 * currently can fail only if source contains 272 * invalid encoded characters 273 */ 274 } 275 276 for (i = 0; len && *from; i++, from += charlen, len -= charlen) { 277 charlen = codepage->char2uni(from, len, &wchar_to); 278 if (charlen < 1) { 279 cifs_dbg(VFS, "strtoUTF16: char2uni of 0x%x returned %d\n", 280 *from, charlen); 281 /* A question mark */ 282 wchar_to = 0x003f; 283 charlen = 1; 284 } 285 put_unaligned_le16(wchar_to, &to[i]); 286 } 287 288success: 289 put_unaligned_le16(0, &to[i]); 290 return i; 291} 292 293/* 294 * cifs_utf16_bytes - how long will a string be after conversion? 295 * @utf16 - pointer to input string 296 * @maxbytes - don't go past this many bytes of input string 297 * @codepage - destination codepage 298 * 299 * Walk a utf16le string and return the number of bytes that the string will 300 * be after being converted to the given charset, not including any null 301 * termination required. Don't walk past maxbytes in the source buffer. 302 */ 303int 304cifs_utf16_bytes(const __le16 *from, int maxbytes, 305 const struct nls_table *codepage) 306{ 307 int i; 308 int charlen, outlen = 0; 309 int maxwords = maxbytes / 2; 310 char tmp[NLS_MAX_CHARSET_SIZE]; 311 __u16 ftmp[3]; 312 313 for (i = 0; i < maxwords; i++) { 314 ftmp[0] = get_unaligned_le16(&from[i]); 315 if (ftmp[0] == 0) 316 break; 317 if (i + 1 < maxwords) 318 ftmp[1] = get_unaligned_le16(&from[i + 1]); 319 else 320 ftmp[1] = 0; 321 if (i + 2 < maxwords) 322 ftmp[2] = get_unaligned_le16(&from[i + 2]); 323 else 324 ftmp[2] = 0; 325 326 charlen = cifs_mapchar(tmp, ftmp, codepage, NO_MAP_UNI_RSVD); 327 outlen += charlen; 328 } 329 330 return outlen; 331} 332 333/* 334 * cifs_strndup_from_utf16 - copy a string from wire format to the local 335 * codepage 336 * @src - source string 337 * @maxlen - don't walk past this many bytes in the source string 338 * @is_unicode - is this a unicode string? 339 * @codepage - destination codepage 340 * 341 * Take a string given by the server, convert it to the local codepage and 342 * put it in a new buffer. Returns a pointer to the new string or NULL on 343 * error. 344 */ 345char * 346cifs_strndup_from_utf16(const char *src, const int maxlen, 347 const bool is_unicode, const struct nls_table *codepage) 348{ 349 int len; 350 char *dst; 351 352 if (is_unicode) { 353 len = cifs_utf16_bytes((__le16 *) src, maxlen, codepage); 354 len += nls_nullsize(codepage); 355 dst = kmalloc(len, GFP_KERNEL); 356 if (!dst) 357 return NULL; 358 cifs_from_utf16(dst, (__le16 *) src, len, maxlen, codepage, 359 NO_MAP_UNI_RSVD); 360 } else { 361 dst = kstrndup(src, maxlen, GFP_KERNEL); 362 } 363 364 return dst; 365} 366 367static __le16 convert_to_sfu_char(char src_char) 368{ 369 __le16 dest_char; 370 371 switch (src_char) { 372 case ':': 373 dest_char = cpu_to_le16(UNI_COLON); 374 break; 375 case '*': 376 dest_char = cpu_to_le16(UNI_ASTERISK); 377 break; 378 case '?': 379 dest_char = cpu_to_le16(UNI_QUESTION); 380 break; 381 case '<': 382 dest_char = cpu_to_le16(UNI_LESSTHAN); 383 break; 384 case '>': 385 dest_char = cpu_to_le16(UNI_GRTRTHAN); 386 break; 387 case '|': 388 dest_char = cpu_to_le16(UNI_PIPE); 389 break; 390 default: 391 dest_char = 0; 392 } 393 394 return dest_char; 395} 396 397static __le16 convert_to_sfm_char(char src_char, bool end_of_string) 398{ 399 __le16 dest_char; 400 401 if (src_char >= 0x01 && src_char <= 0x1F) { 402 dest_char = cpu_to_le16(src_char + 0xF000); 403 return dest_char; 404 } 405 switch (src_char) { 406 case ':': 407 dest_char = cpu_to_le16(SFM_COLON); 408 break; 409 case '"': 410 dest_char = cpu_to_le16(SFM_DOUBLEQUOTE); 411 break; 412 case '*': 413 dest_char = cpu_to_le16(SFM_ASTERISK); 414 break; 415 case '?': 416 dest_char = cpu_to_le16(SFM_QUESTION); 417 break; 418 case '<': 419 dest_char = cpu_to_le16(SFM_LESSTHAN); 420 break; 421 case '>': 422 dest_char = cpu_to_le16(SFM_GRTRTHAN); 423 break; 424 case '|': 425 dest_char = cpu_to_le16(SFM_PIPE); 426 break; 427 case '.': 428 if (end_of_string) 429 dest_char = cpu_to_le16(SFM_PERIOD); 430 else 431 dest_char = 0; 432 break; 433 case ' ': 434 if (end_of_string) 435 dest_char = cpu_to_le16(SFM_SPACE); 436 else 437 dest_char = 0; 438 break; 439 default: 440 dest_char = 0; 441 } 442 443 return dest_char; 444} 445 446/* 447 * Convert 16 bit Unicode pathname to wire format from string in current code 448 * page. Conversion may involve remapping up the six characters that are 449 * only legal in POSIX-like OS (if they are present in the string). Path 450 * names are little endian 16 bit Unicode on the wire 451 */ 452int 453cifsConvertToUTF16(__le16 *target, const char *source, int srclen, 454 const struct nls_table *cp, int map_chars) 455{ 456 int i, charlen; 457 int j = 0; 458 char src_char; 459 __le16 dst_char; 460 wchar_t tmp; 461 wchar_t *wchar_to; /* UTF-16 */ 462 int ret; 463 unicode_t u; 464 465 if (map_chars == NO_MAP_UNI_RSVD) 466 return cifs_strtoUTF16(target, source, PATH_MAX, cp); 467 468 wchar_to = kzalloc(6, GFP_KERNEL); 469 470 for (i = 0; i < srclen; j++) { 471 src_char = source[i]; 472 charlen = 1; 473 474 /* check if end of string */ 475 if (src_char == 0) 476 goto ctoUTF16_out; 477 478 /* see if we must remap this char */ 479 if (map_chars == SFU_MAP_UNI_RSVD) 480 dst_char = convert_to_sfu_char(src_char); 481 else if (map_chars == SFM_MAP_UNI_RSVD) { 482 bool end_of_string; 483 484 /** 485 * Remap spaces and periods found at the end of every 486 * component of the path. The special cases of '.' and 487 * '..' do not need to be dealt with explicitly because 488 * they are addressed in namei.c:link_path_walk(). 489 **/ 490 if ((i == srclen - 1) || (source[i+1] == '\\')) 491 end_of_string = true; 492 else 493 end_of_string = false; 494 495 dst_char = convert_to_sfm_char(src_char, end_of_string); 496 } else 497 dst_char = 0; 498 /* 499 * FIXME: We can not handle remapping backslash (UNI_SLASH) 500 * until all the calls to build_path_from_dentry are modified, 501 * as they use backslash as separator. 502 */ 503 if (dst_char == 0) { 504 charlen = cp->char2uni(source + i, srclen - i, &tmp); 505 dst_char = cpu_to_le16(tmp); 506 507 /* 508 * if no match, use question mark, which at least in 509 * some cases serves as wild card 510 */ 511 if (charlen > 0) 512 goto ctoUTF16; 513 514 /* convert SURROGATE_PAIR */ 515 if (strcmp(cp->charset, "utf8") || !wchar_to) 516 goto unknown; 517 if (*(source + i) & 0x80) { 518 charlen = utf8_to_utf32(source + i, 6, &u); 519 if (charlen < 0) 520 goto unknown; 521 } else 522 goto unknown; 523 ret = utf8s_to_utf16s(source + i, charlen, 524 UTF16_LITTLE_ENDIAN, 525 wchar_to, 6); 526 if (ret < 0) 527 goto unknown; 528 529 i += charlen; 530 dst_char = cpu_to_le16(*wchar_to); 531 if (charlen <= 3) 532 /* 1-3bytes UTF-8 to 2bytes UTF-16 */ 533 put_unaligned(dst_char, &target[j]); 534 else if (charlen == 4) { 535 /* 4bytes UTF-8(surrogate pair) to 4bytes UTF-16 536 * 7-8bytes UTF-8(IVS) divided to 2 UTF-16 537 * (charlen=3+4 or 4+4) */ 538 put_unaligned(dst_char, &target[j]); 539 dst_char = cpu_to_le16(*(wchar_to + 1)); 540 j++; 541 put_unaligned(dst_char, &target[j]); 542 } else if (charlen >= 5) { 543 /* 5-6bytes UTF-8 to 6bytes UTF-16 */ 544 put_unaligned(dst_char, &target[j]); 545 dst_char = cpu_to_le16(*(wchar_to + 1)); 546 j++; 547 put_unaligned(dst_char, &target[j]); 548 dst_char = cpu_to_le16(*(wchar_to + 2)); 549 j++; 550 put_unaligned(dst_char, &target[j]); 551 } 552 continue; 553 554unknown: 555 dst_char = cpu_to_le16(0x003f); 556 charlen = 1; 557 } 558 559ctoUTF16: 560 /* 561 * character may take more than one byte in the source string, 562 * but will take exactly two bytes in the target string 563 */ 564 i += charlen; 565 put_unaligned(dst_char, &target[j]); 566 } 567 568ctoUTF16_out: 569 put_unaligned(0, &target[j]); /* Null terminate target unicode string */ 570 kfree(wchar_to); 571 return j; 572} 573 574/* 575 * cifs_local_to_utf16_bytes - how long will a string be after conversion? 576 * @from - pointer to input string 577 * @maxbytes - don't go past this many bytes of input string 578 * @codepage - source codepage 579 * 580 * Walk a string and return the number of bytes that the string will 581 * be after being converted to the given charset, not including any null 582 * termination required. Don't walk past maxbytes in the source buffer. 583 */ 584 585static int 586cifs_local_to_utf16_bytes(const char *from, int len, 587 const struct nls_table *codepage) 588{ 589 int charlen; 590 int i; 591 wchar_t wchar_to; 592 593 for (i = 0; len && *from; i++, from += charlen, len -= charlen) { 594 charlen = codepage->char2uni(from, len, &wchar_to); 595 /* Failed conversion defaults to a question mark */ 596 if (charlen < 1) 597 charlen = 1; 598 } 599 return 2 * i; /* UTF16 characters are two bytes */ 600} 601 602/* 603 * cifs_strndup_to_utf16 - copy a string to wire format from the local codepage 604 * @src - source string 605 * @maxlen - don't walk past this many bytes in the source string 606 * @utf16_len - the length of the allocated string in bytes (including null) 607 * @cp - source codepage 608 * @remap - map special chars 609 * 610 * Take a string convert it from the local codepage to UTF16 and 611 * put it in a new buffer. Returns a pointer to the new string or NULL on 612 * error. 613 */ 614__le16 * 615cifs_strndup_to_utf16(const char *src, const int maxlen, int *utf16_len, 616 const struct nls_table *cp, int remap) 617{ 618 int len; 619 __le16 *dst; 620 621 len = cifs_local_to_utf16_bytes(src, maxlen, cp); 622 len += 2; /* NULL */ 623 dst = kmalloc(len, GFP_KERNEL); 624 if (!dst) { 625 *utf16_len = 0; 626 return NULL; 627 } 628 cifsConvertToUTF16(dst, src, strlen(src), cp, remap); 629 *utf16_len = len; 630 return dst; 631} 632