1 /* 2 * linux/lib/vsprintf.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 */ 6 7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */ 8 /* 9 * Wirzenius wrote this portably, Torvalds fucked it up :-) 10 */ 11 12 /* 13 * Fri Jul 13 2001 Crutcher Dunnavant <[email protected]> 14 * - changed to provide snprintf and vsnprintf functions 15 * So Feb 1 16:51:32 CET 2004 Juergen Quade <[email protected]> 16 * - scnprintf and vscnprintf 17 */ 18 19 #include <stdarg.h> 20 #include <linux/module.h> 21 #include <linux/types.h> 22 #include <linux/string.h> 23 #include <linux/ctype.h> 24 #include <linux/kernel.h> 25 #include <linux/kallsyms.h> 26 #include <linux/uaccess.h> 27 #include <linux/ioport.h> 28 #include <net/addrconf.h> 29 30 #include <asm/page.h> /* for PAGE_SIZE */ 31 #include <asm/div64.h> 32 #include <asm/sections.h> /* for dereference_function_descriptor() */ 33 34 /* Works only for digits and letters, but small and fast */ 35 #define TOLOWER(x) ((x) | 0x20) 36 37 static unsigned int simple_guess_base(const char *cp) 38 { 39 if (cp[0] == '0') { 40 if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2])) 41 return 16; 42 else 43 return 8; 44 } else { 45 return 10; 46 } 47 } 48 49 /** 50 * simple_strtoull - convert a string to an unsigned long long 51 * @cp: The start of the string 52 * @endp: A pointer to the end of the parsed string will be placed here 53 * @base: The number base to use 54 */ 55 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) 56 { 57 unsigned long long result = 0; 58 59 if (!base) 60 base = simple_guess_base(cp); 61 62 if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x') 63 cp += 2; 64 65 while (isxdigit(*cp)) { 66 unsigned int value; 67 68 value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10; 69 if (value >= base) 70 break; 71 result = result * base + value; 72 cp++; 73 } 74 if (endp) 75 *endp = (char *)cp; 76 77 return result; 78 } 79 EXPORT_SYMBOL(simple_strtoull); 80 81 /** 82 * simple_strtoul - convert a string to an unsigned long 83 * @cp: The start of the string 84 * @endp: A pointer to the end of the parsed string will be placed here 85 * @base: The number base to use 86 */ 87 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base) 88 { 89 return simple_strtoull(cp, endp, base); 90 } 91 EXPORT_SYMBOL(simple_strtoul); 92 93 /** 94 * simple_strtol - convert a string to a signed long 95 * @cp: The start of the string 96 * @endp: A pointer to the end of the parsed string will be placed here 97 * @base: The number base to use 98 */ 99 long simple_strtol(const char *cp, char **endp, unsigned int base) 100 { 101 if (*cp == '-') 102 return -simple_strtoul(cp + 1, endp, base); 103 104 return simple_strtoul(cp, endp, base); 105 } 106 EXPORT_SYMBOL(simple_strtol); 107 108 /** 109 * simple_strtoll - convert a string to a signed long long 110 * @cp: The start of the string 111 * @endp: A pointer to the end of the parsed string will be placed here 112 * @base: The number base to use 113 */ 114 long long simple_strtoll(const char *cp, char **endp, unsigned int base) 115 { 116 if (*cp == '-') 117 return -simple_strtoull(cp + 1, endp, base); 118 119 return simple_strtoull(cp, endp, base); 120 } 121 122 /** 123 * strict_strtoul - convert a string to an unsigned long strictly 124 * @cp: The string to be converted 125 * @base: The number base to use 126 * @res: The converted result value 127 * 128 * strict_strtoul converts a string to an unsigned long only if the 129 * string is really an unsigned long string, any string containing 130 * any invalid char at the tail will be rejected and -EINVAL is returned, 131 * only a newline char at the tail is acceptible because people generally 132 * change a module parameter in the following way: 133 * 134 * echo 1024 > /sys/module/e1000/parameters/copybreak 135 * 136 * echo will append a newline to the tail. 137 * 138 * It returns 0 if conversion is successful and *res is set to the converted 139 * value, otherwise it returns -EINVAL and *res is set to 0. 140 * 141 * simple_strtoul just ignores the successive invalid characters and 142 * return the converted value of prefix part of the string. 143 */ 144 int strict_strtoul(const char *cp, unsigned int base, unsigned long *res) 145 { 146 char *tail; 147 unsigned long val; 148 size_t len; 149 150 *res = 0; 151 len = strlen(cp); 152 if (len == 0) 153 return -EINVAL; 154 155 val = simple_strtoul(cp, &tail, base); 156 if (tail == cp) 157 return -EINVAL; 158 159 if ((*tail == '\0') || 160 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) { 161 *res = val; 162 return 0; 163 } 164 165 return -EINVAL; 166 } 167 EXPORT_SYMBOL(strict_strtoul); 168 169 /** 170 * strict_strtol - convert a string to a long strictly 171 * @cp: The string to be converted 172 * @base: The number base to use 173 * @res: The converted result value 174 * 175 * strict_strtol is similiar to strict_strtoul, but it allows the first 176 * character of a string is '-'. 177 * 178 * It returns 0 if conversion is successful and *res is set to the converted 179 * value, otherwise it returns -EINVAL and *res is set to 0. 180 */ 181 int strict_strtol(const char *cp, unsigned int base, long *res) 182 { 183 int ret; 184 if (*cp == '-') { 185 ret = strict_strtoul(cp + 1, base, (unsigned long *)res); 186 if (!ret) 187 *res = -(*res); 188 } else { 189 ret = strict_strtoul(cp, base, (unsigned long *)res); 190 } 191 192 return ret; 193 } 194 EXPORT_SYMBOL(strict_strtol); 195 196 /** 197 * strict_strtoull - convert a string to an unsigned long long strictly 198 * @cp: The string to be converted 199 * @base: The number base to use 200 * @res: The converted result value 201 * 202 * strict_strtoull converts a string to an unsigned long long only if the 203 * string is really an unsigned long long string, any string containing 204 * any invalid char at the tail will be rejected and -EINVAL is returned, 205 * only a newline char at the tail is acceptible because people generally 206 * change a module parameter in the following way: 207 * 208 * echo 1024 > /sys/module/e1000/parameters/copybreak 209 * 210 * echo will append a newline to the tail of the string. 211 * 212 * It returns 0 if conversion is successful and *res is set to the converted 213 * value, otherwise it returns -EINVAL and *res is set to 0. 214 * 215 * simple_strtoull just ignores the successive invalid characters and 216 * return the converted value of prefix part of the string. 217 */ 218 int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res) 219 { 220 char *tail; 221 unsigned long long val; 222 size_t len; 223 224 *res = 0; 225 len = strlen(cp); 226 if (len == 0) 227 return -EINVAL; 228 229 val = simple_strtoull(cp, &tail, base); 230 if (tail == cp) 231 return -EINVAL; 232 if ((*tail == '\0') || 233 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) { 234 *res = val; 235 return 0; 236 } 237 238 return -EINVAL; 239 } 240 EXPORT_SYMBOL(strict_strtoull); 241 242 /** 243 * strict_strtoll - convert a string to a long long strictly 244 * @cp: The string to be converted 245 * @base: The number base to use 246 * @res: The converted result value 247 * 248 * strict_strtoll is similiar to strict_strtoull, but it allows the first 249 * character of a string is '-'. 250 * 251 * It returns 0 if conversion is successful and *res is set to the converted 252 * value, otherwise it returns -EINVAL and *res is set to 0. 253 */ 254 int strict_strtoll(const char *cp, unsigned int base, long long *res) 255 { 256 int ret; 257 if (*cp == '-') { 258 ret = strict_strtoull(cp + 1, base, (unsigned long long *)res); 259 if (!ret) 260 *res = -(*res); 261 } else { 262 ret = strict_strtoull(cp, base, (unsigned long long *)res); 263 } 264 265 return ret; 266 } 267 EXPORT_SYMBOL(strict_strtoll); 268 269 static int skip_atoi(const char **s) 270 { 271 int i = 0; 272 273 while (isdigit(**s)) 274 i = i*10 + *((*s)++) - '0'; 275 276 return i; 277 } 278 279 /* Decimal conversion is by far the most typical, and is used 280 * for /proc and /sys data. This directly impacts e.g. top performance 281 * with many processes running. We optimize it for speed 282 * using code from 283 * http://www.cs.uiowa.edu/~jones/bcd/decimal.html 284 * (with permission from the author, Douglas W. Jones). */ 285 286 /* Formats correctly any integer in [0,99999]. 287 * Outputs from one to five digits depending on input. 288 * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */ 289 static char *put_dec_trunc(char *buf, unsigned q) 290 { 291 unsigned d3, d2, d1, d0; 292 d1 = (q>>4) & 0xf; 293 d2 = (q>>8) & 0xf; 294 d3 = (q>>12); 295 296 d0 = 6*(d3 + d2 + d1) + (q & 0xf); 297 q = (d0 * 0xcd) >> 11; 298 d0 = d0 - 10*q; 299 *buf++ = d0 + '0'; /* least significant digit */ 300 d1 = q + 9*d3 + 5*d2 + d1; 301 if (d1 != 0) { 302 q = (d1 * 0xcd) >> 11; 303 d1 = d1 - 10*q; 304 *buf++ = d1 + '0'; /* next digit */ 305 306 d2 = q + 2*d2; 307 if ((d2 != 0) || (d3 != 0)) { 308 q = (d2 * 0xd) >> 7; 309 d2 = d2 - 10*q; 310 *buf++ = d2 + '0'; /* next digit */ 311 312 d3 = q + 4*d3; 313 if (d3 != 0) { 314 q = (d3 * 0xcd) >> 11; 315 d3 = d3 - 10*q; 316 *buf++ = d3 + '0'; /* next digit */ 317 if (q != 0) 318 *buf++ = q + '0'; /* most sign. digit */ 319 } 320 } 321 } 322 323 return buf; 324 } 325 /* Same with if's removed. Always emits five digits */ 326 static char *put_dec_full(char *buf, unsigned q) 327 { 328 /* BTW, if q is in [0,9999], 8-bit ints will be enough, */ 329 /* but anyway, gcc produces better code with full-sized ints */ 330 unsigned d3, d2, d1, d0; 331 d1 = (q>>4) & 0xf; 332 d2 = (q>>8) & 0xf; 333 d3 = (q>>12); 334 335 /* 336 * Possible ways to approx. divide by 10 337 * gcc -O2 replaces multiply with shifts and adds 338 * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386) 339 * (x * 0x67) >> 10: 1100111 340 * (x * 0x34) >> 9: 110100 - same 341 * (x * 0x1a) >> 8: 11010 - same 342 * (x * 0x0d) >> 7: 1101 - same, shortest code (on i386) 343 */ 344 d0 = 6*(d3 + d2 + d1) + (q & 0xf); 345 q = (d0 * 0xcd) >> 11; 346 d0 = d0 - 10*q; 347 *buf++ = d0 + '0'; 348 d1 = q + 9*d3 + 5*d2 + d1; 349 q = (d1 * 0xcd) >> 11; 350 d1 = d1 - 10*q; 351 *buf++ = d1 + '0'; 352 353 d2 = q + 2*d2; 354 q = (d2 * 0xd) >> 7; 355 d2 = d2 - 10*q; 356 *buf++ = d2 + '0'; 357 358 d3 = q + 4*d3; 359 q = (d3 * 0xcd) >> 11; /* - shorter code */ 360 /* q = (d3 * 0x67) >> 10; - would also work */ 361 d3 = d3 - 10*q; 362 *buf++ = d3 + '0'; 363 *buf++ = q + '0'; 364 365 return buf; 366 } 367 /* No inlining helps gcc to use registers better */ 368 static noinline char *put_dec(char *buf, unsigned long long num) 369 { 370 while (1) { 371 unsigned rem; 372 if (num < 100000) 373 return put_dec_trunc(buf, num); 374 rem = do_div(num, 100000); 375 buf = put_dec_full(buf, rem); 376 } 377 } 378 379 #define ZEROPAD 1 /* pad with zero */ 380 #define SIGN 2 /* unsigned/signed long */ 381 #define PLUS 4 /* show plus */ 382 #define SPACE 8 /* space if plus */ 383 #define LEFT 16 /* left justified */ 384 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */ 385 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */ 386 387 enum format_type { 388 FORMAT_TYPE_NONE, /* Just a string part */ 389 FORMAT_TYPE_WIDTH, 390 FORMAT_TYPE_PRECISION, 391 FORMAT_TYPE_CHAR, 392 FORMAT_TYPE_STR, 393 FORMAT_TYPE_PTR, 394 FORMAT_TYPE_PERCENT_CHAR, 395 FORMAT_TYPE_INVALID, 396 FORMAT_TYPE_LONG_LONG, 397 FORMAT_TYPE_ULONG, 398 FORMAT_TYPE_LONG, 399 FORMAT_TYPE_UBYTE, 400 FORMAT_TYPE_BYTE, 401 FORMAT_TYPE_USHORT, 402 FORMAT_TYPE_SHORT, 403 FORMAT_TYPE_UINT, 404 FORMAT_TYPE_INT, 405 FORMAT_TYPE_NRCHARS, 406 FORMAT_TYPE_SIZE_T, 407 FORMAT_TYPE_PTRDIFF 408 }; 409 410 struct printf_spec { 411 u16 type; 412 s16 field_width; /* width of output field */ 413 u8 flags; /* flags to number() */ 414 u8 base; 415 s8 precision; /* # of digits/chars */ 416 u8 qualifier; 417 }; 418 419 static char *number(char *buf, char *end, unsigned long long num, 420 struct printf_spec spec) 421 { 422 /* we are called with base 8, 10 or 16, only, thus don't need "G..." */ 423 static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */ 424 425 char tmp[66]; 426 char sign; 427 char locase; 428 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); 429 int i; 430 431 /* locase = 0 or 0x20. ORing digits or letters with 'locase' 432 * produces same digits or (maybe lowercased) letters */ 433 locase = (spec.flags & SMALL); 434 if (spec.flags & LEFT) 435 spec.flags &= ~ZEROPAD; 436 sign = 0; 437 if (spec.flags & SIGN) { 438 if ((signed long long)num < 0) { 439 sign = '-'; 440 num = -(signed long long)num; 441 spec.field_width--; 442 } else if (spec.flags & PLUS) { 443 sign = '+'; 444 spec.field_width--; 445 } else if (spec.flags & SPACE) { 446 sign = ' '; 447 spec.field_width--; 448 } 449 } 450 if (need_pfx) { 451 spec.field_width--; 452 if (spec.base == 16) 453 spec.field_width--; 454 } 455 456 /* generate full string in tmp[], in reverse order */ 457 i = 0; 458 if (num == 0) 459 tmp[i++] = '0'; 460 /* Generic code, for any base: 461 else do { 462 tmp[i++] = (digits[do_div(num,base)] | locase); 463 } while (num != 0); 464 */ 465 else if (spec.base != 10) { /* 8 or 16 */ 466 int mask = spec.base - 1; 467 int shift = 3; 468 469 if (spec.base == 16) 470 shift = 4; 471 do { 472 tmp[i++] = (digits[((unsigned char)num) & mask] | locase); 473 num >>= shift; 474 } while (num); 475 } else { /* base 10 */ 476 i = put_dec(tmp, num) - tmp; 477 } 478 479 /* printing 100 using %2d gives "100", not "00" */ 480 if (i > spec.precision) 481 spec.precision = i; 482 /* leading space padding */ 483 spec.field_width -= spec.precision; 484 if (!(spec.flags & (ZEROPAD+LEFT))) { 485 while (--spec.field_width >= 0) { 486 if (buf < end) 487 *buf = ' '; 488 ++buf; 489 } 490 } 491 /* sign */ 492 if (sign) { 493 if (buf < end) 494 *buf = sign; 495 ++buf; 496 } 497 /* "0x" / "0" prefix */ 498 if (need_pfx) { 499 if (buf < end) 500 *buf = '0'; 501 ++buf; 502 if (spec.base == 16) { 503 if (buf < end) 504 *buf = ('X' | locase); 505 ++buf; 506 } 507 } 508 /* zero or space padding */ 509 if (!(spec.flags & LEFT)) { 510 char c = (spec.flags & ZEROPAD) ? '0' : ' '; 511 while (--spec.field_width >= 0) { 512 if (buf < end) 513 *buf = c; 514 ++buf; 515 } 516 } 517 /* hmm even more zero padding? */ 518 while (i <= --spec.precision) { 519 if (buf < end) 520 *buf = '0'; 521 ++buf; 522 } 523 /* actual digits of result */ 524 while (--i >= 0) { 525 if (buf < end) 526 *buf = tmp[i]; 527 ++buf; 528 } 529 /* trailing space padding */ 530 while (--spec.field_width >= 0) { 531 if (buf < end) 532 *buf = ' '; 533 ++buf; 534 } 535 536 return buf; 537 } 538 539 static char *string(char *buf, char *end, const char *s, struct printf_spec spec) 540 { 541 int len, i; 542 543 if ((unsigned long)s < PAGE_SIZE) 544 s = "(null)"; 545 546 len = strnlen(s, spec.precision); 547 548 if (!(spec.flags & LEFT)) { 549 while (len < spec.field_width--) { 550 if (buf < end) 551 *buf = ' '; 552 ++buf; 553 } 554 } 555 for (i = 0; i < len; ++i) { 556 if (buf < end) 557 *buf = *s; 558 ++buf; ++s; 559 } 560 while (len < spec.field_width--) { 561 if (buf < end) 562 *buf = ' '; 563 ++buf; 564 } 565 566 return buf; 567 } 568 569 static char *symbol_string(char *buf, char *end, void *ptr, 570 struct printf_spec spec, char ext) 571 { 572 unsigned long value = (unsigned long) ptr; 573 #ifdef CONFIG_KALLSYMS 574 char sym[KSYM_SYMBOL_LEN]; 575 if (ext != 'f' && ext != 's') 576 sprint_symbol(sym, value); 577 else 578 kallsyms_lookup(value, NULL, NULL, NULL, sym); 579 580 return string(buf, end, sym, spec); 581 #else 582 spec.field_width = 2 * sizeof(void *); 583 spec.flags |= SPECIAL | SMALL | ZEROPAD; 584 spec.base = 16; 585 586 return number(buf, end, value, spec); 587 #endif 588 } 589 590 static char *resource_string(char *buf, char *end, struct resource *res, 591 struct printf_spec spec, const char *fmt) 592 { 593 #ifndef IO_RSRC_PRINTK_SIZE 594 #define IO_RSRC_PRINTK_SIZE 6 595 #endif 596 597 #ifndef MEM_RSRC_PRINTK_SIZE 598 #define MEM_RSRC_PRINTK_SIZE 10 599 #endif 600 static const struct printf_spec io_spec = { 601 .base = 16, 602 .field_width = IO_RSRC_PRINTK_SIZE, 603 .precision = -1, 604 .flags = SPECIAL | SMALL | ZEROPAD, 605 }; 606 static const struct printf_spec mem_spec = { 607 .base = 16, 608 .field_width = MEM_RSRC_PRINTK_SIZE, 609 .precision = -1, 610 .flags = SPECIAL | SMALL | ZEROPAD, 611 }; 612 static const struct printf_spec dec_spec = { 613 .base = 10, 614 .precision = -1, 615 .flags = 0, 616 }; 617 static const struct printf_spec str_spec = { 618 .field_width = -1, 619 .precision = 10, 620 .flags = LEFT, 621 }; 622 static const struct printf_spec flag_spec = { 623 .base = 16, 624 .precision = -1, 625 .flags = SPECIAL | SMALL, 626 }; 627 628 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8) 629 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */ 630 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4) 631 #define FLAG_BUF_SIZE (2 * sizeof(res->flags)) 632 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref disabled]") 633 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]") 634 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE, 635 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)]; 636 637 char *p = sym, *pend = sym + sizeof(sym); 638 int decode = (fmt[0] == 'R') ? 1 : 0; 639 const struct printf_spec *specp; 640 641 *p++ = '['; 642 if (res->flags & IORESOURCE_IO) { 643 p = string(p, pend, "io ", str_spec); 644 specp = &io_spec; 645 } else if (res->flags & IORESOURCE_MEM) { 646 p = string(p, pend, "mem ", str_spec); 647 specp = &mem_spec; 648 } else if (res->flags & IORESOURCE_IRQ) { 649 p = string(p, pend, "irq ", str_spec); 650 specp = &dec_spec; 651 } else if (res->flags & IORESOURCE_DMA) { 652 p = string(p, pend, "dma ", str_spec); 653 specp = &dec_spec; 654 } else { 655 p = string(p, pend, "??? ", str_spec); 656 specp = &mem_spec; 657 decode = 0; 658 } 659 p = number(p, pend, res->start, *specp); 660 if (res->start != res->end) { 661 *p++ = '-'; 662 p = number(p, pend, res->end, *specp); 663 } 664 if (decode) { 665 if (res->flags & IORESOURCE_MEM_64) 666 p = string(p, pend, " 64bit", str_spec); 667 if (res->flags & IORESOURCE_PREFETCH) 668 p = string(p, pend, " pref", str_spec); 669 if (res->flags & IORESOURCE_DISABLED) 670 p = string(p, pend, " disabled", str_spec); 671 } else { 672 p = string(p, pend, " flags ", str_spec); 673 p = number(p, pend, res->flags, flag_spec); 674 } 675 *p++ = ']'; 676 *p = '\0'; 677 678 return string(buf, end, sym, spec); 679 } 680 681 static char *mac_address_string(char *buf, char *end, u8 *addr, 682 struct printf_spec spec, const char *fmt) 683 { 684 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")]; 685 char *p = mac_addr; 686 int i; 687 char separator; 688 689 if (fmt[1] == 'F') { /* FDDI canonical format */ 690 separator = '-'; 691 } else { 692 separator = ':'; 693 } 694 695 for (i = 0; i < 6; i++) { 696 p = pack_hex_byte(p, addr[i]); 697 if (fmt[0] == 'M' && i != 5) 698 *p++ = separator; 699 } 700 *p = '\0'; 701 702 return string(buf, end, mac_addr, spec); 703 } 704 705 static char *ip4_string(char *p, const u8 *addr, const char *fmt) 706 { 707 int i; 708 bool leading_zeros = (fmt[0] == 'i'); 709 int index; 710 int step; 711 712 switch (fmt[2]) { 713 case 'h': 714 #ifdef __BIG_ENDIAN 715 index = 0; 716 step = 1; 717 #else 718 index = 3; 719 step = -1; 720 #endif 721 break; 722 case 'l': 723 index = 3; 724 step = -1; 725 break; 726 case 'n': 727 case 'b': 728 default: 729 index = 0; 730 step = 1; 731 break; 732 } 733 for (i = 0; i < 4; i++) { 734 char temp[3]; /* hold each IP quad in reverse order */ 735 int digits = put_dec_trunc(temp, addr[index]) - temp; 736 if (leading_zeros) { 737 if (digits < 3) 738 *p++ = '0'; 739 if (digits < 2) 740 *p++ = '0'; 741 } 742 /* reverse the digits in the quad */ 743 while (digits--) 744 *p++ = temp[digits]; 745 if (i < 3) 746 *p++ = '.'; 747 index += step; 748 } 749 *p = '\0'; 750 751 return p; 752 } 753 754 static char *ip6_compressed_string(char *p, const char *addr) 755 { 756 int i, j, range; 757 unsigned char zerolength[8]; 758 int longest = 1; 759 int colonpos = -1; 760 u16 word; 761 u8 hi, lo; 762 bool needcolon = false; 763 bool useIPv4; 764 struct in6_addr in6; 765 766 memcpy(&in6, addr, sizeof(struct in6_addr)); 767 768 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6); 769 770 memset(zerolength, 0, sizeof(zerolength)); 771 772 if (useIPv4) 773 range = 6; 774 else 775 range = 8; 776 777 /* find position of longest 0 run */ 778 for (i = 0; i < range; i++) { 779 for (j = i; j < range; j++) { 780 if (in6.s6_addr16[j] != 0) 781 break; 782 zerolength[i]++; 783 } 784 } 785 for (i = 0; i < range; i++) { 786 if (zerolength[i] > longest) { 787 longest = zerolength[i]; 788 colonpos = i; 789 } 790 } 791 792 /* emit address */ 793 for (i = 0; i < range; i++) { 794 if (i == colonpos) { 795 if (needcolon || i == 0) 796 *p++ = ':'; 797 *p++ = ':'; 798 needcolon = false; 799 i += longest - 1; 800 continue; 801 } 802 if (needcolon) { 803 *p++ = ':'; 804 needcolon = false; 805 } 806 /* hex u16 without leading 0s */ 807 word = ntohs(in6.s6_addr16[i]); 808 hi = word >> 8; 809 lo = word & 0xff; 810 if (hi) { 811 if (hi > 0x0f) 812 p = pack_hex_byte(p, hi); 813 else 814 *p++ = hex_asc_lo(hi); 815 p = pack_hex_byte(p, lo); 816 } 817 else if (lo > 0x0f) 818 p = pack_hex_byte(p, lo); 819 else 820 *p++ = hex_asc_lo(lo); 821 needcolon = true; 822 } 823 824 if (useIPv4) { 825 if (needcolon) 826 *p++ = ':'; 827 p = ip4_string(p, &in6.s6_addr[12], "I4"); 828 } 829 *p = '\0'; 830 831 return p; 832 } 833 834 static char *ip6_string(char *p, const char *addr, const char *fmt) 835 { 836 int i; 837 838 for (i = 0; i < 8; i++) { 839 p = pack_hex_byte(p, *addr++); 840 p = pack_hex_byte(p, *addr++); 841 if (fmt[0] == 'I' && i != 7) 842 *p++ = ':'; 843 } 844 *p = '\0'; 845 846 return p; 847 } 848 849 static char *ip6_addr_string(char *buf, char *end, const u8 *addr, 850 struct printf_spec spec, const char *fmt) 851 { 852 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")]; 853 854 if (fmt[0] == 'I' && fmt[2] == 'c') 855 ip6_compressed_string(ip6_addr, addr); 856 else 857 ip6_string(ip6_addr, addr, fmt); 858 859 return string(buf, end, ip6_addr, spec); 860 } 861 862 static char *ip4_addr_string(char *buf, char *end, const u8 *addr, 863 struct printf_spec spec, const char *fmt) 864 { 865 char ip4_addr[sizeof("255.255.255.255")]; 866 867 ip4_string(ip4_addr, addr, fmt); 868 869 return string(buf, end, ip4_addr, spec); 870 } 871 872 static char *uuid_string(char *buf, char *end, const u8 *addr, 873 struct printf_spec spec, const char *fmt) 874 { 875 char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")]; 876 char *p = uuid; 877 int i; 878 static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}; 879 static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15}; 880 const u8 *index = be; 881 bool uc = false; 882 883 switch (*(++fmt)) { 884 case 'L': 885 uc = true; /* fall-through */ 886 case 'l': 887 index = le; 888 break; 889 case 'B': 890 uc = true; 891 break; 892 } 893 894 for (i = 0; i < 16; i++) { 895 p = pack_hex_byte(p, addr[index[i]]); 896 switch (i) { 897 case 3: 898 case 5: 899 case 7: 900 case 9: 901 *p++ = '-'; 902 break; 903 } 904 } 905 906 *p = 0; 907 908 if (uc) { 909 p = uuid; 910 do { 911 *p = toupper(*p); 912 } while (*(++p)); 913 } 914 915 return string(buf, end, uuid, spec); 916 } 917 918 /* 919 * Show a '%p' thing. A kernel extension is that the '%p' is followed 920 * by an extra set of alphanumeric characters that are extended format 921 * specifiers. 922 * 923 * Right now we handle: 924 * 925 * - 'F' For symbolic function descriptor pointers with offset 926 * - 'f' For simple symbolic function names without offset 927 * - 'S' For symbolic direct pointers with offset 928 * - 's' For symbolic direct pointers without offset 929 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref] 930 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201] 931 * - 'M' For a 6-byte MAC address, it prints the address in the 932 * usual colon-separated hex notation 933 * - 'm' For a 6-byte MAC address, it prints the hex address without colons 934 * - 'MF' For a 6-byte MAC FDDI address, it prints the address 935 * with a dash-separated hex notation 936 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way 937 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4) 938 * IPv6 uses colon separated network-order 16 bit hex with leading 0's 939 * - 'i' [46] for 'raw' IPv4/IPv6 addresses 940 * IPv6 omits the colons (01020304...0f) 941 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006) 942 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order 943 * - 'I6c' for IPv6 addresses printed as specified by 944 * http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00 945 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form 946 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" 947 * Options for %pU are: 948 * b big endian lower case hex (default) 949 * B big endian UPPER case hex 950 * l little endian lower case hex 951 * L little endian UPPER case hex 952 * big endian output byte order is: 953 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15] 954 * little endian output byte order is: 955 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15] 956 * 957 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64 958 * function pointers are really function descriptors, which contain a 959 * pointer to the real address. 960 */ 961 static char *pointer(const char *fmt, char *buf, char *end, void *ptr, 962 struct printf_spec spec) 963 { 964 if (!ptr) 965 return string(buf, end, "(null)", spec); 966 967 switch (*fmt) { 968 case 'F': 969 case 'f': 970 ptr = dereference_function_descriptor(ptr); 971 /* Fallthrough */ 972 case 'S': 973 case 's': 974 return symbol_string(buf, end, ptr, spec, *fmt); 975 case 'R': 976 case 'r': 977 return resource_string(buf, end, ptr, spec, fmt); 978 case 'M': /* Colon separated: 00:01:02:03:04:05 */ 979 case 'm': /* Contiguous: 000102030405 */ 980 /* [mM]F (FDDI, bit reversed) */ 981 return mac_address_string(buf, end, ptr, spec, fmt); 982 case 'I': /* Formatted IP supported 983 * 4: 1.2.3.4 984 * 6: 0001:0203:...:0708 985 * 6c: 1::708 or 1::1.2.3.4 986 */ 987 case 'i': /* Contiguous: 988 * 4: 001.002.003.004 989 * 6: 000102...0f 990 */ 991 switch (fmt[1]) { 992 case '6': 993 return ip6_addr_string(buf, end, ptr, spec, fmt); 994 case '4': 995 return ip4_addr_string(buf, end, ptr, spec, fmt); 996 } 997 break; 998 case 'U': 999 return uuid_string(buf, end, ptr, spec, fmt); 1000 } 1001 spec.flags |= SMALL; 1002 if (spec.field_width == -1) { 1003 spec.field_width = 2*sizeof(void *); 1004 spec.flags |= ZEROPAD; 1005 } 1006 spec.base = 16; 1007 1008 return number(buf, end, (unsigned long) ptr, spec); 1009 } 1010 1011 /* 1012 * Helper function to decode printf style format. 1013 * Each call decode a token from the format and return the 1014 * number of characters read (or likely the delta where it wants 1015 * to go on the next call). 1016 * The decoded token is returned through the parameters 1017 * 1018 * 'h', 'l', or 'L' for integer fields 1019 * 'z' support added 23/7/1999 S.H. 1020 * 'z' changed to 'Z' --davidm 1/25/99 1021 * 't' added for ptrdiff_t 1022 * 1023 * @fmt: the format string 1024 * @type of the token returned 1025 * @flags: various flags such as +, -, # tokens.. 1026 * @field_width: overwritten width 1027 * @base: base of the number (octal, hex, ...) 1028 * @precision: precision of a number 1029 * @qualifier: qualifier of a number (long, size_t, ...) 1030 */ 1031 static int format_decode(const char *fmt, struct printf_spec *spec) 1032 { 1033 const char *start = fmt; 1034 1035 /* we finished early by reading the field width */ 1036 if (spec->type == FORMAT_TYPE_WIDTH) { 1037 if (spec->field_width < 0) { 1038 spec->field_width = -spec->field_width; 1039 spec->flags |= LEFT; 1040 } 1041 spec->type = FORMAT_TYPE_NONE; 1042 goto precision; 1043 } 1044 1045 /* we finished early by reading the precision */ 1046 if (spec->type == FORMAT_TYPE_PRECISION) { 1047 if (spec->precision < 0) 1048 spec->precision = 0; 1049 1050 spec->type = FORMAT_TYPE_NONE; 1051 goto qualifier; 1052 } 1053 1054 /* By default */ 1055 spec->type = FORMAT_TYPE_NONE; 1056 1057 for (; *fmt ; ++fmt) { 1058 if (*fmt == '%') 1059 break; 1060 } 1061 1062 /* Return the current non-format string */ 1063 if (fmt != start || !*fmt) 1064 return fmt - start; 1065 1066 /* Process flags */ 1067 spec->flags = 0; 1068 1069 while (1) { /* this also skips first '%' */ 1070 bool found = true; 1071 1072 ++fmt; 1073 1074 switch (*fmt) { 1075 case '-': spec->flags |= LEFT; break; 1076 case '+': spec->flags |= PLUS; break; 1077 case ' ': spec->flags |= SPACE; break; 1078 case '#': spec->flags |= SPECIAL; break; 1079 case '0': spec->flags |= ZEROPAD; break; 1080 default: found = false; 1081 } 1082 1083 if (!found) 1084 break; 1085 } 1086 1087 /* get field width */ 1088 spec->field_width = -1; 1089 1090 if (isdigit(*fmt)) 1091 spec->field_width = skip_atoi(&fmt); 1092 else if (*fmt == '*') { 1093 /* it's the next argument */ 1094 spec->type = FORMAT_TYPE_WIDTH; 1095 return ++fmt - start; 1096 } 1097 1098 precision: 1099 /* get the precision */ 1100 spec->precision = -1; 1101 if (*fmt == '.') { 1102 ++fmt; 1103 if (isdigit(*fmt)) { 1104 spec->precision = skip_atoi(&fmt); 1105 if (spec->precision < 0) 1106 spec->precision = 0; 1107 } else if (*fmt == '*') { 1108 /* it's the next argument */ 1109 spec->type = FORMAT_TYPE_PRECISION; 1110 return ++fmt - start; 1111 } 1112 } 1113 1114 qualifier: 1115 /* get the conversion qualifier */ 1116 spec->qualifier = -1; 1117 if (*fmt == 'h' || TOLOWER(*fmt) == 'l' || 1118 TOLOWER(*fmt) == 'z' || *fmt == 't') { 1119 spec->qualifier = *fmt++; 1120 if (unlikely(spec->qualifier == *fmt)) { 1121 if (spec->qualifier == 'l') { 1122 spec->qualifier = 'L'; 1123 ++fmt; 1124 } else if (spec->qualifier == 'h') { 1125 spec->qualifier = 'H'; 1126 ++fmt; 1127 } 1128 } 1129 } 1130 1131 /* default base */ 1132 spec->base = 10; 1133 switch (*fmt) { 1134 case 'c': 1135 spec->type = FORMAT_TYPE_CHAR; 1136 return ++fmt - start; 1137 1138 case 's': 1139 spec->type = FORMAT_TYPE_STR; 1140 return ++fmt - start; 1141 1142 case 'p': 1143 spec->type = FORMAT_TYPE_PTR; 1144 return fmt - start; 1145 /* skip alnum */ 1146 1147 case 'n': 1148 spec->type = FORMAT_TYPE_NRCHARS; 1149 return ++fmt - start; 1150 1151 case '%': 1152 spec->type = FORMAT_TYPE_PERCENT_CHAR; 1153 return ++fmt - start; 1154 1155 /* integer number formats - set up the flags and "break" */ 1156 case 'o': 1157 spec->base = 8; 1158 break; 1159 1160 case 'x': 1161 spec->flags |= SMALL; 1162 1163 case 'X': 1164 spec->base = 16; 1165 break; 1166 1167 case 'd': 1168 case 'i': 1169 spec->flags |= SIGN; 1170 case 'u': 1171 break; 1172 1173 default: 1174 spec->type = FORMAT_TYPE_INVALID; 1175 return fmt - start; 1176 } 1177 1178 if (spec->qualifier == 'L') 1179 spec->type = FORMAT_TYPE_LONG_LONG; 1180 else if (spec->qualifier == 'l') { 1181 if (spec->flags & SIGN) 1182 spec->type = FORMAT_TYPE_LONG; 1183 else 1184 spec->type = FORMAT_TYPE_ULONG; 1185 } else if (TOLOWER(spec->qualifier) == 'z') { 1186 spec->type = FORMAT_TYPE_SIZE_T; 1187 } else if (spec->qualifier == 't') { 1188 spec->type = FORMAT_TYPE_PTRDIFF; 1189 } else if (spec->qualifier == 'H') { 1190 if (spec->flags & SIGN) 1191 spec->type = FORMAT_TYPE_BYTE; 1192 else 1193 spec->type = FORMAT_TYPE_UBYTE; 1194 } else if (spec->qualifier == 'h') { 1195 if (spec->flags & SIGN) 1196 spec->type = FORMAT_TYPE_SHORT; 1197 else 1198 spec->type = FORMAT_TYPE_USHORT; 1199 } else { 1200 if (spec->flags & SIGN) 1201 spec->type = FORMAT_TYPE_INT; 1202 else 1203 spec->type = FORMAT_TYPE_UINT; 1204 } 1205 1206 return ++fmt - start; 1207 } 1208 1209 /** 1210 * vsnprintf - Format a string and place it in a buffer 1211 * @buf: The buffer to place the result into 1212 * @size: The size of the buffer, including the trailing null space 1213 * @fmt: The format string to use 1214 * @args: Arguments for the format string 1215 * 1216 * This function follows C99 vsnprintf, but has some extensions: 1217 * %pS output the name of a text symbol with offset 1218 * %ps output the name of a text symbol without offset 1219 * %pF output the name of a function pointer with its offset 1220 * %pf output the name of a function pointer without its offset 1221 * %pR output the address range in a struct resource with decoded flags 1222 * %pr output the address range in a struct resource with raw flags 1223 * %pM output a 6-byte MAC address with colons 1224 * %pm output a 6-byte MAC address without colons 1225 * %pI4 print an IPv4 address without leading zeros 1226 * %pi4 print an IPv4 address with leading zeros 1227 * %pI6 print an IPv6 address with colons 1228 * %pi6 print an IPv6 address without colons 1229 * %pI6c print an IPv6 address as specified by 1230 * http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00 1231 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper 1232 * case. 1233 * %n is ignored 1234 * 1235 * The return value is the number of characters which would 1236 * be generated for the given input, excluding the trailing 1237 * '\0', as per ISO C99. If you want to have the exact 1238 * number of characters written into @buf as return value 1239 * (not including the trailing '\0'), use vscnprintf(). If the 1240 * return is greater than or equal to @size, the resulting 1241 * string is truncated. 1242 * 1243 * Call this function if you are already dealing with a va_list. 1244 * You probably want snprintf() instead. 1245 */ 1246 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 1247 { 1248 unsigned long long num; 1249 char *str, *end; 1250 struct printf_spec spec = {0}; 1251 1252 /* Reject out-of-range values early. Large positive sizes are 1253 used for unknown buffer sizes. */ 1254 if (WARN_ON_ONCE((int) size < 0)) 1255 return 0; 1256 1257 str = buf; 1258 end = buf + size; 1259 1260 /* Make sure end is always >= buf */ 1261 if (end < buf) { 1262 end = ((void *)-1); 1263 size = end - buf; 1264 } 1265 1266 while (*fmt) { 1267 const char *old_fmt = fmt; 1268 int read = format_decode(fmt, &spec); 1269 1270 fmt += read; 1271 1272 switch (spec.type) { 1273 case FORMAT_TYPE_NONE: { 1274 int copy = read; 1275 if (str < end) { 1276 if (copy > end - str) 1277 copy = end - str; 1278 memcpy(str, old_fmt, copy); 1279 } 1280 str += read; 1281 break; 1282 } 1283 1284 case FORMAT_TYPE_WIDTH: 1285 spec.field_width = va_arg(args, int); 1286 break; 1287 1288 case FORMAT_TYPE_PRECISION: 1289 spec.precision = va_arg(args, int); 1290 break; 1291 1292 case FORMAT_TYPE_CHAR: { 1293 char c; 1294 1295 if (!(spec.flags & LEFT)) { 1296 while (--spec.field_width > 0) { 1297 if (str < end) 1298 *str = ' '; 1299 ++str; 1300 1301 } 1302 } 1303 c = (unsigned char) va_arg(args, int); 1304 if (str < end) 1305 *str = c; 1306 ++str; 1307 while (--spec.field_width > 0) { 1308 if (str < end) 1309 *str = ' '; 1310 ++str; 1311 } 1312 break; 1313 } 1314 1315 case FORMAT_TYPE_STR: 1316 str = string(str, end, va_arg(args, char *), spec); 1317 break; 1318 1319 case FORMAT_TYPE_PTR: 1320 str = pointer(fmt+1, str, end, va_arg(args, void *), 1321 spec); 1322 while (isalnum(*fmt)) 1323 fmt++; 1324 break; 1325 1326 case FORMAT_TYPE_PERCENT_CHAR: 1327 if (str < end) 1328 *str = '%'; 1329 ++str; 1330 break; 1331 1332 case FORMAT_TYPE_INVALID: 1333 if (str < end) 1334 *str = '%'; 1335 ++str; 1336 break; 1337 1338 case FORMAT_TYPE_NRCHARS: { 1339 u8 qualifier = spec.qualifier; 1340 1341 if (qualifier == 'l') { 1342 long *ip = va_arg(args, long *); 1343 *ip = (str - buf); 1344 } else if (TOLOWER(qualifier) == 'z') { 1345 size_t *ip = va_arg(args, size_t *); 1346 *ip = (str - buf); 1347 } else { 1348 int *ip = va_arg(args, int *); 1349 *ip = (str - buf); 1350 } 1351 break; 1352 } 1353 1354 default: 1355 switch (spec.type) { 1356 case FORMAT_TYPE_LONG_LONG: 1357 num = va_arg(args, long long); 1358 break; 1359 case FORMAT_TYPE_ULONG: 1360 num = va_arg(args, unsigned long); 1361 break; 1362 case FORMAT_TYPE_LONG: 1363 num = va_arg(args, long); 1364 break; 1365 case FORMAT_TYPE_SIZE_T: 1366 num = va_arg(args, size_t); 1367 break; 1368 case FORMAT_TYPE_PTRDIFF: 1369 num = va_arg(args, ptrdiff_t); 1370 break; 1371 case FORMAT_TYPE_UBYTE: 1372 num = (unsigned char) va_arg(args, int); 1373 break; 1374 case FORMAT_TYPE_BYTE: 1375 num = (signed char) va_arg(args, int); 1376 break; 1377 case FORMAT_TYPE_USHORT: 1378 num = (unsigned short) va_arg(args, int); 1379 break; 1380 case FORMAT_TYPE_SHORT: 1381 num = (short) va_arg(args, int); 1382 break; 1383 case FORMAT_TYPE_INT: 1384 num = (int) va_arg(args, int); 1385 break; 1386 default: 1387 num = va_arg(args, unsigned int); 1388 } 1389 1390 str = number(str, end, num, spec); 1391 } 1392 } 1393 1394 if (size > 0) { 1395 if (str < end) 1396 *str = '\0'; 1397 else 1398 end[-1] = '\0'; 1399 } 1400 1401 /* the trailing null byte doesn't count towards the total */ 1402 return str-buf; 1403 1404 } 1405 EXPORT_SYMBOL(vsnprintf); 1406 1407 /** 1408 * vscnprintf - Format a string and place it in a buffer 1409 * @buf: The buffer to place the result into 1410 * @size: The size of the buffer, including the trailing null space 1411 * @fmt: The format string to use 1412 * @args: Arguments for the format string 1413 * 1414 * The return value is the number of characters which have been written into 1415 * the @buf not including the trailing '\0'. If @size is <= 0 the function 1416 * returns 0. 1417 * 1418 * Call this function if you are already dealing with a va_list. 1419 * You probably want scnprintf() instead. 1420 * 1421 * See the vsnprintf() documentation for format string extensions over C99. 1422 */ 1423 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 1424 { 1425 int i; 1426 1427 i = vsnprintf(buf, size, fmt, args); 1428 1429 return (i >= size) ? (size - 1) : i; 1430 } 1431 EXPORT_SYMBOL(vscnprintf); 1432 1433 /** 1434 * snprintf - Format a string and place it in a buffer 1435 * @buf: The buffer to place the result into 1436 * @size: The size of the buffer, including the trailing null space 1437 * @fmt: The format string to use 1438 * @...: Arguments for the format string 1439 * 1440 * The return value is the number of characters which would be 1441 * generated for the given input, excluding the trailing null, 1442 * as per ISO C99. If the return is greater than or equal to 1443 * @size, the resulting string is truncated. 1444 * 1445 * See the vsnprintf() documentation for format string extensions over C99. 1446 */ 1447 int snprintf(char *buf, size_t size, const char *fmt, ...) 1448 { 1449 va_list args; 1450 int i; 1451 1452 va_start(args, fmt); 1453 i = vsnprintf(buf, size, fmt, args); 1454 va_end(args); 1455 1456 return i; 1457 } 1458 EXPORT_SYMBOL(snprintf); 1459 1460 /** 1461 * scnprintf - Format a string and place it in a buffer 1462 * @buf: The buffer to place the result into 1463 * @size: The size of the buffer, including the trailing null space 1464 * @fmt: The format string to use 1465 * @...: Arguments for the format string 1466 * 1467 * The return value is the number of characters written into @buf not including 1468 * the trailing '\0'. If @size is <= 0 the function returns 0. 1469 */ 1470 1471 int scnprintf(char *buf, size_t size, const char *fmt, ...) 1472 { 1473 va_list args; 1474 int i; 1475 1476 va_start(args, fmt); 1477 i = vsnprintf(buf, size, fmt, args); 1478 va_end(args); 1479 1480 return (i >= size) ? (size - 1) : i; 1481 } 1482 EXPORT_SYMBOL(scnprintf); 1483 1484 /** 1485 * vsprintf - Format a string and place it in a buffer 1486 * @buf: The buffer to place the result into 1487 * @fmt: The format string to use 1488 * @args: Arguments for the format string 1489 * 1490 * The function returns the number of characters written 1491 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid 1492 * buffer overflows. 1493 * 1494 * Call this function if you are already dealing with a va_list. 1495 * You probably want sprintf() instead. 1496 * 1497 * See the vsnprintf() documentation for format string extensions over C99. 1498 */ 1499 int vsprintf(char *buf, const char *fmt, va_list args) 1500 { 1501 return vsnprintf(buf, INT_MAX, fmt, args); 1502 } 1503 EXPORT_SYMBOL(vsprintf); 1504 1505 /** 1506 * sprintf - Format a string and place it in a buffer 1507 * @buf: The buffer to place the result into 1508 * @fmt: The format string to use 1509 * @...: Arguments for the format string 1510 * 1511 * The function returns the number of characters written 1512 * into @buf. Use snprintf() or scnprintf() in order to avoid 1513 * buffer overflows. 1514 * 1515 * See the vsnprintf() documentation for format string extensions over C99. 1516 */ 1517 int sprintf(char *buf, const char *fmt, ...) 1518 { 1519 va_list args; 1520 int i; 1521 1522 va_start(args, fmt); 1523 i = vsnprintf(buf, INT_MAX, fmt, args); 1524 va_end(args); 1525 1526 return i; 1527 } 1528 EXPORT_SYMBOL(sprintf); 1529 1530 #ifdef CONFIG_BINARY_PRINTF 1531 /* 1532 * bprintf service: 1533 * vbin_printf() - VA arguments to binary data 1534 * bstr_printf() - Binary data to text string 1535 */ 1536 1537 /** 1538 * vbin_printf - Parse a format string and place args' binary value in a buffer 1539 * @bin_buf: The buffer to place args' binary value 1540 * @size: The size of the buffer(by words(32bits), not characters) 1541 * @fmt: The format string to use 1542 * @args: Arguments for the format string 1543 * 1544 * The format follows C99 vsnprintf, except %n is ignored, and its argument 1545 * is skiped. 1546 * 1547 * The return value is the number of words(32bits) which would be generated for 1548 * the given input. 1549 * 1550 * NOTE: 1551 * If the return value is greater than @size, the resulting bin_buf is NOT 1552 * valid for bstr_printf(). 1553 */ 1554 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) 1555 { 1556 struct printf_spec spec = {0}; 1557 char *str, *end; 1558 1559 str = (char *)bin_buf; 1560 end = (char *)(bin_buf + size); 1561 1562 #define save_arg(type) \ 1563 do { \ 1564 if (sizeof(type) == 8) { \ 1565 unsigned long long value; \ 1566 str = PTR_ALIGN(str, sizeof(u32)); \ 1567 value = va_arg(args, unsigned long long); \ 1568 if (str + sizeof(type) <= end) { \ 1569 *(u32 *)str = *(u32 *)&value; \ 1570 *(u32 *)(str + 4) = *((u32 *)&value + 1); \ 1571 } \ 1572 } else { \ 1573 unsigned long value; \ 1574 str = PTR_ALIGN(str, sizeof(type)); \ 1575 value = va_arg(args, int); \ 1576 if (str + sizeof(type) <= end) \ 1577 *(typeof(type) *)str = (type)value; \ 1578 } \ 1579 str += sizeof(type); \ 1580 } while (0) 1581 1582 while (*fmt) { 1583 int read = format_decode(fmt, &spec); 1584 1585 fmt += read; 1586 1587 switch (spec.type) { 1588 case FORMAT_TYPE_NONE: 1589 case FORMAT_TYPE_INVALID: 1590 case FORMAT_TYPE_PERCENT_CHAR: 1591 break; 1592 1593 case FORMAT_TYPE_WIDTH: 1594 case FORMAT_TYPE_PRECISION: 1595 save_arg(int); 1596 break; 1597 1598 case FORMAT_TYPE_CHAR: 1599 save_arg(char); 1600 break; 1601 1602 case FORMAT_TYPE_STR: { 1603 const char *save_str = va_arg(args, char *); 1604 size_t len; 1605 1606 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE 1607 || (unsigned long)save_str < PAGE_SIZE) 1608 save_str = "(null)"; 1609 len = strlen(save_str) + 1; 1610 if (str + len < end) 1611 memcpy(str, save_str, len); 1612 str += len; 1613 break; 1614 } 1615 1616 case FORMAT_TYPE_PTR: 1617 save_arg(void *); 1618 /* skip all alphanumeric pointer suffixes */ 1619 while (isalnum(*fmt)) 1620 fmt++; 1621 break; 1622 1623 case FORMAT_TYPE_NRCHARS: { 1624 /* skip %n 's argument */ 1625 u8 qualifier = spec.qualifier; 1626 void *skip_arg; 1627 if (qualifier == 'l') 1628 skip_arg = va_arg(args, long *); 1629 else if (TOLOWER(qualifier) == 'z') 1630 skip_arg = va_arg(args, size_t *); 1631 else 1632 skip_arg = va_arg(args, int *); 1633 break; 1634 } 1635 1636 default: 1637 switch (spec.type) { 1638 1639 case FORMAT_TYPE_LONG_LONG: 1640 save_arg(long long); 1641 break; 1642 case FORMAT_TYPE_ULONG: 1643 case FORMAT_TYPE_LONG: 1644 save_arg(unsigned long); 1645 break; 1646 case FORMAT_TYPE_SIZE_T: 1647 save_arg(size_t); 1648 break; 1649 case FORMAT_TYPE_PTRDIFF: 1650 save_arg(ptrdiff_t); 1651 break; 1652 case FORMAT_TYPE_UBYTE: 1653 case FORMAT_TYPE_BYTE: 1654 save_arg(char); 1655 break; 1656 case FORMAT_TYPE_USHORT: 1657 case FORMAT_TYPE_SHORT: 1658 save_arg(short); 1659 break; 1660 default: 1661 save_arg(int); 1662 } 1663 } 1664 } 1665 1666 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; 1667 #undef save_arg 1668 } 1669 EXPORT_SYMBOL_GPL(vbin_printf); 1670 1671 /** 1672 * bstr_printf - Format a string from binary arguments and place it in a buffer 1673 * @buf: The buffer to place the result into 1674 * @size: The size of the buffer, including the trailing null space 1675 * @fmt: The format string to use 1676 * @bin_buf: Binary arguments for the format string 1677 * 1678 * This function like C99 vsnprintf, but the difference is that vsnprintf gets 1679 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is 1680 * a binary buffer that generated by vbin_printf. 1681 * 1682 * The format follows C99 vsnprintf, but has some extensions: 1683 * see vsnprintf comment for details. 1684 * 1685 * The return value is the number of characters which would 1686 * be generated for the given input, excluding the trailing 1687 * '\0', as per ISO C99. If you want to have the exact 1688 * number of characters written into @buf as return value 1689 * (not including the trailing '\0'), use vscnprintf(). If the 1690 * return is greater than or equal to @size, the resulting 1691 * string is truncated. 1692 */ 1693 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) 1694 { 1695 struct printf_spec spec = {0}; 1696 char *str, *end; 1697 const char *args = (const char *)bin_buf; 1698 1699 if (WARN_ON_ONCE((int) size < 0)) 1700 return 0; 1701 1702 str = buf; 1703 end = buf + size; 1704 1705 #define get_arg(type) \ 1706 ({ \ 1707 typeof(type) value; \ 1708 if (sizeof(type) == 8) { \ 1709 args = PTR_ALIGN(args, sizeof(u32)); \ 1710 *(u32 *)&value = *(u32 *)args; \ 1711 *((u32 *)&value + 1) = *(u32 *)(args + 4); \ 1712 } else { \ 1713 args = PTR_ALIGN(args, sizeof(type)); \ 1714 value = *(typeof(type) *)args; \ 1715 } \ 1716 args += sizeof(type); \ 1717 value; \ 1718 }) 1719 1720 /* Make sure end is always >= buf */ 1721 if (end < buf) { 1722 end = ((void *)-1); 1723 size = end - buf; 1724 } 1725 1726 while (*fmt) { 1727 const char *old_fmt = fmt; 1728 int read = format_decode(fmt, &spec); 1729 1730 fmt += read; 1731 1732 switch (spec.type) { 1733 case FORMAT_TYPE_NONE: { 1734 int copy = read; 1735 if (str < end) { 1736 if (copy > end - str) 1737 copy = end - str; 1738 memcpy(str, old_fmt, copy); 1739 } 1740 str += read; 1741 break; 1742 } 1743 1744 case FORMAT_TYPE_WIDTH: 1745 spec.field_width = get_arg(int); 1746 break; 1747 1748 case FORMAT_TYPE_PRECISION: 1749 spec.precision = get_arg(int); 1750 break; 1751 1752 case FORMAT_TYPE_CHAR: { 1753 char c; 1754 1755 if (!(spec.flags & LEFT)) { 1756 while (--spec.field_width > 0) { 1757 if (str < end) 1758 *str = ' '; 1759 ++str; 1760 } 1761 } 1762 c = (unsigned char) get_arg(char); 1763 if (str < end) 1764 *str = c; 1765 ++str; 1766 while (--spec.field_width > 0) { 1767 if (str < end) 1768 *str = ' '; 1769 ++str; 1770 } 1771 break; 1772 } 1773 1774 case FORMAT_TYPE_STR: { 1775 const char *str_arg = args; 1776 args += strlen(str_arg) + 1; 1777 str = string(str, end, (char *)str_arg, spec); 1778 break; 1779 } 1780 1781 case FORMAT_TYPE_PTR: 1782 str = pointer(fmt+1, str, end, get_arg(void *), spec); 1783 while (isalnum(*fmt)) 1784 fmt++; 1785 break; 1786 1787 case FORMAT_TYPE_PERCENT_CHAR: 1788 case FORMAT_TYPE_INVALID: 1789 if (str < end) 1790 *str = '%'; 1791 ++str; 1792 break; 1793 1794 case FORMAT_TYPE_NRCHARS: 1795 /* skip */ 1796 break; 1797 1798 default: { 1799 unsigned long long num; 1800 1801 switch (spec.type) { 1802 1803 case FORMAT_TYPE_LONG_LONG: 1804 num = get_arg(long long); 1805 break; 1806 case FORMAT_TYPE_ULONG: 1807 case FORMAT_TYPE_LONG: 1808 num = get_arg(unsigned long); 1809 break; 1810 case FORMAT_TYPE_SIZE_T: 1811 num = get_arg(size_t); 1812 break; 1813 case FORMAT_TYPE_PTRDIFF: 1814 num = get_arg(ptrdiff_t); 1815 break; 1816 case FORMAT_TYPE_UBYTE: 1817 num = get_arg(unsigned char); 1818 break; 1819 case FORMAT_TYPE_BYTE: 1820 num = get_arg(signed char); 1821 break; 1822 case FORMAT_TYPE_USHORT: 1823 num = get_arg(unsigned short); 1824 break; 1825 case FORMAT_TYPE_SHORT: 1826 num = get_arg(short); 1827 break; 1828 case FORMAT_TYPE_UINT: 1829 num = get_arg(unsigned int); 1830 break; 1831 default: 1832 num = get_arg(int); 1833 } 1834 1835 str = number(str, end, num, spec); 1836 } /* default: */ 1837 } /* switch(spec.type) */ 1838 } /* while(*fmt) */ 1839 1840 if (size > 0) { 1841 if (str < end) 1842 *str = '\0'; 1843 else 1844 end[-1] = '\0'; 1845 } 1846 1847 #undef get_arg 1848 1849 /* the trailing null byte doesn't count towards the total */ 1850 return str - buf; 1851 } 1852 EXPORT_SYMBOL_GPL(bstr_printf); 1853 1854 /** 1855 * bprintf - Parse a format string and place args' binary value in a buffer 1856 * @bin_buf: The buffer to place args' binary value 1857 * @size: The size of the buffer(by words(32bits), not characters) 1858 * @fmt: The format string to use 1859 * @...: Arguments for the format string 1860 * 1861 * The function returns the number of words(u32) written 1862 * into @bin_buf. 1863 */ 1864 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) 1865 { 1866 va_list args; 1867 int ret; 1868 1869 va_start(args, fmt); 1870 ret = vbin_printf(bin_buf, size, fmt, args); 1871 va_end(args); 1872 1873 return ret; 1874 } 1875 EXPORT_SYMBOL_GPL(bprintf); 1876 1877 #endif /* CONFIG_BINARY_PRINTF */ 1878 1879 /** 1880 * vsscanf - Unformat a buffer into a list of arguments 1881 * @buf: input buffer 1882 * @fmt: format of buffer 1883 * @args: arguments 1884 */ 1885 int vsscanf(const char *buf, const char *fmt, va_list args) 1886 { 1887 const char *str = buf; 1888 char *next; 1889 char digit; 1890 int num = 0; 1891 u8 qualifier; 1892 u8 base; 1893 s16 field_width; 1894 bool is_sign; 1895 1896 while (*fmt && *str) { 1897 /* skip any white space in format */ 1898 /* white space in format matchs any amount of 1899 * white space, including none, in the input. 1900 */ 1901 if (isspace(*fmt)) { 1902 fmt = skip_spaces(++fmt); 1903 str = skip_spaces(str); 1904 } 1905 1906 /* anything that is not a conversion must match exactly */ 1907 if (*fmt != '%' && *fmt) { 1908 if (*fmt++ != *str++) 1909 break; 1910 continue; 1911 } 1912 1913 if (!*fmt) 1914 break; 1915 ++fmt; 1916 1917 /* skip this conversion. 1918 * advance both strings to next white space 1919 */ 1920 if (*fmt == '*') { 1921 while (!isspace(*fmt) && *fmt != '%' && *fmt) 1922 fmt++; 1923 while (!isspace(*str) && *str) 1924 str++; 1925 continue; 1926 } 1927 1928 /* get field width */ 1929 field_width = -1; 1930 if (isdigit(*fmt)) 1931 field_width = skip_atoi(&fmt); 1932 1933 /* get conversion qualifier */ 1934 qualifier = -1; 1935 if (*fmt == 'h' || TOLOWER(*fmt) == 'l' || 1936 TOLOWER(*fmt) == 'z') { 1937 qualifier = *fmt++; 1938 if (unlikely(qualifier == *fmt)) { 1939 if (qualifier == 'h') { 1940 qualifier = 'H'; 1941 fmt++; 1942 } else if (qualifier == 'l') { 1943 qualifier = 'L'; 1944 fmt++; 1945 } 1946 } 1947 } 1948 1949 if (!*fmt || !*str) 1950 break; 1951 1952 base = 10; 1953 is_sign = 0; 1954 1955 switch (*fmt++) { 1956 case 'c': 1957 { 1958 char *s = (char *)va_arg(args, char*); 1959 if (field_width == -1) 1960 field_width = 1; 1961 do { 1962 *s++ = *str++; 1963 } while (--field_width > 0 && *str); 1964 num++; 1965 } 1966 continue; 1967 case 's': 1968 { 1969 char *s = (char *)va_arg(args, char *); 1970 if (field_width == -1) 1971 field_width = SHORT_MAX; 1972 /* first, skip leading white space in buffer */ 1973 str = skip_spaces(str); 1974 1975 /* now copy until next white space */ 1976 while (*str && !isspace(*str) && field_width--) 1977 *s++ = *str++; 1978 *s = '\0'; 1979 num++; 1980 } 1981 continue; 1982 case 'n': 1983 /* return number of characters read so far */ 1984 { 1985 int *i = (int *)va_arg(args, int*); 1986 *i = str - buf; 1987 } 1988 continue; 1989 case 'o': 1990 base = 8; 1991 break; 1992 case 'x': 1993 case 'X': 1994 base = 16; 1995 break; 1996 case 'i': 1997 base = 0; 1998 case 'd': 1999 is_sign = 1; 2000 case 'u': 2001 break; 2002 case '%': 2003 /* looking for '%' in str */ 2004 if (*str++ != '%') 2005 return num; 2006 continue; 2007 default: 2008 /* invalid format; stop here */ 2009 return num; 2010 } 2011 2012 /* have some sort of integer conversion. 2013 * first, skip white space in buffer. 2014 */ 2015 str = skip_spaces(str); 2016 2017 digit = *str; 2018 if (is_sign && digit == '-') 2019 digit = *(str + 1); 2020 2021 if (!digit 2022 || (base == 16 && !isxdigit(digit)) 2023 || (base == 10 && !isdigit(digit)) 2024 || (base == 8 && (!isdigit(digit) || digit > '7')) 2025 || (base == 0 && !isdigit(digit))) 2026 break; 2027 2028 switch (qualifier) { 2029 case 'H': /* that's 'hh' in format */ 2030 if (is_sign) { 2031 signed char *s = (signed char *)va_arg(args, signed char *); 2032 *s = (signed char)simple_strtol(str, &next, base); 2033 } else { 2034 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *); 2035 *s = (unsigned char)simple_strtoul(str, &next, base); 2036 } 2037 break; 2038 case 'h': 2039 if (is_sign) { 2040 short *s = (short *)va_arg(args, short *); 2041 *s = (short)simple_strtol(str, &next, base); 2042 } else { 2043 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *); 2044 *s = (unsigned short)simple_strtoul(str, &next, base); 2045 } 2046 break; 2047 case 'l': 2048 if (is_sign) { 2049 long *l = (long *)va_arg(args, long *); 2050 *l = simple_strtol(str, &next, base); 2051 } else { 2052 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *); 2053 *l = simple_strtoul(str, &next, base); 2054 } 2055 break; 2056 case 'L': 2057 if (is_sign) { 2058 long long *l = (long long *)va_arg(args, long long *); 2059 *l = simple_strtoll(str, &next, base); 2060 } else { 2061 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *); 2062 *l = simple_strtoull(str, &next, base); 2063 } 2064 break; 2065 case 'Z': 2066 case 'z': 2067 { 2068 size_t *s = (size_t *)va_arg(args, size_t *); 2069 *s = (size_t)simple_strtoul(str, &next, base); 2070 } 2071 break; 2072 default: 2073 if (is_sign) { 2074 int *i = (int *)va_arg(args, int *); 2075 *i = (int)simple_strtol(str, &next, base); 2076 } else { 2077 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*); 2078 *i = (unsigned int)simple_strtoul(str, &next, base); 2079 } 2080 break; 2081 } 2082 num++; 2083 2084 if (!next) 2085 break; 2086 str = next; 2087 } 2088 2089 /* 2090 * Now we've come all the way through so either the input string or the 2091 * format ended. In the former case, there can be a %n at the current 2092 * position in the format that needs to be filled. 2093 */ 2094 if (*fmt == '%' && *(fmt + 1) == 'n') { 2095 int *p = (int *)va_arg(args, int *); 2096 *p = str - buf; 2097 } 2098 2099 return num; 2100 } 2101 EXPORT_SYMBOL(vsscanf); 2102 2103 /** 2104 * sscanf - Unformat a buffer into a list of arguments 2105 * @buf: input buffer 2106 * @fmt: formatting of buffer 2107 * @...: resulting arguments 2108 */ 2109 int sscanf(const char *buf, const char *fmt, ...) 2110 { 2111 va_list args; 2112 int i; 2113 2114 va_start(args, fmt); 2115 i = vsscanf(buf, fmt, args); 2116 va_end(args); 2117 2118 return i; 2119 } 2120 EXPORT_SYMBOL(sscanf); 2121