lib/vsprintf.c

   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 <crutcher+kernel@datastacks.com>
  14  * - changed to provide snprintf and vsnprintf functions
  15  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
  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
  29 #include <asm/page.h>           /* for PAGE_SIZE */
  30 #include <asm/div64.h>
  31 #include <asm/sections.h>       /* for dereference_function_descriptor() */
  32
  33 /* Works only for digits and letters, but small and fast */
  34 #define TOLOWER(x) ((x) | 0x20)
  35
  36 static unsigned int simple_guess_base(const char *cp)
  37 {
  38         if (cp[0] == '0') {
  39                 if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
  40                         return 16;
  41                 else
  42                         return 8;
  43         } else {
  44                 return 10;
  45         }
  46 }
  47
  48 /**
  49  * simple_strtoul - convert a string to an unsigned long
  50  * @cp: The start of the string
  51  * @endp: A pointer to the end of the parsed string will be placed here
  52  * @base: The number base to use
  53  */
  54 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  55 {
  56         unsigned long result = 0;
  57
  58         if (!base)
  59                 base = simple_guess_base(cp);
  60
  61         if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
  62                 cp += 2;
  63
  64         while (isxdigit(*cp)) {
  65                 unsigned int value;
  66
  67                 value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
  68                 if (value >= base)
  69                         break;
  70                 result = result * base + value;
  71                 cp++;
  72         }
  73
  74         if (endp)
  75                 *endp = (char *)cp;
  76         return result;
  77 }
  78 EXPORT_SYMBOL(simple_strtoul);
  79
  80 /**
  81  * simple_strtol - convert a string to a signed long
  82  * @cp: The start of the string
  83  * @endp: A pointer to the end of the parsed string will be placed here
  84  * @base: The number base to use
  85  */
  86 long simple_strtol(const char *cp, char **endp, unsigned int base)
  87 {
  88         if(*cp == '-')
  89                 return -simple_strtoul(cp + 1, endp, base);
  90         return simple_strtoul(cp, endp, base);
  91 }
  92 EXPORT_SYMBOL(simple_strtol);
  93
  94 /**
  95  * simple_strtoull - convert a string to an unsigned long long
  96  * @cp: The start of the string
  97  * @endp: A pointer to the end of the parsed string will be placed here
  98  * @base: The number base to use
  99  */
 100 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
 101 {
 102         unsigned long long result = 0;
 103
 104         if (!base)
 105                 base = simple_guess_base(cp);
 106
 107         if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
 108                 cp += 2;
 109
 110         while (isxdigit(*cp)) {
 111                 unsigned int value;
 112
 113                 value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
 114                 if (value >= base)
 115                         break;
 116                 result = result * base + value;
 117                 cp++;
 118         }
 119
 120         if (endp)
 121                 *endp = (char *)cp;
 122         return result;
 123 }
 124 EXPORT_SYMBOL(simple_strtoull);
 125
 126 /**
 127  * simple_strtoll - convert a string to a signed long long
 128  * @cp: The start of the string
 129  * @endp: A pointer to the end of the parsed string will be placed here
 130  * @base: The number base to use
 131  */
 132 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 133 {
 134         if(*cp=='-')
 135                 return -simple_strtoull(cp + 1, endp, base);
 136         return simple_strtoull(cp, endp, base);
 137 }
 138
 139 /**
 140  * strict_strtoul - convert a string to an unsigned long strictly
 141  * @cp: The string to be converted
 142  * @base: The number base to use
 143  * @res: The converted result value
 144  *
 145  * strict_strtoul converts a string to an unsigned long only if the
 146  * string is really an unsigned long string, any string containing
 147  * any invalid char at the tail will be rejected and -EINVAL is returned,
 148  * only a newline char at the tail is acceptible because people generally
 149  * change a module parameter in the following way:
 150  *
 151  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 152  *
 153  * echo will append a newline to the tail.
 154  *
 155  * It returns 0 if conversion is successful and *res is set to the converted
 156  * value, otherwise it returns -EINVAL and *res is set to 0.
 157  *
 158  * simple_strtoul just ignores the successive invalid characters and
 159  * return the converted value of prefix part of the string.
 160  */
 161 int strict_strtoul(const char *cp, unsigned int base, unsigned long *res)
 162 {
 163         char *tail;
 164         unsigned long val;
 165         size_t len;
 166
 167         *res = 0;
 168         len = strlen(cp);
 169         if (len == 0)
 170                 return -EINVAL;
 171
 172         val = simple_strtoul(cp, &tail, base);
 173         if (tail == cp)
 174                 return -EINVAL;
 175         if ((*tail == '\0') ||
 176                 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
 177                 *res = val;
 178                 return 0;
 179         }
 180
 181         return -EINVAL;
 182 }
 183 EXPORT_SYMBOL(strict_strtoul);
 184
 185 /**
 186  * strict_strtol - convert a string to a long strictly
 187  * @cp: The string to be converted
 188  * @base: The number base to use
 189  * @res: The converted result value
 190  *
 191  * strict_strtol is similiar to strict_strtoul, but it allows the first
 192  * character of a string is '-'.
 193  *
 194  * It returns 0 if conversion is successful and *res is set to the converted
 195  * value, otherwise it returns -EINVAL and *res is set to 0.
 196  */
 197 int strict_strtol(const char *cp, unsigned int base, long *res)
 198 {
 199         int ret;
 200         if (*cp == '-') {
 201                 ret = strict_strtoul(cp + 1, base, (unsigned long *)res);
 202                 if (!ret)
 203                         *res = -(*res);
 204         } else {
 205                 ret = strict_strtoul(cp, base, (unsigned long *)res);
 206         }
 207
 208         return ret;
 209 }
 210 EXPORT_SYMBOL(strict_strtol);
 211
 212 /**
 213  * strict_strtoull - convert a string to an unsigned long long strictly
 214  * @cp: The string to be converted
 215  * @base: The number base to use
 216  * @res: The converted result value
 217  *
 218  * strict_strtoull converts a string to an unsigned long long only if the
 219  * string is really an unsigned long long string, any string containing
 220  * any invalid char at the tail will be rejected and -EINVAL is returned,
 221  * only a newline char at the tail is acceptible because people generally
 222  * change a module parameter in the following way:
 223  *
 224  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 225  *
 226  * echo will append a newline to the tail of the string.
 227  *
 228  * It returns 0 if conversion is successful and *res is set to the converted
 229  * value, otherwise it returns -EINVAL and *res is set to 0.
 230  *
 231  * simple_strtoull just ignores the successive invalid characters and
 232  * return the converted value of prefix part of the string.
 233  */
 234 int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res)
 235 {
 236         char *tail;
 237         unsigned long long val;
 238         size_t len;
 239
 240         *res = 0;
 241         len = strlen(cp);
 242         if (len == 0)
 243                 return -EINVAL;
 244
 245         val = simple_strtoull(cp, &tail, base);
 246         if (tail == cp)
 247                 return -EINVAL;
 248         if ((*tail == '\0') ||
 249                 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
 250                 *res = val;
 251                 return 0;
 252         }
 253
 254         return -EINVAL;
 255 }
 256 EXPORT_SYMBOL(strict_strtoull);
 257
 258 /**
 259  * strict_strtoll - convert a string to a long long strictly
 260  * @cp: The string to be converted
 261  * @base: The number base to use
 262  * @res: The converted result value
 263  *
 264  * strict_strtoll is similiar to strict_strtoull, but it allows the first
 265  * character of a string is '-'.
 266  *
 267  * It returns 0 if conversion is successful and *res is set to the converted
 268  * value, otherwise it returns -EINVAL and *res is set to 0.
 269  */
 270 int strict_strtoll(const char *cp, unsigned int base, long long *res)
 271 {
 272         int ret;
 273         if (*cp == '-') {
 274                 ret = strict_strtoull(cp + 1, base, (unsigned long long *)res);
 275                 if (!ret)
 276                         *res = -(*res);
 277         } else {
 278                 ret = strict_strtoull(cp, base, (unsigned long long *)res);
 279         }
 280
 281         return ret;
 282 }
 283 EXPORT_SYMBOL(strict_strtoll);
 284
 285 static int skip_atoi(const char **s)
 286 {
 287         int i=0;
 288
 289         while (isdigit(**s))
 290                 i = i*10 + *((*s)++) - '0';
 291         return i;
 292 }
 293
 294 /* Decimal conversion is by far the most typical, and is used
 295  * for /proc and /sys data. This directly impacts e.g. top performance
 296  * with many processes running. We optimize it for speed
 297  * using code from
 298  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 299  * (with permission from the author, Douglas W. Jones). */
 300
 301 /* Formats correctly any integer in [0,99999].
 302  * Outputs from one to five digits depending on input.
 303  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 304 static char* put_dec_trunc(char *buf, unsigned q)
 305 {
 306         unsigned d3, d2, d1, d0;
 307         d1 = (q>>4) & 0xf;
 308         d2 = (q>>8) & 0xf;
 309         d3 = (q>>12);
 310
 311         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 312         q = (d0 * 0xcd) >> 11;
 313         d0 = d0 - 10*q;
 314         *buf++ = d0 + '0'; /* least significant digit */
 315         d1 = q + 9*d3 + 5*d2 + d1;
 316         if (d1 != 0) {
 317                 q = (d1 * 0xcd) >> 11;
 318                 d1 = d1 - 10*q;
 319                 *buf++ = d1 + '0'; /* next digit */
 320
 321                 d2 = q + 2*d2;
 322                 if ((d2 != 0) || (d3 != 0)) {
 323                         q = (d2 * 0xd) >> 7;
 324                         d2 = d2 - 10*q;
 325                         *buf++ = d2 + '0'; /* next digit */
 326
 327                         d3 = q + 4*d3;
 328                         if (d3 != 0) {
 329                                 q = (d3 * 0xcd) >> 11;
 330                                 d3 = d3 - 10*q;
 331                                 *buf++ = d3 + '0';  /* next digit */
 332                                 if (q != 0)
 333                                         *buf++ = q + '0';  /* most sign. digit */
 334                         }
 335                 }
 336         }
 337         return buf;
 338 }
 339 /* Same with if's removed. Always emits five digits */
 340 static char* put_dec_full(char *buf, unsigned q)
 341 {
 342         /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 343         /* but anyway, gcc produces better code with full-sized ints */
 344         unsigned d3, d2, d1, d0;
 345         d1 = (q>>4) & 0xf;
 346         d2 = (q>>8) & 0xf;
 347         d3 = (q>>12);
 348
 349         /* Possible ways to approx. divide by 10 */
 350         /* gcc -O2 replaces multiply with shifts and adds */
 351         // (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 352         // (x * 0x67) >> 10:  1100111
 353         // (x * 0x34) >> 9:    110100 - same
 354         // (x * 0x1a) >> 8:     11010 - same
 355         // (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 356
 357         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 358         q = (d0 * 0xcd) >> 11;
 359         d0 = d0 - 10*q;
 360         *buf++ = d0 + '0';
 361         d1 = q + 9*d3 + 5*d2 + d1;
 362                 q = (d1 * 0xcd) >> 11;
 363                 d1 = d1 - 10*q;
 364                 *buf++ = d1 + '0';
 365
 366                 d2 = q + 2*d2;
 367                         q = (d2 * 0xd) >> 7;
 368                         d2 = d2 - 10*q;
 369                         *buf++ = d2 + '0';
 370
 371                         d3 = q + 4*d3;
 372                                 q = (d3 * 0xcd) >> 11; /* - shorter code */
 373                                 /* q = (d3 * 0x67) >> 10; - would also work */
 374                                 d3 = d3 - 10*q;
 375                                 *buf++ = d3 + '0';
 376                                         *buf++ = q + '0';
 377         return buf;
 378 }
 379 /* No inlining helps gcc to use registers better */
 380 static noinline char* put_dec(char *buf, unsigned long long num)
 381 {
 382         while (1) {
 383                 unsigned rem;
 384                 if (num < 100000)
 385                         return put_dec_trunc(buf, num);
 386                 rem = do_div(num, 100000);
 387                 buf = put_dec_full(buf, rem);
 388         }
 389 }
 390
 391 #define ZEROPAD 1               /* pad with zero */
 392 #define SIGN    2               /* unsigned/signed long */
 393 #define PLUS    4               /* show plus */
 394 #define SPACE   8               /* space if plus */
 395 #define LEFT    16              /* left justified */
 396 #define SMALL   32              /* Must be 32 == 0x20 */
 397 #define SPECIAL 64              /* 0x */
 398
 399 static char *number(char *buf, char *end, unsigned long long num, int base, int size, int precision, int type)
 400 {
 401         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 402         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 403
 404         char tmp[66];
 405         char sign;
 406         char locase;
 407         int need_pfx = ((type & SPECIAL) && base != 10);
 408         int i;
 409
 410         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 411          * produces same digits or (maybe lowercased) letters */
 412         locase = (type & SMALL);
 413         if (type & LEFT)
 414                 type &= ~ZEROPAD;
 415         sign = 0;
 416         if (type & SIGN) {
 417                 if ((signed long long) num < 0) {
 418                         sign = '-';
 419                         num = - (signed long long) num;
 420                         size--;
 421                 } else if (type & PLUS) {
 422                         sign = '+';
 423                         size--;
 424                 } else if (type & SPACE) {
 425                         sign = ' ';
 426                         size--;
 427                 }
 428         }
 429         if (need_pfx) {
 430                 size--;
 431                 if (base == 16)
 432                         size--;
 433         }
 434
 435         /* generate full string in tmp[], in reverse order */
 436         i = 0;
 437         if (num == 0)
 438                 tmp[i++] = '0';
 439         /* Generic code, for any base:
 440         else do {
 441                 tmp[i++] = (digits[do_div(num,base)] | locase);
 442         } while (num != 0);
 443         */
 444         else if (base != 10) { /* 8 or 16 */
 445                 int mask = base - 1;
 446                 int shift = 3;
 447                 if (base == 16) shift = 4;
 448                 do {
 449                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 450                         num >>= shift;
 451                 } while (num);
 452         } else { /* base 10 */
 453                 i = put_dec(tmp, num) - tmp;
 454         }
 455
 456         /* printing 100 using %2d gives "100", not "00" */
 457         if (i > precision)
 458                 precision = i;
 459         /* leading space padding */
 460         size -= precision;
 461         if (!(type & (ZEROPAD+LEFT))) {
 462                 while(--size >= 0) {
 463                         if (buf < end)
 464                                 *buf = ' ';
 465                         ++buf;
 466                 }
 467         }
 468         /* sign */
 469         if (sign) {
 470                 if (buf < end)
 471                         *buf = sign;
 472                 ++buf;
 473         }
 474         /* "0x" / "0" prefix */
 475         if (need_pfx) {
 476                 if (buf < end)
 477                         *buf = '0';
 478                 ++buf;
 479                 if (base == 16) {
 480                         if (buf < end)
 481                                 *buf = ('X' | locase);
 482                         ++buf;
 483                 }
 484         }
 485         /* zero or space padding */
 486         if (!(type & LEFT)) {
 487                 char c = (type & ZEROPAD) ? '0' : ' ';
 488                 while (--size >= 0) {
 489                         if (buf < end)
 490                                 *buf = c;
 491                         ++buf;
 492                 }
 493         }
 494         /* hmm even more zero padding? */
 495         while (i <= --precision) {
 496                 if (buf < end)
 497                         *buf = '0';
 498                 ++buf;
 499         }
 500         /* actual digits of result */
 501         while (--i >= 0) {
 502                 if (buf < end)
 503                         *buf = tmp[i];
 504                 ++buf;
 505         }
 506         /* trailing space padding */
 507         while (--size >= 0) {
 508                 if (buf < end)
 509                         *buf = ' ';
 510                 ++buf;
 511         }
 512         return buf;
 513 }
 514
 515 static char *string(char *buf, char *end, char *s, int field_width, int precision, int flags)
 516 {
 517         int len, i;
 518
 519         if ((unsigned long)s < PAGE_SIZE)
 520                 s = "<NULL>";
 521
 522         len = strnlen(s, precision);
 523
 524         if (!(flags & LEFT)) {
 525                 while (len < field_width--) {
 526                         if (buf < end)
 527                                 *buf = ' ';
 528                         ++buf;
 529                 }
 530         }
 531         for (i = 0; i < len; ++i) {
 532                 if (buf < end)
 533                         *buf = *s;
 534                 ++buf; ++s;
 535         }
 536         while (len < field_width--) {
 537                 if (buf < end)
 538                         *buf = ' ';
 539                 ++buf;
 540         }
 541         return buf;
 542 }
 543
 544 static char *symbol_string(char *buf, char *end, void *ptr, int field_width, int precision, int flags)
 545 {
 546         unsigned long value = (unsigned long) ptr;
 547 #ifdef CONFIG_KALLSYMS
 548         char sym[KSYM_SYMBOL_LEN];
 549         sprint_symbol(sym, value);
 550         return string(buf, end, sym, field_width, precision, flags);
 551 #else
 552         field_width = 2*sizeof(void *);
 553         flags |= SPECIAL | SMALL | ZEROPAD;
 554         return number(buf, end, value, 16, field_width, precision, flags);
 555 #endif
 556 }
 557
 558 static char *resource_string(char *buf, char *end, struct resource *res, int field_width, int precision, int flags)
 559 {
 560 #ifndef IO_RSRC_PRINTK_SIZE
 561 #define IO_RSRC_PRINTK_SIZE     4
 562 #endif
 563
 564 #ifndef MEM_RSRC_PRINTK_SIZE
 565 #define MEM_RSRC_PRINTK_SIZE    8
 566 #endif
 567
 568         /* room for the actual numbers, the two "0x", -, [, ] and the final zero */
 569         char sym[4*sizeof(resource_size_t) + 8];
 570         char *p = sym, *pend = sym + sizeof(sym);
 571         int size = -1;
 572
 573         if (res->flags & IORESOURCE_IO)
 574                 size = IO_RSRC_PRINTK_SIZE;
 575         else if (res->flags & IORESOURCE_MEM)
 576                 size = MEM_RSRC_PRINTK_SIZE;
 577
 578         *p++ = '[';
 579         p = number(p, pend, res->start, 16, size, -1, SPECIAL | SMALL | ZEROPAD);
 580         *p++ = '-';
 581         p = number(p, pend, res->end, 16, size, -1, SPECIAL | SMALL | ZEROPAD);
 582         *p++ = ']';
 583         *p = 0;
 584
 585         return string(buf, end, sym, field_width, precision, flags);
 586 }
 587
 588 static char *mac_address_string(char *buf, char *end, u8 *addr, int field_width,
 589                                 int precision, int flags)
 590 {
 591         char mac_addr[6 * 3]; /* (6 * 2 hex digits), 5 colons and trailing zero */
 592         char *p = mac_addr;
 593         int i;
 594
 595         for (i = 0; i < 6; i++) {
 596                 p = pack_hex_byte(p, addr[i]);
 597                 if (!(flags & SPECIAL) && i != 5)
 598                         *p++ = ':';
 599         }
 600         *p = '\0';
 601
 602         return string(buf, end, mac_addr, field_width, precision, flags & ~SPECIAL);
 603 }
 604
 605 static char *ip6_addr_string(char *buf, char *end, u8 *addr, int field_width,
 606                          int precision, int flags)
 607 {
 608         char ip6_addr[8 * 5]; /* (8 * 4 hex digits), 7 colons and trailing zero */
 609         char *p = ip6_addr;
 610         int i;
 611
 612         for (i = 0; i < 8; i++) {
 613                 p = pack_hex_byte(p, addr[2 * i]);
 614                 p = pack_hex_byte(p, addr[2 * i + 1]);
 615                 if (!(flags & SPECIAL) && i != 7)
 616                         *p++ = ':';
 617         }
 618         *p = '\0';
 619
 620         return string(buf, end, ip6_addr, field_width, precision, flags & ~SPECIAL);
 621 }
 622
 623 static char *ip4_addr_string(char *buf, char *end, u8 *addr, int field_width,
 624                          int precision, int flags)
 625 {
 626         char ip4_addr[4 * 4]; /* (4 * 3 decimal digits), 3 dots and trailing zero */
 627         char temp[3];   /* hold each IP quad in reverse order */
 628         char *p = ip4_addr;
 629         int i, digits;
 630
 631         for (i = 0; i < 4; i++) {
 632                 digits = put_dec_trunc(temp, addr[i]) - temp;
 633                 /* reverse the digits in the quad */
 634                 while (digits--)
 635                         *p++ = temp[digits];
 636                 if (i != 3)
 637                         *p++ = '.';
 638         }
 639         *p = '\0';
 640
 641         return string(buf, end, ip4_addr, field_width, precision, flags & ~SPECIAL);
 642 }
 643
 644 /*
 645  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 646  * by an extra set of alphanumeric characters that are extended format
 647  * specifiers.
 648  *
 649  * Right now we handle:
 650  *
 651  * - 'F' For symbolic function descriptor pointers
 652  * - 'S' For symbolic direct pointers
 653  * - 'R' For a struct resource pointer, it prints the range of
 654  *       addresses (not the name nor the flags)
 655  * - 'M' For a 6-byte MAC address, it prints the address in the
 656  *       usual colon-separated hex notation
 657  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way (dot-separated
 658  *       decimal for v4 and colon separated network-order 16 bit hex for v6)
 659  * - 'i' [46] for 'raw' IPv4/IPv6 addresses, IPv6 omits the colons, IPv4 is
 660  *       currently the same
 661  *
 662  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
 663  * function pointers are really function descriptors, which contain a
 664  * pointer to the real address.
 665  */
 666 static char *pointer(const char *fmt, char *buf, char *end, void *ptr, int field_width, int precision, int flags)
 667 {
 668         if (!ptr)
 669                 return string(buf, end, "(null)", field_width, precision, flags);
 670
 671         switch (*fmt) {
 672         case 'F':
 673                 ptr = dereference_function_descriptor(ptr);
 674                 /* Fallthrough */
 675         case 'S':
 676                 return symbol_string(buf, end, ptr, field_width, precision, flags);
 677         case 'R':
 678                 return resource_string(buf, end, ptr, field_width, precision, flags);
 679         case 'm':
 680                 flags |= SPECIAL;
 681                 /* Fallthrough */
 682         case 'M':
 683                 return mac_address_string(buf, end, ptr, field_width, precision, flags);
 684         case 'i':
 685                 flags |= SPECIAL;
 686                 /* Fallthrough */
 687         case 'I':
 688                 if (fmt[1] == '6')
 689                         return ip6_addr_string(buf, end, ptr, field_width, precision, flags);
 690                 if (fmt[1] == '4')
 691                         return ip4_addr_string(buf, end, ptr, field_width, precision, flags);
 692                 flags &= ~SPECIAL;
 693                 break;
 694         }
 695         flags |= SMALL;
 696         if (field_width == -1) {
 697                 field_width = 2*sizeof(void *);
 698                 flags |= ZEROPAD;
 699         }
 700         return number(buf, end, (unsigned long) ptr, 16, field_width, precision, flags);
 701 }
 702
 703 /**
 704  * vsnprintf - Format a string and place it in a buffer
 705  * @buf: The buffer to place the result into
 706  * @size: The size of the buffer, including the trailing null space
 707  * @fmt: The format string to use
 708  * @args: Arguments for the format string
 709  *
 710  * This function follows C99 vsnprintf, but has some extensions:
 711  * %pS output the name of a text symbol
 712  * %pF output the name of a function pointer
 713  * %pR output the address range in a struct resource
 714  *
 715  * The return value is the number of characters which would
 716  * be generated for the given input, excluding the trailing
 717  * '\0', as per ISO C99. If you want to have the exact
 718  * number of characters written into @buf as return value
 719  * (not including the trailing '\0'), use vscnprintf(). If the
 720  * return is greater than or equal to @size, the resulting
 721  * string is truncated.
 722  *
 723  * Call this function if you are already dealing with a va_list.
 724  * You probably want snprintf() instead.
 725  */
 726 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 727 {
 728         unsigned long long num;
 729         int base;
 730         char *str, *end, c;
 731
 732         int flags;              /* flags to number() */
 733
 734         int field_width;        /* width of output field */
 735         int precision;          /* min. # of digits for integers; max
 736                                    number of chars for from string */
 737         int qualifier;          /* 'h', 'l', or 'L' for integer fields */
 738                                 /* 'z' support added 23/7/1999 S.H.    */
 739                                 /* 'z' changed to 'Z' --davidm 1/25/99 */
 740                                 /* 't' added for ptrdiff_t */
 741
 742         /* Reject out-of-range values early.  Large positive sizes are
 743            used for unknown buffer sizes. */
 744         if (unlikely((int) size < 0)) {
 745                 /* There can be only one.. */
 746                 static char warn = 1;
 747                 WARN_ON(warn);
 748                 warn = 0;
 749                 return 0;
 750         }
 751
 752         str = buf;
 753         end = buf + size;
 754
 755         /* Make sure end is always >= buf */
 756         if (end < buf) {
 757                 end = ((void *)-1);
 758                 size = end - buf;
 759         }
 760
 761         for (; *fmt ; ++fmt) {
 762                 if (*fmt != '%') {
 763                         if (str < end)
 764                                 *str = *fmt;
 765                         ++str;
 766                         continue;
 767                 }
 768
 769                 /* process flags */
 770                 flags = 0;
 771                 repeat:
 772                         ++fmt;          /* this also skips first '%' */
 773                         switch (*fmt) {
 774                                 case '-': flags |= LEFT; goto repeat;
 775                                 case '+': flags |= PLUS; goto repeat;
 776                                 case ' ': flags |= SPACE; goto repeat;
 777                                 case '#': flags |= SPECIAL; goto repeat;
 778                                 case '0': flags |= ZEROPAD; goto repeat;
 779                         }
 780
 781                 /* get field width */
 782                 field_width = -1;
 783                 if (isdigit(*fmt))
 784                         field_width = skip_atoi(&fmt);
 785                 else if (*fmt == '*') {
 786                         ++fmt;
 787                         /* it's the next argument */
 788                         field_width = va_arg(args, int);
 789                         if (field_width < 0) {
 790                                 field_width = -field_width;
 791                                 flags |= LEFT;
 792                         }
 793                 }
 794
 795                 /* get the precision */
 796                 precision = -1;
 797                 if (*fmt == '.') {
 798                         ++fmt;
 799                         if (isdigit(*fmt))
 800                                 precision = skip_atoi(&fmt);
 801                         else if (*fmt == '*') {
 802                                 ++fmt;
 803                                 /* it's the next argument */
 804                                 precision = va_arg(args, int);
 805                         }
 806                         if (precision < 0)
 807                                 precision = 0;
 808                 }
 809
 810                 /* get the conversion qualifier */
 811                 qualifier = -1;
 812                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 813                     *fmt =='Z' || *fmt == 'z' || *fmt == 't') {
 814                         qualifier = *fmt;
 815                         ++fmt;
 816                         if (qualifier == 'l' && *fmt == 'l') {
 817                                 qualifier = 'L';
 818                                 ++fmt;
 819                         }
 820                 }
 821
 822                 /* default base */
 823                 base = 10;
 824
 825                 switch (*fmt) {
 826                         case 'c':
 827                                 if (!(flags & LEFT)) {
 828                                         while (--field_width > 0) {
 829                                                 if (str < end)
 830                                                         *str = ' ';
 831                                                 ++str;
 832                                         }
 833                                 }
 834                                 c = (unsigned char) va_arg(args, int);
 835                                 if (str < end)
 836                                         *str = c;
 837                                 ++str;
 838                                 while (--field_width > 0) {
 839                                         if (str < end)
 840                                                 *str = ' ';
 841                                         ++str;
 842                                 }
 843                                 continue;
 844
 845                         case 's':
 846                                 str = string(str, end, va_arg(args, char *), field_width, precision, flags);
 847                                 continue;
 848
 849                         case 'p':
 850                                 str = pointer(fmt+1, str, end,
 851                                                 va_arg(args, void *),
 852                                                 field_width, precision, flags);
 853                                 /* Skip all alphanumeric pointer suffixes */
 854                                 while (isalnum(fmt[1]))
 855                                         fmt++;
 856                                 continue;
 857
 858                         case 'n':
 859                                 /* FIXME:
 860                                 * What does C99 say about the overflow case here? */
 861                                 if (qualifier == 'l') {
 862                                         long * ip = va_arg(args, long *);
 863                                         *ip = (str - buf);
 864                                 } else if (qualifier == 'Z' || qualifier == 'z') {
 865                                         size_t * ip = va_arg(args, size_t *);
 866                                         *ip = (str - buf);
 867                                 } else {
 868                                         int * ip = va_arg(args, int *);
 869                                         *ip = (str - buf);
 870                                 }
 871                                 continue;
 872
 873                         case '%':
 874                                 if (str < end)
 875                                         *str = '%';
 876                                 ++str;
 877                                 continue;
 878
 879                                 /* integer number formats - set up the flags and "break" */
 880                         case 'o':
 881                                 base = 8;
 882                                 break;
 883
 884                         case 'x':
 885                                 flags |= SMALL;
 886                         case 'X':
 887                                 base = 16;
 888                                 break;
 889
 890                         case 'd':
 891                         case 'i':
 892                                 flags |= SIGN;
 893                         case 'u':
 894                                 break;
 895
 896                         default:
 897                                 if (str < end)
 898                                         *str = '%';
 899                                 ++str;
 900                                 if (*fmt) {
 901                                         if (str < end)
 902                                                 *str = *fmt;
 903                                         ++str;
 904                                 } else {
 905                                         --fmt;
 906                                 }
 907                                 continue;
 908                 }
 909                 if (qualifier == 'L')
 910                         num = va_arg(args, long long);
 911                 else if (qualifier == 'l') {
 912                         num = va_arg(args, unsigned long);
 913                         if (flags & SIGN)
 914                                 num = (signed long) num;
 915                 } else if (qualifier == 'Z' || qualifier == 'z') {
 916                         num = va_arg(args, size_t);
 917                 } else if (qualifier == 't') {
 918                         num = va_arg(args, ptrdiff_t);
 919                 } else if (qualifier == 'h') {
 920                         num = (unsigned short) va_arg(args, int);
 921                         if (flags & SIGN)
 922                                 num = (signed short) num;
 923                 } else {
 924                         num = va_arg(args, unsigned int);
 925                         if (flags & SIGN)
 926                                 num = (signed int) num;
 927                 }
 928                 str = number(str, end, num, base,
 929                                 field_width, precision, flags);
 930         }
 931         if (size > 0) {
 932                 if (str < end)
 933                         *str = '\0';
 934                 else
 935                         end[-1] = '\0';
 936         }
 937         /* the trailing null byte doesn't count towards the total */
 938         return str-buf;
 939 }
 940 EXPORT_SYMBOL(vsnprintf);
 941
 942 /**
 943  * vscnprintf - Format a string and place it in a buffer
 944  * @buf: The buffer to place the result into
 945  * @size: The size of the buffer, including the trailing null space
 946  * @fmt: The format string to use
 947  * @args: Arguments for the format string
 948  *
 949  * The return value is the number of characters which have been written into
 950  * the @buf not including the trailing '\0'. If @size is <= 0 the function
 951  * returns 0.
 952  *
 953  * Call this function if you are already dealing with a va_list.
 954  * You probably want scnprintf() instead.
 955  *
 956  * See the vsnprintf() documentation for format string extensions over C99.
 957  */
 958 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 959 {
 960         int i;
 961
 962         i=vsnprintf(buf,size,fmt,args);
 963         return (i >= size) ? (size - 1) : i;
 964 }
 965 EXPORT_SYMBOL(vscnprintf);
 966
 967 /**
 968  * snprintf - Format a string and place it in a buffer
 969  * @buf: The buffer to place the result into
 970  * @size: The size of the buffer, including the trailing null space
 971  * @fmt: The format string to use
 972  * @...: Arguments for the format string
 973  *
 974  * The return value is the number of characters which would be
 975  * generated for the given input, excluding the trailing null,
 976  * as per ISO C99.  If the return is greater than or equal to
 977  * @size, the resulting string is truncated.
 978  *
 979  * See the vsnprintf() documentation for format string extensions over C99.
 980  */
 981 int snprintf(char * buf, size_t size, const char *fmt, ...)
 982 {
 983         va_list args;
 984         int i;
 985
 986         va_start(args, fmt);
 987         i=vsnprintf(buf,size,fmt,args);
 988         va_end(args);
 989         return i;
 990 }
 991 EXPORT_SYMBOL(snprintf);
 992
 993 /**
 994  * scnprintf - Format a string and place it in a buffer
 995  * @buf: The buffer to place the result into
 996  * @size: The size of the buffer, including the trailing null space
 997  * @fmt: The format string to use
 998  * @...: Arguments for the format string
 999  *
1000  * The return value is the number of characters written into @buf not including
1001  * the trailing '\0'. If @size is <= 0 the function returns 0.
1002  */
1003
1004 int scnprintf(char * buf, size_t size, const char *fmt, ...)
1005 {
1006         va_list args;
1007         int i;
1008
1009         va_start(args, fmt);
1010         i = vsnprintf(buf, size, fmt, args);
1011         va_end(args);
1012         return (i >= size) ? (size - 1) : i;
1013 }
1014 EXPORT_SYMBOL(scnprintf);
1015
1016 /**
1017  * vsprintf - Format a string and place it in a buffer
1018  * @buf: The buffer to place the result into
1019  * @fmt: The format string to use
1020  * @args: Arguments for the format string
1021  *
1022  * The function returns the number of characters written
1023  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1024  * buffer overflows.
1025  *
1026  * Call this function if you are already dealing with a va_list.
1027  * You probably want sprintf() instead.
1028  *
1029  * See the vsnprintf() documentation for format string extensions over C99.
1030  */
1031 int vsprintf(char *buf, const char *fmt, va_list args)
1032 {
1033         return vsnprintf(buf, INT_MAX, fmt, args);
1034 }
1035 EXPORT_SYMBOL(vsprintf);
1036
1037 /**
1038  * sprintf - Format a string and place it in a buffer
1039  * @buf: The buffer to place the result into
1040  * @fmt: The format string to use
1041  * @...: Arguments for the format string
1042  *
1043  * The function returns the number of characters written
1044  * into @buf. Use snprintf() or scnprintf() in order to avoid
1045  * buffer overflows.
1046  *
1047  * See the vsnprintf() documentation for format string extensions over C99.
1048  */
1049 int sprintf(char * buf, const char *fmt, ...)
1050 {
1051         va_list args;
1052         int i;
1053
1054         va_start(args, fmt);
1055         i=vsnprintf(buf, INT_MAX, fmt, args);
1056         va_end(args);
1057         return i;
1058 }
1059 EXPORT_SYMBOL(sprintf);
1060
1061 /**
1062  * vsscanf - Unformat a buffer into a list of arguments
1063  * @buf:        input buffer
1064  * @fmt:        format of buffer
1065  * @args:       arguments
1066  */
1067 int vsscanf(const char * buf, const char * fmt, va_list args)
1068 {
1069         const char *str = buf;
1070         char *next;
1071         char digit;
1072         int num = 0;
1073         int qualifier;
1074         int base;
1075         int field_width;
1076         int is_sign = 0;
1077
1078         while(*fmt && *str) {
1079                 /* skip any white space in format */
1080                 /* white space in format matchs any amount of
1081                  * white space, including none, in the input.
1082                  */
1083                 if (isspace(*fmt)) {
1084                         while (isspace(*fmt))
1085                                 ++fmt;
1086                         while (isspace(*str))
1087                                 ++str;
1088                 }
1089
1090                 /* anything that is not a conversion must match exactly */
1091                 if (*fmt != '%' && *fmt) {
1092                         if (*fmt++ != *str++)
1093                                 break;
1094                         continue;
1095                 }
1096
1097                 if (!*fmt)
1098                         break;
1099                 ++fmt;
1100
1101                 /* skip this conversion.
1102                  * advance both strings to next white space
1103                  */
1104                 if (*fmt == '*') {
1105                         while (!isspace(*fmt) && *fmt)
1106                                 fmt++;
1107                         while (!isspace(*str) && *str)
1108                                 str++;
1109                         continue;
1110                 }
1111
1112                 /* get field width */
1113                 field_width = -1;
1114                 if (isdigit(*fmt))
1115                         field_width = skip_atoi(&fmt);
1116
1117                 /* get conversion qualifier */
1118                 qualifier = -1;
1119                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
1120                     *fmt == 'Z' || *fmt == 'z') {
1121                         qualifier = *fmt++;
1122                         if (unlikely(qualifier == *fmt)) {
1123                                 if (qualifier == 'h') {
1124                                         qualifier = 'H';
1125                                         fmt++;
1126                                 } else if (qualifier == 'l') {
1127                                         qualifier = 'L';
1128                                         fmt++;
1129                                 }
1130                         }
1131                 }
1132                 base = 10;
1133                 is_sign = 0;
1134
1135                 if (!*fmt || !*str)
1136                         break;
1137
1138                 switch(*fmt++) {
1139                 case 'c':
1140                 {
1141                         char *s = (char *) va_arg(args,char*);
1142                         if (field_width == -1)
1143                                 field_width = 1;
1144                         do {
1145                                 *s++ = *str++;
1146                         } while (--field_width > 0 && *str);
1147                         num++;
1148                 }
1149                 continue;
1150                 case 's':
1151                 {
1152                         char *s = (char *) va_arg(args, char *);
1153                         if(field_width == -1)
1154                                 field_width = INT_MAX;
1155                         /* first, skip leading white space in buffer */
1156                         while (isspace(*str))
1157                                 str++;
1158
1159                         /* now copy until next white space */
1160                         while (*str && !isspace(*str) && field_width--) {
1161                                 *s++ = *str++;
1162                         }
1163                         *s = '\0';
1164                         num++;
1165                 }
1166                 continue;
1167                 case 'n':
1168                         /* return number of characters read so far */
1169                 {
1170                         int *i = (int *)va_arg(args,int*);
1171                         *i = str - buf;
1172                 }
1173                 continue;
1174                 case 'o':
1175                         base = 8;
1176                         break;
1177                 case 'x':
1178                 case 'X':
1179                         base = 16;
1180                         break;
1181                 case 'i':
1182                         base = 0;
1183                 case 'd':
1184                         is_sign = 1;
1185                 case 'u':
1186                         break;
1187                 case '%':
1188                         /* looking for '%' in str */
1189                         if (*str++ != '%')
1190                                 return num;
1191                         continue;
1192                 default:
1193                         /* invalid format; stop here */
1194                         return num;
1195                 }
1196
1197                 /* have some sort of integer conversion.
1198                  * first, skip white space in buffer.
1199                  */
1200                 while (isspace(*str))
1201                         str++;
1202
1203                 digit = *str;
1204                 if (is_sign && digit == '-')
1205                         digit = *(str + 1);
1206
1207                 if (!digit
1208                     || (base == 16 && !isxdigit(digit))
1209                     || (base == 10 && !isdigit(digit))
1210                     || (base == 8 && (!isdigit(digit) || digit > '7'))
1211                     || (base == 0 && !isdigit(digit)))
1212                                 break;
1213
1214                 switch(qualifier) {
1215                 case 'H':       /* that's 'hh' in format */
1216                         if (is_sign) {
1217                                 signed char *s = (signed char *) va_arg(args,signed char *);
1218                                 *s = (signed char) simple_strtol(str,&next,base);
1219                         } else {
1220                                 unsigned char *s = (unsigned char *) va_arg(args, unsigned char *);
1221                                 *s = (unsigned char) simple_strtoul(str, &next, base);
1222                         }
1223                         break;
1224                 case 'h':
1225                         if (is_sign) {
1226                                 short *s = (short *) va_arg(args,short *);
1227                                 *s = (short) simple_strtol(str,&next,base);
1228                         } else {
1229                                 unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
1230                                 *s = (unsigned short) simple_strtoul(str, &next, base);
1231                         }
1232                         break;
1233                 case 'l':
1234                         if (is_sign) {
1235                                 long *l = (long *) va_arg(args,long *);
1236                                 *l = simple_strtol(str,&next,base);
1237                         } else {
1238                                 unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
1239                                 *l = simple_strtoul(str,&next,base);
1240                         }
1241                         break;
1242                 case 'L':
1243                         if (is_sign) {
1244                                 long long *l = (long long*) va_arg(args,long long *);
1245                                 *l = simple_strtoll(str,&next,base);
1246                         } else {
1247                                 unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
1248                                 *l = simple_strtoull(str,&next,base);
1249                         }
1250                         break;
1251                 case 'Z':
1252                 case 'z':
1253                 {
1254                         size_t *s = (size_t*) va_arg(args,size_t*);
1255                         *s = (size_t) simple_strtoul(str,&next,base);
1256                 }
1257                 break;
1258                 default:
1259                         if (is_sign) {
1260                                 int *i = (int *) va_arg(args, int*);
1261                                 *i = (int) simple_strtol(str,&next,base);
1262                         } else {
1263                                 unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
1264                                 *i = (unsigned int) simple_strtoul(str,&next,base);
1265                         }
1266                         break;
1267                 }
1268                 num++;
1269
1270                 if (!next)
1271                         break;
1272                 str = next;
1273         }
1274
1275         /*
1276          * Now we've come all the way through so either the input string or the
1277          * format ended. In the former case, there can be a %n at the current
1278          * position in the format that needs to be filled.
1279          */
1280         if (*fmt == '%' && *(fmt + 1) == 'n') {
1281                 int *p = (int *)va_arg(args, int *);
1282                 *p = str - buf;
1283         }
1284
1285         return num;
1286 }
1287 EXPORT_SYMBOL(vsscanf);
1288
1289 /**
1290  * sscanf - Unformat a buffer into a list of arguments
1291  * @buf:        input buffer
1292  * @fmt:        formatting of buffer
1293  * @...:        resulting arguments
1294  */
1295 int sscanf(const char * buf, const char * fmt, ...)
1296 {
1297         va_list args;
1298         int i;
1299
1300         va_start(args,fmt);
1301         i = vsscanf(buf,fmt,args);
1302         va_end(args);
1303         return i;
1304 }
1305 EXPORT_SYMBOL(sscanf);