release/src-rt-6.x/linux/linux-2.6/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
  28 #include <asm/page.h>           /* for PAGE_SIZE */
  29 #include <asm/div64.h>
  30
  31 /* Works only for digits and letters, but small and fast */
  32 #define TOLOWER(x) ((x) | 0x20)
  33
  34 /**
  35  * simple_strtoul - convert a string to an unsigned long
  36  * @cp: The start of the string
  37  * @endp: A pointer to the end of the parsed string will be placed here
  38  * @base: The number base to use
  39  */
  40 unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
  41 {
  42         unsigned long result = 0,value;
  43
  44         if (!base) {
  45                 base = 10;
  46                 if (*cp == '0') {
  47                         base = 8;
  48                         cp++;
  49                         if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
  50                                 cp++;
  51                                 base = 16;
  52                         }
  53                 }
  54         } else if (base == 16) {
  55                 if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
  56                         cp += 2;
  57         }
  58         while (isxdigit(*cp) &&
  59                (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
  60                 result = result*base + value;
  61                 cp++;
  62         }
  63         if (endp)
  64                 *endp = (char *)cp;
  65         return result;
  66 }
  67
  68 EXPORT_SYMBOL(simple_strtoul);
  69
  70 /**
  71  * simple_strtol - convert a string to a signed long
  72  * @cp: The start of the string
  73  * @endp: A pointer to the end of the parsed string will be placed here
  74  * @base: The number base to use
  75  */
  76 long simple_strtol(const char *cp,char **endp,unsigned int base)
  77 {
  78         if(*cp=='-')
  79                 return -simple_strtoul(cp+1,endp,base);
  80         return simple_strtoul(cp,endp,base);
  81 }
  82
  83 EXPORT_SYMBOL(simple_strtol);
  84
  85 /**
  86  * simple_strtoull - convert a string to an unsigned long long
  87  * @cp: The start of the string
  88  * @endp: A pointer to the end of the parsed string will be placed here
  89  * @base: The number base to use
  90  */
  91 unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base)
  92 {
  93         unsigned long long result = 0,value;
  94
  95         if (!base) {
  96                 base = 10;
  97                 if (*cp == '0') {
  98                         base = 8;
  99                         cp++;
 100                         if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
 101                                 cp++;
 102                                 base = 16;
 103                         }
 104                 }
 105         } else if (base == 16) {
 106                 if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
 107                         cp += 2;
 108         }
 109         while (isxdigit(*cp)
 110          && (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
 111                 result = result*base + value;
 112                 cp++;
 113         }
 114         if (endp)
 115                 *endp = (char *)cp;
 116         return result;
 117 }
 118
 119 EXPORT_SYMBOL(simple_strtoull);
 120
 121 /**
 122  * simple_strtoll - convert a string to a signed long long
 123  * @cp: The start of the string
 124  * @endp: A pointer to the end of the parsed string will be placed here
 125  * @base: The number base to use
 126  */
 127 long long simple_strtoll(const char *cp,char **endp,unsigned int base)
 128 {
 129         if(*cp=='-')
 130                 return -simple_strtoull(cp+1,endp,base);
 131         return simple_strtoull(cp,endp,base);
 132 }
 133
 134 static int skip_atoi(const char **s)
 135 {
 136         int i=0;
 137
 138         while (isdigit(**s))
 139                 i = i*10 + *((*s)++) - '0';
 140         return i;
 141 }
 142
 143 /* Decimal conversion is by far the most typical, and is used
 144  * for /proc and /sys data. This directly impacts e.g. top performance
 145  * with many processes running. We optimize it for speed
 146  * using code from
 147  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 148  * (with permission from the author, Douglas W. Jones). */
 149
 150 /* Formats correctly any integer in [0,99999].
 151  * Outputs from one to five digits depending on input.
 152  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 153 static char* put_dec_trunc(char *buf, unsigned q)
 154 {
 155         unsigned d3, d2, d1, d0;
 156         d1 = (q>>4) & 0xf;
 157         d2 = (q>>8) & 0xf;
 158         d3 = (q>>12);
 159
 160         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 161         q = (d0 * 0xcd) >> 11;
 162         d0 = d0 - 10*q;
 163         *buf++ = d0 + '0'; /* least significant digit */
 164         d1 = q + 9*d3 + 5*d2 + d1;
 165         if (d1 != 0) {
 166                 q = (d1 * 0xcd) >> 11;
 167                 d1 = d1 - 10*q;
 168                 *buf++ = d1 + '0'; /* next digit */
 169
 170                 d2 = q + 2*d2;
 171                 if ((d2 != 0) || (d3 != 0)) {
 172                         q = (d2 * 0xd) >> 7;
 173                         d2 = d2 - 10*q;
 174                         *buf++ = d2 + '0'; /* next digit */
 175
 176                         d3 = q + 4*d3;
 177                         if (d3 != 0) {
 178                                 q = (d3 * 0xcd) >> 11;
 179                                 d3 = d3 - 10*q;
 180                                 *buf++ = d3 + '0';  /* next digit */
 181                                 if (q != 0)
 182                                         *buf++ = q + '0';  /* most sign. digit */
 183                         }
 184                 }
 185         }
 186         return buf;
 187 }
 188 /* Same with if's removed. Always emits five digits */
 189 static char* put_dec_full(char *buf, unsigned q)
 190 {
 191         /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 192         /* but anyway, gcc produces better code with full-sized ints */
 193         unsigned d3, d2, d1, d0;
 194         d1 = (q>>4) & 0xf;
 195         d2 = (q>>8) & 0xf;
 196         d3 = (q>>12);
 197
 198         /* Possible ways to approx. divide by 10 */
 199         /* gcc -O2 replaces multiply with shifts and adds */
 200         // (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 201         // (x * 0x67) >> 10:  1100111
 202         // (x * 0x34) >> 9:    110100 - same
 203         // (x * 0x1a) >> 8:     11010 - same
 204         // (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 205
 206         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 207         q = (d0 * 0xcd) >> 11;
 208         d0 = d0 - 10*q;
 209         *buf++ = d0 + '0';
 210         d1 = q + 9*d3 + 5*d2 + d1;
 211                 q = (d1 * 0xcd) >> 11;
 212                 d1 = d1 - 10*q;
 213                 *buf++ = d1 + '0';
 214
 215                 d2 = q + 2*d2;
 216                         q = (d2 * 0xd) >> 7;
 217                         d2 = d2 - 10*q;
 218                         *buf++ = d2 + '0';
 219
 220                         d3 = q + 4*d3;
 221                                 q = (d3 * 0xcd) >> 11; /* - shorter code */
 222                                 /* q = (d3 * 0x67) >> 10; - would also work */
 223                                 d3 = d3 - 10*q;
 224                                 *buf++ = d3 + '0';
 225                                         *buf++ = q + '0';
 226         return buf;
 227 }
 228 /* No inlining helps gcc to use registers better */
 229 static noinline char* put_dec(char *buf, unsigned long long num)
 230 {
 231         while (1) {
 232                 unsigned rem;
 233                 if (num < 100000)
 234                         return put_dec_trunc(buf, num);
 235                 rem = do_div(num, 100000);
 236                 buf = put_dec_full(buf, rem);
 237         }
 238 }
 239
 240 #define ZEROPAD 1               /* pad with zero */
 241 #define SIGN    2               /* unsigned/signed long */
 242 #define PLUS    4               /* show plus */
 243 #define SPACE   8               /* space if plus */
 244 #define LEFT    16              /* left justified */
 245 #define SMALL   32              /* Must be 32 == 0x20 */
 246 #define SPECIAL 64              /* 0x */
 247
 248 static char *number(char *buf, char *end, unsigned long long num, int base, int size, int precision, int type)
 249 {
 250         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 251         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 252
 253         char tmp[66];
 254         char sign;
 255         char locase;
 256         int need_pfx = ((type & SPECIAL) && base != 10);
 257         int i;
 258
 259         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 260          * produces same digits or (maybe lowercased) letters */
 261         locase = (type & SMALL);
 262         if (type & LEFT)
 263                 type &= ~ZEROPAD;
 264         sign = 0;
 265         if (type & SIGN) {
 266                 if ((signed long long) num < 0) {
 267                         sign = '-';
 268                         num = - (signed long long) num;
 269                         size--;
 270                 } else if (type & PLUS) {
 271                         sign = '+';
 272                         size--;
 273                 } else if (type & SPACE) {
 274                         sign = ' ';
 275                         size--;
 276                 }
 277         }
 278         if (need_pfx) {
 279                 size--;
 280                 if (base == 16)
 281                         size--;
 282         }
 283
 284         /* generate full string in tmp[], in reverse order */
 285         i = 0;
 286         if (num == 0)
 287                 tmp[i++] = '0';
 288         /* Generic code, for any base:
 289         else do {
 290                 tmp[i++] = (digits[do_div(num,base)] | locase);
 291         } while (num != 0);
 292         */
 293         else if (base != 10) { /* 8 or 16 */
 294                 int mask = base - 1;
 295                 int shift = 3;
 296                 if (base == 16) shift = 4;
 297                 do {
 298                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 299                         num >>= shift;
 300                 } while (num);
 301         } else { /* base 10 */
 302                 i = put_dec(tmp, num) - tmp;
 303         }
 304
 305         /* printing 100 using %2d gives "100", not "00" */
 306         if (i > precision)
 307                 precision = i;
 308         /* leading space padding */
 309         size -= precision;
 310         if (!(type & (ZEROPAD+LEFT))) {
 311                 while(--size >= 0) {
 312                         if (buf < end)
 313                                 *buf = ' ';
 314                         ++buf;
 315                 }
 316         }
 317         /* sign */
 318         if (sign) {
 319                 if (buf < end)
 320                         *buf = sign;
 321                 ++buf;
 322         }
 323         /* "0x" / "0" prefix */
 324         if (need_pfx) {
 325                 if (buf < end)
 326                         *buf = '0';
 327                 ++buf;
 328                 if (base == 16) {
 329                         if (buf < end)
 330                                 *buf = ('X' | locase);
 331                         ++buf;
 332                 }
 333         }
 334         /* zero or space padding */
 335         if (!(type & LEFT)) {
 336                 char c = (type & ZEROPAD) ? '0' : ' ';
 337                 while (--size >= 0) {
 338                         if (buf < end)
 339                                 *buf = c;
 340                         ++buf;
 341                 }
 342         }
 343         /* hmm even more zero padding? */
 344         while (i <= --precision) {
 345                 if (buf < end)
 346                         *buf = '0';
 347                 ++buf;
 348         }
 349         /* actual digits of result */
 350         while (--i >= 0) {
 351                 if (buf < end)
 352                         *buf = tmp[i];
 353                 ++buf;
 354         }
 355         /* trailing space padding */
 356         while (--size >= 0) {
 357                 if (buf < end)
 358                         *buf = ' ';
 359                 ++buf;
 360         }
 361         return buf;
 362 }
 363
 364 static char *string(char *buf, char *end, char *s, int field_width, int precision, int flags)
 365 {
 366         int len, i;
 367
 368         if ((unsigned long)s < PAGE_SIZE)
 369                 s = "<NULL>";
 370
 371         len = strnlen(s, precision);
 372
 373         if (!(flags & LEFT)) {
 374                 while (len < field_width--) {
 375                         if (buf < end)
 376                                 *buf = ' ';
 377                         ++buf;
 378                 }
 379         }
 380         for (i = 0; i < len; ++i) {
 381                 if (buf < end)
 382                         *buf = *s;
 383                 ++buf; ++s;
 384         }
 385         while (len < field_width--) {
 386                 if (buf < end)
 387                         *buf = ' ';
 388                 ++buf;
 389         }
 390         return buf;
 391 }
 392
 393 static char *mac_address_string(char *buf, char *end, u8 *addr, int field_width,
 394                                 int precision, int flags)
 395 {
 396         char mac_addr[6 * 3]; /* (6 * 2 hex digits), 5 colons and trailing zero */
 397         char *p = mac_addr;
 398         int i;
 399
 400         for (i = 0; i < 6; i++) {
 401                 p = pack_hex_byte(p, addr[i]);
 402                 if (!(flags & SPECIAL) && i != 5)
 403                         *p++ = ':';
 404         }
 405         *p = '\0';
 406
 407         return string(buf, end, mac_addr, field_width, precision, flags & ~SPECIAL);
 408 }
 409
 410 /*
 411  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 412  * by an extra set of alphanumeric characters that are extended format
 413  * specifiers.
 414  *
 415  * - 'M' For a 6-byte MAC address, it prints the address in the
 416  *       usual colon-separated hex notation
 417  */
 418 static char *pointer(const char *fmt, char *buf, char *end, void *ptr, int field_width, int precision, int flags)
 419 {
 420         switch (*fmt) {
 421         case 'M':
 422                 return mac_address_string(buf, end, ptr, field_width, precision, flags);
 423         }
 424         flags |= SMALL;
 425         if (field_width == -1) {
 426                 field_width = 2*sizeof(void *);
 427                 flags |= ZEROPAD;
 428         }
 429         return number(buf, end, (unsigned long) ptr, 16, field_width, precision, flags);
 430 }
 431
 432 /**
 433  * vsnprintf - Format a string and place it in a buffer
 434  * @buf: The buffer to place the result into
 435  * @size: The size of the buffer, including the trailing null space
 436  * @fmt: The format string to use
 437  * @args: Arguments for the format string
 438  *
 439  * The return value is the number of characters which would
 440  * be generated for the given input, excluding the trailing
 441  * '\0', as per ISO C99. If you want to have the exact
 442  * number of characters written into @buf as return value
 443  * (not including the trailing '\0'), use vscnprintf(). If the
 444  * return is greater than or equal to @size, the resulting
 445  * string is truncated.
 446  *
 447  * Call this function if you are already dealing with a va_list.
 448  * You probably want snprintf() instead.
 449  */
 450 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 451 {
 452         unsigned long long num;
 453         int base;
 454         char *str, *end, c;
 455
 456         int flags;              /* flags to number() */
 457
 458         int field_width;        /* width of output field */
 459         int precision;          /* min. # of digits for integers; max
 460                                    number of chars for from string */
 461         int qualifier;          /* 'h', 'l', or 'L' for integer fields */
 462                                 /* 'z' support added 23/7/1999 S.H.    */
 463                                 /* 'z' changed to 'Z' --davidm 1/25/99 */
 464                                 /* 't' added for ptrdiff_t */
 465
 466         /* Reject out-of-range values early.  Large positive sizes are
 467            used for unknown buffer sizes. */
 468         if (unlikely((int) size < 0)) {
 469                 /* There can be only one.. */
 470                 static char warn = 1;
 471                 WARN_ON(warn);
 472                 warn = 0;
 473                 return 0;
 474         }
 475
 476         str = buf;
 477         end = buf + size;
 478
 479         /* Make sure end is always >= buf */
 480         if (end < buf) {
 481                 end = ((void *)-1);
 482                 size = end - buf;
 483         }
 484
 485         for (; *fmt ; ++fmt) {
 486                 if (*fmt != '%') {
 487                         if (str < end)
 488                                 *str = *fmt;
 489                         ++str;
 490                         continue;
 491                 }
 492
 493                 /* process flags */
 494                 flags = 0;
 495                 repeat:
 496                         ++fmt;          /* this also skips first '%' */
 497                         switch (*fmt) {
 498                                 case '-': flags |= LEFT; goto repeat;
 499                                 case '+': flags |= PLUS; goto repeat;
 500                                 case ' ': flags |= SPACE; goto repeat;
 501                                 case '#': flags |= SPECIAL; goto repeat;
 502                                 case '0': flags |= ZEROPAD; goto repeat;
 503                         }
 504
 505                 /* get field width */
 506                 field_width = -1;
 507                 if (isdigit(*fmt))
 508                         field_width = skip_atoi(&fmt);
 509                 else if (*fmt == '*') {
 510                         ++fmt;
 511                         /* it's the next argument */
 512                         field_width = va_arg(args, int);
 513                         if (field_width < 0) {
 514                                 field_width = -field_width;
 515                                 flags |= LEFT;
 516                         }
 517                 }
 518
 519                 /* get the precision */
 520                 precision = -1;
 521                 if (*fmt == '.') {
 522                         ++fmt;
 523                         if (isdigit(*fmt))
 524                                 precision = skip_atoi(&fmt);
 525                         else if (*fmt == '*') {
 526                                 ++fmt;
 527                                 /* it's the next argument */
 528                                 precision = va_arg(args, int);
 529                         }
 530                         if (precision < 0)
 531                                 precision = 0;
 532                 }
 533
 534                 /* get the conversion qualifier */
 535                 qualifier = -1;
 536                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 537                     *fmt =='Z' || *fmt == 'z' || *fmt == 't') {
 538                         qualifier = *fmt;
 539                         ++fmt;
 540                         if (qualifier == 'l' && *fmt == 'l') {
 541                                 qualifier = 'L';
 542                                 ++fmt;
 543                         }
 544                 }
 545
 546                 /* default base */
 547                 base = 10;
 548
 549                 switch (*fmt) {
 550                         case 'c':
 551                                 if (!(flags & LEFT)) {
 552                                         while (--field_width > 0) {
 553                                                 if (str < end)
 554                                                         *str = ' ';
 555                                                 ++str;
 556                                         }
 557                                 }
 558                                 c = (unsigned char) va_arg(args, int);
 559                                 if (str < end)
 560                                         *str = c;
 561                                 ++str;
 562                                 while (--field_width > 0) {
 563                                         if (str < end)
 564                                                 *str = ' ';
 565                                         ++str;
 566                                 }
 567                                 continue;
 568
 569                         case 's':
 570                                 str = string(str, end, va_arg(args, char *), field_width, precision, flags);
 571                                 continue;
 572
 573                         case 'p':
 574                                 str = pointer(fmt+1, str, end,
 575                                                 va_arg(args, void *),
 576                                                 field_width, precision, flags);
 577                                 /* Skip all alphanumeric pointer suffixes */
 578                                 while (isalnum(fmt[1]))
 579                                         fmt++;
 580                                 continue;
 581
 582                         case 'n':
 583                                 /* FIXME:
 584                                 * What does C99 say about the overflow case here? */
 585                                 if (qualifier == 'l') {
 586                                         long * ip = va_arg(args, long *);
 587                                         *ip = (str - buf);
 588                                 } else if (qualifier == 'Z' || qualifier == 'z') {
 589                                         size_t * ip = va_arg(args, size_t *);
 590                                         *ip = (str - buf);
 591                                 } else {
 592                                         int * ip = va_arg(args, int *);
 593                                         *ip = (str - buf);
 594                                 }
 595                                 continue;
 596
 597                         case '%':
 598                                 if (str < end)
 599                                         *str = '%';
 600                                 ++str;
 601                                 continue;
 602
 603                                 /* integer number formats - set up the flags and "break" */
 604                         case 'o':
 605                                 base = 8;
 606                                 break;
 607
 608                         case 'x':
 609                                 flags |= SMALL;
 610                         case 'X':
 611                                 base = 16;
 612                                 break;
 613
 614                         case 'd':
 615                         case 'i':
 616                                 flags |= SIGN;
 617                         case 'u':
 618                                 break;
 619
 620                         default:
 621                                 if (str < end)
 622                                         *str = '%';
 623                                 ++str;
 624                                 if (*fmt) {
 625                                         if (str < end)
 626                                                 *str = *fmt;
 627                                         ++str;
 628                                 } else {
 629                                         --fmt;
 630                                 }
 631                                 continue;
 632                 }
 633                 if (qualifier == 'L')
 634                         num = va_arg(args, long long);
 635                 else if (qualifier == 'l') {
 636                         num = va_arg(args, unsigned long);
 637                         if (flags & SIGN)
 638                                 num = (signed long) num;
 639                 } else if (qualifier == 'Z' || qualifier == 'z') {
 640                         num = va_arg(args, size_t);
 641                 } else if (qualifier == 't') {
 642                         num = va_arg(args, ptrdiff_t);
 643                 } else if (qualifier == 'h') {
 644                         num = (unsigned short) va_arg(args, int);
 645                         if (flags & SIGN)
 646                                 num = (signed short) num;
 647                 } else {
 648                         num = va_arg(args, unsigned int);
 649                         if (flags & SIGN)
 650                                 num = (signed int) num;
 651                 }
 652                 str = number(str, end, num, base,
 653                                 field_width, precision, flags);
 654         }
 655         if (size > 0) {
 656                 if (str < end)
 657                         *str = '\0';
 658                 else
 659                         end[-1] = '\0';
 660         }
 661         /* the trailing null byte doesn't count towards the total */
 662         return str-buf;
 663 }
 664
 665 EXPORT_SYMBOL(vsnprintf);
 666
 667 /**
 668  * vscnprintf - Format a string and place it in a buffer
 669  * @buf: The buffer to place the result into
 670  * @size: The size of the buffer, including the trailing null space
 671  * @fmt: The format string to use
 672  * @args: Arguments for the format string
 673  *
 674  * The return value is the number of characters which have been written into
 675  * the @buf not including the trailing '\0'. If @size is <= 0 the function
 676  * returns 0.
 677  *
 678  * Call this function if you are already dealing with a va_list.
 679  * You probably want scnprintf() instead.
 680  */
 681 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 682 {
 683         int i;
 684
 685         i=vsnprintf(buf,size,fmt,args);
 686         return (i >= size) ? (size - 1) : i;
 687 }
 688
 689 EXPORT_SYMBOL(vscnprintf);
 690
 691 /**
 692  * snprintf - Format a string and place it in a buffer
 693  * @buf: The buffer to place the result into
 694  * @size: The size of the buffer, including the trailing null space
 695  * @fmt: The format string to use
 696  * @...: Arguments for the format string
 697  *
 698  * The return value is the number of characters which would be
 699  * generated for the given input, excluding the trailing null,
 700  * as per ISO C99.  If the return is greater than or equal to
 701  * @size, the resulting string is truncated.
 702  */
 703 int snprintf(char * buf, size_t size, const char *fmt, ...)
 704 {
 705         va_list args;
 706         int i;
 707
 708         va_start(args, fmt);
 709         i=vsnprintf(buf,size,fmt,args);
 710         va_end(args);
 711         return i;
 712 }
 713
 714 EXPORT_SYMBOL(snprintf);
 715
 716 /**
 717  * scnprintf - Format a string and place it in a buffer
 718  * @buf: The buffer to place the result into
 719  * @size: The size of the buffer, including the trailing null space
 720  * @fmt: The format string to use
 721  * @...: Arguments for the format string
 722  *
 723  * The return value is the number of characters written into @buf not including
 724  * the trailing '\0'. If @size is <= 0 the function returns 0.
 725  */
 726
 727 int scnprintf(char * buf, size_t size, const char *fmt, ...)
 728 {
 729         va_list args;
 730         int i;
 731
 732         va_start(args, fmt);
 733         i = vsnprintf(buf, size, fmt, args);
 734         va_end(args);
 735         return (i >= size) ? (size - 1) : i;
 736 }
 737 EXPORT_SYMBOL(scnprintf);
 738
 739 /**
 740  * vsprintf - Format a string and place it in a buffer
 741  * @buf: The buffer to place the result into
 742  * @fmt: The format string to use
 743  * @args: Arguments for the format string
 744  *
 745  * The function returns the number of characters written
 746  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
 747  * buffer overflows.
 748  *
 749  * Call this function if you are already dealing with a va_list.
 750  * You probably want sprintf() instead.
 751  */
 752 int vsprintf(char *buf, const char *fmt, va_list args)
 753 {
 754         return vsnprintf(buf, INT_MAX, fmt, args);
 755 }
 756
 757 EXPORT_SYMBOL(vsprintf);
 758
 759 /**
 760  * sprintf - Format a string and place it in a buffer
 761  * @buf: The buffer to place the result into
 762  * @fmt: The format string to use
 763  * @...: Arguments for the format string
 764  *
 765  * The function returns the number of characters written
 766  * into @buf. Use snprintf() or scnprintf() in order to avoid
 767  * buffer overflows.
 768  */
 769 int sprintf(char * buf, const char *fmt, ...)
 770 {
 771         va_list args;
 772         int i;
 773
 774         va_start(args, fmt);
 775         i=vsnprintf(buf, INT_MAX, fmt, args);
 776         va_end(args);
 777         return i;
 778 }
 779
 780 EXPORT_SYMBOL(sprintf);
 781
 782 /**
 783  * vsscanf - Unformat a buffer into a list of arguments
 784  * @buf:        input buffer
 785  * @fmt:        format of buffer
 786  * @args:       arguments
 787  */
 788 int vsscanf(const char * buf, const char * fmt, va_list args)
 789 {
 790         const char *str = buf;
 791         char *next;
 792         char digit;
 793         int num = 0;
 794         int qualifier;
 795         int base;
 796         int field_width;
 797         int is_sign = 0;
 798
 799         while(*fmt && *str) {
 800                 /* skip any white space in format */
 801                 /* white space in format matchs any amount of
 802                  * white space, including none, in the input.
 803                  */
 804                 if (isspace(*fmt)) {
 805                         while (isspace(*fmt))
 806                                 ++fmt;
 807                         while (isspace(*str))
 808                                 ++str;
 809                 }
 810
 811                 /* anything that is not a conversion must match exactly */
 812                 if (*fmt != '%' && *fmt) {
 813                         if (*fmt++ != *str++)
 814                                 break;
 815                         continue;
 816                 }
 817
 818                 if (!*fmt)
 819                         break;
 820                 ++fmt;
 821
 822                 /* skip this conversion.
 823                  * advance both strings to next white space
 824                  */
 825                 if (*fmt == '*') {
 826                         while (!isspace(*fmt) && *fmt != '%' && *fmt)
 827                                 fmt++;
 828                         while (!isspace(*str) && *str)
 829                                 str++;
 830                         continue;
 831                 }
 832
 833                 /* get field width */
 834                 field_width = -1;
 835                 if (isdigit(*fmt))
 836                         field_width = skip_atoi(&fmt);
 837
 838                 /* get conversion qualifier */
 839                 qualifier = -1;
 840                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 841                     *fmt == 'Z' || *fmt == 'z') {
 842                         qualifier = *fmt++;
 843                         if (unlikely(qualifier == *fmt)) {
 844                                 if (qualifier == 'h') {
 845                                         qualifier = 'H';
 846                                         fmt++;
 847                                 } else if (qualifier == 'l') {
 848                                         qualifier = 'L';
 849                                         fmt++;
 850                                 }
 851                         }
 852                 }
 853                 base = 10;
 854                 is_sign = 0;
 855
 856                 if (!*fmt || !*str)
 857                         break;
 858
 859                 switch(*fmt++) {
 860                 case 'c':
 861                 {
 862                         char *s = (char *) va_arg(args,char*);
 863                         if (field_width == -1)
 864                                 field_width = 1;
 865                         do {
 866                                 *s++ = *str++;
 867                         } while (--field_width > 0 && *str);
 868                         num++;
 869                 }
 870                 continue;
 871                 case 's':
 872                 {
 873                         char *s = (char *) va_arg(args, char *);
 874                         if(field_width == -1)
 875                                 field_width = INT_MAX;
 876                         /* first, skip leading white space in buffer */
 877                         while (isspace(*str))
 878                                 str++;
 879
 880                         /* now copy until next white space */
 881                         while (*str && !isspace(*str) && field_width--) {
 882                                 *s++ = *str++;
 883                         }
 884                         *s = '\0';
 885                         num++;
 886                 }
 887                 continue;
 888                 case 'n':
 889                         /* return number of characters read so far */
 890                 {
 891                         int *i = (int *)va_arg(args,int*);
 892                         *i = str - buf;
 893                 }
 894                 continue;
 895                 case 'o':
 896                         base = 8;
 897                         break;
 898                 case 'x':
 899                 case 'X':
 900                         base = 16;
 901                         break;
 902                 case 'i':
 903                         base = 0;
 904                 case 'd':
 905                         is_sign = 1;
 906                 case 'u':
 907                         break;
 908                 case '%':
 909                         /* looking for '%' in str */
 910                         if (*str++ != '%')
 911                                 return num;
 912                         continue;
 913                 default:
 914                         /* invalid format; stop here */
 915                         return num;
 916                 }
 917
 918                 /* have some sort of integer conversion.
 919                  * first, skip white space in buffer.
 920                  */
 921                 while (isspace(*str))
 922                         str++;
 923
 924                 digit = *str;
 925                 if (is_sign && digit == '-')
 926                         digit = *(str + 1);
 927
 928                 if (!digit
 929                     || (base == 16 && !isxdigit(digit))
 930                     || (base == 10 && !isdigit(digit))
 931                     || (base == 8 && (!isdigit(digit) || digit > '7'))
 932                     || (base == 0 && !isdigit(digit)))
 933                                 break;
 934
 935                 switch(qualifier) {
 936                 case 'H':       /* that's 'hh' in format */
 937                         if (is_sign) {
 938                                 signed char *s = (signed char *) va_arg(args,signed char *);
 939                                 *s = (signed char) simple_strtol(str,&next,base);
 940                         } else {
 941                                 unsigned char *s = (unsigned char *) va_arg(args, unsigned char *);
 942                                 *s = (unsigned char) simple_strtoul(str, &next, base);
 943                         }
 944                         break;
 945                 case 'h':
 946                         if (is_sign) {
 947                                 short *s = (short *) va_arg(args,short *);
 948                                 *s = (short) simple_strtol(str,&next,base);
 949                         } else {
 950                                 unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
 951                                 *s = (unsigned short) simple_strtoul(str, &next, base);
 952                         }
 953                         break;
 954                 case 'l':
 955                         if (is_sign) {
 956                                 long *l = (long *) va_arg(args,long *);
 957                                 *l = simple_strtol(str,&next,base);
 958                         } else {
 959                                 unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
 960                                 *l = simple_strtoul(str,&next,base);
 961                         }
 962                         break;
 963                 case 'L':
 964                         if (is_sign) {
 965                                 long long *l = (long long*) va_arg(args,long long *);
 966                                 *l = simple_strtoll(str,&next,base);
 967                         } else {
 968                                 unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
 969                                 *l = simple_strtoull(str,&next,base);
 970                         }
 971                         break;
 972                 case 'Z':
 973                 case 'z':
 974                 {
 975                         size_t *s = (size_t*) va_arg(args,size_t*);
 976                         *s = (size_t) simple_strtoul(str,&next,base);
 977                 }
 978                 break;
 979                 default:
 980                         if (is_sign) {
 981                                 int *i = (int *) va_arg(args, int*);
 982                                 *i = (int) simple_strtol(str,&next,base);
 983                         } else {
 984                                 unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
 985                                 *i = (unsigned int) simple_strtoul(str,&next,base);
 986                         }
 987                         break;
 988                 }
 989                 num++;
 990
 991                 if (!next)
 992                         break;
 993                 str = next;
 994         }
 995
 996         /*
 997          * Now we've come all the way through so either the input string or the
 998          * format ended. In the former case, there can be a %n at the current
 999          * position in the format that needs to be filled.
1000          */
1001         if (*fmt == '%' && *(fmt + 1) == 'n') {
1002                 int *p = (int *)va_arg(args, int *);
1003                 *p = str - buf;
1004         }
1005
1006         return num;
1007 }
1008
1009 EXPORT_SYMBOL(vsscanf);
1010
1011 /**
1012  * sscanf - Unformat a buffer into a list of arguments
1013  * @buf:        input buffer
1014  * @fmt:        formatting of buffer
1015  * @...:        resulting arguments
1016  */
1017 int sscanf(const char * buf, const char * fmt, ...)
1018 {
1019         va_list args;
1020         int i;
1021
1022         va_start(args,fmt);
1023         i = vsscanf(buf,fmt,args);
1024         va_end(args);
1025         return i;
1026 }
1027
1028 EXPORT_SYMBOL(sscanf);
1029
1030
1031 /* Simplified asprintf. */
1032 char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
1033 {
1034         unsigned int len;
1035         char *p;
1036         va_list aq;
1037
1038         va_copy(aq, ap);
1039         len = vsnprintf(NULL, 0, fmt, aq);
1040         va_end(aq);
1041
1042         p = kmalloc(len+1, gfp);
1043         if (!p)
1044                 return NULL;
1045
1046         vsnprintf(p, len+1, fmt, ap);
1047
1048         return p;
1049 }
1050 EXPORT_SYMBOL(kvasprintf);
1051
1052 char *kasprintf(gfp_t gfp, const char *fmt, ...)
1053 {
1054         va_list ap;
1055         char *p;
1056
1057         va_start(ap, fmt);
1058         p = kvasprintf(gfp, fmt, ap);
1059         va_end(ap);
1060
1061         return p;
1062 }
1063 EXPORT_SYMBOL(kasprintf);