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