release/src/router/busybox/libbb/xfuncs.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  *
   5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6  * Copyright (C) 2006 Rob Landley
   7  * Copyright (C) 2006 Denys Vlasenko
   8  *
   9  * Licensed under GPLv2, see file LICENSE in this source tree.
  10  */
  11
  12 /* We need to have separate xfuncs.c and xfuncs_printf.c because
  13  * with current linkers, even with section garbage collection,
  14  * if *.o module references any of XXXprintf functions, you pull in
  15  * entire printf machinery. Even if you do not use the function
  16  * which uses XXXprintf.
  17  *
  18  * xfuncs.c contains functions (not necessarily xfuncs)
  19  * which do not pull in printf, directly or indirectly.
  20  * xfunc_printf.c contains those which do.
  21  *
  22  * TODO: move xmalloc() and xatonum() here.
  23  */
  24
  25 #include "libbb.h"
  26
  27 /* Turn on nonblocking I/O on a fd */
  28 void FAST_FUNC ndelay_on(int fd)
  29 {
  30         int flags = fcntl(fd, F_GETFL);
  31         if (flags & O_NONBLOCK)
  32                 return;
  33         fcntl(fd, F_SETFL, flags | O_NONBLOCK);
  34 }
  35
  36 void FAST_FUNC ndelay_off(int fd)
  37 {
  38         int flags = fcntl(fd, F_GETFL);
  39         if (!(flags & O_NONBLOCK))
  40                 return;
  41         fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
  42 }
  43
  44 void FAST_FUNC close_on_exec_on(int fd)
  45 {
  46         fcntl(fd, F_SETFD, FD_CLOEXEC);
  47 }
  48
  49 char* FAST_FUNC strncpy_IFNAMSIZ(char *dst, const char *src)
  50 {
  51 #ifndef IFNAMSIZ
  52         enum { IFNAMSIZ = 16 };
  53 #endif
  54         return strncpy(dst, src, IFNAMSIZ);
  55 }
  56
  57
  58 /* Convert unsigned integer to ascii, writing into supplied buffer.
  59  * A truncated result contains the first few digits of the result ala strncpy.
  60  * Returns a pointer past last generated digit, does _not_ store NUL.
  61  */
  62 void BUG_sizeof(void);
  63 char* FAST_FUNC utoa_to_buf(unsigned n, char *buf, unsigned buflen)
  64 {
  65         unsigned i, out, res;
  66
  67         if (buflen) {
  68                 out = 0;
  69                 if (sizeof(n) == 4)
  70                 // 2^32-1 = 4294967295
  71                         i = 1000000000;
  72 #if UINT_MAX > 4294967295 /* prevents warning about "const too large" */
  73                 else
  74                 if (sizeof(n) == 8)
  75                 // 2^64-1 = 18446744073709551615
  76                         i = 10000000000000000000;
  77 #endif
  78                 else
  79                         BUG_sizeof();
  80                 for (; i; i /= 10) {
  81                         res = n / i;
  82                         n = n % i;
  83                         if (res || out || i == 1) {
  84                                 if (--buflen == 0)
  85                                         break;
  86                                 out++;
  87                                 *buf++ = '0' + res;
  88                         }
  89                 }
  90         }
  91         return buf;
  92 }
  93
  94 /* Convert signed integer to ascii, like utoa_to_buf() */
  95 char* FAST_FUNC itoa_to_buf(int n, char *buf, unsigned buflen)
  96 {
  97         if (!buflen)
  98                 return buf;
  99         if (n < 0) {
 100                 n = -n;
 101                 *buf++ = '-';
 102                 buflen--;
 103         }
 104         return utoa_to_buf((unsigned)n, buf, buflen);
 105 }
 106
 107 // The following two functions use a static buffer, so calling either one a
 108 // second time will overwrite previous results.
 109 //
 110 // The largest 32 bit integer is -2 billion plus NUL, or 1+10+1=12 bytes.
 111 // It so happens that sizeof(int) * 3 is enough for 32+ bit ints.
 112 // (sizeof(int) * 3 + 2 is correct for any width, even 8-bit)
 113
 114 static char local_buf[sizeof(int) * 3];
 115
 116 /* Convert unsigned integer to ascii using a static buffer (returned). */
 117 char* FAST_FUNC utoa(unsigned n)
 118 {
 119         *(utoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
 120
 121         return local_buf;
 122 }
 123
 124 /* Convert signed integer to ascii using a static buffer (returned). */
 125 char* FAST_FUNC itoa(int n)
 126 {
 127         *(itoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
 128
 129         return local_buf;
 130 }
 131
 132 /* Emit a string of hex representation of bytes */
 133 char* FAST_FUNC bin2hex(char *p, const char *cp, int count)
 134 {
 135         while (count) {
 136                 unsigned char c = *cp++;
 137                 /* put lowercase hex digits */
 138                 *p++ = 0x20 | bb_hexdigits_upcase[c >> 4];
 139                 *p++ = 0x20 | bb_hexdigits_upcase[c & 0xf];
 140                 count--;
 141         }
 142         return p;
 143 }
 144
 145 /* Convert "[x]x[:][x]x[:][x]x[:][x]x" hex string to binary, no more than COUNT bytes */
 146 char* FAST_FUNC hex2bin(char *dst, const char *str, int count)
 147 {
 148         errno = EINVAL;
 149         while (*str && count) {
 150                 uint8_t val;
 151                 uint8_t c = *str++;
 152                 if (isdigit(c))
 153                         val = c - '0';
 154                 else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
 155                         val = (c|0x20) - ('a' - 10);
 156                 else
 157                         return NULL;
 158                 val <<= 4;
 159                 c = *str;
 160                 if (isdigit(c))
 161                         val |= c - '0';
 162                 else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
 163                         val |= (c|0x20) - ('a' - 10);
 164                 else if (c == ':' || c == '\0')
 165                         val >>= 4;
 166                 else
 167                         return NULL;
 168
 169                 *dst++ = val;
 170                 if (c != '\0')
 171                         str++;
 172                 if (*str == ':')
 173                         str++;
 174                 count--;
 175         }
 176         errno = (*str ? ERANGE : 0);
 177         return dst;
 178 }
 179
 180 /* Return how long the file at fd is, if there's any way to determine it. */
 181 #ifdef UNUSED
 182 off_t FAST_FUNC fdlength(int fd)
 183 {
 184         off_t bottom = 0, top = 0, pos;
 185         long size;
 186
 187         // If the ioctl works for this, return it.
 188
 189         if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
 190
 191         // FIXME: explain why lseek(SEEK_END) is not used here!
 192
 193         // If not, do a binary search for the last location we can read.  (Some
 194         // block devices don't do BLKGETSIZE right.)
 195
 196         do {
 197                 char temp;
 198
 199                 pos = bottom + (top - bottom) / 2;
 200
 201                 // If we can read from the current location, it's bigger.
 202
 203                 if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) {
 204                         if (bottom == top) bottom = top = (top+1) * 2;
 205                         else bottom = pos;
 206
 207                 // If we can't, it's smaller.
 208
 209                 } else {
 210                         if (bottom == top) {
 211                                 if (!top) return 0;
 212                                 bottom = top/2;
 213                         }
 214                         else top = pos;
 215                 }
 216         } while (bottom + 1 != top);
 217
 218         return pos + 1;
 219 }
 220 #endif
 221
 222 int FAST_FUNC bb_putchar_stderr(char ch)
 223 {
 224         return write(STDERR_FILENO, &ch, 1);
 225 }
 226
 227 ssize_t FAST_FUNC full_write1_str(const char *str)
 228 {
 229         return full_write(STDOUT_FILENO, str, strlen(str));
 230 }
 231
 232 ssize_t FAST_FUNC full_write2_str(const char *str)
 233 {
 234         return full_write(STDERR_FILENO, str, strlen(str));
 235 }
 236
 237 static int wh_helper(int value, int def_val, const char *env_name, int *err)
 238 {
 239         if (value == 0) {
 240                 char *s = getenv(env_name);
 241                 if (s) {
 242                         value = atoi(s);
 243                         /* If LINES/COLUMNS are set, pretend that there is
 244                          * no error getting w/h, this prevents some ugly
 245                          * cursor tricks by our callers */
 246                         *err = 0;
 247                 }
 248         }
 249         if (value <= 1 || value >= 30000)
 250                 value = def_val;
 251         return value;
 252 }
 253
 254 /* It is perfectly ok to pass in a NULL for either width or for
 255  * height, in which case that value will not be set.  */
 256 int FAST_FUNC get_terminal_width_height(int fd, unsigned *width, unsigned *height)
 257 {
 258         struct winsize win;
 259         int err;
 260
 261         win.ws_row = 0;
 262         win.ws_col = 0;
 263         /* I've seen ioctl returning 0, but row/col is (still?) 0.
 264          * We treat that as an error too.  */
 265         err = ioctl(fd, TIOCGWINSZ, &win) != 0 || win.ws_row == 0;
 266         if (height)
 267                 *height = wh_helper(win.ws_row, 24, "LINES", &err);
 268         if (width)
 269                 *width = wh_helper(win.ws_col, 80, "COLUMNS", &err);
 270         return err;
 271 }
 272
 273 int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp)
 274 {
 275         return tcsetattr(STDIN_FILENO, TCSANOW, tp);
 276 }
 277
 278 pid_t FAST_FUNC safe_waitpid(pid_t pid, int *wstat, int options)
 279 {
 280         pid_t r;
 281
 282         do
 283                 r = waitpid(pid, wstat, options);
 284         while ((r == -1) && (errno == EINTR));
 285         return r;
 286 }
 287
 288 pid_t FAST_FUNC wait_any_nohang(int *wstat)
 289 {
 290         return safe_waitpid(-1, wstat, WNOHANG);
 291 }
 292
 293 // Wait for the specified child PID to exit, returning child's error return.
 294 int FAST_FUNC wait4pid(pid_t pid)
 295 {
 296         int status;
 297
 298         if (pid <= 0) {
 299                 /*errno = ECHILD; -- wrong. */
 300                 /* we expect errno to be already set from failed [v]fork/exec */
 301                 return -1;
 302         }
 303         if (safe_waitpid(pid, &status, 0) == -1)
 304                 return -1;
 305         if (WIFEXITED(status))
 306                 return WEXITSTATUS(status);
 307         if (WIFSIGNALED(status))
 308                 return WTERMSIG(status) + 0x180;
 309         return 0;
 310 }
 311
 312 char * FAST_FUNC unparse_uuid(const uint8_t *uu, char *out)
 313 {
 314         char uuid_string[32];
 315
 316         bin2hex(uuid_string, (char *)uu, 16);
 317         /* f.e. UUID=dfd9c173-be52-4d27-99a5-c34c6c2ff55f */
 318         sprintf(out, "%.8s-%.4s-%.4s-%.4s-%.12s",
 319                 uuid_string,
 320                 uuid_string+8,
 321                 uuid_string+8+4,
 322                 uuid_string+8+4+4,
 323                 uuid_string+8+4+4+4
 324         );
 325         return out;
 326 }
 327
 328 static unsigned char fromhex(char c)
 329 {
 330         if (isdigit(c))
 331                 return (c - '0');
 332         return ((c|0x20) - 'a' + 10);
 333 }
 334
 335 /* Parse & verify UUID string */
 336 int FAST_FUNC parse_uuid(const char *s, uint8_t *uuid)
 337 {
 338         int i;
 339
 340         if (strlen(s) != 36 || s[8] != '-' || s[13] != '-'
 341          || s[18] != '-' || s[23] != '-'
 342         ) {
 343                 return -1;
 344         }
 345         for (i = 0; i < 16; i++) {
 346                 if (*s == '-')
 347                         s++;
 348                 if (!isxdigit(s[0]) || !isxdigit(s[1]))
 349                         return -2;
 350                 uuid[i] = ((fromhex(s[0]) << 4) | fromhex(s[1]));
 351                 s += 2;
 352         }
 353
 354         return 0;
 355 }
 356