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