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- /* vi: set sw=4 ts=4: */
- /*
- * Utility routines.
- *
- * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
- * Copyright (C) 2006 Rob Landley
- * Copyright (C) 2006 Denys Vlasenko
- *
- * Licensed under GPL version 2, see file LICENSE in this tarball for details.
- */
- /* We need to have separate xfuncs.c and xfuncs_printf.c because
- * with current linkers, even with section garbage collection,
- * if *.o module references any of XXXprintf functions, you pull in
- * entire printf machinery. Even if you do not use the function
- * which uses XXXprintf.
- *
- * xfuncs.c contains functions (not necessarily xfuncs)
- * which do not pull in printf, directly or indirectly.
- * xfunc_printf.c contains those which do.
- *
- * TODO: move xmalloc() and xatonum() here.
- */
- #include "libbb.h"
- /* Turn on nonblocking I/O on a fd */
- int FAST_FUNC ndelay_on(int fd)
- {
- return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
- }
- int FAST_FUNC ndelay_off(int fd)
- {
- return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK);
- }
- int FAST_FUNC close_on_exec_on(int fd)
- {
- return fcntl(fd, F_SETFD, FD_CLOEXEC);
- }
- char* FAST_FUNC strncpy_IFNAMSIZ(char *dst, const char *src)
- {
- #ifndef IFNAMSIZ
- enum { IFNAMSIZ = 16 };
- #endif
- return strncpy(dst, src, IFNAMSIZ);
- }
- // Convert unsigned integer to ascii, writing into supplied buffer.
- // A truncated result contains the first few digits of the result ala strncpy.
- // Returns a pointer past last generated digit, does _not_ store NUL.
- void BUG_sizeof_unsigned_not_4(void);
- char* FAST_FUNC utoa_to_buf(unsigned n, char *buf, unsigned buflen)
- {
- unsigned i, out, res;
- if (sizeof(unsigned) != 4)
- BUG_sizeof_unsigned_not_4();
- if (buflen) {
- out = 0;
- for (i = 1000000000; i; i /= 10) {
- res = n / i;
- if (res || out || i == 1) {
- if (!--buflen) break;
- out++;
- n -= res*i;
- *buf++ = '0' + res;
- }
- }
- }
- return buf;
- }
- /* Convert signed integer to ascii, like utoa_to_buf() */
- char* FAST_FUNC itoa_to_buf(int n, char *buf, unsigned buflen)
- {
- if (buflen && n < 0) {
- n = -n;
- *buf++ = '-';
- buflen--;
- }
- return utoa_to_buf((unsigned)n, buf, buflen);
- }
- // The following two functions use a static buffer, so calling either one a
- // second time will overwrite previous results.
- //
- // The largest 32 bit integer is -2 billion plus null terminator, or 12 bytes.
- // It so happens that sizeof(int) * 3 is enough for 32+ bits.
- // (sizeof(int) * 3 + 2 is correct for any width, even 8-bit)
- static char local_buf[sizeof(int) * 3];
- // Convert unsigned integer to ascii using a static buffer (returned).
- char* FAST_FUNC utoa(unsigned n)
- {
- *(utoa_to_buf(n, local_buf, sizeof(local_buf))) = '\0';
- return local_buf;
- }
- /* Convert signed integer to ascii using a static buffer (returned). */
- char* FAST_FUNC itoa(int n)
- {
- *(itoa_to_buf(n, local_buf, sizeof(local_buf))) = '\0';
- return local_buf;
- }
- /* Emit a string of hex representation of bytes */
- char* FAST_FUNC bin2hex(char *p, const char *cp, int count)
- {
- while (count) {
- unsigned char c = *cp++;
- /* put lowercase hex digits */
- *p++ = 0x20 | bb_hexdigits_upcase[c >> 4];
- *p++ = 0x20 | bb_hexdigits_upcase[c & 0xf];
- count--;
- }
- return p;
- }
- /* Convert "[x]x[:][x]x[:][x]x[:][x]x" hex string to binary, no more than COUNT bytes */
- char* FAST_FUNC hex2bin(char *dst, const char *str, int count)
- {
- errno = EINVAL;
- while (*str && count) {
- uint8_t val;
- uint8_t c = *str++;
- if (isdigit(c))
- val = c - '0';
- else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
- val = (c|0x20) - ('a' - 10);
- else
- return NULL;
- val <<= 4;
- c = *str;
- if (isdigit(c))
- val |= c - '0';
- else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
- val |= (c|0x20) - ('a' - 10);
- else if (c == ':' || c == '\0')
- val >>= 4;
- else
- return NULL;
- *dst++ = val;
- if (c != '\0')
- str++;
- if (*str == ':')
- str++;
- count--;
- }
- errno = (*str ? ERANGE : 0);
- return dst;
- }
- /* Return how long the file at fd is, if there's any way to determine it. */
- #ifdef UNUSED
- off_t FAST_FUNC fdlength(int fd)
- {
- off_t bottom = 0, top = 0, pos;
- long size;
- // If the ioctl works for this, return it.
- if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
- // FIXME: explain why lseek(SEEK_END) is not used here!
- // If not, do a binary search for the last location we can read. (Some
- // block devices don't do BLKGETSIZE right.)
- do {
- char temp;
- pos = bottom + (top - bottom) / 2;
- // If we can read from the current location, it's bigger.
- if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) {
- if (bottom == top) bottom = top = (top+1) * 2;
- else bottom = pos;
- // If we can't, it's smaller.
- } else {
- if (bottom == top) {
- if (!top) return 0;
- bottom = top/2;
- }
- else top = pos;
- }
- } while (bottom + 1 != top);
- return pos + 1;
- }
- #endif
- char* FAST_FUNC xmalloc_ttyname(int fd)
- {
- char *buf = xzalloc(128);
- int r = ttyname_r(fd, buf, 127);
- if (r) {
- free(buf);
- buf = NULL;
- }
- return buf;
- }
- static int wh_helper(int value, int def_val, const char *env_name, int *err)
- {
- if (value == 0) {
- char *s = getenv(env_name);
- if (s) {
- value = atoi(s);
- /* If LINES/COLUMNS are set, pretent that there is
- * no error getting w/h, this prevents some ugly
- * cursor tricks by our callers */
- *err = 0;
- }
- }
- if (value <= 1 || value >= 30000)
- value = def_val;
- return value;
- }
- /* It is perfectly ok to pass in a NULL for either width or for
- * height, in which case that value will not be set. */
- int FAST_FUNC get_terminal_width_height(int fd, unsigned *width, unsigned *height)
- {
- struct winsize win;
- int err;
- win.ws_row = 0;
- win.ws_col = 0;
- /* I've seen ioctl returning 0, but row/col is (still?) 0.
- * We treat that as an error too. */
- err = ioctl(fd, TIOCGWINSZ, &win) != 0 || win.ws_row == 0;
- if (height)
- *height = wh_helper(win.ws_row, 24, "LINES", &err);
- if (width)
- *width = wh_helper(win.ws_col, 80, "COLUMNS", &err);
- return err;
- }
- int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp)
- {
- return tcsetattr(STDIN_FILENO, TCSANOW, tp);
- }
- void FAST_FUNC generate_uuid(uint8_t *buf)
- {
- /* http://www.ietf.org/rfc/rfc4122.txt
- * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * | time_low |
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * | time_mid | time_hi_and_version |
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * |clk_seq_and_variant | node (0-1) |
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * | node (2-5) |
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * IOW, uuid has this layout:
- * uint32_t time_low (big endian)
- * uint16_t time_mid (big endian)
- * uint16_t time_hi_and_version (big endian)
- * version is a 4-bit field:
- * 1 Time-based
- * 2 DCE Security, with embedded POSIX UIDs
- * 3 Name-based (MD5)
- * 4 Randomly generated
- * 5 Name-based (SHA-1)
- * uint16_t clk_seq_and_variant (big endian)
- * variant is a 3-bit field:
- * 0xx Reserved, NCS backward compatibility
- * 10x The variant specified in rfc4122
- * 110 Reserved, Microsoft backward compatibility
- * 111 Reserved for future definition
- * uint8_t node[6]
- *
- * For version 4, these bits are set/cleared:
- * time_hi_and_version & 0x0fff | 0x4000
- * clk_seq_and_variant & 0x3fff | 0x8000
- */
- pid_t pid;
- int i;
- i = open("/dev/urandom", O_RDONLY);
- if (i >= 0) {
- read(i, buf, 16);
- close(i);
- }
- /* Paranoia. /dev/urandom may be missing.
- * rand() is guaranteed to generate at least [0, 2^15) range,
- * but lowest bits in some libc are not so "random". */
- srand(monotonic_us());
- pid = getpid();
- while (1) {
- for (i = 0; i < 16; i++)
- buf[i] ^= rand() >> 5;
- if (pid == 0)
- break;
- srand(pid);
- pid = 0;
- }
- /* version = 4 */
- buf[4 + 2 ] = (buf[4 + 2 ] & 0x0f) | 0x40;
- /* variant = 10x */
- buf[4 + 2 + 2] = (buf[4 + 2 + 2] & 0x3f) | 0x80;
- }
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