random-getrandom.c File Reference

#include "uv.h"
#include "internal.h"
#include <stddef.h>
#include <dlfcn.h>

Go to the source code of this file.

Typedefs
typedef ssize_t(*	uv__getrandom_cb) (void *, size_t, unsigned)

Functions
static void	uv__random_getrandom_init_once (void)
static int	uv__random_getrandom_init (void)
int	uv__random_getrandom (void *buf, size_t buflen)

Variables
static uv__getrandom_cb	uv__getrandom
static uv_once_t	once = UV_ONCE_INIT

Typedef Documentation

uv__getrandom_cb

typedef ssize_t(* uv__getrandom_cb) (void *, size_t, unsigned)

Definition at line 36 of file random-getrandom.c.

Function Documentation

uv__random_getrandom()

int uv__random_getrandom	(	void *	buf,
		size_t	buflen
	)

Definition at line 56 of file random-getrandom.c.

                                                   {
  ssize_t n;
  size_t pos;
  int rc;
 
  rc = uv__random_getrandom_init();
  if (rc != 0)
    return rc;
 
  for (pos = 0; pos != buflen; pos += n) {
    do {
      n = buflen - pos;
 
      /* Most getrandom() implementations promise that reads <= 256 bytes
       * will always succeed and won't be interrupted by signals.
       * It's therefore useful to split it up in smaller reads because
       * one big read may, in theory, continuously fail with EINTR.
       */
      if (n > 256)
        n = 256;
 
      n = uv__getrandom((char *) buf + pos, n, 0);
    } while (n == -1 && errno == EINTR);
 
    if (n == -1)
      return UV__ERR(errno);
 
    if (n == 0)
      return UV_EIO;
  }
 
  return 0;
}

References buflen, EINTR, n, pos, UV__ERR, uv__getrandom, and uv__random_getrandom_init().

Referenced by uv__random().

uv__random_getrandom_init()

static int uv__random_getrandom_init ( void  )

static

Definition at line 45 of file random-getrandom.c.

                                           {
  uv_once(&once, uv__random_getrandom_init_once);
 
  if (uv__getrandom == NULL)
    return UV_ENOSYS;
 
  return 0;
}

References NULL, once, uv__getrandom, uv__random_getrandom_init_once(), and uv_once().

Referenced by uv__random_getrandom().

uv__random_getrandom_init_once()

static void uv__random_getrandom_init_once ( void  )

static

Definition at line 41 of file random-getrandom.c.

                                                 {
  uv__getrandom = (uv__getrandom_cb) dlsym(RTLD_DEFAULT, "getrandom");
}

References uv__getrandom.

Referenced by uv__random_getrandom_init().

Variable Documentation

once

uv_once_t once = UV_ONCE_INIT

static

Definition at line 39 of file random-getrandom.c.

Referenced by uv__random_getrandom_init().

uv__getrandom

uv__getrandom_cb uv__getrandom

static

Definition at line 38 of file random-getrandom.c.

Referenced by uv__random_getrandom(), uv__random_getrandom_init(), and uv__random_getrandom_init_once().