/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "primpl.h"

#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/time.h>

#if defined(SOLARIS)

static size_t
GetHighResClock(void* buf, size_t maxbytes)
{
    hrtime_t t;
    t = gethrtime();
    if (t) {
        return _pr_CopyLowBits(buf, maxbytes, &t, sizeof(t));
    }
    return 0;
}

#elif defined(AIX)

static size_t
GetHighResClock(void* buf, size_t maxbytes)
{
    return 0;
}

#elif (defined(LINUX) || defined(FREEBSD) || defined(__FreeBSD_kernel__) || \
       defined(NETBSD) || defined(__NetBSD_kernel__) || defined(OPENBSD) || \
       defined(__GNU__))
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

static int fdDevURandom;
static PRCallOnceType coOpenDevURandom;

static PRStatus
OpenDevURandom(void)
{
    fdDevURandom = open("/dev/urandom", O_RDONLY);
    return ((-1 == fdDevURandom) ? PR_FAILURE : PR_SUCCESS);
} /* end OpenDevURandom() */

static size_t
GetDevURandom(void* buf, size_t size)
{
    int bytesIn;
    int rc;

    rc = PR_CallOnce(&coOpenDevURandom, OpenDevURandom);
    if (PR_FAILURE == rc) {
        _PR_MD_MAP_OPEN_ERROR(errno);
        return (0);
    }

    bytesIn = read(fdDevURandom, buf, size);
    if (-1 == bytesIn) {
        _PR_MD_MAP_READ_ERROR(errno);
        return (0);
    }

    return (bytesIn);
} /* end GetDevURandom() */

static size_t
GetHighResClock(void* buf, size_t maxbytes)
{
    return (GetDevURandom(buf, maxbytes));
}

#elif defined(NTO) || defined(QNX) || defined(DARWIN) || defined(RISCOS)
#include <sys/times.h>

static size_t
GetHighResClock(void* buf, size_t maxbytes)
{
    int ticks;
    struct tms buffer;

    ticks = times(&buffer);
    return _pr_CopyLowBits(buf, maxbytes, &ticks, sizeof(ticks));
}
#else
#error ! Platform undefined
#endif /* defined(SOLARIS) */

extern PRSize
_PR_MD_GetRandomNoise(void* buf, PRSize size)
{
    struct timeval tv;
    int n = 0;
    int s;

    n += GetHighResClock(buf, size);
    size -= n;

    GETTIMEOFDAY(&tv);

    if (size > 0) {
        s = _pr_CopyLowBits((char*)buf + n, size, &tv.tv_usec, sizeof(tv.tv_usec));
        size -= s;
        n += s;
    }
    if (size > 0) {
        s = _pr_CopyLowBits((char*)buf + n, size, &tv.tv_sec, sizeof(tv.tv_usec));
        size -= s;
        n += s;
    }

    return n;
} /* end _PR_MD_GetRandomNoise() */
