evutil.c

/*
 * Copyright (c) 2007 Niels Provos <provos@citi.umich.edu>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef WIN32
#include <winsock2.h>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#undef WIN32_LEAN_AND_MEAN
#endif

#include <sys/types.h>
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <errno.h>
#if defined WIN32 && !defined(HAVE_GETTIMEOFDAY_H)
#include <sys/timeb.h>
#endif
#include <stdio.h>
#include <signal.h>

#include <sys/queue.h>
#include "event.h"
#include "event-internal.h"
#include "evutil.h"
#include "log.h"

int
evutil_socketpair(int family, int type, int protocol, int fd[2])
{
#ifndef WIN32
    return socketpair(family, type, protocol, fd);
#else
    /* This code is originally from Tor.  Used with permission. */

    /* This socketpair does not work when localhost is down. So
     * it's really not the same thing at all. But it's close enough
     * for now, and really, when localhost is down sometimes, we
     * have other problems too.
     */
    int listener = -1;
    int connector = -1;
    int acceptor = -1;
    struct sockaddr_in listen_addr;
    struct sockaddr_in connect_addr;
    int size;
    int saved_errno = -1;

    if (protocol
#ifdef AF_UNIX
        || family != AF_UNIX
#endif
       ) {
        EVUTIL_SET_SOCKET_ERROR(WSAEAFNOSUPPORT);
        return -1;
    }
    if (!fd) {
        EVUTIL_SET_SOCKET_ERROR(WSAEINVAL);
        return -1;
    }

    listener = socket(AF_INET, type, 0);
    if (listener < 0)
        return -1;
    memset(&listen_addr, 0, sizeof(listen_addr));
    listen_addr.sin_family = AF_INET;
    listen_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
    listen_addr.sin_port = 0;   /* kernel chooses port.  */
    if (bind(listener, (struct sockaddr*) &listen_addr, sizeof (listen_addr))
        == -1)
        goto tidy_up_and_fail;
    if (listen(listener, 1) == -1)
        goto tidy_up_and_fail;

    connector = socket(AF_INET, type, 0);
    if (connector < 0)
        goto tidy_up_and_fail;
    /* We want to find out the port number to connect to.  */
    size = sizeof(connect_addr);
    if (getsockname(listener, (struct sockaddr*) &connect_addr, &size) == -1)
        goto tidy_up_and_fail;
    if (size != sizeof (connect_addr))
        goto abort_tidy_up_and_fail;
    if (connect(connector, (struct sockaddr*) &connect_addr,
                sizeof(connect_addr)) == -1)
        goto tidy_up_and_fail;

    size = sizeof(listen_addr);
    acceptor = accept(listener, (struct sockaddr*) &listen_addr, &size);
    if (acceptor < 0)
        goto tidy_up_and_fail;
    if (size != sizeof(listen_addr))
        goto abort_tidy_up_and_fail;
    EVUTIL_CLOSESOCKET(listener);
    /* Now check we are talking to ourself by matching port and host on the
       two sockets.  */
    if (getsockname(connector, (struct sockaddr*) &connect_addr, &size) == -1)
        goto tidy_up_and_fail;
    if (size != sizeof (connect_addr)
        || listen_addr.sin_family != connect_addr.sin_family
        || listen_addr.sin_addr.s_addr != connect_addr.sin_addr.s_addr
        || listen_addr.sin_port != connect_addr.sin_port)
        goto abort_tidy_up_and_fail;
    fd[0] = connector;
    fd[1] = acceptor;

    return 0;

abort_tidy_up_and_fail:
    saved_errno = WSAECONNABORTED;
tidy_up_and_fail:
    if (saved_errno < 0)
        saved_errno = WSAGetLastError();
    if (listener != -1)
        EVUTIL_CLOSESOCKET(listener);
    if (connector != -1)
        EVUTIL_CLOSESOCKET(connector);
    if (acceptor != -1)
        EVUTIL_CLOSESOCKET(acceptor);

    EVUTIL_SET_SOCKET_ERROR(saved_errno);
    return -1;
#endif
}

int
evutil_make_socket_nonblocking(int fd)
{
#ifdef WIN32
    {
        unsigned long nonblocking = 1;
        ioctlsocket(fd, FIONBIO, (unsigned long*) &nonblocking);
    }
#else
    {
        int flags;
        if ((flags = fcntl(fd, F_GETFL, NULL)) < 0) {
            event_warn("fcntl(%d, F_GETFL)", fd);
            return -1;
        }
        if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) {
            event_warn("fcntl(%d, F_SETFL)", fd);
            return -1;
        }
    }
#endif
    return 0;
}

ev_int64_t
evutil_strtoll(const char* s, char** endptr, int base)
{
#ifdef HAVE_STRTOLL
    return (ev_int64_t)strtoll(s, endptr, base);
#elif SIZEOF_LONG == 8
    return (ev_int64_t)strtol(s, endptr, base);
#elif defined(WIN32) && defined(_MSC_VER) && _MSC_VER < 1300
    /* XXXX on old versions of MS APIs, we only support base
     * 10. */
    ev_int64_t r;
    if (base != 10)
        return 0;
    r = (ev_int64_t) _atoi64(s);
    while (isspace(*s))
        ++s;
    while (isdigit(*s))
        ++s;
    if (endptr)
        *endptr = (char*) s;
    return r;
#elif defined(WIN32)
    return (ev_int64_t) _strtoi64(s, endptr, base);
#else
#error "I don't know how to parse 64-bit integers."
#endif
}

#ifndef _EVENT_HAVE_GETTIMEOFDAY
int
evutil_gettimeofday(struct timeval* tv, struct timezone* tz)
{
    struct _timeb tb;

    if (tv == NULL)
        return -1;

    _ftime(&tb);
    tv->tv_sec = (long) tb.time;
    tv->tv_usec = ((int) tb.millitm) * 1000;
    return 0;
}
#endif

int
evutil_snprintf(char* buf, size_t buflen, const char* format, ...)
{
    int r;
    va_list ap;
    va_start(ap, format);
    r = evutil_vsnprintf(buf, buflen, format, ap);
    va_end(ap);
    return r;
}

int
evutil_vsnprintf(char* buf, size_t buflen, const char* format, va_list ap)
{
#ifdef _MSC_VER
    int r = _vsnprintf(buf, buflen, format, ap);
    buf[buflen - 1] = '\0';
    if (r >= 0)
        return r;
    else
        return _vscprintf(format, ap);
#else
    int r = vsnprintf(buf, buflen, format, ap);
    buf[buflen - 1] = '\0';
    return r;
#endif
}

static int
evutil_issetugid(void)
{
#ifdef _EVENT_HAVE_ISSETUGID
    return issetugid();
#else

#ifdef _EVENT_HAVE_GETEUID
    if (getuid() != geteuid())
        return 1;
#endif
#ifdef _EVENT_HAVE_GETEGID
    if (getgid() != getegid())
        return 1;
#endif
    return 0;
#endif
}

const char*
evutil_getenv(const char* varname)
{
    if (evutil_issetugid())
        return NULL;

    return getenv(varname);
}