/*

 * Copyright (c) 2008, 2009, 2011, 2012, 2013 Nicira, Inc.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at:

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include <config.h>

#include "signals.h"

#include <errno.h>

#include <limits.h>

#include <signal.h>

#include <stdlib.h>

#include <unistd.h>

#include "openvswitch/poll-loop.h"

#include "socket-util.h"

#include "openvswitch/type-props.h"

#include "util.h"

#include "openvswitch/vlog.h"

VLOG_DEFINE_THIS_MODULE(signals);

#if defined(_NSIG)

#define N_SIGNALS _NSIG

#elif defined(NSIG)

#define N_SIGNALS NSIG

#else

/* We could try harder to get the maximum signal number, but in practice we

 * only care about SIGHUP, which is normally signal 1 anyway. */

#define N_SIGNALS 32

#endif

/* Returns the name of signal 'signum' as a string.  The return value is either

 * a statically allocated constant string or the 'bufsize'-byte buffer

 * 'namebuf'.  'bufsize' should be at least SIGNAL_NAME_BUFSIZE.

 *

 * The string is probably a (possibly multi-word) description of the signal

 * (e.g. "Hangup") instead of just the stringified version of the macro

 * (e.g. "SIGHUP"). */

const char *

signal_name(int signum, char *namebuf, size_t bufsize)

{

#if HAVE_DECL_SYS_SIGLIST

    if (signum >= 0 && signum < N_SIGNALS) {

        const char *name = sys_siglist[signum];

        if (name) {

            return name;

        }

    }

#elif HAVE_SIGDESCR_NP

    const char *name = sigdescr_np(signum);

    if (name) {

        return name;

    }

#endif

    snprintf(namebuf, bufsize, "signal %d", signum);

    return namebuf;

}

void

xsigaction(int signum, const struct sigaction *new, struct sigaction *old)

{

    if (sigaction(signum, new, old)) {

        char namebuf[SIGNAL_NAME_BUFSIZE];

        VLOG_FATAL("sigaction(%s) failed (%s)",

                   signal_name(signum, namebuf, sizeof namebuf),

                   ovs_strerror(errno));

    }

}