/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1988, 1993
 *      The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 */

#include "namespace.h"
#if defined(NLS)
#include <nl_types.h>
#endif
#include <limits.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include "reentrant.h"
#include "un-namespace.h"

#define UPREFIX         "Unknown signal"

static char             sig_ebuf[NL_TEXTMAX];
static char             sig_ebuf_err[NL_TEXTMAX];
static once_t           sig_init_once = ONCE_INITIALIZER;
static thread_key_t     sig_key;
static int              sig_keycreated = 0;

static void
sig_keycreate(void)
{
        sig_keycreated = (thr_keycreate(&sig_key, free) == 0);
}

static char *
sig_tlsalloc(void)
{
        char *ebuf = NULL;

        if (thr_main() != 0)
                ebuf = sig_ebuf;
        else {
                if (thr_once(&sig_init_once, sig_keycreate) != 0 ||
                    !sig_keycreated)
                        goto thr_err;
                if ((ebuf = thr_getspecific(sig_key)) == NULL) {
                        if ((ebuf = malloc(sizeof(sig_ebuf))) == NULL)
                                goto thr_err;
                        if (thr_setspecific(sig_key, ebuf) != 0) {
                                free(ebuf);
                                ebuf = NULL;
                                goto thr_err;
                        }
                }
        }
thr_err:
        if (ebuf == NULL)
                ebuf = sig_ebuf_err;
        return (ebuf);
}

/* XXX: negative 'num' ? (REGR) */
char *
strsignal(int num)
{
        char *ebuf;
        char tmp[20];
        size_t n;
        int signum;
        char *t, *p;

#if defined(NLS)
        int saved_errno = errno;
        nl_catd catd;
        catd = catopen("libc", NL_CAT_LOCALE);
#endif

        ebuf = sig_tlsalloc();

        if (num > 0 && num < sys_nsig) {
                n = strlcpy(ebuf,
#if defined(NLS)
                        catgets(catd, 2, num, sys_siglist[num]),
#else
                        sys_siglist[num],
#endif
                        sizeof(sig_ebuf));
        } else {
                n = strlcpy(ebuf,
#if defined(NLS)
                        catgets(catd, 2, 0xffff, UPREFIX),
#else
                        UPREFIX,
#endif
                        sizeof(sig_ebuf));

                signum = num;
                if (num < 0)
                        signum = -signum;

                t = tmp;
                do {
                        *t++ = "0123456789"[signum % 10];
                } while (signum /= 10);
                if (num < 0)
                        *t++ = '-';

                p = (ebuf + n);
                *p++ = ':';
                *p++ = ' ';

                for (;;) {
                        *p++ = *--t;
                        if (t <= tmp)
                                break;
                }
                *p = '\0';
        }

#if defined(NLS)
        catclose(catd);
        errno = saved_errno;
#endif
        return (ebuf);
}