/*

 * SPDX-License-Identifier: ISC

 *

 * Copyright (c) 2019-2020 Todd C. Miller <Todd.Miller@sudo.ws>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

#include <config.h>

#ifndef HAVE_STR2SIG

#include <errno.h>

#include <string.h>

#ifdef HAVE_STRINGS_H

# include <strings.h>

#endif /* HAVE_STRINGS_H */

#include <ctype.h>

#include <signal.h>

#include <unistd.h>

#include <sudo_compat.h>

#include <sudo_util.h>

#if !defined(HAVE_SIGABBREV_NP)

# if defined(HAVE_DECL_SYS_SIGNAME) && HAVE_DECL_SYS_SIGNAME == 1

#   define sigabbrev_np(_x) sys_signame[(_x)]

# elif defined(HAVE_DECL__SYS_SIGNAME) && HAVE_DECL__SYS_SIGNAME == 1

#   define sigabbrev_np(_x) _sys_signame[(_x)]

# elif defined(HAVE_SYS_SIGABBREV)

#   define sigabbrev_np(_x) sys_sigabbrev[(_x)]

#  if defined(HAVE_DECL_SYS_SIGABBREV) && HAVE_DECL_SYS_SIGABBREV == 0

    /* sys_sigabbrev is not declared by glibc */

    extern const char *const sys_sigabbrev[NSIG];

#  endif

# else

#   define sigabbrev_np(_x) sudo_sys_signame[(_x)]

    extern const char *const sudo_sys_signame[NSIG];

# endif

#endif /* !HAVE_SIGABBREV_NP */

/*

 * Many systems use aliases for source backward compatibility.

 */

static struct sigalias {

    const char *name;

    int number;

} sigaliases[] = {

#ifdef SIGABRT

    { "ABRT", SIGABRT },

#endif

#ifdef SIGCLD

    { "CLD",  SIGCLD },

#endif

#ifdef SIGIO

    { "IO",   SIGIO },

#endif

#ifdef SIGIOT

    { "IOT",  SIGIOT },

#endif

#ifdef SIGLOST

    { "LOST", SIGLOST },

#endif

#ifdef SIGPOLL

    { "POLL", SIGPOLL },

#endif

    { NULL, -1 }

};

/*

 * Translate signal name to number.

 */

int

sudo_str2sig(const char *signame, int *result)

{

    struct sigalias *alias;

    const char *errstr;

    int signo;

    /* Could be a signal number encoded as a string. */

    if (isdigit((unsigned char)signame[0])) {

  signo = (int)sudo_strtonum(signame, 0, NSIG - 1, &errstr);

  if (errstr != NULL)

      return -1;

  *result = signo;

  return 0;

    }

    /* Check real-time signals. */

#if defined(SIGRTMIN)

    if (strncmp(signame, "RTMIN", 5) == 0) {

  if (signame[5] == '\0') {

      *result = SIGRTMIN;

      return 0;

  }

  if (signame[5] == '+') {

      if (isdigit((unsigned char)signame[6])) {

# ifdef _SC_RTSIG_MAX

    const long rtmax = sysconf(_SC_RTSIG_MAX);

# else

    const long rtmax = SIGRTMAX - SIGRTMIN;

# endif

    const int off = signame[6] - '0';

    if (rtmax > 0 && off < rtmax / 2) {

        *result = SIGRTMIN + off;

        return 0;

    }

      }

  }

    }

#endif

#if defined(SIGRTMAX)

    if (strncmp(signame, "RTMAX", 5) == 0) {

  if (signame[5] == '\0') {

      *result = SIGRTMAX;

      return 0;

  }

  if (signame[5] == '-') {

      if (isdigit((unsigned char)signame[6])) {

# ifdef _SC_RTSIG_MAX

    const long rtmax = sysconf(_SC_RTSIG_MAX);

# else

    const long rtmax = SIGRTMAX - SIGRTMIN;

# endif

    const int off = signame[6] - '0';

    if (rtmax > 0 && off < rtmax / 2) {

        *result = SIGRTMAX - off;

        return 0;

    }

      }

  }

    }

#endif

    /* Check aliases. */

    for (alias = sigaliases; alias->name != NULL; alias++) {

  if (strcmp(signame, alias->name) == 0) {

      *result = alias->number;

      return 0;

  }

    }

    for (signo = 1; signo < NSIG; signo++) {

  const char *cp = sigabbrev_np(signo);

  if (cp != NULL) {

      /* On macOS sys_signame[] may contain lower-case names. */

      if (strcasecmp(signame, cp) == 0) {

    *result = signo;

    return 0;

      }

  }

    }

    errno = EINVAL;

    return -1;

}

#endif /* HAVE_STR2SIG */