/* SPDX-License-Identifier: LGPL-2.1+ */

#include <errno.h>

#include <stdarg.h>

#include <stdio.h>

#include "macro.h"

#include "parse-util.h"

#include "signal-util.h"

#include "stdio-util.h"

#include "string-table.h"

#include "string-util.h"

int reset_all_signal_handlers(void) {

        static const struct sigaction sa = {

                .sa_handler = SIG_DFL,

                .sa_flags = SA_RESTART,

        };

        int sig, r = 0;

        for (sig = 1; sig < _NSIG; sig++) {

                /* These two cannot be caught... */

                if (IN_SET(sig, SIGKILL, SIGSTOP))

                        continue;

                /* On Linux the first two RT signals are reserved by

                 * glibc, and sigaction() will return EINVAL for them. */

                if ((sigaction(sig, &sa, NULL) < 0))

                        if (errno != EINVAL && r >= 0)

                                r = -errno;

        }

        return r;

}

int reset_signal_mask(void) {

        sigset_t ss;

        if (sigemptyset(&ss) < 0)

                return -errno;

        if (sigprocmask(SIG_SETMASK, &ss, NULL) < 0)

                return -errno;

        return 0;

}

static int sigaction_many_ap(const struct sigaction *sa, int sig, va_list ap) {

        int r = 0;

        /* negative signal ends the list. 0 signal is skipped. */

        if (sig < 0)

                return 0;

        if (sig > 0) {

                if (sigaction(sig, sa, NULL) < 0)

                        r = -errno;

        }

        while ((sig = va_arg(ap, int)) >= 0) {

                if (sig == 0)

                        continue;

                if (sigaction(sig, sa, NULL) < 0) {

                        if (r >= 0)

                                r = -errno;

                }

        }

        return r;

}

int sigaction_many(const struct sigaction *sa, ...) {

        va_list ap;

        int r;

        va_start(ap, sa);

        r = sigaction_many_ap(sa, 0, ap);

        va_end(ap);

        return r;

}

int ignore_signals(int sig, ...) {

        static const struct sigaction sa = {

                .sa_handler = SIG_IGN,

                .sa_flags = SA_RESTART,

        };

        va_list ap;

        int r;

        va_start(ap, sig);

        r = sigaction_many_ap(&sa, sig, ap);

        va_end(ap);

        return r;

}

int default_signals(int sig, ...) {

        static const struct sigaction sa = {

                .sa_handler = SIG_DFL,

                .sa_flags = SA_RESTART,

        };

        va_list ap;

        int r;

        va_start(ap, sig);

        r = sigaction_many_ap(&sa, sig, ap);

        va_end(ap);

        return r;

}

static int sigset_add_many_ap(sigset_t *ss, va_list ap) {

        int sig, r = 0;

        assert(ss);

        while ((sig = va_arg(ap, int)) >= 0) {

                if (sig == 0)

                        continue;

                if (sigaddset(ss, sig) < 0) {

                        if (r >= 0)

                                r = -errno;

                }

        }

        return r;

}

int sigset_add_many(sigset_t *ss, ...) {

        va_list ap;

        int r;

        va_start(ap, ss);

        r = sigset_add_many_ap(ss, ap);

        va_end(ap);

        return r;

}

int sigprocmask_many(int how, sigset_t *old, ...) {

        va_list ap;

        sigset_t ss;

        int r;

        if (sigemptyset(&ss) < 0)

                return -errno;

        va_start(ap, old);

        r = sigset_add_many_ap(&ss, ap);

        va_end(ap);

        if (r < 0)

                return r;

        if (sigprocmask(how, &ss, old) < 0)

                return -errno;

        return 0;

}

static const char *const __signal_table[] = {

        [SIGHUP] = "HUP",

        [SIGINT] = "INT",

        [SIGQUIT] = "QUIT",

        [SIGILL] = "ILL",

        [SIGTRAP] = "TRAP",

        [SIGABRT] = "ABRT",

        [SIGBUS] = "BUS",

        [SIGFPE] = "FPE",

        [SIGKILL] = "KILL",

        [SIGUSR1] = "USR1",

        [SIGSEGV] = "SEGV",

        [SIGUSR2] = "USR2",

        [SIGPIPE] = "PIPE",

        [SIGALRM] = "ALRM",

        [SIGTERM] = "TERM",

#ifdef SIGSTKFLT

        [SIGSTKFLT] = "STKFLT",  /* Linux on SPARC doesn't know SIGSTKFLT */

#endif

        [SIGCHLD] = "CHLD",

        [SIGCONT] = "CONT",

        [SIGSTOP] = "STOP",

        [SIGTSTP] = "TSTP",

        [SIGTTIN] = "TTIN",

        [SIGTTOU] = "TTOU",

        [SIGURG] = "URG",

        [SIGXCPU] = "XCPU",

        [SIGXFSZ] = "XFSZ",

        [SIGVTALRM] = "VTALRM",

        [SIGPROF] = "PROF",

        [SIGWINCH] = "WINCH",

        [SIGIO] = "IO",

        [SIGPWR] = "PWR",

        [SIGSYS] = "SYS"

};

DEFINE_PRIVATE_STRING_TABLE_LOOKUP(__signal, int);

const char *signal_to_string(int signo) {

        static thread_local char buf[STRLEN("RTMIN+") + DECIMAL_STR_MAX(int) + 1];

        const char *name;

        name = __signal_to_string(signo);

        if (name)

                return name;

        if (signo >= SIGRTMIN && signo <= SIGRTMAX)

                xsprintf(buf, "RTMIN+%d", signo - SIGRTMIN);

        else

                xsprintf(buf, "%d", signo);

        return buf;

}

int signal_from_string(const char *s) {

        const char *p;

        int signo, r;

        /* Check that the input is a signal number. */

        if (safe_atoi(s, &signo) >= 0) {

                if (SIGNAL_VALID(signo))

                        return signo;

                else

                        return -ERANGE;

        }

        /* Drop "SIG" prefix. */

        if (startswith(s, "SIG"))

                s += 3;

        /* Check that the input is a signal name. */

        signo = __signal_from_string(s);

        if (signo > 0)

                return signo;

        /* Check that the input is RTMIN or

         * RTMIN+n (0 <= n <= SIGRTMAX-SIGRTMIN). */

        p = startswith(s, "RTMIN");

        if (p) {

                if (*p == '\0')

                        return SIGRTMIN;

                if (*p != '+')

                        return -EINVAL;

                r = safe_atoi(p, &signo);

                if (r < 0)

                        return r;

                if (signo < 0 || signo > SIGRTMAX - SIGRTMIN)

                        return -ERANGE;

                return signo + SIGRTMIN;

        }

        /* Check that the input is RTMAX or

         * RTMAX-n (0 <= n <= SIGRTMAX-SIGRTMIN). */

        p = startswith(s, "RTMAX");

        if (p) {

                if (*p == '\0')

                        return SIGRTMAX;

                if (*p != '-')

                        return -EINVAL;

                r = safe_atoi(p, &signo);

                if (r < 0)

                        return r;

                if (signo > 0 || signo < SIGRTMIN - SIGRTMAX)

                        return -ERANGE;

                return signo + SIGRTMAX;

        }

        return -EINVAL;

}

void nop_signal_handler(int sig) {

        /* nothing here */

}