/*	$NetBSD: linux32_signal.c,v 1.24 2021/11/26 13:32:38 christos Exp $ */

/*-
 * Copyright (c) 2006 Emmanuel Dreyfus, 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Emmanuel Dreyfus
 * 4. 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 THE AUTHOR 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 AUTHOR 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: linux32_signal.c,v 1.24 2021/11/26 13:32:38 christos Exp $");

#include <sys/param.h>
#include <sys/ucred.h>
#include <sys/signalvar.h>
#include <sys/lwp.h>
#include <sys/time.h>
#include <sys/proc.h>
#include <sys/wait.h>

#include <compat/netbsd32/netbsd32.h>

#include <compat/linux/common/linux_types.h>
#include <compat/linux/common/linux_signal.h>
#include <compat/linux/common/linux_sigevent.h>

#include <compat/linux32/common/linux32_types.h>
#include <compat/linux32/common/linux32_signal.h>
#include <compat/linux32/common/linux32_sigevent.h>
#include <compat/linux32/common/linux32_siginfo.h>
#include <compat/linux32/linux32_syscallargs.h>
#include <compat/linux32/common/linux32_errno.h>
#include <compat/linux32/common/linux32_sched.h>

#define linux32_sigemptyset(s)    memset((s), 0, sizeof(*(s)))
#define linux32_sigismember(s, n) ((s)->sig[((n) - 1) / LINUX32__NSIG_BPW]  \
				    & (1 << ((n) - 1) % LINUX32__NSIG_BPW))
#define linux32_sigaddset(s, n)   ((s)->sig[((n) - 1) / LINUX32__NSIG_BPW]  \
				    |= (1 << ((n) - 1) % LINUX32__NSIG_BPW))

extern const int native_to_linux32_signo[];
extern const int linux32_to_native_signo[];

#ifdef DEBUG_LINUX
#define DPRINTF(a)      uprintf a
#else
#define DPRINTF(a)
#endif

void
linux32_to_native_sigset(sigset_t *bss, const linux32_sigset_t *lss)
{
	int i, newsig;

	sigemptyset(bss);
	for (i = 1; i < LINUX32__NSIG; i++) {
		if (linux32_sigismember(lss, i)) {
			newsig = linux32_to_native_signo[i];
			if (newsig)
				sigaddset(bss, newsig);
		}
	}
}

void
native_to_linux32_sigset(linux32_sigset_t *lss, const sigset_t *bss)
{
	int i, newsig;

	linux32_sigemptyset(lss);
	for (i = 1; i < NSIG; i++) {
		if (sigismember(bss, i)) {
			newsig = native_to_linux32_signo[i];
			if (newsig)
				linux32_sigaddset(lss, newsig);
		}
	}
}

void
native_to_linux32_siginfo(linux32_siginfo_t *lsi, const struct _ksiginfo *ksi)
{
	memset(lsi, 0, sizeof(*lsi));

	lsi->lsi_signo = native_to_linux32_signo[ksi->_signo];
	lsi->lsi_errno = native_to_linux32_errno[ksi->_errno];
	lsi->lsi_code = native_to_linux32_si_code(ksi->_code);

	switch (ksi->_code) {
	case SI_NOINFO:
		break;

	case SI_USER:
		lsi->lsi_pid = ksi->_reason._rt._pid;
		lsi->lsi_uid = ksi->_reason._rt._uid;
		if (lsi->lsi_signo == LINUX_SIGALRM ||
		    lsi->lsi_signo >= LINUX_SIGRTMIN)
			NETBSD32PTR32(lsi->lsi_value.sival_ptr,
			    ksi->_reason._rt._value.sival_ptr);
		break;

	case SI_TIMER:
	case SI_QUEUE:
		lsi->lsi_uid = ksi->_reason._rt._uid;
		lsi->lsi_uid = ksi->_reason._rt._uid;
		NETBSD32PTR32(lsi->lsi_value.sival_ptr,
		    ksi->_reason._rt._value.sival_ptr);
		break;

	case SI_ASYNCIO:
	case SI_MESGQ:
		NETBSD32PTR32(lsi->lsi_value.sival_ptr,
		    ksi->_reason._rt._value.sival_ptr);
		break;

	default:
		switch (ksi->_signo) {
		case SIGCHLD:
			lsi->lsi_uid = ksi->_reason._child._uid;
			lsi->lsi_pid = ksi->_reason._child._pid;
			lsi->lsi_status = native_to_linux32_si_status(
			    ksi->_code, ksi->_reason._child._status);
			lsi->lsi_utime = ksi->_reason._child._utime;
			lsi->lsi_stime = ksi->_reason._child._stime;
			break;

		case SIGILL:
		case SIGFPE:
		case SIGSEGV:
		case SIGBUS:
		case SIGTRAP:
			NETBSD32PTR32(lsi->lsi_addr, ksi->_reason._fault._addr);
			break;

		case SIGIO:
			lsi->lsi_fd = ksi->_reason._poll._fd;
			lsi->lsi_band = ksi->_reason._poll._band;
			break;
		default:
			break;
		}
	}
}

unsigned int 
native_to_linux32_sigflags(const int bsf)
{
	unsigned int lsf = 0;
	if ((bsf & SA_NOCLDSTOP) != 0)
		lsf |= LINUX32_SA_NOCLDSTOP;
	if ((bsf & SA_NOCLDWAIT) != 0)
		lsf |= LINUX32_SA_NOCLDWAIT;
	if ((bsf & SA_ONSTACK) != 0)
		lsf |= LINUX32_SA_ONSTACK;
	if ((bsf & SA_RESTART) != 0)
		lsf |= LINUX32_SA_RESTART;
	if ((bsf & SA_NODEFER) != 0)
		lsf |= LINUX32_SA_NOMASK;
	if ((bsf & SA_RESETHAND) != 0)
		lsf |= LINUX32_SA_ONESHOT;
	if ((bsf & SA_SIGINFO) != 0)
		lsf |= LINUX32_SA_SIGINFO;
	return lsf; 
}
 
int
linux32_to_native_sigflags(const unsigned long lsf)
{
	int bsf = 0;
	if ((lsf & LINUX32_SA_NOCLDSTOP) != 0)
		bsf |= SA_NOCLDSTOP; 
	if ((lsf & LINUX32_SA_NOCLDWAIT) != 0)
		bsf |= SA_NOCLDWAIT;
	if ((lsf & LINUX32_SA_ONSTACK) != 0)
		bsf |= SA_ONSTACK;
	if ((lsf & LINUX32_SA_RESTART) != 0)
		bsf |= SA_RESTART;
	if ((lsf & LINUX32_SA_ONESHOT) != 0)
		bsf |= SA_RESETHAND;
	if ((lsf & LINUX32_SA_NOMASK) != 0)
		bsf |= SA_NODEFER;
	if ((lsf & LINUX32_SA_SIGINFO) != 0)
		bsf |= SA_SIGINFO;
	if ((lsf & ~LINUX32_SA_ALLBITS) != 0) {
#ifdef DEBUG_LINUX
		printf("linux32_old_to_native_sigflags: "
		    "%lx extra bits ignored\n", lsf);
#endif
	}
	return bsf;
}    

void
linux32_to_native_sigaction(struct sigaction *bsa, const struct linux32_sigaction *lsa)
{
	memset(bsa, 0, sizeof(*bsa));
	bsa->sa_handler = NETBSD32PTR64(lsa->linux_sa_handler);
	linux32_to_native_sigset(&bsa->sa_mask, &lsa->linux_sa_mask);
	bsa->sa_flags = linux32_to_native_sigflags(lsa->linux_sa_flags);
}

void
native_to_linux32_sigaction(struct linux32_sigaction *lsa, const struct sigaction *bsa)
{
	memset(lsa, 0, sizeof(*lsa));
	NETBSD32PTR32(lsa->linux_sa_handler, bsa->sa_handler);
	native_to_linux32_sigset(&lsa->linux_sa_mask, &bsa->sa_mask);
	lsa->linux_sa_flags = native_to_linux32_sigflags(bsa->sa_flags);
	NETBSD32PTR32(lsa->linux_sa_restorer, NULL);
}

void
native_to_linux32_sigaltstack(struct linux32_sigaltstack *lss,
    const stack_t *bss)
{
	memset(lss, 0, sizeof(*lss));
	NETBSD32PTR32(lss->ss_sp, bss->ss_sp);
	lss->ss_size = bss->ss_size;
	if (bss->ss_flags & SS_ONSTACK)
	    lss->ss_flags = LINUX32_SS_ONSTACK;
	else if (bss->ss_flags & SS_DISABLE)
	    lss->ss_flags = LINUX32_SS_DISABLE;
	else
	    lss->ss_flags = 0;
}


void
native_to_linux32_old_sigset(linux32_old_sigset_t *lss, const sigset_t *bss)
{
	linux32_sigset_t lsnew;
 
	native_to_linux32_sigset(&lsnew, bss);
 
	/* convert new sigset to old sigset */
	*lss = lsnew.sig[0];
}

void
linux32_old_to_native_sigset(sigset_t *bss, const linux32_old_sigset_t *lss)
{
	linux32_sigset_t ls;

	memset(&ls, 0, sizeof(ls));
	ls.sig[0] = *lss;
	
	linux32_to_native_sigset(bss, &ls);
}

int
linux32_sys_rt_sigaction(struct lwp *l, const struct linux32_sys_rt_sigaction_args *uap, register_t *retval)
{
	/* {
		syscallarg(int) signum;
		syscallarg(const linux32_sigactionp_t) nsa;
		syscallarg(linux32_sigactionp_t) osa;
		syscallarg(netbsd32_size_t) sigsetsize;
	} */
	struct linux32_sigaction nls32;
	struct linux32_sigaction ols32;
	struct sigaction ns;
	struct sigaction os;
	int error;
	int sig;
	int vers = 0;
	void *tramp = NULL;

	if (SCARG(uap, sigsetsize) != sizeof(linux32_sigset_t)) {
		DPRINTF(("rt_sigaction: Inconsistent sigsetsize %u %zu\n", 
		    SCARG(uap, sigsetsize), sizeof(linux32_sigset_t)));
		return EINVAL;
	}

	if (SCARG_P32(uap, nsa) != NULL) {
		if ((error = copyin(SCARG_P32(uap, nsa), 
		    &nls32, sizeof(nls32))) != 0) {
			DPRINTF(("rt_sigaction: Copyin %d\n", error));
			return error;
		}
		linux32_to_native_sigaction(&ns, &nls32);
	}

	sig = SCARG(uap, signum);
	/*
	 * XXX: Linux has 33 realtime signals, the go binary wants to
	 * reset all of them; nothing else uses the last RT signal, so for
	 * now ignore it.
	 */
	if (sig == LINUX__NSIG) {
		uprintf("%s: setting signal %d ignored\n", __func__, sig);
		sig--;	/* back to 63 which is ignored */
	}
	if (sig < 0 || sig >= LINUX32__NSIG) {
		DPRINTF(("rt_sigaction: Bad signal number %d %d\n", 
		    sig, LINUX32__NSIG));
		return EINVAL;
	}
	if (sig > 0 && !linux32_to_native_signo[sig]) {
		/* unknown signal... */
		os.sa_handler = SIG_IGN;
		sigemptyset(&os.sa_mask);
		os.sa_flags = 0;
	} else {
		if ((error = sigaction1(l, 
		    linux32_to_native_signo[sig],	
		    SCARG_P32(uap, nsa) ? &ns : NULL,
		    SCARG_P32(uap, osa) ? &os : NULL,
		    tramp, vers)) != 0) {
			DPRINTF(("rt_sigaction: sigaction %d\n", error));
			return error;
		}
	}

	if (SCARG_P32(uap, osa) != NULL) {
		native_to_linux32_sigaction(&ols32, &os);

		if ((error = copyout(&ols32, SCARG_P32(uap, osa),
		    sizeof(ols32))) != 0) {
			DPRINTF(("rt_sigaction: Copyout %d\n", error));
			return error;
		}
	}

	return 0;
}

int
linux32_sys_rt_sigprocmask(struct lwp *l, const struct linux32_sys_rt_sigprocmask_args *uap, register_t *retval)
{
	/* {
		syscallarg(int) how;
		syscallarg(const linux32_sigsetp_t) set;
		syscallarg(linux32_sigsetp_t) oset;
		syscallarg(netbsd32_size_t) sigsetsize;
	} */
	struct proc *p = l->l_proc;
	linux32_sigset_t nls32, ols32;
	sigset_t ns, os;
	int error;
	int how;

	if (SCARG(uap, sigsetsize) != sizeof(linux32_sigset_t))
		return EINVAL;

	switch (SCARG(uap, how)) {
	case LINUX32_SIG_BLOCK:
		how = SIG_BLOCK;
		break;
	case LINUX32_SIG_UNBLOCK:
		how = SIG_UNBLOCK;
		break;
	case LINUX32_SIG_SETMASK:
		how = SIG_SETMASK;
		break;
	default:
		return EINVAL;
		break;
	}

	if (SCARG_P32(uap, set) != NULL) {
		if ((error = copyin(SCARG_P32(uap, set), 
		    &nls32, sizeof(nls32))) != 0)
			return error;
		linux32_to_native_sigset(&ns, &nls32);
	}

	mutex_enter(p->p_lock);
	error = sigprocmask1(l, how,
	    SCARG_P32(uap, set) ? &ns : NULL,
	    SCARG_P32(uap, oset) ? &os : NULL);
	mutex_exit(p->p_lock);
      
        if (error != 0)
		return error;
		
	if (SCARG_P32(uap, oset) != NULL) {
		native_to_linux32_sigset(&ols32, &os);
		if ((error = copyout(&ols32, 
		    SCARG_P32(uap, oset), sizeof(ols32))) != 0)
			return error;
	}

	return 0;
}

int
linux32_sys_kill(struct lwp *l, const struct linux32_sys_kill_args *uap, register_t *retval)
{
	/* {
		syscallarg(int) pid;
		syscallarg(int) signum;
	} */
 
	struct sys_kill_args ka;
	int sig;
 
	SCARG(&ka, pid) = SCARG(uap, pid);
	sig = SCARG(uap, signum);
	if (sig < 0 || sig >= LINUX32__NSIG)
		return (EINVAL);
	SCARG(&ka, signum) = linux32_to_native_signo[sig];
	return sys_kill(l, &ka, retval);
}  

int
linux32_sys_rt_sigsuspend(struct lwp *l, const struct linux32_sys_rt_sigsuspend_args *uap, register_t *retval)
{
	/* {
		syscallarg(linux32_sigsetp_t) unewset;
                syscallarg(netbsd32_size_t) sigsetsize;
	} */
	linux32_sigset_t lss;
	sigset_t bss;
	int error;

	if (SCARG(uap, sigsetsize) != sizeof(linux32_sigset_t))
		return EINVAL;

	if ((error = copyin(SCARG_P32(uap, unewset), 
	    &lss, sizeof(linux32_sigset_t))) != 0)
		return error;

	linux32_to_native_sigset(&bss, &lss);

	return sigsuspend1(l, &bss);
}

static int
fetchss(const void *u, void *s, size_t len)
{
	int error;
	linux32_sigset_t lss;
	
	if ((error = copyin(u, &lss, sizeof(lss))) != 0)
		return error;

	linux32_to_native_sigset(s, &lss);
	return 0;
}

static int
fetchts(const void *u, void *s, size_t len)
{
	int error;
	struct linux32_timespec lts;
	
	if ((error = copyin(u, &lts, sizeof(lts))) != 0)
		return error;

	linux32_to_native_timespec(s, &lts);
	return 0;
}

static int
fakestorets(const void *u, void *s, size_t len)
{
	/* Do nothing, sigtimedwait does not alter timeout like ours */
	return 0;
}

static int
storeinfo(const void *s, void *u, size_t len)
{
	linux32_siginfo_t lsi;


	native_to_linux32_siginfo(&lsi, &((const siginfo_t *)s)->_info);
	return copyout(&lsi, u, sizeof(lsi));
}

int
linux32_sys_rt_sigtimedwait(struct lwp *l,
    const struct linux32_sys_rt_sigtimedwait_args *uap, register_t *retval)
{
	/* {
		syscallarg(const linux32_sigset_t *) set;
		syscallarg(linux32_siginfo_t *) info);
		syscallarg(const struct linux32_timespec *) timeout;
	} */
	struct sys_____sigtimedwait50_args ap;

	SCARG(&ap, set) = SCARG_P32(uap, set);
	SCARG(&ap, info) = SCARG_P32(uap, info);
	SCARG(&ap, timeout) = SCARG_P32(uap, timeout);

	return sigtimedwait1(l, &ap,
	    retval, fetchss, storeinfo, fetchts, fakestorets);
}

int
linux32_sys_signal(struct lwp *l, const struct linux32_sys_signal_args *uap, register_t *retval)
{
	/* {
		syscallarg(int) signum;
		syscallarg(linux32_handlerp_t) handler;
	} */
        struct sigaction nbsa, obsa;
        int error, sig;

        *retval = -1;

        sig = SCARG(uap, signum);
        if (sig < 0 || sig >= LINUX32__NSIG)
                return EINVAL;

        nbsa.sa_handler = SCARG_P32(uap, handler);
        sigemptyset(&nbsa.sa_mask);
        nbsa.sa_flags = SA_RESETHAND | SA_NODEFER;

        if ((error = sigaction1(l, linux32_to_native_signo[sig],
            &nbsa, &obsa, NULL, 0)) != 0)
		return error;

        *retval = (int)(long)obsa.sa_handler;
        return 0;
}

int
linux32_sys_rt_sigpending(struct lwp *l, const struct linux32_sys_rt_sigpending_args *uap, register_t *retval)
{
	/* {
		syscallarg(linux32_sigsetp_t) set;
		syscallarg(netbsd32_size_t) sigsetsize;
	} */
	sigset_t bss;
	linux32_sigset_t lss;

	if (SCARG(uap, sigsetsize) != sizeof(linux32_sigset_t))
		return EINVAL;

	sigpending1(l, &bss);
	native_to_linux32_sigset(&lss, &bss);
	return copyout(&lss, SCARG_P32(uap, set), sizeof(lss));
}

int
linux32_sys_siggetmask(struct lwp *l, const void *v, register_t *retval)
{
	struct proc *p = l->l_proc;
	sigset_t bss;
	linux32_old_sigset_t lss;
	int error;

	mutex_enter(p->p_lock);
	error = sigprocmask1(l, SIG_SETMASK, 0, &bss);
	mutex_exit(p->p_lock);
	if (error)
		return error;
	native_to_linux32_old_sigset(&lss, &bss);
	*retval = lss;
	return 0;
}

int
linux32_sys_sigsetmask(struct lwp *l, const struct linux32_sys_sigsetmask_args *uap, register_t *retval)
{
	/* {
		syscallarg(linux32_old_sigset_t) mask;
	} */
	sigset_t nbss, obss;
	linux32_old_sigset_t nlss, olss;
	struct proc *p = l->l_proc;
	int error;

	nlss = SCARG(uap, mask);
	linux32_old_to_native_sigset(&nbss, &nlss);
	mutex_enter(p->p_lock);
	error = sigprocmask1(l, SIG_SETMASK, &nbss, &obss);
	mutex_exit(p->p_lock);
	if (error)
		return error;
	native_to_linux32_old_sigset(&olss, &obss);
	*retval = olss;
	return 0;
}

int
linux32_sys_rt_queueinfo(struct lwp *l, const struct linux32_sys_rt_queueinfo_args *uap, register_t *retval)
{
	/*
		syscallarg(int) pid;
		syscallarg(int) sig;
		syscallarg(linux32_siginfop_t) uinfo;
	*/
	int error;
	linux32_siginfo_t info;

	error = copyin(SCARG_P32(uap, uinfo), &info, sizeof(info));
	if (error)
		return error;
	if (info.lsi_code >= 0)
		return EPERM;

	/* XXX To really implement this we need to      */
	/* XXX keep a list of queued signals somewhere. */
	return linux32_sys_kill(l, (const void *)uap, retval);
}

int
native_to_linux32_si_code(int code)
{
	int si_codes[] = {
	    LINUX32_SI_USER, LINUX32_SI_QUEUE, LINUX32_SI_TIMER,
	    LINUX32_SI_ASYNCIO, LINUX32_SI_MESGQ, LINUX32_SI_TKILL /* SI_LWP */
	};

	if (code <= 0 && -code < __arraycount(si_codes))
		return si_codes[-code];

	return code;
}

int
native_to_linux32_si_status(int code, int status)
{
	int sts;

	switch (code) {
	case CLD_CONTINUED:
		sts = LINUX_SIGCONT;
		break;
	case CLD_EXITED:
		sts = WEXITSTATUS(status);
		break;
	case CLD_STOPPED:
	case CLD_TRAPPED:
	case CLD_DUMPED:
	case CLD_KILLED:
	default:
		sts = native_to_linux32_signo[WTERMSIG(status)];
		break;
	}

	return sts;
}

int
linux32_to_native_sigevent(struct sigevent *nsep,
    const struct linux32_sigevent *lsep)
{
	memset(nsep, 0, sizeof(*nsep));

	switch (lsep->sigev_notify) {
	case LINUX_SIGEV_SIGNAL:
		nsep->sigev_notify = SIGEV_SIGNAL;
		break;

	case LINUX_SIGEV_NONE:
		nsep->sigev_notify = SIGEV_NONE;
		break;

	case LINUX_SIGEV_THREAD:
	case LINUX_SIGEV_THREAD_ID:
	default:
		return ENOTSUP;
	}

	nsep->sigev_value.sival_ptr =
	    NETBSD32PTR64(lsep->sigev_value.sival_ptr);

	if (lsep->sigev_signo < 0 || lsep->sigev_signo >= LINUX32__NSIG) {
		return EINVAL;
	}
	nsep->sigev_signo = linux32_to_native_signo[lsep->sigev_signo];

	return 0;
}

int
linux32_sigevent_copyin(const void *src, void *dst, size_t size)
{
	struct linux32_sigevent lse;
	struct sigevent *sep = dst;
	int error;

	KASSERT(size == sizeof(*sep));

	error = copyin(src, &lse, sizeof(lse));
	if (error) {
		return error;
	}

	return linux32_to_native_sigevent(sep, &lse);
}