471 lines
9.2 KiB
C
471 lines
9.2 KiB
C
|
/* $NetBSD: trap.c,v 1.31 2005/01/11 19:38:57 christos Exp $ */
|
||
|
|
|
||
|
|
/*-
|
||
|
|
* Copyright (c) 1991, 1993
|
||
|
|
* The Regents of the University of California. All rights reserved.
|
||
|
|
*
|
||
|
|
* This code is derived from software contributed to Berkeley by
|
||
|
|
* Kenneth Almquist.
|
||
|
|
*
|
||
|
|
* 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 <sys/cdefs.h>
|
||
|
|
#ifndef lint
|
||
|
|
#if 0
|
||
|
|
static char sccsid[] = "@(#)trap.c 8.5 (Berkeley) 6/5/95";
|
||
|
|
#else
|
||
|
|
__RCSID("$NetBSD: trap.c,v 1.31 2005/01/11 19:38:57 christos Exp $");
|
||
|
|
#endif
|
||
|
|
#endif /* not lint */
|
||
|
|
|
||
|
|
#include <signal.h>
|
||
|
|
#include <unistd.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
|
||
|
|
#include "shell.h"
|
||
|
|
#include "main.h"
|
||
|
|
#include "nodes.h" /* for other headers */
|
||
|
|
#include "eval.h"
|
||
|
|
#include "jobs.h"
|
||
|
|
#include "show.h"
|
||
|
|
#include "options.h"
|
||
|
|
#include "syntax.h"
|
||
|
|
#include "output.h"
|
||
|
|
#include "memalloc.h"
|
||
|
|
#include "error.h"
|
||
|
|
#include "trap.h"
|
||
|
|
#include "mystring.h"
|
||
|
|
#include "var.h"
|
||
|
|
|
||
|
|
static const char *sys_signame[NSIG] = {
|
||
|
|
"Unused",
|
||
|
|
"HUP", "INT", "QUIT", "ILL",
|
||
|
|
"TRAP", "ABRT", "BUS", "FPE",
|
||
|
|
"KILL", "USR1", "SEGV", "USR2",
|
||
|
|
"PIPE", "ALRM", "TERM",
|
||
|
|
"Unknown",
|
||
|
|
"CHLD",
|
||
|
|
"CONT", "STOP", "TSTP", "TTIN",
|
||
|
|
"TTOU", "URG", "XCPU", "XFSZ",
|
||
|
|
"VTALRM", "PROF", "WINCH", "IO",
|
||
|
|
"PWR", "SYS"
|
||
|
|
};
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Sigmode records the current value of the signal handlers for the various
|
||
|
|
* modes. A value of zero means that the current handler is not known.
|
||
|
|
* S_HARD_IGN indicates that the signal was ignored on entry to the shell,
|
||
|
|
*/
|
||
|
|
|
||
|
|
#define S_DFL 1 /* default signal handling (SIG_DFL) */
|
||
|
|
#define S_CATCH 2 /* signal is caught */
|
||
|
|
#define S_IGN 3 /* signal is ignored (SIG_IGN) */
|
||
|
|
#define S_HARD_IGN 4 /* signal is ignored permenantly */
|
||
|
|
#define S_RESET 5 /* temporary - to reset a hard ignored sig */
|
||
|
|
|
||
|
|
|
||
|
|
char *trap[NSIG+1]; /* trap handler commands */
|
||
|
|
MKINIT char sigmode[NSIG]; /* current value of signal */
|
||
|
|
char gotsig[NSIG]; /* indicates specified signal received */
|
||
|
|
int pendingsigs; /* indicates some signal received */
|
||
|
|
|
||
|
|
static int getsigaction(int, sig_t *);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* return the signal number described by `p' (as a number or a name)
|
||
|
|
* or -1 if it isn't one
|
||
|
|
*/
|
||
|
|
|
||
|
|
static int
|
||
|
|
signame_to_signum(const char *p)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
if (is_number(p))
|
||
|
|
return number(p);
|
||
|
|
|
||
|
|
if (strcasecmp(p, "exit") == 0 )
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
if (strncasecmp(p, "sig", 3) == 0)
|
||
|
|
p += 3;
|
||
|
|
|
||
|
|
for (i = 0; i < NSIG; ++i)
|
||
|
|
if (strcasecmp (p, sys_signame[i]) == 0)
|
||
|
|
return i;
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Print a list of valid signal names
|
||
|
|
*/
|
||
|
|
static void
|
||
|
|
printsignals(void)
|
||
|
|
{
|
||
|
|
int n;
|
||
|
|
|
||
|
|
out1str("EXIT ");
|
||
|
|
|
||
|
|
for (n = 1; n < NSIG; n++) {
|
||
|
|
out1fmt("%s", sys_signame[n]);
|
||
|
|
if ((n == NSIG/2) || n == (NSIG - 1))
|
||
|
|
out1str("\n");
|
||
|
|
else
|
||
|
|
out1c(' ');
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* The trap builtin.
|
||
|
|
*/
|
||
|
|
|
||
|
|
int
|
||
|
|
trapcmd(int argc, char **argv)
|
||
|
|
{
|
||
|
|
char *action;
|
||
|
|
char **ap;
|
||
|
|
int signo;
|
||
|
|
|
||
|
|
if (argc <= 1) {
|
||
|
|
for (signo = 0 ; signo <= NSIG ; signo++)
|
||
|
|
if (trap[signo] != NULL) {
|
||
|
|
out1fmt("trap -- ");
|
||
|
|
print_quoted(trap[signo]);
|
||
|
|
out1fmt(" %s\n",
|
||
|
|
(signo) ? sys_signame[signo] : "EXIT");
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
ap = argv + 1;
|
||
|
|
|
||
|
|
action = NULL;
|
||
|
|
|
||
|
|
if (strcmp(*ap, "--") == 0)
|
||
|
|
if (*++ap == NULL)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
if (signame_to_signum(*ap) == -1) {
|
||
|
|
if ((*ap)[0] == '-') {
|
||
|
|
if ((*ap)[1] == '\0')
|
||
|
|
ap++;
|
||
|
|
else if ((*ap)[1] == 'l' && (*ap)[2] == '\0') {
|
||
|
|
printsignals();
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
error("bad option %s\n", *ap);
|
||
|
|
}
|
||
|
|
else
|
||
|
|
action = *ap++;
|
||
|
|
}
|
||
|
|
|
||
|
|
while (*ap) {
|
||
|
|
if (is_number(*ap))
|
||
|
|
signo = number(*ap);
|
||
|
|
else
|
||
|
|
signo = signame_to_signum(*ap);
|
||
|
|
|
||
|
|
if (signo < 0 || signo > NSIG)
|
||
|
|
error("%s: bad trap", *ap);
|
||
|
|
|
||
|
|
INTOFF;
|
||
|
|
if (action)
|
||
|
|
action = savestr(action);
|
||
|
|
|
||
|
|
if (trap[signo])
|
||
|
|
ckfree(trap[signo]);
|
||
|
|
|
||
|
|
trap[signo] = action;
|
||
|
|
|
||
|
|
if (signo != 0)
|
||
|
|
setsignal(signo, 0);
|
||
|
|
INTON;
|
||
|
|
ap++;
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Clear traps on a fork or vfork.
|
||
|
|
* Takes one arg vfork, to tell it to not be destructive of
|
||
|
|
* the parents variables.
|
||
|
|
*/
|
||
|
|
|
||
|
|
void
|
||
|
|
clear_traps(int vforked)
|
||
|
|
{
|
||
|
|
char **tp;
|
||
|
|
|
||
|
|
for (tp = trap ; tp <= &trap[NSIG] ; tp++) {
|
||
|
|
if (*tp && **tp) { /* trap not NULL or SIG_IGN */
|
||
|
|
INTOFF;
|
||
|
|
if (!vforked) {
|
||
|
|
ckfree(*tp);
|
||
|
|
*tp = NULL;
|
||
|
|
}
|
||
|
|
if (tp != &trap[0])
|
||
|
|
setsignal(tp - trap, vforked);
|
||
|
|
INTON;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Set the signal handler for the specified signal. The routine figures
|
||
|
|
* out what it should be set to.
|
||
|
|
*/
|
||
|
|
|
||
|
|
long
|
||
|
|
setsignal(int signo, int vforked)
|
||
|
|
{
|
||
|
|
int action;
|
||
|
|
sig_t sigact = SIG_DFL;
|
||
|
|
struct sigaction act, oact;
|
||
|
|
char *t, tsig;
|
||
|
|
|
||
|
|
if ((t = trap[signo]) == NULL)
|
||
|
|
action = S_DFL;
|
||
|
|
else if (*t != '\0')
|
||
|
|
action = S_CATCH;
|
||
|
|
else
|
||
|
|
action = S_IGN;
|
||
|
|
if (rootshell && !vforked && action == S_DFL) {
|
||
|
|
switch (signo) {
|
||
|
|
case SIGINT:
|
||
|
|
if (iflag || minusc || sflag == 0)
|
||
|
|
action = S_CATCH;
|
||
|
|
break;
|
||
|
|
case SIGQUIT:
|
||
|
|
#ifdef DEBUG
|
||
|
|
if (debug)
|
||
|
|
break;
|
||
|
|
#endif
|
||
|
|
/* FALLTHROUGH */
|
||
|
|
case SIGTERM:
|
||
|
|
if (iflag)
|
||
|
|
action = S_IGN;
|
||
|
|
break;
|
||
|
|
#if JOBS
|
||
|
|
case SIGTSTP:
|
||
|
|
case SIGTTOU:
|
||
|
|
if (mflag)
|
||
|
|
action = S_IGN;
|
||
|
|
break;
|
||
|
|
#endif
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
t = &sigmode[signo - 1];
|
||
|
|
tsig = *t;
|
||
|
|
if (tsig == 0) {
|
||
|
|
/*
|
||
|
|
* current setting unknown
|
||
|
|
*/
|
||
|
|
if (!getsigaction(signo, &sigact)) {
|
||
|
|
/*
|
||
|
|
* Pretend it worked; maybe we should give a warning
|
||
|
|
* here, but other shells don't. We don't alter
|
||
|
|
* sigmode, so that we retry every time.
|
||
|
|
*/
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
if (sigact == SIG_IGN) {
|
||
|
|
if (mflag && (signo == SIGTSTP ||
|
||
|
|
signo == SIGTTIN || signo == SIGTTOU)) {
|
||
|
|
tsig = S_IGN; /* don't hard ignore these */
|
||
|
|
} else
|
||
|
|
tsig = S_HARD_IGN;
|
||
|
|
} else {
|
||
|
|
tsig = S_RESET; /* force to be set */
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if (tsig == S_HARD_IGN || tsig == action)
|
||
|
|
return 0;
|
||
|
|
switch (action) {
|
||
|
|
case S_DFL: sigact = SIG_DFL; break;
|
||
|
|
case S_CATCH: sigact = onsig; break;
|
||
|
|
case S_IGN: sigact = SIG_IGN; break;
|
||
|
|
}
|
||
|
|
if (!vforked)
|
||
|
|
*t = action;
|
||
|
|
act.sa_handler = sigact;
|
||
|
|
sigemptyset(&act.sa_mask);
|
||
|
|
act.sa_flags = 0;
|
||
|
|
#ifdef SA_INTERRUPT
|
||
|
|
act.sa_flags |= SA_INTERRUPT;
|
||
|
|
#endif
|
||
|
|
if(sigaction(signo, &act, &oact) < 0)
|
||
|
|
return (long) SIG_ERR;
|
||
|
|
return (long) oact.sa_handler;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Return the current setting for sig w/o changing it.
|
||
|
|
*/
|
||
|
|
static int
|
||
|
|
getsigaction(int signo, sig_t *sigact)
|
||
|
|
{
|
||
|
|
struct sigaction sa;
|
||
|
|
|
||
|
|
if (sigaction(signo, (struct sigaction *)0, &sa) == -1)
|
||
|
|
return 0;
|
||
|
|
*sigact = (sig_t) sa.sa_handler;
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Ignore a signal.
|
||
|
|
*/
|
||
|
|
|
||
|
|
void
|
||
|
|
ignoresig(int signo, int vforked)
|
||
|
|
{
|
||
|
|
if (sigmode[signo - 1] != S_IGN && sigmode[signo - 1] != S_HARD_IGN)
|
||
|
|
bsd_signal(signo, SIG_IGN);
|
||
|
|
if (!vforked)
|
||
|
|
sigmode[signo - 1] = S_HARD_IGN;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
#ifdef mkinit
|
||
|
|
INCLUDE <signal.h>
|
||
|
|
INCLUDE "trap.h"
|
||
|
|
|
||
|
|
SHELLPROC {
|
||
|
|
char *sm;
|
||
|
|
|
||
|
|
clear_traps(0);
|
||
|
|
for (sm = sigmode ; sm < sigmode + NSIG ; sm++) {
|
||
|
|
if (*sm == S_IGN)
|
||
|
|
*sm = S_HARD_IGN;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Signal handler.
|
||
|
|
*/
|
||
|
|
|
||
|
|
void
|
||
|
|
onsig(int signo)
|
||
|
|
{
|
||
|
|
bsd_signal(signo, onsig);
|
||
|
|
if (signo == SIGINT && trap[SIGINT] == NULL) {
|
||
|
|
onint();
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
gotsig[signo - 1] = 1;
|
||
|
|
pendingsigs++;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Called to execute a trap. Perhaps we should avoid entering new trap
|
||
|
|
* handlers while we are executing a trap handler.
|
||
|
|
*/
|
||
|
|
|
||
|
|
void
|
||
|
|
dotrap(void)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
int savestatus;
|
||
|
|
|
||
|
|
for (;;) {
|
||
|
|
for (i = 1 ; ; i++) {
|
||
|
|
if (gotsig[i - 1])
|
||
|
|
break;
|
||
|
|
if (i >= NSIG)
|
||
|
|
goto done;
|
||
|
|
}
|
||
|
|
gotsig[i - 1] = 0;
|
||
|
|
savestatus=exitstatus;
|
||
|
|
evalstring(trap[i], 0);
|
||
|
|
exitstatus=savestatus;
|
||
|
|
}
|
||
|
|
done:
|
||
|
|
pendingsigs = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Controls whether the shell is interactive or not.
|
||
|
|
*/
|
||
|
|
|
||
|
|
|
||
|
|
void
|
||
|
|
setinteractive(int on)
|
||
|
|
{
|
||
|
|
static int is_interactive;
|
||
|
|
|
||
|
|
if (on == is_interactive)
|
||
|
|
return;
|
||
|
|
setsignal(SIGINT, 0);
|
||
|
|
setsignal(SIGQUIT, 0);
|
||
|
|
setsignal(SIGTERM, 0);
|
||
|
|
is_interactive = on;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Called to exit the shell.
|
||
|
|
*/
|
||
|
|
|
||
|
|
void
|
||
|
|
exitshell(int status)
|
||
|
|
{
|
||
|
|
struct jmploc loc1, loc2;
|
||
|
|
char *p;
|
||
|
|
|
||
|
|
TRACE(("pid %d, exitshell(%d)\n", getpid(), status));
|
||
|
|
if (setjmp(loc1.loc)) {
|
||
|
|
goto l1;
|
||
|
|
}
|
||
|
|
if (setjmp(loc2.loc)) {
|
||
|
|
goto l2;
|
||
|
|
}
|
||
|
|
handler = &loc1;
|
||
|
|
if ((p = trap[0]) != NULL && *p != '\0') {
|
||
|
|
trap[0] = NULL;
|
||
|
|
evalstring(p, 0);
|
||
|
|
}
|
||
|
|
l1: handler = &loc2; /* probably unnecessary */
|
||
|
|
flushall();
|
||
|
|
#if JOBS
|
||
|
|
setjobctl(0);
|
||
|
|
#endif
|
||
|
|
l2: _exit(status);
|
||
|
|
/* NOTREACHED */
|
||
|
|
}
|