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/*
* jim-signal.c
*
*/
#include <signal.h>
#include <string.h>
#include <ctype.h>
#include "jimautoconf.h"
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <jim-subcmd.h>
#include <jim-signal.h>
#define MAX_SIGNALS_WIDE (sizeof(jim_wide) * 8)
#if defined(NSIG)
#define MAX_SIGNALS ((NSIG < MAX_SIGNALS_WIDE) ? NSIG : MAX_SIGNALS_WIDE)
#else
#define MAX_SIGNALS MAX_SIGNALS_WIDE
#endif
static jim_wide *sigloc;
static jim_wide sigsblocked;
static struct sigaction *sa_old;
static struct {
int status;
const char *name;
} siginfo[MAX_SIGNALS];
/* Make sure to do this as a wide, not int */
#define sig_to_bit(SIG) ((jim_wide)1 << (SIG))
static void signal_handler(int sig)
{
/* We just remember which signals occurred. Jim_Eval() will
* notice this as soon as it can and throw an error
*/
*sigloc |= sig_to_bit(sig);
}
static void signal_ignorer(int sig)
{
/* We just remember which signals occurred */
sigsblocked |= sig_to_bit(sig);
}
static void signal_init_names(void)
{
#define SET_SIG_NAME(SIG) siginfo[SIG].name = #SIG
SET_SIG_NAME(SIGABRT);
SET_SIG_NAME(SIGALRM);
SET_SIG_NAME(SIGBUS);
SET_SIG_NAME(SIGCHLD);
SET_SIG_NAME(SIGCONT);
SET_SIG_NAME(SIGFPE);
SET_SIG_NAME(SIGHUP);
SET_SIG_NAME(SIGILL);
SET_SIG_NAME(SIGINT);
#ifdef SIGIO
SET_SIG_NAME(SIGIO);
#endif
SET_SIG_NAME(SIGKILL);
SET_SIG_NAME(SIGPIPE);
SET_SIG_NAME(SIGPROF);
SET_SIG_NAME(SIGQUIT);
SET_SIG_NAME(SIGSEGV);
SET_SIG_NAME(SIGSTOP);
SET_SIG_NAME(SIGSYS);
SET_SIG_NAME(SIGTERM);
SET_SIG_NAME(SIGTRAP);
SET_SIG_NAME(SIGTSTP);
SET_SIG_NAME(SIGTTIN);
SET_SIG_NAME(SIGTTOU);
SET_SIG_NAME(SIGURG);
SET_SIG_NAME(SIGUSR1);
SET_SIG_NAME(SIGUSR2);
SET_SIG_NAME(SIGVTALRM);
SET_SIG_NAME(SIGWINCH);
SET_SIG_NAME(SIGXCPU);
SET_SIG_NAME(SIGXFSZ);
#ifdef SIGPWR
SET_SIG_NAME(SIGPWR);
#endif
#ifdef SIGCLD
SET_SIG_NAME(SIGCLD);
#endif
#ifdef SIGEMT
SET_SIG_NAME(SIGEMT);
#endif
#ifdef SIGLOST
SET_SIG_NAME(SIGLOST);
#endif
#ifdef SIGPOLL
SET_SIG_NAME(SIGPOLL);
#endif
#ifdef SIGINFO
SET_SIG_NAME(SIGINFO);
#endif
}
/*
*----------------------------------------------------------------------
*
* Tcl_SignalId --
*
* Return a textual identifier for a signal number.
*
* Results:
* This procedure returns a machine-readable textual identifier
* that corresponds to sig. The identifier is the same as the
* #define name in signal.h.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
const char *Jim_SignalId(int sig)
{
if (sig >=0 && sig < MAX_SIGNALS) {
if (siginfo[sig].name) {
return siginfo[sig].name;
}
}
return "unknown signal";
}
/**
* Given the name of a signal, returns the signal value if found,
* or returns -1 (and sets an error) if not found.
* We accept -SIGINT, SIGINT, INT or any lowercase version or a number,
* either positive or negative.
*/
static int find_signal_by_name(Jim_Interp *interp, const char *name)
{
int i;
const char *pt = name;
/* Remove optional - and SIG from the front of the name */
if (*pt == '-') {
pt++;
}
if (strncasecmp(name, "sig", 3) == 0) {
pt += 3;
}
if (isdigit(UCHAR(pt[0]))) {
i = atoi(pt);
if (i > 0 && i < MAX_SIGNALS) {
return i;
}
}
else {
for (i = 1; i < MAX_SIGNALS; i++) {
/* Jim_SignalId() returns names such as SIGINT, and
* returns "unknown signal" if unknown, so this will work
*/
if (strcasecmp(Jim_SignalId(i) + 3, pt) == 0) {
return i;
}
}
}
Jim_SetResultFormatted(interp, "unknown signal %s", name);
return -1;
}
#define SIGNAL_ACTION_HANDLE 1
#define SIGNAL_ACTION_IGNORE -1
#define SIGNAL_ACTION_DEFAULT 0
static int do_signal_cmd(Jim_Interp *interp, int action, int argc, Jim_Obj *const *argv)
{
struct sigaction sa;
int i;
if (argc == 0) {
Jim_SetResult(interp, Jim_NewListObj(interp, NULL, 0));
for (i = 1; i < MAX_SIGNALS; i++) {
if (siginfo[i].status == action) {
/* Add signal name to the list */
Jim_ListAppendElement(interp, Jim_GetResult(interp),
Jim_NewStringObj(interp, Jim_SignalId(i), -1));
}
}
return JIM_OK;
}
/* Catch all the signals we care about */
if (action != SIGNAL_ACTION_DEFAULT) {
memset(&sa, 0, sizeof(sa));
if (action == SIGNAL_ACTION_HANDLE) {
sa.sa_handler = signal_handler;
}
else {
sa.sa_handler = signal_ignorer;
}
}
/* Iterate through the provided signals */
for (i = 0; i < argc; i++) {
int sig = find_signal_by_name(interp, Jim_String(argv[i]));
if (sig < 0) {
return JIM_ERR;
}
if (action != siginfo[sig].status) {
/* Need to change the action for this signal */
switch (action) {
case SIGNAL_ACTION_HANDLE:
case SIGNAL_ACTION_IGNORE:
if (siginfo[sig].status == SIGNAL_ACTION_DEFAULT) {
if (!sa_old) {
/* Allocate the structure the first time through */
sa_old = Jim_Alloc(sizeof(*sa_old) * MAX_SIGNALS);
}
sigaction(sig, &sa, &sa_old[sig]);
}
else {
sigaction(sig, &sa, 0);
}
break;
case SIGNAL_ACTION_DEFAULT:
/* Restore old handler */
if (sa_old) {
sigaction(sig, &sa_old[sig], 0);
}
}
siginfo[sig].status = action;
}
}
return JIM_OK;
}
static int signal_cmd_handle(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
return do_signal_cmd(interp, SIGNAL_ACTION_HANDLE, argc, argv);
}
static int signal_cmd_ignore(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
return do_signal_cmd(interp, SIGNAL_ACTION_IGNORE, argc, argv);
}
static int signal_cmd_default(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
return do_signal_cmd(interp, SIGNAL_ACTION_DEFAULT, argc, argv);
}
static int signal_set_sigmask_result(Jim_Interp *interp, jim_wide sigmask)
{
int i;
Jim_Obj *listObj = Jim_NewListObj(interp, NULL, 0);
for (i = 0; i < MAX_SIGNALS; i++) {
if (sigmask & sig_to_bit(i)) {
Jim_ListAppendElement(interp, listObj, Jim_NewStringObj(interp, Jim_SignalId(i), -1));
}
}
Jim_SetResult(interp, listObj);
return JIM_OK;
}
static int signal_cmd_check(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
int clear = 0;
jim_wide mask = 0;
jim_wide blocked;
if (argc > 0 && Jim_CompareStringImmediate(interp, argv[0], "-clear")) {
clear++;
}
if (argc > clear) {
int i;
/* Signals specified */
for (i = clear; i < argc; i++) {
int sig = find_signal_by_name(interp, Jim_String(argv[i]));
if (sig < 0 || sig >= MAX_SIGNALS) {
return -1;
}
mask |= sig_to_bit(sig);
}
}
else {
/* No signals specified, so check/clear all */
mask = ~mask;
}
if ((sigsblocked & mask) == 0) {
/* No matching signals, so empty result and nothing to do */
return JIM_OK;
}
/* Be careful we don't have a race condition where signals are cleared but not returned */
blocked = sigsblocked & mask;
if (clear) {
sigsblocked &= ~blocked;
}
/* Set the result */
signal_set_sigmask_result(interp, blocked);
return JIM_OK;
}
static int signal_cmd_throw(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
int sig = SIGINT;
if (argc == 1) {
if ((sig = find_signal_by_name(interp, Jim_String(argv[0]))) < 0) {
return JIM_ERR;
}
}
/* If the signal is ignored (blocked) ... */
if (siginfo[sig].status == SIGNAL_ACTION_IGNORE) {
sigsblocked |= sig_to_bit(sig);
return JIM_OK;
}
/* Just set the signal */
interp->sigmask |= sig_to_bit(sig);
/* Set the canonical name of the signal as the result */
Jim_SetResultString(interp, Jim_SignalId(sig), -1);
/* And simply say we caught the signal */
return JIM_SIGNAL;
}
/*
*-----------------------------------------------------------------------------
*
* Jim_SignalCmd --
* Implements the TCL signal command:
* signal handle|ignore|default|throw ?signals ...?
* signal throw signal
*
* Specifies which signals are handled by Tcl code.
* If the one of the given signals is caught, it causes a JIM_SIGNAL
* exception to be thrown which can be caught by catch.
*
* Use 'signal ignore' to ignore the signal(s)
* Use 'signal default' to go back to the default behaviour
* Use 'signal throw signal' to raise the given signal
*
* If no arguments are given, returns the list of signals which are being handled
*
* Results:
* Standard TCL results.
*
*-----------------------------------------------------------------------------
*/
static const jim_subcmd_type signal_command_table[] = {
{ "handle",
"?signals ...?",
signal_cmd_handle,
0,
-1,
/* Description: Lists handled signals, or adds to handled signals */
},
{ "ignore",
"?signals ...?",
signal_cmd_ignore,
0,
-1,
/* Description: Lists ignored signals, or adds to ignored signals */
},
{ "default",
"?signals ...?",
signal_cmd_default,
0,
-1,
/* Description: Lists defaulted signals, or adds to defaulted signals */
},
{ "check",
"?-clear? ?signals ...?",
signal_cmd_check,
0,
-1,
/* Description: Returns ignored signals which have occurred, and optionally clearing them */
},
{ "throw",
"?signal?",
signal_cmd_throw,
0,
1,
/* Description: Raises the given signal (default SIGINT) */
},
{ NULL }
};
/**
* Restore default signal handling.
*/
static void JimSignalCmdDelete(Jim_Interp *interp, void *privData)
{
int i;
if (sa_old) {
for (i = 1; i < MAX_SIGNALS; i++) {
if (siginfo[i].status != SIGNAL_ACTION_DEFAULT) {
sigaction(i, &sa_old[i], 0);
siginfo[i].status = SIGNAL_ACTION_DEFAULT;
}
}
}
Jim_Free(sa_old);
sa_old = NULL;
sigloc = NULL;
}
static int Jim_AlarmCmd(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
int ret;
if (argc != 2) {
Jim_WrongNumArgs(interp, 1, argv, "seconds");
return JIM_ERR;
}
else {
#ifdef HAVE_UALARM
double t;
ret = Jim_GetDouble(interp, argv[1], &t);
if (ret == JIM_OK) {
if (t < 1) {
ualarm(t * 1e6, 0);
}
else {
alarm(t);
}
}
#else
long t;
ret = Jim_GetLong(interp, argv[1], &t);
if (ret == JIM_OK) {
alarm(t);
}
#endif
}
return ret;
}
static int Jim_SleepCmd(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
int ret;
if (argc != 2) {
Jim_WrongNumArgs(interp, 1, argv, "seconds");
return JIM_ERR;
}
else {
double t;
ret = Jim_GetDouble(interp, argv[1], &t);
if (ret == JIM_OK) {
#ifdef HAVE_USLEEP
usleep((int)((t - (int)t) * 1e6));
#endif
sleep(t);
}
}
return ret;
}
static int Jim_KillCmd(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
int sig;
long pid;
Jim_Obj *pidObj;
const char *signame;
if (argc != 2 && argc != 3) {
Jim_WrongNumArgs(interp, 1, argv, "?SIG|-0? pid");
return JIM_ERR;
}
if (argc == 2) {
sig = SIGTERM;
pidObj = argv[1];
}
else {
signame = Jim_String(argv[1]);
pidObj = argv[2];
/* Special 'kill -0 pid' to determine if a pid exists */
if (strcmp(signame, "-0") == 0 || strcmp(signame, "0") == 0) {
sig = 0;
}
else {
sig = find_signal_by_name(interp, signame);
if (sig < 0) {
return JIM_ERR;
}
}
}
if (Jim_GetLong(interp, pidObj, &pid) != JIM_OK) {
return JIM_ERR;
}
if (kill(pid, sig) == 0) {
return JIM_OK;
}
Jim_SetResultString(interp, "kill: Failed to deliver signal", -1);
return JIM_ERR;
}
int Jim_signalInit(Jim_Interp *interp)
{
if (Jim_PackageProvide(interp, "signal", "1.0", JIM_ERRMSG))
return JIM_ERR;
Jim_CreateCommand(interp, "alarm", Jim_AlarmCmd, 0, 0);
Jim_CreateCommand(interp, "kill", Jim_KillCmd, 0, 0);
/* Sleep is slightly dubious here */
Jim_CreateCommand(interp, "sleep", Jim_SleepCmd, 0, 0);
/* Teach the jim core how to set a result from a sigmask */
interp->signal_set_result = signal_set_sigmask_result;
/* Currently only the top level interp supports signals */
if (!sigloc) {
signal_init_names();
/* Make sure we know where to store the signals which occur */
sigloc = &interp->sigmask;
Jim_CreateCommand(interp, "signal", Jim_SubCmdProc, (void *)signal_command_table, JimSignalCmdDelete);
}
return JIM_OK;
}