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160b24b137
livetrax/libs/pbd/system_exec.cc
Robin Gareus eb6b4f4b15 fix crash on SystemExec::Terminate 
if Terminated() connects in the same thread and deletes the class itself
the closure in interposer_thread() can fail.
2015-10-23 23:29:04 +02:00

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/*
Copyright (C) 2010 Paul Davis
Copyright (C) 2010-2014 Robin Gareus <robin@gareus.org>
Copyright (C) 2005-2008 Lennart Poettering
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <algorithm>
#include <assert.h>
#ifndef COMPILER_MSVC
#include <dirent.h>
#endif
#ifdef PLATFORM_WINDOWS
#include <windows.h>
#else
#include <fcntl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/resource.h>
#endif
#include <glibmm/miscutils.h>
#define USE_VFORK
#include "pbd/file_utils.h"
#include "pbd/search_path.h"
#include "pbd/system_exec.h"
using namespace std;
using namespace PBD;
static void * interposer_thread (void *arg);
#ifndef PLATFORM_WINDOWS /* POSIX Process only */
static void close_fd (int& fd) { if (fd >= 0) ::close (fd); fd = -1; }
#endif
#if (!defined PLATFORM_WINDOWS && defined NO_VFORK)
/*
* This function was part of libasyncns.
* LGPL v2.1
* Copyright 2005-2008 Lennart Poettering
*/
static int close_allv(const int except_fds[]) {
struct rlimit rl;
int fd;
#ifdef __linux__
DIR *d;
assert(except_fds);
if ((d = opendir("/proc/self/fd"))) {
struct dirent *de;
while ((de = readdir(d))) {
int found;
long l;
char *e = NULL;
int i;
if (de->d_name[0] == '.')
continue;
errno = 0;
l = strtol(de->d_name, &e, 10);
if (errno != 0 || !e || *e) {
closedir(d);
errno = EINVAL;
return -1;
}
fd = (int) l;
if ((long) fd != l) {
closedir(d);
errno = EINVAL;
return -1;
}
if (fd < 3)
continue;
if (fd == dirfd(d))
continue;
found = 0;
for (i = 0; except_fds[i] >= 0; i++)
if (except_fds[i] == fd) {
found = 1;
break;
}
if (found) continue;
if (close(fd) < 0) {
int saved_errno;
saved_errno = errno;
closedir(d);
errno = saved_errno;
return -1;
}
}
closedir(d);
return 0;
}
#endif
if (getrlimit(RLIMIT_NOFILE, &rl) < 0)
return -1;
for (fd = 0; fd < (int) rl.rlim_max; fd++) {
int i;
if (fd <= 3)
continue;
for (i = 0; except_fds[i] >= 0; i++)
if (except_fds[i] == fd)
continue;
if (close(fd) < 0 && errno != EBADF)
return -1;
}
return 0;
}
#endif /* not on windows, nor vfork */
void
SystemExec::init ()
{
pthread_mutex_init(&write_lock, NULL);
thread_active=false;
pid = 0;
pin[1] = -1;
nicelevel = 0;
envp = NULL;
#ifdef PLATFORM_WINDOWS
stdinP[0] = stdinP[1] = INVALID_HANDLE_VALUE;
stdoutP[0] = stdoutP[1] = INVALID_HANDLE_VALUE;
stderrP[0] = stderrP[1] = INVALID_HANDLE_VALUE;
#endif
}
SystemExec::SystemExec (std::string c, std::string a)
: cmd(c)
{
init ();
argp = NULL;
make_envp();
make_argp(a);
}
SystemExec::SystemExec (std::string c, char **a)
: cmd(c) , argp(a)
{
init ();
#ifdef PLATFORM_WINDOWS
make_wargs(a);
#endif
make_envp();
}
SystemExec::SystemExec (std::string command, const std::map<char, std::string> subs)
{
init ();
make_argp_escaped(command, subs);
if (find_file (Searchpath (Glib::getenv ("PATH")), argp[0], cmd)) {
// argp[0] exists in $PATH` - set it to the actual path where it was found
free (argp[0]);
argp[0] = strdup(cmd.c_str ());
}
// else argp[0] not found in path - leave it as-is, it might be an absolute path
// Glib::find_program_in_path () is only available in Glib >= 2.28
// cmd = Glib::find_program_in_path (argp[0]);
make_envp();
}
void
SystemExec::make_argp_escaped(std::string command, const std::map<char, std::string> subs)
{
int inquotes = 0;
int n = 0;
size_t i = 0;
std::string arg = "";
argp = (char **) malloc(sizeof(char *));
for (i = 0; i <= command.length(); i++) { // include terminating '\0'
char c = command.c_str()[i];
if (inquotes) {
if (c == '"') {
inquotes = 0;
} else {
// still in quotes - just copy
arg += c;
}
} else switch (c) {
case '%' :
c = command.c_str()[++i];
if (c == '%' || c == '\0') {
// "%%", "%" at end-of-string => "%"
arg += '%';
} else {
// search subs for string to substitute for char
std::map<char, std::string>::const_iterator s = subs.find(c);
if (s != subs.end()) {
// found substitution
arg += s->second;
} else {
// not a valid substitution, just copy
arg += '%';
arg += c;
}
}
break;
case '\\':
c = command.c_str()[++i];
switch (c) {
case ' ' :
case '"' : arg += c; break; // "\\", "\" at end-of-string => "\"
case '\0':
case '\\': arg += '\\'; break;
default : arg += '\\'; arg += c; break;
}
break;
case '"' :
inquotes = 1;
break;
case ' ' :
case '\t':
case '\0':
if (arg.length() > 0) {
// if there wasn't already a space or tab, start a new parameter
argp = (char **) realloc(argp, (n + 2) * sizeof(char *));
argp[n++] = strdup (arg.c_str());
arg = "";
}
break;
default :
arg += c;
break;
}
}
argp[n] = NULL;
}
SystemExec::~SystemExec ()
{
terminate ();
if (envp) {
for (int i=0;envp[i];++i) {
free(envp[i]);
}
free (envp);
}
if (argp) {
for (int i=0;argp[i];++i) {
free(argp[i]);
}
free (argp);
}
#ifdef PLATFORM_WINDOWS
if (w_args) free(w_args);
#endif
pthread_mutex_destroy(&write_lock);
}
static void *
interposer_thread (void *arg) {
SystemExec *sex = static_cast<SystemExec *>(arg);
sex->output_interposer();
pthread_exit(0);
return 0;
}
#ifdef PLATFORM_WINDOWS /* Windows Process */
/* HELPER FUNCTIONS */
static void create_pipe (HANDLE *pipe, bool in) {
SECURITY_ATTRIBUTES secAtt = { sizeof( SECURITY_ATTRIBUTES ), NULL, TRUE };
HANDLE tmpHandle;
if (in) {
if (!CreatePipe(&pipe[0], &tmpHandle, &secAtt, 1024 * 1024)) return;
if (!DuplicateHandle(GetCurrentProcess(), tmpHandle, GetCurrentProcess(), &pipe[1], 0, FALSE, DUPLICATE_SAME_ACCESS)) return;
} else {
if (!CreatePipe(&tmpHandle, &pipe[1], &secAtt, 1024 * 1024)) return;
if (!DuplicateHandle(GetCurrentProcess(), tmpHandle, GetCurrentProcess(), &pipe[0], 0, FALSE, DUPLICATE_SAME_ACCESS)) return;
}
CloseHandle(tmpHandle);
}
static void destroy_pipe (HANDLE pipe[2]) {
if (pipe[0] != INVALID_HANDLE_VALUE) {
CloseHandle(pipe[0]);
pipe[0] = INVALID_HANDLE_VALUE;
}
if (pipe[1] != INVALID_HANDLE_VALUE) {
CloseHandle(pipe[1]);
pipe[1] = INVALID_HANDLE_VALUE;
}
}
static BOOL CALLBACK my_terminateApp(HWND hwnd, LPARAM procId)
{
DWORD currentProcId = 0;
GetWindowThreadProcessId(hwnd, &currentProcId);
if (currentProcId == (DWORD)procId)
PostMessage(hwnd, WM_CLOSE, 0, 0);
return TRUE;
}
/* PROCESS API */
void
SystemExec::make_envp() {
;/* environemt is copied over with CreateProcess(...,env=0 ,..) */
}
void
SystemExec::make_wargs(char **a) {
std::string wa = cmd;
if (cmd[0] != '"' && cmd[cmd.size()] != '"' && strchr(cmd.c_str(), ' ')) { wa = "\"" + cmd + "\""; }
std::replace(cmd.begin(), cmd.end(), '/', '\\' );
char **tmp = ++a;
while (tmp && *tmp) {
wa.append(" \"");
wa.append(*tmp);
if (strlen(*tmp) > 0 && (*tmp)[strlen(*tmp) - 1] == '\\') {
wa.append("\\");
}
wa.append("\"");
tmp++;
}
w_args = strdup(wa.c_str());
}
void
SystemExec::make_argp(std::string args) {
std::string wa = cmd;
if (cmd[0] != '"' && cmd[cmd.size()] != '"' && strchr(cmd.c_str(), ' ')) { wa = "\"" + cmd + "\""; }
std::replace(cmd.begin(), cmd.end(), '/', '\\' );
wa.append(" ");
wa.append(args);
w_args = strdup(wa.c_str());
}
void
SystemExec::terminate ()
{
::pthread_mutex_lock(&write_lock);
close_stdin();
if (pid) {
/* terminate */
EnumWindows(my_terminateApp, (LPARAM)pid->dwProcessId);
PostThreadMessage(pid->dwThreadId, WM_CLOSE, 0, 0);
/* kill ! */
TerminateProcess(pid->hProcess, 0xf291);
CloseHandle(pid->hThread);
CloseHandle(pid->hProcess);
destroy_pipe(stdinP);
destroy_pipe(stdoutP);
destroy_pipe(stderrP);
delete pid;
pid=0;
}
::pthread_mutex_unlock(&write_lock);
}
int
SystemExec::wait (int options)
{
while (is_running()) {
WaitForSingleObject(pid->hProcess, 40);
}
return 0;
}
bool
SystemExec::is_running ()
{
if (!pid) return false;
DWORD exit_code;
if (GetExitCodeProcess(pid->hProcess, &exit_code)) {
if (exit_code == STILL_ACTIVE) return true;
}
return false;
}
int
SystemExec::start (int stderr_mode, const char * /*vfork_exec_wrapper*/)
{
char* working_dir = 0;
if (pid) { return 0; }
pid = new PROCESS_INFORMATION;
memset(pid, 0, sizeof(PROCESS_INFORMATION));
create_pipe(stdinP, true);
create_pipe(stdoutP, false);
if (stderr_mode == 2) {
/* merge stout & stderr */
DuplicateHandle(GetCurrentProcess(), stdoutP[1], GetCurrentProcess(), &stderrP[1], 0, TRUE, DUPLICATE_SAME_ACCESS);
} else if (stderr_mode == 1) {
//TODO read/flush this pipe or close it...
create_pipe(stderrP, false);
} else {
//TODO: keep stderr of this process mode.
}
bool success = false;
STARTUPINFOA startupInfo = { sizeof( STARTUPINFO ), 0, 0, 0,
(unsigned long)CW_USEDEFAULT, (unsigned long)CW_USEDEFAULT,
(unsigned long)CW_USEDEFAULT, (unsigned long)CW_USEDEFAULT,
0, 0, 0,
STARTF_USESTDHANDLES,
0, 0, 0,
stdinP[0], stdoutP[1], stderrP[1]
};
success = CreateProcess(0, w_args,
0, 0, /* bInheritHandles = */ TRUE,
(CREATE_NO_WINDOW&0) | CREATE_UNICODE_ENVIRONMENT | (0&CREATE_NEW_CONSOLE),
/*env = */ 0,
working_dir,
&startupInfo, pid);
if (stdinP[0] != INVALID_HANDLE_VALUE) {
CloseHandle(stdinP[0]);
stdinP[0] = INVALID_HANDLE_VALUE;
}
if (stdoutP[1] != INVALID_HANDLE_VALUE) {
CloseHandle(stdoutP[1]);
stdoutP[1] = INVALID_HANDLE_VALUE;
}
if (stderrP[1] != INVALID_HANDLE_VALUE) {
CloseHandle(stderrP[1]);
stderrP[1] = INVALID_HANDLE_VALUE;
}
if (!success) {
CloseHandle(pid->hThread);
CloseHandle(pid->hProcess);
destroy_pipe(stdinP);
destroy_pipe(stdoutP);
destroy_pipe(stderrP);
delete pid;
pid=0;
return -1;
}
int rv = pthread_create(&thread_id_tt, NULL, interposer_thread, this);
thread_active=true;
if (rv) {
thread_active=false;
terminate();
return -2;
}
Sleep(20);
return 0;
}
void
SystemExec::output_interposer()
{
DWORD bytesRead = 0;
char data[BUFSIZ];
#if 0 // untested code to set up nonblocking
unsigned long l = 1;
ioctlsocket(stdoutP[0], FIONBIO, &l);
#endif
while(1) {
#if 0 // for non-blocking pipes..
DWORD bytesAvail = 0;
PeekNamedPipe(stdoutP[0], 0, 0, 0, &bytesAvail, 0);
if (bytesAvail < 1) {Sleep(500); printf("N/A\n"); continue;}
#endif
if (stdoutP[0] == INVALID_HANDLE_VALUE) break;
if (!ReadFile(stdoutP[0], data, BUFSIZ, &bytesRead, 0)) {
DWORD err = GetLastError();
if (err == ERROR_IO_PENDING) continue;
break;
}
if (bytesRead < 1) continue; /* actually not needed; but this is safe. */
data[bytesRead] = 0;
ReadStdout(data, bytesRead);/* EMIT SIGNAL */
}
Terminated();/* EMIT SIGNAL */
pthread_exit(0);
}
void
SystemExec::close_stdin()
{
if (stdinP[0]!= INVALID_HANDLE_VALUE) FlushFileBuffers(stdinP[0]);
if (stdinP[1]!= INVALID_HANDLE_VALUE) FlushFileBuffers(stdinP[1]);
Sleep(200);
destroy_pipe(stdinP);
}
int
SystemExec::write_to_stdin(std::string d, size_t len)
{
const char *data;
DWORD r,c;
::pthread_mutex_lock(&write_lock);
data=d.c_str();
if (len == 0) {
len=(d.length());
}
c=0;
while (c < len) {
if (!WriteFile(stdinP[1], data+c, len-c, &r, NULL)) {
if (GetLastError() == 0xE8 /*NT_STATUS_INVALID_USER_BUFFER*/) {
Sleep(100);
continue;
} else {
fprintf(stderr, "SYSTEM-EXEC: stdin write error.\n");
break;
}
}
c += r;
}
::pthread_mutex_unlock(&write_lock);
return c;
}
/* end windows process */
#else
/* UNIX/POSIX process */
extern char **environ;
void
SystemExec::make_envp() {
int i=0;
envp = (char **) calloc(1, sizeof(char*));
/* copy current environment */
for (i=0;environ[i];++i) {
envp[i] = strdup(environ[i]);
envp = (char **) realloc(envp, (i+2) * sizeof(char*));
}
envp[i] = 0;
}
void
SystemExec::make_argp(std::string args) {
int argn = 1;
char *cp1;
char *cp2;
char *carg = strdup(args.c_str());
argp = (char **) malloc((argn + 1) * sizeof(char *));
if (argp == (char **) 0) {
free(carg);
return; // FATAL
}
argp[0] = strdup(cmd.c_str());
/* TODO: quotations and escapes
* http://stackoverflow.com/questions/1511797/convert-string-to-argv-in-c
*
* It's actually not needed. All relevant invocations specify 'argp' directly.
* Only 'xjadeo -L -R' uses this function and that uses neither quotations
* nor arguments with white-space.
*/
for (cp1 = cp2 = carg; *cp2 != '\0'; ++cp2) {
if (*cp2 == ' ') {
*cp2 = '\0';
argp[argn++] = strdup(cp1);
cp1 = cp2 + 1;
argp = (char **) realloc(argp, (argn + 1) * sizeof(char *));
}
}
if (cp2 != cp1) {
argp[argn++] = strdup(cp1);
argp = (char **) realloc(argp, (argn + 1) * sizeof(char *));
}
argp[argn] = (char *) 0;
free(carg);
}
void
SystemExec::terminate ()
{
::pthread_mutex_lock(&write_lock);
/* close stdin in an attempt to get the child to exit cleanly.
*/
close_stdin();
if (pid) {
::usleep(200000);
sched_yield();
wait(WNOHANG);
}
/* if pid is non-zero, the child task is still executing (i.e. it did
* not exit in response to stdin being closed). try to kill it.
*/
if (pid) {
::kill(pid, SIGTERM);
::usleep(250000);
sched_yield();
wait(WNOHANG);
}
/* if pid is non-zero, the child task is STILL executing after being
* sent SIGTERM. Act tough ... send SIGKILL
*/
if (pid) {
::fprintf(stderr, "Process is still running! trying SIGKILL\n");
::kill(pid, SIGKILL);
}
wait();
if (thread_active) pthread_join(thread_id_tt, NULL);
thread_active = false;
assert(pid == 0);
::pthread_mutex_unlock(&write_lock);
}
int
SystemExec::wait (int options)
{
int status=0;
int ret;
if (pid==0) return -1;
ret = waitpid (pid, &status, options);
if (ret == pid) {
if (WEXITSTATUS(status) || WIFSIGNALED(status)) {
pid=0;
}
} else {
if (ret != 0) {
if (errno == ECHILD) {
/* no currently running children, reset pid */
pid=0;
}
} /* else the process is still running */
}
return status;
}
bool
SystemExec::is_running ()
{
int status=0;
if (pid==0) return false;
if (::waitpid(pid, &status, WNOHANG)==0) return true;
return false;
}
int
SystemExec::start (int stderr_mode, const char *vfork_exec_wrapper)
{
if (is_running()) {
return 0; // mmh what to return here?
}
int r;
if (::pipe(pin) < 0 || ::pipe(pout) < 0 || ::pipe(pok) < 0) {
/* Something unexpected went wrong creating a pipe. */
return -1;
}
#ifndef NO_VFORK
r = ::vfork();
#else
r = ::fork();
#endif
if (r < 0) {
/* failed to fork */
return -2;
}
if (r > 0) {
/* main */
pid=r;
/* check if execve was successful. */
close_fd(pok[1]);
char buf;
for ( ;; ) {
ssize_t n = ::read(pok[0], &buf, 1 );
if ( n==1 ) {
/* child process returned from execve */
pid=0;
close_fd(pok[0]);
close_fd(pok[1]);
close_fd(pin[1]);
close_fd(pin[0]);
close_fd(pout[1]);
close_fd(pout[0]);
return -3;
} else if ( n==-1 ) {
if ( errno==EAGAIN || errno==EINTR )
continue;
}
break;
}
close_fd(pok[0]);
/* child started successfully */
close_fd(pout[1]);
close_fd(pin[0]);
int rv = pthread_create(&thread_id_tt, NULL, interposer_thread, this);
thread_active=true;
if (rv) {
thread_active=false;
terminate();
return -2;
}
return 0; /* all systems go - return to main */
}
#ifdef NO_VFORK
/* child process - exec external process */
close_fd(pok[0]);
::fcntl(pok[1], F_SETFD, FD_CLOEXEC);
close_fd(pin[1]);
if (pin[0] != STDIN_FILENO) {
::dup2(pin[0], STDIN_FILENO);
}
close_fd(pin[0]);
close_fd(pout[0]);
if (pout[1] != STDOUT_FILENO) {
::dup2(pout[1], STDOUT_FILENO);
}
if (stderr_mode == 2) {
/* merge STDERR into output */
if (pout[1] != STDERR_FILENO) {
::dup2(pout[1], STDERR_FILENO);
}
} else if (stderr_mode == 1) {
/* ignore STDERR */
::close(STDERR_FILENO);
} else {
/* keep STDERR */
}
if (pout[1] != STDOUT_FILENO && pout[1] != STDERR_FILENO) {
close_fd(pout[1]);
}
if (nicelevel !=0) {
::nice(nicelevel);
}
#ifdef HAVE_SIGSET
sigset(SIGPIPE, SIG_DFL);
#else
signal(SIGPIPE, SIG_DFL);
#endif
if (!vfork_exec_wrapper) {
error << _("Cannot start external process, no vfork wrapper") << endmsg;
return -1;
}
int good_fds[2] = { pok[1], -1 };
close_allv(good_fds);
::execve(argp[0], argp, envp);
/* if we reach here something went wrong.. */
char buf = 0;
(void) ::write(pok[1], &buf, 1 );
close_fd(pok[1]);
exit(-1);
return -1;
#else
/* XXX this should be done before vfork()
* calling malloc here only increases the time vfork() blocks
*/
int argn = 0;
for (int i=0;argp[i];++i) { argn++; }
char **argx = (char **) malloc((argn + 10) * sizeof(char *));
argx[0] = strdup(vfork_exec_wrapper); // XXX
#define FDARG(NUM, FDN) \
argx[NUM] = (char*) calloc(6, sizeof(char)); snprintf(argx[NUM], 6, "%d", FDN);
FDARG(1, pok[0])
FDARG(2, pok[1])
FDARG(3, pin[0])
FDARG(4, pin[1])
FDARG(5, pout[0])
FDARG(6, pout[1])
FDARG(7, stderr_mode)
FDARG(8, nicelevel)
for (int i=0;argp[i];++i) {
argx[9+i] = argp[i];
}
argx[argn+9] = NULL;
::execve(argx[0], argx, envp);
/* if we reach here something went wrong.. */
char buf = 0;
(void) ::write(pok[1], &buf, 1 );
close_fd(pok[1]);
exit(-1);
return -1;
#endif
}
void
SystemExec::output_interposer()
{
int rfd=pout[0];
char buf[BUFSIZ];
ssize_t r;
unsigned long l = 1;
ioctl(rfd, FIONBIO, &l); // set non-blocking I/O
for (;fcntl(rfd, F_GETFL)!=-1;) {
r = read(rfd, buf, sizeof(buf));
if (r < 0 && (errno == EINTR || errno == EAGAIN)) {
fd_set rfds;
struct timeval tv;
FD_ZERO(&rfds);
FD_SET(rfd, &rfds);
tv.tv_sec = 0;
tv.tv_usec = 10000;
int rv = select(1, &rfds, NULL, NULL, &tv);
if (rv == -1) {
break;
}
continue;
}
if (r <= 0) {
break;
}
buf[r]=0;
std::string rv = std::string(buf,r); // TODO: check allocation strategy
ReadStdout(rv, r);/* EMIT SIGNAL */
}
Terminated();/* EMIT SIGNAL */
pthread_exit(0);
}
void
SystemExec::close_stdin()
{
if (pin[1]<0) return;
close_fd(pin[0]);
close_fd(pin[1]);
close_fd(pout[0]);
close_fd(pout[1]);
}
int
SystemExec::write_to_stdin(std::string d, size_t len)
{
const char *data;
ssize_t r;
size_t c;
::pthread_mutex_lock(&write_lock);
data=d.c_str();
if (len == 0) {
len=(d.length());
}
c=0;
while (c < len) {
for (;;) {
r=::write(pin[1], data+c, len-c);
if (r < 0 && (errno == EINTR || errno == EAGAIN)) {
sleep(1);
continue;
}
if ((size_t) r != (len-c)) {
::pthread_mutex_unlock(&write_lock);
return c;
}
break;
}
c += r;
}
fsync(pin[1]);
::pthread_mutex_unlock(&write_lock);
return c;
}
#endif // end UNIX process
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