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#include <util/generic/yexception.h>
#include <cerrno>
#include <cstdlib>
#include <util/system/info.h>
#if defined(_win_)
#include <io.h>
#else
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#endif
#include "daemon.h"
#ifdef _unix_
using namespace NDaemonMaker;
static bool Fork(EParent parent) {
pid_t pid = fork();
if (pid > 0) {
int status = 0;
while (waitpid(pid, &status, 0) < 0 && errno == EINTR) {
}
if (parent == callExitFromParent) {
_exit(0);
} else {
return true;
}
} else if (pid < 0) {
ythrow TSystemError() << "Cannot fork";
}
if (setsid() < 0) {
ythrow TSystemError() << "Cannot setsid";
}
pid = fork();
if (pid > 0) {
_exit(0);
} else if (pid < 0) {
ythrow TSystemError() << "Cannot second fork";
}
return false;
}
#endif
static void CloseFromToExcept(int from, int to, const int* except) {
(void)from;
(void)to;
(void)except;
#ifdef _unix_
int mfd = NSystemInfo::MaxOpenFiles();
for (int s = from; s < mfd && (to == -1 || s < to); s++) {
for (const int* ex = except; *ex >= 0; ++ex) {
if (s == *ex) {
goto dontclose;
}
}
while (close(s) == -1) {
if (errno == EBADF) {
break;
}
if (errno != EINTR) {
ythrow TSystemError() << "close(" << s << ") failed";
}
}
dontclose:;
}
#endif /* _unix_ */
}
bool NDaemonMaker::MakeMeDaemon(ECloseDescriptors cd, EStdIoDescriptors iod, EChDir chd, EParent parent) {
(void)cd;
(void)iod;
(void)chd;
#ifdef _unix_
if (Fork(parent)) {
return true;
}
if (chd == chdirRoot) {
if (chdir("/")) {
ythrow TSystemError() << "chdir(\"/\") failed";
}
}
int fd[4] = {-1, -1, -1, -1};
switch (iod) {
case openYandexStd:
fd[0] = open("yandex.stdin", O_RDONLY);
if (fd[0] < 0) {
ythrow TSystemError() << "Cannot open 'yandex.stdin'";
}
fd[1] = open("yandex.stdout", O_WRONLY | O_APPEND | O_CREAT, 660);
if (fd[1] < 0) {
ythrow TSystemError() << "Cannot open 'yandex.stdout'";
}
fd[2] = open("yandex.stderr", O_WRONLY | O_APPEND | O_CREAT, 660);
if (fd[2] < 0) {
ythrow TSystemError() << "Cannot open 'yandex.stderr'";
}
break;
case openDevNull:
fd[0] = open("/dev/null", O_RDWR, 0);
break;
case openNone:
break;
default:
ythrow yexception() << "Unknown open descriptors mode: " << (int)iod;
}
const int except[4] = {
fd[0],
fd[1],
fd[2],
-1};
if (closeAll == cd) {
CloseFromToExcept(0, -1, except);
} else if (closeStdIoOnly == cd) {
CloseFromToExcept(0, 3, except);
} else {
ythrow yexception() << "Unknown close descriptors mode: " << (int)cd;
}
switch (iod) {
case openYandexStd:
/* Assuming that open(2) acquires fds in order. */
dup2(fd[0], STDIN_FILENO);
if (fd[0] > 2) {
close(fd[0]);
}
dup2(fd[1], STDOUT_FILENO);
if (fd[1] > 2) {
close(fd[1]);
}
dup2(fd[2], STDERR_FILENO);
if (fd[2] > 2) {
close(fd[2]);
}
break;
case openDevNull:
dup2(fd[0], STDIN_FILENO);
dup2(fd[0], STDOUT_FILENO);
dup2(fd[0], STDERR_FILENO);
if (fd[0] > 2) {
close(fd[0]);
}
break;
default:
break;
}
return false;
#else
return true;
#endif
}
void NDaemonMaker::CloseFrom(int fd) {
static const int except[1] = {-1};
CloseFromToExcept(fd, -1, except);
}
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