barrier/platform/CUnixPlatform.cpp

225 lines
4.0 KiB
C++

#include "CUnixPlatform.h"
#include "CLog.h"
#include <cstring>
#include <unistd.h>
#include <pwd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <syslog.h>
#include <signal.h>
//
// CUnixPlatform
//
CUnixPlatform::CUnixPlatform()
{
// do nothing
}
CUnixPlatform::~CUnixPlatform()
{
// do nothing
}
bool
CUnixPlatform::installDaemon(const char*, const char*, const char*, const char*)
{
// daemons don't require special installation
return true;
}
CUnixPlatform::EResult
CUnixPlatform::uninstallDaemon(const char*)
{
// daemons don't require special installation
return kSuccess;
}
int
CUnixPlatform::daemonize(const char* name, DaemonFunc func)
{
// fork so shell thinks we're done and so we're not a process
// group leader
switch (fork()) {
case -1:
// failed
return -1;
case 0:
// child
break;
default:
// parent exits
exit(0);
}
// become leader of a new session
setsid();
// chdir to root so we don't keep mounted filesystems points busy
chdir("/");
// mask off permissions for any but owner
umask(077);
// close open files. we only expect stdin, stdout, stderr to be open.
close(0);
close(1);
close(2);
// attach file descriptors 0, 1, 2 to /dev/null so inadvertent use
// of standard I/O safely goes in the bit bucket.
open("/dev/null", O_RDONLY);
open("/dev/null", O_RDWR);
dup(1);
// hook up logger
installDaemonLogger(name);
// invoke function
return func(this, 1, &name);
}
void
CUnixPlatform::installDaemonLogger(const char* name)
{
openlog(name, 0, LOG_DAEMON);
CLog::setOutputter(&CUnixPlatform::deamonLogger);
}
int
CUnixPlatform::restart(RestartFunc func, int minErrorCode)
{
for (;;) {
switch (fork()) {
default:
{
// parent process. wait for child to exit.
int status;
if (wait(&status) == -1) {
// wait failed. this is unexpected so bail.
log((CLOG_CRIT "wait() failed"));
return minErrorCode;
}
// what happened? if the child exited normally with a
// status less than 16 then the child was deliberately
// terminated so we also terminate.
if (WIFEXITED(status) && WEXITSTATUS(status) < minErrorCode) {
return WEXITSTATUS(status);
}
// did child die horribly?
if (WIFSIGNALED(status)) {
switch (WTERMSIG(status)) {
case SIGHUP:
case SIGINT:
case SIGQUIT:
case SIGTERM:
break;
default:
// uh oh. bail out.
return 16;
}
}
}
break;
case -1:
// fork() failed. log the error and proceed as a child
log((CLOG_WARN "fork() failed; cannot automatically restart on error"));
// fall through
case 0:
// child process
return func();
}
}
}
const char*
CUnixPlatform::getBasename(const char* pathname) const
{
if (pathname == NULL) {
return NULL;
}
const char* basename = strrchr(pathname, '/');
if (basename != NULL) {
return basename + 1;
}
else {
return pathname;
}
}
CString
CUnixPlatform::getUserDirectory() const
{
// FIXME -- use geteuid? shouldn't run this setuid anyway.
struct passwd* pwent = getpwuid(getuid());
if (pwent != NULL && pwent->pw_dir != NULL) {
return pwent->pw_dir;
}
else {
return CString();
}
}
CString
CUnixPlatform::getSystemDirectory() const
{
return "/etc";
}
CString
CUnixPlatform::addPathComponent(const CString& prefix,
const CString& suffix) const
{
CString path;
path.reserve(prefix.size() + 1 + suffix.size());
path += prefix;
if (path.size() == 0 || path[path.size() - 1] != '/') {
path += '/';
}
path += suffix;
return path;
}
bool
CUnixPlatform::deamonLogger(int priority, const char* msg)
{
// convert priority
switch (priority) {
case CLog::kFATAL:
case CLog::kERROR:
priority = LOG_ERR;
break;
case CLog::kWARNING:
priority = LOG_WARNING;
break;
case CLog::kNOTE:
priority = LOG_NOTICE;
break;
case CLog::kINFO:
priority = LOG_INFO;
break;
default:
priority = LOG_DEBUG;
break;
}
// log it
syslog(priority, "%s", msg);
return true;
}