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// systemtap compile-server web api server
// Copyright (C) 2017-2018 Red Hat Inc.
//
// This file is part of systemtap, and is free software. You can
// redistribute it and/or modify it under the terms of the GNU General
// Public License (GPL); either version 2, or (at your option) any
// later version.
#include "server.h"
#include "api.h"
#include <iostream>
#include "../staputil.h"
#include "nss_funcs.h"
#include "utils.h"
#include "../nsscommon.h"
extern "C" {
#include <string.h>
#include <signal.h>
#include <errno.h>
#include <sys/signalfd.h>
#include <getopt.h>
}
server *httpd = NULL;
static void *
signal_thread(void *arg)
{
int signal_fd = (int)(long)arg;
while (1) {
struct signalfd_siginfo si;
ssize_t s;
s = read(signal_fd, &si, sizeof(si));
if (s != sizeof(si)) {
server_error(_F("signal fd read error: %s", strerror(errno)));
continue;
}
// FIXME: we might think about using SIGHUP to aks us to
// re-read configuration data.
if (si.ssi_signo == SIGINT || si.ssi_signo == SIGTERM
|| si.ssi_signo == SIGHUP || si.ssi_signo == SIGQUIT) {
// Since we're using signalfd(), we can call code that
// isn't signal-safe (like server::stop).
if (httpd)
httpd->stop();
break;
}
else if (si.ssi_signo == SIGCHLD) {
// We just ignore SIGCHLD. We need to keep it enabled for
// waitpid() to work properly.
}
else {
server_error(_F("Got unhandled signal %d", si.ssi_signo));
}
}
close(signal_fd);
return NULL;
}
static void
setup_main_signals(pthread_t *tid)
{
static sigset_t s;
/* Block several signals; other threads created by main() will
* inherit a copy of the signal mask. */
sigemptyset(&s);
sigaddset(&s, SIGINT);
sigaddset(&s, SIGTERM);
sigaddset(&s, SIGHUP);
sigaddset(&s, SIGQUIT);
sigaddset(&s, SIGCHLD);
pthread_sigmask(SIG_BLOCK, &s, NULL);
/* Create a signalfd. This way we can synchronously handle the
* signals. */
int signal_fd = signalfd(-1, &s, SFD_CLOEXEC);
if (signal_fd < 0) {
server_error(_F("Failed to create signal file descriptor: %s",
strerror(errno)));
exit(1);
}
/* Let the special signal thread handle signals. */
if (pthread_create(tid, NULL, signal_thread, (void *)(long)signal_fd) < 0) {
server_error(_F("Failed to create thread: %s", strerror(errno)));
exit(1);
}
}
// FIXME: the default port of 1234 was just chosen at random. A better
// port default needs to be chosen.
static uint16_t port = 1234;
static string cert_db_path;
void
parse_cmdline(int argc, char *const argv[])
{
enum {
LONG_OPT_PORT = 256,
LONG_OPT_SSL,
LONG_OPT_LOG,
};
static struct option long_options[] = {
{ "port", 1, NULL, LONG_OPT_PORT },
{ "ssl", 1, NULL, LONG_OPT_SSL },
{ "log", 1, NULL, LONG_OPT_LOG },
{ NULL, 0, NULL, 0 }
};
while (true) {
int grc = getopt_long(argc, argv, "", long_options, NULL);
char *num_endptr;
unsigned long port_tmp;
if (grc < 0)
break;
switch (grc) {
case LONG_OPT_PORT:
errno = 0;
port_tmp = strtoul(optarg, &num_endptr, 10);
if (*num_endptr != '\0') {
server_error(_F("%s: cannot parse number '--port=%s'", argv[0],
optarg));
exit(1);
}
if (errno != 0 || port_tmp > 65535) {
server_error(_F("%s: invalid entry: port must be between"
" 0 and 65535 '--port=%s'", argv[0], optarg));
exit(1);
}
port = (uint16_t)port_tmp;
break;
case LONG_OPT_SSL:
cert_db_path = optarg;
break;
case LONG_OPT_LOG:
start_log(optarg, true);
break;
default:
break;
}
}
for (int i = optind; i < argc; i++) {
server_error(_F("%s: unrecognized argument '%s'", argv[0], argv[i]));
}
}
int
main(int argc, char *const argv[])
{
pthread_t tid;
// Get rid of a few standard environment variables (which might
// cause us to do unintended things).
if (unsetenv("IFS") || unsetenv("CDPATH") || unsetenv("ENV")
|| unsetenv("BASH_ENV")) {
server_error(_F("unsetenv failed: %s", strerror(errno)));
return 1;
}
// Make sure we're not root. Since we connect directly to the
// internet, we can't (safely) run as root.
if (geteuid () == 0) {
server_error("For security reasons, invocation of stap-httpd as"
" root is not supported.");
return 1;
}
setup_main_signals(&tid);
parse_cmdline(argc, argv);
// Initialize NSS.
if (nss_init(cert_db_path) != 0)
return 1;
// Create the server and ask the api to register its handlers.
httpd = new server(port, cert_db_path);
api_add_request_handlers(*httpd);
// Wait for the server to shut itself down.
httpd->wait();
delete httpd;
// Clean up the signal thread.
pthread_join(tid, NULL);
// Ask the api to do its cleanup.
api_cleanup();
// Shutdown NSS.
nss_shutdown(cert_db_path);
end_log();
return 0;
}
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