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// Copyright 2015 Google Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#define _GNU_SOURCE
#include <unistd.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <signal.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include "process-tools.h"
int SwitchToEuid() {
int uid = getuid();
int euid = geteuid();
if (uid != euid) {
CHECK_CALL(setreuid(euid, euid));
}
return euid;
}
int SwitchToEgid() {
int gid = getgid();
int egid = getegid();
if (gid != egid) {
CHECK_CALL(setregid(egid, egid));
}
return egid;
}
void Redirect(const char *target_path, int fd, const char *name) {
if (target_path != NULL && strcmp(target_path, "-") != 0) {
int fd_out;
const int flags = O_WRONLY | O_CREAT | O_TRUNC | O_APPEND;
CHECK_CALL(fd_out = open(target_path, flags, 0666),
"Could not open %s for redirection of %s", target_path, name);
CHECK_CALL(dup2(fd_out, fd));
CHECK_CALL(close(fd_out));
}
}
void RedirectStdout(const char *stdout_path) {
Redirect(stdout_path, STDOUT_FILENO, "stdout");
}
void RedirectStderr(const char *stderr_path) {
Redirect(stderr_path, STDERR_FILENO, "stderr");
}
void KillEverything(int pgrp, bool gracefully, double graceful_kill_delay) {
if (gracefully) {
kill(-pgrp, SIGTERM);
// Round up fractional seconds in this polling implementation.
int kill_delay = (int)(ceil(graceful_kill_delay));
// If the process is still alive, give it some time to die gracefully.
while (kill_delay-- > 0 && kill(-pgrp, 0) == 0) {
sleep(1);
}
}
kill(-pgrp, SIGKILL);
}
void HandleSignal(int sig, void (*handler)(int)) {
struct sigaction sa = {.sa_handler = handler};
CHECK_CALL(sigemptyset(&sa.sa_mask));
CHECK_CALL(sigaction(sig, &sa, NULL));
}
void UnHandle(int sig) { HandleSignal(sig, SIG_DFL); }
void ClearSignalMask() {
// Use an empty signal mask for the process.
sigset_t empty_sset;
CHECK_CALL(sigemptyset(&empty_sset));
CHECK_CALL(sigprocmask(SIG_SETMASK, &empty_sset, NULL));
// Set the default signal handler for all signals.
for (int i = 1; i < NSIG; ++i) {
if (i == SIGKILL || i == SIGSTOP) {
continue;
}
struct sigaction sa = {.sa_handler = SIG_DFL};
CHECK_CALL(sigemptyset(&sa.sa_mask));
// Ignore possible errors, because we might not be allowed to set the
// handler for certain signals, but we still want to try.
sigaction(i, &sa, NULL);
}
}
void SetTimeout(double timeout_secs) {
if (timeout_secs <= 0) {
return;
}
double int_val, fraction_val;
fraction_val = modf(timeout_secs, &int_val);
struct itimerval timer = {.it_interval.tv_sec = 0,
.it_interval.tv_usec = 0,
.it_value.tv_sec = (long)int_val,
.it_value.tv_usec = (long)(fraction_val * 1e6)};
CHECK_CALL(setitimer(ITIMER_REAL, &timer, NULL));
}
int WaitChild(pid_t pid, const char *name) {
int err, status;
do {
err = waitpid(pid, &status, 0);
} while (err == -1 && errno == EINTR);
if (err == -1) {
DIE("wait on %s (pid %d) failed\n", name, pid);
}
return status;
}
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