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/*
* uAnytun
*
* uAnytun is a tiny implementation of SATP. Unlike Anytun which is a full
* featured implementation uAnytun has no support for multiple connections
* or synchronisation. It is a small single threaded implementation intended
* to act as a client on small platforms.
* The secure anycast tunneling protocol (satp) defines a protocol used
* for communication between any combination of unicast and anycast
* tunnel endpoints. It has less protocol overhead than IPSec in Tunnel
* mode and allows tunneling of every ETHER TYPE protocol (e.g.
* ethernet, ip, arp ...). satp directly includes cryptography and
* message authentication based on the methods used by SRTP. It is
* intended to deliver a generic, scaleable and secure solution for
* tunneling and relaying of packets of any protocol.
*
*
* Copyright (C) 2007-2017 Christian Pointner <equinox@anytun.org>
*
* This file is part of uAnytun.
*
* uAnytun 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 3 of the License, or
* any later version.
*
* uAnytun 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 uAnytun. If not, see <http://www.gnu.org/licenses/>.
*
* In addition, as a special exception, the copyright holders give
* permission to link the code of portions of this program with the
* OpenSSL library under certain conditions as described in each
* individual source file, and distribute linked combinations
* including the two.
* You must obey the GNU General Public License in all respects
* for all of the code used other than OpenSSL. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you
* do not wish to do so, delete this exception statement from your
* version. If you delete this exception statement from all source
* files in the program, then also delete it here.
*/
#include "datatypes.h"
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/wait.h>
#include <sys/select.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "sysexec.h"
#include "log.h"
int uanytun_exec(const char* script, char* const argv[], char* const evp[])
{
if(!script)
return -1;
int pipefd[2];
if(pipe(pipefd) == -1) {
log_printf(ERROR, "executing script '%s' pipe() error: %s", script, strerror(errno));
return -1;
}
pid_t pid;
pid = fork();
if(pid == -1) {
log_printf(ERROR, "executing script '%s' fork() error: %s", script, strerror(errno));
return -1;
}
if(!pid) {
int fd;
for (fd=getdtablesize();fd>=0;--fd) // close all file descriptors
if(fd != pipefd[1]) close(fd);
fd = open("/dev/null",O_RDWR); // stdin
if(fd == -1)
log_printf(WARNING, "can't open stdin");
else {
if(dup(fd) == -1) // stdout
log_printf(WARNING, "can't open stdout");
if(dup(fd) == -1) // stderr
log_printf(WARNING, "can't open stderr");
}
execve(script, argv, evp);
// if execve returns, an error occurred, but logging doesn't work
// because we closed all file descriptors, so just write errno to
// pipe and call exit
int ret = write(pipefd[1], (void*)(&errno), sizeof(errno));
if(ret == -1) exit(-1);
exit(-1);
}
close(pipefd[1]);
int status = 0;
waitpid(pid, &status, 0);
fd_set rfds;
FD_ZERO(&rfds);
FD_SET(pipefd[0], &rfds);
struct timeval tv = { 0 , 0 };
if(select(pipefd[0]+1, &rfds, NULL, NULL, &tv) == 1) {
int err = 0;
if(read(pipefd[0], (void*)(&err), sizeof(err)) >= sizeof(err)) {
log_printf(NOTICE, "script '%s' exec() error: %s", script, strerror(err));
close(pipefd[0]);
return -1;
}
}
if(WIFEXITED(status))
log_printf(NOTICE, "script '%s' returned %d", script, WEXITSTATUS(status));
else if(WIFSIGNALED(status))
log_printf(NOTICE, "script '%s' terminated after signal %d", script, WTERMSIG(status));
else
log_printf(ERROR, "executing script '%s': unknown error", script);
close(pipefd[0]);
return status;
}
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