core-agent-linux/qrexec/qrexec-fork-server.c
Simon Gaiser f4c402e7c7 qrexec-fork-server: Always initialize addrlen argument of accept()
With the old code the addrlen argument were uninitialized on the first
call resulting in errors depending on the compiler behavior.
2018-03-15 20:45:12 +01:00

129 lines
3.3 KiB
C

/*
* The Qubes OS Project, http://www.qubes-os.org
*
* Copyright (C) 2015 Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
*
* This program 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 2
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/un.h>
#include "qrexec.h"
#include <libvchan.h>
#include "libqrexec-utils.h"
#include "qrexec-agent.h"
extern char **environ;
void do_exec(char *cmd)
{
char *shell;
signal(SIGCHLD, SIG_DFL);
signal(SIGPIPE, SIG_DFL);
/* call QUBESRPC if requested */
exec_qubes_rpc_if_requested(cmd, environ);
/* otherwise, pass it to shell */
shell = getenv("SHELL");
if (!shell)
shell = "/bin/sh";
execl(shell, basename(shell), "-c", cmd, NULL);
perror("execl");
exit(1);
}
void handle_vchan_error(const char *op)
{
fprintf(stderr, "Error while vchan %s, exiting\n", op);
exit(1);
}
void handle_single_command(int fd, struct qrexec_cmd_info *info) {
char cmdline[info->cmdline_len+1];
if (!read_all(fd, cmdline, info->cmdline_len))
return;
cmdline[info->cmdline_len] = 0;
handle_new_process(info->type, info->connect_domain,
info->connect_port,
cmdline, info->cmdline_len);
}
int main(int argc, char **argv) {
int s, fd;
char *socket_path;
struct qrexec_cmd_info info;
struct sockaddr_un peer;
unsigned int addrlen;
if (argc == 2) {
socket_path = argv[1];
} else if (argc == 1) {
/* this will be leaked, but we don't care as the process will then terminate */
if (asprintf(&socket_path, QREXEC_FORK_SERVER_SOCKET, getenv("USER")) < 0) {
fprintf(stderr, "Memory allocation failed\n");
exit(1);
}
} else {
fprintf(stderr, "Usage: %s [socket path]\n", argv[0]);
exit(1);
}
s = get_server_socket(socket_path);
if (fcntl(s, F_SETFD, O_CLOEXEC) < 0) {
perror("fcntl");
exit(1);
}
/* fork into background */
switch (fork()) {
case -1:
perror("fork");
exit(1);
case 0:
break;
default:
exit(0);
}
signal(SIGCHLD, SIG_IGN);
register_exec_func(do_exec);
while (1) {
addrlen = sizeof(peer);
fd = accept(s, (struct sockaddr *) &peer, &addrlen);
if (fd < 0)
break;
if (read_all(fd, &info, sizeof(info))) {
handle_single_command(fd, &info);
}
close(fd);
}
close(s);
unlink(socket_path);
return 0;
}