Esempio n. 1
0
int sandbox(void* sandbox_arg) {
	// Get rid of unused parameter warning
	(void)sandbox_arg;

	pid_t child_pid = getpid();
	if (arg_debug)
		printf("Initializing child process\n");	

 	// close each end of the unused pipes
 	close(parent_to_child_fds[1]);
 	close(child_to_parent_fds[0]);
 
 	// wait for parent to do base setup
 	wait_for_other(parent_to_child_fds[0]);

	if (arg_debug && child_pid == 1)
		printf("PID namespace installed\n");

	//****************************
	// set hostname
	//****************************
	if (cfg.hostname) {
		if (sethostname(cfg.hostname, strlen(cfg.hostname)) < 0)
			errExit("sethostname");
	}

	//****************************
	// mount namespace
	//****************************
	// mount events are not forwarded between the host the sandbox
	if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL) < 0) {
		chk_chroot();
	}
	
	
	//****************************
	// log sandbox data
	//****************************
	if (cfg.name)
		fs_logger2("sandbox name:", cfg.name);
	fs_logger2int("sandbox pid:", (int) sandbox_pid);
	if (cfg.chrootdir)
		fs_logger("sandbox filesystem: chroot");
	else if (arg_overlay)	
		fs_logger("sandbox filesystem: overlay");
	else
		fs_logger("sandbox filesystem: local");
	fs_logger("install mount namespace");
	
	//****************************
	// netfilter etc.
	//****************************
	if (arg_netfilter && any_bridge_configured()) { // assuming by default the client filter
		netfilter(arg_netfilter_file);
	}
	if (arg_netfilter6 && any_bridge_configured()) { // assuming by default the client filter
		netfilter6(arg_netfilter6_file);
	}

	// load IBUS env variables
	if (arg_nonetwork || any_bridge_configured() || any_interface_configured()) {
		// do nothing - there are problems with ibus version 1.5.11
	}
	else
		env_ibus_load();
	
	// grab a copy of cp command
	fs_build_cp_command();
	
	// trace pre-install
	if (arg_trace || arg_tracelog)
		fs_trace_preload();

	//****************************
	// configure filesystem
	//****************************
#ifdef HAVE_SECCOMP
	int enforce_seccomp = 0;
#endif
#ifdef HAVE_CHROOT		
	if (cfg.chrootdir) {
		fs_chroot(cfg.chrootdir);
		// redo cp command
		fs_build_cp_command();
		
		// force caps and seccomp if not started as root
		if (getuid() != 0) {
			// force default seccomp inside the chroot, no keep or drop list
			// the list build on top of the default drop list is kept intact
			arg_seccomp = 1;
#ifdef HAVE_SECCOMP
			enforce_seccomp = 1;
#endif
			if (cfg.seccomp_list_drop) {
				free(cfg.seccomp_list_drop);
				cfg.seccomp_list_drop = NULL;
			}
			if (cfg.seccomp_list_keep) {
				free(cfg.seccomp_list_keep);
				cfg.seccomp_list_keep = NULL;
			}
			
			// disable all capabilities
			if (arg_caps_default_filter || arg_caps_list)
				fprintf(stderr, "Warning: all capabilities disabled for a regular user during chroot\n");
			arg_caps_drop_all = 1;
			
			// drop all supplementary groups; /etc/group file inside chroot
			// is controlled by a regular usr
			arg_nogroups = 1;
			if (!arg_quiet)
				printf("Dropping all Linux capabilities and enforcing default seccomp filter\n");
		}
		else
			arg_seccomp = 1;
						
		//****************************
		// trace pre-install, this time inside chroot
		//****************************
		if (arg_trace || arg_tracelog)
			fs_trace_preload();
	}
	else 
#endif		
	if (arg_overlay)	
		fs_overlayfs();
	else
		fs_basic_fs();
	

	//****************************
	// set hostname in /etc/hostname
	//****************************
	if (cfg.hostname) {
		fs_hostname(cfg.hostname);
	}
	
	//****************************
	// private mode
	//****************************
	if (arg_private) {
		if (cfg.home_private)	// --private=
			fs_private_homedir();
		else // --private
			fs_private();
	}
	
	if (arg_private_dev)
		fs_private_dev();
	if (arg_private_etc) {
		fs_private_etc_list();
		// create /etc/ld.so.preload file again
		if (arg_trace || arg_tracelog)
			fs_trace_preload();
	}
	if (arg_private_bin)
		fs_private_bin_list();
	if (arg_private_tmp)
		fs_private_tmp();
	
	//****************************
	// apply the profile file
	//****************************
	if (cfg.profile) {
		// apply all whitelist commands ... 
		fs_whitelist();
		
		// ... followed by blacklist commands
		fs_blacklist();
	}
	
	//****************************
	// install trace
	//****************************
	if (arg_trace || arg_tracelog)
		fs_trace();
		
	//****************************
	// update /proc, /dev, /boot directorymy
	//****************************
	fs_proc_sys_dev_boot();
	
	//****************************
	// --nosound and fix for pulseaudio 7.0
	//****************************
	if (arg_nosound)
		pulseaudio_disable();
	else
		pulseaudio_init();
	
	//****************************
	// networking
	//****************************
	if (arg_nonetwork) {
		net_if_up("lo");
		if (arg_debug)
			printf("Network namespace enabled, only loopback interface available\n");
	}
	else if (any_bridge_configured() || any_interface_configured()) {
		// configure lo and eth0...eth3
		net_if_up("lo");
		
		if (mac_not_zero(cfg.bridge0.macsandbox))
			net_config_mac(cfg.bridge0.devsandbox, cfg.bridge0.macsandbox);
		sandbox_if_up(&cfg.bridge0);
		
		if (mac_not_zero(cfg.bridge1.macsandbox))
			net_config_mac(cfg.bridge1.devsandbox, cfg.bridge1.macsandbox);
		sandbox_if_up(&cfg.bridge1);
		
		if (mac_not_zero(cfg.bridge2.macsandbox))
			net_config_mac(cfg.bridge2.devsandbox, cfg.bridge2.macsandbox);
		sandbox_if_up(&cfg.bridge2);
		
		if (mac_not_zero(cfg.bridge3.macsandbox))
			net_config_mac(cfg.bridge3.devsandbox, cfg.bridge3.macsandbox);
		sandbox_if_up(&cfg.bridge3);
		
		// add a default route
		if (cfg.defaultgw) {
			// set the default route
			if (net_add_route(0, 0, cfg.defaultgw))
				fprintf(stderr, "Warning: cannot configure default route\n");
		}
		
		// enable interfaces
		if (cfg.interface0.configured && cfg.interface0.ip) {
			if (arg_debug)
				printf("Configuring %d.%d.%d.%d address on interface %s\n", PRINT_IP(cfg.interface0.ip), cfg.interface0.dev);
			net_if_ip(cfg.interface0.dev, cfg.interface0.ip, cfg.interface0.mask, cfg.interface0.mtu);
			net_if_up(cfg.interface0.dev);
		}			
		if (cfg.interface1.configured && cfg.interface1.ip) {
			if (arg_debug)
				printf("Configuring %d.%d.%d.%d address on interface %s\n", PRINT_IP(cfg.interface1.ip), cfg.interface1.dev);
			net_if_ip(cfg.interface1.dev, cfg.interface1.ip, cfg.interface1.mask, cfg.interface1.mtu);
			net_if_up(cfg.interface1.dev);
		}			
		if (cfg.interface2.configured && cfg.interface2.ip) {
			if (arg_debug)
				printf("Configuring %d.%d.%d.%d address on interface %s\n", PRINT_IP(cfg.interface2.ip), cfg.interface2.dev);
			net_if_ip(cfg.interface2.dev, cfg.interface2.ip, cfg.interface2.mask, cfg.interface2.mtu);
			net_if_up(cfg.interface2.dev);
		}			
		if (cfg.interface3.configured && cfg.interface3.ip) {
			if (arg_debug)
				printf("Configuring %d.%d.%d.%d address on interface %s\n", PRINT_IP(cfg.interface3.ip), cfg.interface3.dev);
			net_if_ip(cfg.interface3.dev, cfg.interface3.ip, cfg.interface3.mask, cfg.interface3.mtu);
			net_if_up(cfg.interface3.dev);
		}			
			
		if (arg_debug)
			printf("Network namespace enabled\n");
	}
	
	// if any dns server is configured, it is time to set it now
	fs_resolvconf();
	fs_logger_print();
	fs_logger_change_owner();

	// print network configuration
	if (!arg_quiet) {
		if (any_bridge_configured() || any_interface_configured() || cfg.defaultgw || cfg.dns1) {
			printf("\n");
			if (any_bridge_configured() || any_interface_configured())
				net_ifprint();
			if (cfg.defaultgw != 0)
				printf("Default gateway %d.%d.%d.%d\n", PRINT_IP(cfg.defaultgw));
			if (cfg.dns1 != 0)
				printf("DNS server %d.%d.%d.%d\n", PRINT_IP(cfg.dns1));
			if (cfg.dns2 != 0)
				printf("DNS server %d.%d.%d.%d\n", PRINT_IP(cfg.dns2));
			if (cfg.dns3 != 0)
				printf("DNS server %d.%d.%d.%d\n", PRINT_IP(cfg.dns3));
			printf("\n");
		}
	}
	
	fs_delete_cp_command();

	//****************************
	// set application environment
	//****************************
	prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); // kill the child in case the parent died
	int cwd = 0;
	if (cfg.cwd) {
		if (chdir(cfg.cwd) == 0)
			cwd = 1;
	}
	
	if (!cwd) {
		if (chdir("/") < 0)
			errExit("chdir");
		if (cfg.homedir) {
			struct stat s;
			if (stat(cfg.homedir, &s) == 0) {
				/* coverity[toctou] */
				if (chdir(cfg.homedir) < 0)
					errExit("chdir");
			}
		}
	}
	
	// set environment
	env_defaults();
	
	// set user-supplied environment variables
	env_apply();

	// set nice
	if (arg_nice) {
		errno = 0;
		int rv = nice(cfg.nice);
		(void) rv;
		if (errno) {
			fprintf(stderr, "Warning: cannot set nice value\n");
			errno = 0;
		}
	}
	
	// clean /tmp/.X11-unix sockets
	fs_x11();
	
	//****************************
	// set security filters
	//****************************
	// set capabilities
	if (!arg_noroot)
		set_caps();

	// set rlimits
	set_rlimits();

	// set seccomp
#ifdef HAVE_SECCOMP
	// install protocol filter
	if (cfg.protocol) {
		protocol_filter();	// install filter	
		protocol_filter_save();	// save filter in PROTOCOL_CFG
	}

	// if a keep list is available, disregard the drop list
	if (arg_seccomp == 1) {
		if (cfg.seccomp_list_keep)
			seccomp_filter_keep();
		else if (cfg.seccomp_list_errno)
			seccomp_filter_errno(); 
		else
			seccomp_filter_drop(enforce_seccomp);
	}
#endif

	// set cpu affinity
	if (cfg.cpus) {
		save_cpu(); // save cpu affinity mask to CPU_CFG file
		set_cpu_affinity();
	}
	
	// save cgroup in CGROUP_CFG file
	if (cfg.cgroup)
		save_cgroup();

	//****************************************
	// drop privileges or create a new user namespace
	//****************************************
	save_nogroups();
	if (arg_noroot) {
		int rv = unshare(CLONE_NEWUSER);
		if (rv == -1) {
			fprintf(stderr, "Error: cannot mount a new user namespace\n");
			perror("unshare");
			drop_privs(arg_nogroups);
		}
	}
	else
		drop_privs(arg_nogroups);
 	
	// notify parent that new user namespace has been created so a proper
 	// UID/GID map can be setup
 	notify_other(child_to_parent_fds[1]);
 	close(child_to_parent_fds[1]);
 
 	// wait for parent to finish setting up a proper UID/GID map
 	wait_for_other(parent_to_child_fds[0]);
 	close(parent_to_child_fds[0]);

	// somehow, the new user namespace resets capabilities;
	// we need to do them again
	if (arg_noroot) {
		set_caps();
		if (arg_debug)
			printf("noroot user namespace installed\n");
	}


	//****************************************
	// fork the application and monitor it
	//****************************************
	pid_t app_pid = fork();
	if (app_pid == -1)
		errExit("fork");
		
	if (app_pid == 0) {
		prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); // kill the child in case the parent died
		start_application();	// start app
	}

	monitor_application(app_pid);	// monitor application
	
	return 0;
}
Esempio n. 2
0
int sandbox(void* sandbox_arg) {
	// Get rid of unused parameter warning
	(void)sandbox_arg;

	pid_t child_pid = getpid();
	if (arg_debug)
		printf("Initializing child process\n");	

 	// close each end of the unused pipes
 	close(parent_to_child_fds[1]);
 	close(child_to_parent_fds[0]);
 
 	// wait for parent to do base setup
 	wait_for_other(parent_to_child_fds[0]);

	if (arg_debug && child_pid == 1)
		printf("PID namespace installed\n");

	//****************************
	// set hostname
	//****************************
	if (cfg.hostname) {
		if (sethostname(cfg.hostname, strlen(cfg.hostname)) < 0)
			errExit("sethostname");
	}

	//****************************
	// mount namespace
	//****************************
	// mount events are not forwarded between the host the sandbox
	if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL) < 0) {
		chk_chroot();
	}
	
	//****************************
	// netfilter
	//****************************
	if (arg_netfilter && any_bridge_configured()) { // assuming by default the client filter
		netfilter(arg_netfilter_file);
	}

	//****************************
	// trace pre-install
	//****************************
	if (arg_trace)
		fs_trace_preload();

	//****************************
	// configure filesystem
	//****************************
	
#ifdef HAVE_CHROOT		
	if (cfg.chrootdir) {
		fs_chroot(cfg.chrootdir);
		// force caps and seccomp if not started as root
		if (getuid() != 0) {
			// force default seccomp inside the chroot, no keep or drop list
			// the list build on top of the default drop list is kept intact
			arg_seccomp = 1;
			if (arg_seccomp_list_drop) {
				free(arg_seccomp_list_drop);
				arg_seccomp_list_drop = NULL;
			}
			if (arg_seccomp_list_keep) {
				free(arg_seccomp_list_keep);
				arg_seccomp_list_keep = NULL;
			}
			
			// disable all capabilities
			if (arg_caps_default_filter || arg_caps_list)
				fprintf(stderr, "Warning: all capabilities disabled for a regular user during chroot\n");
			arg_caps_drop_all = 1;
			
			// drop all supplementary groups; /etc/group file inside chroot
			// is controlled by a regular usr
			arg_nogroups = 1;
			printf("Dropping all Linux capabilities and enforcing default seccomp filter\n");
		}
						
		//****************************
		// trace pre-install, this time inside chroot
		//****************************
		if (arg_trace)
			fs_trace_preload();
	}
	else 
#endif		
	if (arg_overlay)
		fs_overlayfs();
	else
		fs_basic_fs();
	

	//****************************
	// set hostname in /etc/hostname
	//****************************
	if (cfg.hostname) {
		fs_hostname(cfg.hostname);
	}
	
	//****************************
	// apply the profile file
	//****************************
	if (cfg.profile)
		fs_blacklist(cfg.homedir);
	
	//****************************
	// private mode
	//****************************
	if (arg_private) {
		if (cfg.home_private)	// --private=
			fs_private_homedir();
		else if (cfg.home_private_keep) // --private-home=
			fs_private_home_list();
		else // --private
			fs_private();
	}
	
	if (arg_private_dev)
		fs_private_dev();
	if (arg_private_etc)
		fs_private_etc_list();
	
	//****************************
	// install trace
	//****************************
	if (arg_trace)
		fs_trace();
		
	//****************************
	// update /proc, /dev, /boot directorymy
	//****************************
	fs_proc_sys_dev_boot();
	
	//****************************
	// networking
	//****************************
	if (arg_nonetwork) {
		net_if_up("lo");
		if (arg_debug)
			printf("Network namespace enabled, only loopback interface available\n");
	}
	else if (any_bridge_configured()) {
		// configure lo and eth0...eth3
		net_if_up("lo");
		
		if (mac_not_zero(cfg.bridge0.macsandbox))
			net_config_mac(cfg.bridge0.devsandbox, cfg.bridge0.macsandbox);
		sandbox_if_up(&cfg.bridge0);
		
		if (mac_not_zero(cfg.bridge1.macsandbox))
			net_config_mac(cfg.bridge1.devsandbox, cfg.bridge1.macsandbox);
		sandbox_if_up(&cfg.bridge1);
		
		if (mac_not_zero(cfg.bridge2.macsandbox))
			net_config_mac(cfg.bridge2.devsandbox, cfg.bridge2.macsandbox);
		sandbox_if_up(&cfg.bridge2);
		
		if (mac_not_zero(cfg.bridge3.macsandbox))
			net_config_mac(cfg.bridge3.devsandbox, cfg.bridge3.macsandbox);
		sandbox_if_up(&cfg.bridge3);
		
		// add a default route
		if (cfg.defaultgw) {
			// set the default route
			if (net_add_route(0, 0, cfg.defaultgw))
				fprintf(stderr, "Warning: cannot configure default route\n");
		}
			
		if (arg_debug)
			printf("Network namespace enabled\n");
	}
	
	// if any dns server is configured, it is time to set it now
	fs_resolvconf();

	// print network configuration
	if (any_bridge_configured() || cfg.defaultgw || cfg.dns1) {
		printf("\n");
		if (any_bridge_configured())
			net_ifprint();
		if (cfg.defaultgw != 0)
			printf("Default gateway %d.%d.%d.%d\n", PRINT_IP(cfg.defaultgw));
		if (cfg.dns1 != 0)
			printf("DNS server %d.%d.%d.%d\n", PRINT_IP(cfg.dns1));
		if (cfg.dns2 != 0)
			printf("DNS server %d.%d.%d.%d\n", PRINT_IP(cfg.dns2));
		if (cfg.dns3 != 0)
			printf("DNS server %d.%d.%d.%d\n", PRINT_IP(cfg.dns3));
		printf("\n");
	}
	
	

	//****************************
	// start executable
	//****************************
	prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); // kill the child in case the parent died
	int cwd = 0;
	if (cfg.cwd) {
		if (chdir(cfg.cwd) == 0)
			cwd = 1;
	}
	
	if (!cwd) {
		if (chdir("/") < 0)
			errExit("chdir");
		if (cfg.homedir) {
			struct stat s;
			if (stat(cfg.homedir, &s) == 0) {
				/* coverity[toctou] */
				if (chdir(cfg.homedir) < 0)
					errExit("chdir");
			}
		}
	}
	
	// set environment
	// fix qt 4.8
	if (setenv("QT_X11_NO_MITSHM", "1", 1) < 0)
		errExit("setenv");
	if (setenv("container", "firejail", 1) < 0) // LXC sets container=lxc,
		errExit("setenv");
	if (arg_zsh && setenv("SHELL", "/usr/bin/zsh", 1) < 0)
		errExit("setenv");
	if (arg_csh && setenv("SHELL", "/bin/csh", 1) < 0)
		errExit("setenv");
	if (cfg.shell && setenv("SHELL", cfg.shell, 1) < 0)
		errExit("setenv");
	// set prompt color to green
	//export PS1='\[\e[1;32m\][\u@\h \W]\$\[\e[0m\] '
	if (setenv("PROMPT_COMMAND", "export PS1=\"\\[\\e[1;32m\\][\\u@\\h \\W]\\$\\[\\e[0m\\] \"", 1) < 0)
		errExit("setenv");
	// set user-supplied environment variables
	env_apply();

	// set capabilities
	if (!arg_noroot)
		set_caps();

	// set rlimits
	set_rlimits();

	// set seccomp
#ifdef HAVE_SECCOMP
	// if a keep list is available, disregard the drop list
	if (arg_seccomp == 1) {
		if (arg_seccomp_list_keep)
			seccomp_filter_keep(); // this will also save the fmyilter to MNT_DIR/seccomp file
		else
			seccomp_filter_drop(); // this will also save the filter to MNT_DIR/seccomp file
	}
#endif

	// set cpu affinity
	if (cfg.cpus) {
		save_cpu(); // save cpu affinity mask to MNT_DIR/cpu file
		set_cpu_affinity();
	}
	
	// save cgroup in MNT_DIR/cgroup file
	if (cfg.cgroup)
		save_cgroup();

	//****************************************
	// drop privileges or create a new user namespace
	//****************************************
	save_nogroups();
	if (arg_noroot) {
		int rv = unshare(CLONE_NEWUSER);
		if (rv == -1) {
			fprintf(stderr, "Error: cannot mount a new user namespace\n");
			perror("unshare");
			drop_privs(arg_nogroups);
		}
	}
	else
		drop_privs(arg_nogroups);
 	
	// notify parent that new user namespace has been created so a proper
 	// UID/GID map can be setup
 	notify_other(child_to_parent_fds[1]);
 	close(child_to_parent_fds[1]);
 
 	// wait for parent to finish setting up a proper UID/GID map
 	wait_for_other(parent_to_child_fds[0]);
 	close(parent_to_child_fds[0]);

	// somehow, the new user namespace resets capabilities;
	// we need to do them again
	if (arg_noroot) {
		set_caps();
		if (arg_debug)
			printf("User namespace (noroot) installed\n");
	}


	//****************************************
	// start the program without using a shell
	//****************************************
	if (arg_shell_none) {
		if (arg_debug) {
			int i;
			for (i = cfg.original_program_index; i < cfg.original_argc; i++) {
				if (cfg.original_argv[i] == NULL)
					break;
				printf("execvp argument %d: %s\n", i - cfg.original_program_index, cfg.original_argv[i]);
			}
		}

		if (!arg_command)
			printf("Child process initialized\n");
		execvp(cfg.original_argv[cfg.original_program_index], &cfg.original_argv[cfg.original_program_index]);
	}
	//****************************************
	// start the program using a shell
	//****************************************
	else {
		// choose the shell requested by the user, or use bash as default
		char *sh;
		if (cfg.shell)
	 		sh = cfg.shell;
		else if (arg_zsh)
			sh = "/usr/bin/zsh";
		else if (arg_csh)
			sh = "/bin/csh";
		else
			sh = "/bin/bash";
			
		char *arg[5];
		int index = 0;
		arg[index++] = sh;
		arg[index++] = "-c";
		assert(cfg.command_line);
		if (arg_debug)
			printf("Starting %s\n", cfg.command_line);
		if (arg_doubledash) 
			arg[index++] = "--";
		arg[index++] = cfg.command_line;
		arg[index] = NULL;
		assert(index < 5);
		
		if (arg_debug) {
			char *msg;
			if (asprintf(&msg, "sandbox %d, execvp into %s", sandbox_pid, cfg.command_line) == -1)
				errExit("asprintf");
			logmsg(msg);
			free(msg);
		}
		
		if (arg_debug) {
			int i;
			for (i = 0; i < 5; i++) {
				if (arg[i] == NULL)
					break;
				printf("execvp argument %d: %s\n", i, arg[i]);
			}
		}
		
		if (!arg_command)
			printf("Child process initialized\n");
		execvp(sh, arg);
	}
	

	perror("execvp");
	return 0;
}