Module: PhusionPassenger::NativeSupport

Defined in:
ext/phusion_passenger/native_support.c

Constant Summary collapse

UNIX_PATH_MAX =

The maximum length of a Unix socket path, including terminating null.

INT2NUM(sizeof(addr.sun_path))

Class Method Summary collapse

Class Method Details

.accept(fileno) ⇒ Object

Accept a new client from the given socket.

  • fileno (integer): The file descriptor of the server socket.

  • Returns: The accepted client’s file descriptor.

  • Raises SystemCallError if something went wrong.



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# File 'ext/phusion_passenger/native_support.c', line 239

static VALUE
f_accept(VALUE self, VALUE fileno) {
	int fd = accept(NUM2INT(fileno), NULL, NULL);
	if (fd == -1) {
		rb_sys_fail("accept() failed");
		return Qnil;
	} else {
		return INT2NUM(fd);
	}
}

.close_all_file_descriptors(exceptions) ⇒ Object

Close all file descriptors, except those given in the exceptions array. For example, the following would close all file descriptors except standard input (0) and standard output (1).

close_all_file_descriptors([0, 1])



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# File 'ext/phusion_passenger/native_support.c', line 259

static VALUE
close_all_file_descriptors(VALUE self, VALUE exceptions) {
	long i, j;
	
	for (i = sysconf(_SC_OPEN_MAX) - 1; i >= 0; i--) {
		int is_exception = 0;
		for (j = 0; j < RARRAY_LEN(exceptions) && !is_exception; j++) {
			long fd = NUM2INT(rb_ary_entry(exceptions, j));
			is_exception = i == fd;
		}
		if (!is_exception) {
			close(i);
		}
	}
	return Qnil;
}

.create_unix_socket(filename, backlog) ⇒ Object

Create a SOCK_STREAM server Unix socket. Unlike Ruby’s UNIXServer class, this function is also able to create Unix sockets on the abstract namespace by prepending the filename with a null byte.

  • filename (string): The filename of the Unix socket to create.

  • backlog (integer): The backlog to use for listening on the socket.

  • Returns: The file descriptor of the created Unix socket, as an integer.

  • Raises SystemCallError if something went wrong.



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# File 'ext/phusion_passenger/native_support.c', line 190

static VALUE
create_unix_socket(VALUE self, VALUE filename, VALUE backlog) {
	int fd, ret;
	struct sockaddr_un addr;
	char *filename_str;
	long filename_length;
	
	filename_str = RSTRING_PTR(filename);
	filename_length = RSTRING_LEN(filename);
	
	fd = socket(PF_UNIX, SOCK_STREAM, 0);
	if (fd == -1) {
		rb_sys_fail("Cannot create a Unix socket");
		return Qnil;
	}
	
	addr.sun_family = AF_UNIX;
	memcpy(addr.sun_path, filename_str, MIN(filename_length, sizeof(addr.sun_path)));
	addr.sun_path[sizeof(addr.sun_path) - 1] = '\0';
	
	ret = bind(fd, (const struct sockaddr *) &addr, sizeof(addr));
	if (ret == -1) {
		int e = errno;
		close(fd);
		errno = e;
		rb_sys_fail("Cannot bind Unix socket");
		return Qnil;
	}
	
	ret = listen(fd, NUM2INT(backlog));
	if (ret == -1) {
		int e = errno;
		close(fd);
		errno = e;
		rb_sys_fail("Cannot listen on Unix socket");
		return Qnil;
	}
	return INT2NUM(fd);
}

.disable_stdio_buffering ⇒ Object

Disables any kind of buffering on the C stdout and stderr variables, so that fprintf() on stdout and stderr have immediate effect.



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# File 'ext/phusion_passenger/native_support.c', line 282

static VALUE
disable_stdio_buffering() {
	setvbuf(stdout, NULL, _IONBF, 0);
	setvbuf(stderr, NULL, _IONBF, 0);
	return Qnil;
}

.recv_fd(socket_fd) ⇒ Object

Receive a file descriptor from the given Unix socket. Returns the received file descriptor as an integer. Raises SystemCallError if something went wrong.

You do not have call this method directly. A convenience wrapper is provided by IO#recv_io.



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# File 'ext/phusion_passenger/native_support.c', line 123

static VALUE
recv_fd(VALUE self, VALUE socket_fd) {
	struct msghdr msg;
	struct iovec vec;
	char dummy[1];
	#if defined(__APPLE__) || defined(__SOLARIS__) || defined(__arm__)
		// File descriptor passing macros (CMSG_*) seem to be broken
		// on 64-bit MacOS X. This structure works around the problem.
		struct {
			struct cmsghdr header;
			int fd;
		} control_data;
		#define EXPECTED_CMSG_LEN sizeof(control_data)
	#else
		char control_data[CMSG_SPACE(sizeof(int))];
		#define EXPECTED_CMSG_LEN CMSG_LEN(sizeof(int))
	#endif
	struct cmsghdr *control_header;

	msg.msg_name    = NULL;
	msg.msg_namelen = 0;
	
	dummy[0]       = '\0';
	vec.iov_base   = dummy;
	vec.iov_len    = sizeof(dummy);
	msg.msg_iov    = &vec;
	msg.msg_iovlen = 1;

	msg.msg_control    = (caddr_t) &control_data;
	msg.msg_controllen = sizeof(control_data);
	msg.msg_flags      = 0;
	
	if (recvmsg(NUM2INT(socket_fd), &msg, 0) == -1) {
		rb_sys_fail("Cannot read file descriptor with recvmsg()");
		return Qnil;
	}
	
	control_header = CMSG_FIRSTHDR(&msg);
	if (control_header == NULL) {
		rb_raise(rb_eIOError, "No valid file descriptor received.");
		return Qnil;
	}
	if (control_header->cmsg_len   != EXPECTED_CMSG_LEN
	 || control_header->cmsg_level != SOL_SOCKET
	 || control_header->cmsg_type  != SCM_RIGHTS) {
		rb_raise(rb_eIOError, "No valid file descriptor received.");
		return Qnil;
	}
	#if defined(__APPLE__) || defined(__SOLARIS__) || defined(__arm__)
		return INT2NUM(control_data.fd);
	#else
		return INT2NUM(*((int *) CMSG_DATA(control_header)));
	#endif
}

.send_fd(socket_fd, fd_to_send) ⇒ Object

Send a file descriptor over the given Unix socket. You do not have to call this function directly. A convenience wrapper is provided by IO#send_io.

  • socket_fd (integer): The file descriptor of the socket.

  • fd_to_send (integer): The file descriptor to send.

  • Raises SystemCallError if something went wrong.



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# File 'ext/phusion_passenger/native_support.c', line 63

static VALUE
send_fd(VALUE self, VALUE socket_fd, VALUE fd_to_send) {
	struct msghdr msg;
	struct iovec vec;
	char dummy[1];
	#if defined(__APPLE__) || defined(__SOLARIS__) || defined(__arm__)
		struct {
			struct cmsghdr header;
			int fd;
		} control_data;
	#else
		char control_data[CMSG_SPACE(sizeof(int))];
	#endif
	struct cmsghdr *control_header;
	int control_payload;
	
	msg.msg_name = NULL;
	msg.msg_namelen = 0;
	
	/* Linux and Solaris require msg_iov to be non-NULL. */
	dummy[0]       = '\0';
	vec.iov_base   = dummy;
	vec.iov_len    = sizeof(dummy);
	msg.msg_iov    = &vec;
	msg.msg_iovlen = 1;
	
	msg.msg_control    = (caddr_t) &control_data;
	msg.msg_controllen = sizeof(control_data);
	msg.msg_flags      = 0;
	
	control_header = CMSG_FIRSTHDR(&msg);
	control_header->cmsg_level = SOL_SOCKET;
	control_header->cmsg_type  = SCM_RIGHTS;
	control_payload = NUM2INT(fd_to_send);
	#if defined(__APPLE__) || defined(__SOLARIS__) || defined(__arm__)
		control_header->cmsg_len = sizeof(control_data);
		control_data.fd = control_payload;
	#else
		control_header->cmsg_len = CMSG_LEN(sizeof(int));
		memcpy(CMSG_DATA(control_header), &control_payload, sizeof(int));
	#endif
	
	if (sendmsg(NUM2INT(socket_fd), &msg, 0) == -1) {
		rb_sys_fail("sendmsg(2)");
		return Qnil;
	}
	
	return Qnil;
}