buffer.c

DHCP服务器源码

	unsigned first_byte;
	omapi_buffer_t *buffer;
	unsigned char *bufp;
	int sig_flags = SIG_MODE_UPDATE;
	omapi_connection_object_t *c;
	isc_result_t status;

	if (!h || h -> type != omapi_type_connection)
		return ISC_R_INVALIDARG;
	c = (omapi_connection_object_t *)h;

	if (size > c -> in_bytes)
		return ISC_R_NOMORE;
	bufp = buf;
	bytes_remaining = size;
	buffer = c -> inbufs;

	while (bytes_remaining) {
		if (!buffer)
			return ISC_R_UNEXPECTED;
		if (BYTES_IN_BUFFER (buffer)) {
			if (buffer -> head == (sizeof buffer -> buf) - 1)
				first_byte = 0;
			else
				first_byte = buffer -> head + 1;

			if (first_byte > buffer -> tail) {
				bytes_this_copy = (sizeof buffer -> buf -
						   first_byte);
			} else {
				bytes_this_copy =
					buffer -> tail - first_byte;
			}
			if (bytes_this_copy > bytes_remaining)
				bytes_this_copy = bytes_remaining;
			if (bufp) {
				if (c -> in_key) {
					if (!c -> in_context)
						sig_flags |= SIG_MODE_INIT;
					status = omapi_connection_sign_data
						(sig_flags,
						 c -> in_key,
						 &c -> in_context,
						 (unsigned char *)
						 &buffer -> buf [first_byte],
						 bytes_this_copy,
						 (omapi_typed_data_t **)0);
					if (status != ISC_R_SUCCESS)
						return status;
				}

				memcpy (bufp, &buffer -> buf [first_byte],
					bytes_this_copy);
				bufp += bytes_this_copy;
			}
			bytes_remaining -= bytes_this_copy;
			buffer -> head = first_byte + bytes_this_copy - 1;
			c -> in_bytes -= bytes_this_copy;
		}
			
		if (!BYTES_IN_BUFFER (buffer))
			buffer = buffer -> next;
	}

	/* Get rid of any input buffers that we emptied. */
	buffer = (omapi_buffer_t *)0;
	while (c -> inbufs &&
	       !BYTES_IN_BUFFER (c -> inbufs)) {
		if (c -> inbufs -> next) {
			omapi_buffer_reference (&buffer,
						c -> inbufs -> next, MDL);
			omapi_buffer_dereference (&c -> inbufs -> next, MDL);
		}
		omapi_buffer_dereference (&c -> inbufs, MDL);
		if (buffer) {
			omapi_buffer_reference
				(&c -> inbufs, buffer, MDL);
			omapi_buffer_dereference (&buffer, MDL);
		}
	}
	return ISC_R_SUCCESS;
}

isc_result_t omapi_connection_writer (omapi_object_t *h)
{
	unsigned bytes_this_write;
	int bytes_written;
	unsigned first_byte;
	omapi_buffer_t *buffer;
	unsigned char *bufp;
	omapi_connection_object_t *c;
	isc_result_t status;

	if (!h || h -> type != omapi_type_connection)
		return ISC_R_INVALIDARG;
	c = (omapi_connection_object_t *)h;

	/* Already flushed... */
	if (!c -> out_bytes)
		return ISC_R_SUCCESS;

	buffer = c -> outbufs;

	while (c -> out_bytes) {
		if (!buffer)
			return ISC_R_UNEXPECTED;
		if (BYTES_IN_BUFFER (buffer)) {
			if (buffer -> head == (sizeof buffer -> buf) - 1)
				first_byte = 0;
			else
				first_byte = buffer -> head + 1;

			if (first_byte > buffer -> tail) {
				bytes_this_write = (sizeof buffer -> buf -
						   first_byte);
			} else {
				bytes_this_write =
					buffer -> tail - first_byte;
			}
			bytes_written = write (c -> socket,
					       &buffer -> buf [first_byte],
					       bytes_this_write);
			/* If the write failed with EWOULDBLOCK or we wrote
			   zero bytes, a further write would block, so we have
			   flushed as much as we can for now.   Other errors
			   are really errors. */
			if (bytes_written < 0) {
				if (errno == EWOULDBLOCK || errno == EAGAIN)
					return ISC_R_SUCCESS;
				else if (errno == EPIPE)
					return ISC_R_NOCONN;
#ifdef EDQUOT
				else if (errno == EFBIG || errno == EDQUOT)
#else
				else if (errno == EFBIG)
#endif
					return ISC_R_NORESOURCES;
				else if (errno == ENOSPC)
					return ISC_R_NOSPACE;
				else if (errno == EIO)
					return ISC_R_IOERROR;
				else if (errno == EINVAL)
					return ISC_R_INVALIDARG;
				else if (errno == ECONNRESET)
					return ISC_R_SHUTTINGDOWN;
				else
					return ISC_R_UNEXPECTED;
			}
			if (bytes_written == 0)
				return ISC_R_SUCCESS;

#if defined (TRACING)
			if (trace_record ()) {
				trace_iov_t iov [2];
				int32_t connect_index;
				
				connect_index = htonl (c -> index);
				
				iov [0].buf = (char *)&connect_index;
				iov [0].len = sizeof connect_index;
				iov [1].buf = &buffer -> buf [buffer -> tail];
				iov [1].len = bytes_written;
				
				status = (trace_write_packet_iov
					  (trace_connection_input, 2, iov,
					   MDL));
				if (status != ISC_R_SUCCESS) {
					trace_stop ();
					log_error ("trace %s output: %s",
						   "connection",
						   isc_result_totext (status));
				}
			}
#endif

			buffer -> head = first_byte + bytes_written - 1;
			c -> out_bytes -= bytes_written;

			/* If we didn't finish out the write, we filled the
			   O.S. output buffer and a further write would block,
			   so stop trying to flush now. */
			if (bytes_written != bytes_this_write)
				return ISC_R_SUCCESS;
		}
			
		if (!BYTES_IN_BUFFER (buffer))
			buffer = buffer -> next;
	}
		
	/* Get rid of any output buffers we emptied. */
	buffer = (omapi_buffer_t *)0;
	while (c -> outbufs &&
	       !BYTES_IN_BUFFER (c -> outbufs)) {
		if (c -> outbufs -> next) {
			omapi_buffer_reference (&buffer,
						c -> outbufs -> next, MDL);
			omapi_buffer_dereference (&c -> outbufs -> next, MDL);
		}
		omapi_buffer_dereference (&c -> outbufs, MDL);
		if (buffer) {
			omapi_buffer_reference (&c -> outbufs, buffer, MDL);
			omapi_buffer_dereference (&buffer, MDL);
		}
	}
	return ISC_R_SUCCESS;
}

isc_result_t omapi_connection_get_uint32 (omapi_object_t *c,
					  u_int32_t *result)
{
	u_int32_t inbuf;
	isc_result_t status;

	status = omapi_connection_copyout ((unsigned char *)&inbuf,
					   c, sizeof inbuf);
	if (status != ISC_R_SUCCESS)
		return status;

	*result = ntohl (inbuf);
	return ISC_R_SUCCESS;
}

isc_result_t omapi_connection_put_uint32 (omapi_object_t *c,
					  u_int32_t value)
{
	u_int32_t inbuf;
	isc_result_t status;

	inbuf = htonl (value);
	
	return omapi_connection_copyin (c, (unsigned char *)&inbuf,
					sizeof inbuf);
}

isc_result_t omapi_connection_get_uint16 (omapi_object_t *c,
					  u_int16_t *result)
{
	u_int16_t inbuf;
	isc_result_t status;

	status = omapi_connection_copyout ((unsigned char *)&inbuf,
					   c, sizeof inbuf);
	if (status != ISC_R_SUCCESS)
		return status;

	*result = ntohs (inbuf);
	return ISC_R_SUCCESS;
}

isc_result_t omapi_connection_put_uint16 (omapi_object_t *c,
					  u_int32_t value)
{
	u_int16_t inbuf;
	isc_result_t status;

	inbuf = htons (value);
	
	return omapi_connection_copyin (c, (unsigned char *)&inbuf,
					sizeof inbuf);
}

isc_result_t omapi_connection_write_typed_data (omapi_object_t *c,
						omapi_typed_data_t *data)
{
	isc_result_t status;
	omapi_handle_t handle;

	/* Null data is valid. */
	if (!data)
		return omapi_connection_put_uint32 (c, 0);

	switch (data -> type) {
	      case omapi_datatype_int:
		status = omapi_connection_put_uint32 (c, sizeof (u_int32_t));
		if (status != ISC_R_SUCCESS)
			return status;
		return omapi_connection_put_uint32 (c, ((u_int32_t)
							(data -> u.integer)));

	      case omapi_datatype_string:
	      case omapi_datatype_data:
		status = omapi_connection_put_uint32 (c, data -> u.buffer.len);
		if (status != ISC_R_SUCCESS)
			return status;
		if (data -> u.buffer.len)
			return omapi_connection_copyin
				(c, data -> u.buffer.value,
				 data -> u.buffer.len);
		return ISC_R_SUCCESS;

	      case omapi_datatype_object:
		if (data -> u.object) {
			status = omapi_object_handle (&handle,
						      data -> u.object);
			if (status != ISC_R_SUCCESS)
				return status;
		} else
			handle = 0;
		status = omapi_connection_put_uint32 (c, sizeof handle);
		if (status != ISC_R_SUCCESS)
			return status;
		return omapi_connection_put_uint32 (c, handle);

	}
	return ISC_R_INVALIDARG;
}

isc_result_t omapi_connection_put_name (omapi_object_t *c, const char *name)
{
	isc_result_t status;
	unsigned len = strlen (name);

	status = omapi_connection_put_uint16 (c, len);
	if (status != ISC_R_SUCCESS)
		return status;
	return omapi_connection_copyin (c, (const unsigned char *)name, len);
}

isc_result_t omapi_connection_put_string (omapi_object_t *c,
					  const char *string)
{
	isc_result_t status;
	unsigned len;

	if (string)
		len = strlen (string);
	else
		len = 0;

	status = omapi_connection_put_uint32 (c, len);
	if (status != ISC_R_SUCCESS)
		return status;
	if (len)
		return omapi_connection_copyin
			(c, (const unsigned char *)string, len);
	return ISC_R_SUCCESS;
}

isc_result_t omapi_connection_put_handle (omapi_object_t *c, omapi_object_t *h)
{
	isc_result_t status;
	omapi_handle_t handle;

	if (h) {
		status = omapi_object_handle (&handle, h);
		if (status != ISC_R_SUCCESS)
			return status;
	} else
		handle = 0;	/* The null handle. */
	status = omapi_connection_put_uint32 (c, sizeof handle);
	if (status != ISC_R_SUCCESS)
		return status;
	return omapi_connection_put_uint32 (c, handle);
}