/*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <config.h>
#include "stream-provider.h"
-#include <assert.h>
#include <errno.h>
#include <inttypes.h>
#include <netinet/in.h>
#include <string.h>
#include "coverage.h"
#include "dynamic-string.h"
+#include "fatal-signal.h"
#include "flow.h"
+#include "jsonrpc.h"
#include "ofp-print.h"
#include "ofpbuf.h"
#include "openflow/nicira-ext.h"
#include "openflow/openflow.h"
+#include "ovs-thread.h"
#include "packets.h"
#include "poll-loop.h"
#include "random.h"
+#include "socket-util.h"
#include "util.h"
-
-#define THIS_MODULE VLM_stream
#include "vlog.h"
+VLOG_DEFINE_THIS_MODULE(stream);
+
+COVERAGE_DEFINE(pstream_open);
+COVERAGE_DEFINE(stream_open);
+
/* State of an active stream.*/
enum stream_state {
SCS_CONNECTING, /* Underlying stream is not connected. */
SCS_DISCONNECTED /* Connection failed or connection closed. */
};
-static struct stream_class *stream_classes[] = {
+static const struct stream_class *stream_classes[] = {
&tcp_stream_class,
+#ifndef _WIN32
&unix_stream_class,
+#endif
+#ifdef HAVE_OPENSSL
+ &ssl_stream_class,
+#endif
};
-static struct pstream_class *pstream_classes[] = {
+static const struct pstream_class *pstream_classes[] = {
&ptcp_pstream_class,
+#ifndef _WIN32
&punix_pstream_class,
+#endif
+#ifdef HAVE_OPENSSL
+ &pssl_pstream_class,
+#endif
};
+#ifdef _WIN32
+static void
+do_winsock_start(void)
+{
+ WSADATA wsaData;
+ int error;
+
+ error = WSAStartup(MAKEWORD(2, 2), &wsaData);
+ if (error != 0) {
+ VLOG_FATAL("WSAStartup failed: %s", sock_strerror(sock_errno()));
+ }
+}
+
+static void
+winsock_start(void)
+{
+ static pthread_once_t once = PTHREAD_ONCE_INIT;
+ pthread_once(&once, do_winsock_start);
+}
+#endif
+
/* Check the validity of the stream class structures. */
static void
check_stream_classes(void)
size_t i;
for (i = 0; i < ARRAY_SIZE(stream_classes); i++) {
- struct stream_class *class = stream_classes[i];
- assert(class->name != NULL);
- assert(class->open != NULL);
- if (class->close || class->recv || class->send || class->wait) {
- assert(class->close != NULL);
- assert(class->recv != NULL);
- assert(class->send != NULL);
- assert(class->wait != NULL);
+ const struct stream_class *class = stream_classes[i];
+ ovs_assert(class->name != NULL);
+ ovs_assert(class->open != NULL);
+ if (class->close || class->recv || class->send || class->run
+ || class->run_wait || class->wait) {
+ ovs_assert(class->close != NULL);
+ ovs_assert(class->recv != NULL);
+ ovs_assert(class->send != NULL);
+ ovs_assert(class->wait != NULL);
} else {
/* This class delegates to another one. */
}
}
for (i = 0; i < ARRAY_SIZE(pstream_classes); i++) {
- struct pstream_class *class = pstream_classes[i];
- assert(class->name != NULL);
- assert(class->listen != NULL);
+ const struct pstream_class *class = pstream_classes[i];
+ ovs_assert(class->name != NULL);
+ ovs_assert(class->listen != NULL);
if (class->close || class->accept || class->wait) {
- assert(class->close != NULL);
- assert(class->accept != NULL);
- assert(class->wait != NULL);
+ ovs_assert(class->close != NULL);
+ ovs_assert(class->accept != NULL);
+ ovs_assert(class->wait != NULL);
} else {
/* This class delegates to another one. */
}
/* Prints information on active (if 'active') and passive (if 'passive')
* connection methods supported by the stream. */
void
-stream_usage(const char *name, bool active, bool passive)
+stream_usage(const char *name, bool active, bool passive,
+ bool bootstrap OVS_UNUSED)
{
/* Really this should be implemented via callbacks into the stream
* providers, but that seems too heavy-weight to bother with at the
printf("Active %s connection methods:\n", name);
printf(" tcp:IP:PORT "
"PORT at remote IP\n");
+#ifdef HAVE_OPENSSL
+ printf(" ssl:IP:PORT "
+ "SSL PORT at remote IP\n");
+#endif
printf(" unix:FILE "
"Unix domain socket named FILE\n");
}
printf("Passive %s connection methods:\n", name);
printf(" ptcp:PORT[:IP] "
"listen to TCP PORT on IP\n");
+#ifdef HAVE_OPENSSL
+ printf(" pssl:PORT[:IP] "
+ "listen for SSL on PORT on IP\n");
+#endif
printf(" punix:FILE "
"listen on Unix domain socket FILE\n");
}
+
+#ifdef HAVE_OPENSSL
+ printf("PKI configuration (required to use SSL):\n"
+ " -p, --private-key=FILE file with private key\n"
+ " -c, --certificate=FILE file with certificate for private key\n"
+ " -C, --ca-cert=FILE file with peer CA certificate\n");
+ if (bootstrap) {
+ printf(" --bootstrap-ca-cert=FILE file with peer CA certificate "
+ "to read or create\n");
+ }
+#endif
}
-/* Attempts to connect a stream to a remote peer. 'name' is a connection name
- * in the form "TYPE:ARGS", where TYPE is an active stream class's name and
- * ARGS are stream class-specific.
- *
- * Returns 0 if successful, otherwise a positive errno value. If successful,
- * stores a pointer to the new connection in '*streamp', otherwise a null
- * pointer. */
-int
-stream_open(const char *name, struct stream **streamp)
+/* Given 'name', a stream name in the form "TYPE:ARGS", stores the class
+ * named "TYPE" into '*classp' and returns 0. Returns EAFNOSUPPORT and stores
+ * a null pointer into '*classp' if 'name' is in the wrong form or if no such
+ * class exists. */
+static int
+stream_lookup_class(const char *name, const struct stream_class **classp)
{
size_t prefix_len;
size_t i;
- COVERAGE_INC(stream_open);
check_stream_classes();
- *streamp = NULL;
+ *classp = NULL;
prefix_len = strcspn(name, ":");
- if (prefix_len == strlen(name)) {
+ if (name[prefix_len] == '\0') {
return EAFNOSUPPORT;
}
for (i = 0; i < ARRAY_SIZE(stream_classes); i++) {
- struct stream_class *class = stream_classes[i];
+ const struct stream_class *class = stream_classes[i];
if (strlen(class->name) == prefix_len
&& !memcmp(class->name, name, prefix_len)) {
- struct stream *stream;
- char *suffix_copy = xstrdup(name + prefix_len + 1);
- int retval = class->open(name, suffix_copy, &stream);
- free(suffix_copy);
- if (!retval) {
- assert(stream->state != SCS_CONNECTING
- || stream->class->connect);
- *streamp = stream;
- }
- return retval;
+ *classp = class;
+ return 0;
}
}
return EAFNOSUPPORT;
}
+/* Returns 0 if 'name' is a stream name in the form "TYPE:ARGS" and TYPE is
+ * a supported stream type, otherwise EAFNOSUPPORT. */
+int
+stream_verify_name(const char *name)
+{
+ const struct stream_class *class;
+ return stream_lookup_class(name, &class);
+}
+
+/* Attempts to connect a stream to a remote peer. 'name' is a connection name
+ * in the form "TYPE:ARGS", where TYPE is an active stream class's name and
+ * ARGS are stream class-specific.
+ *
+ * Returns 0 if successful, otherwise a positive errno value. If successful,
+ * stores a pointer to the new connection in '*streamp', otherwise a null
+ * pointer. */
int
-stream_open_block(const char *name, struct stream **streamp)
+stream_open(const char *name, struct stream **streamp, uint8_t dscp)
{
+ const struct stream_class *class;
struct stream *stream;
+ char *suffix_copy;
int error;
- error = stream_open(name, &stream);
- while (error == EAGAIN) {
- stream_connect_wait(stream);
- poll_block();
- error = stream_connect(stream);
- assert(error != EINPROGRESS);
+ COVERAGE_INC(stream_open);
+
+#ifdef _WIN32
+ winsock_start();
+#endif
+
+ /* Look up the class. */
+ error = stream_lookup_class(name, &class);
+ if (!class) {
+ goto error;
+ }
+
+ /* Call class's "open" function. */
+ suffix_copy = xstrdup(strchr(name, ':') + 1);
+ error = class->open(name, suffix_copy, &stream, dscp);
+ free(suffix_copy);
+ if (error) {
+ goto error;
+ }
+
+ /* Success. */
+ *streamp = stream;
+ return 0;
+
+error:
+ *streamp = NULL;
+ return error;
+}
+
+/* Blocks until a previously started stream connection attempt succeeds or
+ * fails. 'error' should be the value returned by stream_open() and 'streamp'
+ * should point to the stream pointer set by stream_open(). Returns 0 if
+ * successful, otherwise a positive errno value other than EAGAIN or
+ * EINPROGRESS. If successful, leaves '*streamp' untouched; on error, closes
+ * '*streamp' and sets '*streamp' to null.
+ *
+ * Typical usage:
+ * error = stream_open_block(stream_open("tcp:1.2.3.4:5", &stream), &stream);
+ */
+int
+stream_open_block(int error, struct stream **streamp)
+{
+ struct stream *stream = *streamp;
+
+ fatal_signal_run();
+
+ if (!error) {
+ while ((error = stream_connect(stream)) == EAGAIN) {
+ stream_run(stream);
+ stream_run_wait(stream);
+ stream_connect_wait(stream);
+ poll_block();
+ }
+ ovs_assert(error != EINPROGRESS);
}
+
if (error) {
stream_close(stream);
*streamp = NULL;
return stream ? stream->name : "(null)";
}
-/* Returns the IP address of the peer, or 0 if the peer is not connected over
- * an IP-based protocol or if its IP address is not yet known. */
-uint32_t
-stream_get_remote_ip(const struct stream *stream)
-{
- return stream->remote_ip;
-}
-
-/* Returns the transport port of the peer, or 0 if the connection does not
- * contain a port or if the port is not yet known. */
-uint16_t
-stream_get_remote_port(const struct stream *stream)
-{
- return stream->remote_port;
-}
-
-/* Returns the IP address used to connect to the peer, or 0 if the connection
- * is not an IP-based protocol or if its IP address is not yet known. */
-uint32_t
-stream_get_local_ip(const struct stream *stream)
-{
- return stream->local_ip;
-}
-
-/* Returns the transport port used to connect to the peer, or 0 if the
- * connection does not contain a port or if the port is not yet known. */
-uint16_t
-stream_get_local_port(const struct stream *stream)
-{
- return stream->local_port;
-}
-
static void
scs_connecting(struct stream *stream)
{
int retval = (stream->class->connect)(stream);
- assert(retval != EINPROGRESS);
+ ovs_assert(retval != EINPROGRESS);
if (!retval) {
stream->state = SCS_CONNECTED;
} else if (retval != EAGAIN) {
}
}
-/* Tries to complete the connection on 'stream', which must be an active
- * stream. If 'stream''s connection is complete, returns 0 if the connection
- * was successful or a positive errno value if it failed. If the
- * connection is still in progress, returns EAGAIN. */
+/* Tries to complete the connection on 'stream'. If 'stream''s connection is
+ * complete, returns 0 if the connection was successful or a positive errno
+ * value if it failed. If the connection is still in progress, returns
+ * EAGAIN. */
int
stream_connect(struct stream *stream)
{
return stream->error;
default:
- NOT_REACHED();
+ OVS_NOT_REACHED();
}
} while (stream->state != last_state);
: (stream->class->send)(stream, buffer, n));
}
+/* Allows 'stream' to perform maintenance activities, such as flushing
+ * output buffers. */
+void
+stream_run(struct stream *stream)
+{
+ if (stream->class->run) {
+ (stream->class->run)(stream);
+ }
+}
+
+/* Arranges for the poll loop to wake up when 'stream' needs to perform
+ * maintenance activities. */
+void
+stream_run_wait(struct stream *stream)
+{
+ if (stream->class->run_wait) {
+ (stream->class->run_wait)(stream);
+ }
+}
+
+/* Arranges for the poll loop to wake up when 'stream' is ready to take an
+ * action of the given 'type'. */
void
stream_wait(struct stream *stream, enum stream_wait_type wait)
{
- assert(wait == STREAM_CONNECT || wait == STREAM_RECV
- || wait == STREAM_SEND);
+ ovs_assert(wait == STREAM_CONNECT || wait == STREAM_RECV
+ || wait == STREAM_SEND);
switch (stream->state) {
case SCS_CONNECTING:
stream_wait(stream, STREAM_SEND);
}
-/* Attempts to start listening for remote stream connections. 'name' is a
- * connection name in the form "TYPE:ARGS", where TYPE is an passive stream
- * class's name and ARGS are stream class-specific.
- *
- * Returns 0 if successful, otherwise a positive errno value. If successful,
- * stores a pointer to the new connection in '*pstreamp', otherwise a null
- * pointer. */
-int
-pstream_open(const char *name, struct pstream **pstreamp)
+/* Given 'name', a pstream name in the form "TYPE:ARGS", stores the class
+ * named "TYPE" into '*classp' and returns 0. Returns EAFNOSUPPORT and stores
+ * a null pointer into '*classp' if 'name' is in the wrong form or if no such
+ * class exists. */
+static int
+pstream_lookup_class(const char *name, const struct pstream_class **classp)
{
size_t prefix_len;
size_t i;
check_stream_classes();
- *pstreamp = NULL;
+ *classp = NULL;
prefix_len = strcspn(name, ":");
- if (prefix_len == strlen(name)) {
+ if (name[prefix_len] == '\0') {
return EAFNOSUPPORT;
}
for (i = 0; i < ARRAY_SIZE(pstream_classes); i++) {
- struct pstream_class *class = pstream_classes[i];
+ const struct pstream_class *class = pstream_classes[i];
if (strlen(class->name) == prefix_len
&& !memcmp(class->name, name, prefix_len)) {
- char *suffix_copy = xstrdup(name + prefix_len + 1);
- int retval = class->listen(name, suffix_copy, pstreamp);
- free(suffix_copy);
- if (retval) {
- *pstreamp = NULL;
- }
- return retval;
+ *classp = class;
+ return 0;
}
}
return EAFNOSUPPORT;
}
+/* Returns 0 if 'name' is a pstream name in the form "TYPE:ARGS" and TYPE is
+ * a supported pstream type, otherwise EAFNOSUPPORT. */
+int
+pstream_verify_name(const char *name)
+{
+ const struct pstream_class *class;
+ return pstream_lookup_class(name, &class);
+}
+
+/* Returns 1 if the stream or pstream specified by 'name' needs periodic probes
+ * to verify connectivity. For [p]streams which need probes, it can take a
+ * long time to notice the connection has been dropped. Returns 0 if the
+ * stream or pstream does not need probes, and -1 if 'name' is not valid. */
+int
+stream_or_pstream_needs_probes(const char *name)
+{
+ const struct pstream_class *pclass;
+ const struct stream_class *class;
+
+ if (!stream_lookup_class(name, &class)) {
+ return class->needs_probes;
+ } else if (!pstream_lookup_class(name, &pclass)) {
+ return pclass->needs_probes;
+ } else {
+ return -1;
+ }
+}
+
+/* Attempts to start listening for remote stream connections. 'name' is a
+ * connection name in the form "TYPE:ARGS", where TYPE is an passive stream
+ * class's name and ARGS are stream class-specific.
+ *
+ * Returns 0 if successful, otherwise a positive errno value. If successful,
+ * stores a pointer to the new connection in '*pstreamp', otherwise a null
+ * pointer. */
+int
+pstream_open(const char *name, struct pstream **pstreamp, uint8_t dscp)
+{
+ const struct pstream_class *class;
+ struct pstream *pstream;
+ char *suffix_copy;
+ int error;
+
+ COVERAGE_INC(pstream_open);
+
+#ifdef _WIN32
+ winsock_start();
+#endif
+
+ /* Look up the class. */
+ error = pstream_lookup_class(name, &class);
+ if (!class) {
+ goto error;
+ }
+
+ /* Call class's "open" function. */
+ suffix_copy = xstrdup(strchr(name, ':') + 1);
+ error = class->listen(name, suffix_copy, &pstream, dscp);
+ free(suffix_copy);
+ if (error) {
+ goto error;
+ }
+
+ /* Success. */
+ *pstreamp = pstream;
+ return 0;
+
+error:
+ *pstreamp = NULL;
+ return error;
+}
+
/* Returns the name that was used to open 'pstream'. The caller must not
* modify or free the name. */
const char *
if (retval) {
*new_stream = NULL;
} else {
- assert((*new_stream)->state != SCS_CONNECTING
- || (*new_stream)->class->connect);
+ ovs_assert((*new_stream)->state != SCS_CONNECTING
+ || (*new_stream)->class->connect);
}
return retval;
}
+/* Tries to accept a new connection on 'pstream'. If successful, stores the
+ * new connection in '*new_stream' and returns 0. Otherwise, returns a
+ * positive errno value.
+ *
+ * pstream_accept_block() blocks until a connection is ready or until an error
+ * occurs. It will not return EAGAIN. */
+int
+pstream_accept_block(struct pstream *pstream, struct stream **new_stream)
+{
+ int error;
+
+ fatal_signal_run();
+ while ((error = pstream_accept(pstream, new_stream)) == EAGAIN) {
+ pstream_wait(pstream);
+ poll_block();
+ }
+ if (error) {
+ *new_stream = NULL;
+ }
+ return error;
+}
+
void
pstream_wait(struct pstream *pstream)
{
(pstream->class->wait)(pstream);
}
+
+int
+pstream_set_dscp(struct pstream *pstream, uint8_t dscp)
+{
+ if (pstream->class->set_dscp) {
+ return pstream->class->set_dscp(pstream, dscp);
+ }
+ return 0;
+}
+
+/* Returns the transport port on which 'pstream' is listening, or 0 if the
+ * concept doesn't apply. */
+ovs_be16
+pstream_get_bound_port(const struct pstream *pstream)
+{
+ return pstream->bound_port;
+}
\f
/* Initializes 'stream' as a new stream named 'name', implemented via 'class'.
* The initial connection status, supplied as 'connect_status', is interpreted
*
* The caller retains ownership of 'name'. */
void
-stream_init(struct stream *stream, struct stream_class *class,
+stream_init(struct stream *stream, const struct stream_class *class,
int connect_status, const char *name)
{
+ memset(stream, 0, sizeof *stream);
stream->class = class;
stream->state = (connect_status == EAGAIN ? SCS_CONNECTING
: !connect_status ? SCS_CONNECTED
: SCS_DISCONNECTED);
stream->error = connect_status;
stream->name = xstrdup(name);
+ ovs_assert(stream->state != SCS_CONNECTING || class->connect);
}
void
-stream_set_remote_ip(struct stream *stream, uint32_t ip)
+pstream_init(struct pstream *pstream, const struct pstream_class *class,
+ const char *name)
{
- stream->remote_ip = ip;
+ memset(pstream, 0, sizeof *pstream);
+ pstream->class = class;
+ pstream->name = xstrdup(name);
}
void
-stream_set_remote_port(struct stream *stream, uint16_t port)
+pstream_set_bound_port(struct pstream *pstream, ovs_be16 port)
{
- stream->remote_port = port;
+ pstream->bound_port = port;
}
+\f
+static int
+count_fields(const char *s_)
+{
+ char *s, *field, *save_ptr;
+ int n = 0;
+
+ save_ptr = NULL;
+ s = xstrdup(s_);
+ for (field = strtok_r(s, ":", &save_ptr); field != NULL;
+ field = strtok_r(NULL, ":", &save_ptr)) {
+ n++;
+ }
+ free(s);
-void
-stream_set_local_ip(struct stream *stream, uint32_t ip)
+ return n;
+}
+
+/* Like stream_open(), but the port defaults to 'default_port' if no port
+ * number is given. */
+int
+stream_open_with_default_port(const char *name_,
+ uint16_t default_port,
+ struct stream **streamp,
+ uint8_t dscp)
{
- stream->local_ip = ip;
+ char *name;
+ int error;
+
+ if ((!strncmp(name_, "tcp:", 4) || !strncmp(name_, "ssl:", 4))
+ && count_fields(name_) < 3) {
+ if (default_port == OFP_OLD_PORT) {
+ VLOG_WARN_ONCE("The default OpenFlow port number will change "
+ "from %d to %d in a future release",
+ OFP_OLD_PORT, OFP_PORT);
+ } else if (default_port == OVSDB_OLD_PORT) {
+ VLOG_WARN_ONCE("The default OVSDB port number will change "
+ "from %d to %d in a future release",
+ OVSDB_OLD_PORT, OVSDB_PORT);
+ }
+ name = xasprintf("%s:%d", name_, default_port);
+ } else {
+ name = xstrdup(name_);
+ }
+ error = stream_open(name, streamp, dscp);
+ free(name);
+
+ return error;
}
-void
-stream_set_local_port(struct stream *stream, uint16_t port)
+/* Like pstream_open(), but port defaults to 'default_port' if no port
+ * number is given. */
+int
+pstream_open_with_default_port(const char *name_,
+ uint16_t default_port,
+ struct pstream **pstreamp,
+ uint8_t dscp)
+{
+ char *name;
+ int error;
+
+ if ((!strncmp(name_, "ptcp:", 5) || !strncmp(name_, "pssl:", 5))
+ && count_fields(name_) < 2) {
+ name = xasprintf("%s%d", name_, default_port);
+ } else {
+ name = xstrdup(name_);
+ }
+ error = pstream_open(name, pstreamp, dscp);
+ free(name);
+
+ return error;
+}
+
+/*
+ * This function extracts IP address and port from the target string.
+ *
+ * - On success, function returns true and fills *ss structure with port
+ * and IP address. If port was absent in target string then it will use
+ * corresponding default port value.
+ * - On error, function returns false and *ss contains garbage.
+ */
+bool
+stream_parse_target_with_default_port(const char *target,
+ uint16_t default_port,
+ struct sockaddr_storage *ss)
+{
+ return ((!strncmp(target, "tcp:", 4) || !strncmp(target, "ssl:", 4))
+ && inet_parse_active(target + 4, default_port, ss));
+}
+
+/* Attempts to guess the content type of a stream whose first few bytes were
+ * the 'size' bytes of 'data'. */
+static enum stream_content_type
+stream_guess_content(const uint8_t *data, ssize_t size)
+{
+ if (size >= 2) {
+#define PAIR(A, B) (((A) << 8) | (B))
+ switch (PAIR(data[0], data[1])) {
+ case PAIR(0x16, 0x03): /* Handshake, version 3. */
+ return STREAM_SSL;
+ case PAIR('{', '"'):
+ return STREAM_JSONRPC;
+ case PAIR(OFP10_VERSION, 0 /* OFPT_HELLO */):
+ return STREAM_OPENFLOW;
+ }
+ }
+
+ return STREAM_UNKNOWN;
+}
+
+/* Returns a string represenation of 'type'. */
+static const char *
+stream_content_type_to_string(enum stream_content_type type)
{
- stream->local_port = port;
+ switch (type) {
+ case STREAM_UNKNOWN:
+ default:
+ return "unknown";
+
+ case STREAM_JSONRPC:
+ return "JSON-RPC";
+
+ case STREAM_OPENFLOW:
+ return "OpenFlow";
+
+ case STREAM_SSL:
+ return "SSL";
+ }
}
+/* Attempts to guess the content type of a stream whose first few bytes were
+ * the 'size' bytes of 'data'. If this is done successfully, and the guessed
+ * content type is other than 'expected_type', then log a message in vlog
+ * module 'module', naming 'stream_name' as the source, explaining what
+ * content was expected and what was actually received. */
void
-pstream_init(struct pstream *pstream, struct pstream_class *class,
- const char *name)
+stream_report_content(const void *data, ssize_t size,
+ enum stream_content_type expected_type,
+ struct vlog_module *module, const char *stream_name)
{
- pstream->class = class;
- pstream->name = xstrdup(name);
+ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 5);
+ enum stream_content_type actual_type;
+
+ actual_type = stream_guess_content(data, size);
+ if (actual_type != expected_type && actual_type != STREAM_UNKNOWN) {
+ vlog_rate_limit(module, VLL_WARN, &rl,
+ "%s: received %s data on %s channel",
+ stream_name,
+ stream_content_type_to_string(actual_type),
+ stream_content_type_to_string(expected_type));
+ }
}