Resolved issue #914

CHANGES.md

@@ -6,6 +6,7 @@
   * Duplicate code in generated cisco-ios-xe Go bundle ([#891](https://github.com/CiscoDevNet/ydk-gen/issues/891))
   * Memory leaks in YDK C++ core ([#899](https://github.com/CiscoDevNet/ydk-gen/issues/899))
   * Memory leaks in YDK C++ gNMI Service component ([#902](https://github.com/CiscoDevNet/ydk-gen/issues/902))
+  * RPC execution stuck when NETCONF server closes session unexpectedly ([#914](https://github.com/CiscoDevNet/ydk-gen/issues/914))
 
 ##### Note
   The solution for GitHub issue ([#891](https://github.com/CiscoDevNet/ydk-gen/issues/891)) changed model API. However all model bundles generated with YDK-Gen version 0.7.3 and later are still compatible with core YDK components.

sdk/cpp/CHANGES.md

@@ -6,6 +6,7 @@
   * Duplicate code in generated cisco-ios-xe Go bundle ([#891](https://github.com/CiscoDevNet/ydk-gen/issues/891))
   * Memory leaks in YDK C++ core ([#899](https://github.com/CiscoDevNet/ydk-gen/issues/899))
   * Memory leaks in YDK C++ gNMI Service component ([#902](https://github.com/CiscoDevNet/ydk-gen/issues/902))
+  * RPC execution stuck when NETCONF server closes session unexpectedly ([#914](https://github.com/CiscoDevNet/ydk-gen/issues/914))
 
 ##### Note
   The solution for GitHub issue ([#891](https://github.com/CiscoDevNet/ydk-gen/issues/891)) changed model API. However all model bundles generated with YDK-Gen version 0.7.3 and later are still compatible with core YDK components.

sdk/cpp/core/CMakeLists.txt

@@ -365,8 +365,8 @@ set(libnetconf_headers_location ${CMAKE_CURRENT_BINARY_DIR}/project_libnetconf/h
 include(ExternalProject)
 ExternalProject_Add(project_libnetconf
     PREFIX "${CMAKE_CURRENT_BINARY_DIR}/project_libnetconf"
-    URL "https://github.com/abhikeshav/libnetconf/archive/master.zip"
-    CONFIGURE_COMMAND "./configure"
+    URL "https://github.com/ygorelik/libnetconf/archive/master.zip"
+    CONFIGURE_COMMAND ./configure
     BUILD_COMMAND "make"
     INSTALL_DIR "${libnetconf_location}"
     INSTALL_COMMAND mkdir -p ${libnetconf_headers_location}/libnetconf && cp ${libnetconf_headers} ${libnetconf_headers_location}/libnetconf

sdk/cpp/core/src/netconf_client.hpp

@@ -40,6 +40,7 @@ class NetconfClient
     virtual std::string execute_payload(const std::string & payload) = 0;
     virtual std::vector<std::string> get_capabilities() = 0;
     virtual std::string get_hostname_port() = 0;
+    virtual void perform_session_check(const std::string & message) = 0;
 };
 
 

sdk/cpp/core/src/netconf_session.cpp

@@ -241,6 +241,11 @@ NetconfSession::~NetconfSession()
     YLOG_INFO("Disconnected from device");
 }
 
+void NetconfSession::check_session_state()
+{
+    client->perform_session_check("Netconf session is not connected");
+}
+
 vector<string> NetconfSession::get_capabilities() const
 {
     return server_capabilities;

sdk/cpp/core/src/netconf_ssh_client.cpp

@@ -21,10 +21,10 @@
 //
 //////////////////////////////////////////////////////////////////
 
-
 #include <iostream>
 #include <sstream>
 #include <stdio.h>
+#include <signal.h>
 
 #include <libnetconf.h>
 #include <libnetconf_ssh.h>
@@ -100,6 +100,10 @@ NetconfSSHClient::NetconfSSHClient(
 
 int NetconfSSHClient::connect()
 {
+    // We expect write failures to occur, but we want to handle them where
+    // the error occurs rather than in a SIGPIPE handler.
+    signal(SIGPIPE, SIG_IGN);
+
     session = nc_session_connect(hostname.c_str(), port, username.c_str(), NULL);
     perform_session_check("Could not connect to " + hostname);
     init_capabilities();
@@ -129,19 +133,21 @@ void NetconfSSHClient::init_capabilities()
 
 string NetconfSSHClient::execute_payload(const string & payload)
 {
-    perform_session_check("Could not execute payload. Not connected to " + hostname);
+    perform_session_check("Cannot not execute payload. Not connected to " + hostname);
 
     nc_reply *reply;
     nc_rpc *rpc = build_rpc_request(payload);
 
-    YLOG_DEBUG("Netconf SSH Client: sending rpc");
+    YLOG_DEBUG("Netconf SSH Client: sending RPC");
     const nc_msgid msgid = nc_session_send_rpc(session, rpc);
     if (msgid == NULL) {
-        YLOG_ERROR("Could not send payload {}", payload );
-        throw(YClientError{"Could not send payload"});
+        YLOG_ERROR("Failed to send RPC\n{}", payload );
+        throw(YClientError{"Failed to send RPC"});
     }
 
-    YLOG_DEBUG("Netconf SSH Client: receiving rpc");
+    perform_session_check("Cannot not receive RPC reply. Not connected to " + hostname);
+
+    YLOG_DEBUG("Netconf SSH Client: receiving reply RPC");
     NC_MSG_TYPE msg_type = nc_session_recv_reply(session, timeout, &reply);
     YLOG_DEBUG("Netconf SSH Client: processing reply");
     string receive_msg = process_rpc_reply(msg_type, reply);
@@ -163,8 +169,8 @@ nc_rpc* NetconfSSHClient::build_rpc_request(const string & payload)
 
     if (rpc == NULL)
     {
-        YLOG_ERROR("Could not build rpc payload: {}", payload );
-        throw(YClientError{"Could not build payload"});
+        YLOG_ERROR("Could not build RPC payload:\n{}", payload );
+        throw(YClientError{"Could not build RPC payload"});
     }
     return rpc;
 }
@@ -192,7 +198,7 @@ string NetconfSSHClient::process_rpc_reply(int msg_type, const nc_rpc* reply)
             throw(YClientError{"Connection timed out"});
         case NC_MSG_UNKNOWN:
             YLOG_ERROR("RPC error occurred");
-            throw(YClientError{"RPC error occured"});
+            throw(YClientError{"RPC error occurred"});
     }
     return {};
 }
@@ -245,7 +251,7 @@ char* NetconfSSHClient::clb_set_interactive(const char *name, const char *instru
     char* password_buffer = (char*) malloc(sizeof(char) * (password_string.size() + 1));
     snprintf(password_buffer, password_string.size() + 1, "%s", password_string.c_str());
 
-    YLOG_DEBUG("looked up password for interactive: {}", password_buffer);
+    YLOG_DEBUG("Looked up password for interactive: {}", password_buffer);
     return password_buffer;
 }
 
@@ -255,7 +261,7 @@ char* NetconfSSHClient::clb_set_passphrase(const char *user_name, const char *ho
     char* password_buffer = (char*) malloc(sizeof(char) * (password_string.size() + 1));
     snprintf(password_buffer, password_string.size() + 1, "%s", password_string.c_str());
 
-    YLOG_DEBUG("looked up password for passphrase: {}", password_buffer);
+    YLOG_DEBUG("Looked up password for passphrase: {}", password_buffer);
     return password_buffer;
 }
 
@@ -267,12 +273,28 @@ int NetconfSSHClient::clb_ssh_host_authenticity_check(const char *hostname,
 
 void NetconfSSHClient::perform_session_check(const string & message)
 {
-    if (session == NULL)
+    int session_status = nc_session_get_status(session);
+    YLOG_DEBUG("NetconfSSHClient: NC session status: {}", session_status);
+    if (session_status != NC_SESSION_STATUS_WORKING && session_status != NC_SESSION_STATUS_CLOSING)
     {
-        YLOG_ERROR(message.c_str());
-        throw(YClientError{message});
+        string msg = message + ": Session status: ";
+        if (session_status == NC_SESSION_STATUS_ERROR)
+            msg += "Undefined";
+        else if (session_status == NC_SESSION_STATUS_STARTUP)
+            msg += "Setting up";
+        else if (session_status == NC_SESSION_STATUS_CLOSED)
+            msg += "Closed";
+        else if (session_status == NC_SESSION_STATUS_DUMMY)
+            msg += "Dummy";
+        YLOG_ERROR(msg.c_str());
+        throw(YClientError{msg});
+    }
+    if (!nc_session_is_ssh_connected(session))
+    {
+        string msg = message + ": SSH session is not connected";
+        YLOG_ERROR(msg.c_str());
+        throw(YClientError{msg});
     }
 }
 
-
 }

sdk/cpp/core/src/netconf_ssh_client.hpp

@@ -41,11 +41,9 @@ namespace ydk
 
 class NetconfSSHClient : public NetconfClient
 {
-
-public:
+  public:
     static std::map<std::pair<std::string, std::string>, std::string> password_lookup;
 
-public:
     NetconfSSHClient(
         std::string  username, 
         std::string  password,
@@ -69,7 +67,9 @@ class NetconfSSHClient : public NetconfClient
     virtual std::vector<std::string> get_capabilities();
     virtual std::string get_hostname_port();
 
-private:
+    void perform_session_check(const std::string & message);
+
+  private:
 
     static void clb_print(NC_VERB_LEVEL level, const char* msg);
     static void clb_error_print(const char* tag, const char* type,
@@ -79,15 +79,12 @@ class NetconfSSHClient : public NetconfClient
     static char* clb_set_password(const char* username, const char* hostname);
     static char* clb_set_interactive(const char *name, const char *instruction, const char *prompt, int echo);
     static char* clb_set_passphrase(const char *username, const char *hostname, const char *priv_key_file);
-    static int clb_ssh_host_authenticity_check(const char *hostname,
-            ssh_session session);
+    static int clb_ssh_host_authenticity_check(const char *hostname, ssh_session session);
 
     nc_rpc* build_rpc_request(const std::string & payload);
     std::string process_rpc_reply(int reply_type, const nc_reply* reply);
     void init_capabilities();
-    void perform_session_check(const std::string & message);
 
-private:
     struct nc_session *session;
 
     std::string username;

sdk/cpp/core/src/netconf_tcp_client.cpp

@@ -326,6 +326,21 @@ void NetconfTCPClient::check_timeout(CURLcode res, int for_recv, const char* fmt
     }
 }
 
+void NetconfTCPClient::perform_session_check(const std::string & message)
+{
+    // get socket descriptor
+    // CURLINFO_LASTSOCKET is deprecated after curl >= 7.45.0 (470272)
+    CURLcode res;
+    #if LIBCURL_VERSION_NUM >= 470272
+    res = curl_easy_getinfo(curl, CURLINFO_ACTIVESOCKET, &sockfd);
+    #else
+    res = curl_easy_getinfo(curl, CURLINFO_LASTSOCKET, &sockfd);
+    #endif
+
+    std::string msg = message + ": Unable to retrieve sockfd: {}";
+    check_ok(res, msg.c_str());
+}
+
 // from libcurl examples
 /* Auxiliary function that waits on the socket. */
 static int wait_on_socket(curl_socket_t sockfd, int for_recv, long timeout_ms)

sdk/cpp/core/src/netconf_tcp_client.hpp

@@ -41,6 +41,8 @@ class NetconfTCPClient : public NetconfClient
     virtual std::vector<std::string> get_capabilities();
     virtual std::string get_hostname_port();
 
+    void perform_session_check(const std::string & message);
+
 private:
     void initialize(const std::string& address, int port);
     void initialize_curl(const std::string& address, int port);

sdk/cpp/core/src/path_api.hpp

@@ -1086,11 +1086,11 @@ class NetconfSession : public Session {
 
     // This function is for YDK internal tests only
     std::shared_ptr<path::DataNode> handle_action_rpc_output(const std::string & rpc_reply, path::DataNode& action_dn);
+    void check_session_state();		// throws YClientError exception when state is other than connected
 
   private:
     std::vector<std::string> get_yang_1_1_capabilities() const;
-    std::shared_ptr<DataNode> handle_crud_edit(
-        Rpc& rpc, Annotation ann) const;
+    std::shared_ptr<DataNode> handle_crud_edit(Rpc& rpc, Annotation ann) const;
     std::shared_ptr<DataNode> handle_crud_read(Rpc& rpc) const;
     std::shared_ptr<DataNode> handle_netconf_operation(Rpc& ydk_rpc) const;
     void initialize_client_with_key(const std::string& address,

sdk/cpp/core/tests/core_test.cpp

@@ -69,7 +69,10 @@ class TestClient: public ydk::NetconfClient
     ~TestClient()
     {
     }
-
+    void perform_session_check(const std::string & message)
+    {
+        return;
+    }
     int connect()
     {
         return 0;

sdk/python/CHANGES.md

@@ -4,6 +4,7 @@
   * YDK netconf read fails when <data> tag has namespace prefix ([#799](https://github.com/CiscoDevNet/ydk-gen/issues/799))
   * YDK return value of YANG action missing some attributes ([#871](https://github.com/CiscoDevNet/ydk-gen/issues/871))
   * Duplicate code in generated cisco-ios-xe Go bundle ([#891](https://github.com/CiscoDevNet/ydk-gen/issues/891))
+  * YDK-Py docker container does not support Python3 ([#905](https://github.com/CiscoDevNet/ydk-gen/issues/905))
   * Installation documentation for YDK-Py needs an update ([#906](https://github.com/CiscoDevNet/ydk-gen/issues/906))
   * README file for YDK-Py repo is not rendering correctly ([#907](https://github.com/CiscoDevNet/ydk-gen/issues/907))