subprojects/ncsid/src/ncsi_state_machine.cpp - openbmc/google-misc - Gitiles

 // Copyright 2021 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //      http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 #include "ncsi_state_machine.h"

 #include "common_defs.h"
 #include "platforms/nemora/portable/default_addresses.h"
 #include "platforms/nemora/portable/ncsi_fsm.h"

 #include <arpa/inet.h>
 #include <fmt/printf.h>
 #include <netinet/ether.h>
 #include <unistd.h>

 #include <chrono>
 #include <cstdint>
 #include <cstdlib>
 #include <cstring>
 #include <string>
 #include <thread>
 #include <utility>

 #define ETHER_NCSI 0x88f8

 // Only log messages a single time and drop all duplicates to prevent log spam.
 // Having duplicate messages printed has historically not been helpful in
 // debugging issues with this program.
 static void do_log(std::string&& line)
 {
     constexpr auto line_dup_time = std::chrono::hours(1);
     static std::chrono::steady_clock::time_point last_line_time;
     static size_t line_rep_count = 0;
     static std::string last_line;

     auto now = std::chrono::steady_clock::now();
     if (line != last_line || line_dup_time + last_line_time < now)
     {
         if (line_rep_count > 0)
         {
             fmt::print(stderr, "... Repeated {} times ...\n", line_rep_count);
         }
         fmt::print(stderr, "{}", line);
         last_line = std::move(line);
         last_line_time = now;
         line_rep_count = 0;
     }
     else
     {
         line_rep_count++;
     }
 }

 #define CPRINTF(...) do_log(fmt::sprintf(__VA_ARGS__))

 #ifdef NCSID_VERBOSE_LOGGING
 #define DEBUG_PRINTF printf
 #else
 #define DEBUG_PRINTF(...)
 #endif

 namespace ncsi
 {

 namespace
 {

 const char kStateFormat[] = "l2_config=%d/%d l3l4_config=%d/%d test=%d/%d";
 // This assumes that the number of states is < 100, so each number
 // in the format above does not take more than two characters to represent,
 // thus %d (two characters) is substituted for the number which is also
 // two characters max.
 constexpr auto kStateFormatLen = sizeof(kStateFormat);

 void snprintf_state(char* buffer, int size, const ncsi_state_t* state)
 {
     (void)snprintf(buffer, size, kStateFormat, state->l2_config_state,
                    NCSI_STATE_L2_CONFIG_END, state->l3l4_config_state,
                    NCSI_STATE_L3L4_CONFIG_END, state->test_state,
                    NCSI_STATE_TEST_END);
 }

 void print_state(const ncsi_state_t& state)
 {
     (void)state;
     DEBUG_PRINTF(kStateFormat, state.l2_config_state, NCSI_STATE_L2_CONFIG_END,
                  state.l3l4_config_state, NCSI_STATE_L3L4_CONFIG_END,
                  state.test_state, NCSI_STATE_TEST_END);
     DEBUG_PRINTF(" restart_delay_count=%d\n", state.restart_delay_count);
 }

 const uint8_t echo_pattern[NCSI_OEM_ECHO_PATTERN_SIZE] = {
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,
     0xFF, 0xFF, 0xFF, 0xFF, 0x5A, 0x5A, 0x5A, 0x5A, 0x5A, 0x5A, 0x5A, 0x5A,
     0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0x12, 0x34, 0x56, 0x78,
     0x9A, 0xBC, 0xDE, 0xF0, 0xFE, 0xDC, 0xBA, 0x98, 0x76, 0x54, 0x32, 0x10};

 } // namespace

 void StateMachine::reset()
 {
     std::memset(&ncsi_state_, 0, sizeof(ncsi_state_));
     ncsi_state_.restart_delay_count = NCSI_FSM_RESTART_DELAY_COUNT - 1;
     network_debug_.ncsi.test.max_tries = MAX_TRIES;
     // This needs to be initialized in the firmware.
     network_debug_.ncsi.test.ch_under_test = 0;
     network_debug_.ncsi.oem_filter_disable = false;

     network_debug_.ncsi.pending_stop = false;
     network_debug_.ncsi.enabled = true;
     network_debug_.ncsi.loopback = false;
 }

 StateMachine::StateMachine()
 {
     reset();
     network_debug_.ncsi.pending_restart = true;
     std::memcpy(network_debug_.ncsi.test.ping.tx, echo_pattern,
                 sizeof(echo_pattern));
 }

 StateMachine::~StateMachine()
 {
     CPRINTF("[NCSI stopping]\n");
 }

 size_t StateMachine::poll_l2_config()
 {
     size_t len = 0;
     mac_addr_t mac;
     net_config_->get_mac_addr(&mac);
     ncsi_response_type_t response_type = ncsi_fsm_poll_l2_config(
         &ncsi_state_, &network_debug_, &ncsi_buf_, &mac);

     auto* response = reinterpret_cast<ncsi_simple_response_t*>(ncsi_buf_.data);

     if (response_type == NCSI_RESPONSE_ACK)
     {
         /* If the response is MAC response, some extra handling needed. */
         if ((NCSI_RESPONSE | NCSI_OEM_COMMAND) ==
             response->hdr.control_packet_type)
         {
             auto* oem_response =
                 reinterpret_cast<ncsi_oem_simple_response_t*>(ncsi_buf_.data);
             if (oem_response->oem_header.oem_cmd ==
                 NCSI_OEM_COMMAND_GET_HOST_MAC)
             {
                 net_config_->set_mac_addr(mac);
             }
         }
     }
     else if (NCSI_RESPONSE_NONE == response_type)
     {
         /* Buffer is ready to be sent. */
         len = ncsi_buf_.len;
         ncsi_buf_.len = 0;
     }
     else
     {
         report_ncsi_error(response_type);
     }

     return len;
 }

 size_t StateMachine::poll_simple(ncsi_simple_poll_f poll_func)
 {
     mac_addr_t mac;
     net_config_->get_mac_addr(&mac);
     const uint16_t rx_port = DEFAULT_ADDRESSES_RX_PORT;

     ncsi_response_type_t response_type =
         poll_func(&ncsi_state_, &network_debug_, &ncsi_buf_, &mac, 0, rx_port);

     auto* response = reinterpret_cast<ncsi_simple_response_t*>(ncsi_buf_.data);

     size_t len = 0;
     if (response_type == NCSI_RESPONSE_NONE)
     {
         /* Buffer is ready to be sent, or we are done. */
         len = ncsi_buf_.len;
         ncsi_buf_.len = 0;
     }
     else if (response->hdr.control_packet_type ==
              (NCSI_RESPONSE | NCSI_GET_LINK_STATUS))
     {
         auto status_response =
             reinterpret_cast<ncsi_link_status_response_t*>(response);
         bool new_link_up = ntohl(status_response->link_status.link_status) &
                            NCSI_LINK_STATUS_UP;
         if (!link_up_ || new_link_up != *link_up_)
         {
             CPRINTF("[NCSI link %s]\n", new_link_up ? "up" : "down");
             link_up_ = new_link_up;
         }
     }
     else if (response->hdr.control_packet_type ==
              (NCSI_RESPONSE | NCSI_OEM_COMMAND))
     {
         auto* oem_response =
             reinterpret_cast<ncsi_oem_simple_response_t*>(ncsi_buf_.data);
         if (oem_response->oem_header.oem_cmd == NCSI_OEM_COMMAND_GET_FILTER)
         {
             bool new_hostless = ncsi_fsm_is_nic_hostless(&ncsi_state_);
             if (!hostless_ || new_hostless != *hostless_)
             {
                 CPRINTF("[NCSI nic %s]\n",
                         new_hostless ? "hostless" : "hostfull");
                 net_config_->set_nic_hostless(new_hostless);
                 hostless_ = new_hostless;
             }
         }
     }
     else if (response_type != NCSI_RESPONSE_ACK)
     {
         report_ncsi_error(response_type);
     }

     return len;
 }

 void StateMachine::report_ncsi_error(ncsi_response_type_t response_type)
 {
     char state_string[kStateFormatLen];
     snprintf_state(state_string, sizeof(state_string), &ncsi_state_);
     auto* response =
         reinterpret_cast<const ncsi_simple_response_t*>(ncsi_buf_.data);
     switch (response_type)
     {
         case NCSI_RESPONSE_UNDERSIZED:
             if (!ncsi_buf_.len)
             {
                 network_debug_.ncsi.rx_error.timeout_count++;
                 CPRINTF("[NCSI timeout in state %s]\n", state_string);
             }
             else
             {
                 network_debug_.ncsi.rx_error.undersized_count++;
                 CPRINTF("[NCSI undersized response in state %s]\n",
                         state_string);
             }
             break;
         case NCSI_RESPONSE_NACK:
             network_debug_.ncsi.rx_error.nack_count++;
             CPRINTF(
                 "[NCSI nack in state %s. Response: 0x%04x Reason: 0x%04x]\n",
                 state_string, ntohs(response->response_code),
                 ntohs(response->reason_code));
             break;
         case NCSI_RESPONSE_UNEXPECTED_TYPE:
             network_debug_.ncsi.rx_error.unexpected_type_count++;
             CPRINTF("[NCSI unexpected response in state %s. Response type: "
                     "0x%02x]\n",
                     state_string, response->hdr.control_packet_type);
             break;
         case NCSI_RESPONSE_UNEXPECTED_SIZE:
         {
             int expected_size;
             if ((NCSI_RESPONSE | NCSI_OEM_COMMAND) ==
                 response->hdr.control_packet_type)
             {
                 auto* oem_response =
                     reinterpret_cast<ncsi_oem_simple_response_t*>(
                         ncsi_buf_.data);
                 expected_size = ncsi_oem_get_response_size(
                     oem_response->oem_header.oem_cmd);
             }
             else
             {
                 expected_size = ncsi_get_response_size(
                     response->hdr.control_packet_type & (~NCSI_RESPONSE));
             }
             network_debug_.ncsi.rx_error.unexpected_size_count++;
             CPRINTF("[NCSI unexpected response size in state %s."
                     " Expected %d]\n",
                     state_string, expected_size);
         }
         break;
         case NCSI_RESPONSE_OEM_FORMAT_ERROR:
             network_debug_.ncsi.rx_error.unexpected_type_count++;
             CPRINTF("[NCSI OEM format error]\n");
             break;
         case NCSI_RESPONSE_UNEXPECTED_PARAMS:
             CPRINTF("[NCSI OEM Filter MAC or TCP/IP Config Mismatch]\n");
             break;
         default:
             /* NCSI_RESPONSE_ACK and NCSI_RESPONSE_NONE are not errors and need
              * not be handled here, so this branch is just to complete the
              * switch.
              */
             CPRINTF("[NCSI OK]\n");
             break;
     }
 }

 int StateMachine::receive_ncsi()
 {
     int len;
     do
     {
         // Return value of zero means timeout
         len = sock_io_->recv(ncsi_buf_.data, sizeof(ncsi_buf_.data));
         if (len > 0)
         {
             auto* hdr = reinterpret_cast<struct ether_header*>(ncsi_buf_.data);
             if (ETHER_NCSI == ntohs(hdr->ether_type))
             {
                 ncsi_buf_.len = len;
                 break;
             }
         }

         ncsi_buf_.len = 0;
     } while (len > 0);

     return ncsi_buf_.len;
 }

 void StateMachine::run_test_fsm(size_t* tx_len)
 {
     // Sleep and restart when test FSM finishes.
     if (is_test_done())
     {
         std::this_thread::sleep_for(std::chrono::seconds(retest_delay_s_));
         // Skip over busy wait in state machine - already waited.
         ncsi_state_.retest_delay_count = NCSI_FSM_RESTART_DELAY_COUNT;
     }
     // until NCSI_STATE_TEST_END
     *tx_len = poll_simple(ncsi_fsm_poll_test);
 }

 void StateMachine::run(int max_rounds)
 {
     if (!net_config_ || !sock_io_)
     {
         CPRINTF("StateMachine configuration incomplete: "
                 "net_config_: <%p>, sock_io_: <%p>",
                 reinterpret_cast<void*>(net_config_),
                 reinterpret_cast<void*>(sock_io_));
         return;
     }

     bool infinite_loop = (max_rounds <= 0);
     while (infinite_loop || --max_rounds >= 0)
     {
         receive_ncsi();

         size_t tx_len = 0;
         switch (ncsi_fsm_connection_state(&ncsi_state_, &network_debug_))
         {
             case NCSI_CONNECTION_DOWN:
             case NCSI_CONNECTION_LOOPBACK:
                 tx_len = poll_l2_config();
                 break;
             case NCSI_CONNECTION_UP:
                 if (!is_test_done() || ncsi_fsm_is_nic_hostless(&ncsi_state_))
                 {
                     run_test_fsm(&tx_len);
                 }
                 else
                 {
                     // - Only start L3/L4 config when test is finished
                     // (it will last until success
                     // (i.e. NCSI_CONNECTION_UP_AND_CONFIGURED) or fail.
                     tx_len = poll_simple(ncsi_fsm_poll_l3l4_config);
                 }
                 break;
             case NCSI_CONNECTION_UP_AND_CONFIGURED:
                 run_test_fsm(&tx_len);
                 break;
             case NCSI_CONNECTION_DISABLED:
                 if (network_debug_.ncsi.pending_restart)
                 {
                     network_debug_.ncsi.enabled = true;
                 }
                 break;
             default:
                 fail();
         }

         if (tx_len)
         {
             print_state(ncsi_state_);

             sock_io_->write(ncsi_buf_.data, tx_len);
         }
     }
 }

 void StateMachine::clear_state()
 {
     // This implicitly resets:
     //   l2_config_state   to NCSI_STATE_L2_CONFIG_BEGIN
     //   l3l4_config_state to NCSI_STATE_L3L4_CONFIG_BEGIN
     //   test_state        to NCSI_STATE_TEST_BEGIN
     std::memset(&ncsi_state_, 0, sizeof(ncsi_state_));
 }

 void StateMachine::fail()
 {
     network_debug_.ncsi.fail_count++;
     clear_state();
 }

 void StateMachine::set_sockio(net::SockIO* sock_io)
 {
     sock_io_ = sock_io;
 }

 void StateMachine::set_net_config(net::ConfigBase* net_config)
 {
     net_config_ = net_config;
 }

 void StateMachine::set_retest_delay(unsigned delay)
 {
     retest_delay_s_ = delay;
 }

 } // namespace ncsi
	// Copyright 2021 Google LLC
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	#include "ncsi_state_machine.h"

	#include "common_defs.h"
	#include "platforms/nemora/portable/default_addresses.h"
	#include "platforms/nemora/portable/ncsi_fsm.h"

	#include <arpa/inet.h>
	#include <fmt/printf.h>
	#include <netinet/ether.h>
	#include <unistd.h>

	#include <chrono>
	#include <cstdint>
	#include <cstdlib>
	#include <cstring>
	#include <string>
	#include <thread>
	#include <utility>

	#define ETHER_NCSI 0x88f8

	// Only log messages a single time and drop all duplicates to prevent log spam.
	// Having duplicate messages printed has historically not been helpful in
	// debugging issues with this program.
	static void do_log(std::string&& line)
	{
	constexpr auto line_dup_time = std::chrono::hours(1);
	static std::chrono::steady_clock::time_point last_line_time;
	static size_t line_rep_count = 0;
	static std::string last_line;

	auto now = std::chrono::steady_clock::now();
	if (line != last_line \|\| line_dup_time + last_line_time < now)
	{
	if (line_rep_count > 0)
	{
	fmt::print(stderr, "... Repeated {} times ...\n", line_rep_count);
	}
	fmt::print(stderr, "{}", line);
	last_line = std::move(line);
	last_line_time = now;
	line_rep_count = 0;
	}
	else
	{
	line_rep_count++;
	}
	}

	#define CPRINTF(...) do_log(fmt::sprintf(__VA_ARGS__))

	#ifdef NCSID_VERBOSE_LOGGING
	#define DEBUG_PRINTF printf
	#else
	#define DEBUG_PRINTF(...)
	#endif

	namespace ncsi
	{

	namespace
	{

	const char kStateFormat[] = "l2_config=%d/%d l3l4_config=%d/%d test=%d/%d";
	// This assumes that the number of states is < 100, so each number
	// in the format above does not take more than two characters to represent,
	// thus %d (two characters) is substituted for the number which is also
	// two characters max.
	constexpr auto kStateFormatLen = sizeof(kStateFormat);

	void snprintf_state(char* buffer, int size, const ncsi_state_t* state)
	{
	(void)snprintf(buffer, size, kStateFormat, state->l2_config_state,
	NCSI_STATE_L2_CONFIG_END, state->l3l4_config_state,
	NCSI_STATE_L3L4_CONFIG_END, state->test_state,
	NCSI_STATE_TEST_END);
	}

	void print_state(const ncsi_state_t& state)
	{
	(void)state;
	DEBUG_PRINTF(kStateFormat, state.l2_config_state, NCSI_STATE_L2_CONFIG_END,
	state.l3l4_config_state, NCSI_STATE_L3L4_CONFIG_END,
	state.test_state, NCSI_STATE_TEST_END);
	DEBUG_PRINTF(" restart_delay_count=%d\n", state.restart_delay_count);
	}

	const uint8_t echo_pattern[NCSI_OEM_ECHO_PATTERN_SIZE] = {
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,
	0xFF, 0xFF, 0xFF, 0xFF, 0x5A, 0x5A, 0x5A, 0x5A, 0x5A, 0x5A, 0x5A, 0x5A,
	0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0x12, 0x34, 0x56, 0x78,
	0x9A, 0xBC, 0xDE, 0xF0, 0xFE, 0xDC, 0xBA, 0x98, 0x76, 0x54, 0x32, 0x10};

	} // namespace

	void StateMachine::reset()
	{
	std::memset(&ncsi_state_, 0, sizeof(ncsi_state_));
	ncsi_state_.restart_delay_count = NCSI_FSM_RESTART_DELAY_COUNT - 1;
	network_debug_.ncsi.test.max_tries = MAX_TRIES;
	// This needs to be initialized in the firmware.
	network_debug_.ncsi.test.ch_under_test = 0;
	network_debug_.ncsi.oem_filter_disable = false;

	network_debug_.ncsi.pending_stop = false;
	network_debug_.ncsi.enabled = true;
	network_debug_.ncsi.loopback = false;
	}

	StateMachine::StateMachine()
	{
	reset();
	network_debug_.ncsi.pending_restart = true;
	std::memcpy(network_debug_.ncsi.test.ping.tx, echo_pattern,
	sizeof(echo_pattern));
	}

	StateMachine::~StateMachine()
	{
	CPRINTF("[NCSI stopping]\n");
	}

	size_t StateMachine::poll_l2_config()
	{
	size_t len = 0;
	mac_addr_t mac;
	net_config_->get_mac_addr(&mac);
	ncsi_response_type_t response_type = ncsi_fsm_poll_l2_config(
	&ncsi_state_, &network_debug_, &ncsi_buf_, &mac);

	auto* response = reinterpret_cast<ncsi_simple_response_t*>(ncsi_buf_.data);

	if (response_type == NCSI_RESPONSE_ACK)
	{
	/* If the response is MAC response, some extra handling needed. */
	if ((NCSI_RESPONSE \| NCSI_OEM_COMMAND) ==
	response->hdr.control_packet_type)
	{
	auto* oem_response =
	reinterpret_cast<ncsi_oem_simple_response_t*>(ncsi_buf_.data);
	if (oem_response->oem_header.oem_cmd ==
	NCSI_OEM_COMMAND_GET_HOST_MAC)
	{
	net_config_->set_mac_addr(mac);
	}
	}
	}
	else if (NCSI_RESPONSE_NONE == response_type)
	{
	/* Buffer is ready to be sent. */
	len = ncsi_buf_.len;
	ncsi_buf_.len = 0;
	}
	else
	{
	report_ncsi_error(response_type);
	}

	return len;
	}

	size_t StateMachine::poll_simple(ncsi_simple_poll_f poll_func)
	{
	mac_addr_t mac;
	net_config_->get_mac_addr(&mac);
	const uint16_t rx_port = DEFAULT_ADDRESSES_RX_PORT;

	ncsi_response_type_t response_type =
	poll_func(&ncsi_state_, &network_debug_, &ncsi_buf_, &mac, 0, rx_port);

	auto* response = reinterpret_cast<ncsi_simple_response_t*>(ncsi_buf_.data);

	size_t len = 0;
	if (response_type == NCSI_RESPONSE_NONE)
	{
	/* Buffer is ready to be sent, or we are done. */
	len = ncsi_buf_.len;
	ncsi_buf_.len = 0;
	}
	else if (response->hdr.control_packet_type ==
	(NCSI_RESPONSE \| NCSI_GET_LINK_STATUS))
	{
	auto status_response =
	reinterpret_cast<ncsi_link_status_response_t*>(response);
	bool new_link_up = ntohl(status_response->link_status.link_status) &
	NCSI_LINK_STATUS_UP;
	if (!link_up_ \|\| new_link_up != *link_up_)
	{
	CPRINTF("[NCSI link %s]\n", new_link_up ? "up" : "down");
	link_up_ = new_link_up;
	}
	}
	else if (response->hdr.control_packet_type ==
	(NCSI_RESPONSE \| NCSI_OEM_COMMAND))
	{
	auto* oem_response =
	reinterpret_cast<ncsi_oem_simple_response_t*>(ncsi_buf_.data);
	if (oem_response->oem_header.oem_cmd == NCSI_OEM_COMMAND_GET_FILTER)
	{
	bool new_hostless = ncsi_fsm_is_nic_hostless(&ncsi_state_);
	if (!hostless_ \|\| new_hostless != *hostless_)
	{
	CPRINTF("[NCSI nic %s]\n",
	new_hostless ? "hostless" : "hostfull");
	net_config_->set_nic_hostless(new_hostless);
	hostless_ = new_hostless;
	}
	}
	}
	else if (response_type != NCSI_RESPONSE_ACK)
	{
	report_ncsi_error(response_type);
	}

	return len;
	}

	void StateMachine::report_ncsi_error(ncsi_response_type_t response_type)
	{
	char state_string[kStateFormatLen];
	snprintf_state(state_string, sizeof(state_string), &ncsi_state_);
	auto* response =
	reinterpret_cast<const ncsi_simple_response_t*>(ncsi_buf_.data);
	switch (response_type)
	{
	case NCSI_RESPONSE_UNDERSIZED:
	if (!ncsi_buf_.len)
	{
	network_debug_.ncsi.rx_error.timeout_count++;
	CPRINTF("[NCSI timeout in state %s]\n", state_string);
	}
	else
	{
	network_debug_.ncsi.rx_error.undersized_count++;
	CPRINTF("[NCSI undersized response in state %s]\n",
	state_string);
	}
	break;
	case NCSI_RESPONSE_NACK:
	network_debug_.ncsi.rx_error.nack_count++;
	CPRINTF(
	"[NCSI nack in state %s. Response: 0x%04x Reason: 0x%04x]\n",
	state_string, ntohs(response->response_code),
	ntohs(response->reason_code));
	break;
	case NCSI_RESPONSE_UNEXPECTED_TYPE:
	network_debug_.ncsi.rx_error.unexpected_type_count++;
	CPRINTF("[NCSI unexpected response in state %s. Response type: "
	"0x%02x]\n",
	state_string, response->hdr.control_packet_type);
	break;
	case NCSI_RESPONSE_UNEXPECTED_SIZE:
	{
	int expected_size;
	if ((NCSI_RESPONSE \| NCSI_OEM_COMMAND) ==
	response->hdr.control_packet_type)
	{
	auto* oem_response =
	reinterpret_cast<ncsi_oem_simple_response_t*>(
	ncsi_buf_.data);
	expected_size = ncsi_oem_get_response_size(
	oem_response->oem_header.oem_cmd);
	}
	else
	{
	expected_size = ncsi_get_response_size(
	response->hdr.control_packet_type & (~NCSI_RESPONSE));
	}
	network_debug_.ncsi.rx_error.unexpected_size_count++;
	CPRINTF("[NCSI unexpected response size in state %s."
	" Expected %d]\n",
	state_string, expected_size);
	}
	break;
	case NCSI_RESPONSE_OEM_FORMAT_ERROR:
	network_debug_.ncsi.rx_error.unexpected_type_count++;
	CPRINTF("[NCSI OEM format error]\n");
	break;
	case NCSI_RESPONSE_UNEXPECTED_PARAMS:
	CPRINTF("[NCSI OEM Filter MAC or TCP/IP Config Mismatch]\n");
	break;
	default:
	/* NCSI_RESPONSE_ACK and NCSI_RESPONSE_NONE are not errors and need
	* not be handled here, so this branch is just to complete the
	* switch.
	*/
	CPRINTF("[NCSI OK]\n");
	break;
	}
	}

	int StateMachine::receive_ncsi()
	{
	int len;
	do
	{
	// Return value of zero means timeout
	len = sock_io_->recv(ncsi_buf_.data, sizeof(ncsi_buf_.data));
	if (len > 0)
	{
	auto* hdr = reinterpret_cast<struct ether_header*>(ncsi_buf_.data);
	if (ETHER_NCSI == ntohs(hdr->ether_type))
	{
	ncsi_buf_.len = len;
	break;
	}
	}

	ncsi_buf_.len = 0;
	} while (len > 0);

	return ncsi_buf_.len;
	}

	void StateMachine::run_test_fsm(size_t* tx_len)
	{
	// Sleep and restart when test FSM finishes.
	if (is_test_done())
	{
	std::this_thread::sleep_for(std::chrono::seconds(retest_delay_s_));
	// Skip over busy wait in state machine - already waited.
	ncsi_state_.retest_delay_count = NCSI_FSM_RESTART_DELAY_COUNT;
	}
	// until NCSI_STATE_TEST_END
	*tx_len = poll_simple(ncsi_fsm_poll_test);
	}

	void StateMachine::run(int max_rounds)
	{
	if (!net_config_ \|\| !sock_io_)
	{
	CPRINTF("StateMachine configuration incomplete: "
	"net_config_: <%p>, sock_io_: <%p>",
	reinterpret_cast<void*>(net_config_),
	reinterpret_cast<void*>(sock_io_));
	return;
	}

	bool infinite_loop = (max_rounds <= 0);
	while (infinite_loop \|\| --max_rounds >= 0)
	{
	receive_ncsi();

	size_t tx_len = 0;
	switch (ncsi_fsm_connection_state(&ncsi_state_, &network_debug_))
	{
	case NCSI_CONNECTION_DOWN:
	case NCSI_CONNECTION_LOOPBACK:
	tx_len = poll_l2_config();
	break;
	case NCSI_CONNECTION_UP:
	if (!is_test_done() \|\| ncsi_fsm_is_nic_hostless(&ncsi_state_))
	{
	run_test_fsm(&tx_len);
	}
	else
	{
	// - Only start L3/L4 config when test is finished
	// (it will last until success
	// (i.e. NCSI_CONNECTION_UP_AND_CONFIGURED) or fail.
	tx_len = poll_simple(ncsi_fsm_poll_l3l4_config);
	}
	break;
	case NCSI_CONNECTION_UP_AND_CONFIGURED:
	run_test_fsm(&tx_len);
	break;
	case NCSI_CONNECTION_DISABLED:
	if (network_debug_.ncsi.pending_restart)
	{
	network_debug_.ncsi.enabled = true;
	}
	break;
	default:
	fail();
	}

	if (tx_len)
	{
	print_state(ncsi_state_);

	sock_io_->write(ncsi_buf_.data, tx_len);
	}
	}
	}

	void StateMachine::clear_state()
	{
	// This implicitly resets:
	// l2_config_state to NCSI_STATE_L2_CONFIG_BEGIN
	// l3l4_config_state to NCSI_STATE_L3L4_CONFIG_BEGIN
	// test_state to NCSI_STATE_TEST_BEGIN
	std::memset(&ncsi_state_, 0, sizeof(ncsi_state_));
	}

	void StateMachine::fail()
	{
	network_debug_.ncsi.fail_count++;
	clear_state();
	}

	void StateMachine::set_sockio(net::SockIO* sock_io)
	{
	sock_io_ = sock_io;
	}

	void StateMachine::set_net_config(net::ConfigBase* net_config)
	{
	net_config_ = net_config;
	}

	void StateMachine::set_retest_delay(unsigned delay)
	{
	retest_delay_s_ = delay;
	}

	} // namespace ncsi