1 /*
2  * Copyright 2021 Google LLC
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 #include "ncsi_sockio.h"
19 #include "net_config.h"
20 #include "net_iface.h"
21 #include "platforms/nemora/portable/ncsi_client.h"
22 #include "platforms/nemora/portable/ncsi_fsm.h"
23 #include "platforms/nemora/portable/net_types.h"
24 
25 #include <optional>
26 
27 namespace ncsi
28 {
29 
30 typedef ncsi_response_type_t (*ncsi_simple_poll_f)(ncsi_state_t*,
31                                                    network_debug_t*,
32                                                    ncsi_buf_t*, mac_addr_t*,
33                                                    uint32_t, uint16_t);
34 
35 // This class encapsulates three state machines:
36 //  * L2 -- performs basic NC-SI setup, reads NIC MAC addr
37 //  * L3/4 -- once network is configured on the interface,
38 //      sets up NC-SI filter in the NIC.
39 //  * Test -- runs several basic NC-SI link tests, like
40 //      ECHO Request/Reply, checks filter setup etc.
41 //      Also, reads hostless/host-based flag from the NIC, see
42 //      ncsi_fsm.c:is_nic_hostless() for details.
43 class StateMachine
44 {
45   public:
46     StateMachine();
47 
48     void set_sockio(net::SockIO* sock_io);
49 
50     void set_net_config(net::ConfigBase* net_config);
51 
52     // NC-SI State Machine's main function.
53     // max_rounds = 0 means run forever.
54     void run(int max_rounds = 0);
55 
56     // How often Test FSM re-runs, in seconds.
57     void set_retest_delay(unsigned int delay);
58 
59   private:
60     // Reset the state machine
61     void reset();
62 
63     // Poll L2 state machine. Each call advances it by one step.
64     // Its implementation is taken directly from EC.
65     size_t poll_l2_config();
66 
67     // This function is used to poll both L3/4 and Test state machine,
68     // depending on the function passed in as an argument.
69     size_t poll_simple(ncsi_simple_poll_f poll_func);
70 
71     // Helper function for printing NC-SI error to stdout.
72     void report_ncsi_error(ncsi_response_type_t response_type);
73 
74     int receive_ncsi();
75 
76     // Helper function for advancing the test FSM.
77     void run_test_fsm(size_t* tx_len);
78 
79     // Clear the state and reset all state machines.
80     void clear_state();
81 
82     // In current implementation this is the same as clear state,
83     // except that it also increments the failure counter.
84     void fail();
85 
86     // Return true if the test state machine finished successfully.
87     bool is_test_done() const
88     {
89         return ncsi_state_.test_state == NCSI_STATE_TEST_END;
90     }
91 
92     // Max number of times a state machine is going to retry a command.
93     static constexpr auto MAX_TRIES = 5;
94 
95     // How long (in seconds) to wait before re-running NC-SI test state
96     // machine.
97     unsigned int retest_delay_s_ = 1;
98 
99     // The last known state of the link on the NIC
100     std::optional<bool> link_up_;
101 
102     // The last known hostless mode of the NIC
103     std::optional<bool> hostless_;
104 
105     // net_config_ is used to query and set network configuration.
106     // The StateMachine does not own the pointer and it is the
107     // responsibility of the client to make sure that it outlives the
108     // StateMachine.
109     net::ConfigBase* net_config_ = nullptr;
110 
111     // sock_io_ is used to read and write NC-SI packets.
112     // The StateMachine does not own the pointer. It is the responsibility
113     // of the client to make sure that sock_io_ outlives the StateMachine.
114     net::SockIO* sock_io_ = nullptr;
115 
116     // Both ncsi_state_ and network_debug_ parameters represent the state of
117     // the NC-SI state machine. The names and definitions are taken directly
118     // from EC.
119     ncsi_state_t ncsi_state_;
120     network_debug_t network_debug_;
121 
122     // Depending on the state ncsi_buf_ represents either the NC-SI packet
123     // received from the NIC or NC-SI packet that was (or about to be)
124     // sent to the NIC.
125     ncsi_buf_t ncsi_buf_;
126 };
127 
128 } // namespace ncsi
129