xref: /openbmc/google-misc/dhcp-done/subprojects/ncsid/src/ncsi_state_machine.h (revision dab96f131fb3a46d93f1093feccc9095d8589ece)
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*