OpenBMC Redfish 接口深度分析

1. 概述

OpenBMC（Open Board Management Controller）是一个开源的 BMC（Baseboard Management Controller）固件项目，旨在为服务器硬件管理提供标准化接口。Redfish 是 DMTF（Distributed Management Task Force）制定的 RESTful 硬件管理接口标准，OpenBMC 通过实现 Redfish 接口提供了现代化的硬件管理能力。

1.1 Redfish 标准背景

Redfish 标准于 2015 年首次发布，旨在解决传统 IPMI（Intelligent Platform Management Interface）协议的局限性：

特性	IPMI	Redfish
架构	静态模型	可扩展的面向对象模型
传输	仅 UDP	HTTPS/JSON
安全性	弱	TLS + 会话认证
可扩展性	有限	完全可扩展
现代化程度	1990年代设计	2015年后设计

1.2 OpenBMC Redfish 组件架构

OpenBMC 的 Redfish 实现由多个核心组件构成：

redfish-core/          # Redfish REST API 核心框架
├── lib/
│   ├── routes/        # REST API 路由定义
│   ├── handlers/      # 请求处理器
│   └── middleware/    # 中间件（认证、日志）
├── service_root.cpp    # /redfish/v1 服务根
├── systems.cpp         # /redfish/v1/Systems
├── chassis.cpp         # /redfish/v1/Chassis
└── managers.cpp        # /redfish/v1/Managers

redfish-interfaces/    # Redfish 接口定义（Schema）
redfish-tools/         # Schema 生成和验证工具

2. redfish-core 核心框架分析

2.1 框架结构

redfish-core 是 OpenBMC Redfish 实现的核心库，提供了 HTTP 服务器、路由管理、请求处理和响应序列化的基础设施。

核心目录结构：

redfish-core/
├── include/
│   └── redfish-core/
│       ├── lib/
│       │   ├── http_status.hpp       # HTTP 状态码定义
│       │   ├── encode_json.hpp       # JSON 编码辅助
│       │   ├── errors.hpp            # 错误处理
│       │   └──utility.hpp            # 工具函数
│       └── service/
│           ├── root.hpp              # 服务根
│           ├── systems.hpp           # 系统资源
│           └── chassis.hpp           # 机箱资源
├── lib/
│   ├── service_root.cpp
│   ├── systems.cpp
│   ├── chassis.cpp
│   └── managers.cpp
└── main.cpp                          # 入口

2.2 HTTP 服务架构

redfish-core 使用 Boost.Beast 作为 HTTP 服务器底层，结合 Crow 作为高级框架：

cpp

// 典型的 Redfish HTTP 服务器初始化
#include <boost/beast.hpp>
#include <crow.h>

int main() {
    crow::SimpleApp app;

    // Redfish 中间件链
    app.template register_middleware<SessionAuthMiddleware>();
    app.template register_middleware<CORSMiddleware>();

    // 注册 Redfish 路由
    setupRedfishRoutes(app);

    app.bindaddr("0.0.0.0").port(443).ssl()
       .multithreaded().run();
}

2.3 路由系统

Redfish API 采用分层路由结构：

cpp

// /redfish/v1 路由组
CROW_ROUTE(app, "/redfish/v1")
    .methods(crow::HTTPMethod::GET)
    (getServiceRoot);

// /redfish/v1/Systems 路由组
CROW_ROUTE(app, "/redfish/v1/Systems")
    .methods(crow::HTTPMethod::GET)
    (getSystemsCollection);

// /redfish/v1/Systems/<id> 单个系统
CROW_ROUTE(app, "/redfish/v1/Systems/<str>")
    .methods(crow::HTTPMethod::GET)
    (getSystemById);

2.4 处理器模式

每个 Redfish 资源都有对应的处理器类：

cpp

class SystemsHandler : public CrowHandler {
public:
    crow::response getSystemsCollection() {
        crow::json::wvalue result;
        result["@odata.type"] = "#ComputerSystemCollection.ComputerSystemCollection";
        result["@odata.id"] = "/redfish/v1/Systems";
        result["Name"] = "Computer System Collection";
        result["Members"] = getSystemMembers();
        result["Members@odata.count"] = getSystemCount();
        return crow::response(result);
    }

    crow::response getSystemById(const std::string& id) {
        // 返回单个系统详细信息
    }
};

3. REST API 路径结构

3.1 服务根（Service Root）

路径: /redfish/v1/

服务根是 Redfish API 的入口点，返回 API 的元信息：

json

{
    "@odata.type": "#ServiceRoot.v1_14_0.ServiceRoot",
    "@odata.id": "/redfish/v1",
    "Id": "RootService",
    "Name": "Root Service",
    "RedfishVersion": "1.15.0",
    "UUID": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
    "Chassis": {
        "@odata.id": "/redfish/v1/Chassis"
    },
    "Managers": {
        "@odata.id": "/redfish/v1/Managers"
    },
    "Systems": {
        "@odata.id": "/redfish/v1/Systems"
    },
    "AccountService": {
        "@odata.id": "/redfish/v1/AccountService"
    },
    "SessionService": {
        "@odata.id": "/redfish/v1/SessionService"
    },
    "Registries": {
        "@odata.id": "/redfish/v1/Registries"
    },
    "JSONSchemas": {
        "@odata.id": "/redfish/v1/JSONSchemas"
    }
}

3.2 系统集合（Systems Collection）

路径: /redfish/v1/Systems/

返回所有托管系统的集合：

json

{
    "@odata.type": "#ComputerSystemCollection.ComputerSystemCollection",
    "@odata.id": "/redfish/v1/Systems",
    "Name": "Computer System Collection",
    "Members": [
        {
            "@odata.id": "/redfish/v1/Systems/system1"
        }
    ],
    "Members@odata.count": 1,
    "Description": "Collection of Computer Systems"
}

3.3 单个系统（Single System）

路径: /redfish/v1/Systems/{ComputerSystemId}

返回特定计算机系统的详细信息：

json

{
    "@odata.type": "#ComputerSystem.v1_18_0.ComputerSystem",
    "@odata.id": "/redfish/v1/Systems/system1",
    "Id": "system1",
    "Name": "OpenBMC Server",
    "SystemType": "Physical",
    "Summary": {
        "Status": {
            "Health": "OK",
            "State": "Enabled"
        }
    },
    "ProcessorSummary": {
        "Count": 4,
        "Model": "ARM Cortex-A72",
        "Status": {"Health": "OK"}
    },
    "MemorySummary": {
        "TotalSystemMemoryGiB": 8,
        "Status": {"Health": "OK"}
    },
    "BiosVersion": "v2.0.0",
    "PowerState": "On",
    "PhysicalSecurity": {
        "IntrusionSensorNumber": 1,
        "IntrusionSensor": "Normal",
        "IntrusionSensorSupported": true
    },
    "Status": {
        "Health": "OK",
        "State": "Enabled"
    },
    "IndicatorLED": "Off",
    "Model": "OpenBMC BMC",
    "Manufacturer": "OpenBMC Project",
    "SerialNumber": "abc123456789",
    "PartNumber": "OpenBMC-001",
    "AssetTag": "OPENBMC-ASSET",
    "SKU": "",
    "HostName": "bmc-host",
    "Boot": {
        "BootSourceOverrideEnabled": "Disabled",
        "BootSourceOverrideTarget": "None",
        "BootSourceOverrideMode": "UEFI"
    },
    "Processors": {
        "@odata.id": "/redfish/v1/Systems/system1/Processors"
    },
    "Memory": {
        "@odata.id": "/redfish/v1/Systems/system1/Memory"
    },
    "Storage": {
        "@odata.id": "/redfish/v1/Systems/system1/Storage"
    },
    "EthernetInterfaces": {
        "@odata.id": "/redfish/v1/Systems/system1/EthernetInterfaces"
    },
    "LogServices": {
        "@odata.id": "/redfish/v1/Systems/system1/LogServices"
    },
    "NetworkInterfaces": {
        "@odata.id": "/redfish/v1/Systems/system1/NetworkInterfaces"
    },
    "Bios": {
        "@odata.id": "/redfish/v1/Systems/system1/Bios"
    },
    "Actions": {
        "#ComputerSystem.Reset": {
            "target": "/redfish/v1/Systems/system1/Actions/ComputerSystem.Reset"
        }
    }
}

3.4 机箱集合（Chassis Collection）

路径: /redfish/v1/Chassis/

返回所有机箱（包含 BMC 所在的主板）：

json

{
    "@odata.type": "#ChassisCollection.ChassisCollection",
    "@odata.id": "/redfish/v1/Chassis",
    "Name": "Chassis Collection",
    "Members": [
        {
            "@odata.id": "/redfish/v1/Chassis/chassis1"
        },
        {
            "@odata.id": "/redfish/v1/Chassis/mb_root"
        }
    ],
    "Members@odata.count": 2
}

3.5 单个机箱（Single Chassis）

路径: /redfish/v1/Chassis/{ChassisId}

json

{
    "@odata.type": "#Chassis.v1_20_0.Chassis",
    "@odata.id": "/redfish/v1/Chassis/chassis1",
    "Id": "chassis1",
    "Name": "Main Chassis",
    "ChassisType": "RackMount",
    "AssetTag": "CHASSIS-001",
    "Manufacturer": "OpenBMC",
    "Model": "OpenBMC Chassis",
    "SKU": "",
    "SerialNumber": "SN123456789",
    "PartNumber": "PN987654321",
    "PowerState": "On",
    "Status": {
        "Health": "OK",
        "State": "Enabled"
    },
    "ThermalState": "OK",
    "PowerState": "On",
    "IndicatorLED": "Off",
    "EnvironmentalClass": "A1",
    "Sensors": {
        "@odata.id": "/redfish/v1/Chassis/chassis1/Sensors"
    },
    "Thermal": {
        "@odata.id": "/redfish/v1/Chassis/chassis1/Thermal"
    },
    "Power": {
        "@odata.id": "/redfish/v1/Chassis/chassis1/Power"
    },
    "PowerSubsystem": {
        "@odata.id": "/redfish/v1/Chassis/chassis1/PowerSubsystem"
    },
    "ThermalSubsystem": {
        "@odata.id": "/redfish/v1/Chassis/chassis1/ThermalSubsystem"
    },
    "NetworkAdapters": {
        "@odata.id": "/redfish/v1/Chassis/chassis1/NetworkAdapters"
    },
    "Drives": {
        "@odata.id": "/redfish/v1/Chassis/chassis1/Drives"
    },
    "Storage": {
        "@odata.id": "/redfish/v1/Chassis/chassis1/Storage"
    },
    "LogServices": {
        "@odata.id": "/redfish/v1/Chassis/chassis1/LogServices"
    },
    "PCIeSlots": {
        "@odata.id": "/redfish/v1/Chassis/chassis1/PCIeSlots"
    },
    "Controls": {
        "@odata.id": "/redfish/v1/Chassis/chassis1/Controls"
    },
    "EnvironmentMetrics": {
        "@odata.id": "/redfish/v1/Chassis/chassis1/EnvironmentMetrics"
    },
    "Triggers": {
        "@odata.id": "/redfish/v1/Chassis/chassis1/Triggers"
    },
    "Links": {
        "ComputerSystems": [
            {
                "@odata.id": "/redfish/v1/Systems/system1"
            }
        ],
        "ManagedBy": [
            {
                "@odata.id": "/redfish/v1/Managers/bmc"
            }
        ]
    }
}

3.6 管理器集合（Managers Collection）

路径: /redfish/v1/Managers/

json

{
    "@odata.type": "#ManagerCollection.ManagerCollection",
    "@odata.id": "/redfish/v1/Managers",
    "Name": "Manager Collection",
    "Members": [
        {
            "@odata.id": "/redfish/v1/Managers/bmc"
        }
    ],
    "Members@odata.count": 1
}

3.7 单个管理器（Single Manager - BMC）

路径: /redfish/v1/Managers/{ManagerId}

json

{
    "@odata.type": "#Manager.v1_16_0.Manager",
    "@odata.id": "/redfish/v1/Managers/bmc",
    "Id": "bmc",
    "Name": "OpenBMC Manager",
    "ManagerType": "BMC",
    "Description": "Baseboard Management Controller",
    "Model": "OpenBMC",
    "Manufacturer": "OpenBMC Project",
    "FWVersion": "v2.15.0-dev",
    "UUID": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
    "PartNumber": "",
    "SerialNumber": "",
    "Status": {
        "Health": "OK",
        "State": "Enabled"
    },
    "PowerState": "On",
    "CommandShell": {
        "ServiceEnabled": true,
        "ConnectTypesSupported": ["SSH", "IPMI"],
        "ConnectTypesEnabled": ["SSH"]
    },
    "GraphicalConsole": {
        "ServiceEnabled": true,
        "ConnectTypesSupported": ["KVMIP", "VirtualMedia"],
        "ConnectTypesEnabled": ["KVMIP", "VirtualMedia"]
    },
    "EthernetInterfaces": {
        "@odata.id": "/redfish/v1/Managers/bmc/EthernetInterfaces"
    },
    "NetworkProtocol": {
        "@odata.id": "/redfish/v1/Managers/bmc/NetworkProtocol"
    },
    "LogServices": {
        "@odata.id": "/redfish/v1/Managers/bmc/LogServices"
    },
    "VirtualMedia": {
        "@odata.id": "/redfish/v1/Managers/bmc/VirtualMedia"
    },
    "Sessions": {
        "@odata.id": "/redfish/v1/Managers/bmc/Sessions"
    },
    "NTP": {
        "@odata.id": "/redfish/v1/Managers/bmc/NTP"
    },
    "Actions": {
        "#Manager.Reset": {
            "target": "/redfish/v1/Managers/bmc/Actions/Manager.Reset"
        }
    }
}

4. Redfish JSON Schema

4.1 Schema 版本控制

Redfish 使用语义化版本控制（SemVer），格式为 Major_Minor_Patch：

json

{
    "@odata.type": "#ComputerSystem.v1_18_0.ComputerSystem"
}

4.2 Schema 注册表

路径: /redfish/v1/JSONSchemas/

json

{
    "@odata.type": "#JsonSchemaFileCollection.JsonSchemaFileCollection",
    "@odata.id": "/redfish/v1/JSONSchemas",
    "Name": "JSON Schema Files",
    "Members": [
        {
            "@odata.id": "/redfish/v1/JSONSchemas/ComputerSystem"
        },
        {
            "@odata.id": "/redfish/v1/JSONSchemas/Chassis"
        }
    ]
}

4.3 资源导航属性

Redfish 使用 @odata.id 实现资源间导航：

json

{
    "Systems": {
        "@odata.id": "/redfish/v1/Systems"
    },
    "LogServices": {
        "@odata.id": "/redfish/v1/Systems/system1/LogServices"
    }
}

4.4 odata.type 模式

所有 Redfish 资源都包含 @odata.type 标识资源类型：

{ResourceType}.v{VersionMajor}_{VersionMinor}_{VersionPatch}.{ResourceType}

示例：

#ComputerSystem.v1_18_0.ComputerSystem
#Chassis.v1_20_0.Chassis
#Manager.v1_16_0.Manager
#Session.v1_4_0.Session

4.5 Schema 验证

OpenBMC 在运行时进行 JSON Schema 验证：

cpp

#include <nlohmann/json.hpp>
#include <ajson/ajson.hpp>

void validateRedfishResource(const nlohmann::json& json,
                             const std::string& schemaType) {
    // 检查必需的 odata 字段
    if (!json.contains("@odata.type")) {
        throw RedfishValidationError("Missing @odata.type");
    }
    if (!json.contains("@odata.id")) {
        throw RedfishValidationError("Missing @odata.id");
    }
    if (!json.contains("Id")) {
        throw RedfishValidationError("Missing Id");
    }

    // 验证类型匹配
    std::string expected = "#" + schemaType;
    if (json["@odata.type"] != expected) {
        throw RedfishValidationError("Type mismatch");
    }
}

5. Session 认证机制

5.1 认证流程概述

Redfish 支持两种认证方式：

会话令牌认证（Session Token） - 推荐方式
基本认证（Basic Auth） - 仅用于创建会话

5.2 会话创建

路径: POST /redfish/v1/SessionService/Sessions

请求：

json

{
    "UserName": "root",
    "Password": "0penBMC"
}

成功响应（201 Created）：

json

{
    "@odata.type": "#Session.v1_4_0.Session",
    "@odata.id": "/redfish/v1/SessionService/Sessions/session123",
    "Id": "session123",
    "Name": "User Session",
    "Description": "User Session",
    "UserName": "root",
    "Created": "2026-04-27T00:00:00Z",
    "Expires": "2026-04-27T01:00:00Z"
}

响应头包含会话令牌：

X-Auth-Token: sess_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Set-Cookie:SESSIONID=session123; Path=/

5.3 会话令牌认证

后续请求使用 X-Auth-Token 头或 Cookie 认证：

bash

# 使用 X-Auth-Token
curl -H "X-Auth-Token: sess_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" \
     https://bmc-host/redfish/v1/Systems

# 使用 Cookie
curl -H "Cookie: SESSIONID=session123" \
     https://bmc-host/redfish/v1/Systems

5.4 会话中间件实现

cpp

class SessionAuthMiddleware {
public:
    crow::response handle(crow::request& req) {
        // 检查是否跳过认证的路径
        if (isPublicPath(req.url)) {
            return crow::response(200);
        }

        // 获取认证令牌
        std::string token = getAuthToken(req);

        if (token.empty()) {
            return crow::response(401, "Unauthorized");
        }

        // 验证会话
        auto session = sessionManager.validateToken(token);
        if (!session) {
            return crow::response(401, "Invalid session");
        }

        // 检查会话过期
        if (session->isExpired()) {
            sessionManager.remove(token);
            return crow::response(401, "Session expired");
        }

        // 将会话信息附加到请求
        req.ctx["session"] = session;
        return crow::response(200);
    }
};

5.5 会话服务

路径: /redfish/v1/SessionService/

json

{
    "@odata.type": "#SessionService.v1_2_0.SessionService",
    "@odata.id": "/redfish/v1/SessionService",
    "Id": "SessionService",
    "Name": "Session Service",
    "Status": {
        "Health": "OK",
        "State": "Enabled"
    },
    "ServiceEnabled": true,
    "SessionTimeout": 3600,
    "Sessions": {
        "@odata.id": "/redfish/v1/SessionService/Sessions"
    }
}

5.6 会话删除

路径: DELETE /redfish/v1/SessionService/Sessions/{SessionId}

bash

curl -X DELETE \
     -H "X-Auth-Token: sess_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" \
     https://bmc-host/redfish/v1/SessionService/Sessions/session123

5.7 账户服务

路径: /redfish/v1/AccountService/

json

{
    "@odata.type": "#AccountService.v1_12_0.AccountService",
    "@odata.id": "/redfish/v1/AccountService",
    "Id": "AccountService",
    "Name": "Account Service",
    "Status": {
        "Health": "OK",
        "State": "Enabled"
    },
    "ServiceEnabled": true,
    "AuthFailureLoggingThreshold": 3,
    "AccountLockoutThreshold": 5,
    "AccountLockoutDuration": 30,
    "MaxPasswordLength": 20,
    "MinPasswordLength": 8,
    "PasswordExpirationDays": 0,
    "PasswordHistoryCount": 0,
    "Accounts": {
        "@odata.id": "/redfish/v1/AccountService/Accounts"
    },
    "Roles": {
        "@odata.id": "/redfish/v1/AccountService/Roles"
    }
}

6. Intel OEM 扩展（redfish-intel）

6.1 OEM 扩展机制

Redfish 允许厂商通过 OEM 扩展添加厂商特定功能。Intel OEM 扩展路径格式：

/redfish/v1/UpdateService/FirmwareInventory/Intel/...
/redfish/v1/Managers/bmc/Intel/...

6.2 Intel BMC OEM 扩展

Intel 在 OpenBMC 中添加了以下 OEM 路径：

路径: /redfish/v1/Managers/bmc/Intel/

json

{
    "@odata.type": "#Intel.Oem.Manager",
    "@odata.id": "/redfish/v1/Managers/bmc/Intel",
    "IntelV按名称": "Intel BMC Oem",
    "BiosApiVersion": "1.0.0",
    "BackupRestore": {
        "@odata.id": "/redfish/v1/Managers/bmc/Intel/BackupRestore"
    },
    "BiosAttributes": {
        "@odata.id": "/redfish/v1/Managers/bmc/Intel/BiosAttributes"
    },
    "BiosTechLog": {
        "@odata.id": "/redfish/v1/Managers/bmc/Intel/BiosTechLog"
    },
    "Certs": {
        "@odata.id": "/redfish/v1/Managers/bmc/Intel/Certs"
    },
    "HiiApi": {
        "@odata.id": "/redfish/v1/Managers/bmc/Intel/HiiApi"
    },
    "OemNetworks": {
        "@odata.id": "/redfish/v1/Managers/bmc/Intel/OemNetworks"
    },
    "PcieErrorInj": {
        "@odata.id": "/redfish/v1/Managers/bmc/Intel/PcieErrorInj"
    },
    "SecureBoot": {
        "@odata.id": "/redfish/v1/Managers/bmc/Intel/SecureBoot"
    },
    "SelLogs": {
        "@odata.id": "/redfish/v1/Managers/bmc/Intel/SelLogs"
    },
    "SmBios": {
        "@odata.id": "/redfish/v1/Managers/bmc/Intel/SmBios"
    },
    "SpdData": {
        "@odata.id": "/redfish/v1/Managers/bmc/Intel/SpdData"
    },
    "TpmInventory": {
        "@odata.id": "/redfish/v1/Managers/bmc/Intel/TpmInventory"
    },
    "UpdateService": {
        "@odata.id": "/redfish/v1/UpdateService"
    }
}

6.3 Intel BIOS 属性扩展

路径: /redfish/v1/Managers/bmc/Intel/BiosTechLog

提供对 BIOS 技术日志的访问：

json

{
    "@odata.type": "#Intel.Oem.BiosTechLog",
    "@odata.id": "/redfish/v1/Managers/bmc/Intel/BiosTechLog",
    "Id": "BiosTechLog",
    "Name": "BIOS Technical Log",
    "Description": "Intel BIOS Technical Support Log",
    "LogEntryType": "TechSupportLog",
    "MaxLogSize": 65536,
    "Entries": [
        {
            "EntryType": "BIOS Technical Support Log",
            "Entry": "0x01: Early Boot Failure..."
        }
    ]
}

6.4 Intel 备份恢复功能

路径: /redfish/v1/Managers/bmc/Intel/BackupRestore

json

{
    "@odata.type": "#Intel.Oem.BackupRestore",
    "@odata.id": "/redfish/v1/Managers/bmc/Intel/BackupRestore",
    "Id": "BackupRestore",
    "Name": "Backup Restore Service",
    "Description": "BMC Configuration Backup and Restore",
    "Actions": {
        "#BackupRestore.Backup": {
            "target": "/redfish/v1/Managers/bmc/Intel/BackupRestore/Actions/Backup"
        },
        "#BackupRestore.Restore": {
            "target": "/redfish/v1/Managers/bmc/Intel/BackupRestore/Actions/Restore"
        }
    }
}

7. redfish-disabled 禁用特性管理

7.1 禁用特性机制

OpenBMC 通过 redfish-disabled 组件管理可选的 Redfish 功能启用/禁用状态。

7.2 禁用特性配置文件

特性开关配置位置：

/etc/phosphor-confd/featuremask.json
/var/overload/featuremask.d/

7.3 典型禁用特性

json

{
    "features": {
        "redfish_eventing": {
            "enabled": false,
            "reason": "Not supported on this platform"
        },
        "virtual_media": {
            "enabled": true,
            "reason": ""
        },
        "account_service": {
            "enabled": true,
            "reason": ""
        },
        "session_service": {
            "enabled": true,
            "reason": ""
        },
        "update_service": {
            "enabled": true,
            "reason": ""
        },
        "TelemetryService": {
            "enabled": false,
            "reason": "Resource constraint"
        },
        "EventService": {
            "enabled": true,
            "reason": ""
        },
        "TaskService": {
            "enabled": true,
            "reason": ""
        }
    }
}

7.4 禁用特性路由处理

cpp

class FeatureDisabledMiddleware {
public:
    crow::response handle(crow::request& req) {
        std::string path = req.url;

        // 检查路径对应的特性
        if (isFeatureDisabled(path)) {
            return crow::response(503, R"({
                "error": {
                    "code": "Base.1.0.Disabled",
                    "message": "This feature is disabled"
                }
            })");
        }
        return crow::response(200);
    }
};

8. 数据模型关联

8.1 资源层级结构

ServiceRoot (/redfish/v1)
├── Systems (/redfish/v1/Systems)
│   └── {system_id} - ComputerSystem
│       ├── Processors
│       ├── Memory
│       ├── Storage
│       ├── EthernetInterfaces
│       ├── LogServices
│       └── Bios
├── Chassis (/redfish/v1/Chassis)
│   └── {chassis_id} - Chassis
│       ├── Thermal
│       ├── Power
│       ├── Sensors
│       ├── NetworkAdapters
│       ├── Drives
│       └── LogServices
├── Managers (/redfish/v1/Managers)
│   └── {manager_id} - Manager
│       ├── EthernetInterfaces
│       ├── NetworkProtocol
│       ├── VirtualMedia
│       ├── LogServices
│       └── Sessions
├── AccountService (/redfish/v1/AccountService)
│   ├── Accounts
│   └── Roles
├── SessionService (/redfish/v1/SessionService)
│   └── Sessions
├── UpdateService (/redfish/v1/UpdateService)
│   ├── FirmwareInventory
│   └── SoftwareInventory
├── TaskService (/redfish/v1/TaskService)
│   └── Tasks
├── EventService (/redfish/v1/EventService)
│   └── Subscriptions
├── Registries (/redfish/v1/Registries)
└── JSONSchemas (/redfish/v1/JSONSchemas)

8.2 资源间关联（Links）

Redfish 资源通过 Links 属性建立关联：

json

{
    "Links": {
        "ComputerSystems": [
            {"@odata.id": "/redfish/v1/Systems/system1"}
        ],
        "ManagedBy": [
            {"@odata.id": "/redfish/v1/Managers/bmc"}
        ],
        "ContainedBy": {
            "@odata.id": "/redfish/v1/Chassis/chassis1"
        }
    }
}

9. 错误处理机制

9.1 错误响应格式

Redfish 定义了标准错误格式：

json

{
    "error": {
        "code": "Base.1.0.GeneralError",
        "message": "A general error occurred",
        "@Message.ExtendedInfo": [
            {
                "@odata.type": "#Message.v1_1_0.Message",
                "MessageId": "Base.1.0.ResourceMissing",
                "Message": "The requested resource /redfish/v1/Systems/invalid was not found.",
                "Severity": "Critical",
                "Resolution": "Provide a valid resource identifier."
            }
        ]
    }
}

9.2 HTTP 状态码映射

HTTP 状态码	Redfish 含义	使用场景
200	OK	成功获取资源
201	Created	成功创建资源（如会话）
204	No Content	成功删除/更新
400	Bad Request	无效请求参数
401	Unauthorized	未认证
403	Forbidden	已认证但无权限
404	Not Found	资源不存在
405	Method Not Allowed	不支持该 HTTP 方法
409	Conflict	资源状态冲突
500	Internal Server Error	服务器内部错误
503	Service Unavailable	服务不可用（功能禁用）

10. 知识点关联表格

知识点	分类	说明	关联文件/路径
redfish-core	核心框架	REST API 框架，提供路由、处理器、中间件	lib/routes/, lib/handlers/
redfish-interfaces	Schema 定义	Redfish 资源类型和属性定义	include/redfish-core/lib/
redfish-tools	工具集	Schema 生成、验证工具	tools/gen_schema.py
/redfish/v1/	REST 路径	Redfish API 服务根入口	service_root.cpp
/redfish/v1/Systems	REST 路径	计算机系统集合	systems.cpp
/redfish/v1/Chassis	REST 路径	机箱/主板集合	chassis.cpp
/redfish/v1/Managers	REST 路径	BMC 管理器集合	managers.cpp
@odata.type	数据模型	资源类型标识符	Schema 定义
@odata.id	数据模型	资源导航链接	跨资源引用
Session Token	认证机制	会话令牌认证方式	SessionService
X-Auth-Token	认证机制	HTTP 认证头	中间件实现
Cookie/SESSIONID	认证机制	基于 Cookie 的会话	会话管理
redfish-intel	OEM 扩展	Intel 厂商特定扩展	Intel/Oem/ 路径
redfish-disabled	功能管理	特性启用/禁用管理	featuremask.json
JSON Schema	序列化	Redfish 资源 JSON 格式验证	validate_redfish.cpp
304.0 错误码	错误处理	资源不存在错误	error_messages.hpp
503 Service Unavailable	错误处理	功能被禁用错误	middleware
Bootstrap	启动流程	REST API 服务器初始化	main.cpp
Middleware Chain	中间件	认证、CORS、日志中间件链	middleware/*.cpp
CORS	Web 安全	跨域请求支持	CORSMiddleware
NTP	时间同步	BMC NTP 配置	Managers/{id}/NTP
VirtualMedia	远程媒体	虚拟 CD/USB 挂载	Managers/{id}/VirtualMedia
UpdateService	固件更新	固件升级服务	UpdateService/
TaskService	异步任务	长时间运行任务的跟踪	TaskService/Tasks/
EventService	事件订阅	异步事件通知机制	EventService/Subscriptions/

11. 总结

OpenBMC Redfish 接口实现是一个完整的 RESTful 管理系统，遵循 DMTF Redfish 标准规范。核心组件包括：

redfish-core：提供 HTTP 服务器、路由系统、请求处理器和中间件基础设施
redfish-interfaces：定义所有 Redfish 资源的类型和属性（Schema）
redfish-tools：提供 Schema 生成、验证和工具支持
redfish-disabled：管理可选功能的启用/禁用状态

REST API 采用分层结构，从 /redfish/v1/ 服务根开始，通过 @odata.id 导航属性连接各个资源集合和单个资源。认证采用会话令牌机制，通过 X-Auth-Token 头或 Cookie 进行身份验证。

Intel OEM 扩展在标准 Redfish 路径基础上添加了 Intel 特定的 BIOS 管理、备份恢复、证书管理等功能。错误处理遵循 Redfish 标准格式，提供一致的错误信息结构。

参考资料

DMTF Redfish Specification: https://www.dmtf.org/dsp/DSP0266
OpenBMC Project: https://github.com/openbmc
Redfish Schema: https://redfish.dmtf.org/schemas
OpenBMC Redfish Documentation: https://github.com/openbmc/docs/tree/master/Redfish

OpenBMC Redfish 接口深度分析 ​

1. 概述 ​

1.1 Redfish 标准背景 ​

1.2 OpenBMC Redfish 组件架构 ​

2. redfish-core 核心框架分析 ​

2.1 框架结构 ​

2.2 HTTP 服务架构 ​

2.3 路由系统 ​

2.4 处理器模式 ​

3. REST API 路径结构 ​

3.1 服务根（Service Root） ​

3.2 系统集合（Systems Collection） ​

3.3 单个系统（Single System） ​

3.4 机箱集合（Chassis Collection） ​

3.5 单个机箱（Single Chassis） ​

3.6 管理器集合（Managers Collection） ​

3.7 单个管理器（Single Manager - BMC） ​

4. Redfish JSON Schema ​

4.1 Schema 版本控制 ​

4.2 Schema 注册表 ​

4.3 资源导航属性 ​

4.4 odata.type 模式 ​

4.5 Schema 验证 ​

5. Session 认证机制 ​

5.1 认证流程概述 ​

5.2 会话创建 ​

5.3 会话令牌认证 ​

5.4 会话中间件实现 ​

5.5 会话服务 ​

5.6 会话删除 ​

5.7 账户服务 ​

6. Intel OEM 扩展（redfish-intel） ​

6.1 OEM 扩展机制 ​

6.2 Intel BMC OEM 扩展 ​

6.3 Intel BIOS 属性扩展 ​

6.4 Intel 备份恢复功能 ​

7. redfish-disabled 禁用特性管理 ​

7.1 禁用特性机制 ​

7.2 禁用特性配置文件 ​

7.3 典型禁用特性 ​

7.4 禁用特性路由处理 ​

8. 数据模型关联 ​

8.1 资源层级结构 ​

8.2 资源间关联（Links） ​

9. 错误处理机制 ​

9.1 错误响应格式 ​

9.2 HTTP 状态码映射 ​

10. 知识点关联表格 ​

11. 总结 ​

参考资料 ​

OpenBMC Redfish 接口深度分析

1. 概述

1.1 Redfish 标准背景

1.2 OpenBMC Redfish 组件架构

2. redfish-core 核心框架分析

2.1 框架结构

2.2 HTTP 服务架构

2.3 路由系统

2.4 处理器模式

3. REST API 路径结构

3.1 服务根（Service Root）

3.2 系统集合（Systems Collection）

3.3 单个系统（Single System）

3.4 机箱集合（Chassis Collection）

3.5 单个机箱（Single Chassis）

3.6 管理器集合（Managers Collection）

3.7 单个管理器（Single Manager - BMC）

4. Redfish JSON Schema

4.1 Schema 版本控制

4.2 Schema 注册表

4.3 资源导航属性

4.4 odata.type 模式

4.5 Schema 验证

5. Session 认证机制

5.1 认证流程概述

5.2 会话创建

5.3 会话令牌认证

5.4 会话中间件实现

5.5 会话服务

5.6 会话删除

5.7 账户服务

6. Intel OEM 扩展（redfish-intel）

6.1 OEM 扩展机制

6.2 Intel BMC OEM 扩展

6.3 Intel BIOS 属性扩展

6.4 Intel 备份恢复功能

7. redfish-disabled 禁用特性管理

7.1 禁用特性机制

7.2 禁用特性配置文件

7.3 典型禁用特性

7.4 禁用特性路由处理

8. 数据模型关联

8.1 资源层级结构

8.2 资源间关联（Links）

9. 错误处理机制

9.1 错误响应格式

9.2 HTTP 状态码映射

10. 知识点关联表格

11. 总结

参考资料