v2ray 全局管理一个 server 实例，所有功能都会被注册到该实例上。其为 core.Instance 类型：
// Instance combines all functionalities in V2Ray.
type Instance struct {
access sync.Mutex
features []features.Feature
featureResolutions []resolution
running bool
}
这里的 featureResolution 在正常运行的情况下，启动之后一定是空的，如果非空，说明在 feature 注册阶段发生了错误。
features 为 Feature 数组，Feature 也是 interface：
// Feature is the interface for V2Ray features. All features must implement this interface.
// All existing features have an implementation in app directory. These features can be replaced by third-party ones.
type Feature interface {
// Start starts the runnable object. Upon the method returning nil, the object begins to function properly.
Start() error
Close() error
// Type returns the type of the object.
// Usually it returns (*Type)(nil) of the object.
Type() interface{}
}
main 函数流程：
func main() {
// 根据启动时传入的文件位置加载并解析配置
// 并根据配置生成全局 server 实例
server, err := startV2Ray()
// 调用 server.features 中所有 Feature 的 Start 方法
server.Start()
defer server.Close()
// Explicitly triggering GC to remove garbage from config loading.
runtime.GC()
{
osSignals := make(chan os.Signal, 1)
signal.Notify(osSignals, os.Interrupt, os.Kill, syscall.SIGTERM)
<-osSignals
}
}
可见主要分三步：
- 根据用户配置生成相应的数据结构
- 依次启动 server 上的各种 feature
- 监听信号，等待退出
读取配置文件的过程没什么可说的，server 实例的生成过程如下：
// 根据用户配置，创建一个 Instance 对象
// 这里返回的 instance 还没有启动
// 配置中至少需要包含一个 dispatcher，一个 inboundhandler manager 和一个 outbound handler manager。其它 feature 都是可选的。
func New(config *Config) (*Instance, error) {
var server = &Instance{}
for _, appSettings := range config.App {
settings, err := appSettings.GetInstance()
obj, err := CreateObject(server, settings)
if feature, ok := obj.(features.Feature); ok {
server.AddFeature(feature)
}
}
essentialFeatures := []struct {
Type interface{}
Instance features.Feature
}{
{dns.ClientType(), localdns.New()},
{policy.ManagerType(), policy.DefaultManager{}},
{routing.RouterType(), routing.DefaultRouter{}},
{stats.ManagerType(), stats.NoopManager{}},
}
// 用户没有提供的话，需要保证 essentialFeatuers 里面这四个模块有对应的默认实现
for _, f := range essentialFeatures {
if server.GetFeature(f.Type) == nil {
server.AddFeature(f.Instance)
}
}
// 注册 inbound handlers
if err := addInboundHandlers(server, config.Inbound); err != nil {
return nil, err
}
// 注册 outbound handlers
if err := addOutboundHandlers(server, config.Outbound); err != nil {
return nil, err
}
return server, nil
}
可见 feature 大部分是由用户代码提供的，在用户提供的 feature 不全时，v2ray 会把 dns、policy、routing、stats 这几个模块使用默认实现进行占位。server 初始化时会将 inbound 和 outbound 对应的 handler 注册好。
package common
import (
"context"
"reflect"
)
// ConfigCreator is a function to create an object by a config.
type ConfigCreator func(ctx context.Context, config interface{}) (interface{}, error)
var (
typeCreatorRegistry = make(map[reflect.Type]ConfigCreator)
)
// RegisterConfig registers a global config creator. The config can be nil but must have a type.
func RegisterConfig(config interface{}, configCreator ConfigCreator) error {
configType := reflect.TypeOf(config)
if _, found := typeCreatorRegistry[configType]; found {
return newError(configType.Name() + " is already registered").AtError()
}
typeCreatorRegistry[configType] = configCreator
return nil
}
// CreateObject creates an object by its config. The config type must be registered through RegisterConfig().
func CreateObject(ctx context.Context, config interface{}) (interface{}, error) {
configType := reflect.TypeOf(config)
creator, found := typeCreatorRegistry[configType]
if !found {
return nil, newError(configType.String() + " is not registered").AtError()
}
return creator(ctx, config)
}
启动后可通过 dlv 查看这些 feature 具体的类型：
*v2ray.com/core/app/dispatcher.DefaultDispatcher {
*v2ray.com/core/app/proxyman/inbound.Manager {
*v2ray.com/core/app/proxyman/outbound.Manager {
*v2ray.com/core/app/log.Instance {
*v2ray.com/core/app/router.Router {
*v2ray.com/core/app/dns.Server {
v2ray.com/core/features/policy.DefaultManager {},
v2ray.com/core/features/stats.NoopManager {},
每一个 feature 启动在主流程中均调用 Start，我们只要依次查看其 Start 流程即可。
// Start implements common.Runnable.
func (*DefaultDispatcher) Start() error {
return nil
}
啥都没干
// Start implements common.Runnable.
func (m *Manager) Start() error {
m.access.Lock()
defer m.access.Unlock()
m.running = true
for _, handler := range m.taggedHandlers {
if err := handler.Start(); err != nil {
return err
}
}
for _, handler := range m.untaggedHandler {
if err := handler.Start(); err != nil {
return err
}
}
return nil
}
(dlv) p server.features[1].taggedHandlers["socksinbound"].workers
[]v2ray.com/core/app/proxyman/inbound.worker len: 2, cap: 2, [
*v2ray.com/core/app/proxyman/inbound.tcpWorker {
address: v2ray.com/core/common/net.Address(v2ray.com/core/common/net.ipv4Address) *(*"v2ray.com/core/common/net.Address")(0xc000210000),
port: 1081,
proxy: v2ray.com/core/proxy.Inbound(*v2ray.com/core/proxy/socks.Server) ...,
stream: *(*v2ray.com/core/transport/internet.MemoryStreamConfig)(0xc000204460),
recvOrigDest: false,
tag: "socksinbound",
dispatcher: v2ray.com/core/features/routing.Dispatcher(*v2ray.com/core/common/mux.Server) ...,
sniffingConfig: *v2ray.com/core/app/proxyman.SniffingConfig nil,
uplinkCounter: v2ray.com/core/features/stats.Counter nil,
downlinkCounter: v2ray.com/core/features/stats.Counter nil,
hub: v2ray.com/core/transport/internet.Listener(*v2ray.com/core/transport/internet/tcp.Listener) ...,},
*v2ray.com/core/app/proxyman/inbound.udpWorker {
RWMutex: (*sync.RWMutex)(0xc000206460),
proxy: v2ray.com/core/proxy.Inbound(*v2ray.com/core/proxy/socks.Server) ...,
hub: *(*v2ray.com/core/transport/internet/udp.Hub)(0xc0001fc9e0),
address: v2ray.com/core/common/net.Address(v2ray.com/core/common/net.ipv4Address) *(*"v2ray.com/core/common/net.Address")(0xc000206490),
port: 1081,
tag: "socksinbound",
stream: *(*v2ray.com/core/transport/internet.MemoryStreamConfig)(0xc000204460),
dispatcher: v2ray.com/core/features/routing.Dispatcher(*v2ray.com/core/common/mux.Server) ...,
uplinkCounter: v2ray.com/core/features/stats.Counter nil,
downlinkCounter: v2ray.com/core/features/stats.Counter nil,
checker: *(*v2ray.com/core/common/task.Periodic)(0xc0001c2750),
activeConn: map[v2ray.com/core/app/proxyman/inbound.connID]*v2ray.com/core/app/proxyman/inbound.udpConn [],},
]
(dlv) p server.features[1].taggedHandlers["httpinbound"].workers
[]v2ray.com/core/app/proxyman/inbound.worker len: 1, cap: 1, [
*v2ray.com/core/app/proxyman/inbound.tcpWorker {
address: v2ray.com/core/common/net.Address(v2ray.com/core/common/net.ipv4Address) *(*"v2ray.com/core/common/net.Address")(0xc000210090),
port: 8001,
proxy: v2ray.com/core/proxy.Inbound(*v2ray.com/core/proxy/http.Server) ...,
stream: *(*v2ray.com/core/transport/internet.MemoryStreamConfig)(0xc0002046e0),
recvOrigDest: false,
tag: "httpinbound",
dispatcher: v2ray.com/core/features/routing.Dispatcher(*v2ray.com/core/common/mux.Server) ...,
sniffingConfig: *v2ray.com/core/app/proxyman.SniffingConfig nil,
uplinkCounter: v2ray.com/core/features/stats.Counter nil,
downlinkCounter: v2ray.com/core/features/stats.Counter nil,
hub: v2ray.com/core/transport/internet.Listener(*v2ray.com/core/transport/internet/tcp.Listener) ...,},
]
(dlv)// Start implements core.Feature
func (m *Manager) Start() error {
m.access.Lock()
defer m.access.Unlock()
m.running = true
for _, h := range m.taggedHandler {
if err := h.Start(); err != nil {
return err
}
}
for _, h := range m.untaggedHandlers {
if err := h.Start(); err != nil {
return err
}
}
return nil
}
(dlv) p server.features[2].taggedHandler
map[string]v2ray.com/core/features/outbound.Handler [
"v2.com_1.1.1.2": *v2ray.com/core/app/proxyman/outbound.Handler {
tag: "v2.com_1.1.1.2",
senderSettings: *(*v2ray.com/core/app/proxyman.SenderConfig)(0xc000200200),
streamSettings: *(*v2ray.com/core/transport/internet.MemoryStreamConfig)(0xc000204d20),
proxy: v2ray.com/core/proxy.Outbound(*v2ray.com/core/proxy/vmess/outbound.Handler) ...,
outboundManager: v2ray.com/core/features/outbound.Manager(*v2ray.com/core/app/proxyman/outbound.Manager) ...,
mux: *v2ray.com/core/common/mux.ClientManager nil,},
"v2.com_1.0.7.2": *v2ray.com/core/app/proxyman/outbound.Handler {
tag: "v2.com_1.0.7.2",
senderSettings: *(*v2ray.com/core/app/proxyman.SenderConfig)(0xc000200480),
streamSettings: *(*v2ray.com/core/transport/internet.MemoryStreamConfig)(0xc000205720),
proxy: v2ray.com/core/proxy.Outbound(*v2ray.com/core/proxy/vmess/outbound.Handler) ...,
outboundManager: v2ray.com/core/features/outbound.Manager(*v2ray.com/core/app/proxyman/outbound.Manager) ...,
mux: *v2ray.com/core/common/mux.ClientManager nil,},
"decline": *v2ray.com/core/app/proxyman/outbound.Handler {
tag: "decline",
senderSettings: *(*v2ray.com/core/app/proxyman.SenderConfig)(0xc000200700),
streamSettings: *(*v2ray.com/core/transport/internet.MemoryStreamConfig)(0xc000205860),
proxy: v2ray.com/core/proxy.Outbound(*v2ray.com/core/proxy/blackhole.Handler) ...,
outboundManager: v2ray.com/core/features/outbound.Manager(*v2ray.com/core/app/proxyman/outbound.Manager) ...,
mux: *v2ray.com/core/common/mux.ClientManager nil,},
"direct": *v2ray.com/core/app/proxyman/outbound.Handler {
tag: "direct",
senderSettings: *(*v2ray.com/core/app/proxyman.SenderConfig)(0xc000200740),
streamSettings: *(*v2ray.com/core/transport/internet.MemoryStreamConfig)(0xc0002059f0),
proxy: v2ray.com/core/proxy.Outbound(*v2ray.com/core/proxy/freedom.Handler) ...,
outboundManager: v2ray.com/core/features/outbound.Manager(*v2ray.com/core/app/proxyman/outbound.Manager) ...,
mux: *v2ray.com/core/common/mux.ClientManager nil,},
]
(dlv)// Start implements common.Runnable.Start().
func (g *Instance) Start() error {
if err := g.startInternal(); err != nil {
return err
}
newError("Logger started").AtDebug().WriteToLog()
return nil
}
// Start implements common.Runnable.
func (*Router) Start() error {
return nil
}
// Start implements common.Runnable.
func (s *Server) Start() error {
return nil
}
// Start implements common.Runnable.
func (DefaultManager) Start() error {
return nil
}
func (NoopManager) Start() error { return nil }
这部分比较古典，没什么可说的：
osSignals := make(chan os.Signal, 1)
signal.Notify(osSignals, os.Interrupt, os.Kill, syscall.SIGTERM)
<-osSignals