Add DHCP DNS server support

adapter/router.go

@@ -47,6 +47,20 @@ type Router interface {
 	SetV2RayServer(server V2RayServer)
 }
 
+type routerContextKey struct{}
+
+func ContextWithRouter(ctx context.Context, router Router) context.Context {
+	return context.WithValue(ctx, (*routerContextKey)(nil), router)
+}
+
+func RouterFromContext(ctx context.Context) Router {
+	metadata := ctx.Value((*routerContextKey)(nil))
+	if metadata == nil {
+		return nil
+	}
+	return metadata.(Router)
+}
+
 type Rule interface {
 	Service
 	Type() string

constant/dhcp.go

@@ -0,0 +1,8 @@
+package constant
+
+import "time"
+
+const (
+	DHCPTTL     = time.Hour
+	DHCPTimeout = time.Minute
+)

docs/configuration/dns/server.md

@@ -31,7 +31,7 @@ The tag of the dns server.
 The address of the dns server.
 
 | Protocol | Format                        |
-|----------|-----------------------------|
+|----------|-------------------------------|
 | `System` | `local`                       |
 | `TCP`    | `tcp://1.0.0.1`               |
 | `UDP`    | `8.8.8.8` `udp://8.8.4.4`     |
@@ -40,6 +40,7 @@ The address of the dns server.
 | `QUIC`   | `quic://dns.adguard.com`      |
 | `HTTP3`  | `h3://8.8.8.8/dns-query`      |
 | `RCode`  | `rcode://refused`             |
+| `DHCP`   | `dhcp://auto` or `dhcp://en0` |
 
 !!! warning ""
 
@@ -53,6 +54,10 @@ The address of the dns server.
 
     the RCode transport is often used to block queries. Use with rules and the `disable_cache` rule option.
 
+!!! warning ""
+
+    DHCP transport is not included by default, see [Installation](/#installation).
+
 | RCode             | Description           | 
 |-------------------|-----------------------|
 | `success`         | `No error`            |

docs/configuration/dns/server.zh.md

@@ -31,7 +31,7 @@ DNS 服务器的标签。
 DNS 服务器的地址。
 
 | 协议       | 格式                           |
-|----------|-----------------------------|
+|----------|------------------------------|
 | `System` | `local`                      |
 | `TCP`    | `tcp://1.0.0.1`              |
 | `UDP`    | `8.8.8.8` `udp://8.8.4.4`    |
@@ -40,6 +40,7 @@ DNS 服务器的地址。
 | `QUIC`   | `quic://dns.adguard.com`     |
 | `HTTP3`  | `h3://8.8.8.8/dns-query`     |
 | `RCode`  | `rcode://refused`            |
+| `DHCP`   | `dhcp://auto` 或 `dhcp://en0` |
 
 !!! warning ""
 
@@ -53,6 +54,10 @@ DNS 服务器的地址。
 
     RCode 传输层传输层常用于屏蔽请求. 与 DNS 规则和 `disable_cache` 规则选项一起使用。
 
+!!! warning ""
+
+    默认安装不包含 DHCP 传输层，请参阅 [安装](/zh/#_2)。
+
 | RCode             | 描述       | 
 |-------------------|----------|
 | `success`         | `无错误`    |

docs/index.md

@@ -24,8 +24,9 @@ go install -v -tags with_clash_api github.com/sagernet/sing-box/cmd/sing-box@lat
 
 | Build Tag                          | Description                                                                                                                                                                                                                                                                                                                     |
 |------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| `with_quic`                        | Build with QUIC support, see [QUIC and HTTP3 dns transports](./configuration/dns/server), [Naive inbound](./configuration/inbound/naive), [Hysteria Inbound](./configuration/inbound/hysteria), [Hysteria Outbound](./configuration/outbound/hysteria) and [V2Ray Transport#QUIC](./configuration/shared/v2ray-transport#quic). |
+| `with_quic`                        | Build with QUIC support, see [QUIC and HTTP3 DNS transports](./configuration/dns/server), [Naive inbound](./configuration/inbound/naive), [Hysteria Inbound](./configuration/inbound/hysteria), [Hysteria Outbound](./configuration/outbound/hysteria) and [V2Ray Transport#QUIC](./configuration/shared/v2ray-transport#quic). |
 | `with_grpc`                        | Build with standard gRPC support, see [V2Ray Transport#gRPC](./configuration/shared/v2ray-transport#grpc).                                                                                                                                                                                                                      |
+| `with_dhcp`                        | Build with DHCP support, see [DHCP DNS transport](./configuration/dns/server).                                                                                                                                                                                                                                                  |
 | `with_wireguard`                   | Build with WireGuard support, see [WireGuard outbound](./configuration/outbound/wireguard).                                                                                                                                                                                                                                     |
 | `with_shadowsocksr`                | Build with ShadowsocksR support, see [ShadowsocksR outbound](./configuration/outbound/shadowsocksr).                                                                                                                                                                                                                            |
 | `with_ech`                         | Build with TLS ECH extension support for TLS outbound, see [TLS](./configuration/shared/tls#ech).                                                                                                                                                                                                                               |

docs/index.zh.md

@@ -26,6 +26,7 @@ go install -v -tags with_clash_api github.com/sagernet/sing-box/cmd/sing-box@lat
 |------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `with_quic`                  | 启用 QUIC 支持，参阅 [QUIC 和 HTTP3 DNS 传输层](./configuration/dns/server)，[Naive 入站](./configuration/inbound/naive)，[Hysteria 入站](./configuration/inbound/hysteria)，[Hysteria 出站](./configuration/outbound/hysteria) 和 [V2Ray 传输层#QUIC](./configuration/shared/v2ray-transport#quic)。 |
 | `with_grpc`                  | 启用标准 gRPC 支持，参阅 [V2Ray 传输层#gRPC](./configuration/shared/v2ray-transport#grpc)。                                                                                                                                                                                               |
+| `with_dhcp`                  | 启用 DHCP 支持，参阅 [DHCP DNS 传输层](./configuration/dns/server)。                                                                                                                                                                                                                    |
 | `with_wireguard`             | 启用 WireGuard 支持，参阅 [WireGuard 出站](./configuration/outbound/wireguard)。                                                                                                                                                                                                       |
 | `with_shadowsocksr`          | 启用 ShadowsocksR 支持，参阅 [ShadowsocksR 出站](./configuration/outbound/shadowsocksr)。                                                                                                                                                                                              |
 | `with_ech`                   | 启用 TLS ECH 扩展支持，参阅 [TLS](./configuration/shared/tls#ech)。                                                                                                                                                                                                                    |

go.mod

@@ -14,6 +14,7 @@ require (
 	github.com/go-chi/render v1.0.2
 	github.com/gofrs/uuid v4.4.0+incompatible
 	github.com/hashicorp/yamux v0.1.1
+	github.com/insomniacslk/dhcp v0.0.0-20221215072855-de60144f33f8
 	github.com/logrusorgru/aurora v2.0.3+incompatible
 	github.com/mholt/acmez v1.0.4
 	github.com/miekg/dns v1.1.50
@@ -59,6 +60,7 @@ require (
 	github.com/google/btree v1.0.1 // indirect
 	github.com/google/pprof v0.0.0-20210407192527-94a9f03dee38 // indirect
 	github.com/inconshreveable/mousetrap v1.0.1 // indirect
+	github.com/josharian/native v1.1.0 // indirect
 	github.com/klauspost/compress v1.15.15 // indirect
 	github.com/klauspost/cpuid/v2 v2.1.1 // indirect
 	github.com/libdns/libdns v0.2.1 // indirect
@@ -72,6 +74,7 @@ require (
 	github.com/sagernet/go-tun2socks v1.16.12-0.20220818015926-16cb67876a61 // indirect
 	github.com/sagernet/netlink v0.0.0-20220905062125-8043b4a9aa97 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/u-root/uio v0.0.0-20221213070652-c3537552635f // indirect
 	github.com/vishvananda/netns v0.0.0-20211101163701-50045581ed74 // indirect
 	go.uber.org/multierr v1.6.0 // indirect
 	golang.org/x/mod v0.6.0 // indirect

go.sum

@@ -24,6 +24,7 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
 github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
+github.com/fanliao/go-promise v0.0.0-20141029170127-1890db352a72/go.mod h1:PjfxuH4FZdUyfMdtBio2lsRr1AKEaVPwelzuHuh8Lqc=
 github.com/fsnotify/fsnotify v1.6.0 h1:n+5WquG0fcWoWp6xPWfHdbskMCQaFnG6PfBrh1Ky4HY=
 github.com/fsnotify/fsnotify v1.6.0/go.mod h1:sl3t1tCWJFWoRz9R8WJCbQihKKwmorjAbSClcnxKAGw=
 github.com/go-chi/chi/v5 v5.0.8 h1:lD+NLqFcAi1ovnVZpsnObHGW4xb4J8lNmoYVfECH1Y0=
@@ -43,15 +44,32 @@ github.com/golang/protobuf v1.5.2 h1:ROPKBNFfQgOUMifHyP+KYbvpjbdoFNs+aK7DXlji0Tw
 github.com/golang/protobuf v1.5.2/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
 github.com/google/btree v1.0.1 h1:gK4Kx5IaGY9CD5sPJ36FHiBJ6ZXl0kilRiiCj+jdYp4=
 github.com/google/btree v1.0.1/go.mod h1:xXMiIv4Fb/0kKde4SpL7qlzvu5cMJDRkFDxJfI9uaxA=
+github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
+github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
+github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
+github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 github.com/google/pprof v0.0.0-20210407192527-94a9f03dee38 h1:yAJXTCF9TqKcTiHJAE8dj7HMvPfh66eeA2JYW7eFpSE=
 github.com/google/pprof v0.0.0-20210407192527-94a9f03dee38/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
+github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
 github.com/hashicorp/yamux v0.1.1 h1:yrQxtgseBDrq9Y652vSRDvsKCJKOUD+GzTS4Y0Y8pvE=
 github.com/hashicorp/yamux v0.1.1/go.mod h1:CtWFDAQgb7dxtzFs4tWbplKIe2jSi3+5vKbgIO0SLnQ=
+github.com/hugelgupf/socketpair v0.0.0-20190730060125-05d35a94e714/go.mod h1:2Goc3h8EklBH5mspfHFxBnEoURQCGzQQH1ga9Myjvis=
 github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/inconshreveable/mousetrap v1.0.1 h1:U3uMjPSQEBMNp1lFxmllqCPM6P5u/Xq7Pgzkat/bFNc=
 github.com/inconshreveable/mousetrap v1.0.1/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/insomniacslk/dhcp v0.0.0-20221215072855-de60144f33f8 h1:Z72DOke2yOK0Ms4Z2LK1E1OrRJXOxSj5DllTz2FYTRg=
+github.com/insomniacslk/dhcp v0.0.0-20221215072855-de60144f33f8/go.mod h1:m5WMe03WCvWcXjRnhvaAbAAXdCnu20J5P+mmH44ZzpE=
+github.com/josharian/native v1.0.1-0.20221213033349-c1e37c09b531/go.mod h1:7X/raswPFr05uY3HiLlYeyQntB6OO7E/d2Cu7qoaN2w=
+github.com/josharian/native v1.1.0 h1:uuaP0hAbW7Y4l0ZRQ6C9zfb7Mg1mbFKry/xzDAfmtLA=
+github.com/josharian/native v1.1.0/go.mod h1:7X/raswPFr05uY3HiLlYeyQntB6OO7E/d2Cu7qoaN2w=
+github.com/jsimonetti/rtnetlink v0.0.0-20190606172950-9527aa82566a/go.mod h1:Oz+70psSo5OFh8DBl0Zv2ACw7Esh6pPUphlvZG9x7uw=
+github.com/jsimonetti/rtnetlink v0.0.0-20200117123717-f846d4f6c1f4/go.mod h1:WGuG/smIU4J/54PblvSbh+xvCZmpJnFgr3ds6Z55XMQ=
+github.com/jsimonetti/rtnetlink v0.0.0-20201009170750-9c6f07d100c1/go.mod h1:hqoO/u39cqLeBLebZ8fWdE96O7FxrAsRYhnVOdgHxok=
+github.com/jsimonetti/rtnetlink v0.0.0-20201110080708-d2c240429e6c/go.mod h1:huN4d1phzjhlOsNIjFsw2SVRbwIHj3fJDMEU2SDPTmg=
+github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
 github.com/klauspost/compress v1.15.15 h1:EF27CXIuDsYJ6mmvtBRlEuB2UVOqHG1tAXgZ7yIO+lw=
 github.com/klauspost/compress v1.15.15/go.mod h1:ZcK2JAFqKOpnBlxcLsJzYfrS9X1akm9fHZNnD9+Vo/4=
 github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
@@ -65,6 +83,13 @@ github.com/libdns/libdns v0.2.1 h1:Wu59T7wSHRgtA0cfxC+n1c/e+O3upJGWytknkmFEDis=
 github.com/libdns/libdns v0.2.1/go.mod h1:yQCXzk1lEZmmCPa857bnk4TsOiqYasqpyOEeSObbb40=
 github.com/logrusorgru/aurora v2.0.3+incompatible h1:tOpm7WcpBTn4fjmVfgpQq0EfczGlG91VSDkswnjF5A8=
 github.com/logrusorgru/aurora v2.0.3+incompatible/go.mod h1:7rIyQOR62GCctdiQpZ/zOJlFyk6y+94wXzv6RNZgaR4=
+github.com/mdlayher/ethernet v0.0.0-20190606142754-0394541c37b7/go.mod h1:U6ZQobyTjI/tJyq2HG+i/dfSoFUt8/aZCM+GKtmFk/Y=
+github.com/mdlayher/netlink v0.0.0-20190409211403-11939a169225/go.mod h1:eQB3mZE4aiYnlUsyGGCOpPETfdQq4Jhsgf1fk3cwQaA=
+github.com/mdlayher/netlink v1.0.0/go.mod h1:KxeJAFOFLG6AjpyDkQ/iIhxygIUKD+vcwqcnu43w/+M=
+github.com/mdlayher/netlink v1.1.0/go.mod h1:H4WCitaheIsdF9yOYu8CFmCgQthAPIWZmcKp9uZHgmY=
+github.com/mdlayher/netlink v1.1.1/go.mod h1:WTYpFb/WTvlRJAyKhZL5/uy69TDDpHHu2VZmb2XgV7o=
+github.com/mdlayher/raw v0.0.0-20190606142536-fef19f00fc18/go.mod h1:7EpbotpCmVZcu+KCX4g9WaRNuu11uyhiW7+Le1dKawg=
+github.com/mdlayher/raw v0.0.0-20191009151244-50f2db8cc065/go.mod h1:7EpbotpCmVZcu+KCX4g9WaRNuu11uyhiW7+Le1dKawg=
 github.com/mholt/acmez v1.0.4 h1:N3cE4Pek+dSolbsofIkAYz6H1d3pE+2G0os7QHslf80=
 github.com/mholt/acmez v1.0.4/go.mod h1:qFGLZ4u+ehWINeJZjzPlsnjJBCPAADWTcIqE/7DAYQY=
 github.com/miekg/dns v1.1.50 h1:DQUfb9uc6smULcREF09Uc+/Gd46YWqJd5DbpPE9xkcA=
@@ -121,6 +146,8 @@ github.com/sagernet/websocket v0.0.0-20220913015213-615516348b4e h1:7uw2njHFGE+V
 github.com/sagernet/websocket v0.0.0-20220913015213-615516348b4e/go.mod h1:45TUl8+gH4SIKr4ykREbxKWTxkDlSzFENzctB1dVRRY=
 github.com/sagernet/wireguard-go v0.0.0-20221116151939-c99467f53f2c h1:vK2wyt9aWYHHvNLWniwijBu/n4pySypiKRhN32u/JGo=
 github.com/sagernet/wireguard-go v0.0.0-20221116151939-c99467f53f2c/go.mod h1:euOmN6O5kk9dQmgSS8Df4psAl3TCjxOz0NW60EWkSaI=
+github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
+github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
 github.com/spf13/cobra v1.6.1 h1:o94oiPyS4KD1mPy2fmcYYHHfCxLqYjJOhGsCHFZtEzA=
 github.com/spf13/cobra v1.6.1/go.mod h1:IOw/AERYS7UzyrGinqmz6HLUo219MORXGxhbaJUqzrY=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
@@ -130,11 +157,14 @@ github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSS
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
+github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
+github.com/u-root/uio v0.0.0-20221213070652-c3537552635f h1:dpx1PHxYqAnXzbryJrWP1NQLzEjwcVgFLhkknuFQ7ww=
+github.com/u-root/uio v0.0.0-20221213070652-c3537552635f/go.mod h1:IogEAUBXDEwX7oR/BMmCctShYs80ql4hF0ySdzGxf7E=
 github.com/vishvananda/netns v0.0.0-20211101163701-50045581ed74 h1:gga7acRE695APm9hlsSMoOoE65U4/TcqNj90mc69Rlg=
 github.com/vishvananda/netns v0.0.0-20211101163701-50045581ed74/go.mod h1:DD4vA1DwXk04H54A1oHXtwZmA0grkVMdPxx/VGLCah0=
 github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
@@ -155,6 +185,7 @@ go4.org/netipx v0.0.0-20230125063823-8449b0a6169f/go.mod h1:tgPU4N2u9RByaTN3NC2p
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190404164418-38d8ce5564a5/go.mod h1:WFFai1msRO1wXaEeE5yQxYXgSfI8pQAWXbQop6sCtWE=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20210513164829-c07d793c2f9a/go.mod h1:P+XmwS30IXTQdn5tA2iutPOUgjI07+tq3H3K9MVA1s8=
 golang.org/x/crypto v0.5.0 h1:U/0M97KRkSFvyD/3FSmdP5W5swImpNgle/EHFhOsQPE=
 golang.org/x/crypto v0.5.0/go.mod h1:NK/OQwhpMQP3MwtdjgLlYHnH9ebylxKWv3e0fK+mkQU=
@@ -166,7 +197,14 @@ golang.org/x/mod v0.6.0 h1:b9gGHsz9/HhJ3HF5DHQytPpuwocVTChQJK3AvoLRD5I=
 golang.org/x/mod v0.6.0/go.mod h1:4mET923SAdbXp2ki8ey+zGs1SLqsuM2Y0uvdZR/fUNI=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190419010253-1f3472d942ba/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190603091049-60506f45cf65/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20190827160401-ba9fcec4b297/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20191007182048-72f939374954/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20200202094626-16171245cfb2/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20201010224723-4f7140c49acb/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
+golang.org/x/net v0.0.0-20201110031124-69a78807bb2b/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
 golang.org/x/net v0.0.0-20210525063256-abc453219eb5/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
@@ -178,10 +216,20 @@ golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190312061237-fead79001313/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190403152447-81d4e9dc473e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190411185658-b44545bcd369/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190418153312-f0ce4c0180be/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190606122018-79a91cf218c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190826190057-c7b8b68b1456/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191008105621-543471e840be/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191204072324-ce4227a45e2e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200202164722-d101bd2416d5/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200217220822-9197077df867/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201009025420-dfb3f7c4e634/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201101102859-da207088b7d1/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -189,6 +237,7 @@ golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220622161953-175b2fd9d664/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220704084225-05e143d24a9e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220731174439-a90be440212d/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220908164124-27713097b956/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
@@ -207,6 +256,7 @@ golang.org/x/time v0.0.0-20191024005414-555d28b269f0 h1:/5xXl8Y5W96D+TtHSlonuFqG
 golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.1.1/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
 golang.org/x/tools v0.1.5/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=

include/dhcp.go

@@ -0,0 +1,5 @@
+//go:build with_dhcp
+
+package include
+
+import _ "github.com/sagernet/sing-box/transport/dhcp"

include/dhcp_stub.go

@@ -0,0 +1,18 @@
+//go:build !with_dhcp
+
+package include
+
+import (
+	"context"
+
+	"github.com/sagernet/sing-dns"
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
+	N "github.com/sagernet/sing/common/network"
+)
+
+func init() {
+	dns.RegisterTransport([]string{"dhcp"}, func(ctx context.Context, logger logger.ContextLogger, dialer N.Dialer, link string) (dns.Transport, error) {
+		return nil, E.New(`DHCP is not included in this build, rebuild with -tags with_dhcp`)
+	})
+}

route/router.go

@@ -159,6 +159,7 @@ func NewRouter(ctx context.Context, logFactory log.Factory, options option.Route
 		transportTags[i] = tag
 		transportTagMap[tag] = true
 	}
+	ctx = adapter.ContextWithRouter(ctx, router)
 	for {
 		lastLen := len(dummyTransportMap)
 		for i, server := range dnsOptions.Servers {
@@ -173,7 +174,7 @@ func NewRouter(ctx context.Context, logFactory log.Factory, options option.Route
 				detour = dialer.NewDetour(router, server.Detour)
 			}
 			switch server.Address {
-			case "local", "rcode":
+			case "local":
 			default:
 				serverURL, _ := url.Parse(server.Address)
 				var serverAddress string
@@ -193,11 +194,15 @@ func NewRouter(ctx context.Context, logFactory log.Factory, options option.Route
 					} else {
 						continue
 					}
-				} else if notIpAddress != nil && (serverURL == nil || serverURL.Scheme != "rcode") {
+				} else if notIpAddress != nil {
+					switch serverURL.Scheme {
+					case "rcode", "dhcp":
+					default:
 						return nil, E.New("parse dns server[", tag, "]: missing address_resolver")
 					}
 				}
-			transport, err := dns.CreateTransport(ctx, logFactory.NewLogger(F.ToString("dns/transport[", i, "]")), detour, server.Address)
+			}
+			transport, err := dns.CreateTransport(ctx, logFactory.NewLogger(F.ToString("dns/transport[", tag, "]")), detour, server.Address)
 			if err != nil {
 				return nil, E.Cause(err, "parse dns server[", tag, "]")
 			}
@@ -392,14 +397,20 @@ func (r *Router) Start() error {
 			return err
 		}
 	}
-	for _, rule := range r.rules {
+	if r.interfaceMonitor != nil {
-		err := rule.Start()
+		err := r.interfaceMonitor.Start()
 		if err != nil {
 			return err
 		}
 	}
-	for _, rule := range r.dnsRules {
+	if r.networkMonitor != nil {
-		err := rule.Start()
+		err := r.networkMonitor.Start()
+		if err != nil {
+			return err
+		}
+	}
+	if r.packageManager != nil {
+		err := r.packageManager.Start()
 		if err != nil {
 			return err
 		}
@@ -424,22 +435,22 @@ func (r *Router) Start() error {
 		r.geositeCache = nil
 		r.geositeReader = nil
 	}
-	if r.interfaceMonitor != nil {
+	for i, rule := range r.rules {
-		err := r.interfaceMonitor.Start()
+		err := rule.Start()
 		if err != nil {
-			return err
+			return E.Cause(err, "initialize rule[", i, "]")
 		}
 	}
-	if r.networkMonitor != nil {
+	for i, rule := range r.dnsRules {
-		err := r.networkMonitor.Start()
+		err := rule.Start()
 		if err != nil {
-			return err
+			return E.Cause(err, "initialize DNS rule[", i, "]")
 		}
 	}
-	if r.packageManager != nil {
+	for i, transport := range r.transports {
-		err := r.packageManager.Start()
+		err := transport.Start()
 		if err != nil {
-			return err
+			return E.Cause(err, "initialize DNS server[", i, "]")
 		}
 	}
 	return nil
@@ -458,6 +469,12 @@ func (r *Router) Close() error {
 			return err
 		}
 	}
+	for _, transport := range r.transports {
+		err := transport.Close()
+		if err != nil {
+			return err
+		}
+	}
 	return common.Close(
 		common.PtrOrNil(r.geoIPReader),
 		r.interfaceMonitor,

transport/dhcp/server.go

@@ -0,0 +1,262 @@
+package dhcp
+
+import (
+	"context"
+	"net"
+	"net/netip"
+	"net/url"
+	"os"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/dialer"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing-dns"
+	"github.com/sagernet/sing-tun"
+	"github.com/sagernet/sing/common"
+	"github.com/sagernet/sing/common/buf"
+	"github.com/sagernet/sing/common/control"
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+	"github.com/sagernet/sing/common/task"
+	"github.com/sagernet/sing/common/x/list"
+
+	"github.com/insomniacslk/dhcp/dhcpv4"
+	mDNS "github.com/miekg/dns"
+)
+
+func init() {
+	dns.RegisterTransport([]string{"dhcp"}, NewTransport)
+}
+
+type Transport struct {
+	ctx               context.Context
+	router            adapter.Router
+	logger            logger.Logger
+	interfaceName     string
+	autoInterface     bool
+	interfaceCallback *list.Element[tun.DefaultInterfaceUpdateCallback]
+	transports        []dns.Transport
+	updateAccess      sync.Mutex
+	updatedAt         time.Time
+}
+
+func NewTransport(ctx context.Context, logger logger.ContextLogger, dialer N.Dialer, link string) (dns.Transport, error) {
+	linkURL, err := url.Parse(link)
+	if err != nil {
+		return nil, err
+	}
+	if linkURL.Host == "" {
+		return nil, E.New("missing interface name for DHCP")
+	}
+	router := adapter.RouterFromContext(ctx)
+	if router == nil {
+		return nil, E.New("missing router in context")
+	}
+	transport := &Transport{
+		ctx:           ctx,
+		router:        router,
+		logger:        logger,
+		interfaceName: linkURL.Host,
+		autoInterface: linkURL.Host == "auto",
+	}
+	return transport, nil
+}
+
+func (t *Transport) Start() error {
+	err := t.fetchServers()
+	if err != nil {
+		return err
+	}
+	if t.autoInterface {
+		t.interfaceCallback = t.router.InterfaceMonitor().RegisterCallback(t.interfaceUpdated)
+	}
+	return nil
+}
+
+func (t *Transport) Close() error {
+	if t.interfaceCallback != nil {
+		t.router.InterfaceMonitor().UnregisterCallback(t.interfaceCallback)
+	}
+	return nil
+}
+
+func (t *Transport) Raw() bool {
+	return true
+}
+
+func (t *Transport) Exchange(ctx context.Context, message *mDNS.Msg) (*mDNS.Msg, error) {
+	err := t.fetchServers()
+	if err != nil {
+		return nil, err
+	}
+
+	if len(t.transports) == 0 {
+		return nil, E.New("dhcp: empty DNS servers from response")
+	}
+
+	var response *mDNS.Msg
+	for _, transport := range t.transports {
+		response, err = transport.Exchange(ctx, message)
+		if err == nil {
+			return response, nil
+		}
+	}
+	return nil, err
+}
+
+func (t *Transport) fetchInterface() (*net.Interface, error) {
+	interfaceName := t.interfaceName
+	if t.autoInterface {
+		if t.router.NetworkMonitor() == nil {
+			return nil, E.New("missing monitor for auto DHCP, set route.auto_detect_interface")
+		}
+		interfaceName = t.router.InterfaceMonitor().DefaultInterfaceName(netip.Addr{})
+	}
+	if interfaceName == "" {
+		return nil, E.New("missing default interface")
+	}
+	return net.InterfaceByName(interfaceName)
+}
+
+func (t *Transport) fetchServers() error {
+	if time.Since(t.updatedAt) < C.DHCPTTL {
+		return nil
+	}
+	t.updateAccess.Lock()
+	defer t.updateAccess.Unlock()
+	if time.Since(t.updatedAt) < C.DHCPTTL {
+		return nil
+	}
+	return t.updateServers()
+}
+
+func (t *Transport) updateServers() error {
+	iface, err := t.fetchInterface()
+	if err != nil {
+		return E.Cause(err, "dhcp: prepare interface")
+	}
+
+	t.logger.Info("dhcp: query DNS servers on ", iface.Name)
+	fetchCtx, cancel := context.WithTimeout(t.ctx, C.DHCPTimeout)
+	err = t.fetchServers0(fetchCtx, iface)
+	cancel()
+	if err != nil {
+		return err
+	} else if len(t.transports) == 0 {
+		return E.New("dhcp: empty DNS servers response")
+	} else {
+		t.updatedAt = time.Now()
+		return nil
+	}
+}
+
+func (t *Transport) interfaceUpdated(int) error {
+	return t.updateServers()
+}
+
+func (t *Transport) fetchServers0(ctx context.Context, iface *net.Interface) error {
+	var listener net.ListenConfig
+	listener.Control = control.Append(listener.Control, control.BindToInterfaceFunc(t.router.InterfaceFinder(), func(network string, address string) (interfaceName string, interfaceIndex int) {
+		return iface.Name, iface.Index
+	}))
+	listener.Control = control.Append(listener.Control, control.ReuseAddr())
+	packetConn, err := listener.ListenPacket(t.ctx, "udp4", "0.0.0.0:68")
+	if err != nil {
+		return err
+	}
+	defer packetConn.Close()
+
+	discovery, err := dhcpv4.NewDiscovery(iface.HardwareAddr, dhcpv4.WithBroadcast(true), dhcpv4.WithRequestedOptions(dhcpv4.OptionDomainNameServer))
+	if err != nil {
+		return err
+	}
+
+	_, err = packetConn.WriteTo(discovery.ToBytes(), &net.UDPAddr{IP: net.IPv4bcast, Port: 67})
+	if err != nil {
+		return err
+	}
+
+	var group task.Group
+	group.Append0(func(ctx context.Context) error {
+		return t.fetchServersResponse(iface, packetConn, discovery.TransactionID)
+	})
+	group.Cleanup(func() {
+		packetConn.Close()
+	})
+	return group.Run(ctx)
+}
+
+func (t *Transport) fetchServersResponse(iface *net.Interface, packetConn net.PacketConn, transactionID dhcpv4.TransactionID) error {
+	_buffer := buf.StackNewSize(dhcpv4.MaxMessageSize)
+	defer common.KeepAlive(_buffer)
+	buffer := common.Dup(_buffer)
+	defer buffer.Release()
+
+	for {
+		_, _, err := buffer.ReadPacketFrom(packetConn)
+		if err != nil {
+			return err
+		}
+
+		dhcpPacket, err := dhcpv4.FromBytes(buffer.Bytes())
+		if err != nil {
+			t.logger.Trace("dhcp: parse DHCP response: ", err)
+			return err
+		}
+
+		if dhcpPacket.MessageType() != dhcpv4.MessageTypeOffer {
+			t.logger.Trace("dhcp: expected OFFER response, but got ", dhcpPacket.MessageType())
+			continue
+		}
+
+		if dhcpPacket.TransactionID != transactionID {
+			t.logger.Trace("dhcp: expected transaction ID ", transactionID, ", but got ", dhcpPacket.TransactionID)
+			continue
+		}
+
+		dns := dhcpPacket.DNS()
+		if len(dns) == 0 {
+			return nil
+		}
+
+		var addrs []netip.Addr
+		for _, ip := range dns {
+			addr, _ := netip.AddrFromSlice(ip)
+			addrs = append(addrs, addr.Unmap())
+		}
+		return t.recreateServers(iface, addrs)
+	}
+}
+
+func (t *Transport) recreateServers(iface *net.Interface, serverAddrs []netip.Addr) error {
+	if len(serverAddrs) > 0 {
+		t.logger.Info("dhcp: updated DNS servers from ", iface.Name, ": [", strings.Join(common.Map(serverAddrs, func(it netip.Addr) string {
+			return it.String()
+		}), ","), "]")
+	}
+
+	serverDialer := dialer.NewDefault(t.router, option.DialerOptions{
+		BindInterface:      iface.Name,
+		UDPFragmentDefault: true,
+	})
+	var transports []dns.Transport
+	for _, serverAddr := range serverAddrs {
+		serverTransport, err := dns.NewUDPTransport(t.ctx, serverDialer, M.Socksaddr{Addr: serverAddr, Port: 53})
+		if err != nil {
+			return err
+		}
+		transports = append(transports, serverTransport)
+	}
+	t.transports = transports
+	return nil
+}
+
+func (t *Transport) Lookup(ctx context.Context, domain string, strategy dns.DomainStrategy) ([]netip.Addr, error) {
+	return nil, os.ErrInvalid
+}