dhcp reads done, moving on to offers

cmd/kdhcpd/BUILD.bazel

@@ -9,7 +9,7 @@ go_library(
         "//config",
         "//server",
         "@com_github_peterbourgon_ff_v3//ffcli",
-        "@dev_wntrmute_git_kyle_goutils//syslog",
+        "@dev_wntrmute_git_kyle_goutils//log",
     ],
 )
 

cmd/kdhcpd/main.go

@@ -6,7 +6,7 @@ import (
 	"os"
 	"strings"
 
-	log "git.wntrmute.dev/kyle/goutils/syslog"
+	"git.wntrmute.dev/kyle/goutils/log"
 	"git.wntrmute.dev/kyle/kdhcp/config"
 	"git.wntrmute.dev/kyle/kdhcp/server"
 	"github.com/peterbourgon/ff/v3/ffcli"

config/BUILD.bazel

@@ -10,7 +10,7 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//iptools",
-        "@dev_wntrmute_git_kyle_goutils//syslog",
+        "@dev_wntrmute_git_kyle_goutils//log",
         "@in_gopkg_yaml_v2//:yaml_v2",
     ],
 )

config/config.go

@@ -6,7 +6,7 @@ import (
 	"io/ioutil"
 	"net"
 
-	log "git.wntrmute.dev/kyle/goutils/syslog"
+	log "git.wntrmute.dev/kyle/goutils/log"
 	"git.wntrmute.dev/kyle/kdhcp/iptools"
 	"gopkg.in/yaml.v2"
 )

config/path.go

@@ -5,7 +5,7 @@ import (
 	"os/user"
 	"path/filepath"
 
-	log "git.wntrmute.dev/kyle/goutils/syslog"
+	log "git.wntrmute.dev/kyle/goutils/log"
 )
 
 func FindConfigPath() string {

deps.bzl

@@ -1,6 +1,13 @@
 load("@bazel_gazelle//:deps.bzl", "go_repository")
 
 def go_dependencies():
+    go_repository(
+        name = "com_github_benbjohnson_clock",
+        importpath = "github.com/benbjohnson/clock",
+        sum = "h1:g+rSsSaAzhHJYcIQE78hJ3AhyjjtQvleKDjlhdBnIhc=",
+        version = "v1.3.3",
+    )
+
     go_repository(
         name = "com_github_cloudflare_cfssl",
         importpath = "github.com/cloudflare/cfssl",
@@ -14,12 +21,32 @@ def go_dependencies():
         sum = "h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=",
         version = "v1.1.1",
     )
+    go_repository(
+        name = "com_github_google_certificate_transparency_go",
+        importpath = "github.com/google/certificate-transparency-go",
+        sum = "h1:Yf1aXowfZ2nuboBsg7iYGLmwsOARdV86pfH3g95wXmE=",
+        version = "v1.0.21",
+    )
+
     go_repository(
         name = "com_github_hashicorp_go_syslog",
         importpath = "github.com/hashicorp/go-syslog",
         sum = "h1:KaodqZuhUoZereWVIYmpUgZysurB1kBLX2j0MwMrUAE=",
         version = "v1.0.0",
     )
+    go_repository(
+        name = "com_github_kr_fs",
+        importpath = "github.com/kr/fs",
+        sum = "h1:Jskdu9ieNAYnjxsi0LbQp1ulIKZV1LAFgK1tWhpZgl8=",
+        version = "v0.1.0",
+    )
+    go_repository(
+        name = "com_github_kr_pretty",
+        importpath = "github.com/kr/pretty",
+        sum = "h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=",
+        version = "v0.1.0",
+    )
+
     go_repository(
         name = "com_github_kr_text",
         importpath = "github.com/kr/text",
@@ -51,6 +78,13 @@ def go_dependencies():
         sum = "h1:/f3b24xrDhkhddlaobPe2JgBqfdt+gC/NYl0QY9IOuI=",
         version = "v1.12.0",
     )
+    go_repository(
+        name = "com_github_pmezard_go_difflib",
+        importpath = "github.com/pmezard/go-difflib",
+        sum = "h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=",
+        version = "v1.0.0",
+    )
+
     go_repository(
         name = "com_github_stretchr_testify",
         importpath = "github.com/stretchr/testify",
@@ -60,15 +94,15 @@ def go_dependencies():
     go_repository(
         name = "dev_wntrmute_git_kyle_goutils",
         importpath = "git.wntrmute.dev/kyle/goutils",
-        sum = "h1:CRCBlmSXOTkShbqC6j9lgxh4lb+khzc2zpIJYGQJtnc=",
+        sum = "h1:+lk6uUMcpJK49sEGEMCOns3WVd2ThH/htMWnsyXEGl8=",
-        version = "v1.6.6",
+        version = "v1.7.0",
     )
 
     go_repository(
         name = "in_gopkg_check_v1",
         importpath = "gopkg.in/check.v1",
-        sum = "h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=",
+        sum = "h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=",
-        version = "v0.0.0-20161208181325-20d25e280405",
+        version = "v1.0.0-20180628173108-788fd7840127",
     )
     go_repository(
         name = "in_gopkg_yaml_v2",
@@ -76,6 +110,13 @@ def go_dependencies():
         sum = "h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=",
         version = "v2.4.0",
     )
+    go_repository(
+        name = "in_gopkg_yaml_v3",
+        importpath = "gopkg.in/yaml.v3",
+        sum = "h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=",
+        version = "v3.0.0-20200313102051-9f266ea9e77c",
+    )
+
     go_repository(
         name = "org_golang_x_crypto",
         importpath = "golang.org/x/crypto",

dhcp/BUILD.bazel

@@ -9,5 +9,5 @@ go_library(
     ],
     importpath = "git.wntrmute.dev/kyle/kdhcp/dhcp",
     visibility = ["//visibility:public"],
-    deps = ["@dev_wntrmute_git_kyle_goutils//syslog"],
+    deps = ["@dev_wntrmute_git_kyle_goutils//log"],
 )

dhcp/options.go

@@ -33,6 +33,8 @@ const (
 	OptionTagNBScope              OptionTag = 47
 	OptionTagMessageType          OptionTag = 53
 	OptionTagParameterRequestList OptionTag = 55
+	OptionTagDHCPMaxMessageSize   OptionTag = 57
+	OptionTagClientID             OptionTag = 61
 	OptionTagDomainSearch         OptionTag = 119
 	OptionTagClasslessStaticRoute OptionTag = 121
 	OptionTagEnd                  OptionTag = 255
@@ -53,6 +55,8 @@ var optionStrings = map[OptionTag]string{
 	OptionTagNBScope:              "NetBIOS scope",
 	OptionTagMessageType:          "message type",
 	OptionTagParameterRequestList: "parameter request list",
+	OptionTagDHCPMaxMessageSize:   "DHCP max message size",
+	OptionTagClientID:             "client ID",
 	OptionTagDomainSearch:         "search domain",
 	OptionTagClasslessStaticRoute: "classless static route",
 	OptionTagEnd:                  "end",

dhcp/packet.go

@@ -8,7 +8,7 @@ import (
 	"net"
 	"strings"
 
-	log "git.wntrmute.dev/kyle/goutils/syslog"
+	log "git.wntrmute.dev/kyle/goutils/log"
 )
 
 const (
@@ -46,6 +46,7 @@ type BootRequest struct {
 
 	DHCPType          DHCPMessageType // option 53
 	HostName          string          // option 12
+	ClientID          string          // option 61
 	ParameterRequests []OptionTag
 	endOptions        bool
 }

dhcp/read_options.go

@@ -6,7 +6,7 @@ import (
 	"fmt"
 	"io"
 
-	log "git.wntrmute.dev/kyle/goutils/syslog"
+	log "git.wntrmute.dev/kyle/goutils/log"
 )
 
 var optionRegistry = map[OptionTag]Option{
@@ -14,6 +14,7 @@ var optionRegistry = map[OptionTag]Option{
 	OptionTagHostName:             OptionHostName,
 	OptionTagMessageType:          OptionMessageType,
 	OptionTagParameterRequestList: OptionParameterRequestList,
+	OptionTagClientID:             OptionClientID,
 	OptionTagEnd:                  OptionEnd,
 }
 
@@ -22,6 +23,19 @@ func OptionPad(req *BootRequest, r io.Reader) error {
 	return nil
 }
 
+func getOptionLength(r io.Reader) (int, error) {
+	var length uint8
+	read := newPacketReaderFunc(r)
+
+	if err := read(&length); err != nil {
+		return -1, fmt.Errorf("dhcp: reading option length for DHCP Message Type")
+	} else if length == 0 {
+		return -1, errors.New("dhcp: read option length 0, but expected option length for DHCP Host Name is >= 1")
+	}
+
+	return int(length), nil
+}
+
 // OptionHostName reads a DHCP host name option.
 //
 // 3.14. Host Name Option
@@ -33,13 +47,9 @@ func OptionPad(req *BootRequest, r io.Reader) error {
 
 // The code for this option is 12, and its minimum length is 1.
 func OptionHostName(req *BootRequest, r io.Reader) error {
-	read := newPacketReaderFunc(r)
+	length, err := getOptionLength(r)
-
+	if err != nil {
-	var length uint8
+		return err
-	if err := read(&length); err != nil {
-		return fmt.Errorf("dhcp: reading option length for DHCP Message Type")
-	} else if length == 0 {
-		return errors.New("dhcp: read option length 0, but expected option length for DHCP Host Name is >= 1")
 	}
 
 	hostName := make([]byte, int(length))
@@ -56,9 +66,8 @@ func OptionHostName(req *BootRequest, r io.Reader) error {
 func OptionMessageType(req *BootRequest, r io.Reader) error {
 	read := newPacketReaderFunc(r)
 
-	var length uint8
+	if length, err := getOptionLength(r); err != nil {
-	if err := read(&length); err != nil {
+		return err
-		return fmt.Errorf("dhcp: reading option length for DHCP Message Type")
 	} else if length != 1 {
 		return fmt.Errorf("dhcp: read option length %d, but expected option length for DHCP Message Type is 1", length)
 	}
@@ -71,11 +80,9 @@ func OptionMessageType(req *BootRequest, r io.Reader) error {
 }
 
 func OptionParameterRequestList(req *BootRequest, r io.Reader) error {
-	read := newPacketReaderFunc(r)
+	length, err := getOptionLength(r)
-
+	if err != nil {
-	var length uint8
+		return err
-	if err := read(&length); err != nil {
-		return fmt.Errorf("dhcp: reading option length for DHCP Message Type")
 	} else if length == 0 {
 		return fmt.Errorf("dhcp: read option length %d, but expected option length for DHCP Parameter Request is >= 1", length)
 	}
@@ -96,6 +103,25 @@ func OptionParameterRequestList(req *BootRequest, r io.Reader) error {
 	return nil
 }
 
+func OptionClientID(req *BootRequest, r io.Reader) error {
+	length, err := getOptionLength(r)
+	if err != nil {
+		return err
+	} else if length == 0 {
+		return fmt.Errorf("dhcp: read option length %d, but expected option length for DHCP Parameter Request is >= 1", length)
+	}
+
+	var clientID = make([]byte, int(length))
+	if n, err := r.Read(clientID); err != nil {
+		return fmt.Errorf("dhcp: while reading client ID: %w", err)
+	} else if n != int(length) {
+		return fmt.Errorf("dhcp: only read %d bytes of client ID, expected %d bytes", n, length)
+	}
+
+	req.ClientID = string(clientID)
+	return nil
+}
+
 func OptionEnd(req *BootRequest, r io.Reader) error {
 	req.endOptions = true
 	return nil
@@ -108,7 +134,27 @@ func ReadOption(req *BootRequest, tag byte, r io.Reader) error {
 		return f(req, r)
 	}
 
-	return fmt.Errorf("dhcp: unknown/unhandled option %d", opt)
+	return readUnknownOption(req, tag, r)
+}
+
+func readUnknownOption(req *BootRequest, tag byte, r io.Reader) error {
+	length, err := getOptionLength(r)
+	if err != nil {
+		return err
+	} else if length == 0 {
+		log.Debugf("skipped option %d/%02x with length 0", tag, tag)
+		return nil
+	}
+
+	var data = make([]byte, length)
+	if n, err := r.Read(data); err != nil {
+		return fmt.Errorf("dhcp: while skipping unknown tag %d/%02x: %w", tag, tag, err)
+	} else if n != int(length) {
+		return fmt.Errorf("dhcp: only read %d bytes of unknown tag %d/%02x, expected %d bytes", n, tag, tag, length)
+	}
+
+	log.Infof("skipped unknown tag %d/%02x with data %0x", tag, tag, data)
+	return nil
 }
 
 const magicCookieLength = 4

go.mod

@@ -2,12 +2,16 @@ module git.wntrmute.dev/kyle/kdhcp
 
 go 1.20
 
-require github.com/hashicorp/go-syslog v1.0.0
+require github.com/hashicorp/go-syslog v1.0.0 // indirect
 
 require (
-	github.com/davecgh/go-spew v1.1.1
 	github.com/peterbourgon/ff/v3 v3.3.0
 	gopkg.in/yaml.v2 v2.4.0
 )
 
-require git.wntrmute.dev/kyle/goutils v1.6.6 // indirect
+require github.com/davecgh/go-spew v1.1.1 // indirect
+
+require (
+	git.wntrmute.dev/kyle/goutils v1.7.0
+	github.com/benbjohnson/clock v1.3.3
+)

go.sum

@@ -1,12 +1,16 @@
-git.wntrmute.dev/kyle/goutils v1.6.6 h1:CRCBlmSXOTkShbqC6j9lgxh4lb+khzc2zpIJYGQJtnc=
+git.wntrmute.dev/kyle/goutils v1.7.0 h1:+lk6uUMcpJK49sEGEMCOns3WVd2ThH/htMWnsyXEGl8=
-git.wntrmute.dev/kyle/goutils v1.6.6/go.mod h1:p0m2YprqMXkqtxTPKCiRcmgYo/D/9DtAIRfNVFE3JBg=
+git.wntrmute.dev/kyle/goutils v1.7.0/go.mod h1:hMcPr+XSYXjQ/IRTziNVYmUmb9BPATZc+cyehSjBs0w=
+github.com/benbjohnson/clock v1.3.3 h1:g+rSsSaAzhHJYcIQE78hJ3AhyjjtQvleKDjlhdBnIhc=
+github.com/benbjohnson/clock v1.3.3/go.mod h1:J11/hYXuz8f4ySSvYwY0FKfm+ezbsZBKZxNJlLklBHA=
 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/hashicorp/go-syslog v1.0.0 h1:KaodqZuhUoZereWVIYmpUgZysurB1kBLX2j0MwMrUAE=
 github.com/hashicorp/go-syslog v1.0.0/go.mod h1:qPfqrKkXGihmCqbJM2mZgkZGvKG1dFdvsLplgctolz4=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/peterbourgon/ff/v3 v3.3.0 h1:PaKe7GW8orVFh8Unb5jNHS+JZBwWUMa2se0HM6/BI24=
 github.com/peterbourgon/ff/v3 v3.3.0/go.mod h1:zjJVUhx+twciwfDl0zBcFzl4dW8axCRyXE/eKY9RztQ=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=

iptools/BUILD.bazel

@@ -11,7 +11,10 @@ go_library(
     ],
     importpath = "git.wntrmute.dev/kyle/kdhcp/iptools",
     visibility = ["//visibility:public"],
-    deps = ["@dev_wntrmute_git_kyle_goutils//assert"],
+    deps = [
+        "@dev_wntrmute_git_kyle_goutils//assert",
+        "@dev_wntrmute_git_kyle_goutils//log",
+    ],
 )
 
 go_test(

iptools/lease_info.go

@@ -15,6 +15,10 @@ type LeaseInfo struct {
 	Expires         time.Time       `yaml:"expires"`
 }
 
+func (li *LeaseInfo) String() string {
+	return fmt.Sprintf("lease[hostname=%s addr=%s hw=%x expires=%s]", li.HostName, li.Addr, li.HardwareAddress, li.Expires)
+}
+
 type sortableLease []*LeaseInfo
 
 func (a sortableLease) Len() int           { return len(a) }

iptools/pool.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"git.wntrmute.dev/kyle/goutils/assert"
+	"git.wntrmute.dev/kyle/goutils/log"
 )
 
 const DefaultExpiry = 168 * time.Hour
@@ -23,7 +24,7 @@ type Pool struct {
 }
 
 func (p *Pool) lock() {
-	if p.lock == nil {
+	if p.mtx == nil {
 		p.mtx = &sync.Mutex{}
 	}
 
@@ -48,6 +49,7 @@ func NewPool(name string, r *Range) (*Pool, error) {
 		Expiry:     r.Expiry,
 		NoHostName: r.NoHostName,
 		Available:  enumerateRange(name, r, true),
+		Limbo:      map[netip.Addr]*LeaseInfo{},
 	}
 
 	return p, nil
@@ -114,39 +116,40 @@ func (p *Pool) Accept(addr netip.Addr, t time.Time) error {
 
 // Update checks expirations on leases, moving any expired leases back
 // to the available pool and removing any limbo leases that are expired.
-func (p *Pool) Update(t time.Time) {
+func (p *Pool) Update(t time.Time) bool {
 	p.lock()
 	defer p.unlock()
 
-	p.update(t)
+	return p.update(t)
 }
 
-func (p *Pool) update(t time.Time) {
+func (p *Pool) update(t time.Time) bool {
-	evictedHosts := []netip.Addr{}
+	var updated bool
 
 	for k, v := range p.Active {
 		if v.IsExpired(t) {
-			evictedHosts = append(evictedHosts, k)
+			updated = true
+			log.Infof("expiring active address %s for %x", v.Addr, v.HardwareAddress)
+			delete(p.Active, k)
 			v = v.Reset()
 			p.Available = append(p.Available, v)
 		}
 	}
 
-	for _, ip := range evictedHosts {
-		delete(p.Active, ip)
-	}
-
 	for k, v := range p.Limbo {
 		if v.IsExpired(t) {
+			updated = true
+			log.Infof("expiring limbo address %s for %x", v.Addr, v.HardwareAddress)
 			delete(p.Limbo, k)
 			v = v.Reset()
 			p.Available = append(p.Available, v)
 		}
 	}
 
-	p.Sort()
+	p.sort()
+	return updated
 }
 
-func (p *Pool) Renew(lease LeaseInfo, t time.Time) {
+func (p *Pool) Renew(lease *LeaseInfo, t time.Time) {
-
+	p.Active[lease.Addr].ResetExpiry(t, p.Expiry)
 }

server/BUILD.bazel

@@ -15,7 +15,8 @@ go_library(
         "//config",
         "//dhcp",
         "//iptools",
-        "@dev_wntrmute_git_kyle_goutils//syslog",
+        "@com_github_benbjohnson_clock//:clock",
+        "@dev_wntrmute_git_kyle_goutils//log",
         "@in_gopkg_yaml_v2//:yaml_v2",
     ],
 )

server/lease_state.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"os"
 
-	log "git.wntrmute.dev/kyle/goutils/syslog"
+	log "git.wntrmute.dev/kyle/goutils/log"
 	"git.wntrmute.dev/kyle/kdhcp/iptools"
 	"gopkg.in/yaml.v2"
 )

server/pools.go

@@ -3,8 +3,9 @@ package server
 import (
 	"fmt"
 	"net/netip"
+	"time"
 
-	log "git.wntrmute.dev/kyle/goutils/syslog"
+	log "git.wntrmute.dev/kyle/goutils/log"
 	"git.wntrmute.dev/kyle/kdhcp/iptools"
 )
 
@@ -35,3 +36,14 @@ func (srv *Server) loadPoolsFromConfig() error {
 
 	return nil
 }
+
+func (srv *Server) updatePoolLoop() {
+	for {
+		time.Sleep(time.Minute)
+		for _, p := range srv.Pools {
+			if p.Update(srv.clock.Now()) {
+				log.Debugln("pools updated")
+			}
+		}
+	}
+}

server/server.go

@@ -5,10 +5,11 @@ import (
 	"net"
 	"time"
 
-	log "git.wntrmute.dev/kyle/goutils/syslog"
+	log "git.wntrmute.dev/kyle/goutils/log"
 	"git.wntrmute.dev/kyle/kdhcp/config"
 	"git.wntrmute.dev/kyle/kdhcp/dhcp"
 	"git.wntrmute.dev/kyle/kdhcp/iptools"
+	"github.com/benbjohnson/clock"
 )
 
 const (
@@ -22,6 +23,8 @@ type Server struct {
 	Config *config.Config
 	Pools  map[string]*iptools.Pool
 	Static map[string]*iptools.LeaseInfo
+
+	clock clock.Clock
 }
 
 func (s *Server) Close() error {
@@ -62,23 +65,34 @@ func (s *Server) WriteTo(b []byte, addr net.Addr) error {
 	return errors.New("server: not implemented")
 }
 
-func (s *Server) AcceptPacket() error {
+func (s *Server) AcceptPacket() (*dhcp.BootRequest, error) {
 	request, err := s.ReadDHCPRequest()
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	log.Debugf("BOOTP request received from %x", request.HardwareAddress)
-	return nil
+	return request, nil
 }
 
 func (s *Server) Listen() {
+	go s.updatePoolLoop()
+
 	for {
-		if err := s.AcceptPacket(); err != nil {
+		req, err := s.AcceptPacket()
+		if err != nil {
 			log.Errf("server: error reading packet: %s", err)
 			continue
 		}
-		break
+
+		lease := s.SelectLease(req, s.clock.Now())
+		if err != nil {
+			log.Err("server: couldn't find available lease")
+			continue
+		}
+
+		log.Infof("available lease: %s", lease)
+		continue
 	}
 }
 
@@ -87,6 +101,7 @@ func New(cfg *config.Config) (*Server, error) {
 		Config: cfg,
 		Pools:  map[string]*iptools.Pool{},
 		Static: map[string]*iptools.LeaseInfo{},
+		clock:  clock.New(),
 	}
 
 	if err := srv.loadPoolsFromConfig(); err != nil {