feat: lldp

.golangci.yml

@@ -29,6 +29,9 @@ linters:
       - linters:
           - gochecknoinits
         path: internal/logging/sse.go
+      - linters:
+          - govet
+        path: internal/lldp/bpf.go
     paths:
       - third_party$
       - builtin$

.vscode/settings.json

@@ -10,5 +10,6 @@
     ]
   },
   "git.ignoreLimitWarning": true,
-  "cmake.sourceDirectory": "/workspaces/kvm-static-ip/internal/native/cgo"
+  "cmake.sourceDirectory": "/workspaces/kvm-static-ip/internal/native/cgo",
+  "cmake.ignoreCMakeListsMissing": true
 }

go.mod

@@ -55,13 +55,16 @@ require (
 	github.com/go-playground/universal-translator v0.18.1 // indirect
 	github.com/go-playground/validator/v10 v10.27.0 // indirect
 	github.com/goccy/go-json v0.10.5 // indirect
+	github.com/google/gopacket v1.1.19 // indirect
+	github.com/jellydator/ttlcache/v3 v3.4.0 // indirect
 	github.com/jonboulle/clockwork v0.5.0 // indirect
 	github.com/josharian/native v1.1.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/klauspost/cpuid/v2 v2.3.0 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
 	github.com/mattn/go-colorable v0.1.14 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/mdlayher/ethernet v0.0.0-20220221185849-529eae5b6118 // indirect
 	github.com/mdlayher/packet v1.1.2 // indirect
 	github.com/mdlayher/socket v0.4.1 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect

go.sum

@@ -57,9 +57,13 @@ github.com/go-playground/validator/v10 v10.27.0/go.mod h1:I5QpIEbmr8On7W0TktmJAu
 github.com/goccy/go-json v0.10.5 h1:Fq85nIqj+gXn/S5ahsiTlK3TmC85qgirsdTP/+DeaC4=
 github.com/goccy/go-json v0.10.5/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PULtXL6M=
 github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
+github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8/DtOE=
 github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
 github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/google/gopacket v1.1.19 h1:ves8RnFZPGiFnTS0uPQStjwru6uO6h+nlr9j6fL7kF8=
+github.com/google/gopacket v1.1.19/go.mod h1:iJ8V8n6KS+z2U1A8pUwu8bW5SyEMkXJB8Yo/Vo+TKTo=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/guregu/null/v6 v6.0.0 h1:N14VRS+4di81i1PXRiprbQJ9EM9gqBa0+KVMeS/QSjQ=
@@ -70,8 +74,11 @@ github.com/hugelgupf/socketpair v0.0.0-20190730060125-05d35a94e714 h1:/jC7qQFrv8
 github.com/hugelgupf/socketpair v0.0.0-20190730060125-05d35a94e714/go.mod h1:2Goc3h8EklBH5mspfHFxBnEoURQCGzQQH1ga9Myjvis=
 github.com/insomniacslk/dhcp v0.0.0-20250919081422-f80a1952f48e h1:nu5z6Kg+gMNW6tdqnVjg/QEJ8Nw71IJQqOtWj00XHEU=
 github.com/insomniacslk/dhcp v0.0.0-20250919081422-f80a1952f48e/go.mod h1:qfvBmyDNp+/liLEYWRvqny/PEz9hGe2Dz833eXILSmo=
+github.com/jellydator/ttlcache/v3 v3.4.0 h1:YS4P125qQS0tNhtL6aeYkheEaB/m8HCqdMMP4mnWdTY=
+github.com/jellydator/ttlcache/v3 v3.4.0/go.mod h1:Hw9EgjymziQD3yGsQdf1FqFdpp7YjFMd4Srg5EJlgD4=
 github.com/jonboulle/clockwork v0.5.0 h1:Hyh9A8u51kptdkR+cqRpT1EebBwTn1oK9YfGYbdFz6I=
 github.com/jonboulle/clockwork v0.5.0/go.mod h1:3mZlmanh0g2NDKO5TWZVJAfofYk64M7XN3SzBPjZF60=
+github.com/josharian/native v1.0.0/go.mod h1:7X/raswPFr05uY3HiLlYeyQntB6OO7E/d2Cu7qoaN2w=
 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=
@@ -99,10 +106,14 @@ github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/
 github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
 github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/mdlayher/ethernet v0.0.0-20220221185849-529eae5b6118 h1:2oDp6OOhLxQ9JBoUuysVz9UZ9uI6oLUbvAZu0x8o+vE=
+github.com/mdlayher/ethernet v0.0.0-20220221185849-529eae5b6118/go.mod h1:ZFUnHIVchZ9lJoWoEGUg8Q3M4U8aNNWA3CVSUTkW4og=
 github.com/mdlayher/ndp v1.1.0 h1:QylGKGVtH60sKZUE88+IW5ila1Z/M9/OXhWdsVKuscs=
 github.com/mdlayher/ndp v1.1.0/go.mod h1:FmgESgemgjl38vuOIyAHWUUL6vQKA/pQNkvXdWsdQFM=
+github.com/mdlayher/packet v1.0.0/go.mod h1:eE7/ctqDhoiRhQ44ko5JZU2zxB88g+JH/6jmnjzPjOU=
 github.com/mdlayher/packet v1.1.2 h1:3Up1NG6LZrsgDVn6X4L9Ge/iyRyxFEFD9o6Pr3Q1nQY=
 github.com/mdlayher/packet v1.1.2/go.mod h1:GEu1+n9sG5VtiRE4SydOmX5GTwyyYlteZiFU+x0kew4=
+github.com/mdlayher/socket v0.2.1/go.mod h1:QLlNPkFR88mRUNQIzRBMfXxwKal8H7u1h3bL1CV+f0E=
 github.com/mdlayher/socket v0.4.1 h1:eM9y2/jlbs1M615oshPQOHZzj6R6wMT7bX5NPiQvn2U=
 github.com/mdlayher/socket v0.4.1/go.mod h1:cAqeGjoufqdxWkD7DkpyS+wcefOtmu5OQ8KuoJGIReA=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
@@ -206,14 +217,28 @@ go.yaml.in/yaml/v2 v2.4.3 h1:6gvOSjQoTB3vt1l+CU+tSyi/HOjfOjRLJ4YwYZGwRO0=
 go.yaml.in/yaml/v2 v2.4.3/go.mod h1:zSxWcmIDjOzPXpjlTTbAsKokqkDNAVtZO0WOMiT90s8=
 golang.org/x/arch v0.20.0 h1:dx1zTU0MAE98U+TQ8BLl7XsJbgze2WnNKF/8tGp/Q6c=
 golang.org/x/arch v0.20.0/go.mod h1:bdwinDaKcfZUGpH09BB7ZmOfhalA8lQdzl62l8gGWsk=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.43.0 h1:dduJYIi3A3KOfdGOHX8AVZ/jGiyPa3IbBozJ5kNuE04=
 golang.org/x/crypto v0.43.0/go.mod h1:BFbav4mRNlXJL4wNeejLpWxB7wMbc79PdRGhWKncxR0=
+golang.org/x/lint v0.0.0-20200302205851-738671d3881b/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
+golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190503192946-f4e77d36d62c/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 v0.46.0 h1:giFlY12I07fugqwPuWJi68oOnpfqFnJIJzaIIm2JVV4=
 golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/oauth2 v0.32.0 h1:jsCblLleRMDrxMN29H3z/k1KliIvpLgCkE6R8FXXNgY=
 golang.org/x/oauth2 v0.32.0/go.mod h1:lzm5WQJQwKZ3nwavOZ3IS5Aulzxi68dUSgRHujetwEA=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.17.0 h1:l60nONMj9l5drqw6jlhIELNv9I0A4OFgRsG9k2oT9Ug=
 golang.org/x/sync v0.17.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220209214540-3681064d5158/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220622161953-175b2fd9d664/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
@@ -224,8 +249,12 @@ golang.org/x/sys v0.37.0 h1:fdNQudmxPjkdUTPnLn5mdQv7Zwvbvpaxqs831goi9kQ=
 golang.org/x/sys v0.37.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 golang.org/x/term v0.36.0 h1:zMPR+aF8gfksFprF/Nc/rd1wRS1EI6nDBGyWAvDzx2Q=
 golang.org/x/term v0.36.0/go.mod h1:Qu394IJq6V6dCBRgwqshf3mPF85AqzYEzofzRdZkWss=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.30.0 h1:yznKA/E9zq54KzlzBEAWn1NXSQ8DIp/NYMy88xJjl4k=
 golang.org/x/text v0.30.0/go.mod h1:yDdHFIX9t+tORqspjENWgzaCVXgk0yYnYuSZ8UzzBVM=
+golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/protobuf v1.36.10 h1:AYd7cD/uASjIL6Q9LiTjz8JLcrh/88q5UObnmY3aOOE=
 google.golang.org/protobuf v1.36.10/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

internal/lldp/afpacket.go

@@ -0,0 +1,109 @@
+package lldp
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"syscall"
+	"unsafe"
+
+	"github.com/google/gopacket/afpacket"
+	"golang.org/x/sys/unix"
+)
+
+const (
+	afPacketBufferSize = 2 // in MiB
+	afPacketSnaplen    = 9216
+)
+
+// afpacketComputeSize computes the block_size and the num_blocks in such a way that the
+// allocated mmap buffer is close to but smaller than targetSizeMb.
+// The restriction is that the blockSize must be divisible by both the
+// frameSize and pageSize.
+//
+// See also: https://github.com/google/gopacket/blob/master/examples/afpacket/afpacket.go#L118
+func afPacketComputeSize(
+	targetSizeMb int,
+	snapLen int,
+	pageSize int,
+) (
+	frameSize int,
+	blockSize int,
+	numBlocks int,
+	err error,
+) {
+	if snapLen < pageSize {
+		// When snapLen < pageSize, find the largest value <= pageSize that
+		// is a multiple of snapLen and divides evenly into pageSize.
+		// This ensures frameSize is a divisor of pageSize.
+		// Example: snapLen=512, pageSize=4096 -> frameSize=512
+		// Example: snapLen=1000, pageSize=4096 -> frameSize=1024
+		frameSize = pageSize / (pageSize / snapLen)
+	} else {
+		// When snapLen >= pageSize, round up to the next multiple of pageSize.
+		// Example: snapLen=9216, pageSize=4096 -> frameSize=12288 (3 pages)
+		frameSize = ((snapLen / pageSize) + 1) * pageSize
+	}
+
+	// 128 is the default from the gopacket library so just use that
+	blockSize = frameSize * 128
+	numBlocks = (targetSizeMb * 1024 * 1024) / blockSize
+
+	if numBlocks == 0 {
+		return 0, 0, 0, fmt.Errorf("interface bufferSize is too small")
+	}
+
+	return frameSize, blockSize, numBlocks, nil
+}
+
+func afPacketNewTPacket(ifName string) (*afpacket.TPacket, error) {
+	szFrame, szBlock, numBlocks, err := afPacketComputeSize(
+		afPacketBufferSize,
+		afPacketSnaplen,
+		os.Getpagesize(),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return afpacket.NewTPacket(
+		afpacket.OptInterface(ifName),
+		afpacket.OptFrameSize(szFrame),
+		afpacket.OptBlockSize(szBlock),
+		afpacket.OptNumBlocks(numBlocks),
+		afpacket.OptAddVLANHeader(false),
+		afpacket.SocketRaw,
+		afpacket.TPacketVersion3,
+	)
+}
+
+type ifreq struct {
+	ifrName   [IFNAMSIZ]byte
+	ifrHwaddr syscall.RawSockaddr
+}
+
+func addMulticastAddr(ifName string, addr net.HardwareAddr) error {
+	fd, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, 0)
+	if err != nil {
+		return err
+	}
+	defer syscall.Close(fd)
+
+	var name [IFNAMSIZ]byte
+	copy(name[:], []byte(ifName))
+
+	ifr := &ifreq{
+		ifrName:   name,
+		ifrHwaddr: toRawSockaddr(addr),
+	}
+
+	_, _, ep := unix.Syscall(
+		unix.SYS_IOCTL, uintptr(fd),
+		unix.SIOCADDMULTI, uintptr(unsafe.Pointer(ifr)),
+	)
+
+	if ep != 0 {
+		return syscall.Errno(ep)
+	}
+	return nil
+}

internal/lldp/afpacket_arm.go

@@ -0,0 +1,15 @@
+//go:build arm && linux
+
+package lldp
+
+import (
+	"net"
+	"syscall"
+)
+
+func toRawSockaddr(mac net.HardwareAddr) (sockaddr syscall.RawSockaddr) {
+	for i, n := range mac {
+		sockaddr.Data[i] = uint8(n)
+	}
+	return
+}

internal/lldp/afpacket_nonarm.go

@@ -0,0 +1,15 @@
+//go:build !arm && linux
+
+package lldp
+
+import (
+	"net"
+	"syscall"
+)
+
+func toRawSockaddr(mac net.HardwareAddr) (sockaddr syscall.RawSockaddr) {
+	for i, n := range mac {
+		sockaddr.Data[i] = int8(n)
+	}
+	return
+}

internal/lldp/bpf.go

@@ -0,0 +1,21 @@
+package lldp
+
+import "golang.org/x/net/bpf"
+
+// from lldpd
+// https://github.com/lldpd/lldpd/blob/9034c9332cca0c8b1a20e1287f0e5fed81f7eb2a/src/daemon/lldpd.h#L246
+var bpfFilter = []bpf.RawInstruction{
+	{0x30, 0, 0, 0x00000000}, {0x54, 0, 0, 0x00000001}, {0x15, 0, 16, 0x00000001},
+	{0x28, 0, 0, 0x0000000c}, {0x15, 0, 6, 0x000088cc},
+	{0x20, 0, 0, 0x00000002}, {0x15, 2, 0, 0xc200000e},
+	{0x15, 1, 0, 0xc2000003}, {0x15, 0, 2, 0xc2000000},
+	{0x28, 0, 0, 0x00000000}, {0x15, 12, 13, 0x00000180},
+	{0x20, 0, 0, 0x00000002}, {0x15, 0, 2, 0x52cccccc},
+	{0x28, 0, 0, 0x00000000}, {0x15, 8, 9, 0x000001e0},
+	{0x15, 1, 0, 0x0ccccccc}, {0x15, 0, 2, 0x81000100},
+	{0x28, 0, 0, 0x00000000}, {0x15, 4, 5, 0x00000100},
+	{0x20, 0, 0, 0x00000002}, {0x15, 0, 3, 0x2b000000},
+	{0x28, 0, 0, 0x00000000}, {0x15, 0, 1, 0x000000e0},
+	{0x6, 0, 0, 0x00040000},
+	{0x6, 0, 0, 0x00000000},
+}