Output iface name when --output-meta is set

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/cheggaaa/pb/v3 v3.1.4
 	github.com/cilium/ebpf v0.11.0
 	github.com/cloudflare/cbpfc v0.0.0-20221017140110-11acb56438a2
+	github.com/jsimonetti/rtnetlink v1.3.5
 	github.com/mitchellh/go-ps v1.0.0
 	github.com/spf13/pflag v1.0.5
 	github.com/vishvananda/netns v0.0.4
@@ -17,11 +18,16 @@ require (
 require (
 	github.com/VividCortex/ewma v1.2.0 // indirect
 	github.com/fatih/color v1.15.0 // indirect
+	github.com/google/go-cmp v0.5.9 // indirect
+	github.com/josharian/native v1.1.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.19 // indirect
 	github.com/mattn/go-runewidth v0.0.14 // indirect
+	github.com/mdlayher/netlink v1.7.2 // indirect
+	github.com/mdlayher/socket v0.4.1 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/rivo/uniseg v0.2.0 // indirect
 	golang.org/x/exp v0.0.0-20230224173230-c95f2b4c22f2 // indirect
 	golang.org/x/mod v0.12.0 // indirect
+	golang.org/x/sync v0.3.0 // indirect
 )

go.sum

@@ -14,6 +14,11 @@ github.com/frankban/quicktest v1.14.0/go.mod h1:NeW+ay9A/U67EYXNFA1nPE8e/tnQv/09
 github.com/frankban/quicktest v1.14.5 h1:dfYrrRyLtiqT9GyKXgdh+k4inNeTvmGbuSgZ3lx3GhA=
 github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+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 v1.3.5 h1:hVlNQNRlLDGZz31gBPicsG7Q53rnlsz1l1Ix/9XlpVA=
+github.com/jsimonetti/rtnetlink v1.3.5/go.mod h1:0LFedyiTkebnd43tE4YAkWGIq9jQphow4CcwxaT2Y00=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
@@ -28,6 +33,10 @@ github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APP
 github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/mattn/go-runewidth v0.0.14 h1:+xnbZSEeDbOIg5/mE6JF0w6n9duR1l3/WmbinWVwUuU=
 github.com/mattn/go-runewidth v0.0.14/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
+github.com/mdlayher/netlink v1.7.2 h1:/UtM3ofJap7Vl4QWCPDGXY8d3GIY2UGSDbK+QWmY8/g=
+github.com/mdlayher/netlink v1.7.2/go.mod h1:xraEF7uJbxLhc5fpHL4cPe221LI2bdttWlU+ZGLfQSw=
+github.com/mdlayher/socket v0.4.1 h1:eM9y2/jlbs1M615oshPQOHZzj6R6wMT7bX5NPiQvn2U=
+github.com/mdlayher/socket v0.4.1/go.mod h1:cAqeGjoufqdxWkD7DkpyS+wcefOtmu5OQ8KuoJGIReA=
 github.com/mitchellh/go-ps v1.0.0 h1:i6ampVEEF4wQFF+bkYfwYgY+F/uYJDktmvLPf7qIgjc=
 github.com/mitchellh/go-ps v1.0.0/go.mod h1:J4lOc8z8yJs6vUwklHw2XEIiT4z4C40KtWVN3nvg8Pg=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
@@ -47,6 +56,8 @@ golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/net v0.0.0-20210917221730-978cfadd31cf/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.15.0 h1:ugBLEUaxABaB5AJqW9enI0ACdci2RUd4eP51NTBvuJ8=
 golang.org/x/net v0.15.0/go.mod h1:idbUs1IY1+zTqbi8yxTbhexhEEk5ur9LInksu6HrEpk=
+golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
+golang.org/x/sync v0.3.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210906170528-6f6e22806c34/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

internal/pwru/output.go

@@ -5,18 +5,24 @@
 package pwru
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"log"
 	"net"
 	"os"
+	"path/filepath"
 	"runtime"
+	"strconv"
 	"syscall"
 	"time"
 
 	"github.com/cilium/ebpf"
 	"github.com/cilium/ebpf/btf"
+	"github.com/jsimonetti/rtnetlink"
 	ps "github.com/mitchellh/go-ps"
+	"github.com/vishvananda/netns"
+	"golang.org/x/sys/unix"
 
 	"github.com/cilium/pwru/internal/byteorder"
 )
@@ -32,6 +38,7 @@ type output struct {
 	writer        io.Writer
 	kprobeMulti   bool
 	kfreeReasons  map[uint64]string
+	ifaceCache    map[uint64]map[uint32]string
 }
 
 func NewOutput(flags *Flags, printSkbMap *ebpf.Map, printStackMap *ebpf.Map,
@@ -52,6 +59,14 @@ func NewOutput(flags *Flags, printSkbMap *ebpf.Map, printStackMap *ebpf.Map,
 		log.Printf("Unable to load packet drop reaons: %v", err)
 	}
 
+	var ifs map[uint64]map[uint32]string
+	if flags.OutputMeta {
+		ifs, err = getIfaces()
+		if err != nil {
+			log.Printf("Failed to retrieve all ifaces from all network namespaces: %v. Some iface names might be not shown.", err)
+		}
+	}
+
 	return &output{
 		flags:         flags,
 		lastSeenSkb:   map[uint64]uint64{},
@@ -61,6 +76,7 @@ func NewOutput(flags *Flags, printSkbMap *ebpf.Map, printStackMap *ebpf.Map,
 		writer:        writer,
 		kprobeMulti:   kprobeMulti,
 		kfreeReasons:  reasons,
+		ifaceCache:    ifs,
 	}, nil
 }
 
@@ -132,7 +148,10 @@ func (o *output) Print(event *Event) {
 	o.lastSeenSkb[event.SAddr] = event.Timestamp
 
 	if o.flags.OutputMeta {
-		fmt.Fprintf(o.writer, " netns=%d mark=0x%x ifindex=%d proto=%x mtu=%d len=%d", event.Meta.Netns, event.Meta.Mark, event.Meta.Ifindex, event.Meta.Proto, event.Meta.MTU, event.Meta.Len)
+		fmt.Fprintf(o.writer, " netns=%d mark=0x%x iface=%s proto=%x mtu=%d len=%d",
+			event.Meta.Netns, event.Meta.Mark,
+			o.getIfaceName(event.Meta.Netns, event.Meta.Ifindex),
+			event.Meta.Proto, event.Meta.MTU, event.Meta.Len)
 	}
 
 	if o.flags.OutputTuple {
@@ -165,6 +184,15 @@ func (o *output) Print(event *Event) {
 	fmt.Fprintln(o.writer)
 }
 
+func (o *output) getIfaceName(netnsInode, ifindex uint32) string {
+	if ifaces, ok := o.ifaceCache[uint64(netnsInode)]; ok {
+		if name, ok := ifaces[ifindex]; ok {
+			return fmt.Sprintf("%d(%s)", ifindex, name)
+		}
+	}
+	return fmt.Sprintf("%d", ifindex)
+}
+
 func protoToStr(proto uint8) string {
 	switch proto {
 	case syscall.IPPROTO_TCP:
@@ -212,3 +240,97 @@ func getKFreeSKBReasons(spec *btf.Spec) (map[uint64]string, error) {
 
 	return ret, nil
 }
+
+func getIfaces() (map[uint64]map[uint32]string, error) {
+	var err error
+	procPath := "/proc"
+
+	ifaceCache := make(map[uint64]map[uint32]string)
+
+	dirs, err := os.ReadDir(procPath)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, d := range dirs {
+		if !d.IsDir() {
+			continue
+		}
+
+		// skip non-process dirs
+		if _, err := strconv.Atoi(d.Name()); err != nil {
+			continue
+		}
+
+		// get inode of netns
+		path := filepath.Join(procPath, d.Name(), "ns", "net")
+		fd, err0 := os.Open(path)
+		if err0 != nil {
+			err = errors.Join(err, err0)
+			continue
+		}
+		var stat unix.Stat_t
+		if err0 := unix.Fstat(int(fd.Fd()), &stat); err != nil {
+			err = errors.Join(err, err0)
+			continue
+		}
+		inode := stat.Ino
+
+		if _, exists := ifaceCache[inode]; exists {
+			continue // we already checked that netns
+		} else {
+			ifaceCache[inode] = make(map[uint32]string)
+		}
+
+		ifaces, err0 := getIfacesInNetNs(path)
+		if err0 != nil {
+			err = errors.Join(err, err0)
+			continue
+		}
+
+		ifaceCache[inode] = ifaces
+
+	}
+
+	return ifaceCache, err
+
+}
+
+func getIfacesInNetNs(path string) (map[uint32]string, error) {
+	current, err := netns.Get()
+	if err != nil {
+		return nil, err
+	}
+
+	remote, err := netns.GetFromPath(path)
+	if err != nil {
+		return nil, err
+	}
+
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	if err := netns.Set(remote); err != nil {
+		return nil, err
+	}
+
+	defer netns.Set(current)
+
+	conn, err := rtnetlink.Dial(nil)
+	if err != nil {
+		return nil, err
+	}
+	defer conn.Close()
+
+	msg, err := conn.Link.List()
+	if err != nil {
+		return nil, err
+	}
+
+	ifaces := make(map[uint32]string)
+	for _, link := range msg {
+		ifaces[link.Index] = link.Attributes.Name
+	}
+
+	return ifaces, nil
+}