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wgengine/netstack, net/ping: stop using pro-bing and use our net/ping instead

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Fixes #19633
Fixes #13760

Change-Id: I0fa9423523a3a0fb1dfcde57de0f26e51723ff97
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick
2026-05-04 19:46:00 +00:00
committed by Brad Fitzpatrick
parent 81569e891f
commit 883d4fd2cd
12 changed files with 108 additions and 76 deletions
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net/ping/ping.go
+62 -13
View File
@@ -29,8 +29,10 @@ import (
)
const (
v4Type = "ip4:icmp"
v6Type = "ip6:icmp"
v4Type = "ip4:icmp"
v6Type = "ip6:icmp"
v4UDPType = "udp4" // unprivileged datagram-oriented ICMPv4
v6UDPType = "udp6" // unprivileged datagram-oriented ICMPv6
)
type response struct {
@@ -54,12 +56,30 @@ type ListenPacketer interface {
// A new instance should be created for each concurrent set of ping requests;
// this type should not be reused.
type Pinger struct {
// options that must be set before the first call to Send
// Unprivileged, when set, makes the Pinger use non-privileged
// datagram-oriented ICMP sockets ("udp4"/"udp6") opened via
// golang.org/x/net/icmp.ListenPacket instead of raw ICMP sockets
// ("ip4:icmp"/"ip6:icmp") opened via the configured ListenPacketer.
//
// Unprivileged mode is supported on macOS, iOS, and Linux (subject to
// the /proc/sys/net/ipv4/ping_group_range sysctl). When set, the
// ListenPacketer passed to New is ignored and the kernel rewrites the
// outgoing ICMP echo ID to match the socket; replies are matched by
// sequence number and echo data only.
//
// Must be set before the first call to Send.
Unprivileged bool
Verbose bool // verbose logging
Logf logger.Logf // optional logging function; if nil, logs to the standard logger
lp ListenPacketer
// closed guards against send incrementing the waitgroup concurrently with close.
closed atomic.Bool
Logf logger.Logf
Verbose bool
closed atomic.Bool
timeNow func() time.Time
id uint16 // uint16 per RFC 792
wg sync.WaitGroup
@@ -95,7 +115,17 @@ func (p *Pinger) mkconn(ctx context.Context, typ, addr string) (net.PacketConn,
return nil, net.ErrClosed
}
c, err := p.lp.ListenPacket(ctx, typ, addr)
var c net.PacketConn
var err error
if p.Unprivileged {
// icmp.ListenPacket on "udp4"/"udp6" opens a datagram-oriented
// ICMP socket that does not require elevated privileges. The
// returned *icmp.PacketConn implements net.PacketConn and, on
// Darwin/iOS, strips the IPv4 header on read via IP_STRIPHDR.
c, err = icmp.ListenPacket(typ, addr)
} else {
c, err = p.lp.ListenPacket(ctx, typ, addr)
}
if err != nil {
return nil, err
}
@@ -125,7 +155,7 @@ func (p *Pinger) getConn(ctx context.Context, typ string) (net.PacketConn, error
}
var addr = "0.0.0.0"
if typ == v6Type {
if typ == v6Type || typ == v6UDPType {
addr = "::"
}
c, err := p.mkconn(ctx, typ, addr)
@@ -216,9 +246,9 @@ func (p *Pinger) handleResponse(buf []byte, now time.Time, typ string) {
// and IPv6.
var icmpType icmp.Type
switch typ {
case v4Type:
case v4Type, v4UDPType:
icmpType = ipv4.ICMPTypeEchoReply
case v6Type:
case v6Type, v6UDPType:
icmpType = ipv6.ICMPTypeEchoReply
default:
p.vlogf("handleResponse: unknown icmp.Type")
@@ -243,7 +273,10 @@ func (p *Pinger) handleResponse(buf []byte, now time.Time, typ string) {
}
// We assume we sent this if the ID in the response is ours.
if uint16(resp.ID) != p.id {
// In unprivileged ICMP DGRAM mode the kernel rewrites the ID to match
// the socket, so the value we set on the way out is not what comes
// back; rely on sequence and data matching instead.
if !p.Unprivileged && uint16(resp.ID) != p.id {
p.vlogf("handleResponse: wanted ID=%d; got %d", p.id, resp.ID)
return
}
@@ -294,14 +327,30 @@ func (p *Pinger) Send(ctx context.Context, dest net.Addr, data []byte) (time.Dur
}
if ap.Is6() {
icmpType = ipv6.ICMPTypeEchoRequest
conn, err = p.getConn(ctx, v6Type)
typ := v6Type
if p.Unprivileged {
typ = v6UDPType
}
conn, err = p.getConn(ctx, typ)
} else {
conn, err = p.getConn(ctx, v4Type)
typ := v4Type
if p.Unprivileged {
typ = v4UDPType
}
conn, err = p.getConn(ctx, typ)
}
if err != nil {
return 0, err
}
// In unprivileged ICMP DGRAM mode (icmp.ListenPacket on "udp4"/"udp6"),
// the kernel requires a *net.UDPAddr destination for WriteTo even though
// the wire packet is ICMP.
writeDst := dest
if p.Unprivileged {
writeDst = &net.UDPAddr{IP: ap.AsSlice(), Zone: ap.Zone()}
}
m := icmp.Message{
Type: icmpType,
Code: 0,
@@ -324,7 +373,7 @@ func (p *Pinger) Send(ctx context.Context, dest net.Addr, data []byte) (time.Dur
p.mu.Unlock()
start := p.timeNow()
n, err := conn.WriteTo(b, dest)
n, err := conn.WriteTo(b, writeDst)
if err != nil {
return 0, err
} else if n != len(b) {