volume: validate copy/tail source addresses before dialing (#11390)

* pb: stop exiting the process on malformed server addresses

ServerToGrpcAddress and GrpcAddressToServerAddress called glog.Fatalf
when hostAndPort could not parse the port, which os.Exit(255)ed the whole
process. A caller-supplied copy or tail source address reached this path
synchronously in the serving goroutine, so one anonymous VolumeCopy with
a non-numeric port terminated the volume server.

Log the parse error and return the input unchanged instead: the dial or
request that consumes the address then fails as an ordinary error.

* volume: validate copy and tail source addresses before dialing

VolumeCopy, VolumeEcShardsCopy and VolumeTailReceiver dial a
caller-supplied source address (SourceDataNode / SourceVolumeServer)
with no endpoint validation, so an anonymous caller could aim the volume
server at loopback, link-local (cloud metadata) or other unintended
destinations and read dial behavior back as a connectivity oracle.

Apply the same peer-target deny list FetchAndWriteNeedle uses for
replica targets: the source must be a bare host:port whose host is not
loopback, link-local or unspecified; cluster peers stay reachable on
private networks, and -volume.allowUntrustedRemoteEndpoints opts out.
The loopback-using copy tests set the flag to keep exercising the copy
path in process.

* rust volume: validate copy and tail source addresses before dialing

Mirror the Go guard on the Rust volume server: volume_copy,
volume_ec_shards_copy and volume_tail_receiver dial a caller-supplied
source address, so run it through validate_replica_target first (bare
host:port; no loopback, link-local or unspecified hosts; private peers
stay allowed). --volume.allowUntrustedRemoteEndpoints opts out; the test
fixture and the Rust test-cluster launcher set it so loopback sources in
tests keep working.

* volume: pin validated copy/tail source addresses at dial time

validateReplicaTarget resolves the source hostname once, but the gRPC
client resolved it again at connect, leaving a DNS-rebinding window for
hostname sources. The copy and tail source dials now run through the
same guardedDialerPolicy the remote-storage path uses, so every resolved
address is re-checked against the replica deny list (private peers
allowed) immediately before the TCP connect. guardedDialerPolicy also
moves to util.OutboundDialContext so the guarded path keeps the -ip.bind
source binding the default gRPC dialer had.

The Rust volume server mirrors this with connect_guarded, a tonic
connector that resolves, re-checks each address, and connects to the
first passing IP; handlers use it whenever the untrusted-endpoint
opt-out is off. A handler-level test now exercises the enabled
validation branches for all three source-taking RPCs.

* pb: return empty server address for malformed grpc addresses

GrpcAddressToServerAddress used to return the unparseable input on a
hostAndPort failure, so a malformed raft address (e.g. "host:abc")
flowed into admin dashboard master maps unchanged. Return an empty
string instead, skip empty conversions at the two raft-cluster merge
sites, and drop the now-stale comment about the fatal exit the earlier
commit removed.

* test: opt erasure-coding loopback clusters out of the remote endpoint guard

The erasure-coding suites drive VolumeEcShardsCopy / VolumeCopy between
volume servers bound to 127.0.0.1, which the copy/tail source guard now
rejects by default. Pass -volume.allowUntrustedRemoteEndpoints to the
test volume launches, matching what the volume_server framework
harnesses already do.

* admin: only claim fallback master leadership on an empty raft response

A nonempty RaftListClusterServers response whose entries were all
rejected left masterMap empty, so the fallback marked the reachable
current master as leader the same way a genuinely empty (non-raft)
response does. Track whether the successful response returned zero
servers and only promote the fallback master then.

test/erasure_coding/admin_dockertest/ec_integration_test.go

@@ -129,7 +129,7 @@ func ensureEnvironment(t *testing.T) {
 			port := 8080 + i - 1
 			dir := filepath.Join("tmp", volName)
 			os.MkdirAll(dir, 0755)
-			startWeed(t, volName, "volume", "-dir="+dir, "-mserver=localhost:9333", fmt.Sprintf("-port=%d", port), "-ip=localhost")
+			startWeed(t, volName, "volume", "-dir="+dir, "-mserver=localhost:9333", fmt.Sprintf("-port=%d", port), "-ip=localhost", "-volume.allowUntrustedRemoteEndpoints")
 		}(i)
 	}
 	volWg.Wait()

test/erasure_coding/chaos_lifecycle_test.go

@@ -1215,6 +1215,7 @@ func (c *chaosCluster) startVolumeServer(ctx context.Context, i int, logName str
 		"-max", strings.Join(maxVolumes, ","),
 		"-minFreeSpace", "0",
 		"-master", chaosMasterAddr,
+		"-volume.allowUntrustedRemoteEndpoints",
 		"-ip", "127.0.0.1",
 		"-dataCenter", "dc1",
 		"-rack", fmt.Sprintf("rack%d", i),

test/erasure_coding/ec_integration_test.go

@@ -439,6 +439,7 @@ func startSeaweedFSCluster(ctx context.Context, dataDir string) (*TestCluster, e
 			"-dir", volumeDir,
 			"-max", "10",
 			"-master", "127.0.0.1:9333",
+			"-volume.allowUntrustedRemoteEndpoints",
 			"-ip", "127.0.0.1",
 			"-dataCenter", "dc1",
 			"-rack", rack,
@@ -1082,6 +1083,7 @@ func startMultiDiskCluster(ctx context.Context, dataDir string) (*MultiDiskClust
 			"-dir", strings.Join(diskDirs, ","),
 			"-max", strings.Join(maxVolumes, ","),
 			"-master", "127.0.0.1:9334",
+			"-volume.allowUntrustedRemoteEndpoints",
 			"-ip", "127.0.0.1",
 			"-dataCenter", "dc1",
 			"-rack", rack,
@@ -1478,6 +1480,7 @@ func startClusterWithDiskType(ctx context.Context, dataDir string, diskType stri
 			"-dir", diskDir,
 			"-max", "10",
 			"-mserver", "127.0.0.1:9335",
+			"-volume.allowUntrustedRemoteEndpoints",
 			"-ip", "127.0.0.1",
 			"-dataCenter", "dc1",
 			"-rack", rack,
@@ -1708,6 +1711,7 @@ func startMixedDiskTypeCluster(ctx context.Context, dataDir string) (*MultiDiskC
 			"-dir", diskDir,
 			"-max", "10",
 			"-mserver", "127.0.0.1:9336",
+			"-volume.allowUntrustedRemoteEndpoints",
 			"-ip", "127.0.0.1",
 			"-dataCenter", "dc1",
 			"-rack", rack,
@@ -2030,6 +2034,7 @@ func startLimitedSsdCluster(ctx context.Context, dataDir string) (*MultiDiskClus
 			"-dir", diskDir,
 			"-max", "10",
 			"-mserver", "127.0.0.1:9337",
+			"-volume.allowUntrustedRemoteEndpoints",
 			"-ip", "127.0.0.1",
 			"-dataCenter", "dc1",
 			"-rack", config.rack,
@@ -2112,6 +2117,7 @@ func startMultiRackCluster(ctx context.Context, dataDir string) (*MultiDiskClust
 			"-dir", diskDir,
 			"-max", "10",
 			"-mserver", "127.0.0.1:9338",
+			"-volume.allowUntrustedRemoteEndpoints",
 			"-ip", "127.0.0.1",
 			"-dataCenter", "dc1",
 			"-rack", rack,

test/erasure_coding/multidisk_shell_lifecycle_test.go

@@ -233,6 +233,7 @@ func (c *MultiDiskCluster) startVolumeServers(ctx context.Context) error {
 			"-dir", strings.Join(diskDirs, ","),
 			"-max", strings.Join(maxVolumes, ","),
 			"-master", "127.0.0.1:9334",
+			"-volume.allowUntrustedRemoteEndpoints",
 			"-ip", "127.0.0.1",
 			"-dataCenter", "dc1",
 			"-rack", fmt.Sprintf("rack%d", i),