Exclude loopback from valid IP addresses (#29992)

Excludes loopback IP addresses from being valid IP addresses unless private addresses are explicitly allowed

ci/localnet-sanity.sh

@@ -74,10 +74,12 @@ source multinode-demo/common.sh --prebuild
 
 nodes=(
   "multinode-demo/bootstrap-validator.sh \
+    --allow-private-addr \
     --no-restart \
     --init-complete-file init-complete-node0.log \
     --dynamic-port-range 8000-8050"
   "multinode-demo/validator.sh \
+    --allow-private-addr \
     --no-restart \
     --dynamic-port-range 8050-8100
     --init-complete-file init-complete-node1.log \
@@ -90,6 +92,7 @@ if [[ extraNodes -gt 0 ]]; then
     portEnd=$((portStart + 49))
     nodes+=(
       "multinode-demo/validator.sh \
+        --allow-private-addr \
         --no-restart \
         --dynamic-port-range $portStart-$portEnd
         --label dyn$i \
@@ -317,7 +320,7 @@ while [[ $iteration -le $iterations ]]; do
     set -x
     client_keypair=/tmp/client-id.json-$$
     $solana_keygen new --no-passphrase -fso $client_keypair || exit $?
-    $solana_gossip spy -n 127.0.0.1:8001 --num-nodes-exactly $numNodes || exit $?
+    $solana_gossip --allow-private-addr spy -n 127.0.0.1:8001 --num-nodes-exactly $numNodes || exit $?
     rm -rf $client_keypair
   ) || flag_error
 

docs/src/cluster/bench-tps.md

@@ -75,6 +75,13 @@ NDEBUG=1 SOLANA_CUDA=1 ./multinode-demo/bootstrap-validator.sh
 NDEBUG=1 SOLANA_CUDA=1 ./multinode-demo/validator.sh
 ```
 
+To run multiple nodes on the same machine using loopback IP address, pass parameter to allow private addresses
+
+```bash
+NDEBUG=1 ./multinode-demo/bootstrap-validator.sh --allow-private-addr
+NDEBUG=1 ./multinode-demo/validator-x.sh --allow-private-addr
+```
+
 ### Testnet Client Demo
 
 Now that your singlenode or multinode testnet is up and running let's send it some transactions!

streamer/src/socket.rs

@@ -24,15 +24,14 @@ impl SocketAddrSpace {
         match addr.ip() {
             IpAddr::V4(addr) => {
                 // TODO: Consider excluding:
-                //    addr.is_loopback() || addr.is_link_local()
-                // || addr.is_broadcast() || addr.is_documentation()
-                // || addr.is_unspecified()
-                !addr.is_private()
+                //    addr.is_link_local() || addr.is_broadcast()
+                // || addr.is_documentation() || addr.is_unspecified()
+                !(addr.is_private() || addr.is_loopback())
             }
-            IpAddr::V6(_) => {
+            IpAddr::V6(addr) => {
                 // TODO: Consider excluding:
-                // addr.is_loopback() || addr.is_unspecified(),
-                true
+                // addr.is_unspecified(),
+                !addr.is_loopback()
             }
         }
     }