Merge #20965: net, rpc: return NET_UNROUTABLE as not_publicly_routable, automate helps

96635e61777add29b6a34d47767a63f43b2919af init: use GetNetworkNames() in -onlynet help (Jon Atack)
0dbde700a6e9894a8ead20f2eebd0ff6554ef2d9 rpc: use GetNetworkNames() in getnetworkinfo and getpeerinfo helps (Jon Atack)
1c3af37881adbbc37fb9924bcf69c403fcae1ae7 net: create GetNetworkNames() (Jon Atack)
b45eae4d5332f1da71ba9ec983fe7818fa4d32e9 net: update NET_UNROUTABLE to not_publicly_routable in GetNetworkName() (Jon Atack)

Pull request description:

  per the IRC discussion today at http://www.erisian.com.au/bitcoin-core-dev/log-2021-01-19.html#l-87

  - return a more helpful string name for `Network::NET_UNROUTABLE`: "not_publicly_routable" instead of "unroutable"
  - update the RPC getpeerinfo "network" help, and automate it and the getnetworkinfo "network#name" and the -onlynet help doc generation

ACKs for top commit:
  theStack:
    re-ACK 96635e61777add29b6a34d47767a63f43b2919af 🌳
  MarcoFalke:
    review ACK 96635e61777add29b6a34d47767a63f43b2919af 🐗

Tree-SHA512: 511a7d987126b48a7a090739aa7c4964b6186a3ff8f5f7eec9233dd816c6b7a6dc91b3ea6b824aa68f218a8a3ebdc6ffd214e9a88af38f2bf23f3257c4284c3a

7 files changed, 29 insertions, 7 deletions

diff --git a/src/init.cpp b/src/init.cpp
index f71fae41e7..96fb32ce2a 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -446,7 +446,7 @@ void SetupServerArgs(NodeContext& node)
     argsman.AddArg("-maxtimeadjustment", strprintf("Maximum allowed median peer time offset adjustment. Local perspective of time may be influenced by peers forward or backward by this amount. (default: %u seconds)", DEFAULT_MAX_TIME_ADJUSTMENT), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-maxuploadtarget=<n>", strprintf("Tries to keep outbound traffic under the given target (in MiB per 24h). Limit does not apply to peers with 'download' permission. 0 = no limit (default: %d)", DEFAULT_MAX_UPLOAD_TARGET), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-onion=<ip:port>", "Use separate SOCKS5 proxy to reach peers via Tor onion services, set -noonion to disable (default: -proxy)", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
-    argsman.AddArg("-onlynet=<net>", "Make outgoing connections only through network <net> (ipv4, ipv6 or onion). Incoming connections are not affected by this option. This option can be specified multiple times to allow multiple networks. Warning: if it is used with ipv4 or ipv6 but not onion and the -onion or -proxy option is set, then outbound onion connections will still be made; use -noonion or -onion=0 to disable outbound onion connections in this case.", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
+    argsman.AddArg("-onlynet=<net>", "Make outgoing connections only through network <net> (" + Join(GetNetworkNames(), ", ") + "). Incoming connections are not affected by this option. This option can be specified multiple times to allow multiple networks. Warning: if it is used with ipv4 or ipv6 but not onion and the -onion or -proxy option is set, then outbound onion connections will still be made; use -noonion or -onion=0 to disable outbound onion connections in this case.", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-peerbloomfilters", strprintf("Support filtering of blocks and transaction with bloom filters (default: %u)", DEFAULT_PEERBLOOMFILTERS), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-peerblockfilters", strprintf("Serve compact block filters to peers per BIP 157 (default: %u)", DEFAULT_PEERBLOCKFILTERS), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-permitbaremultisig", strprintf("Relay non-P2SH multisig (default: %u)", DEFAULT_PERMIT_BAREMULTISIG), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
diff --git a/src/netaddress.h b/src/netaddress.h
index b9eade7fd5..d0986557f7 100644
--- a/src/netaddress.h
+++ b/src/netaddress.h
@@ -36,7 +36,7 @@ static constexpr int ADDRV2_FORMAT = 0x20000000;
  * @note An address may belong to more than one network, for example `10.0.0.1`
  * belongs to both `NET_UNROUTABLE` and `NET_IPV4`.
  * Keep these sequential starting from 0 and `NET_MAX` as the last entry.
- * We have loops like `for (int i = 0; i < NET_MAX; i++)` that expect to iterate
+ * We have loops like `for (int i = 0; i < NET_MAX; ++i)` that expect to iterate
  * over all enum values and also `GetExtNetwork()` "extends" this enum by
  * introducing standalone constants starting from `NET_MAX`.
  */
diff --git a/src/netbase.cpp b/src/netbase.cpp
index 24188f83c6..0c5b3a220e 100644
--- a/src/netbase.cpp
+++ b/src/netbase.cpp
@@ -59,7 +59,7 @@ enum Network ParseNetwork(const std::string& net_in) {
 std::string GetNetworkName(enum Network net)
 {
     switch (net) {
-    case NET_UNROUTABLE: return "unroutable";
+    case NET_UNROUTABLE: return "not_publicly_routable";
     case NET_IPV4: return "ipv4";
     case NET_IPV6: return "ipv6";
     case NET_ONION: return "onion";
@@ -72,6 +72,20 @@ std::string GetNetworkName(enum Network net)
     assert(false);
 }
 
+std::vector<std::string> GetNetworkNames(bool append_unroutable)
+{
+    std::vector<std::string> names;
+    for (int n = 0; n < NET_MAX; ++n) {
+        const enum Network network{static_cast<Network>(n)};
+        if (network == NET_UNROUTABLE || network == NET_I2P || network == NET_CJDNS || network == NET_INTERNAL) continue;
+        names.emplace_back(GetNetworkName(network));
+    }
+    if (append_unroutable) {
+        names.emplace_back(GetNetworkName(NET_UNROUTABLE));
+    }
+    return names;
+}
+
 bool static LookupIntern(const std::string& name, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup)
 {
     vIP.clear();
diff --git a/src/netbase.h b/src/netbase.h
index afc373ef49..847a72ca8e 100644
--- a/src/netbase.h
+++ b/src/netbase.h
@@ -42,6 +42,8 @@ public:
 
 enum Network ParseNetwork(const std::string& net);
 std::string GetNetworkName(enum Network net);
+/** Return a vector of publicly routable Network names; optionally append NET_UNROUTABLE. */
+std::vector<std::string> GetNetworkNames(bool append_unroutable = false);
 bool SetProxy(enum Network net, const proxyType &addrProxy);
 bool GetProxy(enum Network net, proxyType &proxyInfoOut);
 bool IsProxy(const CNetAddr &addr);
diff --git a/src/rpc/net.cpp b/src/rpc/net.cpp
index 47d77b341a..e83f66dd12 100644
--- a/src/rpc/net.cpp
+++ b/src/rpc/net.cpp
@@ -104,7 +104,7 @@ static RPCHelpMan getpeerinfo()
                             {RPCResult::Type::STR, "addr", "(host:port) The IP address and port of the peer"},
                             {RPCResult::Type::STR, "addrbind", "(ip:port) Bind address of the connection to the peer"},
                             {RPCResult::Type::STR, "addrlocal", "(ip:port) Local address as reported by the peer"},
-                            {RPCResult::Type::STR, "network", "Network (ipv4, ipv6, or onion) the peer connected through"},
+                            {RPCResult::Type::STR, "network", "Network (" + Join(GetNetworkNames(/* append_unroutable */ true), ", ") + ")"},
                             {RPCResult::Type::NUM, "mapped_as", "The AS in the BGP route to the peer used for diversifying\n"
                                                                 "peer selection (only available if the asmap config flag is set)"},
                             {RPCResult::Type::STR_HEX, "services", "The services offered"},
@@ -587,7 +587,7 @@ static RPCHelpMan getnetworkinfo()
                         {
                             {RPCResult::Type::OBJ, "", "",
                             {
-                                {RPCResult::Type::STR, "name", "network (ipv4, ipv6 or onion)"},
+                                {RPCResult::Type::STR, "name", "network (" + Join(GetNetworkNames(), ", ") + ")"},
                                 {RPCResult::Type::BOOL, "limited", "is the network limited using -onlynet?"},
                                 {RPCResult::Type::BOOL, "reachable", "is the network reachable?"},
                                 {RPCResult::Type::STR, "proxy", "(\"host:port\") the proxy that is used for this network, or empty if none"},
diff --git a/test/functional/feature_proxy.py b/test/functional/feature_proxy.py
index cd5eff9184..2983feaa0d 100755
--- a/test/functional/feature_proxy.py
+++ b/test/functional/feature_proxy.py
@@ -44,8 +44,8 @@ from test_framework.netutil import test_ipv6_local
 
 RANGE_BEGIN = PORT_MIN + 2 * PORT_RANGE  # Start after p2p and rpc ports
 
-# Networks returned by RPC getpeerinfo, defined in src/netbase.cpp::GetNetworkName()
-NET_UNROUTABLE = "unroutable"
+# Networks returned by RPC getpeerinfo.
+NET_UNROUTABLE = "not_publicly_routable"
 NET_IPV4 = "ipv4"
 NET_IPV6 = "ipv6"
 NET_ONION = "onion"
diff --git a/test/functional/rpc_net.py b/test/functional/rpc_net.py
index cf46616681..2d41963beb 100755
--- a/test/functional/rpc_net.py
+++ b/test/functional/rpc_net.py
@@ -104,6 +104,9 @@ class NetTest(BitcoinTestFramework):
         assert_equal(peer_info[1][0]['connection_type'], 'manual')
         assert_equal(peer_info[1][1]['connection_type'], 'inbound')
 
+        # Check dynamically generated networks list in getpeerinfo help output.
+        assert "(ipv4, ipv6, onion, not_publicly_routable)" in self.nodes[0].help("getpeerinfo")
+
     def test_getnettotals(self):
         self.log.info("Test getnettotals")
         # Test getnettotals and getpeerinfo by doing a ping. The bytes
@@ -152,6 +155,9 @@ class NetTest(BitcoinTestFramework):
         for info in network_info:
             assert_net_servicesnames(int(info["localservices"], 0x10), info["localservicesnames"])
 
+        # Check dynamically generated networks list in getnetworkinfo help output.
+        assert "(ipv4, ipv6, onion)" in self.nodes[0].help("getnetworkinfo")
+
     def test_getaddednodeinfo(self):
         self.log.info("Test getaddednodeinfo")
         assert_equal(self.nodes[0].getaddednodeinfo(), [])