From c33fbab25c82b6a18773b80e8b355c987066ae5a Mon Sep 17 00:00:00 2001
From: Vasil Dimov <vd@FreeBSD.org>
Date: Mon, 4 Jan 2021 18:37:52 +0100
Subject: net: allow CSubNet of non-IP networks

Allow creation of valid `CSubNet` objects of non-IP networks and only
match the single address they were created from (like /32 for IPv4 or
/128 for IPv6).

This fixes a deficiency in `CConnman::DisconnectNode(const CNetAddr& addr)`
and in `BanMan` which assume that creating a subnet from any address
using the `CSubNet(CNetAddr)` constructor would later match that address
only. Before this change a non-IP subnet would be invalid and would not
match any address.

Github-Pull: #20852
Rebased-From: 94d335da7f8232bc653c9b08b0a33b517b4c98ad
---
 src/netaddress.cpp | 81 ++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 67 insertions(+), 14 deletions(-)

(limited to 'src/netaddress.cpp')

diff --git a/src/netaddress.cpp b/src/netaddress.cpp
index 35e9161f58..e0d4638dd6 100644
--- a/src/netaddress.cpp
+++ b/src/netaddress.cpp
@@ -1063,15 +1063,24 @@ CSubNet::CSubNet(const CNetAddr& addr, const CNetAddr& mask) : CSubNet()
 
 CSubNet::CSubNet(const CNetAddr& addr) : CSubNet()
 {
-    valid = addr.IsIPv4() || addr.IsIPv6();
-    if (!valid) {
+    switch (addr.m_net) {
+    case NET_IPV4:
+    case NET_IPV6:
+        valid = true;
+        assert(addr.m_addr.size() <= sizeof(netmask));
+        memset(netmask, 0xFF, addr.m_addr.size());
+        break;
+    case NET_ONION:
+    case NET_I2P:
+    case NET_CJDNS:
+        valid = true;
+        break;
+    case NET_INTERNAL:
+    case NET_UNROUTABLE:
+    case NET_MAX:
         return;
     }
 
-    assert(addr.m_addr.size() <= sizeof(netmask));
-
-    memset(netmask, 0xFF, addr.m_addr.size());
-
     network = addr;
 }
 
@@ -1083,6 +1092,21 @@ bool CSubNet::Match(const CNetAddr &addr) const
 {
     if (!valid || !addr.IsValid() || network.m_net != addr.m_net)
         return false;
+
+    switch (network.m_net) {
+    case NET_IPV4:
+    case NET_IPV6:
+        break;
+    case NET_ONION:
+    case NET_I2P:
+    case NET_CJDNS:
+    case NET_INTERNAL:
+        return addr == network;
+    case NET_UNROUTABLE:
+    case NET_MAX:
+        return false;
+    }
+
     assert(network.m_addr.size() == addr.m_addr.size());
     for (size_t x = 0; x < addr.m_addr.size(); ++x) {
         if ((addr.m_addr[x] & netmask[x]) != network.m_addr[x]) {
@@ -1094,18 +1118,35 @@ bool CSubNet::Match(const CNetAddr &addr) const
 
 std::string CSubNet::ToString() const
 {
-    assert(network.m_addr.size() <= sizeof(netmask));
+    std::string suffix;
 
-    uint8_t cidr = 0;
+    switch (network.m_net) {
+    case NET_IPV4:
+    case NET_IPV6: {
+        assert(network.m_addr.size() <= sizeof(netmask));
 
-    for (size_t i = 0; i < network.m_addr.size(); ++i) {
-        if (netmask[i] == 0x00) {
-            break;
+        uint8_t cidr = 0;
+
+        for (size_t i = 0; i < network.m_addr.size(); ++i) {
+            if (netmask[i] == 0x00) {
+                break;
+            }
+            cidr += NetmaskBits(netmask[i]);
         }
-        cidr += NetmaskBits(netmask[i]);
+
+        suffix = strprintf("/%u", cidr);
+        break;
+    }
+    case NET_ONION:
+    case NET_I2P:
+    case NET_CJDNS:
+    case NET_INTERNAL:
+    case NET_UNROUTABLE:
+    case NET_MAX:
+        break;
     }
 
-    return network.ToString() + strprintf("/%u", cidr);
+    return network.ToString() + suffix;
 }
 
 bool CSubNet::IsValid() const
@@ -1115,7 +1156,19 @@ bool CSubNet::IsValid() const
 
 bool CSubNet::SanityCheck() const
 {
-    if (!(network.IsIPv4() || network.IsIPv6())) return false;
+    switch (network.m_net) {
+    case NET_IPV4:
+    case NET_IPV6:
+        break;
+    case NET_ONION:
+    case NET_I2P:
+    case NET_CJDNS:
+        return true;
+    case NET_INTERNAL:
+    case NET_UNROUTABLE:
+    case NET_MAX:
+        return false;
+    }
 
     for (size_t x = 0; x < network.m_addr.size(); ++x) {
         if (network.m_addr[x] & ~netmask[x]) return false;
-- 
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