Full and clearer implementation of GitHub issue #588

2 files changed, 42 insertions, 0 deletions

diff --git a/node/Capability.hpp b/node/Capability.hpp
index c0336243..407884ad 100644
--- a/node/Capability.hpp
+++ b/node/Capability.hpp
@@ -278,6 +278,13 @@ public:
 					b.append((uint32_t)rules[i].v.tag.id);
 					b.append((uint32_t)rules[i].v.tag.value);
 					break;
+				case ZT_NETWORK_RULE_MATCH_INTEGER_RANGE:
+					b.append((uint8_t)19);
+					b.append((uint64_t)rules[i].v.intRange.start);
+					b.append((uint64_t)(rules[i].v.intRange.start + (uint64_t)rules[i].v.intRange.end)); // more future-proof
+					b.append((uint16_t)rules[i].v.intRange.idx);
+					b.append((uint8_t)rules[i].v.intRange.format);
+					break;
 			}
 		}
 	}
@@ -366,6 +373,12 @@ public:
 					rules[ruleCount].v.tag.id = b.template at<uint32_t>(p);
 					rules[ruleCount].v.tag.value = b.template at<uint32_t>(p + 4);
 					break;
+				case ZT_NETWORK_RULE_MATCH_INTEGER_RANGE:
+					rules[ruleCount].v.intRange.start = b.template at<uint64_t>(p);
+					rules[ruleCount].v.intRange.end = (uint32_t)(b.template at<uint64_t>(p + 8) - rules[ruleCount].v.intRange.start);
+					rules[ruleCount].v.intRange.idx = b.template at<uint16_t>(p + 16);
+					rules[ruleCount].v.intRange.format = (uint8_t)b[p + 18];
+					break;
 			}
 			p += fieldLen;
 			++ruleCount;
diff --git a/node/Network.cpp b/node/Network.cpp
index 111e4736..a9e8539e 100644
--- a/node/Network.cpp
+++ b/node/Network.cpp
@@ -493,6 +493,35 @@ static _doZtFilterResult _doZtFilter(
 					}
 				}
 			}	break;
+			case ZT_NETWORK_RULE_MATCH_INTEGER_RANGE: {
+				uint64_t integer = 0;
+				const unsigned int bits = (rules[rn].v.intRange.format & 63) + 1;
+				const unsigned int bytes = ((bits + 8 - 1) / 8); // integer ceiling of division by 8
+				if ((rules[rn].v.intRange.format & 0x80) == 0) {
+					// Big-endian
+					unsigned int idx = rules[rn].v.intRange.idx + (8 - bytes);
+					const unsigned int eof = idx + bytes;
+					if (eof <= frameLen) {
+						while (idx < eof) {
+							integer <<= 8;
+							integer |= frameData[idx++];
+						}
+					}
+					integer &= 0xffffffffffffffffULL >> (64 - bits);
+				} else {
+					// Little-endian
+					unsigned int idx = rules[rn].v.intRange.idx;
+					const unsigned int eof = idx + bytes;
+					if (eof <= frameLen) {
+						while (idx < eof) {
+							integer >>= 8;
+							integer |= ((uint64_t)frameData[idx++]) << 56;
+						}
+					}
+					integer >>= (64 - bits);
+				}
+				thisRuleMatches = (uint8_t)((integer >= rules[rn].v.intRange.start)&&(integer <= (rules[rn].v.intRange.start + (uint64_t)rules[rn].v.intRange.end)));
+			}	break;
 
 			// The result of an unsupported MATCH is configurable at the network
 			// level via a flag.