Merge #19818: p2p: change `CInv::type` from `int` to `uint32_t`, fix UBSan warning

7984c39be1 test framework: serialize/deserialize inv type as unsigned int (Jon Atack)
407175e0c2 p2p: change CInv::type from int to uint32_t (Jon Atack)

Pull request description:

  Fixes UBSan implicit-integer-sign-change issue per https://github.com/bitcoin/bitcoin/pull/19610#issuecomment-680686460.

  Credit to Crypt-iQ for finding and reporting the issue and to vasild for the original review suggestion in https://github.com/bitcoin/bitcoin/pull/19590#pullrequestreview-455788826.

  Closes #19678.

ACKs for top commit:
  laanwj:
    ACK 7984c39be1
  MarcoFalke:
    ACK 7984c39be1 🌻
  vasild:
    ACK 7984c39be

Tree-SHA512: 59f3a75f40ce066ca6f0bb1927197254238302b4073af1574bdbfe6ed580876437be804be4e47d51467d604f0d9e3a5875159f7f2edbb2351fdb2bb9465100b5

src/protocol.cpp

@@ -163,7 +163,7 @@ CInv::CInv()
     hash.SetNull();
 }
 
-CInv::CInv(int typeIn, const uint256& hashIn) : type(typeIn), hash(hashIn) {}
+CInv::CInv(uint32_t typeIn, const uint256& hashIn) : type(typeIn), hash(hashIn) {}
 
 bool operator<(const CInv& a, const CInv& b)
 {

src/protocol.h

@@ -408,7 +408,7 @@ class CInv
 {
 public:
     CInv();
-    CInv(int typeIn, const uint256& hashIn);
+    CInv(uint32_t typeIn, const uint256& hashIn);
 
     SERIALIZE_METHODS(CInv, obj) { READWRITE(obj.type, obj.hash); }
 
@@ -435,7 +435,7 @@ public:
         return type == MSG_BLOCK || type == MSG_FILTERED_BLOCK || type == MSG_CMPCT_BLOCK || type == MSG_WITNESS_BLOCK;
     }
 
-    int type;
+    uint32_t type;
     uint256 hash;
 };
 

test/functional/test_framework/messages.py

@@ -245,8 +245,8 @@ class CInv:
         MSG_TX | MSG_WITNESS_FLAG: "WitnessTx",
         MSG_BLOCK | MSG_WITNESS_FLAG: "WitnessBlock",
         MSG_FILTERED_BLOCK: "filtered Block",
-        4: "CompactBlock",
-        5: "WTX",
+        MSG_CMPCT_BLOCK: "CompactBlock",
+        MSG_WTX: "WTX",
     }
 
     def __init__(self, t=0, h=0):
@@ -254,12 +254,12 @@ class CInv:
         self.hash = h
 
     def deserialize(self, f):
-        self.type = struct.unpack("<i", f.read(4))[0]
+        self.type = struct.unpack("<I", f.read(4))[0]
         self.hash = deser_uint256(f)
 
     def serialize(self):
         r = b""
-        r += struct.pack("<i", self.type)
+        r += struct.pack("<I", self.type)
         r += ser_uint256(self.hash)
         return r