Drop unnecessary size checks and corrections for Netlink attributes.

Some Netlink attributes have a fixed size. The map attempted to make adding
attributes safer and easier by having default sizes for certain attributes.
However, attributes are identified via their enums, which often overlap for
different types of requests, making these default sizes not hold true for all
attributes that map to it.

PiperOrigin-RevId: 778632075

Author: kerumeto

test/syscalls/linux/socket_netlink_netfilter_util.cc

@@ -27,13 +27,6 @@
 namespace gvisor {
 namespace testing {
 
-static const std::map<uint16_t, size_t> kNetfilterAttributeSizes = {
-    {NFTA_TABLE_FLAGS, sizeof(uint32_t)},
-    {NFTA_TABLE_HANDLE, sizeof(uint64_t)},
-    {NFTA_TABLE_USE, sizeof(uint32_t)},
-    {NFTA_TABLE_OWNER, sizeof(uint32_t)},
-};
-
 NlReq& NlReq::MsgType(uint8_t message_type) {
   message_type_ = message_type;
   return *this;
@@ -54,22 +47,13 @@ NlReq& NlReq::Family(uint8_t family) {
   return *this;
 }
 
-// Method to add an attribute to the message. If there is a default
-// size for the attribute type, it will be used.
-// Otherwise, assumes the payload is of at least size payload_size.
+// Method to add an attribute to the message. payload_size must be the size of
+// the payload in bytes.
 NlReq& NlReq::RawAttr(uint16_t attr_type, const void* payload,
                       size_t payload_size) {
-  // Check if the attribute type has a standard size. Otherwise
-  // use the provided size.
-  size_t attr_size;
-  if (kNetfilterAttributeSizes.count(attr_type)) {
-    attr_size = kNetfilterAttributeSizes.at(attr_type);
-  } else {
-    attr_size = payload_size;
-  }
-
   // Store a pointer to the payload and the size to construct it later.
-  attributes_[attr_type] = {reinterpret_cast<const char*>(payload), attr_size};
+  attributes_[attr_type] = {reinterpret_cast<const char*>(payload),
+                            payload_size};
   return *this;
 }
 

test/syscalls/linux/socket_netlink_netfilter_util.h

@@ -86,9 +86,8 @@ class NlReq {
   NlReq& Seq(uint32_t seq);
   NlReq& Family(uint8_t family);
 
-  // Method to add an attribute to the message. If there is a default
-  // size for the attribute type, it will be used.
-  // Otherwise, assumes the payload is of at least size payload_size.
+  // Method to add an attribute to the message. payload_size must be the size of
+  // the payload in bytes.
   NlReq& RawAttr(uint16_t attr_type, const void* payload, size_t payload_size);
 
   // Method to add a string attribute to the message.