Merge bitcoin/bitcoin#25421: net: convert standalone IsSelectableSocket() and SetSocketNonBlocking() to Sock methods

b527b549504672704a61f70d2565b9489aaaba91 net: convert standalone SetSocketNonBlocking() to Sock::SetNonBlocking() (Vasil Dimov)
29f66f76826056f53d971ac734b7ed49b39848d3 moveonly: move SetSocketNonBlocking() from netbase to util/sock (Vasil Dimov)
b4bac556791b5bb8aa118d4c1fed42c3fe45550c net: convert standalone IsSelectableSocket() to Sock::IsSelectable() (Vasil Dimov)
5db7d2ca0aa51ff25f97bf21ce0cbc9e6b741cbd moveonly: move IsSelectableSocket() from compat.h to sock.{h,cpp} (Vasil Dimov)

Pull request description:

  _This is a piece of #21878, chopped off to ease review._

  * convert standalone `IsSelectableSocket()` to `Sock::IsSelectable()`
  * convert standalone `SetSocketNonBlocking()` to `Sock::SetNonBlocking()`

  This further encapsulates syscalls inside the `Sock` class and makes the callers mockable.

ACKs for top commit:
  jonatack:
    ACK b527b549504672704a61f70d2565b9489aaaba91 review/debug build/unit tests at each commit, cross-referenced the changes with `man select` and `man errno`, ran a signet node on the last commit with ip4/ip6//tor/i2p/cjdns and network connections were nominal
  dergoegge:
    Code review ACK b527b549504672704a61f70d2565b9489aaaba91

Tree-SHA512: af783ce558c7a89e173f7ab323fb3517103d765c19b5d14de29f64706b4e1fea3653492e8ea73ae972699986aaddf2ae72c7cfaa7dad7614254283083b7d2632

1 files changed, 3 insertions, 19 deletions

diff --git a/src/netbase.cpp b/src/netbase.cpp
index a5f7bda875..8169b40ea6 100644
--- a/src/netbase.cpp
+++ b/src/netbase.cpp
@@ -304,8 +304,7 @@ enum class IntrRecvError {
  *          read.
  *
  * @see This function can be interrupted by calling InterruptSocks5(bool).
- *      Sockets can be made non-blocking with SetSocketNonBlocking(const
- *      SOCKET&).
+ *      Sockets can be made non-blocking with Sock::SetNonBlocking().
  */
 static IntrRecvError InterruptibleRecv(uint8_t* data, size_t len, int timeout, const Sock& sock)
 {
@@ -503,7 +502,7 @@ std::unique_ptr<Sock> CreateSockTCP(const CService& address_family)
 
     // Ensure that waiting for I/O on this socket won't result in undefined
     // behavior.
-    if (!IsSelectableSocket(sock->Get())) {
+    if (!sock->IsSelectable()) {
         LogPrintf("Cannot create connection: non-selectable socket created (fd >= FD_SETSIZE ?)\n");
         return nullptr;
     }
@@ -525,7 +524,7 @@ std::unique_ptr<Sock> CreateSockTCP(const CService& address_family)
     }
 
     // Set the non-blocking option on the socket.
-    if (!SetSocketNonBlocking(sock->Get())) {
+    if (!sock->SetNonBlocking()) {
         LogPrintf("Error setting socket to non-blocking: %s\n", NetworkErrorString(WSAGetLastError()));
         return nullptr;
     }
@@ -717,21 +716,6 @@ bool LookupSubNet(const std::string& subnet_str, CSubNet& subnet_out)
     return false;
 }
 
-bool SetSocketNonBlocking(const SOCKET& hSocket)
-{
-#ifdef WIN32
-    u_long nOne = 1;
-    if (ioctlsocket(hSocket, FIONBIO, &nOne) == SOCKET_ERROR) {
-#else
-    int fFlags = fcntl(hSocket, F_GETFL, 0);
-    if (fcntl(hSocket, F_SETFL, fFlags | O_NONBLOCK) == SOCKET_ERROR) {
-#endif
-        return false;
-    }
-
-    return true;
-}
-
 void InterruptSocks5(bool interrupt)
 {
     interruptSocks5Recv = interrupt;