Move socket-errno code into lib/net

1 files changed, 103 insertions, 0 deletions

diff --git a/src/lib/net/socket.c b/src/lib/net/socket.c
index cd18d70839..ae384bcd47 100644
--- a/src/lib/net/socket.c
+++ b/src/lib/net/socket.c
@@ -691,3 +691,106 @@ write_all_to_socket(tor_socket_t fd, const char *buf, size_t count)
   }
   return (ssize_t)count;
 }
+
+/**
+ * On Windows, WSAEWOULDBLOCK is not always correct: when you see it,
+ * you need to ask the socket for its actual errno.  Also, you need to
+ * get your errors from WSAGetLastError, not errno.  (If you supply a
+ * socket of -1, we check WSAGetLastError, but don't correct
+ * WSAEWOULDBLOCKs.)
+ *
+ * The upshot of all of this is that when a socket call fails, you
+ * should call tor_socket_errno <em>at most once</em> on the failing
+ * socket to get the error.
+ */
+#if defined(_WIN32)
+int
+tor_socket_errno(tor_socket_t sock)
+{
+  int optval, optvallen=sizeof(optval);
+  int err = WSAGetLastError();
+  if (err == WSAEWOULDBLOCK && SOCKET_OK(sock)) {
+    if (getsockopt(sock, SOL_SOCKET, SO_ERROR, (void*)&optval, &optvallen))
+      return err;
+    if (optval)
+      return optval;
+  }
+  return err;
+}
+#endif /* defined(_WIN32) */
+
+#if defined(_WIN32)
+#define E(code, s) { code, (s " [" #code " ]") }
+struct { int code; const char *msg; } windows_socket_errors[] = {
+  E(WSAEINTR, "Interrupted function call"),
+  E(WSAEACCES, "Permission denied"),
+  E(WSAEFAULT, "Bad address"),
+  E(WSAEINVAL, "Invalid argument"),
+  E(WSAEMFILE, "Too many open files"),
+  E(WSAEWOULDBLOCK,  "Resource temporarily unavailable"),
+  E(WSAEINPROGRESS, "Operation now in progress"),
+  E(WSAEALREADY, "Operation already in progress"),
+  E(WSAENOTSOCK, "Socket operation on nonsocket"),
+  E(WSAEDESTADDRREQ, "Destination address required"),
+  E(WSAEMSGSIZE, "Message too long"),
+  E(WSAEPROTOTYPE, "Protocol wrong for socket"),
+  E(WSAENOPROTOOPT, "Bad protocol option"),
+  E(WSAEPROTONOSUPPORT, "Protocol not supported"),
+  E(WSAESOCKTNOSUPPORT, "Socket type not supported"),
+  /* What's the difference between NOTSUPP and NOSUPPORT? :) */
+  E(WSAEOPNOTSUPP, "Operation not supported"),
+  E(WSAEPFNOSUPPORT,  "Protocol family not supported"),
+  E(WSAEAFNOSUPPORT, "Address family not supported by protocol family"),
+  E(WSAEADDRINUSE, "Address already in use"),
+  E(WSAEADDRNOTAVAIL, "Cannot assign requested address"),
+  E(WSAENETDOWN, "Network is down"),
+  E(WSAENETUNREACH, "Network is unreachable"),
+  E(WSAENETRESET, "Network dropped connection on reset"),
+  E(WSAECONNABORTED, "Software caused connection abort"),
+  E(WSAECONNRESET, "Connection reset by peer"),
+  E(WSAENOBUFS, "No buffer space available"),
+  E(WSAEISCONN, "Socket is already connected"),
+  E(WSAENOTCONN, "Socket is not connected"),
+  E(WSAESHUTDOWN, "Cannot send after socket shutdown"),
+  E(WSAETIMEDOUT, "Connection timed out"),
+  E(WSAECONNREFUSED, "Connection refused"),
+  E(WSAEHOSTDOWN, "Host is down"),
+  E(WSAEHOSTUNREACH, "No route to host"),
+  E(WSAEPROCLIM, "Too many processes"),
+  /* Yes, some of these start with WSA, not WSAE. No, I don't know why. */
+  E(WSASYSNOTREADY, "Network subsystem is unavailable"),
+  E(WSAVERNOTSUPPORTED, "Winsock.dll out of range"),
+  E(WSANOTINITIALISED, "Successful WSAStartup not yet performed"),
+  E(WSAEDISCON, "Graceful shutdown now in progress"),
+#ifdef WSATYPE_NOT_FOUND
+  E(WSATYPE_NOT_FOUND, "Class type not found"),
+#endif
+  E(WSAHOST_NOT_FOUND, "Host not found"),
+  E(WSATRY_AGAIN, "Nonauthoritative host not found"),
+  E(WSANO_RECOVERY, "This is a nonrecoverable error"),
+  E(WSANO_DATA, "Valid name, no data record of requested type)"),
+
+  /* There are some more error codes whose numeric values are marked
+   * <b>OS dependent</b>. They start with WSA_, apparently for the same
+   * reason that practitioners of some craft traditions deliberately
+   * introduce imperfections into their baskets and rugs "to allow the
+   * evil spirits to escape."  If we catch them, then our binaries
+   * might not report consistent results across versions of Windows.
+   * Thus, I'm going to let them all fall through.
+   */
+  { -1, NULL },
+};
+/** There does not seem to be a strerror equivalent for Winsock errors.
+ * Naturally, we have to roll our own.
+ */
+const char *
+tor_socket_strerror(int e)
+{
+  int i;
+  for (i=0; windows_socket_errors[i].code >= 0; ++i) {
+    if (e == windows_socket_errors[i].code)
+      return windows_socket_errors[i].msg;
+  }
+  return strerror(e);
+}
+#endif /* defined(_WIN32) */