Curl_getconnectinfo: avoid checking if the connection is closed

It doesn't benefit us much as the connection could get closed at
any time, and also by checking we lose the ability to determine
if the socket was closed by reading zero bytes.

Reported-by: Michael Kaufmann

Closes https://github.com/curl/curl/pull/1134

1 files changed, 27 insertions, 18 deletions

diff --git a/lib/connect.c b/lib/connect.c
index f86c31d4d..284726ae3 100644
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -1247,24 +1247,6 @@ curl_socket_t Curl_getconnectinfo(struct Curl_easy *data,
       /* only store this if the caller cares for it */
       *connp = c;
     sockfd = c->sock[FIRSTSOCKET];
-    /* we have a socket connected, let's determine if the server shut down */
-    /* determine if ssl */
-    if(c->ssl[FIRSTSOCKET].use) {
-      /* use the SSL context */
-      if(!Curl_ssl_check_cxn(c))
-        return CURL_SOCKET_BAD;   /* FIN received */
-    }
-/* Minix 3.1 doesn't support any flags on recv; just assume socket is OK */
-#ifdef MSG_PEEK
-    else if(sockfd != CURL_SOCKET_BAD) {
-      /* use the socket */
-      char buf;
-      if(recv((RECV_TYPE_ARG1)sockfd, (RECV_TYPE_ARG2)&buf,
-              (RECV_TYPE_ARG3)1, (RECV_TYPE_ARG4)MSG_PEEK) == 0) {
-        return CURL_SOCKET_BAD;   /* FIN received */
-      }
-    }
-#endif
   }
   else
     return CURL_SOCKET_BAD;
@@ -1273,6 +1255,33 @@ curl_socket_t Curl_getconnectinfo(struct Curl_easy *data,
 }
 
 /*
+ * Check if a connection seems to be alive.
+ */
+bool Curl_connalive(struct connectdata *conn)
+{
+  /* First determine if ssl */
+  if(conn->ssl[FIRSTSOCKET].use) {
+    /* use the SSL context */
+    if(!Curl_ssl_check_cxn(conn))
+      return false;   /* FIN received */
+  }
+/* Minix 3.1 doesn't support any flags on recv; just assume socket is OK */
+#ifdef MSG_PEEK
+  else if(conn->sock[FIRSTSOCKET] == CURL_SOCKET_BAD)
+    return false;
+  else {
+    /* use the socket */
+    char buf;
+    if(recv((RECV_TYPE_ARG1)conn->sock[FIRSTSOCKET], (RECV_TYPE_ARG2)&buf,
+            (RECV_TYPE_ARG3)1, (RECV_TYPE_ARG4)MSG_PEEK) == 0) {
+      return false;   /* FIN received */
+    }
+  }
+#endif
+  return true;
+}
+
+/*
  * Close a socket.
  *
  * 'conn' can be NULL, beware!