From f2a4c06ce5c1e3c9a5129cfa38af257565e2eb3f Mon Sep 17 00:00:00 2001
From: Damjan Jovanovic <damjan.jov@gmail.com>
Date: Thu, 1 Aug 2019 06:11:21 +0200
Subject: [PATCH] ws2_32: WSARecvMsg allows a NULL control buffer when no
 control messages arrive.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=43286
Signed-off-by: Damjan Jovanovic <damjan.jov@gmail.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
(cherry picked from commit aa2c84a9db064a16598c4198c435e2e5896dd059)
Signed-off-by: Michael Stefaniuc <mstefani@winehq.org>
---
 dlls/ws2_32/socket.c     |  8 +++++---
 dlls/ws2_32/tests/sock.c | 17 +++++++++++++++--
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/dlls/ws2_32/socket.c b/dlls/ws2_32/socket.c
index 542dc9a7a84..989d800ecd2 100644
--- a/dlls/ws2_32/socket.c
+++ b/dlls/ws2_32/socket.c
@@ -878,10 +878,12 @@ static inline int convert_control_headers(struct msghdr *hdr, WSABUF *control)
         }
     }
 
-error:
     /* Set the length of the returned control headers */
-    control->len = (ptr == NULL ? 0 : (char*)ptr - (char*)cmsg_win);
-    return (ptr != NULL);
+    control->len = (char*)ptr - (char*)cmsg_win;
+    return 1;
+error:
+    control->len = 0;
+    return 0;
 #else /* IP_PKTINFO */
     control->len = 0;
     return 1;
diff --git a/dlls/ws2_32/tests/sock.c b/dlls/ws2_32/tests/sock.c
index b32d1c053df..64b1f781f7d 100644
--- a/dlls/ws2_32/tests/sock.c
+++ b/dlls/ws2_32/tests/sock.c
@@ -2108,8 +2108,6 @@ static void test_ip_pktinfo(void)
         /* Setup the server side socket */
         rc=bind(s1, (struct sockaddr*)&s1addr, sizeof(s1addr));
         ok(rc != SOCKET_ERROR, "bind() failed error: %d\n", WSAGetLastError());
-        rc=setsockopt(s1, IPPROTO_IP, IP_PKTINFO, (const char*)&yes, sizeof(yes));
-        ok(rc == 0, "failed to set IPPROTO_IP flag IP_PKTINFO!\n");
 
         /* Build "client" side socket */
         addrlen = sizeof(s2addr);
@@ -2133,6 +2131,21 @@ static void test_ip_pktinfo(void)
         err=WSAGetLastError();
         ok(rc == SOCKET_ERROR && err == WSAEFAULT, "WSARecvMsg() failed error: %d (ret = %d)\n", err, rc);
 
+        /* Test that when no control data arrives, a 0-length NULL-valued control buffer should succeed */
+        SetLastError(0xdeadbeef);
+        rc=sendto(s2, msg, sizeof(msg), 0, (struct sockaddr*)&s2addr, sizeof(s2addr));
+        ok(rc == sizeof(msg), "sendto() failed error: %d\n", WSAGetLastError());
+        ok(GetLastError() == ERROR_SUCCESS, "Expected 0, got %d\n", GetLastError());
+        hdr.Control.buf = NULL;
+        hdr.Control.len = 0;
+        rc=pWSARecvMsg(s1, &hdr, &dwSize, NULL, NULL);
+        ok(rc == 0, "WSARecvMsg() failed error: %d\n", WSAGetLastError());
+        hdr.Control.buf = pktbuf;
+
+        /* Now start IP_PKTINFO for future tests */
+        rc=setsockopt(s1, IPPROTO_IP, IP_PKTINFO, (const char*)&yes, sizeof(yes));
+        ok(rc == 0, "failed to set IPPROTO_IP flag IP_PKTINFO!\n");
+
         /*
          * Send a packet from the client to the server and test for specifying
          * a short control header.