[PATCH] ws2_32: Divide values returned by SO_RCVBUF and SO_SNDBUF getsockopt options by two.

[Alistair Leslie-Hughes]

From: Sebastian Lackner

man 7 socket
...
SO_SNDBUF/SO_RCVBUF
 Sets or gets the maximum socket send buffer in bytes.  The  kernel
   doubles this value (to allow space for bookkeeping overhead)
...

Signed-off-by: Alistair Leslie-Hughes 
---
 dlls/ws2_32/socket.c     | 8 ++++++++
 dlls/ws2_32/tests/sock.c | 4 ++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/dlls/ws2_32/socket.c b/dlls/ws2_32/socket.c
index 914df17..3954964 100644
--- a/dlls/ws2_32/socket.c
+++ b/dlls/ws2_32/socket.c
@@ -3813,6 +3813,14 @@ INT WINAPI WS_getsockopt(SOCKET s, INT level,
                 SetLastError(wsaErrno());
                 ret = SOCKET_ERROR;
             }
+        #ifdef __linux__
+            else if (optname == SO_RCVBUF || optname == SO_SNDBUF)
+            {
+                /* For SO_RCVBUF / SO_SNDBUF, the Linux kernel always sets twice the value.
+                 * Divide by two to ensure applications do not get confused by the result. */
+                *(int *)optval /= 2;
+            }
+        #endif
             release_sock_fd( s, fd );
             return ret;
         case WS_SO_ACCEPTCONN:
diff --git a/dlls/ws2_32/tests/sock.c b/dlls/ws2_32/tests/sock.c
index 6dd1491..76506ca 100644
--- a/dlls/ws2_32/tests/sock.c
+++ b/dlls/ws2_32/tests/sock.c
@@ -1458,7 +1458,7 @@ static void test_set_getsockopt(void)
     value = 0xdeadbeef;
     err = getsockopt(s, SOL_SOCKET, SO_SNDBUF, (char *)&value, &size);
     ok( !err, "getsockopt(SO_SNDBUF) failed error: %u\n", WSAGetLastError() );
-    todo_wine ok( value == 4096, "expected 4096, got %u\n", value );
+    ok( value == 4096, "expected 4096, got %u\n", value );

/* SO_RCVBUF */
     value = 4096;
@@ -1468,7 +1468,7 @@ static void test_set_getsockopt(void)
     value = 0xdeadbeef;
     err = getsockopt(s, SOL_SOCKET, SO_RCVBUF, (char *)&value, &size);
     ok( !err, "getsockopt(SO_RCVBUF) failed error: %u\n", WSAGetLastError() );
-    todo_wine ok( value == 4096, "expected 4096, got %u\n", value );
+    ok( value == 4096, "expected 4096, got %u\n", value );

/* SO_LINGER */
     for( i = 0; i < sizeof(linger_testvals)/sizeof(LINGER);i++) {

[Marvin]

Hi,

While running your changed tests on Windows, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?
Full results can be found at
https://testbot.winehq.org/JobDetails.pl?Key=38627

Your paranoid android.

=== w7pro64 (64 bit sock) ===
sock.c:8592: Test failed: The wrong first client was accepted by acceptex: 2 != 1

[Alexandre Julliard]

Alistair Leslie-Hughes  writes:
> From: Sebastian Lackner
>
> man 7 socket
> ...
> SO_SNDBUF/SO_RCVBUF
>  Sets or gets the maximum socket send buffer in bytes.  The  kernel
>    doubles this value (to allow space for bookkeeping overhead)
> ...
> Signed-off-by: Alistair Leslie-Hughes
>
> dlls/ws2_32/socket.c     | 8 ++++++++
>  dlls/ws2_32/tests/sock.c | 4 ++--
>  2 files changed, 10 insertions(+), 2 deletions(-)

This was already discussed, it's not clear that the fix is still needed,
but if it is, it should be done in a way that works on all platforms. See
https://www.winehq.org/pipermail/wine-devel/2014-November/105878.html
for the discussion.