diff options
Diffstat (limited to 'winsup/cygwin/net.cc')
| -rw-r--r-- | winsup/cygwin/net.cc | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/winsup/cygwin/net.cc b/winsup/cygwin/net.cc index 509269a83..f9cb1de15 100644 --- a/winsup/cygwin/net.cc +++ b/winsup/cygwin/net.cc @@ -495,6 +495,34 @@ fdsock (cygheap_fdmanip& fd, const device *dev, SOCKET soc) fd->uninterruptible_io (true); debug_printf ("fd %d, name '%s', soc %p", (int) fd, dev->name, soc); + /* Usually sockets are inheritable IFS objects. Unfortunately some virus + scanners or other network-oriented software replace normal sockets + with their own kind, which is running through a filter driver. + + The result is that these new sockets are not normal kernel objects + anymore. They are typically not marked as inheritable, nor are they + IFS handles, as normal OS sockets are. They are in fact not inheritable + to child processes, and subsequent socket calls in the child process + will fail with error 10038, WSAENOTSOCK. And worse, while DuplicateHandle + on these sockets mostly works in the process which created the socket, + DuplicateHandle does quite often not work anymore in a child process. + It does not help to mark them inheritable via SetHandleInformation. + + The only way to make these sockets usable in child processes is to + duplicate them via WSADuplicateSocket/WSASocket calls. This requires + some incredible amount of extra processing so we only do this on + affected systems. If we recognize a non-inheritable socket, or if + the XP1_IFS_HANDLES flag is not set in a call to WSADuplicateSocket, + we switch to inheritance/dup via WSADuplicateSocket/WSASocket for + that socket. */ + DWORD flags; + WSAPROTOCOL_INFOW wpi; + if (!GetHandleInformation ((HANDLE) soc, &flags) + || !(flags & HANDLE_FLAG_INHERIT) + || WSADuplicateSocketW (soc, GetCurrentProcessId (), &wpi) + || !(wpi.dwServiceFlags1 & XP1_IFS_HANDLES)) + ((fhandler_socket *) fd)->init_fixup_before (); + /* Raise default buffer sizes (instead of WinSock default 8K). 64K appear to have the best size/performance ratio for a default |