[newlib-cygwin] Fix the handling of out-of-band (OOB) data in a socket.
Corinna Vinschen
corinna@sourceware.org
Fri Jun 22 10:15:00 GMT 2018
https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=9c84bfd47922aad4881f80243320422b621c95dc
commit 9c84bfd47922aad4881f80243320422b621c95dc
Author: Takashi Yano <takashi.yano@nifty.ne.jp>
Date: Thu Jun 21 23:11:49 2018 +0900
Fix the handling of out-of-band (OOB) data in a socket.
* fhandler.h (class fhandler_socket_inet): Add variable bool oobinline.
* fhandler_socket_inet.cc (fhandler_socket_inet::fhandler_socket_inet):
Initialize variable oobinline.
(fhandler_socket_inet::recv_internal): Make the handling of OOB data
as consistent with POSIX as possible. Add simulation of inline mode
for OOB data as a workaround for broken winsock behavior.
(fhandler_socket_inet::setsockopt): Ditto.
(fhandler_socket_inet::getsockopt): Ditto.
(fhandler_socket_wsock::ioctl): Fix return value of SIOCATMARK command.
The return value of SIOCATMARK of winsock is almost opposite to
expectation.
* fhandler_socket_local.cc (fhandler_socket_local::recv_internal):
Remove the handling of OOB data from AF_LOCAL domain socket. Operation
related to OOB data will result in an error like Linux does.
(fhandler_socket_local::sendto): Ditto.
(fhandler_socket_local::sendmsg): Ditto.
This fixes the issue reported in following post.
https://cygwin.com/ml/cygwin/2018-06/msg00143.html
Diff:
---
winsup/cygwin/fhandler.h | 2 +
winsup/cygwin/fhandler_socket_inet.cc | 94 ++++++++++++++++++++++++++++++++--
winsup/cygwin/fhandler_socket_local.cc | 33 ++++++++++--
3 files changed, 120 insertions(+), 9 deletions(-)
diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
index 2ec460a..39a674c 100644
--- a/winsup/cygwin/fhandler.h
+++ b/winsup/cygwin/fhandler.h
@@ -684,6 +684,8 @@ class fhandler_socket_wsock: public fhandler_socket
class fhandler_socket_inet: public fhandler_socket_wsock
{
+ private:
+ bool oobinline; /* True if option SO_OOBINLINE is set */
protected:
int af_local_connect () { return 0; }
diff --git a/winsup/cygwin/fhandler_socket_inet.cc b/winsup/cygwin/fhandler_socket_inet.cc
index db301f3..555c3a9 100644
--- a/winsup/cygwin/fhandler_socket_inet.cc
+++ b/winsup/cygwin/fhandler_socket_inet.cc
@@ -685,7 +685,8 @@ fhandler_socket_wsock::set_socket_handle (SOCKET sock, int af, int type,
}
fhandler_socket_inet::fhandler_socket_inet () :
- fhandler_socket_wsock ()
+ fhandler_socket_wsock (),
+ oobinline (false)
{
}
@@ -1044,10 +1045,11 @@ fhandler_socket_inet::recv_internal (LPWSAMSG wsamsg, bool use_recvmsg)
{
ssize_t res = 0;
DWORD ret = 0, wret;
- int evt_mask = FD_READ | ((wsamsg->dwFlags & MSG_OOB) ? FD_OOB : 0);
+ int evt_mask = (wsamsg->dwFlags & MSG_OOB) ? FD_OOB : FD_READ;
LPWSABUF &wsabuf = wsamsg->lpBuffers;
ULONG &wsacnt = wsamsg->dwBufferCount;
static NO_COPY LPFN_WSARECVMSG WSARecvMsg;
+ bool read_oob = false;
/* CV 2014-10-26: Do not check for the connect_state at this point. In
certain scenarios there's no way to check the connect state reliably.
@@ -1086,12 +1088,64 @@ fhandler_socket_inet::recv_internal (LPWSAMSG wsamsg, bool use_recvmsg)
waitall = false;
}
+ /* recv() returns EINVAL if MSG_OOB flag is set in inline mode. */
+ if (oobinline && (wsamsg->dwFlags & MSG_OOB))
+ {
+ set_errno (EINVAL);
+ return SOCKET_ERROR;
+ }
+
+ /* Check whether OOB data is ready or not */
+ if (get_socket_type () == SOCK_STREAM)
+ if ((wsamsg->dwFlags & MSG_OOB) || oobinline)
+ {
+ u_long atmark = 0;
+#ifdef __x86_64__
+ /* SIOCATMARK = _IOR('s',7,u_long) */
+ int err = ::ioctlsocket (get_socket (), _IOR('s',7,u_long), &atmark);
+#else
+ int err = ::ioctlsocket (get_socket (), SIOCATMARK, &atmark);
+#endif
+ if (err)
+ {
+ set_winsock_errno ();
+ return SOCKET_ERROR;
+ }
+ /* If there is no OOB data, recv() with MSG_OOB returns EINVAL.
+ Note: The return value of SIOCATMARK in non-inline mode of
+ winsock is FALSE if OOB data exists, TRUE otherwise. */
+ if (atmark && (wsamsg->dwFlags & MSG_OOB))
+ {
+ /* No OOB data */
+ set_errno (EINVAL);
+ return SOCKET_ERROR;
+ }
+ /* Inline mode for out-of-band (OOB) data of winsock is
+ completely broken. That is, SIOCATMARK always returns
+ TRUE in inline mode. Due to this problem, application
+ cannot determine OOB data at all. Therefore the behavior
+ of a socket with SO_OOBINLINE set is simulated using
+ a socket with SO_OOBINLINE not set. In this fake inline
+ mode, the order of the OOB and non-OOB data is not
+ preserved. OOB data is read before non-OOB data sent
+ prior to the OOB data. However, this most likely is
+ not a problem in most cases. */
+ /* If there is OOB data, read OOB data using MSG_OOB in
+ fake inline mode. */
+ if (!atmark && oobinline)
+ {
+ read_oob = true;
+ evt_mask = FD_OOB;
+ }
+ }
+
/* Note: Don't call WSARecvFrom(MSG_PEEK) without actually having data
waiting in the buffers, otherwise the event handling gets messed up
for some reason. */
while (!(res = wait_for_events (evt_mask | FD_CLOSE, wait_flags))
|| saw_shutdown_read ())
{
+ DWORD dwFlags = wsamsg->dwFlags | (read_oob ? MSG_OOB : 0);
if (use_recvmsg)
res = WSARecvMsg (get_socket (), wsamsg, &wret, NULL, NULL);
/* This is working around a really weird problem in WinSock.
@@ -1113,11 +1167,11 @@ fhandler_socket_inet::recv_internal (LPWSAMSG wsamsg, bool use_recvmsg)
namelen is a valid pointer while name is NULL. Both parameters are
ignored for TCP sockets, so this only occurs when using UDP socket. */
else if (!wsamsg->name || get_socket_type () == SOCK_STREAM)
- res = WSARecv (get_socket (), wsabuf, wsacnt, &wret, &wsamsg->dwFlags,
+ res = WSARecv (get_socket (), wsabuf, wsacnt, &wret, &dwFlags,
NULL, NULL);
else
res = WSARecvFrom (get_socket (), wsabuf, wsacnt, &wret,
- &wsamsg->dwFlags, wsamsg->name, &wsamsg->namelen,
+ &dwFlags, wsamsg->name, &wsamsg->namelen,
NULL, NULL);
if (!res)
{
@@ -1561,6 +1615,23 @@ fhandler_socket_inet::setsockopt (int level, int optname, const void *optval,
set_errno (EDOM);
return ret;
+ case SO_OOBINLINE:
+ /* Inline mode for out-of-band (OOB) data of winsock is
+ completely broken. That is, SIOCATMARK always returns
+ TRUE in inline mode. Due to this problem, application
+ cannot determine OOB data at all. Therefore the behavior
+ of a socket with SO_OOBINLINE set is simulated using
+ a socket with SO_OOBINLINE not set. In this fake inline
+ mode, the order of the OOB and non-OOB data is not
+ preserved. OOB data is read before non-OOB data sent
+ prior to the OOB data. However, this most likely is
+ not a problem in most cases. */
+ /* Here, instead of actually setting inline mode, simply
+ set the variable oobinline. */
+ oobinline = *(int *) optval ? true : false;
+ ignore = true;
+ break;
+
default:
break;
}
@@ -1713,6 +1784,10 @@ fhandler_socket_inet::getsockopt (int level, int optname, const void *optval,
return 0;
}
+ case SO_OOBINLINE:
+ *(int *) optval = oobinline ? 1 : 0;
+ return 0;
+
default:
break;
}
@@ -1850,6 +1925,17 @@ fhandler_socket_wsock::ioctl (unsigned int cmd, void *p)
}
else
res = ::ioctlsocket (get_socket (), cmd, (u_long *) p);
+ /* In winsock, the return value of SIOCATMARK is FALSE if
+ OOB data exists, TRUE otherwise. This is almost opposite
+ to expectation. */
+#ifdef __x86_64__
+ /* SIOCATMARK = _IOR('s',7,u_long) */
+ if (cmd == _IOR('s',7,u_long) && !res)
+ *(u_long *)p = !*(u_long *)p;
+#else
+ if (cmd == SIOCATMARK && !res)
+ *(u_long *)p = !*(u_long *)p;
+#endif
break;
default:
res = fhandler_socket::ioctl (cmd, p);
diff --git a/winsup/cygwin/fhandler_socket_local.cc b/winsup/cygwin/fhandler_socket_local.cc
index 90d8d5a..2e01f30 100644
--- a/winsup/cygwin/fhandler_socket_local.cc
+++ b/winsup/cygwin/fhandler_socket_local.cc
@@ -1065,7 +1065,7 @@ fhandler_socket_local::recv_internal (LPWSAMSG wsamsg, bool use_recvmsg)
{
ssize_t res = 0;
DWORD ret = 0, wret;
- int evt_mask = FD_READ | ((wsamsg->dwFlags & MSG_OOB) ? FD_OOB : 0);
+ int evt_mask = FD_READ;
LPWSABUF &wsabuf = wsamsg->lpBuffers;
ULONG &wsacnt = wsamsg->dwBufferCount;
static NO_COPY LPFN_WSARECVMSG WSARecvMsg;
@@ -1080,7 +1080,15 @@ fhandler_socket_local::recv_internal (LPWSAMSG wsamsg, bool use_recvmsg)
DWORD wait_flags = wsamsg->dwFlags;
bool waitall = !!(wait_flags & MSG_WAITALL);
- wsamsg->dwFlags &= (MSG_OOB | MSG_PEEK | MSG_DONTROUTE);
+
+ /* Out-of-band data not supported by AF_LOCAL */
+ if (wsamsg->dwFlags & MSG_OOB)
+ {
+ set_errno (EOPNOTSUPP);
+ return SOCKET_ERROR;
+ }
+
+ wsamsg->dwFlags &= (MSG_PEEK | MSG_DONTROUTE);
if (use_recvmsg)
{
if (!WSARecvMsg
@@ -1104,7 +1112,7 @@ fhandler_socket_local::recv_internal (LPWSAMSG wsamsg, bool use_recvmsg)
set_winsock_errno ();
return SOCKET_ERROR;
}
- if (is_nonblocking () || (wsamsg->dwFlags & (MSG_OOB | MSG_PEEK)))
+ if (is_nonblocking () || (wsamsg->dwFlags & MSG_PEEK))
waitall = false;
}
@@ -1114,6 +1122,7 @@ fhandler_socket_local::recv_internal (LPWSAMSG wsamsg, bool use_recvmsg)
while (!(res = wait_for_events (evt_mask | FD_CLOSE, wait_flags))
|| saw_shutdown_read ())
{
+ DWORD dwFlags = wsamsg->dwFlags;
if (use_recvmsg)
res = WSARecvMsg (get_socket (), wsamsg, &wret, NULL, NULL);
/* This is working around a really weird problem in WinSock.
@@ -1135,11 +1144,11 @@ fhandler_socket_local::recv_internal (LPWSAMSG wsamsg, bool use_recvmsg)
namelen is a valid pointer while name is NULL. Both parameters are
ignored for TCP sockets, so this only occurs when using UDP socket. */
else if (!wsamsg->name || get_socket_type () == SOCK_STREAM)
- res = WSARecv (get_socket (), wsabuf, wsacnt, &wret, &wsamsg->dwFlags,
+ res = WSARecv (get_socket (), wsabuf, wsacnt, &wret, &dwFlags,
NULL, NULL);
else
res = WSARecvFrom (get_socket (), wsabuf, wsacnt, &wret,
- &wsamsg->dwFlags, wsamsg->name, &wsamsg->namelen,
+ &dwFlags, wsamsg->name, &wsamsg->namelen,
NULL, NULL);
if (!res)
{
@@ -1236,6 +1245,13 @@ fhandler_socket_local::sendto (const void *in_ptr, size_t len, int flags,
char *ptr = (char *) in_ptr;
struct sockaddr_storage sst;
+ /* Out-of-band data not supported by AF_LOCAL */
+ if (flags & MSG_OOB)
+ {
+ set_errno (EOPNOTSUPP);
+ return SOCKET_ERROR;
+ }
+
if (to && get_inet_addr_local (to, tolen, &sst, &tolen) == SOCKET_ERROR)
return SOCKET_ERROR;
@@ -1274,6 +1290,13 @@ fhandler_socket_local::sendmsg (const struct msghdr *msg, int flags)
struct sockaddr_storage sst;
int len = 0;
+ /* Out-of-band data not supported by AF_LOCAL */
+ if (flags & MSG_OOB)
+ {
+ set_errno (EOPNOTSUPP);
+ return SOCKET_ERROR;
+ }
+
if (msg->msg_name
&& get_inet_addr_local ((struct sockaddr *) msg->msg_name,
msg->msg_namelen, &sst, &len) == SOCKET_ERROR)
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