Introduce and apply krb5_storage_from_socket

On Windows a file descriptor is an int value allocated by the
local module instance of the C Run Time Library.  A socket handle is a
SOCKET value allocated by a Winsock Provider for the requested family and
protocol.   These two values cannot be mixed and there is no mechanism for
converting between the two.   The _get_osfhandle() and _open_osfhandle()
functions can work with a standard HANDLE (file, pipe, etc) but cannot be
used for a SOCKET.

The Heimdal krb5_storage_from_fd() routine counted on the osf conversion
functions working on SOCKET values.  Since they do not any attempt to call
krb5_storage_from_fd() on a socket resulted in an assertion being thrown
by the C RTL.

Another problem is SOCKET value truncation when storing a 64-bit value
into a 32-bit int.

To address these problems a new krb5_storage_from_socket() routine is
introduced.  This routine setups a krb5_storage that stores a socket value
as a rk_socket_t and provides a set of helper routines that always use
network ready functions.

The krb5_storage_from_fd() routines no longer use net_read() and
net_write() but provide helpers that follow their logic so that pipes can
be processed.

All call sites that allocate a socket now store the socket as rk_socket_t
and call krb5_storage_from_socket().

All locations that previously called the bare close() on a socket value
now call rk_closesocket().

Change-Id: I045f775b2a5dbf5cf803751409490bc27fffe597

lib/krb5/store_sock.c

@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) 1997 - 2004 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "krb5_locl.h"
+#include "store-int.h"
+
+#ifdef _WIN32
+#include <winsock2.h>
+#endif
+
+typedef struct socket_storage {
+    krb5_socket_t sock;
+} socket_storage;
+
+#define SOCK(S) (((socket_storage*)(S)->data)->sock)
+
+static ssize_t
+socket_fetch(krb5_storage * sp, void *data, size_t size)
+{
+    return net_read(SOCK(sp), data, size);
+}
+
+static ssize_t
+socket_store(krb5_storage * sp, const void *data, size_t size)
+{
+    return net_write(SOCK(sp), data, size);
+}
+
+static off_t
+socket_seek(krb5_storage * sp, off_t offset, int whence)
+{
+    return lseek(SOCK(sp), offset, whence);
+}
+
+static int
+socket_trunc(krb5_storage * sp, off_t offset)
+{
+    if (ftruncate(SOCK(sp), offset) == -1)
+	return errno;
+    return 0;
+}
+
+static int
+socket_sync(krb5_storage * sp)
+{
+    if (fsync(SOCK(sp)) == -1)
+	return errno;
+    return 0;
+}
+
+static void
+socket_free(krb5_storage * sp)
+{
+    rk_closesocket(SOCK(sp));
+}
+
+/**
+ *
+ *
+ * @return A krb5_storage on success, or NULL on out of memory error.
+ *
+ * @ingroup krb5_storage
+ *
+ * @sa krb5_storage_emem()
+ * @sa krb5_storage_from_mem()
+ * @sa krb5_storage_from_readonly_mem()
+ * @sa krb5_storage_from_data()
+ * @sa krb5_storage_from_fd()
+ */
+
+KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
+krb5_storage_from_socket(krb5_socket_t sock_in)
+{
+    krb5_storage *sp;
+    int saved_errno;
+    krb5_socket_t sock;
+
+#ifdef _WIN32
+    WSAPROTOCOL_INFO info;
+
+    if (WSADuplicateSocket(sock_in, GetCurrentProcessId(), &info) == 0)
+    {
+
+	sock = WSASocket( FROM_PROTOCOL_INFO,
+			  FROM_PROTOCOL_INFO,
+			  FROM_PROTOCOL_INFO,
+			  &info, 0, 0);
+    }
+#else
+    sock = dup(sock_in);
+#endif
+
+    if (sock == rk_INVALID_SOCKET)
+	return NULL;
+
+    errno = ENOMEM;
+    sp = malloc(sizeof(krb5_storage));
+    if (sp == NULL) {
+	saved_errno = errno;
+	rk_closesocket(sock);
+	errno = saved_errno;
+	return NULL;
+    }
+
+    errno = ENOMEM;
+    sp->data = malloc(sizeof(socket_storage));
+    if (sp->data == NULL) {
+	saved_errno = errno;
+	rk_closesocket(sock);
+	free(sp);
+	errno = saved_errno;
+	return NULL;
+    }
+    sp->flags = 0;
+    sp->eof_code = HEIM_ERR_EOF;
+    SOCK(sp) = sock;
+    sp->fetch = socket_fetch;
+    sp->store = socket_store;
+    sp->seek = socket_seek;
+    sp->trunc = socket_trunc;
+    sp->fsync = socket_sync;
+    sp->free = socket_free;
+    sp->max_alloc = UINT_MAX/8;
+    return sp;
+}