[1/3] qemu-iotests: add unix socket help program

diff --git a/configure b/configure
index 18fa608..0a18038 100755
--- a/configure
+++ b/configure
@@ -4507,7 +4507,7 @@  if [ "$dtc_internal" = "yes" ]; then
 fi
 
 # build tree in object directory in case the source is not in the current directory
-DIRS="tests tests/tcg tests/tcg/cris tests/tcg/lm32 tests/libqos tests/qapi-schema tests/tcg/xtensa"
+DIRS="tests tests/tcg tests/tcg/cris tests/tcg/lm32 tests/libqos tests/qapi-schema tests/tcg/xtensa tests/qemu-iotests"
 DIRS="$DIRS pc-bios/optionrom pc-bios/spapr-rtas pc-bios/s390-ccw"
 DIRS="$DIRS roms/seabios roms/vgabios"
 DIRS="$DIRS qapi-generated"
diff --git a/tests/Makefile b/tests/Makefile
index baba9e9..57131db 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -172,6 +172,8 @@  tests/boot-order-test$(EXESUF): tests/boot-order-test.o $(libqos-obj-y)
 tests/tmp105-test$(EXESUF): tests/tmp105-test.o $(libqos-omap-obj-y)
 tests/i440fx-test$(EXESUF): tests/i440fx-test.o $(libqos-pc-obj-y)
 tests/fw_cfg-test$(EXESUF): tests/fw_cfg-test.o $(libqos-pc-obj-y)
+tests/qemu-iotests/socket_scm_helper(EXESUF): tests/qemu-iotests/socket_scm_helper.o
+	$(call LINK, $^)
 
 # QTest rules
 
@@ -250,7 +252,7 @@  check-report.html: check-report.xml
 # Other tests
 
 .PHONY: check-tests/qemu-iotests-quick.sh
-check-tests/qemu-iotests-quick.sh: tests/qemu-iotests-quick.sh qemu-img$(EXESUF) qemu-io$(EXESUF)
+check-tests/qemu-iotests-quick.sh: tests/qemu-iotests-quick.sh qemu-img$(EXESUF) qemu-io$(EXESUF) tests/qemu-iotests/socket_scm_helper$(EXESUF)
 	$<
 
 .PHONY: check-tests/test-qapi.py
diff --git a/tests/qemu-iotests/socket_scm_helper.c b/tests/qemu-iotests/socket_scm_helper.c
new file mode 100644
index 0000000..1955a3e
--- /dev/null
+++ b/tests/qemu-iotests/socket_scm_helper.c
@@ -0,0 +1,119 @@ 
+/*
+ * SCM_RIGHT with unix socket help program for test
+ *
+ * Copyright IBM, Inc. 2013
+ *
+ * Authors:
+ *  Wenchao Xia    <xiawenc@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <stdlib.h>
+
+/* #define SOCKET_SCM_DEBUG */
+
+static int send_fd(int fd, int fd_to_send, const char *data, size_t len)
+{
+    struct msghdr msg;
+    struct iovec iov[1];
+    int ret;
+    char control[CMSG_SPACE(sizeof(int))];
+    struct cmsghdr *cmsg;
+
+    if (fd < 0) {
+        fprintf(stderr, "Socket fd is invalid.\n");
+        return -1;
+    }
+    if (fd_to_send < 0) {
+        fprintf(stderr, "Fd to send is invalid.\n");
+        return -1;
+    }
+    if (data == NULL || len <= 0) {
+        fprintf(stderr, "Data buffer must be valid.\n");
+        return -1;
+    }
+
+    memset(&msg, 0, sizeof(msg));
+    memset(control, 0, sizeof(control));
+
+    iov[0].iov_base = (void *)data;
+    iov[0].iov_len = len;
+
+    msg.msg_iov = iov;
+    msg.msg_iovlen = 1;
+
+    msg.msg_control = control;
+    msg.msg_controllen = sizeof(control);
+
+    cmsg = CMSG_FIRSTHDR(&msg);
+
+    cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+    cmsg->cmsg_level = SOL_SOCKET;
+    cmsg->cmsg_type = SCM_RIGHTS;
+    memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
+
+    do {
+        ret = sendmsg(fd, &msg, 0);
+    } while (ret < 0 && errno == EINTR);
+
+    if (ret < 0) {
+        fprintf(stderr, "Failed to send msg, reason: %s.\n", strerror(errno));
+    }
+
+    return ret;
+}
+
+/*
+ * To make things simple, the caller need to specify:
+ * 1. socket fd.
+ * 2. fd to send.
+ * 3. msg to send.
+ */
+int main(int argc, char **argv, char **envp)
+{
+    int sock, fd, ret, buflen;
+    const char *buf;
+#ifdef SOCKET_SCM_DEBUG
+    int i;
+    for (i = 0; i < argc; i++) {
+        fprintf(stderr, "Parameter %d: %s.\n", i, argv[i]);
+    }
+#endif
+
+    if (argc < 4) {
+        fprintf(stderr,
+                "Invalid parameter, use it as:\n"
+                "%s SOCKET_FD FD_TO_SEND MSG.\n",
+                argv[0]);
+        return 1;
+    }
+
+    errno = 0;
+    sock = strtol(argv[1], NULL, 10);
+    if (errno) {
+        fprintf(stderr, "Failed in strtol for socket fd, reason: %s.\n",
+                strerror(errno));
+        return 1;
+    }
+    fd = strtol(argv[2], NULL, 10);
+    if (errno) {
+        fprintf(stderr, "Failed in strtol for fd to send, reason: %s.\n",
+                strerror(errno));
+        return 1;
+    }
+
+    buf = argv[3];
+    buflen = strlen(buf);
+
+    ret = send_fd(sock, fd, buf, buflen);
+    if (ret < 0) {
+        return 1;
+    }
+    return 0;
+}