libqtest: split QMP part in libqmp

This will help moving QAPI/QMP in a common subproject.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Thomas Huth <thuth@redhat.com>

tests/qtest/libqmp.c

@@ -0,0 +1,233 @@
+/*
+ * QTest
+ *
+ * Copyright IBM, Corp. 2012
+ * Copyright Red Hat, Inc. 2012
+ * Copyright SUSE LINUX Products GmbH 2013
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *  Paolo Bonzini     <pbonzini@redhat.com>
+ *  Andreas Färber    <afaerber@suse.de>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+
+#include "libqmp.h"
+
+#include "qapi/error.h"
+#include "qapi/qmp/json-parser.h"
+#include "qapi/qmp/qjson.h"
+
+#define SOCKET_MAX_FDS 16
+
+typedef struct {
+    JSONMessageParser parser;
+    QDict *response;
+} QMPResponseParser;
+
+static void socket_send(int fd, const char *buf, size_t size)
+{
+    size_t res = qemu_write_full(fd, buf, size);
+
+    assert(res == size);
+}
+
+static void qmp_response(void *opaque, QObject *obj, Error *err)
+{
+    QMPResponseParser *qmp = opaque;
+
+    assert(!obj != !err);
+
+    if (err) {
+        error_prepend(&err, "QMP JSON response parsing failed: ");
+        error_report_err(err);
+        abort();
+    }
+
+    g_assert(!qmp->response);
+    qmp->response = qobject_to(QDict, obj);
+    g_assert(qmp->response);
+}
+
+QDict *qmp_fd_receive(int fd)
+{
+    QMPResponseParser qmp;
+    bool log = getenv("QTEST_LOG") != NULL;
+
+    qmp.response = NULL;
+    json_message_parser_init(&qmp.parser, qmp_response, &qmp, NULL);
+    while (!qmp.response) {
+        ssize_t len;
+        char c;
+
+        len = read(fd, &c, 1);
+        if (len == -1 && errno == EINTR) {
+            continue;
+        }
+
+        if (len == -1 || len == 0) {
+            fprintf(stderr, "Broken pipe\n");
+            abort();
+        }
+
+        if (log) {
+            g_assert(write(2, &c, 1) == 1);
+        }
+        json_message_parser_feed(&qmp.parser, &c, 1);
+    }
+    if (log) {
+        g_assert(write(2, "\n", 1) == 1);
+    }
+    json_message_parser_destroy(&qmp.parser);
+
+    return qmp.response;
+}
+
+/* Sends a message and file descriptors to the socket.
+ * It's needed for qmp-commands like getfd/add-fd */
+static void socket_send_fds(int socket_fd, int *fds, size_t fds_num,
+                            const char *buf, size_t buf_size)
+{
+    ssize_t ret;
+    struct msghdr msg = { 0 };
+    char control[CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS)] = { 0 };
+    size_t fdsize = sizeof(int) * fds_num;
+    struct cmsghdr *cmsg;
+    struct iovec iov = { .iov_base = (char *)buf, .iov_len = buf_size };
+
+    msg.msg_iov = &iov;
+    msg.msg_iovlen = 1;
+
+    if (fds && fds_num > 0) {
+        g_assert_cmpuint(fds_num, <, SOCKET_MAX_FDS);
+
+        msg.msg_control = control;
+        msg.msg_controllen = CMSG_SPACE(fdsize);
+
+        cmsg = CMSG_FIRSTHDR(&msg);
+        cmsg->cmsg_len = CMSG_LEN(fdsize);
+        cmsg->cmsg_level = SOL_SOCKET;
+        cmsg->cmsg_type = SCM_RIGHTS;
+        memcpy(CMSG_DATA(cmsg), fds, fdsize);
+    }
+
+    do {
+        ret = sendmsg(socket_fd, &msg, 0);
+    } while (ret < 0 && errno == EINTR);
+    g_assert_cmpint(ret, >, 0);
+}
+
+/**
+ * Allow users to send a message without waiting for the reply,
+ * in the case that they choose to discard all replies up until
+ * a particular EVENT is received.
+ */
+void qmp_fd_vsend_fds(int fd, int *fds, size_t fds_num,
+                      const char *fmt, va_list ap)
+{
+    QObject *qobj;
+
+    /* Going through qobject ensures we escape strings properly */
+    qobj = qobject_from_vjsonf_nofail(fmt, ap);
+
+    /* No need to send anything for an empty QObject.  */
+    if (qobj) {
+        int log = getenv("QTEST_LOG") != NULL;
+        GString *str = qobject_to_json(qobj);
+
+        /*
+         * BUG: QMP doesn't react to input until it sees a newline, an
+         * object, or an array.  Work-around: give it a newline.
+         */
+        g_string_append_c(str, '\n');
+
+        if (log) {
+            fprintf(stderr, "%s", str->str);
+        }
+        /* Send QMP request */
+        if (fds && fds_num > 0) {
+            socket_send_fds(fd, fds, fds_num, str->str, str->len);
+        } else {
+            socket_send(fd, str->str, str->len);
+        }
+
+        g_string_free(str, true);
+        qobject_unref(qobj);
+    }
+}
+
+void qmp_fd_vsend(int fd, const char *fmt, va_list ap)
+{
+    qmp_fd_vsend_fds(fd, NULL, 0, fmt, ap);
+}
+
+
+QDict *qmp_fdv(int fd, const char *fmt, va_list ap)
+{
+    qmp_fd_vsend_fds(fd, NULL, 0, fmt, ap);
+
+    return qmp_fd_receive(fd);
+}
+
+QDict *qmp_fd(int fd, const char *fmt, ...)
+{
+    va_list ap;
+    QDict *response;
+
+    va_start(ap, fmt);
+    response = qmp_fdv(fd, fmt, ap);
+    va_end(ap);
+    return response;
+}
+
+void qmp_fd_send(int fd, const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    qmp_fd_vsend(fd, fmt, ap);
+    va_end(ap);
+}
+
+void qmp_fd_vsend_raw(int fd, const char *fmt, va_list ap)
+{
+    bool log = getenv("QTEST_LOG") != NULL;
+    char *str = g_strdup_vprintf(fmt, ap);
+
+    if (log) {
+        fprintf(stderr, "%s", str);
+    }
+    socket_send(fd, str, strlen(str));
+    g_free(str);
+}
+
+void qmp_fd_send_raw(int fd, const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    qmp_fd_vsend_raw(fd, fmt, ap);
+    va_end(ap);
+}
+
+bool qmp_rsp_is_err(QDict *rsp)
+{
+    QDict *error = qdict_get_qdict(rsp, "error");
+    qobject_unref(rsp);
+    return !!error;
+}
+
+void qmp_expect_error_and_unref(QDict *rsp, const char *class)
+{
+    QDict *error = qdict_get_qdict(rsp, "error");
+
+    g_assert_cmpstr(qdict_get_try_str(error, "class"), ==, class);
+    g_assert_nonnull(qdict_get_try_str(error, "desc"));
+    g_assert(!qdict_haskey(rsp, "return"));
+
+    qobject_unref(rsp);
+}