qemu

libqmp.c (5924B)

---

 /*
  * 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"
 
 #ifndef _WIN32
 #include <sys/socket.h>
 #endif
 
 #include "qemu/cutils.h"
 #include "qemu/sockets.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)
 {
     ssize_t res = qemu_send_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 = recv(fd, &c, 1, 0);
         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;
 }
 
 #ifndef _WIN32
 /* 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);
 }
 #endif
 
 /**
  * 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.
  */
 static void
 _qmp_fd_vsend_fds(int fd, int *fds, size_t fds_num,
                   const char *fmt, va_list ap)
 {
     QObject *qobj;
 
 #ifdef _WIN32
     assert(fds_num == 0);
 #endif
 
     /* 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);
         }
 
 #ifndef _WIN32
         /* Send QMP request */
         if (fds && fds_num > 0) {
             socket_send_fds(fd, fds, fds_num, str->str, str->len);
         } else
 #endif
         {
             socket_send(fd, str->str, str->len);
         }
 
         g_string_free(str, true);
         qobject_unref(qobj);
     }
 }
 
 #ifndef _WIN32
 void qmp_fd_vsend_fds(int fd, int *fds, size_t fds_num,
                       const char *fmt, va_list ap)
 {
     _qmp_fd_vsend_fds(fd, fds, fds_num, fmt, ap);
 }
 #endif
 
 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);
 }