tests/qtest/libqmp.c

   1 /*
   2  * QTest
   3  *
   4  * Copyright IBM, Corp. 2012
   5  * Copyright Red Hat, Inc. 2012
   6  * Copyright SUSE LINUX Products GmbH 2013
   7  *
   8  * Authors:
   9  *  Anthony Liguori   <aliguori@us.ibm.com>
  10  *  Paolo Bonzini     <pbonzini@redhat.com>
  11  *  Andreas Färber    <afaerber@suse.de>
  12  *
  13  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  14  * See the COPYING file in the top-level directory.
  15  */
  16
  17 #include "qemu/osdep.h"
  18
  19 #include "libqmp.h"
  20
  21 #ifndef _WIN32
  22 #include <sys/socket.h>
  23 #endif
  24
  25 #include "qemu/cutils.h"
  26 #include "qemu/sockets.h"
  27 #include "qapi/error.h"
  28 #include "qapi/qmp/json-parser.h"
  29 #include "qapi/qmp/qjson.h"
  30
  31 #define SOCKET_MAX_FDS 16
  32
  33 typedef struct {
  34     JSONMessageParser parser;
  35     QDict *response;
  36 } QMPResponseParser;
  37
  38 static void socket_send(int fd, const char *buf, size_t size)
  39 {
  40     ssize_t res = qemu_send_full(fd, buf, size);
  41
  42     assert(res == size);
  43 }
  44
  45 static void qmp_response(void *opaque, QObject *obj, Error *err)
  46 {
  47     QMPResponseParser *qmp = opaque;
  48
  49     assert(!obj != !err);
  50
  51     if (err) {
  52         error_prepend(&err, "QMP JSON response parsing failed: ");
  53         error_report_err(err);
  54         abort();
  55     }
  56
  57     g_assert(!qmp->response);
  58     qmp->response = qobject_to(QDict, obj);
  59     g_assert(qmp->response);
  60 }
  61
  62 QDict *qmp_fd_receive(int fd)
  63 {
  64     QMPResponseParser qmp;
  65     bool log = getenv("QTEST_LOG") != NULL;
  66
  67     qmp.response = NULL;
  68     json_message_parser_init(&qmp.parser, qmp_response, &qmp, NULL);
  69     while (!qmp.response) {
  70         ssize_t len;
  71         char c;
  72
  73         len = recv(fd, &c, 1, 0);
  74         if (len == -1 && errno == EINTR) {
  75             continue;
  76         }
  77
  78         if (len == -1 || len == 0) {
  79             fprintf(stderr, "Broken pipe\n");
  80             abort();
  81         }
  82
  83         if (log) {
  84             g_assert(write(2, &c, 1) == 1);
  85         }
  86         json_message_parser_feed(&qmp.parser, &c, 1);
  87     }
  88     if (log) {
  89         g_assert(write(2, "\n", 1) == 1);
  90     }
  91     json_message_parser_destroy(&qmp.parser);
  92
  93     return qmp.response;
  94 }
  95
  96 #ifndef _WIN32
  97 /* Sends a message and file descriptors to the socket.
  98  * It's needed for qmp-commands like getfd/add-fd */
  99 static void socket_send_fds(int socket_fd, int *fds, size_t fds_num,
 100                             const char *buf, size_t buf_size)
 101 {
 102     ssize_t ret;
 103     struct msghdr msg = { 0 };
 104     char control[CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS)] = { 0 };
 105     size_t fdsize = sizeof(int) * fds_num;
 106     struct cmsghdr *cmsg;
 107     struct iovec iov = { .iov_base = (char *)buf, .iov_len = buf_size };
 108
 109     msg.msg_iov = &iov;
 110     msg.msg_iovlen = 1;
 111
 112     if (fds && fds_num > 0) {
 113         g_assert_cmpuint(fds_num, <, SOCKET_MAX_FDS);
 114
 115         msg.msg_control = control;
 116         msg.msg_controllen = CMSG_SPACE(fdsize);
 117
 118         cmsg = CMSG_FIRSTHDR(&msg);
 119         cmsg->cmsg_len = CMSG_LEN(fdsize);
 120         cmsg->cmsg_level = SOL_SOCKET;
 121         cmsg->cmsg_type = SCM_RIGHTS;
 122         memcpy(CMSG_DATA(cmsg), fds, fdsize);
 123     }
 124
 125     do {
 126         ret = sendmsg(socket_fd, &msg, 0);
 127     } while (ret < 0 && errno == EINTR);
 128     g_assert_cmpint(ret, >, 0);
 129 }
 130 #endif
 131
 132 /**
 133  * Allow users to send a message without waiting for the reply,
 134  * in the case that they choose to discard all replies up until
 135  * a particular EVENT is received.
 136  */
 137 static G_GNUC_PRINTF(4, 0) void
 138 _qmp_fd_vsend_fds(int fd, int *fds, size_t fds_num,
 139                   const char *fmt, va_list ap)
 140 {
 141     QObject *qobj;
 142
 143 #ifdef _WIN32
 144     assert(fds_num == 0);
 145 #endif
 146
 147     /* Going through qobject ensures we escape strings properly */
 148     qobj = qobject_from_vjsonf_nofail(fmt, ap);
 149
 150     /* No need to send anything for an empty QObject.  */
 151     if (qobj) {
 152         int log = getenv("QTEST_LOG") != NULL;
 153         GString *str = qobject_to_json(qobj);
 154
 155         /*
 156          * BUG: QMP doesn't react to input until it sees a newline, an
 157          * object, or an array.  Work-around: give it a newline.
 158          */
 159         g_string_append_c(str, '\n');
 160
 161         if (log) {
 162             fprintf(stderr, "%s", str->str);
 163         }
 164
 165 #ifndef _WIN32
 166         /* Send QMP request */
 167         if (fds && fds_num > 0) {
 168             socket_send_fds(fd, fds, fds_num, str->str, str->len);
 169         } else
 170 #endif
 171         {
 172             socket_send(fd, str->str, str->len);
 173         }
 174
 175         g_string_free(str, true);
 176         qobject_unref(qobj);
 177     }
 178 }
 179
 180 #ifndef _WIN32
 181 void qmp_fd_vsend_fds(int fd, int *fds, size_t fds_num,
 182                       const char *fmt, va_list ap)
 183 {
 184     _qmp_fd_vsend_fds(fd, fds, fds_num, fmt, ap);
 185 }
 186 #endif
 187
 188 void qmp_fd_vsend(int fd, const char *fmt, va_list ap)
 189 {
 190     _qmp_fd_vsend_fds(fd, NULL, 0, fmt, ap);
 191 }
 192
 193
 194 QDict *qmp_fdv(int fd, const char *fmt, va_list ap)
 195 {
 196     _qmp_fd_vsend_fds(fd, NULL, 0, fmt, ap);
 197
 198     return qmp_fd_receive(fd);
 199 }
 200
 201 QDict *qmp_fd(int fd, const char *fmt, ...)
 202 {
 203     va_list ap;
 204     QDict *response;
 205
 206     va_start(ap, fmt);
 207     response = qmp_fdv(fd, fmt, ap);
 208     va_end(ap);
 209     return response;
 210 }
 211
 212 void qmp_fd_send(int fd, const char *fmt, ...)
 213 {
 214     va_list ap;
 215
 216     va_start(ap, fmt);
 217     qmp_fd_vsend(fd, fmt, ap);
 218     va_end(ap);
 219 }
 220
 221 void qmp_fd_vsend_raw(int fd, const char *fmt, va_list ap)
 222 {
 223     bool log = getenv("QTEST_LOG") != NULL;
 224     char *str = g_strdup_vprintf(fmt, ap);
 225
 226     if (log) {
 227         fprintf(stderr, "%s", str);
 228     }
 229     socket_send(fd, str, strlen(str));
 230     g_free(str);
 231 }
 232
 233 void qmp_fd_send_raw(int fd, const char *fmt, ...)
 234 {
 235     va_list ap;
 236
 237     va_start(ap, fmt);
 238     qmp_fd_vsend_raw(fd, fmt, ap);
 239     va_end(ap);
 240 }
 241
 242 bool qmp_rsp_is_err(QDict *rsp)
 243 {
 244     QDict *error = qdict_get_qdict(rsp, "error");
 245     qobject_unref(rsp);
 246     return !!error;
 247 }
 248
 249 void qmp_expect_error_and_unref(QDict *rsp, const char *class)
 250 {
 251     QDict *error = qdict_get_qdict(rsp, "error");
 252
 253     g_assert_cmpstr(qdict_get_try_str(error, "class"), ==, class);
 254     g_assert_nonnull(qdict_get_try_str(error, "desc"));
 255     g_assert(!qdict_haskey(rsp, "return"));
 256
 257     qobject_unref(rsp);
 258 }