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