summaryrefslogtreecommitdiff
path: root/qga/commands.c
blob: 0f80ce65a424c29b2f0d1722238dbed9b09a56c0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
/*
 * QEMU Guest Agent common/cross-platform command implementations
 *
 * Copyright IBM Corp. 2012
 *
 * Authors:
 *  Michael Roth      <mdroth@linux.vnet.ibm.com>
 *
 * 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 <glib.h>
#include "qga/guest-agent-core.h"
#include "qga-qmp-commands.h"
#include "qapi/qmp/qerror.h"

/* Maximum captured guest-exec out_data/err_data - 16MB */
#define GUEST_EXEC_MAX_OUTPUT (16*1024*1024)
/* Allocation and I/O buffer for reading guest-exec out_data/err_data - 4KB */
#define GUEST_EXEC_IO_SIZE (4*1024)

/* Note: in some situations, like with the fsfreeze, logging may be
 * temporarilly disabled. if it is necessary that a command be able
 * to log for accounting purposes, check ga_logging_enabled() beforehand,
 * and use the QERR_QGA_LOGGING_DISABLED to generate an error
 */
void slog(const gchar *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);
    g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap);
    va_end(ap);
}

int64_t qmp_guest_sync_delimited(int64_t id, Error **errp)
{
    ga_set_response_delimited(ga_state);
    return id;
}

int64_t qmp_guest_sync(int64_t id, Error **errp)
{
    return id;
}

void qmp_guest_ping(Error **errp)
{
    slog("guest-ping called");
}

static void qmp_command_info(QmpCommand *cmd, void *opaque)
{
    GuestAgentInfo *info = opaque;
    GuestAgentCommandInfo *cmd_info;
    GuestAgentCommandInfoList *cmd_info_list;

    cmd_info = g_new0(GuestAgentCommandInfo, 1);
    cmd_info->name = g_strdup(qmp_command_name(cmd));
    cmd_info->enabled = qmp_command_is_enabled(cmd);
    cmd_info->success_response = qmp_has_success_response(cmd);

    cmd_info_list = g_new0(GuestAgentCommandInfoList, 1);
    cmd_info_list->value = cmd_info;
    cmd_info_list->next = info->supported_commands;
    info->supported_commands = cmd_info_list;
}

struct GuestAgentInfo *qmp_guest_info(Error **errp)
{
    GuestAgentInfo *info = g_new0(GuestAgentInfo, 1);

    info->version = g_strdup(QEMU_VERSION);
    qmp_for_each_command(qmp_command_info, info);
    return info;
}

struct GuestExecIOData {
    guchar *data;
    gsize size;
    gsize length;
    gint closed;
    bool truncated;
    const char *name;
};
typedef struct GuestExecIOData GuestExecIOData;

struct GuestExecInfo {
    GPid pid;
    int64_t pid_numeric;
    gint status;
    bool has_output;
    gint finished;
    GuestExecIOData in;
    GuestExecIOData out;
    GuestExecIOData err;
    QTAILQ_ENTRY(GuestExecInfo) next;
};
typedef struct GuestExecInfo GuestExecInfo;

static struct {
    QTAILQ_HEAD(, GuestExecInfo) processes;
} guest_exec_state = {
    .processes = QTAILQ_HEAD_INITIALIZER(guest_exec_state.processes),
};

static int64_t gpid_to_int64(GPid pid)
{
#ifdef G_OS_WIN32
    return GetProcessId(pid);
#else
    return (int64_t)pid;
#endif
}

static GuestExecInfo *guest_exec_info_add(GPid pid)
{
    GuestExecInfo *gei;

    gei = g_new0(GuestExecInfo, 1);
    gei->pid = pid;
    gei->pid_numeric = gpid_to_int64(pid);
    QTAILQ_INSERT_TAIL(&guest_exec_state.processes, gei, next);

    return gei;
}

static GuestExecInfo *guest_exec_info_find(int64_t pid_numeric)
{
    GuestExecInfo *gei;

    QTAILQ_FOREACH(gei, &guest_exec_state.processes, next) {
        if (gei->pid_numeric == pid_numeric) {
            return gei;
        }
    }

    return NULL;
}

GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **err)
{
    GuestExecInfo *gei;
    GuestExecStatus *ges;

    slog("guest-exec-status called, pid: %u", (uint32_t)pid);

    gei = guest_exec_info_find(pid);
    if (gei == NULL) {
        error_setg(err, QERR_INVALID_PARAMETER, "pid");
        return NULL;
    }

    ges = g_new0(GuestExecStatus, 1);

    bool finished = g_atomic_int_get(&gei->finished);

    /* need to wait till output channels are closed
     * to be sure we captured all output at this point */
    if (gei->has_output) {
        finished = finished && g_atomic_int_get(&gei->out.closed);
        finished = finished && g_atomic_int_get(&gei->err.closed);
    }

    ges->exited = finished;
    if (finished) {
        /* Glib has no portable way to parse exit status.
         * On UNIX, we can get either exit code from normal termination
         * or signal number.
         * On Windows, it is either the same exit code or the exception
         * value for an unhandled exception that caused the process
         * to terminate.
         * See MSDN for GetExitCodeProcess() and ntstatus.h for possible
         * well-known codes, e.g. C0000005 ACCESS_DENIED - analog of SIGSEGV
         * References:
         *   https://msdn.microsoft.com/en-us/library/windows/desktop/ms683189(v=vs.85).aspx
         *   https://msdn.microsoft.com/en-us/library/aa260331(v=vs.60).aspx
         */
#ifdef G_OS_WIN32
        /* Additionally WIN32 does not provide any additional information
         * on whetherthe child exited or terminated via signal.
         * We use this simple range check to distingish application exit code
         * (usually value less then 256) and unhandled exception code with
         * ntstatus (always value greater then 0xC0000005). */
        if ((uint32_t)gei->status < 0xC0000000U) {
            ges->has_exitcode = true;
            ges->exitcode = gei->status;
        } else {
            ges->has_signal = true;
            ges->signal = gei->status;
        }
#else
        if (WIFEXITED(gei->status)) {
            ges->has_exitcode = true;
            ges->exitcode = WEXITSTATUS(gei->status);
        } else if (WIFSIGNALED(gei->status)) {
            ges->has_signal = true;
            ges->signal = WTERMSIG(gei->status);
        }
#endif
        if (gei->out.length > 0) {
            ges->has_out_data = true;
            ges->out_data = g_base64_encode(gei->out.data, gei->out.length);
            g_free(gei->out.data);
            ges->has_out_truncated = gei->out.truncated;
        }

        if (gei->err.length > 0) {
            ges->has_err_data = true;
            ges->err_data = g_base64_encode(gei->err.data, gei->err.length);
            g_free(gei->err.data);
            ges->has_err_truncated = gei->err.truncated;
        }

        QTAILQ_REMOVE(&guest_exec_state.processes, gei, next);
        g_free(gei);
    }

    return ges;
}

/* Get environment variables or arguments array for execve(). */
static char **guest_exec_get_args(const strList *entry, bool log)
{
    const strList *it;
    int count = 1, i = 0;  /* reserve for NULL terminator */
    char **args;
    char *str; /* for logging array of arguments */
    size_t str_size = 1;

    for (it = entry; it != NULL; it = it->next) {
        count++;
        str_size += 1 + strlen(it->value);
    }

    str = g_malloc(str_size);
    *str = 0;
    args = g_malloc(count * sizeof(char *));
    for (it = entry; it != NULL; it = it->next) {
        args[i++] = it->value;
        pstrcat(str, str_size, it->value);
        if (it->next) {
            pstrcat(str, str_size, " ");
        }
    }
    args[i] = NULL;

    if (log) {
        slog("guest-exec called: \"%s\"", str);
    }
    g_free(str);

    return args;
}

static void guest_exec_child_watch(GPid pid, gint status, gpointer data)
{
    GuestExecInfo *gei = (GuestExecInfo *)data;

    g_debug("guest_exec_child_watch called, pid: %d, status: %u",
            (int32_t)gpid_to_int64(pid), (uint32_t)status);

    gei->status = status;
    gei->finished = true;

    g_spawn_close_pid(pid);
}

/** Reset ignored signals back to default. */
static void guest_exec_task_setup(gpointer data)
{
#if !defined(G_OS_WIN32)
    struct sigaction sigact;

    memset(&sigact, 0, sizeof(struct sigaction));
    sigact.sa_handler = SIG_DFL;

    if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
        slog("sigaction() failed to reset child process's SIGPIPE: %s",
             strerror(errno));
    }
#endif
}

static gboolean guest_exec_input_watch(GIOChannel *ch,
        GIOCondition cond, gpointer p_)
{
    GuestExecIOData *p = (GuestExecIOData *)p_;
    gsize bytes_written = 0;
    GIOStatus status;
    GError *gerr = NULL;

    /* nothing left to write */
    if (p->size == p->length) {
        goto done;
    }

    status = g_io_channel_write_chars(ch, (gchar *)p->data + p->length,
            p->size - p->length, &bytes_written, &gerr);

    /* can be not 0 even if not G_IO_STATUS_NORMAL */
    if (bytes_written != 0) {
        p->length += bytes_written;
    }

    /* continue write, our callback will be called again */
    if (status == G_IO_STATUS_NORMAL || status == G_IO_STATUS_AGAIN) {
        return true;
    }

    if (gerr) {
        g_warning("qga: i/o error writing to input_data channel: %s",
                gerr->message);
        g_error_free(gerr);
    }

done:
    g_io_channel_shutdown(ch, true, NULL);
    g_io_channel_unref(ch);
    g_atomic_int_set(&p->closed, 1);
    g_free(p->data);

    return false;
}

static gboolean guest_exec_output_watch(GIOChannel *ch,
        GIOCondition cond, gpointer p_)
{
    GuestExecIOData *p = (GuestExecIOData *)p_;
    gsize bytes_read;
    GIOStatus gstatus;

    if (cond == G_IO_HUP || cond == G_IO_ERR) {
        goto close;
    }

    if (p->size == p->length) {
        gpointer t = NULL;
        if (!p->truncated && p->size < GUEST_EXEC_MAX_OUTPUT) {
            t = g_try_realloc(p->data, p->size + GUEST_EXEC_IO_SIZE);
        }
        if (t == NULL) {
            /* ignore truncated output */
            gchar buf[GUEST_EXEC_IO_SIZE];

            p->truncated = true;
            gstatus = g_io_channel_read_chars(ch, buf, sizeof(buf),
                                              &bytes_read, NULL);
            if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) {
                goto close;
            }

            return true;
        }
        p->size += GUEST_EXEC_IO_SIZE;
        p->data = t;
    }

    /* Calling read API once.
     * On next available data our callback will be called again */
    gstatus = g_io_channel_read_chars(ch, (gchar *)p->data + p->length,
            p->size - p->length, &bytes_read, NULL);
    if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) {
        goto close;
    }

    p->length += bytes_read;

    return true;

close:
    g_io_channel_unref(ch);
    g_atomic_int_set(&p->closed, 1);
    return false;
}

GuestExec *qmp_guest_exec(const char *path,
                       bool has_arg, strList *arg,
                       bool has_env, strList *env,
                       bool has_input_data, const char *input_data,
                       bool has_capture_output, bool capture_output,
                       Error **err)
{
    GPid pid;
    GuestExec *ge = NULL;
    GuestExecInfo *gei;
    char **argv, **envp;
    strList arglist;
    gboolean ret;
    GError *gerr = NULL;
    gint in_fd, out_fd, err_fd;
    GIOChannel *in_ch, *out_ch, *err_ch;
    GSpawnFlags flags;
    bool has_output = (has_capture_output && capture_output);

    arglist.value = (char *)path;
    arglist.next = has_arg ? arg : NULL;

    argv = guest_exec_get_args(&arglist, true);
    envp = guest_exec_get_args(has_env ? env : NULL, false);

    flags = G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD;
    if (!has_output) {
        flags |= G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL;
    }

    ret = g_spawn_async_with_pipes(NULL, argv, envp, flags,
            guest_exec_task_setup, NULL, &pid, has_input_data ? &in_fd : NULL,
            has_output ? &out_fd : NULL, has_output ? &err_fd : NULL, &gerr);
    if (!ret) {
        error_setg(err, QERR_QGA_COMMAND_FAILED, gerr->message);
        g_error_free(gerr);
        goto done;
    }

    ge = g_new0(GuestExec, 1);
    ge->pid = gpid_to_int64(pid);

    gei = guest_exec_info_add(pid);
    gei->has_output = has_output;
    g_child_watch_add(pid, guest_exec_child_watch, gei);

    if (has_input_data) {
        gei->in.data = g_base64_decode(input_data, &gei->in.size);
#ifdef G_OS_WIN32
        in_ch = g_io_channel_win32_new_fd(in_fd);
#else
        in_ch = g_io_channel_unix_new(in_fd);
#endif
        g_io_channel_set_encoding(in_ch, NULL, NULL);
        g_io_channel_set_buffered(in_ch, false);
        g_io_channel_set_flags(in_ch, G_IO_FLAG_NONBLOCK, NULL);
        g_io_add_watch(in_ch, G_IO_OUT, guest_exec_input_watch, &gei->in);
    }

    if (has_output) {
#ifdef G_OS_WIN32
        out_ch = g_io_channel_win32_new_fd(out_fd);
        err_ch = g_io_channel_win32_new_fd(err_fd);
#else
        out_ch = g_io_channel_unix_new(out_fd);
        err_ch = g_io_channel_unix_new(err_fd);
#endif
        g_io_channel_set_encoding(out_ch, NULL, NULL);
        g_io_channel_set_encoding(err_ch, NULL, NULL);
        g_io_channel_set_buffered(out_ch, false);
        g_io_channel_set_buffered(err_ch, false);
        g_io_add_watch(out_ch, G_IO_IN | G_IO_HUP,
                guest_exec_output_watch, &gei->out);
        g_io_add_watch(err_ch, G_IO_IN | G_IO_HUP,
                guest_exec_output_watch, &gei->err);
    }

done:
    g_free(argv);
    g_free(envp);

    return ge;
}