[qemu.git] / qga / channel-win32.c

#include "qemu/osdep.h"
#include <windows.h>
#include <io.h>
#include "qga/guest-agent-core.h"
#include "qga/channel.h"

typedef struct GAChannelReadState {
    guint thread_id;
    uint8_t *buf;
    size_t buf_size;
    size_t cur; /* current buffer start */
    size_t pending; /* pending buffered bytes to read */
    OVERLAPPED ov;
    bool ov_pending; /* whether on async read is outstanding */
} GAChannelReadState;

struct GAChannel {
    HANDLE handle;
    GAChannelCallback cb;
    gpointer user_data;
    GAChannelReadState rstate;
    GIOCondition pending_events; /* TODO: use GAWatch.pollfd.revents */
    GSource *source;
};

typedef struct GAWatch {
    GSource source;
    GPollFD pollfd;
    GAChannel *channel;
    GIOCondition events_mask;
} GAWatch;

/*
 * Called by glib prior to polling to set up poll events if polling is needed.
 *
 */
static gboolean ga_channel_prepare(GSource *source, gint *timeout_ms)
{
    GAWatch *watch = (GAWatch *)source;
    GAChannel *c = (GAChannel *)watch->channel;
    GAChannelReadState *rs = &c->rstate;
    DWORD count_read, count_to_read = 0;
    bool success;
    GIOCondition new_events = 0;

    g_debug("prepare");
    /* go ahead and submit another read if there's room in the buffer
     * and no previous reads are outstanding
     */
    if (!rs->ov_pending) {
        if (rs->cur + rs->pending >= rs->buf_size) {
            if (rs->cur) {
                memmove(rs->buf, rs->buf + rs->cur, rs->pending);
                rs->cur = 0;
            }
        }
        count_to_read = rs->buf_size - rs->cur - rs->pending;
    }

    if (rs->ov_pending || count_to_read <= 0) {
            goto out;
    }

    /* submit the read */
    success = ReadFile(c->handle, rs->buf + rs->cur + rs->pending,
                       count_to_read, &count_read, &rs->ov);
    if (success) {
        rs->pending += count_read;
        rs->ov_pending = false;
    } else {
        if (GetLastError() == ERROR_IO_PENDING) {
            rs->ov_pending = true;
        } else {
            new_events |= G_IO_ERR;
        }
    }

out:
    /* don't block forever, iterate the main loop every once in a while */
    *timeout_ms = 500;
    /* if there's data in the read buffer, or another event is pending,
     * skip polling and issue user cb.
     */
    if (rs->pending) {
        new_events |= G_IO_IN;
    }
    c->pending_events |= new_events;
    return !!c->pending_events;
}

/*
 * Called by glib after an outstanding read request is completed.
 */
static gboolean ga_channel_check(GSource *source)
{
    GAWatch *watch = (GAWatch *)source;
    GAChannel *c = (GAChannel *)watch->channel;
    GAChannelReadState *rs = &c->rstate;
    DWORD count_read, error;
    BOOL success;

    GIOCondition new_events = 0;

    g_debug("check");

    /* failing this implies we issued a read that completed immediately,
     * yet no data was placed into the buffer (and thus we did not skip
     * polling). but since EOF is not obtainable until we retrieve an
     * overlapped result, it must be the case that there was data placed
     * into the buffer, or an error was generated by Readfile(). in either
     * case, we should've skipped the polling for this round.
     */
    g_assert(rs->ov_pending);

    success = GetOverlappedResult(c->handle, &rs->ov, &count_read, FALSE);
    if (success) {
        g_debug("thread: overlapped result, count_read: %d", (int)count_read);
        rs->pending += count_read;
        new_events |= G_IO_IN;
    } else {
        error = GetLastError();
        if (error == 0 || error == ERROR_HANDLE_EOF ||
            error == ERROR_NO_SYSTEM_RESOURCES ||
            error == ERROR_OPERATION_ABORTED) {
            /* note: On WinXP SP3 with rhel6ga virtio-win-1.1.16 vioser drivers,
             * ENSR seems to be synonymous with when we'd normally expect
             * ERROR_HANDLE_EOF. So treat it as such. Microsoft's
             * recommendation for ERROR_NO_SYSTEM_RESOURCES is to
             * retry the read, so this happens to work out anyway. On newer
             * virtio-win driver, this seems to be replaced with EOA, so
             * handle that in the same fashion.
             */
            new_events |= G_IO_HUP;
        } else if (error != ERROR_IO_INCOMPLETE) {
            g_critical("error retrieving overlapped result: %d", (int)error);
            new_events |= G_IO_ERR;
        }
    }

    if (new_events) {
        rs->ov_pending = 0;
    }
    c->pending_events |= new_events;

    return !!c->pending_events;
}

/*
 * Called by glib after either prepare or check routines signal readiness
 */
static gboolean ga_channel_dispatch(GSource *source, GSourceFunc unused,
                                    gpointer user_data)
{
    GAWatch *watch = (GAWatch *)source;
    GAChannel *c = (GAChannel *)watch->channel;
    GAChannelReadState *rs = &c->rstate;
    gboolean success;

    g_debug("dispatch");
    success = c->cb(watch->pollfd.revents, c->user_data);

    if (c->pending_events & G_IO_ERR) {
        g_critical("channel error, removing source");
        return false;
    }

    /* TODO: replace rs->pending with watch->revents */
    c->pending_events &= ~G_IO_HUP;
    if (!rs->pending) {
        c->pending_events &= ~G_IO_IN;
    } else {
        c->pending_events = 0;
    }
    return success;
}

static void ga_channel_finalize(GSource *source)
{
    g_debug("finalize");
}

GSourceFuncs ga_channel_watch_funcs = {
    ga_channel_prepare,
    ga_channel_check,
    ga_channel_dispatch,
    ga_channel_finalize
};

static GSource *ga_channel_create_watch(GAChannel *c)
{
    GSource *source = g_source_new(&ga_channel_watch_funcs, sizeof(GAWatch));
    GAWatch *watch = (GAWatch *)source;

    watch->channel = c;
    watch->pollfd.fd = (gintptr) c->rstate.ov.hEvent;
    g_source_add_poll(source, &watch->pollfd);

    return source;
}

GIOStatus ga_channel_read(GAChannel *c, char *buf, size_t size, gsize *count)
{
    GAChannelReadState *rs = &c->rstate;
    GIOStatus status;
    size_t to_read = 0;

    if (c->pending_events & G_IO_ERR) {
        return G_IO_STATUS_ERROR;
    }

    *count = to_read = MIN(size, rs->pending);
    if (to_read) {
        memcpy(buf, rs->buf + rs->cur, to_read);
        rs->cur += to_read;
        rs->pending -= to_read;
        status = G_IO_STATUS_NORMAL;
    } else {
        status = G_IO_STATUS_AGAIN;
    }

    return status;
}

static GIOStatus ga_channel_write(GAChannel *c, const char *buf, size_t size,
                                  size_t *count)
{
    GIOStatus status;
    OVERLAPPED ov = {0};
    BOOL ret;
    DWORD written;

    ov.hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
    ret = WriteFile(c->handle, buf, size, &written, &ov);
    if (!ret) {
        if (GetLastError() == ERROR_IO_PENDING) {
            /* write is pending */
            ret = GetOverlappedResult(c->handle, &ov, &written, TRUE);
            if (!ret) {
                if (!GetLastError()) {
                    status = G_IO_STATUS_AGAIN;
                } else {
                    status = G_IO_STATUS_ERROR;
                }
            } else {
                /* write is complete */
                status = G_IO_STATUS_NORMAL;
                *count = written;
            }
        } else {
            status = G_IO_STATUS_ERROR;
        }
    } else {
        /* write returned immediately */
        status = G_IO_STATUS_NORMAL;
        *count = written;
    }

    if (ov.hEvent) {
        CloseHandle(ov.hEvent);
        ov.hEvent = NULL;
    }
    return status;
}

GIOStatus ga_channel_write_all(GAChannel *c, const char *buf, size_t size)
{
    GIOStatus status = G_IO_STATUS_NORMAL;
    size_t count = 0;

    while (size) {
        status = ga_channel_write(c, buf, size, &count);
        if (status == G_IO_STATUS_NORMAL) {
            size -= count;
            buf += count;
        } else if (status != G_IO_STATUS_AGAIN) {
            break;
        }
    }

    return status;
}

static gboolean ga_channel_open(GAChannel *c, GAChannelMethod method,
                                const gchar *path)
{
    COMMTIMEOUTS comTimeOut = {0};
    gchar newpath[MAXPATHLEN] = {0};
    comTimeOut.ReadIntervalTimeout = 1;

    if (method != GA_CHANNEL_VIRTIO_SERIAL && method != GA_CHANNEL_ISA_SERIAL) {
        g_critical("unsupported communication method");
        return false;
    }

    if (method == GA_CHANNEL_ISA_SERIAL){
        snprintf(newpath, sizeof(newpath), "\\\\.\\%s", path);
    }else {
        g_strlcpy(newpath, path, sizeof(newpath));
    }

    c->handle = CreateFile(newpath, GENERIC_READ | GENERIC_WRITE, 0, NULL,
                           OPEN_EXISTING,
                           FILE_FLAG_NO_BUFFERING | FILE_FLAG_OVERLAPPED, NULL);
    if (c->handle == INVALID_HANDLE_VALUE) {
        g_critical("error opening path %s", newpath);
        return false;
    }

    if (method == GA_CHANNEL_ISA_SERIAL && !SetCommTimeouts(c->handle,&comTimeOut)) {
        g_critical("error setting timeout for com port: %lu",GetLastError());
        CloseHandle(c->handle);
        return false;
    }

    return true;
}

GAChannel *ga_channel_new(GAChannelMethod method, const gchar *path,
                          GAChannelCallback cb, gpointer opaque)
{
    GAChannel *c = g_new0(GAChannel, 1);
    SECURITY_ATTRIBUTES sec_attrs;

    if (!ga_channel_open(c, method, path)) {
        g_critical("error opening channel");
        g_free(c);
        return NULL;
    }

    c->cb = cb;
    c->user_data = opaque;

    sec_attrs.nLength = sizeof(SECURITY_ATTRIBUTES);
    sec_attrs.lpSecurityDescriptor = NULL;
    sec_attrs.bInheritHandle = false;

    c->rstate.buf_size = QGA_READ_COUNT_DEFAULT;
    c->rstate.buf = g_malloc(QGA_READ_COUNT_DEFAULT);
    c->rstate.ov.hEvent = CreateEvent(&sec_attrs, FALSE, FALSE, NULL);

    c->source = ga_channel_create_watch(c);
    g_source_attach(c->source, NULL);
    return c;
}

void ga_channel_free(GAChannel *c)
{
    if (c->source) {
        g_source_destroy(c->source);
    }
    if (c->rstate.ov.hEvent) {
        CloseHandle(c->rstate.ov.hEvent);
    }
    g_free(c->rstate.buf);
    g_free(c);
}
Commit	Line	Data
4459bf38	1	#include "qemu/osdep.h"
7868e26e	2	#include <windows.h>
7868e26e MR	3	#include <io.h>
	4	#include "qga/guest-agent-core.h"
	5	#include "qga/channel.h"
	6
	7	typedef struct GAChannelReadState {
	8	guint thread_id;
	9	uint8_t *buf;
	10	size_t buf_size;
	11	size_t cur; /* current buffer start */
	12	size_t pending; /* pending buffered bytes to read */
	13	OVERLAPPED ov;
	14	bool ov_pending; /* whether on async read is outstanding */
	15	} GAChannelReadState;
	16
	17	struct GAChannel {
	18	HANDLE handle;
	19	GAChannelCallback cb;
	20	gpointer user_data;
	21	GAChannelReadState rstate;
	22	GIOCondition pending_events; /* TODO: use GAWatch.pollfd.revents */
	23	GSource *source;
	24	};
	25
	26	typedef struct GAWatch {
	27	GSource source;
	28	GPollFD pollfd;
	29	GAChannel *channel;
	30	GIOCondition events_mask;
	31	} GAWatch;
	32
	33	/*
	34	* Called by glib prior to polling to set up poll events if polling is needed.
	35	*
	36	*/
	37	static gboolean ga_channel_prepare(GSource source, gint timeout_ms)
	38	{
	39	GAWatch watch = (GAWatch )source;
	40	GAChannel c = (GAChannel )watch->channel;
	41	GAChannelReadState *rs = &c->rstate;
	42	DWORD count_read, count_to_read = 0;
	43	bool success;
	44	GIOCondition new_events = 0;
	45
	46	g_debug("prepare");
	47	/* go ahead and submit another read if there's room in the buffer
	48	* and no previous reads are outstanding
	49	*/
	50	if (!rs->ov_pending) {
	51	if (rs->cur + rs->pending >= rs->buf_size) {
	52	if (rs->cur) {
	53	memmove(rs->buf, rs->buf + rs->cur, rs->pending);
	54	rs->cur = 0;
	55	}
	56	}
	57	count_to_read = rs->buf_size - rs->cur - rs->pending;
	58	}
	59
	60	if (rs->ov_pending \|\| count_to_read <= 0) {
	61	goto out;
	62	}
	63
	64	/* submit the read */
	65	success = ReadFile(c->handle, rs->buf + rs->cur + rs->pending,
	66	count_to_read, &count_read, &rs->ov);
67	if (success) {
68	rs->pending += count_read;
69	rs->ov_pending = false;
70	} else {
71	if (GetLastError() == ERROR_IO_PENDING) {
72	rs->ov_pending = true;
73	} else {
74	new_events \|= G_IO_ERR;
75	}
76	}
77
78	out:
cb8d4c8f	79	/* don't block forever, iterate the main loop every once in a while */
7868e26e MR	80	*timeout_ms = 500;
	81	/* if there's data in the read buffer, or another event is pending,
	82	* skip polling and issue user cb.
	83	*/
	84	if (rs->pending) {
	85	new_events \|= G_IO_IN;
	86	}
	87	c->pending_events \|= new_events;
	88	return !!c->pending_events;
	89	}
	90
	91	/*
	92	* Called by glib after an outstanding read request is completed.
	93	*/
	94	static gboolean ga_channel_check(GSource *source)
	95	{
	96	GAWatch watch = (GAWatch )source;
	97	GAChannel c = (GAChannel )watch->channel;
	98	GAChannelReadState *rs = &c->rstate;
	99	DWORD count_read, error;
	100	BOOL success;
	101
	102	GIOCondition new_events = 0;
	103
	104	g_debug("check");
	105
	106	/* failing this implies we issued a read that completed immediately,
	107	* yet no data was placed into the buffer (and thus we did not skip
	108	* polling). but since EOF is not obtainable until we retrieve an
	109	* overlapped result, it must be the case that there was data placed
	110	* into the buffer, or an error was generated by Readfile(). in either
	111	* case, we should've skipped the polling for this round.
	112	*/
	113	g_assert(rs->ov_pending);
	114
	115	success = GetOverlappedResult(c->handle, &rs->ov, &count_read, FALSE);
	116	if (success) {
	117	g_debug("thread: overlapped result, count_read: %d", (int)count_read);
	118	rs->pending += count_read;
	119	new_events \|= G_IO_IN;
	120	} else {
	121	error = GetLastError();
	122	if (error == 0 \|\| error == ERROR_HANDLE_EOF \|\|
	123	error == ERROR_NO_SYSTEM_RESOURCES \|\|
	124	error == ERROR_OPERATION_ABORTED) {
	125	/* note: On WinXP SP3 with rhel6ga virtio-win-1.1.16 vioser drivers,
	126	* ENSR seems to be synonymous with when we'd normally expect
	127	* ERROR_HANDLE_EOF. So treat it as such. Microsoft's
	128	* recommendation for ERROR_NO_SYSTEM_RESOURCES is to
	129	* retry the read, so this happens to work out anyway. On newer
	130	* virtio-win driver, this seems to be replaced with EOA, so
	131	* handle that in the same fashion.
	132	*/
	133	new_events \|= G_IO_HUP;
	134	} else if (error != ERROR_IO_INCOMPLETE) {
	135	g_critical("error retrieving overlapped result: %d", (int)error);
	136	new_events \|= G_IO_ERR;
	137	}
	138	}
	139
	140	if (new_events) {
	141	rs->ov_pending = 0;
	142	}
	143	c->pending_events \|= new_events;
144
145	return !!c->pending_events;
146	}
147
148	/*
149	* Called by glib after either prepare or check routines signal readiness
150	*/
151	static gboolean ga_channel_dispatch(GSource *source, GSourceFunc unused,
152	gpointer user_data)
153	{
154	GAWatch watch = (GAWatch )source;
155	GAChannel c = (GAChannel )watch->channel;
156	GAChannelReadState *rs = &c->rstate;
157	gboolean success;
158
159	g_debug("dispatch");
160	success = c->cb(watch->pollfd.revents, c->user_data);
161
162	if (c->pending_events & G_IO_ERR) {
163	g_critical("channel error, removing source");
164	return false;
165	}
166
167	/* TODO: replace rs->pending with watch->revents */
168	c->pending_events &= ~G_IO_HUP;
169	if (!rs->pending) {
170	c->pending_events &= ~G_IO_IN;
171	} else {
172	c->pending_events = 0;
173	}
174	return success;
175	}
176
177	static void ga_channel_finalize(GSource *source)
178	{
179	g_debug("finalize");
180	}
181
182	GSourceFuncs ga_channel_watch_funcs = {
183	ga_channel_prepare,
184	ga_channel_check,
185	ga_channel_dispatch,
186	ga_channel_finalize
187	};
188
189	static GSource ga_channel_create_watch(GAChannel c)
190	{
191	GSource *source = g_source_new(&ga_channel_watch_funcs, sizeof(GAWatch));
192	GAWatch watch = (GAWatch )source;
193
194	watch->channel = c;
195	watch->pollfd.fd = (gintptr) c->rstate.ov.hEvent;
196	g_source_add_poll(source, &watch->pollfd);
197
198	return source;
199	}
200
201	GIOStatus ga_channel_read(GAChannel c, char buf, size_t size, gsize *count)
202	{
203	GAChannelReadState *rs = &c->rstate;
204	GIOStatus status;
205	size_t to_read = 0;
206
207	if (c->pending_events & G_IO_ERR) {
208	return G_IO_STATUS_ERROR;
209	}
210
211	*count = to_read = MIN(size, rs->pending);
212	if (to_read) {
213	memcpy(buf, rs->buf + rs->cur, to_read);
214	rs->cur += to_read;
215	rs->pending -= to_read;
216	status = G_IO_STATUS_NORMAL;
217	} else {
218	status = G_IO_STATUS_AGAIN;
219	}
220
221	return status;
222	}
223
224	static GIOStatus ga_channel_write(GAChannel c, const char buf, size_t size,
225	size_t *count)
226	{
227	GIOStatus status;
228	OVERLAPPED ov = {0};
229	BOOL ret;
230	DWORD written;
231
232	ov.hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
233	ret = WriteFile(c->handle, buf, size, &written, &ov);
234	if (!ret) {
235	if (GetLastError() == ERROR_IO_PENDING) {
236	/* write is pending */
237	ret = GetOverlappedResult(c->handle, &ov, &written, TRUE);
238	if (!ret) {
239	if (!GetLastError()) {
240	status = G_IO_STATUS_AGAIN;
241	} else {
242	status = G_IO_STATUS_ERROR;
243	}
244	} else {
245	/* write is complete */
246	status = G_IO_STATUS_NORMAL;
247	*count = written;
248	}
249	} else {
250	status = G_IO_STATUS_ERROR;
251	}
252	} else {
253	/* write returned immediately */
254	status = G_IO_STATUS_NORMAL;
255	*count = written;
256	}
257
b71706d1 JC	258	if (ov.hEvent) {
	259	CloseHandle(ov.hEvent);
	260	ov.hEvent = NULL;
	261	}
7868e26e MR	262	return status;
	263	}
	264
	265	GIOStatus ga_channel_write_all(GAChannel c, const char buf, size_t size)
	266	{
c7e775e4	267	GIOStatus status = G_IO_STATUS_NORMAL;
e853ea1c	268	size_t count = 0;
7868e26e MR	269
	270	while (size) {
	271	status = ga_channel_write(c, buf, size, &count);
	272	if (status == G_IO_STATUS_NORMAL) {
	273	size -= count;
	274	buf += count;
	275	} else if (status != G_IO_STATUS_AGAIN) {
	276	break;
	277	}
	278	}
	279
	280	return status;
	281	}
	282
	283	static gboolean ga_channel_open(GAChannel *c, GAChannelMethod method,
	284	const gchar *path)
	285	{
a749f42d MM	286	COMMTIMEOUTS comTimeOut = {0};
	287	gchar newpath[MAXPATHLEN] = {0};
	288	comTimeOut.ReadIntervalTimeout = 1;
	289
	290	if (method != GA_CHANNEL_VIRTIO_SERIAL && method != GA_CHANNEL_ISA_SERIAL) {
7868e26e MR	291	g_critical("unsupported communication method");
	292	return false;
	293	}
	294
a749f42d MM	295	if (method == GA_CHANNEL_ISA_SERIAL){
	296	snprintf(newpath, sizeof(newpath), "\\\\.\\%s", path);
	297	}else {
	298	g_strlcpy(newpath, path, sizeof(newpath));
	299	}
	300
	301	c->handle = CreateFile(newpath, GENERIC_READ \| GENERIC_WRITE, 0, NULL,
7868e26e MR	302	OPEN_EXISTING,
	303	FILE_FLAG_NO_BUFFERING \| FILE_FLAG_OVERLAPPED, NULL);
	304	if (c->handle == INVALID_HANDLE_VALUE) {
c69403fc	305	g_critical("error opening path %s", newpath);
7868e26e MR	306	return false;
	307	}
	308
a749f42d MM	309	if (method == GA_CHANNEL_ISA_SERIAL && !SetCommTimeouts(c->handle,&comTimeOut)) {
	310	g_critical("error setting timeout for com port: %lu",GetLastError());
	311	CloseHandle(c->handle);
	312	return false;
	313	}
	314
7868e26e MR	315	return true;
	316	}
	317
	318	GAChannel ga_channel_new(GAChannelMethod method, const gchar path,
	319	GAChannelCallback cb, gpointer opaque)
	320	{
f3a06403	321	GAChannel *c = g_new0(GAChannel, 1);
7868e26e MR	322	SECURITY_ATTRIBUTES sec_attrs;
	323
	324	if (!ga_channel_open(c, method, path)) {
	325	g_critical("error opening channel");
	326	g_free(c);
	327	return NULL;
	328	}
	329
	330	c->cb = cb;
	331	c->user_data = opaque;
	332
	333	sec_attrs.nLength = sizeof(SECURITY_ATTRIBUTES);
	334	sec_attrs.lpSecurityDescriptor = NULL;
	335	sec_attrs.bInheritHandle = false;
	336
	337	c->rstate.buf_size = QGA_READ_COUNT_DEFAULT;
	338	c->rstate.buf = g_malloc(QGA_READ_COUNT_DEFAULT);
	339	c->rstate.ov.hEvent = CreateEvent(&sec_attrs, FALSE, FALSE, NULL);
	340
	341	c->source = ga_channel_create_watch(c);
	342	g_source_attach(c->source, NULL);
	343	return c;
	344	}
	345
	346	void ga_channel_free(GAChannel *c)
	347	{
	348	if (c->source) {
	349	g_source_destroy(c->source);
	350	}
	351	if (c->rstate.ov.hEvent) {
	352	CloseHandle(c->rstate.ov.hEvent);
	353	}
	354	g_free(c->rstate.buf);
	355	g_free(c);
	356	}