From be2808a3bf0d5fed81d01872323717d457753133 Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Tue, 26 Feb 2008 14:50:45 +0000 Subject: [PATCH] ioemu: VNC updates should be sent only when requested. Reading qemu code I realized that the qemu vnc server sometimes sends framebuffer updates even if the client didn't request any. This is not consistent with the RFB protocol spec and can break some clients. This patch strictly enforces compliance with the RFB protocol making sure framebuffer updates are sent only if the client requested one. Doing so is more difficult than it seems because some framebuffer pseudo-encoding updates cannot be discarded but must be sent anyway: for example desktop resize and pixel format change messages. To solve the problem I wrote a queue that stores those messages and sends them as soon as the client asks for an update. Since 90% of the times the queue is used to store only few elements, the queue allocates 10 elements at the beginning and every time it runs out of elements allocates other 10 elements. This is should drastically limit the number of malloc and free needed to maintain the queue. I did some stress tests in the last couple of days and seems to work well. Signed-off-by: Stefano Stabellini --- tools/ioemu/vnc.c | 196 ++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 174 insertions(+), 22 deletions(-) diff --git a/tools/ioemu/vnc.c b/tools/ioemu/vnc.c index 60174070ca..e14fb61750 100644 --- a/tools/ioemu/vnc.c +++ b/tools/ioemu/vnc.c @@ -137,6 +137,23 @@ enum { #endif /* CONFIG_VNC_TLS */ +#define QUEUE_ALLOC_UNIT 10 + +typedef struct _QueueItem +{ + int x, y, w, h; + int32_t enc; + struct _QueueItem *next; +} QueueItem; + +typedef struct _Queue +{ + QueueItem *queue_start; + int start_count; + QueueItem *queue_end; + int end_count; +} Queue; + struct VncState { QEMUTimer *timer; @@ -152,6 +169,9 @@ struct VncState uint64_t *update_row; /* outstanding updates */ int has_update; /* there's outstanding updates in the * visible area */ + + int update_requested; /* the client requested an update */ + uint8_t *old_data; int depth; /* internal VNC frame buffer byte per pixel */ int has_resize; @@ -186,6 +206,9 @@ struct VncState Buffer output; Buffer input; + + Queue upqueue; + kbd_layout_t *kbd_layout; /* current output mode information */ VncWritePixels *write_pixels; @@ -248,6 +271,11 @@ static void _vnc_update_client(void *opaque); static void vnc_update_client(void *opaque); static void vnc_client_read(void *opaque); static void framebuffer_set_updated(VncState *vs, int x, int y, int w, int h); +static void pixel_format_message (VncState *vs); +static void enqueue_framebuffer_update(VncState *vs, int x, int y, int w, int h, int32_t encoding); +static void dequeue_framebuffer_update(VncState *vs); +static int is_empty_queue(VncState *vs); +static void free_queue(VncState *vs); #if 0 static inline void vnc_set_bit(uint32_t *d, int k) @@ -370,13 +398,18 @@ static void vnc_dpy_resize(DisplayState *ds, int w, int h) ds->height = h; ds->linesize = w * vs->depth; if (vs->csock != -1 && vs->has_resize && size_changed) { - vnc_write_u8(vs, 0); /* msg id */ - vnc_write_u8(vs, 0); - vnc_write_u16(vs, 1); /* number of rects */ - vnc_framebuffer_update(vs, 0, 0, ds->width, ds->height, -223); - vnc_flush(vs); - vs->width = ds->width; - vs->height = ds->height; + vs->width = ds->width; + vs->height = ds->height; + if (vs->update_requested) { + vnc_write_u8(vs, 0); /* msg id */ + vnc_write_u8(vs, 0); + vnc_write_u16(vs, 1); /* number of rects */ + vnc_framebuffer_update(vs, 0, 0, ds->width, ds->height, -223); + vnc_flush(vs); + vs->update_requested--; + } else { + enqueue_framebuffer_update(vs, 0, 0, ds->width, ds->height, -223); + } } vs->dirty_pixel_shift = 0; for (o = DIRTY_PIXEL_BITS; o < ds->width; o *= 2) @@ -553,7 +586,8 @@ static void vnc_copy(DisplayState *ds, int src_x, int src_y, int dst_x, int dst_ return; } - if (src_x < vs->visible_x || src_y < vs->visible_y || + if (!vs->update_requested || + src_x < vs->visible_x || src_y < vs->visible_y || dst_x < vs->visible_x || dst_y < vs->visible_y || (src_x + w) > (vs->visible_x + vs->visible_w) || (src_y + h) > (vs->visible_y + vs->visible_h) || @@ -592,6 +626,7 @@ static void vnc_copy(DisplayState *ds, int src_x, int src_y, int dst_x, int dst_ vnc_write_u16(vs, src_x); vnc_write_u16(vs, src_y); vnc_flush(vs); + vs->update_requested--; } else framebuffer_set_updated(vs, dst_x, dst_y, w, h); } @@ -624,8 +659,21 @@ static void _vnc_update_client(void *opaque) int maxx, maxy; int tile_bytes = vs->depth * DP2X(vs, 1); - if (vs->csock == -1) + if (!vs->update_requested || vs->csock == -1) return; + while (!is_empty_queue(vs) && vs->update_requested) { + int enc = vs->upqueue.queue_end->enc; + dequeue_framebuffer_update(vs); + switch (enc) { + case 0x574D5669: + pixel_format_message(vs); + break; + default: + break; + } + vs->update_requested--; + } + if (!vs->update_requested) return; now = qemu_get_clock(rt_clock); @@ -717,8 +765,11 @@ static void _vnc_update_client(void *opaque) vs->output.buffer[saved_offset] = (n_rectangles >> 8) & 0xFF; vs->output.buffer[saved_offset + 1] = n_rectangles & 0xFF; - if (n_rectangles == 0) + if (n_rectangles == 0) { + vs->output.offset = saved_offset - 2; goto backoff; + } else + vs->update_requested--; vs->has_update = 0; vnc_flush(vs); @@ -735,7 +786,8 @@ static void _vnc_update_client(void *opaque) vs->timer_interval += VNC_REFRESH_INTERVAL_INC; if (vs->timer_interval > VNC_REFRESH_INTERVAL_MAX) { vs->timer_interval = VNC_REFRESH_INTERVAL_MAX; - if (now - vs->last_update_time >= VNC_MAX_UPDATE_INTERVAL) { + if (now - vs->last_update_time >= VNC_MAX_UPDATE_INTERVAL && + vs->update_requested) { /* Send a null update. If the client is no longer interested (e.g. minimised) it'll ignore this, and we can stop scanning the buffer until it sends another @@ -752,6 +804,7 @@ static void _vnc_update_client(void *opaque) send_framebuffer_update(vs, 0, 0, 1, 1); vnc_flush(vs); vs->last_update_time = now; + vs->update_requested--; return; } } @@ -821,6 +874,88 @@ static void buffer_append(Buffer *buffer, const void *data, size_t len) buffer->offset += len; } +static void enqueue_framebuffer_update(VncState *vs, int x, int y, int w, int h, + int32_t encoding) +{ + Queue *q = &vs->upqueue; + if (q->queue_end != NULL) { + if (q->queue_end != q->queue_start || q->start_count != q->end_count) { + if (q->queue_end->next == NULL) { + q->queue_end->next = (QueueItem *) qemu_mallocz (sizeof(QueueItem) * QUEUE_ALLOC_UNIT); + q->end_count = QUEUE_ALLOC_UNIT; + } + q->queue_end = q->queue_end->next; + } + } else { + q->queue_end = (QueueItem *) qemu_mallocz (sizeof(QueueItem) * QUEUE_ALLOC_UNIT); + q->queue_start = q->queue_end; + q->start_count = QUEUE_ALLOC_UNIT; + q->end_count = QUEUE_ALLOC_UNIT; + } + q->end_count--; + + q->queue_end->x = x; + q->queue_end->y = y; + q->queue_end->w = w; + q->queue_end->h = h; + q->queue_end->enc = encoding; + q->queue_end->next = (q->end_count > 0) ? (q->queue_end + 1) : NULL; +} + +static void dequeue_framebuffer_update(VncState *vs) +{ + Queue *q = &vs->upqueue; + if (q->queue_start == NULL || + (q->queue_end == q->queue_start && q->start_count == q->end_count)) + return; + + vnc_write_u8(vs, 0); + vnc_write_u8(vs, 0); + vnc_write_u16(vs, 1); + vnc_framebuffer_update(vs, q->queue_start->x, q->queue_start->y, + q->queue_start->w, q->queue_start->h, q->queue_start->enc); + + q->start_count--; + if (q->queue_end != q->queue_start) { + if (!q->start_count) { + QueueItem *i = q->queue_start; + q->queue_start = q->queue_start->next; + q->start_count = QUEUE_ALLOC_UNIT; + free (i - QUEUE_ALLOC_UNIT + 1); + } else + q->queue_start = q->queue_start->next; + } else { + q->queue_end = q->queue_end - QUEUE_ALLOC_UNIT + q->end_count + 1; + q->queue_start = q->queue_end; + q->end_count = QUEUE_ALLOC_UNIT; + q->start_count = QUEUE_ALLOC_UNIT; + } +} + +static int is_empty_queue(VncState *vs) +{ + Queue *q = &vs->upqueue; + if (q->queue_end == NULL) return 1; + if (q->queue_end == q->queue_start && q->start_count == q->end_count) return 1; + return 0; +} + +static void free_queue(VncState *vs) +{ + Queue *q = &vs->upqueue; + while (q->queue_start != NULL) { + QueueItem *i; + q->queue_start = q->queue_start + q->start_count - 1; + i = q->queue_start; + q->queue_start = q->queue_start->next; + free(i - QUEUE_ALLOC_UNIT + 1); + q->start_count = QUEUE_ALLOC_UNIT; + } + q->queue_end = NULL; + q->start_count = 0; + q->end_count = 0; +} + static int vnc_client_io_error(VncState *vs, int ret, int last_errno) { if (ret == 0 || ret == -1) { @@ -833,6 +968,8 @@ static int vnc_client_io_error(VncState *vs, int ret, int last_errno) vs->csock = -1; buffer_reset(&vs->input); buffer_reset(&vs->output); + free_queue(vs); + vs->update_requested = 0; #if CONFIG_VNC_TLS if (vs->tls_session) { gnutls_deinit(vs->tls_session); @@ -1044,12 +1181,18 @@ static void client_cut_text(VncState *vs, size_t len, char *text) static void check_pointer_type_change(VncState *vs, int absolute) { if (vs->has_pointer_type_change && vs->absolute != absolute) { - vnc_write_u8(vs, 0); - vnc_write_u8(vs, 0); - vnc_write_u16(vs, 1); - vnc_framebuffer_update(vs, absolute, 0, + if (vs->update_requested) { + vnc_write_u8(vs, 0); + vnc_write_u8(vs, 0); + vnc_write_u16(vs, 1); + vnc_framebuffer_update(vs, absolute, 0, vs->ds->width, vs->ds->height, -257); - vnc_flush(vs); + vnc_flush(vs); + vs->update_requested--; + } else { + enqueue_framebuffer_update(vs, absolute, 0, + vs->ds->width, vs->ds->height, -257); + } } vs->absolute = absolute; } @@ -1316,6 +1459,7 @@ static void framebuffer_update_request(VncState *vs, int incremental, vs->visible_w = w; vs->visible_h = h; + vs->update_requested++; qemu_mod_timer(vs->timer, qemu_get_clock(rt_clock)); } @@ -1536,12 +1680,17 @@ static void vnc_dpy_colourdepth(DisplayState *ds, int depth) vnc_client_error(vs); } else if (vs->csock != -1 && vs->has_WMVi) { /* Sending a WMVi message to notify the client*/ - vnc_write_u8(vs, 0); /* msg id */ - vnc_write_u8(vs, 0); - vnc_write_u16(vs, 1); /* number of rects */ - vnc_framebuffer_update(vs, 0, 0, ds->width, ds->height, 0x574D5669); - pixel_format_message(vs); - vnc_flush(vs); + if (vs->update_requested) { + vnc_write_u8(vs, 0); /* msg id */ + vnc_write_u8(vs, 0); + vnc_write_u16(vs, 1); /* number of rects */ + vnc_framebuffer_update(vs, 0, 0, ds->width, ds->height, 0x574D5669); + pixel_format_message(vs); + vnc_flush(vs); + vs->update_requested--; + } else { + enqueue_framebuffer_update(vs, 0, 0, ds->width, ds->height, 0x574D5669); + } } else { if (vs->pix_bpp == 4 && vs->depth == 4 && host_big_endian_flag == vs->pix_big_endian && @@ -2291,6 +2440,7 @@ static void vnc_listen_read(void *opaque) framebuffer_set_updated(vs, 0, 0, vs->ds->width, vs->ds->height); vs->has_resize = 0; vs->has_hextile = 0; + vs->update_requested = 0; vs->ds->dpy_copy = NULL; vnc_timer_init(vs); } @@ -2413,6 +2563,8 @@ void vnc_display_close(DisplayState *ds) vs->csock = -1; buffer_reset(&vs->input); buffer_reset(&vs->output); + free_queue(vs); + vs->update_requested = 0; #if CONFIG_VNC_TLS if (vs->tls_session) { gnutls_deinit(vs->tls_session); -- 2.30.2