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ui: convert VNC server to use QIOChannelWebsock

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Remove custom websock handling code from the VNC server and use
the QIOChannelWebsock class instead.

Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This commit is contained in:
Daniel P. Berrange 2015-03-11 15:53:49 +00:00
parent 2cc452281e
commit d5f042232c
4 changed files with 35 additions and 397 deletions
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338
ui/vnc-ws.c
View File

@ -19,10 +19,7 @@
*/
#include "vnc.h"
#include "qemu/main-loop.h"
#include "crypto/hash.h"
static void vncws_handshake_read(VncState *vs);
#include "io/channel-websock.h"
static void vncws_tls_handshake_done(Object *source,
Error *err,
@ -34,6 +31,7 @@ static void vncws_tls_handshake_done(Object *source,
VNC_DEBUG("Handshake failed %s\n", error_get_pretty(err));
vnc_client_error(vs);
} else {
VNC_DEBUG("TLS handshake complete, starting websocket handshake\n");
vs->ioc_tag = qio_channel_add_watch(
QIO_CHANNEL(vs->ioc), G_IO_IN, vncws_handshake_io, vs, NULL);
}
@ -79,38 +77,21 @@ gboolean vncws_tls_handshake_io(QIOChannel *ioc G_GNUC_UNUSED,
return TRUE;
}
static void vncws_handshake_read(VncState *vs)
static void vncws_handshake_done(Object *source,
Error *err,
gpointer user_data)
{
uint8_t *handshake_end;
long ret;
/* Typical HTTP headers from novnc are 512 bytes, so limiting
* total header size to 4096 is easily enough. */
size_t want = 4096 - vs->ws_input.offset;
buffer_reserve(&vs->ws_input, want);
ret = vnc_client_read_buf(vs, buffer_end(&vs->ws_input), want);
VncState *vs = user_data;
if (!ret) {
if (vs->disconnecting) {
vnc_disconnect_finish(vs);
}
return;
}
vs->ws_input.offset += ret;
handshake_end = (uint8_t *)g_strstr_len((char *)vs->ws_input.buffer,
vs->ws_input.offset, WS_HANDSHAKE_END);
if (handshake_end) {
if (vs->ioc_tag) {
g_source_remove(vs->ioc_tag);
}
if (err) {
VNC_DEBUG("Websock handshake failed %s\n", error_get_pretty(err));
vnc_client_error(vs);
} else {
VNC_DEBUG("Websock handshake complete, starting VNC protocol\n");
vnc_init_state(vs);
vs->ioc_tag = qio_channel_add_watch(
vs->ioc, G_IO_IN, vnc_client_io, vs, NULL);
vncws_process_handshake(vs, vs->ws_input.buffer, vs->ws_input.offset);
buffer_advance(&vs->ws_input, handshake_end - vs->ws_input.buffer +
strlen(WS_HANDSHAKE_END));
} else if (vs->ws_input.offset >= 4096) {
VNC_DEBUG("End of headers not found in first 4096 bytes\n");
vnc_client_error(vs);
}
}
@ -120,280 +101,23 @@ gboolean vncws_handshake_io(QIOChannel *ioc G_GNUC_UNUSED,
void *opaque)
{
VncState *vs = opaque;
vncws_handshake_read(vs);
QIOChannelWebsock *wioc;
VNC_DEBUG("Websocket negotiate starting\n");
if (vs->ioc_tag) {
g_source_remove(vs->ioc_tag);
vs->ioc_tag = 0;
}
wioc = qio_channel_websock_new_server(vs->ioc);
object_unref(OBJECT(vs->ioc));
vs->ioc = QIO_CHANNEL(wioc);
qio_channel_websock_handshake(wioc,
vncws_handshake_done,
vs,
NULL);
return TRUE;
}
long vnc_client_read_ws(VncState *vs)
{
int ret, err;
uint8_t *payload;
size_t payload_size, header_size;
VNC_DEBUG("Read websocket %p size %zd offset %zd\n", vs->ws_input.buffer,
vs->ws_input.capacity, vs->ws_input.offset);
buffer_reserve(&vs->ws_input, 4096);
ret = vnc_client_read_buf(vs, buffer_end(&vs->ws_input), 4096);
if (!ret) {
return 0;
}
vs->ws_input.offset += ret;
ret = 0;
/* consume as much of ws_input buffer as possible */
do {
if (vs->ws_payload_remain == 0) {
err = vncws_decode_frame_header(&vs->ws_input,
&header_size,
&vs->ws_payload_remain,
&vs->ws_payload_mask);
if (err <= 0) {
return err;
}
buffer_advance(&vs->ws_input, header_size);
}
if (vs->ws_payload_remain != 0) {
err = vncws_decode_frame_payload(&vs->ws_input,
&vs->ws_payload_remain,
&vs->ws_payload_mask,
&payload,
&payload_size);
if (err < 0) {
return err;
}
if (err == 0) {
return ret;
}
ret += err;
buffer_reserve(&vs->input, payload_size);
buffer_append(&vs->input, payload, payload_size);
buffer_advance(&vs->ws_input, payload_size);
}
} while (vs->ws_input.offset > 0);
return ret;
}
long vnc_client_write_ws(VncState *vs)
{
long ret;
VNC_DEBUG("Write WS: Pending output %p size %zd offset %zd\n",
vs->output.buffer, vs->output.capacity, vs->output.offset);
vncws_encode_frame(&vs->ws_output, vs->output.buffer, vs->output.offset);
buffer_reset(&vs->output);
ret = vnc_client_write_buf(vs, vs->ws_output.buffer, vs->ws_output.offset);
if (!ret) {
return 0;
}
buffer_advance(&vs->ws_output, ret);
if (vs->ws_output.offset == 0) {
if (vs->ioc_tag) {
g_source_remove(vs->ioc_tag);
}
vs->ioc_tag = qio_channel_add_watch(
vs->ioc, G_IO_IN, vnc_client_io, vs, NULL);
}
return ret;
}
static char *vncws_extract_handshake_entry(const char *handshake,
size_t handshake_len, const char *name)
{
char *begin, *end, *ret = NULL;
char *line = g_strdup_printf("%s%s: ", WS_HANDSHAKE_DELIM, name);
begin = g_strstr_len(handshake, handshake_len, line);
if (begin != NULL) {
begin += strlen(line);
end = g_strstr_len(begin, handshake_len - (begin - handshake),
WS_HANDSHAKE_DELIM);
if (end != NULL) {
ret = g_strndup(begin, end - begin);
}
}
g_free(line);
return ret;
}
static void vncws_send_handshake_response(VncState *vs, const char* key)
{
char combined_key[WS_CLIENT_KEY_LEN + WS_GUID_LEN + 1];
char *accept = NULL, *response = NULL;
Error *err = NULL;
g_strlcpy(combined_key, key, WS_CLIENT_KEY_LEN + 1);
g_strlcat(combined_key, WS_GUID, WS_CLIENT_KEY_LEN + WS_GUID_LEN + 1);
/* hash and encode it */
if (qcrypto_hash_base64(QCRYPTO_HASH_ALG_SHA1,
combined_key,
WS_CLIENT_KEY_LEN + WS_GUID_LEN,
&accept,
&err) < 0) {
VNC_DEBUG("Hashing Websocket combined key failed %s\n",
error_get_pretty(err));
error_free(err);
vnc_client_error(vs);
return;
}
response = g_strdup_printf(WS_HANDSHAKE, accept);
vnc_client_write_buf(vs, (const uint8_t *)response, strlen(response));
g_free(accept);
g_free(response);
vs->encode_ws = 1;
vnc_init_state(vs);
}
void vncws_process_handshake(VncState *vs, uint8_t *line, size_t size)
{
char *protocols = vncws_extract_handshake_entry((const char *)line, size,
"Sec-WebSocket-Protocol");
char *version = vncws_extract_handshake_entry((const char *)line, size,
"Sec-WebSocket-Version");
char *key = vncws_extract_handshake_entry((const char *)line, size,
"Sec-WebSocket-Key");
if (protocols && version && key
&& g_strrstr(protocols, "binary")
&& !strcmp(version, WS_SUPPORTED_VERSION)
&& strlen(key) == WS_CLIENT_KEY_LEN) {
vncws_send_handshake_response(vs, key);
} else {
VNC_DEBUG("Defective Websockets header or unsupported protocol\n");
vnc_client_error(vs);
}
g_free(protocols);
g_free(version);
g_free(key);
}
void vncws_encode_frame(Buffer *output, const void *payload,
const size_t payload_size)
{
size_t header_size = 0;
unsigned char opcode = WS_OPCODE_BINARY_FRAME;
union {
char buf[WS_HEAD_MAX_LEN];
WsHeader ws;
} header;
if (!payload_size) {
return;
}
header.ws.b0 = 0x80 | (opcode & 0x0f);
if (payload_size <= 125) {
header.ws.b1 = (uint8_t)payload_size;
header_size = 2;
} else if (payload_size < 65536) {
header.ws.b1 = 0x7e;
header.ws.u.s16.l16 = cpu_to_be16((uint16_t)payload_size);
header_size = 4;
} else {
header.ws.b1 = 0x7f;
header.ws.u.s64.l64 = cpu_to_be64(payload_size);
header_size = 10;
}
buffer_reserve(output, header_size + payload_size);
buffer_append(output, header.buf, header_size);
buffer_append(output, payload, payload_size);
}
int vncws_decode_frame_header(Buffer *input,
size_t *header_size,
size_t *payload_remain,
WsMask *payload_mask)
{
unsigned char opcode = 0, fin = 0, has_mask = 0;
size_t payload_len;
WsHeader *header = (WsHeader *)input->buffer;
if (input->offset < WS_HEAD_MIN_LEN + 4) {
/* header not complete */
return 0;
}
fin = (header->b0 & 0x80) >> 7;
opcode = header->b0 & 0x0f;
has_mask = (header->b1 & 0x80) >> 7;
payload_len = header->b1 & 0x7f;
if (opcode == WS_OPCODE_CLOSE) {
/* disconnect */
return -1;
}
/* Websocket frame sanity check:
* * Websocket fragmentation is not supported.
* * All websockets frames sent by a client have to be masked.
* * Only binary encoding is supported.
*/
if (!fin || !has_mask || opcode != WS_OPCODE_BINARY_FRAME) {
VNC_DEBUG("Received faulty/unsupported Websocket frame\n");
return -2;
}
if (payload_len < 126) {
*payload_remain = payload_len;
*header_size = 6;
*payload_mask = header->u.m;
} else if (payload_len == 126 && input->offset >= 8) {
*payload_remain = be16_to_cpu(header->u.s16.l16);
*header_size = 8;
*payload_mask = header->u.s16.m16;
} else if (payload_len == 127 && input->offset >= 14) {
*payload_remain = be64_to_cpu(header->u.s64.l64);
*header_size = 14;
*payload_mask = header->u.s64.m64;
} else {
/* header not complete */
return 0;
}
return 1;
}
int vncws_decode_frame_payload(Buffer *input,
size_t *payload_remain, WsMask *payload_mask,
uint8_t **payload, size_t *payload_size)
{
size_t i;
uint32_t *payload32;
*payload = input->buffer;
/* If we aren't at the end of the payload, then drop
* off the last bytes, so we're always multiple of 4
* for purpose of unmasking, except at end of payload
*/
if (input->offset < *payload_remain) {
*payload_size = input->offset - (input->offset % 4);
} else {
*payload_size = *payload_remain;
}
if (*payload_size == 0) {
return 0;
}
*payload_remain -= *payload_size;
/* unmask frame */
/* process 1 frame (32 bit op) */
payload32 = (uint32_t *)(*payload);
for (i = 0; i < *payload_size / 4; i++) {
payload32[i] ^= payload_mask->u;
}
/* process the remaining bytes (if any) */
for (i *= 4; i < *payload_size; i++) {
(*payload)[i] ^= payload_mask->c[i % 4];
}
return 1;
}

63
ui/vnc-ws.h
View File

@ -21,74 +21,11 @@
#ifndef __QEMU_UI_VNC_WS_H
#define __QEMU_UI_VNC_WS_H
#define B64LEN(__x) (((__x + 2) / 3) * 12 / 3)
#define SHA1_DIGEST_LEN 20
#define WS_ACCEPT_LEN (B64LEN(SHA1_DIGEST_LEN) + 1)
#define WS_CLIENT_KEY_LEN 24
#define WS_GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
#define WS_GUID_LEN strlen(WS_GUID)
#define WS_HANDSHAKE "HTTP/1.1 101 Switching Protocols\r\n\
Upgrade: websocket\r\n\
Connection: Upgrade\r\n\
Sec-WebSocket-Accept: %s\r\n\
Sec-WebSocket-Protocol: binary\r\n\
\r\n"
#define WS_HANDSHAKE_DELIM "\r\n"
#define WS_HANDSHAKE_END "\r\n\r\n"
#define WS_SUPPORTED_VERSION "13"
#define WS_HEAD_MIN_LEN sizeof(uint16_t)
#define WS_HEAD_MAX_LEN (WS_HEAD_MIN_LEN + sizeof(uint64_t) + sizeof(uint32_t))
typedef union WsMask {
char c[4];
uint32_t u;
} WsMask;
typedef struct QEMU_PACKED WsHeader {
unsigned char b0;
unsigned char b1;
union {
struct QEMU_PACKED {
uint16_t l16;
WsMask m16;
} s16;
struct QEMU_PACKED {
uint64_t l64;
WsMask m64;
} s64;
WsMask m;
} u;
} WsHeader;
enum {
WS_OPCODE_CONTINUATION = 0x0,
WS_OPCODE_TEXT_FRAME = 0x1,
WS_OPCODE_BINARY_FRAME = 0x2,
WS_OPCODE_CLOSE = 0x8,
WS_OPCODE_PING = 0x9,
WS_OPCODE_PONG = 0xA
};
gboolean vncws_tls_handshake_io(QIOChannel *ioc,
GIOCondition condition,
void *opaque);
gboolean vncws_handshake_io(QIOChannel *ioc,
GIOCondition condition,
void *opaque);
long vnc_client_write_ws(VncState *vs);
long vnc_client_read_ws(VncState *vs);
void vncws_process_handshake(VncState *vs, uint8_t *line, size_t size);
void vncws_encode_frame(Buffer *output, const void *payload,
const size_t payload_size);
int vncws_decode_frame_header(Buffer *input,
size_t *header_size,
size_t *payload_remain,
WsMask *payload_mask);
int vncws_decode_frame_payload(Buffer *input,
size_t *payload_remain, WsMask *payload_mask,
uint8_t **payload, size_t *payload_size);
#endif /* __QEMU_UI_VNC_WS_H */

27
ui/vnc.c
View File

@ -1192,8 +1192,6 @@ void vnc_disconnect_finish(VncState *vs)
buffer_free(&vs->input);
buffer_free(&vs->output);
buffer_free(&vs->ws_input);
buffer_free(&vs->ws_output);
qapi_free_VncClientInfo(vs->info);
@ -1352,11 +1350,7 @@ static void vnc_client_write_locked(VncState *vs)
} else
#endif /* CONFIG_VNC_SASL */
{
if (vs->encode_ws) {
vnc_client_write_ws(vs);
} else {
vnc_client_write_plain(vs);
}
vnc_client_write_plain(vs);
}
}
@ -1364,7 +1358,7 @@ static void vnc_client_write(VncState *vs)
{
vnc_lock_output(vs);
if (vs->output.offset || vs->ws_output.offset) {
if (vs->output.offset) {
vnc_client_write_locked(vs);
} else if (vs->ioc != NULL) {
if (vs->ioc_tag) {
@ -1451,18 +1445,7 @@ static void vnc_client_read(VncState *vs)
ret = vnc_client_read_sasl(vs);
else
#endif /* CONFIG_VNC_SASL */
if (vs->encode_ws) {
ret = vnc_client_read_ws(vs);
if (ret == -1) {
vnc_disconnect_start(vs);
return;
} else if (ret == -2) {
vnc_client_error(vs);
return;
}
} else {
ret = vnc_client_read_plain(vs);
}
ret = vnc_client_read_plain(vs);
if (!ret) {
if (vs->disconnecting) {
vnc_disconnect_finish(vs);
@ -1552,7 +1535,7 @@ void vnc_write_u8(VncState *vs, uint8_t value)
void vnc_flush(VncState *vs)
{
vnc_lock_output(vs);
if (vs->ioc != NULL && (vs->output.offset || vs->ws_output.offset)) {
if (vs->ioc != NULL && vs->output.offset) {
vnc_client_write_locked(vs);
}
vnc_unlock_output(vs);
@ -2950,8 +2933,6 @@ static void vnc_connect(VncDisplay *vd, QIOChannelSocket *sioc,
buffer_init(&vs->input, "vnc-input/%p", sioc);
buffer_init(&vs->output, "vnc-output/%p", sioc);
buffer_init(&vs->ws_input, "vnc-ws_input/%p", sioc);
buffer_init(&vs->ws_output, "vnc-ws_output/%p", sioc);
buffer_init(&vs->jobs_buffer, "vnc-jobs_buffer/%p", sioc);
buffer_init(&vs->tight.tight, "vnc-tight/%p", sioc);

4
ui/vnc.h
View File

@ -293,10 +293,6 @@ struct VncState
Buffer output;
Buffer input;
Buffer ws_input;
Buffer ws_output;
size_t ws_payload_remain;
WsMask ws_payload_mask;
/* current output mode information */
VncWritePixels *write_pixels;
PixelFormat client_pf;