int lws_extension_callback_deflate_frame(
struct libwebsocket_context *context,
struct libwebsocket_extension *ext,
struct libwebsocket *wsi,
enum libwebsocket_extension_callback_reasons reason,
void *user, void *in, size_t len)
{
struct lws_ext_deflate_frame_conn *conn =
(struct lws_ext_deflate_frame_conn *)user;
struct lws_tokens *eff_buf = (struct lws_tokens *)in;
size_t current_payload, remaining_payload, total_payload;
int n;
size_t len_so_far;
switch (reason) {
/*
* for deflate-frame, both client and server sides act the same
*/
case LWS_EXT_CALLBACK_CLIENT_CONSTRUCT:
case LWS_EXT_CALLBACK_CONSTRUCT:
conn->zs_in.zalloc = conn->zs_out.zalloc = Z_NULL;
conn->zs_in.zfree = conn->zs_out.zfree = Z_NULL;
conn->zs_in.opaque = conn->zs_out.opaque = Z_NULL;
n = inflateInit2(&conn->zs_in, -LWS_ZLIB_WINDOW_BITS);
if (n != Z_OK) {
lwsl_ext("deflateInit returned %d\n", n);
return 1;
}
n = deflateInit2(&conn->zs_out,
(context->listen_port ?
DEFLATE_FRAME_COMPRESSION_LEVEL_SERVER :
DEFLATE_FRAME_COMPRESSION_LEVEL_CLIENT),
Z_DEFLATED,
-LWS_ZLIB_WINDOW_BITS, LWS_ZLIB_MEMLEVEL,
Z_DEFAULT_STRATEGY);
if (n != Z_OK) {
lwsl_ext("deflateInit2 returned %d\n", n);
return 1;
}
conn->buf_pre_used = 0;
conn->buf_pre_length = 0;
conn->buf_in_length = sizeof(conn->buf_in);
conn->buf_out_length = sizeof(conn->buf_out);
conn->compressed_out = 0;
conn->buf_pre = NULL;
conn->buf_in = lws_malloc(LWS_SEND_BUFFER_PRE_PADDING +
conn->buf_in_length +
LWS_SEND_BUFFER_POST_PADDING);
if (!conn->buf_in)
goto bail;
conn->buf_out = lws_malloc(LWS_SEND_BUFFER_PRE_PADDING +
conn->buf_out_length +
LWS_SEND_BUFFER_POST_PADDING);
if (!conn->buf_out)
goto bail;
lwsl_ext("zlibs constructed\n");
break;
bail:
lwsl_err("Out of mem\n");
(void)inflateEnd(&conn->zs_in);
(void)deflateEnd(&conn->zs_out);
return -1;
case LWS_EXT_CALLBACK_DESTROY:
lws_free(conn->buf_pre);
lws_free(conn->buf_in);
lws_free(conn->buf_out);
conn->buf_pre_used = 0;
conn->buf_pre_length = 0;
conn->buf_in_length = 0;
conn->buf_out_length = 0;
conn->compressed_out = 0;
(void)inflateEnd(&conn->zs_in);
(void)deflateEnd(&conn->zs_out);
lwsl_ext("zlibs destructed\n");
break;
case LWS_EXT_CALLBACK_PAYLOAD_RX:
if (!(wsi->u.ws.rsv & 0x40))
return 0;
/*
* inflate the incoming payload
*/
current_payload = eff_buf->token_len;
remaining_payload = wsi->u.ws.rx_packet_length;
if (remaining_payload) {
total_payload = conn->buf_pre_used +
current_payload +
remaining_payload;
if (conn->buf_pre_length < total_payload) {
conn->buf_pre_length = total_payload;
lws_free(conn->buf_pre);
conn->buf_pre = lws_malloc(total_payload + 4);
if (!conn->buf_pre) {
lwsl_err("Out of memory\n");
return -1;
}
}
memcpy(conn->buf_pre + conn->buf_pre_used,
eff_buf->token, current_payload);
conn->buf_pre_used += current_payload;
eff_buf->token = NULL;
eff_buf->token_len = 0;
return 0;
}
if (conn->buf_pre_used) {
total_payload = conn->buf_pre_used +
current_payload;
memcpy(conn->buf_pre + conn->buf_pre_used,
eff_buf->token, current_payload);
conn->buf_pre_used = 0;
conn->zs_in.next_in = conn->buf_pre;
} else {
total_payload = current_payload;
conn->zs_in.next_in = (unsigned char *)eff_buf->token;
}
conn->zs_in.next_in[total_payload + 0] = 0;
conn->zs_in.next_in[total_payload + 1] = 0;
conn->zs_in.next_in[total_payload + 2] = 0xff;
conn->zs_in.next_in[total_payload + 3] = 0xff;
conn->zs_in.avail_in = total_payload + 4;
conn->zs_in.next_out =
conn->buf_in + LWS_SEND_BUFFER_PRE_PADDING;
conn->zs_in.avail_out = conn->buf_in_length;
while (1) {
n = inflate(&conn->zs_in, Z_SYNC_FLUSH);
switch (n) {
case Z_NEED_DICT:
case Z_STREAM_ERROR:
case Z_DATA_ERROR:
case Z_MEM_ERROR:
/*
* screwed.. close the connection...
* we will get a destroy callback to take care
* of closing nicely
*/
lwsl_info("zlib error inflate %d: %s\n",
n, conn->zs_in.msg);
return -1;
}
if (conn->zs_in.avail_out)
break;
len_so_far = conn->zs_in.next_out -
(conn->buf_in + LWS_SEND_BUFFER_PRE_PADDING);
conn->buf_in_length *= 2;
if (conn->buf_in_length > LWS_MAX_ZLIB_CONN_BUFFER) {
lwsl_ext("zlib in buffer hit limit %u\n",
LWS_MAX_ZLIB_CONN_BUFFER);
return -1;
}
conn->buf_in = lws_realloc(conn->buf_in,
LWS_SEND_BUFFER_PRE_PADDING +
conn->buf_in_length +
LWS_SEND_BUFFER_POST_PADDING);
if (!conn->buf_in) {
lwsl_err("Out of memory\n");
return -1;
}
lwsl_debug(
"deflate-frame ext RX did realloc to %ld\n",
conn->buf_in_length);
conn->zs_in.next_out = conn->buf_in +
LWS_SEND_BUFFER_PRE_PADDING + len_so_far;
conn->zs_in.avail_out =
conn->buf_in_length - len_so_far;
}
/* rewrite the buffer pointers and length */
eff_buf->token =
(char *)(conn->buf_in + LWS_SEND_BUFFER_PRE_PADDING);
eff_buf->token_len = (int)(conn->zs_in.next_out -
(conn->buf_in + LWS_SEND_BUFFER_PRE_PADDING));
return 0;
case LWS_EXT_CALLBACK_PAYLOAD_TX:
/*
* deflate the outgoing payload
*/
current_payload = eff_buf->token_len;
conn->zs_out.next_in = (unsigned char *)eff_buf->token;
conn->zs_out.avail_in = current_payload;
conn->zs_out.next_out =
conn->buf_out + LWS_SEND_BUFFER_PRE_PADDING;
conn->zs_out.avail_out = conn->buf_out_length;
while (1) {
n = deflate(&conn->zs_out, Z_SYNC_FLUSH);
if (n == Z_STREAM_ERROR) {
/*
* screwed.. close the connection... we will
* get a destroy callback to take care of
* closing nicely
*/
lwsl_ext("zlib error deflate\n");
return -1;
}
if (conn->zs_out.avail_out)
break;
len_so_far = (conn->zs_out.next_out -
(conn->buf_out +
LWS_SEND_BUFFER_PRE_PADDING));
conn->buf_out_length *= 2;
if (conn->buf_out_length > LWS_MAX_ZLIB_CONN_BUFFER) {
lwsl_ext("zlib out hit limit %u\n",
LWS_MAX_ZLIB_CONN_BUFFER);
return -1;
}
conn->buf_out = lws_realloc(conn->buf_out,
LWS_SEND_BUFFER_PRE_PADDING +
conn->buf_out_length +
LWS_SEND_BUFFER_POST_PADDING);
if (!conn->buf_out) {
lwsl_err("Out of memory\n");
return -1;
}
lwsl_debug(
"deflate-frame ext TX did realloc to %ld\n",
conn->buf_in_length);
conn->zs_out.next_out = (conn->buf_out +
LWS_SEND_BUFFER_PRE_PADDING + len_so_far);
conn->zs_out.avail_out =
(conn->buf_out_length - len_so_far);
}
conn->compressed_out = 1;
/* rewrite the buffer pointers and length */
eff_buf->token = (char *)(conn->buf_out +
LWS_SEND_BUFFER_PRE_PADDING);
eff_buf->token_len = (int)(conn->zs_out.next_out -
(conn->buf_out + LWS_SEND_BUFFER_PRE_PADDING)) - 4;
return 0;
case LWS_EXT_CALLBACK_PACKET_TX_PRESEND:
if (conn->compressed_out) {
conn->compressed_out = 0;
*((unsigned char *)eff_buf->token) |= 0x40;
}
break;
case LWS_EXT_CALLBACK_CHECK_OK_TO_PROPOSE_EXTENSION:
/* Avoid x-webkit-deflate-frame extension on client */
if (!strcmp((char *)in, "x-webkit-deflate-frame"))
return 1;
break;
default:
break;
}
return 0;
}
static inline int libwebsock_read_header(libwebsock_frame *frame, libwebsock_client_state *frame_state) {
int i, new_size;
enum WS_FRAME_STATE state;
state = frame->state;
switch (state) {
case sw_start:
if (frame->rawdata_idx < 2) {
return 0;
}
frame->state = sw_got_two;
case sw_got_two:
frame->mask_offset = 2;
frame->fin = (*(frame->rawdata) & 0x80) == 0x80 ? 1 : 0;
frame->opcode = *(frame->rawdata) & 0xf;
frame->payload_len_short = *(frame->rawdata + 1) & 0x7f;
frame->state = sw_got_short_len;
case sw_got_short_len:
switch (frame->payload_len_short) {
case 126:
if (frame->rawdata_idx < 4) {
return 0;
}
frame->mask_offset += 2;
frame->payload_offset = frame->mask_offset + MASK_LENGTH;
frame->payload_len = ntohs(
*((unsigned short int *) (frame->rawdata + 2)));
frame->state = sw_got_full_len;
break;
case 127:
if (frame->rawdata_idx < 10) {
return 0;
}
frame->mask_offset += 8;
frame->payload_offset = frame->mask_offset + MASK_LENGTH;
frame->payload_len = ntohl(*((unsigned int *) (frame->rawdata + 6)));
frame->state = sw_got_full_len;
break;
default:
frame->payload_len = frame->payload_len_short;
frame->payload_offset = frame->mask_offset + MASK_LENGTH;
frame->state = sw_got_full_len;
break;
}
case sw_got_full_len:
if (frame->rawdata_idx < frame->payload_offset) {
return 0;
}
for (i = 0; i < MASK_LENGTH; i++) {
frame->mask[i] = *(frame->rawdata + frame->mask_offset + i) & 0xff;
}
frame->state = sw_loaded_mask;
frame->size = frame->payload_offset + frame->payload_len;
if (frame->size > frame->rawdata_sz) {
// Before resizing the handler for rawdata, make sure
// the frame does not exceed our maximum size allowed
new_size = frame->size;
new_size--;
new_size |= new_size >> 1;
new_size |= new_size >> 2;
new_size |= new_size >> 4;
new_size |= new_size >> 8;
new_size |= new_size >> 16;
new_size++;
frame->rawdata_sz = new_size;
frame->rawdata = (char *) lws_realloc(frame->rawdata, new_size);
}
return 1;
case sw_loaded_mask:
return 1;
//case sw_frame_toolarge:
}
