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android / platform / external / libwebsockets / a6cbece1 / . / lib / parsers.c
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/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010 Andy Green <andy@warmcat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation:
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
#include "private-libwebsockets.h"
const struct lws_tokens lws_tokens[WSI_TOKEN_COUNT] = {
[WSI_TOKEN_GET_URI] = { "GET ", 4 },
[WSI_TOKEN_HOST] = { "Host:", 5 },
[WSI_TOKEN_CONNECTION] = { "Connection:", 11 },
[WSI_TOKEN_KEY1] = { "Sec-WebSocket-Key1:", 19 },
[WSI_TOKEN_KEY2] = { "Sec-WebSocket-Key2:", 19 },
[WSI_TOKEN_PROTOCOL] = { "Sec-WebSocket-Protocol:", 23 },
[WSI_TOKEN_UPGRADE] = { "Upgrade:", 8 },
[WSI_TOKEN_ORIGIN] = { "Origin:", 7 },
[WSI_TOKEN_DRAFT] = { "Sec-WebSocket-Draft:", 20 },
[WSI_TOKEN_CHALLENGE] = { "\x0d\x0a", 2 },
[WSI_TOKEN_KEY] = { "Sec-WebSocket-Key:", 18 },
[WSI_TOKEN_VERSION] = { "Sec-WebSocket-Version:", 22 },
[WSI_TOKEN_ACCEPT] = { "Sec-WebSocket-Accept:", 21 },
[WSI_TOKEN_NONCE] = { "Sec-WebSocket-Nonce:", 20 },
[WSI_TOKEN_HTTP] = { "HTTP/1.1 ", 9 },
[WSI_TOKEN_SWORIGIN] = { "Sec-WebSocket-Origin:", 21 },
};
int libwebsocket_parse(struct libwebsocket *wsi, unsigned char c)
{
int n;
switch (wsi->parser_state) {
case WSI_TOKEN_GET_URI:
case WSI_TOKEN_HOST:
case WSI_TOKEN_CONNECTION:
case WSI_TOKEN_KEY1:
case WSI_TOKEN_KEY2:
case WSI_TOKEN_PROTOCOL:
case WSI_TOKEN_UPGRADE:
case WSI_TOKEN_ORIGIN:
case WSI_TOKEN_SWORIGIN:
case WSI_TOKEN_DRAFT:
case WSI_TOKEN_CHALLENGE:
case WSI_TOKEN_KEY:
case WSI_TOKEN_VERSION:
case WSI_TOKEN_ACCEPT:
case WSI_TOKEN_NONCE:
case WSI_TOKEN_HTTP:
debug("WSI_TOKEN_(%d) '%c'\n", wsi->parser_state, c);
/* collect into malloc'd buffers */
/* optional space swallow */
if (!wsi->utf8_token[wsi->parser_state].token_len && c == ' ')
break;
/* special case space terminator for get-uri */
if (wsi->parser_state == WSI_TOKEN_GET_URI && c == ' ') {
wsi->utf8_token[wsi->parser_state].token[
wsi->utf8_token[wsi->parser_state].token_len] = '\0';
wsi->parser_state = WSI_TOKEN_SKIPPING;
break;
}
/* allocate appropriate memory */
if (wsi->utf8_token[wsi->parser_state].token_len ==
wsi->current_alloc_len - 1) {
/* need to extend */
wsi->current_alloc_len += LWS_ADDITIONAL_HDR_ALLOC;
if (wsi->current_alloc_len >= LWS_MAX_HEADER_LEN) {
/* it's waaay to much payload, fail it */
strcpy(wsi->utf8_token[wsi->parser_state].token,
"!!! Length exceeded maximum supported !!!");
wsi->parser_state = WSI_TOKEN_SKIPPING;
break;
}
wsi->utf8_token[wsi->parser_state].token =
realloc(wsi->utf8_token[wsi->parser_state].token,
wsi->current_alloc_len);
}
/* bail at EOL */
if (wsi->parser_state != WSI_TOKEN_CHALLENGE && c == '\x0d') {
wsi->utf8_token[wsi->parser_state].token[
wsi->utf8_token[wsi->parser_state].token_len] = '\0';
wsi->parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
break;
}
wsi->utf8_token[wsi->parser_state].token[
wsi->utf8_token[wsi->parser_state].token_len++] = c;
/* per-protocol end of headers management */
if (wsi->parser_state != WSI_TOKEN_CHALLENGE)
break;
/* -76 has no version header */
if (!wsi->utf8_token[WSI_TOKEN_VERSION].token_len &&
wsi->utf8_token[wsi->parser_state].token_len != 8)
break;
/* <= 03 has old handshake with version header */
if (wsi->utf8_token[WSI_TOKEN_VERSION].token_len &&
atoi(wsi->utf8_token[WSI_TOKEN_VERSION].token) < 4 &&
wsi->utf8_token[wsi->parser_state].token_len != 8)
break;
/* For any supported protocol we have enough payload */
debug("Setting WSI_PARSING_COMPLETE\n");
wsi->parser_state = WSI_PARSING_COMPLETE;
break;
/* collecting and checking a name part */
case WSI_TOKEN_NAME_PART:
debug("WSI_TOKEN_NAME_PART '%c'\n", c);
if (wsi->name_buffer_pos == sizeof(wsi->name_buffer) - 1) {
/* name bigger than we can handle, skip until next */
wsi->parser_state = WSI_TOKEN_SKIPPING;
break;
}
wsi->name_buffer[wsi->name_buffer_pos++] = c;
wsi->name_buffer[wsi->name_buffer_pos] = '\0';
for (n = 0; n < WSI_TOKEN_COUNT; n++) {
if (wsi->name_buffer_pos != lws_tokens[n].token_len)
continue;
if (strcmp(lws_tokens[n].token, wsi->name_buffer))
continue;
debug("known hdr '%s'\n", wsi->name_buffer);
wsi->parser_state = WSI_TOKEN_GET_URI + n;
wsi->current_alloc_len = LWS_INITIAL_HDR_ALLOC;
wsi->utf8_token[wsi->parser_state].token =
malloc(wsi->current_alloc_len);
wsi->utf8_token[wsi->parser_state].token_len = 0;
n = WSI_TOKEN_COUNT;
}
/* colon delimiter means we just don't know this name */
if (wsi->parser_state == WSI_TOKEN_NAME_PART && c == ':') {
debug("skipping unknown header '%s'\n",
wsi->name_buffer);
wsi->parser_state = WSI_TOKEN_SKIPPING;
break;
}
if (wsi->parser_state != WSI_TOKEN_CHALLENGE)
break;
/* don't look for payload when it can just be http headers */
if (!wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len) {
/* they're HTTP headers, not websocket upgrade! */
debug("Setting WSI_PARSING_COMPLETE "
"from http headers\n");
wsi->parser_state = WSI_PARSING_COMPLETE;
}
/* 04 version has no packet content after end of hdrs */
if (wsi->utf8_token[WSI_TOKEN_VERSION].token_len &&
atoi(wsi->utf8_token[WSI_TOKEN_VERSION].token) >= 4) {
debug("04 header completed\n");
wsi->parser_state = WSI_PARSING_COMPLETE;
}
/* client parser? */
if (wsi->ietf_spec_revision >= 4) {
debug("04 header completed\n");
wsi->parser_state = WSI_PARSING_COMPLETE;
}
break;
/* skipping arg part of a name we didn't recognize */
case WSI_TOKEN_SKIPPING:
debug("WSI_TOKEN_SKIPPING '%c'\n", c);
if (c == '\x0d')
wsi->parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
break;
case WSI_TOKEN_SKIPPING_SAW_CR:
debug("WSI_TOKEN_SKIPPING_SAW_CR '%c'\n", c);
if (c == '\x0a')
wsi->parser_state = WSI_TOKEN_NAME_PART;
else
wsi->parser_state = WSI_TOKEN_SKIPPING;
wsi->name_buffer_pos = 0;
break;
/* we're done, ignore anything else */
case WSI_PARSING_COMPLETE:
debug("WSI_PARSING_COMPLETE '%c'\n", c);
break;
default: /* keep gcc happy */
break;
}
return 0;
}
static inline unsigned char
xor_mask(struct libwebsocket *wsi, unsigned char c)
{
c ^= wsi->masking_key_04[wsi->frame_mask_index++];
if (wsi->frame_mask_index == 20)
wsi->frame_mask_index = 0;
return c;
}
static int libwebsocket_rx_sm(struct libwebsocket *wsi, unsigned char c)
{
int n;
unsigned char buf[20 + 4];
switch (wsi->lws_rx_parse_state) {
case LWS_RXPS_NEW:
switch (wsi->ietf_spec_revision) {
/* Firefox 4.0b6 likes this as of 30 Oct */
case 0:
if (c == 0xff)
wsi->lws_rx_parse_state = LWS_RXPS_SEEN_76_FF;
if (c == 0) {
wsi->lws_rx_parse_state =
LWS_RXPS_EAT_UNTIL_76_FF;
wsi->rx_user_buffer_head = 0;
}
break;
case 4:
wsi->frame_masking_nonce_04[0] = c;
wsi->lws_rx_parse_state = LWS_RXPS_04_MASK_NONCE_1;
break;
}
break;
case LWS_RXPS_04_MASK_NONCE_1:
wsi->frame_masking_nonce_04[1] = c;
wsi->lws_rx_parse_state = LWS_RXPS_04_MASK_NONCE_2;
break;
case LWS_RXPS_04_MASK_NONCE_2:
wsi->frame_masking_nonce_04[2] = c;
wsi->lws_rx_parse_state = LWS_RXPS_04_MASK_NONCE_3;
break;
case LWS_RXPS_04_MASK_NONCE_3:
wsi->frame_masking_nonce_04[3] = c;
/*
* we are able to compute the frame key now
* it's a SHA1 of ( frame nonce we were just sent, concatenated
* with the connection masking key we computed at handshake
* time ) -- yeah every frame from the client invokes a SHA1
* for no real reason so much for lightweight.
*/
buf[0] = wsi->frame_masking_nonce_04[0];
buf[1] = wsi->frame_masking_nonce_04[1];
buf[2] = wsi->frame_masking_nonce_04[2];
buf[3] = wsi->frame_masking_nonce_04[3];
memcpy(buf + 4, wsi->masking_key_04, 20);
/*
* wsi->frame_mask_04 will be our recirculating 20-byte XOR key
* for this frame
*/
SHA1((unsigned char *)buf, 4 + 20, wsi->frame_mask_04);
/*
* start from the zero'th byte in the XOR key buffer since
* this is the start of a frame with a new key
*/
wsi->frame_mask_index = 0;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_1;
break;
/*
* 04 logical framing from the spec (all this is masked when incoming
* and has to be unmasked)
*
* We ignore the possibility of extension data because we don't
* negotiate any extensions at the moment.
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-------+-+-------------+-------------------------------+
* |F|R|R|R| opcode|R| Payload len | Extended payload length |
* |I|S|S|S| (4) |S| (7) | (16/63) |
* |N|V|V|V| |V| | (if payload len==126/127) |
* | |1|2|3| |4| | |
* +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +
* | Extended payload length continued, if payload len == 127 |
* + - - - - - - - - - - - - - - - +-------------------------------+
* | | Extension data |
* +-------------------------------+ - - - - - - - - - - - - - - - +
* : :
* +---------------------------------------------------------------+
* : Application data :
* +---------------------------------------------------------------+
*
* We pass payload through to userland as soon as we get it, ignoring
* FIN. It's up to userland to buffer it up if it wants to see a
* whole unfragmented block of the original size (which may be up to
* 2^63 long!)
*/
case LWS_RXPS_04_FRAME_HDR_1:
/*
* 04 spec defines the opcode like this: (1, 2, and 3 are
* "control frame" opcodes which may not be fragmented or
* have size larger than 126)
*
* frame-opcode =
* %x0 ; continuation frame
* / %x1 ; connection close
* / %x2 ; ping
* / %x3 ; pong
* / %x4 ; text frame
* / %x5 ; binary frame
* / %x6-F ; reserved
*
* FIN (b7)
*/
c = xor_mask(wsi, c);
if (c & 0x70) {
fprintf(stderr,
"Frame has extensions set illegally 1\n");
/* kill the connection */
return -1;
}
wsi->opcode = c & 0xf;
wsi->final = !!((c >> 7) & 1);
if (wsi->final &&
wsi->opcode == LWS_WS_OPCODE_04__CONTINUATION &&
wsi->rx_packet_length == 0) {
fprintf(stderr,
"Frame starts with final continuation\n");
/* kill the connection */
return -1;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN;
break;
case LWS_RXPS_04_FRAME_HDR_LEN:
c = xor_mask(wsi, c);
if (c & 0x80) {
fprintf(stderr, "Frame has extensions "
"set illegally 2\n");
/* kill the connection */
return -1;
}
switch (c) {
case 126:
/* control frames are not allowed to have big lengths */
switch (wsi->opcode) {
case LWS_WS_OPCODE_04__CLOSE:
case LWS_WS_OPCODE_04__PING:
case LWS_WS_OPCODE_04__PONG:
fprintf(stderr, "Control frame asking for "
"extended length is illegal\n");
/* kill the connection */
return -1;
default:
break;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_2;
break;
case 127:
/* control frames are not allowed to have big lengths */
switch (wsi->opcode) {
case LWS_WS_OPCODE_04__CLOSE:
case LWS_WS_OPCODE_04__PING:
case LWS_WS_OPCODE_04__PONG:
fprintf(stderr, "Control frame asking for "
"extended length is illegal\n");
/* kill the connection */
return -1;
default:
break;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8;
break;
default:
wsi->rx_packet_length = c;
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
break;
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_2:
c = xor_mask(wsi, c);
wsi->rx_packet_length = c << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_1:
c = xor_mask(wsi, c);
wsi->rx_packet_length |= c;
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_8:
c = xor_mask(wsi, c);
if (c & 0x80) {
fprintf(stderr, "b63 of length must be zero\n");
/* kill the connection */
return -1;
}
#if defined __LP64__
wsi->rx_packet_length = ((size_t)c) << 56;
#else
wsi->rx_packet_length = 0;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_7;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_7:
#if defined __LP64__
wsi->rx_packet_length |= ((size_t)xor_mask(wsi, c)) << 48;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_6;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_6:
#if defined __LP64__
wsi->rx_packet_length |= ((size_t)xor_mask(wsi, c)) << 40;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_5;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_5:
#if defined __LP64__
wsi->rx_packet_length |= ((size_t)xor_mask(wsi, c)) << 32;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_4;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_4:
wsi->rx_packet_length |= ((size_t)xor_mask(wsi, c)) << 24;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_3;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_3:
wsi->rx_packet_length |= ((size_t)xor_mask(wsi, c)) << 16;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_2;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_2:
wsi->rx_packet_length |= ((size_t)xor_mask(wsi, c)) << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_1:
wsi->rx_packet_length |= ((size_t)xor_mask(wsi, c));
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
break;
case LWS_RXPS_EAT_UNTIL_76_FF:
if (c == 0xff) {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto issue;
}
wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
(wsi->rx_user_buffer_head++)] = c;
if (wsi->rx_user_buffer_head != MAX_USER_RX_BUFFER)
break;
issue:
if (wsi->protocol->callback)
wsi->protocol->callback(wsi, LWS_CALLBACK_RECEIVE,
wsi->user_space,
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head);
wsi->rx_user_buffer_head = 0;
break;
case LWS_RXPS_SEEN_76_FF:
if (c)
break;
debug("Seen that client is requesting "
"a v76 close, sending ack\n");
buf[0] = 0xff;
buf[1] = 0;
n = libwebsocket_write(wsi, buf, 2, LWS_WRITE_HTTP);
if (n < 0) {
fprintf(stderr, "ERROR writing to socket");
return -1;
}
debug(" v76 close ack sent, server closing skt\n");
/* returning < 0 will get it closed in parent */
return -1;
case LWS_RXPS_PULLING_76_LENGTH:
break;
case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED:
wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
(wsi->rx_user_buffer_head++)] = xor_mask(wsi, c);
if (--wsi->rx_packet_length == 0) {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
if (wsi->rx_user_buffer_head != MAX_USER_RX_BUFFER)
break;
spill:
/*
* is this frame a control packet we should take care of at this
* layer? If so service it and hide it from the user callback
*/
switch (wsi->opcode) {
case LWS_WS_OPCODE_04__CLOSE:
/* parrot the close packet payload back */
n = libwebsocket_write(wsi, (unsigned char *)
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head, LWS_WRITE_CLOSE);
/* close the connection */
return -1;
case LWS_WS_OPCODE_04__PING:
/* parrot the ping packet payload back as a pong*/
n = libwebsocket_write(wsi, (unsigned char *)
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head, LWS_WRITE_PONG);
/* ... then just drop it */
wsi->rx_user_buffer_head = 0;
return 0;
case LWS_WS_OPCODE_04__PONG:
/* keep the statistics... */
wsi->pings_vs_pongs--;
/* ... then just drop it */
wsi->rx_user_buffer_head = 0;
return 0;
default:
break;
}
/*
* No it's real payload, pass it up to the user callback.
* It's nicely buffered with the pre-padding taken care of
* so it can be sent straight out again using libwebsocket_write
*/
wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
wsi->rx_user_buffer_head] = '\0';
if (wsi->protocol->callback)
wsi->protocol->callback(wsi, LWS_CALLBACK_RECEIVE,
wsi->user_space,
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head);
wsi->rx_user_buffer_head = 0;
break;
}
return 0;
}
int libwebsocket_client_rx_sm(struct libwebsocket *wsi, unsigned char c)
{
int n;
unsigned char buf[20 + 4];
int callback_action = LWS_CALLBACK_CLIENT_RECEIVE;
switch (wsi->lws_rx_parse_state) {
case LWS_RXPS_NEW:
switch (wsi->ietf_spec_revision) {
/* Firefox 4.0b6 likes this as of 30 Oct */
case 0:
if (c == 0xff)
wsi->lws_rx_parse_state = LWS_RXPS_SEEN_76_FF;
if (c == 0) {
wsi->lws_rx_parse_state =
LWS_RXPS_EAT_UNTIL_76_FF;
wsi->rx_user_buffer_head = 0;
}
break;
case 4:
/*
* 04 logical framing from the spec (all this is masked when
* incoming and has to be unmasked)
*
* We ignore the possibility of extension data because we don't
* negotiate any extensions at the moment.
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-------+-+-------------+-------------------------------+
* |F|R|R|R| opcode|R| Payload len | Extended payload length |
* |I|S|S|S| (4) |S| (7) | (16/63) |
* |N|V|V|V| |V| | (if payload len==126/127) |
* | |1|2|3| |4| | |
* +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +
* | Extended payload length continued, if payload len == 127 |
* + - - - - - - - - - - - - - - - +-------------------------------+
* | | Extension data |
* +-------------------------------+ - - - - - - - - - - - - - - - +
* : :
* +---------------------------------------------------------------+
* : Application data :
* +---------------------------------------------------------------+
*
* We pass payload through to userland as soon as we get it, ignoring
* FIN. It's up to userland to buffer it up if it wants to see a
* whole unfragmented block of the original size (which may be up to
* 2^63 long!)
*/
/*
* 04 spec defines the opcode like this: (1, 2, and 3 are
* "control frame" opcodes which may not be fragmented or
* have size larger than 126)
*
* frame-opcode =
* %x0 ; continuation frame
* / %x1 ; connection close
* / %x2 ; ping
* / %x3 ; pong
* / %x4 ; text frame
* / %x5 ; binary frame
* / %x6-F ; reserved
*
* FIN (b7)
*/
if (c & 0x70) {
fprintf(stderr, "Frame has extensions set "
"illegally on first framing byte %02X\n", c);
/* kill the connection */
return -1;
}
wsi->opcode = c & 0xf;
wsi->final = !!((c >> 7) & 1);
if (wsi->final &&
wsi->opcode == LWS_WS_OPCODE_04__CONTINUATION &&
wsi->rx_packet_length == 0) {
fprintf(stderr,
"Frame starts with final continuation\n");
/* kill the connection */
return -1;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN;
break;
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN:
if (c & 0x80) {
fprintf(stderr,
"Frame has extensions set illegally 4\n");
/* kill the connection */
return -1;
}
switch (c) {
case 126:
/* control frames are not allowed to have big lengths */
switch (wsi->opcode) {
case LWS_WS_OPCODE_04__CLOSE:
case LWS_WS_OPCODE_04__PING:
case LWS_WS_OPCODE_04__PONG:
fprintf(stderr, "Control frame asking for "
"extended length is illegal\n");
/* kill the connection */
return -1;
default:
break;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_2;
break;
case 127:
/* control frames are not allowed to have big lengths */
switch (wsi->opcode) {
case LWS_WS_OPCODE_04__CLOSE:
case LWS_WS_OPCODE_04__PING:
case LWS_WS_OPCODE_04__PONG:
fprintf(stderr, "Control frame asking for "
"extended length is illegal\n");
/* kill the connection */
return -1;
default:
break;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8;
break;
default:
wsi->rx_packet_length = c;
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
break;
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_2:
wsi->rx_packet_length = c << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_1:
wsi->rx_packet_length |= c;
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_8:
if (c & 0x80) {
fprintf(stderr, "b63 of length must be zero\n");
/* kill the connection */
return -1;
}
#if defined __LP64__
wsi->rx_packet_length = ((size_t)c) << 56;
#else
wsi->rx_packet_length =0;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_7;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_7:
#if defined __LP64__
wsi->rx_packet_length |= ((size_t)c) << 48;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_6;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_6:
#if defined __LP64__
wsi->rx_packet_length |= ((size_t)c) << 40;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_5;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_5:
#if defined __LP64__
wsi->rx_packet_length |= ((size_t)c) << 32;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_4;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_4:
wsi->rx_packet_length |= ((size_t)c) << 24;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_3;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_3:
wsi->rx_packet_length |= ((size_t)c) << 16;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_2;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_2:
wsi->rx_packet_length |= ((size_t)c) << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_1:
wsi->rx_packet_length |= (size_t)c;
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
break;
case LWS_RXPS_EAT_UNTIL_76_FF:
if (c == 0xff) {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto issue;
}
wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
(wsi->rx_user_buffer_head++)] = c;
if (wsi->rx_user_buffer_head != MAX_USER_RX_BUFFER)
break;
issue:
if (wsi->protocol->callback)
wsi->protocol->callback(wsi,
LWS_CALLBACK_CLIENT_RECEIVE,
wsi->user_space,
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head);
wsi->rx_user_buffer_head = 0;
break;
case LWS_RXPS_SEEN_76_FF:
if (c)
break;
debug("Seen that client is requesting "
"a v76 close, sending ack\n");
buf[0] = 0xff;
buf[1] = 0;
n = libwebsocket_write(wsi, buf, 2, LWS_WRITE_HTTP);
if (n < 0) {
fprintf(stderr, "ERROR writing to socket");
return -1;
}
debug(" v76 close ack sent, server closing skt\n");
/* returning < 0 will get it closed in parent */
return -1;
case LWS_RXPS_PULLING_76_LENGTH:
break;
case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED:
wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
(wsi->rx_user_buffer_head++)] = c;
if (--wsi->rx_packet_length == 0) {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
if (wsi->rx_user_buffer_head != MAX_USER_RX_BUFFER)
break;
spill:
/*
* is this frame a control packet we should take care of at this
* layer? If so service it and hide it from the user callback
*/
switch (wsi->opcode) {
case LWS_WS_OPCODE_04__CLOSE:
/* parrot the close packet payload back */
n = libwebsocket_write(wsi, (unsigned char *)
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head, LWS_WRITE_CLOSE);
/* close the connection */
return -1;
case LWS_WS_OPCODE_04__PING:
/* parrot the ping packet payload back as a pong*/
n = libwebsocket_write(wsi, (unsigned char *)
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head, LWS_WRITE_PONG);
break;
case LWS_WS_OPCODE_04__PONG:
/* keep the statistics... */
wsi->pings_vs_pongs--;
/* issue it */
callback_action = LWS_CALLBACK_CLIENT_RECEIVE_PONG;
break;
default:
break;
}
/*
* No it's real payload, pass it up to the user callback.
* It's nicely buffered with the pre-padding taken care of
* so it can be sent straight out again using libwebsocket_write
*/
if (wsi->protocol->callback)
wsi->protocol->callback(wsi, callback_action,
wsi->user_space,
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head);
wsi->rx_user_buffer_head = 0;
break;
default:
fprintf(stderr, "client rx illegal state\n");
return 1;
}
return 0;
}
int libwebsocket_interpret_incoming_packet(struct libwebsocket *wsi,
unsigned char *buf, size_t len)
{
int n;
#ifdef DEBUG
fprintf(stderr, "received %d byte packet\n", (int)len);
for (n = 0; n < len; n++)
fprintf(stderr, "%02X ", buf[n]);
fprintf(stderr, "\n");
#endif
/* let the rx protocol state machine have as much as it needs */
n = 0;
while (n < len)
if (libwebsocket_rx_sm(wsi, buf[n++]) < 0)
return -1;
return 0;
}
static int
libwebsocket_04_frame_mask_generate(struct libwebsocket *wsi)
{
int fd;
char buf[4 + 20];
int n;
/* fetch the per-frame nonce */
fd = open(SYSTEM_RANDOM_FILEPATH, O_RDONLY);
if (fd < 1) {
fprintf(stderr, "Unable to open random device %s\n",
SYSTEM_RANDOM_FILEPATH);
return 1;
}
n = read(fd, wsi->frame_masking_nonce_04, 4);
if (n != 4) {
fprintf(stderr, "Unable to read from random device %s %d\n",
SYSTEM_RANDOM_FILEPATH, n);
return 1;
}
close(fd);
/*
* the frame key is the frame nonce (4 bytes) followed by the
* connection masking key, hashed by SHA1
*/
memcpy(buf, wsi->frame_masking_nonce_04, 4);
memcpy(buf + 4, wsi->masking_key_04, 20);
/* concatenate the nonce with the connection key then hash it */
SHA1((unsigned char *)buf, 4 + 20, wsi->frame_mask_04);
/* start masking from first byte of masking key buffer */
wsi->frame_mask_index = 0;
return 0;
}
/**
* libwebsocket_write() - Apply protocol then write data to client
* @wsi: Websocket instance (available from user callback)
* @buf: The data to send. For data being sent on a websocket
* connection (ie, not default http), this buffer MUST have
* LWS_SEND_BUFFER_PRE_PADDING bytes valid BEFORE the pointer
* and an additional LWS_SEND_BUFFER_POST_PADDING bytes valid
* in the buffer after (buf + len). This is so the protocol
* header and trailer data can be added in-situ.
* @len: Count of the data bytes in the payload starting from buf
* @protocol: Use LWS_WRITE_HTTP to reply to an http connection, and one
* of LWS_WRITE_BINARY or LWS_WRITE_TEXT to send appropriate
* data on a websockets connection. Remember to allow the extra
* bytes before and after buf if LWS_WRITE_BINARY or LWS_WRITE_TEXT
* are used.
*
* This function provides the way to issue data back to the client
* for both http and websocket protocols.
*
* In the case of sending using websocket protocol, be sure to allocate
* valid storage before and after buf as explained above. This scheme
* allows maximum efficiency of sending data and protocol in a single
* packet while not burdening the user code with any protocol knowledge.
*/
int libwebsocket_write(struct libwebsocket *wsi, unsigned char *buf,
size_t len, enum libwebsocket_write_protocol protocol)
{
int n;
int pre = 0;
int post = 0;
unsigned int shift = 7;
if (len == 0) {
fprintf(stderr, "zero length libwebsocket_write attempt\n");
return 0;
}
if (protocol == LWS_WRITE_HTTP)
goto send_raw;
/* websocket protocol, either binary or text */
if (wsi->state != WSI_STATE_ESTABLISHED)
return -1;
switch (wsi->ietf_spec_revision) {
/* chrome likes this as of 30 Oct */
/* Firefox 4.0b6 likes this as of 30 Oct */
case 0:
if ((protocol & 0xf) == LWS_WRITE_BINARY) {
/* in binary mode we send 7-bit used length blocks */
pre = 1;
while (len & (127 << shift)) {
pre++;
shift += 7;
}
n = 0;
shift -= 7;
while (shift >= 0) {
if (shift)
buf[0 - pre + n] =
((len >> shift) & 127) | 0x80;
else
buf[0 - pre + n] =
((len >> shift) & 127);
n++;
shift -= 7;
}
break;
}
/* frame type = text, length-free spam mode */
buf[-1] = 0;
buf[len] = 0xff; /* EOT marker */
pre = 1;
post = 1;
break;
case 4:
switch (protocol & 0xf) {
case LWS_WRITE_TEXT:
n = LWS_WS_OPCODE_04__TEXT_FRAME;
break;
case LWS_WRITE_BINARY:
n = LWS_WS_OPCODE_04__BINARY_FRAME;
break;
case LWS_WRITE_CLOSE:
n = LWS_WS_OPCODE_04__CLOSE;
break;
case LWS_WRITE_PING:
n = LWS_WS_OPCODE_04__PING;
wsi->pings_vs_pongs++;
break;
case LWS_WRITE_PONG:
n = LWS_WS_OPCODE_04__PONG;
break;
default:
fprintf(stderr, "libwebsocket_write: unknown write "
"opcode / protocol\n");
return -1;
}
if (!(protocol & LWS_WRITE_NO_FIN))
n |= 1 << 7;
if (len < 126) {
buf[-2] = n;
buf[-1] = len;
pre = 2;
} else {
if (len < 65536) {
buf[-4] = n;
buf[-3] = 126;
buf[-2] = len >> 8;
buf[-1] = len;
pre = 4;
} else {
buf[-10] = n;
buf[-9] = 127;
#if defined __LP64__
buf[-8] = (len >> 56) & 0x7f;
buf[-7] = len >> 48;
buf[-6] = len >> 40;
buf[-5] = len >> 32;
#else
buf[-8] = 0;
buf[-7] = 0;
buf[-6] = 0;
buf[-5] = 0;
#endif
buf[-4] = len >> 24;
buf[-3] = len >> 16;
buf[-2] = len >> 8;
buf[-1] = len;
pre = 10;
}
}
break;
}
#if 0
for (n = 0; n < (len + pre + post); n++)
fprintf(stderr, "%02X ", buf[n - pre]);
fprintf(stderr, "\n");
#endif
/*
* Deal with masking if appropriate
*/
if (wsi->client_mode && wsi->ietf_spec_revision == 4) {
if (libwebsocket_04_frame_mask_generate(wsi)) {
fprintf(stderr, "libwebsocket_write: "
"frame mask generation failed\n");
return 1;
}
/*
* use the XOR masking against everything we send
* past the frame nonce
*/
for (n = 0; n < (len + pre + post); n++)
buf[n - pre] = xor_mask(wsi, buf[n - pre]);
/* make space for the frame nonce in clear */
pre += 4;
/* copy the frame nonce into place */
memcpy(&buf[0 - pre], wsi->frame_masking_nonce_04, 4);
}
send_raw:
#ifdef LWS_OPENSSL_SUPPORT
if (wsi->ssl) {
n = SSL_write(wsi->ssl, buf - pre, len + pre + post);
if (n < 0) {
fprintf(stderr, "ERROR writing to socket\n");
return -1;
}
} else {
#endif
n = send(wsi->sock, buf - pre, len + pre + post, MSG_NOSIGNAL);
if (n < 0) {
fprintf(stderr, "ERROR writing to socket\n");
return -1;
}
#ifdef LWS_OPENSSL_SUPPORT
}
#endif
debug("written %d bytes to client\n", (int)len);
return 0;
}
/**
* libwebsockets_serve_http_file() - Send a file back to the client using http
* @wsi: Websocket instance (available from user callback)
* @file: The file to issue over http
* @content_type: The http content type, eg, text/html
*
* This function is intended to be called from the callback in response
* to http requests from the client. It allows the callback to issue
* local files down the http link in a single step.
*/
int libwebsockets_serve_http_file(struct libwebsocket *wsi, const char *file,
const char *content_type)
{
int fd;
struct stat stat;
char buf[512];
char *p = buf;
int n;
fd = open(file, O_RDONLY);
if (fd < 1) {
p += sprintf(p, "HTTP/1.0 400 Bad\x0d\x0a"
"Server: libwebsockets\x0d\x0a"
"\x0d\x0a"
);
libwebsocket_write(wsi, (unsigned char *)buf, p - buf,
LWS_WRITE_HTTP);
return -1;
}
fstat(fd, &stat);
p += sprintf(p, "HTTP/1.0 200 OK\x0d\x0a"
"Server: libwebsockets\x0d\x0a"
"Content-Type: %s\x0d\x0a"
"Content-Length: %u\x0d\x0a"
"\x0d\x0a", content_type, (unsigned int)stat.st_size);
libwebsocket_write(wsi, (unsigned char *)buf, p - buf, LWS_WRITE_HTTP);
n = 1;
while (n > 0) {
n = read(fd, buf, 512);
if (n <= 0)
continue;
libwebsocket_write(wsi, (unsigned char *)buf, n,
LWS_WRITE_HTTP);
}
close(fd);
return 0;
}
/**
* libwebsockets_remaining_packet_payload() - Bytes to come before "overall"
* rx packet is complete
* @wsi: Websocket instance (available from user callback)
*
* This function is intended to be called from the callback if the
* user code is interested in "complete packets" from the client.
* libwebsockets just passes through payload as it comes and issues a buffer
* additionally when it hits a built-in limit. The LWS_CALLBACK_RECEIVE
* callback handler can use this API to find out if the buffer it has just
* been given is the last piece of a "complete packet" from the client --
* when that is the case libwebsockets_remaining_packet_payload() will return
* 0.
*
* Many protocols won't care becuse their packets are always small.
*/
size_t
libwebsockets_remaining_packet_payload(struct libwebsocket *wsi)
{
return wsi->rx_packet_length;
}