about summary refs log tree commit diff
path: root/src/engine/external/libwebsockets/parsers.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/engine/external/libwebsockets/parsers.c')
-rw-r--r--src/engine/external/libwebsockets/parsers.c1015
1 files changed, 1015 insertions, 0 deletions
diff --git a/src/engine/external/libwebsockets/parsers.c b/src/engine/external/libwebsockets/parsers.c
new file mode 100644
index 00000000..2b4a900b
--- /dev/null
+++ b/src/engine/external/libwebsockets/parsers.c
@@ -0,0 +1,1015 @@
+/*
+ * libwebsockets - small server side websockets and web server implementation
+ *
+ * Copyright (C) 2010-2013 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"
+
+unsigned char lextable[] = {
+	#include "lextable.h"
+};
+
+#define FAIL_CHAR 0x08
+
+int lextable_decode(int pos, char c)
+{
+
+	c = tolower(c);
+
+	while (1) {
+		if (lextable[pos] & (1 << 7)) { /* 1-byte, fail on mismatch */
+			if ((lextable[pos] & 0x7f) != c)
+				return -1;
+			/* fall thru */
+			pos++;
+			if (lextable[pos] == FAIL_CHAR)
+				return -1;
+			return pos;
+		}
+
+		if (lextable[pos] == FAIL_CHAR)
+			return -1;
+
+		/* b7 = 0, end or 3-byte */
+		if (lextable[pos] < FAIL_CHAR) /* terminal marker */
+			return pos;
+
+		if (lextable[pos] == c) /* goto */
+			return pos + (lextable[pos + 1]) +
+						(lextable[pos + 2] << 8);
+		/* fall thru goto */
+		pos += 3;
+		/* continue */
+	}
+}
+
+int lws_allocate_header_table(struct libwebsocket *wsi)
+{
+	/* Be sure to free any existing header data to avoid mem leak: */
+	lws_free_header_table(wsi);
+	wsi->u.hdr.ah = lws_malloc(sizeof(*wsi->u.hdr.ah));
+	if (wsi->u.hdr.ah == NULL) {
+		lwsl_err("Out of memory\n");
+		return -1;
+	}
+	memset(wsi->u.hdr.ah->frag_index, 0, sizeof(wsi->u.hdr.ah->frag_index));
+	wsi->u.hdr.ah->next_frag_index = 0;
+	wsi->u.hdr.ah->pos = 0;
+
+	return 0;
+}
+
+int lws_free_header_table(struct libwebsocket *wsi)
+{
+	lws_free2(wsi->u.hdr.ah);
+	wsi->u.hdr.ah = NULL;
+	return 0;
+};
+
+LWS_VISIBLE int lws_hdr_total_length(struct libwebsocket *wsi, enum lws_token_indexes h)
+{
+	int n;
+	int len = 0;
+
+	n = wsi->u.hdr.ah->frag_index[h];
+	if (!n)
+		return 0;
+	do {
+		len += wsi->u.hdr.ah->frags[n].len;
+		n = wsi->u.hdr.ah->frags[n].next_frag_index;
+	} while (n);
+
+	return len;
+}
+
+LWS_VISIBLE int lws_hdr_copy(struct libwebsocket *wsi, char *dest, int len,
+						enum lws_token_indexes h)
+{
+	int toklen = lws_hdr_total_length(wsi, h);
+	int n;
+
+	if (toklen >= len)
+		return -1;
+
+	n = wsi->u.hdr.ah->frag_index[h];
+	if (!n)
+		return 0;
+
+	do {
+		strcpy(dest,
+			&wsi->u.hdr.ah->data[wsi->u.hdr.ah->frags[n].offset]);
+		dest += wsi->u.hdr.ah->frags[n].len;
+		n = wsi->u.hdr.ah->frags[n].next_frag_index;
+	} while (n);
+
+	return toklen;
+}
+
+char *lws_hdr_simple_ptr(struct libwebsocket *wsi, enum lws_token_indexes h)
+{
+	int n;
+
+	n = wsi->u.hdr.ah->frag_index[h];
+	if (!n)
+		return NULL;
+
+	return &wsi->u.hdr.ah->data[wsi->u.hdr.ah->frags[n].offset];
+}
+
+int lws_hdr_simple_create(struct libwebsocket *wsi,
+				enum lws_token_indexes h, const char *s)
+{
+	wsi->u.hdr.ah->next_frag_index++;
+	if (wsi->u.hdr.ah->next_frag_index ==
+	       sizeof(wsi->u.hdr.ah->frags) / sizeof(wsi->u.hdr.ah->frags[0])) {
+		lwsl_warn("More hdr frags than we can deal with, dropping\n");
+		return -1;
+	}
+
+	wsi->u.hdr.ah->frag_index[h] = wsi->u.hdr.ah->next_frag_index;
+
+	wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].offset =
+							     wsi->u.hdr.ah->pos;
+	wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].len = 0;
+	wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].next_frag_index =
+									      0;
+
+	do {
+		if (wsi->u.hdr.ah->pos == sizeof(wsi->u.hdr.ah->data)) {
+			lwsl_err("Ran out of header data space\n");
+			return -1;
+		}
+		wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = *s;
+		if (*s)
+			wsi->u.hdr.ah->frags[
+					wsi->u.hdr.ah->next_frag_index].len++;
+	} while (*s++);
+
+	return 0;
+}
+
+static char char_to_hex(const char c)
+{
+	if (c >= '0' && c <= '9')
+		return c - '0';
+
+	if (c >= 'a' && c <= 'f')
+		return c - 'a' + 10;
+
+	if (c >= 'A' && c <= 'F')
+		return c - 'A' + 10;
+
+	return -1;
+}
+
+static int issue_char(struct libwebsocket *wsi, unsigned char c)
+{
+	if (wsi->u.hdr.ah->pos == sizeof(wsi->u.hdr.ah->data)) {
+		lwsl_warn("excessive header content\n");
+		return -1;
+	}
+
+	if( wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].len >= 
+		wsi->u.hdr.current_token_limit) {
+		lwsl_warn("header %i exceeds limit\n", wsi->u.hdr.parser_state);
+		return 1;
+	};
+
+	wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = c;
+	if (c)
+		wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].len++;
+
+	return 0;
+}
+
+int libwebsocket_parse(
+		struct libwebsocket_context *context,
+		struct libwebsocket *wsi, unsigned char c)
+{
+	int n;
+
+	switch (wsi->u.hdr.parser_state) {
+	default:
+
+		lwsl_parser("WSI_TOK_(%d) '%c'\n", wsi->u.hdr.parser_state, c);
+
+		/* collect into malloc'd buffers */
+		/* optional initial space swallow */
+		if (!wsi->u.hdr.ah->frags[wsi->u.hdr.ah->frag_index[
+				      wsi->u.hdr.parser_state]].len && c == ' ')
+			break;
+
+		if ((wsi->u.hdr.parser_state != WSI_TOKEN_GET_URI) &&
+			(wsi->u.hdr.parser_state != WSI_TOKEN_POST_URI) &&
+			(wsi->u.hdr.parser_state != WSI_TOKEN_OPTIONS_URI))
+			goto check_eol;
+
+		/* special URI processing... end at space */
+
+		if (c == ' ') {
+			/* enforce starting with / */
+			if (!wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].len)
+				if (issue_char(wsi, '/') < 0)
+					return -1;
+
+			/* begin parsing HTTP version: */
+			if (issue_char(wsi, '\0') < 0)
+				return -1;
+			wsi->u.hdr.parser_state = WSI_TOKEN_HTTP;
+			goto start_fragment;
+		}
+
+		/* special URI processing... convert %xx */
+
+		switch (wsi->u.hdr.ues) {
+		case URIES_IDLE:
+			if (c == '%') {
+				wsi->u.hdr.ues = URIES_SEEN_PERCENT;
+				goto swallow;
+			}
+			break;
+		case URIES_SEEN_PERCENT:
+			if (char_to_hex(c) < 0) {
+				/* regurgitate */
+				if (issue_char(wsi, '%') < 0)
+					return -1;
+				wsi->u.hdr.ues = URIES_IDLE;
+				/* continue on to assess c */
+				break;
+			}
+			wsi->u.hdr.esc_stash = c;
+			wsi->u.hdr.ues = URIES_SEEN_PERCENT_H1;
+			goto swallow;
+			
+		case URIES_SEEN_PERCENT_H1:
+			if (char_to_hex(c) < 0) {
+				/* regurgitate */
+				issue_char(wsi, '%');
+				wsi->u.hdr.ues = URIES_IDLE;
+				/* regurgitate + assess */
+				if (libwebsocket_parse(context, wsi, wsi->u.hdr.esc_stash) < 0)
+					return -1;
+				/* continue on to assess c */
+				break;
+			}
+			c = (char_to_hex(wsi->u.hdr.esc_stash) << 4) |
+					char_to_hex(c);
+			wsi->u.hdr.ues = URIES_IDLE;
+			break;
+		}
+
+		/*
+		 * special URI processing... 
+		 *  convert /.. or /... or /../ etc to /
+		 *  convert /./ to /
+		 *  convert // or /// etc to /
+		 *  leave /.dir or whatever alone
+		 */
+
+		switch (wsi->u.hdr.ups) {
+		case URIPS_IDLE:
+			/* issue the first / always */
+			if (c == '/')
+				wsi->u.hdr.ups = URIPS_SEEN_SLASH;
+			break;
+		case URIPS_SEEN_SLASH:
+			/* swallow subsequent slashes */
+			if (c == '/')
+				goto swallow;
+			/* track and swallow the first . after / */
+			if (c == '.') {
+				wsi->u.hdr.ups = URIPS_SEEN_SLASH_DOT;
+				goto swallow;
+			}
+			wsi->u.hdr.ups = URIPS_IDLE;
+			break;
+		case URIPS_SEEN_SLASH_DOT:
+			/* swallow second . */
+			if (c == '.') {
+				/* 
+				 * back up one dir level if possible
+				 * safe against header fragmentation because
+				 * the method URI can only be in 1 fragment
+				 */
+				if (wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].len > 2) {
+					wsi->u.hdr.ah->pos--;
+					wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].len--;
+					do {
+						wsi->u.hdr.ah->pos--;
+						wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].len--;
+					} while (wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].len > 1 &&
+							wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos] != '/');
+				}
+				wsi->u.hdr.ups = URIPS_SEEN_SLASH_DOT_DOT;
+				goto swallow;
+			}
+			/* change /./ to / */
+			if (c == '/') {
+				wsi->u.hdr.ups = URIPS_SEEN_SLASH;
+				goto swallow;
+			}
+			/* it was like /.dir ... regurgitate the . */
+			wsi->u.hdr.ups = URIPS_IDLE;
+			issue_char(wsi, '.');
+			break;
+			
+		case URIPS_SEEN_SLASH_DOT_DOT:
+			/* swallow prior .. chars and any subsequent . */
+			if (c == '.')
+				goto swallow;
+			/* last issued was /, so another / == // */
+			if (c == '/')
+				goto swallow;
+			/* last we issued was / so SEEN_SLASH */
+			wsi->u.hdr.ups = URIPS_SEEN_SLASH;
+			break;
+		case URIPS_ARGUMENTS:
+			/* leave them alone */
+			break;
+		}
+
+		if (c == '?') { /* start of URI arguments */
+			/* seal off uri header */
+			wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = '\0';
+
+			/* move to using WSI_TOKEN_HTTP_URI_ARGS */
+			wsi->u.hdr.ah->next_frag_index++;
+			wsi->u.hdr.ah->frags[
+				wsi->u.hdr.ah->next_frag_index].offset =
+							     wsi->u.hdr.ah->pos;
+			wsi->u.hdr.ah->frags[
+					wsi->u.hdr.ah->next_frag_index].len = 0;
+			wsi->u.hdr.ah->frags[
+			    wsi->u.hdr.ah->next_frag_index].next_frag_index = 0;
+
+			wsi->u.hdr.ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS] =
+						 wsi->u.hdr.ah->next_frag_index;
+
+			/* defeat normal uri path processing */
+			wsi->u.hdr.ups = URIPS_ARGUMENTS;
+			goto swallow;
+		}
+
+check_eol:
+
+		/* bail at EOL */
+		if (wsi->u.hdr.parser_state != WSI_TOKEN_CHALLENGE &&
+								  c == '\x0d') {
+			c = '\0';
+			wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
+			lwsl_parser("*\n");
+		}
+
+		n = issue_char(wsi, c);
+		if (n < 0)
+			return -1;
+		if (n > 0)
+			wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
+
+swallow:
+		/* per-protocol end of headers management */
+
+		if (wsi->u.hdr.parser_state == WSI_TOKEN_CHALLENGE)
+			goto set_parsing_complete;
+		break;
+
+		/* collecting and checking a name part */
+	case WSI_TOKEN_NAME_PART:
+		lwsl_parser("WSI_TOKEN_NAME_PART '%c'\n", c);
+
+		wsi->u.hdr.lextable_pos =
+				lextable_decode(wsi->u.hdr.lextable_pos, c);
+
+		if (wsi->u.hdr.lextable_pos < 0) {
+			/* this is not a header we know about */
+			if (wsi->u.hdr.ah->frag_index[WSI_TOKEN_GET_URI] ||
+				wsi->u.hdr.ah->frag_index[WSI_TOKEN_POST_URI] ||
+				wsi->u.hdr.ah->frag_index[WSI_TOKEN_OPTIONS_URI] ||
+				wsi->u.hdr.ah->frag_index[WSI_TOKEN_HTTP]) {
+				/*
+				 * already had the method, no idea what
+				 * this crap is, ignore
+				 */
+				wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
+				break;
+			}
+			/*
+			 * hm it's an unknown http method in fact,
+			 * treat as dangerous
+			 */
+
+			lwsl_info("Unknown method - dropping\n");
+			return -1;
+		}
+		if (lextable[wsi->u.hdr.lextable_pos] < FAIL_CHAR) {
+
+			/* terminal state */
+
+			n = ((unsigned int)lextable[wsi->u.hdr.lextable_pos] << 8) |
+					lextable[wsi->u.hdr.lextable_pos + 1];
+
+			lwsl_parser("known hdr %d\n", n);
+			if (n == WSI_TOKEN_GET_URI &&
+				wsi->u.hdr.ah->frag_index[WSI_TOKEN_GET_URI]) {
+				lwsl_warn("Duplicated GET\n");
+				return -1;
+			}
+			if (n == WSI_TOKEN_POST_URI &&
+				wsi->u.hdr.ah->frag_index[WSI_TOKEN_POST_URI]) {
+				lwsl_warn("Duplicated POST\n");
+				return -1;
+			}
+			if (n == WSI_TOKEN_OPTIONS_URI &&
+				wsi->u.hdr.ah->frag_index[WSI_TOKEN_OPTIONS_URI]) {
+				lwsl_warn("Duplicated OPTIONS\n");
+				return -1;
+			}
+
+			/*
+			 * WSORIGIN is protocol equiv to ORIGIN,
+			 * JWebSocket likes to send it, map to ORIGIN
+			 */
+			if (n == WSI_TOKEN_SWORIGIN)
+				n = WSI_TOKEN_ORIGIN;
+
+			wsi->u.hdr.parser_state = (enum lws_token_indexes)
+							(WSI_TOKEN_GET_URI + n);
+
+			if (context->token_limits)
+				wsi->u.hdr.current_token_limit =
+					context->token_limits->token_limit[wsi->u.hdr.parser_state];
+			else
+				wsi->u.hdr.current_token_limit = sizeof(wsi->u.hdr.ah->data);
+
+			if (wsi->u.hdr.parser_state == WSI_TOKEN_CHALLENGE)
+				goto set_parsing_complete;
+
+			goto start_fragment;
+		}
+		break;
+
+start_fragment:
+		wsi->u.hdr.ah->next_frag_index++;
+		if (wsi->u.hdr.ah->next_frag_index ==
+				sizeof(wsi->u.hdr.ah->frags) /
+					      sizeof(wsi->u.hdr.ah->frags[0])) {
+			lwsl_warn("More hdr frags than we can deal with\n");
+			return -1;
+		}
+
+		wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].offset =
+							     wsi->u.hdr.ah->pos;
+		wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].len = 0;
+		wsi->u.hdr.ah->frags[
+			    wsi->u.hdr.ah->next_frag_index].next_frag_index = 0;
+
+		n = wsi->u.hdr.ah->frag_index[wsi->u.hdr.parser_state];
+		if (!n) { /* first fragment */
+			wsi->u.hdr.ah->frag_index[wsi->u.hdr.parser_state] =
+						 wsi->u.hdr.ah->next_frag_index;
+			break;
+		}
+		/* continuation */
+		while (wsi->u.hdr.ah->frags[n].next_frag_index)
+				n = wsi->u.hdr.ah->frags[n].next_frag_index;
+		wsi->u.hdr.ah->frags[n].next_frag_index =
+						 wsi->u.hdr.ah->next_frag_index;
+
+		if (wsi->u.hdr.ah->pos == sizeof(wsi->u.hdr.ah->data)) {
+			lwsl_warn("excessive header content\n");
+			return -1;
+		}
+
+		wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = ' ';
+		wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].len++;
+		break;
+
+		/* skipping arg part of a name we didn't recognize */
+	case WSI_TOKEN_SKIPPING:
+		lwsl_parser("WSI_TOKEN_SKIPPING '%c'\n", c);
+
+		if (c == '\x0d')
+			wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
+		break;
+
+	case WSI_TOKEN_SKIPPING_SAW_CR:
+		lwsl_parser("WSI_TOKEN_SKIPPING_SAW_CR '%c'\n", c);
+		if (c == '\x0a') {
+			wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
+			wsi->u.hdr.lextable_pos = 0;
+		} else
+			wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
+		break;
+		/* we're done, ignore anything else */
+
+	case WSI_PARSING_COMPLETE:
+		lwsl_parser("WSI_PARSING_COMPLETE '%c'\n", c);
+		break;
+	}
+
+	return 0;
+
+set_parsing_complete:
+
+	if (lws_hdr_total_length(wsi, WSI_TOKEN_UPGRADE)) {
+		if (lws_hdr_total_length(wsi, WSI_TOKEN_VERSION))
+			wsi->ietf_spec_revision =
+			       atoi(lws_hdr_simple_ptr(wsi, WSI_TOKEN_VERSION));
+
+		lwsl_parser("v%02d hdrs completed\n", wsi->ietf_spec_revision);
+	}
+	wsi->u.hdr.parser_state = WSI_PARSING_COMPLETE;
+	wsi->hdr_parsing_completed = 1;
+
+	return 0;
+}
+
+
+/**
+ * lws_frame_is_binary: true if the current frame was sent in binary mode
+ *
+ * @wsi: the connection we are inquiring about
+ *
+ * This is intended to be called from the LWS_CALLBACK_RECEIVE callback if
+ * it's interested to see if the frame it's dealing with was sent in binary
+ * mode.
+ */
+
+LWS_VISIBLE int lws_frame_is_binary(struct libwebsocket *wsi)
+{
+	return wsi->u.ws.frame_is_binary;
+}
+
+int
+libwebsocket_rx_sm(struct libwebsocket *wsi, unsigned char c)
+{
+	int n;
+	struct lws_tokens eff_buf;
+	int ret = 0;
+
+	switch (wsi->lws_rx_parse_state) {
+	case LWS_RXPS_NEW:
+
+		switch (wsi->ietf_spec_revision) {
+		case 13:
+			/*
+			 * no prepended frame key any more
+			 */
+			wsi->u.ws.all_zero_nonce = 1;
+			goto handle_first;
+
+		default:
+			lwsl_warn("lws_rx_sm: unknown spec version %d\n",
+						       wsi->ietf_spec_revision);
+			break;
+		}
+		break;
+	case LWS_RXPS_04_MASK_NONCE_1:
+		wsi->u.ws.frame_masking_nonce_04[1] = c;
+		if (c)
+			wsi->u.ws.all_zero_nonce = 0;
+		wsi->lws_rx_parse_state = LWS_RXPS_04_MASK_NONCE_2;
+		break;
+	case LWS_RXPS_04_MASK_NONCE_2:
+		wsi->u.ws.frame_masking_nonce_04[2] = c;
+		if (c)
+			wsi->u.ws.all_zero_nonce = 0;
+		wsi->lws_rx_parse_state = LWS_RXPS_04_MASK_NONCE_3;
+		break;
+	case LWS_RXPS_04_MASK_NONCE_3:
+		wsi->u.ws.frame_masking_nonce_04[3] = c;
+		if (c)
+			wsi->u.ws.all_zero_nonce = 0;
+
+		/*
+		 * start from the zero'th byte in the XOR key buffer since
+		 * this is the start of a frame with a new key
+		 */
+
+		wsi->u.ws.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:
+handle_first:
+
+		wsi->u.ws.opcode = c & 0xf;
+		wsi->u.ws.rsv = c & 0x70;
+		wsi->u.ws.final = !!((c >> 7) & 1);
+
+		switch (wsi->u.ws.opcode) {
+		case LWS_WS_OPCODE_07__TEXT_FRAME:
+		case LWS_WS_OPCODE_07__BINARY_FRAME:
+			wsi->u.ws.frame_is_binary =
+			     wsi->u.ws.opcode == LWS_WS_OPCODE_07__BINARY_FRAME;
+			break;
+		}
+		wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN;
+		break;
+
+	case LWS_RXPS_04_FRAME_HDR_LEN:
+
+		wsi->u.ws.this_frame_masked = !!(c & 0x80);
+
+		switch (c & 0x7f) {
+		case 126:
+			/* control frames are not allowed to have big lengths */
+			if (wsi->u.ws.opcode & 8)
+				goto illegal_ctl_length;
+
+			wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_2;
+			break;
+		case 127:
+			/* control frames are not allowed to have big lengths */
+			if (wsi->u.ws.opcode & 8)
+				goto illegal_ctl_length;
+
+			wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8;
+			break;
+		default:
+			wsi->u.ws.rx_packet_length = c & 0x7f;
+			if (wsi->u.ws.this_frame_masked)
+				wsi->lws_rx_parse_state =
+						LWS_RXPS_07_COLLECT_FRAME_KEY_1;
+			else
+				if (wsi->u.ws.rx_packet_length)
+					wsi->lws_rx_parse_state =
+					LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
+				else {
+					wsi->lws_rx_parse_state = LWS_RXPS_NEW;
+					goto spill;
+				}
+			break;
+		}
+		break;
+
+	case LWS_RXPS_04_FRAME_HDR_LEN16_2:
+		wsi->u.ws.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->u.ws.rx_packet_length |= c;
+		if (wsi->u.ws.this_frame_masked)
+			wsi->lws_rx_parse_state =
+					LWS_RXPS_07_COLLECT_FRAME_KEY_1;
+		else
+			wsi->lws_rx_parse_state =
+				LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
+		break;
+
+	case LWS_RXPS_04_FRAME_HDR_LEN64_8:
+		if (c & 0x80) {
+			lwsl_warn("b63 of length must be zero\n");
+			/* kill the connection */
+			return -1;
+		}
+#if defined __LP64__
+		wsi->u.ws.rx_packet_length = ((size_t)c) << 56;
+#else
+		wsi->u.ws.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->u.ws.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->u.ws.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->u.ws.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->u.ws.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->u.ws.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->u.ws.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->u.ws.rx_packet_length |= ((size_t)c);
+		if (wsi->u.ws.this_frame_masked)
+			wsi->lws_rx_parse_state =
+					LWS_RXPS_07_COLLECT_FRAME_KEY_1;
+		else
+			wsi->lws_rx_parse_state =
+				LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
+		break;
+
+	case LWS_RXPS_07_COLLECT_FRAME_KEY_1:
+		wsi->u.ws.frame_masking_nonce_04[0] = c;
+		if (c)
+			wsi->u.ws.all_zero_nonce = 0;
+		wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_2;
+		break;
+
+	case LWS_RXPS_07_COLLECT_FRAME_KEY_2:
+		wsi->u.ws.frame_masking_nonce_04[1] = c;
+		if (c)
+			wsi->u.ws.all_zero_nonce = 0;
+		wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_3;
+		break;
+
+	case LWS_RXPS_07_COLLECT_FRAME_KEY_3:
+		wsi->u.ws.frame_masking_nonce_04[2] = c;
+		if (c)
+			wsi->u.ws.all_zero_nonce = 0;
+		wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_4;
+		break;
+
+	case LWS_RXPS_07_COLLECT_FRAME_KEY_4:
+		wsi->u.ws.frame_masking_nonce_04[3] = c;
+		if (c)
+			wsi->u.ws.all_zero_nonce = 0;
+		wsi->lws_rx_parse_state =
+					LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
+		wsi->u.ws.frame_mask_index = 0;
+		if (wsi->u.ws.rx_packet_length == 0) {
+			wsi->lws_rx_parse_state = LWS_RXPS_NEW;
+			goto spill;
+		}
+		break;
+
+
+	case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED:
+
+		if (!wsi->u.ws.rx_user_buffer) {
+			lwsl_err("NULL user buffer...\n");
+			return 1;
+		}
+
+		if (wsi->u.ws.all_zero_nonce)
+			wsi->u.ws.rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
+			       (wsi->u.ws.rx_user_buffer_head++)] = c;
+		else
+			wsi->u.ws.rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
+			       (wsi->u.ws.rx_user_buffer_head++)] =
+				   c ^ wsi->u.ws.frame_masking_nonce_04[
+					    (wsi->u.ws.frame_mask_index++) & 3];
+
+		if (--wsi->u.ws.rx_packet_length == 0) {
+			/* spill because we have the whole frame */
+			wsi->lws_rx_parse_state = LWS_RXPS_NEW;
+			goto spill;
+		}
+
+		/*
+		 * if there's no protocol max frame size given, we are
+		 * supposed to default to LWS_MAX_SOCKET_IO_BUF
+		 */
+
+		if (!wsi->protocol->rx_buffer_size &&
+			 		wsi->u.ws.rx_user_buffer_head !=
+			 				  LWS_MAX_SOCKET_IO_BUF)
+			break;
+		else
+			if (wsi->protocol->rx_buffer_size &&
+					wsi->u.ws.rx_user_buffer_head !=
+						  wsi->protocol->rx_buffer_size)
+			break;
+
+		/* spill because we filled our rx buffer */
+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
+		 */
+
+		lwsl_parser("spill on %s\n", wsi->protocol->name);
+
+		switch (wsi->u.ws.opcode) {
+		case LWS_WS_OPCODE_07__CLOSE:
+			/* is this an acknowledgement of our close? */
+			if (wsi->state == WSI_STATE_AWAITING_CLOSE_ACK) {
+				/*
+				 * fine he has told us he is closing too, let's
+				 * finish our close
+				 */
+				lwsl_parser("seen client close ack\n");
+				return -1;
+			}
+			lwsl_parser("server sees client close packet\n");
+			/* parrot the close packet payload back */
+			n = libwebsocket_write(wsi, (unsigned char *)
+				&wsi->u.ws.rx_user_buffer[
+					LWS_SEND_BUFFER_PRE_PADDING],
+					wsi->u.ws.rx_user_buffer_head,
+							       LWS_WRITE_CLOSE);
+			if (n < 0)
+				lwsl_info("write of close ack failed %d\n", n);
+			wsi->state = WSI_STATE_RETURNED_CLOSE_ALREADY;
+			/* close the connection */
+			return -1;
+
+		case LWS_WS_OPCODE_07__PING:
+			lwsl_info("received %d byte ping, sending pong\n",
+						 wsi->u.ws.rx_user_buffer_head);
+
+			if (wsi->u.ws.ping_payload_len) {
+				/* 
+				 * there is already a pending ping payload
+				 * we should just log and drop
+				 */
+				lwsl_parser("DROP PING since one pending\n");
+				goto ping_drop;
+			}
+			
+			/* control packets can only be < 128 bytes long */
+			if (wsi->u.ws.ping_payload_len > 128 - 4) {
+				lwsl_parser("DROP PING payload too large\n");
+				goto ping_drop;
+			}
+			
+			/* if existing buffer is too small, drop it */
+			if (wsi->u.ws.ping_payload_buf &&
+			    wsi->u.ws.ping_payload_alloc < wsi->u.ws.rx_user_buffer_head) {
+				lws_free2(wsi->u.ws.ping_payload_buf);
+			}
+
+			/* if no buffer, allocate it */
+			if (!wsi->u.ws.ping_payload_buf) {
+				wsi->u.ws.ping_payload_buf = lws_malloc(wsi->u.ws.rx_user_buffer_head
+									+ LWS_SEND_BUFFER_PRE_PADDING);
+				wsi->u.ws.ping_payload_alloc = wsi->u.ws.rx_user_buffer_head;
+			}
+			
+			/* stash the pong payload */
+			memcpy(wsi->u.ws.ping_payload_buf + LWS_SEND_BUFFER_PRE_PADDING,
+			       &wsi->u.ws.rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
+				wsi->u.ws.rx_user_buffer_head);
+			
+			wsi->u.ws.ping_payload_len = wsi->u.ws.rx_user_buffer_head;
+			
+			/* get it sent as soon as possible */
+			libwebsocket_callback_on_writable(wsi->protocol->owning_server, wsi);
+ping_drop:
+			wsi->u.ws.rx_user_buffer_head = 0;
+			return 0;
+
+		case LWS_WS_OPCODE_07__PONG:
+			/* ... then just drop it */
+			wsi->u.ws.rx_user_buffer_head = 0;
+			return 0;
+
+		case LWS_WS_OPCODE_07__TEXT_FRAME:
+		case LWS_WS_OPCODE_07__BINARY_FRAME:
+		case LWS_WS_OPCODE_07__CONTINUATION:
+			break;
+
+		default:
+			lwsl_parser("passing opc %x up to exts\n",
+							wsi->u.ws.opcode);
+			/*
+			 * It's something special we can't understand here.
+			 * Pass the payload up to the extension's parsing
+			 * state machine.
+			 */
+
+			eff_buf.token = &wsi->u.ws.rx_user_buffer[
+						   LWS_SEND_BUFFER_PRE_PADDING];
+			eff_buf.token_len = wsi->u.ws.rx_user_buffer_head;
+
+			if (lws_ext_callback_for_each_active(wsi,
+				LWS_EXT_CALLBACK_EXTENDED_PAYLOAD_RX,
+					&eff_buf, 0) <= 0) /* not handle or fail */
+				lwsl_ext("ext opc opcode 0x%x unknown\n",
+							      wsi->u.ws.opcode);
+
+			wsi->u.ws.rx_user_buffer_head = 0;
+			return 0;
+		}
+
+		/*
+		 * 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
+		 */
+
+		eff_buf.token = &wsi->u.ws.rx_user_buffer[
+						LWS_SEND_BUFFER_PRE_PADDING];
+		eff_buf.token_len = wsi->u.ws.rx_user_buffer_head;
+		
+		if (lws_ext_callback_for_each_active(wsi,
+				LWS_EXT_CALLBACK_PAYLOAD_RX, &eff_buf, 0) < 0)
+			return -1;
+
+		if (eff_buf.token_len > 0) {
+			eff_buf.token[eff_buf.token_len] = '\0';
+
+			if (wsi->protocol->callback)
+				ret = user_callback_handle_rxflow(
+						wsi->protocol->callback,
+						wsi->protocol->owning_server,
+						wsi, LWS_CALLBACK_RECEIVE,
+						wsi->user_space,
+						eff_buf.token,
+						eff_buf.token_len);
+		    else
+			    lwsl_err("No callback on payload spill!\n");
+		}
+
+		wsi->u.ws.rx_user_buffer_head = 0;
+		break;
+	}
+
+	return ret;
+
+illegal_ctl_length:
+
+	lwsl_warn("Control frame with xtended length is illegal\n");
+	/* kill the connection */
+	return -1;
+}
+
+
+/**
+ * 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.
+ */
+
+LWS_VISIBLE size_t
+libwebsockets_remaining_packet_payload(struct libwebsocket *wsi)
+{
+	return wsi->u.ws.rx_packet_length;
+}