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941 lines
26 KiB
941 lines
26 KiB
/*
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* websockets.c - deal with WebSockets clients.
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*
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* This code should be independent of any changes in the RFB protocol. It is
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* an additional handshake and framing of normal sockets:
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* http://www.whatwg.org/specs/web-socket-protocol/
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*
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*/
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/*
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* Copyright (C) 2010 Joel Martin
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*
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* This is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This software is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this software; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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* USA.
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*/
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#include <rfb/rfb.h>
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#include <resolv.h> /* __b64_ntop */
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/* errno */
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#include <errno.h>
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#include <md5.h>
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#include <byteswap.h>
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#include "rfbconfig.h"
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#include "rfbssl.h"
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#if defined(__BYTE_ORDER) && defined(__BIG_ENDIAN) && __BYTE_ORDER == __BIG_ENDIAN
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#define WS_NTOH64(n) (n)
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#define WS_NTOH32(n) (n)
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#define WS_NTOH16(n) (n)
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#define WS_HTON64(n) (n)
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#define WS_HTON16(n) (n)
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#else
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#define WS_NTOH64(n) bswap_64(n)
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#define WS_NTOH32(n) bswap_32(n)
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#define WS_NTOH16(n) bswap_16(n)
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#define WS_HTON64(n) bswap_64(n)
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#define WS_HTON16(n) bswap_16(n)
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#endif
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#define B64LEN(__x) (((__x + 2) / 3) * 12 / 3)
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#define WSHLENMAX 14 /* 2 + sizeof(uint64_t) + sizeof(uint32_t) */
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enum {
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WEBSOCKETS_VERSION_HIXIE,
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WEBSOCKETS_VERSION_HYBI
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};
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#include <sys/syscall.h>
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static int gettid() {
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return (int)syscall(SYS_gettid);
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}
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typedef int (*wsEncodeFunc)(rfbClientPtr cl, const char *src, int len, char **dst);
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typedef int (*wsDecodeFunc)(rfbClientPtr cl, char *dst, int len);
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typedef struct ws_ctx_s {
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char encodeBuf[B64LEN(UPDATE_BUF_SIZE) + WSHLENMAX]; /* base64 + maximum frame header length */
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char decodeBuf[8192]; /* TODO: what makes sense? */
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char readbuf[8192];
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int readbufstart;
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int readbuflen;
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int dblen;
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char carryBuf[3]; /* For base64 carry-over */
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int carrylen;
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int version;
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int base64;
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wsEncodeFunc encode;
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wsDecodeFunc decode;
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} ws_ctx_t;
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typedef union ws_mask_s {
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char c[4];
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uint32_t u;
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} ws_mask_t;
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typedef struct __attribute__ ((__packed__)) ws_header_s {
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unsigned char b0;
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unsigned char b1;
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union {
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struct __attribute__ ((__packed__)) {
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uint16_t l16;
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ws_mask_t m16;
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};
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struct __attribute__ ((__packed__)) {
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uint64_t l64;
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ws_mask_t m64;
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};
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ws_mask_t m;
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};
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} ws_header_t;
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enum
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{
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WS_OPCODE_CONTINUATION = 0x0,
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WS_OPCODE_TEXT_FRAME,
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WS_OPCODE_BINARY_FRAME,
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WS_OPCODE_CLOSE = 0x8,
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WS_OPCODE_PING,
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WS_OPCODE_PONG
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};
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#define FLASH_POLICY_RESPONSE "<cross-domain-policy><allow-access-from domain=\"*\" to-ports=\"*\" /></cross-domain-policy>\n"
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#define SZ_FLASH_POLICY_RESPONSE 93
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/*
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* draft-ietf-hybi-thewebsocketprotocol-10
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* 5.2.2. Sending the Server's Opening Handshake
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*/
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#define GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
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#define SERVER_HANDSHAKE_HIXIE "HTTP/1.1 101 Web Socket Protocol Handshake\r\n\
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Upgrade: WebSocket\r\n\
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Connection: Upgrade\r\n\
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%sWebSocket-Origin: %s\r\n\
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%sWebSocket-Location: %s://%s%s\r\n\
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%sWebSocket-Protocol: %s\r\n\
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\r\n%s"
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#define SERVER_HANDSHAKE_HYBI "HTTP/1.1 101 Switching Protocols\r\n\
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Upgrade: websocket\r\n\
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Connection: Upgrade\r\n\
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Sec-WebSocket-Accept: %s\r\n\
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Sec-WebSocket-Protocol: %s\r\n\
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\r\n"
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#define WEBSOCKETS_CLIENT_CONNECT_WAIT_MS 100
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#define WEBSOCKETS_CLIENT_SEND_WAIT_MS 100
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#define WEBSOCKETS_MAX_HANDSHAKE_LEN 4096
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#if defined(__linux__) && defined(NEED_TIMEVAL)
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struct timeval
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{
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long int tv_sec,tv_usec;
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}
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;
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#endif
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static rfbBool webSocketsHandshake(rfbClientPtr cl, char *scheme);
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void webSocketsGenMd5(char * target, char *key1, char *key2, char *key3);
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static int webSocketsEncodeHybi(rfbClientPtr cl, const char *src, int len, char **dst);
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static int webSocketsEncodeHixie(rfbClientPtr cl, const char *src, int len, char **dst);
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static int webSocketsDecodeHybi(rfbClientPtr cl, char *dst, int len);
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static int webSocketsDecodeHixie(rfbClientPtr cl, char *dst, int len);
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static int
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min (int a, int b) {
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return a < b ? a : b;
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}
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#ifdef LIBVNCSERVER_WITH_CLIENT_GCRYPT
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#else
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#include <openssl/sha.h>
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static void webSocketsGenSha1Key(char *target, int size, char *key)
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{
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SHA_CTX c;
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unsigned char tmp[SHA_DIGEST_LENGTH];
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SHA1_Init(&c);
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SHA1_Update(&c, key, strlen(key));
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SHA1_Update(&c, GUID, sizeof(GUID) - 1);
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SHA1_Final(tmp, &c);
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if (-1 == __b64_ntop(tmp, SHA_DIGEST_LENGTH, target, size))
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rfbErr("b64_ntop failed\n");
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}
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#endif
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/*
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* rfbWebSocketsHandshake is called to handle new WebSockets connections
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*/
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rfbBool
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webSocketsCheck (rfbClientPtr cl)
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{
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char bbuf[4], *scheme;
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int ret;
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ret = rfbPeekExactTimeout(cl, bbuf, 4,
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WEBSOCKETS_CLIENT_CONNECT_WAIT_MS);
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if ((ret < 0) && (errno == ETIMEDOUT)) {
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rfbLog("Normal socket connection\n");
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return TRUE;
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} else if (ret <= 0) {
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rfbErr("webSocketsHandshake: unknown connection error\n");
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return FALSE;
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}
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if (strncmp(bbuf, "<", 1) == 0) {
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rfbLog("Got Flash policy request, sending response\n");
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if (rfbWriteExact(cl, FLASH_POLICY_RESPONSE,
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SZ_FLASH_POLICY_RESPONSE) < 0) {
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rfbErr("webSocketsHandshake: failed sending Flash policy response");
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}
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return FALSE;
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} else if (strncmp(bbuf, "\x16", 1) == 0 || strncmp(bbuf, "\x80", 1) == 0) {
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rfbLog("Got TLS/SSL WebSockets connection\n");
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if (-1 == rfbssl_init(cl)) {
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rfbErr("webSocketsHandshake: rfbssl_init failed\n");
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return FALSE;
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}
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ret = rfbPeekExactTimeout(cl, bbuf, 4, WEBSOCKETS_CLIENT_CONNECT_WAIT_MS);
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scheme = "wss";
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} else {
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scheme = "ws";
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}
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if (strncmp(bbuf, "GET ", 4) != 0) {
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rfbErr("webSocketsHandshake: invalid client header\n");
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return FALSE;
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}
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rfbLog("Got '%s' WebSockets handshake\n", scheme);
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if (!webSocketsHandshake(cl, scheme)) {
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return FALSE;
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}
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/* Start WebSockets framing */
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return TRUE;
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}
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static rfbBool
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webSocketsHandshake(rfbClientPtr cl, char *scheme)
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{
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char *buf, *response, *line;
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int n, linestart = 0, len = 0, llen, base64 = 0;
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char prefix[5], trailer[17];
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char *path = NULL, *host = NULL, *origin = NULL, *protocol = NULL;
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char *key1 = NULL, *key2 = NULL, *key3 = NULL;
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char *sec_ws_origin = NULL;
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char *sec_ws_key = NULL;
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char sec_ws_version = 0;
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ws_ctx_t *wsctx = NULL;
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buf = (char *) malloc(WEBSOCKETS_MAX_HANDSHAKE_LEN);
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if (!buf) {
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rfbLogPerror("webSocketsHandshake: malloc");
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return FALSE;
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}
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response = (char *) malloc(WEBSOCKETS_MAX_HANDSHAKE_LEN);
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if (!response) {
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free(buf);
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rfbLogPerror("webSocketsHandshake: malloc");
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return FALSE;
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}
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while (len < WEBSOCKETS_MAX_HANDSHAKE_LEN-1) {
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if ((n = rfbReadExactTimeout(cl, buf+len, 1,
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WEBSOCKETS_CLIENT_SEND_WAIT_MS)) <= 0) {
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if ((n < 0) && (errno == ETIMEDOUT)) {
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break;
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}
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if (n == 0)
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rfbLog("webSocketsHandshake: client gone\n");
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else
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rfbLogPerror("webSocketsHandshake: read");
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return FALSE;
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}
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len += 1;
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llen = len - linestart;
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if (((llen >= 2)) && (buf[len-1] == '\n')) {
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line = buf+linestart;
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if ((llen == 2) && (strncmp("\r\n", line, 2) == 0)) {
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if (key1 && key2) {
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if ((n = rfbReadExact(cl, buf+len, 8)) <= 0) {
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if ((n < 0) && (errno == ETIMEDOUT)) {
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break;
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}
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if (n == 0)
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rfbLog("webSocketsHandshake: client gone\n");
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else
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rfbLogPerror("webSocketsHandshake: read");
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return FALSE;
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}
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rfbLog("Got key3\n");
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key3 = buf+len;
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len += 8;
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} else {
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buf[len] = '\0';
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}
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break;
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} else if ((llen >= 16) && ((strncmp("GET ", line, min(llen,4))) == 0)) {
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/* 16 = 4 ("GET ") + 1 ("/.*") + 11 (" HTTP/1.1\r\n") */
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path = line+4;
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buf[len-11] = '\0'; /* Trim trailing " HTTP/1.1\r\n" */
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base64 = TRUE;
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cl->wspath = strdup(path);
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/* rfbLog("Got path: %s\n", path); */
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} else if ((strncasecmp("host: ", line, min(llen,6))) == 0) {
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host = line+6;
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buf[len-2] = '\0';
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/* rfbLog("Got host: %s\n", host); */
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} else if ((strncasecmp("origin: ", line, min(llen,8))) == 0) {
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origin = line+8;
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buf[len-2] = '\0';
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/* rfbLog("Got origin: %s\n", origin); */
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} else if ((strncasecmp("sec-websocket-key1: ", line, min(llen,20))) == 0) {
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key1 = line+20;
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buf[len-2] = '\0';
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/* rfbLog("Got key1: %s\n", key1); */
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} else if ((strncasecmp("sec-websocket-key2: ", line, min(llen,20))) == 0) {
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key2 = line+20;
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buf[len-2] = '\0';
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/* rfbLog("Got key2: %s\n", key2); */
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/* HyBI */
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} else if ((strncasecmp("sec-websocket-protocol: ", line, min(llen,24))) == 0) {
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protocol = line+24;
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buf[len-2] = '\0';
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rfbLog("Got protocol: %s\n", protocol);
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} else if ((strncasecmp("sec-websocket-origin: ", line, min(llen,22))) == 0) {
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sec_ws_origin = line+22;
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buf[len-2] = '\0';
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} else if ((strncasecmp("sec-websocket-key: ", line, min(llen,19))) == 0) {
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sec_ws_key = line+19;
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buf[len-2] = '\0';
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} else if ((strncasecmp("sec-websocket-version: ", line, min(llen,23))) == 0) {
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sec_ws_version = strtol(line+23, NULL, 10);
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buf[len-2] = '\0';
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}
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linestart = len;
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}
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}
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if (!(path && host && (origin || sec_ws_origin))) {
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rfbErr("webSocketsHandshake: incomplete client handshake\n");
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free(response);
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free(buf);
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return FALSE;
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}
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/*
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if ((!protocol) || (!strcasestr(protocol, "base64"))) {
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rfbErr("webSocketsHandshake: base64 subprotocol not supported by client\n");
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free(response);
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free(buf);
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return FALSE;
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}
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*/
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/*
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* Generate the WebSockets server response based on the the headers sent
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* by the client.
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*/
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if (sec_ws_version) {
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char accept[SHA_DIGEST_LENGTH * 3];
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rfbLog(" - WebSockets client version hybi-%02d\n", sec_ws_version);
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webSocketsGenSha1Key(accept, sizeof(accept), sec_ws_key);
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len = snprintf(response, WEBSOCKETS_MAX_HANDSHAKE_LEN,
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SERVER_HANDSHAKE_HYBI, accept, protocol);
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} else {
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/* older hixie handshake, this could be removed if
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* a final standard is established */
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if (!(key1 && key2 && key3)) {
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rfbLog(" - WebSockets client version hixie-75\n");
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prefix[0] = '\0';
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trailer[0] = '\0';
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} else {
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rfbLog(" - WebSockets client version hixie-76\n");
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snprintf(prefix, 5, "Sec-");
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webSocketsGenMd5(trailer, key1, key2, key3);
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}
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len = snprintf(response, WEBSOCKETS_MAX_HANDSHAKE_LEN,
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SERVER_HANDSHAKE_HIXIE, prefix, origin, prefix, scheme,
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host, path, prefix, protocol, trailer);
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}
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if (rfbWriteExact(cl, response, len) < 0) {
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rfbErr("webSocketsHandshake: failed sending WebSockets response\n");
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free(response);
|
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free(buf);
|
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return FALSE;
|
|
}
|
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/* rfbLog("webSocketsHandshake: %s\n", response); */
|
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free(response);
|
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free(buf);
|
|
|
|
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wsctx = calloc(1, sizeof(ws_ctx_t));
|
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if (sec_ws_version) {
|
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wsctx->version = WEBSOCKETS_VERSION_HYBI;
|
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wsctx->encode = webSocketsEncodeHybi;
|
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wsctx->decode = webSocketsDecodeHybi;
|
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} else {
|
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wsctx->version = WEBSOCKETS_VERSION_HIXIE;
|
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wsctx->encode = webSocketsEncodeHixie;
|
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wsctx->decode = webSocketsDecodeHixie;
|
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}
|
|
wsctx->base64 = base64;
|
|
cl->wsctx = (wsCtx *)wsctx;
|
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return TRUE;
|
|
}
|
|
|
|
void
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webSocketsGenMd5(char * target, char *key1, char *key2, char *key3)
|
|
{
|
|
unsigned int i, spaces1 = 0, spaces2 = 0;
|
|
unsigned long num1 = 0, num2 = 0;
|
|
unsigned char buf[17];
|
|
for (i=0; i < strlen(key1); i++) {
|
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if (key1[i] == ' ') {
|
|
spaces1 += 1;
|
|
}
|
|
if ((key1[i] >= 48) && (key1[i] <= 57)) {
|
|
num1 = num1 * 10 + (key1[i] - 48);
|
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}
|
|
}
|
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num1 = num1 / spaces1;
|
|
|
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for (i=0; i < strlen(key2); i++) {
|
|
if (key2[i] == ' ') {
|
|
spaces2 += 1;
|
|
}
|
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if ((key2[i] >= 48) && (key2[i] <= 57)) {
|
|
num2 = num2 * 10 + (key2[i] - 48);
|
|
}
|
|
}
|
|
num2 = num2 / spaces2;
|
|
|
|
/* Pack it big-endian */
|
|
buf[0] = (num1 & 0xff000000) >> 24;
|
|
buf[1] = (num1 & 0xff0000) >> 16;
|
|
buf[2] = (num1 & 0xff00) >> 8;
|
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buf[3] = num1 & 0xff;
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|
|
|
buf[4] = (num2 & 0xff000000) >> 24;
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|
buf[5] = (num2 & 0xff0000) >> 16;
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buf[6] = (num2 & 0xff00) >> 8;
|
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buf[7] = num2 & 0xff;
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|
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strncpy((char *)buf+8, key3, 8);
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buf[16] = '\0';
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|
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md5_buffer((char *)buf, 16, target);
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|
target[16] = '\0';
|
|
|
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return;
|
|
}
|
|
|
|
static int
|
|
webSocketsEncodeHixie(rfbClientPtr cl, const char *src, int len, char **dst)
|
|
{
|
|
int i, sz = 0;
|
|
unsigned char chr;
|
|
ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
|
|
|
|
wsctx->encodeBuf[sz++] = '\x00';
|
|
if (wsctx->base64) {
|
|
len = __b64_ntop((unsigned char *)src, len, wsctx->encodeBuf+sz, sizeof(wsctx->encodeBuf) - (sz + 1));
|
|
if (len < 0) {
|
|
return len;
|
|
}
|
|
sz += len;
|
|
} else {
|
|
for (i=0; i < len; i++) {
|
|
chr = src[i];
|
|
if (chr < 128) {
|
|
if (chr == 0x00) {
|
|
wsctx->encodeBuf[sz++] = '\xc4';
|
|
wsctx->encodeBuf[sz++] = '\x80';
|
|
} else {
|
|
wsctx->encodeBuf[sz++] = chr;
|
|
}
|
|
} else {
|
|
if (chr < 192) {
|
|
wsctx->encodeBuf[sz++] = '\xc2';
|
|
wsctx->encodeBuf[sz++] = chr;
|
|
} else {
|
|
wsctx->encodeBuf[sz++] = '\xc3';
|
|
wsctx->encodeBuf[sz++] = chr - 64;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
wsctx->encodeBuf[sz++] = '\xff';
|
|
*dst = wsctx->encodeBuf;
|
|
return sz;
|
|
}
|
|
|
|
static int
|
|
ws_read(rfbClientPtr cl, char *buf, int len)
|
|
{
|
|
int n;
|
|
if (cl->sslctx) {
|
|
n = rfbssl_read(cl, buf, len);
|
|
} else {
|
|
n = read(cl->sock, buf, len);
|
|
}
|
|
return n;
|
|
}
|
|
|
|
static int
|
|
ws_peek(rfbClientPtr cl, char *buf, int len)
|
|
{
|
|
int n;
|
|
if (cl->sslctx) {
|
|
n = rfbssl_peek(cl, buf, len);
|
|
} else {
|
|
while (-1 == (n = recv(cl->sock, buf, len, MSG_PEEK))) {
|
|
if (errno != EAGAIN)
|
|
break;
|
|
}
|
|
}
|
|
return n;
|
|
}
|
|
|
|
static int
|
|
webSocketsDecodeHixie(rfbClientPtr cl, char *dst, int len)
|
|
{
|
|
int retlen = 0, n, i, avail, modlen, needlen, actual;
|
|
char *buf, *end = NULL;
|
|
unsigned char chr, chr2;
|
|
ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
|
|
|
|
buf = wsctx->decodeBuf;
|
|
|
|
n = ws_peek(cl, buf, len*2+2);
|
|
|
|
if (n <= 0) {
|
|
rfbErr("%s: peek (%d) %m\n", __func__, errno);
|
|
return n;
|
|
}
|
|
|
|
|
|
if (wsctx->base64) {
|
|
/* Base64 encoded WebSockets stream */
|
|
|
|
if (buf[0] == '\xff') {
|
|
i = ws_read(cl, buf, 1); /* Consume marker */
|
|
buf++;
|
|
n--;
|
|
}
|
|
if (n == 0) {
|
|
errno = EAGAIN;
|
|
return -1;
|
|
}
|
|
if (buf[0] == '\x00') {
|
|
i = ws_read(cl, buf, 1); /* Consume marker */
|
|
buf++;
|
|
n--;
|
|
}
|
|
if (n == 0) {
|
|
errno = EAGAIN;
|
|
return -1;
|
|
}
|
|
|
|
/* end = memchr(buf, '\xff', len*2+2); */
|
|
end = memchr(buf, '\xff', n);
|
|
if (!end) {
|
|
end = buf + n;
|
|
}
|
|
avail = end - buf;
|
|
|
|
len -= wsctx->carrylen;
|
|
|
|
/* Determine how much base64 data we need */
|
|
modlen = len + (len+2)/3;
|
|
needlen = modlen;
|
|
if (needlen % 4) {
|
|
needlen += 4 - (needlen % 4);
|
|
}
|
|
|
|
if (needlen > avail) {
|
|
/* rfbLog("Waiting for more base64 data\n"); */
|
|
errno = EAGAIN;
|
|
return -1;
|
|
}
|
|
|
|
/* Any carryover from previous decode */
|
|
for (i=0; i < wsctx->carrylen; i++) {
|
|
/* rfbLog("Adding carryover %d\n", wsctx->carryBuf[i]); */
|
|
dst[i] = wsctx->carryBuf[i];
|
|
retlen += 1;
|
|
}
|
|
|
|
/* Decode the rest of what we need */
|
|
buf[needlen] = '\x00'; /* Replace end marker with end of string */
|
|
/* rfbLog("buf: %s\n", buf); */
|
|
n = __b64_pton(buf, (unsigned char *)dst+retlen, 2+len);
|
|
if (n < len) {
|
|
rfbErr("Base64 decode error\n");
|
|
errno = EIO;
|
|
return -1;
|
|
}
|
|
retlen += n;
|
|
|
|
/* Consume the data from socket */
|
|
i = ws_read(cl, buf, needlen);
|
|
|
|
wsctx->carrylen = n - len;
|
|
retlen -= wsctx->carrylen;
|
|
for (i=0; i < wsctx->carrylen; i++) {
|
|
/* rfbLog("Saving carryover %d\n", dst[retlen + i]); */
|
|
wsctx->carryBuf[i] = dst[retlen + i];
|
|
}
|
|
} else {
|
|
/* UTF-8 encoded WebSockets stream */
|
|
|
|
actual = 0;
|
|
for (needlen = 0; needlen < n && actual < len; needlen++) {
|
|
chr = buf[needlen];
|
|
if ((chr > 0) && (chr < 128)) {
|
|
actual++;
|
|
} else if ((chr > 127) && (chr < 255)) {
|
|
if (needlen + 1 >= n) {
|
|
break;
|
|
}
|
|
needlen++;
|
|
actual++;
|
|
}
|
|
}
|
|
|
|
if (actual < len) {
|
|
errno = EAGAIN;
|
|
return -1;
|
|
}
|
|
|
|
/* Consume what we need */
|
|
if ((n = ws_read(cl, buf, needlen)) < needlen) {
|
|
return n;
|
|
}
|
|
|
|
while (retlen < len) {
|
|
chr = buf[0];
|
|
buf += 1;
|
|
if (chr == 0) {
|
|
/* Begin frame marker, just skip it */
|
|
} else if (chr == 255) {
|
|
/* Begin frame marker, just skip it */
|
|
} else if (chr < 128) {
|
|
dst[retlen++] = chr;
|
|
} else {
|
|
chr2 = buf[0];
|
|
buf += 1;
|
|
switch (chr) {
|
|
case (unsigned char) '\xc2':
|
|
dst[retlen++] = chr2;
|
|
break;
|
|
case (unsigned char) '\xc3':
|
|
dst[retlen++] = chr2 + 64;
|
|
break;
|
|
case (unsigned char) '\xc4':
|
|
dst[retlen++] = 0;
|
|
break;
|
|
default:
|
|
rfbErr("Invalid UTF-8 encoding\n");
|
|
errno = EIO;
|
|
return -1;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* rfbLog("<< webSocketsDecode, retlen: %d\n", retlen); */
|
|
return retlen;
|
|
}
|
|
|
|
static int
|
|
webSocketsDecodeHybi(rfbClientPtr cl, char *dst, int len)
|
|
{
|
|
char *buf, *payload, *rbuf;
|
|
int ret = -1, result = -1;
|
|
int total = 0;
|
|
ws_mask_t mask;
|
|
ws_header_t *header;
|
|
int i, j;
|
|
unsigned char opcode;
|
|
ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
|
|
int flength, fin, fhlen, blen;
|
|
|
|
// rfbLog(" <== %s[%d]: %d cl: %p, wsctx: %p-%p (%d)\n", __func__, gettid(), len, cl, wsctx, (char *)wsctx + sizeof(ws_ctx_t), sizeof(ws_ctx_t));
|
|
|
|
if (wsctx->readbuflen) {
|
|
/* simply return what we have */
|
|
if (wsctx->readbuflen > len) {
|
|
memcpy(dst, wsctx->readbuf + wsctx->readbufstart, len);
|
|
result = len;
|
|
wsctx->readbuflen -= len;
|
|
wsctx->readbufstart += len;
|
|
} else {
|
|
memcpy(dst, wsctx->readbuf + wsctx->readbufstart, wsctx->readbuflen);
|
|
result = wsctx->readbuflen;
|
|
wsctx->readbuflen = 0;
|
|
wsctx->readbufstart = 0;
|
|
}
|
|
goto spor;
|
|
}
|
|
|
|
buf = wsctx->decodeBuf;
|
|
header = (ws_header_t *)wsctx->decodeBuf;
|
|
|
|
if (-1 == (ret = ws_peek(cl, buf, B64LEN(len) + WSHLENMAX))) {
|
|
rfbErr("%s: peek; %m\n", __func__);
|
|
goto spor;
|
|
}
|
|
|
|
if (ret < 2) {
|
|
rfbErr("%s: peek; got %d bytes\n", __func__, ret);
|
|
goto spor; /* Incomplete frame header */
|
|
}
|
|
|
|
opcode = header->b0 & 0x0f;
|
|
fin = (header->b0 & 0x80) >> 7;
|
|
flength = header->b1 & 0x7f;
|
|
|
|
/*
|
|
* 4.3. Client-to-Server Masking
|
|
*
|
|
* The client MUST mask all frames sent to the server. A server MUST
|
|
* close the connection upon receiving a frame with the MASK bit set to 0.
|
|
**/
|
|
if (!(header->b1 & 0x80)) {
|
|
rfbErr("%s: got frame without mask\n", __func__, ret);
|
|
errno = EIO;
|
|
goto spor;
|
|
}
|
|
|
|
if (flength < 126) {
|
|
fhlen = 2;
|
|
mask = header->m;
|
|
} else if (flength == 126 && 4 <= ret) {
|
|
flength = WS_NTOH16(header->l16);
|
|
fhlen = 4;
|
|
mask = header->m16;
|
|
} else if (flength == 127 && 10 <= ret) {
|
|
flength = WS_NTOH64(header->l64);
|
|
fhlen = 10;
|
|
mask = header->m64;
|
|
} else {
|
|
/* Incomplete frame header */
|
|
rfbErr("%s: incomplete frame header\n", __func__, ret);
|
|
errno = EIO;
|
|
goto spor;
|
|
}
|
|
|
|
/* absolute length of frame */
|
|
total = fhlen + flength + 4;
|
|
payload = buf + fhlen + 4; /* header length + mask */
|
|
|
|
if (-1 == (ret = ws_read(cl, buf, total))) {
|
|
rfbErr("%s: read; %m", __func__);
|
|
return ret;
|
|
} else if (ret < total) {
|
|
/* TODO: hmm? */
|
|
rfbLog("%s: read; got partial data\n", __func__);
|
|
} else {
|
|
buf[ret] = '\0';
|
|
}
|
|
|
|
/* process 1 frame */
|
|
for (i = 0; i < flength; i++) {
|
|
j = i % 4;
|
|
payload[i] ^= mask.c[j];
|
|
}
|
|
|
|
switch (opcode) {
|
|
case WS_OPCODE_CLOSE:
|
|
rfbLog("got closure, reason %d\n", WS_NTOH16(((uint16_t *)payload)[0]));
|
|
errno = ECONNRESET;
|
|
break;
|
|
case WS_OPCODE_TEXT_FRAME:
|
|
if (-1 == (flength = __b64_pton(payload, (unsigned char *)wsctx->decodeBuf, sizeof(wsctx->decodeBuf)))) {
|
|
rfbErr("%s: Base64 decode error; %m\n", __func__);
|
|
break;
|
|
}
|
|
payload = wsctx->decodeBuf;
|
|
/* fall through */
|
|
case WS_OPCODE_BINARY_FRAME:
|
|
if (flength > len) {
|
|
memcpy(wsctx->readbuf, payload + len, flength - len);
|
|
wsctx->readbufstart = 0;
|
|
wsctx->readbuflen = flength - len;
|
|
flength = len;
|
|
}
|
|
memcpy(dst, payload, flength);
|
|
result = flength;
|
|
break;
|
|
default:
|
|
rfbErr("unhandled opcode %d, b0: %02x, b1: %02x\n", (int)opcode, header->b0, header->b1);
|
|
}
|
|
|
|
/* single point of return, if someone has questions :-) */
|
|
spor:
|
|
/* rfbLog("%s: ret: %d/%d\n", __func__, result, len); */
|
|
return result;
|
|
}
|
|
|
|
static int
|
|
webSocketsEncodeHybi(rfbClientPtr cl, const char *src, int len, char **dst)
|
|
{
|
|
int blen, ret = -1, sz = 0;
|
|
unsigned char opcode = '\0'; /* TODO: option! */
|
|
ws_header_t *header;
|
|
ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
|
|
|
|
|
|
/* Optional opcode:
|
|
* 0x0 - continuation
|
|
* 0x1 - text frame (base64 encode buf)
|
|
* 0x2 - binary frame (use raw buf)
|
|
* 0x8 - connection close
|
|
* 0x9 - ping
|
|
* 0xA - pong
|
|
**/
|
|
if (!len) {
|
|
rfbLog("%s: nothing to encode\n", __func__);
|
|
return 0;
|
|
}
|
|
|
|
header = (ws_header_t *)wsctx->encodeBuf;
|
|
|
|
if (wsctx->base64) {
|
|
opcode = WS_OPCODE_TEXT_FRAME;
|
|
/* calculate the resulting size */
|
|
blen = B64LEN(len);
|
|
} else {
|
|
blen = len;
|
|
}
|
|
|
|
header->b0 = 0x80 | (opcode & 0x0f);
|
|
if (blen <= 125) {
|
|
header->b1 = (uint8_t)blen;
|
|
sz = 2;
|
|
} else if (blen <= 65536) {
|
|
header->b1 = 0x7e;
|
|
header->l16 = WS_HTON16((uint16_t)blen);
|
|
sz = 4;
|
|
} else {
|
|
header->b1 = 0x7f;
|
|
header->l64 = WS_HTON64(blen);
|
|
sz = 10;
|
|
}
|
|
|
|
if (wsctx->base64) {
|
|
if (-1 == (ret = __b64_ntop((unsigned char *)src, len, wsctx->encodeBuf + sz, sizeof(wsctx->encodeBuf) - sz))) {
|
|
rfbErr("%s: Base 64 encode failed\n", __func__);
|
|
} else {
|
|
if (ret != blen)
|
|
rfbErr("%s: Base 64 encode; something weird happened\n", __func__);
|
|
ret += sz;
|
|
}
|
|
} else {
|
|
memcpy(wsctx->encodeBuf + sz, src, len);
|
|
ret = sz + len;
|
|
}
|
|
|
|
*dst = wsctx->encodeBuf;
|
|
return ret;
|
|
}
|
|
|
|
int
|
|
webSocketsEncode(rfbClientPtr cl, const char *src, int len, char **dst)
|
|
{
|
|
return ((ws_ctx_t *)cl->wsctx)->encode(cl, src, len, dst);
|
|
}
|
|
|
|
int
|
|
webSocketsDecode(rfbClientPtr cl, char *dst, int len)
|
|
{
|
|
return ((ws_ctx_t *)cl->wsctx)->decode(cl, dst, len);
|
|
}
|
|
|
|
|
|
/* returns TRUE if client sent an close frame or a single end of marker
|
|
* was received, FALSE otherwise
|
|
*
|
|
* Note: This is a Hixie-only hack!
|
|
**/
|
|
rfbBool
|
|
webSocketCheckDisconnect(rfbClientPtr cl)
|
|
{
|
|
ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
|
|
/* With Base64 encoding we need at least 4 bytes */
|
|
char peekbuf[4];
|
|
int n;
|
|
|
|
if (wsctx->version == WEBSOCKETS_VERSION_HYBI)
|
|
return FALSE;
|
|
|
|
if (cl->sslctx)
|
|
n = rfbssl_peek(cl, peekbuf, 4);
|
|
else
|
|
n = recv(cl->sock, peekbuf, 4, MSG_PEEK);
|
|
|
|
if (n <= 0) {
|
|
if (n != 0)
|
|
rfbErr("%s: peek; %m", __func__);
|
|
rfbCloseClient(cl);
|
|
return TRUE;
|
|
}
|
|
|
|
if (peekbuf[0] == '\xff') {
|
|
int doclose = 0;
|
|
/* Make sure we don't miss a client disconnect on an end frame
|
|
* marker. Because we use a peek buffer in some cases it is not
|
|
* applicable to wait for more data per select(). */
|
|
switch (n) {
|
|
case 3:
|
|
if (peekbuf[1] == '\xff' && peekbuf[2] == '\x00')
|
|
doclose = 1;
|
|
break;
|
|
case 2:
|
|
if (peekbuf[1] == '\x00')
|
|
doclose = 1;
|
|
break;
|
|
default:
|
|
;
|
|
}
|
|
|
|
if (cl->sslctx)
|
|
n = rfbssl_read(cl, peekbuf, n);
|
|
else
|
|
n = read(cl->sock, peekbuf, n);
|
|
|
|
if (doclose) {
|
|
rfbErr("%s: websocket close frame received\n", __func__);
|
|
rfbCloseClient(cl);
|
|
}
|
|
return TRUE;
|
|
}
|
|
return FALSE;
|
|
}
|
|
|