diff options
author | Andreas Weigel <andreaswe@securepoint.de> | 2017-02-16 10:10:33 +0100 |
---|---|---|
committer | Christian Beier <dontmind@freeshell.org> | 2017-05-14 20:38:15 +0200 |
commit | bcefa591cd7b4f8c635a9cadd3438bb5bf5ad814 (patch) | |
tree | e10ab07bb6400fefac69c1a2b3a765cee58fefb3 /libvncserver | |
parent | aac95a9dcf4bbba87b76c72706c3221a842ca433 (diff) | |
download | libtdevnc-bcefa591cd7b4f8c635a9cadd3438bb5bf5ad814.tar.gz libtdevnc-bcefa591cd7b4f8c635a9cadd3438bb5bf5ad814.zip |
factor out hybi decode part to make it testable
remove direct dependency on rfbClientPtr structure in hybi decode
function(s)
Diffstat (limited to 'libvncserver')
-rw-r--r-- | libvncserver/websockets.c | 603 | ||||
-rw-r--r-- | libvncserver/ws_decode.c | 448 | ||||
-rw-r--r-- | libvncserver/ws_decode.h | 160 |
3 files changed, 631 insertions, 580 deletions
diff --git a/libvncserver/websockets.c b/libvncserver/websockets.c index 4ed04c7..ab947ae 100644 --- a/libvncserver/websockets.c +++ b/libvncserver/websockets.c @@ -34,10 +34,6 @@ /* errno */ #include <errno.h> -#ifndef _MSC_VER -#include <resolv.h> /* __b64_ntop */ -#endif - #ifdef LIBVNCSERVER_HAVE_ENDIAN_H #include <endian.h> #elif LIBVNCSERVER_HAVE_SYS_ENDIAN_H @@ -55,36 +51,8 @@ #include "rfb/rfbconfig.h" #include "rfbssl.h" #include "rfbcrypto.h" +#include "ws_decode.h" -#if defined(__APPLE__) - -#include <libkern/OSByteOrder.h> -#define WS_NTOH64(n) OSSwapBigToHostInt64(n) -#define WS_NTOH32(n) OSSwapBigToHostInt32(n) -#define WS_NTOH16(n) OSSwapBigToHostInt16(n) -#define WS_HTON64(n) OSSwapHostToBigInt64(n) -#define WS_HTON16(n) OSSwapHostToBigInt16(n) - -#else - -#define WS_NTOH64(n) htobe64(n) -#define WS_NTOH32(n) htobe32(n) -#define WS_NTOH16(n) htobe16(n) -#define WS_HTON64(n) htobe64(n) -#define WS_HTON16(n) htobe16(n) - -#endif - -#define B64LEN(__x) (((__x + 2) / 3) * 12 / 3) -#define WSHLENMAX 14 /* 2 + sizeof(uint64_t) + sizeof(uint32_t) */ -#define WS_HYBI_MASK_LEN 4 - -#define ARRAYSIZE(a) ((sizeof(a) / sizeof((a[0]))) / (size_t)(!(sizeof(a) % sizeof((a[0]))))) - -enum { - WEBSOCKETS_VERSION_HIXIE, - WEBSOCKETS_VERSION_HYBI -}; #if 0 #include <sys/syscall.h> @@ -93,104 +61,6 @@ static int gettid() { } #endif -typedef int (*wsEncodeFunc)(rfbClientPtr cl, const char *src, int len, char **dst); -typedef int (*wsDecodeFunc)(rfbClientPtr cl, char *dst, int len); - - -enum { - /* header not yet received completely */ - WS_HYBI_STATE_HEADER_PENDING, - /* data available */ - WS_HYBI_STATE_DATA_AVAILABLE, - WS_HYBI_STATE_DATA_NEEDED, - /* received a complete frame */ - WS_HYBI_STATE_FRAME_COMPLETE, - /* received part of a 'close' frame */ - WS_HYBI_STATE_CLOSE_REASON_PENDING, - /* */ - WS_HYBI_STATE_ERR -}; - -typedef union ws_mask_s { - char c[4]; - uint32_t u; -} ws_mask_t; - -/* XXX: The union and the structs do not need to be named. - * We are working around a bug present in GCC < 4.6 which prevented - * it from recognizing anonymous structs and unions. - * See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=4784 - */ -typedef struct -#if __GNUC__ -__attribute__ ((__packed__)) -#endif -ws_header_s { - unsigned char b0; - unsigned char b1; - union { - struct -#if __GNUC__ - __attribute__ ((__packed__)) -#endif - { - uint16_t l16; - ws_mask_t m16; - } s16; - struct -#if __GNUC__ -__attribute__ ((__packed__)) -#endif - { - uint64_t l64; - ws_mask_t m64; - } s64; - ws_mask_t m; - } u; -} ws_header_t; - -typedef struct ws_header_data_s { - ws_header_t *data; - /** bytes read */ - int nRead; - /** mask value */ - ws_mask_t mask; - /** length of frame header including payload len, but without mask */ - int headerLen; - /** length of the payload data */ - int payloadLen; - /** opcode */ - unsigned char opcode; -} ws_header_data_t; - -typedef struct ws_ctx_s { - char codeBufDecode[B64LEN(UPDATE_BUF_SIZE) + WSHLENMAX]; /* base64 + maximum frame header length */ - char codeBufEncode[B64LEN(UPDATE_BUF_SIZE) + WSHLENMAX]; /* base64 + maximum frame header length */ - char *writePos; - unsigned char *readPos; - int readlen; - int hybiDecodeState; - char carryBuf[3]; /* For base64 carry-over */ - int carrylen; - int version; - int base64; - ws_header_data_t header; - int nReadRaw; - int nToRead; - wsEncodeFunc encode; - wsDecodeFunc decode; -} ws_ctx_t; - -enum -{ - WS_OPCODE_CONTINUATION = 0x0, - WS_OPCODE_TEXT_FRAME, - WS_OPCODE_BINARY_FRAME, - WS_OPCODE_CLOSE = 0x8, - WS_OPCODE_PING, - WS_OPCODE_PONG -}; - #define FLASH_POLICY_RESPONSE "<cross-domain-policy><allow-access-from domain=\"*\" to-ports=\"*\" /></cross-domain-policy>\n" #define SZ_FLASH_POLICY_RESPONSE 93 @@ -238,10 +108,11 @@ void webSocketsGenMd5(char * target, char *key1, char *key2, char *key3); static int webSocketsEncodeHybi(rfbClientPtr cl, const char *src, int len, char **dst); static int webSocketsEncodeHixie(rfbClientPtr cl, const char *src, int len, char **dst); -static int webSocketsDecodeHybi(rfbClientPtr cl, char *dst, int len); -static int webSocketsDecodeHixie(rfbClientPtr cl, char *dst, int len); +static int webSocketsDecodeHixie(ws_ctx_t *wsctx, char *dst, int len); + +static int ws_read(void *cl, char *buf, int len); +static int ws_peek(void *cl, char *buf, int len); -static void hybiDecodeCleanup(ws_ctx_t *wsctx); static int min (int a, int b) { @@ -503,6 +374,8 @@ webSocketsHandshake(rfbClientPtr cl, char *scheme) wsctx->encode = webSocketsEncodeHixie; wsctx->decode = webSocketsDecodeHixie; } + wsctx->ctxInfo.readFunc = ws_read; + wsctx->ctxInfo.peekFunc = ws_peek; wsctx->base64 = base64; hybiDecodeCleanup(wsctx); cl->wsctx = (wsCtx *)wsctx; @@ -578,9 +451,10 @@ webSocketsEncodeHixie(rfbClientPtr cl, const char *src, int len, char **dst) } static int -ws_read(rfbClientPtr cl, char *buf, int len) +ws_read(void *ctxPtr, char *buf, int len) { int n; + rfbClientPtr cl = ctxPtr; if (cl->sslctx) { n = rfbssl_read(cl, buf, len); } else { @@ -590,9 +464,10 @@ ws_read(rfbClientPtr cl, char *buf, int len) } static int -ws_peek(rfbClientPtr cl, char *buf, int len) +ws_peek(void *ctxPtr, char *buf, int len) { int n; + rfbClientPtr cl = ctxPtr; if (cl->sslctx) { n = rfbssl_peek(cl, buf, len); } else { @@ -605,15 +480,15 @@ ws_peek(rfbClientPtr cl, char *buf, int len) } static int -webSocketsDecodeHixie(rfbClientPtr cl, char *dst, int len) +webSocketsDecodeHixie(ws_ctx_t *wsctx, char *dst, int len) { int retlen = 0, n, i, avail, modlen, needlen; char *buf, *end = NULL; - ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx; buf = wsctx->codeBufDecode; - n = ws_peek(cl, buf, len*2+2); + //n = ws_peek(cl, buf, len*2+2); + n = wsctx->ctxInfo.peekFunc(wsctx->ctxInfo.ctxPtr, buf, len*2+2); if (n <= 0) { /* save errno because rfbErr() will tamper it */ @@ -627,7 +502,8 @@ webSocketsDecodeHixie(rfbClientPtr cl, char *dst, int len) /* Base64 encoded WebSockets stream */ if (buf[0] == '\xff') { - i = ws_read(cl, buf, 1); /* Consume marker */ + //i = ws_read(cl, buf, 1); /* Consume marker */ + i = wsctx->ctxInfo.readFunc(wsctx->ctxInfo.ctxPtr, buf, 1); buf++; n--; } @@ -636,7 +512,8 @@ webSocketsDecodeHixie(rfbClientPtr cl, char *dst, int len) return -1; } if (buf[0] == '\x00') { - i = ws_read(cl, buf, 1); /* Consume marker */ + //i = ws_read(cl, buf, 1); /* Consume marker */ + i = wsctx->ctxInfo.readFunc(wsctx->ctxInfo.ctxPtr, buf, 1); buf++; n--; } @@ -686,7 +563,8 @@ webSocketsDecodeHixie(rfbClientPtr cl, char *dst, int len) retlen += n; /* Consume the data from socket */ - i = ws_read(cl, buf, needlen); + //i = ws_read(cl, buf, needlen); + i = wsctx->ctxInfo.readFunc(wsctx->ctxInfo.ctxPtr, buf, needlen); wsctx->carrylen = n - len; retlen -= wsctx->carrylen; @@ -700,443 +578,6 @@ webSocketsDecodeHixie(rfbClientPtr cl, char *dst, int len) } static int -hybiRemaining(ws_ctx_t *wsctx) -{ - return wsctx->nToRead - wsctx->nReadRaw; -} - -static void -hybiDecodeCleanup(ws_ctx_t *wsctx) -{ - wsctx->header.payloadLen = 0; - wsctx->header.mask.u = 0; - wsctx->nReadRaw = 0; - wsctx->nToRead= 0; - wsctx->carrylen = 0; - wsctx->readPos = (unsigned char *)wsctx->codeBufDecode; - wsctx->readlen = 0; - wsctx->hybiDecodeState = WS_HYBI_STATE_HEADER_PENDING; - wsctx->writePos = NULL; - rfbLog("cleaned up wsctx\n"); -} - -/** - * Return payload data that has been decoded/unmasked from - * a websocket frame. - * - * @param[out] dst destination buffer - * @param[in] len bytes to copy to destination buffer - * @param[in,out] wsctx internal state of decoding procedure - * @param[out] number of bytes actually written to dst buffer - * @return next hybi decoding state - */ -static int -hybiReturnData(char *dst, int len, ws_ctx_t *wsctx, int *nWritten) -{ - int nextState = WS_HYBI_STATE_ERR; - - /* if we have something already decoded copy and return */ - if (wsctx->readlen > 0) { - /* simply return what we have */ - if (wsctx->readlen > len) { - rfbLog("copy to %d bytes to dst buffer; readPos=%p, readLen=%d\n", len, wsctx->readPos, wsctx->readlen); - memcpy(dst, wsctx->readPos, len); - *nWritten = len; - wsctx->readlen -= len; - wsctx->readPos += len; - nextState = WS_HYBI_STATE_DATA_AVAILABLE; - } else { - rfbLog("copy to %d bytes to dst buffer; readPos=%p, readLen=%d\n", wsctx->readlen, wsctx->readPos, wsctx->readlen); - memcpy(dst, wsctx->readPos, wsctx->readlen); - *nWritten = wsctx->readlen; - wsctx->readlen = 0; - wsctx->readPos = NULL; - if (hybiRemaining(wsctx) == 0) { - nextState = WS_HYBI_STATE_FRAME_COMPLETE; - } else { - nextState = WS_HYBI_STATE_DATA_NEEDED; - } - } - rfbLog("after copy: readPos=%p, readLen=%d\n", wsctx->readPos, wsctx->readlen); - } else if (wsctx->hybiDecodeState == WS_HYBI_STATE_CLOSE_REASON_PENDING) { - nextState = WS_HYBI_STATE_CLOSE_REASON_PENDING; - } - return nextState; -} - -/** - * Read an RFC 6455 websocket frame (IETF hybi working group). - * - * Internal state is updated according to bytes received and the - * decoding of header information. - * - * @param[in] cl client ptr with ptr to raw socket and ws_ctx_t ptr - * @param[out] sockRet emulated recv return value - * @return next hybi decoding state; WS_HYBI_STATE_HEADER_PENDING indicates - * that the header was not received completely. - */ -static int -hybiReadHeader(rfbClientPtr cl, int *sockRet) -{ - int ret; - ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx; - char *headerDst = wsctx->codeBufDecode + wsctx->nReadRaw; - int n = WSHLENMAX - wsctx->nReadRaw; - - rfbLog("header_read to %p with len=%d\n", headerDst, n); - ret = ws_read(cl, headerDst, n); - rfbLog("read %d bytes from socket\n", ret); - if (ret <= 0) { - if (-1 == ret) { - /* save errno because rfbErr() will tamper it */ - int olderrno = errno; - rfbErr("%s: peek; %m\n", __func__); - errno = olderrno; - *sockRet = -1; - } else { - *sockRet = 0; - } - return WS_HYBI_STATE_ERR; - } - - wsctx->nReadRaw += ret; - if (wsctx->nReadRaw < 2) { - /* cannot decode header with less than two bytes */ - errno = EAGAIN; - *sockRet = -1; - return WS_HYBI_STATE_HEADER_PENDING; - } - - /* first two header bytes received; interpret header data and get rest */ - wsctx->header.data = (ws_header_t *)wsctx->codeBufDecode; - - wsctx->header.opcode = wsctx->header.data->b0 & 0x0f; - - /* fin = (header->b0 & 0x80) >> 7; */ /* not used atm */ - wsctx->header.payloadLen = wsctx->header.data->b1 & 0x7f; - rfbLog("first header bytes received; opcode=%d lenbyte=%d\n", wsctx->header.opcode, wsctx->header.payloadLen); - - /* - * 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 (!(wsctx->header.data->b1 & 0x80)) { - rfbErr("%s: got frame without mask ret=%d\n", __func__, ret); - errno = EIO; - *sockRet = -1; - return WS_HYBI_STATE_ERR; - } - - if (wsctx->header.payloadLen < 126 && wsctx->nReadRaw >= 6) { - wsctx->header.headerLen = 2 + WS_HYBI_MASK_LEN; - wsctx->header.mask = wsctx->header.data->u.m; - } else if (wsctx->header.payloadLen == 126 && 8 <= wsctx->nReadRaw) { - wsctx->header.headerLen = 4 + WS_HYBI_MASK_LEN; - wsctx->header.payloadLen = WS_NTOH16(wsctx->header.data->u.s16.l16); - wsctx->header.mask = wsctx->header.data->u.s16.m16; - } else if (wsctx->header.payloadLen == 127 && 14 <= wsctx->nReadRaw) { - wsctx->header.headerLen = 10 + WS_HYBI_MASK_LEN; - wsctx->header.payloadLen = WS_NTOH64(wsctx->header.data->u.s64.l64); - wsctx->header.mask = wsctx->header.data->u.s64.m64; - } else { - /* Incomplete frame header, try again */ - rfbErr("%s: incomplete frame header; ret=%d\n", __func__, ret); - errno = EAGAIN; - *sockRet = -1; - return WS_HYBI_STATE_HEADER_PENDING; - } - - /* absolute length of frame */ - wsctx->nToRead = wsctx->header.headerLen + wsctx->header.payloadLen; - - /* set payload pointer just after header */ - wsctx->writePos = wsctx->codeBufDecode + wsctx->nReadRaw; - - wsctx->readPos = (unsigned char *)(wsctx->codeBufDecode + wsctx->header.headerLen); - - rfbLog("header complete: state=%d flen=%d writeTo=%p\n", wsctx->hybiDecodeState, wsctx->nToRead, wsctx->writePos); - - return WS_HYBI_STATE_DATA_NEEDED; -} - -static int -hybiWsFrameComplete(ws_ctx_t *wsctx) -{ - return wsctx != NULL && hybiRemaining(wsctx) == 0; -} - -static char * -hybiPayloadStart(ws_ctx_t *wsctx) -{ - return wsctx->codeBufDecode + wsctx->header.headerLen; -} - - -/** - * Read the remaining payload bytes from associated raw socket. - * - * - try to read remaining bytes from socket - * - unmask all multiples of 4 - * - if frame incomplete but some bytes are left, these are copied to - * the carry buffer - * - if opcode is TEXT: Base64-decode all unmasked received bytes - * - set state for reading decoded data - * - reset write position to begin of buffer (+ header) - * --> before we retrieve more data we let the caller clear all bytes - * from the reception buffer - * - execute return data routine - * - * Sets errno corresponding to what it gets from the underlying - * socket or EIO if some internal sanity check fails. - * - * @param[in] cl client ptr with raw socket reference - * @param[out] dst destination buffer - * @param[in] len size of destination buffer - * @param[out] sockRet emulated recv return value - * @return next hybi decode state - */ -static int -hybiReadAndDecode(rfbClientPtr cl, char *dst, int len, int *sockRet) -{ - int n; - int i; - int toReturn; - int toDecode; - int bufsize; - int nextRead; - unsigned char *data; - uint32_t *data32; - ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx; - - /* if data was carried over, copy to start of buffer */ - memcpy(wsctx->writePos, wsctx->carryBuf, wsctx->carrylen); - wsctx->writePos += wsctx->carrylen; - - /* -1 accounts for potential '\0' terminator for base64 decoding */ - bufsize = wsctx->codeBufDecode + ARRAYSIZE(wsctx->codeBufDecode) - wsctx->writePos - 1; - if (hybiRemaining(wsctx) > bufsize) { - nextRead = bufsize; - } else { - nextRead = hybiRemaining(wsctx); - } - - rfbLog("calling read with buf=%p and len=%d (decodebuf=%p headerLen=%d\n)", wsctx->writePos, nextRead, wsctx->codeBufDecode, wsctx->header.headerLen); - - if (wsctx->nReadRaw < wsctx->nToRead) { - /* decode more data */ - if (-1 == (n = ws_read(cl, wsctx->writePos, nextRead))) { - int olderrno = errno; - rfbErr("%s: read; %m", __func__); - errno = olderrno; - *sockRet = -1; - return WS_HYBI_STATE_ERR; - } else if (n == 0) { - *sockRet = 0; - return WS_HYBI_STATE_ERR; - } - wsctx->nReadRaw += n; - rfbLog("read %d bytes from socket; nRead=%d\n", n, wsctx->nReadRaw); - } else { - n = 0; - } - - wsctx->writePos += n; - - if (wsctx->nReadRaw >= wsctx->nToRead) { - if (wsctx->nReadRaw > wsctx->nToRead) { - rfbErr("%s: internal error, read past websocket frame", __func__); - errno=EIO; - *sockRet = -1; - return WS_HYBI_STATE_ERR; - } - } - - toDecode = wsctx->writePos - hybiPayloadStart(wsctx); - rfbLog("toDecode=%d from n=%d carrylen=%d headerLen=%d\n", toDecode, n, wsctx->carrylen, wsctx->header.headerLen); - if (toDecode < 0) { - rfbErr("%s: internal error; negative number of bytes to decode: %d", __func__, toDecode); - errno=EIO; - *sockRet = -1; - return WS_HYBI_STATE_ERR; - } - - /* for a possible base64 decoding, we decode multiples of 4 bytes until - * the whole frame is received and carry over any remaining bytes in the carry buf*/ - data = (unsigned char *)hybiPayloadStart(wsctx); - data32= (uint32_t *)data; - - for (i = 0; i < (toDecode >> 2); i++) { - data32[i] ^= wsctx->header.mask.u; - } - rfbLog("mask decoding; i=%d toDecode=%d\n", i, toDecode); - - if (wsctx->hybiDecodeState == WS_HYBI_STATE_FRAME_COMPLETE) { - /* process the remaining bytes (if any) */ - for (i*=4; i < toDecode; i++) { - data[i] ^= wsctx->header.mask.c[i % 4]; - } - - /* all data is here, no carrying */ - wsctx->carrylen = 0; - } else { - /* carry over remaining, non-multiple-of-four bytes */ - wsctx->carrylen = toDecode - (i * 4); - if (wsctx->carrylen < 0 || wsctx->carrylen > ARRAYSIZE(wsctx->carryBuf)) { - rfbErr("%s: internal error, invalid carry over size: carrylen=%d, toDecode=%d, i=%d", __func__, wsctx->carrylen, toDecode, i); - *sockRet = -1; - errno = EIO; - return WS_HYBI_STATE_ERR; - } - rfbLog("carrying over %d bytes from %p to %p\n", wsctx->carrylen, wsctx->writePos + (i * 4), wsctx->carryBuf); - memcpy(wsctx->carryBuf, data + (i * 4), wsctx->carrylen); - } - - toReturn = toDecode - wsctx->carrylen; - - switch (wsctx->header.opcode) { - case WS_OPCODE_CLOSE: - - /* this data is not returned as payload data */ - if (hybiWsFrameComplete(wsctx)) { - rfbLog("got closure, reason %d\n", WS_NTOH16(((uint16_t *)data)[0])); - errno = ECONNRESET; - *sockRet = -1; - return WS_HYBI_STATE_FRAME_COMPLETE; - } else { - rfbErr("%s: close reason with long frame not supported", __func__); - errno = EIO; - *sockRet = -1; - return WS_HYBI_STATE_ERR; - } - break; - case WS_OPCODE_TEXT_FRAME: - data[toReturn] = '\0'; - rfbLog("Initiate Base64 decoding in %p with max size %d and '\\0' at %p\n", data, bufsize, data + toReturn); - if (-1 == (wsctx->readlen = b64_pton((char *)data, data, bufsize))) { - rfbErr("Base64 decode error in %s; data=%p bufsize=%d", __func__, data, bufsize); - rfbErr("%s: Base64 decode error; %m\n", __func__); - } - wsctx->writePos = hybiPayloadStart(wsctx); - break; - case WS_OPCODE_BINARY_FRAME: - wsctx->readlen = toReturn; - wsctx->writePos = hybiPayloadStart(wsctx); - break; - default: - rfbErr("%s: unhandled opcode %d, b0: %02x, b1: %02x\n", __func__, (int)wsctx->header.opcode, wsctx->header.data->b0, wsctx->header.data->b1); - } - wsctx->readPos = data; - - return hybiReturnData(dst, len, wsctx, sockRet); -} - -/** - * Read function for websocket-socket emulation. - * - * 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|M| Payload len | Extended payload length | - * |I|S|S|S| (4) |A| (7) | (16/64) | - * |N|V|V|V| |S| | (if payload len==126/127) | - * | |1|2|3| |K| | | - * +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - + - * | Extended payload length continued, if payload len == 127 | - * + - - - - - - - - - - - - - - - +-------------------------------+ - * | |Masking-key, if MASK set to 1 | - * +-------------------------------+-------------------------------+ - * | Masking-key (continued) | Payload Data | - * +-------------------------------- - - - - - - - - - - - - - - - + - * : Payload Data continued ... : - * + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + - * | Payload Data continued ... | - * +---------------------------------------------------------------+ - * - * Using the decode buffer, this function: - * - reads the complete header from the underlying socket - * - reads any remaining data bytes - * - unmasks the payload data using the provided mask - * - decodes Base64 encoded text data - * - copies len bytes of decoded payload data into dst - * - * Emulates a read call on a socket. - */ -static int -webSocketsDecodeHybi(rfbClientPtr cl, char *dst, int len) -{ - int result = -1; - ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx; - /* int fin; */ /* not used atm */ - - /* 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)); */ - rfbLog("%s_enter: len=%d; " - "CTX: readlen=%d readPos=%p " - "writeTo=%p " - "state=%d toRead=%d remaining=%d " - " nReadRaw=%d carrylen=%d carryBuf=%p\n", - __func__, len, - wsctx->readlen, wsctx->readPos, - wsctx->writePos, - wsctx->hybiDecodeState, wsctx->nToRead, hybiRemaining(wsctx), - wsctx->nReadRaw, wsctx->carrylen, wsctx->carryBuf); - - switch (wsctx->hybiDecodeState){ - case WS_HYBI_STATE_HEADER_PENDING: - wsctx->hybiDecodeState = hybiReadHeader(cl, &result); - if (wsctx->hybiDecodeState == WS_HYBI_STATE_ERR) { - goto spor; - } - if (wsctx->hybiDecodeState != WS_HYBI_STATE_HEADER_PENDING) { - - /* when header is complete, try to read some more data */ - wsctx->hybiDecodeState = hybiReadAndDecode(cl, dst, len, &result); - } - break; - case WS_HYBI_STATE_DATA_AVAILABLE: - wsctx->hybiDecodeState = hybiReturnData(dst, len, wsctx, &result); - break; - case WS_HYBI_STATE_DATA_NEEDED: - wsctx->hybiDecodeState = hybiReadAndDecode(cl, dst, len, &result); - break; - case WS_HYBI_STATE_CLOSE_REASON_PENDING: - wsctx->hybiDecodeState = hybiReadAndDecode(cl, dst, len, &result); - break; - default: - /* invalid state */ - rfbErr("%s: called with invalid state %d\n", wsctx->hybiDecodeState); - result = -1; - errno = EIO; - wsctx->hybiDecodeState = WS_HYBI_STATE_ERR; - } - - /* single point of return, if someone has questions :-) */ -spor: - /* rfbLog("%s: ret: %d/%d\n", __func__, result, len); */ - if (wsctx->hybiDecodeState == WS_HYBI_STATE_FRAME_COMPLETE) { - rfbLog("frame received successfully, cleaning up: read=%d hlen=%d plen=%d\n", wsctx->header.nRead, wsctx->header.headerLen, wsctx->header.payloadLen); - /* frame finished, cleanup state */ - hybiDecodeCleanup(wsctx); - } else if (wsctx->hybiDecodeState == WS_HYBI_STATE_ERR) { - hybiDecodeCleanup(wsctx); - } - rfbLog("%s_exit: len=%d; " - "CTX: readlen=%d readPos=%p " - "writePos=%p " - "state=%d toRead=%d remaining=%d " - "nRead=%d carrylen=%d carryBuf=%p " - "result=%d\n", - __func__, len, - wsctx->readlen, wsctx->readPos, - wsctx->writePos, - wsctx->hybiDecodeState, wsctx->nToRead, hybiRemaining(wsctx), - wsctx->nReadRaw, wsctx->carrylen, wsctx->carryBuf, - result); - return result; -} - -static int webSocketsEncodeHybi(rfbClientPtr cl, const char *src, int len, char **dst) { int blen, ret = -1, sz = 0; @@ -1210,7 +651,9 @@ webSocketsEncode(rfbClientPtr cl, const char *src, int len, char **dst) int webSocketsDecode(rfbClientPtr cl, char *dst, int len) { - return ((ws_ctx_t *)cl->wsctx)->decode(cl, dst, len); + ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx; + wsctx->ctxInfo.ctxPtr = cl; + return wsctx->decode(wsctx, dst, len); } diff --git a/libvncserver/ws_decode.c b/libvncserver/ws_decode.c new file mode 100644 index 0000000..e74a33c --- /dev/null +++ b/libvncserver/ws_decode.c @@ -0,0 +1,448 @@ +#include "ws_decode.h" + +#include <syslog.h> +#include <string.h> +#include <errno.h> + +#define WS_HYBI_MASK_LEN 4 + + +static int +hybiRemaining(ws_ctx_t *wsctx) +{ + return wsctx->nToRead - wsctx->nReadRaw; +} + +void +hybiDecodeCleanup(ws_ctx_t *wsctx) +{ + wsctx->header.payloadLen = 0; + wsctx->header.mask.u = 0; + wsctx->nReadRaw = 0; + wsctx->nToRead= 0; + wsctx->carrylen = 0; + wsctx->readPos = (unsigned char *)wsctx->codeBufDecode; + wsctx->readlen = 0; + wsctx->hybiDecodeState = WS_HYBI_STATE_HEADER_PENDING; + wsctx->writePos = NULL; + rfbLog("cleaned up wsctx\n"); +} + +/** + * Return payload data that has been decoded/unmasked from + * a websocket frame. + * + * @param[out] dst destination buffer + * @param[in] len bytes to copy to destination buffer + * @param[in,out] wsctx internal state of decoding procedure + * @param[out] number of bytes actually written to dst buffer + * @return next hybi decoding state + */ +static int +hybiReturnData(char *dst, int len, ws_ctx_t *wsctx, int *nWritten) +{ + int nextState = WS_HYBI_STATE_ERR; + + /* if we have something already decoded copy and return */ + if (wsctx->readlen > 0) { + /* simply return what we have */ + if (wsctx->readlen > len) { + rfbLog("copy to %d bytes to dst buffer; readPos=%p, readLen=%d\n", len, wsctx->readPos, wsctx->readlen); + memcpy(dst, wsctx->readPos, len); + *nWritten = len; + wsctx->readlen -= len; + wsctx->readPos += len; + nextState = WS_HYBI_STATE_DATA_AVAILABLE; + } else { + rfbLog("copy to %d bytes to dst buffer; readPos=%p, readLen=%d\n", wsctx->readlen, wsctx->readPos, wsctx->readlen); + memcpy(dst, wsctx->readPos, wsctx->readlen); + *nWritten = wsctx->readlen; + wsctx->readlen = 0; + wsctx->readPos = NULL; + if (hybiRemaining(wsctx) == 0) { + nextState = WS_HYBI_STATE_FRAME_COMPLETE; + } else { + nextState = WS_HYBI_STATE_DATA_NEEDED; + } + } + rfbLog("after copy: readPos=%p, readLen=%d\n", wsctx->readPos, wsctx->readlen); + } else if (wsctx->hybiDecodeState == WS_HYBI_STATE_CLOSE_REASON_PENDING) { + nextState = WS_HYBI_STATE_CLOSE_REASON_PENDING; + } + return nextState; +} + +/** + * Read an RFC 6455 websocket frame (IETF hybi working group). + * + * Internal state is updated according to bytes received and the + * decoding of header information. + * + * @param[in] cl client ptr with ptr to raw socket and ws_ctx_t ptr + * @param[out] sockRet emulated recv return value + * @return next hybi decoding state; WS_HYBI_STATE_HEADER_PENDING indicates + * that the header was not received completely. + */ +static int +hybiReadHeader(ws_ctx_t *wsctx, int *sockRet) +{ + int ret; + char *headerDst = wsctx->codeBufDecode + wsctx->nReadRaw; + int n = WSHLENMAX - wsctx->nReadRaw; + + rfbLog("header_read to %p with len=%d\n", headerDst, n); + //ret = ws_read(cl, headerDst, n); + ret = wsctx->ctxInfo.readFunc(wsctx->ctxInfo.ctxPtr, headerDst, n); + rfbLog("read %d bytes from socket\n", ret); + if (ret <= 0) { + if (-1 == ret) { + /* save errno because rfbErr() will tamper it */ + int olderrno = errno; + rfbErr("%s: peek; %m\n", __func__); + errno = olderrno; + *sockRet = -1; + } else { + *sockRet = 0; + } + return WS_HYBI_STATE_ERR; + } + + wsctx->nReadRaw += ret; + if (wsctx->nReadRaw < 2) { + /* cannot decode header with less than two bytes */ + errno = EAGAIN; + *sockRet = -1; + return WS_HYBI_STATE_HEADER_PENDING; + } + + /* first two header bytes received; interpret header data and get rest */ + wsctx->header.data = (ws_header_t *)wsctx->codeBufDecode; + + wsctx->header.opcode = wsctx->header.data->b0 & 0x0f; + + /* fin = (header->b0 & 0x80) >> 7; */ /* not used atm */ + wsctx->header.payloadLen = wsctx->header.data->b1 & 0x7f; + rfbLog("first header bytes received; opcode=%d lenbyte=%d\n", wsctx->header.opcode, wsctx->header.payloadLen); + + /* + * 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 (!(wsctx->header.data->b1 & 0x80)) { + rfbErr("%s: got frame without mask ret=%d\n", __func__, ret); + syslog(LOG_ERR, "%s: got frame without mask; ret=%d\n", __func__, ret); + errno = EIO; + *sockRet = -1; + return WS_HYBI_STATE_ERR; + } + + if (wsctx->header.payloadLen < 126 && wsctx->nReadRaw >= 6) { + wsctx->header.headerLen = 2 + WS_HYBI_MASK_LEN; + wsctx->header.mask = wsctx->header.data->u.m; + } else if (wsctx->header.payloadLen == 126 && 8 <= wsctx->nReadRaw) { + wsctx->header.headerLen = 4 + WS_HYBI_MASK_LEN; + wsctx->header.payloadLen = WS_NTOH16(wsctx->header.data->u.s16.l16); + wsctx->header.mask = wsctx->header.data->u.s16.m16; + } else if (wsctx->header.payloadLen == 127 && 14 <= wsctx->nReadRaw) { + wsctx->header.headerLen = 10 + WS_HYBI_MASK_LEN; + wsctx->header.payloadLen = WS_NTOH64(wsctx->header.data->u.s64.l64); + wsctx->header.mask = wsctx->header.data->u.s64.m64; + } else { + /* Incomplete frame header, try again */ + rfbErr("%s: incomplete frame header; ret=%d\n", __func__, ret); + errno = EAGAIN; + *sockRet = -1; + return WS_HYBI_STATE_HEADER_PENDING; + } + + /* absolute length of frame */ + wsctx->nToRead = wsctx->header.headerLen + wsctx->header.payloadLen; + + /* update write position for next bytes */ + wsctx->writePos = wsctx->codeBufDecode + wsctx->nReadRaw; + + /* set payload pointer just after header */ + wsctx->readPos = (unsigned char *)(wsctx->codeBufDecode + wsctx->header.headerLen); + + rfbLog("header complete: state=%d flen=%d writeTo=%p\n", wsctx->hybiDecodeState, wsctx->nToRead, wsctx->writePos); + + return WS_HYBI_STATE_DATA_NEEDED; +} + +static int +hybiWsFrameComplete(ws_ctx_t *wsctx) +{ + return wsctx != NULL && hybiRemaining(wsctx) == 0; +} + +static char * +hybiPayloadStart(ws_ctx_t *wsctx) +{ + return wsctx->codeBufDecode + wsctx->header.headerLen; +} + + +/** + * Read the remaining payload bytes from associated raw socket. + * + * - try to read remaining bytes from socket + * - unmask all multiples of 4 + * - if frame incomplete but some bytes are left, these are copied to + * the carry buffer + * - if opcode is TEXT: Base64-decode all unmasked received bytes + * - set state for reading decoded data + * - reset write position to begin of buffer (+ header) + * --> before we retrieve more data we let the caller clear all bytes + * from the reception buffer + * - execute return data routine + * + * Sets errno corresponding to what it gets from the underlying + * socket or EIO if some internal sanity check fails. + * + * @param[in] cl client ptr with raw socket reference + * @param[out] dst destination buffer + * @param[in] len size of destination buffer + * @param[out] sockRet emulated recv return value + * @return next hybi decode state + */ +static int +hybiReadAndDecode(ws_ctx_t *wsctx, char *dst, int len, int *sockRet) +{ + int n; + int i; + int toReturn; + int toDecode; + int bufsize; + int nextRead; + unsigned char *data; + uint32_t *data32; + + /* if data was carried over, copy to start of buffer */ + memcpy(wsctx->writePos, wsctx->carryBuf, wsctx->carrylen); + wsctx->writePos += wsctx->carrylen; + + /* -1 accounts for potential '\0' terminator for base64 decoding */ + bufsize = wsctx->codeBufDecode + ARRAYSIZE(wsctx->codeBufDecode) - wsctx->writePos - 1; + if (hybiRemaining(wsctx) > bufsize) { + nextRead = bufsize; + } else { + nextRead = hybiRemaining(wsctx); + } + + rfbLog("calling read with buf=%p and len=%d (decodebuf=%p headerLen=%d)\n", wsctx->writePos, nextRead, wsctx->codeBufDecode, wsctx->header.headerLen); + + if (wsctx->nReadRaw < wsctx->nToRead) { + /* decode more data */ + //if (-1 == (n = ws_read(cl, wsctx->writePos, nextRead))) { + if (-1 == (n = wsctx->ctxInfo.readFunc(wsctx->ctxInfo.ctxPtr, wsctx->writePos, nextRead))) { + int olderrno = errno; + rfbErr("%s: read; %m", __func__); + errno = olderrno; + *sockRet = -1; + return WS_HYBI_STATE_ERR; + } else if (n == 0) { + *sockRet = 0; + return WS_HYBI_STATE_ERR; + } + wsctx->nReadRaw += n; + rfbLog("read %d bytes from socket; nRead=%d\n", n, wsctx->nReadRaw); + } else { + n = 0; + } + + wsctx->writePos += n; + + if (wsctx->nReadRaw >= wsctx->nToRead) { + if (wsctx->nReadRaw > wsctx->nToRead) { + rfbErr("%s: internal error, read past websocket frame", __func__); + errno=EIO; + *sockRet = -1; + return WS_HYBI_STATE_ERR; + } + } + + toDecode = wsctx->writePos - hybiPayloadStart(wsctx); + rfbLog("toDecode=%d from n=%d carrylen=%d headerLen=%d\n", toDecode, n, wsctx->carrylen, wsctx->header.headerLen); + if (toDecode < 0) { + rfbErr("%s: internal error; negative number of bytes to decode: %d", __func__, toDecode); + errno=EIO; + *sockRet = -1; + return WS_HYBI_STATE_ERR; + } + + /* for a possible base64 decoding, we decode multiples of 4 bytes until + * the whole frame is received and carry over any remaining bytes in the carry buf*/ + data = (unsigned char *)hybiPayloadStart(wsctx); + data32= (uint32_t *)data; + + for (i = 0; i < (toDecode >> 2); i++) { + data32[i] ^= wsctx->header.mask.u; + } + rfbLog("mask decoding; i=%d toDecode=%d\n", i, toDecode); + + if (wsctx->hybiDecodeState == WS_HYBI_STATE_FRAME_COMPLETE) { + /* process the remaining bytes (if any) */ + for (i*=4; i < toDecode; i++) { + data[i] ^= wsctx->header.mask.c[i % 4]; + } + + /* all data is here, no carrying */ + wsctx->carrylen = 0; + } else { + /* carry over remaining, non-multiple-of-four bytes */ + wsctx->carrylen = toDecode - (i * 4); + if (wsctx->carrylen < 0 || wsctx->carrylen > ARRAYSIZE(wsctx->carryBuf)) { + syslog(LOG_ERR, "%s: internal error, invalid carry over size: carrylen=%d, toDecode=%d, i=%d", __func__, wsctx->carrylen, toDecode, i); + *sockRet = -1; + errno = EIO; + return WS_HYBI_STATE_ERR; + } + rfbLog("carrying over %d bytes from %p to %p\n", wsctx->carrylen, wsctx->writePos + (i * 4), wsctx->carryBuf); + memcpy(wsctx->carryBuf, data + (i * 4), wsctx->carrylen); + } + + toReturn = toDecode - wsctx->carrylen; + + switch (wsctx->header.opcode) { + case WS_OPCODE_CLOSE: + + /* this data is not returned as payload data */ + if (hybiWsFrameComplete(wsctx)) { + rfbLog("got closure, reason %d\n", WS_NTOH16(((uint16_t *)data)[0])); + rfbLog("got close cmd, reason %d\n", WS_NTOH16(((uint16_t *)data)[0])); + errno = ECONNRESET; + *sockRet = -1; + return WS_HYBI_STATE_FRAME_COMPLETE; + } else { + rfbErr("%s: close reason with long frame not supported", __func__); + errno = EIO; + *sockRet = -1; + return WS_HYBI_STATE_ERR; + } + break; + case WS_OPCODE_TEXT_FRAME: + data[toReturn] = '\0'; + rfbLog("Initiate Base64 decoding in %p with max size %d and '\\0' at %p\n", data, bufsize, data + toReturn); + if (-1 == (wsctx->readlen = b64_pton((char *)data, data, bufsize))) { + syslog(LOG_ERR, "Base64 decode error in %s; data=%p bufsize=%d", __func__, data, bufsize); + rfbErr("%s: Base64 decode error; %m\n", __func__); + } + wsctx->writePos = hybiPayloadStart(wsctx); + break; + case WS_OPCODE_BINARY_FRAME: + wsctx->readlen = toReturn; + wsctx->writePos = hybiPayloadStart(wsctx); + rfbLog("set readlen=%d writePos=%p\n", wsctx->readlen, wsctx->writePos); + break; + default: + rfbErr("%s: unhandled opcode %d, b0: %02x, b1: %02x\n", __func__, (int)wsctx->header.opcode, wsctx->header.data->b0, wsctx->header.data->b1); + } + wsctx->readPos = data; + + return hybiReturnData(dst, len, wsctx, sockRet); +} + +/** + * Read function for websocket-socket emulation. + * + * 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|M| Payload len | Extended payload length | + * |I|S|S|S| (4) |A| (7) | (16/64) | + * |N|V|V|V| |S| | (if payload len==126/127) | + * | |1|2|3| |K| | | + * +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - + + * | Extended payload length continued, if payload len == 127 | + * + - - - - - - - - - - - - - - - +-------------------------------+ + * | |Masking-key, if MASK set to 1 | + * +-------------------------------+-------------------------------+ + * | Masking-key (continued) | Payload Data | + * +-------------------------------- - - - - - - - - - - - - - - - + + * : Payload Data continued ... : + * + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + + * | Payload Data continued ... | + * +---------------------------------------------------------------+ + * + * Using the decode buffer, this function: + * - reads the complete header from the underlying socket + * - reads any remaining data bytes + * - unmasks the payload data using the provided mask + * - decodes Base64 encoded text data + * - copies len bytes of decoded payload data into dst + * + * Emulates a read call on a socket. + */ +int +webSocketsDecodeHybi(ws_ctx_t *wsctx, char *dst, int len) +{ + int result = -1; + /* int fin; */ /* not used atm */ + + /* 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)); */ + rfbLog("%s_enter: len=%d; " + "CTX: readlen=%d readPos=%p " + "writeTo=%p " + "state=%d toRead=%d remaining=%d " + " nReadRaw=%d carrylen=%d carryBuf=%p\n", + __func__, len, + wsctx->readlen, wsctx->readPos, + wsctx->writePos, + wsctx->hybiDecodeState, wsctx->nToRead, hybiRemaining(wsctx), + wsctx->nReadRaw, wsctx->carrylen, wsctx->carryBuf); + + switch (wsctx->hybiDecodeState){ + case WS_HYBI_STATE_HEADER_PENDING: + wsctx->hybiDecodeState = hybiReadHeader(wsctx, &result); + if (wsctx->hybiDecodeState == WS_HYBI_STATE_ERR) { + goto spor; + } + if (wsctx->hybiDecodeState != WS_HYBI_STATE_HEADER_PENDING) { + + /* when header is complete, try to read some more data */ + wsctx->hybiDecodeState = hybiReadAndDecode(wsctx, dst, len, &result); + } + break; + case WS_HYBI_STATE_DATA_AVAILABLE: + wsctx->hybiDecodeState = hybiReturnData(dst, len, wsctx, &result); + break; + case WS_HYBI_STATE_DATA_NEEDED: + wsctx->hybiDecodeState = hybiReadAndDecode(wsctx, dst, len, &result); + break; + case WS_HYBI_STATE_CLOSE_REASON_PENDING: + wsctx->hybiDecodeState = hybiReadAndDecode(wsctx, dst, len, &result); + break; + default: + /* invalid state */ + rfbErr("%s: called with invalid state %d\n", wsctx->hybiDecodeState); + result = -1; + errno = EIO; + wsctx->hybiDecodeState = WS_HYBI_STATE_ERR; + } + + /* single point of return, if someone has questions :-) */ +spor: + /* rfbLog("%s: ret: %d/%d\n", __func__, result, len); */ + if (wsctx->hybiDecodeState == WS_HYBI_STATE_FRAME_COMPLETE) { + rfbLog("frame received successfully, cleaning up: read=%d hlen=%d plen=%d\n", wsctx->header.nRead, wsctx->header.headerLen, wsctx->header.payloadLen); + /* frame finished, cleanup state */ + hybiDecodeCleanup(wsctx); + } else if (wsctx->hybiDecodeState == WS_HYBI_STATE_ERR) { + hybiDecodeCleanup(wsctx); + } + rfbLog("%s_exit: len=%d; " + "CTX: readlen=%d readPos=%p " + "writePos=%p " + "state=%d toRead=%d remaining=%d " + "nRead=%d carrylen=%d carryBuf=%p " + "result=%d\n", + __func__, len, + wsctx->readlen, wsctx->readPos, + wsctx->writePos, + wsctx->hybiDecodeState, wsctx->nToRead, hybiRemaining(wsctx), + wsctx->nReadRaw, wsctx->carrylen, wsctx->carryBuf, + result); + return result; +} diff --git a/libvncserver/ws_decode.h b/libvncserver/ws_decode.h new file mode 100644 index 0000000..e75c4d1 --- /dev/null +++ b/libvncserver/ws_decode.h @@ -0,0 +1,160 @@ +#ifndef _WS_DECODE_H_ +#define _WS_DECODE_H_ + +#include <stdint.h> +#include <rfb/rfb.h> +#ifndef _MSC_VER +#include <resolv.h> /* __b64_ntop */ +#endif + + + +enum { + WEBSOCKETS_VERSION_HIXIE, + WEBSOCKETS_VERSION_HYBI +}; + +#if defined(__APPLE__) + +#include <libkern/OSByteOrder.h> +#define WS_NTOH64(n) OSSwapBigToHostInt64(n) +#define WS_NTOH32(n) OSSwapBigToHostInt32(n) +#define WS_NTOH16(n) OSSwapBigToHostInt16(n) +#define WS_HTON64(n) OSSwapHostToBigInt64(n) +#define WS_HTON16(n) OSSwapHostToBigInt16(n) + +#else + +#define WS_NTOH64(n) htobe64(n) +#define WS_NTOH32(n) htobe32(n) +#define WS_NTOH16(n) htobe16(n) +#define WS_HTON64(n) htobe64(n) +#define WS_HTON16(n) htobe16(n) + +#endif + +#define B64LEN(__x) (((__x + 2) / 3) * 12 / 3) +#define WSHLENMAX 14 /* 2 + sizeof(uint64_t) + sizeof(uint32_t) */ +#define WS_HYBI_MASK_LEN 4 + +#define ARRAYSIZE(a) ((sizeof(a) / sizeof((a[0]))) / (size_t)(!(sizeof(a) % sizeof((a[0]))))) + +enum { + WEBSOCKETS_VERSION_HIXIE, + WEBSOCKETS_VERSION_HYBI +}; + +struct ws_ctx_s; +typedef struct ws_ctx_s ws_ctx_t; + +typedef int (*wsEncodeFunc)(rfbClientPtr cl, const char *src, int len, char **dst); +typedef int (*wsDecodeFunc)(ws_ctx_t *wsctx, char *dst, int len); + +typedef int (*wsReadFunc)(void *ctx, char *dst, int len); +typedef int (*wsPeekFunc)(void *ctx, char *dst, int len); + +typedef struct ctxInfo_s{ + void *ctxPtr; + wsReadFunc readFunc; + wsPeekFunc peekFunc; +} ctxInfo_t; + +enum { + /* header not yet received completely */ + WS_HYBI_STATE_HEADER_PENDING, + /* data available */ + WS_HYBI_STATE_DATA_AVAILABLE, + WS_HYBI_STATE_DATA_NEEDED, + /* received a complete frame */ + WS_HYBI_STATE_FRAME_COMPLETE, + /* received part of a 'close' frame */ + WS_HYBI_STATE_CLOSE_REASON_PENDING, + /* */ + WS_HYBI_STATE_ERR +}; + +typedef union ws_mask_s { + char c[4]; + uint32_t u; +} ws_mask_t; + +/* XXX: The union and the structs do not need to be named. + * We are working around a bug present in GCC < 4.6 which prevented + * it from recognizing anonymous structs and unions. + * See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=4784 + */ +typedef struct +#if __GNUC__ +__attribute__ ((__packed__)) +#endif +ws_header_s { + unsigned char b0; + unsigned char b1; + union { + struct +#if __GNUC__ + __attribute__ ((__packed__)) +#endif + { + uint16_t l16; + ws_mask_t m16; + } s16; + struct +#if __GNUC__ +__attribute__ ((__packed__)) +#endif + { + uint64_t l64; + ws_mask_t m64; + } s64; + ws_mask_t m; + } u; +} ws_header_t; + +typedef struct ws_header_data_s { + ws_header_t *data; + /** bytes read */ + int nRead; + /** mask value */ + ws_mask_t mask; + /** length of frame header including payload len, but without mask */ + int headerLen; + /** length of the payload data */ + int payloadLen; + /** opcode */ + unsigned char opcode; +} ws_header_data_t; + +typedef struct ws_ctx_s { + char codeBufDecode[2048 + WSHLENMAX]; /* base64 + maximum frame header length */ + char codeBufEncode[B64LEN(UPDATE_BUF_SIZE) + WSHLENMAX]; /* base64 + maximum frame header length */ + char *writePos; + unsigned char *readPos; + int readlen; + int hybiDecodeState; + char carryBuf[3]; /* For base64 carry-over */ + int carrylen; + int version; + int base64; + ws_header_data_t header; + int nReadRaw; + int nToRead; + wsEncodeFunc encode; + wsDecodeFunc decode; + ctxInfo_t ctxInfo; +} ws_ctx_t; + +enum +{ + WS_OPCODE_CONTINUATION = 0x0, + WS_OPCODE_TEXT_FRAME, + WS_OPCODE_BINARY_FRAME, + WS_OPCODE_CLOSE = 0x8, + WS_OPCODE_PING, + WS_OPCODE_PONG +}; + +int webSocketsDecodeHybi(ws_ctx_t *wsctx, char *dst, int len); + +void hybiDecodeCleanup(ws_ctx_t *wsctx); +#endif |