[sr-dev] git:pd/websocket: core: improved de-buffering for websockets

Module: sip-router Branch: pd/websocket Commit: 1718093cfad0ea8085d20a7b5fd995f93c91a48a URL: http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=1718093… Author: Peter Dunkley &lt;peter.dunkley(a)crocodile-rcs.com&gt; Committer: Peter Dunkley &lt;peter.dunkley(a)crocodile-rcs.com&gt; Date: Sat Jun 16 22:58:36 2012 +0100 core: improved de-buffering for websockets - This should handle the case that the full TCP packet hasn't been received when the read function is called. Not sure how to explicitly test this though. --- tcp_read.c | 127 ++++++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 files changed, 116 insertions(+), 11 deletions(-) diff --git a/tcp_read.c b/tcp_read.c index c68dbdd..ccb5481 100644 --- a/tcp_read.c +++ b/tcp_read.c @@ -110,11 +110,6 @@ int is_msg_complete(struct tcp_req* r); #define HTTP11CONTINUE_LEN (sizeof(HTTP11CONTINUE)-1) #endif -#ifdef READ_WS -static int ws_process_msg(char* tcpbuf, unsigned int len, - struct receive_info* rcv_info, struct tcp_connection* con); -#endif - #define TCPCONN_TIMEOUT_MIN_RUN 1 /* run the timers each new tick */ /* types used in io_wait* */ @@ -444,10 +439,6 @@ int tcp_read_headers(struct tcp_connection *c, int* read_flags) if (bytes<=0) return bytes; } p=r->parsed; -#ifdef READ_WS - if (c->flags & F_CONN_WS) - return ws_process_msg(p, bytes, &c->rcv, c); -#endif while(p<r->pos && r->error==TCP_REQ_OK){ switch((unsigned char)r->state){ @@ -1025,6 +1016,110 @@ int msrp_process_msg(char* tcpbuf, unsigned int len, #endif #ifdef READ_WS +static int tcp_read_ws(struct tcp_connection *c, int* read_flags) +{ + int bytes, pos, mask_present; + unsigned long len; + char *p; + struct tcp_req *r; + + r=&c->req; + if (unlikely(r->parsed < r->pos)) + bytes = 0; + else + { +#ifdef USE_TLS + if (unlikely(c->type == PROTO_TLS)) + bytes = tls_read(c, read_flags); + else +#endif + bytes = tcp_read(c, read_flags); + + if (bytes <= 0) + return 0; + } + + p = r->parsed; + pos = 0; + + /* + 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 ... | + +---------------------------------------------------------------+ + + Do minimal parse required to make sure the full message has been + received (websocket module will do full parse and validation). + */ + + /* Process first two bytes */ + if (bytes < pos + 2) + goto skip; + pos++; + mask_present = p[pos] & 0x80; + len = (p[pos++] & 0xff) & ~0x80; + + /* Work out real length */ + if (len == 126) + { + if (bytes < pos + 2) + goto skip; + + len = 0; + len |= (p[pos++] & 0xff) << 8; + len |= (p[pos++] & 0xff) << 0; + } + else if (len == 127) + { + if (bytes < pos + 8) + goto skip; + + /* Only decoding the last four bytes of the length... + This limits the size of WebSocket messages that can be + handled to 2^32 - which should be plenty for SIP! */ + len = 0; + pos += 4; + len |= (p[pos++] & 0xff) << 24; + len |= (p[pos++] & 0xff) << 16; + len |= (p[pos++] & 0xff) << 8; + len |= (p[pos++] & 0xff) << 0; + } + + /* Skip mask */ + if (mask_present) + { + if (bytes < pos + 4) + goto skip; + pos += 4; + } + + /* Now check the whole message has been received */ + if (bytes < pos + len) + goto skip; + + pos += len; + r->bytes_to_go = bytes - pos; + r->flags |= F_TCP_REQ_COMPLETE; + r->parsed = &p[pos]; + +skip: + return bytes; +} + static int ws_process_msg(char* tcpbuf, unsigned int len, struct receive_info* rcv_info, struct tcp_connection* con) { @@ -1145,7 +1240,12 @@ int tcp_read_req(struct tcp_connection* con, int* bytes_read, int* read_flags) again: if (likely(req->error==TCP_REQ_OK)){ - bytes=tcp_read_headers(con, read_flags); +#ifdef READ_WS + if (unlikely(con->flags&F_CONN_WS)) + bytes=tcp_read_ws(con, read_flags); + else +#endif + bytes=tcp_read_headers(con, read_flags); #ifdef EXTRA_DEBUG /* if timeout state=0; goto end__req; */ DBG("read= %d bytes, parsed=%d, state=%d, error=%d\n", @@ -1173,7 +1273,6 @@ again: resp=CONN_EOF; goto end_req; } - } if (unlikely(req->error!=TCP_REQ_OK)){ LOG(L_ERR,"ERROR: tcp_read_req: bad request, state=%d, error=%d " @@ -1261,6 +1360,12 @@ again: &con->rcv, con); }else #endif +#ifdef READ_WS + if (unlikely(con->flags&F_CONN_WS)){ + ret = ws_process_msg(req->start, req->parsed-req->start, + &con->rcv, con); + }else +#endif ret = receive_tcp_msg(req->start, req->parsed-req->start, &con->rcv, con);