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Freescale mcu OpenTCP-1.0.4.doc.html.zip 文档

00378                                                 }
00379 
00380                                                 <span class="keywordflow">return</span> 0;
00381                                         }<span class="keywordflow">else</span>{
00382                                                 <span class="comment">/* nope, skip other bytes */</span>
00383                                                 <span class="keywordflow">while</span>(tmp_int--)
00384                                                         <a class="code" href="system_8h.html#a9">RECEIVE_NETWORK_B</a>();
00385                                         }
00386                                 }<span class="keywordflow">else</span>{
00387 
00388                                         DEBUGOUT(<span class="stringliteral">"DNS: RR.CLASS not INET. Skipping!\r\n"</span>);
00389 
00390                                         <span class="comment">/* skip TTL and read RDLENGTH*/</span>
00391                                         <span class="keywordflow">for</span>(tmp_byte=0;tmp_byte&lt;6;tmp_byte++){
00392                                                 tmp_int=(tmp_int&lt;&lt;8)+<a class="code" href="system_8h.html#a9">RECEIVE_NETWORK_B</a>();
00393                                         }
00394 
00395                                         <span class="comment">/* skip RDATA */</span>
00396                                         <span class="keywordflow">while</span>(tmp_int--)
00397                                                 <a class="code" href="system_8h.html#a9">RECEIVE_NETWORK_B</a>();
00398                                 }
00399                                 <span class="comment">/* decrement counters */</span>
00400                                 <span class="keywordflow">if</span>(dns_ancount)
00401                                         dns_ancount--;
00402                                 <span class="keywordflow">else</span>
00403                                         <span class="keywordflow">if</span>(dns_nscount)
00404                                                 dns_nscount--;
00405 
00406                         }
00407                         <span class="keywordflow">break</span>;
00408 
00409                 <span class="keywordflow">default</span>:
00410                         DEBUGOUT(<span class="stringliteral">"DNS: unknown UDP event :-("</span>);
00411                         <span class="keywordflow">break</span>;
00412         }
00413         <span class="keywordflow">return</span> 0;
00414 }
00415 
<a name="l00445"></a><a class="code" href="dns_8c.html#a14">00445</a> UINT8 <a class="code" href="dns_8c.html#a14">get_host_by_name</a>(UINT8 *host_name_ptr, <span class="keywordtype">void</span> (*listener)(UINT8 , UINT32 )){
00446 
00447         UINT8 *buf_ptr;
00448         INT8 i;
00449         UINT16 total;
00450 
00451         <span class="keywordflow">switch</span>(dns_state){
00452 
00453                 <span class="keywordflow">case</span> DNS_STATE_READY:
00454                         <a class="code" href="dns_8c.html#a3">dns_state</a>=DNS_STATE_BUSY;
00455                         <a class="code" href="dns_8c.html#a8">dns_hostptr</a>=host_name_ptr;
00456                         dns_event_listener=listener;
00457                         <a class="code" href="dns_8c.html#a7">dns_tmp_ip</a>=<a class="code" href="dns_8h.html#a1">DNS_SERVER_IP</a>;
00458                         <a class="code" href="dns_8c.html#a6">dns_retries</a>=<a class="code" href="dns_8h.html#a3">DNS_NUM_RETRIES</a>;
00459                         <a class="code" href="timers_8c.html#a6">init_timer</a>(<a class="code" href="dns_8c.html#a5">dns_timer</a>,<a class="code" href="dns_8h.html#a2">DNS_RESEND_PERIOD</a>*<a class="code" href="timers_8h.html#a1">TIMERTIC</a>);
00460                         <span class="keywordflow">break</span>;
00461 
00462                 <span class="keywordflow">case</span> DNS_STATE_BUSY:
00463                         DEBUGOUT(<span class="stringliteral">"DNS: Error, trying to invoke two DNS requests at the same time!\r\n"</span>);
00464                         <span class="keywordflow">return</span>  <a class="code" href="dns_8h.html#a13">DNS_ERROR_BUSY</a>;
00465 
00466 
00467                 <span class="keywordflow">case</span> DNS_STATE_RESEND:
00468                         <span class="keywordflow">if</span>(host_name_ptr!=<a class="code" href="dns_8c.html#a8">dns_hostptr</a>){
00469                                 DEBUGOUT(<span class="stringliteral">"DNS: Ptrs different. Can't do that! \r\n"</span>);
00470                                 <span class="keywordflow">return</span> <a class="code" href="dns_8h.html#a13">DNS_ERROR_BUSY</a>;
00471                         }
00472                         <span class="keywordflow">break</span>;
00473 
00474                 <span class="keywordflow">default</span>:
00475                         DEBUGOUT(<span class="stringliteral">"DNS: What am I doing in this state?\r\n"</span>);
00476                         <a class="code" href="system_8h.html#a6">RESET_SYSTEM</a>();
00477         }
00478 
00479 
00480         <span class="comment">/* OK, create message in the Netbuf transmit buffer */</span>
00481 
00482         buf_ptr=net_buf+<a class="code" href="tcp__ip_8h.html#a62">UDP_APP_OFFSET</a>;
00483 
00484         <span class="comment">/* first the header */</span>
00485         *((UINT16 *)buf_ptr)=0xAAAA; <span class="comment">/* id, fixed for now*/</span>
00486         buf_ptr+=2;
00487 
00488         *buf_ptr++=0x01;
00489         *buf_ptr++=0x00;
00490 
00491         <span class="comment">/*question count*/</span>
00492         *buf_ptr++=0x00;
00493         *buf_ptr++=0x01;
00494 
00495         <span class="comment">/* others are zero */</span>
00496         <span class="keywordflow">for</span>(i=0;i&lt;6;i++)
00497                 *buf_ptr++=0x00;
00498 
00499         <span class="comment">/* ok, create the question section */</span>
00500         total=0;
00501 
00502         <span class="keywordflow">while</span>((*host_name_ptr)!=<span class="charliteral">'\0'</span>){
00503 
00504                 <span class="comment">/* we are still not at the end. Reserve space for count */</span>
00505                 buf_ptr++;
00506                 i=0;
00507 
00508                 <span class="keywordflow">while</span>(((*host_name_ptr)!=<span class="charliteral">'.'</span>)&amp;&amp;((*host_name_ptr)!=<span class="charliteral">'\0'</span>)){
00509                         i++;
00510                         *buf_ptr++=*host_name_ptr++;
00511                         <span class="keywordflow">if</span>(buf_ptr==(net_buf+<a class="code" href="group__opentcp__config.html#a4">NETWORK_TX_BUFFER_SIZE</a>)){
00512                                 DEBUGOUT(<span class="stringliteral">"DNS: Buffer overflow!!!\r\n"</span>);
00513                                 <span class="keywordflow">return</span>(DNS_ERROR_OVERFLOW);
00514                         }
00515                 }
00516 
00517                 <span class="comment">/* label shorter than 63 bytes or less? */</span>
00518                 <span class="keywordflow">if</span>((i&lt;=0)||(i&gt;=64)){
00519                         DEBUGOUT(<span class="stringliteral">"DNS: Label size wrong! Aborting....\r\n"</span>);
00520                         <span class="keywordflow">return</span>(DNS_ERROR_LABEL);
00521                 }
00522 
00523                 <span class="comment">/* it seems ok for now. Increase total name length*/</span>
00524                 total+=i;
00525 
00526                 <span class="keywordflow">if</span>(total&gt;=264){
00527                         DEBUGOUT(<span class="stringliteral">"DNS: Name size wrong! Aborting....\r\n"</span>);
00528                         <span class="keywordflow">return</span>(DNS_ERROR_NAME);
00529                 }
00530 
00531                 *(buf_ptr-i-1)=i;       <span class="comment">/* store label length */</span>
00532 
00533                 <span class="comment">/* ok, where are we ? */</span>
00534                 <span class="keywordflow">if</span>((*host_name_ptr)==<span class="charliteral">'.'</span>){
00535                         <span class="comment">/* still not at the end, skip dot */</span>
00536                         host_name_ptr++;
00537                 }<span class="keywordflow">else</span>
00538                         <span class="keywordflow">if</span>((*host_name_ptr)==<span class="charliteral">'\0'</span>){
00539                                 <span class="comment">/* OHO, finished,</span>
00540 <span class="comment">                                        add ZERO,QTYPE and QCLASS */</span>
00541                                 *buf_ptr++=0x00;
00542                                 *buf_ptr++=0x00;
00543                                 *buf_ptr++=0x01;
00544                                 *buf_ptr++=0x00;
00545                                 *buf_ptr++=0x01;
00546                                 kick_WD();
00547                                 <span class="comment">/* ok, now send the request */</span>
00548                                 <span class="keywordflow">return</span> <a class="code" href="udp_8c.html#a7">udp_send</a>(<a class="code" href="dns_8c.html#a4">dns_socket</a>,<a class="code" href="dns_8c.html#a7">dns_tmp_ip</a>,<a class="code" href="dns_8h.html#a0">DNS_UDP_PORT</a>,net_buf+<a class="code" href="tcp__ip_8h.html#a62">UDP_APP_OFFSET</a>,<a class="code" href="group__opentcp__config.html#a4">NETWORK_TX_BUFFER_SIZE</a>-<a class="code" href="tcp__ip_8h.html#a62">UDP_APP_OFFSET</a>,buf_ptr-(net_buf+<a class="code" href="tcp__ip_8h.html#a62">UDP_APP_OFFSET</a>));
00549                         }
00550         }
00551 }
00552 
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