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<a name="l00148"></a>00148 <span class="keywordflow">do</span> {<a name="l00149"></a>00149 n = *query++;<a name="l00150"></a>00150 <a name="l00151"></a>00151 <span class="keywordflow">while</span>(n > 0) {<a name="l00152"></a>00152 <span class="comment">/* printf("%c", *query);*/</span><a name="l00153"></a>00153 ++query;<a name="l00154"></a>00154 --n;<a name="l00155"></a>00155 };<a name="l00156"></a>00156 <span class="comment">/* printf(".");*/</span><a name="l00157"></a>00157 } <span class="keywordflow">while</span>(*query != 0);<a name="l00158"></a>00158 <span class="comment">/* printf("\n");*/</span><a name="l00159"></a>00159 <span class="keywordflow">return</span> query + 1;<a name="l00160"></a>00160 }<a name="l00161"></a>00161 <span class="comment">/*---------------------------------------------------------------------------*/</span><span class="comment"></span><a name="l00162"></a>00162 <span class="comment">/** \internal</span><a name="l00163"></a>00163 <span class="comment"> * Runs through the list of names to see if there are any that have</span><a name="l00164"></a>00164 <span class="comment"> * not yet been queried and, if so, sends out a query.</span><a name="l00165"></a>00165 <span class="comment"> */</span><a name="l00166"></a>00166 <span class="comment">/*---------------------------------------------------------------------------*/</span><a name="l00167"></a>00167 <span class="keyword">static</span> <span class="keywordtype">void</span><a name="l00168"></a>00168 check_entries(<span class="keywordtype">void</span>)<a name="l00169"></a>00169 {<a name="l00170"></a>00170 <span class="keyword">register</span> <span class="keyword">struct </span>dns_hdr *hdr;<a name="l00171"></a>00171 <span class="keywordtype">char</span> *query, *nptr, *nameptr;<a name="l00172"></a>00172 <span class="keyword">static</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> i;<a name="l00173"></a>00173 <span class="keyword">static</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> n;<a name="l00174"></a>00174 <span class="keyword">register</span> <span class="keyword">struct </span>namemap *namemapptr;<a name="l00175"></a>00175 <a name="l00176"></a>00176 <span class="keywordflow">for</span>(i = 0; i < <a class="code" href="a00160.html#g221d37ccde7e3fd0dd2c2eb0a6b15493">RESOLV_ENTRIES</a>; ++i) {<a name="l00177"></a>00177 namemapptr = &names[i];<a name="l00178"></a>00178 <span class="keywordflow">if</span>(namemapptr->state == <a name="a131"></a><a class="code" href="a00102.html#bf4401501f1389872141a78b63f325a3">STATE_NEW</a> ||<a name="l00179"></a>00179 namemapptr->state == <a name="a132"></a><a class="code" href="a00102.html#55735650f879293d9b7b5fda6753d147">STATE_ASKING</a>) {<a name="l00180"></a>00180 <span class="keywordflow">if</span>(namemapptr->state == <a class="code" href="a00102.html#55735650f879293d9b7b5fda6753d147">STATE_ASKING</a>) {<a name="l00181"></a>00181 <span class="keywordflow">if</span>(--namemapptr->tmr == 0) {<a name="l00182"></a>00182 <span class="keywordflow">if</span>(++namemapptr->retries == <a name="a133"></a><a class="code" href="a00160.html#gecf13b8dc783db2202ca5c34fe117fc3">MAX_RETRIES</a>) {<a name="l00183"></a>00183 namemapptr->state = <a name="a134"></a><a class="code" href="a00102.html#7bf0c086c7c41c12cc63324327932d91">STATE_ERROR</a>;<a name="l00184"></a>00184 <a name="a135"></a><a class="code" href="a00160.html#g6d9751d534453425c7a5a215d1d4414c">resolv_found</a>(namemapptr->name, <a class="code" href="a00160.html#g070d2ce7b6bb7e5c05602aa8c308d0c4">NULL</a>);<a name="l00185"></a>00185 <span class="keywordflow">continue</span>;<a name="l00186"></a>00186 }<a name="l00187"></a>00187 namemapptr->tmr = namemapptr->retries;<a name="l00188"></a>00188 } <span class="keywordflow">else</span> {<a name="l00189"></a>00189 <span class="comment">/* printf("Timer %d\n", namemapptr->tmr);*/</span><a name="l00190"></a>00190 <span class="comment">/* Its timer has not run out, so we move on to next</span><a name="l00191"></a>00191 <span class="comment"> entry. */</span><a name="l00192"></a>00192 <span class="keywordflow">continue</span>;<a name="l00193"></a>00193 }<a name="l00194"></a>00194 } <span class="keywordflow">else</span> {<a name="l00195"></a>00195 namemapptr->state = <a class="code" href="a00102.html#55735650f879293d9b7b5fda6753d147">STATE_ASKING</a>;<a name="l00196"></a>00196 namemapptr->tmr = 1;<a name="l00197"></a>00197 namemapptr->retries = 0;<a name="l00198"></a>00198 }<a name="l00199"></a>00199 hdr = (<span class="keyword">struct </span>dns_hdr *)<a name="a136"></a><a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">uip_appdata</a>;<a name="l00200"></a>00200 memset(hdr, 0, <span class="keyword">sizeof</span>(<span class="keyword">struct</span> dns_hdr));<a name="l00201"></a>00201 hdr->id = <a name="a137"></a><a class="code" href="a00148.html#ga22b04cac8cf283ca12f028578bebc06">htons</a>(i);<a name="l00202"></a>00202 hdr->flags1 = <a name="a138"></a><a class="code" href="a00102.html#72d99b1623afa14bd58c667b748c2ddc">DNS_FLAG1_RD</a>;<a name="l00203"></a>00203 hdr->numquestions = <a name="a139"></a><a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>(1);<a name="l00204"></a>00204 query = (<span class="keywordtype">char</span> *)<a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">uip_appdata</a> + 12;<a name="l00205"></a>00205 nameptr = namemapptr->name;<a name="l00206"></a>00206 --nameptr;<a name="l00207"></a>00207 <span class="comment">/* Convert hostname into suitable query format. */</span><a name="l00208"></a>00208 <span class="keywordflow">do</span> {<a name="l00209"></a>00209 ++nameptr;<a name="l00210"></a>00210 nptr = query;<a name="l00211"></a>00211 ++query;<a name="l00212"></a>00212 <span class="keywordflow">for</span>(n = 0; *nameptr != <span class="charliteral">'.'</span> && *nameptr != 0; ++nameptr) {<a name="l00213"></a>00213 *query = *nameptr;<a name="l00214"></a>00214 ++query;<a name="l00215"></a>00215 ++n;<a name="l00216"></a>00216 }<a name="l00217"></a>00217 *nptr = n;<a name="l00218"></a>00218 } <span class="keywordflow">while</span>(*nameptr != 0);<a name="l00219"></a>00219 {<a name="l00220"></a>00220 <span class="keyword">static</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> endquery[] =<a name="l00221"></a>00221 {0,0,1,0,1};<a name="l00222"></a>00222 memcpy(query, endquery, 5);<a name="l00223"></a>00223 }<a name="l00224"></a>00224 <a name="a140"></a><a class="code" href="a00147.html#ge5ab69d40013e6cf86ef1763c95d920e">uip_udp_send</a>((<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span>)(query + 5 - (<span class="keywordtype">char</span> *)<a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">uip_appdata</a>));<a name="l00225"></a>00225 <span class="keywordflow">break</span>;<a name="l00226"></a>00226 }<a name="l00227"></a>00227 }<a name="l00228"></a>00228 }<a name="l00229"></a>00229 <span class="comment">/*---------------------------------------------------------------------------*/</span><span class="comment"></span><a name="l00230"></a>00230 <span class="comment">/** \internal</span><a name="l00231"></a>00231 <span class="comment"> * Called when new UDP data arrives.</span><a name="l00232"></a>00232 <span class="comment"> */</span><a name="l00233"></a>00233 <span class="comment">/*---------------------------------------------------------------------------*/</span><a name="l00234"></a>00234 <span class="keyword">static</span> <span class="keywordtype">void</span><a name="l00235"></a>00235 newdata(<span class="keywordtype">void</span>)<a name="l00236"></a>00236 {<a name="l00237"></a>00237 <span class="keywordtype">char</span> *nameptr;<a name="l00238"></a>00238 <span class="keyword">struct </span>dns_answer *ans;<a name="l00239"></a>00239 <span class="keyword">struct </span>dns_hdr *hdr;<a name="l00240"></a>00240 <span class="keyword">static</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> nquestions, nanswers;<a name="l00241"></a>00241 <span class="keyword">static</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> i;<a name="l00242"></a>00242 <span class="keyword">register</span> <span class="keyword">struct </span>namemap *namemapptr;<a name="l00243"></a>00243 <a name="l00244"></a>00244 hdr = (<span class="keyword">struct </span>dns_hdr *)<a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">uip_appdata</a>;<a name="l00245"></a>00245 <span class="comment">/* printf("ID %d\n", htons(hdr->id));</span><a name="l00246"></a>00246 <span class="comment"> printf("Query %d\n", hdr->flags1 & DNS_FLAG1_RESPONSE);</span><a name="l00247"></a>00247 <span class="comment"> printf("Error %d\n", hdr->flags2 & DNS_FLAG2_ERR_MASK);</span><a name="l00248"></a>00248 <span class="comment"> printf("Num questions %d, answers %d, authrr %d, extrarr %d\n",</span><a name="l00249"></a>00249 <span class="comment"> htons(hdr->numquestions),</span><a name="l00250"></a>00250 <span class="comment"> htons(hdr->numanswers),</span><a name="l00251"></a>00251 <span class="comment"> htons(hdr->numauthrr),</span><a name="l00252"></a>00252 <span class="comment"> htons(hdr->numextrarr));</span><a name="l00253"></a>00253 <span class="comment"> */</span><a name="l00254"></a>00254 <a name="l00255"></a>00255 <span class="comment">/* The ID in the DNS header should be our entry into the name</span><a name="l00256"></a>00256 <span class="comment"> table. */</span><a name="l00257"></a>00257 i = <a class="code" href="a00148.html#ga22b04cac8cf283ca12f028578bebc06">htons</a>(hdr->id);<a name="l00258"></a>00258 namemapptr = &names[i];<a name="l00259"></a>00259 <span class="keywordflow">if</span>(i < <a class="code" href="a00160.html#g221d37ccde7e3fd0dd2c2eb0a6b15493">RESOLV_ENTRIES</a> &&<a name="l00260"></a>00260 namemapptr->state == <a class="code" href="a00102.html#55735650f879293d9b7b5fda6753d147">STATE_ASKING</a>) {<a name="l00261"></a>00261 <a name="l00262"></a>00262 <span class="comment">/* This entry is now finished. */</span><a name="l00263"></a>00263 namemapptr->state = <a name="a141"></a><a class="code" href="a00102.html#876c82c946543cd70c141e41417138e0">STATE_DONE</a>;<a name="l00264"></a>00264 namemapptr->err = hdr->flags2 & <a name="a142"></a><a class="code" href="a00102.html#9f6c329c04baba17fe0f5b2a6597d713">DNS_FLAG2_ERR_MASK</a>;<a name="l00265"></a>00265 <a name="l00266"></a>00266 <span class="comment">/* Check for error. If so, call callback to inform. */</span><a name="l00267"></a>00267 <span class="keywordflow">if</span>(namemapptr->err != 0) {<a name="l00268"></a>00268 namemapptr->state = <a class="code" href="a00102.html#7bf0c086c7c41c12cc63324327932d91">STATE_ERROR</a>;<a name="l00269"></a>00269 <a class="code" href="a00160.html#g6d9751d534453425c7a5a215d1d4414c">resolv_found</a>(namemapptr->name, <a class="code" href="a00160.html#g070d2ce7b6bb7e5c05602aa8c308d0c4">NULL</a>);<a name="l00270"></a>00270 <span class="keywordflow">return</span>;<a name="l00271"></a>00271 }<a name="l00272"></a>00272 <a name="l00273"></a>00273 <span class="comment">/* We only care about the question(s) and the answers. The authrr</span><a name="l00274"></a>00274 <span class="comment"> and the extrarr are simply discarded. */</span><a name="l00275"></a>00275 nquestions = <a class="code" href="a00148.html#ga22b04cac8cf283ca12f028578bebc06">htons</a>(hdr->numquestions);<a name="l00276"></a>00276 nanswers = <a class="code" href="a00148.html#ga22b04cac8cf283ca12f028578bebc06">htons</a>(hdr->numanswers);<a name="l00277"></a>00277 <a name="l00278"></a>00278 <span class="comment">/* Skip the name in the question. XXX: This should really be</span><a name="l00279"></a>00279 <span class="comment"> checked agains the name in the question, to be sure that they</span><a name="l00280"></a>00280 <span class="comment"> match. */</span><a name="l00281"></a>00281 nameptr = parse_name((<span class="keywordtype">char</span> *)<a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">uip_appdata</a> + 12) + 4;<a name="l00282"></a>00282 <a name="l00283"></a>00283 <span class="keywordflow">while</span>(nanswers > 0) {<a name="l00284"></a>00284 <span class="comment">/* The first byte in the answer resource record determines if it</span><a name="l00285"></a>00285 <span class="comment"> is a compressed record or a normal one. */</span><a name="l00286"></a>00286 <span class="keywordflow">if</span>(*nameptr & 0xc0) {<a name="l00287"></a>00287 <span class="comment">/* Compressed name. */</span><a name="l00288"></a>00288 nameptr +=2;<a name="l00289"></a>00289 <span class="comment">/* printf("Compressed anwser\n");*/</span><a name="l00290"></a>00290 } <span class="keywordflow">else</span> {<a name="l00291"></a>00291 <span class="comment">/* Not compressed name. */</span><a name="l00292"></a>00292 nameptr = parse_name((<span class="keywordtype">char</span> *)nameptr);<a name="l00293"></a>00293 }<a name="l00294"></a>00294 <a name="l00295"></a>00295 ans = (<span class="keyword">struct </span>dns_answer *)nameptr;<a name="l00296"></a>00296 <span class="comment">/* printf("Answer: type %x, class %x, ttl %x, length %x\n",</span><a name="l00297"></a>00297 <span class="comment"> htons(ans->type), htons(ans->class), (htons(ans->ttl[0])</span><a name="l00298"></a>00298 <span class="comment"> << 16) | htons(ans->ttl[1]), htons(ans->len));*/</span><a name="l00299"></a>00299 <a name="l00300"></a>00300 <span class="comment">/* Check for IP address type and Internet class. Others are</span><a name="l00301"></a>00301 <span class="comment"> discarded. */</span><a name="l00302"></a>00302 <span class="keywordflow">if</span>(ans->type == <a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>(1) &&<a name="l00303"></a>00303 ans->class == <a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>(1) &&<a name="l00304"></a>00304 ans->len == <a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>(4)) {<a name="l00305"></a>00305 <span class="comment">/* printf("IP address %d.%d.%d.%d\n",</span><a name="l00306"></a>00306 <span class="comment"> htons(ans->ipaddr[0]) >> 8,</span><a name="l00307"></a>00307 <span class="comment"> htons(ans->ipaddr[0]) & 0xff,</span><a name="l00308"></a>00308 <span class="comment"> htons(ans->ipaddr[1]) >> 8,</span><a name="l00309"></a>00309 <span class="comment"> htons(ans->ipaddr[1]) & 0xff);*/</span>⌨️ 快捷键说明
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