dhcpc_8c-source.html

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

00218 
00219                 <span class="keywordflow">case</span> DHCP_STATE_REBOOTING:
00220                         <span class="keywordflow">if</span>(sec)
00221                                 <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>--;
00222                         
00223                         <span class="keywordflow">if</span>(!<a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>){
00224                                 <span class="keywordflow">if</span>(<a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>&gt;=32){
00225                                         <span class="comment">/* we need to restart, we don't want to wait more</span>
00226 <span class="comment">                                         * than 30 secs for retransmissions</span>
00227 <span class="comment">                                         */</span>
00228                                          <a class="code" href="dhcpc_8c.html#a0">dhcpc_state</a>=DHCP_STATE_INIT_REBOOT;
00229                                 }<span class="keywordflow">else</span>{
00230                                         <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>=<a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>;
00231                                         <a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>&lt;&lt;=1;   <span class="comment">/* exponential backoff retransmission */</span>
00232                                         <a class="code" href="dhcpc_8c.html#a9">dhcpc_send_message</a>(DHCP_REQUEST);
00233                                 }                       
00234                         }               
00235                         <span class="keywordflow">break</span>;
00236                 <span class="keywordflow">case</span> DHCP_STATE_INIT:
00237                         <span class="comment">/* switch to selecting, send DHCPDISCOVER and initialize</span>
00238 <span class="comment">                         * timeout timer</span>
00239 <span class="comment">                         */</span>
00240                         DEBUGOUT(<span class="stringliteral">"DHCP State=INIT; Sending DHCPDISCOVER message; State INIT--&gt;SELECTING\r\n"</span>);
00241                         <a class="code" href="dhcpc_8c.html#a0">dhcpc_state</a>=DHCP_STATE_SELECTING;
00242                         <a class="code" href="dhcpc_8c.html#a9">dhcpc_send_message</a>(DHCP_DISCOVER);
00243                         <span class="comment">/* T1 will be timeout timer. T2 will hold next timeout value */</span>
00244                         <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>=4;     <span class="comment">/* next retransmission after 4 secs */</span>
00245                         <a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>=8;     <span class="comment">/* after 4 secs expire, this will be next timeout */</span>
00246                         <span class="keywordflow">break</span>;
00247                 <span class="keywordflow">case</span> DHCP_STATE_SELECTING:
00248                         <span class="comment">/* one second expired ? */</span>
00249                         <span class="keywordflow">if</span>(sec)
00250                                 <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>--;
00251                         
00252                         <span class="comment">/* timeout expired without receiving DHCPOFFER ? */</span>
00253                         <span class="keywordflow">if</span>(!<a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>){
00254                                 DEBUGOUT(<span class="stringliteral">"DHCP State=SELECTING; "</span>);
00255                                 <span class="comment">/* yes, retransmit or restart the process */</span>
00256                                 <span class="keywordflow">if</span>(<a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>&gt;=32){
00257                                         <span class="comment">/* we need to restart, we don't want to wait more</span>
00258 <span class="comment">                                         * than 30 secs for retransmissions</span>
00259 <span class="comment">                                         */</span>
00260                                          <a class="code" href="dhcpc_8c.html#a0">dhcpc_state</a>=DHCP_STATE_INIT;
00261                                          DEBUGOUT(<span class="stringliteral">"Timeout for retransmissions too big; State SELECTING--&gt;INIT\r\n"</span>);
00262                                 }<span class="keywordflow">else</span>{
00263                                         DEBUGOUT(<span class="stringliteral">"Retransmitting DHCPDISCOVER\r\n"</span>);
00264                                         <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>=<a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>;
00265                                         <a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>&lt;&lt;=1;   <span class="comment">/* exponential backoff retransmission */</span>
00266                                         <a class="code" href="dhcpc_8c.html#a9">dhcpc_send_message</a>(DHCP_DISCOVER);
00267                                 }
00268                         }
00269                         <span class="keywordflow">break</span>;
00270                 <span class="keywordflow">case</span> DHCP_STATE_REQUESTING:
00271                         <span class="comment">/* DHCPREQUEST sent, waiting for proper response. Retransmit</span>
00272 <span class="comment">                         * if necessary</span>
00273 <span class="comment">                         */</span>
00274                         <span class="keywordflow">if</span>(sec)
00275                                 <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>--;
00276                          
00277                         <span class="keywordflow">if</span>(!<a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>){
00278                                 <span class="comment">/* timeout occured without receiving DHCPACK */</span>
00279                                 DEBUGOUT(<span class="stringliteral">"DHCP State=REQUESTING; "</span>);
00280                                 <span class="keywordflow">if</span>(<a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>&gt;=32){
00281                                         <span class="comment">/* we need to restart, we don't want to wait more</span>
00282 <span class="comment">                                         * than 30 secs for retransmissions. Restart whole</span>
00283 <span class="comment">                                         * process</span>
00284 <span class="comment">                                         */</span>
00285                                          <a class="code" href="dhcpc_8c.html#a0">dhcpc_state</a>=DHCP_STATE_INIT;
00286                                          DEBUGOUT(<span class="stringliteral">"Timeout for retransmits too big; State REQUESTING--&gt;INIT\r\n"</span>);
00287                                 }<span class="keywordflow">else</span>{
00288                                         DEBUGOUT(<span class="stringliteral">"Retransmitting DHCPREQUEST\r\n"</span>);
00289                                         <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>=<a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>;
00290                                         <a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>&lt;&lt;=1;   <span class="comment">/* exponential backoff retransmission */</span>
00291                                         <a class="code" href="dhcpc_8c.html#a9">dhcpc_send_message</a>(DHCP_REQUEST);
00292                                 }                               
00293                         } 
00294                         <span class="keywordflow">break</span>;
00295                 <span class="keywordflow">case</span> DHCP_STATE_BOUND:
00296                         <span class="comment">/* wait for T1 to expire */</span>
00297                         <span class="keywordflow">if</span>(sec){
00298                                 <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>--;
00299                                 <a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>--;
00300                         }
00301                         <span class="keywordflow">if</span>(!<a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>){
00302                                 DEBUGOUT(<span class="stringliteral">"DHCP State=BOUND; Starting renewing process; State BOUND--&gt;RENEWING\r\n"</span>);
00303                                 <span class="comment">/* T1 expired, start renewing process */</span>
00304                                 <a class="code" href="dhcpc_8c.html#a0">dhcpc_state</a>=DHCP_STATE_RENEWING;
00305                                 
00306                                 <a class="code" href="dhcpc_8c.html#a9">dhcpc_send_message</a>(DHCP_REQUEST);
00307                                 
00308                                 <span class="comment">/* T1 will be used for retransmissions untill we</span>
00309 <span class="comment">                                 * return to BOUND state or reset to INIT state</span>
00310 <span class="comment">                                 */</span>
00311                                 <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>=10;    <span class="comment">/* fixed 10sec retransmissions */</span>
00312                         }
00313                         <span class="keywordflow">break</span>;
00314                 <span class="keywordflow">case</span> DHCP_STATE_RENEWING:
00315                         <span class="keywordflow">if</span>(sec){
00316                                 <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>--;
00317                                 <a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>--;
00318                         }
00319                         
00320                         <span class="keywordflow">if</span>(!<a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>){
00321                                 DEBUGOUT(<span class="stringliteral">"DHCP State=RENEWING; T2 expired; State RENEWING--&gt;REBINDING\r\n"</span>);
00322                                 <span class="comment">/* oh no, T2 also expired. switch to rebinding state. This</span>
00323 <span class="comment">                                 * is our last attempt to retain this IP address.</span>
00324 <span class="comment">                                 */</span>
00325                                 <a class="code" href="dhcpc_8c.html#a0">dhcpc_state</a>=DHCP_STATE_REBINDING;
00326                                 
00327                                 <a class="code" href="dhcpc_8c.html#a9">dhcpc_send_message</a>(DHCP_REQUEST);
00328                                 
00329                                 <span class="comment">/* dhcpc_t1 will be used for timeouts */</span>
00330                                 <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>=5;     <span class="comment">/* 5 second retransmits */</span>
00331                                 
00332                                 <span class="comment">/* dhcpc_t2 will be used for fixed numer of retries. This</span>
00333 <span class="comment">                                 * is a bit different than per RFC, but we don't want </span>
00334 <span class="comment">                                 * another 32-bit timer value for keeping lease time.</span>
00335 <span class="comment">                                 */</span>
00336                                 <a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>=10;
00337                         }<span class="keywordflow">else</span>
00338                                 <span class="keywordflow">if</span>(!<a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>){
00339                                         DEBUGOUT(<span class="stringliteral">"DHCP State=RENEWING; Retransmitting DHCPREQUEST\r\n"</span>);        
00340                                         <span class="comment">/* retransmit DHCP REQUEST messages */</span>
00341                                         <a class="code" href="dhcpc_8c.html#a9">dhcpc_send_message</a>(DHCP_REQUEST);
00342                                         <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>=10;
00343                                 }
00344                         <span class="keywordflow">break</span>;
00345                 <span class="keywordflow">case</span> DHCP_STATE_REBINDING:
00346                         <span class="keywordflow">if</span>(sec)
00347                                 <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>--;
00348                         
00349                         <span class="keywordflow">if</span>(!<a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>){
00350                         
00351                                 <a class="code" href="dhcpc_8c.html#a4">dhcpc_t1</a>=5;     <span class="comment">/* 5 second retransmits */</span>
00352                                 
00353                                 <a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>--;     <span class="comment">/* retransmit count */</span>
00354                                 
00355                                 <span class="keywordflow">if</span>(!<a class="code" href="dhcpc_8c.html#a5">dhcpc_t2</a>){
00356                                         DEBUGOUT(<span class="stringliteral">"DHCP State=REBINDING; Lease time expired; State REBINDING--&gt;INIT\r\n"</span>);
00357                                         <span class="comment">/* used up retransmission. Assume that lease time</span>