北郵計(jì)算機(jī)網(wǎng)絡(luò)課程設(shè)計(jì)DNS服務(wù)器

1、北郵計(jì)算機(jī)網(wǎng)絡(luò)課程設(shè)計(jì) DNS 服務(wù)器1 環(huán)境操作系統(tǒng)隨意,語(yǔ)言 python2.72. 文件Socket.py 說(shuō)明 完成緩存檢測(cè),確定是回應(yīng),還是轉(zhuǎn)發(fā),如果是回應(yīng),確定是本地回 應(yīng)還是外部應(yīng)答轉(zhuǎn)發(fā)import socketimport mydicimport charhandleimport makeframes = socket.socket(socket.AF_INET, socket.SOCK_DGRAMport = 53the_dic = mydic.get_web_ip(client_request = client_request_index = reverse_map = k

2、ey_record = 0client_wait = s.bind('',porttime_rest = 0request_general = ''print 'running'while True:try:msg , (client,port = s.recvfrom(1024except:print 'Time out! 'continuerequest = request = list(msgrequre_web = charhandle.get_request(request12:website = ''.

3、join(requre_webif(port = 53:answer = answer = list(msgprint "Type:Remote Response"print "remote answer is: "response_ip = msg-4+msg-3+msg-2+msg-1char_ip = socket.inet_ntoa(response_ipprint website + ' has the ip : '+char_ipfre = mydic.storeForUpdate(website,char_ip print

4、'with the frequence of '+ str(fre#real_request = client_requestrequest0+request1for each_client in client_wait:my_key = client_requestrequest0+request1+str(each_client if client_request_index.get(my_key != None :s.sendto(msg,client_request_indexmy_keyprint "Response to ip and Client por

5、t:"print client_request_indexmy_keybreakelse:print "Type: Client Request"print "ip and port:"print (client,port# requre_web = charhandle.get_request(request12:# website = ''.join(requre_webprint "Request website:"+websiteif(the_dic.get(website != None:print

6、 "Found in local cache:"re_ip = the_dic.get(websiteprint re_ipfre = mydic.storeForUpdate(websiteprint re_ip0+' with frequence '+str(frezhen = makeframe.make(re_ip0,msgs.sendto(zhen,(client,portelse:print "need to ask remote server"key_record = key_record + 1request_genera

7、l = key_recordclient_requestrequest0+request1+str(client = request_generalclient_request_indexrequest_general = (client,portif client not in client_wait:client_wait.append(client# select authority DNS server as you wishtime_rest = time_rest+1try:if(time_rest = 50:print 'pay attention'print &

8、#39;#'mydic.updateCache(print '#'the_dic = mydic.get_web_ip(time_rest = 0except:print 'not valid frequence'print '-'s.close(Mydic.py 完成本地查詢(xún), LRU 算法維護(hù)本地緩存, socket.py 第 97行的 time_request值可以 確定更新緩存的頻率,可以直接輸出在 dnsrelay.txt 內(nèi),但是為了方便觀測(cè)變化,我輸出到 了 dnsrelaycopy.txt 里面,運(yùn)行一段時(shí)間之后,可以去看

9、看學(xué)習(xí)到的新條目import pickleimport osimport threadingA=d_web_ip = d_ip_web = update_dic = data = open('dnsrelay.txt'for each_line in data:try:(ip,sitecopy = each_line.split(' ',1(site,nothing = str(sitecopy.split('n',1d_web_ipsite = ip,1d_ip_webip = siteexcept:print 'file error&

10、#39;data.close(try:with open('newdnsrelay.pickle','wb' as newdnsrelay_file:pickle.dump(d_web_ip,newdnsrelay_fileexcept IOError as err:print 'File error:'+str(errexcept pickle.PickleError as perr:print 'Pickling error:'+str(perrdef get_web_ip(:with open('newdnsrela

11、y.pickle','rb' as f:global update_dicupdate_dic = pickle.load(freturn update_dic.copy(return(Nonedef storeForUpdate(web_site, add = None:global update_dicif(update_dic.get(web_site != None:add_frequen = update_dicweb_siteadd_frequen1 = add_frequen1 + 1print web_site+' frequence incra

12、se 1,with ip '+add_frequen0 return add_frequen1else:update_dicweb_site = add,1print 'record for a new site'return 1def updateCache(:global update_dicm = update_dic.copy(t = threading.Thread(target = my_thread,kwargs = m print 'ready to update local cache't.start(t.join(def my_thr

13、ead(*argu,*arg:frequence = remain_dic = for each_key in arg:tmp = argeach_keyif(tmp1 not in frequence:frequence.append(tmp1print 'various frequence:'for each in frequence:print 'have '+ str(eachfor each_key in remain_dic:arg.pop(each_key#enimilate bani = 0while(i < 30:max_frequenc

14、e = max(frequencefor each_key in arg:tmp = argeach_keyif(tmp1 = max_frequence:remain_diceach_key = tmp0i = i + 1if(i = 30:break;frequence.remove(max_frequenceif(not frequence:#no morebreak;updateFile(remain_dicdef updateFile(new_dic:f = open('dnsrelaycopy.txt','w'for each_key in new_

15、dic:word = str(new_diceach_key + ' ' + str(each_key f.write(wordf.write('n' new_diceach_key = new_diceach_key,0 try: with open('newdnsrelay.pickle','wb' as newdnsrelay_file: pickle.dump(new_dic,newdnsrelay_file except IOError as err: print 'File error:'+str(er

16、r except pickle.PickleError as perr: print 'Pickling error:'+str(perr Makefram.py 成幀模塊，形成對(duì)外圍權(quán)威服務(wù)器的詢(xún)問(wèn)幀 import socket def make(re_ip,msg: tmp_list = for ch in msg: tmp_list.append(ch tmp_list4:12 = 'x00','x01','x00','x01','x00','x00','x00'

17、;,'x00' tmp_list = tmp_list+'xc0','x0c','x00','x01','x00 ','x01','x00','x00','x02','x58','x00','x04' dive_ip = socket.inet_aton(re_ip ch_ip = for each_ch in dive_ip: ch_ip.append(each_ch tmp_list

18、= tmp_list + ch_ip re_msg = ''.join(tmp_list return re_msg Charhandle.py 提取出報(bào)文中的 url def get_request(your_list: my_list = new_list = my_list.extend(your_list re_list = thelen = ord(my_list0 try: while thelen != 0: new_list = new_list + my_list1:thelen+1 my_list0:thelen+1 = thelen = ord(my_list0 new_list.append('.' except IndexError: print &qu