udp传输

#include <stdio.h> #include <stdlib.h> #include <sys/types.h> #include <sys/socket.h> #include <sys/signal.h> #include <sys/time.h> #include <sys/resource.h> #include <netinet/in.h> #include<errno.h> #include <arpa/inet.h> #include <netdb.h> #include <string.h> #include<unistd.h> #include<sys/stat.h> #include<sys/wait.h> unsigned short portbase=0; #define QLEN 32 #define LINELEN 4096 int passivesock(const char *service,const char* transport,int qlen) { struct servent *pse; struct protoent *ppe; struct sockaddr_in sin; int s,type; memset(&sin,0,sizeof(sin)); sin.sin_family=AF_INET; sin.sin_addr.s_addr=INADDR_ANY; if(pse=getservbyname(service,transport)) sin.sin_port=htons(ntohs((unsigned short)pse->s_port)+portbase); else if((sin.sin_port=htons((unsigned short)atoi(service)))==0) {perror("cannot get service entry\n");exit(1);} //errexit("cannot get \"%s\"service entry\n",service); if((ppe=getprotobyname(transport))==0) {perror("cannot get protocol entry\n");exit(1);} //errexit("cannot get \"%s\"protocol entry\n",transport); if(!strcmp(transport,"udp")) type=SOCK_DGRAM; else type=SOCK_STREAM; if((s=socket(PF_INET,type,ppe->p_proto))<0) {perror("cannot create socket\n");exit(1);} // errexit("cannot create socket:%s\n",strerro(errno)); if(bind(s,(struct sockaddr *)&sin,sizeof(sin))<0) {perror("cannot bind to port\n");exit(1);} //errexit("cannot bind to %s port:%s\n",service,strerro(errno)); if(type==SOCK_STREAM&&listen(s,qlen)<0) {perror("cannot listen on port\n");exit(1);} // errexit("cannot listen on %s port:%S\n",service,strerror(errno)); return s; } int TCPechod(int fd) { char buf[LINELEN]; int c; while(c=read(fd,buf,sizeof(buf))){ if(c<0) {perror("erro read\n");exit(1);} if(write(fd,buf,c)<0) {perror("erro write\n");exit(1);} } return 0; } reaper(int sig) { int status; while(wait3(&status,WNOHANG,(struct rusage*)0)>=0); } int main(int argc, char *argv[]) { char *service="echo"; char *transport="tcp"; struct sockaddr_in fsin; unsigned int alen; int msock,ssock; int sec; time_t start,finish; char *t; switch(argc) { case 1: break; case 3: transport=argv[2]; case 2: service=argv[1]; break; default: {perror("usage:filetransmit[port[tcp/udp]]\n");exit(1);} } msock=passivesock(service,transport,QLEN); signal(SIGCHILD,reaper); if(!strcmp(transport,"tcp")) //tcp transmit while(1) { alen=sizeof(fsin); if((ssock=accept(msock,(struct sockaddr*)&fsin,&alen))<0) { perror("Accpet error!"); continue; } time(&start); t=(char*)ctime(&start); printf("start a connection from %s time:%s\n",inet_ntoa(fsin.sin_addr),t); switch(fork()) { case 0: close(msock); TCPechod(ssock); time(&finish); t=(char*)ctime(&finish); sec=finish-start; printf("finish the connection from %s time:%s,run time: %d seconds\n",inet_ntoa(fsin.sin_addr),t,sec); exit(0); default: close(ssock); break; case -1: perror("error fork\n"); exit(1); } } else //udp transmit { } return 0; }