学步园

以下代码为基于sctp协议的一对一模式(TCP)的服务器端代码。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/sctp.h>
#include <unistd.h>
#include <arpa/inet.h>
 


 const int buf_size = 1024;
 const int echo_port = 19000;
 
 char* usage_msg="usage: sctp_echo [ip_addr]+ istreams ostreams";
 void usage()
 {
     fprintf(stderr,"%s\n",usage_msg);
     exit(1);
 }
 
 int main(int argc, char** argv)
 {
 
     char buf[buf_size];
 
     int sockfd, client_sockfd,flags;
     int nread,len;
     struct sockaddr_in serv_addr, client_addr;
     struct sctp_initmsg initmsg;
     struct sctp_status status;
     
     struct sctp_sndrcvinfo sinfo;
     
 
    
     
     int addr_count = 1;
     
 
     if(argc < 4) usage();
 
     sockfd = socket(AF_INET,SOCK_STREAM,IPPROTO_SCTP);
     if(sockfd < 0)
     {
         fprintf(stderr,"socket descriptor is invalid.");
         exit(1);
     }
     
     serv_addr.sin_family = AF_INET;
     serv_addr.sin_addr.s_addr = inet_addr(argv[1]);
     serv_addr.sin_port = htons(echo_port);
 
     int brst = sctp_bindx(sockfd,(struct sockaddr*)&serv_addr,
                 addr_count,SCTP_BINDX_ADD_ADDR);
     if(brst == -1)
     {
         fprintf(stderr,"error while binding address.");
         exit(1);
     }
 
     memset(&initmsg,0,sizeof(initmsg));
     initmsg.sinit_max_instreams = atoi(argv[2]);
     initmsg.sinit_num_ostreams = atoi(argv[3]);
     fprintf(stdout,"asking for input streams:%d, output streams %d\n",
             initmsg.sinit_max_instreams, initmsg.sinit_num_ostreams);
     
     brst = setsockopt(sockfd,IPPROTO_SCTP,SCTP_INITMSG,
             &initmsg,sizeof(initmsg));
     if(brst != 0)
     {
         fprintf(stderr,"error while setting sctp options.\n");
         exit(1);
     }
 
     listen(sockfd,5);
 
     for(;;)
     {
         len = sizeof(client_addr);
         client_sockfd = accept(sockfd, (struct sockaddr*)&client_addr, (socklen_t*)&len);
         if(client_sockfd == -1)
         {
             fprintf(stderr,"error while accepting connection, continue.\n");
             continue;
         }
 
         memset(&status,0,sizeof(status));
         len = sizeof(status);
         status.sstat_assoc_id = 0;
 
         brst = getsockopt(client_sockfd,IPPROTO_SCTP,SCTP_STATUS,&status,(socklen_t*)&len);
         if(brst == -1)
         {
             fprintf(stderr,"error while getting socket option.\n");
         }
 
         fprintf(stdout,"input stream:%d, output stream:%d\n",
                 status.sstat_instrms, status.sstat_outstrms);
         for(;;)
         {
             len = sizeof(&sinfo);
             memset(buf,0,buf_size);
             nread = sctp_recvmsg(client_sockfd,buf,buf_size,
                     (struct sockaddr*)&client_addr, (socklen_t*)&len, (sctp_sndrcvinfo*)&sinfo, &flags);
             if(nread <= 0) break;
             fprintf(stdout,"%s\n",buf);
             fprintf(stdout,"read %d bytes on channel %d\n", 
                     nread, sinfo.sinfo_stream); 
         }
         close(client_sockfd);
     }
 
     return 0;
 }