SCTP server client Code in C

Client.c

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

#define RECVBUFSIZE     4096
#define PPID            1234

int main()
{
       int SctpScocket, in, flags;
       socklen_t opt_len;
       char * szAddress;
       int iPort;
       char * szMsg;
       int iMsgSize;
       char a[1024];

    
       struct sockaddr_in servaddr = {0};
       struct sctp_status status = {0};
       struct sctp_sndrcvinfo sndrcvinfo = {0};
       struct sctp_event_subscribe events = {0};
       struct sctp_initmsg initmsg = {0};
       char * szRecvBuffer[RECVBUFSIZE + 1] = {0};
       socklen_t from_len = (socklen_t) sizeof(struct sockaddr_in);


       //get the arguments
       szAddress = "127.0.0.1";
       iPort = 5001;
      
       printf("Starting SCTP client connection to %s:%u\n", szAddress, iPort);

     
       SctpScocket = socket(AF_INET, SOCK_STREAM, IPPROTO_SCTP);
       printf("socket created...\n");

       //set the association options
       initmsg.sinit_num_ostreams = 1;
       setsockopt( SctpScocket, IPPROTO_SCTP, SCTP_INITMSG, &initmsg,sizeof(initmsg));
       printf("setsockopt succeeded...\n");

       bzero( (void *)&servaddr, sizeof(servaddr) );
       servaddr.sin_family = AF_INET;
       servaddr.sin_port = htons(iPort);
       servaddr.sin_addr.s_addr = inet_addr( szAddress );

      
       connect( SctpScocket, (struct sockaddr *)&servaddr, sizeof(servaddr));
       printf("connect succeeded...\n");

       //check status
       opt_len = (socklen_t) sizeof(struct sctp_status);
       getsockopt(SctpScocket, IPPROTO_SCTP, SCTP_STATUS, &status, &opt_len);
      
       while(1)
       {
       printf("Sending Role  to server: ");
       gets(a);
       sctp_sendmsg(SctpScocket, (const void *)a, iMsgSize, NULL, 0,htonl(PPID), 0, 0 , 0, 0);

       //read response from test server
       in = sctp_recvmsg(SctpScocket, (void*)szRecvBuffer, RECVBUFSIZE,(struct sockaddr *)&servaddr, &from_len, &sndrcvinfo, &flags);
       if (in > 0 && in < RECVBUFSIZE - 1)
       {
               szRecvBuffer[in] = 0;
               printf("Received from server: %s\n",szRecvBuffer);
        }
      } 
       printf("exiting...\n");

       close(SctpScocket);
       return 0;
}

Server.c

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

#define RECVBUFSIZE             4096
#define PPID                    1234

int main() {
       int SctpScocket, n, flags;
       socklen_t from_len;

       struct sockaddr_in addr = {0};
       struct sctp_sndrcvinfo sinfo = {0};
       struct sctp_event_subscribe event = {0};
       char pRecvBuffer[RECVBUFSIZE + 1] = {0};

       char * szAddress;
       int iPort;
       char * szMsg;
       int iMsgSize;

       //get the arguments
       szAddress = "127.0.0.1";
       iPort = 5001;
       szMsg = "Hello Client";
       iMsgSize = strlen(szMsg);
       if (iMsgSize > 1024)
       {
               printf("Message is too big for this test\n");
               return 0;
       }

       //here we may fail if sctp is not supported
       SctpScocket = socket(AF_INET, SOCK_SEQPACKET, IPPROTO_SCTP);
       printf("socket created...\n");

       //make sure we receive MSG_NOTIFICATION
       setsockopt(SctpScocket, IPPROTO_SCTP, SCTP_EVENTS, &event,sizeof(struct sctp_event_subscribe));
       printf("setsockopt succeeded...\n");

       addr.sin_family = AF_INET;
       addr.sin_port = htons(iPort);
       addr.sin_addr.s_addr = inet_addr(szAddress);

       //bind to specific server address and port
       bind(SctpScocket, (struct sockaddr *)&addr, sizeof(struct sockaddr_in));
       printf("bind succeeded...\n");

       //wait for connections
       listen(SctpScocket, 1);
       printf("listen succeeded...\n");

        int count = 0,i;
        char a[20][10],d[20][10];
        char send_data[1024];

        strcpy(a[0],"Abraham");
        strcpy(a[1],"Buck");
        strcpy(a[2],"Casper");
        strcpy(a[3],"Dammy");
        strcpy(d[0],"1");
        strcpy(d[1],"2");
        strcpy(d[2],"3");
        strcpy(d[3],"4");



       while(1)
       {
               //each time erase the stuff
               flags = 0;
               memset((void *)&addr, 0, sizeof(struct sockaddr_in));
               from_len = (socklen_t)sizeof(struct sockaddr_in);
               memset((void *)&sinfo, 0, sizeof(struct sctp_sndrcvinfo));

               n = sctp_recvmsg(SctpScocket, (void*)pRecvBuffer, RECVBUFSIZE,(struct sockaddr *)&addr, &from_len, &sinfo, &flags);
               if (-1 == n)
               {
                       printf("Error with sctp_recvmsg: -1... waiting\n");
                       printf("errno: %d\n", errno);
                       perror("Description: ");
                       sleep(1);
                       continue;
               }

               if (flags & MSG_NOTIFICATION)
               {
                       printf("Notification received!\n");
                       printf("From %s:%u\n", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port));
               }
               else
               {
                       printf("Received from %s:%u on stream %d, PPID %d.: %s\n",
                               inet_ntoa(addr.sin_addr),
                               ntohs(addr.sin_port),
                               sinfo.sinfo_stream,
                               ntohl(sinfo.sinfo_ppid),
                               pRecvBuffer
                       );

             int p = 0;
                     for(i=0;i<4;i++)
                     {
                        if(strcmp(pRecvBuffer,d[i]) == 0)
                        {
                             strcpy(send_data,a[i]);p=1;
                        }
                     }
                     if(p == 0)
                      strcpy(send_data,"No one on that role.");

               }

               //send message to client
               printf("Sending to client: %s\n", send_data);
               sctp_sendmsg(SctpScocket, (const void *)send_data, strlen(send_data), (struct sockaddr *)&addr, from_len, htonl(PPID), 0, 0 /*stream 0*/, 0, 0);

               //close server when exit is received
               if (0 == strcmp(pRecvBuffer, "exit"))
               {
                       break;
               }
       }//while

       printf("exiting...\n");

       close(SctpScocket);
       return (0);
}
 

To run this you have to have sctp library installed. then comand like >>$ gcc -g -lsctp filename