sendv_client.c

// cc -o sendv_client sendv_client.c
// Run after starting recvv_server in another console

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <arpa/inet.h>
#include <netinet/sctp.h>
#include <unistd.h>

#define IOV_MAX (sysconf(_SC_IOV_MAX))

int main(){
  int fileno, num_ip;
  ssize_t num_bytes;
  struct iovec iov[IOV_MAX];
  struct sctp_sendv_spa spa;
  struct sockaddr_in addrs[2];
  sctp_assoc_t assoc;

  bzero(&iov, sizeof(iov));
  bzero(&spa, sizeof(spa));

  fileno = socket(AF_INET, SOCK_SEQPACKET, IPPROTO_SCTP);

  if(fileno < 0){
    printf("socket() failed: %s\n", strerror(errno));
    return -1;
  }

  addrs[0].sin_family = AF_INET;
  addrs[0].sin_port = htons(62324);
  addrs[0].sin_addr.s_addr = inet_addr("1.1.1.1");
  addrs[0].sin_len = sizeof(struct sockaddr_in);

  addrs[1].sin_family = AF_INET;
  addrs[1].sin_port = htons(62324);
  addrs[1].sin_addr.s_addr = inet_addr("1.1.1.2");
  addrs[1].sin_len = sizeof(struct sockaddr_in);

  if(sctp_connectx(fileno, (struct sockaddr *)&addrs, 2, &assoc) < 0){
    printf("sctp_connectx failed: %s\n", strerror(errno));
    close(fileno);
    return -1;
  }

  spa.sendv_sndinfo.snd_flags = SCTP_UNORDERED;
  //spa.sendv_sndinfo.snd_assoc_id = 1;

  iov[0].iov_base = "hello";
  iov[0].iov_len = 5;
  iov[1].iov_base = "world";
  iov[1].iov_len = 5;

  num_bytes = sctp_sendv(
    fileno,
    iov,
    2,
    (struct sockaddr*)&addrs,
    2,
    &spa,
    sizeof(spa),
    SCTP_SENDV_SPA,
    0
  );

  if(num_bytes < 0){
    printf("sctp_sendv failed: %s\n", strerror(errno));
    close(fileno);
    return -1;
  }
  else{
    printf("Sent %li bytes.\n", num_bytes);
  }

  close(fileno);

  return 0;
}