SCTP 一对多模式 （UDP模式）的服务器端代码

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

static void handle_event(void *buf)
{

struct sctp_assoc_change   *sac;
struct sctp_send_failed    *ssf;
struct sctp_paddr_change   *spc;
struct sctp_remote_error   *sre;
struct sctp_shutdown_event *sse;

union sctp_notification  *snp;

snp = (sctp_notification*)buf;
switch (snp->sn_header.sn_type)
{

case SCTP_ASSOC_CHANGE:
{
sac = &snp->sn_assoc_change;
printf("assoc_change: state=%hu, error=%hu, instr=%hu outstr=%hu associd=%d\n",
sac->sac_state,
sac->sac_error,
sac->sac_inbound_streams,
sac->sac_outbound_streams,
sac->sac_assoc_id);
break;
}
case SCTP_SEND_FAILED:
{
ssf = &snp->sn_send_failed;
printf("sendfailed: len=%hu err=%d assoc_i=%d ssf_data=%d\n", ssf->ssf_length, ssf->ssf_error, ssf->ssf_assoc_id, ssf->ssf_data[0]);
break;
}
case SCTP_PEER_ADDR_CHANGE:
{
spc = &snp->sn_paddr_change;
struct sockaddr_in  *sin = (struct sockaddr_in *)&spc->spc_aaddr;
char  addrbuf[INET6_ADDRSTRLEN];
inet_ntop(AF_INET, &sin->sin_addr, addrbuf, INET6_ADDRSTRLEN);
printf("peeraddrchange: %s state=%d, error=%d\n", addrbuf, spc->spc_state, spc->spc_error);
break;
}
case SCTP_REMOTE_ERROR:
{
sre = &snp->sn_remote_error;
printf("remote_error: err=%hu len=%hu\n", ntohs(sre->sre_error), ntohs(sre->sre_length));
break;
}

case SCTP_SHUTDOWN_EVENT:
{
sse = &snp->sn_shutdown_event;
printf("shutdown event: assoc_id=%d\n", sse->sse_assoc_id);
break;
}
default:
{
printf("unknown type: %hu\n", snp->sn_header.sn_type);
break;
}
}
}

int main(int agrc, char* agrv[])
{
/* Create a 1-to-many style SCTP socket. */
int fd = -1;
if ((fd = socket(AF_INET, SOCK_SEQPACKET, IPPROTO_SCTP)) < 0)
{
perror("socket");
exit(1);
}

/* Enable all notifications and events */
struct sctp_event_subscribe event;
event.sctp_data_io_event = 1;
event.sctp_association_event = 1;
event.sctp_address_event = 1;
event.sctp_send_failure_event = 1;
event.sctp_peer_error_event = 1;
event.sctp_shutdown_event = 1;
event.sctp_partial_delivery_event = 1;
event.sctp_adaption_layer_event = 1;
if (setsockopt(fd, IPPROTO_SCTP, SCTP_EVENTS, &event, sizeof(event)) != 0)
{
perror("setevent failed");
exit(1);
}

/* Configure auto-close timer. */
int timeout = 5;
if (setsockopt(fd, IPPROTO_SCTP, SCTP_AUTOCLOSE, &timeout, 4) < 0)
{
perror("setsockopt SCTP_AUTOCLOSE");
exit(1);
}

/* Bind the socket to all local addresses. */
struct sockaddr_in sin;
bzero((char*)&sin, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_port = htons(19000);
sin.sin_addr.s_addr = inet_addr("192.168.10.120");
if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)) == -1)
{
perror("bind");
exit(1);
}

/* Enable accepting associations. */
if (listen(fd, 1) < 0)
{
perror("listen");
exit(1);
}

char buffer[256];
int bufferlen = 256;
bzero(buffer, bufferlen);

struct sockaddr_in clientaddr;
int fromlen = sizeof(clientaddr);
struct sctp_sndrcvinfo sndrcvinfo;
int msg_flag;

while(true)
{

int length = sctp_recvmsg(fd, buffer, bufferlen, (struct sockaddr*)&clientaddr, (socklen_t*)&fromlen, &sndrcvinfo, &msg_flag);

if (msg_flag &  MSG_NOTIFICATION)
{
printf("****************************************************\n");
printf("Event: notificaiton length=%d\n", length);
handle_event((void*)buffer);
}
else
{
printf("****************************************************\n");
printf("Event: data event length=%d\n", length);
char addrbuf[100];
inet_ntop(AF_INET, &clientaddr.sin_addr, addrbuf, INET6_ADDRSTRLEN);
int port = ntohs(clientaddr.sin_port);
printf("data from=%s:%d\n", addrbuf, port);
printf("data=%s\n", buffer);
}
}

if (close(fd) < 0)
{
perror("close");
exit(1);
}

return (0);
}