[Error] RECVMSG

["Nguyễn Phước Thành" <ht22.pt@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 556 bytes --]

I am coding apps transfer file with LKSCTP. With server receiver file. I 
use recvmsg(sk,&inmessage,0). And I want get infomation header of this 
packet, but I check inmessage. inmessage.msg_controllen=0, and 
inmessage.msg_flags=136. What's 136. In client I just send flags=0. And 
msg_control, msg_controllen with full infomation.
And cmsg = CMSG_FIRSTHDR(&inmessage); always return NULL so I can't 
write data to file.
Please help me.
I attacth code send_file recv_file. I have checked client. It's ok. But 
I don't know why infomation header is NULL.


[-- Attachment #2: code_server.c --]
[-- Type: text/plain, Size: 2408 bytes --]

void recv_file(int sk)
{
    char incmsg[CMSG_SPACE(sizeof(_sctp_cmsg_data_t))];
	struct iovec iov;
	struct msghdr inmessage;
    struct cmsghdr *cmsg;
    _sctp_cmsg_data_t *sinfo;
	int error;
    static char buffer[1024];
    int buffer_size=1024;
    int check_listen;

 	/* Mark sk as being able to accept new associations */
	check_listen = listen(sk, 5);
	if (check_listen != 0) {
		printf("\n\n\t\tlisten Failure:  %s.\n\n\n",
		       strerror(errno));
		exit(1);
	}
	/* Initialize inmessage with enough space for DATA... */
	memset(&inmessage, 0, sizeof(inmessage));
	if ((iov.iov_base = malloc(5000)) == NULL) {
		printf(" Can't allocate memory.\n");
		exit(1);
	}
	iov.iov_base = buffer;
	iov.iov_len = 5000;
    inmessage.msg_iov = &iov;
	inmessage.msg_iovlen = 1;
	/* or a control message.  */
	inmessage.msg_control = incmsg;
	inmessage.msg_controllen = sizeof(incmsg);
    int writebyte=0;
    int fd[10];
     int check_file=0;
    for(check_file=0;check_file<count_file;check_file++)
    {
        fd[check_file] = fopen(localfile[check_file],"w");
        if(fd[check_file]==-1)
            return;
    }
	printf(" listening...\n");
	/* Get the messages sent */
    int time_clock=0;
    time_t start, finish;
    clock_t start_c, finish_c;
	long duration=0;
    double duration_c=0;
    long temp;
	while ((error = recvmsg(sk, &inmessage, MSG_WAITALL))>=0) {
        if( !(inmessage.msg_flags & MSG_NOTIFICATION )){
            cmsg = CMSG_FIRSTHDR(&inmessage);
            if(cmsg==NULL)continue;
            sinfo = (struct sctp_sndrcvinfo*)CMSG_DATA(cmsg);
            writebyte=fwrite(buffer,error,1,fd[sinfo->sinfo_stream]);
            if(time_clock==0)
                {
                    time_clock=1;
                    start=time(NULL);
                    start_c=clock();
                }
        }
		else {
			union sctp_notification *sn;
			sn = (union sctp_notification *)iov.iov_base;
			if ((sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) &&
			    (sn->sn_assoc_change.sac_state
			     == SCTP_SHUTDOWN_COMP))
                             break;
                    }

        }
    finish=time(NULL);
    finish_c=clock();
    temp=finish_c-start_c;
    duration_c=(double)temp/CLOCKS_PER_SEC;
    duration=finish-start;
	printf("the file has been transferred in %d secs and %2.3f secs.\n",duration,duration_c);
	close(fd);
         close(sk);
} /* command_listen() */

[-- Attachment #3: code_client.c --]
[-- Type: text/plain, Size: 5609 bytes --]

oid send_file(int sk)
{
    struct msghdr outmsg;
    char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
    struct cmsghdr *cmsg;
    struct sctp_sndrcvinfo *sinfo;
    struct iovec iov;
    char message[1024];
    struct hostent *hst;
    struct sockaddr *addrs;
    int msglen;
    int error = 0;
    int try_error=0;
    int stream = 0;
    //Kiem lai dia chi dich va gan cac thong tin phu hop
        if (remote_host != NULL) {
		hst = gethostbyname(remote_host);
		if (hst == NULL || hst->h_length < 1) {
			fprintf(stderr, "%s: bad hostname: \n",
				remote_host);
			exit(1);
		}
		ra_family = hst->h_addrtype;
                ra_len = sizeof(remote_addr);
                ra_raw = &remote_addr.sin_addr;
		remote_addr.sin_port = htons(8000);
		remote_addr.sin_family = AF_INET;
		memcpy(ra_raw, hst->h_addr_list[0], hst->h_length);
        }
        else
        {
            //Hostname khong ton tai thoat chuong trinh...
            printf("Not found remote host!!!\n");
            printf("Shutdown program.\n");
            exit(1);
        }
        printf("Host name is %s.\n",remote_host);
        // KIem tra su ton tai cua ket noi toi remote addrs
        if ((SOCK_SEQPACKET == socket_type) && associd &&
            (0 != test_sk_for_assoc(sk, associd))) {
		associd = test_recv_assoc_change(sk);
		printf("Old association gone, Starting a new one!\n");
		new_connection = 1;
	}
        int fd[10];
        int check_file=0;
        for(check_file=0;check_file<count_file;check_file++)
        {

            if ( localfile[check_file] == NULL ) fd[check_file] = 0;
            //fd = open(localfile,O_RDONLY);
            fd[check_file] = fopen(localfile[check_file],"r");
            if(fd[check_file]==-1)
            {
                printf("Read file error.\n");
                exit(1);
            }
            printf("Ready to send file....\n");
        }
        msglen=fread(message,1024,1,fd[0]);
        do {
            /* Initialize the message struct we use to pass
		 * messages to the remote socket.
             */
            try_error++;
            if(try_error==100)
            {
                printf("Can't connect remote address,program shutdown.\n");
                exit(1);
            }
            iov.iov_base = message;
            iov.iov_len = sizeof(message);
            outmsg.msg_name=&remote_host;
            outmsg.msg_namelen=sizeof(remote_host);
            outmsg.msg_iov = &iov;
            outmsg.msg_iovlen = 1;
            outmsg.msg_control = outcmsg;;
            outmsg.msg_controllen = sizeof(outcmsg);
            outmsg.msg_name = &remote_addr;
            outmsg.msg_namelen = ra_len;
            cmsg = CMSG_FIRSTHDR(&outmsg);
            cmsg->cmsg_level = IPPROTO_SCTP;
            cmsg->cmsg_type = SCTP_SNDRCV;
            cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
            outmsg.msg_controllen = cmsg->cmsg_len;
            sinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
            memset(sinfo, 0, sizeof(struct sctp_sndrcvinfo));
            sinfo->sinfo_flags = 0;
            sinfo->sinfo_stream = 0;
            error = sendmsg(sk, &outmsg, MSG_WAITALL);
            if (error != sizeof(message))
		printf(stderr, ": error: %s.\n", strerror(errno));
	} while (error != sizeof(message));

    /* If this is the first message sent over a UDP-style socket,
     * get the associd from the SCTP_ASSOC_CHANGE notification.
     */
	if ((SOCK_SEQPACKET == socket_type) && (0 == associd))
			associd = test_recv_assoc_change(sk);

	/* Verify there is no association.  */
	if (0 != test_sk_for_assoc(sk, associd)) {
		printf("No association is present now!!\n");
		new_connection = 1;
		}
        else {
		if (new_connection) {
		int rc = sctp_getpaddrs(sk, associd, &addrs);
		if (0 >= rc) {
                    if (rc == 0) {
			fprintf(stderr, "sctp_getpaddrs failed, no peers.\n");
                    } else {
			fprintf(stderr, "sctp_getpaddrs failed %s(%d).\n", strerror(errno), errno);
			}
                         exit(1);
		}
		printf("New connection, peer addresses\n");
		//print_addr_buf(addrs, rc);
		sctp_freepaddrs(addrs);
		new_connection = 0;
		}
    }
    iov.iov_base = buffer;
	iov.iov_len = 1;
	outmsg.msg_iov = &iov;
	outmsg.msg_iovlen = 1;
        int end_file[count_file];
        for(check_file=0;check_file<count_file;check_file++)
        {
            end_file[check_file]=0;
        }
        /* open the file */
        time_t start, finish;
        clock_t start_c, finish_c;
	long duration=0;
    double duration_c=0;
    long temp;
	start=time(NULL);
        start_c=clock();
        printf("Return code Realy....\n");
        while(finished_file<count_file)
        {
            for(check_file=0;check_file<count_file;check_file++)
            {
                if(end_file[check_file]==1) continue;
                msglen = fread(message,1024,1,fd[check_file]);
                if(msglen<=0)
                {
                    end_file[check_file]=1;
                    finished_file++;
                    continue;
                }
                stream=check_file;
                sinfo->sinfo_stream = stream;
                iov.iov_len = sizeof(message);
                error = sendmsg(sk, &outmsg, MSG_WAITALL);
            }
        }
        finish=time(NULL);
        finish_c=clock();
        temp=finish_c-start_c;
        duration_c=(double)temp/CLOCKS_PER_SEC;
        duration=finish-start;
	//duration=finish-start;
	printf("the file has been transferred in %d secs and %2.3f secs.\n",duration,duration_c);
	close(fd);
	close(sk);
}