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Conference turris::digital_unix

Title:	DIGITAL UNIX(FORMERLY KNOWN AS DEC OSF/1)
Notice:	Welcome to the Digital UNIX Conference
Moderator:	SMURF::DENHAM

Created:	Thu Mar 16 1995
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	10068
Total number of notes:	35879

8762.0. "A novice question about sockets." by CADSYS::BOGDANOV () Fri Feb 07 1997 17:53

Hi,
	I'm running through the network programming course and trying to get a
small program to work. However, the 'setsockopt' call alwys gives me an Invalid
argument message. I was not able to figure out a reason for it. Can somebody
help?

     . . .

    if ((sd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
	perror("socket error"), exit(1);

    memset(&addr, 0, sizeof addr);

    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = inet_addr(SERV_ADDR);
    addr.sin_port = htons(SERV_PORT);

    if (connect(sd, (struct sockaddr *)&addr, sizeof(addr)) == -1)
	perror("connect error"), exit(1);

       
    {
	int to = 2;
	if (setsockopt(sd, SOL_SOCKET, SO_RCVTIMEO, &to, 4) == -1)
	    perror("set sock opt"), exit(0);

	// Here is a message
	// set sock opt: Invalid argument
    }

    . . .
 

I'm running osf 3.2d

>> Serge

T.R	Title	User	Personal Name	Date	Lines
8762.1		netrix.lkg.dec.com::thomas	The Code Warrior	`Fri Feb 07 1997 21:32`	1
	SO_RCVTIMEO takes a struct timeval, not an int.
8762.2		VAXCPU::michaud	Jeff Michaud - ObjectBroker	`Fri Feb 07 1997 22:03`	7
	> I'm running through the network programming course .... > if (setsockopt(sd, SOL_SOCKET, SO_RCVTIMEO, &to, 4) == -1) ^ I'd take off major points right here for hardcoding in a "magic" number into the code like this. The 4 should be replaced with "sizeof to" (w/out the quotes).
8762.3		VAXCPU::michaud	Jeff Michaud - ObjectBroker	`Fri Feb 07 1997 22:05`	8
	> SO_RCVTIMEO takes a struct timeval, not an int. And this looks like .0 should file a QAR against the setsockopt man page which says: "SO_RCVTIMEO Sets receive time out. This option takes an int value." ^^^
8762.4	Thanks a lot	CADSYS::BOGDANOV		`Mon Feb 10 1997 12:09`	7
	> SO_RCVTIMEO takes a struct timeval, not an int. QAR #51438. The same mistake was done in internal 'self-peace' cource on Network Application Programming (EY-K021E-SG-0001).
8762.5	I should have checked it first!	CADSYS::BOGDANOV		`Mon Feb 10 1997 12:28`	17
	> SO_RCVTIMEO takes a struct timeval, not an int. Oops. Still cannot get it to work: struct timeval to; . . . to.tv_sec = 2; to.tv_usec = 0; if (setsockopt(sd, SOL_SOCKET, SO_RCVTIMEO, &to, sizeof to ) == -1) perror("set sock opt"); //, exit(0); . . . set sock opt: Argument out of domain
8762.6		IOSG::MARSHALL		`Mon Feb 10 1997 13:33`	10
	struct timeval to; . . . to.tv_sec = 2; to.tv_usec = 0; set sock opt: Argument out of domain WAG: do you explicitly zero all the other elements of the timeval struct? Scott
8762.7		VAXCPU::michaud	Jeff Michaud - ObjectBroker	`Mon Feb 10 1997 13:39`	10
	>> to.tv_sec = 2; >> to.tv_usec = 0; > WAG: do you explicitly zero all the other elements of the timeval struct? timeval has only the two members above > set sock opt: Argument out of domain this sounds like it 2 seconds is not a valid timeout (ie. it's too small or too big).
8762.8		CADSYS::BOGDANOV		`Mon Feb 10 1997 13:54`	5
	I got it to work on DUNIX 4.0A . It looks like a BUG on 3.2D-1. >> Serge