Date: Sat, 8 Apr 2000 12:38:20 -0400 (EDT) From: Sean Peck <speck@news1.newsindex.com> To: Alfred Perlstein <bright@wintelcom.net> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: FreeBSD 3.3 fork/Exec bug? Message-ID: <Pine.BSI.3.95.1000408122156.882A-100000@news1.newsindex.com> In-Reply-To: <20000408084711.W4381@fw.wintelcom.net>
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Alfred,
Here is the code being used.
This is the Server Code, xxx are the IP of box, yyy is port this server is
listening too passed to the client
user_port = socket_config(xxxx);
while (y<1){
if(!fork()){
printf("Starting Client %d\n",getpid());
close(user_port);
execlp("./client","client","XXX.XXX.XXX.XXX","YYYY",NULL);
printf("Ending forked %d\n",xxx);
exit(0);
}
y++;
}
=========================================================================================
This is the client main
sleep(10); //this is just to make sure that the server is ready to
// listen added for tracing and testing of this bug
if(argc<3){printf("Usage get host port\n");exit(0);}
strcpy(localhostname,argv[1]);
port1 = atoi(argv[2]);
printf("Connectiong to %s port %d\n",localhostname,port1);
signal(SIGPIPE,SIG_IGN);
result=10;
printf("GETTING PAGE FROM SERVER\n");
while((strcmp(buf,"NONE")!=0)&&(result!=TCP_CONNECT_NONE)&&(timeout!=10)){
memset(buf,0,sizeof(buf));
result=10;
timeout=0;
while((result !=1)&&(result!=TCP_CONNECT_NONE)&&(timeout!=10)){
result = tcp_get_conn(localhostname,port1,10,&sock1);
if(result==TCP_CONNECT_TIMEOUT){timeout++;}
}
printf("result %d\n",result); //This is coming back 1 in both the
// fork/execlp and in direct from shell
// running
printf("ERRNO %d\n",errno); // this is coming back 36 in both shell and
// fork/execlp
if ((result!=TCP_CONNECT_NONE)&&(timeout!=10)){
write(sock1,"GIMME\n",6);
bufp=buf;
//Does not appeart to be blocking
while((size=read(sock1, bufp, (5000-(bufp-buf))))>0){
printf("size %d\n",size);
bufp+=size;
}
}
close(sock1);
printf("GOT INFO\n");
if(timeout==10){strcpy(buf,"NONE");}
printf("GOT BUF: %s\n",buf); // In fork this comes back with Empty
// string, but has valid data if
// run seperately. When forked, Server
// just stays in select state, never
// gets any connections, but clients
// execute as if they have one.
=================================================================================
Here is the tcp_get_connection() code
/*
* given a HOST name and service PORT number, return connected TCP
* socket to the requested service at the requested host. It will
* timeout after SECS (if < 0 then hang). Passes back socket in SOCKP
* and returns error codes.
*/
/* tcp_get_conn return codes */
#define TCP_NO_ERROR 1 /* no error */
#define TCP_NOT_FOUND 2 /* host not found */
#define TCP_SOCKET_FAILURE 3 /* socket create failure
*/
#define TCP_CONNECT_ERROR 4 /* socket connect error */
#define TCP_CONNECT_TIMEOUT 5 /* socket connect timeout
*/
#define TCP_CONNECT_NONE 6 /* socket didn't connect
*/
#define TCP_TRANSFER_ERROR 7 /* read/write error */
EXPORT int tcp_get_conn(const char * host, const int port,
const int secs, int * sockp)
{
struct sockaddr_in sadr;
struct hostent *hostp;
struct timeval timeout, *timeoutp;
fd_set fds;
char **addrp, okay = 0;
int sock, ret;
#ifdef __osf__
struct itimerval timer;
#endif
/* locate host */
hostp = gethostbyname(host);
if (hostp == NULL)
return TCP_NOT_FOUND;
/* setup internet port */
sadr.sin_family = (u_short)AF_INET;
sadr.sin_port = htons(port);
sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (sock < 0)
return TCP_SOCKET_FAILURE;
#ifndef __osf__
/* make the fd non-blocking */
(void)fcntl(sock, F_SETFL, fcntl(sock, F_GETFL, 0) | O_NONBLOCK);
#endif
if (secs < 0)
timeoutp = 0L;
else
timeoutp = &timeout;
FD_ZERO(&fds);
/* try to connect to the remote server */
for (addrp = hostp->h_addr_list; *addrp != NULL; addrp++) {
(void)memcpy((void *)&sadr.sin_addr, *addrp, sizeof(sadr.sin_addr));
#ifdef __osf__
/* set the timer */
timer.it_interval = timeout;
setitimer(ITIMER_REAL, &timer, NULL);
(void)signal(SIGALRM, catch_alarm);
alarm_caught = FALSE;
#endif
/* connect or start the connection */
ret = connect(sock, (void *)&sadr, sizeof(sadr));
#ifdef __osf__
/* disable the timer */
timer.it_value.tv_sec = 0;
timer.it_value.tv_usec = 0;
setitimer(ITIMER_REAL, &timer, NULL);
(void)signal(SIGALRM, SIG_IGN);
#endif
if (ret == 0) {
okay = 1;
break;
}
#ifdef __osf__
(void)close(sock);
if (alarm_caught)
return TCP_CONNECT_TIMEOUT;
else
return TCP_CONNECT_ERROR;
#endif
/* not waiting for connection? */
if (errno != EINPROGRESS && errno != EWOULDBLOCK) {
/* connection refused? */
if (errno == ECONNREFUSED)
continue;
/* otherwise error */
(void)close(sock);
return TCP_CONNECT_ERROR;
}
for (;;) {
FD_SET(sock, &fds);
if (secs >= 0) {
timeout.tv_sec = secs;
timeout.tv_usec = 0;
}
ret = select(sock + 1, 0L, &fds, 0L, timeoutp);
if (ret > 0 && FD_ISSET(sock, &fds)) {
okay = 1;
break;
}
if (ret == 0) {
(void)close(sock);
return TCP_CONNECT_TIMEOUT;
}
if (ret < 0 && errno != EINTR) {
(void)close(sock);
return TCP_CONNECT_ERROR;
}
}
if (okay)
break;
}
/* connection made? */
if (okay) {
#ifndef __osf__
/* turn off non-blocking */
(void)fcntl(sock, F_SETFL, fcntl(sock, F_GETFL, 0) & ~O_NONBLOCK);
#endif
*sockp = sock;
return TCP_NO_ERROR;
}
(void)close(sock);
return TCP_CONNECT_NONE;
}
Sean Peck
News Index -- The original News Only Search Engine.
http://www.newsindex.com/
On Sat, 8 Apr 2000, Alfred Perlstein wrote:
> * Sean Peck <speck@news1.newsindex.com> [000408 07:58] wrote:
> >
> > I am having a bizarre problem with a system on FreeBSD.
> >
> > The system consists of a server who forks its clients.
> > When the clients are forked, they try to connect to the server and get
> > information. Unfortunately when they fork off (fork/execlp), they say
> > they connected to
> > server and recieved nothing, yet the server does not register the
> > connection or request for info. If I run the client independently (not
> > via fork/execlp) everything works just fine.
> >
> > This code is deployed and operational on BSDi without a problem, so I
> > assume that this is OS related, does anyone know anything about, or can
> > help me with this?
>
> Without some example code to demostrate the problem there's not much
> we can do to address this.
>
> --
> -Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org]
> "I have the heart of a child; I keep it in a jar on my desk."
>
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