accept trouble

Hello guys...


Could you tell me why this little tcp server code below
send me an ernno 22 : Invalid argument
when I try to connect it with telnet client (or another)

It seems its accept() which fails but why ???

I've tested this code under CygWin, it works, but under Linux
(gentoo 2005 et RH 7.2) it doesn't


#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>
#include <setjmp.h>
#ifdef SUN
#include <signal.h>
#else
#include <sys/signal.h>
#endif
#include <sys/wait.h>
#include <dlfcn.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>

#define SA struct sockaddr
#define SA_IN struct sockaddr_in



/*
*/
static int init_nw(char *address, int port, SA_IN *servaddr)
{
struct hostent *inf;
int f_on=1;
int s;

s = socket(AF_INET, SOCK_STREAM, 0);

if (s<0)
return 0;

setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (void *) &f_on, sizeof(int));
setsockopt(s, SOL_SOCKET, SO_KEEPALIVE, (void *) &f_on, sizeof(int));

memset(servaddr, 0, sizeof(SA_IN));
servaddr->sin_family = AF_INET;
servaddr->sin_port = htons((unsigned short)port);

if (address==NULL || strlen(address)==0)
servaddr->sin_addr.s_addr = htonl(INADDR_ANY);
else
servaddr->sin_addr.s_addr = inet_addr(address);

if (servaddr->sin_addr.s_addr==INADDR_NONE)
{
inf = gethostbyname(address);

if (inf==NULL)
return 0;

memcpy( &servaddr->sin_addr.s_addr, inf->h_addr, inf->h_length );
}

return s;
}






/*
*
*/
int main(int argc, char *argv[])
{
int sock, sd, r;
SA_IN servaddr;
int rf, f=0;
char ok[2048];
SA addr;
socklen_t fromlen;

sd = init_nw("", 5600, &servaddr);

if (sd<=0)
{
exit(500);
}

// blocking
r = fcntl(sd, F_SETFL, f & (~O_NONBLOCK) );

if (r<0)
{
exit(500);
}


if ( bind(sd, (SA *) &servaddr, sizeof(servaddr))==-1 )
{
exit(501);
}


r = listen( sd, 5);


while(1)
{
errno=0;

/* always send errno = 22 Invalid argument ?????? */
fromlen = sizeof(SA);
sock = accept(sd, (SA *) &addr, &fromlen);

if (errno==0)
{
rf = fork();


/* father will still listener forever */
if (!rf)
{
int x;
fcntl(sock, F_SETFL, f & (~O_NONBLOCK) );

shutdown(sd, SHUT_RDWR);

recv(sock, ok, 2048, 0);

sprintf(ok, "01101996 123 444");
send(sock, ok, strlen(ok)+1, 0);

/* no return from client just to "block" the child */
recv(sock, ok, 2048, 0);

shutdown(sock, SHUT_RDWR);

break;
}
}
else
{
perror(">>>");
}
}



shutdown(sd, SHUT_RDWR);

return 0;
}

stef wrote:
> Hello guys...
>
>
> Could you tell me why this little tcp server code below
> send me an ernno 22 : Invalid argument
> when I try to connect it with telnet client (or another)
>
> It seems its accept() which fails but why ???
>
> I've tested this code under CygWin, it works, but under Linux
> (gentoo 2005 et RH 7.2) it doesn't
>
>
> #include <stdio.h>
> #include <unistd.h>
> #include <fcntl.h>
> #include <time.h>
> #include <setjmp.h>
> #ifdef SUN
> #include <signal.h>
> #else
> #include <sys/signal.h>
> #endif
> #include <sys/wait.h>
> #include <dlfcn.h>
> #include <sys/types.h>
> #include <sys/socket.h>
> #include <netinet/in.h>
> #include <arpa/inet.h>
> #include <netdb.h>
> #include <unistd.h>
> #include <errno.h>
> #include <stdio.h>
> #include <stdlib.h>
> #include <strings.h>
>
> #define SA struct sockaddr
> #define SA_IN struct sockaddr_in
>
>
>
> /*
> */
> static int init_nw(char *address, int port, SA_IN *servaddr)
> {
> struct hostent *inf;
> int f_on=1;
> int s;
>
> s = socket(AF_INET, SOCK_STREAM, 0);
>
> if (s<0)
> return 0;
>
> setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (void *) &f_on, sizeof(int));
> setsockopt(s, SOL_SOCKET, SO_KEEPALIVE, (void *) &f_on, sizeof(int));
what do these calls to setsockopt return?
>
> memset(servaddr, 0, sizeof(SA_IN));
> servaddr->sin_family = AF_INET;
> servaddr->sin_port = htons((unsigned short)port);
>
> if (address==NULL || strlen(address)==0)
> servaddr->sin_addr.s_addr = htonl(INADDR_ANY);
> else
> servaddr->sin_addr.s_addr = inet_addr(address);
>
> if (servaddr->sin_addr.s_addr==INADDR_NONE)
> {
> inf = gethostbyname(address);
>
> if (inf==NULL)
> return 0;
>
> memcpy( &servaddr->sin_addr.s_addr, inf->h_addr, inf->h_length );
> }
>
> return s;
> }
>
>
>
>
>
>
> /*
> *
> */
> int main(int argc, char *argv[])
> {
> int sock, sd, r;
> SA_IN servaddr;
> int rf, f=0;
> char ok[2048];
> SA addr;
perhaps addr should be defined as SA_IN

> socklen_t fromlen;
>
> sd = init_nw("", 5600, &servaddr);
>
> if (sd<=0)
> {
> exit(500);
> }
>
> // blocking
> r = fcntl(sd, F_SETFL, f & (~O_NONBLOCK) );
>
> if (r<0)
> {
> exit(500);
> }
>
>
> if ( bind(sd, (SA *) &servaddr, sizeof(servaddr))==-1 )
> {
> exit(501);
> }
>
>
> r = listen( sd, 5);

what does listen return?

>
>
> while(1)
> {
> errno=0;
>
> /* always send errno = 22 Invalid argument ?????? */
> fromlen = sizeof(SA);
> sock = accept(sd, (SA *) &addr, &fromlen);
>
> if (errno==0)
> {
> rf = fork();
>
>
> /* father will still listener forever */
> if (!rf)
> {
> int x;
> fcntl(sock, F_SETFL, f & (~O_NONBLOCK) );
>
> shutdown(sd, SHUT_RDWR);
>
> recv(sock, ok, 2048, 0);
>
> sprintf(ok, "01101996 123 444");
> send(sock, ok, strlen(ok)+1, 0);
>
> /* no return from client just to "block" the child */
> recv(sock, ok, 2048, 0);
>
> shutdown(sock, SHUT_RDWR);
>
> break;
> }
> }
> else
> {
> perror(">>>");
> }
> }
>
>
>
> shutdown(sd, SHUT_RDWR);
>
> return 0;
> }
>
can't see any major flaws at quick glance, sorry i can't be of more help