Hello all,
I am working on NFS interoperabiity and I experiment some problems with UDP.
The problem appear between the linux 2.6.10rc1 and 2.6.10rc2, and is still
present in the last kernel (2.6.11rc3)
With NFSv3:
Client send a 32k file splited into 22 IP fragments. The problem is the server
only receive 17 fragments.
More investigation tell me that the server reveive 17 fragments because the
client only send 17 IP fragments.
As the NFS client code is exactly the same between the 2.6.10rc1 and 2.6.10rc2
I tried to write a simple UDP client server, to be sure there is no relation
between this bug and NFS.
Client create a buffer of X bytes and fill it with the 'A' symbol. Then it
write it over a udp socket (sendto).
Server read the first 1024KB sent.
If X is <26000 the write is done with sucess.
Else it fail. (Typicaly for a 32KB size, as for NFS)
Network card is the intel e1000 ethernet card. I tried with rxpolling turned
on and off. Bug doesnot appear in loopback.
Anyone interrested in that?
Vincent ROQUETA
/****************************************
* Simple Client
* Port : 9999
* argument 1 : buffer size to send
* argument 2 : server ip adress.
****************************************/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
int main (int argc, char * argv[])
{
int sock;
struct sockaddr_in name;
int size;
char *ip;
size=atoi(argv[1]);
ip=argv[2];
char DATA[size];
sock = socket (AF_INET, SOCK_DGRAM, 0);
if (sock < 0)
{
perror ("socket");
return 1;
}
bzero (&name, sizeof (name));
memset(DATA, 'A', sizeof(DATA));
name.sin_family = AF_INET;
name.sin_addr.s_addr = inet_addr (ip);
name.sin_port = htons(9999);
fprintf(stdout, "client UDP, port: %d\n", ntohs(name.sin_port));
if(sendto(sock,DATA,sizeof(DATA),0,(struct sockaddr
*)&name,sizeof(name))<0)
{
perror("sendto");
close(sock);
return 1;
} close(sock);
return 0;
}
/********************************************
* Simple server
* port 9999
********************************************/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
int main (int argc, char * argv[])
{
int sock;
size_t length;
struct sockaddr_in name;
char buf [1024];
int nbr=0;
while (1)
{
bzero (&name, sizeof (name));
sock = socket (AF_INET, SOCK_DGRAM, 0);
if (sock < 0)
{
perror ("socket");
return 1;
}
name.sin_family = AF_INET;
name.sin_addr.s_addr = INADDR_ANY;
name.sin_port = htons(9999);
if (bind (sock, (struct sockaddr *)&name, sizeof (name)) < 0)
{
perror ("bind");
close (sock);
return 1;
}
if (getsockname (sock, (struct sockaddr *)&name, &length) < 0)
{
perror ("getsockname");
close (sock);
return 1;
}
printf ("Socket UDP port #%d\n", ntohs (name.sin_port));
nbr++;
printf("read nb%d\n",nbr);
if(read(sock, buf, 1024)<0)
{
perror ("read");
close (sock);
return 1;
}
printf ("%s", buf);
printf("\n");
close (sock);
}
return 0;
}
> Network card is the intel e1000 ethernet card. I tried with rxpolling
> turned on and off. Bug doesnot appear in loopback.
Compiling with the linux 2.6.10rc1 e1000 driver does not change anything. That
may not come from the driver.
Vincent ROQUETA
Vincent Roqueta wrote:
> Hello all,
>
> I am working on NFS interoperabiity and I experiment some problems with UDP.
> The problem appear between the linux 2.6.10rc1 and 2.6.10rc2, and is still
> present in the last kernel (2.6.11rc3)
>
> With NFSv3:
> Client send a 32k file splited into 22 IP fragments. The problem is the server
> only receive 17 fragments.
> More investigation tell me that the server reveive 17 fragments because the
> client only send 17 IP fragments.
>
> As the NFS client code is exactly the same between the 2.6.10rc1 and 2.6.10rc2
> I tried to write a simple UDP client server, to be sure there is no relation
> between this bug and NFS.
>
> Client create a buffer of X bytes and fill it with the 'A' symbol. Then it
> write it over a udp socket (sendto).
> Server read the first 1024KB sent.
>
> If X is <26000 the write is done with sucess.
> Else it fail. (Typicaly for a 32KB size, as for NFS)
Try setting the socket send buffer size larger. By default it's
quite small, and so it may not accept a large UDP frame.
Ben
--
Ben Greear <[email protected]>
Candela Technologies Inc http://www.candelatech.com