* Fw: [Bugme-new] [Bug 7909] New: malfunction of udp_get_port() in wildcard ports assigning
@ 2007-01-31 18:32 Andrew Morton
2007-01-31 19:52 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Andrew Morton @ 2007-01-31 18:32 UTC (permalink / raw)
To: netdev
Cc: bugme-daemon@kernel-bugs.osdl.org, Konstantin.Petrov,
Alexandra.Kossovsky
Begin forwarded message:
Date: Wed, 31 Jan 2007 03:50:56 -0800
From: bugme-daemon@bugzilla.kernel.org
To: bugme-new@lists.osdl.org
Subject: [Bugme-new] [Bug 7909] New: malfunction of udp_get_port() in wildcard ports assigning
http://bugzilla.kernel.org/show_bug.cgi?id=7909
Summary: malfunction of udp_get_port() in wildcard ports
assigning
Kernel Version: 2.6.19
Status: NEW
Severity: normal
Owner: shemminger@osdl.org
Submitter: Konstantin.Petrov@oktetlabs.ru
CC: Alexandra.Kossovsky@oktetlabs.ru
Most recent kernel where this bug did *NOT* occur: 2.6.18.4
Distribution: Debian
Hardware Environment: PCs x86-64 and i686
Software Environment:
Problem Description:
repeated binding of datagram sockets to some IP with wildcard
port fails after ~three hundred iterations with errno EADDRINUSE.
List of really assigned ports looks strangely:
...PORT[128-port-numbers-gap]PORT[128-port-numbers-gap]...
Steps to reproduce:
See code:
#include <stdio.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/errno.h>
int
main(int argc, char **argv)
{
int iut_s;
int retval;
struct sockaddr_in servaddr,
cliaddr;
socklen_t namelen;
char addr_buf[16];
int i;
/* Read command line arguments */
if (argc != 2)
{
printf("\nuse pco_iut <local IP>\n");
return -1;
}
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
inet_pton(AF_INET, argv[1], &servaddr.sin_addr);
servaddr.sin_port = 0;
for (i = 0; i < 1024; i++)
{
if ( (iut_s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
{
printf("\nFailed to create socket No %d error %d\n", i + 1,
errno);
return -1;
}
if (bind(iut_s,(struct sockaddr *) &servaddr, sizeof(servaddr)) != 0)
{
printf("\nFailed to bind socket No %d error %d\n", i + 1,
errno);
return -1;
}
namelen = sizeof(cliaddr);
if (getsockname(iut_s, (struct sockaddr *)&cliaddr, &namelen) != 0)
{
printf("\ngetsockname() error errno %d\n", errno);
return -1;
}
else
{
inet_ntop(AF_INET, &cliaddr.sin_addr,
addr_buf, 16);
printf("\nBound to %s:%d\n",
addr_buf,
ntohs(cliaddr.sin_port));
}
}
return 0;
}
The reason of this issue is IMHO in udp_get_port() function
which was added in 2.6.19 version to replace udp_v4_get_port()
in older versions.
In ugp_get_port() we see the strange piece of code
.................................................................
size = 0;
sk_for_each(sk2, node, head)
if (++size < best_size_so_far) {
best_size_so_far = size;
best = result;
}
}
result = best;
for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result +=
UDP_HTABLE_SIZE) {
..........................................................................
which means that sk_for_each(...) iteration is repeated only once.
No such problem in older kernels where the similar
piece of code in udp_v4_get_port() looks like
..........................................................................
size = 0;
sk_for_each(sk2, node, list)
if (++size >= best_size_so_far)
goto next;
best_size_so_far = size;
best = result;
next:;
}
result = best;
for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result +=
UDP_HTABLE_SIZE) {
..........................................................................
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^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [Bugme-new] [Bug 7909] New: malfunction of udp_get_port() in wildcard ports assigning
2007-01-31 18:32 Fw: [Bugme-new] [Bug 7909] New: malfunction of udp_get_port() in wildcard ports assigning Andrew Morton
@ 2007-01-31 19:52 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2007-01-31 19:52 UTC (permalink / raw)
To: akpm; +Cc: netdev, bugme-daemon, Konstantin.Petrov, Alexandra.Kossovsky
This was fixed several weeks ago.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2007-01-31 18:32 Fw: [Bugme-new] [Bug 7909] New: malfunction of udp_get_port() in wildcard ports assigning Andrew Morton
2007-01-31 19:52 ` David Miller
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