Hi Sven,
This is what I find in 2.4.20-8,
#define IPQ_QMAX_DEFAULT 1024
#define IPQ_PROC_FS_NAME "ip_queue"
#define NET_IPQ_QMAX 2088
#define NET_IPQ_QMAX_NAME "ip_queue_maxlen"
........................................................
static inline int ( line 69)
__ipq_enqueue_entry(struct ipq_queue_entry *entry)
{
if (queue_total >= queue_maxlen) { >>>> len being checked against
queue_maxlen >>>)
if (net_ratelimit())
printk(KERN_WARNING "ip_queue: full at %d entries, "
"dropping packet(s).\n", queue_total);
return -ENOSPC;
}
list_add(&entry->list, &queue_list);
queue_total++;
return 0;
}
.............................................................
and ... ( line 584)
static int sysctl_maxlen = IPQ_QMAX_DEFAULT;
static struct ctl_table_header *ipq_sysctl_header;
>>> sysctl value for "ip_queue_maxlen goes into sysctl_maxlen, and besides these 3 or 4 line sysctl_maxlen is not used anywhere, nor is it assigned
to queue_maxlen anywhere >>>>
static ctl_table ipq_table[] = {
{ NET_IPQ_QMAX, NET_IPQ_QMAX_NAME, &sysctl_maxlen,
sizeof(sysctl_maxlen), 0644, NULL, proc_dointvec },
{ 0 }
};
static ctl_table ipq_dir_table[] = {
{NET_IPV4, "ipv4", NULL, 0, 0555, ipq_table, 0, 0, 0, 0, 0},
{ 0 }
};
static ctl_table ipq_root_table[] = {
{CTL_NET, "net", NULL, 0, 0555, ipq_dir_table, 0, 0, 0, 0, 0},
{ 0 }
};
Sven Schuster <schuster.sven@xxxxxx>@nl.linux.org on 07/15/2004 12:21:27 PM
Sent by: kernelnewbies-bounce@xxxxxxxxxxxx
To: Amit Kumar Singh/HSS@HSS
cc: kernelnewbies@xxxxxxxxxxxx, netfilter@xxxxxxxxxxxxxxxxxxx
Subject: Re: sysctl ip_queue_maxlen variable
Hit Amit,
On Thu, Jul 15, 2004 at 11:17:22AM +0530, aksingh@xxxxxxxxxxx told us:
>
> Hi,
>
> how does the sysctl ip_queue_maxlen variable
> work(net.ipv4.ip_queue_maxlen). This is used by the ip_queue.o module in
> the kernel to queue packets that have to be sent to user land using
netlink
> sockets. I felt that this sysctl variable helped us define the max length
> for the queue maintained by ip_queue.o, but when I looked at ip_queue.c ,
> the value for the sysctl variable is stored at &sysctl_maxlen, where as
> before enqueing a packet using the function __ipq_enqueue_entry, the
> present len is compared against the variable queue_maxlen and not against
> sysctl_maxlen, why is that so ?? so afterall is the queue max len
> configurable ?? i have tried using sysctl from command line on
> ip_queue_maxlen, it works fine and allows me to set it to any value
> sizeof(int), but is this value usde somewhere inside ip_queue, I could
not
> find that in ip_queue.c ... any clues ??
in which kernel version did you find this?? I've looked at 2.6.8-rc1
and 2.4.26, and in both kernel versions the variable used for the
sysctl and for checking in ip_queue.c. There is no variable
sysctl_maxlen in this file.
(from 2.4.26, around line 590):
static ctl_table ipq_table[] = {
{ NET_IPQ_QMAX, NET_IPQ_QMAX_NAME, &queue_maxlen,
sizeof(queue_maxlen), 0644, NULL, proc_dointvec },
{ 0 }
};
(from 2.4.26, around line 67, function __ipq_enqueue_entry):
if (queue_total >= queue_maxlen) {
if (net_ratelimit())
printk(KERN_WARNING "ip_queue: full at %d entries, "
"dropping packet(s).\n", queue_total);
return -ENOSPC;
}
HTH
Sven
>
> regards
> Amit
--
Linux zion 2.6.8-rc1 #3 Mon Jul 12 22:38:00 CEST 2004 i686 athlon i386
GNU/Linux
08:45:07 up 2 days, 10:02, 1 user, load average: 0.08, 0.06, 0.01
(See attached file: C.DTF)
Attachment:
C.DTF
Description: Binary data
