Revision 523b929d5446c023e1219aa81455a8c766cac883 authored by Pablo Neira Ayuso on 25 October 2014, 16:40:26 UTC, committed by Pablo Neira Ayuso on 31 October 2014, 11:50:08 UTC
If the packet is received via the bridge stack, this cannot reject packets from the IP stack. This adds functions to build the reject packet and send it from the bridge stack. Comments and assumptions on this patch: 1) Validate the IPv4 and IPv6 headers before further processing, given that the packet comes from the bridge stack, we cannot assume they are clean. Truncated packets are dropped, we follow similar approach in the existing iptables match/target extensions that need to inspect layer 4 headers that is not available. This also includes packets that are directed to multicast and broadcast ethernet addresses. 2) br_deliver() is exported to inject the reject packet via bridge localout -> postrouting. So the approach is similar to what we already do in the iptables reject target. The reject packet is sent to the bridge port from which we have received the original packet. 3) The reject packet is forged based on the original packet. The TTL is set based on sysctl_ip_default_ttl for IPv4 and per-net ipv6.devconf_all hoplimit for IPv6. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
1 parent 8bfcdf6
xor.c
/*
* xor.c : Multiple Devices driver for Linux
*
* Copyright (C) 1996, 1997, 1998, 1999, 2000,
* Ingo Molnar, Matti Aarnio, Jakub Jelinek, Richard Henderson.
*
* Dispatch optimized RAID-5 checksumming functions.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* You should have received a copy of the GNU General Public License
* (for example /usr/src/linux/COPYING); if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#define BH_TRACE 0
#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/raid/xor.h>
#include <linux/jiffies.h>
#include <linux/preempt.h>
#include <asm/xor.h>
/* The xor routines to use. */
static struct xor_block_template *active_template;
void
xor_blocks(unsigned int src_count, unsigned int bytes, void *dest, void **srcs)
{
unsigned long *p1, *p2, *p3, *p4;
p1 = (unsigned long *) srcs[0];
if (src_count == 1) {
active_template->do_2(bytes, dest, p1);
return;
}
p2 = (unsigned long *) srcs[1];
if (src_count == 2) {
active_template->do_3(bytes, dest, p1, p2);
return;
}
p3 = (unsigned long *) srcs[2];
if (src_count == 3) {
active_template->do_4(bytes, dest, p1, p2, p3);
return;
}
p4 = (unsigned long *) srcs[3];
active_template->do_5(bytes, dest, p1, p2, p3, p4);
}
EXPORT_SYMBOL(xor_blocks);
/* Set of all registered templates. */
static struct xor_block_template *__initdata template_list;
#define BENCH_SIZE (PAGE_SIZE)
static void __init
do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)
{
int speed;
unsigned long now, j;
int i, count, max;
tmpl->next = template_list;
template_list = tmpl;
preempt_disable();
/*
* Count the number of XORs done during a whole jiffy, and use
* this to calculate the speed of checksumming. We use a 2-page
* allocation to have guaranteed color L1-cache layout.
*/
max = 0;
for (i = 0; i < 5; i++) {
j = jiffies;
count = 0;
while ((now = jiffies) == j)
cpu_relax();
while (time_before(jiffies, now + 1)) {
mb(); /* prevent loop optimzation */
tmpl->do_2(BENCH_SIZE, b1, b2);
mb();
count++;
mb();
}
if (count > max)
max = count;
}
preempt_enable();
speed = max * (HZ * BENCH_SIZE / 1024);
tmpl->speed = speed;
printk(KERN_INFO " %-10s: %5d.%03d MB/sec\n", tmpl->name,
speed / 1000, speed % 1000);
}
static int __init
calibrate_xor_blocks(void)
{
void *b1, *b2;
struct xor_block_template *f, *fastest;
/*
* Note: Since the memory is not actually used for _anything_ but to
* test the XOR speed, we don't really want kmemcheck to warn about
* reading uninitialized bytes here.
*/
b1 = (void *) __get_free_pages(GFP_KERNEL | __GFP_NOTRACK, 2);
if (!b1) {
printk(KERN_WARNING "xor: Yikes! No memory available.\n");
return -ENOMEM;
}
b2 = b1 + 2*PAGE_SIZE + BENCH_SIZE;
/*
* If this arch/cpu has a short-circuited selection, don't loop through
* all the possible functions, just test the best one
*/
fastest = NULL;
#ifdef XOR_SELECT_TEMPLATE
fastest = XOR_SELECT_TEMPLATE(fastest);
#endif
#define xor_speed(templ) do_xor_speed((templ), b1, b2)
if (fastest) {
printk(KERN_INFO "xor: automatically using best "
"checksumming function:\n");
xor_speed(fastest);
goto out;
} else {
printk(KERN_INFO "xor: measuring software checksum speed\n");
XOR_TRY_TEMPLATES;
fastest = template_list;
for (f = fastest; f; f = f->next)
if (f->speed > fastest->speed)
fastest = f;
}
printk(KERN_INFO "xor: using function: %s (%d.%03d MB/sec)\n",
fastest->name, fastest->speed / 1000, fastest->speed % 1000);
#undef xor_speed
out:
free_pages((unsigned long)b1, 2);
active_template = fastest;
return 0;
}
static __exit void xor_exit(void) { }
MODULE_LICENSE("GPL");
/* when built-in xor.o must initialize before drivers/md/md.o */
core_initcall(calibrate_xor_blocks);
module_exit(xor_exit);
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