/*
 * netsniff-ng - the packet sniffing beast
 * Copyright 2009, 2010 Daniel Borkmann.
 * Subject to the GPL, version 2.
 */

#include <stdio.h>
#include <stdint.h>
#include <endian.h>
#include <netinet/in.h>    /* for ntohs() */
#include <asm/byteorder.h>

#include "proto.h"
#include "protos.h"
#include "dissector_eth.h"
#include "built_in.h"
#include "pkt_buff.h"

struct tcphdr {
	uint16_t source;
	uint16_t dest;
	uint32_t seq;
	uint32_t ack_seq;
#if defined(__LITTLE_ENDIAN_BITFIELD)
	__extension__ uint16_t res1:4,
			       doff:4,
			       fin:1,
			       syn:1,
			       rst:1,
			       psh:1,
			       ack:1,
			       urg:1,
			       ece:1,
			       cwr:1;
#elif defined(__BIG_ENDIAN_BITFIELD)
	__extension__ uint16_t doff:4,
			       res1:4,
			       cwr:1,
			       ece:1,
			       urg:1,
			       ack:1,
			       psh:1,
			       rst:1,
			       syn:1,
			       fin:1;
#else
# error  "Adjust your <asm/byteorder.h> defines"
#endif
	uint16_t window;
	uint16_t check;
	uint16_t urg_ptr;
} __packed;

static void tcp(struct pkt_buff *pkt)
{
	struct tcphdr *tcp = (struct tcphdr *) pkt_pull(pkt, sizeof(*tcp));
	uint16_t src, dest;
	char *src_name, *dest_name;

	if (tcp == NULL)
		return;

	src = ntohs(tcp->source);
	dest = ntohs(tcp->dest);

	src_name = lookup_port_tcp(src);
	dest_name = lookup_port_tcp(dest);

	tprintf(" [ TCP ");
	tprintf("Port (%u", src);
	if (src_name)
		tprintf(" (%s%s%s)", colorize_start(bold), src_name,
			colorize_end());
	tprintf(" => %u", dest);
	if (dest_name)
		tprintf(" (%s%s%s)", colorize_start(bold), dest_name,
			colorize_end());
	tprintf("), ");
	tprintf("SN (0x%x), ", ntohl(tcp->seq));
	tprintf("AN (0x%x), ", ntohl(tcp->ack_seq));
	tprintf("DataOff (%u), ", tcp->doff);
	tprintf("Res (%u), ", tcp->res1);
	tprintf("Flags (");
	if (tcp->fin)
		tprintf("FIN ");
	if (tcp->syn)
		tprintf("SYN ");
	if (tcp->rst)
		tprintf("RST ");
	if (tcp->psh)
		tprintf("PSH ");
	if (tcp->ack)
		tprintf("ACK ");
	if (tcp->urg)
		tprintf("URG ");
	if (tcp->ece)
		tprintf("ECE ");
	if (tcp->cwr)
		tprintf("CWR ");
	tprintf("), ");
	tprintf("Window (%u), ", ntohs(tcp->window));
	tprintf("CSum (0x%.4x), ", ntohs(tcp->check));
	tprintf("UrgPtr (%u)", ntohs(tcp->urg_ptr));
	tprintf(" ]\n");
}

static void tcp_less(struct pkt_buff *pkt)
{
	struct tcphdr *tcp = (struct tcphdr *) pkt_pull(pkt, sizeof(*tcp));
	uint16_t src, dest;
	char *src_name, *dest_name;

	if (tcp == NULL)
		return;

	src = ntohs(tcp->source);
	dest = ntohs(tcp->dest);

	src_name = lookup_port_tcp(src);
	dest_name = lookup_port_tcp(dest);

	tprintf(" TCP %u", src);
	if(src_name)
		tprintf("(%s%s%s)", colorize_start(bold), src_name,
			colorize_end());
	tprintf("/%u", dest);
	if(dest_name)
		tprintf("(%s%s%s)", colorize_start(bold), dest_name,
			colorize_end());
	tprintf(" F%s",colorize_start(bold));
	if (tcp->fin)
		tprintf(" FIN");
	if (tcp->syn)
		tprintf(" SYN");
	if (tcp->rst)
		tprintf(" RST");
	if (tcp->psh)
		tprintf(" PSH");
	if (tcp->ack)
		tprintf(" ACK");
	if (tcp->urg)
		tprintf(" URG");
	if (tcp->ece)
		tprintf(" ECE");
	if (tcp->cwr)
		tprintf(" CWR");
	tprintf("%s Win %u S/A 0x%x/0x%x", colorize_end(),
		ntohs(tcp->window), ntohl(tcp->seq), ntohl(tcp->ack_seq));
}

struct protocol tcp_ops = {
	.key = 0x06,
	.print_full = tcp,
	.print_less = tcp_less,
};
 colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Douglas Miller &lt;dougmill@linux.vnet.ibm.com&gt;</td><td class='right'>2017-01-28 06:42:20 -0600</td></tr>
<tr><th>committer</th><td>Tejun Heo &lt;tj@kernel.org&gt;</td><td class='right'>2017-01-28 07:49:42 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/parisc/Kconfig?id=966d2b04e070bc040319aaebfec09e0144dc3341'>966d2b04e070bc040319aaebfec09e0144dc3341</a> (<a href='/cgit.cgi/linux/net-next.git/patch/sound/parisc/Kconfig?id=966d2b04e070bc040319aaebfec09e0144dc3341'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=966d2b04e070bc040319aaebfec09e0144dc3341'>4b96156e3d1dd4dfd6039b7c219c9dc4616da52d</a> /<a href='/cgit.cgi/linux/net-next.git/tree/sound/parisc/Kconfig?id=966d2b04e070bc040319aaebfec09e0144dc3341'>sound/parisc/Kconfig</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/parisc/Kconfig?id=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>1b1bc42c1692e9b62756323c675a44cb1a1f9dbd</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/parisc/Kconfig?id=966d2b04e070bc040319aaebfec09e0144dc3341&amp;id2=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>diff</a>)</td></tr></table>
<div class='commit-subject'>percpu-refcount: fix reference leak during percpu-atomic transition</div><div class='commit-msg'>percpu_ref_tryget() and percpu_ref_tryget_live() should return
"true" IFF they acquire a reference. But the return value from
atomic_long_inc_not_zero() is a long and may have high bits set,
e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines
is bool so the reference may actually be acquired but the routines
return "false" which results in a reference leak since the caller
assumes it does not need to do a corresponding percpu_ref_put().

This was seen when performing CPU hotplug during I/O, as hangs in
blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start)
raced with percpu_ref_tryget (blk_mq_timeout_work).
Sample stack trace:

__switch_to+0x2c0/0x450
__schedule+0x2f8/0x970
schedule+0x48/0xc0
blk_mq_freeze_queue_wait+0x94/0x120
blk_mq_queue_reinit_work+0xb8/0x180
blk_mq_queue_reinit_prepare+0x84/0xa0
cpuhp_invoke_callback+0x17c/0x600
cpuhp_up_callbacks+0x58/0x150
_cpu_up+0xf0/0x1c0
do_cpu_up+0x120/0x150
cpu_subsys_online+0x64/0xe0
device_online+0xb4/0x120
online_store+0xb4/0xc0
dev_attr_store+0x68/0xa0
sysfs_kf_write+0x80/0xb0
kernfs_fop_write+0x17c/0x250
__vfs_write+0x6c/0x1e0
vfs_write+0xd0/0x270
SyS_write+0x6c/0x110
system_call+0x38/0xe0

Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS,
and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests.
However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0
and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set.

The fix is to make the tryget routines use an actual boolean internally instead
of the atomic long result truncated to a int.

Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints
Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751
Signed-off-by: Douglas Miller &lt;dougmill@linux.vnet.ibm.com&gt;
Reviewed-by: Jens Axboe &lt;axboe@fb.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints")
Cc: stable@vger.kernel.org # v3.18+
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=966d2b04e070bc040319aaebfec09e0144dc3341'>Diffstat</a> (limited to 'sound/parisc/Kconfig')</div><table summary='diffstat' class='diffstat'>