/*
 * tcp_diag.c	Module for monitoring TCP transport protocols sockets.
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 *	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 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/net.h>
#include <linux/sock_diag.h>
#include <linux/inet_diag.h>

#include <linux/tcp.h>

#include <net/tcp.h>

static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
			      void *_info)
{
	struct tcp_info *info = _info;

	if (sk_state_load(sk) == TCP_LISTEN) {
		r->idiag_rqueue = sk->sk_ack_backlog;
		r->idiag_wqueue = sk->sk_max_ack_backlog;
	} else if (sk->sk_type == SOCK_STREAM) {
		const struct tcp_sock *tp = tcp_sk(sk);

		r->idiag_rqueue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
		r->idiag_wqueue = tp->write_seq - tp->snd_una;
	}
	if (info)
		tcp_get_info(sk, info);
}

static void tcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
			  const struct inet_diag_req_v2 *r, struct nlattr *bc)
{
	inet_diag_dump_icsk(&tcp_hashinfo, skb, cb, r, bc);
}

static int tcp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
			     const struct inet_diag_req_v2 *req)
{
	return inet_diag_dump_one_icsk(&tcp_hashinfo, in_skb, nlh, req);
}

#ifdef CONFIG_INET_DIAG_DESTROY
static int tcp_diag_destroy(struct sk_buff *in_skb,
			    const struct inet_diag_req_v2 *req)
{
	struct net *net = sock_net(in_skb->sk);
	struct sock *sk = inet_diag_find_one_icsk(net, &tcp_hashinfo, req);
	int err;

	if (IS_ERR(sk))
		return PTR_ERR(sk);

	err = sock_diag_destroy(sk, ECONNABORTED);

	sock_gen_put(sk);

	return err;
}
#endif

static const struct inet_diag_handler tcp_diag_handler = {
	.dump		 = tcp_diag_dump,
	.dump_one	 = tcp_diag_dump_one,
	.idiag_get_info	 = tcp_diag_get_info,
	.idiag_type	 = IPPROTO_TCP,
	.idiag_info_size = sizeof(struct tcp_info),
#ifdef CONFIG_INET_DIAG_DESTROY
	.destroy	 = tcp_diag_destroy,
#endif
};

static int __init tcp_diag_init(void)
{
	return inet_diag_register(&tcp_diag_handler);
}

static void __exit tcp_diag_exit(void)
{
	inet_diag_unregister(&tcp_diag_handler);
}

module_init(tcp_diag_init);
module_exit(tcp_diag_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-6 /* AF_INET - IPPROTO_TCP */);

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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=90427ef5d2a4b9a24079889bf16afdcdaebc4240'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include?id=90427ef5d2a4b9a24079889bf16afdcdaebc4240'>include</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='90427ef5d2a4b9a24079889bf16afdcdaebc4240'/><table><tr><td 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>Dimitris Michailidis &lt;dmichail@google.com&gt;</td><td class='right'>2017-01-30 14:09:42 -0800</td></tr>
<tr><th>committer</th><td>David S. Miller &lt;davem@davemloft.net&gt;</td><td class='right'>2017-01-31 13:16:59 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include?id=90427ef5d2a4b9a24079889bf16afdcdaebc4240'>90427ef5d2a4b9a24079889bf16afdcdaebc4240</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include?id=90427ef5d2a4b9a24079889bf16afdcdaebc4240'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=90427ef5d2a4b9a24079889bf16afdcdaebc4240'>05a3105bb966ada2f06b1c29dfcaa5e3bbf89223</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include?id=90427ef5d2a4b9a24079889bf16afdcdaebc4240'>include</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include?id=c73e44269369e936165f0f9b61f1f09a11dae01c'>c73e44269369e936165f0f9b61f1f09a11dae01c</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include?id=90427ef5d2a4b9a24079889bf16afdcdaebc4240&amp;id2=c73e44269369e936165f0f9b61f1f09a11dae01c'>diff</a>)</td></tr></table>
<div class='commit-subject'>ipv6: fix flow labels when the traffic class is non-0</div><div class='commit-msg'>ip6_make_flowlabel() determines the flow label for IPv6 packets. It's
supposed to be passed a flow label, which it returns as is if non-0 and
in some other cases, otherwise it calculates a new value.

The problem is callers often pass a flowi6.flowlabel, which may also
contain traffic class bits. If the traffic class is non-0
ip6_make_flowlabel() mistakes the non-0 it gets as a flow label and
returns the whole thing. Thus it can return a 'flow label' longer than
20b and the low 20b of that is typically 0 resulting in packets with 0
label. Moreover, different packets of a flow may be labeled differently.
For a TCP flow with ECN non-payload and payload packets get different
labels as exemplified by this pair of consecutive packets:

(pure ACK)
Internet Protocol Version 6, Src: 2002:af5:11a3::, Dst: 2002:af5:11a2::
    0110 .... = Version: 6
    .... 0000 0000 .... .... .... .... .... = Traffic Class: 0x00 (DSCP: CS0, ECN: Not-ECT)
        .... 0000 00.. .... .... .... .... .... = Differentiated Services Codepoint: Default (0)
        .... .... ..00 .... .... .... .... .... = Explicit Congestion Notification: Not ECN-Capable Transport (0)
    .... .... .... 0001 1100 1110 0100 1001 = Flow Label: 0x1ce49
    Payload Length: 32
    Next Header: TCP (6)

(payload)
Internet Protocol Version 6, Src: 2002:af5:11a3::, Dst: 2002:af5:11a2::
    0110 .... = Version: 6
    .... 0000 0010 .... .... .... .... .... = Traffic Class: 0x02 (DSCP: CS0, ECN: ECT(0))
        .... 0000 00.. .... .... .... .... .... = Differentiated Services Codepoint: Default (0)
        .... .... ..10 .... .... .... .... .... = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)
    .... .... .... 0000 0000 0000 0000 0000 = Flow Label: 0x00000
    Payload Length: 688
    Next Header: TCP (6)

This patch allows ip6_make_flowlabel() to be passed more than just a
flow label and has it extract the part it really wants. This was simpler
than modifying the callers. With this patch packets like the above become

Internet Protocol Version 6, Src: 2002:af5:11a3::, Dst: 2002:af5:11a2::
    0110 .... = Version: 6
    .... 0000 0000 .... .... .... .... .... = Traffic Class: 0x00 (DSCP: CS0, ECN: Not-ECT)
        .... 0000 00.. .... .... .... .... .... = Differentiated Services Codepoint: Default (0)
        .... .... ..00 .... .... .... .... .... = Explicit Congestion Notification: Not ECN-Capable Transport (0)
    .... .... .... 1010 1111 1010 0101 1110 = Flow Label: 0xafa5e
    Payload Length: 32
    Next Header: TCP (6)

Internet Protocol Version 6, Src: 2002:af5:11a3::, Dst: 2002:af5:11a2::
    0110 .... = Version: 6
    .... 0000 0010 .... .... .... .... .... = Traffic Class: 0x02 (DSCP: CS0, ECN: ECT(0))
        .... 0000 00.. .... .... .... .... .... = Differentiated Services Codepoint: Default (0)
        .... .... ..10 .... .... .... .... .... = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)
    .... .... .... 1010 1111 1010 0101 1110 = Flow Label: 0xafa5e
    Payload Length: 688
    Next Header: TCP (6)

Signed-off-by: Dimitris Michailidis &lt;dmichail@google.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=90427ef5d2a4b9a24079889bf16afdcdaebc4240'>Diffstat</a> (limited to 'include')</div><table summary='diffstat' class='diffstat'><tr><td class='mode'>-rw-r--r--</td><td class='upd'><a href='/cgit.cgi/linux/net-next.git/diff/include/net/ipv6.h?id=90427ef5d2a4b9a24079889bf16afdcdaebc4240'>include/net/ipv6.h</a></td><td class='right'>5</td><td class='graph'><table summary='file diffstat' width='5%'><tr><td class='add' style='width: 100.0%;'/><td class='rem' style='width: 0.0%;'/><td class='none' style='width: 0.0%;'/></tr></table></td></tr>
</table><div class='diffstat-summary'>1 files changed, 5 insertions, 0 deletions</div><table summary='diff' class='diff'><tr><td><div class='head'>diff --git a/include/net/ipv6.h b/include/net/ipv6.h