linux/net/dccp/diag.c
Arnaldo Carvalho de Melo a693722aec dccp_diag: LISTEN sockets don't have CCIDs
And thus when we try to use 'ss -danemi' on these sockets that have no
ccid blocks (data collected using systemtap after I fixed the problem):

dccp_diag_get_info sk=0xffff8801220a3100, dp->dccps_hc_rx_ccid=0x0000000000000000, dp->dccps_hc_tx_ccid=0x0000000000000000

We get an OOPS:

mica.ghostprotocols.net login: BUG: unable to handle kernel NULL pointer
dereferenc0
IP: [<ffffffffa0136082>] dccp_diag_get_info+0x82/0xc0 [dccp_diag]
PGD 12106f067 PUD 122488067 PMD 0
Oops: 0000 [#1] PREEMPT

Fix is trivial, and 'ss -d' is working again:

[root@mica ~]# ss -danemi
State   Recv-Q Send-Q   Local Address:Port   Peer Address:Port 
LISTEN  0      0                    *:5001              *:*
ino:7288 sk:220a3100ffff8801
	 mem:(r0,w0,f0,t0) cwnd:0 ssthresh:0
[root@mica ~]# 

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-17 16:08:01 -08:00

74 lines
1.9 KiB
C

/*
* net/dccp/diag.c
*
* An implementation of the DCCP protocol
* Arnaldo Carvalho de Melo <acme@mandriva.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/inet_diag.h>
#include "ccid.h"
#include "dccp.h"
static void dccp_get_info(struct sock *sk, struct tcp_info *info)
{
struct dccp_sock *dp = dccp_sk(sk);
const struct inet_connection_sock *icsk = inet_csk(sk);
memset(info, 0, sizeof(*info));
info->tcpi_state = sk->sk_state;
info->tcpi_retransmits = icsk->icsk_retransmits;
info->tcpi_probes = icsk->icsk_probes_out;
info->tcpi_backoff = icsk->icsk_backoff;
info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
if (dp->dccps_hc_rx_ackvec != NULL)
info->tcpi_options |= TCPI_OPT_SACK;
if (dp->dccps_hc_rx_ccid != NULL)
ccid_hc_rx_get_info(dp->dccps_hc_rx_ccid, sk, info);
if (dp->dccps_hc_tx_ccid != NULL)
ccid_hc_tx_get_info(dp->dccps_hc_tx_ccid, sk, info);
}
static void dccp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
void *_info)
{
r->idiag_rqueue = r->idiag_wqueue = 0;
if (_info != NULL)
dccp_get_info(sk, _info);
}
static const struct inet_diag_handler dccp_diag_handler = {
.idiag_hashinfo = &dccp_hashinfo,
.idiag_get_info = dccp_diag_get_info,
.idiag_type = DCCPDIAG_GETSOCK,
.idiag_info_size = sizeof(struct tcp_info),
};
static int __init dccp_diag_init(void)
{
return inet_diag_register(&dccp_diag_handler);
}
static void __exit dccp_diag_fini(void)
{
inet_diag_unregister(&dccp_diag_handler);
}
module_init(dccp_diag_init);
module_exit(dccp_diag_fini);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
MODULE_DESCRIPTION("DCCP inet_diag handler");
MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_INET_DIAG, DCCPDIAG_GETSOCK);