2 * sctp_probe - Observe the SCTP flow with kprobes.
4 * The idea for this came from Werner Almesberger's umlsim
5 * Copyright (C) 2004, Stephen Hemminger <shemminger@osdl.org>
7 * Modified for SCTP from Stephen Hemminger's code
8 * Copyright (C) 2010, Wei Yongjun <yjwei@cn.fujitsu.com>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27 #include <linux/kernel.h>
28 #include <linux/kprobes.h>
29 #include <linux/socket.h>
30 #include <linux/sctp.h>
31 #include <linux/proc_fs.h>
32 #include <linux/vmalloc.h>
33 #include <linux/module.h>
34 #include <linux/kfifo.h>
35 #include <linux/time.h>
36 #include <net/net_namespace.h>
38 #include <net/sctp/sctp.h>
39 #include <net/sctp/sm.h>
41 MODULE_SOFTDEP("pre: sctp");
42 MODULE_AUTHOR("Wei Yongjun <yjwei@cn.fujitsu.com>");
43 MODULE_DESCRIPTION("SCTP snooper");
44 MODULE_LICENSE("GPL");
46 static int port __read_mostly
= 0;
47 MODULE_PARM_DESC(port
, "Port to match (0=all)");
48 module_param(port
, int, 0);
50 static unsigned int fwmark __read_mostly
= 0;
51 MODULE_PARM_DESC(fwmark
, "skb mark to match (0=no mark)");
52 module_param(fwmark
, uint
, 0);
54 static int bufsize __read_mostly
= 64 * 1024;
55 MODULE_PARM_DESC(bufsize
, "Log buffer size (default 64k)");
56 module_param(bufsize
, int, 0);
58 static int full __read_mostly
= 1;
59 MODULE_PARM_DESC(full
, "Full log (1=every ack packet received, 0=only cwnd changes)");
60 module_param(full
, int, 0);
62 static const char procname
[] = "sctpprobe";
67 wait_queue_head_t wait
;
68 struct timespec tstart
;
71 static __printf(1, 2) void printl(const char *fmt
, ...)
78 len
= vscnprintf(tbuf
, sizeof(tbuf
), fmt
, args
);
81 kfifo_in_locked(&sctpw
.fifo
, tbuf
, len
, &sctpw
.lock
);
85 static int sctpprobe_open(struct inode
*inode
, struct file
*file
)
87 kfifo_reset(&sctpw
.fifo
);
88 getnstimeofday(&sctpw
.tstart
);
93 static ssize_t
sctpprobe_read(struct file
*file
, char __user
*buf
,
94 size_t len
, loff_t
*ppos
)
96 int error
= 0, cnt
= 0;
109 error
= wait_event_interruptible(sctpw
.wait
,
110 kfifo_len(&sctpw
.fifo
) != 0);
114 cnt
= kfifo_out_locked(&sctpw
.fifo
, tbuf
, len
, &sctpw
.lock
);
115 error
= copy_to_user(buf
, tbuf
, cnt
) ? -EFAULT
: 0;
120 return error
? error
: cnt
;
123 static const struct file_operations sctpprobe_fops
= {
124 .owner
= THIS_MODULE
,
125 .open
= sctpprobe_open
,
126 .read
= sctpprobe_read
,
127 .llseek
= noop_llseek
,
130 static sctp_disposition_t
jsctp_sf_eat_sack(struct net
*net
,
131 const struct sctp_endpoint
*ep
,
132 const struct sctp_association
*asoc
,
133 const sctp_subtype_t type
,
135 sctp_cmd_seq_t
*commands
)
137 struct sctp_chunk
*chunk
= arg
;
138 struct sk_buff
*skb
= chunk
->skb
;
139 struct sctp_transport
*sp
;
140 static __u32 lcwnd
= 0;
143 sp
= asoc
->peer
.primary_path
;
145 if (((port
== 0 && fwmark
== 0) ||
146 asoc
->peer
.port
== port
||
147 ep
->base
.bind_addr
.port
== port
||
148 (fwmark
> 0 && skb
->mark
== fwmark
)) &&
149 (full
|| sp
->cwnd
!= lcwnd
)) {
152 getnstimeofday(&now
);
153 now
= timespec_sub(now
, sctpw
.tstart
);
155 printl("%lu.%06lu ", (unsigned long) now
.tv_sec
,
156 (unsigned long) now
.tv_nsec
/ NSEC_PER_USEC
);
158 printl("%p %5d %5d %5d %8d %5d ", asoc
,
159 ep
->base
.bind_addr
.port
, asoc
->peer
.port
,
160 asoc
->pathmtu
, asoc
->peer
.rwnd
, asoc
->unack_data
);
162 list_for_each_entry(sp
, &asoc
->peer
.transport_addr_list
,
164 if (sp
== asoc
->peer
.primary_path
)
167 printl("%pISc %2u %8u %8u %8u %8u %8u ",
168 &sp
->ipaddr
, sp
->state
, sp
->cwnd
, sp
->ssthresh
,
169 sp
->flight_size
, sp
->partial_bytes_acked
,
179 static struct jprobe sctp_recv_probe
= {
181 .symbol_name
= "sctp_sf_eat_sack_6_2",
183 .entry
= jsctp_sf_eat_sack
,
186 static __init
int sctp_setup_jprobe(void)
188 int ret
= register_jprobe(&sctp_recv_probe
);
191 if (request_module("sctp"))
193 ret
= register_jprobe(&sctp_recv_probe
);
200 static __init
int sctpprobe_init(void)
204 /* Warning: if the function signature of sctp_sf_eat_sack_6_2,
205 * has been changed, you also have to change the signature of
206 * jsctp_sf_eat_sack, otherwise you end up right here!
208 BUILD_BUG_ON(__same_type(sctp_sf_eat_sack_6_2
,
209 jsctp_sf_eat_sack
) == 0);
211 init_waitqueue_head(&sctpw
.wait
);
212 spin_lock_init(&sctpw
.lock
);
213 if (kfifo_alloc(&sctpw
.fifo
, bufsize
, GFP_KERNEL
))
216 if (!proc_create(procname
, S_IRUSR
, init_net
.proc_net
,
220 ret
= sctp_setup_jprobe();
224 pr_info("probe registered (port=%d/fwmark=%u) bufsize=%u\n",
225 port
, fwmark
, bufsize
);
229 remove_proc_entry(procname
, init_net
.proc_net
);
231 kfifo_free(&sctpw
.fifo
);
235 static __exit
void sctpprobe_exit(void)
237 kfifo_free(&sctpw
.fifo
);
238 remove_proc_entry(procname
, init_net
.proc_net
);
239 unregister_jprobe(&sctp_recv_probe
);
242 module_init(sctpprobe_init
);
243 module_exit(sctpprobe_exit
);