2 * dccp_probe - Observe the DCCP 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 DCCP from Stephen Hemminger's code
8 * Copyright (C) 2006, Ian McDonald <ian.mcdonald@jandi.co.nz>
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 #include <linux/kernel.h>
26 #include <linux/kprobes.h>
27 #include <linux/socket.h>
28 #include <linux/dccp.h>
29 #include <linux/proc_fs.h>
30 #include <linux/module.h>
31 #include <linux/kfifo.h>
32 #include <linux/vmalloc.h>
33 #include <net/net_namespace.h>
37 #include "ccids/ccid3.h"
41 static int bufsize
= 64 * 1024;
43 static const char procname
[] = "dccpprobe";
48 wait_queue_head_t wait
;
49 struct timespec tstart
;
52 static void printl(const char *fmt
, ...)
62 now
= timespec_sub(now
, dccpw
.tstart
);
64 len
= sprintf(tbuf
, "%lu.%06lu ",
65 (unsigned long) now
.tv_sec
,
66 (unsigned long) now
.tv_nsec
/ NSEC_PER_USEC
);
67 len
+= vscnprintf(tbuf
+len
, sizeof(tbuf
)-len
, fmt
, args
);
70 kfifo_put(dccpw
.fifo
, tbuf
, len
);
74 static int jdccp_sendmsg(struct kiocb
*iocb
, struct sock
*sk
,
75 struct msghdr
*msg
, size_t size
)
77 const struct inet_sock
*inet
= inet_sk(sk
);
78 struct ccid3_hc_tx_sock
*hc
= NULL
;
80 if (ccid_get_current_tx_ccid(dccp_sk(sk
)) == DCCPC_CCID3
)
81 hc
= ccid3_hc_tx_sk(sk
);
83 if (port
== 0 || ntohs(inet
->dport
) == port
||
84 ntohs(inet
->sport
) == port
) {
86 printl("%pI4:%u %pI4:%u %d %d %d %d %u %llu %llu %d\n",
87 &inet
->saddr
, ntohs(inet
->sport
),
88 &inet
->daddr
, ntohs(inet
->dport
), size
,
89 hc
->tx_s
, hc
->tx_rtt
, hc
->tx_p
,
90 hc
->tx_x_calc
, hc
->tx_x_recv
>> 6,
91 hc
->tx_x
>> 6, hc
->tx_t_ipi
);
93 printl("%pI4:%u %pI4:%u %d\n",
94 &inet
->saddr
, ntohs(inet
->sport
),
95 &inet
->daddr
, ntohs(inet
->dport
), size
);
102 static struct jprobe dccp_send_probe
= {
104 .symbol_name
= "dccp_sendmsg",
106 .entry
= jdccp_sendmsg
,
109 static int dccpprobe_open(struct inode
*inode
, struct file
*file
)
111 kfifo_reset(dccpw
.fifo
);
112 getnstimeofday(&dccpw
.tstart
);
116 static ssize_t
dccpprobe_read(struct file
*file
, char __user
*buf
,
117 size_t len
, loff_t
*ppos
)
119 int error
= 0, cnt
= 0;
132 error
= wait_event_interruptible(dccpw
.wait
,
133 __kfifo_len(dccpw
.fifo
) != 0);
137 cnt
= kfifo_get(dccpw
.fifo
, tbuf
, len
);
138 error
= copy_to_user(buf
, tbuf
, cnt
) ? -EFAULT
: 0;
143 return error
? error
: cnt
;
146 static const struct file_operations dccpprobe_fops
= {
147 .owner
= THIS_MODULE
,
148 .open
= dccpprobe_open
,
149 .read
= dccpprobe_read
,
152 static __init
int dccpprobe_init(void)
156 init_waitqueue_head(&dccpw
.wait
);
157 spin_lock_init(&dccpw
.lock
);
158 dccpw
.fifo
= kfifo_alloc(bufsize
, GFP_KERNEL
, &dccpw
.lock
);
159 if (IS_ERR(dccpw
.fifo
))
160 return PTR_ERR(dccpw
.fifo
);
162 if (!proc_net_fops_create(&init_net
, procname
, S_IRUSR
, &dccpprobe_fops
))
165 ret
= register_jprobe(&dccp_send_probe
);
169 pr_info("DCCP watch registered (port=%d)\n", port
);
172 proc_net_remove(&init_net
, procname
);
174 kfifo_free(dccpw
.fifo
);
177 module_init(dccpprobe_init
);
179 static __exit
void dccpprobe_exit(void)
181 kfifo_free(dccpw
.fifo
);
182 proc_net_remove(&init_net
, procname
);
183 unregister_jprobe(&dccp_send_probe
);
186 module_exit(dccpprobe_exit
);
188 MODULE_PARM_DESC(port
, "Port to match (0=all)");
189 module_param(port
, int, 0);
191 MODULE_PARM_DESC(bufsize
, "Log buffer size (default 64k)");
192 module_param(bufsize
, int, 0);
194 MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>");
195 MODULE_DESCRIPTION("DCCP snooper");
196 MODULE_LICENSE("GPL");