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Ian McDonalde41542f2006-09-22 14:28:01 +12001/*
2 * dccp_probe - Observe the DCCP flow with kprobes.
3 *
4 * The idea for this came from Werner Almesberger's umlsim
5 * Copyright (C) 2004, Stephen Hemminger <shemminger@osdl.org>
6 *
7 * Modified for DCCP from Stephen Hemminger's code
8 * Copyright (C) 2006, Ian McDonald <ian.mcdonald@jandi.co.nz>
9 *
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.
14 *
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.
19 *
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.
23 */
24
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090033#include <linux/gfp.h>
Eric W. Biederman457c4cb2007-09-12 12:01:34 +020034#include <net/net_namespace.h>
Ian McDonalde41542f2006-09-22 14:28:01 +120035
36#include "dccp.h"
37#include "ccid.h"
38#include "ccids/ccid3.h"
39
40static int port;
41
42static int bufsize = 64 * 1024;
43
44static const char procname[] = "dccpprobe";
45
Gerrit Renker1e2f0e52008-06-11 11:19:09 +010046static struct {
Stefani Seibold45465482009-12-21 14:37:26 -080047 struct kfifo fifo;
Ian McDonalde41542f2006-09-22 14:28:01 +120048 spinlock_t lock;
49 wait_queue_head_t wait;
YOSHIFUJI Hideakicdd04d92008-04-21 14:28:45 -070050 struct timespec tstart;
Ian McDonalde41542f2006-09-22 14:28:01 +120051} dccpw;
52
53static void printl(const char *fmt, ...)
54{
55 va_list args;
56 int len;
YOSHIFUJI Hideakicdd04d92008-04-21 14:28:45 -070057 struct timespec now;
Ian McDonalde41542f2006-09-22 14:28:01 +120058 char tbuf[256];
59
60 va_start(args, fmt);
YOSHIFUJI Hideakicdd04d92008-04-21 14:28:45 -070061 getnstimeofday(&now);
Ian McDonalde41542f2006-09-22 14:28:01 +120062
YOSHIFUJI Hideakicdd04d92008-04-21 14:28:45 -070063 now = timespec_sub(now, dccpw.tstart);
Ian McDonalde41542f2006-09-22 14:28:01 +120064
65 len = sprintf(tbuf, "%lu.%06lu ",
66 (unsigned long) now.tv_sec,
YOSHIFUJI Hideakicdd04d92008-04-21 14:28:45 -070067 (unsigned long) now.tv_nsec / NSEC_PER_USEC);
Ian McDonalde41542f2006-09-22 14:28:01 +120068 len += vscnprintf(tbuf+len, sizeof(tbuf)-len, fmt, args);
69 va_end(args);
70
Stefani Seibold7acd72e2009-12-21 14:37:28 -080071 kfifo_in_locked(&dccpw.fifo, tbuf, len, &dccpw.lock);
Ian McDonalde41542f2006-09-22 14:28:01 +120072 wake_up(&dccpw.wait);
73}
74
Ying Xue1b784142015-03-02 15:37:48 +080075static int jdccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
Ian McDonalde41542f2006-09-22 14:28:01 +120076{
Ian McDonalde41542f2006-09-22 14:28:01 +120077 const struct inet_sock *inet = inet_sk(sk);
Gerrit Renker996ccf42009-10-05 00:53:13 +000078 struct ccid3_hc_tx_sock *hc = NULL;
Ian McDonalde41542f2006-09-22 14:28:01 +120079
Gerrit Renker71c262a2008-11-23 16:04:59 -080080 if (ccid_get_current_tx_ccid(dccp_sk(sk)) == DCCPC_CCID3)
Gerrit Renker996ccf42009-10-05 00:53:13 +000081 hc = ccid3_hc_tx_sk(sk);
Ian McDonalde41542f2006-09-22 14:28:01 +120082
Eric Dumazetc720c7e2009-10-15 06:30:45 +000083 if (port == 0 || ntohs(inet->inet_dport) == port ||
84 ntohs(inet->inet_sport) == port) {
Gerrit Renker996ccf42009-10-05 00:53:13 +000085 if (hc)
Gerrit Renker388d5e92009-10-05 00:53:11 +000086 printl("%pI4:%u %pI4:%u %d %d %d %d %u %llu %llu %d\n",
Eric Dumazetc720c7e2009-10-15 06:30:45 +000087 &inet->inet_saddr, ntohs(inet->inet_sport),
88 &inet->inet_daddr, ntohs(inet->inet_dport), size,
Gerrit Renker996ccf42009-10-05 00:53:13 +000089 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);
Ian McDonalde41542f2006-09-22 14:28:01 +120092 else
Harvey Harrison21454aa2008-10-31 00:54:56 -070093 printl("%pI4:%u %pI4:%u %d\n",
Eric Dumazetc720c7e2009-10-15 06:30:45 +000094 &inet->inet_saddr, ntohs(inet->inet_sport),
95 &inet->inet_daddr, ntohs(inet->inet_dport),
96 size);
Ian McDonalde41542f2006-09-22 14:28:01 +120097 }
98
99 jprobe_return();
100 return 0;
101}
102
103static struct jprobe dccp_send_probe = {
Ian McDonalde1b74412006-11-20 18:41:37 -0200104 .kp = {
105 .symbol_name = "dccp_sendmsg",
106 },
Michael Ellerman9e367d82007-07-19 01:48:10 -0700107 .entry = jdccp_sendmsg,
Ian McDonalde41542f2006-09-22 14:28:01 +1200108};
109
110static int dccpprobe_open(struct inode *inode, struct file *file)
111{
Stefani Seibold45465482009-12-21 14:37:26 -0800112 kfifo_reset(&dccpw.fifo);
YOSHIFUJI Hideakicdd04d92008-04-21 14:28:45 -0700113 getnstimeofday(&dccpw.tstart);
Ian McDonalde41542f2006-09-22 14:28:01 +1200114 return 0;
115}
116
117static ssize_t dccpprobe_read(struct file *file, char __user *buf,
118 size_t len, loff_t *ppos)
119{
120 int error = 0, cnt = 0;
121 unsigned char *tbuf;
122
Bill Nottingham75202e72007-05-31 21:33:35 -0700123 if (!buf)
Ian McDonalde41542f2006-09-22 14:28:01 +1200124 return -EINVAL;
125
126 if (len == 0)
127 return 0;
128
129 tbuf = vmalloc(len);
130 if (!tbuf)
131 return -ENOMEM;
132
133 error = wait_event_interruptible(dccpw.wait,
Stefani Seibolde64c0262009-12-21 14:37:28 -0800134 kfifo_len(&dccpw.fifo) != 0);
Ian McDonalde41542f2006-09-22 14:28:01 +1200135 if (error)
136 goto out_free;
137
Stefani Seibold7acd72e2009-12-21 14:37:28 -0800138 cnt = kfifo_out_locked(&dccpw.fifo, tbuf, len, &dccpw.lock);
Pavel Emelyanov653252c2008-04-25 01:49:48 -0700139 error = copy_to_user(buf, tbuf, cnt) ? -EFAULT : 0;
Ian McDonalde41542f2006-09-22 14:28:01 +1200140
141out_free:
142 vfree(tbuf);
143
144 return error ? error : cnt;
145}
146
Arjan van de Ven9a321442007-02-12 00:55:35 -0800147static const struct file_operations dccpprobe_fops = {
Ian McDonalde41542f2006-09-22 14:28:01 +1200148 .owner = THIS_MODULE,
149 .open = dccpprobe_open,
150 .read = dccpprobe_read,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200151 .llseek = noop_llseek,
Ian McDonalde41542f2006-09-22 14:28:01 +1200152};
153
154static __init int dccpprobe_init(void)
155{
156 int ret = -ENOMEM;
157
158 init_waitqueue_head(&dccpw.wait);
159 spin_lock_init(&dccpw.lock);
Stefani Seiboldc1e13f22009-12-21 14:37:27 -0800160 if (kfifo_alloc(&dccpw.fifo, bufsize, GFP_KERNEL))
Stefani Seibold45465482009-12-21 14:37:26 -0800161 return ret;
Gao fengd4beaa62013-02-18 01:34:54 +0000162 if (!proc_create(procname, S_IRUSR, init_net.proc_net, &dccpprobe_fops))
Ian McDonalde41542f2006-09-22 14:28:01 +1200163 goto err0;
164
Wang Weidong965cdea2013-12-17 19:24:33 -0700165 ret = register_jprobe(&dccp_send_probe);
166 if (ret) {
167 ret = request_module("dccp");
168 if (!ret)
169 ret = register_jprobe(&dccp_send_probe);
170 }
171
Ian McDonalde41542f2006-09-22 14:28:01 +1200172 if (ret)
173 goto err1;
174
175 pr_info("DCCP watch registered (port=%d)\n", port);
176 return 0;
177err1:
Gao fengece31ff2013-02-18 01:34:56 +0000178 remove_proc_entry(procname, init_net.proc_net);
Ian McDonalde41542f2006-09-22 14:28:01 +1200179err0:
Stefani Seibold45465482009-12-21 14:37:26 -0800180 kfifo_free(&dccpw.fifo);
Ian McDonalde41542f2006-09-22 14:28:01 +1200181 return ret;
182}
183module_init(dccpprobe_init);
184
185static __exit void dccpprobe_exit(void)
186{
Stefani Seibold45465482009-12-21 14:37:26 -0800187 kfifo_free(&dccpw.fifo);
Gao fengece31ff2013-02-18 01:34:56 +0000188 remove_proc_entry(procname, init_net.proc_net);
Ian McDonalde41542f2006-09-22 14:28:01 +1200189 unregister_jprobe(&dccp_send_probe);
190
191}
192module_exit(dccpprobe_exit);
193
194MODULE_PARM_DESC(port, "Port to match (0=all)");
195module_param(port, int, 0);
196
197MODULE_PARM_DESC(bufsize, "Log buffer size (default 64k)");
198module_param(bufsize, int, 0);
199
200MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>");
201MODULE_DESCRIPTION("DCCP snooper");
202MODULE_LICENSE("GPL");