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authorIan McDonald <ian.mcdonald@jandi.co.nz>2006-09-21 22:28:01 -0400
committerArnaldo Carvalho de Melo <acme@mandriva.com>2006-09-24 17:08:17 -0400
commite41542f5167d6b506607f8dd111fa0a3e468ccb8 (patch)
tree89fefd3feb59f11f256dd276038a562c09b4602d /net/dccp/probe.c
parent3dd9a7c3a155ee96160876cba92439fdc96d7e0b (diff)
[DCCP]: Introduce dccp_probe
This adds DCCP probing shamelessly ripped off from TCP probes by Stephen Hemminger. I've put in here support for further CCID3 variables as well. Andrea/Arnaldo might look to extend for CCID2. Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Diffstat (limited to 'net/dccp/probe.c')
-rw-r--r--net/dccp/probe.c198
1 files changed, 198 insertions, 0 deletions
diff --git a/net/dccp/probe.c b/net/dccp/probe.c
new file mode 100644
index 000000000000..146496fce2e2
--- /dev/null
+++ b/net/dccp/probe.c
@@ -0,0 +1,198 @@
1/*
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>
33
34#include "dccp.h"
35#include "ccid.h"
36#include "ccids/ccid3.h"
37
38static int port;
39
40static int bufsize = 64 * 1024;
41
42static const char procname[] = "dccpprobe";
43
44struct {
45 struct kfifo *fifo;
46 spinlock_t lock;
47 wait_queue_head_t wait;
48 struct timeval tstart;
49} dccpw;
50
51static void printl(const char *fmt, ...)
52{
53 va_list args;
54 int len;
55 struct timeval now;
56 char tbuf[256];
57
58 va_start(args, fmt);
59 do_gettimeofday(&now);
60
61 now.tv_sec -= dccpw.tstart.tv_sec;
62 now.tv_usec -= dccpw.tstart.tv_usec;
63 if (now.tv_usec < 0) {
64 --now.tv_sec;
65 now.tv_usec += 1000000;
66 }
67
68 len = sprintf(tbuf, "%lu.%06lu ",
69 (unsigned long) now.tv_sec,
70 (unsigned long) now.tv_usec);
71 len += vscnprintf(tbuf+len, sizeof(tbuf)-len, fmt, args);
72 va_end(args);
73
74 kfifo_put(dccpw.fifo, tbuf, len);
75 wake_up(&dccpw.wait);
76}
77
78static int jdccp_sendmsg(struct kiocb *iocb, struct sock *sk,
79 struct msghdr *msg, size_t size)
80{
81 const struct dccp_minisock *dmsk = dccp_msk(sk);
82 const struct inet_sock *inet = inet_sk(sk);
83 const struct ccid3_hc_tx_sock *hctx;
84
85 if (dmsk->dccpms_tx_ccid == DCCPC_CCID3)
86 hctx = ccid3_hc_tx_sk(sk);
87 else
88 hctx = NULL;
89
90 if (port == 0 || ntohs(inet->dport) == port ||
91 ntohs(inet->sport) == port) {
92 if (hctx)
93 printl("%d.%d.%d.%d:%u %d.%d.%d.%d:%u %d %d %d %d %d\n",
94 NIPQUAD(inet->saddr), ntohs(inet->sport),
95 NIPQUAD(inet->daddr), ntohs(inet->dport), size,
96 hctx->ccid3hctx_s, hctx->ccid3hctx_rtt,
97 hctx->ccid3hctx_p, hctx->ccid3hctx_t_ipi);
98 else
99 printl("%d.%d.%d.%d:%u %d.%d.%d.%d:%u %d\n",
100 NIPQUAD(inet->saddr), ntohs(inet->sport),
101 NIPQUAD(inet->daddr), ntohs(inet->dport), size);
102 }
103
104 jprobe_return();
105 return 0;
106}
107
108static struct jprobe dccp_send_probe = {
109 .kp = { .addr = (kprobe_opcode_t *)&dccp_sendmsg, },
110 .entry = (kprobe_opcode_t *)&jdccp_sendmsg,
111};
112
113static int dccpprobe_open(struct inode *inode, struct file *file)
114{
115 kfifo_reset(dccpw.fifo);
116 do_gettimeofday(&dccpw.tstart);
117 return 0;
118}
119
120static ssize_t dccpprobe_read(struct file *file, char __user *buf,
121 size_t len, loff_t *ppos)
122{
123 int error = 0, cnt = 0;
124 unsigned char *tbuf;
125
126 if (!buf || len < 0)
127 return -EINVAL;
128
129 if (len == 0)
130 return 0;
131
132 tbuf = vmalloc(len);
133 if (!tbuf)
134 return -ENOMEM;
135
136 error = wait_event_interruptible(dccpw.wait,
137 __kfifo_len(dccpw.fifo) != 0);
138 if (error)
139 goto out_free;
140
141 cnt = kfifo_get(dccpw.fifo, tbuf, len);
142 error = copy_to_user(buf, tbuf, cnt);
143
144out_free:
145 vfree(tbuf);
146
147 return error ? error : cnt;
148}
149
150static struct file_operations dccpprobe_fops = {
151 .owner = THIS_MODULE,
152 .open = dccpprobe_open,
153 .read = dccpprobe_read,
154};
155
156static __init int dccpprobe_init(void)
157{
158 int ret = -ENOMEM;
159
160 init_waitqueue_head(&dccpw.wait);
161 spin_lock_init(&dccpw.lock);
162 dccpw.fifo = kfifo_alloc(bufsize, GFP_KERNEL, &dccpw.lock);
163
164 if (!proc_net_fops_create(procname, S_IRUSR, &dccpprobe_fops))
165 goto err0;
166
167 ret = register_jprobe(&dccp_send_probe);
168 if (ret)
169 goto err1;
170
171 pr_info("DCCP watch registered (port=%d)\n", port);
172 return 0;
173err1:
174 proc_net_remove(procname);
175err0:
176 kfifo_free(dccpw.fifo);
177 return ret;
178}
179module_init(dccpprobe_init);
180
181static __exit void dccpprobe_exit(void)
182{
183 kfifo_free(dccpw.fifo);
184 proc_net_remove(procname);
185 unregister_jprobe(&dccp_send_probe);
186
187}
188module_exit(dccpprobe_exit);
189
190MODULE_PARM_DESC(port, "Port to match (0=all)");
191module_param(port, int, 0);
192
193MODULE_PARM_DESC(bufsize, "Log buffer size (default 64k)");
194module_param(bufsize, int, 0);
195
196MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>");
197MODULE_DESCRIPTION("DCCP snooper");
198MODULE_LICENSE("GPL");