Commit | Line | Data |
---|---|---|
e41542f5 IM |
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 | ||
38 | static int port; | |
39 | ||
40 | static int bufsize = 64 * 1024; | |
41 | ||
42 | static const char procname[] = "dccpprobe"; | |
43 | ||
44 | struct { | |
45 | struct kfifo *fifo; | |
46 | spinlock_t lock; | |
47 | wait_queue_head_t wait; | |
48 | struct timeval tstart; | |
49 | } dccpw; | |
50 | ||
51 | static 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 | ||
78 | static 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 | ||
108 | static struct jprobe dccp_send_probe = { | |
e1b7441e IM |
109 | .kp = { |
110 | .symbol_name = "dccp_sendmsg", | |
111 | }, | |
112 | .entry = JPROBE_ENTRY(jdccp_sendmsg), | |
e41542f5 IM |
113 | }; |
114 | ||
115 | static int dccpprobe_open(struct inode *inode, struct file *file) | |
116 | { | |
117 | kfifo_reset(dccpw.fifo); | |
118 | do_gettimeofday(&dccpw.tstart); | |
119 | return 0; | |
120 | } | |
121 | ||
122 | static ssize_t dccpprobe_read(struct file *file, char __user *buf, | |
123 | size_t len, loff_t *ppos) | |
124 | { | |
125 | int error = 0, cnt = 0; | |
126 | unsigned char *tbuf; | |
127 | ||
128 | if (!buf || len < 0) | |
129 | return -EINVAL; | |
130 | ||
131 | if (len == 0) | |
132 | return 0; | |
133 | ||
134 | tbuf = vmalloc(len); | |
135 | if (!tbuf) | |
136 | return -ENOMEM; | |
137 | ||
138 | error = wait_event_interruptible(dccpw.wait, | |
139 | __kfifo_len(dccpw.fifo) != 0); | |
140 | if (error) | |
141 | goto out_free; | |
142 | ||
143 | cnt = kfifo_get(dccpw.fifo, tbuf, len); | |
144 | error = copy_to_user(buf, tbuf, cnt); | |
145 | ||
146 | out_free: | |
147 | vfree(tbuf); | |
148 | ||
149 | return error ? error : cnt; | |
150 | } | |
151 | ||
152 | static struct file_operations dccpprobe_fops = { | |
153 | .owner = THIS_MODULE, | |
154 | .open = dccpprobe_open, | |
155 | .read = dccpprobe_read, | |
156 | }; | |
157 | ||
158 | static __init int dccpprobe_init(void) | |
159 | { | |
160 | int ret = -ENOMEM; | |
161 | ||
162 | init_waitqueue_head(&dccpw.wait); | |
163 | spin_lock_init(&dccpw.lock); | |
164 | dccpw.fifo = kfifo_alloc(bufsize, GFP_KERNEL, &dccpw.lock); | |
ac16ca64 AM |
165 | if (IS_ERR(dccpw.fifo)) |
166 | return PTR_ERR(dccpw.fifo); | |
e41542f5 IM |
167 | |
168 | if (!proc_net_fops_create(procname, S_IRUSR, &dccpprobe_fops)) | |
169 | goto err0; | |
170 | ||
171 | ret = register_jprobe(&dccp_send_probe); | |
172 | if (ret) | |
173 | goto err1; | |
174 | ||
175 | pr_info("DCCP watch registered (port=%d)\n", port); | |
176 | return 0; | |
177 | err1: | |
178 | proc_net_remove(procname); | |
179 | err0: | |
180 | kfifo_free(dccpw.fifo); | |
181 | return ret; | |
182 | } | |
183 | module_init(dccpprobe_init); | |
184 | ||
185 | static __exit void dccpprobe_exit(void) | |
186 | { | |
187 | kfifo_free(dccpw.fifo); | |
188 | proc_net_remove(procname); | |
189 | unregister_jprobe(&dccp_send_probe); | |
190 | ||
191 | } | |
192 | module_exit(dccpprobe_exit); | |
193 | ||
194 | MODULE_PARM_DESC(port, "Port to match (0=all)"); | |
195 | module_param(port, int, 0); | |
196 | ||
197 | MODULE_PARM_DESC(bufsize, "Log buffer size (default 64k)"); | |
198 | module_param(bufsize, int, 0); | |
199 | ||
200 | MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>"); | |
201 | MODULE_DESCRIPTION("DCCP snooper"); | |
202 | MODULE_LICENSE("GPL"); |