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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> | |
457c4cbc | 33 | #include <net/net_namespace.h> |
e41542f5 IM |
34 | |
35 | #include "dccp.h" | |
36 | #include "ccid.h" | |
37 | #include "ccids/ccid3.h" | |
38 | ||
39 | static int port; | |
40 | ||
41 | static int bufsize = 64 * 1024; | |
42 | ||
43 | static const char procname[] = "dccpprobe"; | |
44 | ||
45 | struct { | |
46 | struct kfifo *fifo; | |
47 | spinlock_t lock; | |
48 | wait_queue_head_t wait; | |
49 | struct timeval tstart; | |
50 | } dccpw; | |
51 | ||
52 | static void printl(const char *fmt, ...) | |
53 | { | |
54 | va_list args; | |
55 | int len; | |
56 | struct timeval now; | |
57 | char tbuf[256]; | |
58 | ||
59 | va_start(args, fmt); | |
60 | do_gettimeofday(&now); | |
61 | ||
62 | now.tv_sec -= dccpw.tstart.tv_sec; | |
63 | now.tv_usec -= dccpw.tstart.tv_usec; | |
64 | if (now.tv_usec < 0) { | |
65 | --now.tv_sec; | |
66 | now.tv_usec += 1000000; | |
67 | } | |
68 | ||
69 | len = sprintf(tbuf, "%lu.%06lu ", | |
70 | (unsigned long) now.tv_sec, | |
71 | (unsigned long) now.tv_usec); | |
72 | len += vscnprintf(tbuf+len, sizeof(tbuf)-len, fmt, args); | |
73 | va_end(args); | |
74 | ||
75 | kfifo_put(dccpw.fifo, tbuf, len); | |
76 | wake_up(&dccpw.wait); | |
77 | } | |
78 | ||
79 | static int jdccp_sendmsg(struct kiocb *iocb, struct sock *sk, | |
80 | struct msghdr *msg, size_t size) | |
81 | { | |
82 | const struct dccp_minisock *dmsk = dccp_msk(sk); | |
83 | const struct inet_sock *inet = inet_sk(sk); | |
84 | const struct ccid3_hc_tx_sock *hctx; | |
85 | ||
86 | if (dmsk->dccpms_tx_ccid == DCCPC_CCID3) | |
87 | hctx = ccid3_hc_tx_sk(sk); | |
88 | else | |
89 | hctx = NULL; | |
90 | ||
91 | if (port == 0 || ntohs(inet->dport) == port || | |
92 | ntohs(inet->sport) == port) { | |
93 | if (hctx) | |
fddc2feb GR |
94 | printl("%d.%d.%d.%d:%u %d.%d.%d.%d:%u %d %d %d %d %u " |
95 | "%llu %llu %d\n", | |
96 | NIPQUAD(inet->saddr), ntohs(inet->sport), | |
97 | NIPQUAD(inet->daddr), ntohs(inet->dport), size, | |
98 | hctx->ccid3hctx_s, hctx->ccid3hctx_rtt, | |
99 | hctx->ccid3hctx_p, hctx->ccid3hctx_x_calc, | |
100 | hctx->ccid3hctx_x_recv >> 6, | |
101 | hctx->ccid3hctx_x >> 6, hctx->ccid3hctx_t_ipi); | |
e41542f5 IM |
102 | else |
103 | printl("%d.%d.%d.%d:%u %d.%d.%d.%d:%u %d\n", | |
fddc2feb GR |
104 | NIPQUAD(inet->saddr), ntohs(inet->sport), |
105 | NIPQUAD(inet->daddr), ntohs(inet->dport), size); | |
e41542f5 IM |
106 | } |
107 | ||
108 | jprobe_return(); | |
109 | return 0; | |
110 | } | |
111 | ||
112 | static struct jprobe dccp_send_probe = { | |
e1b7441e IM |
113 | .kp = { |
114 | .symbol_name = "dccp_sendmsg", | |
115 | }, | |
9e367d85 | 116 | .entry = jdccp_sendmsg, |
e41542f5 IM |
117 | }; |
118 | ||
119 | static int dccpprobe_open(struct inode *inode, struct file *file) | |
120 | { | |
121 | kfifo_reset(dccpw.fifo); | |
122 | do_gettimeofday(&dccpw.tstart); | |
123 | return 0; | |
124 | } | |
125 | ||
126 | static ssize_t dccpprobe_read(struct file *file, char __user *buf, | |
127 | size_t len, loff_t *ppos) | |
128 | { | |
129 | int error = 0, cnt = 0; | |
130 | unsigned char *tbuf; | |
131 | ||
75202e76 | 132 | if (!buf) |
e41542f5 IM |
133 | return -EINVAL; |
134 | ||
135 | if (len == 0) | |
136 | return 0; | |
137 | ||
138 | tbuf = vmalloc(len); | |
139 | if (!tbuf) | |
140 | return -ENOMEM; | |
141 | ||
142 | error = wait_event_interruptible(dccpw.wait, | |
143 | __kfifo_len(dccpw.fifo) != 0); | |
144 | if (error) | |
145 | goto out_free; | |
146 | ||
147 | cnt = kfifo_get(dccpw.fifo, tbuf, len); | |
148 | error = copy_to_user(buf, tbuf, cnt); | |
149 | ||
150 | out_free: | |
151 | vfree(tbuf); | |
152 | ||
153 | return error ? error : cnt; | |
154 | } | |
155 | ||
9a32144e | 156 | static const struct file_operations dccpprobe_fops = { |
e41542f5 IM |
157 | .owner = THIS_MODULE, |
158 | .open = dccpprobe_open, | |
159 | .read = dccpprobe_read, | |
160 | }; | |
161 | ||
162 | static __init int dccpprobe_init(void) | |
163 | { | |
164 | int ret = -ENOMEM; | |
165 | ||
166 | init_waitqueue_head(&dccpw.wait); | |
167 | spin_lock_init(&dccpw.lock); | |
168 | dccpw.fifo = kfifo_alloc(bufsize, GFP_KERNEL, &dccpw.lock); | |
ac16ca64 AM |
169 | if (IS_ERR(dccpw.fifo)) |
170 | return PTR_ERR(dccpw.fifo); | |
e41542f5 | 171 | |
457c4cbc | 172 | if (!proc_net_fops_create(&init_net, procname, S_IRUSR, &dccpprobe_fops)) |
e41542f5 IM |
173 | goto err0; |
174 | ||
175 | ret = register_jprobe(&dccp_send_probe); | |
176 | if (ret) | |
177 | goto err1; | |
178 | ||
179 | pr_info("DCCP watch registered (port=%d)\n", port); | |
180 | return 0; | |
181 | err1: | |
457c4cbc | 182 | proc_net_remove(&init_net, procname); |
e41542f5 IM |
183 | err0: |
184 | kfifo_free(dccpw.fifo); | |
185 | return ret; | |
186 | } | |
187 | module_init(dccpprobe_init); | |
188 | ||
189 | static __exit void dccpprobe_exit(void) | |
190 | { | |
191 | kfifo_free(dccpw.fifo); | |
457c4cbc | 192 | proc_net_remove(&init_net, procname); |
e41542f5 IM |
193 | unregister_jprobe(&dccp_send_probe); |
194 | ||
195 | } | |
196 | module_exit(dccpprobe_exit); | |
197 | ||
198 | MODULE_PARM_DESC(port, "Port to match (0=all)"); | |
199 | module_param(port, int, 0); | |
200 | ||
201 | MODULE_PARM_DESC(bufsize, "Log buffer size (default 64k)"); | |
202 | module_param(bufsize, int, 0); | |
203 | ||
204 | MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>"); | |
205 | MODULE_DESCRIPTION("DCCP snooper"); | |
206 | MODULE_LICENSE("GPL"); |