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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 <linux/gfp.h>
34#include <net/net_namespace.h>
35
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
46static struct {
47 struct kfifo fifo;
48 spinlock_t lock;
49 wait_queue_head_t wait;
50 struct timespec tstart;
51} dccpw;
52
53static void printl(const char *fmt, ...)
54{
55 va_list args;
56 int len;
57 struct timespec now;
58 char tbuf[256];
59
60 va_start(args, fmt);
61 getnstimeofday(&now);
62
63 now = timespec_sub(now, dccpw.tstart);
64
65 len = sprintf(tbuf, "%lu.%06lu ",
66 (unsigned long) now.tv_sec,
67 (unsigned long) now.tv_nsec / NSEC_PER_USEC);
68 len += vscnprintf(tbuf+len, sizeof(tbuf)-len, fmt, args);
69 va_end(args);
70
71 kfifo_in_locked(&dccpw.fifo, tbuf, len, &dccpw.lock);
72 wake_up(&dccpw.wait);
73}
74
75static int jdccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
76{
77 const struct inet_sock *inet = inet_sk(sk);
78 struct ccid3_hc_tx_sock *hc = NULL;
79
80 if (ccid_get_current_tx_ccid(dccp_sk(sk)) == DCCPC_CCID3)
81 hc = ccid3_hc_tx_sk(sk);
82
83 if (port == 0 || ntohs(inet->inet_dport) == port ||
84 ntohs(inet->inet_sport) == port) {
85 if (hc)
86 printl("%pI4:%u %pI4:%u %d %d %d %d %u %llu %llu %d\n",
87 &inet->inet_saddr, ntohs(inet->inet_sport),
88 &inet->inet_daddr, ntohs(inet->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);
92 else
93 printl("%pI4:%u %pI4:%u %d\n",
94 &inet->inet_saddr, ntohs(inet->inet_sport),
95 &inet->inet_daddr, ntohs(inet->inet_dport),
96 size);
97 }
98
99 jprobe_return();
100 return 0;
101}
102
103static struct jprobe dccp_send_probe = {
104 .kp = {
105 .symbol_name = "dccp_sendmsg",
106 },
107 .entry = jdccp_sendmsg,
108};
109
110static int dccpprobe_open(struct inode *inode, struct file *file)
111{
112 kfifo_reset(&dccpw.fifo);
113 getnstimeofday(&dccpw.tstart);
114 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
123 if (!buf)
124 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,
134 kfifo_len(&dccpw.fifo) != 0);
135 if (error)
136 goto out_free;
137
138 cnt = kfifo_out_locked(&dccpw.fifo, tbuf, len, &dccpw.lock);
139 error = copy_to_user(buf, tbuf, cnt) ? -EFAULT : 0;
140
141out_free:
142 vfree(tbuf);
143
144 return error ? error : cnt;
145}
146
147static const struct file_operations dccpprobe_fops = {
148 .owner = THIS_MODULE,
149 .open = dccpprobe_open,
150 .read = dccpprobe_read,
151 .llseek = noop_llseek,
152};
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);
160 if (kfifo_alloc(&dccpw.fifo, bufsize, GFP_KERNEL))
161 return ret;
162 if (!proc_create(procname, S_IRUSR, init_net.proc_net, &dccpprobe_fops))
163 goto err0;
164
165 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
172 if (ret)
173 goto err1;
174
175 pr_info("DCCP watch registered (port=%d)\n", port);
176 return 0;
177err1:
178 remove_proc_entry(procname, init_net.proc_net);
179err0:
180 kfifo_free(&dccpw.fifo);
181 return ret;
182}
183module_init(dccpprobe_init);
184
185static __exit void dccpprobe_exit(void)
186{
187 kfifo_free(&dccpw.fifo);
188 remove_proc_entry(procname, init_net.proc_net);
189 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");
203
