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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 kiocb *iocb, struct sock *sk,
76 struct msghdr *msg, size_t size)
77{
78 const struct inet_sock *inet = inet_sk(sk);
79 struct ccid3_hc_tx_sock *hc = NULL;
80
81 if (ccid_get_current_tx_ccid(dccp_sk(sk)) == DCCPC_CCID3)
82 hc = ccid3_hc_tx_sk(sk);
83
84 if (port == 0 || ntohs(inet->inet_dport) == port ||
85 ntohs(inet->inet_sport) == port) {
86 if (hc)
87 printl("%pI4:%u %pI4:%u %d %d %d %d %u %llu %llu %d\n",
88 &inet->inet_saddr, ntohs(inet->inet_sport),
89 &inet->inet_daddr, ntohs(inet->inet_dport), size,
90 hc->tx_s, hc->tx_rtt, hc->tx_p,
91 hc->tx_x_calc, hc->tx_x_recv >> 6,
92 hc->tx_x >> 6, hc->tx_t_ipi);
93 else
94 printl("%pI4:%u %pI4:%u %d\n",
95 &inet->inet_saddr, ntohs(inet->inet_sport),
96 &inet->inet_daddr, ntohs(inet->inet_dport),
97 size);
98 }
99
100 jprobe_return();
101 return 0;
102}
103
104static struct jprobe dccp_send_probe = {
105 .kp = {
106 .symbol_name = "dccp_sendmsg",
107 },
108 .entry = jdccp_sendmsg,
109};
110
111static int dccpprobe_open(struct inode *inode, struct file *file)
112{
113 kfifo_reset(&dccpw.fifo);
114 getnstimeofday(&dccpw.tstart);
115 return 0;
116}
117
118static ssize_t dccpprobe_read(struct file *file, char __user *buf,
119 size_t len, loff_t *ppos)
120{
121 int error = 0, cnt = 0;
122 unsigned char *tbuf;
123
124 if (!buf)
125 return -EINVAL;
126
127 if (len == 0)
128 return 0;
129
130 tbuf = vmalloc(len);
131 if (!tbuf)
132 return -ENOMEM;
133
134 error = wait_event_interruptible(dccpw.wait,
135 kfifo_len(&dccpw.fifo) != 0);
136 if (error)
137 goto out_free;
138
139 cnt = kfifo_out_locked(&dccpw.fifo, tbuf, len, &dccpw.lock);
140 error = copy_to_user(buf, tbuf, cnt) ? -EFAULT : 0;
141
142out_free:
143 vfree(tbuf);
144
145 return error ? error : cnt;
146}
147
148static const struct file_operations dccpprobe_fops = {
149 .owner = THIS_MODULE,
150 .open = dccpprobe_open,
151 .read = dccpprobe_read,
152 .llseek = noop_llseek,
153};
154
155static __init int dccpprobe_init(void)
156{
157 int ret = -ENOMEM;
158
159 init_waitqueue_head(&dccpw.wait);
160 spin_lock_init(&dccpw.lock);
161 if (kfifo_alloc(&dccpw.fifo, bufsize, GFP_KERNEL))
162 return ret;
163 if (!proc_net_fops_create(&init_net, procname, S_IRUSR, &dccpprobe_fops))
164 goto err0;
165
166 try_then_request_module((ret = register_jprobe(&dccp_send_probe)) == 0,
167 "dccp");
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(&init_net, 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(&init_net, 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");
199
