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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 <net/net_namespace.h>
34
35#include "dccp.h"
36#include "ccid.h"
37#include "ccids/ccid3.h"
38
39static int port;
40
41static int bufsize = 64 * 1024;
42
43static const char procname[] = "dccpprobe";
44
45static struct {
46 struct kfifo *fifo;
47 spinlock_t lock;
48 wait_queue_head_t wait;
49 struct timespec tstart;
50} dccpw;
51
52static void printl(const char *fmt, ...)
53{
54 va_list args;
55 int len;
56 struct timespec now;
57 char tbuf[256];
58
59 va_start(args, fmt);
60 getnstimeofday(&now);
61
62 now = timespec_sub(now, dccpw.tstart);
63
64 len = sprintf(tbuf, "%lu.%06lu ",
65 (unsigned long) now.tv_sec,
66 (unsigned long) now.tv_nsec / NSEC_PER_USEC);
67 len += vscnprintf(tbuf+len, sizeof(tbuf)-len, fmt, args);
68 va_end(args);
69
70 kfifo_put(dccpw.fifo, tbuf, len);
71 wake_up(&dccpw.wait);
72}
73
74static int jdccp_sendmsg(struct kiocb *iocb, struct sock *sk,
75 struct msghdr *msg, size_t size)
76{
77 const struct inet_sock *inet = inet_sk(sk);
78 struct ccid3_hc_tx_sock *hctx = NULL;
79
80 if (ccid_get_current_tx_ccid(dccp_sk(sk)) == DCCPC_CCID3)
81 hctx = ccid3_hc_tx_sk(sk);
82
83 if (port == 0 || ntohs(inet->dport) == port ||
84 ntohs(inet->sport) == port) {
85 if (hctx)
86 printl("%pI4:%u %pI4:%u %d %d %d %d %u "
87 "%llu %llu %d\n",
88 &inet->saddr, ntohs(inet->sport),
89 &inet->daddr, ntohs(inet->dport), size,
90 hctx->ccid3hctx_s, hctx->ccid3hctx_rtt,
91 hctx->ccid3hctx_p, hctx->ccid3hctx_x_calc,
92 hctx->ccid3hctx_x_recv >> 6,
93 hctx->ccid3hctx_x >> 6, hctx->ccid3hctx_t_ipi);
94 else
95 printl("%pI4:%u %pI4:%u %d\n",
96 &inet->saddr, ntohs(inet->sport),
97 &inet->daddr, ntohs(inet->dport), 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_get(dccpw.fifo, tbuf, len);
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};
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 dccpw.fifo = kfifo_alloc(bufsize, GFP_KERNEL, &dccpw.lock);
161 if (IS_ERR(dccpw.fifo))
162 return PTR_ERR(dccpw.fifo);
163
164 if (!proc_net_fops_create(&init_net, 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(&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
