diff options
-rw-r--r-- | net/Kconfig | 15 | ||||
-rw-r--r-- | net/ipv4/Makefile | 1 | ||||
-rw-r--r-- | net/ipv4/tcp_probe.c | 179 |
3 files changed, 195 insertions, 0 deletions
diff --git a/net/Kconfig b/net/Kconfig index 4193cdcd3ae7..ff0db804eed8 100644 --- a/net/Kconfig +++ b/net/Kconfig | |||
@@ -215,6 +215,21 @@ config NET_PKTGEN | |||
215 | To compile this code as a module, choose M here: the | 215 | To compile this code as a module, choose M here: the |
216 | module will be called pktgen. | 216 | module will be called pktgen. |
217 | 217 | ||
218 | config NET_TCPPROBE | ||
219 | tristate "TCP connection probing" | ||
220 | depends on INET && EXPERIMENTAL && PROC_FS && KPROBES | ||
221 | ---help--- | ||
222 | This module allows for capturing the changes to TCP connection | ||
223 | state in response to incoming patckets. It is used for debugging | ||
224 | TCP congestion avoidance modules. If you don't understand | ||
225 | what was just said, you don't need it: say N. | ||
226 | |||
227 | Documentation on how to use the packet generator can be found | ||
228 | at http://linux-net.osdl.org/index.php/TcpProbe | ||
229 | |||
230 | To compile this code as a module, choose M here: the | ||
231 | module will be called tcp_probe. | ||
232 | |||
218 | endmenu | 233 | endmenu |
219 | 234 | ||
220 | endmenu | 235 | endmenu |
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile index f30faefc2672..38b8039bdd55 100644 --- a/net/ipv4/Makefile +++ b/net/ipv4/Makefile | |||
@@ -36,6 +36,7 @@ obj-$(CONFIG_IP_VS) += ipvs/ | |||
36 | obj-$(CONFIG_INET_DIAG) += inet_diag.o | 36 | obj-$(CONFIG_INET_DIAG) += inet_diag.o |
37 | obj-$(CONFIG_IP_ROUTE_MULTIPATH_CACHED) += multipath.o | 37 | obj-$(CONFIG_IP_ROUTE_MULTIPATH_CACHED) += multipath.o |
38 | obj-$(CONFIG_INET_TCP_DIAG) += tcp_diag.o | 38 | obj-$(CONFIG_INET_TCP_DIAG) += tcp_diag.o |
39 | obj-$(CONFIG_NET_TCPPROBE) += tcp_probe.o | ||
39 | obj-$(CONFIG_TCP_CONG_BIC) += tcp_bic.o | 40 | obj-$(CONFIG_TCP_CONG_BIC) += tcp_bic.o |
40 | obj-$(CONFIG_TCP_CONG_CUBIC) += tcp_cubic.o | 41 | obj-$(CONFIG_TCP_CONG_CUBIC) += tcp_cubic.o |
41 | obj-$(CONFIG_TCP_CONG_WESTWOOD) += tcp_westwood.o | 42 | obj-$(CONFIG_TCP_CONG_WESTWOOD) += tcp_westwood.o |
diff --git a/net/ipv4/tcp_probe.c b/net/ipv4/tcp_probe.c new file mode 100644 index 000000000000..be94d526c7cb --- /dev/null +++ b/net/ipv4/tcp_probe.c | |||
@@ -0,0 +1,179 @@ | |||
1 | /* | ||
2 | * tcpprobe - Observe the TCP 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 | * This program is free software; you can redistribute it and/or modify | ||
8 | * it under the terms of the GNU General Public License as published by | ||
9 | * the Free Software Foundation; either version 2 of the License, or | ||
10 | * (at your option) any later version. | ||
11 | * | ||
12 | * This program is distributed in the hope that it will be useful, | ||
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
15 | * GNU General Public License for more details. | ||
16 | * | ||
17 | * You should have received a copy of the GNU General Public License | ||
18 | * along with this program; if not, write to the Free Software | ||
19 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | ||
20 | */ | ||
21 | |||
22 | #include <linux/kernel.h> | ||
23 | #include <linux/kprobes.h> | ||
24 | #include <linux/socket.h> | ||
25 | #include <linux/tcp.h> | ||
26 | #include <linux/proc_fs.h> | ||
27 | #include <linux/module.h> | ||
28 | #include <linux/kfifo.h> | ||
29 | #include <linux/vmalloc.h> | ||
30 | |||
31 | #include <net/tcp.h> | ||
32 | |||
33 | MODULE_AUTHOR("Stephen Hemminger <shemminger@osdl.org>"); | ||
34 | MODULE_DESCRIPTION("TCP cwnd snooper"); | ||
35 | MODULE_LICENSE("GPL"); | ||
36 | |||
37 | static int port = 0; | ||
38 | MODULE_PARM_DESC(port, "Port to match (0=all)"); | ||
39 | module_param(port, int, 0); | ||
40 | |||
41 | static int bufsize = 64*1024; | ||
42 | MODULE_PARM_DESC(bufsize, "Log buffer size (default 64k)"); | ||
43 | module_param(bufsize, int, 0); | ||
44 | |||
45 | static const char procname[] = "tcpprobe"; | ||
46 | |||
47 | struct { | ||
48 | struct kfifo *fifo; | ||
49 | spinlock_t lock; | ||
50 | wait_queue_head_t wait; | ||
51 | struct timeval tstart; | ||
52 | } tcpw; | ||
53 | |||
54 | static void printl(const char *fmt, ...) | ||
55 | { | ||
56 | va_list args; | ||
57 | int len; | ||
58 | struct timeval now; | ||
59 | char tbuf[256]; | ||
60 | |||
61 | va_start(args, fmt); | ||
62 | do_gettimeofday(&now); | ||
63 | |||
64 | now.tv_sec -= tcpw.tstart.tv_sec; | ||
65 | now.tv_usec -= tcpw.tstart.tv_usec; | ||
66 | if (now.tv_usec < 0) { | ||
67 | --now.tv_sec; | ||
68 | now.tv_usec += 1000000; | ||
69 | } | ||
70 | |||
71 | len = sprintf(tbuf, "%lu.%06lu ", now.tv_sec, now.tv_usec); | ||
72 | len += vscnprintf(tbuf+len, sizeof(tbuf)-len, fmt, args); | ||
73 | va_end(args); | ||
74 | |||
75 | kfifo_put(tcpw.fifo, tbuf, len); | ||
76 | wake_up(&tcpw.wait); | ||
77 | } | ||
78 | |||
79 | static int jtcp_sendmsg(struct kiocb *iocb, struct sock *sk, | ||
80 | struct msghdr *msg, size_t size) | ||
81 | { | ||
82 | const struct tcp_sock *tp = tcp_sk(sk); | ||
83 | const struct inet_sock *inet = inet_sk(sk); | ||
84 | |||
85 | if (port == 0 || ntohs(inet->dport) == port || | ||
86 | ntohs(inet->sport) == port) { | ||
87 | printl("%d.%d.%d.%d:%u %d.%d.%d.%d:%u %d %#x %#x %u %u %u\n", | ||
88 | NIPQUAD(inet->saddr), ntohs(inet->sport), | ||
89 | NIPQUAD(inet->daddr), ntohs(inet->dport), | ||
90 | size, tp->snd_nxt, tp->snd_una, | ||
91 | tp->snd_cwnd, tcp_current_ssthresh(sk), | ||
92 | tp->snd_wnd); | ||
93 | } | ||
94 | |||
95 | jprobe_return(); | ||
96 | return 0; | ||
97 | } | ||
98 | |||
99 | static struct jprobe tcp_send_probe = { | ||
100 | .kp = { .addr = (kprobe_opcode_t *) &tcp_sendmsg, }, | ||
101 | .entry = (kprobe_opcode_t *) &jtcp_sendmsg, | ||
102 | }; | ||
103 | |||
104 | |||
105 | static int tcpprobe_open(struct inode * inode, struct file * file) | ||
106 | { | ||
107 | kfifo_reset(tcpw.fifo); | ||
108 | do_gettimeofday(&tcpw.tstart); | ||
109 | return 0; | ||
110 | } | ||
111 | |||
112 | static ssize_t tcpprobe_read(struct file *file, char __user *buf, | ||
113 | size_t len, loff_t *ppos) | ||
114 | { | ||
115 | int error = 0, cnt; | ||
116 | unsigned char *tbuf; | ||
117 | |||
118 | if (!buf || len < 0) | ||
119 | return -EINVAL; | ||
120 | |||
121 | if (len == 0) | ||
122 | return 0; | ||
123 | |||
124 | tbuf = vmalloc(len); | ||
125 | if (!tbuf) | ||
126 | return -ENOMEM; | ||
127 | |||
128 | error = wait_event_interruptible(tcpw.wait, | ||
129 | __kfifo_len(tcpw.fifo) != 0); | ||
130 | if (error) | ||
131 | return error; | ||
132 | |||
133 | cnt = kfifo_get(tcpw.fifo, tbuf, len); | ||
134 | error = copy_to_user(buf, tbuf, cnt); | ||
135 | |||
136 | vfree(tbuf); | ||
137 | |||
138 | return error ? error : cnt; | ||
139 | } | ||
140 | |||
141 | static struct file_operations tcpprobe_fops = { | ||
142 | .owner = THIS_MODULE, | ||
143 | .open = tcpprobe_open, | ||
144 | .read = tcpprobe_read, | ||
145 | }; | ||
146 | |||
147 | static __init int tcpprobe_init(void) | ||
148 | { | ||
149 | int ret = -ENOMEM; | ||
150 | |||
151 | init_waitqueue_head(&tcpw.wait); | ||
152 | spin_lock_init(&tcpw.lock); | ||
153 | tcpw.fifo = kfifo_alloc(bufsize, GFP_KERNEL, &tcpw.lock); | ||
154 | |||
155 | if (!proc_net_fops_create(procname, S_IRUSR, &tcpprobe_fops)) | ||
156 | goto err0; | ||
157 | |||
158 | ret = register_jprobe(&tcp_send_probe); | ||
159 | if (ret) | ||
160 | goto err1; | ||
161 | |||
162 | pr_info("TCP watch registered (port=%d)\n", port); | ||
163 | return 0; | ||
164 | err1: | ||
165 | proc_net_remove(procname); | ||
166 | err0: | ||
167 | kfifo_free(tcpw.fifo); | ||
168 | return ret; | ||
169 | } | ||
170 | module_init(tcpprobe_init); | ||
171 | |||
172 | static __exit void tcpprobe_exit(void) | ||
173 | { | ||
174 | kfifo_free(tcpw.fifo); | ||
175 | proc_net_remove(procname); | ||
176 | unregister_jprobe(&tcp_send_probe); | ||
177 | |||
178 | } | ||
179 | module_exit(tcpprobe_exit); | ||