Commit | Line | Data |
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787a51a0 WY |
1 | /* |
2 | * sctp_probe - Observe the SCTP 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 SCTP from Stephen Hemminger's code | |
8 | * Copyright (C) 2010, Wei Yongjun <yjwei@cn.fujitsu.com> | |
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 | ||
145ce502 JP |
25 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
26 | ||
787a51a0 WY |
27 | #include <linux/kernel.h> |
28 | #include <linux/kprobes.h> | |
29 | #include <linux/socket.h> | |
30 | #include <linux/sctp.h> | |
31 | #include <linux/proc_fs.h> | |
f5460618 | 32 | #include <linux/vmalloc.h> |
787a51a0 WY |
33 | #include <linux/module.h> |
34 | #include <linux/kfifo.h> | |
35 | #include <linux/time.h> | |
36 | #include <net/net_namespace.h> | |
37 | ||
38 | #include <net/sctp/sctp.h> | |
39 | #include <net/sctp/sm.h> | |
40 | ||
41 | MODULE_AUTHOR("Wei Yongjun <yjwei@cn.fujitsu.com>"); | |
42 | MODULE_DESCRIPTION("SCTP snooper"); | |
43 | MODULE_LICENSE("GPL"); | |
44 | ||
45 | static int port __read_mostly = 0; | |
46 | MODULE_PARM_DESC(port, "Port to match (0=all)"); | |
47 | module_param(port, int, 0); | |
48 | ||
49 | static int bufsize __read_mostly = 64 * 1024; | |
50 | MODULE_PARM_DESC(bufsize, "Log buffer size (default 64k)"); | |
51 | module_param(bufsize, int, 0); | |
52 | ||
53 | static int full __read_mostly = 1; | |
54 | MODULE_PARM_DESC(full, "Full log (1=every ack packet received, 0=only cwnd changes)"); | |
55 | module_param(full, int, 0); | |
56 | ||
57 | static const char procname[] = "sctpprobe"; | |
58 | ||
59 | static struct { | |
60 | struct kfifo fifo; | |
61 | spinlock_t lock; | |
62 | wait_queue_head_t wait; | |
63 | struct timespec tstart; | |
64 | } sctpw; | |
65 | ||
66 | static void printl(const char *fmt, ...) | |
67 | { | |
68 | va_list args; | |
69 | int len; | |
70 | char tbuf[256]; | |
71 | ||
72 | va_start(args, fmt); | |
73 | len = vscnprintf(tbuf, sizeof(tbuf), fmt, args); | |
74 | va_end(args); | |
75 | ||
76 | kfifo_in_locked(&sctpw.fifo, tbuf, len, &sctpw.lock); | |
77 | wake_up(&sctpw.wait); | |
78 | } | |
79 | ||
80 | static int sctpprobe_open(struct inode *inode, struct file *file) | |
81 | { | |
82 | kfifo_reset(&sctpw.fifo); | |
83 | getnstimeofday(&sctpw.tstart); | |
84 | ||
85 | return 0; | |
86 | } | |
87 | ||
88 | static ssize_t sctpprobe_read(struct file *file, char __user *buf, | |
89 | size_t len, loff_t *ppos) | |
90 | { | |
91 | int error = 0, cnt = 0; | |
92 | unsigned char *tbuf; | |
93 | ||
94 | if (!buf) | |
95 | return -EINVAL; | |
96 | ||
97 | if (len == 0) | |
98 | return 0; | |
99 | ||
100 | tbuf = vmalloc(len); | |
101 | if (!tbuf) | |
102 | return -ENOMEM; | |
103 | ||
104 | error = wait_event_interruptible(sctpw.wait, | |
105 | kfifo_len(&sctpw.fifo) != 0); | |
106 | if (error) | |
107 | goto out_free; | |
108 | ||
109 | cnt = kfifo_out_locked(&sctpw.fifo, tbuf, len, &sctpw.lock); | |
110 | error = copy_to_user(buf, tbuf, cnt) ? -EFAULT : 0; | |
111 | ||
112 | out_free: | |
113 | vfree(tbuf); | |
114 | ||
115 | return error ? error : cnt; | |
116 | } | |
117 | ||
118 | static const struct file_operations sctpprobe_fops = { | |
119 | .owner = THIS_MODULE, | |
120 | .open = sctpprobe_open, | |
121 | .read = sctpprobe_read, | |
6038f373 | 122 | .llseek = noop_llseek, |
787a51a0 WY |
123 | }; |
124 | ||
1e558174 DB |
125 | static sctp_disposition_t jsctp_sf_eat_sack(struct net *net, |
126 | const struct sctp_endpoint *ep, | |
127 | const struct sctp_association *asoc, | |
128 | const sctp_subtype_t type, | |
129 | void *arg, | |
130 | sctp_cmd_seq_t *commands) | |
787a51a0 WY |
131 | { |
132 | struct sctp_transport *sp; | |
133 | static __u32 lcwnd = 0; | |
134 | struct timespec now; | |
135 | ||
136 | sp = asoc->peer.primary_path; | |
137 | ||
138 | if ((full || sp->cwnd != lcwnd) && | |
139 | (!port || asoc->peer.port == port || | |
140 | ep->base.bind_addr.port == port)) { | |
141 | lcwnd = sp->cwnd; | |
142 | ||
143 | getnstimeofday(&now); | |
144 | now = timespec_sub(now, sctpw.tstart); | |
145 | ||
146 | printl("%lu.%06lu ", (unsigned long) now.tv_sec, | |
147 | (unsigned long) now.tv_nsec / NSEC_PER_USEC); | |
148 | ||
149 | printl("%p %5d %5d %5d %8d %5d ", asoc, | |
150 | ep->base.bind_addr.port, asoc->peer.port, | |
151 | asoc->pathmtu, asoc->peer.rwnd, asoc->unack_data); | |
152 | ||
153 | list_for_each_entry(sp, &asoc->peer.transport_addr_list, | |
154 | transports) { | |
155 | if (sp == asoc->peer.primary_path) | |
156 | printl("*"); | |
157 | ||
158 | if (sp->ipaddr.sa.sa_family == AF_INET) | |
159 | printl("%pI4 ", &sp->ipaddr.v4.sin_addr); | |
160 | else | |
161 | printl("%pI6 ", &sp->ipaddr.v6.sin6_addr); | |
162 | ||
163 | printl("%2u %8u %8u %8u %8u %8u ", | |
164 | sp->state, sp->cwnd, sp->ssthresh, | |
165 | sp->flight_size, sp->partial_bytes_acked, | |
166 | sp->pathmtu); | |
167 | } | |
168 | printl("\n"); | |
169 | } | |
170 | ||
171 | jprobe_return(); | |
172 | return 0; | |
173 | } | |
174 | ||
175 | static struct jprobe sctp_recv_probe = { | |
176 | .kp = { | |
177 | .symbol_name = "sctp_sf_eat_sack_6_2", | |
178 | }, | |
179 | .entry = jsctp_sf_eat_sack, | |
180 | }; | |
181 | ||
182 | static __init int sctpprobe_init(void) | |
183 | { | |
184 | int ret = -ENOMEM; | |
185 | ||
22222997 DB |
186 | /* Warning: if the function signature of sctp_sf_eat_sack_6_2, |
187 | * has been changed, you also have to change the signature of | |
188 | * jsctp_sf_eat_sack, otherwise you end up right here! | |
189 | */ | |
190 | BUILD_BUG_ON(__same_type(sctp_sf_eat_sack_6_2, | |
191 | jsctp_sf_eat_sack) == 0); | |
192 | ||
787a51a0 WY |
193 | init_waitqueue_head(&sctpw.wait); |
194 | spin_lock_init(&sctpw.lock); | |
195 | if (kfifo_alloc(&sctpw.fifo, bufsize, GFP_KERNEL)) | |
196 | return ret; | |
197 | ||
d4beaa66 G |
198 | if (!proc_create(procname, S_IRUSR, init_net.proc_net, |
199 | &sctpprobe_fops)) | |
787a51a0 WY |
200 | goto free_kfifo; |
201 | ||
202 | ret = register_jprobe(&sctp_recv_probe); | |
203 | if (ret) | |
204 | goto remove_proc; | |
205 | ||
145ce502 | 206 | pr_info("probe registered (port=%d)\n", port); |
787a51a0 WY |
207 | |
208 | return 0; | |
209 | ||
210 | remove_proc: | |
211 | proc_net_remove(&init_net, procname); | |
212 | free_kfifo: | |
213 | kfifo_free(&sctpw.fifo); | |
214 | return ret; | |
215 | } | |
216 | ||
217 | static __exit void sctpprobe_exit(void) | |
218 | { | |
219 | kfifo_free(&sctpw.fifo); | |
220 | proc_net_remove(&init_net, procname); | |
221 | unregister_jprobe(&sctp_recv_probe); | |
222 | } | |
223 | ||
224 | module_init(sctpprobe_init); | |
225 | module_exit(sctpprobe_exit); |