Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 1 | /* |
| 2 | * dccp_probe - Observe the DCCP 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 DCCP from Stephen Hemminger's code |
| 8 | * Copyright (C) 2006, Ian McDonald <ian.mcdonald@jandi.co.nz> |
| 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 | |
| 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> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 33 | #include <linux/gfp.h> |
Eric W. Biederman | 457c4cb | 2007-09-12 12:01:34 +0200 | [diff] [blame] | 34 | #include <net/net_namespace.h> |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 35 | |
| 36 | #include "dccp.h" |
| 37 | #include "ccid.h" |
| 38 | #include "ccids/ccid3.h" |
| 39 | |
| 40 | static int port; |
| 41 | |
| 42 | static int bufsize = 64 * 1024; |
| 43 | |
| 44 | static const char procname[] = "dccpprobe"; |
| 45 | |
Gerrit Renker | 1e2f0e5 | 2008-06-11 11:19:09 +0100 | [diff] [blame] | 46 | static struct { |
Stefani Seibold | 4546548 | 2009-12-21 14:37:26 -0800 | [diff] [blame] | 47 | struct kfifo fifo; |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 48 | spinlock_t lock; |
| 49 | wait_queue_head_t wait; |
YOSHIFUJI Hideaki | cdd04d9 | 2008-04-21 14:28:45 -0700 | [diff] [blame] | 50 | struct timespec tstart; |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 51 | } dccpw; |
| 52 | |
| 53 | static void printl(const char *fmt, ...) |
| 54 | { |
| 55 | va_list args; |
| 56 | int len; |
YOSHIFUJI Hideaki | cdd04d9 | 2008-04-21 14:28:45 -0700 | [diff] [blame] | 57 | struct timespec now; |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 58 | char tbuf[256]; |
| 59 | |
| 60 | va_start(args, fmt); |
YOSHIFUJI Hideaki | cdd04d9 | 2008-04-21 14:28:45 -0700 | [diff] [blame] | 61 | getnstimeofday(&now); |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 62 | |
YOSHIFUJI Hideaki | cdd04d9 | 2008-04-21 14:28:45 -0700 | [diff] [blame] | 63 | now = timespec_sub(now, dccpw.tstart); |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 64 | |
| 65 | len = sprintf(tbuf, "%lu.%06lu ", |
| 66 | (unsigned long) now.tv_sec, |
YOSHIFUJI Hideaki | cdd04d9 | 2008-04-21 14:28:45 -0700 | [diff] [blame] | 67 | (unsigned long) now.tv_nsec / NSEC_PER_USEC); |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 68 | len += vscnprintf(tbuf+len, sizeof(tbuf)-len, fmt, args); |
| 69 | va_end(args); |
| 70 | |
Stefani Seibold | 7acd72e | 2009-12-21 14:37:28 -0800 | [diff] [blame] | 71 | kfifo_in_locked(&dccpw.fifo, tbuf, len, &dccpw.lock); |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 72 | wake_up(&dccpw.wait); |
| 73 | } |
| 74 | |
| 75 | static int jdccp_sendmsg(struct kiocb *iocb, struct sock *sk, |
| 76 | struct msghdr *msg, size_t size) |
| 77 | { |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 78 | const struct inet_sock *inet = inet_sk(sk); |
Gerrit Renker | 996ccf4 | 2009-10-05 00:53:13 +0000 | [diff] [blame] | 79 | struct ccid3_hc_tx_sock *hc = NULL; |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 80 | |
Gerrit Renker | 71c262a | 2008-11-23 16:04:59 -0800 | [diff] [blame] | 81 | if (ccid_get_current_tx_ccid(dccp_sk(sk)) == DCCPC_CCID3) |
Gerrit Renker | 996ccf4 | 2009-10-05 00:53:13 +0000 | [diff] [blame] | 82 | hc = ccid3_hc_tx_sk(sk); |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 83 | |
Eric Dumazet | c720c7e | 2009-10-15 06:30:45 +0000 | [diff] [blame] | 84 | if (port == 0 || ntohs(inet->inet_dport) == port || |
| 85 | ntohs(inet->inet_sport) == port) { |
Gerrit Renker | 996ccf4 | 2009-10-05 00:53:13 +0000 | [diff] [blame] | 86 | if (hc) |
Gerrit Renker | 388d5e9 | 2009-10-05 00:53:11 +0000 | [diff] [blame] | 87 | printl("%pI4:%u %pI4:%u %d %d %d %d %u %llu %llu %d\n", |
Eric Dumazet | c720c7e | 2009-10-15 06:30:45 +0000 | [diff] [blame] | 88 | &inet->inet_saddr, ntohs(inet->inet_sport), |
| 89 | &inet->inet_daddr, ntohs(inet->inet_dport), size, |
Gerrit Renker | 996ccf4 | 2009-10-05 00:53:13 +0000 | [diff] [blame] | 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); |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 93 | else |
Harvey Harrison | 21454aa | 2008-10-31 00:54:56 -0700 | [diff] [blame] | 94 | printl("%pI4:%u %pI4:%u %d\n", |
Eric Dumazet | c720c7e | 2009-10-15 06:30:45 +0000 | [diff] [blame] | 95 | &inet->inet_saddr, ntohs(inet->inet_sport), |
| 96 | &inet->inet_daddr, ntohs(inet->inet_dport), |
| 97 | size); |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 98 | } |
| 99 | |
| 100 | jprobe_return(); |
| 101 | return 0; |
| 102 | } |
| 103 | |
| 104 | static struct jprobe dccp_send_probe = { |
Ian McDonald | e1b7441 | 2006-11-20 18:41:37 -0200 | [diff] [blame] | 105 | .kp = { |
| 106 | .symbol_name = "dccp_sendmsg", |
| 107 | }, |
Michael Ellerman | 9e367d8 | 2007-07-19 01:48:10 -0700 | [diff] [blame] | 108 | .entry = jdccp_sendmsg, |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 109 | }; |
| 110 | |
| 111 | static int dccpprobe_open(struct inode *inode, struct file *file) |
| 112 | { |
Stefani Seibold | 4546548 | 2009-12-21 14:37:26 -0800 | [diff] [blame] | 113 | kfifo_reset(&dccpw.fifo); |
YOSHIFUJI Hideaki | cdd04d9 | 2008-04-21 14:28:45 -0700 | [diff] [blame] | 114 | getnstimeofday(&dccpw.tstart); |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 115 | return 0; |
| 116 | } |
| 117 | |
| 118 | static 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 | |
Bill Nottingham | 75202e7 | 2007-05-31 21:33:35 -0700 | [diff] [blame] | 124 | if (!buf) |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 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, |
Stefani Seibold | e64c026 | 2009-12-21 14:37:28 -0800 | [diff] [blame] | 135 | kfifo_len(&dccpw.fifo) != 0); |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 136 | if (error) |
| 137 | goto out_free; |
| 138 | |
Stefani Seibold | 7acd72e | 2009-12-21 14:37:28 -0800 | [diff] [blame] | 139 | cnt = kfifo_out_locked(&dccpw.fifo, tbuf, len, &dccpw.lock); |
Pavel Emelyanov | 653252c | 2008-04-25 01:49:48 -0700 | [diff] [blame] | 140 | error = copy_to_user(buf, tbuf, cnt) ? -EFAULT : 0; |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 141 | |
| 142 | out_free: |
| 143 | vfree(tbuf); |
| 144 | |
| 145 | return error ? error : cnt; |
| 146 | } |
| 147 | |
Arjan van de Ven | 9a32144 | 2007-02-12 00:55:35 -0800 | [diff] [blame] | 148 | static const struct file_operations dccpprobe_fops = { |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 149 | .owner = THIS_MODULE, |
| 150 | .open = dccpprobe_open, |
| 151 | .read = dccpprobe_read, |
| 152 | }; |
| 153 | |
| 154 | static __init int dccpprobe_init(void) |
| 155 | { |
| 156 | int ret = -ENOMEM; |
| 157 | |
| 158 | init_waitqueue_head(&dccpw.wait); |
| 159 | spin_lock_init(&dccpw.lock); |
Stefani Seibold | c1e13f2 | 2009-12-21 14:37:27 -0800 | [diff] [blame] | 160 | if (kfifo_alloc(&dccpw.fifo, bufsize, GFP_KERNEL)) |
Stefani Seibold | 4546548 | 2009-12-21 14:37:26 -0800 | [diff] [blame] | 161 | return ret; |
Eric W. Biederman | 457c4cb | 2007-09-12 12:01:34 +0200 | [diff] [blame] | 162 | if (!proc_net_fops_create(&init_net, procname, S_IRUSR, &dccpprobe_fops)) |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 163 | goto err0; |
| 164 | |
Gerrit Renker | 1386be5 | 2010-02-02 20:16:56 +0000 | [diff] [blame] | 165 | try_then_request_module((ret = register_jprobe(&dccp_send_probe)) == 0, |
| 166 | "dccp"); |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 167 | if (ret) |
| 168 | goto err1; |
| 169 | |
| 170 | pr_info("DCCP watch registered (port=%d)\n", port); |
| 171 | return 0; |
| 172 | err1: |
Eric W. Biederman | 457c4cb | 2007-09-12 12:01:34 +0200 | [diff] [blame] | 173 | proc_net_remove(&init_net, procname); |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 174 | err0: |
Stefani Seibold | 4546548 | 2009-12-21 14:37:26 -0800 | [diff] [blame] | 175 | kfifo_free(&dccpw.fifo); |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 176 | return ret; |
| 177 | } |
| 178 | module_init(dccpprobe_init); |
| 179 | |
| 180 | static __exit void dccpprobe_exit(void) |
| 181 | { |
Stefani Seibold | 4546548 | 2009-12-21 14:37:26 -0800 | [diff] [blame] | 182 | kfifo_free(&dccpw.fifo); |
Eric W. Biederman | 457c4cb | 2007-09-12 12:01:34 +0200 | [diff] [blame] | 183 | proc_net_remove(&init_net, procname); |
Ian McDonald | e41542f | 2006-09-22 14:28:01 +1200 | [diff] [blame] | 184 | unregister_jprobe(&dccp_send_probe); |
| 185 | |
| 186 | } |
| 187 | module_exit(dccpprobe_exit); |
| 188 | |
| 189 | MODULE_PARM_DESC(port, "Port to match (0=all)"); |
| 190 | module_param(port, int, 0); |
| 191 | |
| 192 | MODULE_PARM_DESC(bufsize, "Log buffer size (default 64k)"); |
| 193 | module_param(bufsize, int, 0); |
| 194 | |
| 195 | MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>"); |
| 196 | MODULE_DESCRIPTION("DCCP snooper"); |
| 197 | MODULE_LICENSE("GPL"); |