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/*
* dccp_probe - Observe the DCCP flow with kprobes .
*
* The idea for this came from Werner Almesberger ' s umlsim
* Copyright ( C ) 2004 , Stephen Hemminger < shemminger @ osdl . org >
*
* Modified for DCCP from Stephen Hemminger ' s code
* Copyright ( C ) 2006 , Ian McDonald < ian . mcdonald @ jandi . co . nz >
*
* This program is free software ; you can redistribute it and / or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation ; either version 2 of the License , or
* ( at your option ) any later version .
*
* This program is distributed in the hope that it will be useful ,
* but WITHOUT ANY WARRANTY ; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE . See the
* GNU General Public License for more details .
*
* You should have received a copy of the GNU General Public License
* along with this program ; if not , write to the Free Software
* Foundation , Inc . , 675 Mass Ave , Cambridge , MA 0213 9 , USA .
*/
# include <linux/kernel.h>
# include <linux/kprobes.h>
# include <linux/socket.h>
# include <linux/dccp.h>
# include <linux/proc_fs.h>
# include <linux/module.h>
# include <linux/kfifo.h>
# include <linux/vmalloc.h>
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# include <net/net_namespace.h>
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# include "dccp.h"
# include "ccid.h"
# include "ccids/ccid3.h"
static int port ;
static int bufsize = 64 * 1024 ;
static const char procname [ ] = " dccpprobe " ;
struct {
struct kfifo * fifo ;
spinlock_t lock ;
wait_queue_head_t wait ;
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struct timespec tstart ;
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} dccpw ;
static void printl ( const char * fmt , . . . )
{
va_list args ;
int len ;
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struct timespec now ;
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char tbuf [ 256 ] ;
va_start ( args , fmt ) ;
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getnstimeofday ( & now ) ;
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now = timespec_sub ( now , dccpw . tstart ) ;
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len = sprintf ( tbuf , " %lu.%06lu " ,
( unsigned long ) now . tv_sec ,
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( unsigned long ) now . tv_nsec / NSEC_PER_USEC ) ;
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len + = vscnprintf ( tbuf + len , sizeof ( tbuf ) - len , fmt , args ) ;
va_end ( args ) ;
kfifo_put ( dccpw . fifo , tbuf , len ) ;
wake_up ( & dccpw . wait ) ;
}
static int jdccp_sendmsg ( struct kiocb * iocb , struct sock * sk ,
struct msghdr * msg , size_t size )
{
const struct dccp_minisock * dmsk = dccp_msk ( sk ) ;
const struct inet_sock * inet = inet_sk ( sk ) ;
const struct ccid3_hc_tx_sock * hctx ;
if ( dmsk - > dccpms_tx_ccid = = DCCPC_CCID3 )
hctx = ccid3_hc_tx_sk ( sk ) ;
else
hctx = NULL ;
if ( port = = 0 | | ntohs ( inet - > dport ) = = port | |
ntohs ( inet - > sport ) = = port ) {
if ( hctx )
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printl ( " %d.%d.%d.%d:%u %d.%d.%d.%d:%u %d %d %d %d %u "
" %llu %llu %d \n " ,
NIPQUAD ( inet - > saddr ) , ntohs ( inet - > sport ) ,
NIPQUAD ( inet - > daddr ) , ntohs ( inet - > dport ) , size ,
hctx - > ccid3hctx_s , hctx - > ccid3hctx_rtt ,
hctx - > ccid3hctx_p , hctx - > ccid3hctx_x_calc ,
hctx - > ccid3hctx_x_recv > > 6 ,
hctx - > ccid3hctx_x > > 6 , hctx - > ccid3hctx_t_ipi ) ;
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else
printl ( " %d.%d.%d.%d:%u %d.%d.%d.%d:%u %d \n " ,
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NIPQUAD ( inet - > saddr ) , ntohs ( inet - > sport ) ,
NIPQUAD ( inet - > daddr ) , ntohs ( inet - > dport ) , size ) ;
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}
jprobe_return ( ) ;
return 0 ;
}
static struct jprobe dccp_send_probe = {
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. kp = {
. symbol_name = " dccp_sendmsg " ,
} ,
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. entry = jdccp_sendmsg ,
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} ;
static int dccpprobe_open ( struct inode * inode , struct file * file )
{
kfifo_reset ( dccpw . fifo ) ;
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getnstimeofday ( & dccpw . tstart ) ;
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return 0 ;
}
static ssize_t dccpprobe_read ( struct file * file , char __user * buf ,
size_t len , loff_t * ppos )
{
int error = 0 , cnt = 0 ;
unsigned char * tbuf ;
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if ( ! buf )
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return - EINVAL ;
if ( len = = 0 )
return 0 ;
tbuf = vmalloc ( len ) ;
if ( ! tbuf )
return - ENOMEM ;
error = wait_event_interruptible ( dccpw . wait ,
__kfifo_len ( dccpw . fifo ) ! = 0 ) ;
if ( error )
goto out_free ;
cnt = kfifo_get ( dccpw . fifo , tbuf , len ) ;
error = copy_to_user ( buf , tbuf , cnt ) ;
out_free :
vfree ( tbuf ) ;
return error ? error : cnt ;
}
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static const struct file_operations dccpprobe_fops = {
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. owner = THIS_MODULE ,
. open = dccpprobe_open ,
. read = dccpprobe_read ,
} ;
static __init int dccpprobe_init ( void )
{
int ret = - ENOMEM ;
init_waitqueue_head ( & dccpw . wait ) ;
spin_lock_init ( & dccpw . lock ) ;
dccpw . fifo = kfifo_alloc ( bufsize , GFP_KERNEL , & dccpw . lock ) ;
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if ( IS_ERR ( dccpw . fifo ) )
return PTR_ERR ( dccpw . fifo ) ;
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if ( ! proc_net_fops_create ( & init_net , procname , S_IRUSR , & dccpprobe_fops ) )
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goto err0 ;
ret = register_jprobe ( & dccp_send_probe ) ;
if ( ret )
goto err1 ;
pr_info ( " DCCP watch registered (port=%d) \n " , port ) ;
return 0 ;
err1 :
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proc_net_remove ( & init_net , procname ) ;
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err0 :
kfifo_free ( dccpw . fifo ) ;
return ret ;
}
module_init ( dccpprobe_init ) ;
static __exit void dccpprobe_exit ( void )
{
kfifo_free ( dccpw . fifo ) ;
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proc_net_remove ( & init_net , procname ) ;
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unregister_jprobe ( & dccp_send_probe ) ;
}
module_exit ( dccpprobe_exit ) ;
MODULE_PARM_DESC ( port , " Port to match (0=all) " ) ;
module_param ( port , int , 0 ) ;
MODULE_PARM_DESC ( bufsize , " Log buffer size (default 64k) " ) ;
module_param ( bufsize , int , 0 ) ;
MODULE_AUTHOR ( " Ian McDonald <ian.mcdonald@jandi.co.nz> " ) ;
MODULE_DESCRIPTION ( " DCCP snooper " ) ;
MODULE_LICENSE ( " GPL " ) ;