[DCCP]: Introduce dccp_probe

	  Just say N.

	  Just say N.

config NET_DCCPPROBE

	tristate "DCCP connection probing"

	depends on PROC_FS && KPROBES

	---help---

	This module allows for capturing the changes to DCCP connection

	state in response to incoming packets. It is used for debugging

	DCCP congestion avoidance modules. If you don't understand

	what was just said, you don't need it: say N.

	Documentation on how to use the packet generator can be found

	at http://linux-net.osdl.org/index.php/DccpProbe

	To compile this code as a module, choose M here: the

	module will be called dccp_probe.

endmenu

endmenu

endmenu

endmenu

dccp-$(CONFIG_IP_DCCP_ACKVEC) += ackvec.o

dccp-$(CONFIG_IP_DCCP_ACKVEC) += ackvec.o

obj-$(CONFIG_INET_DCCP_DIAG) += dccp_diag.o

obj-$(CONFIG_INET_DCCP_DIAG) += dccp_diag.o

obj-$(CONFIG_NET_DCCPPROBE) += dccp_probe.o

dccp-$(CONFIG_SYSCTL) += sysctl.o

dccp-$(CONFIG_SYSCTL) += sysctl.o

dccp_diag-y := diag.o

dccp_diag-y := diag.o

dccp_probe-y := probe.o

obj-y += ccids/

obj-y += ccids/

/*

 * 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 02139, 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>

#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;

	struct timeval	  tstart;

} dccpw;

static void printl(const char *fmt, ...)

{

	va_list args;

	int len;

	struct timeval now;

	char tbuf[256];

	va_start(args, fmt);

	do_gettimeofday(&now);

	now.tv_sec -= dccpw.tstart.tv_sec;

	now.tv_usec -= dccpw.tstart.tv_usec;

	if (now.tv_usec < 0) {

		--now.tv_sec;

		now.tv_usec += 1000000;

	}

	len = sprintf(tbuf, "%lu.%06lu ",

		      (unsigned long) now.tv_sec,

		      (unsigned long) now.tv_usec);

	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)

			printl("%d.%d.%d.%d:%u %d.%d.%d.%d:%u %d %d %d %d %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_t_ipi);

		else

			printl("%d.%d.%d.%d:%u %d.%d.%d.%d:%u %d\n",

			   NIPQUAD(inet->saddr), ntohs(inet->sport),

			   NIPQUAD(inet->daddr), ntohs(inet->dport), size);

	}

	jprobe_return();

	return 0;

}

static struct jprobe dccp_send_probe = {

	.kp	= { .addr = (kprobe_opcode_t *)&dccp_sendmsg, },

	.entry	= (kprobe_opcode_t *)&jdccp_sendmsg,

};

static int dccpprobe_open(struct inode *inode, struct file *file)

{

	kfifo_reset(dccpw.fifo);

	do_gettimeofday(&dccpw.tstart);

	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;

	if (!buf || len < 0)

		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;

}

static struct file_operations dccpprobe_fops = {

	.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);

	if (!proc_net_fops_create(procname, S_IRUSR, &dccpprobe_fops))

		goto err0;

	ret = register_jprobe(&dccp_send_probe);

	if (ret)

		goto err1;

	pr_info("DCCP watch registered (port=%d)\n", port);

	return 0;

err1:

	proc_net_remove(procname);

err0:

	kfifo_free(dccpw.fifo);

	return ret;

}

module_init(dccpprobe_init);

static __exit void dccpprobe_exit(void)

{

	kfifo_free(dccpw.fifo);

	proc_net_remove(procname);

	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");