net: sctp: Remove debug SCTP probe module

if IP_SCTP

config NET_SCTPPROBE

	tristate "SCTP: Association probing"

        depends on PROC_FS && KPROBES

        ---help---

        This module allows for capturing the changes to SCTP association

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

        SCTP congestion control algorithms. If you don't understand

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

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

        module will be called sctp_probe.

config SCTP_DBG_OBJCNT

	bool "SCTP: Debug object counts"

	depends on PROC_FS

#

obj-$(CONFIG_IP_SCTP) += sctp.o

obj-$(CONFIG_NET_SCTPPROBE) += sctp_probe.o

obj-$(CONFIG_INET_SCTP_DIAG) += sctp_diag.o

sctp-y := sm_statetable.o sm_statefuns.o sm_sideeffect.o \

	  offload.o stream_sched.o stream_sched_prio.o \

	  stream_sched_rr.o stream_interleave.o

sctp_probe-y := probe.o

sctp-$(CONFIG_SCTP_DBG_OBJCNT) += objcnt.o

sctp-$(CONFIG_PROC_FS) += proc.o

sctp-$(CONFIG_SYSCTL) += sysctl.o

/*

 * sctp_probe - Observe the SCTP flow with kprobes.

 *

 * The idea for this came from Werner Almesberger's umlsim

 * Copyright (C) 2004, Stephen Hemminger <shemminger@osdl.org>

 *

 * Modified for SCTP from Stephen Hemminger's code

 * Copyright (C) 2010, Wei Yongjun <yjwei@cn.fujitsu.com>

 *

 * 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.

 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>

#include <linux/kprobes.h>

#include <linux/socket.h>

#include <linux/sctp.h>

#include <linux/proc_fs.h>

#include <linux/vmalloc.h>

#include <linux/module.h>

#include <linux/kfifo.h>

#include <linux/time.h>

#include <net/net_namespace.h>

#include <net/sctp/sctp.h>

#include <net/sctp/sm.h>

MODULE_SOFTDEP("pre: sctp");

MODULE_AUTHOR("Wei Yongjun <yjwei@cn.fujitsu.com>");

MODULE_DESCRIPTION("SCTP snooper");

MODULE_LICENSE("GPL");

static int port __read_mostly = 0;

MODULE_PARM_DESC(port, "Port to match (0=all)");

module_param(port, int, 0);

static unsigned int fwmark __read_mostly = 0;

MODULE_PARM_DESC(fwmark, "skb mark to match (0=no mark)");

module_param(fwmark, uint, 0);

static int bufsize __read_mostly = 64 * 1024;

MODULE_PARM_DESC(bufsize, "Log buffer size (default 64k)");

module_param(bufsize, int, 0);

static int full __read_mostly = 1;

MODULE_PARM_DESC(full, "Full log (1=every ack packet received,  0=only cwnd changes)");

module_param(full, int, 0);

static const char procname[] = "sctpprobe";

static struct {

	struct kfifo	  fifo;

	spinlock_t	  lock;

	wait_queue_head_t wait;

	struct timespec64 tstart;

} sctpw;

static __printf(1, 2) void printl(const char *fmt, ...)

{

	va_list args;

	int len;

	char tbuf[256];

	va_start(args, fmt);

	len = vscnprintf(tbuf, sizeof(tbuf), fmt, args);

	va_end(args);

	kfifo_in_locked(&sctpw.fifo, tbuf, len, &sctpw.lock);

	wake_up(&sctpw.wait);

}

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

{

	kfifo_reset(&sctpw.fifo);

	ktime_get_ts64(&sctpw.tstart);

	return 0;

}

static ssize_t sctpprobe_read(struct file *file, char __user *buf,

			      size_t len, loff_t *ppos)

{

	int error = 0, cnt = 0;

	unsigned char *tbuf;

	if (!buf)

		return -EINVAL;

	if (len == 0)

		return 0;

	tbuf = vmalloc(len);

	if (!tbuf)

		return -ENOMEM;

	error = wait_event_interruptible(sctpw.wait,

					 kfifo_len(&sctpw.fifo) != 0);

	if (error)

		goto out_free;

	cnt = kfifo_out_locked(&sctpw.fifo, tbuf, len, &sctpw.lock);

	error = copy_to_user(buf, tbuf, cnt) ? -EFAULT : 0;

out_free:

	vfree(tbuf);

	return error ? error : cnt;

}

static const struct file_operations sctpprobe_fops = {

	.owner	= THIS_MODULE,

	.open	= sctpprobe_open,

	.read	= sctpprobe_read,

	.llseek = noop_llseek,

};

static enum sctp_disposition jsctp_sf_eat_sack(

					struct net *net,

					const struct sctp_endpoint *ep,

					const struct sctp_association *asoc,

					const union sctp_subtype type,

					void *arg,

					struct sctp_cmd_seq *commands)

{

	struct sctp_chunk *chunk = arg;

	struct sk_buff *skb = chunk->skb;

	struct sctp_transport *sp;

	static __u32 lcwnd = 0;

	struct timespec64 now;

	sp = asoc->peer.primary_path;

	if (((port == 0 && fwmark == 0) ||

	     asoc->peer.port == port ||

	     ep->base.bind_addr.port == port ||

	     (fwmark > 0 && skb->mark == fwmark)) &&

	    (full || sp->cwnd != lcwnd)) {

		lcwnd = sp->cwnd;

		ktime_get_ts64(&now);

		now = timespec64_sub(now, sctpw.tstart);

		printl("%lu.%06lu ", (unsigned long) now.tv_sec,

		       (unsigned long) now.tv_nsec / NSEC_PER_USEC);

		printl("%p %5d %5d %5d %8d %5d ", asoc,

		       ep->base.bind_addr.port, asoc->peer.port,

		       asoc->pathmtu, asoc->peer.rwnd, asoc->unack_data);

		list_for_each_entry(sp, &asoc->peer.transport_addr_list,

					transports) {

			if (sp == asoc->peer.primary_path)

				printl("*");

			printl("%pISc %2u %8u %8u %8u %8u %8u ",

			       &sp->ipaddr, sp->state, sp->cwnd, sp->ssthresh,

			       sp->flight_size, sp->partial_bytes_acked,

			       sp->pathmtu);

		}

		printl("\n");

	}

	jprobe_return();

	return 0;

}

static struct jprobe sctp_recv_probe = {

	.kp	= {

		.symbol_name = "sctp_sf_eat_sack_6_2",

	},

	.entry	= jsctp_sf_eat_sack,

};

static __init int sctp_setup_jprobe(void)

{

	int ret = register_jprobe(&sctp_recv_probe);

	if (ret) {

		if (request_module("sctp"))

			goto out;

		ret = register_jprobe(&sctp_recv_probe);

	}

out:

	return ret;

}

static __init int sctpprobe_init(void)

{

	int ret = -ENOMEM;

	/* Warning: if the function signature of sctp_sf_eat_sack_6_2,

	 * has been changed, you also have to change the signature of

	 * jsctp_sf_eat_sack, otherwise you end up right here!

	 */

	BUILD_BUG_ON(__same_type(sctp_sf_eat_sack_6_2,

				 jsctp_sf_eat_sack) == 0);

	init_waitqueue_head(&sctpw.wait);

	spin_lock_init(&sctpw.lock);

	if (kfifo_alloc(&sctpw.fifo, bufsize, GFP_KERNEL))

		return ret;

	if (!proc_create(procname, S_IRUSR, init_net.proc_net,

			 &sctpprobe_fops))

		goto free_kfifo;

	ret = sctp_setup_jprobe();

	if (ret)

		goto remove_proc;

	pr_info("probe registered (port=%d/fwmark=%u) bufsize=%u\n",

		port, fwmark, bufsize);

	return 0;

remove_proc:

	remove_proc_entry(procname, init_net.proc_net);

free_kfifo:

	kfifo_free(&sctpw.fifo);

	return ret;

}

static __exit void sctpprobe_exit(void)

{

	kfifo_free(&sctpw.fifo);

	remove_proc_entry(procname, init_net.proc_net);

	unregister_jprobe(&sctp_recv_probe);

}

module_init(sctpprobe_init);

module_exit(sctpprobe_exit);