#!/bin/sh
#
# rwsnoop - snoop read/write events.
#           Originally written using DTrace (Solaris 10 3/05).
#
# This is measuring reads and writes at the application level. This matches
# the syscalls read, and write.
#
# $Id: rwsnoop,v 1.1.1.1 2015/09/30 22:01:06 christos Exp $
#
# USAGE:	rwsnoop [-jPtvZ] [-n name] [-p pid]
# 
#		rwsnoop		# default output
#
#		-P		# print parent process ID
#		-t		# print timestamp, us
#		-v		# print time, string
#		-J		# print jail ID
#		-n name		# this process name only
#		-p PID		# this PID only
#	eg,
#		rwsnoop -J		# print jail ID
#		rwsnoop -n bash 	# monitor processes named "bash"
#		rwsnoop > out.txt	# recommended
#
# NOTE:
# 	rwsnoop usually prints plenty of output, which itself will cause
#	more output. It can be better to redirect the output of rwsnoop
#	to a file to prevent this.
#
# FIELDS:
#		TIME		Timestamp, us
#		TIMESTR		Time, string
#		JAIL		JAIL ID
#		UID		User ID
#		PID		Process ID
#		PPID		Parent Process ID
#		CMD		Process name
#		D		Direction, Read or Write
#		BYTES		Total bytes during sample, -1 for error
#		FILE		Filename, if file based
#
# Reads and writes that are not file based, for example with sockets, will
# print "<unknown>" as the filename.
#
# SEE ALSO:	rwtop
#
# COPYRIGHT: Copyright (c) 2005 Brendan Gregg.
#
# CDDL HEADER START
#
#  The contents of this file are subject to the terms of the
#  Common Development and Distribution License, Version 1.0 only
#  (the "License").  You may not use this file except in compliance
#  with the License.
#
#  You can obtain a copy of the license at Docs/cddl1.txt
#  or http://www.opensolaris.org/os/licensing.
#  See the License for the specific language governing permissions
#  and limitations under the License.
#
# CDDL HEADER END
#
# TODO:
#  Track readv and writev.
#
# Author: Brendan Gregg  [Sydney, Australia]
#
# 24-Jul-2005   Brendan Gregg   Created this.
# 17-Sep-2005	   "      "	Increased switchrate.
# 17-Sep-2005	   "      "	Last update.
# 26-Jul-2014   George Neville-Neil	Port to FreeBSD
#


##############################
# --- Process Arguments ---
#

### default variables
opt_name=0; opt_pid=0; opt_jailid=0; opt_time=0; opt_timestr=0
opt_bytes=1; filter=0; pname=.; pid=0; opt_ppid=0;

### process options
while getopts n:Pp:jtvZ name
do
	case $name in
	n)	opt_name=1; pname=$OPTARG ;;
	p)	opt_pid=1; pid=$OPTARG ;;
	P)	opt_ppid=1 ;;
	t)	opt_time=1 ;;
	v)	opt_timestr=1 ;;
	J)	opt_jailid=1 ;;
	h|?)	cat <<-END >&2
		USAGE: rwsnoop [-jPtvZ] [-n name] [-p pid]
 
		                -P       # print parent process ID
		                -t       # print timestamp, us
		                -v       # print time, string
		                -J       # print jail ID
		                -n name  # this process name only
		                -p PID   # this PID only
		   eg,
		        rwsnoop          # default output
		        rwsnoop -J       # print jail ID
		        rwsnoop -n bash  # monitor processes named "bash"
		END
		exit 1
	esac
done

shift $(( $OPTIND - 1 ))

### option logic
if [ $opt_name -ne 0 ]; then
	filter=1
fi

if [ $opt_pid -ne 0 ]; then
	filter=1
fi

#################################
# --- Main Program, DTrace ---
#
/usr/sbin/dtrace -n '
 /*
  * Command line arguments
  */
 inline int OPT_jailid 	= '$opt_jailid';
 inline int OPT_bytes 	= '$opt_bytes';
 inline int OPT_name 	= '$opt_name';
 inline int OPT_ppid 	= '$opt_ppid';
 inline int OPT_pid 	= '$opt_pid';
 inline int OPT_time 	= '$opt_time';
 inline int OPT_timestr	= '$opt_timestr';
 inline int FILTER 	= '$filter';
 inline int PID		= '$pid';
 inline string NAME 	= "'$pname'";
 
 #pragma D option quiet
 #pragma D option switchrate=10hz

 /*
  * Print header
  */
 dtrace:::BEGIN 
 {
	/* print header */
	OPT_time    ? printf("%-14s ", "TIME") : 1;
	OPT_timestr ? printf("%-20s ", "TIMESTR") : 1;
	OPT_jailid    ? printf("%5s ", "JAILID") : 1;
	OPT_ppid    ? printf("%6s ", "PPID") : 1;
	printf("%5s %6s %-12s %4s %1s %7s\n",
	    "UID", "PID", "CMD", "FD", "D", "BYTES");
 }

 /*
  * Check event is being traced
  */
 syscall::*read:entry,
 syscall::*write:entry
 /pid != $pid/
 { 
	/* default is to trace unless filtering, */
	self->ok = FILTER ? 0 : 1;

	/* check each filter, */
	(OPT_name == 1 && NAME == execname)? self->ok = 1 : 1;
	(OPT_pid == 1 && PID == pid) ? self->ok = 1 : 1;

	/* save file descriptor */
	self->fd = self->ok ? arg0 : 0;
 }

 /*
  * Save read details
  */
 syscall::*read:return
 /self->ok/
 {
	self->rw = "R";
	self->size = arg0;
 }

 /*
  * Save write details
  */
 syscall::*write:entry
 /self->ok/
 {
	self->rw = "W";
	self->size = arg2;
 }

 /*
  * Process event
  */
 syscall::*read:return,
 syscall::*write:entry
 /self->ok/
 {
	/*
	 * Fetch filename
         * XXX Not yet implemented.
	 */
/*

	this->filistp = curthread->t_procp->p_user.u_finfo.fi_list;
	this->ufentryp = (uf_entry_t *)((uint64_t)this->filistp +
	    (uint64_t)self->fd * (uint64_t)sizeof(uf_entry_t));
	this->filep = this->ufentryp->uf_file;
	this->vnodep = this->filep != 0 ? this->filep->f_vnode : 0;
	self->vpath = this->vnodep ? (this->vnodep->v_path != 0 ? 
	    cleanpath(this->vnodep->v_path) : "<unknown>") : "<unknown>";
*/
	/*
	 * Print details
	 */
	OPT_time    ? printf("%-14d ", timestamp / 1000) : 1;
	OPT_timestr ? printf("%-20Y ", walltimestamp) : 1;
	OPT_jailid    ? printf("%5d ", curpsinfo->pr_jailid) : 1;
	OPT_ppid    ? printf("%6d ", ppid) : 1;
	printf("%5d %6d %-12.12s %4d %1s %7d\n",
	    uid, pid, execname, self->fd, self->rw, (int)self->size);
	
	self->ok = 0;
	self->fd = 0;
	self->rw = 0;
	self->size = 0;
	self->vpath = 0;
 }
'