/*
** ATOP - System & Process Monitor 
** 
** The program 'atop' offers the possibility to view the activity of
** the system on system-level as well as process-level.
** 
** This source-file contains functions to read the process-administration
** of every running process from kernel-space and extract the required
** activity-counters.
** ==========================================================================
** Author:      Gerlof Langeveld - AT Computing, Nijmegen, Holland
** E-mail:      gerlof@ATComputing.nl
** Date:        November 1996
** LINUX-port:  June 2000
** --------------------------------------------------------------------------
** Copyright (C) 2000-2005 Gerlof Langeveld
**
** 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, 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
** --------------------------------------------------------------------------
**
** $Log: photoproc.c,v $
** Revision 1.24  2006/02/07 06:47:35  gerlof
** Removed swap-counter.
**
** Revision 1.23  2005/10/21 09:49:57  gerlof
** Per-user accumulation of resource consumption.
**
** Revision 1.22  2004/12/14 15:05:58  gerlof
** Implementation of patch-recognition for disk and network-statistics.
**
** Revision 1.21  2004/09/23 09:07:49  gerlof
** Solved segmentation fault by checking pval.
**
** Revision 1.20  2004/09/08 06:01:01  gerlof
** Correct the priority of a process by adding 100 (the kernel
** subtracts 100 when showing the value via /proc).
**
** Revision 1.19  2004/09/02 10:49:45  gerlof
** Added sleep-average to process-info.
**
** Revision 1.18  2004/08/31 09:51:36  gerlof
** Gather information about underlying threads.
**
** Revision 1.17  2003/07/07 09:26:59  gerlof
** Cleanup code (-Wall proof).
**
** Revision 1.16  2003/06/30 11:30:43  gerlof
** Enlarge counters to 'long long'.
**
** Revision 1.15  2003/02/06 12:09:23  gerlof
** Exchange tab-character in command-line by space.
**
** Revision 1.14  2003/01/24 14:19:39  gerlof
** Exchange newline byte in command-line by space.
**
** Revision 1.13  2003/01/17 14:21:41  root
** Change-directory to /proc to optimize opening /proc-files
** via relative path-names i.s.o. absolute path-names.
**
** Revision 1.12  2003/01/17 07:31:29  gerlof
** Store the full command-line for every process.
**
** Revision 1.11  2003/01/06 13:03:09  gerlof
** Improved command-name parsing (command-names containing a close-bracket
** were not parsed correctly).
**
** Revision 1.10  2002/10/03 11:12:39  gerlof
** Modify (effective) uid/gid to real uid/gid.
**
** Revision 1.9  2002/07/24 11:13:31  gerlof
** Changed to ease porting to other UNIX-platforms.
**
** Revision 1.8  2002/07/08 09:27:45  gerlof
** Avoid buffer overflow during sprintf by using snprintf.
**
** Revision 1.7  2002/01/22 13:39:53  gerlof
** Support for number of cpu's.
**
** Revision 1.6  2001/11/22 08:33:43  gerlof
** Add priority per process.
**
** Revision 1.5  2001/11/13 08:26:15  gerlof
** Small bug-fixes.
**
** Revision 1.4  2001/11/07 09:18:43  gerlof
** Use /proc instead of /dev/kmem for process-level statistics.
**
** Revision 1.3  2001/10/04 13:57:34  gerlof
** Explicit include of sched.h (i.s.o. linux/sched.h via linux/mm.h).
**
** Revision 1.2  2001/10/04 08:47:26  gerlof
** Improved verification of kernel-symbol addresses
**
** Revision 1.1  2001/10/02 10:43:29  gerlof
** Initial revision
**
*/

static const char rcsid[] = "$Id: photoproc.c,v 1.24 2006/02/07 06:47:35 gerlof Exp $";

#include <sys/types.h>
#include <sys/param.h>
#include <dirent.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>

#include "atop.h"
#include "photoproc.h"

#define	SCANSTAT 	"%c   %*d  %*d  %*d  %*d  %*d  "	\
			"%*d  %lld %*d  %lld %*d  %lld "	\
			"%lld %*d  %*d  %d   %d   %*d  "	\
			"%*d  %lld %lld %lld %*d  %lld "	\
			"%lld %*d  %*d  %*d  %*d  %*d  " 	\
			"%*d  %*d  %*d  %lld %*d  %*d  "	\
			"%d   %d   %d "

/* ATOP-extension line of /proc/pid/stat */
#define ATOPSTAT	"%lld %llu %lld %llu %lld %llu %lld %llu "	\
			"%lld %llu %lld %llu %lld %lld"

static int	fillproc(struct pstat *);

int
photoproc(struct pstat *proclist, int maxproc)
{
	static int	firstcall = 1;

	register struct pstat	*curproc;

	FILE		*fp;
	DIR		*dirp;
	struct dirent	*entp;
	char		origdir[1024];
	int		nr, i, nthreads, pval=0;

	/*
	** one-time initialization stuff
	*/
	if (firstcall)
	{
		/*
		** check if this kernel is patched for additional
		** per-process counters
		*/
		if ( (fp = fopen("/proc/1/stat", "r")) )
		{
			char	line[4096];

			/*
			** when the patch is installed, the output
			** of /proc/pid/stat contains two lines
			*/
			(void) fgets(line, sizeof line, fp);

			if ( fgets(line, sizeof line, fp) != NULL)
				kernpatch |= PATCHSTAT;

			fclose(fp);
		}

		firstcall = 0;
	}

	/*
	** read all subdirectory-names below the /proc directory
	*/
	getcwd(origdir, sizeof origdir);
	chdir("/proc");
	dirp = opendir(".");

	while ( (entp = readdir(dirp)) && pval < maxproc )
	{
		/*
		** skip non-numerical names
		*/
		if (!isdigit(entp->d_name[0]))
			continue;

		/*
		** change to the process' subdirectory
		*/
		if ( chdir(entp->d_name) != 0 )
			continue;

		/*
		** call fillproc to open the required files and gather
		** the process' info
		*/
		curproc	= proclist+pval;

		if ( (nthreads = fillproc(curproc)) == 0 )
		{
			chdir("..");
			continue;
		}

		pval++;

		/*
		** store the full command line;
		** the command-line may contain:
		**    - null-bytes as a separator between the arguments
		**    - newlines (e.g. arguments for awk or sed)
		**    - tabs (e.g. arguments for awk or sed)
		** these special bytes will be converted to spaces
		*/
		memset(curproc->gen.cmdline, 0, CMDLEN+1);

		if ( (fp = fopen("cmdline", "r")) != NULL)
		{
			register char *p = curproc->gen.cmdline;

			nr = fread(p, 1, CMDLEN, fp);
			fclose(fp);

			if (nr >= 0)	/* anything read ? */
			{
				for (i=0; i < nr-1; i++, p++)
				{
					switch (*p)
					{
					   case '\0':
					   case '\n':
					   case '\t':
						*p = ' ';
					}
				}
			}
		}

#if	0
		/*
		** Linux >= 2.6
		** For multithreaded processes, the subdirectory 'task'
		** contains "pid's" again for the threads related to
		** this process.
		**
		** This piece of code is not valid any more due to modified
		** accounting by the kernel.
		*/ 
		if ( nthreads > 1 && chdir("task") == 0 )
		{
			DIR		*dirtaskp;
			struct dirent	*enttaskp;

			dirtaskp = opendir(".");

			while ( (enttaskp = readdir(dirtaskp))
							&& pval < maxproc)
			{
				/*
				** skip non-numerical names
				*/
				if (!isdigit(enttaskp->d_name[0]))
					continue;

				/*
				** change to the underlying process' subdir
				*/
				if ( chdir(enttaskp->d_name) != 0 )
					continue;

				/*
				** call fillproc to open the required files
				** and gather the process' info
				*/
				curproc	= proclist+pval;

				if ( fillproc(curproc) )
					pval++;

				chdir("..");
			}

			closedir(dirtaskp);
			chdir("..");
		}
#endif

		chdir("..");
	}

	closedir(dirp);

	chdir(origdir);

	return pval;
}

static int
fillproc(struct pstat *curproc)
{
	static time_t	bootepoch;
	FILE		*fp;
	int		nr;
	char		line[4096], *cmdhead, *cmdtail;
	char		command[64], state;
	int		pid, tgid, ruid, rgid, prio, policy, rtprio, nice,
			curcpu, nthreads, sleepavg;
	count_t		utime, stime, starttime;
	count_t		minflt, majflt, size, rss, nswap,
			startcode, endcode,
			dskrio=0, dskwio=0, dskrsz=0, dskwsz=0,
			tcpsnd=0, tcprcv=0, tcpssz=0, tcprsz=0,
			udpsnd=0, udprcv=0, udpssz=0, udprsz=0,
			rawsnd=0, rawrcv=0;

	if (bootepoch == 0)
		bootepoch = getboot();

	/*
	** open file "stat" and obtain required info
	*/
	if ( (fp = fopen("stat", "r")) == NULL)
		return 0;

	(void) fgets(line, sizeof line, fp);

	sscanf(line, "%d", &pid);		/* fetch pid */

	cmdhead = strchr (line, '(');		/* fetch commandname */
	cmdtail = strrchr(line, ')');
	if ( (nr = cmdtail-cmdhead-1) > sizeof command)
		nr = sizeof command;
	memcpy(command, cmdhead+1, nr);
	memset(&command[nr], 0, sizeof command - nr);

	rtprio = policy = 0;

	nr = sscanf(cmdtail+2, SCANSTAT,
		&state,    &minflt,    &majflt,
		&utime,    &stime,     &prio,      &nice,    &starttime,
		&size,     &rss,       &startcode, &endcode, &nswap,
		&curcpu,   &rtprio,    &policy);

	if ( fgets(line, sizeof line, fp) != NULL)
	{
		sscanf(line, ATOPSTAT,
			&dskrio, &dskrsz, &dskwio, &dskwsz,
			&tcpsnd, &tcpssz, &tcprcv, &tcprsz,
			&udpsnd, &udpssz, &udprcv, &udprsz,
			&rawsnd, &rawrcv);
	}

	fclose(fp);

	if (nr < 14)		/* parsing succeeded ? */
		return 0;

	/*
	** open file "status" and obtain required info
	*/
	if ( (fp = fopen("status", "r")) == NULL)
		return 0;

	tgid     = pid;		/* for compat with 2.4 */
	nthreads = 1;		/* for compat with 2.4 */
	sleepavg = 0;		/* for compat with 2.4 */

	while (fgets(line, sizeof line, fp))
	{
		if (memcmp(line, "SleepAVG:", 9)==0)
		{
			sscanf(line, "SleepAVG: %d%%", &sleepavg);
			continue;
		}

		if (memcmp(line, "Tgid:", 4)==0)
		{
			sscanf(line, "Tgid: %d", &tgid);
			continue;
		}

		if (memcmp(line, "Uid:", 4)==0)
		{
			sscanf(line, "Uid: %d", &ruid);
			continue;
		}

		if (memcmp(line, "Gid:", 4)==0)
		{
			sscanf(line, "Gid: %d", &rgid);
			continue;
		}

		if (memcmp(line, "Threads:", 8)==0)
		{
			sscanf(line, "Threads: %d", &nthreads);
			break;
		}
	}

	fclose(fp);

	/*
	** store required info in process-structure
	*/
	curproc->gen.pid   = pid;
	curproc->gen.ruid  = ruid;
	curproc->gen.rgid  = rgid;
	curproc->gen.tgid  = tgid;
	curproc->gen.nthr  = nthreads;
	curproc->gen.state = state;

	strncpy(curproc->gen.name, command, PNAMLEN);
	curproc->gen.name[PNAMLEN] = 0;

	curproc->gen.excode   = 0;
	curproc->gen.btime    = starttime/HZ+bootepoch;
	curproc->cpu.utime    = utime;
	curproc->cpu.stime    = stime;
	curproc->cpu.nice     = nice;
	curproc->cpu.prio     = prio + 100; /* was subtracted by kernel */
	curproc->cpu.rtprio   = rtprio;
	curproc->cpu.policy   = policy;
	curproc->cpu.curcpu   = curcpu;
	curproc->cpu.sleepavg = sleepavg;

	curproc->mem.minflt = minflt;
	curproc->mem.majflt = majflt;
	curproc->mem.vmem   = size / 1024;
	curproc->mem.rmem   = rss  * (getpagesz()/1024);
	curproc->mem.vgrow  = 0;	/* calculated later */
	curproc->mem.rgrow  = 0;	/* calculated later */
	curproc->mem.shtext = (endcode-startcode)/1024;

	curproc->dsk.rio    = dskrio;
	curproc->dsk.rsz    = dskrsz;
	curproc->dsk.wio    = dskwio;
	curproc->dsk.wsz    = dskwsz;
	curproc->net.tcpsnd = tcpsnd;
	curproc->net.tcpssz = tcpssz;
	curproc->net.tcprcv = tcprcv;
	curproc->net.tcprsz = tcprsz;
	curproc->net.udpsnd = udpsnd;
	curproc->net.udpssz = udpssz;
	curproc->net.udprcv = udprcv;
	curproc->net.udprsz = udprsz;
	curproc->net.rawsnd = rawsnd;
	curproc->net.rawrcv = rawrcv;

	return nthreads;
}