/*
** Copyright (c) 1986, 1994, 1996, 2000, 2002
**	Jeff Forys (jeffware@marjum.com).  All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that: (1) Redistributions of
** source code must retain the above copyright notice, this list of
** conditions and the following disclaimer, (2) Redistributions in
** binary form must reproduce the above copyright notice, this list
** of conditions and the following disclaimer in the documentation
** and/or other materials provided with the distribution, (3) All
** advertising materials mentioning features or use of this software
** must display the following acknowledgment: ``This product includes
** software developed by Jeff Forys (jeffware@marjum.com).'', (4)
** The name of the author may not be used to endorse or promote products
** derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
** WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#ifndef lint
static char rcsid[] = "$Id: umax-42.c,v 1.8 2005/04/06 23:49:35 forys Exp $";
#endif

#define	NO_MEXTERN
#include "conf.h"
#undef	NO_MEXTERN

#include <sys/time.h>
#include <sys/resource.h>

#include <stdio.h>

#define	CRIT_PID	1	/* Query kills for pids .LE. this number */

/*
 * Define SigNames, NSig, and TtyDevDir here; they are used by other
 * routines and must be global.  Everyone seems to have their own
 * idea as to what NSIG should be.  Here, `NSig' is the number of
 * signals available, not counting zero.
 */
char *SigMap[] = { "0",
	"HUP", "INT", "QUIT", "ILL", "TRAP", "IOT",		/*  1 -  6 */
	"EMT", "FPE", "KILL", "BUS", "SEGV", "SYS",		/*  7 - 12 */
	"PIPE", "ALRM", "TERM", "URG", "STOP", "TSTP",		/* 13 - 18 */
	"CONT", "CHLD", "TTIN", "TTOU", "IO", "XCPU",		/* 19 - 24 */
	"XFSZ", "VTALRM", "PROF", "28", "29", "30",		/* 25 - 30 */
	"31", "32",						/* 31 - 32 */
};
int NSig = NSIG;

#define	SETCMD(dst,src,maxlen) {			\
	extern char *rindex();				\
	if (maxlen > 0) src[maxlen] = '\0';		\
	dst = (dst = rindex(src, '/')) ? ++dst: src;	\
}

static char *TtyDevDir = "/dev";

int	Skill;			/* set 1 if running `skill', 0 if `snice' */
int	PrioMin, PrioMax;	/* min and max process priorities */
int	SigPri;			/* signal to send or priority to set */
pid_T	MyPid;			/* pid of this process */
uid_T	MyUid;			/* uid of this process */
char	*ProgName;		/* program name */

/*
 * This is the machine-dependent initialization routine.
 *
 *   - The following global variables must be initialized:
 *     MyPid, MyUid, ProgName, Skill, PrioMin, PrioMax, SigPri
 *   - The working directory will be changed to that which contains the
 *     tty devices (`TtyDevDir'); this makes argument parsing go faster.
 *   - If possible, this routine should raise the priority of this process.
 */
void
MdepInit(pname)
	char *pname;
{
	extern char *rindex(), *SysErr();

	MyPid = (pid_T) getpid();
	MyUid = (uid_T) getuid();
	SETCMD(ProgName, pname, 0)

	/*
	 * If we are running as root, raise our priority to better
	 * catch runaway processes.
	 */
	if (MyUid == ROOTUID)
		(void) setpriority(PRIO_PROCESS, MyPid, PRIO_MIN);

	/*
	 * Determine what we are doing to processes we find.  We will
	 * either send them a signal (skill), or renice them (snice).
	 */
	Skill = (strcmp(ProgName, "snice") != 0);

	/*
	 * chdir to `TtyDevDir' to speed up tty argument parsing.
	 */
	if (chdir(TtyDevDir) < 0) {
		fprintf(stderr, "%s: chdir(%s): %s\n", ProgName, TtyDevDir,
		        SysErr());
		exit(EX_SERR);
	}

	/*
	 * Set up minimum and maximum process priorities.
	 * Initialize SigPri to either default signal (`skill') or
	 * default priority (`snice').
	 */
	PrioMin = PRIO_MIN;
	PrioMax = PRIO_MAX;
	SigPri = Skill? SIGTERM: 4;
}

/*
 * Carry out an action on a particular process.  If this is `skill',
 * then send the process a signal, otherwise this is `snice' so change
 * it's priority.
 *
 * If 0 is returned, the operation was successful, otherwise -1 is
 * returned and `errno' set.
 */
int
MdepAction(pid)
	pid_T pid;
{
	if (Skill)
		return(kill((int)pid, SigPri));
	else
		return(setpriority(PRIO_PROCESS, (int)pid, SigPri));
}

/* disable regular expresions: regex(3) availability unknown */
NULL_REGEX_FUNCS

/*
 * Now, set up everything we need to write a GetProc() routine.
 */

#include <sys/statistics.h>
#include <sys/procstats.h>

extern	off_t lseek();

#ifndef SZOMB
#define	SZOMB	0x08
#endif

/*
 * GetProc()
 *
 * Fill in and return a `struct ProcInfo' with information about the
 * next process.  If no processes are left, return NULL.
 *
 * Fflag support:
 *	If Fflag is set we will try to avoid stat'ing ttys for dev_t's.
 *	We can do this only if TtyIndx is zero.
 */
struct ProcInfo *
GetProc()
{
	extern int errno;
	extern char *SysErr();
	static struct stat_descr pdesc;
	static struct proc_config pconf;
	static struct proc_detail *procsp;
	static struct ProcInfo procinfo;
	register struct proc_detail *aproc;
	static int thisproc = 0;
	static int initialized = 0;
	static int needtty = 1;			/* Fflag support */

	/*
	 * Read in all the processes at once, into a large block of memory;
	 * if `pinfo' is big enough, we'll use that, o/w we will calloc()
	 * what we need.  Either way, `procsp' will point to the next proc.
	 *
	 * The first time thisproc == 0, we do the `procsp' initialization.
	 * The second time thisproc == 0, we are finished and return NULL.
	 * The following `while' is for sanity; it could be an `if'.
	 */
	while (thisproc == 0) {
		extern char *calloc();
		char *errstr = "%s: %s: %s\n";

		if (initialized)
			return((struct ProcInfo *)NULL);

		pdesc.sd_next = NULL;
		pdesc.sd_subsys = SUBSYS_PROC;
		pdesc.sd_type = PROCTYPE_CONFIG;
		pdesc.sd_options = NULL;
		pdesc.sd_objid = NULL;
		pdesc.sd_addr = (char *)&pconf;
		pdesc.sd_size = sizeof(struct proc_config);

		if (inq_stats(1, &pdesc) < 0) {
			fprintf(stderr, errstr, ProgName, "inq_stats(CONFIG)",
			        SysErr());
			exit(EX_SERR);
		}
		thisproc = pconf.pc_nprocs;

		if ((procsp = (struct proc_detail *) calloc((unsigned)thisproc,
		     sizeof(struct proc_detail))) == NULL) {
			fprintf(stderr, errstr, ProgName, "GetProc",
			        "out of memory");
			exit(EX_SERR);
		}

		pdesc.sd_next = NULL;
		pdesc.sd_subsys = SUBSYS_PROC;
		pdesc.sd_type = PROCTYPE_DETAIL;
		pdesc.sd_options = PROC_DETAIL_ALL|PROC_DETAIL_ALLPROC;
		pdesc.sd_objid = NULL;
		pdesc.sd_addr = (char *)procsp;
		pdesc.sd_size = thisproc * sizeof(struct proc_detail);

		if (inq_stats(1, &pdesc) < 0) {
			fprintf(stderr, errstr, ProgName, "inq_stats(DETAIL)",
			        SysErr());
			exit(EX_SERR);
		}

		thisproc = pdesc.sd_sizeused / sizeof (struct proc_detail);

		/*
		 * We can avoid a stat() syscall if we dont need dev_t's.
		 */
		if (Fflag && TtyIndx == 0)
			needtty = 0;

		initialized = 1;
	}

	/*
	 * Trudge thru `procsp'.  Decrement `thisproc' as we go.
	 */
	aproc = procsp++;
	thisproc--;

	/*
	 * Make sure this isn't a "zombie" process.  If it is, we are
	 * finished; fill in procinfo and return.
	 */
	procinfo.pi_flags = 0;
	procinfo.pi_pid = (pid_T) aproc->pd_pid;
	procinfo.pi_uid = (uid_T) aproc->pd_uid;

	if (aproc->pd_flag & SZOMB) {	/* zombie */
		static char *zombie = "<defunct>";
		procinfo.pi_flags |= PI_ZOMBIE;
		procinfo.pi_cmd = zombie;
	}

	if (procinfo.pi_flags)
		return(&procinfo);

	/*
	 * Fill in the rest of `procinfo'.
	 */
	if (aproc->pd_pid <= CRIT_PID)	/* special */
		procinfo.pi_flags |= PI_ASKUSR;

	/* set path-stripped command name */
	SETCMD(procinfo.pi_cmd, aproc->pd_command, 12)

	/*
	 * Encore gives us a character string representing the device.
	 * We want the actual device major/minor!
	 */
	if (needtty && *aproc->pd_device != '?') {
		static struct stat st;
		if (stat(aproc->pd_device, &st) >= 0 &&
		    (st.st_mode & S_IFMT) == S_IFCHR) {
			procinfo.pi_flags |= PI_CTLTTY;
			procinfo.pi_tty = (tty_T) st.st_rdev;
		}
	}

	return(&procinfo);
}