/*
** 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: bsd-44.c,v 1.19 2005/04/06 23:49:34 forys Exp $";
#endif

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

/*
 * With FreeBSD 2.2 <sys/user.h> is required (again).
 */
#if (__FreeBSD__ >= 2)
#include <osreldate.h>
#if (__FreeBSD_version >= 220000)
#include <sys/user.h>
#endif
#endif

#include <sys/resource.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>

/*
 * 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", "ABRT",		/*  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", "WINCH", "INFO", "USR1",	/* 25 - 30 */
	"USR2"							/* 31      */
#ifdef __NetBSD__
	, "PWR"							/* 32      */
#endif
};
int NSig = NSIG - 1;

#define	SETCMD(dst,src,maxlen) {			\
	if (maxlen > 0) src[maxlen] = '\0';		\
	dst = (dst = strrchr(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 *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 = (strstr(ProgName, "snice") == NULL);

	/*
	 * 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 <kvm.h>
#include <fcntl.h>

#if defined(BSD4_4) && (BSD < 199306)
#include <sys/kinfo.h>
#include <sys/kinfo_proc.h>
#define	_ALLPROCFLAG	KINFO_PROC_ALL
#else
#include <sys/sysctl.h>
#include <limits.h>
#define	_ALLPROCFLAG	KERN_PROC_ALL
#endif

#ifndef	P_WEXIT		/* backward compatibility */
#define	P_WEXIT	SWEXIT
#endif

static	char	*pidmap[] = { "swapper", "init", "pagedaemon" };
static	int	pidmapsiz = sizeof(pidmap) / sizeof(pidmap[0]);

#define	PROC(kprocp)	kprocp->kp_proc
#define	EPROC(kprocp)	kprocp->kp_eproc

/*
 * GetProc()
 *
 * Fill in and return a `struct ProcInfo' with information about the
 * next process.  If no processes are left, return NULL.
 */
struct ProcInfo *
GetProc()
{
	static struct ProcInfo procinfo;
	static int nproc = -1;
	static struct kinfo_proc *aproc;
	static kvm_t *kd = NULL;
#ifdef	_POSIX2_LINE_MAX
	char errbuf[_POSIX2_LINE_MAX];
#else
	char errbuf[2048];
#endif

	/*
	 * If this is our first time here, prepare to read procs from kernel.
	 */
	if (nproc == -1) {
		kd = kvm_openfiles((char *)NULL, (char *)NULL, (char *)NULL,
		                   O_RDONLY, errbuf);
		if (kd == NULL) {
			fprintf(stderr, "%s: %s\n", ProgName, errbuf);
			exit(EX_SERR);
		}

		if ((aproc=kvm_getprocs(kd, _ALLPROCFLAG, 0, &nproc)) == NULL) {
			fprintf(stderr, "%s: %s\n", ProgName, kvm_geterr(kd));
			exit(EX_SERR);
		}
	}

	if (nproc == 0) {
		if (kd != NULL) {
			kvm_close(kd);
			kd = NULL;
		}
		return((struct ProcInfo *)NULL);
	}

	do {
		if (PROC(aproc).p_stat != 0) {
			/*
			 * Make sure this isn't a "zombie" or "exiting"
			 * process.  If it is, fill in procinfo and return.
			 */
			procinfo.pi_flags = 0;
			procinfo.pi_pid = (pid_T) PROC(aproc).p_pid;
			procinfo.pi_uid = (uid_T) EPROC(aproc).e_ucred.cr_uid;

			if (PROC(aproc).p_stat == SZOMB) {	/* zombie */
				static char *zombie = "<defunct>";
				procinfo.pi_flags |= PI_ZOMBIE;
				procinfo.pi_cmd = zombie;
			} else if (PROC(aproc).p_flag & P_WEXIT) { /* exiting */
				static char *exiting = "<exiting>";
				procinfo.pi_flags |= PI_SWEXIT;
				procinfo.pi_cmd = exiting;
			}

			if (procinfo.pi_flags) {
				nproc--;
				aproc++;
				return(&procinfo);
			}
		}
	} while (PROC(aproc).p_stat == 0);

	/*
	 * We now have a process (`aproc').
	 * Fill in the rest of `procinfo'.
	 */
	if (EPROC(aproc).e_tdev != NODEV) {	/* controlling tty */
		procinfo.pi_flags |= PI_CTLTTY;
		procinfo.pi_tty = (tty_T) EPROC(aproc).e_tdev;
	}

	if (PROC(aproc).p_pid < pidmapsiz) {	/* special */
		procinfo.pi_cmd = pidmap[PROC(aproc).p_pid];
		procinfo.pi_flags |= PI_ASKUSR;
	} else				 /* set path-stripped command name */
		SETCMD(procinfo.pi_cmd, PROC(aproc).p_comm, MAXCOMLEN)

	nproc--;
	aproc++;
	return(&procinfo);
}