#ifndef __linux__
JNIEXPORT jstring JNICALL Java_gnu_io_CommPortIdentifier_native_1psmisc_1report_1owner (JNIEnv *env, jobject obj, jstring arg)
{
	return (*env)->NewStringUTF(env, "Unknown Application");
}
#else

/* loosly based on fuser.c by Werner Almesberger. */
/* fuser.c - identify processes using files */

/* Copyright 1993-1998 Werner Almesberger. See file COPYING for details. 
psmisc (fuser, killall and pstree) program code, documentation and
auxiliary programs are
Copyright 1993-1998 Werner Almesberger.
All rights reserved.

Redistribution and use in source and binary forms of parts of or the
whole original or derived work are permitted provided that the
original work is properly attributed to the author. The name of the
author may not be used to endorse or promote products derived from
this software without specific prior written permission. This work
is provided "as is" and without any express or implied warranties.
*/
#include <stdio.h>
#include <string.h>
#include <dirent.h>
#include <pwd.h>
#include <signal.h>
#include <sys/stat.h>
#include <linux/major.h>
#include <unistd.h>
#include <sys/types.h>
#include <stdlib.h>
#include "gnu_io_CommPortIdentifier.h"

#define COMM_LEN 16
#define PROC_BASE  "/proc"
#define UID_UNKNOWN -1
#define NAME_FIELD 20 /* space reserved for file name */
#define REF_FILE   1	/* an open file */
#define REF_ROOT   2	/* current root */
#define REF_CWD    4	/* current directory */
#define REF_EXE    8	/* executable */
#define REF_MMAP  16	/* mmap'ed file or library */
#define FLAG_UID   2	/* show uid */
#define FLAG_VERB  4	/* show verbose output */
#define FLAG_DEV   8	/* show all processes using this device */


char returnstring[256];
void parse_args(const char *);
typedef struct {
    const char *name;
} SPACE_DSC;

typedef enum { it_proc,it_mount,it_loop,it_swap } ITEM_TYPE;

typedef struct item_dsc {
    ITEM_TYPE type;
    union {
	struct {
	    pid_t pid;
	    int uid; /* must also accept UID_UNKNOWN */
	    int ref_set;
	} proc;
	struct {
	    const char *path;
	} misc;
    } u;
    struct item_dsc *next;
} ITEM_DSC;

typedef struct file_dsc {
    const char *name;  /* NULL if previous entry has name */
    dev_t dev;
    ino_t ino;
    int flags,sig_num;
    SPACE_DSC *name_space; /* or NULL if no indication */
    ITEM_DSC *items;
    struct file_dsc *named,*next;
} FILE_DSC;

static SPACE_DSC name_spaces[] = { };
static FILE_DSC *files = NULL;
static FILE_DSC *last_named = NULL;
static int all = 0,found_item = 0;

static void add_file(const char *path,unsigned long device,unsigned long inode, pid_t pid,int ref)
{
    struct stat st;
    FILE_DSC *file,*next;
    ITEM_DSC **item,*this;
    unsigned long mount_dev;

    if (device) mount_dev = device;
    for (file = files; file; file = next) {
	next = file->next;
	if (file->flags & FLAG_DEV ? mount_dev && mount_dev == file->dev :
	  device == file->dev && inode == file->ino) {
	    if (!file->name) file = file->named;
	    for (item = &file->items; *item; item = &(*item)->next)
		if ((*item)->type == it_proc && (*item)->u.proc.pid >= pid)
		    break;
	    if (*item && (*item)->u.proc.pid == pid) this = *item;
	    else {
		if (!(this = malloc(sizeof(ITEM_DSC)))) {
		    perror("malloc");
		    exit(1);
		}
		this->type = it_proc;
		this->u.proc.pid = pid;
		this->u.proc.uid = UID_UNKNOWN;
		this->u.proc.ref_set = 0;
		this->next = *item;
		*item = this;
		found_item = 1;
	    }
	    this->u.proc.ref_set |= ref;
	    if ((file->flags & (FLAG_UID | FLAG_VERB)) && this->u.proc.uid == UID_UNKNOWN && lstat(path,&st) >= 0) 
		this->u.proc.uid = st.st_uid;
	}
    }
}

static void check_dir(const char *rel,pid_t pid,int type)
{
    DIR *dir;
    struct dirent *de;
    char path[PATH_MAX+1];
    struct stat st;

    if (!(dir = opendir(rel))) return;
    while (de = readdir(dir))
	if (strcmp(de->d_name,".") && strcmp(de->d_name,"..")) {
	    sprintf(path,"%s/%s",rel,de->d_name);
            if (stat(path,&st) >= 0)
               add_file(path,st.st_dev,st.st_ino,pid,type);
	}
    (void) closedir(dir);
}


extern void scan_fd(void)
{
    DIR *dir;
    struct dirent *de;
    char path[PATH_MAX+1];
    pid_t pid;
    int empty;

    if (!(dir = opendir(PROC_BASE))) {
	perror(PROC_BASE);
	exit(1);
    }
    empty = 1;
    while (de = readdir(dir))
	if (pid = atoi(de->d_name)) {
	    empty = 0;
	    sprintf(path,"%s/%d",PROC_BASE,pid);
	    if (chdir(path) >= 0) {
		check_dir("fd",pid,REF_FILE);
	    }
	}
    (void) closedir(dir);
    if (empty) {
	fprintf(stderr,PROC_BASE " is empty (not mounted ?)\n");
	exit(1);
    }
}

extern void show_user(const char tstring[],char *rs)
{
    const ITEM_DSC *item;
    FILE *f;
    const struct passwd *pw;
    const char *user,*scan;
    char tmp[10],path[PATH_MAX+1],comm[COMM_LEN+1];
    int dummy;
    int keeper;
    pid_t self;
    const char *name;
    int uid;
    char temp[80];

    parse_args(tstring);
    scan_fd();
    if (seteuid(getuid()) < 0) { 
	sprintf(rs, "%s", "Unknown Linux Application");
	return; 
    }
    self = getpid();
    if (!files->name || !(files->items || all))
    {
	 sprintf(rs, "%s", "Unknown Linux Application");
	 return; 
    }
    scan = files->name;
    strcat(returnstring," ");
    item = files->items;
    sprintf(path,PROC_BASE "/%d/stat",item->u.proc.pid);
    strcpy(comm,"???");
    if (f = fopen(path,"r")) {
	(void) fscanf(f,"%d (%[^)]",&dummy,comm);
	(void) fclose(f);
    }
    name = comm;
    uid = item->u.proc.uid;
    if (uid == UID_UNKNOWN) user = "???";
    else if (pw = getpwuid(uid)) user = pw->pw_name;
    else {
	sprintf(tmp,"%d",uid);
	user = tmp;
    }
    strcat(returnstring,user);
    strcat(returnstring," PID = ");
    sprintf(temp,"%6d ",item->u.proc.pid);
    strcat(returnstring,temp);
    strcat(returnstring,"Program = ");
    if (name)
    {
	 for (scan = name; *scan; scan++)
	 {
	      if (*scan == '\\') 
	      {
		  sprintf(temp,"\\\\");
		  strcat(returnstring,temp);
	      }
	      else if (*scan > ' ' && *scan <= '~')
	      {
		  keeper=strlen(returnstring);
		  returnstring[keeper]= *scan;
		  returnstring[keeper+1]= '\0';
	      }
	      else { 
		  sprintf(temp,"\\%03o", scan);
		  strcat(returnstring,temp);
	      }
	 }
    }
    strcpy(rs,returnstring);
}
static void enter_item(const char *name,int flags,int sig_number,dev_t dev, ino_t ino,SPACE_DSC *name_space)
{
    static FILE_DSC *last = NULL;
    FILE_DSC *new;

    if (!(new = malloc(sizeof(FILE_DSC)))) {
	perror("malloc");
	exit(1);
    }
    if (last_named && !strcmp(last_named->name,name) &&
      last_named->name_space == name_space) new->name = NULL;
    else if (!(new->name = strdup(name))) {
	    perror("strdup");
	    exit(1);
	}
    new->flags = flags;
    new->sig_num = sig_number;
    new->items = NULL;
    new->next = NULL;
    new->dev = dev;
    new->ino = ino;
    new->name_space = name_space;
    if (last) last->next = new;
    else files = new;
    last = new;
    new->named = last_named;
    if (new->name) last_named = new;
}
 void parse_args(const char *argv)
{
    SPACE_DSC *name_space;
    int flags,sig_number,no_files;
    SPACE_DSC *this_name_space;
    struct stat st;

    flags = 0;
    sig_number = SIGKILL;
    name_space = name_spaces;
    no_files = 1;
    flags |= FLAG_UID;
    no_files = 0;
    last_named = NULL;
    this_name_space = name_space;
    if (this_name_space == name_spaces) {
       if (stat(argv,&st) < 0) {
          perror(argv);
          exit(0);
       }
       if (!S_ISSOCK(st.st_mode) || (flags & FLAG_DEV))
          enter_item(argv,flags,sig_number,st.st_dev,st.st_ino,NULL);
    }
}


JNIEXPORT jstring JNICALL Java_gnu_io_CommPortIdentifier_native_1psmisc_1report_1owner (JNIEnv *env, jobject obj, jstring arg)
{
	char returnstring[256];
	const char *str = (*env)->GetStringUTFChars(env, arg, 0);
        show_user(str,returnstring);
	(*env)->ReleaseStringUTFChars(env, arg, str);
	return (*env)->NewStringUTF(env, returnstring);
}
#endif /* __linux__ */
