#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <kvm.h>
#include <paths.h>

#include "util.h"

#ifdef HAVE_CONFIG_H
#include "../config.h"
#endif

static void usage();
static void printJailIds();
static void runJailPs(int argc, char* argv[]);

int main(int argc, char* argv[])
{
	int ch = 0;
	int simple = 0;
	int jid = 0;

	while((ch = getopt(argc, argv, "x")) != -1)
	{
		switch(ch)
		{
		case 'x':
			simple = 1;
			break;

		case '?':
		default:
			usage();
		}
	}

	argc -= optind;
	argv += optind;

	/* Make sure we have a jail name or id */
	if(argc == 0)
		usage();

	if(running_in_jail())
		errx(1, "can't run from inside jail");

	/* Translate the jail name into an id if neccessary */
	name = argv[0];
	jid = translate_jail_name(argv[0]);
	if(jid == -1)
		errx(1, "unknown jail host name: %s", argv[0]);

	argc--;
	argv++;

	/* Go into the jail */
	if(jail_attach(jid) == -1)
		err(1, "couldn't attach to jail");

	if(simple)
	{
		if(argc > 0)
			usage();

		print_jail_ids();
	}

	else
	{
		/* This function never returns */
		run_jail_ps(argc, argv);
	}

	return 0;
}

static void usage()
{
	fprintf(stderr, "usage: jps [-x] jail [ ps_options ... ]\n");
	exit(2);
}

static void run_jail_ps(int argc, char* argv[])
{
	char* args[];
	int i;

	if(!check_jail_command(NULL, "/bin/ps"))
		exit(1);

	/*
	 * TODO: We need to purge down the environment here.
	 * If the jail is in any way malicious or compromised
	 * then it could have replaced /bin/ps which we run...
	 */

	args = alloca(sizeof(char*) * (argc + 2));
	args[0] = "ps";

	for(i = 0; i < argc; i++)
		args[i + 1] = argv[i];

  args[i + 1] = NULL;

  run_jail_command(NULL, "/bin/ps", args, 0);
}

static void print_jail_ids()
{
	kvm_t* kd;
	struct kinfo_proc* kp;
	char errbuf[_POSIX2_LINE_MAX];

	/* Open kernel interface */
	kd = kvm_openfiles(_PATH_DEVNULL, _PATH_DEVNULL, _PATH_DEVNULL,
									   O_RDONLY, errbuf);
	if(kd == NULL)
		errx(1, "couldn't connect to kernel: %s", errbuf);

	/* Get all processes and print the pids */
	if((kp = kvm_getprocs(kd, KERN_PROC_ALL, 0, &nentries)) == 0)
		errx(1, "couldn't list processes: %s", kvm_geterr(kd));

	for(i = 0; i < nentries; i++)
		printf("%d ", (int)(kp[i].ki_pid));

	fputc(stdout, '\n');
	kvm_close(kd);
}