/* Copyright (C) 1998-99 Martin Baulig

   This file is part of LibGTop 1.0.

   Contributed by Martin Baulig <martin@home-of-linux.org>, April 1998.

   LibGTop 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 of the License,

   or (at your option) any later version.

   LibGTop 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 LibGTop; see the file COPYING. If not, write to the

   Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

   Boston, MA 02110-1301, USA.

*/

#include <config.h>

#include <glib.h>

#include <errno.h>

#include <glibtop.h>

#include <glibtop/open.h>

struct nlist _glibtop_nlist[] = {

#ifdef i386

    { "avenrun" },		/* 0 */

    { "ccpu" },			/* 1 */

    { "mpid" },			/* 2 */

    { "nproc" },		/* 3 */

    { "proc" },			/* 4 */

    { "total" },		/* 5 */

    { "cp_time" },		/* 6 */

    { "pages" },		/* 7 */

    { "epages" },		/* 8 */

    { "shminfo" },		/* 9 */

    { "msginfo" },		/* 10 */

    { "seminfo" },		/* 11 */

#else

    { "_avenrun" },		/* 0 */

    { "_ccpu" },		/* 1 */

    { "_mpid" },		/* 2 */

    { "_nproc" },		/* 3 */

    { "_proc" },		/* 4 */

    { "_total" },		/* 5 */

    { "_cp_time" },		/* 6 */

    { "_pages" },		/* 7 */

    { "_epages" },		/* 8 */

    { "_shminfo" },		/* 9 */

    { "_msginfo" },		/* 10 */

    { "_seminfo" },		/* 11 */

#ifdef MULTIPROCESSOR

    { "_ncpu" },

    { "_mp_time" },

#endif

#endif

    { 0 }

};

/* Opens pipe to gtop server. Returns 0 on success and -1 on error. */

/* !!! THIS FUNCTION RUNS SUID ROOT - CHANGE WITH CAUTION !!! */

void

glibtop_init_p (glibtop *server, const unsigned long features,

		const unsigned flags)

{

	if (server == NULL)

		glibtop_error_r (NULL, "glibtop_init_p (server == NULL)");

	glibtop_open_p (server, "glibtop", features, flags);

}

void

glibtop_open_p (glibtop *server, const char *program_name,

		const unsigned long features, const unsigned flags)

{

	register int pagesize;

	/* !!! WE ARE ROOT HERE - CHANGE WITH CAUTION !!! */

	server->name = program_name;

	server->machine->uid = getuid ();

	server->machine->euid = geteuid ();

	server->machine->gid = getgid ();

	server->machine->egid = getegid ();

	/* initialize the kernel interface */

	server->machine->kd = kvm_open (NULL, NULL, NULL, O_RDONLY, "libgtop");

	if (server->machine->kd == NULL)

		glibtop_error_io_r (server, "kvm_open");

	/* get the list of symbols we want to access in the kernel */

	server->machine->nlist_count = kvm_nlist

		(server->machine->kd, _glibtop_nlist);

	if (server->machine->nlist_count < 0)

		glibtop_error_io_r (server, "nlist");

#ifdef MULTIPROCESSOR

	/* were ncpu and xp_time not found in the nlist? */

	if ((server->machine->nlist_count > 0) &&

	    (_glibtop_nlist[X_NCPU].n_type == 0) &&

	    (_glibtop_nlist[X_MP_TIME].n_type == 0)) {

		/* we were compiled on an MP system but we are not running

		 * on one, so we will pretend this didn't happen and set

		 * ncpu = 1 */

		server->machine->nlist_count -= 2;

		server->machine->ncpu = 1;

	}

#endif

#ifdef solbourne

	{

		unsigned int status, type;

		/* Get the number of CPUs on this system.  */

		syscall(SYS_getcpustatus, &status,

			&server->machine->ncpu, &type);

	}

#endif

	/* Make sure all of the symbols were found. */

	if ((server->machine->nlist_count > 0) &&

	    (_glibtop_check_nlist (server, _glibtop_nlist) > 0))

		_exit (1);

	/* Get process array stuff. */

	(void) _glibtop_getkval (server, _glibtop_nlist[X_NPROC].n_value,

				 (int *)(&server->machine->nproc),

				 sizeof (server->machine->nproc),

				 _glibtop_nlist[X_NPROC].n_name);

	(void) _glibtop_getkval (server, _glibtop_nlist[X_PROC].n_value,

				 (int *)(&server->machine->ptable_offset),

				 sizeof (server->machine->ptable_offset),

				 _glibtop_nlist[X_PROC].n_name);

	server->machine->ptable_size = (unsigned long) server->machine->nproc *

		(unsigned long) sizeof (struct proc);

	server->machine->proc_table = g_malloc

		(server, server->machine->ptable_size);

	/* This are for the memory statistics. */

	(void) _glibtop_getkval (server, _glibtop_nlist[X_PAGES].n_value,

				 (int *)(&server->machine->pages),

				 sizeof (server->machine->pages),

				 _glibtop_nlist[X_PAGES].n_name);

	(void) _glibtop_getkval (server, _glibtop_nlist[X_EPAGES].n_value,

				 (int *)(&server->machine->epages),

				 sizeof (server->machine->epages),

				 _glibtop_nlist[X_EPAGES].n_name);

	server->machine->bytesize = server->machine->epages -

		server->machine->pages;

	server->machine->count = server->machine->bytesize /

		sizeof (struct page);

	server->machine->physpage = (struct page *)

		g_malloc (server->machine->bytesize);

	/* get the page size with "getpagesize" and

	 * calculate pageshift from it */

	pagesize = getpagesize();

	server->machine->pageshift = 0;

	while (pagesize > 1) {

		server->machine->pageshift++;

		pagesize >>= 1;

	}

	/* we only need the amount of log(2)1024 for our conversion */

	server->machine->pageshift -= LOG1024;

	/* Drop priviledges. */

	if (setreuid (server->machine->euid, server->machine->uid))

		_exit (1);

	if (setregid (server->machine->egid, server->machine->gid))

		_exit (1);

	/* !!! END OF SUID ROOT PART !!! */

	/* Our effective uid is now those of the user invoking the server,

	 * so we do no longer have any priviledges. */

	/* NOTE: On SunOS, we do not need to be suid root, we just need to

	 * be sgid kmem.

	 *

	 * The server will only use setegid() to get back it's priviledges,

	 * so it will fail if it is suid root and not sgid kmem. */

}

/* Used internally. Returns number of symbols that cannot be found in

 * the nlist. */

int

_glibtop_check_nlist (void *server, register struct nlist *nlst)

{

	register int not_found;

	/* check to see if we got ALL the symbols we requested */

	/* this will write one line to stderr for every symbol not found */

	not_found = 0;

	while (nlst->n_name != NULL) {

#ifdef i386

		if (nlst->n_value == 0) {

			glibtop_error_r (server,

					 "kernel: no symbol named `%s'",

					 nlst->n_name);

			not_found++;

		}

#else

		if (nlst->n_type == 0) {

			glibtop_error_r (server,

					 "kernel: no symbol named `%s'",

					 nlst->n_name);

			not_found++;

		}

#endif

		nlst++;

	}

	return not_found;

}

/* Used internally. Fetches value from kernel. */

int

_glibtop_getkval (void *void_server, unsigned long offset, int *ptr,

		  int size, char *refstr)

{

	glibtop	*server = (glibtop *) void_server;

	if (kvm_read (server->machine->kd, offset, ptr, size) != size)

		{

			if (*refstr == '!') return 0;

			glibtop_error_r (server, "kvm_read(%s): %s",

					 refstr, g_strerror (errno));

		}

	return 1;

}

/* Used internally. Reads process table from kernel. */

void

_glibtop_read_proc_table (void *void_server)

{

	glibtop *server = (glibtop *) void_server;

	/* !!! THE FOLLOWING CODE RUNS SGID KMEM - CHANGE WITH CAUTION !!! */

	setregid (server->machine->gid, server->machine->egid);

	/* Read process table from kernel. */

	(void) _glibtop_getkval (server, server->machine->ptable_offset,

				 (int *) server->machine->proc_table,

				 (size_t) server->machine->ptable_size,

				 _glibtop_nlist[X_PROC].n_name);

	if (setregid (server->machine->egid, server->machine->gid))

		_exit (1);

	/* !!! END OF SGID KMEM PART !!! */

}

/* Used internally. Finds pid in process table. */

struct proc *

_glibtop_find_pid (void *void_server, pid_t pid)

{

	register struct proc *pp;

	register int i;

	glibtop *server = (glibtop *) void_server;

	for (pp = server->machine->proc_table, i = 0;

	     i < server->machine->nproc; pp++, i++) {

		if ((pp->p_stat != 0) && (pp->p_pid == pid))

			return pp;

	}

	return NULL;

}