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/*
* Ident-2 - an Identity server for UNIX
* Copyright (C) 1998-2001 Michael Bacarella
* Copyright (C) 2003 Netgraft Corporation
* Copyright (C) 2005 Greg Schenzel
*
* This program 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.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Please view the file README for program information.
*/
/*
* Support for all OSes with lsof installed.
* Added 3/27/05 by Greg Schenzel (inittab@netizenweb.com)
*/
#include "ident2.h"
#define PID_FILE "/var/run/ident2.pid"
/**
** drop to the lowest permission level
** possible. 'nobody' is ideal for most
**/
int
m_reduce_rights (void)
{
struct passwd *pw;
if ((geteuid() && getuid())
|| Dont_Change_Uid == TRUE)
return 0;
if ((pw = getpwnam ("nobody")) == NULL) {
syslog (LOG_ERR, "error: getpwnam(nobody): %s",
strerror (errno));
return -1;
}
if (setuid (pw->pw_uid) == -1) {
syslog (LOG_ERR, "error: setuid(%d): %s",
pw->pw_uid, strerror (errno));
return -1;
}
return 0;
}
/**
** find what user belongs to the connection
** described by LPORT, RPORT, RADDR, and LADDR.
** return the uid.
**/
int
m_get_uid (struct in_addr *laddr, u_short lp,
struct in_addr *raddr, u_short rp)
{
FILE *fp;
char cmd[256]; //check for overflow
unsigned char *locad = (unsigned char *)&(laddr->s_addr);
unsigned char *remad = (unsigned char *)&(raddr->s_addr);
int uid, pid;
char concmd[45];
sprintf(cmd, "%s -i @%hhu.%hhu.%hhu.%hhu:%hu -n -l -P | grep %hhu.%hhu.%hhu.%hhu:%hu", LSOF_LOCATION,
locad[0], locad[1], locad[2], locad[3], lp,
remad[0], remad[1], remad[2], remad[3], rp);
// syslog(LOG_ERR, "about to run: %s", cmd);
if ((fp = popen (cmd, "r")) == NULL) {
syslog (LOG_ERR, "error reading from lsof: %s",
strerror (errno));
return -1;
}
//concmd and pid are useless placeholders for us. ignore the rest
if (fscanf(fp, "%s %d %d",
concmd, &pid, &uid) < 1) {
uid = -1;
}
pclose(fp);
return uid;
}
/*
* records the pid for service management purposes.
* example: under Red Hat,Debian,etc pid is written to
* /var/run/identd.pid
* PID support suggested (and previously implemented)
* by Alexander Reelsen.
*/
int
m_register_pid (void)
{
#ifdef HAS_VAR_RUN
FILE *fp;
if ((fp = fopen (PID_FILE, "w")) == NULL) {
syslog (LOG_WARNING, "couldn't record pid in %s: %s -- "
"automatic shutdown with system not available",
PID_FILE, strerror (errno));
return -1;
}
fprintf (fp, "%u\n", (unsigned int)getpid());
fclose (fp);
#endif
return 0;
}
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