"Fossies" - the Fresh Open Source Software Archive

Member "ident2-v1.07_FINAL/sys/m_linux.c" (22 Jul 2005, 3169 Bytes) of package /linux/privat/old/ident2-v1.07_FINAL.tar.gz:

    1 /*
    2  * Ident-2 - an Identity server for UNIX
    3  * Copyright (C) 1998-2001 Michael Bacarella
    4  * Copyright (C) 2003 Netgraft Corporation
    5  *
    6  * This program is free software; you can redistribute it and/or
    7  * modify it under the terms of the GNU General Public License
    8  * as published by the Free Software Foundation; either version 2
    9  * of the License, or (at your option) any later version.
   10  *
   11  * This program is distributed in the hope that it will be useful,
   12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   14  * GNU General Public License for more details.
   15  *
   16  * You should have received a copy of the GNU General Public License
   17  * along with this program; if not, write to the Free Software
   18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
   19  *
   20  * Please view the file README for program information.
   21  */
   22 
   23 /*
   24  *  Support for Linux machine dependancies
   25  */
   26 
   27 #include "ident2.h"
   28 
   29 #define PID_FILE "/var/run/ident2.pid"
   30 
   31     /**
   32      ** drop to the lowest permission level
   33      ** possible. 'nobody' is ideal for linux
   34      **/
   35 int
   36 m_reduce_rights (void)
   37 {
   38     struct passwd *pw;
   39 
   40     if ((geteuid() && getuid())
   41     || Dont_Change_Uid == TRUE)
   42         return 0;
   43 
   44     if ((pw = getpwnam ("nobody")) == NULL) {
   45         syslog (LOG_ERR, "error: getpwnam(nobody): %s",
   46                 strerror (errno));
   47         return -1;
   48     } 
   49     if (setuid (pw->pw_uid) == -1) {
   50         syslog (LOG_ERR, "error: setuid(%d): %s",
   51             pw->pw_uid, strerror (errno));
   52         return -1;
   53     }
   54     return 0;
   55 }
   56 
   57 
   58     /**
   59      ** find what user belongs to the connection
   60      ** described by LPORT, RPORT, RADDR, and LADDR.
   61      ** return the uid.
   62      **/    
   63 int
   64 m_get_uid (struct in_addr *laddr, u_short lp,
   65     struct in_addr *raddr, u_short rp)
   66 {
   67     FILE    *fp;
   68     char    buf[150];
   69 
   70     if ((fp = fopen ("/proc/net/tcp", "r")) == NULL) {
   71         syslog (LOG_ERR, "error reading /proc/net/tcp: %s",
   72                 strerror (errno));
   73         return -1;
   74     }
   75 
   76     fgets (buf, 149, fp);       /* eat header!)*$ */
   77 
   78     while (fgets (buf, 149, fp)) {
   79         unsigned long local_addr, remote_addr;
   80         unsigned long tx_queue, rx_queue, tm_when;
   81         int sl, uid, retrnsmt, st, tr, local_port, remote_port;
   82         
   83         if (sscanf (buf, "%d: %lX:%x %lX:%x %x %lX:%lX %x:%lX %x %d",
   84 
   85             &sl, &local_addr, &local_port, &remote_addr,
   86             &remote_port, &st, &tx_queue, &rx_queue,
   87             &tr, &tm_when, &retrnsmt, &uid) == 12) {
   88 
   89             if (lp == local_port && rp == remote_port
   90             && remote_addr == raddr->s_addr) {
   91                 if (laddr == NULL) {
   92                     fclose (fp);
   93                     return uid;
   94                 }
   95                 else if (laddr->s_addr
   96                 == local_addr) {
   97                     fclose (fp);
   98                     return uid;
   99                 }
  100             }
  101         }
  102     }
  103     fclose (fp);
  104     return -1;
  105 }
  106 
  107     /*
  108      *  records the pid for service management purposes.
  109      *  example: under Red Hat,Debian,etc pid is written to
  110      *  /var/run/identd.pid
  111      *  PID support suggested (and previously implemented)
  112      *  by Alexander Reelsen.
  113      */
  114 int
  115 m_register_pid (void)
  116 {
  117 #ifdef HAS_VAR_RUN
  118     FILE    *fp;
  119 
  120     if ((fp = fopen (PID_FILE, "w")) == NULL) {
  121         syslog (LOG_WARNING, "couldn't record pid in %s: %s -- "
  122             "automatic shutdown with system not available",
  123             PID_FILE, strerror (errno));
  124         return -1;
  125     }
  126     fprintf (fp, "%u\n", getpid ()); 
  127     fclose (fp);
  128 #endif  
  129     return 0;
  130 }