src/misc-progs/restartdhcp.c

   1 /* SmoothWall helper program - restartdhcp
   2  *
   3  * This program is distributed under the terms of the GNU General Public
   4  * Licence.  See the file COPYING for details.
   5  *
   6  * (c) Lawrence Manning, 2001
   7  * Simple program intended to be installed setuid(0) that can be used for
   8  * restarting DHCPd.
   9  *
  10  * $Id: restartdhcp.c,v 1.5.2.1 2004/11/03 13:50:26 alanh Exp $
  11  *
  12  */
  13
  14 #include "libsmooth.h"
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <unistd.h>
  18 #include <fcntl.h>
  19 #include <string.h>
  20 #include <sys/types.h>
  21 #include <sys/stat.h>
  22 #include <signal.h>
  23 #include "setuid.h"
  24
  25 int main(void)
  26 {
  27         int fd = -1;
  28         int fdblue = -1;
  29         char buffer[STRING_SIZE];
  30         char blue_dev[STRING_SIZE] = "", green_dev[STRING_SIZE] = "";
  31         int pid;
  32         struct keyvalue *kv = NULL;
  33
  34         if (!(initsetuid()))
  35                 exit(1);
  36
  37         memset(buffer, 0, STRING_SIZE);
  38
  39         /* Init the keyvalue structure */
  40         kv=initkeyvalues();
  41
  42         /* Read in the current values */
  43         if (!readkeyvalues(kv, CONFIG_ROOT "/ethernet/settings"))
  44         {
  45                 fprintf(stderr, "Cannot read ethernet settings\n");
  46                 exit(1);
  47         }
  48
  49         if (!findkey(kv, "GREEN_DEV", green_dev))
  50         {
  51                 fprintf(stderr, "Cannot read GREEN_DEV\n");
  52                 exit(1);
  53         }
  54
  55         if (!VALID_DEVICE(green_dev))
  56         {
  57                 fprintf(stderr, "Bad GREEN_DEV: %s\n", green_dev);
  58                 exit(1);
  59         }
  60
  61         /* Get the BLUE interface details */
  62         findkey(kv, "BLUE_DEV", blue_dev);
  63
  64         freekeyvalues(kv);
  65
  66         if ((fdblue = open(CONFIG_ROOT "/dhcp/enable_blue", O_RDONLY)) != -1)
  67         {
  68                 close(fdblue);
  69                 if (!VALID_DEVICE(blue_dev))
  70                 {
  71                         fprintf(stderr, "Bad BLUE_DEV: %s\n", blue_dev);
  72                         exit(1);
  73                 }
  74         }
  75
  76         if ((fd = open("/var/run/dhcpd.pid", O_RDONLY)) != -1)
  77         {
  78                 if (read(fd, buffer, STRING_SIZE - 1) == -1)
  79                         fprintf(stderr, "Couldn't read from pid file\n");
  80                 else
  81                 {
  82                         pid = atoi(buffer);
  83                         if (pid <= 1)
  84                                 fprintf(stderr, "Bad pid value\n");
  85                         else
  86                         {
  87                                 if (kill(pid, SIGTERM) == -1)
  88                                         fprintf(stderr, "Unable to send SIGTERM\n");
  89                                 else
  90                                         unlink("/var/run/dhcpd.pid");
  91                         }
  92                 }
  93                 safe_system("/bin/killall -KILL dhcpd");
  94                 close(fd);
  95         }
  96
  97         safe_system("/sbin/iptables -F DHCPBLUEINPUT");
  98
  99         buffer[0] = '\0';
 100
 101         if ((fd = open(CONFIG_ROOT "/dhcp/enable_green", O_RDONLY)) != -1)
 102         {
 103                 close(fd);
 104                 if ((fdblue = open(CONFIG_ROOT "/dhcp/enable_blue", O_RDONLY)) != -1)
 105                 {
 106                         close(fdblue);
 107
 108                         snprintf(buffer, STRING_SIZE-1, "/sbin/iptables -A DHCPBLUEINPUT -p tcp --source-port 68 --destination-port 67 -i %s -j ACCEPT > /dev/null 2>&1", blue_dev);
 109                         safe_system(buffer);
 110                         snprintf(buffer, STRING_SIZE-1, "/sbin/iptables -A DHCPBLUEINPUT -p udp --source-port 68 --destination-port 67 -i %s -j ACCEPT > /dev/null 2>&1", blue_dev);
 111                         safe_system(buffer);
 112                         snprintf(buffer, STRING_SIZE-1, "/usr/sbin/dhcpd -q %s %s", green_dev, blue_dev);
 113                 } else {
 114                         snprintf(buffer, STRING_SIZE-1, "/usr/sbin/dhcpd -q %s", green_dev);
 115                 }
 116                 safe_system(buffer);
 117         } else {
 118                 if ((fdblue = open(CONFIG_ROOT "/dhcp/enable_blue", O_RDONLY)) != -1)
 119                 {
 120                         close(fdblue);
 121
 122                         snprintf(buffer, STRING_SIZE-1, "/sbin/iptables -A DHCPBLUEINPUT -p tcp --source-port 68 --destination-port 67 -i %s -j ACCEPT > /dev/null 2>&1", blue_dev);
 123                         safe_system(buffer);
 124                         snprintf(buffer, STRING_SIZE-1, "/sbin/iptables -A DHCPBLUEINPUT -p udp --source-port 68 --destination-port 67 -i %s -j ACCEPT > /dev/null 2>&1", blue_dev);
 125                         safe_system(buffer);
 126                         snprintf(buffer, STRING_SIZE-1,  "/usr/sbin/dhcpd -q %s", blue_dev);
 127                         safe_system(buffer);
 128                 }
 129         }
 130
 131         if (buffer[0] != '\0')
 132         {
 133                 /* Silly dhcpd creates pids with mode 640 */
 134                 sleep (1);
 135                 if ((fd = open("/var/run/dhcpd.pid", 0)) == -1)
 136                 {
 137                         fprintf(stderr, "No pid file\n");
 138                         return 1;
 139                 }
 140                 fchmod(fd, 00644);
 141                 close(fd);
 142         }
 143
 144         return 0;
 145 }