src/misc-progs/sshctrl.c

   1 /* SmoothWall helper program - sshctrl
   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) Mark Wormgoor, 2001
   7  * Simple program intended to be installed setuid(0) that can be used for
   8  * restarting SSHd.
   9  *
  10  * $Id: sshctrl.c,v 1.3 2003/12/11 10:57:34 riddles Exp $
  11  *
  12  */
  13
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <unistd.h>
  17 #include <string.h>
  18 #include <sys/types.h>
  19 #include <fcntl.h>
  20 #include <signal.h>
  21 #include <errno.h>
  22 #include "libsmooth.h"
  23 #include "setuid.h"
  24
  25 #define BUFFER_SIZE 1024
  26
  27 char command[BUFFER_SIZE];
  28
  29 int main(int argc, char *argv[])
  30 {
  31         if (argc < 2) {
  32                                 int fd, config_fd, rc, pid;
  33                                 char buffer[STRING_SIZE], command[STRING_SIZE] = "/bin/sed -e '";
  34                                 struct keyvalue *kv = NULL;
  35
  36                                 if (!(initsetuid()))
  37                                                 exit(1);
  38
  39                                 kv = initkeyvalues();
  40                                 if (!readkeyvalues(kv, CONFIG_ROOT "/remote/settings")){
  41                                                 fprintf(stderr, "Cannot read remote access settings\n");
  42                                                 exit(1);
  43                                 }
  44
  45                                 /* By using O_CREAT with O_EXCL open() will fail if the file already exists,
  46                                 * this prevents 2 copies of sshctrl both trying to edit the config file
  47                                 * at once. It also prevents race conditions, but these shouldn't be
  48                                 * possible as /etc/ssh/ should only be writable by root anyhow
  49                                 */
  50
  51                                 if ((config_fd = open( "/etc/ssh/sshd_config.new", O_WRONLY|O_CREAT|O_EXCL, 0644 )) == -1 ){
  52                                                 perror("Unable to open new config file");
  53                                                 freekeyvalues(kv);
  54                                                 exit(1);
  55                                 }
  56
  57                                 if(findkey(kv, "ENABLE_SSH_PROTOCOL1", buffer) && !strcmp(buffer,"on"))
  58                                                 strlcat(command, "s/^Protocol .*$/Protocol 2,1/;", STRING_SIZE - 1 );
  59                                 else
  60                                                 strlcat(command, "s/^Protocol .*$/Protocol 2/;", STRING_SIZE - 1 );
  61
  62                                 if(findkey(kv, "ENABLE_SSH_KEYS", buffer) && !strcmp(buffer,"off"))
  63                                                 strlcat(command, "s/^RSAAuthentication .*$/RSAAuthentication no/;"              "s/^PubkeyAuthentication .*$/PubkeyAuthentication no/;", STRING_SIZE - 1 );
  64                                 else
  65                                                 strlcat(command, "s/^RSAAuthentication .*$/RSAAuthentication yes/;"             "s/^PubkeyAuthentication .*$/PubkeyAuthentication yes/;", STRING_SIZE - 1 );
  66
  67                                 if(findkey(kv, "ENABLE_SSH_PASSWORDS", buffer) && !strcmp(buffer,"off"))
  68                                                 strlcat(command, "s/^PasswordAuthentication .*$/PasswordAuthentication no/;", STRING_SIZE - 1 );
  69                                 else
  70                                                 strlcat(command, "s/^PasswordAuthentication .*$/PasswordAuthentication yes/;", STRING_SIZE - 1 );
  71
  72                                 if(findkey(kv, "ENABLE_SSH_PORTFW", buffer) && !strcmp(buffer,"on"))
  73                                                 strlcat(command, "s/^AllowTcpForwarding .*$/AllowTcpForwarding yes/;", STRING_SIZE - 1 );
  74                                 else
  75                                                 strlcat(command, "s/^AllowTcpForwarding .*$/AllowTcpForwarding no/;", STRING_SIZE - 1 );
  76
  77                                 if(findkey(kv, "SSH_PORT", buffer) && !strcmp(buffer,"on"))
  78                                                 strlcat(command, "s/^Port .*$/Port 22/", STRING_SIZE - 1 );
  79                                 else
  80                                                 strlcat(command, "s/^Port .*$/Port 222/", STRING_SIZE - 1 );
  81
  82                                 freekeyvalues(kv);
  83
  84                                 snprintf(buffer, STRING_SIZE - 1, "' /etc/ssh/sshd_config >&%d", config_fd );
  85                                 strlcat(command, buffer, STRING_SIZE - 1);
  86
  87                                 if((rc = unpriv_system(command,99,99)) != 0){
  88                                                 fprintf(stderr, "sed returned bad exit code: %d\n", rc);
  89                                                 close(config_fd);
  90                                                 unlink("/etc/ssh/sshd_config.new");
  91                                                 exit(1);
  92                                 }
  93
  94                                 close(config_fd);
  95                                 if (rename("/etc/ssh/sshd_config.new","/etc/ssh/sshd_config") != 0){
  96                                                 perror("Unable to replace old config file");
  97                                                 unlink("/etc/ssh/sshd_config.new");
  98                                                 exit(1);
  99                                 }
 100
 101                                 memset(buffer, 0, STRING_SIZE);
 102
 103                                 if ((fd = open("/var/run/sshd.pid", O_RDONLY)) != -1){
 104                                                 if (read(fd, buffer, STRING_SIZE - 1) == -1)
 105                                                                 fprintf(stderr, "Couldn't read from pid file\n");
 106                                                 else{
 107                                                                 pid = atoi(buffer);
 108                                                                 if (pid <= 1)
 109                                                                                 fprintf(stderr, "Bad pid value\n");
 110                                                                 else{
 111                                                                                 if (kill(pid, SIGTERM) == -1)
 112                                                                                                 fprintf(stderr, "Unable to send SIGTERM\n");
 113                                                                                 else
 114                                                                                                 unlink("/var/run/sshd.pid");
 115                                                                                 }
 116                                                                 }
 117                                                 close(fd);
 118                                 }
 119                                 else{
 120                                                 if (errno != ENOENT){
 121                                                                 perror("Unable to open pid file");
 122                                                                 exit(1);
 123                                                 }
 124                                 }
 125
 126                                 if ((fd = open(CONFIG_ROOT "/remote/enablessh", O_RDONLY)) != -1){
 127                                                 close(fd);
 128                                                 safe_system("/usr/sbin/sshd");
 129                                 }
 130
 131                                 return 0;
 132         }
 133         else if (strcmp(argv[1], "tempstart") == 0) {
 134                                 safe_system("/usr/local/bin/sshctrl");
 135                                 sleep(5);
 136                                 unlink("/var/ipfire/remote/enablessh");
 137                                 safe_system("cat /var/ipfire/remote/settings | sed 's/ENABLE_SSH=on/ENABLE_SSH=off/' > /var/ipfire/remote/settings2 && mv /var/ipfire/remote/settings2 /var/ipfire/remote/settings");
 138         safe_system("chown nobody.nobody /var/ipfire/remote/settings");
 139                                 snprintf(command, BUFFER_SIZE-1, "sleep %s && /usr/local/bin/sshctrl &", argv[2]);
 140                                 safe_system(command);
 141         }
 142 }