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Viewing changes to plugins.d/splashy.c

  • Committer: Teddy Hogeborn
  • Date: 2008-09-23 18:52:33 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080923185233-a6zir2neltxk2qvd
* debian/mandos-client.lintian-overrides: Ignore setuid
                                          "plugins.d/splashy".

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plugins.d/splashy.c
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#define _GNU_SOURCE             /* asprintf() */
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#include <signal.h>             /* sig_atomic_t, struct sigaction,
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                                   sigemptyset(), sigaddset(), SIGINT,
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                                   SIGHUP, SIGTERM, sigaction,
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                                   SIG_IGN, kill(), SIGKILL */
 
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                                   sigemptyset(), sigaddset(),
 
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                                   sigaction, SIGINT, SIG_IGN, SIGHUP,
 
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                                   SIGTERM, kill(), SIGKILL */
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#include <stddef.h>             /* NULL */
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#include <stdlib.h>             /* getenv() */
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#include <stdio.h>              /* asprintf(), perror() */
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#include <stdlib.h>             /* EXIT_FAILURE, free(), strtoul(),
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                                   EXIT_SUCCESS */
 
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#include <stdlib.h>             /* EXIT_FAILURE, EXIT_SUCCESS,
 
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                                   strtoul(), free() */
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#include <sys/types.h>          /* pid_t, DIR, struct dirent,
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                                   ssize_t */
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#include <dirent.h>             /* opendir(), readdir(), closedir() */
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#include <sys/stat.h>           /* struct stat, lstat(), S_ISLNK */
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#include <iso646.h>             /* not, or, and */
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#include <unistd.h>             /* readlink(), fork(), execl(),
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                                   sleep(), dup2() STDERR_FILENO,
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                                   STDOUT_FILENO, _exit() */
 
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                                   _exit */
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#include <string.h>             /* memcmp() */
 
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#include <iso646.h>             /* and */
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#include <errno.h>              /* errno */
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#include <sys/wait.h>           /* waitpid(), WIFEXITED(),
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                                   WEXITSTATUS() */
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  interrupted_by_signal = 1;
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}
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int main(__attribute__((unused))int argc,
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         __attribute__((unused))char **argv){
 
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int main(__attribute__((unused))int argc, char **argv){
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  int ret = 0;
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  /* Create prompt string */
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      }
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      /* Find the executable name by doing readlink() on the
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         /proc/<pid>/exe link */
 
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      char *exe_link;
 
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      ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
 
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      if(ret == -1){
 
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        perror("asprintf");
 
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        free(prompt);
 
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        closedir(proc_dir);
 
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        return EXIT_FAILURE;
 
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      }
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      char exe_target[sizeof(splashy_name)];
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      ssize_t sret;
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      {
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        char *exe_link;
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        ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
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        if(ret == -1){
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          perror("asprintf");
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          free(prompt);
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          closedir(proc_dir);
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          return EXIT_FAILURE;
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        }
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        /* Check that it refers to a symlink owned by root:root */
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        struct stat exe_stat;
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        ret = lstat(exe_link, &exe_stat);
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        if(ret == -1){
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          perror("lstat");
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          free(exe_link);
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          free(prompt);
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          closedir(proc_dir);
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          return EXIT_FAILURE;
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        }
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        if(not S_ISLNK(exe_stat.st_mode)
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           or exe_stat.st_uid != 0
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           or exe_stat.st_gid != 0){
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          free(exe_link);
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          continue;
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        }
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        sret = readlink(exe_link, exe_target, sizeof(exe_target));
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        free(exe_link);
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      }
 
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      ssize_t sret = readlink(exe_link, exe_target,
 
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                              sizeof(exe_target));
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      if((sret == ((ssize_t)sizeof(exe_target)-1))
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         and (memcmp(splashy_name, exe_target,
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                     sizeof(exe_target)-1) == 0)){
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      free(prompt);
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      return EXIT_FAILURE;
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    }
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    if(old_action.sa_handler != SIG_IGN){
 
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    if (old_action.sa_handler != SIG_IGN){
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      ret = sigaction(SIGINT, &new_action, NULL);
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      if(ret == -1){
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        perror("sigaction");
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      free(prompt);
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      return EXIT_FAILURE;
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    }
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    if(old_action.sa_handler != SIG_IGN){
 
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    if (old_action.sa_handler != SIG_IGN){
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      ret = sigaction(SIGHUP, &new_action, NULL);
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      if(ret == -1){
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        perror("sigaction");
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      free(prompt);
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      return EXIT_FAILURE;
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    }
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    if(old_action.sa_handler != SIG_IGN){
 
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    if (old_action.sa_handler != SIG_IGN){
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      ret = sigaction(SIGTERM, &new_action, NULL);
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      if(ret == -1){
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        perror("sigaction");
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      const char splashy_command[] = "/sbin/splashy_update";
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      ret = execl(splashy_command, splashy_command, prompt,
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                  (char *)NULL);
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      if(not interrupted_by_signal){
 
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      if(not interrupted_by_signal and errno != ENOENT){
 
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        /* Don't report "File not found", since splashy might not be
 
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           installed. */
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        perror("execl");
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      }
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      free(prompt);
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      _exit(EXIT_FAILURE);
 
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      return EXIT_FAILURE;
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    }
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  }
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  free(prompt);
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  /* Wait for command to complete */
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  if(not interrupted_by_signal and splashy_command_pid != 0){
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    int status;
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    ret = waitpid(splashy_command_pid, &status, 0);
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    if(ret == -1){
212
 
      if(errno != EINTR){
213
 
        perror("waitpid");
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      }
215
 
      if(errno == ECHILD){
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        splashy_command_pid = 0;
217
 
      }
218
 
    } else {
219
 
      /* The child process has exited */
220
 
      splashy_command_pid = 0;
221
 
      if(not interrupted_by_signal and WIFEXITED(status)
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         and WEXITSTATUS(status)==0){
223
 
        return EXIT_SUCCESS;
224
 
      }
 
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  int status;
 
187
  while(not interrupted_by_signal){
 
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    waitpid(splashy_command_pid, &status, 0);
 
189
    if(not interrupted_by_signal
 
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       and WIFEXITED(status) and WEXITSTATUS(status)==0){
 
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      return EXIT_SUCCESS;
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    }
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  }
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  kill(splashy_pid, SIGTERM);
228
 
  if(interrupted_by_signal and splashy_command_pid != 0){
 
195
  if(interrupted_by_signal){
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    kill(splashy_command_pid, SIGTERM);
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  }
231
 
  sleep(2);
232
 
  while(kill(splashy_pid, 0) == 0){
233
 
    kill(splashy_pid, SIGKILL);
234
 
    sleep(1);
235
 
  }
 
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236
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  pid_t new_splashy_pid = fork();
237
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  if(new_splashy_pid == 0){
238
 
    /* Child; will become new splashy process */
239
 
    
240
 
    /* Make the effective user ID (root) the only user ID instead of
241
 
       the real user ID (mandos) */
242
 
    ret = setuid(geteuid());
243
 
    if(ret == -1){
244
 
      perror("setuid");
 
201
    while(kill(splashy_pid, 0)){
 
202
      sleep(2);
 
203
      kill(splashy_pid, SIGKILL);
 
204
      sleep(1);
245
205
    }
246
 
    
247
 
    setsid();
248
 
    ret = chdir("/");
249
 
/*     if(fork() != 0){ */
250
 
/*       _exit(EXIT_SUCCESS); */
251
 
/*     } */
252
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    ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
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    if(ret == -1){
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      perror("dup2");
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      _exit(EXIT_FAILURE);
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    }
257
 
    
258
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    execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
259
 
    if(not interrupted_by_signal){
260
 
      perror("execl");
261
 
    }
262
 
    _exit(EXIT_FAILURE);
263
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  }
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  return EXIT_FAILURE;