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Viewing changes to plugins.d/password-prompt.c

  • Committer: Björn Påhlsson
  • Date: 2011-02-27 15:45:24 UTC
  • mto: This revision was merged to the branch mainline in revision 467.
  • Revision ID: belorn@fukt.bsnet.se-20110227154524-zac8443jod8v1g1g
fixed bug with conflict detection between plymouthd and password-prompt

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Lines of Context:
plugins.d/password-prompt.c
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                                   SIGQUIT, SIGHUP, SIGTERM,
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                                   raise() */
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#include <stddef.h>             /* NULL, size_t, ssize_t */
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#include <sys/types.h>          /* ssize_t, struct dirent, pid_t, ssize_t */
 
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#include <sys/types.h>          /* ssize_t, struct dirent, pid_t,
 
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                                   ssize_t, open() */
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#include <stdlib.h>             /* EXIT_SUCCESS, EXIT_FAILURE,
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                                   getenv(), free() */
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#include <dirent.h>             /* scandir(), alphasort() */
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#include <iso646.h>             /* or, not */
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#include <stdbool.h>            /* bool, false, true */
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#include <inttypes.h>           /* strtoumax() */
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#include <sys/stat.h>           /* struct stat, lstat() */
 
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#include <sys/stat.h>           /* struct stat, lstat(), open() */
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#include <string.h>             /* strlen, rindex, memcmp */
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#include <argp.h>               /* struct argp_option, struct
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                                   argp_state, struct argp,
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                                   ARGP_ERR_UNKNOWN */
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#include <sysexits.h>           /* EX_SOFTWARE, EX_OSERR,
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                                   EX_UNAVAILABLE, EX_IOERR, EX_OK */
 
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#include <fcntl.h>              /* open() */
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volatile sig_atomic_t quit_now = 0;
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int signal_received;
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const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
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/* Needed for conflic resolution */
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const char plymouthd_path[] = "/sbin/plymouth";
 
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const char plymouthd_name[] = "plymouthd";
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static void termination_handler(int signum){
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bool conflict_detection(void){
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  /* plymouth conflicts with password-promt since both want to control the
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     associated terminal. Password-prompt exit since plymouth perferms the same
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     functionallity.
 
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  /* plymouth conflicts with password-prompt since both want to read
 
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     from the terminal.  Password-prompt will exit if it detects
 
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     plymouth since plymouth performs the same functionality.
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   */
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  int is_plymouth(const struct dirent *proc_entry){
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    int ret;
 
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    int cl_fd;
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    {
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      uintmax_t maxvalue;
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      char *tmp;
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        return 0;
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      }
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    }
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    char exe_target[sizeof(plymouthd_path)];
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    char *exe_link;
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    ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
 
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    char *cmdline_filename;
 
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    ret = asprintf(&cmdline_filename, "/proc/%s/cmdline", proc_entry->d_name);
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    if(ret == -1){
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      error(0, errno, "asprintf");
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      return 0;
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    }
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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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      free(exe_link);
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      if(errno != ENOENT){
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        error(0, errno, "lstat");
 
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    /* Open /proc/<pid>/cmdline  */
 
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    cl_fd = open(cmdline_filename, O_RDONLY);
 
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    free(cmdline_filename);
 
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    if(cl_fd == -1){
 
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      error(0, errno, "open");
 
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      return 0;
 
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    }
 
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    char *cmdline = NULL;
 
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    {
 
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      size_t cmdline_len = 0;
 
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      size_t cmdline_allocated = 0;
 
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      char *tmp;
 
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      const size_t blocksize = 1024;
 
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      ssize_t sret;
 
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      do {
 
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        /* Allocate more space? */
 
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        if(cmdline_len + blocksize + 1 > cmdline_allocated){
 
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          tmp = realloc(cmdline, cmdline_allocated + blocksize + 1);
 
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          if(tmp == NULL){
 
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            error(0, errno, "realloc");
 
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            free(cmdline);
 
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            close(cl_fd);
 
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            return 0;
 
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          }
 
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          cmdline = tmp;
 
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          cmdline_allocated += blocksize;
 
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        }
 
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        /* Read data */
 
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        sret = read(cl_fd, cmdline + cmdline_len,
 
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                    cmdline_allocated - cmdline_len);
 
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        if(sret == -1){
 
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          error(0, errno, "read");
 
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          free(cmdline);
 
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          close(cl_fd);
 
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          return 0;
 
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        }
 
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        cmdline_len += (size_t)sret;
 
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      } while(sret != 0);
 
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      ret = close(cl_fd);
 
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      if(ret == -1){
 
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        error(0, errno, "close");
 
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        free(cmdline);
 
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        return 0;
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      }
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      return 0;
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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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      return 0;
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    }
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    ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
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    free(exe_link);
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    if((sret != (ssize_t)sizeof(plymouthd_path)-1) or
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       (memcmp(plymouthd_path, exe_target,
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               sizeof(plymouthd_path)-1) != 0)){
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      return 0;
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    }
 
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      cmdline[cmdline_len] = '\0'; /* Make sure it is terminated */
 
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    }
 
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    /* we now have cmdline */
 
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    /* get basename */
 
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    char *cmdline_base = strrchr(cmdline, '/');
 
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    if(cmdline_base != NULL){
 
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      cmdline_base += 1;                /* skip the slash */
 
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    } else {
 
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      cmdline_base = cmdline;
 
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    }
 
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    if(strcmp(cmdline_base, plymouthd_name) != 0){
 
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      free(cmdline);
 
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      return 0;
 
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    }
 
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    free(cmdline);
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    return 1;
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  }
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  if (ret == -1){
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    error(1, errno, "scandir");
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  }
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  if (ret < 0){
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    return 1;
 
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  if (ret > 0){
 
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    return true;
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  } else {
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    return 0;
 
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    return false;
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  }
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}
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