1  /* Copyright (C) 1991-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <errno.h>
      19  #include <stdio.h>
      20  #include <pwd.h>
      21  #include <stdlib.h>
      22  #include <nss.h>
      23  
      24  #define _S(x)	x ?: ""
      25  
      26  /* Write an entry to the given stream.  This must know the format of
      27     the password file.  If the input contains invalid characters,
      28     return EINVAL, or replace them with spaces (if they are contained
      29     in the GECOS field).  */
      30  int
      31  putpwent (const struct passwd *p, FILE *stream)
      32  {
      33    if (p == NULL || stream == NULL
      34        || p->pw_name == NULL || !__nss_valid_field (p->pw_name)
      35        || !__nss_valid_field (p->pw_passwd)
      36        || !__nss_valid_field (p->pw_dir)
      37        || !__nss_valid_field (p->pw_shell))
      38      {
      39        __set_errno (EINVAL);
      40        return -1;
      41      }
      42  
      43    int ret;
      44    char *gecos_alloc;
      45    const char *gecos = __nss_rewrite_field (p->pw_gecos, &gecos_alloc);
      46  
      47    if (gecos == NULL)
      48      return -1;
      49  
      50    if (p->pw_name[0] == '+' || p->pw_name[0] == '-')
      51        ret = fprintf (stream, "%s:%s:::%s:%s:%s\n",
      52  		     p->pw_name, _S (p->pw_passwd),
      53  		     gecos, _S (p->pw_dir), _S (p->pw_shell));
      54    else
      55        ret = fprintf (stream, "%s:%s:%lu:%lu:%s:%s:%s\n",
      56  		     p->pw_name, _S (p->pw_passwd),
      57  		     (unsigned long int) p->pw_uid,
      58  		     (unsigned long int) p->pw_gid,
      59  		     gecos, _S (p->pw_dir), _S (p->pw_shell));
      60  
      61    free (gecos_alloc);
      62    if (ret >= 0)
      63      ret = 0;
      64    return ret;
      65  }