Move nss_compat from nis to nss subdir and install it unconditionally

This has been tested that local lookup still works with and
without an installed libnss_nis, and that NIS lookup works when
libnss_nis is available.

1 files changed, 1131 insertions, 0 deletions

diff --git a/nss/nss_compat/compat-pwd.c b/nss/nss_compat/compat-pwd.c
new file mode 100644
index 0000000..b16eef5
--- /dev/null
+++ b/nss/nss_compat/compat-pwd.c
@@ -0,0 +1,1131 @@
+/* Copyright (C) 1996-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 1996.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <netdb.h>
+#include <nss.h>
+#include <nsswitch.h>
+#include <pwd.h>
+#include <stdio_ext.h>
+#include <string.h>
+#include <libc-lock.h>
+#include <kernel-features.h>
+
+#include "netgroup.h"
+#include "nisdomain.h"
+
+static service_user *ni;
+static enum nss_status (*nss_setpwent) (int stayopen);
+static enum nss_status (*nss_getpwnam_r) (const char *name,
+					  struct passwd * pwd, char *buffer,
+					  size_t buflen, int *errnop);
+static enum nss_status (*nss_getpwuid_r) (uid_t uid, struct passwd * pwd,
+					  char *buffer, size_t buflen,
+					  int *errnop);
+static enum nss_status (*nss_getpwent_r) (struct passwd * pwd, char *buffer,
+					  size_t buflen, int *errnop);
+static enum nss_status (*nss_endpwent) (void);
+
+/* Get the declaration of the parser function.  */
+#define ENTNAME pwent
+#define STRUCTURE passwd
+#define EXTERN_PARSER
+#include <nss/nss_files/files-parse.c>
+
+/* Structure for remembering -@netgroup and -user members ... */
+#define BLACKLIST_INITIAL_SIZE 512
+#define BLACKLIST_INCREMENT 256
+struct blacklist_t
+{
+  char *data;
+  int current;
+  int size;
+};
+
+struct ent_t
+{
+  bool netgroup;
+  bool first;
+  bool files;
+  enum nss_status setent_status;
+  FILE *stream;
+  struct blacklist_t blacklist;
+  struct passwd pwd;
+  struct __netgrent netgrdata;
+};
+typedef struct ent_t ent_t;
+
+static ent_t ext_ent = { false, false, true, NSS_STATUS_SUCCESS, NULL,
+			 { NULL, 0, 0 },
+			 { NULL, NULL, 0, 0, NULL, NULL, NULL }};
+
+/* Protect global state against multiple changers.  */
+__libc_lock_define_initialized (static, lock)
+
+/* Prototypes for local functions.  */
+static void blacklist_store_name (const char *, ent_t *);
+static bool in_blacklist (const char *, int, ent_t *);
+
+/* Initialize the NSS interface/functions. The calling function must
+   hold the lock.  */
+static void
+init_nss_interface (void)
+{
+  if (__nss_database_lookup ("passwd_compat", NULL, "nis", &ni) >= 0)
+    {
+      nss_setpwent = __nss_lookup_function (ni, "setpwent");
+      nss_getpwnam_r = __nss_lookup_function (ni, "getpwnam_r");
+      nss_getpwuid_r = __nss_lookup_function (ni, "getpwuid_r");
+      nss_getpwent_r = __nss_lookup_function (ni, "getpwent_r");
+      nss_endpwent = __nss_lookup_function (ni, "endpwent");
+    }
+}
+
+static void
+give_pwd_free (struct passwd *pwd)
+{
+  free (pwd->pw_name);
+  free (pwd->pw_passwd);
+  free (pwd->pw_gecos);
+  free (pwd->pw_dir);
+  free (pwd->pw_shell);
+
+  memset (pwd, '\0', sizeof (struct passwd));
+}
+
+static size_t
+pwd_need_buflen (struct passwd *pwd)
+{
+  size_t len = 0;
+
+  if (pwd->pw_passwd != NULL)
+    len += strlen (pwd->pw_passwd) + 1;
+
+  if (pwd->pw_gecos != NULL)
+    len += strlen (pwd->pw_gecos) + 1;
+
+  if (pwd->pw_dir != NULL)
+    len += strlen (pwd->pw_dir) + 1;
+
+  if (pwd->pw_shell != NULL)
+    len += strlen (pwd->pw_shell) + 1;
+
+  return len;
+}
+
+static void
+copy_pwd_changes (struct passwd *dest, struct passwd *src,
+		  char *buffer, size_t buflen)
+{
+  if (src->pw_passwd != NULL && strlen (src->pw_passwd))
+    {
+      if (buffer == NULL)
+	dest->pw_passwd = strdup (src->pw_passwd);
+      else if (dest->pw_passwd &&
+	       strlen (dest->pw_passwd) >= strlen (src->pw_passwd))
+	strcpy (dest->pw_passwd, src->pw_passwd);
+      else
+	{
+	  dest->pw_passwd = buffer;
+	  strcpy (dest->pw_passwd, src->pw_passwd);
+	  buffer += strlen (dest->pw_passwd) + 1;
+	  buflen = buflen - (strlen (dest->pw_passwd) + 1);
+	}
+    }
+
+  if (src->pw_gecos != NULL && strlen (src->pw_gecos))
+    {
+      if (buffer == NULL)
+	dest->pw_gecos = strdup (src->pw_gecos);
+      else if (dest->pw_gecos &&
+	       strlen (dest->pw_gecos) >= strlen (src->pw_gecos))
+	strcpy (dest->pw_gecos, src->pw_gecos);
+      else
+	{
+	  dest->pw_gecos = buffer;
+	  strcpy (dest->pw_gecos, src->pw_gecos);
+	  buffer += strlen (dest->pw_gecos) + 1;
+	  buflen = buflen - (strlen (dest->pw_gecos) + 1);
+	}
+    }
+  if (src->pw_dir != NULL && strlen (src->pw_dir))
+    {
+      if (buffer == NULL)
+	dest->pw_dir = strdup (src->pw_dir);
+      else if (dest->pw_dir && strlen (dest->pw_dir) >= strlen (src->pw_dir))
+	strcpy (dest->pw_dir, src->pw_dir);
+      else
+	{
+	  dest->pw_dir = buffer;
+	  strcpy (dest->pw_dir, src->pw_dir);
+	  buffer += strlen (dest->pw_dir) + 1;
+	  buflen = buflen - (strlen (dest->pw_dir) + 1);
+	}
+    }
+
+  if (src->pw_shell != NULL && strlen (src->pw_shell))
+    {
+      if (buffer == NULL)
+	dest->pw_shell = strdup (src->pw_shell);
+      else if (dest->pw_shell &&
+	       strlen (dest->pw_shell) >= strlen (src->pw_shell))
+	strcpy (dest->pw_shell, src->pw_shell);
+      else
+	{
+	  dest->pw_shell = buffer;
+	  strcpy (dest->pw_shell, src->pw_shell);
+	  buffer += strlen (dest->pw_shell) + 1;
+	  buflen = buflen - (strlen (dest->pw_shell) + 1);
+	}
+    }
+}
+
+static enum nss_status
+internal_setpwent (ent_t *ent, int stayopen, int needent)
+{
+  enum nss_status status = NSS_STATUS_SUCCESS;
+
+  ent->first = ent->netgroup = false;
+  ent->files = true;
+  ent->setent_status = NSS_STATUS_SUCCESS;
+
+  /* If something was left over free it.  */
+  if (ent->netgroup)
+    __internal_endnetgrent (&ent->netgrdata);
+
+  if (ent->blacklist.data != NULL)
+    {
+      ent->blacklist.current = 1;
+      ent->blacklist.data[0] = '|';
+      ent->blacklist.data[1] = '\0';
+    }
+  else
+    ent->blacklist.current = 0;
+
+  if (ent->stream == NULL)
+    {
+      ent->stream = fopen ("/etc/passwd", "rme");
+
+      if (ent->stream == NULL)
+	status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
+      else
+	/* We take care of locking ourself.  */
+	__fsetlocking (ent->stream, FSETLOCKING_BYCALLER);
+    }
+  else
+    rewind (ent->stream);
+
+  give_pwd_free (&ent->pwd);
+
+  if (needent && status == NSS_STATUS_SUCCESS && nss_setpwent)
+    ent->setent_status = nss_setpwent (stayopen);
+
+  return status;
+}
+
+
+enum nss_status
+_nss_compat_setpwent (int stayopen)
+{
+  enum nss_status result;
+
+  __libc_lock_lock (lock);
+
+  if (ni == NULL)
+    init_nss_interface ();
+
+  result = internal_setpwent (&ext_ent, stayopen, 1);
+
+  __libc_lock_unlock (lock);
+
+  return result;
+}
+
+
+static enum nss_status
+internal_endpwent (ent_t *ent)
+{
+  if (ent->stream != NULL)
+    {
+      fclose (ent->stream);
+      ent->stream = NULL;
+    }
+
+  if (ent->netgroup)
+    __internal_endnetgrent (&ent->netgrdata);
+
+  ent->first = ent->netgroup = false;
+
+  if (ent->blacklist.data != NULL)
+    {
+      ent->blacklist.current = 1;
+      ent->blacklist.data[0] = '|';
+      ent->blacklist.data[1] = '\0';
+    }
+  else
+    ent->blacklist.current = 0;
+
+  give_pwd_free (&ent->pwd);
+
+  return NSS_STATUS_SUCCESS;
+}
+
+enum nss_status
+_nss_compat_endpwent (void)
+{
+  enum nss_status result;
+
+  __libc_lock_lock (lock);
+
+  if (nss_endpwent)
+    nss_endpwent ();
+
+  result = internal_endpwent (&ext_ent);
+
+  __libc_lock_unlock (lock);
+
+  return result;
+}
+
+
+static enum nss_status
+getpwent_next_nss_netgr (const char *name, struct passwd *result, ent_t *ent,
+			 char *group, char *buffer, size_t buflen,
+			 int *errnop)
+{
+  char *curdomain = NULL, *host, *user, *domain, *p2;
+  int status;
+  size_t p2len;
+
+  /* Leave function if NSS module does not support getpwnam_r,
+     we need this function here.  */
+  if (!nss_getpwnam_r)
+    return NSS_STATUS_UNAVAIL;
+
+  if (ent->first)
+    {
+      memset (&ent->netgrdata, 0, sizeof (struct __netgrent));
+      __internal_setnetgrent (group, &ent->netgrdata);
+      ent->first = false;
+    }
+
+  while (1)
+    {
+      status = __internal_getnetgrent_r (&host, &user, &domain,
+					 &ent->netgrdata, buffer, buflen,
+					 errnop);
+      if (status != 1)
+	{
+	  __internal_endnetgrent (&ent->netgrdata);
+	  ent->netgroup = 0;
+	  give_pwd_free (&ent->pwd);
+	  return NSS_STATUS_RETURN;
+	}
+
+      if (user == NULL || user[0] == '-')
+	continue;
+
+      if (domain != NULL)
+	{
+	  if (curdomain == NULL
+	      && __nss_get_default_domain (&curdomain) != 0)
+	    {
+	      __internal_endnetgrent (&ent->netgrdata);
+	      ent->netgroup = false;
+	      give_pwd_free (&ent->pwd);
+	      return NSS_STATUS_UNAVAIL;
+	    }
+	  if (strcmp (curdomain, domain) != 0)
+	    continue;
+	}
+
+      /* If name != NULL, we are called from getpwnam.  */
+      if (name != NULL)
+	if (strcmp (user, name) != 0)
+	  continue;
+
+      p2len = pwd_need_buflen (&ent->pwd);
+      if (p2len > buflen)
+	{
+	  *errnop = ERANGE;
+	  return NSS_STATUS_TRYAGAIN;
+	}
+      p2 = buffer + (buflen - p2len);
+      buflen -= p2len;
+
+      if (nss_getpwnam_r (user, result, buffer, buflen, errnop) !=
+	  NSS_STATUS_SUCCESS)
+	continue;
+
+      if (!in_blacklist (result->pw_name, strlen (result->pw_name), ent))
+	{
+	  /* Store the User in the blacklist for possible the "+" at the
+	     end of /etc/passwd */
+	  blacklist_store_name (result->pw_name, ent);
+	  copy_pwd_changes (result, &ent->pwd, p2, p2len);
+	  break;
+	}
+    }
+
+  return NSS_STATUS_SUCCESS;
+}
+
+/* get the next user from NSS  (+ entry) */
+static enum nss_status
+getpwent_next_nss (struct passwd *result, ent_t *ent, char *buffer,
+		   size_t buflen, int *errnop)
+{
+  enum nss_status status;
+  char *p2;
+  size_t p2len;
+
+  /* Return if NSS module does not support getpwent_r.  */
+  if (!nss_getpwent_r)
+    return NSS_STATUS_UNAVAIL;
+
+  /* If the setpwent call failed, say so.  */
+  if (ent->setent_status != NSS_STATUS_SUCCESS)
+    return ent->setent_status;
+
+  p2len = pwd_need_buflen (&ent->pwd);
+  if (p2len > buflen)
+    {
+      *errnop = ERANGE;
+      return NSS_STATUS_TRYAGAIN;
+    }
+  p2 = buffer + (buflen - p2len);
+  buflen -= p2len;
+
+  if (ent->first)
+    ent->first = false;
+
+  do
+    {
+      if ((status = nss_getpwent_r (result, buffer, buflen, errnop)) !=
+	  NSS_STATUS_SUCCESS)
+	return status;
+    }
+  while (in_blacklist (result->pw_name, strlen (result->pw_name), ent));
+
+  copy_pwd_changes (result, &ent->pwd, p2, p2len);
+
+  return NSS_STATUS_SUCCESS;
+}
+
+/* This function handle the +user entrys in /etc/passwd */
+static enum nss_status
+getpwnam_plususer (const char *name, struct passwd *result, ent_t *ent,
+		   char *buffer, size_t buflen, int *errnop)
+{
+  if (!nss_getpwnam_r)
+    return NSS_STATUS_UNAVAIL;
+
+  struct passwd pwd;
+  memset (&pwd, '\0', sizeof (struct passwd));
+
+  copy_pwd_changes (&pwd, result, NULL, 0);
+
+  size_t plen = pwd_need_buflen (&pwd);
+  if (plen > buflen)
+    {
+      *errnop = ERANGE;
+      return NSS_STATUS_TRYAGAIN;
+    }
+  char *p = buffer + (buflen - plen);
+  buflen -= plen;
+
+  enum nss_status status = nss_getpwnam_r (name, result, buffer, buflen,
+					   errnop);
+  if (status != NSS_STATUS_SUCCESS)
+    return status;
+
+  if (in_blacklist (result->pw_name, strlen (result->pw_name), ent))
+    return NSS_STATUS_NOTFOUND;
+
+  copy_pwd_changes (result, &pwd, p, plen);
+  give_pwd_free (&pwd);
+  /* We found the entry.  */
+  return NSS_STATUS_SUCCESS;
+}
+
+static enum nss_status
+getpwent_next_file (struct passwd *result, ent_t *ent,
+		    char *buffer, size_t buflen, int *errnop)
+{
+  struct parser_data *data = (void *) buffer;
+  while (1)
+    {
+      fpos_t pos;
+      char *p;
+      int parse_res;
+
+      do
+	{
+	  /* We need at least 3 characters for one line.  */
+	  if (__glibc_unlikely (buflen < 3))
+	    {
+	    erange:
+	      *errnop = ERANGE;
+	      return NSS_STATUS_TRYAGAIN;
+	    }
+
+	  fgetpos (ent->stream, &pos);
+	  buffer[buflen - 1] = '\xff';
+	  p = fgets_unlocked (buffer, buflen, ent->stream);
+	  if (p == NULL && feof_unlocked (ent->stream))
+	    return NSS_STATUS_NOTFOUND;
+
+	  if (p == NULL || __builtin_expect (buffer[buflen - 1] != '\xff', 0))
+	    {
+	    erange_reset:
+	      fsetpos (ent->stream, &pos);
+	      goto erange;
+	    }
+
+	  /* Terminate the line for any case.  */
+	  buffer[buflen - 1] = '\0';
+
+	  /* Skip leading blanks.  */
+	  while (isspace (*p))
+	    ++p;
+	}
+      while (*p == '\0' || *p == '#' ||	/* Ignore empty and comment lines.  */
+	     /* Parse the line.  If it is invalid, loop to
+	        get the next line of the file to parse.  */
+	     !(parse_res = _nss_files_parse_pwent (p, result, data, buflen,
+						   errnop)));
+
+      if (__glibc_unlikely (parse_res == -1))
+	/* The parser ran out of space.  */
+	goto erange_reset;
+
+      if (result->pw_name[0] != '+' && result->pw_name[0] != '-')
+	/* This is a real entry.  */
+	break;
+
+      /* -@netgroup */
+      if (result->pw_name[0] == '-' && result->pw_name[1] == '@'
+	  && result->pw_name[2] != '\0')
+	{
+	  /* XXX Do not use fixed length buffer.  */
+	  char buf2[1024];
+	  char *user, *host, *domain;
+	  struct __netgrent netgrdata;
+
+	  memset (&netgrdata, 0, sizeof (struct __netgrent));
+	  __internal_setnetgrent (&result->pw_name[2], &netgrdata);
+	  while (__internal_getnetgrent_r (&host, &user, &domain, &netgrdata,
+					   buf2, sizeof (buf2), errnop))
+	    {
+	      if (user != NULL && user[0] != '-')
+		blacklist_store_name (user, ent);
+	    }
+	  __internal_endnetgrent (&netgrdata);
+	  continue;
+	}
+
+      /* +@netgroup */
+      if (result->pw_name[0] == '+' && result->pw_name[1] == '@'
+	  && result->pw_name[2] != '\0')
+	{
+	  enum nss_status status;
+
+	  ent->netgroup = true;
+	  ent->first = true;
+	  copy_pwd_changes (&ent->pwd, result, NULL, 0);
+
+	  status = getpwent_next_nss_netgr (NULL, result, ent,
+					    &result->pw_name[2],
+					    buffer, buflen, errnop);
+	  if (status == NSS_STATUS_RETURN)
+	    continue;
+	  else
+	    return status;
+	}
+
+      /* -user */
+      if (result->pw_name[0] == '-' && result->pw_name[1] != '\0'
+	  && result->pw_name[1] != '@')
+	{
+	  blacklist_store_name (&result->pw_name[1], ent);
+	  continue;
+	}
+
+      /* +user */
+      if (result->pw_name[0] == '+' && result->pw_name[1] != '\0'
+	  && result->pw_name[1] != '@')
+	{
+	  size_t len = strlen (result->pw_name);
+	  char buf[len];
+	  enum nss_status status;
+
+	  /* Store the User in the blacklist for the "+" at the end of
+	     /etc/passwd */
+	  memcpy (buf, &result->pw_name[1], len);
+	  status = getpwnam_plususer (&result->pw_name[1], result, ent,
+				      buffer, buflen, errnop);
+	  blacklist_store_name (buf, ent);
+
+	  if (status == NSS_STATUS_SUCCESS)	/* We found the entry. */
+	    break;
+	  else if (status == NSS_STATUS_RETURN	/* We couldn't parse the entry */
+		   || status == NSS_STATUS_NOTFOUND)	/* entry doesn't exist */
+	    continue;
+	  else
+	    {
+	      if (status == NSS_STATUS_TRYAGAIN)
+		{
+		  /* The parser ran out of space */
+		  fsetpos (ent->stream, &pos);
+		  *errnop = ERANGE;
+		}
+	      return status;
+	    }
+	}
+
+      /* +:... */
+      if (result->pw_name[0] == '+' && result->pw_name[1] == '\0')
+	{
+	  ent->files = false;
+	  ent->first = true;
+	  copy_pwd_changes (&ent->pwd, result, NULL, 0);
+
+	  return getpwent_next_nss (result, ent, buffer, buflen, errnop);
+	}
+    }
+
+  return NSS_STATUS_SUCCESS;
+}
+
+
+static enum nss_status
+internal_getpwent_r (struct passwd *pw, ent_t *ent, char *buffer,
+		     size_t buflen, int *errnop)
+{
+  if (ent->netgroup)
+    {
+      enum nss_status status;
+
+      /* We are searching members in a netgroup */
+      /* Since this is not the first call, we don't need the group name */
+      status = getpwent_next_nss_netgr (NULL, pw, ent, NULL, buffer, buflen,
+					errnop);
+      if (status == NSS_STATUS_RETURN)
+	return getpwent_next_file (pw, ent, buffer, buflen, errnop);
+      else
+	return status;
+    }
+  else if (ent->files)
+    return getpwent_next_file (pw, ent, buffer, buflen, errnop);
+  else
+    return getpwent_next_nss (pw, ent, buffer, buflen, errnop);
+
+}
+
+enum nss_status
+_nss_compat_getpwent_r (struct passwd *pwd, char *buffer, size_t buflen,
+			int *errnop)
+{
+  enum nss_status result = NSS_STATUS_SUCCESS;
+
+  __libc_lock_lock (lock);
+
+  /* Be prepared that the setpwent function was not called before.  */
+  if (ni == NULL)
+    init_nss_interface ();
+
+  if (ext_ent.stream == NULL)
+    result = internal_setpwent (&ext_ent, 1, 1);
+
+  if (result == NSS_STATUS_SUCCESS)
+    result = internal_getpwent_r (pwd, &ext_ent, buffer, buflen, errnop);
+
+  __libc_lock_unlock (lock);
+
+  return result;
+}
+
+/* Searches in /etc/passwd and the NIS/NIS+ map for a special user */
+static enum nss_status
+internal_getpwnam_r (const char *name, struct passwd *result, ent_t *ent,
+		     char *buffer, size_t buflen, int *errnop)
+{
+  struct parser_data *data = (void *) buffer;
+
+  while (1)
+    {
+      fpos_t pos;
+      char *p;
+      int parse_res;
+
+      do
+	{
+	  /* We need at least 3 characters for one line.  */
+	  if (__glibc_unlikely (buflen < 3))
+	    {
+	    erange:
+	      *errnop = ERANGE;
+	      return NSS_STATUS_TRYAGAIN;
+	    }
+
+	  fgetpos (ent->stream, &pos);
+	  buffer[buflen - 1] = '\xff';
+	  p = fgets_unlocked (buffer, buflen, ent->stream);
+	  if (p == NULL && feof_unlocked (ent->stream))
+	    {
+	      return NSS_STATUS_NOTFOUND;
+	    }
+	  if (p == NULL || __builtin_expect (buffer[buflen - 1] != '\xff', 0))
+	    {
+	    erange_reset:
+	      fsetpos (ent->stream, &pos);
+	      goto erange;
+	    }
+
+	  /* Terminate the line for any case.  */
+	  buffer[buflen - 1] = '\0';
+
+	  /* Skip leading blanks.  */
+	  while (isspace (*p))
+	    ++p;
+	}
+      while (*p == '\0' || *p == '#' ||	/* Ignore empty and comment lines.  */
+	     /* Parse the line.  If it is invalid, loop to
+	        get the next line of the file to parse.  */
+	     !(parse_res = _nss_files_parse_pwent (p, result, data, buflen,
+						   errnop)));
+
+      if (__glibc_unlikely (parse_res == -1))
+	/* The parser ran out of space.  */
+	goto erange_reset;
+
+      /* This is a real entry.  */
+      if (result->pw_name[0] != '+' && result->pw_name[0] != '-')
+	{
+	  if (strcmp (result->pw_name, name) == 0)
+	    return NSS_STATUS_SUCCESS;
+	  else
+	    continue;
+	}
+
+      /* -@netgroup */
+      if (result->pw_name[0] == '-' && result->pw_name[1] == '@'
+	  && result->pw_name[2] != '\0')
+	{
+	  if (innetgr (&result->pw_name[2], NULL, name, NULL))
+	    return NSS_STATUS_NOTFOUND;
+	  continue;
+	}
+
+      /* +@netgroup */
+      if (result->pw_name[0] == '+' && result->pw_name[1] == '@'
+	  && result->pw_name[2] != '\0')
+	{
+	  enum nss_status status;
+
+	  if (innetgr (&result->pw_name[2], NULL, name, NULL))
+	    {
+	      status = getpwnam_plususer (name, result, ent, buffer,
+					  buflen, errnop);
+
+	      if (status == NSS_STATUS_RETURN)
+		continue;
+
+	      return status;
+	    }
+	  continue;
+	}
+
+      /* -user */
+      if (result->pw_name[0] == '-' && result->pw_name[1] != '\0'
+	  && result->pw_name[1] != '@')
+	{
+	  if (strcmp (&result->pw_name[1], name) == 0)
+	    return NSS_STATUS_NOTFOUND;
+	  else
+	    continue;
+	}
+
+      /* +user */
+      if (result->pw_name[0] == '+' && result->pw_name[1] != '\0'
+	  && result->pw_name[1] != '@')
+	{
+	  if (strcmp (name, &result->pw_name[1]) == 0)
+	    {
+	      enum nss_status status;
+
+	      status = getpwnam_plususer (name, result, ent, buffer, buflen,
+					  errnop);
+	      if (status == NSS_STATUS_RETURN)
+		/* We couldn't parse the entry */
+		return NSS_STATUS_NOTFOUND;
+	      else
+		return status;
+	    }
+	}
+
+      /* +:... */
+      if (result->pw_name[0] == '+' && result->pw_name[1] == '\0')
+	{
+	  enum nss_status status;
+
+	  status = getpwnam_plususer (name, result, ent,
+				      buffer, buflen, errnop);
+	  if (status == NSS_STATUS_SUCCESS)	/* We found the entry. */
+	    break;
+	  else if (status == NSS_STATUS_RETURN)	/* We couldn't parse the entry */
+	    return NSS_STATUS_NOTFOUND;
+	  else
+	    return status;
+	}
+    }
+  return NSS_STATUS_SUCCESS;
+}
+
+enum nss_status
+_nss_compat_getpwnam_r (const char *name, struct passwd *pwd,
+			char *buffer, size_t buflen, int *errnop)
+{
+  enum nss_status result;
+  ent_t ent = { false, false, true, NSS_STATUS_SUCCESS, NULL, { NULL, 0, 0 },
+		{ NULL, NULL, 0, 0, NULL, NULL, NULL }};
+
+  if (name[0] == '-' || name[0] == '+')
+    return NSS_STATUS_NOTFOUND;
+
+  __libc_lock_lock (lock);
+
+  if (ni == NULL)
+    init_nss_interface ();
+
+  __libc_lock_unlock (lock);
+
+  result = internal_setpwent (&ent, 0, 0);
+
+  if (result == NSS_STATUS_SUCCESS)
+    result = internal_getpwnam_r (name, pwd, &ent, buffer, buflen, errnop);
+
+  internal_endpwent (&ent);
+
+  return result;
+}
+
+/* This function handle the + entry in /etc/passwd for getpwuid */
+static enum nss_status
+getpwuid_plususer (uid_t uid, struct passwd *result, char *buffer,
+		   size_t buflen, int *errnop)
+{
+  struct passwd pwd;
+  char *p;
+  size_t plen;
+
+  if (!nss_getpwuid_r)
+    return NSS_STATUS_UNAVAIL;
+
+  memset (&pwd, '\0', sizeof (struct passwd));
+
+  copy_pwd_changes (&pwd, result, NULL, 0);
+
+  plen = pwd_need_buflen (&pwd);
+  if (plen > buflen)
+    {
+      *errnop = ERANGE;
+      return NSS_STATUS_TRYAGAIN;
+    }
+  p = buffer + (buflen - plen);
+  buflen -= plen;
+
+  if (nss_getpwuid_r (uid, result, buffer, buflen, errnop) ==
+      NSS_STATUS_SUCCESS)
+    {
+      copy_pwd_changes (result, &pwd, p, plen);
+      give_pwd_free (&pwd);
+      /* We found the entry.  */
+      return NSS_STATUS_SUCCESS;
+    }
+  else
+    {
+      /* Give buffer the old len back */
+      buflen += plen;
+      give_pwd_free (&pwd);
+    }
+  return NSS_STATUS_RETURN;
+}
+
+/* Searches in /etc/passwd and the NSS subsystem for a special user id */
+static enum nss_status
+internal_getpwuid_r (uid_t uid, struct passwd *result, ent_t *ent,
+		     char *buffer, size_t buflen, int *errnop)
+{
+  struct parser_data *data = (void *) buffer;
+
+  while (1)
+    {
+      fpos_t pos;
+      char *p;
+      int parse_res;
+
+      do
+	{
+	  /* We need at least 3 characters for one line.  */
+	  if (__glibc_unlikely (buflen < 3))
+	    {
+	    erange:
+	      *errnop = ERANGE;
+	      return NSS_STATUS_TRYAGAIN;
+	    }
+
+	  fgetpos (ent->stream, &pos);
+	  buffer[buflen - 1] = '\xff';
+	  p = fgets_unlocked (buffer, buflen, ent->stream);
+	  if (p == NULL && feof_unlocked (ent->stream))
+	    return NSS_STATUS_NOTFOUND;
+
+	  if (p == NULL || __builtin_expect (buffer[buflen - 1] != '\xff', 0))
+	    {
+	    erange_reset:
+	      fsetpos (ent->stream, &pos);
+	      goto erange;
+	    }
+
+	  /* Terminate the line for any case.  */
+	  buffer[buflen - 1] = '\0';
+
+	  /* Skip leading blanks.  */
+	  while (isspace (*p))
+	    ++p;
+	}
+      while (*p == '\0' || *p == '#' ||	/* Ignore empty and comment lines.  */
+	     /* Parse the line.  If it is invalid, loop to
+	        get the next line of the file to parse.  */
+	     !(parse_res = _nss_files_parse_pwent (p, result, data, buflen,
+						   errnop)));
+
+      if (__glibc_unlikely (parse_res == -1))
+	/* The parser ran out of space.  */
+	goto erange_reset;
+
+      /* This is a real entry.  */
+      if (result->pw_name[0] != '+' && result->pw_name[0] != '-')
+	{
+	  if (result->pw_uid == uid)
+	    return NSS_STATUS_SUCCESS;
+	  else
+	    continue;
+	}
+
+      /* -@netgroup */
+      if (result->pw_name[0] == '-' && result->pw_name[1] == '@'
+	  && result->pw_name[2] != '\0')
+	{
+	  /* -1, because we remove first two character of pw_name.  */
+	  size_t len = strlen (result->pw_name) - 1;
+	  char buf[len];
+	  enum nss_status status;
+
+	  memcpy (buf, &result->pw_name[2], len);
+
+	  status = getpwuid_plususer (uid, result, buffer, buflen, errnop);
+	  if (status == NSS_STATUS_SUCCESS &&
+	      innetgr (buf, NULL, result->pw_name, NULL))
+	    return NSS_STATUS_NOTFOUND;
+
+	  continue;
+	}
+
+      /* +@netgroup */
+      if (result->pw_name[0] == '+' && result->pw_name[1] == '@'
+	  && result->pw_name[2] != '\0')
+	{
+	  /* -1, because we remove first two characters of pw_name.  */
+	  size_t len = strlen (result->pw_name) - 1;
+	  char buf[len];
+	  enum nss_status status;
+
+	  memcpy (buf, &result->pw_name[2], len);
+
+	  status = getpwuid_plususer (uid, result, buffer, buflen, errnop);
+
+	  if (status == NSS_STATUS_RETURN)
+	    continue;
+
+	  if (status == NSS_STATUS_SUCCESS)
+	    {
+	      if (innetgr (buf, NULL, result->pw_name, NULL))
+		return NSS_STATUS_SUCCESS;
+	    }
+	  else if (status == NSS_STATUS_RETURN)	/* We couldn't parse the entry */
+	    return NSS_STATUS_NOTFOUND;
+	  else
+	    return status;
+
+	  continue;
+	}
+
+      /* -user */
+      if (result->pw_name[0] == '-' && result->pw_name[1] != '\0'
+	  && result->pw_name[1] != '@')
+	{
+	  size_t len = strlen (result->pw_name);
+	  char buf[len];
+	  enum nss_status status;
+
+	  memcpy (buf, &result->pw_name[1], len);
+
+	  status = getpwuid_plususer (uid, result, buffer, buflen, errnop);
+	  if (status == NSS_STATUS_SUCCESS &&
+	      innetgr (buf, NULL, result->pw_name, NULL))
+	    return NSS_STATUS_NOTFOUND;
+	  continue;
+	}
+
+      /* +user */
+      if (result->pw_name[0] == '+' && result->pw_name[1] != '\0'
+	  && result->pw_name[1] != '@')
+	{
+	  size_t len = strlen (result->pw_name);
+	  char buf[len];
+	  enum nss_status status;
+
+	  memcpy (buf, &result->pw_name[1], len);
+
+	  status = getpwuid_plususer (uid, result, buffer, buflen, errnop);
+
+	  if (status == NSS_STATUS_RETURN)
+	    continue;
+
+	  if (status == NSS_STATUS_SUCCESS)
+	    {
+	      if (strcmp (buf, result->pw_name) == 0)
+		return NSS_STATUS_SUCCESS;
+	    }
+	  else if (status == NSS_STATUS_RETURN)	/* We couldn't parse the entry */
+	    return NSS_STATUS_NOTFOUND;
+	  else
+	    return status;
+
+	  continue;
+	}
+
+      /* +:... */
+      if (result->pw_name[0] == '+' && result->pw_name[1] == '\0')
+	{
+	  enum nss_status status;
+
+	  status = getpwuid_plususer (uid, result, buffer, buflen, errnop);
+	  if (status == NSS_STATUS_SUCCESS)	/* We found the entry. */
+	    break;
+	  else if (status == NSS_STATUS_RETURN)	/* We couldn't parse the entry */
+	    return NSS_STATUS_NOTFOUND;
+	  else
+	    return status;
+	}
+    }
+  return NSS_STATUS_SUCCESS;
+}
+
+enum nss_status
+_nss_compat_getpwuid_r (uid_t uid, struct passwd *pwd,
+			char *buffer, size_t buflen, int *errnop)
+{
+  enum nss_status result;
+  ent_t ent = { false, false, true, NSS_STATUS_SUCCESS, NULL, { NULL, 0, 0 },
+		{ NULL, NULL, 0, 0, NULL, NULL, NULL }};
+
+  __libc_lock_lock (lock);
+
+  if (ni == NULL)
+    init_nss_interface ();
+
+  __libc_lock_unlock (lock);
+
+  result = internal_setpwent (&ent, 0, 0);
+
+  if (result == NSS_STATUS_SUCCESS)
+    result = internal_getpwuid_r (uid, pwd, &ent, buffer, buflen, errnop);
+
+  internal_endpwent (&ent);
+
+  return result;
+}
+
+
+/* Support routines for remembering -@netgroup and -user entries.
+   The names are stored in a single string with `|' as separator. */
+static void
+blacklist_store_name (const char *name, ent_t *ent)
+{
+  int namelen = strlen (name);
+  char *tmp;
+
+  /* first call, setup cache */
+  if (ent->blacklist.size == 0)
+    {
+      ent->blacklist.size = MAX (BLACKLIST_INITIAL_SIZE, 2 * namelen);
+      ent->blacklist.data = malloc (ent->blacklist.size);
+      if (ent->blacklist.data == NULL)
+	return;
+      ent->blacklist.data[0] = '|';
+      ent->blacklist.data[1] = '\0';
+      ent->blacklist.current = 1;
+    }
+  else
+    {
+      if (in_blacklist (name, namelen, ent))
+	return;			/* no duplicates */
+
+      if (ent->blacklist.current + namelen + 1 >= ent->blacklist.size)
+	{
+	  ent->blacklist.size += MAX (BLACKLIST_INCREMENT, 2 * namelen);
+	  tmp = realloc (ent->blacklist.data, ent->blacklist.size);
+	  if (tmp == NULL)
+	    {
+	      free (ent->blacklist.data);
+	      ent->blacklist.size = 0;
+	      return;
+	    }
+	  ent->blacklist.data = tmp;
+	}
+    }
+
+  tmp = stpcpy (ent->blacklist.data + ent->blacklist.current, name);
+  *tmp++ = '|';
+  *tmp = '\0';
+  ent->blacklist.current += namelen + 1;
+
+  return;
+}
+
+/* Returns whether ent->blacklist contains name.  */
+static bool
+in_blacklist (const char *name, int namelen, ent_t *ent)
+{
+  char buf[namelen + 3];
+  char *cp;
+
+  if (ent->blacklist.data == NULL)
+    return false;
+
+  buf[0] = '|';
+  cp = stpcpy (&buf[1], name);
+  *cp++ = '|';
+  *cp = '\0';
+  return strstr (ent->blacklist.data, buf) != NULL;
+}