From 299210c1fa67e2dfb564475986fce11cd33db9ad Mon Sep 17 00:00:00 2001

From: Florian Weimer <fweimer@redhat.com>

Date: Thu, 16 Jul 2020 16:12:46 +0200

Subject: [PATCH 01/11] nss_files: Consolidate file opening in

 __nss_files_fopen

Tested-by: Carlos O'Donell <carlos@redhat.com>

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

---

 include/nss_files.h              | 28 ++++++++++++++++++++++++

 nss/Makefile                     |  2 +-

 nss/Versions                     |  1 +

 nss/nss_files/files-XXX.c        |  3 ++-

 nss/nss_files/files-alias.c      |  5 +++--

 nss/nss_files/files-initgroups.c |  6 ++---

 nss/nss_files/files-netgrp.c     |  5 ++---

 nss/nss_files_fopen.c            | 47 ++++++++++++++++++++++++++++++++++++++++

 8 files changed, 86 insertions(+), 11 deletions(-)

 create mode 100644 include/nss_files.h

 create mode 100644 nss/nss_files_fopen.c

diff -rupN a/include/nss_files.h b/include/nss_files.h

--- a/include/nss_files.h	1969-12-31 19:00:00.000000000 -0500

+++ b/include/nss_files.h	2020-09-11 21:28:42.027034988 -0400

@@ -0,0 +1,28 @@

+/* Internal routines for nss_files.

+   Copyright (C) 2020 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   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

+   <https://www.gnu.org/licenses/>.  */

+

+#ifndef _NSS_FILES_H

+#define _NSS_FILES_H

+

+#include <stdio.h>

+

+/* Open PATH for reading, as a data source for nss_files.  */

+FILE *__nss_files_fopen (const char *path);

+libc_hidden_proto (__nss_files_fopen)

+

+#endif /* _NSS_FILES_H */

diff -rupN a/nss/Makefile b/nss/Makefile

--- a/nss/Makefile	2020-09-11 21:24:05.569544894 -0400

+++ b/nss/Makefile	2020-09-11 21:28:42.035035292 -0400

@@ -28,7 +28,7 @@ headers			:= nss.h

 routines		= nsswitch getnssent getnssent_r digits_dots \

 			  valid_field valid_list_field rewrite_field \

 			  $(addsuffix -lookup,$(databases)) \

-			  compat-lookup nss_hash

+			  compat-lookup nss_hash nss_files_fopen

 # These are the databases that go through nss dispatch.

 # Caution: if you add a database here, you must add its real name

diff -rupN a/nss/Versions b/nss/Versions

--- a/nss/Versions	2020-09-11 21:24:04.852517683 -0400

+++ b/nss/Versions	2020-09-11 21:28:42.041035519 -0400

@@ -21,6 +21,7 @@ libc {

     __nss_passwd_lookup2; __nss_group_lookup2; __nss_hosts_lookup2;

     __nss_services_lookup2; __nss_next2; __nss_lookup;

     __nss_hash; __nss_database_lookup2;

+    __nss_files_fopen;

   }

 }

diff -rupN a/nss/nss_files/files-XXX.c b/nss/nss_files/files-XXX.c

--- a/nss/nss_files/files-XXX.c	2018-08-01 01:10:47.000000000 -0400

+++ b/nss/nss_files/files-XXX.c	2020-09-11 21:28:42.049035823 -0400

@@ -22,6 +22,7 @@

 #include <fcntl.h>

 #include <libc-lock.h>

 #include "nsswitch.h"

+#include <nss_files.h>

 #include <kernel-features.h>

@@ -74,7 +75,7 @@ internal_setent (FILE **stream)

   if (*stream == NULL)

     {

-      *stream = fopen (DATAFILE, "rce");

+      *stream = __nss_files_fopen (DATAFILE);

       if (*stream == NULL)

 	status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;

diff -rupN a/nss/nss_files/files-alias.c b/nss/nss_files/files-alias.c

--- a/nss/nss_files/files-alias.c	2020-09-11 21:24:02.004409596 -0400

+++ b/nss/nss_files/files-alias.c	2020-09-11 21:28:42.055036051 -0400

@@ -29,6 +29,7 @@

 #include <kernel-features.h>

 #include "nsswitch.h"

+#include <nss_files.h>

 /* Locks the static variables in this file.  */

 __libc_lock_define_initialized (static, lock)

@@ -47,7 +48,7 @@ internal_setent (FILE **stream)

   if (*stream == NULL)

     {

-      *stream = fopen ("/etc/aliases", "rce");

+      *stream = __nss_files_fopen ("/etc/aliases");

       if (*stream == NULL)

 	status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;

@@ -213,7 +214,7 @@ get_next_alias (FILE *stream, const char

 		      first_unused = cp;

-		      listfile = fopen (&cp[9], "rce");

+		      listfile = __nss_files_fopen (&cp[9]);

 		      /* If the file does not exist we simply ignore

 			 the statement.  */

 		      if (listfile != NULL

diff -rupN a/nss/nss_files/files-initgroups.c b/nss/nss_files/files-initgroups.c

--- a/nss/nss_files/files-initgroups.c	2018-08-01 01:10:47.000000000 -0400

+++ b/nss/nss_files/files-initgroups.c	2020-09-11 22:08:25.130740010 -0400

@@ -25,22 +25,20 @@

 #include <stdbool.h>

 #include <stdlib.h>

 #include <scratch_buffer.h>

+#include <nss_files.h>

 enum nss_status

 _nss_files_initgroups_dyn (const char *user, gid_t group, long int *start,

 			   long int *size, gid_t **groupsp, long int limit,

 			   int *errnop)

 {

-  FILE *stream = fopen ("/etc/group", "rce");

+  FILE *stream = __nss_files_fopen ("/etc/group");

   if (stream == NULL)

     {

       *errnop = errno;

       return *errnop == ENOMEM ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;

     }

-  /* No other thread using this stream.  */

-  __fsetlocking (stream, FSETLOCKING_BYCALLER);

-

   char *line = NULL;

   size_t linelen = 0;

   enum nss_status status = NSS_STATUS_SUCCESS;

diff -rupN a/nss/nss_files/files-netgrp.c b/nss/nss_files/files-netgrp.c

--- a/nss/nss_files/files-netgrp.c	2018-08-01 01:10:47.000000000 -0400

+++ b/nss/nss_files/files-netgrp.c	2020-09-11 21:28:42.068036544 -0400

@@ -26,6 +26,7 @@

 #include <string.h>

 #include "nsswitch.h"

 #include "netgroup.h"

+#include <nss_files.h>

 #define DATAFILE	"/etc/netgroup"

@@ -62,7 +63,7 @@ _nss_files_setnetgrent (const char *grou

     return NSS_STATUS_UNAVAIL;

   /* Find the netgroups file and open it.  */

-  fp = fopen (DATAFILE, "rce");

+  fp = __nss_files_fopen (DATAFILE);

   if (fp == NULL)

     status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;

   else

@@ -76,8 +77,6 @@ _nss_files_setnetgrent (const char *grou

       status = NSS_STATUS_NOTFOUND;

       result->cursor = result->data;

-      __fsetlocking (fp, FSETLOCKING_BYCALLER);

-

       while (!feof_unlocked (fp))

 	{

 	  ssize_t curlen = getline (&line, &line_len, fp);

diff -rupN a/nss/nss_files_fopen.c b/nss/nss_files_fopen.c

--- a/nss/nss_files_fopen.c	1969-12-31 19:00:00.000000000 -0500

+++ b/nss/nss_files_fopen.c	2020-09-11 21:28:42.074036771 -0400

@@ -0,0 +1,47 @@

+/* Open an nss_files database file.

+   Copyright (C) 2020 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   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

+   <https://www.gnu.org/licenses/>.  */

+

+#include <nss_files.h>

+

+#include <errno.h>

+#include <stdio_ext.h>

+

+FILE *

+__nss_files_fopen (const char *path)

+{

+  FILE *fp = fopen (path, "rce");

+  if (fp == NULL)

+    return NULL;

+

+  /* The stream is not shared across threads.  */

+  __fsetlocking (fp, FSETLOCKING_BYCALLER);

+

+  /* This tells libio that the file is seekable, and that fp->_offset

+     is correct, ensuring that __ftello64 is efficient (bug 26257).  */

+  if (__fseeko64 (fp, 0, SEEK_SET) < 0)

+    {

+      /* nss_files requires seekable files, to deal with repeated

+         reads of the same line after reporting ERANGE.  */

+      fclose (fp);

+      __set_errno (ESPIPE);

+      return NULL;

+    }

+

+  return fp;

+}

+libc_hidden_def (__nss_files_fopen)