[01/11] nss_files: Consolidate file opening in __nss_files_fopen
Commit Message
---
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
Comments
On 7/17/20 4:30 AM, Florian Weimer via Libc-alpha wrote:
OK for 2.32.
Introduces __nss_files_open.
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 --git a/include/nss_files.h b/include/nss_files.h
> new file mode 100644
> index 0000000000..17144b7932
> --- /dev/null
> +++ b/include/nss_files.h
> @@ -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 --git a/nss/Makefile b/nss/Makefile
> index cbb70167a9..00f4d89310 100644
> --- a/nss/Makefile
> +++ b/nss/Makefile
> @@ -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 --git a/nss/Versions b/nss/Versions
> index afc82a23c2..f489cb6eb0 100644
> --- a/nss/Versions
> +++ b/nss/Versions
> @@ -18,6 +18,7 @@ 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 --git a/nss/nss_files/files-XXX.c b/nss/nss_files/files-XXX.c
> index 73d2d5cb31..9cc5137953 100644
> --- a/nss/nss_files/files-XXX.c
> +++ b/nss/nss_files/files-XXX.c
> @@ -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 --git a/nss/nss_files/files-alias.c b/nss/nss_files/files-alias.c
> index 6aff7b4c10..43fb2c49a5 100644
> --- a/nss/nss_files/files-alias.c
> +++ b/nss/nss_files/files-alias.c
> @@ -29,6 +29,7 @@
> #include <kernel-features.h>
>
> #include "nsswitch.h"
> +#include <nss_files.h>
>
> NSS_DECLARE_MODULE_FUNCTIONS (files)
>
> @@ -49,7 +50,7 @@ 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;
> @@ -215,7 +216,7 @@ get_next_alias (FILE *stream, const char *match, struct aliasent *result,
>
> 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 --git a/nss/nss_files/files-initgroups.c b/nss/nss_files/files-initgroups.c
> index 577d6ddf1e..b6f505984a 100644
> --- a/nss/nss_files/files-initgroups.c
> +++ b/nss/nss_files/files-initgroups.c
> @@ -26,6 +26,7 @@
> #include <stdlib.h>
> #include <scratch_buffer.h>
> #include <nss.h>
> +#include <nss_files.h>
>
> NSS_DECLARE_MODULE_FUNCTIONS (files)
>
> @@ -34,16 +35,13 @@ _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 --git a/nss/nss_files/files-netgrp.c b/nss/nss_files/files-netgrp.c
> index 2c580af01d..66e16b7c77 100644
> --- a/nss/nss_files/files-netgrp.c
> +++ b/nss/nss_files/files-netgrp.c
> @@ -26,6 +26,7 @@
> #include <string.h>
> #include "nsswitch.h"
> #include "netgroup.h"
> +#include <nss_files.h>
>
> NSS_DECLARE_MODULE_FUNCTIONS (files)
>
> @@ -64,7 +65,7 @@ _nss_files_setnetgrent (const char *group, struct __netgrent *result)
> 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
> @@ -78,8 +79,6 @@ _nss_files_setnetgrent (const char *group, struct __netgrent *result)
> 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 --git a/nss/nss_files_fopen.c b/nss/nss_files_fopen.c
> new file mode 100644
> index 0000000000..594e421657
> --- /dev/null
> +++ b/nss/nss_files_fopen.c
> @@ -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)
OK.
This activates the stream. After this libio is allowed to assume that the
underlying fd will not be changed by the user (which is the library itself).
> + {
> + /* 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)
>
new file mode 100644
@@ -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 */
@@ -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
@@ -18,6 +18,7 @@ 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;
}
}
@@ -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;
@@ -29,6 +29,7 @@
#include <kernel-features.h>
#include "nsswitch.h"
+#include <nss_files.h>
NSS_DECLARE_MODULE_FUNCTIONS (files)
@@ -49,7 +50,7 @@ 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;
@@ -215,7 +216,7 @@ get_next_alias (FILE *stream, const char *match, struct aliasent *result,
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
@@ -26,6 +26,7 @@
#include <stdlib.h>
#include <scratch_buffer.h>
#include <nss.h>
+#include <nss_files.h>
NSS_DECLARE_MODULE_FUNCTIONS (files)
@@ -34,16 +35,13 @@ _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;
@@ -26,6 +26,7 @@
#include <string.h>
#include "nsswitch.h"
#include "netgroup.h"
+#include <nss_files.h>
NSS_DECLARE_MODULE_FUNCTIONS (files)
@@ -64,7 +65,7 @@ _nss_files_setnetgrent (const char *group, struct __netgrent *result)
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
@@ -78,8 +79,6 @@ _nss_files_setnetgrent (const char *group, struct __netgrent *result)
status = NSS_STATUS_NOTFOUND;
result->cursor = result->data;
- __fsetlocking (fp, FSETLOCKING_BYCALLER);
-
while (!feof_unlocked (fp))
{
ssize_t curlen = getline (&line, &line_len, fp);
new file mode 100644
@@ -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)