From 299210c1fa67e2dfb564475986fce11cd33db9ad Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Thu, 16 Jul 2020 16:12:46 +0200 Subject: [PATCH] nss_files: Consolidate file opening in __nss_files_fopen Tested-by: Carlos O'Donell Reviewed-by: Carlos O'Donell --- 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 0000000..17144b7 --- /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 + . */ + +#ifndef _NSS_FILES_H +#define _NSS_FILES_H + +#include + +/* 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 cbb7016..00f4d89 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 afc82a2..f489cb6 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 73d2d5c..9cc5137 100644 --- a/nss/nss_files/files-XXX.c +++ b/nss/nss_files/files-XXX.c @@ -22,6 +22,7 @@ #include #include #include "nsswitch.h" +#include #include @@ -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 6aff7b4..43fb2c4 100644 --- a/nss/nss_files/files-alias.c +++ b/nss/nss_files/files-alias.c @@ -29,6 +29,7 @@ #include #include "nsswitch.h" +#include 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 577d6dd..b6f5059 100644 --- a/nss/nss_files/files-initgroups.c +++ b/nss/nss_files/files-initgroups.c @@ -26,6 +26,7 @@ #include #include #include +#include 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 2c580af..66e16b7 100644 --- a/nss/nss_files/files-netgrp.c +++ b/nss/nss_files/files-netgrp.c @@ -26,6 +26,7 @@ #include #include "nsswitch.h" #include "netgroup.h" +#include 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 0000000..594e421 --- /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 + . */ + +#include + +#include +#include + +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) -- 2.7.4