From a8874eadae699b5d4583aab3a860e06ecfcf5e5a Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Mon, 12 Aug 1996 02:44:03 +0000 Subject: Last minute change. Mon Aug 12 04:33:09 1996 Ulrich Drepper * nss/nsswitch.c (__nss_database_lookup): Always release locks before returning. Reported by Miles Bader. (distributes): Add databases.def. --- nss/Makefile | 5 ++- nss/XXX-lookup.c | 11 +++--- nss/databases.def | 31 +++++++++++++++ nss/nss.h | 54 +++++++++++++++++++++++++ nss/nsswitch.c | 116 ++++++++++++++++++++++++++++++++++++++++-------------- nss/nsswitch.h | 15 +------ 6 files changed, 182 insertions(+), 50 deletions(-) create mode 100644 nss/databases.def create mode 100644 nss/nss.h (limited to 'nss') diff --git a/nss/Makefile b/nss/Makefile index f23f5f3fbb..5dcae4d40e 100644 --- a/nss/Makefile +++ b/nss/Makefile @@ -21,13 +21,16 @@ # subdir := nss +headers := nss.h distribute := nsswitch.h XXX-lookup.c getXXbyYY.c getXXbyYY_r.c \ - getXXent.c getXXent_r.c + getXXent.c getXXent_r.c databases.def # This is the trivial part which goes into libc itself. routines = nsswitch $(addsuffix -lookup,$(databases)) # These are the databases that go through nss dispatch. +# Caution: if you add a database here, you must add its real name +# in databases.def, too. databases = proto service hosts network grp pwd rpc ethers \ spwd diff --git a/nss/XXX-lookup.c b/nss/XXX-lookup.c index 4a2d25cb42..1b43018d47 100644 --- a/nss/XXX-lookup.c +++ b/nss/XXX-lookup.c @@ -35,25 +35,26 @@ Boston, MA 02111-1307, USA. */ #define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post) #define CONCAT3_2(Pre, Name, Post) Pre##Name##Post +#define DATABASE_NAME_SYMBOL CONCAT3_1 (__nss_, DATABASE_NAME, _database) #define DATABASE_NAME_STRING STRINGIFY1 (DATABASE_NAME) #define STRINGIFY1(Name) STRINGIFY2 (Name) #define STRINGIFY2(Name) #Name #ifndef DEFAULT_CONFIG -#define DEFAULT_CONFIG 0 +#define DEFAULT_CONFIG NULL #endif -static service_user *database = NULL; +service_user *DATABASE_NAME_SYMBOL = NULL; int DB_LOOKUP_FCT (service_user **ni, const char *fct_name, void **fctp) { - if (database == NULL + if (DATABASE_NAME_SYMBOL == NULL && __nss_database_lookup (DATABASE_NAME_STRING, DEFAULT_CONFIG, - &database) < 0) + &DATABASE_NAME_SYMBOL) < 0) return -1; - *ni = database; + *ni = DATABASE_NAME_SYMBOL; return __nss_lookup (ni, fct_name, fctp); } diff --git a/nss/databases.def b/nss/databases.def new file mode 100644 index 0000000000..98772bac76 --- /dev/null +++ b/nss/databases.def @@ -0,0 +1,31 @@ +/* List of all databases defined for the NSS in GNU C Library. +Copyright (C) 1996 Free Software Foundation, Inc. +This file is part of the GNU C Library. +Contributed by Ulrich Drepper , 1996. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, +Boston, MA 02111-1307, USA. */ + +/* This list must be kept sorted!!! */ + +DEFINE_DATABASE (ethers) +DEFINE_DATABASE (group) +DEFINE_DATABASE (hosts) +DEFINE_DATABASE (networks) +DEFINE_DATABASE (passwd) +DEFINE_DATABASE (protocols) +DEFINE_DATABASE (rpc) +DEFINE_DATABASE (services) +DEFINE_DATABASE (shadow) diff --git a/nss/nss.h b/nss/nss.h new file mode 100644 index 0000000000..e9acb93bcc --- /dev/null +++ b/nss/nss.h @@ -0,0 +1,54 @@ +/* Copyright (C) 1996 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 Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, +Boston, MA 02111-1307, USA. */ + +/* Define interface to NSS. This is meant for the interface functions + and for implementors of new services. */ + +#ifndef _NSS_H + +#define _NSS_H 1 +#include + +/* Revision number of NSS interface (must be a string). */ +#define NSS_SHLIB_REVISION ".1" + + +__BEGIN_DECLS + +/* Possible results of lookup using a nss_* function. */ +enum nss_status +{ + NSS_STATUS_TRYAGAIN = -2, + NSS_STATUS_UNAVAIL, + NSS_STATUS_NOTFOUND, + NSS_STATUS_SUCCESS, +}; + + +/* Overwrite service selection for database DBNAME using specification + in STRING. + This function should only be used by system programs which have to + work around non-existing services (e.e., while booting). + Attention: Using this function repeatedly will slowly eat up the + whole memory since previous selection data cannot be freed. */ +extern int __nss_configure_lookup __P ((__const char *__dbname, + __const char *__string)); + +__END_DECLS + +#endif /* nss.h */ diff --git a/nss/nsswitch.c b/nss/nsswitch.c index 1349e0ca08..0a4c9482d2 100644 --- a/nss/nsswitch.c +++ b/nss/nsswitch.c @@ -19,6 +19,7 @@ Boston, MA 02111-1307, USA. */ #include #include +#include #include #include #include @@ -30,7 +31,6 @@ Boston, MA 02111-1307, USA. */ #include "../elf/link.h" /* We need some help from ld.so. */ /* Prototypes for the local functions. */ -static void nss_init (void); static void *nss_lookup_function (service_user *ni, const char *fct_name); static name_database *nss_parse_file (const char *fname); static name_database_entry *nss_getline (char *line); @@ -39,6 +39,27 @@ static service_library *nss_new_service (name_database *database, const char *name); +/* Declare external database variables. */ +#define DEFINE_DATABASE(name) \ + extern service_user *__nss_##name##_database; \ + weak_extern (__nss_##name##_database) +#include "databases.def" +#undef DEFINE_DATABASE + +/* Structure to map database name to variable. */ +static struct +{ + const char *name; + service_user **dbp; +} databases[] = +{ +#define DEFINE_DATABASE(name) \ + { #name, &__nss_##name##_database }, +#include "databases.def" +#undef DEFINE_DATABASE +}; + + __libc_lock_define_initialized (static, lock) @@ -50,35 +71,29 @@ static int nss_initialized; static name_database *service_table; -static void -nss_init (void) -{ - /* Prevent multiple threads to change the service table. */ - __libc_lock_lock (lock); - - if (service_table == NULL) - service_table = nss_parse_file (_PATH_NSSWITCH_CONF); - - __libc_lock_unlock (lock); -} - - /* -1 == database not found 0 == database entry pointer stored */ int __nss_database_lookup (const char *database, const char *defconfig, service_user **ni) { - name_database_entry *entry; + /* Prevent multiple threads to change the service table. */ + __libc_lock_lock (lock); - if (nss_initialized == 0) - nss_init (); + /* Reconsider database variable in case some other thread called + `__nss_configure_lookup' while we waited for the lock. */ + if (*ni != NULL) + return 0; + + if (nss_initialized == 0 && service_table == NULL) + /* Read config file. */ + service_table = nss_parse_file (_PATH_NSSWITCH_CONF); /* Test whether configuration data is available. */ - if (service_table) + if (service_table != NULL) { - /* Return first `service_user' entry for DATABASE. - XXX Will use perfect hashing function for known databases. */ + /* Return first `service_user' entry for DATABASE. */ + name_database_entry *entry; /* XXX Could use some faster mechanism here. But each database is only requested once and so this might not be critical. */ @@ -91,17 +106,14 @@ __nss_database_lookup (const char *database, const char *defconfig, } /* No configuration data is available, either because nsswitch.conf - doesn't exist or because it doesn't have a line for this database. */ - entry = malloc (sizeof *entry); - if (entry == NULL) - return -1; - entry->name = database; - /* DEFCONFIG specifies the default service list for this database, + doesn't exist or because it doesn't has a line for this database. + + DEFCONFIG specifies the default service list for this database, or null to use the most common default. */ - entry->service = nss_parse_service_list (defconfig ?: - "compat [NOTFOUND=return] files"); + *ni = nss_parse_service_list (defconfig ?: "compat [NOTFOUND=return] files"); + + __libc_lock_unlock (lock); - *ni = entry->service; return 0; } @@ -168,6 +180,48 @@ __nss_next (service_user **ni, const char *fct_name, void **fctp, int status, } +int +__nss_configure_lookup (const char *dbname, const char *service_line) +{ + service_user *new_db; + size_t cnt; + + for (cnt = 0; cnt < sizeof databases; ++cnt) + if (strcmp (dbname, databases[cnt].name) == 0) + break; + + if (cnt == sizeof databases) + { + errno = EINVAL; + return -1; + } + + /* Test whether it is really used. */ + if (databases[cnt].dbp == NULL) + /* Nothing to do, but we could do. */ + return 0; + + /* Try to generate new data. */ + new_db = nss_parse_service_list (service_line); + if (new_db == NULL) + { + /* Illegal service specification. */ + errno = EINVAL; + return -1; + } + + /* Prevent multiple threads to change the service table. */ + __libc_lock_lock (lock); + + /* Install new rules. */ + *databases[cnt].dbp = new_db; + + __libc_lock_unlock (lock); + + return 0; +} + + static int nss_dlerror_run (void (*operate) (void)) { @@ -385,7 +439,9 @@ nss_parse_file (const char *fname) } -/* Read the source names: ` ( "[" "=" "]" )*'. */ +/* Read the source names: + `( ( "[" "!"? ( "=" )+ "]" )? )*' + */ static service_user * nss_parse_service_list (const char *line) { diff --git a/nss/nsswitch.h b/nss/nsswitch.h index c4d4d11193..0c99f147fd 100644 --- a/nss/nsswitch.h +++ b/nss/nsswitch.h @@ -23,24 +23,11 @@ Boston, MA 02111-1307, USA. */ #include #include +#include #include #include -/* Revision number of NSS interface (must be a string). */ -#define NSS_SHLIB_REVISION ".1" - - -/* Possible results of lookup using a nss_* function. */ -enum nss_status -{ - NSS_STATUS_TRYAGAIN = -2, - NSS_STATUS_UNAVAIL, - NSS_STATUS_NOTFOUND, - NSS_STATUS_SUCCESS, -}; - - /* Actions performed after lookup finished. */ typedef enum { -- cgit v1.2.3