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Generalize framework to register monitoring of files in nscd

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nscd can clear caches when certain files change.  The list of files
was hardcoded so far and worked for nss_files and nss_dns and those
modules which need no monitoring.  nss_db, for instance, has its
own set of files to monitor.  Now the NSS modules themselves can
request that certain files are monitored.
This commit is contained in:
Ulrich Drepper
2011-07-11 14:50:24 -04:00
parent 23bee3e867
commit 319b9ad4bc
12 changed files with 446 additions and 159 deletions
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42
ChangeLog
View File

@ -1,3 +1,45 @@
2011-07-11 Ulrich Drepper <drepper@gmail.com>
* nscd/nscd.h (struct traced_file): Define.
(struct database_dyn): Remove inotify_descr, reset_res, and filename
elements. Add traced_files.
(inotify_fd): Declare.
(register_traced_file): Declare.
* nscd/connections.c (dbs): Remove reset_res and filename initializers.
(inotify_fd): Export.
(resolv_conf_descr): Remove.
(nscd_init): Move inotify descriptor creation to main.
Don't register files for notification here.
(register_traced_file): New function.
(invalidate_cache): Don't use reset_res to determine whether to call
res_init, go through the list of registered files.
(main_loop_poll): The inotify descriptors are now stored in the
structures for the traced files.
(main_loop_epoll): Likewise
* nscd/nscd.c (main): Create inotify socket here. Pass extra argument
to __nss_disable_nscd.
* nscd/cache.c (prune_cache): There is no single inotify descriptor
for a database anymore. Check the records for all the registered
files instead.
* nss/Makefile (libnss_files-routines): Add files-init.
(libnss_db-routines): Add db-init.
* nss/Versions [libnss_files] (GLIBC_PRIVATE): Add _nss_files_init.
[libnss_db] (GLIBC_PRIVATE): Add _nss_db_init.
* nss/nss_db/db-init.c: New file.
* nss/nss_files/files-init.c: New file.
* nss/nsswitch.c (nss_load_library): New function. Broken out of
__nss_lookup_function.
(__nss_lookup_function): Call nss_load_library.
(nss_load_all_libraries): New function.
(__nss_disable_nscd): Take parameter with callback function for files
to register. Set is_nscd. Load all the DSOs for the NSS modules
used for the cached services.
* nss/nsswitch.h (__nss_disable_nscd): Adjust prototype.
* sysdeps/unix/sysv/linux/Makefile [subdir=nscd]: Pass the various -D
options for features to all the files in nscd.
* nss/nsswitch.c (nss_parse_file): Add missing fclose.
2011-07-10 Roland McGrath <roland@hack.frob.com> 2011-07-10 Roland McGrath <roland@hack.frob.com>
* csu/elf-init.c (__libc_csu_init): Comment typo. * csu/elf-init.c (__libc_csu_init): Comment typo.

46
nscd/cache.c
View File

@ -264,28 +264,40 @@ prune_cache (struct database_dyn *table, time_t now, int fd)
/* If we check for the modification of the underlying file we invalidate /* If we check for the modification of the underlying file we invalidate
the entries also in this case. */ the entries also in this case. */
if (table->inotify_descr < 0 && table->check_file && now != LONG_MAX) if (table->check_file && now != LONG_MAX)
{ {
struct stat64 st; struct traced_file *runp = table->traced_files;
if (stat64 (table->filename, &st) < 0) while (runp != NULL)
{ {
char buf[128]; #ifdef HAVE_INOTIFY
/* We cannot stat() the file, disable file checking if the if (runp->inotify_descr == -1)
file does not exist. */ #endif
dbg_log (_("cannot stat() file `%s': %s"),
table->filename, strerror_r (errno, buf, sizeof (buf)));
if (errno == ENOENT)
table->check_file = 0;
}
else
{
if (st.st_mtime != table->file_mtime)
{ {
/* The file changed. Invalidate all entries. */ struct stat64 st;
now = LONG_MAX;
table->file_mtime = st.st_mtime; if (stat64 (runp->fname, &st) < 0)
{
char buf[128];
/* We cannot stat() the file, disable file checking if the
file does not exist. */
dbg_log (_("cannot stat() file `%s': %s"),
runp->fname, strerror_r (errno, buf, sizeof (buf)));
if (errno == ENOENT)
table->check_file = 0;
}
else
{
if (st.st_mtime != table->file_mtime)
{
/* The file changed. Invalidate all entries. */
now = LONG_MAX;
table->file_mtime = st.st_mtime;
}
}
} }
runp = runp->next;
} }
} }

165
nscd/connections.c
View File

@ -117,8 +117,6 @@ struct database_dyn dbs[lastdb] =
.shared = 0, .shared = 0,
.max_db_size = DEFAULT_MAX_DB_SIZE, .max_db_size = DEFAULT_MAX_DB_SIZE,
.suggested_module = DEFAULT_SUGGESTED_MODULE, .suggested_module = DEFAULT_SUGGESTED_MODULE,
.reset_res = 0,
.filename = "/etc/passwd",
.db_filename = _PATH_NSCD_PASSWD_DB, .db_filename = _PATH_NSCD_PASSWD_DB,
.disabled_iov = &pwd_iov_disabled, .disabled_iov = &pwd_iov_disabled,
.postimeout = 3600, .postimeout = 3600,
@ -138,8 +136,6 @@ struct database_dyn dbs[lastdb] =
.shared = 0, .shared = 0,
.max_db_size = DEFAULT_MAX_DB_SIZE, .max_db_size = DEFAULT_MAX_DB_SIZE,
.suggested_module = DEFAULT_SUGGESTED_MODULE, .suggested_module = DEFAULT_SUGGESTED_MODULE,
.reset_res = 0,
.filename = "/etc/group",
.db_filename = _PATH_NSCD_GROUP_DB, .db_filename = _PATH_NSCD_GROUP_DB,
.disabled_iov = &grp_iov_disabled, .disabled_iov = &grp_iov_disabled,
.postimeout = 3600, .postimeout = 3600,
@ -159,8 +155,6 @@ struct database_dyn dbs[lastdb] =
.shared = 0, .shared = 0,
.max_db_size = DEFAULT_MAX_DB_SIZE, .max_db_size = DEFAULT_MAX_DB_SIZE,
.suggested_module = DEFAULT_SUGGESTED_MODULE, .suggested_module = DEFAULT_SUGGESTED_MODULE,
.reset_res = 1,
.filename = "/etc/hosts",
.db_filename = _PATH_NSCD_HOSTS_DB, .db_filename = _PATH_NSCD_HOSTS_DB,
.disabled_iov = &hst_iov_disabled, .disabled_iov = &hst_iov_disabled,
.postimeout = 3600, .postimeout = 3600,
@ -180,8 +174,6 @@ struct database_dyn dbs[lastdb] =
.shared = 0, .shared = 0,
.max_db_size = DEFAULT_MAX_DB_SIZE, .max_db_size = DEFAULT_MAX_DB_SIZE,
.suggested_module = DEFAULT_SUGGESTED_MODULE, .suggested_module = DEFAULT_SUGGESTED_MODULE,
.reset_res = 0,
.filename = "/etc/services",
.db_filename = _PATH_NSCD_SERVICES_DB, .db_filename = _PATH_NSCD_SERVICES_DB,
.disabled_iov = &serv_iov_disabled, .disabled_iov = &serv_iov_disabled,
.postimeout = 28800, .postimeout = 28800,
@ -232,10 +224,7 @@ static int sock;
#ifdef HAVE_INOTIFY #ifdef HAVE_INOTIFY
/* Inotify descriptor. */ /* Inotify descriptor. */
static int inotify_fd = -1; int inotify_fd = -1;
/* Watch descriptor for resolver configuration file. */
static int resolv_conf_descr = -1;
#endif #endif
#ifndef __ASSUME_SOCK_CLOEXEC #ifndef __ASSUME_SOCK_CLOEXEC
@ -523,19 +512,6 @@ nscd_init (void)
/* No configuration for this value, assume a default. */ /* No configuration for this value, assume a default. */
nthreads = 4; nthreads = 4;
#ifdef HAVE_INOTIFY
/* Use inotify to recognize changed files. */
inotify_fd = inotify_init1 (IN_NONBLOCK);
# ifndef __ASSUME_IN_NONBLOCK
if (inotify_fd == -1 && errno == ENOSYS)
{
inotify_fd = inotify_init ();
if (inotify_fd != -1)
fcntl (inotify_fd, F_SETFL, O_RDONLY | O_NONBLOCK);
}
# endif
#endif
for (size_t cnt = 0; cnt < lastdb; ++cnt) for (size_t cnt = 0; cnt < lastdb; ++cnt)
if (dbs[cnt].enabled) if (dbs[cnt].enabled)
{ {
@ -840,40 +816,6 @@ cannot set socket to close on exec: %s; disabling paranoia mode"),
dbs[cnt].shared = 0; dbs[cnt].shared = 0;
assert (dbs[cnt].ro_fd == -1); assert (dbs[cnt].ro_fd == -1);
} }
dbs[cnt].inotify_descr = -1;
if (dbs[cnt].check_file)
{
#ifdef HAVE_INOTIFY
if (inotify_fd < 0
|| (dbs[cnt].inotify_descr
= inotify_add_watch (inotify_fd, dbs[cnt].filename,
IN_DELETE_SELF | IN_MODIFY)) < 0)
/* We cannot notice changes in the main thread. */
#endif
{
/* We need the modification date of the file. */
struct stat64 st;
if (stat64 (dbs[cnt].filename, &st) < 0)
{
/* We cannot stat() the file, disable file checking. */
dbg_log (_("cannot stat() file `%s': %s"),
dbs[cnt].filename, strerror (errno));
dbs[cnt].check_file = 0;
}
else
dbs[cnt].file_mtime = st.st_mtime;
}
}
#ifdef HAVE_INOTIFY
if (cnt == hstdb && inotify_fd >= -1)
/* We also monitor the resolver configuration file. */
resolv_conf_descr = inotify_add_watch (inotify_fd,
_PATH_RESCONF,
IN_DELETE_SELF | IN_MODIFY);
#endif
} }
/* Create the socket. */ /* Create the socket. */
@ -940,12 +882,50 @@ cannot set socket to close on exec: %s; disabling paranoia mode"),
exit (1); exit (1);
} }
/* Change to unprivileged uid/gid/groups if specifed in config file */ /* Change to unprivileged uid/gid/groups if specified in config file */
if (server_user != NULL) if (server_user != NULL)
finish_drop_privileges (); finish_drop_privileges ();
} }
void
register_traced_file (size_t dbidx, struct traced_file *finfo)
{
if (! dbs[dbidx].check_file)
return;
if (__builtin_expect (debug_level > 0, 0))
dbg_log (_("register trace file %s for database %s"),
finfo->fname, dbnames[dbidx]);
#ifdef HAVE_INOTIFY
if (inotify_fd < 0
|| (finfo->inotify_descr = inotify_add_watch (inotify_fd, finfo->fname,
IN_DELETE_SELF
| IN_MODIFY)) < 0)
#endif
{
/* We need the modification date of the file. */
struct stat64 st;
if (stat64 (finfo->fname, &st) < 0)
{
/* We cannot stat() the file, disable file checking. */
dbg_log (_("cannot stat() file `%s': %s"),
finfo->fname, strerror (errno));
return;
}
finfo->inotify_descr = -1;
finfo->mtime = st.st_mtime;
}
/* Queue up the file name. */
finfo->next = dbs[dbidx].traced_files;
dbs[dbidx].traced_files = finfo;
}
/* Close the connections. */ /* Close the connections. */
void void
close_sockets (void) close_sockets (void)
@ -963,11 +943,20 @@ invalidate_cache (char *key, int fd)
for (number = pwddb; number < lastdb; ++number) for (number = pwddb; number < lastdb; ++number)
if (strcmp (key, dbnames[number]) == 0) if (strcmp (key, dbnames[number]) == 0)
{ {
if (dbs[number].reset_res) if (number == hstdb)
res_init (); {
struct traced_file *runp = dbs[hstdb].traced_files;
while (runp != NULL)
if (runp->call_res_init)
{
res_init ();
break;
}
else
runp = runp->next;
}
break; break;
} }
if (number == lastdb) if (number == lastdb)
{ {
@ -1913,16 +1902,21 @@ disabled inotify after read error %d"),
/* Check which of the files changed. */ /* Check which of the files changed. */
for (size_t dbcnt = 0; dbcnt < lastdb; ++dbcnt) for (size_t dbcnt = 0; dbcnt < lastdb; ++dbcnt)
if (inev.i.wd == dbs[dbcnt].inotify_descr)
{
to_clear[dbcnt] = true;
goto next;
}
if (inev.i.wd == resolv_conf_descr)
{ {
res_init (); struct traced_file *finfo = dbs[dbcnt].traced_files;
to_clear[hstdb] = true;
while (finfo != NULL)
{
if (finfo->inotify_descr == inev.i.wd)
{
to_clear[dbcnt] = true;
if (finfo->call_res_init)
res_init ();
goto next;
}
finfo = finfo->next;
}
} }
next:; next:;
} }
@ -2089,7 +2083,7 @@ main_loop_epoll (int efd)
while (1) while (1)
{ {
ssize_t nb = TEMP_FAILURE_RETRY (read (inotify_fd, &inev, ssize_t nb = TEMP_FAILURE_RETRY (read (inotify_fd, &inev,
sizeof (inev))); sizeof (inev)));
if (nb < (ssize_t) sizeof (struct inotify_event)) if (nb < (ssize_t) sizeof (struct inotify_event))
{ {
if (__builtin_expect (nb == -1 && errno != EAGAIN, 0)) if (__builtin_expect (nb == -1 && errno != EAGAIN, 0))
@ -2108,16 +2102,21 @@ main_loop_epoll (int efd)
/* Check which of the files changed. */ /* Check which of the files changed. */
for (size_t dbcnt = 0; dbcnt < lastdb; ++dbcnt) for (size_t dbcnt = 0; dbcnt < lastdb; ++dbcnt)
if (inev.i.wd == dbs[dbcnt].inotify_descr)
{
to_clear[dbcnt] = true;
goto next;
}
if (inev.i.wd == resolv_conf_descr)
{ {
res_init (); struct traced_file *finfo = dbs[dbcnt].traced_files;
to_clear[hstdb] = true;
while (finfo != NULL)
{
if (finfo->inotify_descr == inev.i.wd)
{
to_clear[dbcnt] = true;
if (finfo->call_res_init)
res_init ();
goto next;
}
finfo = finfo->next;
}
} }
next:; next:;
} }

18
nscd/nscd.c
View File

@ -46,6 +46,9 @@
#include "selinux.h" #include "selinux.h"
#include "../nss/nsswitch.h" #include "../nss/nsswitch.h"
#include <device-nrs.h> #include <device-nrs.h>
#ifdef HAVE_INOTIFY
# include <sys/inotify.h>
#endif
/* Get libc version number. */ /* Get libc version number. */
#include <version.h> #include <version.h>
@ -272,8 +275,21 @@ main (int argc, char **argv)
/* Cleanup files created by a previous 'bind'. */ /* Cleanup files created by a previous 'bind'. */
unlink (_PATH_NSCDSOCKET); unlink (_PATH_NSCDSOCKET);
#ifdef HAVE_INOTIFY
/* Use inotify to recognize changed files. */
inotify_fd = inotify_init1 (IN_NONBLOCK);
# ifndef __ASSUME_IN_NONBLOCK
if (inotify_fd == -1 && errno == ENOSYS)
{
inotify_fd = inotify_init ();
if (inotify_fd != -1)
fcntl (inotify_fd, F_SETFL, O_RDONLY | O_NONBLOCK);
}
# endif
#endif
/* Make sure we do not get recursive calls. */ /* Make sure we do not get recursive calls. */
__nss_disable_nscd (); __nss_disable_nscd (register_traced_file);
/* Init databases. */ /* Init databases. */
nscd_init (); nscd_init ();

19
nscd/nscd.h
View File

@ -62,6 +62,17 @@ typedef enum
#define MAX_STACK_USE ((8 * NSCD_THREAD_STACKSIZE) / 10) #define MAX_STACK_USE ((8 * NSCD_THREAD_STACKSIZE) / 10)
/* Registered filename used to fill database. */
struct traced_file
{
time_t mtime;
struct traced_file *next;
int call_res_init;
int inotify_descr;
char fname[];
};
/* Structure describing dynamic part of one database. */ /* Structure describing dynamic part of one database. */
struct database_dyn struct database_dyn
{ {
@ -73,13 +84,11 @@ struct database_dyn
int enabled; int enabled;
int check_file; int check_file;
int inotify_descr;
int clear_cache; int clear_cache;
int persistent; int persistent;
int shared; int shared;
int propagate; int propagate;
int reset_res; struct traced_file *traced_files;
const char filename[16];
const char *db_filename; const char *db_filename;
time_t file_mtime; time_t file_mtime;
size_t suggested_module; size_t suggested_module;
@ -147,6 +156,9 @@ extern int nthreads;
/* Maximum number of threads to use. */ /* Maximum number of threads to use. */
extern int max_nthreads; extern int max_nthreads;
/* Inotify descriptor. */
extern int inotify_fd;
/* User name to run server processes as. */ /* User name to run server processes as. */
extern const char *server_user; extern const char *server_user;
@ -191,6 +203,7 @@ extern int nscd_open_socket (void);
/* connections.c */ /* connections.c */
extern void nscd_init (void); extern void nscd_init (void);
extern void register_traced_file (size_t dbidx, struct traced_file *finfo);
extern void close_sockets (void); extern void close_sockets (void);
extern void start_threads (void) __attribute__ ((__noreturn__)); extern void start_threads (void) __attribute__ ((__noreturn__));

4
nss/Makefile
View File

@ -66,14 +66,14 @@ vpath %.c $(subdir-dirs) ../locale/programs ../intl
libnss_files-routines := $(addprefix files-,$(databases)) \ libnss_files-routines := $(addprefix files-,$(databases)) \
files-initgroups files-have_o_cloexec files-initgroups files-have_o_cloexec files-init
distribute += files-XXX.c files-parse.c distribute += files-XXX.c files-parse.c
libnss_db-dbs := $(addprefix db-,\ libnss_db-dbs := $(addprefix db-,\
$(filter-out hosts network key alias,\ $(filter-out hosts network key alias,\
$(databases))) \ $(databases))) \
db-initgroups db-initgroups
libnss_db-routines := $(libnss_db-dbs) db-open hash-string libnss_db-routines := $(libnss_db-dbs) db-open db-init hash-string
generated += $(filter-out db-alias.c db-netgrp.c, \ generated += $(filter-out db-alias.c db-netgrp.c, \
$(addsuffix .c,$(libnss_db-dbs))) $(addsuffix .c,$(libnss_db-dbs)))
distribute += $(addprefix nss_db/, db-XXX.c nss_db.h) distribute += $(addprefix nss_db/, db-XXX.c nss_db.h)

4
nss/Versions
View File

@ -97,6 +97,8 @@ libnss_files {
_nss_files_getsecretkey; _nss_files_getsecretkey;
_nss_files_initgroups_dyn; _nss_files_initgroups_dyn;
_nss_files_init;
} }
} }
@ -153,5 +155,7 @@ libnss_db {
_nss_db_getspnam_r; _nss_db_getspnam_r;
_nss_db_initgroups_dyn; _nss_db_initgroups_dyn;
_nss_db_init;
} }
} }

54
nss/nss_db/db-init.c Normal file
View File

@ -0,0 +1,54 @@
/* Initialization in nss_db module.
Copyright (C) 2011 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <paths.h>
#include <nscd/nscd.h>
static union
{
struct traced_file file;
char buf[sizeof (struct traced_file) + sizeof (_PATH_VARDB "passwd.db")];
} pwd_traced_file;
static union
{
struct traced_file file;
char buf[sizeof (struct traced_file) + sizeof (_PATH_VARDB "group.db")];
} grp_traced_file;
static union
{
struct traced_file file;
char buf[sizeof (struct traced_file) + sizeof (_PATH_VARDB "services.db")];
} serv_traced_file;
void
_nss_db_init (void (*cb) (size_t, struct traced_file *))
{
strcpy (pwd_traced_file.file.fname,_PATH_VARDB "passwd.db");
cb (pwddb, &pwd_traced_file.file);
strcpy (grp_traced_file.file.fname, _PATH_VARDB "group.db");
cb (grpdb, &grp_traced_file.file);
strcpy (serv_traced_file.file.fname, _PATH_VARDB "services.db");
cb (servdb, &serv_traced_file.file);
}

72
nss/nss_files/files-init.c Normal file
View File

@ -0,0 +1,72 @@
/* Initialization in nss_files module.
Copyright (C) 2011 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <nscd/nscd.h>
static union
{
struct traced_file file;
char buf[sizeof (struct traced_file) + sizeof ("/etc/passwd")];
} pwd_traced_file;
static union
{
struct traced_file file;
char buf[sizeof (struct traced_file) + sizeof ("/etc/group")];
} grp_traced_file;
static union
{
struct traced_file file;
char buf[sizeof (struct traced_file) + sizeof ("/etc/hosts")];
} hst_traced_file;
static union
{
struct traced_file file;
char buf[sizeof (struct traced_file) + sizeof ("/etc/resolv.conf")];
} resolv_traced_file;
static union
{
struct traced_file file;
char buf[sizeof (struct traced_file) + sizeof ("/etc/services")];
} serv_traced_file;
void
_nss_files_init (void (*cb) (size_t, struct traced_file *))
{
strcpy (pwd_traced_file.file.fname, "/etc/passwd");
cb (pwddb, &pwd_traced_file.file);
strcpy (grp_traced_file.file.fname, "/etc/group");
cb (grpdb, &grp_traced_file.file);
strcpy (hst_traced_file.file.fname, "/etc/hosts");
cb (hstdb, &hst_traced_file.file);
resolv_traced_file.file.call_res_init = 1;
strcpy (resolv_traced_file.file.fname, "/etc/resolv.conf");
cb (hstdb, &resolv_traced_file.file);
strcpy (serv_traced_file.file.fname, "/etc/services");
cb (servdb, &serv_traced_file.file);
}

165
nss/nsswitch.c
View File

@ -1,4 +1,5 @@
/* Copyright (C) 1996-1999,2001-2007,2009,2010 Free Software Foundation, Inc. /* Copyright (C) 1996-1999,2001-2007,2009,2010,2011
Free Software Foundation, Inc.
This file is part of the GNU C Library. This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
@ -40,6 +41,7 @@
#include "nsswitch.h" #include "nsswitch.h"
#include "../nscd/nscd_proto.h" #include "../nscd/nscd_proto.h"
#include <sysdep.h>
/* Prototypes for the local functions. */ /* Prototypes for the local functions. */
static name_database *nss_parse_file (const char *fname) internal_function; static name_database *nss_parse_file (const char *fname) internal_function;
@ -86,6 +88,12 @@ static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;
static name_database *service_table; static name_database *service_table;
/* Nonzero if this is the nscd process. */
static bool is_nscd;
/* The callback passed to the init functions when nscd is used. */
static void (*nscd_init_cb) (size_t, struct traced_file *);
/* -1 == database not found /* -1 == database not found
0 == database entry pointer stored */ 0 == database entry pointer stored */
int int
@ -129,7 +137,7 @@ __nss_database_lookup (const char *database, const char *alternate_name,
} }
/* No configuration data is available, either because nsswitch.conf /* No configuration data is available, either because nsswitch.conf
doesn't exist or because it doesn't has a line for this database. doesn't exist or because it doesn't have a line for this database.
DEFCONFIG specifies the default service list for this database, DEFCONFIG specifies the default service list for this database,
or null to use the most common default. */ or null to use the most common default. */
@ -285,6 +293,79 @@ known_compare (const void *p1, const void *p2)
} }
#if !defined DO_STATIC_NSS || defined SHARED
/* Load library. */
static int
nss_load_library (service_user *ni)
{
if (ni->library == NULL)
{
/* This service has not yet been used. Fetch the service
library for it, creating a new one if need be. If there
is no service table from the file, this static variable
holds the head of the service_library list made from the
default configuration. */
static name_database default_table;
ni->library = nss_new_service (service_table ?: &default_table,
ni->name);
if (ni->library == NULL)
return -1;
}
if (ni->library->lib_handle == NULL)
{
/* Load the shared library. */
size_t shlen = (7 + strlen (ni->library->name) + 3
+ strlen (__nss_shlib_revision) + 1);
int saved_errno = errno;
char shlib_name[shlen];
/* Construct shared object name. */
__stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name,
"libnss_"),
ni->library->name),
".so"),
__nss_shlib_revision);
ni->library->lib_handle = __libc_dlopen (shlib_name);
if (ni->library->lib_handle == NULL)
{
/* Failed to load the library. */
ni->library->lib_handle = (void *) -1l;
__set_errno (saved_errno);
}
else if (is_nscd)
{
/* Call the init function when nscd is used. */
size_t initlen = (5 + strlen (ni->library->name)
+ strlen ("_init") + 1);
char init_name[initlen];
/* Construct the init function name. */
__stpcpy (__stpcpy (__stpcpy (init_name,
"_nss_"),
ni->library->name),
"_init");
/* Find the optional init function. */
void (*ifct) (void (*) (size_t, struct traced_file *))
= __libc_dlsym (ni->library->lib_handle, init_name);
if (ifct != NULL)
{
void (*cb) (size_t, struct traced_file *) = nscd_init_cb;
# ifdef PTR_DEMANGLE
PTR_DEMANGLE (cb);
# endif
ifct (cb);
}
}
}
return 0;
}
#endif
void * void *
__nss_lookup_function (service_user *ni, const char *fct_name) __nss_lookup_function (service_user *ni, const char *fct_name)
{ {
@ -331,47 +412,13 @@ __nss_lookup_function (service_user *ni, const char *fct_name)
*found = known; *found = known;
known->fct_name = fct_name; known->fct_name = fct_name;
if (ni->library == NULL)
{
/* This service has not yet been used. Fetch the service
library for it, creating a new one if need be. If there
is no service table from the file, this static variable
holds the head of the service_library list made from the
default configuration. */
static name_database default_table;
ni->library = nss_new_service (service_table ?: &default_table,
ni->name);
if (ni->library == NULL)
{
/* This only happens when out of memory. */
free (known);
goto remove_from_tree;
}
}
#if !defined DO_STATIC_NSS || defined SHARED #if !defined DO_STATIC_NSS || defined SHARED
if (ni->library->lib_handle == NULL) /* Load the appropriate library. */
if (nss_load_library (ni) != 0)
{ {
/* Load the shared library. */ /* This only happens when out of memory. */
size_t shlen = (7 + strlen (ni->library->name) + 3 free (known);
+ strlen (__nss_shlib_revision) + 1); goto remove_from_tree;
int saved_errno = errno;
char shlib_name[shlen];
/* Construct shared object name. */
__stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name,
"libnss_"),
ni->library->name),
".so"),
__nss_shlib_revision);
ni->library->lib_handle = __libc_dlopen (shlib_name);
if (ni->library->lib_handle == NULL)
{
/* Failed to load the library. */
ni->library->lib_handle = (void *) -1l;
__set_errno (saved_errno);
}
} }
if (ni->library->lib_handle == (void *) -1l) if (ni->library->lib_handle == (void *) -1l)
@ -463,7 +510,10 @@ nss_parse_file (const char *fname)
result = (name_database *) malloc (sizeof (name_database)); result = (name_database *) malloc (sizeof (name_database));
if (result == NULL) if (result == NULL)
return NULL; {
fclose (fp);
return NULL;
}
result->entry = NULL; result->entry = NULL;
result->library = NULL; result->library = NULL;
@ -724,16 +774,45 @@ nss_new_service (name_database *database, const char *name)
} }
#ifdef SHARED
/* Load all libraries for the service. */
static void
nss_load_all_libraries (const char *service, const char *def)
{
service_user *ni = NULL;
if (__nss_database_lookup (service, NULL, def, &ni) == 0)
while (ni != NULL)
{
nss_load_library (ni);
ni = ni->next;
}
}
/* Called by nscd and nscd alone. */ /* Called by nscd and nscd alone. */
void void
__nss_disable_nscd (void) __nss_disable_nscd (void (*cb) (size_t, struct traced_file *))
{ {
# ifdef PTR_MANGLE
PTR_MANGLE (cb);
# endif
nscd_init_cb = cb;
is_nscd = true;
/* Find all the relevant modules so that the init functions are called. */
nss_load_all_libraries ("passwd", "compat [NOTFOUND=return] files");
nss_load_all_libraries ("group", "compat [NOTFOUND=return] files");
nss_load_all_libraries ("hosts", "dns [!UNAVAIL=return] files");
nss_load_all_libraries ("services", NULL);
/* Disable all uses of NSCD. */ /* Disable all uses of NSCD. */
__nss_not_use_nscd_passwd = -1; __nss_not_use_nscd_passwd = -1;
__nss_not_use_nscd_group = -1; __nss_not_use_nscd_group = -1;
__nss_not_use_nscd_hosts = -1; __nss_not_use_nscd_hosts = -1;
__nss_not_use_nscd_services = -1; __nss_not_use_nscd_services = -1;
} }
#endif
/* Free all resources if necessary. */ /* Free all resources if necessary. */

8
nss/nsswitch.h
View File

@ -1,4 +1,4 @@
/* Copyright (C) 1996-1999,2001,2002,2003,2004,2007,2010 /* Copyright (C) 1996-1999,2001,2002,2003,2004,2007,2010,2011
Free Software Foundation, Inc. Free Software Foundation, Inc.
This file is part of the GNU C Library. This file is part of the GNU C Library.
@ -153,8 +153,10 @@ extern void *__nss_lookup_function (service_user *ni, const char *fct_name);
libc_hidden_proto (__nss_lookup_function) libc_hidden_proto (__nss_lookup_function)
/* Called by NSCD to disable recursive calls. */ /* Called by NSCD to disable recursive calls and enable special handling
extern void __nss_disable_nscd (void); when used in nscd. */
struct traced_file;
extern void __nss_disable_nscd (void (*) (size_t, struct traced_file *));
typedef int (*db_lookup_function) (service_user **, const char *, const char *, typedef int (*db_lookup_function) (service_user **, const char *, const char *,

8
sysdeps/unix/sysv/linux/Makefile
View File

@ -161,12 +161,6 @@ CFLAGS-mq_receive.c += -fexceptions
endif endif
ifeq ($(subdir),nscd) ifeq ($(subdir),nscd)
CFLAGS-connections.c += -DHAVE_EPOLL -DHAVE_SENDFILE -DHAVE_INOTIFY sysdep-CFLAGS += -DHAVE_EPOLL -DHAVE_SENDFILE -DHAVE_INOTIFY
CFLAGS-pwdcache.c += -DHAVE_SENDFILE
CFLAGS-grpcache.c += -DHAVE_SENDFILE
CFLAGS-hstcache.c += -DHAVE_SENDFILE
CFLAGS-aicache.c += -DHAVE_SENDFILE
CFLAGS-initgrcache.c += -DHAVE_SENDFILE
CFLAGS-servicescache.c += -DHAVE_SENDFILE
CFLAGS-gai.c += -DNEED_NETLINK CFLAGS-gai.c += -DNEED_NETLINK
endif endif