glibc/nscd/grpcache.c

606 lines
12 KiB
C

/* Copyright (c) 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 1998.
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. */
#include <errno.h>
#include <grp.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <rpcsvc/nis.h>
#include <sys/types.h>
#include "dbg_log.h"
#include "nscd.h"
static unsigned long modulo = 211;
static unsigned long postimeout = 3600;
static unsigned long negtimeout = 60;
static unsigned long poshit = 0;
static unsigned long posmiss = 0;
static unsigned long neghit = 0;
static unsigned long negmiss = 0;
struct grphash
{
time_t create;
struct grphash *next;
struct group *grp;
};
typedef struct grphash grphash;
struct gidhash
{
struct gidhash *next;
struct grphash *grptr;
};
typedef struct gidhash gidhash;
struct neghash
{
time_t create;
struct neghash *next;
char *key;
};
typedef struct neghash neghash;
static grphash *grptbl;
static gidhash *gidtbl;
static neghash *negtbl;
static pthread_rwlock_t grplock = PTHREAD_RWLOCK_INITIALIZER;
static pthread_rwlock_t neglock = PTHREAD_RWLOCK_INITIALIZER;
static void *grptable_update (void *);
static void *negtable_update (void *);
void
get_gr_stat (stat_response_header *stat)
{
stat->gr_poshit = poshit;
stat->gr_posmiss = posmiss;
stat->gr_neghit = neghit;
stat->gr_negmiss = negmiss;
stat->gr_size = modulo;
stat->gr_posttl = postimeout;
stat->gr_negttl = negtimeout;
}
void
set_grp_modulo (unsigned long mod)
{
modulo = mod;
}
void
set_pos_grp_ttl (unsigned long ttl)
{
postimeout = ttl;
}
void
set_neg_grp_ttl (unsigned long ttl)
{
negtimeout = ttl;
}
int
cache_grpinit ()
{
pthread_attr_t attr;
pthread_t thread;
grptbl = calloc (modulo, sizeof (grphash));
if (grptbl == NULL)
return -1;
gidtbl = calloc (modulo, sizeof (grphash));
if (gidtbl == NULL)
return -1;
negtbl = calloc (modulo, sizeof (neghash));
if (negtbl == NULL)
return -1;
pthread_attr_init (&attr);
pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
pthread_create (&thread, NULL, grptable_update, &attr);
pthread_create (&thread, NULL, negtable_update, &attr);
pthread_attr_destroy (&attr);
return 0;
}
static struct group *
save_grp (struct group *src)
{
struct group *dest;
unsigned long int l;
dest = calloc (1, sizeof (struct group));
dest->gr_name = strdup (src->gr_name);
dest->gr_passwd = strdup (src->gr_passwd);
dest->gr_gid = src->gr_gid;
/* How many members does this group have? */
l = 0;
while (src->gr_mem[l])
++l;
dest->gr_mem = calloc (1, sizeof (char *) * (l+1));
l = 0;
while (src->gr_mem[l])
{
dest->gr_mem[l] = strdup (src->gr_mem[l]);
++l;
}
return dest;
}
static void
free_grp (struct group *src)
{
unsigned long int l;
free (src->gr_name);
free (src->gr_passwd);
l = 0;
while (src->gr_mem[l])
{
free (src->gr_mem[l]);
++l;
}
free (src->gr_mem);
free (src);
}
static int
add_cache (struct group *grp)
{
grphash *work;
unsigned long int hash = __nis_hash (grp->gr_name,
strlen (grp->gr_name)) % modulo;
if (debug_flag)
dbg_log (_("grp_add_cache (%s)"), grp->gr_name);
work = &grptbl[hash];
if (grptbl[hash].grp == NULL)
grptbl[hash].grp = save_grp (grp);
else
{
while (work->next != NULL)
work = work->next;
work->next = calloc (1, sizeof (grphash));
work->next->grp = save_grp (grp);
work = work->next;
}
time (&work->create);
gidtbl[grp->gr_gid % modulo].grptr = work;
return 0;
}
static struct group *
cache_search_name (const char *name)
{
grphash *work;
unsigned long int hash = __nis_hash (name, strlen(name)) % modulo;
work = &grptbl[hash];
while (work->grp != NULL)
{
if (strcmp (work->grp->gr_name, name) == 0)
return work->grp;
if (work->next != NULL)
work = work->next;
else
return NULL;
}
return NULL;
}
static struct group *
cache_search_gid (gid_t gid)
{
gidhash *work;
work = &gidtbl[gid % modulo];
while (work->grptr != NULL)
{
if (work->grptr->grp->gr_gid == gid)
return work->grptr->grp;
if (work->next != NULL)
work = work->next;
else
return NULL;
}
return NULL;
}
static int
add_negcache (char *key)
{
neghash *work;
unsigned long int hash = __nis_hash (key, strlen (key)) % modulo;
if (debug_flag)
dbg_log (_("grp_add_netgache (%s|%ld)"), key, hash);
work = &negtbl[hash];
if (negtbl[hash].key == NULL)
{
negtbl[hash].key = strdup (key);
negtbl[hash].next = NULL;
}
else
{
while (work->next != NULL)
work = work->next;
work->next = calloc (1, sizeof (neghash));
work->next->key = strdup (key);
work = work->next;
}
time (&work->create);
return 0;
}
static int
cache_search_neg (const char *key)
{
neghash *work;
unsigned long int hash = __nis_hash (key, strlen (key)) % modulo;
if (debug_flag)
dbg_log (_("grp_cache_search_neg (%s|%ld)"), key, hash);
work = &negtbl[hash];
while (work->key != NULL)
{
if (strcmp (work->key, key) == 0)
return 1;
if (work->next != NULL)
work = work->next;
else
return 0;
}
return 0;
}
void *
cache_getgrnam (void *v_param)
{
param_t *param = (param_t *)v_param;
struct group *grp;
pthread_rwlock_rdlock (&grplock);
grp = cache_search_name (param->key);
/* I don't like it to hold the read only lock longer, but it is
necessary to avoid to much malloc/free/strcpy. */
if (grp != NULL)
{
if (debug_flag)
dbg_log (_("Found \"%s\" in cache !"), param->key);
++poshit;
gr_send_answer (param->conn, grp);
close_socket (param->conn);
pthread_rwlock_unlock (&grplock);
}
else
{
int status;
int buflen = 1024;
char *buffer = calloc (1, buflen);
struct group resultbuf;
if (debug_flag)
dbg_log (_("Doesn't found \"%s\" in cache !"), param->key);
pthread_rwlock_unlock (&grplock);
pthread_rwlock_rdlock (&neglock);
status = cache_search_neg (param->key);
pthread_rwlock_unlock (&neglock);
if (status == 0)
{
while (buffer != NULL
&& (getgrnam_r (param->key, &resultbuf, buffer, buflen, &grp)
!= 0)
&& errno == ERANGE)
{
errno = 0;
buflen += 1024;
buffer = realloc (buffer, buflen);
}
if (buffer != NULL && grp != NULL)
{
struct group *tmp;
++poshit;
pthread_rwlock_wrlock (&grplock);
/* While we are waiting on the lock, somebody else could
add this entry. */
tmp = cache_search_name (param->key);
if (tmp == NULL)
add_cache (grp);
pthread_rwlock_unlock (&grplock);
}
else
{
pthread_rwlock_wrlock (&neglock);
add_negcache (param->key);
++negmiss;
pthread_rwlock_unlock (&neglock);
}
}
else
++neghit;
gr_send_answer (param->conn, grp);
close_socket (param->conn);
if (buffer != NULL)
free (buffer);
}
free (param->key);
free (param);
return NULL;
}
void *
cache_gr_disabled (void *v_param)
{
param_t *param = (param_t *)v_param;
if (debug_flag)
dbg_log (_("\tgroup cache is disabled\n"));
gr_send_disabled (param->conn);
return NULL;
}
void *
cache_getgrgid (void *v_param)
{
param_t *param = (param_t *)v_param;
struct group *grp, resultbuf;
gid_t gid = strtol (param->key, NULL, 10);
pthread_rwlock_rdlock (&grplock);
grp = cache_search_gid (gid);
/* I don't like it to hold the read only lock longer, but it is
necessary to avoid to much malloc/free/strcpy. */
if (grp != NULL)
{
if (debug_flag)
dbg_log (_("Found \"%d\" in cache !"), gid);
++poshit;
gr_send_answer (param->conn, grp);
close_socket (param->conn);
pthread_rwlock_unlock (&grplock);
}
else
{
int buflen = 1024;
char *buffer = malloc (buflen);
int status;
if (debug_flag)
dbg_log (_("Doesn't found \"%d\" in cache !"), gid);
pthread_rwlock_unlock (&grplock);
pthread_rwlock_rdlock (&neglock);
status = cache_search_neg (param->key);
pthread_rwlock_unlock (&neglock);
if (status == 0)
{
while (buffer != NULL
&& (getgrgid_r (gid, &resultbuf, buffer, buflen, &grp) != 0)
&& errno == ERANGE)
{
errno = 0;
buflen += 1024;
buffer = realloc (buffer, buflen);
}
if (buffer != NULL && grp != NULL)
{
struct group *tmp;
++posmiss;
pthread_rwlock_wrlock (&grplock);
/* While we are waiting on the lock, somebody else could
add this entry. */
tmp = cache_search_gid (gid);
if (tmp == NULL)
add_cache (grp);
pthread_rwlock_unlock (&grplock);
}
else
{
++negmiss;
pthread_rwlock_wrlock (&neglock);
add_negcache (param->key);
pthread_rwlock_unlock (&neglock);
}
}
else
++neghit;
gr_send_answer (param->conn, grp);
close_socket (param->conn);
if (buffer != NULL)
free (buffer);
}
free (param->key);
free (param);
return NULL;
}
void *
grptable_update (void *v)
{
time_t now;
int i;
sleep (20);
while (!do_shutdown)
{
if (debug_flag > 2)
dbg_log (_("(grptable_update) Wait for write lock!"));
pthread_rwlock_wrlock (&grplock);
if (debug_flag > 2)
dbg_log (_("(grptable_update) Have write lock"));
time (&now);
for (i = 0; i < modulo; ++i)
{
grphash *work = &grptbl[i];
while (work && work->grp)
{
if ((now - work->create) >= postimeout)
{
gidhash *uh = &gidtbl[work->grp->gr_gid % modulo];
if (debug_flag)
dbg_log (_("Give \"%s\" free"), work->grp->gr_name);
while (uh && uh->grptr)
{
if (uh->grptr->grp->gr_gid == work->grp->gr_gid)
{
if (debug_flag > 3)
dbg_log (_("Give gid for \"%s\" free"),
work->grp->gr_name);
if (uh->next != NULL)
{
gidhash *tmp = uh->next;
uh->grptr = tmp->grptr;
uh->next = tmp->next;
free (tmp);
}
else
uh->grptr = NULL;
}
uh = uh->next;
}
free_grp (work->grp);
if (work->next != NULL)
{
grphash *tmp = work->next;
work->create = tmp->create;
work->next = tmp->next;
work->grp = tmp->grp;
free (tmp);
}
else
work->grp = NULL;
}
work = work->next;
}
}
if (debug_flag > 2)
dbg_log (_("(pwdtable_update) Release wait lock\n"));
pthread_rwlock_unlock (&grplock);
sleep (20);
}
return NULL;
}
void *
negtable_update (void *v)
{
time_t now;
int i;
sleep (30);
while (!do_shutdown)
{
if (debug_flag > 2)
dbg_log (_("(negtable_update) Wait for write lock!"));
pthread_rwlock_wrlock (&neglock);
if (debug_flag > 2)
dbg_log (_("(negtable_update) Have write lock"));
time (&now);
for (i = 0; i < modulo; ++i)
{
neghash *work = &negtbl[i];
while (work && work->key)
{
if ((now - work->create) >= negtimeout)
{
if (debug_flag)
dbg_log (_("Give \"%s\" free"), work->key);
free (work->key);
if (work->next != NULL)
{
neghash *tmp = work->next;
work->create = tmp->create;
work->next = tmp->next;
work->key = tmp->key;
free (tmp);
}
else
work->key = NULL;
}
work = work->next;
}
}
if (debug_flag > 2)
dbg_log (_("(negtable_update) Release wait lock"));
pthread_rwlock_unlock (&neglock);
sleep (10);
}
return NULL;
}