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-rw-r--r--nscd/grpcache.c698
1 files changed, 164 insertions, 534 deletions
diff --git a/nscd/grpcache.c b/nscd/grpcache.c
index f34780ac4e..1645d71e41 100644
--- a/nscd/grpcache.c
+++ b/nscd/grpcache.c
@@ -1,6 +1,7 @@
-/* Copyright (c) 1998 Free Software Foundation, Inc.
+/* Cache handling for group lookup.
+ 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.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 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
@@ -15,605 +16,234 @@
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. */
+ Boston, MA 02111-1307, USA. */
+#include <assert.h>
#include <errno.h>
+#include <error.h>
#include <grp.h>
-#include <pthread.h>
+#include <stddef.h>
+#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
-#include <rpcsvc/nis.h>
-#include <sys/types.h>
-#include "dbg_log.h"
#include "nscd.h"
+#include "dbg_log.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
+/* This is the standard reply in case the service is disabled. */
+static const gr_response_header disabled =
{
- time_t create;
- struct grphash *next;
- struct group *grp;
+ version: NSCD_VERSION,
+ found: -1,
+ gr_name_len: 0,
+ gr_passwd_len: 0,
+ gr_gid: -1,
+ gr_mem_cnt: 0,
};
-typedef struct grphash grphash;
-struct gidhash
+/* This is the struct describing how to write this record. */
+const struct iovec grp_iov_disabled =
{
- struct gidhash *next;
- struct group *grptr;
+ iov_base: (void *) &disabled,
+ iov_len: sizeof (disabled)
};
-typedef struct gidhash gidhash;
-struct neghash
+
+/* This is the standard reply in case we haven't found the dataset. */
+static const gr_response_header notfound =
{
- time_t create;
- struct neghash *next;
- char *key;
+ version: NSCD_VERSION,
+ found: 0,
+ gr_name_len: 0,
+ gr_passwd_len: 0,
+ gr_gid: -1,
+ gr_mem_cnt: 0,
};
-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)
+/* This is the struct describing how to write this record. */
+static const struct iovec iov_notfound =
{
- 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;
-}
+ iov_base: (void *) &notfound,
+ iov_len: sizeof (notfound)
+};
-void
-set_grp_modulo (unsigned long mod)
-{
- modulo = mod;
-}
-void
-set_pos_grp_ttl (unsigned long ttl)
+struct groupdata
{
- postimeout = ttl;
-}
+ gr_response_header resp;
+ char strdata[0];
+};
-void
-set_neg_grp_ttl (unsigned long ttl)
-{
- negtimeout = ttl;
-}
-int
-cache_grpinit ()
+static void
+cache_addgr (struct database *db, int fd, request_header *req, void *key,
+ struct group *grp)
{
- pthread_attr_t attr;
- pthread_t thread;
+ ssize_t total;
+ ssize_t written;
+ time_t t = time (NULL);
- 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;
- size_t tlen;
- size_t name_len = strlen (src->gr_name) + 1;
- size_t passwd_len = strlen (src->gr_passwd) + 1;
- char *cp;
-
- /* How many members does this group have? */
- l = tlen = 0;
- while (src->gr_mem[l] != NULL)
- tlen += strlen (src->gr_mem[l++]) + 1;
-
- dest = malloc (sizeof (struct group) + (l + 1) * sizeof (char *)
- + name_len + passwd_len + tlen);
- if (dest == NULL)
- return NULL;
-
- dest->gr_mem = (char **) (dest + 1);
- cp = (char *) (dest->gr_mem + l + 1);
-
- dest->gr_name = cp;
- cp = mempcpy (cp, src->gr_name, name_len);
- dest->gr_passwd = cp;
- cp = mempcpy (cp, src->gr_passwd, passwd_len);
- dest->gr_gid = src->gr_gid;
-
- l = 0;
- while (src->gr_mem[l] != NULL)
+ if (grp == NULL)
{
- dest->gr_mem[l] = cp;
- cp = stpcpy (cp, src->gr_mem[l]) + 1;
- ++l;
- }
- dest->gr_mem[l] = NULL;
+ /* We have no data. This means we send the standard reply for this
+ case. */
+ void *copy;
- return dest;
-}
+ total = sizeof (notfound);
-static void
-free_grp (struct group *src)
-{
- free (src);
-}
+ written = writev (fd, &iov_notfound, 1);
-static int
-add_cache (struct group *grp)
-{
- grphash *work;
- gidhash *gidwork;
- unsigned long int hash = __nis_hash (grp->gr_name,
- strlen (grp->gr_name)) % modulo;
+ copy = malloc (req->key_len);
+ if (copy == NULL)
+ error (EXIT_FAILURE, errno, _("while allocating key copy"));
+ memcpy (copy, key, req->key_len);
- if (debug_flag)
- dbg_log (_("grp_add_cache (%s)"), grp->gr_name);
+ /* Compute the timeout time. */
+ t += db->negtimeout;
- work = &grptbl[hash];
+ /* Now get the lock to safely insert the records. */
+ pthread_rwlock_rdlock (&db->lock);
- if (grptbl[hash].grp == NULL)
- grptbl[hash].grp = save_grp (grp);
- else
- {
- while (work->next != NULL)
- work = work->next;
+ cache_add (req->type, copy, req->key_len, &iov_notfound,
+ sizeof (notfound), (void *) -1, 0, t, db);
- work->next = calloc (1, sizeof (grphash));
- work->next->grp = save_grp (grp);
- work = work->next;
+ pthread_rwlock_unlock (&db->lock);
}
-
- time (&work->create);
- gidwork = &gidtbl[grp->gr_gid % modulo];
- if (gidwork->grptr == NULL)
- gidwork->grptr = work->grp;
else
{
- while (gidwork->next != NULL)
- gidwork = gidwork->next;
+ /* Determine the I/O structure. */
+ struct groupdata *data;
+ size_t gr_name_len = strlen (grp->gr_name) + 1;
+ size_t gr_passwd_len = strlen (grp->gr_passwd) + 1;
+ size_t gr_mem_cnt = 0;
+ size_t *gr_mem_len;
+ size_t gr_mem_len_total = 0;
+ char *gr_name;
+ char *cp;
+ char buf[12];
+ ssize_t n;
+ size_t cnt;
+
+ /* We need this to insert the `bygid' entry. */
+ n = snprintf (buf, sizeof (buf), "%d", grp->gr_gid) + 1;
+
+ /* Determine the length of all members. */
+ while (grp->gr_mem[gr_mem_cnt])
+ ++gr_mem_cnt;
+ gr_mem_len = (size_t *) alloca (gr_mem_cnt * sizeof (size_t));
+ for (gr_mem_cnt = 0; grp->gr_mem[gr_mem_cnt]; ++gr_mem_cnt)
+ {
+ gr_mem_len[gr_mem_cnt] = strlen (grp->gr_mem[gr_mem_cnt]) + 1;
+ gr_mem_len_total += gr_mem_len[gr_mem_cnt];
+ }
- gidwork->next = calloc (1, sizeof (gidhash));
- gidwork->next->grptr = work->grp;
- }
+ /* We allocate all data in one memory block: the iov vector,
+ the response header and the dataset itself. */
+ total = (sizeof (struct groupdata)
+ + gr_mem_cnt * sizeof (size_t)
+ + gr_name_len + gr_passwd_len + gr_mem_len_total);
+ data = (struct groupdata *) malloc (total + n);
+ if (data == NULL)
+ /* There is no reason to go on. */
+ error (EXIT_FAILURE, errno, _("while allocating cache entry"));
- return 0;
-}
+ data->resp.found = 1;
+ data->resp.gr_name_len = gr_name_len;
+ data->resp.gr_passwd_len = gr_passwd_len;
+ data->resp.gr_gid = grp->gr_gid;
+ data->resp.gr_mem_cnt = gr_mem_cnt;
-static struct group *
-cache_search_name (const char *name)
-{
- grphash *work;
- unsigned long int hash = __nis_hash (name, strlen(name)) % modulo;
+ cp = data->strdata;
- work = &grptbl[hash];
+ /* This is the member string length array. */
+ cp = mempcpy (cp, gr_mem_len, gr_mem_cnt * sizeof (size_t));
+ gr_name = cp = mempcpy (cp, grp->gr_name, gr_name_len);
+ cp = mempcpy (cp, grp->gr_passwd, gr_passwd_len);
- 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;
+ for (cnt = 0; cnt < gr_mem_cnt; ++cnt)
+ cp = mempcpy (cp, grp->gr_mem[cnt], gr_mem_len[cnt]);
- work = &gidtbl[gid % modulo];
+ /* Finally the stringified GID value. */
+ memcpy (cp, buf, n);
- while (work->grptr != NULL)
- {
- if (work->grptr->gr_gid == gid)
- return work->grptr;
- if (work->next != NULL)
- work = work->next;
- else
- return NULL;
- }
- return NULL;
-}
+ /* Write the result. */
+ written = write (fd, &data->resp, total);
-static int
-add_negcache (char *key)
-{
- neghash *work;
- unsigned long int hash = __nis_hash (key, strlen (key)) % modulo;
+ /* Compute the timeout time. */
+ t += db->postimeout;
- if (debug_flag)
- dbg_log (_("grp_add_netgache (%s|%ld)"), key, hash);
+ /* Now get the lock to safely insert the records. */
+ pthread_rwlock_rdlock (&db->lock);
- work = &negtbl[hash];
+ /* We have to add the value for both, byname and byuid. */
+ cache_add (GETGRBYNAME, gr_name, gr_name_len, data,
+ total, data, 0, t, db);
- if (negtbl[hash].key == NULL)
- {
- negtbl[hash].key = strdup (key);
- negtbl[hash].next = NULL;
- }
- else
- {
- while (work->next != NULL)
- work = work->next;
+ cache_add (GETGRBYGID, cp, n, data, total, data, 1, t, db);
- work->next = calloc (1, sizeof (neghash));
- work->next->key = strdup (key);
- work = work->next;
+ pthread_rwlock_unlock (&db->lock);
}
- 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 (written != total)
{
- if (strcmp (work->key, key) == 0)
- return 1;
- if (work->next != NULL)
- work = work->next;
- else
- return 0;
+ char buf[256];
+ dbg_log (_("short write in %s: %s"), __FUNCTION__,
+ strerror_r (errno, buf, sizeof (buf)));
}
- 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);
+void
+addgrbyname (struct database *db, int fd, request_header *req, void *key)
+{
+ /* Search for the entry matching the key. Please note that we don't
+ look again in the table whether the dataset is now available. We
+ simply insert it. It does not matter if it is in there twice. The
+ pruning function only will look at the timestamp. */
+ int buflen = 256;
+ char *buffer = alloca (buflen);
+ struct group resultbuf;
+ struct group *grp;
- /* I don't like it to hold the read only lock longer, but it is
- necessary to avoid to much malloc/free/strcpy. */
+ if (debug_level > 0)
+ dbg_log (_("Haven't found \"%s\" in group cache!"), key);
- if (grp != NULL)
+ while (getgrnam_r (key, &resultbuf, buffer, buflen, &grp) != 0
+ && errno == ERANGE)
{
- 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);
+ errno = 0;
+ buflen += 256;
+ buffer = alloca (buflen);
}
- 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;
+ cache_addgr (db, fd, req, key, grp);
}
-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;
-}
-
-static void *
-grptable_update (void *v)
-{
- time_t now;
- int i;
+void
+addgrbygid (struct database *db, int fd, request_header *req, void *key)
+{
+ /* Search for the entry matching the key. Please note that we don't
+ look again in the table whether the dataset is now available. We
+ simply insert it. It does not matter if it is in there twice. The
+ pruning function only will look at the timestamp. */
+ int buflen = 256;
+ char *buffer = alloca (buflen);
+ struct group resultbuf;
+ struct group *grp;
+ gid_t gid = atol (key);
- sleep (20);
+ if (debug_level > 0)
+ dbg_log (_("Haven't found \"%d\" in group cache!"), gid);
- while (!do_shutdown)
+ while (getgrgid_r (gid, &resultbuf, buffer, buflen, &grp) != 0
+ && errno == ERANGE)
{
- 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->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 (_("(grptable_update) Release wait lock"));
- pthread_rwlock_unlock (&grplock);
- sleep (20);
+ errno = 0;
+ buflen += 256;
+ buffer = alloca (buflen);
}
- return NULL;
-}
-
-static void *
-negtable_update (void *v)
-{
- time_t now;
- int i;
-
- sleep (30);
- while (!do_shutdown)
- {
- if (debug_flag > 2)
- dbg_log (_("(neggrptable_update) Wait for write lock!"));
-
- pthread_rwlock_wrlock (&neglock);
-
- if (debug_flag > 2)
- dbg_log (_("(neggrptable_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 (_("(neggrptable_update) Release wait lock"));
- pthread_rwlock_unlock (&neglock);
- sleep (10);
- }
- return NULL;
+ cache_addgr (db, fd, req, key, grp);
}
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