diff options
Diffstat (limited to 'nscd/grpcache.c')
| -rw-r--r-- | nscd/grpcache.c | 698 |
1 files changed, 164 insertions, 534 deletions
diff --git a/nscd/grpcache.c b/nscd/grpcache.c index f34780a..1645d71 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 *) ¬found, + 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); } |