diff options
Diffstat (limited to 'nscd/pwdcache.c')
| -rw-r--r-- | nscd/pwdcache.c | 581 |
1 files changed, 581 insertions, 0 deletions
diff --git a/nscd/pwdcache.c b/nscd/pwdcache.c new file mode 100644 index 0000000..a367666 --- /dev/null +++ b/nscd/pwdcache.c @@ -0,0 +1,581 @@ +/* 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 <malloc.h> +#include <pthread.h> +#include <pwd.h> +#include <string.h> +#include <rpcsvc/nis.h> +#include <sys/types.h> + +#include "dbg_log.h" +#include "nscd.h" + +static unsigned long int modulo = 211; +static unsigned long int postimeout = 600; +static unsigned long int negtimeout = 20; + +static unsigned long int poshit = 0; +static unsigned long int posmiss = 0; +static unsigned long int neghit = 0; +static unsigned long int negmiss = 0; + +struct pwdhash +{ + time_t create; + struct pwdhash *next; + struct passwd *pwd; +}; +typedef struct pwdhash pwdhash; + +struct uidhash +{ + struct uidhash *next; + struct pwdhash *pwptr; +}; +typedef struct uidhash uidhash; + +struct neghash +{ + time_t create; + struct neghash *next; + char *key; +}; +typedef struct neghash neghash; + +static pwdhash *pwdtbl; +static uidhash *uidtbl; +static neghash *negtbl; + +static pthread_rwlock_t pwdlock = PTHREAD_RWLOCK_INITIALIZER; +static pthread_rwlock_t neglock = PTHREAD_RWLOCK_INITIALIZER; + +static void *pwdtable_update (void *); +static void *negtable_update (void *); + +void +get_pw_stat (stat_response_header *stat) +{ + stat->pw_poshit = poshit; + stat->pw_posmiss = posmiss; + stat->pw_neghit = neghit; + stat->pw_negmiss = negmiss; + stat->pw_size = modulo; + stat->pw_posttl = postimeout; + stat->pw_negttl = negtimeout; +} + +void +set_pwd_modulo (unsigned long int mod) +{ + modulo = mod; +} + +void +set_pos_pwd_ttl (unsigned long int ttl) +{ + postimeout = ttl; +} + +void +set_neg_pwd_ttl (unsigned long int ttl) +{ + negtimeout = ttl; +} + +int +cache_pwdinit () +{ + pthread_t thread; + + pwdtbl = calloc (modulo, sizeof (pwdhash)); + if (pwdtbl == NULL) + return -1; + uidtbl = calloc (modulo, sizeof (pwdhash)); + if (uidtbl == NULL) + return -1; + negtbl = calloc (modulo, sizeof (neghash)); + if (negtbl == NULL) + return -1; + + pthread_create (&thread, NULL, pwdtable_update, (void *)NULL); + pthread_detach (thread); + pthread_create (&thread, NULL, negtable_update, (void *)NULL); + pthread_detach (thread); + return 0; +} + +static struct passwd * +save_pwd (struct passwd *src) +{ + struct passwd *dest; + + dest = calloc (1, sizeof (struct passwd)); + dest->pw_name = strdup (src->pw_name); + dest->pw_passwd = strdup (src->pw_passwd); + dest->pw_uid = src->pw_uid; + dest->pw_gid = src->pw_gid; + dest->pw_gecos = strdup (src->pw_gecos); + dest->pw_dir = strdup (src->pw_dir); + dest->pw_shell = strdup (src->pw_shell); + + return dest; +} + +static void +free_pwd (struct passwd *src) +{ + free (src->pw_name); + free (src->pw_passwd); + free (src->pw_gecos); + free (src->pw_dir); + free (src->pw_shell); + free (src); +} + +static int +add_cache (struct passwd *pwd) +{ + pwdhash *work; + unsigned long int hash = __nis_hash (pwd->pw_name, + strlen (pwd->pw_name)) % modulo; + + if (debug_flag) + dbg_log (_("add_cache (%s)"), pwd->pw_name); + + work = &pwdtbl[hash]; + + if (pwdtbl[hash].pwd == NULL) + pwdtbl[hash].pwd = save_pwd (pwd); + else + { + while (work->next != NULL) + work = work->next; + + work->next = calloc (1, sizeof (pwdhash)); + work->next->pwd = save_pwd (pwd); + work = work->next; + } + /* Set a pointer from the pwuid hash table to the pwname hash table */ + time (&work->create); + uidtbl[pwd->pw_uid % modulo].pwptr = work; + + return 0; +} + +static struct passwd * +cache_search_name (const char *name) +{ + pwdhash *work; + unsigned long int hash = __nis_hash (name, strlen (name)) % modulo; + + work = &pwdtbl[hash]; + + while (work->pwd != NULL) + { + if (strcmp (work->pwd->pw_name, name) == 0) + return work->pwd; + if (work->next != NULL) + work = work->next; + else + return NULL; + } + return NULL; +} + +static struct passwd * +cache_search_uid (uid_t uid) +{ + uidhash *work; + + work = &uidtbl[uid % modulo]; + + while (work->pwptr != NULL) + { + if (work->pwptr->pwd->pw_uid == uid) + return work->pwptr->pwd; + 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 (_("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; + } + /* Set a pointer from the pwuid hash table to the pwname hash table */ + 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; + + work = &negtbl[hash]; + + if (debug_flag) + dbg_log (_("cache_search_neg (%s|%ld)"), key, 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_getpwnam (void *v_param) +{ + param_t *param = (param_t *)v_param; + struct passwd *pwd, resultbuf; + + pthread_rwlock_rdlock (&pwdlock); + pwd = 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 (pwd != NULL) + { + if (debug_flag) + dbg_log (_("Found \"%s\" in cache !"), param->key); + + ++poshit; + pw_send_answer (param->conn, pwd); + close_socket (param->conn); + + pthread_rwlock_unlock (&pwdlock); + pwd = &resultbuf; + } + else + { + int status; + int buflen = 1024; + char *buffer = malloc (buflen); + + if (debug_flag) + dbg_log (_("Doesn't found \"%s\" in cache !"), param->key); + + pthread_rwlock_unlock (&pwdlock); + + pthread_rwlock_rdlock (&neglock); + status = cache_search_neg (param->key); + pthread_rwlock_unlock (&neglock); + + if (status == 0) + { + while (buffer != NULL + && (getpwnam_r (param->key, &resultbuf, buffer, buflen, &pwd) + != 0) + && errno == ERANGE) + { + errno = 0; + buflen += 1024; + buffer = realloc (buffer, buflen); + } + + if (buffer != NULL && pwd != NULL) + { + struct passwd *tmp; + + ++posmiss; + pthread_rwlock_wrlock (&pwdlock); + /* While we are waiting on the lock, somebody else could + add this entry. */ + tmp = cache_search_name (param->key); + if (tmp == NULL) + add_cache (pwd); + pthread_rwlock_unlock (&pwdlock); + } + else + { + ++negmiss; + pthread_rwlock_wrlock (&neglock); + add_negcache (param->key); + pthread_rwlock_unlock (&neglock); + } + } + else + ++neghit; + pw_send_answer (param->conn, pwd); + close_socket (param->conn); + if (buffer != NULL) + free (buffer); + } + free (param->key); + free (param); + return NULL; +} + +void * +cache_pw_disabled (void *v_param) +{ + param_t *param = (param_t *)v_param; + + pw_send_disabled (param->conn); + return NULL; +} + +void * +cache_getpwuid (void *v_param) +{ + param_t *param = (param_t *)v_param; + struct passwd *pwd, resultbuf; + uid_t uid = strtol (param->key, NULL, 10); + + pthread_rwlock_rdlock (&pwdlock); + pwd = cache_search_uid (uid); + + /* I don't like it to hold the read only lock longer, but it is + necessary to avoid to much malloc/free/strcpy. */ + + if (pwd != NULL) + { + if (debug_flag) + dbg_log (_("Found \"%d\" in cache !"), uid); + + ++poshit; + pw_send_answer (param->conn, pwd); + close_socket (param->conn); + + pthread_rwlock_unlock (&pwdlock); + } + else + { + int buflen = 1024; + char *buffer = malloc (buflen); + int status; + + if (debug_flag) + dbg_log (_("Doesn't found \"%d\" in cache !"), uid); + + pthread_rwlock_unlock (&pwdlock); + + pthread_rwlock_rdlock (&neglock); + status = cache_search_neg (param->key); + pthread_rwlock_unlock (&neglock); + + if (status == 0) + { + while (buffer != NULL + && (getpwuid_r (uid, &resultbuf, buffer, buflen, &pwd) != 0) + && errno == ERANGE) + { + errno = 0; + buflen += 1024; + buffer = realloc (buffer, buflen); + } + + if (buffer != NULL && pwd != NULL) + { + struct passwd *tmp; + + ++posmiss; + pthread_rwlock_wrlock (&pwdlock); + /* While we are waiting on the lock, somebody else could + add this entry. */ + tmp = cache_search_uid (uid); + if (tmp == NULL) + add_cache (pwd); + pthread_rwlock_unlock (&pwdlock); + } + else + { + ++negmiss; + pthread_rwlock_wrlock (&neglock); + add_negcache (param->key); + pthread_rwlock_unlock (&neglock); + } + } + else + ++neghit; + + pw_send_answer (param->conn, pwd); + close_socket (param->conn); + if (buffer != NULL) + free (buffer); + } + free (param->key); + free (param); + return NULL; +} + +void * +pwdtable_update (void *v) +{ + time_t now; + int i; + + sleep (20); + + while (!do_shutdown) + { + if (debug_flag > 2) + dbg_log (_("(pwdtable_update) Wait for write lock!")); + + pthread_rwlock_wrlock (&pwdlock); + + if (debug_flag > 2) + dbg_log (_("(pwdtable_update) Have write lock")); + + time (&now); + for (i = 0; i < modulo; ++i) + { + pwdhash *work = &pwdtbl[i]; + + while (work && work->pwd) + { + if ((now - work->create) >= postimeout) + { + uidhash *uh = &uidtbl[work->pwd->pw_uid % modulo]; + + if (debug_flag) + dbg_log (_("Give \"%s\" free"), work->pwd->pw_name); + + while (uh != NULL && uh->pwptr) + { + if (uh->pwptr->pwd->pw_uid == work->pwd->pw_uid) + { + if (debug_flag) + dbg_log (_("Give uid for \"%s\" free"), + work->pwd->pw_name); + if (uh->next != NULL) + { + uidhash *tmp = uh->next; + uh->pwptr = tmp->pwptr; + uh->next = tmp->next; + free (tmp); + } + else + uh->pwptr = NULL; + } + uh = uh->next; + } + + free_pwd (work->pwd); + if (work->next != NULL) + { + pwdhash *tmp = work->next; + work->create = tmp->create; + work->next = tmp->next; + work->pwd = tmp->pwd; + free (tmp); + } + else + work->pwd = NULL; + } + work = work->next; + } + } + if (debug_flag > 2) + dbg_log (_("(pwdtable_update) Release wait lock")); + pthread_rwlock_unlock (&pwdlock); + 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) + 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) + dbg_log (_("(negtable_update) Release wait lock")); + + pthread_rwlock_unlock (&neglock); + sleep (10); + } + return NULL; +} |