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authorJakub Jelinek <jakub@redhat.com>2007-01-31 09:14:21 +0000
committerJakub Jelinek <jakub@redhat.com>2007-01-31 09:14:21 +0000
commit1a77d37f9228d51d727f1caff2689137785232b9 (patch)
treed59b0c6fe37e90d5fa0cb1d2ce7e795521ac53cb /nscd/nscd_getpw_r.c
parentee3142006a497a5216aef39ea8277a1c313b9747 (diff)
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* nscd/nscd-client.h (__nscd_cache_search): Remove const qualifier
from return value. * nscd/nscd_helper.c: Include string.h. (__nscd_cache_search): Remove const qualifier from return value. On strict alignment architectures check hash entry and data head alignment. * nscd/nscd_getpw_r.c (nscd_getpw_r): Don't crash or fail because mmapped data during GC cycle contains garbage. If __nscd_drop_map_ref fails, decrement mapped->counter when returning error or if retrying with NO_MAPPING, only __nscd_unmap if counter dropped to 0. * nscd/nscd_getgr_r.c (nscd_getgr_r): Likewise. * nscd/nscd_initgroups.c (__nscd_getgrouplist): Likewise. * nscd/nscd_gethst_r.c (nscd_gethst_r): Likewise. * nscd/nscd_getai.c (__nscd_getai): Likewise. * nscd/nscd_getserv_r.c (nscd_getserv_r): Likewise. 2007-01-31 Jakub Jelinek <jakub@redhat.com> * nscd/nscd-client.h (__nscd_cache_search): Remove const qualifier from return value. * nscd/nscd_helper.c: Include string.h. (__nscd_cache_search): Remove const qualifier from return value. On strict alignment architectures check hash entry and data head alignment. * nscd/nscd_getpw_r.c (nscd_getpw_r): Don't crash or fail because mmapped data during GC cycle contains garbage. If __nscd_drop_map_ref fails, decrement mapped->counter when returning error or if retrying with NO_MAPPING, only __nscd_unmap if counter dropped to 0. * nscd/nscd_getgr_r.c (nscd_getgr_r): Likewise. * nscd/nscd_initgroups.c (__nscd_getgrouplist): Likewise. * nscd/nscd_gethst_r.c (nscd_gethst_r): Likewise. * nscd/nscd_getai.c (__nscd_getai): Likewise. * nscd/nscd_getserv_r.c (nscd_getserv_r): Likewise.
Diffstat (limited to 'nscd/nscd_getpw_r.c')
-rw-r--r--nscd/nscd_getpw_r.c70
1 files changed, 39 insertions, 31 deletions
diff --git a/nscd/nscd_getpw_r.c b/nscd/nscd_getpw_r.c
index e8e4d7364f..b84baa1a66 100644
--- a/nscd/nscd_getpw_r.c
+++ b/nscd/nscd_getpw_r.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 1998, 1999, 2003, 2004, 2005 Free Software Foundation, Inc.
+/* Copyright (C) 1998, 1999, 2003, 2004, 2005, 2007
+ Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Thorsten Kukuk <kukuk@uni-paderborn.de>, 1998.
@@ -88,76 +89,81 @@ nscd_getpw_r (const char *key, size_t keylen, request_type type,
struct passwd **result)
{
int gc_cycle;
+ int nretries = 0;
+
/* If the mapping is available, try to search there instead of
communicating with the nscd. */
struct mapped_database *mapped;
mapped = __nscd_get_map_ref (GETFDPW, "passwd", &map_handle, &gc_cycle);
retry:;
- const pw_response_header *pw_resp = NULL;
const char *pw_name = NULL;
int retval = -1;
const char *recend = (const char *) ~UINTMAX_C (0);
+ pw_response_header pw_resp;
if (mapped != NO_MAPPING)
{
- const struct datahead *found = __nscd_cache_search (type, key, keylen,
- mapped);
+ struct datahead *found = __nscd_cache_search (type, key, keylen, mapped);
if (found != NULL)
{
- pw_resp = &found->data[0].pwdata;
- pw_name = (const char *) (pw_resp + 1);
+ pw_name = (const char *) (&found->data[0].pwdata + 1);
+ pw_resp = found->data[0].pwdata;
recend = (const char *) found->data + found->recsize;
+ /* Now check if we can trust pw_resp fields. If GC is
+ in progress, it can contain anything. */
+ if (mapped->head->gc_cycle != gc_cycle)
+ {
+ retval = -2;
+ goto out;
+ }
}
}
- pw_response_header pw_resp_mem;
int sock = -1;
- if (pw_resp == NULL)
+ if (pw_name == NULL)
{
- sock = __nscd_open_socket (key, keylen, type, &pw_resp_mem,
- sizeof (pw_resp_mem));
+ sock = __nscd_open_socket (key, keylen, type, &pw_resp,
+ sizeof (pw_resp));
if (sock == -1)
{
__nss_not_use_nscd_passwd = 1;
goto out;
}
-
- pw_resp = &pw_resp_mem;
}
/* No value found so far. */
*result = NULL;
- if (__builtin_expect (pw_resp->found == -1, 0))
+ if (__builtin_expect (pw_resp.found == -1, 0))
{
/* The daemon does not cache this database. */
__nss_not_use_nscd_passwd = 1;
goto out_close;
}
- if (pw_resp->found == 1)
+ if (pw_resp.found == 1)
{
/* Set the information we already have. */
- resultbuf->pw_uid = pw_resp->pw_uid;
- resultbuf->pw_gid = pw_resp->pw_gid;
+ resultbuf->pw_uid = pw_resp.pw_uid;
+ resultbuf->pw_gid = pw_resp.pw_gid;
char *p = buffer;
/* get pw_name */
resultbuf->pw_name = p;
- p += pw_resp->pw_name_len;
+ p += pw_resp.pw_name_len;
/* get pw_passwd */
resultbuf->pw_passwd = p;
- p += pw_resp->pw_passwd_len;
+ p += pw_resp.pw_passwd_len;
/* get pw_gecos */
resultbuf->pw_gecos = p;
- p += pw_resp->pw_gecos_len;
+ p += pw_resp.pw_gecos_len;
/* get pw_dir */
resultbuf->pw_dir = p;
- p += pw_resp->pw_dir_len;
+ p += pw_resp.pw_dir_len;
/* get pw_pshell */
resultbuf->pw_shell = p;
- p += pw_resp->pw_shell_len;
+ p += pw_resp.pw_shell_len;
ssize_t total = p - buffer;
if (__builtin_expect (pw_name + total > recend, 0))
@@ -189,14 +195,14 @@ nscd_getpw_r (const char *key, size_t keylen, request_type type,
memcpy (resultbuf->pw_name, pw_name, total);
/* Try to detect corrupt databases. */
- if (resultbuf->pw_name[pw_resp->pw_name_len - 1] != '\0'
- || resultbuf->pw_passwd[pw_resp->pw_passwd_len - 1] != '\0'
- || resultbuf->pw_gecos[pw_resp->pw_gecos_len - 1] != '\0'
- || resultbuf->pw_dir[pw_resp->pw_dir_len - 1] != '\0'
- || resultbuf->pw_shell[pw_resp->pw_shell_len - 1] != '\0')
+ if (resultbuf->pw_name[pw_resp.pw_name_len - 1] != '\0'
+ || resultbuf->pw_passwd[pw_resp.pw_passwd_len - 1] != '\0'
+ || resultbuf->pw_gecos[pw_resp.pw_gecos_len - 1] != '\0'
+ || resultbuf->pw_dir[pw_resp.pw_dir_len - 1] != '\0'
+ || resultbuf->pw_shell[pw_resp.pw_shell_len - 1] != '\0')
{
/* We cannot use the database. */
- retval = -1;
+ retval = mapped->head->gc_cycle != gc_cycle ? -2 : -1;
goto out_close;
}
@@ -215,19 +221,21 @@ nscd_getpw_r (const char *key, size_t keylen, request_type type,
if (sock != -1)
close_not_cancel_no_status (sock);
out:
- if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0 && retval != -1)
+ if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0)
{
/* When we come here this means there has been a GC cycle while we
were looking for the data. This means the data might have been
inconsistent. Retry if possible. */
- if ((gc_cycle & 1) != 0)
+ if ((gc_cycle & 1) != 0 || ++nretries == 5 || retval == -1)
{
/* nscd is just running gc now. Disable using the mapping. */
- __nscd_unmap (mapped);
+ if (atomic_decrement_val (&mapped->counter) == 0)
+ __nscd_unmap (mapped);
mapped = NO_MAPPING;
}
- goto retry;
+ if (retval != -1)
+ goto retry;
}
return retval;