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Diffstat (limited to 'nscd/nscd_getgr_r.c')
-rw-r--r--nscd/nscd_getgr_r.c154
1 files changed, 114 insertions, 40 deletions
diff --git a/nscd/nscd_getgr_r.c b/nscd/nscd_getgr_r.c
index b9cde73044..3a66bb849b 100644
--- a/nscd/nscd_getgr_r.c
+++ b/nscd/nscd_getgr_r.c
@@ -18,6 +18,7 @@
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
+#include <assert.h>
#include <errno.h>
#include <grp.h>
#include <stdint.h>
@@ -25,6 +26,7 @@
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/un.h>
@@ -64,36 +66,82 @@ __nscd_getgrgid_r (gid_t gid, struct group *resultbuf, char *buffer,
}
+libc_locked_map_ptr (map_handle);
+/* Note that we only free the structure if necessary. The memory
+ mapping is not removed since it is not visible to the malloc
+ handling. */
+libc_freeres_fn (gr_map_free)
+{
+
+ if (map_handle.mapped != NO_MAPPING)
+ free (map_handle.mapped);
+}
+
+
static int
internal_function
nscd_getgr_r (const char *key, size_t keylen, request_type type,
struct group *resultbuf, char *buffer, size_t buflen,
struct group **result)
{
- gr_response_header gr_resp;
- int sock = __nscd_open_socket (key, keylen, type, &gr_resp,
- sizeof (gr_resp));
- if (sock == -1)
+ const gr_response_header *gr_resp = NULL;
+ const uint32_t *len = NULL;
+ const char *gr_name = NULL;
+ size_t gr_name_len = 0;
+ int retval = -1;
+ int gc_cycle;
+ const char *recend = (const char *) ~UINTMAX_C (0);
+
+ /* If the mapping is available, try to search there instead of
+ communicating with the nscd. */
+ struct mapped_database *mapped = __nscd_get_map_ref (GETFDGR, "group",
+ &map_handle, &gc_cycle);
+ retry:
+ if (mapped != NO_MAPPING)
{
- __nss_not_use_nscd_group = 1;
- return -1;
+ const struct datahead *found = __nscd_cache_search (type, key, keylen,
+ mapped);
+ if (found != NULL)
+ {
+ gr_resp = &found->data[0].grdata;
+ len = (const uint32_t *) (gr_resp + 1);
+ /* The alignment is always sufficient. */
+ assert (((uintptr_t) len & (__alignof__ (*len) - 1)) == 0);
+ gr_name = ((const char *) len
+ + gr_resp->gr_mem_cnt * sizeof (uint32_t));
+ gr_name_len = gr_resp->gr_name_len + gr_resp->gr_passwd_len;
+ recend = (const char *) found->data + found->recsize;
+ }
+ }
+
+ gr_response_header gr_resp_mem;
+ int sock = -1;
+ if (gr_resp == NULL)
+ {
+ sock = __nscd_open_socket (key, keylen, type, &gr_resp_mem,
+ sizeof (gr_resp_mem));
+ if (sock == -1)
+ {
+ __nss_not_use_nscd_group = 1;
+ goto out;
+ }
+
+ gr_resp = &gr_resp_mem;
}
/* No value found so far. */
- int retval = -1;
*result = NULL;
- if (gr_resp.found == -1)
+ if (__builtin_expect (gr_resp->found == -1, 0))
{
/* The daemon does not cache this database. */
__nss_not_use_nscd_group = 1;
- goto out;
+ goto out_close;
}
- if (gr_resp.found == 1)
+ if (gr_resp->found == 1)
{
struct iovec vec[2];
- uint32_t *len;
char *p = buffer;
size_t total_len;
uintptr_t align;
@@ -103,71 +151,90 @@ nscd_getgr_r (const char *key, size_t keylen, request_type type,
align the pointer. */
align = ((__alignof__ (char *) - (p - ((char *) 0)))
& (__alignof__ (char *) - 1));
- total_len = align + (1 + gr_resp.gr_mem_cnt) * sizeof (char *)
- + gr_resp.gr_name_len + gr_resp.gr_passwd_len;
+ total_len = (align + (1 + gr_resp->gr_mem_cnt) * sizeof (char *)
+ + gr_resp->gr_name_len + gr_resp->gr_passwd_len);
if (__builtin_expect (buflen < total_len, 0))
{
no_room:
__set_errno (ERANGE);
retval = ERANGE;
- goto out;
+ goto out_close;
}
buflen -= total_len;
p += align;
resultbuf->gr_mem = (char **) p;
- p += (1 + gr_resp.gr_mem_cnt) * sizeof (char *);
+ p += (1 + gr_resp->gr_mem_cnt) * sizeof (char *);
/* Set pointers for strings. */
resultbuf->gr_name = p;
- p += gr_resp.gr_name_len;
+ p += gr_resp->gr_name_len;
resultbuf->gr_passwd = p;
- p += gr_resp.gr_passwd_len;
+ p += gr_resp->gr_passwd_len;
/* Fill in what we know now. */
- resultbuf->gr_gid = gr_resp.gr_gid;
+ resultbuf->gr_gid = gr_resp->gr_gid;
- /* Allocate array to store lengths. */
- len = (uint32_t *) alloca (gr_resp.gr_mem_cnt * sizeof (uint32_t));
+ /* Read the length information, group name, and password. */
+ if (len == NULL)
+ {
+ /* Allocate array to store lengths. */
+ len = (uint32_t *) alloca (gr_resp->gr_mem_cnt * sizeof (uint32_t));
- total_len = gr_resp.gr_mem_cnt * sizeof (uint32_t);
- vec[0].iov_base = len;
- vec[0].iov_len = total_len;
- vec[1].iov_base = resultbuf->gr_name;
- vec[1].iov_len = gr_resp.gr_name_len + gr_resp.gr_passwd_len;
- total_len += gr_resp.gr_name_len + gr_resp.gr_passwd_len;
+ vec[0].iov_base = (void *) len;
+ vec[0].iov_len = gr_resp->gr_mem_cnt * sizeof (uint32_t);
+ vec[1].iov_base = resultbuf->gr_name;
+ vec[1].iov_len = gr_resp->gr_name_len + gr_resp->gr_passwd_len;
+ total_len = vec[0].iov_len + vec[1].iov_len;
- /* Get this data. */
- size_t n = TEMP_FAILURE_RETRY (__readv (sock, vec, 2));
- if (__builtin_expect (n != total_len, 0))
- goto out;
+ /* Get this data. */
+ size_t n = TEMP_FAILURE_RETRY (__readv (sock, vec, 2));
+ if (__builtin_expect (n != total_len, 0))
+ goto out_close;
+ }
+ else
+ /* We already have the data. Just copy the group name and
+ password. */
+ memcpy (resultbuf->gr_name, gr_name, gr_name_len);
/* Clear the terminating entry. */
- resultbuf->gr_mem[gr_resp.gr_mem_cnt] = NULL;
+ resultbuf->gr_mem[gr_resp->gr_mem_cnt] = NULL;
/* Prepare reading the group members. */
total_len = 0;
- for (cnt = 0; cnt < gr_resp.gr_mem_cnt; ++cnt)
+ for (cnt = 0; cnt < gr_resp->gr_mem_cnt; ++cnt)
{
resultbuf->gr_mem[cnt] = p;
total_len += len[cnt];
p += len[cnt];
}
+ if (__builtin_expect (gr_name + gr_name_len + total_len > recend, 0))
+ goto out_close;
if (__builtin_expect (total_len > buflen, 0))
goto no_room;
retval = 0;
- n = TEMP_FAILURE_RETRY (__read (sock, resultbuf->gr_mem[0],
- total_len));
- if (__builtin_expect (n != total_len, 0))
+ if (gr_name == NULL)
{
- /* The `errno' to some value != ERANGE. */
- __set_errno (ENOENT);
- retval = ENOENT;
+ size_t n = TEMP_FAILURE_RETRY (__read (sock, resultbuf->gr_mem[0],
+ total_len));
+ if (__builtin_expect (n != total_len, 0))
+ {
+ /* The `errno' to some value != ERANGE. */
+ __set_errno (ENOENT);
+ retval = ENOENT;
+ }
+ else
+ *result = resultbuf;
}
else
- *result = resultbuf;
+ {
+ /* Copy the group member names. */
+ memcpy (resultbuf->gr_mem[0], gr_name + gr_name_len, total_len);
+
+ *result = resultbuf;
+ }
}
else
{
@@ -177,8 +244,15 @@ nscd_getgr_r (const char *key, size_t keylen, request_type type,
retval = 0;
}
+ out_close:
+ if (sock != -1)
+ close_not_cancel_no_status (sock);
out:
- close_not_cancel_no_status (sock);
+ 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. */
+ goto retry;
return retval;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-23 16:53:35 +0000