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-rw-r--r--nscd/nscd_helper.c253
1 files changed, 64 insertions, 189 deletions
diff --git a/nscd/nscd_helper.c b/nscd/nscd_helper.c
index 71ea53e19d..0e16cb8aeb 100644
--- a/nscd/nscd_helper.c
+++ b/nscd/nscd_helper.c
@@ -1,5 +1,4 @@
-/* Copyright (C) 1998-2002,2003,2004,2005,2006,2007
- Free Software Foundation, Inc.
+/* Copyright (C) 1998-2002, 2003, 2004 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
@@ -22,14 +21,11 @@
#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
-#include <string.h>
-#include <time.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/poll.h>
#include <sys/socket.h>
#include <sys/stat.h>
-#include <sys/time.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <not-cancel.h>
@@ -38,64 +34,6 @@
#include "nscd-client.h"
-ssize_t
-__readall (int fd, void *buf, size_t len)
-{
- size_t n = len;
- ssize_t ret;
- do
- {
- ret = TEMP_FAILURE_RETRY (__read (fd, buf, n));
- if (ret <= 0)
- break;
- buf = (char *) buf + ret;
- n -= ret;
- }
- while (n > 0);
- return ret < 0 ? ret : len - n;
-}
-
-
-ssize_t
-__readvall (int fd, const struct iovec *iov, int iovcnt)
-{
- ssize_t ret = TEMP_FAILURE_RETRY (__readv (fd, iov, iovcnt));
- if (ret <= 0)
- return ret;
-
- size_t total = 0;
- for (int i = 0; i < iovcnt; ++i)
- total += iov[i].iov_len;
-
- if (ret < total)
- {
- struct iovec iov_buf[iovcnt];
- ssize_t r = ret;
-
- struct iovec *iovp = memcpy (iov_buf, iov, iovcnt * sizeof (*iov));
- do
- {
- while (iovp->iov_len <= r)
- {
- r -= iovp->iov_len;
- --iovcnt;
- ++iovp;
- }
- iovp->iov_base = (char *) iovp->iov_base + r;
- iovp->iov_len -= r;
- r = TEMP_FAILURE_RETRY (__readv (fd, iovp, iovcnt));
- if (r <= 0)
- break;
- ret += r;
- }
- while (ret < total);
- if (r < 0)
- ret = r;
- }
- return ret;
-}
-
-
static int
open_socket (void)
{
@@ -139,36 +77,6 @@ __nscd_unmap (struct mapped_database *mapped)
}
-static int
-wait_on_socket (int sock)
-{
- struct pollfd fds[1];
- fds[0].fd = sock;
- fds[0].events = POLLIN | POLLERR | POLLHUP;
- int n = __poll (fds, 1, 5 * 1000);
- if (n == -1 && __builtin_expect (errno == EINTR, 0))
- {
- /* Handle the case where the poll() call is interrupted by a
- signal. We cannot just use TEMP_FAILURE_RETRY since it might
- lead to infinite loops. */
- struct timeval now;
- (void) __gettimeofday (&now, NULL);
- long int end = (now.tv_sec + 5) * 1000 + (now.tv_usec + 500) / 1000;
- while (1)
- {
- long int timeout = end - (now.tv_sec * 1000
- + (now.tv_usec + 500) / 1000);
- n = __poll (fds, 1, timeout);
- if (n != -1 || errno != EINTR)
- break;
- (void) __gettimeofday (&now, NULL);
- }
- }
-
- return n;
-}
-
-
/* Try to get a file descriptor for the shared meory segment
containing the database. */
static struct mapped_database *
@@ -178,115 +86,102 @@ get_mapping (request_type type, const char *key,
struct mapped_database *result = NO_MAPPING;
#ifdef SCM_RIGHTS
const size_t keylen = strlen (key) + 1;
+ char resdata[keylen];
int saved_errno = errno;
int mapfd = -1;
/* Send the request. */
- struct
- {
- request_header req;
- char key[keylen];
- } reqdata;
- size_t real_sizeof_reqdata = sizeof (request_header) + keylen;
+ struct iovec iov[2];
+ request_header req;
int sock = open_socket ();
if (sock < 0)
goto out;
- reqdata.req.version = NSCD_VERSION;
- reqdata.req.type = type;
- reqdata.req.key_len = keylen;
- memcpy (reqdata.key, key, keylen);
-
-# ifndef MSG_NOSIGNAL
-# define MSG_NOSIGNAL 0
-# endif
- if (__builtin_expect (TEMP_FAILURE_RETRY (__send (sock, &reqdata,
- real_sizeof_reqdata,
- MSG_NOSIGNAL))
- != real_sizeof_reqdata, 0))
+ req.version = NSCD_VERSION;
+ req.type = type;
+ req.key_len = keylen;
+
+ iov[0].iov_base = &req;
+ iov[0].iov_len = sizeof (req);
+ iov[1].iov_base = (void *) key;
+ iov[1].iov_len = keylen;
+
+ if (TEMP_FAILURE_RETRY (__writev (sock, iov, 2))
+ != iov[0].iov_len + iov[1].iov_len)
/* We cannot even write the request. */
goto out_close2;
/* Room for the data sent along with the file descriptor. We expect
the key name back. */
-# define resdata reqdata.key
- struct iovec iov[1];
iov[0].iov_base = resdata;
iov[0].iov_len = keylen;
- union
- {
- struct cmsghdr hdr;
- char bytes[CMSG_SPACE (sizeof (int))];
- } buf;
+ char buf[CMSG_SPACE (sizeof (int))];
struct msghdr msg = { .msg_iov = iov, .msg_iovlen = 1,
- .msg_control = buf.bytes,
- .msg_controllen = sizeof (buf) };
+ .msg_control = buf, .msg_controllen = sizeof (buf) };
struct cmsghdr *cmsg = CMSG_FIRSTHDR (&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN (sizeof (int));
- /* This access is well-aligned since BUF is correctly aligned for an
- int and CMSG_DATA preserves this alignment. */
*(int *) CMSG_DATA (cmsg) = -1;
msg.msg_controllen = cmsg->cmsg_len;
- if (wait_on_socket (sock) <= 0)
- goto out_close2;
-
- if (__builtin_expect (TEMP_FAILURE_RETRY (__recvmsg (sock, &msg, 0))
- != keylen, 0))
+ struct pollfd fds[1];
+ fds[0].fd = sock;
+ fds[0].events = POLLIN | POLLERR | POLLHUP;
+ if (__poll (fds, 1, 5 * 1000) <= 0)
+ /* Failure or timeout. */
goto out_close2;
- if (__builtin_expect (CMSG_FIRSTHDR (&msg) == NULL
- || (CMSG_FIRSTHDR (&msg)->cmsg_len
- != CMSG_LEN (sizeof (int))), 0))
+ if (TEMP_FAILURE_RETRY (__recvmsg (sock, &msg, 0)) != keylen)
goto out_close2;
mapfd = *(int *) CMSG_DATA (cmsg);
+ if (CMSG_FIRSTHDR (&msg)->cmsg_len != CMSG_LEN (sizeof (int)))
+ goto out_close;
+
struct stat64 st;
- if (__builtin_expect (strcmp (resdata, key) != 0, 0)
- || __builtin_expect (fstat64 (mapfd, &st) != 0, 0)
- || __builtin_expect (st.st_size < sizeof (struct database_pers_head), 0))
+ if (strcmp (resdata, key) != 0
+ || fstat64 (mapfd, &st) != 0
+ || st.st_size < sizeof (struct database_pers_head))
goto out_close;
struct database_pers_head head;
- if (__builtin_expect (TEMP_FAILURE_RETRY (__pread (mapfd, &head,
- sizeof (head), 0))
- != sizeof (head), 0))
+ if (TEMP_FAILURE_RETRY (__pread (mapfd, &head, sizeof (head), 0))
+ != sizeof (head))
goto out_close;
- if (__builtin_expect (head.version != DB_VERSION, 0)
- || __builtin_expect (head.header_size != sizeof (head), 0)
+ if (head.version != DB_VERSION || head.header_size != sizeof (head)
/* This really should not happen but who knows, maybe the update
thread got stuck. */
- || __builtin_expect (! head.nscd_certainly_running
- && head.timestamp + MAPPING_TIMEOUT < time (NULL),
- 0))
+ || (! head.nscd_certainly_running
+ && head.timestamp + MAPPING_TIMEOUT < time (NULL)))
goto out_close;
size_t size = (sizeof (head) + roundup (head.module * sizeof (ref_t), ALIGN)
+ head.data_size);
- if (__builtin_expect (st.st_size < size, 0))
+ if (st.st_size < size)
goto out_close;
/* The file is large enough, map it now. */
void *mapping = __mmap (NULL, size, PROT_READ, MAP_SHARED, mapfd, 0);
- if (__builtin_expect (mapping != MAP_FAILED, 1))
+ if (mapping != MAP_FAILED)
{
/* Allocate a record for the mapping. */
- struct mapped_database *newp = malloc (sizeof (*newp));
+ struct mapped_database *newp;
+
+ newp = malloc (sizeof (*newp));
if (newp == NULL)
{
/* Ugh, after all we went through the memory allocation failed. */
- __munmap (mapping, size);
+ __munmap (result, size);
goto out_close;
}
@@ -294,7 +189,6 @@ get_mapping (request_type type, const char *key,
newp->data = ((char *) mapping + head.header_size
+ roundup (head.module * sizeof (ref_t), ALIGN));
newp->mapsize = size;
- newp->datasize = head.data_size;
/* Set counter to 1 to show it is usable. */
newp->counter = 1;
@@ -321,18 +215,17 @@ get_mapping (request_type type, const char *key,
struct mapped_database *
__nscd_get_map_ref (request_type type, const char *name,
- volatile struct locked_map_ptr *mapptr, int *gc_cyclep)
+ struct locked_map_ptr *mapptr, int *gc_cyclep)
{
struct mapped_database *cur = mapptr->mapped;
if (cur == NO_MAPPING)
return cur;
int cnt = 0;
- while (__builtin_expect (atomic_compare_and_exchange_val_acq (&mapptr->lock,
- 1, 0) != 0, 0))
+ while (atomic_compare_and_exchange_val_acq (&mapptr->lock, 1, 0) != 0)
{
// XXX Best number of rounds?
- if (__builtin_expect (++cnt > 5, 0))
+ if (++cnt > 5)
return NO_MAPPING;
atomic_delay ();
@@ -345,10 +238,8 @@ __nscd_get_map_ref (request_type type, const char *name,
/* If not mapped or timestamp not updated, request new map. */
if (cur == NULL
|| (cur->head->nscd_certainly_running == 0
- && cur->head->timestamp + MAPPING_TIMEOUT < time (NULL))
- || cur->head->data_size > cur->datasize)
- cur = get_mapping (type, name,
- (struct mapped_database **) &mapptr->mapped);
+ && cur->head->timestamp + MAPPING_TIMEOUT < time (NULL)))
+ cur = get_mapping (type, name, &mapptr->mapped);
if (__builtin_expect (cur != NO_MAPPING, 1))
{
@@ -366,50 +257,28 @@ __nscd_get_map_ref (request_type type, const char *name,
}
-/* Don't return const struct datahead *, as eventhough the record
- is normally constant, it can change arbitrarily during nscd
- garbage collection. */
-struct datahead *
+const struct datahead *
__nscd_cache_search (request_type type, const char *key, size_t keylen,
const struct mapped_database *mapped)
{
unsigned long int hash = __nis_hash (key, keylen) % mapped->head->module;
- size_t datasize = mapped->datasize;
ref_t work = mapped->head->array[hash];
- while (work != ENDREF && work + sizeof (struct hashentry) <= datasize)
+ while (work != ENDREF)
{
struct hashentry *here = (struct hashentry *) (mapped->data + work);
-#ifndef _STRING_ARCH_unaligned
- /* Although during garbage collection when moving struct hashentry
- records around we first copy from old to new location and then
- adjust pointer from previous hashentry to it, there is no barrier
- between those memory writes. It is very unlikely to hit it,
- so check alignment only if a misaligned load can crash the
- application. */
- if ((uintptr_t) here & (__alignof__ (*here) - 1))
- return NULL;
-#endif
-
- if (type == here->type
- && keylen == here->len
- && here->key + keylen <= datasize
- && memcmp (key, mapped->data + here->key, keylen) == 0
- && here->packet + sizeof (struct datahead) <= datasize)
+ if (type == here->type && keylen == here->len
+ && memcmp (key, mapped->data + here->key, keylen) == 0)
{
/* We found the entry. Increment the appropriate counter. */
- struct datahead *dh
+ const struct datahead *dh
= (struct datahead *) (mapped->data + here->packet);
-#ifndef _STRING_ARCH_unaligned
- if ((uintptr_t) dh & (__alignof__ (*dh) - 1))
- return NULL;
-#endif
-
/* See whether we must ignore the entry or whether something
is wrong because garbage collection is in progress. */
- if (dh->usable && here->packet + dh->allocsize <= datasize)
+ if (dh->usable && ((char *) dh + dh->allocsize
+ <= (char *) mapped->head + mapped->mapsize))
return dh;
}
@@ -442,13 +311,19 @@ __nscd_open_socket (const char *key, size_t keylen, request_type type,
vec[1].iov_len = keylen;
ssize_t nbytes = TEMP_FAILURE_RETRY (__writev (sock, vec, 2));
- if (nbytes == (ssize_t) (sizeof (request_header) + keylen)
- /* Wait for data. */
- && wait_on_socket (sock) > 0)
+ if (nbytes == (ssize_t) (sizeof (request_header) + keylen))
{
- nbytes = TEMP_FAILURE_RETRY (__read (sock, response, responselen));
- if (nbytes == (ssize_t) responselen)
- return sock;
+ /* Wait for data. */
+ struct pollfd fds[1];
+ fds[0].fd = sock;
+ fds[0].events = POLLIN | POLLERR | POLLHUP;
+ if (__poll (fds, 1, 5 * 1000) > 0)
+ {
+ nbytes = TEMP_FAILURE_RETRY (__read (sock, response,
+ responselen));
+ if (nbytes == (ssize_t) responselen)
+ return sock;
+ }
}
close_not_cancel_no_status (sock);
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-08 20:24:09 +0000