27822ce67f
This patch defines _STRING_ARCH_unaligned to 0 on default bits/string.h header to avoid undefined compiler warnings on platforms that do not define it. It also make adjustments in code where tests checked if macro existed or not.
389 lines
11 KiB
C
389 lines
11 KiB
C
/* Copyright (C) 2007-2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2007.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <assert.h>
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#include <errno.h>
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#include <string.h>
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#include <not-cancel.h>
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#include <_itoa.h>
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#include <stdint.h>
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#include "nscd-client.h"
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#include "nscd_proto.h"
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int __nss_not_use_nscd_services;
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static int nscd_getserv_r (const char *crit, size_t critlen, const char *proto,
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request_type type, struct servent *resultbuf,
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char *buf, size_t buflen, struct servent **result);
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int
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__nscd_getservbyname_r (const char *name, const char *proto,
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struct servent *result_buf, char *buf, size_t buflen,
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struct servent **result)
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{
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return nscd_getserv_r (name, strlen (name), proto, GETSERVBYNAME, result_buf,
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buf, buflen, result);
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}
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int
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__nscd_getservbyport_r (int port, const char *proto,
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struct servent *result_buf, char *buf, size_t buflen,
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struct servent **result)
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{
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char portstr[3 * sizeof (int) + 2];
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portstr[sizeof (portstr) - 1] = '\0';
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char *cp = _itoa_word (port, portstr + sizeof (portstr) - 1, 10, 0);
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return nscd_getserv_r (cp, portstr + sizeof (portstr) - 1 - cp, proto,
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GETSERVBYPORT, result_buf, buf, buflen, result);
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}
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libc_locked_map_ptr (, __serv_map_handle) attribute_hidden;
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/* Note that we only free the structure if necessary. The memory
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mapping is not removed since it is not visible to the malloc
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handling. */
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libc_freeres_fn (serv_map_free)
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{
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if (__serv_map_handle.mapped != NO_MAPPING)
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{
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void *p = __serv_map_handle.mapped;
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__serv_map_handle.mapped = NO_MAPPING;
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free (p);
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}
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}
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static int
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nscd_getserv_r (const char *crit, size_t critlen, const char *proto,
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request_type type, struct servent *resultbuf,
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char *buf, size_t buflen, struct servent **result)
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{
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int gc_cycle;
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int nretries = 0;
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size_t alloca_used = 0;
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/* If the mapping is available, try to search there instead of
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communicating with the nscd. */
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struct mapped_database *mapped;
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mapped = __nscd_get_map_ref (GETFDSERV, "services", &__serv_map_handle,
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&gc_cycle);
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size_t protolen = proto == NULL ? 0 : strlen (proto);
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size_t keylen = critlen + 1 + protolen + 1;
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int alloca_key = __libc_use_alloca (keylen);
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char *key;
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if (alloca_key)
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key = alloca_account (keylen, alloca_used);
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else
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{
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key = malloc (keylen);
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if (key == NULL)
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return -1;
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}
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memcpy (__mempcpy (__mempcpy (key, crit, critlen),
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"/", 1), proto ?: "", protolen + 1);
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retry:;
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const char *s_name = NULL;
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const char *s_proto = NULL;
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int alloca_aliases_len = 0;
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const uint32_t *aliases_len = NULL;
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const char *aliases_list = NULL;
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int retval = -1;
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const char *recend = (const char *) ~UINTMAX_C (0);
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int sock = -1;
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serv_response_header serv_resp;
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if (mapped != NO_MAPPING)
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{
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struct datahead *found = __nscd_cache_search (type, key, keylen, mapped,
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sizeof serv_resp);
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if (found != NULL)
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{
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s_name = (char *) (&found->data[0].servdata + 1);
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serv_resp = found->data[0].servdata;
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s_proto = s_name + serv_resp.s_name_len;
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alloca_aliases_len = 1;
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aliases_len = (uint32_t *) (s_proto + serv_resp.s_proto_len);
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aliases_list = ((char *) aliases_len
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+ serv_resp.s_aliases_cnt * sizeof (uint32_t));
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recend = (const char *) found->data + found->recsize;
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/* Now check if we can trust serv_resp fields. If GC is
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in progress, it can contain anything. */
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if (mapped->head->gc_cycle != gc_cycle)
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{
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retval = -2;
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goto out;
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}
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if (__builtin_expect ((const char *) aliases_len
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+ serv_resp.s_aliases_cnt * sizeof (uint32_t)
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> recend, 0))
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goto out;
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#if !_STRING_ARCH_unaligned
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/* The aliases_len array in the mapped database might very
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well be unaligned. We will access it word-wise so on
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platforms which do not tolerate unaligned accesses we
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need to make an aligned copy. */
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if (((uintptr_t) aliases_len & (__alignof__ (*aliases_len) - 1))
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!= 0)
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{
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uint32_t *tmp;
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alloca_aliases_len
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= __libc_use_alloca (alloca_used
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+ (serv_resp.s_aliases_cnt
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* sizeof (uint32_t)));
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if (alloca_aliases_len)
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tmp = alloca_account (serv_resp.s_aliases_cnt
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* sizeof (uint32_t),
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alloca_used);
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else
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{
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tmp = malloc (serv_resp.s_aliases_cnt * sizeof (uint32_t));
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if (tmp == NULL)
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{
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retval = ENOMEM;
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goto out;
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}
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}
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aliases_len = memcpy (tmp, aliases_len,
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serv_resp.s_aliases_cnt
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* sizeof (uint32_t));
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}
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#endif
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}
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}
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if (s_name == NULL)
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{
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sock = __nscd_open_socket (key, keylen, type, &serv_resp,
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sizeof (serv_resp));
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if (sock == -1)
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{
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__nss_not_use_nscd_services = 1;
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goto out;
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}
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}
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/* No value found so far. */
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*result = NULL;
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if (__glibc_unlikely (serv_resp.found == -1))
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{
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/* The daemon does not cache this database. */
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__nss_not_use_nscd_services = 1;
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goto out_close;
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}
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if (serv_resp.found == 1)
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{
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char *cp = buf;
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uintptr_t align1;
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uintptr_t align2;
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size_t total_len;
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ssize_t cnt;
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int n;
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/* A first check whether the buffer is sufficiently large is possible. */
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/* Now allocate the buffer the array for the group members. We must
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align the pointer and the base of the h_addr_list pointers. */
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align1 = ((__alignof__ (char *) - (cp - ((char *) 0)))
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& (__alignof__ (char *) - 1));
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align2 = ((__alignof__ (char *) - ((cp + align1 + serv_resp.s_name_len
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+ serv_resp.s_proto_len)
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- ((char *) 0)))
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& (__alignof__ (char *) - 1));
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if (buflen < (align1 + serv_resp.s_name_len + serv_resp.s_proto_len
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+ align2
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+ (serv_resp.s_aliases_cnt + 1) * sizeof (char *)))
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{
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no_room:
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__set_errno (ERANGE);
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retval = ERANGE;
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goto out_close;
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}
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cp += align1;
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/* Prepare the result as far as we can. */
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resultbuf->s_aliases = (char **) cp;
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cp += (serv_resp.s_aliases_cnt + 1) * sizeof (char *);
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resultbuf->s_name = cp;
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cp += serv_resp.s_name_len;
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resultbuf->s_proto = cp;
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cp += serv_resp.s_proto_len + align2;
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resultbuf->s_port = serv_resp.s_port;
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if (s_name == NULL)
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{
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struct iovec vec[2];
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vec[0].iov_base = resultbuf->s_name;
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vec[0].iov_len = serv_resp.s_name_len + serv_resp.s_proto_len;
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total_len = vec[0].iov_len;
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n = 1;
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if (serv_resp.s_aliases_cnt > 0)
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{
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assert (alloca_aliases_len == 0);
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alloca_aliases_len
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= __libc_use_alloca (alloca_used
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+ (serv_resp.s_aliases_cnt
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* sizeof (uint32_t)));
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if (alloca_aliases_len)
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aliases_len = alloca_account (serv_resp.s_aliases_cnt
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* sizeof (uint32_t),
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alloca_used);
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else
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{
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aliases_len = malloc (serv_resp.s_aliases_cnt
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* sizeof (uint32_t));
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if (aliases_len == NULL)
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{
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retval = ENOMEM;
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goto out_close;
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}
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}
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vec[n].iov_base = (void *) aliases_len;
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vec[n].iov_len = serv_resp.s_aliases_cnt * sizeof (uint32_t);
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total_len += serv_resp.s_aliases_cnt * sizeof (uint32_t);
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++n;
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}
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if ((size_t) __readvall (sock, vec, n) != total_len)
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goto out_close;
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}
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else
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memcpy (resultbuf->s_name, s_name,
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serv_resp.s_name_len + serv_resp.s_proto_len);
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/* Now we also can read the aliases. */
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total_len = 0;
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for (cnt = 0; cnt < serv_resp.s_aliases_cnt; ++cnt)
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{
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resultbuf->s_aliases[cnt] = cp;
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cp += aliases_len[cnt];
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total_len += aliases_len[cnt];
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}
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resultbuf->s_aliases[cnt] = NULL;
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if (__builtin_expect ((const char *) aliases_list + total_len > recend,
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0))
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{
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/* aliases_len array might contain garbage during nscd GC cycle,
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retry rather than fail in that case. */
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if (aliases_list != NULL && mapped->head->gc_cycle != gc_cycle)
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retval = -2;
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goto out_close;
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}
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/* See whether this would exceed the buffer capacity. */
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if (__glibc_unlikely (cp > buf + buflen))
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{
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/* aliases_len array might contain garbage during nscd GC cycle,
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retry rather than fail in that case. */
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if (aliases_list != NULL && mapped->head->gc_cycle != gc_cycle)
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{
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retval = -2;
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goto out_close;
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}
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goto no_room;
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}
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/* And finally read the aliases. */
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if (aliases_list == NULL)
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{
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if (total_len == 0
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|| ((size_t) __readall (sock, resultbuf->s_aliases[0], total_len)
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== total_len))
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{
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retval = 0;
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*result = resultbuf;
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}
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}
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else
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{
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memcpy (resultbuf->s_aliases[0], aliases_list, total_len);
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/* Try to detect corrupt databases. */
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if (resultbuf->s_name[serv_resp.s_name_len - 1] != '\0'
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|| resultbuf->s_proto[serv_resp.s_proto_len - 1] != '\0'
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|| ({for (cnt = 0; cnt < serv_resp.s_aliases_cnt; ++cnt)
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if (resultbuf->s_aliases[cnt][aliases_len[cnt] - 1]
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!= '\0')
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break;
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cnt < serv_resp.s_aliases_cnt; }))
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{
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/* We cannot use the database. */
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if (mapped->head->gc_cycle != gc_cycle)
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retval = -2;
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goto out_close;
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}
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retval = 0;
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*result = resultbuf;
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}
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}
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else
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{
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/* Set errno to 0 to indicate no error, just no found record. */
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__set_errno (0);
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/* Even though we have not found anything, the result is zero. */
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retval = 0;
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}
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out_close:
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if (sock != -1)
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close_not_cancel_no_status (sock);
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out:
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if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0)
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{
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/* When we come here this means there has been a GC cycle while we
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were looking for the data. This means the data might have been
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inconsistent. Retry if possible. */
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if ((gc_cycle & 1) != 0 || ++nretries == 5 || retval == -1)
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{
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/* nscd is just running gc now. Disable using the mapping. */
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if (atomic_decrement_val (&mapped->counter) == 0)
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__nscd_unmap (mapped);
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mapped = NO_MAPPING;
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}
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if (retval != -1)
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{
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if (!alloca_aliases_len)
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free ((void *) aliases_len);
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goto retry;
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}
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}
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if (!alloca_aliases_len)
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free ((void *) aliases_len);
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if (!alloca_key)
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free (key);
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return retval;
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}
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