diff options
Diffstat (limited to 'nscd/nscd_getai.c')
| -rw-r--r-- | nscd/nscd_getai.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/nscd/nscd_getai.c b/nscd/nscd_getai.c new file mode 100644 index 0000000000..453f459425 --- /dev/null +++ b/nscd/nscd_getai.c @@ -0,0 +1,164 @@ +/* Copyright (C) 2004 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@redhat.com>, 2004. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <assert.h> +#include <errno.h> +#include <netdb.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/mman.h> +#include <not-cancel.h> + +#include "nscd-client.h" + + +/* Define in nscd_gethst_r.c. */ +extern int __nss_not_use_nscd_hosts; + + +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); +} + + +int +__nscd_getai (const char *key, struct nscd_ai_result **result, int *h_errnop) +{ + size_t keylen = strlen (key) + 1; + const ai_response_header *ai_resp = NULL; + struct nscd_ai_result *resultbuf = NULL; + const char *recend = (const char *) ~UINTMAX_C (0); + char *respdata = NULL; + int retval = -1; + int sock = -1; + int gc_cycle; + + /* If the mapping is available, try to search there instead of + communicating with the nscd. */ + struct mapped_database *mapped = __nscd_get_map_ref (GETFDHST, "hosts", + &map_handle, &gc_cycle); + retry: + if (mapped != MAP_FAILED) + { + const struct datahead *found = __nscd_cache_search (GETAI, key, keylen, + mapped); + if (found != NULL) + { + ai_resp = &found->data[0].aidata; + respdata = (char *) (ai_resp + 1); + recend = (const char *) found->data + found->recsize; + } + } + + /* If we do not have the cache mapped, try to get the data over the + socket. */ + ai_response_header ai_resp_mem; + if (ai_resp == NULL) + { + sock = __nscd_open_socket (key, keylen, GETAI, &ai_resp_mem, + sizeof (ai_resp_mem)); + if (sock == -1) + { + /* nscd not running or wrong version or hosts caching disabled. */ + __nss_not_use_nscd_hosts = 1; + goto out;; + } + + ai_resp = &ai_resp_mem; + } + + if (ai_resp->found == 1) + { + size_t datalen = ai_resp->naddrs + ai_resp->addrslen + ai_resp->canonlen; + + /* This check is really only affects the case where the data + comes from the mapped cache. */ + if ((char *) (ai_resp + 1) + datalen > recend) + { + assert (sock == -1); + goto out; + } + + /* Create result. */ + resultbuf = (struct nscd_ai_result *) malloc (sizeof (*resultbuf) + + datalen); + if (resultbuf == NULL) + { + *h_errnop = NETDB_INTERNAL; + return -1; + } + + /* Set up the data structure, including pointers. */ + resultbuf->naddrs = ai_resp->naddrs; + resultbuf->addrs = (char *) (resultbuf + 1); + resultbuf->family = (uint8_t *) (resultbuf->addrs + ai_resp->addrslen); + if (ai_resp->canonlen != 0) + resultbuf->canon = (char *) (resultbuf->family + resultbuf->naddrs); + else + resultbuf->canon = NULL; + + if (respdata == NULL) + { + /* Read the data from the socket. */ + if ((size_t) TEMP_FAILURE_RETRY (__read (sock, resultbuf + 1, + datalen)) == datalen) + { + retval = 0; + *result = resultbuf; + } + } + else + { + /* Copy the data in the block. */ + memcpy (resultbuf + 1, respdata, datalen); + + retval = 0; + *result = resultbuf; + } + } + else + { + /* Store the error number. */ + *h_errnop = ai_resp->error; + + /* The `errno' to some value != ERANGE. */ + __set_errno (ENOENT); + /* Even though we have not found anything, the result is zero. */ + retval = 0; + } + + if (sock != -1) + close_not_cancel_no_status (sock); + out: + 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; +} |