/nscd/nscd_getpw_r.c
C | 241 lines | 171 code | 28 blank | 42 comment | 49 complexity | c3824b6c90bdd3dcb84b1ebca04b1b87 MD5 | raw file
- /* Copyright (C) 1998-2016 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by Thorsten Kukuk <kukuk@uni-paderborn.de>, 1998.
- 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, see
- <http://www.gnu.org/licenses/>. */
- #include <assert.h>
- #include <errno.h>
- #include <pwd.h>
- #include <stdint.h>
- #include <stdio.h>
- #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>
- #include <not-cancel.h>
- #include <_itoa.h>
- #include "nscd-client.h"
- #include "nscd_proto.h"
- int __nss_not_use_nscd_passwd;
- static int nscd_getpw_r (const char *key, size_t keylen, request_type type,
- struct passwd *resultbuf, char *buffer,
- size_t buflen, struct passwd **result)
- internal_function;
- int
- __nscd_getpwnam_r (const char *name, struct passwd *resultbuf, char *buffer,
- size_t buflen, struct passwd **result)
- {
- if (name == NULL)
- return -1;
- return nscd_getpw_r (name, strlen (name) + 1, GETPWBYNAME, resultbuf,
- buffer, buflen, result);
- }
- int
- __nscd_getpwuid_r (uid_t uid, struct passwd *resultbuf, char *buffer,
- size_t buflen, struct passwd **result)
- {
- char buf[3 * sizeof (uid_t)];
- buf[sizeof (buf) - 1] = '\0';
- char *cp = _itoa_word (uid, buf + sizeof (buf) - 1, 10, 0);
- return nscd_getpw_r (cp, buf + sizeof (buf) - cp, GETPWBYUID, resultbuf,
- buffer, buflen, result);
- }
- libc_locked_map_ptr (static, 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 (pw_map_free)
- {
- if (map_handle.mapped != NO_MAPPING)
- {
- void *p = map_handle.mapped;
- map_handle.mapped = NO_MAPPING;
- free (p);
- }
- }
- static int
- internal_function
- nscd_getpw_r (const char *key, size_t keylen, request_type type,
- struct passwd *resultbuf, char *buffer, size_t buflen,
- 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 char *pw_name = NULL;
- int retval = -1;
- const char *recend = (const char *) ~UINTMAX_C (0);
- pw_response_header pw_resp;
- if (mapped != NO_MAPPING)
- {
- struct datahead *found = __nscd_cache_search (type, key, keylen, mapped,
- sizeof pw_resp);
- if (found != NULL)
- {
- 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;
- }
- }
- }
- int sock = -1;
- if (pw_name == NULL)
- {
- sock = __nscd_open_socket (key, keylen, type, &pw_resp,
- sizeof (pw_resp));
- if (sock == -1)
- {
- __nss_not_use_nscd_passwd = 1;
- goto out;
- }
- }
- /* No value found so far. */
- *result = NULL;
- if (__glibc_unlikely (pw_resp.found == -1))
- {
- /* The daemon does not cache this database. */
- __nss_not_use_nscd_passwd = 1;
- goto out_close;
- }
- 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;
- char *p = buffer;
- /* get pw_name */
- resultbuf->pw_name = p;
- p += pw_resp.pw_name_len;
- /* get pw_passwd */
- resultbuf->pw_passwd = p;
- p += pw_resp.pw_passwd_len;
- /* get pw_gecos */
- resultbuf->pw_gecos = p;
- p += pw_resp.pw_gecos_len;
- /* get pw_dir */
- resultbuf->pw_dir = p;
- p += pw_resp.pw_dir_len;
- /* get pw_pshell */
- resultbuf->pw_shell = p;
- p += pw_resp.pw_shell_len;
- ssize_t total = p - buffer;
- if (__glibc_unlikely (pw_name + total > recend))
- goto out_close;
- if (__glibc_unlikely (buflen < total))
- {
- __set_errno (ERANGE);
- retval = ERANGE;
- goto out_close;
- }
- retval = 0;
- if (pw_name == NULL)
- {
- ssize_t nbytes = __readall (sock, buffer, total);
- if (__glibc_unlikely (nbytes != total))
- {
- /* The `errno' to some value != ERANGE. */
- __set_errno (ENOENT);
- retval = ENOENT;
- }
- else
- *result = resultbuf;
- }
- else
- {
- /* Copy the various strings. */
- 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')
- {
- /* We cannot use the database. */
- retval = mapped->head->gc_cycle != gc_cycle ? -2 : -1;
- goto out_close;
- }
- *result = resultbuf;
- }
- }
- else
- {
- /* Set errno to 0 to indicate no error, just no found record. */
- __set_errno (0);
- /* Even though we have not found anything, the result is zero. */
- retval = 0;
- }
- out_close:
- 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 if possible. */
- if ((gc_cycle & 1) != 0 || ++nretries == 5 || retval == -1)
- {
- /* nscd is just running gc now. Disable using the mapping. */
- if (atomic_decrement_val (&mapped->counter) == 0)
- __nscd_unmap (mapped);
- mapped = NO_MAPPING;
- }
- if (retval != -1)
- goto retry;
- }
- return retval;
- }