/**************************************************************************** * libs/libc/grp/lib_getgrbufr.c * * Copyright (C) 2019 Gregory Nutt. All rights reserved. * Author: Michael Jung * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include "grp/lib_grp.h" /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: getgrbuf_r * * Description: * libc/grp internal helper function for getgrgid_r and getgrnam_r to setup * the caller supplied 'grp' and 'buf' buffers once a matching entry has * been found. * * Input Parameters: * gid - Value to set grp->gr_gid to. * name - Value to set grp->gr_name to. * passwd - Value to set grp->passwd to. * grp - Pointer to the space to store the retrieved group structure in. * buf - String fields pointed to by the group struct are stored here. * buflen - The length of buf in bytes. * result - Pointer to the resulting group struct, or NULL in case of fail. * * Returned Value: * On success getgrgid_r returns 0 and sets *result to grp. In case of * failure an error number is returned. * ****************************************************************************/ int getgrbuf_r(gid_t gid, FAR const char *name, FAR const char *passwd, FAR struct group *grp, FAR char *buf, size_t buflen, FAR struct group **result) { size_t reqdlen; size_t padlen; /* In 'buf' a NULL pointer value will be stored, which must be naturally * aligned, followed by the null terminated group name string and the null * terminated passwd string 'x' (indicating 'no password'). Make sure * sufficient buffer space was supplied by the caller. */ padlen = sizeof(FAR void *) - ((uintptr_t)buf % sizeof(FAR char *)); reqdlen = sizeof(FAR void *) + strlen(name) + 1 + strlen(passwd) + 1; if (buflen < padlen + reqdlen) { /* Insufficient buffer space supplied. */ *result = NULL; return ERANGE; } grp->gr_mem = (FAR char **)&buf[padlen]; grp->gr_name = &buf[padlen + sizeof(FAR char *)]; grp->gr_passwd = &buf[padlen + sizeof(FAR char *) + strlen(name) + 1]; strcpy(grp->gr_name, name); strcpy(grp->gr_passwd, passwd); grp->gr_gid = gid; *grp->gr_mem = NULL; *result = grp; return 0; }