/**************************************************************************** * libs/libc/pwd/lib_find_pwdfile.c * * Copyright (C) 2019 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include "pwd/lib_pwd.h" /**************************************************************************** * Private Types ****************************************************************************/ typedef CODE int (pwd_foreach_match_t)(FAR const struct passwd *entry, uintptr_t arg); /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: pwd_match_name * * Description: * Called for each record in the passwd file. Returns "1" if the record * matches the user name (passed as arg) * * Input Parameters: * entry - The parsed passwd file record * arg - A pointer to the user name to match * * Returned Value: * < 0 : An error has occurred. * = 0 : No entry name does not match. * = 1 : The entry name matches * ****************************************************************************/ static int pwd_match_name(FAR const struct passwd *entry, uintptr_t arg) { FAR const char *uname = (FAR const char *)arg; return strcmp(entry->pw_name, uname) == 0 ? 1 : 0; } /**************************************************************************** * Name: pwd_match_uid * * Description: * Called for each record in the passwd file. Returns "1" if the record * matches the user ID (passed as arg) * * Input Parameters: * entry - The parsed passwd file record * arg - The user ID to match * * Returned Value: * < 0 : An error has occurred. * = 0 : No entry name does not match. * = 1 : The entry name matches * ****************************************************************************/ static int pwd_match_uid(FAR const struct passwd *entry, uintptr_t arg) { int match_uid = (int)arg; return match_uid == entry->pw_uid ? 1 : 0; } /**************************************************************************** * Name: pwd_foreach * * Description: * Visit each record in passwd file. * * Input Parameters: * match - The match function to call on each record * arg - Argument passed to the match function * entry - Location to return the parsed passwd file entry * buffer - I/O buffer used to access the passwd file * buflen - The size of the I/O buffer in bytes * * Returned Value: * < 0 : An error has occurred. * = 0 : No entry with this name was found. * = 1 : The entry with this name was found. * ****************************************************************************/ static int pwd_foreach(pwd_foreach_match_t match, uintptr_t arg, FAR struct passwd *entry, FAR char *buffer, size_t buflen) { FAR FILE *stream; FAR char *ptr; FAR char *save; int ret; stream = fopen(CONFIG_LIBC_PASSWD_FILEPATH, "r"); if (stream == NULL) { int errcode = get_errno(); DEBUGASSERT(errcode > 0); return -errcode; } /* Read the password file line by line until the record with the matching * username is found, or until the end of the file is reached. * * The format of the password file is: * * user:x:uid:uid:home * * Where: * user: User name * x: Encrypted password * uid: User ID * uid: Group ID * home: Login directory */ while (fgets(buffer, buflen, stream) != NULL) { ptr = buffer; entry->pw_name = ptr; /* Skip to the end of the name and properly terminate it. The name * must be terminated with the field delimiter ':'. */ for (; *ptr != '\n' && *ptr != '\0' && *ptr != ':'; ptr++) { } if (*ptr == '\n' || *ptr == '\0') { /* Bad line format? */ continue; } *ptr++ = '\0'; /* Skip to the end of the password and properly terminate it. The * password must be terminated with the field delimiter ':'. */ for (; *ptr != '\n' && *ptr != '\0' && *ptr != ':'; ptr++) { } if (*ptr == '\n' || *ptr == '\0') { /* Bad line format? */ continue; } *ptr++ = '\0'; save = ptr; /* Skip to the end of the user ID and properly terminate it. The * user ID must be terminated with the field delimiter ':'. */ for (; *ptr != '\n' && *ptr != '\0' && *ptr != ':'; ptr++) { } if (*ptr == '\n' || *ptr == '\0') { /* Bad line format? */ continue; } *ptr++ = '\0'; entry->pw_uid = (uid_t)atoi(save); save = ptr; /* Skip to the end of the group ID and properly terminate it. The * group ID must be terminated with the field delimiter ':'. */ for (; *ptr != '\n' && *ptr != '\0' && *ptr != ':'; ptr++) { } if (*ptr == '\n' || *ptr == '\0') { /* Bad line format? */ continue; } *ptr++ = '\0'; entry->pw_gid = (gid_t)atoi(save); entry->pw_dir = ptr; /* Skip to the end of the home directory and properly terminate it. * The home directory must be the last thing on the line. */ for (; *ptr != '\n' && *ptr != '\0' /* && *ptr != ':' */ ; ptr++) { } *ptr++ = '\0'; entry->pw_shell = ROOT_SHELL; /* Check for a match */ ret = match(entry, arg); if (ret != 0) { /* We either have the match or an error occurred. */ fclose(stream); return ret; } } fclose(stream); return 0; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: pwd_findby_name * * Description: * Find passwd file entry using the user name. * * Input Parameters: * uname - The user name * entry - Location to return the parsed passwd file entry * buffer - I/O buffer used to access the passwd file * buflen - The size of the I/O buffer in bytes * * Returned Value: * < 0 : An error has occurred. * = 0 : No entry with this name was found. * = 1 : The entry with this name was found. * ****************************************************************************/ int pwd_findby_name(FAR const char *uname, FAR struct passwd *entry, FAR char *buffer, size_t buflen) { return pwd_foreach(pwd_match_name, (uintptr_t)uname, entry, buffer, buflen); } /**************************************************************************** * Name: pwd_findby_uid * * Description: * Find passwd file entry using the user ID. * * Input Parameters: * uid - The user ID * entry - Location to return the parsed passwd file entry * buffer - I/O buffer used to access the passwd file * buflen - The size of the I/O buffer in bytes * * Returned Value: * < 0 : An error has occurred. * = 0 : No entry with this name was found. * = 1 : The entry with this name was found. * ****************************************************************************/ int pwd_findby_uid(uid_t uid, FAR struct passwd *entry, FAR char *buffer, size_t buflen) { /* Verify that the UID is in the valid range of 0 through INT16_MAX. * OpenGroup.org does not specify a UID_MAX or UID_MIN. Instead we use a * priori knowledge that uid_t is type int16_t. */ if ((uint16_t)uid > INT16_MAX) { return -EINVAL; } return pwd_foreach(pwd_match_uid, (uintptr_t)uid, entry, buffer, buflen); }