/*
* Load and unload nsscash files (header)
*
* Copyright (C) 2019 Simon Ruderich
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*/
#ifndef FILE_H
#define FILE_H
#include
#include
#include
// Magic value at the beginning of each nsscash file (8 byte, without the
// trailing NUL)
#define MAGIC "NSS-CASH"
// Defined in Makefile
#ifndef NSSCASH_PASSWD_FILE
# define NSSCASH_PASSWD_FILE "/etc/passwd.nsscash"
#endif
#ifndef NSSCASH_GROUP_FILE
# define NSSCASH_GROUP_FILE "/etc/group.nsscash"
#endif
// header describes the on-disk (and, after loading via mmap, in-memory)
// structure of nsscash files.
struct header {
char magic[8]; // magic string
uint64_t version; // also doubles as byte-order check
uint64_t count; // number of entries in this file
// All offsets are relative to data
uint64_t off_orig_index;
uint64_t off_id_index;
uint64_t off_name_index;
uint64_t off_data;
char data[];
} __attribute__((packed));
// file represents an open nsscash file.
struct file {
int fd;
size_t size;
const struct header *header;
uint64_t next_index; // used by getpwent (pw.c)
};
bool map_file(const char *path, struct file *f) __attribute__((visibility("hidden")));
void unmap_file(struct file *f) __attribute__((visibility("hidden")));
#endif