posix.c

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/*
 * TARFS - Immutable (read-only) filesystem for embedded systems.
 *
 * Copyright (c) 2026 Viacheslav Logunov
 * SPDX-License-Identifier: MMIT
 *
 * Author:
 *   Viacheslav Logunov <vvb333007@gmail.com>
 *
 * Project:
 *   https://github.com/vvb333007/tarfs
 *
 *
 * @file posix.c
 * @brief Missing POSIX API implementation
 */
 

 
 
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <stdatomic.h>
 
#include <unistd.h>
#include <dirent.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/types.h>
 
 
#include "config.h"
#include "os.h"
#include "fs.h"
#include "file.h"
#include "inode.h"
#include "tar.h"
#include "dir.h"
#include "posix.h"
 
 
#if CONFIG_TARFS_HAVE_MMAP
void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset) {
 
  struct ioctl_req io;
 
  /* FIOGETFD returns the FS index and local fd, suitable for tarf_ , tard_ functions */
  if ((ioctl(fd, FIOGETFD, &io) >= 0))
    return tarf_mmap((void *)(uintptr_t)io.fs_idx, addr, length, prot, flags, io.fd, offset);
 
  /*errno should be set by the ioctl() */
  return MAP_FAILED;
 
}
 

int munmap(void *addr, size_t length) {
 
  struct tarfs_fs *fs;
  uintptr_t vaddr = (uintptr_t )addr;
 
  if (addr != NULL && length > 0) {
    tarfs_lock();
    for (int i = 0; i < TARFS_MAX_FS; i++) {
 
      fs = tarfs_getfs(i);
 
      if (fs != NULL && 
          vaddr >= (uintptr_t)fs->fs_vaddr &&
          vaddr < ((uintptr_t)fs->fs_vaddr + fs->fs_size)) {
        tarfs_unlock();
        return tarf_munmap((void *)(uintptr_t )i, addr, length);
      }
    }
  }
  log("address %p does not belong to mmap()\r\n", addr);
  errno = EINVAL;
  return -1;
}
#endif /* CONFIG_TARFS_HAVE_MMAP */
 
 
 
#if CONFIG_TARFS_HAVE_DUPFD
int dupfd(int fd) {
 
  struct ioctl_req io;
 
  /* FIOGETFD returns the FS index and local fd, suitable for tarf_ , tard_ functions */
  if ((ioctl(fd, FIOGETFD, &io) >= 0)) {
    /* TODO: this is bad, but ESP-IDF has no mechanism to convert local to global */
    int fd_offset = fd - io.fd; 
    return fd_offset + tarf_dupfd((void *)(uintptr_t)io.fs_idx, io.fd);
  }
 
  /*errno should be set by the ioctl() */
  return -1;
}
#endif /* CONFIG_TARFS_HAVE_DUPFD */
 
 
#if CONFIG_TARFS_HAVE_FDOPENDIR
DIR *fdopendir(int fd) {
 
  
  struct ioctl_req io;
 
  /* Convert our global fd to local fd number so tarf_ and tard_ functions can be used 
   * FIOGETFD returns the FS index and local fd 
   */
  if (ioctl(fd, FIOGETFD, &io) >= 0)
    return tard_fdopendir((void *)(uintptr_t)io.fs_idx, io.fd);
 
  return NULL;
}
#endif /* CONFIG_TARFS_HAVE_FDOPENDIR */
 
 
 
#if CONFIG_TARFS_HAVE_STATVFS
int statvfs(const char *path, struct statvfs *st) {
 
  int fs_idx;
 
  if ((fs_idx = tarfs_fsindex(path)) >= 0)
    return tarfs_statvfs((void *)(intptr_t)fs_idx, st);
  
  errno = ENODEV;
  return -1;
}
#endif /* CONFIG_TARFS_HAVE_STATVFS */
 
 
#if CONFIG_TARFS_HAVE_SENDFILE

ssize_t sendfile(int out_fd, int in_fd, off_t *offset, size_t count) {
 
  struct ioctl_req io;
 
  /* Convert our global fd to local fd number so tarf_ and tard_ functions can be used 
   * FIOGETFD returns the FS index and local fd 
   */
  if (ioctl(in_fd, FIOGETFD, &io) >= 0)
    return tarf_sendfile((void *)(uintptr_t)io.fs_idx, out_fd, io.fd, offset, count);
 
  /*errno should be set by the ioctl() */
  return -1;
}
#endif /* #if CONFIG_TARFS_HAVE_SENDFILE */
 
/* TODO: implement lstat*/