fuserace.c

#define _XOPEN_SOURCE 500
#define _GNU_SOURCE
#define FUSE_USE_VERSION 26

#include <stdio.h>
#include <fuse.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>

#define PATH_MAX 1024
#define BASEDIR "/tmp/RACE"

void get_path(char *fpath, const char *path) {
  snprintf(fpath, PATH_MAX, "%s%s.%d", BASEDIR, path, fuse_get_context()->uid);
}

int r_open(const char *path, struct fuse_file_info *fi)
{
    char *fpath = malloc(PATH_MAX);
    get_path(fpath, path);
    fi->fh = open(fpath, fi->flags);
    free(fpath);
    if (fi->fh < 0) {
      return -errno;
    } else {
      return 0;
    }
}

int r_read(const char *path, char *buf, size_t size, off_t offset, struct fuse_file_info *fi) {
  return pread(fi->fh, buf, size, offset);
}

int r_release(const char *path, struct fuse_file_info *fi) {
  return close(fi->fh);
}

int r_getattr(const char *path, struct stat *statbuf) {
  int retstat = 0;
  if (strcmp(path, "/") == 0) {
    statbuf->st_mode = S_IFDIR | 0755;
    statbuf->st_nlink = 2;
  } else if (strcmp(path, "/a") == 0) {
    char *fpath = malloc(PATH_MAX);
    get_path(fpath, path);
    retstat = lstat(fpath, statbuf);
    free(fpath);
  }
  return retstat;
}

struct fuse_operations r_oper = {
  .getattr = r_getattr,
  .open = r_open,
  .read = r_read,
  .release = r_release,
};

int main(int argc, char *argv[]) {
  return fuse_main(argc, argv, &r_oper, NULL);
}